Month: November 2024

Furthermore, if woody annual increments were considered this proportion would be even lower. Likewise the observed 1.7 Mg ha−1 in fruit represents ~14% of total biomass , which is within 10% of other studies in the region at similar vine densities. More importantly, this study reports the fraction of C that could be recovered from wine making and returned to the soil for potential long term storage. However, this study is restricted to the agronomic and environmental conditions of the site, and the methodology would require validation and potential adjustment in other locations and conditions. Few studies have conducted a thorough evaluation of below ground vine biomass in vineyards, although Elderfield did estimate that fine roots contributed 20–30% of total NPP and that C was responsible for 45% of that dry matter. More recently, Brunori et al. studied the capability of grapevines to efficiently store C throughout the growing season and found that root systems contributed to between 9 and 26% of the total vine C fixation in a model Vitis vinifera sativa L. cv Merlot/berlandieri rupestris vineyard. The results of our study provide a utilitarian analysis of C storage in mature wine grape vines, including above and below ground fractions and annual vs. perennial allocations. Such information constitutes the basic unit of measurement from which one can then estimate the contribution of wine grapes to C budgets at multiple scales— fruit, plant or vineyard level—and by region, sector, or in mixed crop analyses. Our study builds on earlier research that focused on the basic physiology, development and allocation of biomass in vines. Previous research has also examined vineyard-level carbon at the landscape level with coarser estimates of the absolute C storage capacity of vines of different ages, pe grow bag as well as the relative contribution of vines and woody biomass in natural vegetation in mixed vineyard-wild land landscapes.

The combination of findings from those studies, together with the more precise and complete carbon-by-vine structure assessment provided here, mean that managers now have access to methods and analytical tools that allow precise and detailed C estimates from the individual vine to whole-farm scales. As carbon accounting in vineyard landscapes becomes more sophisticated, widespread and economically relevant, such vineyard-level analyses will become increasingly important for informing management decisions. The greater vine-level measuring precision that this study affords should also translate into improved scaled-up C assessments . In California alone, for example, there are more than 230,000 ha are planted in vines. Given that for many, if not most of those hectares, the exact number of individual vines is known, it is easy to see how improvements in vine-level measuring accuracy can have benefits from the individual farmer to the entire sector. Previous efforts to develop rough allometric woody biomass equations for vines notwithstanding, there is still a need to improve our precision in estimating of how biomass changes with different parameters. Because the present analysis was conducted for 15 year old Cabernet vines, there is now a need for calibrating how vine C varies with age, varietal and training system. There is also uncertainty around the influence of grafting onto root stock on C accumulation in vines. As mentioned in the methods, the vines in this study were not grafted—an artifact of the root-limiting duripan approximately 50 cm below the soil surface. The site’s location on the flat, valley bottom of a river floodplain also means that its topography, while typical of other vineyard sites per se, created conditions that limit soil depth, drainage and decomposition. As such, the physical conditions examined here may differ significantly from more hilly regions in California, such as Sonoma and Mendocino counties. Similarly, the lack of a surrounding natural vegetation buffer at this site compared to other vineyards may mean that the ecological conditions of the soil communities may or may not have been broadly typical of those found in other vineyard sites.

Thus, to the extent that future studies can document the degree to which such parameters influence C accumulation in vines or across sites, they will improve the accuracy and utility of C estimation methods and enable viticulturists to be among the first sectors in agriculture for which accurate C accounting is an industry wide possibility. The current study was also designed to complement a growing body of research focusing on soil-vine interactions. Woody carbon reserves and sugar accumulation play a supportive role in grape quality, the main determinant of crop value in wine grapes. The extent to which biomass production, especially in below ground reservoirs, relates to soil carbon is of immediate interest for those focused on nutrient cycling, plant health and fruit production, as well as for those concerned with C storage. The soil-vine interface may also be the area where management techniques can have the highest impact on C stocks and harvest potential. We expect the below ground estimates of root biomass and C provided here will be helpful in this regard and for developing a more thorough understanding of below ground C stores at the landscape level. For example, Williams et al. estimated this component to be the largest reservoir of C in the vineyard landscape they examined, but they did not include root biomass in their calculations. Others have assumed root systems to be ~30% of vine biomass based on the reported biomass values for roots, trunk, and cordons. With the contribution of this study, the magnitude of the below ground reservoir can now be updated.Wine is a commodity of worldwide importance, and vineyards constitute a significant land use and contribution to economies across Mediterranean biome and beyond. Like orchards and tree plantations, grapevines are a perennial crop that stores C long-term in woody tissue, thereby helping to mitigate GHG emissions. Our study provides estimates of C in grape vines by vine component, as well as a simple measurement tool kit that growers can use to estimate the C in their vines and vineyard blocks. The equations presented here represent some of the first allometric models for estimating grapevine C from berries to blocks, with the hope that widespread use and refinement of these techniques may lead to recognition and credit for the C storage potential of vineyards and other perennial woody crops, such as orchards. The successful implementation of these methods, if applied widely to multiple cropping systems, could improve the precision of measurement and the understanding of C in agricultural systems relative to other human activities.Ultra-high-energy neutrino astronomy expands the opportunity to learn more about the fierce processes of astronomical objects. Neutrinos are ideal messengers because they have negligible mass, are neutral in charge, and, due to the fact that they only interact through the weak force, have a low interaction probability. Once created, these properties allow them to travel through space unhindered by intervening matter or radiation such as dust, gas, and electromagnetic fields. The same properties also make them challenging to detect. Even at the extreme energies relevant to radio neutrino detectors, neutrinos rarely interact with matter. When this feature is combined with the low expected fluxes, and stringent experimental upper limits have been published by the IceCube Collaboration, the detector architecture must incorporate large volumes of target material.

A rough estimate suggests that instrumented volumes must reach of order one teraton to observe a few neutrinos per year for commonly discussed theoretical models of neutrino production. Radio based neutrinos experiments have been successfully explored in the past with pilot arrays such as the ARA experiment and the ARIANNA experiment, the latter being the focal point of this paper. These efforts helped focus in on the radio techniques required to operate in extremely cold and harsh conditions. While these experiments showed the technical feasibility, they were too small to measure the low neutrino flux. Undeterred, several radio-based experiments in development are further illustrating the capabilities of this detection method, such as ARIANNA-200, the radio component of IceCube-Gen2 , the Radio Neutrino Observatory in Greenland, Giant Radio Array for Neutrino Detection, Taiwan Astroparticle Radiowave Observatory for Geo-synchrotron Emissions, growing bags and Payload for Ultrahigh Energy Observations, a successor to ANITA. These experiments exploit various target materials such as ice, water, mountains, and air. The challenge for experimenters is to reach the teraton detection volumes at a reasonable cost. One of the most promising methods for observing UHE neutrinos in large target volumes exploits radio detection in ice. For this reason, locations such as Greenland and Antarctica are popular sites for radio detection experiments. Ice is transparent to radio signals, with field attenuation lengths ranging from 0.5 km at Moore’s Bay to more than a kilometer in colder ice found at the South Pole or the Greenland ice sheet. Radio pulses are created via the Askaryan effect when interacting neutrinos create particles showers in ice, which in turn generate a time-varying negative charge excess that produces radio emission in the 50 MHz to 1 GHz range. The radio technique enables cost-efficient instrumentation for monitoring large detection volumes. However, because of the low flux of UHE neutrinos, event rates are still small even for the large array of hundreds of radio detector stations that is foreseen for the next-generation neutrino observatory at the South Pole, IceCube-Gen2. Thus, improving the sensitivity of the detector is one of the primary objectives. The easiest way to increase the sensitivity — but also the most expensive way — is to build more radio detector stations. A more efficient way is to increase the sensitivity of each radio detector station and a lot of work has been made towards this goal. The sensitivity can be increased by simply lowering the trigger threshold which records additional neutrino interactions that produce smaller signal strengths in the radio detector. The problem with this is that the trigger thresholds are already set close to the thermal noise floor such that the trigger rate is dominated by unavoidable thermal noise fluctuations. For example, an amplitude threshold trigger with a two out of four antenna coincidence logic has a trigger rate increases by about six orders-of-magnitude if the trigger threshold is lowered from four times the RMS noise, RMS noise, to just three time RMS noise. Therefore, the trigger threshold is limited by the maximum data rate a radio detector can handle which is typically on the order of 1 Hz if a high-speed communication link exists. If the communication relies on Iridium satellite communication, the maximum data rate is limited to 0.3 mHz. However, if thermal noise fluctuations are identified and rejected in real time, the trigger thresholds can be lowered while maintaining the same data rate, thus increasing the sensitivity of the detector. The sensitivity can be improved by up to a factor of two with the intelligent trigger system presented here . In this paper it is demonstrated that deep learning can be used to reject thermal noise in real time by implementing these techniques in the current ARIANNA data acquisition system. Deep learning, a modern rebranding of neural networks, has been shown to outperform other methods in a variety of scientific and engineering areas, including in physics. The significant amount of data that need to be classified in real time with low latency in high energy physics experiments makes deep learning an ideal tool to use. By rejecting thermal events, the trigger rate can be increased dramatically while maintaining the required low rate of event transmission over the communication links from the remotely located ARIANNA stations. Overall, lower thresholds increase the effective volume of ice observed by each station, which is proportional to the sensitivity of the detector. This paper is organized as follows. Additional details on the ARIANNA detector are provided, along with the expected gain in sensitivity for this study. Next the trade off between network efficiency and processing time is assessed to find the optimal deep learning models for a representative sample of microprocessor platforms. The deep learning method is then compared to a template matching study to determine how well the more common approach performs. Then the current ARIANNA data acquisition system is evaluated to determine the suitability for a deep learning filter. Moreover, the specific predictions for the optimal deep learning model are experimentally verified for the current microprocessor hardware. Lastly, the deep learning filter is tested on measured cosmic rays to verify that they are classified similar to neutrino signal and not rejected as thermal noise.

Light is generally not a factor because there is usually a large enough leaf area and sufficient light levels to saturate this source to sink relationship. Sun-exposed Cabernet Sauvignon berries in the vineyard had higher TSS than shaded berries. This sunlight effect was attributed largely to an increase in berry temperature rather than an increase in the fluence rate per se. A higher grapevine water status results in larger berry size and lower sugar concentrations and water deficit is known to increase sugar concentrations in Cabernet Sauvignon. However, temperature is thought to have the largest effect on sugar concentration. Other transcriptomic data in the present study indicated that BOD berries were more mature at a lower sugar level than RNO berries. These included the transcript abundance profiles of genes involved in autophagy, auxin and ABA signaling, iron homeostasis and seed development. Many of these DEGs had an accelerated rate of change in BOD berries. While these transcripts are in the skins, they may be influenced by signals coming from the seed. In addition, there was a higher transcript abundance for most genes involved with the circadian clock in BOD berries. PHYB can regulate the circadian clock and PHYB activity is very sensitive to night temperatures ; PHYB reversion is accelerated to the inactive form at warmer temperature. The inactivity of phytochrome promotes the expression of RVE1, which promotes auxin concentrations and seed dormancy. Thus, all things considered, plastic plant pot it is likely that temperature and/or the temperature differentials between day and night significantly contributed to the differences in the rate of berry development and sugar accumulation in the two locations.

Determining maturity of grapes is a difficult and error prone process. Reliable markers could aid in the decision of when to harvest the grapes. “Optimum” maturity is a judgement call and will ultimately depend on the winemaker’s or grower’s specific goals or preferences. A combination of empirical factors can be utilized including °Brix, total acidity, berry tasting in the mouth for aroma and tannins, seed color, etc. °Brix or total soluble solids by itself may not be the best marker for berry ripening as it appears to be uncoupled from berry maturity by temperature. Phenylpropanoid metabolism, including anthocyanin metabolism, is also highly sensitive to both abiotic and biotic stresses and may not be a good indicator of full maturity. Thus, color may not be a good indicator either. Specific developmental signals from the seed or embryo, such as those involved with auxin and ABA signaling, may provide more reliable markers for berry ripening in diverse environments, but will not be useful in seedless grapes. Aromatic compounds may also be reliable markers but they will need to be generic, developmental markers that are not influenced by the environment. This study revealed many genes that are not reliable markers because they were expressed differently in different environments. One candidate marker that is noteworthy is ATG18G . Its transcript abundance increased and was relatively linear with increasing °Brix and these trends were offset at the two locations relative to their level of putative fruit maturity . ATG18G is required for the autophagy process and maybe important during the fruit ripening phase. It was found to be a hub gene in a gene subnetwork associated with fruit ripening and chloroplast degradation. Further testing will be required to know if it is essential for fruit ripening and whether its transcript abundance is influenced by abiotic and biotic stresses in grape berry skins.The ultimate function of a fruit is to produce fully mature seeds in order to reproduce another generation of plants. The ripe berry exhibits multiple traits that signal to other organisms when the fruit is ready for consumption and seed dispersal.

In this study, we show that there were large differences in transcript abundance in grape skins in two different locations with different environments, confirming our original hypothesis. We also identified a set of DEGs with common profiles in the two locations. The observations made in this study provide lists of such genes and generated a large number of hypotheses to be tested in the future. WGCNA was particularly powerful and enhanced our analyses. The transcript abundance during the late stages of berry ripening was very dynamic and may respond to many of the environmental and developmental factors identified in this study. Functional analysis of the genes and GO enrichment analysis were very useful tools to elucidate these factors. Some of the factors identified were temperature, moisture, light and biotic stress. The results of this study indicated that berries still have a “sense of place” during the late stages of berry ripening. Future studies are required to follow up on these observations. It appears that fruit ripening is very malleable. Manipulation of the canopy may offer a powerful lever to adjust gene expression and berry composition, since these parameters are strongly affected by light and temperature.Doorbells have been playing an important role in protecting the security of modern homes since they were invented. A doorbell allows visitors to announce their presence and request entry into a building as well as enables the occupant to verity the identity of the guests to help prevent home robbery or invasion at a moment’s notice. There are two types of doorbells depending on the requirement of wall wiring: the wired doorbells and the wireless doorbells. The former requires a wire to connect both the front door button and the back door button to a transformer, while the latter transfer the signal wirelessly using telephone technology. Modern buildings are typically equipped with wireless doorbell systems that employ radio technology to signal doorbells and answer the doors remotely.

Although these doorbells are much more convenient than wired ones, they do not always satisfy the demands of modern homes for the following three reasons. First, the answering machines are normally located at a fixed place , if a occupant wants to answer the doorbell, he/she has to go to the answering machines. Second, if the occupant would like to see the visitors outside, he/she has to go to door. Third, the occupant has no way to answer or admit guests when he/she is not at home, nor to keep a record of guests. As smart home technology matures, smart doorbells can solve this problem greatly by connecting the doorbells to the Internet and allowing users to answer the bell through a smart device such as a smartphone or tablet. This enables a home owner to answer and admit a visitor anywhere when a smart device connecting to the Internet is available. However, such smart doorbells are quite expensive due to technical and manufacturing difficulties. The high prices make these products unavailable to most home users with limited budgets, nursery pots hindering the pervasiveness of smart doorbells. This is confirmed by a research shows that less than 4% of U.S. households have a smart doorbell system to protect the security of the homes. To solve this problem, we introduce the Dashbell- a low-cost smart doorbell system for home use. The doorbell system uses a cheap, WiFi-enabled device-the Amazon Dash Button to serve as the doorbell, and connects it to the Internet, allowing users to answer the bell anywhere using a smart device such as a smartphone or a tablet. With such as solution, users may purchase a smart doorbell system at a price as low as 40 US dollars, which significantly increases the affordability of the smart doorbells.A smart doorbell is an integral part of a smart home, which helps protect the security of the home by avoiding unwanted access such as robbery and invasion. The controller of the smart home can potentially answer the bell and decide whether to admit a visitor outside the door or not through adaptive learning and other technologies. Because of the important role that smart doorbells play on building a smart home, many techniques and methodologies have been invented during past few years. The existing smart doorbells provide an integrated solution, which means that the working mechanisms or the implementation details are hidden and unknown to the users. If there is a failure, users have to seek help from professionals for repairs or maintenance. It is also very likely that users need to replace the whole smart doorbells due to a failure of a component in the system.Amazon Dash Button is a WiFi-enabled device that allows consumers to reorder frequently used daily products like trash bags, toilet towels or refill blades by pressing a button. A dash button can be purchased via online and costs 4.99 US dollars . Recently, it has been found that the dash button can be tweaked to track baby habits. We employ this feature of the dash button and use it as a doorbell of the Dashbell system. Alternatives to Dash Button include portable door bell kits, and wireless door chime trigger with motion sensors, both of which can be purchased for less than 5 US dollars.Modern homes are typically equipped with Wi-Fi routers and have access to the Internet. Smartphones are also highly available to the majority of population. To build a budget smart doorbell system like Dashbell, the user only needs to purchase a Amazon Dash Button , a Raspberry Pi , a webcam , and a buzzer.

The user can sign up to request for free Amazon Web Service. The total cost of a Dashbell system is less than 40 US dollars. The Dashbell system differentiates existing smart doorbell systems in the following aspects. First, Dashbell is much cheaper than existing smart doorbells. Second, Dashbell is a distributed system rather than an integrated one, which enables faster fault detection and diagnosis. For instance, if some of the components fail to operate, one can just identify and fix or replace the parts by checking each individual device instead of disassembling or replacing the whole doorbell system. Third, given that most smart doorbell devices are expensive devices, they can be potentially detached and stolen. However, with the Dashbell, only the Dash button, which is inexpensive and replaceable, needs to be placed outside the home, making it a much better alternative in terms of the device’s own security. Lastly, unlike exisiting smart doorbells, which are only sold in limited places and through particular channels, the components of the Dashbell system are highly available. While the Dashbell provides several useful features and enhanced security over a conventional doorbell, there are a few security and privacy issues associated with it. Since the device is connected via a home WiFi network, it is possible to compromise the network and use the device, grant access to unauthorized visitors or collect data using it without the owners consent. We advise users to keep their network secured with a password. Our system also takes pictures of visitors without their consent and stores them on the server. Since this is personally identifiable information, we have made sure the server and all communication channels are secure. Using secure communication channels and encrypting user data while storing on the server would be helpful in this regard. The mobile application also has an additional layer of security so that only owner can grant access to a visitor.The ability of a genotype to produce different phenotypes as a function of environmental cues is known as phenotypic plasticity . Phenotypic plasticity is considered one of the main processes by which plants, as sessile organisms, can face and adapt to the spatio-temporal variation of environmental factors . Grapevine berries are characterized by high phenotypic plasticity and a genotype can present variability within berries, among berriesin a cluster, and among vines . Berry phenotypic traits, such as the content of sugars, acids, phenolic, anthocyanins, and flavor compounds, are the result of cultivar and environmental influences , and often strong G × E interactions . Although grapevine plasticity in response to environmental conditions and viticulture practices may provide advantages related to the adaptation of a cultivar to specific growing conditions, it may also cause irregular ripening and large inter-seasonal fluctuations , which are undesirable characteristics for wine making . Due to its complex nature, the study of phenotypic plasticity is challenging and the mechanisms by which the genes affecting plastic responses operate are poorly characterized . In fact it is often difficult to assess the performance of different phenotypes in different environments . It has been suggested that genetic and epigenetic regulation of gene expression might be at the basis of phenotypic plasticity through the activation of alternative gene pathways or multiple genes .

ZigBee End Devices are not fully functional devices, they send information only to their parent node, which can be either a Router or Coordinator. Generally, End Devices form the bulk of sensor nodes in a network structure. In order to facilitate long battery life, ZigBee protocols allow for an easily programmable sleep mode for End Devices, periodically limiting computation and thus power consumption. Coordinator and Router nodes continually transmit beacon signals to alert child nodes of their presence. Upon waking, End Devices wait for a beacon signal and relay information before continuing their sleep cycle.There are two types of UART schemes available for Xbee modules, AT and API mode. AT mode is synonymous with transparent mode, each module has a single network destination and personal address. Configuration of network parameters must be done through command mode, either by the user or a micro controller. AT mode is useful for simple point-to-point communication or non-modular network topology. API mode is recommended for larger networks with more complicated overall topologies. Messages contain a personal and destination address, plastic flower buckets wholesale which can be changed during run time depending on message type, making mesh topology simple to implement.

Additionally, API mode contains packet delivery confirmation messages and has the option of escape parameters.Grapevine berry ripening can be divided into three major stages. In stage 1, berry size increases sigmoidally. Stage 2 is known as a lag phase where there is no increase in berry size. Stage 3 is considered the ripening stage. Veraison is at the beginning of the ripening stage and is characterized by the initiation of color development, softening of the berry and rapid accumulation of the hexoses, glucose and fructose. Berry growth is sigmoidal in Stage 3 and the berries double in size. Many of the flavor compounds and volatile aromas are derived from the skin and synthesized at the end of this stage. Many grape flavor compounds are produced as glycosylated, cysteinylated and glutathionylated precursors and phenolics and many of the precursors of the flavor compounds are converted to various flavors by yeast during the fermentation process of wine. Nevertheless, there are distinct fruit flavors and aromas that are produced and can be tasted in the fruit, many of which are derived from terpenoids, fatty acids and amino acids. Terpenes are important compounds for distinguishing important cultivar fruit characteristics. There are 69 putatively functional, 20 partial and 63 partial pseudogenes in the terpene synthase family that have been identified in the Pinot Noir reference genome. Terpene synthases are multi-functional enzymes using multiple substrates and producing multiple products.

More than half of the putatively functional terpene synthases in the Pinot Noir reference genome have been functionally annotated experimentally and distinct differences have been found in some of these enzymes amongst three grape varieties: Pinot Noir, Cabernet Sauvignon and Gewürztraminer. Other aromatic compounds also contribute significant cultivar characteristics. C13-norisoprenoids are flavor compounds derived from carotenoids by the action of the carotenoid cleavage dioxygenase enzymes . Cabernet Sauvignon, Sauvignon Blanc and Cabernet Franc are characterized by specific volatile thiols and methoxypyrazines. Enzymes involved in the production of these aromas have been recently characterized. Phenolic compounds play a central role in the physical mouthfeel properties of red wine; recent work relates quality with tannin levels. While the grape genotype has a tremendous impact on tannin content, the environment also plays a very large role in grape composition. The pathway for phenolic biosynthesis is well known, but the mechanisms of environmental influence are poorly understood. Ultimately, there is an interaction between molecular genetics and the environment. Flavor is influenced by climate, topography and viticultural practices. For example, water deficit alters gene expression of enzymes involved in aroma biosynthesis in grapes, which is genotype dependent, and may lead to increased levels of compounds, such as terpenes and hexyl acetate, that contribute to fruity volatile aromas. The grapevine berry can be subdivided into the skin, pulp and seeds. The skin includes the outer epidermis and inner hypodermis . A thick waxy cuticle covers the epidermis.

The hypodermal cells contain chloroplasts, which lose their chlorophyll at veraison and become modified plastids; they are the sites of terpenoid biosynthesis and carotenoid catabolism. Anthocyanins and tannins accumulate in the vacuoles of hypodermal cells. Pulp cells are the main contributors to the sugar and organic acid content of the berries. Pulp cells also have a much higher set of transcripts involved in carbohydrate metabolism, but a lower set of transcripts involved in lipid, amino acid, vitamin, nitrogen and sulfur metabolism than in the skins. Hormones can influence berry development and ripening. Concentrations of auxin, cytokinins and gibberellins tend to increase in early fruit development of the first stage. At veraison, these hormone concentrations have declined concomitant with a peak in abscisic acid concentration just before veraison. Auxin prolongs the Stage 2 lag phase and inhibits anthocyanin biosynthesis and color development in Stage 3. Grapevine, a non-climacteric fruit, is not very sensitive to ethylene; however, ethylene appears to be necessary for normal fruit ripening. Ethylene concentration is highest at anthesis, but declines to low levels upon fruit set; ethylene concentrations rise slightly thereafter and peak just before veraison then decline to low levels by maturity. Ethylene also plays a role in the ripening of another non-climacteric fruit, strawberry. ABA also appears to be important in grape berry ripening during veraison when ABA concentrations increase resulting in increased expression of anthocyanin biosynthetic genes and anthocyanin accumulation in the skin. ABA induces ABF2, a transcription factor that affects berry ripening by stimulating berry softening and phenylpropanoid accumulation. In addition, ABA affects sugar accumulation in ripening berries by stimulating acid invertase activity and the induction of sugar transporters. It is not clear whether ABA directly affects flavor volatiles , but there could be indirect effects due to competition for common precursors in the carotenoid pathway. Many grape berry ripening studies have focused on targeted sampling over a broad range of berry development stages, but generally with an emphasis around veraison, when berry ripening is considered to begin. In this study, a narrower focus is taken on the late ripening stages where many berry flavors are known to develop in the skin. We show that that the abundance of transcripts involved in ethylene signaling is increased along with those associated with terpenoid and fatty acid metabolism, particularly in the skin.Cabernet Sauvignon clusters were harvested in 2008 from a commercial vineyard in Paso Robles, California at various times after veraison with a focus on targeting °Brix levels near maturity. Dates and metabolic details that establish the developmental state of the berries at each harvest are presented in Additional file 1. Berries advanced by harvest date with the typical developmental changes for Cabernet Sauvignon: decreases in titratable acidity and 2- isobutyl-3-methoxypyrazine concentrations and increases in sugar and color . Transcriptomic analysis focused on four harvest dates having average cluster °Brix levels of 22.6, 23.2, 25.0 and 36.7. Wines made in an earlier study from grapes harvested at comparable levels of sugars or total soluble solids to those in the present study showed clear sensory differences. Six biological replicates, black flower buckets comprising two clusters each, were separated into skins and pulp in preparation for RNA extraction and transcriptomic analysis using the NimbleGen Grape Whole-Genome Microarray. Thus, a 4 × 2 factorial experimental design was established. A note of caution must be added here. There are high similarities amongst members in certain Vitis gene families , making it very likely that cross-hybridization can occur with probes on the microarray with high similarity to other genes.

We estimate approximately 13,000 genes have the potential for cross-hybridization, with at least one probe of a set of four unique probes for that gene on the microarray potentially cross-hybridizing with probes for another gene on the microarray. Genes with the potential for cross hybridization have been identified and are highlighted in light red in Additional file 2. The rationale to include them is that although individual genes can not be uniquely separated, the probe sets can identify a gene and its highly similar gene family members, thus, providing some useful information about the biological responses of the plant. An additional approach was taken, removing cross-hybridizing probes before quantitative data analysis . Many of the significant genes were unaffected by this processing, but 3600 genes were completely removed from the analysis. Thus, it was felt that valuable information was lost using such a stringent approach. The less stringent approach allowing for analysis of genes with potential cross hybridization was used here in the rest of the analyses. To assess the main processes affected by these treatments, the gene ontologies of significantly affected transcripts were analyzed for statistical significance using BinGO. Based on transcripts that had significant changes in abundance with °Brix level, 230 biological processes were significantly over represented in this group . The three top over represented processes were response to abiotic stress, bio-synthetic process, and response to chemical stimulus, a rather generic set of categories. Tissue differences were more revealing at the stage when flavors peak; 4865 transcripts that were significantly higher in skins compared to pulp at 23.2 °Brix were tested for over represented GO functional categories . Some of the top GO categories included photosynthesis, isoprenoid biosynthesis, and pigment biosynthesis . Some of the transcripts with the largest differences between skin and pulp at 23.2 °Brix are β-ketoacyl-CoA synthase , taxane 10-β-hydroxylase , wax synthase, a lipase, an ABC transporter, and phenylalanine ammonia-lyase . The abundance of 5716 transcripts was significantly higher in pulp than skin at 23.2 °Brix . Some of the top GO categories over represented were a variety of transport processes and small GTPase mediated signal transduction . Some of the transcripts with the largest differences in abundance with pulp greater than skin at 23.2 °Brix were polygalacturonase , flavonol synthase, stachyose synthase, an amino acid transporter, a potassium channel , and HRE2 . The transcript abundance of 2053 genes had significantly differential expression across °Brix levels and tissues . The top GO categories over represented in this set involved photosynthesis and phenylpropanoid metabolism, both associated with the berry skin . Other flavorcentric categories of the 57 categories over represented include aromatic compound biosynthesis, fatty acid metabolism and alcohol catabolism. This transcript set was further analyzed by dividing into 10 clusters using k-means clustering . The over represented GO categories were determined for each cluster . Eight of the 10 clusters had distinct over represented GO categories; two clusters did not have any over represented GO categories, meaning that the genes in these two clusters were assigned to GO categories of expected proportions when compared to the entire NimbleGen array. Clusters 1, 8, 9 and 10 had a large number of over represented categories. Many GO categories within a cluster are subsets of others in that cluster and were grouped together. For example, cluster 4 had four over represented GO categories, oxygen transport, gas transport, heat acclimation and response to heat. The four categories could be grouped into two, as two are subsets of the others; this is how they were listed in Table 1.To properly annotate the AP2/ERF super family of Vitis vinifera according to the IGGP Supernomenclature committee instructions, a phylogenetic tree was generated for the AP2/ERF super family of Arabidopsis thaliana and Vitis vinifera using the TAIR 10 and V1 gene models, respectively . The labeled family classifications were derived from the Arabidopsis naming scheme by Nakano et al.. There are 130 members in the VitisAP2/ERF super family in the Pinot Noir reference genome. However, the six paralogs of ERF6 discussed above belong to a Vitis vinifera clade in subfamily IX and are distinctly different or separate from any Arabidopsis subfamily IX ERF TFs . All of these TFs in this clade are orthologs of AtERF6. VviERF6L1 [UniProt: F6I2N8; VIT_16s0013g00900] had one of the most interesting profiles of the 12 members of this clade because its transcript abundance peaked at 23.2 °Brix . Using k-means clustering, VviERF6L1 fell within Cluster 8 with 369 transcripts, including five additional VviERF6 paralogs. The top GO categories associated with Cluster 8 were genes associated with terpenoid metabolism and pigment biosynthesis . Other interesting flavor associated categories included fatty acid and alcohol metabolism . Representative transcripts from Cluster 8 that were correlated with the transcript abundance profile of VviERF6L1 can be seen in Figure 4.

As shown in Figs. 5.14 and 5.15, more subtle features of the transport curve can also be associated with the reversal of domains that do not bridge contacts. In the absence of significant magnetic disorder ferromagnetic domain walls minimize surface tension. In two dimensions, domain walls are pinned geometrically in devices of finite size with convex internal geometry. As discussed in Fig. 5.15, we observe pinning of domain walls at positions that do not correspond to minimal length internal chords of our device geometry–suggesting that magnetic order couples to structural disorder directly. This is corroborated by the fact that the observed domain reversals associated with the Barkhausen jumps are consistent over repeated thermal cycles between cryogenic and room temperature. Together, these findings suggest a close analogy topolycrystalline spin ferromagnets, which host ferromagnetic domain walls that are strongly pinned to crystalline grain boundaries ; indeed, these crystalline grains are responsible for Barkhausen noise as it was originally described. Although crystalline defects on the atomic scale are unlikely in tBLG thanks to the high quality of the constituent graphene and hBN layers, the thermodynamic instability of magic angle twisted bilayer graphene makes it highly susceptible to inhomogeneity at scales larger than the moir´e period, as shown in prior spatially resolved studies. For example, procona valencia buckets the twist angle between the layersas well as their registry to the underlying hBN substrate may all vary spatially, providing potential pinning sites.

Moir´e disorder may thus be analogous to crystalline disorder in conventional ferromagnets, which gives rise to Barkhausen noise as it was originally described. A subtler issue raised by our data is the density dependence of magnetic pinning; as shown in Fig. 5.3, Bc does not simply track 1/m across the entire density range, in particular failing to collapse with the rise in m in the Chern magnet gap. This suggests nontrivial dependence of either the pinning potential or the magnetocrystalline anisotropy energy on the realized many body state. Understanding the pinning dynamics is critical for stabilizing magnetism in tBLG and the growing class of related orbital magnets, which includes both moir´e systems as well as more traditional crystalline systems such as rhombohedral graphite. In order to understand the microscopic mechanism behind magnetic grain boundaries in the Chern magnet phase in tBLG/hBN, we used nanoSQUID magnetometry to map the local moir´e super lattice unit cell area, and thus the local twist angle, in this device, using techniques discussed in the literature. This technique involves applying a large magnetic field to the tBLG/hBN device and then using the chiral edge state magnetization of the Landau levels produced by the gap between the moir´e band and the dispersive bands to extract the electron density at which full filling of the moir´e super lattice band occurs . The strength of this Landau level’s magnetization can be mapped in real space , and the density at which maximum magnetization occurs can be processed into a local twist angle as a function of position . It was noted in that the moir´e super lattice twist angle distribution in tBLG is characterized by slow long length scale variations interspersed with thin wrinkles, across which the local twist angle changes rapidly. These are also present in the sample imaged here .

The magnetic grain boundaries we extracted by observing the domain dynamics of the Chern magnet appear to correspond to a subset of these moir´e super lattice wrinkles. It may thus be the case that these wrinkles serve a function in moir´e super lattice magnetism analogous to that of crystalline grain boundaries in more traditional transition metal magnets, pinning magnetic domain walls to structural disorder and producing Barkhausen noise in measurements of macroscopic properties.In tBLG, a set of moir´e subbands is created through rotational misalignment of a pair of identical graphene monolayers. In twisted monolayer-bilayer graphene a set of moir´e subbands is created through rotational misalignment of a graphene monolayer and a graphene bilayer. These systems both support Chern magnets. Both systems are also members of a class of moir´e super lattices known as homobilayers; in these systems, the 2D crystals forming the moir´e super lattice share the same lattice constant, and the moir´e super lattice appears as a result of rotational misalignment, as illustrated in Fig. 5.17A. Homobilayers have many desirable properties; the most important one is that the twist angle can easily be used as a variational parameter for minimizing the bandwidth of the moir´e subbands, producing the so-called ‘magic angle’ tBLG and tMBG systems. Homobilayers do, however, have some undesirable properties. Although local variations in electron density are negligible in these devices, the local filling factor of the moir´e super lattice varies with the moir´e unit cell area, and thus with the relative twist angle. The tBLG moir´e super lattice is shown for two different twist angles in 5. B-C across the magic angle regime; it is clear that the unit cell area couples strongly to twist angle in this regime, illustrating the sensitivity of these devices to twist angle disorder. The relative twist angle of the two crystals in moir´e super lattice devices is never uniform. Imaging studies have clearly shown that local twist angle variations provide the dominant source of disorder in tBLG .

Phenomena discovered in tBLG devices are notoriously difficult to replicate. Orbital magnetism at B = 0 has only been realized in a handful of tBLG devices, and quantization of the anomalous Hall resistance has only been demonstrated in a single tBLG device, in spite of years of sustained effort by several research groups. A mixture of careful device design limiting the active area of devices and the use of local probes has allowed researchers to make many important discoveries while sidestepping the twist angle disorder issue- indeed, some exotic phases are known in tBLG only from a single device, or even from individual scanning probe experiments- but if the field is ever to realize sophisticated devices incorporating these exotic electronic ground states the problem needs to be addressed.There is another way to make a moir´e super lattice. Two different 2D crystals with different lattice constants will form a moir´e super lattice without a relative twist angle; these systems are known as heterobilayers . These systems do not have ‘magic angles’ in the same sense that tBLG and tMBG do, and as a result there is no meaningful sense in which they are flat band systems, but interactions are so strong that they form interaction-driven phases at commensurate filling of the moir´e super lattice anyway. Indeed, many of the interaction-driven insulators these systems support survive to temperatures well above 100 K. The most important way in which heterobilayers differ from homobilayers, however, is in their insensitivity to twist angle disorder. In the small angle regime, the moir´e unit cell area of a heterobilayer is almost completely independent of twist angle, as illustrated in 5.17E-F. A new intrinsic Chern magnet was discovered in one of these systems, a heterobilayer moir´e super lattice formed through alignment of MoTe2 and WSe2 monolayers. The researchers who discovered this phase measured a well-quantized QAH effect in electronic transport in several devices, procona buckets demonstrating much better repeatability than was observed in tBLG. The unit cell area as a function of twist angle is plotted for three moir´e super lattices that support Chern insulators in 5.17G, with the magic angle regime highlighted for the homobilayers, demonstrating greatly diminished sensitivity of unit cell area to local twist angle in the heterobilayer AB-MoTe2/WSe2. MoTe2/WSe2 does have its own sources of disorder, but it is now clear that the insensitivity of this system to twist angle disorder has solved the replication issue for Chern magnets in moir´e super lattices. Dozens of MoTe2/WSe2 devices showing well-quantized QAH effects have now been fabricated, and these devices are all considerably larger and more uniform than the singular tBLG device that was shown to support a QAH effect, and was discussed in the previous chapters. The existence of reliable, high-yield fabrication processes for repeatably realizing uniform intrinsic Chern magnets is an important development, and this has opened the door to a wide variety of devices and measurements that would not have been feasible in tBLG/hBN.The basic physics of this electronic phase differs markedly from the systems we have so far discussed, and we will start our discussion of MoTe2/WSe2 by comparing and contrasting it with graphene moir´e super lattices. In tBLG/hBN and its cousins, valley and spin degeneracy and the absence of significant spin-orbit coupling combine to make the moir´e subbands fourfold degenerate. When inversion symmetry is broken the resulting valley subbands can have finite Chern numbers, so that when the system forms a valley ferromagnet a Chern magnet naturally appears.

Spin order may be present but is not necessary to realize the Chern magnet; it need not have any meaningful relationship with the valley order, since spin-orbit coupling is absent. MoTe2/WSe2 has strong spin-orbit coupling, and as a result, the spin order is locked to the valley degree of freedom. This manifests most obviously as a reduction of the degeneracy of the moir´e subbands; these are twofold degenerate in MoTe2/WSe2 and all other TMD-based moir´e super lattices. The closest imaginable analog of the tBLG/hBN Chern magnet in this system is one in which interactions favor the formation of a valley-polarized ferromagnet, at which point the finite Chern number of the valley subbands would produce a Chern magnet. This was widely assumed to be the case at the time of the system’s discovery. There is now substantial evidence that this system instead forms a valley coherent state stabilized by its spin order, which would require a new mechanism for generating the Berry curvature necessary to produce a Chern magnet. In general I think it is fair to say that the details of the microscopic mechanism responsible for producing the Chern magnet in this system are not yet well understood. In light of the differences between these two systems, there was no particular reason to expect the same phenomena in MoTe2/WSe2 as in tBLG/hBN. As will shortly be explained, current-switching of the magnetic order was indeed found in MoTe2/WSe2. The fact that we find current-switching of magnetic order in both the tBLG/hBN Chern magnet and the AB-MoTe2/WSe2 Chern magnet is interesting. It may suggest that the phenomenon is a simple consequence of the presence of a finite Chern number; i.e., that it is a consequence of a local torque exerted by the spin/valley Hall effect,which is itself a simple consequence of the spin Hall effect and finite Berry curvature. These ideas will be discussed in the following sections.In spin torque magnetic memories, electrically actuated spin currents are used to switch a magnetic bit. Typically, these require a multi-layer geometry including both a free ferromagnetic layer and a second layer providing spin injection. For example, spin may be injected by a nonmagnetic layer exhibiting a large spin Hall effect, a phenomenon known as spin-orbit torque. Here, we demonstrate a spin-orbit torque magnetic bit in a single two-dimensional system with intrinsic magnetism and strong Berry curvature. We study AB-stacked MoTe2/WSe2, which hosts a magnetic Chern insulator at a carrier density of one hole per moir´e super lattice site. We observe hysteretic switching of the resistivity as a function of applied current. Magnetic imaging reveals that current switches correspond to reversals of individual magnetic domains. The real space pattern of domain reversals aligns with spin accumulation measured near the high Berry curvature Hubbard band edges. This suggests that intrinsic spin or valley Hall torques drive the observed current-driven magnetic switching in both MoTe2/WSe2 and other moir´e materials. The switching current density is significantly less than those reported in other platforms, suggesting moir´e heterostructures are a suitable platform for efficient control of magnetic order. To support a magnetic Chern insulator and thus exhibit a quantized anomalous Hall effect, a two dimensional electron system must host both spontaneously broken time-reversal symmetry and bands with finite Chern numbers. This makes Chern magnets ideal substrates upon which to engineer low-current magnetic switches, because the same Berry curvature responsible for the finite Chern number also produces spin or valley Hall effects that may be used to effect magnetic switching. Recently, moir´e heterostructures emerged as a versatile platform for realizing intrinsic Chern magnets. In these systems, two layers with mismatched lattices are combined, producing a long-wavelength moir´e pattern that reconstructs the single particle band structure within a reduced super lattice Brillouin zone.

Measuring a magnetic field with a SQUID does not require optical access; many other magnetic field measurement techniques do. Together, these facts mean that scanning SQUIDs are often the best tools available for probing extremely low temperature phenomena. NanoSQUID sensors also have many advantages over planar SQUIDs. The most obvious, of course, has already been discussed, and that is their higher spatial resolution. A less obvious advantage- indeed, an advantage that became clear only after the first nanoSQUID sensors were fabricated and tested- is the geometry of the thin superconducting contacts, which under normal circumstances are aligned with the axis of the applied magnetic field. Large magnetic fields tend to destroy superconducting phases, so superconducting devices are all limited by the maximum magnetic fields at which they can operate. This so-called critical field HC is not an intensive property; there is a large-size limit that can be measured and tabulated for different materials, but the critical field of an individual piece of superconductor is a strong function of geometry. A thin superconducting film in the plane of an applied magnetic field can accommodate much higher magnetic field magnitudes than can be accomodated by a large piece of the same superconductor. The bulk limit for lead at low temperature is about 80 mT; we routinely make lead nanoSQUIDs that can survive magnetic fields of 1 T, plastic planters wholesale and we have on occasion made nanoSQUIDs that can survive magnetic fields above 2 T.

It turns out that many of the most useful magnetic imaging techniques are limited to low field operation. This thesis will focus primarily on low field phenomena, but there are also many magnetic phenomena that require high magnetic fields to appear, including the quantum Hall effect and a variety of magnetic phase transitions. The nanoSQUID technique is useful for studying these as well.Above about 0.2 T, superconductivity begins to rapidly degrade in the nanoSQUID sensor, destroying the sensitivity of the sensor and rendering it useless as a sensor of magnetic field. This limits this particular nanoSQUID to operation in the regime −0.2T < B < 0.2T. This is fairly general to indium nanoSQUIDs; their precise critical fields vary, but are generally considerably below those of lead nanoSQUID sensors. As with any sensor, measurements with nanoSQUIDs are contaminated with noise, and the dependence of that noise on SQUID bias and magnetic field can be characterized. A characterization of the noise spectrum of the indium nanoSQUID shown in Fig. 1.6A is shown in Fig. 1.6B. In nanoSQUID sensors, local maxima in critical current are often associated with high noise and thus low magnetic field sensitivity . This produces ‘blind spots’ in magnetic field for nanoSQUID sensors. These blind spots often in practice include B = 0, making true zero-field operation challenging for nanoSQUID sensors. Technologies exist for circumventing this issue[54], but in practice we mostly work around it.

The low magnetic field DC response of a lead nanoSQUID is shown in Fig. 1.6C. A higher magnetic field characterization is shown in Fig. 1.6D, illustrating the collapse of superconductivity in this nanoSQUID at a considerably higher magnetic field of about 0.75 T. The inventor of the technique has been active in developing ways to deposit other materials onto micropipettes for use as nanoSQUID sensors, and has succeeded in producing aluminum, niobium, tin, and alloyed molybdenum/rhenium nanoSQUIDs, in addition of course to indium and lead nanoSQUIDs. The MoRe nanoSQUIDs in particular are capable of operating in extremely large ambient magnetic fields, up to about 5T. The magnetic field noise floor of nanoSQUID sensors seems to vary for different materials as well. We do not have a strong model explaining why this is the case, but it is empirically true that indium and lead nanoSQUIDs have particularly low noise floors. Plots illustrating the dependence on magnetic field of the magnetic field sensitivity of a lead nanoSQUID sensor 80 nm in diamater are shown in Fig. 1.7. NanoSQUID sensors have some unique disadvantages as well. Like planar SQUIDs, nanoSQUIDs require superconductivity to function, which limits them to fairly low operating temperatures. In planar SQUIDs it is often possible to keep the SQUID itself cold while scanning over a much hotter sample, but nanoSQUID sensors are extremely poorly thermalized to their scan heads, which means that they generally are thermalized either to the surface over which they are scanning or to the black body spectrum of the vessel in which they are contained .

This gives nanoSQUID sensors some interesting capabilities, namely that under the right conditions they can function as extremely sensitive scanning probe thermometers, but it also comes with some drawbacks. NanoSQUIDs composed of superconductors with critical temperatures below 4.2 K, the boiling point of helium-4 at atmospheric pressure, must thus have actively cooled thermal radiation shields to operate in very high vacuum, and of course imaging of hot samples is completely out of the question for these sensors. A variety of exciting opportunities exist for the application of sensitive magnetic imaging techniques to biological systems, and this is not a realistic option for nanoSQUID sensors. NanoSQUIDs are quite fragile and can be easily destroyed by vibrations, necessitating vibration isolation systems, and the superconducting film on the apex of the micropipette is quite thin, typically between 15 and 20 nm, so superconducting materials that oxidize in air will be quickly degraded. Thankfully indium and lead do not oxidize rapidly, but they do oxidize at a finite rate, so nanoSQUIDs composed of these materials only last for a few days when left in air. Storage in high vacuum can improve their lifespan, but generally not indefinitely. In summary, scanning probe microscopes fitted with nanoSQUID sensors can function as magnetometry microscopes with 30-250 nm resolution. They are capable of operating at very low temperatures and magnetic fields of up to several Tesla. Their high sensitivities allow them to detect the minute magnetic fields emitted by electronic phases composed entirely of electrons forced into a two dimensional heterostructure with an electrostatic gate. We will discuss some of the properties of two dimensional heterostructures next.Many crystalline compounds have cleavage planes; that is, planes along which cracks propagate most readily. When such compounds are stressed beyond their yield strength, they tend to break up into pieces with characteristic shapes that inherit the anisotropy of the chemical bonds forming the crystal out of which they are composed. Indeed, this observation was a compelling piece of early evidence for the existence of crystallinity, and even atoms themselves. There exists a class of materials withcovalent bonds between unit cells in a two dimensional plane and much weaker van der Waals bonds in the out-of-plane direction, producing extraordinarily strong chemical bond anisotropy. In these materials, known as ‘van der Waals’ or ‘two dimensional’ materials, this anisotropy produces cleavage planes that tend to break bulk crystals up into two dimensional planar pieces. Exfoliation is theprocess of preparing a thin piece of such a crystal through mechanical means. In some of these materials, the chemical bond anistropy is so strong that it is possible to prepare large flakes that are atomically thin . These two dimensional crystals have properties quite different from their bulk counterparts. They do have a set of discrete translation symmetries, plastic plant pot which makes them crystals, but they only have these symmetries along two axes- there is no sense in which a one-atom-thick crystal has any out-of-plane translation symmetries. For this reason they have band structures that differ markedly from their three dimensional counterparts. A variety of techniques have been developed for preparing atomically thin flakes from van der Waals materials, but by far the most successful has been scotch tape exfoliation. In this process, a chunk of a van der Waals crystal is placed on a piece of scotch tape. This separates the chunk of van der Waals crystal along its cleavage planes into two pieces of comparable size on opposite sides of the piece of tape. This process is repeated several times, further dividing the number of atomic layers in each chunk with each successive repetition. If we assume we are dividing the number of atomic layers in each piece roughly in half with each round, after N repetitions the resulting crystals should have thicknesses reduced by a factor of 2 1 N .

This is enough to reduce each flake to atomic dimensions after a small number of repetitions of the process. This process is, of course, self-limiting; once the flakesreach atomic dimensions, they cannot be further subdivided. Graphite can be exfoliated through this process into flakes one or a few atoms thick and dozens of microns in width, a width-to-thickness aspect ratio of 105 . As previously discussed, this process cannot be executed on every material. It depends critically on scotch tape bonding more strongly to a layer of the crystal than that layer bonds to other layers within the crystal. It also depends on very strong in-plane bonds within the material, which must support the large stresses associated with reaching such high aspect ratios; materials with weaker in-plane bonds will rip or crumble. In practice these materials are almost always processed further after they have been mechanically exfoliated, and the preparation process typically begins when they are pressed onto a silicon wafer to facilitate easy handling. Samples prepared in this way are called ‘exfoliated heterostructures.’ It is of course interesting that this process allows us to prepare atomically thin crystals, but another important advantage it provides is a way to produce monocrystalline samples without investing much effort in cleanly crystallizing the material; mechanical separation functions in these materials as a way to separate the domains of polycrystalline materials. Graphene was the first material to be more or less mastered in the context of mechanical exfoliation, but a variety of other van der Waals materials followed, adding substantial diversity to the kinds of material properties that can be integrated into devices composed of exfoliated heterostructures. Monolayer graphene is metallic at all available electron densities and displacement fields, but hexagonal boron nitride, or hBN, is a large bandgap insulator, making it useful as a dielectric in electronic devices. Exfoliatable semiconductors exist as well, in the form of a large class of materials known as transition metal dichalcogenides, or TMDs, including WSe2, WS2, WTe2, MoSe2, MoS2, and MoTe2. Exfoliatable superconductors, magnets, and other exotic phases are all now known, and the preparation and mechanical exfoliation of new classes of van der Waals materials remains an area of active research. Once two dimensional crystals have been placed onto a silicon substrate, they can be picked up and manipulated by soft, sticky plastic stamps under an optical microscope. This allows researchers to prepare entire electronic devices composed only of two dimensional crystals; these are known as ‘stacks.’ These structures have projections onto the silicon surface that are reasonably large, but remain atomically thin- capacitors have been demonstrated with gates a single atom thick, and dielectrics a few atoms thick. Researchers have developed fabrication recipes for executing many ofthe operations with which an electrical engineer working with silicon integrated circuits would be familiar, including photolithography, etching, and metallization. I think it is important to be clear about what the process of exfoliation is and what it isn’t. It is true that mechanical exfoliation makes it possible to fabricate devices that are smaller than the current state of the art of silicon lithography in the out-of-plane direction. However, these techniques hold few advantages for reducing the planar footprint of electronic devices, so there is no meaningful sense in which they themselves represent an important technological breakthrough in the process of miniaturization of commercial electronic devices. Furthermore, and perhaps more importantly, it has not yet been demonstrated that these techniques can be scaled to produce large numbers of devices, and there are plenty of reasons to believe that this will be uniquely challenging. What they do provide is a convenient way for us to produce two dimensional monocrystalline devices with exceptionally low disorder for which electron density and band structure can be conveniently accessed as independent variables. That is valuable for furthering our understanding of condensed matter phenomena, independent of whether the fabrication procedures for making these material systems can ever be scaled up enough to be viable for use in technologies.

For example, Adafruit sells ADCs with resolutions ranging from 8‐ to 16‐bits and includes open‐ source software libraries and hardware design for interfacing them with a Raspberry Pi or other single‐board computer. Some sensing applications, however, such as thermocouple psychrometry and load cell measurement, involve the detection of small changes within a large measurement range. These applications may require higher than 16‐bit resolution, thus necessitating an ADC with higher resolution along with low‐noise and low‐drift electronic components. The DAQ system described here provides high resolution at a significantly lower cost than commercial laboratory DAQ systems with similar specifications. It uses the ADS1262 ADC , which has 32‐bit resolution, very low noise and drift , as well as many built‐in features . The ADS1262 and ADS1263 are identical except that the ADS1263 also includes one additional independently controlled 24‐bit ADC. The ADS1262 was used in the system described here, but the ADS1263 can also be used and will perform the same. These features allow this ADC to be used with many different types of sensors; however, the manufacturer of this ADC does not provide a software library that allows it to be easily interfaced with a Linux computer like the Raspberry Pi. To address this, we describe here the open‐source software libraries we developed to provide this interface, called piadcs, and the electronic system design required to use this ADC with a Raspberry Pi to make ultra‐ high‐resolution measurements.The DAQ system consists of a relatively simple hardware design based around a Raspberry Pi and the ADS1262/3 , 10 plastic plant pots and the piadcs software libraries enable users to easily configure the ADS1262/3 and to collect, convert, and store the output data.

The ADS1262/3 is a good choice for a custom DAQ system because of its extremely high resolution and many features that give it flexibility . Functions to modify these settings are found in both piadcs libraries. There are functions for both reading data continuously or reading on command. Communication between the Raspberry Pi and the ADS1262/3 uses a combination of SPI and GPIO. The Go version of the library uses the Periph library to control the SPI and GPIO interfaces, and the Python version uses Spidev and RPi.GPIO . There are other ADCs on the market that use highly similar programming to the ADS1262/3, and the piadcs libraries are extendable to such ADCs. The libraries also contain documentation and examples that provide a template for programming other ADCs.There are two functionally equivalent versions of the piadcs library: one is written in Python and the other in Go. The two versions offer different advantages and disadvantages due to differences between the two languages. Python is one of the most widely used programming languages, but as an interpreted language, it runs slower and does not have support for concurrency. Go is less commonly used but still among the top 20 most‐used programming languages . Go is a compiled language, which provides performance advantages over Python and is simpler to read than other compiled languages . Both versions of the piadcs library are available on GitHub.Both are installed as packages, and detailed instructions for installation and usage can be found in the README file on GitHub. In brief, the Python library is installed from the command line using the “pip3” command and the Go library is installed using the “go get” command. The “Examples” folders found in the libraries contain code examples showing how to use the different functions in the library to change ADC settings and collect data from the ADC.

These libraries were designed to run on a Raspberry Pi model 4B or 3B+ running Raspberry Pi OS. It may also be possible to run them on other models provided they are running an up‐to‐date version of the same operating system, but we have not tested this. There are many helpful guides available on how to get started with a Raspberry Pi and the Raspberry Pi OS. For an official source, the documentation section of the Raspberry Pi website provides a detailed guide .The DAQ system can be built using the materials listed in Table 1 for about US$100. The wiring diagram shown in Figure 1 illustrates how the components are connected. The ADS1262/3 can be connected to the Raspberry Pi using one SPI bus and three GPIO pins. In our setup , they are connected via the Raspberry Pi’s SPI_0 and GPIO pins 4, 22, and 27, but any of the available SPI interfaces and GPIO pins could be used. These connections must be specified in the code. Several breakout boards are available for connecting the ADS1262/3 to solderless breadboards for prototyping. A breakout board from ProtoCentral was used in the development of these libraries, but an alternative from Olimex would also be suitable . A Raspberry Pi–specific “HAT” for the ADS1263 is available from Waveshare . It is compatible with the piadcs libraries, but it is not suitable for low‐noise measurements in that one cannot electrically isolate the Raspberry Pi and the ADC because they share the same power supply; moreover, this board situates heat‐generating components near the temperature sensor of the ADC. High‐resolution measurements require low system noise. In our DAQ system, low noise is achieved by electrically isolating the ADS1262/3 from the Raspberry Pi. This requires separate power supplies. The Raspberry Pi is powered by a standard USB‐C wall adapter , which is usually sold with the computer, whereas the ADS1262/3 is powered by 9‐V batteries connected to linear voltage regulators. Batteries are preferable to wall supplies because they do not generate any 60 Hz AC noise. The ADS1262/3 draws less than 6.5 mA, and so a battery lasts for several weeks. The digital communication channels between the ADS1262/3 and the Raspberry Pi are also isolated using the ADuM4151 7‐channel SPIsolator .

All the components for this custom DAQ system can be wired onto a solderless breadboard or made into a printed circuit board. A solderless breadboard setup was used for the test measurement shown in Figure 2.It is possible to make very low noise measurements with this DAQ system as long as the aforementioned electrical considerations are addressed. System performance was tested with and without sensors connected. We first measured baseline system noise with no sensors connected and found that, at slower data rates , the system noise is remarkably low and the system has better than 1 ppm precision. As the data rate increases, the noise increases and precision decreases somewhat but is still very good . The ADS1262/3 has 16 different data rates available ranging from 2.5 to 38,400 samples/second, but our DAQ system only performs well at data rates up to 14,400 samples/ second. This is due to a breakdown in serial communication that occurs at higher speeds and could potentially be solved in future releases. Although the ADC used in this system has a nominal resolution of 32‐bits, the actual system precision is lower, especially as the data rate increases. Noise remaining in the system , along with the inherent tradeoff between ADC speed and resolution, causes the effective resolution of an ADC to be lower than its nominal resolution . The noise floor and, therefore, the effective resolution of our system is very close to that specified in the ADS1262 datasheet for the data rates and digital filters tested , plastic pots large and is a major improvement over other existing open‐source DAQ systems for the Raspberry Pi. System performance with a connected sensor was tested by measuring the output of a K‐type thermocouple submerged in an ice bath using our DAQ system. This setup was able to measure the ice bath temperature with a noise level of less than ±0.01°C ; this was achieved using only the analog front end provided on the ADS1262 with the PGA set to the maximum setting of 32 V/V. An external ultra‐low‐noise amplifier set to a higher gain could be used instead of the onboard PGA to further decrease noise for applications requiring very low‐level measurements . Our DAQ system has significantly better noise performance than other Raspberry Pi thermocouple DAQ systems. For example, the MCC 134 Thermocouple DAQ HAT for Raspberry Pi has greater than 0.5°C measurement error with the same type of thermocouple. This is likely due partly to large thermal gradients caused by placing the DAQ board on top of the heat‐generating components of the Raspberry Pi.Two assumptions have guided the study of concept learning ever since Hull . The first is that category learning amounts to learning a common label for sets of objects. This assumption is explicit in the ubiquitous supervised classification task, in which people receive feedback when classifying visually presented stimuli. This paradigm has been used to determine, for example, whether prototype models are superior to exemplar models . Over the years, researchers have taught people to group objects into sets and have examined the resulting representations. A second assumption has been that information about a category learned in one context, should not transfer well to another. Consider the goal of distinguishing roses from raspberry bushes. If the most diagnostic feature is the presence of berries, then people will learn that the berry feature should receive the most attention weight . However, when one later has to distinguish raspberry from cranberry bushes, thorns suddenly become diagnostic, because while both have red berries, only the raspberry bush has thorns.

The problem is that optimizing attention for one category contrast is not always optimal for another . The consequence of ignoring irrelevant dimensions for one set of category contrasts means that the learner has to re-attend those dimensions when familiar categories are contrasted in novel ways. That is, the learner has to relearn about raspberries. In this manner, the heralded powers of selective attention assumed by present theories are predicted to harm performance when previously irrelevant dimensions become relevant. The mechanisms of attention allocation in many computational models of category learning suggest that people learn to attend to only that information needed to distinguish the two categories being acquired. The problem we raise is that after learning one classification in which, say, cue A is most diagnostic, people should have trouble learning a second classification in which B is the good cue, because prior classifications have taught people to ignore it . We ask two questions in this study. First, how rigid are learners’ representations across different learning tasks? Second, can attention provide an explanatory variable for differences in what is learned between tasks? We speculate that flexible category representations are necessary for everyday classification, since particular category contrasts are not always known ahead of time by the categorizer. Previous research points to inference as being a likely candidate for producing flexible representations. To the extent that inference but not classification produces flexible category representations, it may reflect a more ecologically valid task for studying the kinds of concepts that people use everyday.Other tasks, where the goal is not to classify, but to learn about the properties of categories, may yield a flexible representation that can handle novel contrasts. Research that has expanded the array of concept acquisition tasks led us to consider a task that may produce flexible conceptual representations. Whereas classification involves predicting the category label from features, feature inference learning involves predicting a missing feature from other features and the category label. So rather than determining that a plant is a raspberry bush,the inference task asks learners to determine whether a raspberry bush has thorns, or some other property. Comparisons of the feature inference task with supervised classification are of current interest, with evidence that inference produces different representations. It has been found that inference produces: increased sensitivity to within-category correlations of features , increased sensitivity to nondiagnostic, prototypical features , more prototypical-feature inferences, and faster learning of linearly separable categories . Thus, in spite inference and classification tasks being formally identical , it is possible that the resulting flexiblity of category representations can also differ. The above-cited evidence suggests that whereas classification learning may foster attention to the diagnostic dimensions that serve to distinguish between categories, inference learning may focus categorizers on within category information. Our hypothesis is that because the within-category information acquired by inference learners is not tied to any particular set of contrast categories, such knowledge yields a more general and flexible representation. As a consequence, with respect to novel contrasts, inference learners may be at an advantage over classification learners.

The pretrained models of these architectures were fine tuned with our proposed insect dataset so that they can be used for the yellow fly detection application, as fine tuning is also one of the common solutions for data scarcity problem in object detection. Because the models had been trained with COCO dataset, which is a large dataset having over 200,000 labeled images with 1.5 million object instances for 80 object categories, and, hence, contains common features for object detection problem, fine tuning the models with 200 yellow fly images helped the models perform the yellow fly detection task.To solve the real-time object detection in the yellow fly detection problem, variants of Single-Shot Multibox Detector are used. The SSD method was first proposed in [36] by Wei Liu et al. and described as a one stage object detection method that completely omits the region proposal and pixel/feature resampling stages used in region proposal-based techniques such as Faster-RCNN. The SSD network is based on a feed-forward network that uses default bounding boxes with different shapes, ratios, and scales to produce a fixed-size collection of bounding boxes with corresponding shape offsets and confidence scores. In addition, the early layers of the network are based on a standard image classification without classification layers, blueberry container size which is called the base network. In this work, MobileNetV1 and MobileNetV2 are used as base networks for the SSD detection models.

The elimination of region proposal and pixel/feature resampling stages helps to improve the processing speed of the model compared to two-stage techniques such as Faster-RCNN with a small trade-off in the model’s accuracy, which enables the implementation of real-time object detection with high accuracy on embedded system for yellow fly detection problem.The approach was first proposed in [37] by A. Howard et al. and was described as a lightweight deep neural network for mobile and embedded system applications with an efficient trade-off between latency and accuracy. The model is based on depth wise separable convolution including depth wise convolution layer which is used to apply a single filter per input channel, and pointwise convolution layer, which creates a linear combination of the output of the depth wise layer. In addition, to construct the model further less computationally expensive, width multiplier, which is used to thin the network uniformly at each layer, and resolution multiplier, which is applied to input images and the internal representation of each layer, were introduced as a hyperparameter to tune, and choose the size of the model.The MobileNetV2 approach was first presented in by M. Sandler et al. The approach is built based on MobileNetV1; therefore, it also makes use of the depth wise separable convolution architecture which consists of depth wise convolution layer and 1×1 point wise convolution layer. In addition, the approach also utilizes linear bottleneck layers in convolutional blocks to optimize the neural architecture. Moreover, inverted residual design is also used in the model to implement shortcuts between bottlenecks with the purpose of improving the ability of gradient propagation across the multiplier layers. Nevertheless, the implementation of the inverted design also showed better performance and significantly more memory efficiency in the work. The training and evaluation of the SSD with MobileNetV1 and MobileNetV2 base networks is based on the pre-trained models provided in the Object Detection API in TensorFlow Model Garden.

The models were also trained on the Google Colab Pro environment to utilize the provided GPUs for the training purpose.The assessments in this research are dedicated to search for the most appropriate object detection method among the current state-of-the-art algorithms which have been implemented for insect and fly recognition under our hardware constraints and problem definition. As we only target one type of fruit flies that particularly causes harm to the citrus fruits, we have replaced the yellow sticky paper with a white disc containing the special attractant as a hard refinement to pick up only the flies we are interested in. The object detection problem is then simplified to only one-class object detection, which eases the need for exhausting feature extraction. However, the general constraints, such as correctness and fastness, for an object detection task on an edge-device still hold since early detection and separation of the infected areas are extremely important to the fruit yield.Ultimately, SSD-MobileNetV1, SSD-MobileNetV2 and YOLOv4-tiny are the best candidates for these requirements because they utilize extracted features from a backbone classification model to automatically propose object-related regions instead of using a region-proposal module to pool the related regions before classifying them as many two stage object detection models, such as Fast-RCNN and Faster-RCNN.Regarding the correctness, YOLOv4-tiny clearly outperforms the two SSD models over all the evaluations on four different types of testset with very high and stable results. This could make YOLOv4-tiny become the most probable candidate, because YOLOv4-tiny demonstrates a robust testing performance towards citrus fruit fly detection although it has been fine-tuned only on a training dataset without augmentation effects. SSD-MobileNetV2 shows appropriate robustness given its small number of trainable parameters by yielding good results in two over four testsets, while SSD-MobileNetV1 only works with the original testset. Nevertheless, SSD-MobileNetv2 fails dramatically with the Blurry testset, which simulates a very frequent event that could happen in a fruit field. YOLOv4-tiny is no doubt the chosen one among the three methods if we would not have taken other aspects into account.

Conventionally, highly accurate object detection methods trade their processing speed for its better performance due to the employment of more parameters in their architecture. While missing a fraction of time could lead to undetectable events in which the flies appear, our second choice, which is the SSD-MobileNetV2 model, should be considered. To realize this choice after extensive performance analysis with four different testsets, SSD-MobileNetV2 must have been fine tuned with more augmented versions of the original training dataset before going to production to leverage its robustness to the level of YOLOv4-tiny while retaining its processing speed. Moreover, TFLITE version of SSD-models are also tested on a cloud TPU Google engine, TPUv2, for the feasibility of edge-device deployment. The overall assessment table for YOLOv4-tiny and SSD-MobileNetV2 is shown in Table 2 in terms of F1-Score and inference time.While San Joaquin Valley vineyards are currently fertilized with boron through the soil and foliage , some growers have expressed interest in applying boron via drip irrigation or “fertigation.” Fertigation is a relatively simple, cost-effective and efficient way to apply nutrients. However, irrigation water with more than 1 part per million boron can lead to vine toxicity, so the safety of boron fertigation is also a concern. Our research evaluates the safety and efficacy of boron fertigation in grapevines using drip irrigation. Boron is unique among the micronutrients due to the narrow range between deficiency and toxicity in soil and plant tissues. For grapevines, this range is 0.15 ppm to 1 ppm in saturated soil extracts, and 30 ppm to 80 ppm in leaf tissue. The goal of boron fertilization of grapevines is to keep tissue levels within this narrow range, since both deficiency and toxicity can have serious negative effects on vine growth and production. Fertilization amounts must be precise to avoid toxicity while providing adequate boron to satisfy grapevine requirements . On the east side of the San Joaquin Valley, boron deficiency of grapevines occurs on soils formed from igneous rocks of the Sierra Nevada. This parent material is low in total boron, growing raspberries in containers which is crystallized in borosilicate minerals that are highly resistant to weathering. Boron deficiency is often associated with sandy soils and vineyard areas with excessive leaching, such as in low spots or near leaky irrigation valves. Vine symptoms of boron deficiency are more widespread and pronounced following high rainfall years, when greater amounts of soluble boron are leached from the root zone. In addition, snowmelt water has very low levels of boron, and vineyards irrigated primarily with this water have a greater risk of deficiency. Boron is required for the germination and growth of pollen during flowering, and vines that are deficient in this micronutrient will have clusters that set numerous shot berries, small berries with a distinctive pumpkin shape. When boron deficiency is severe, vines produce almost no crop. Foliar symptoms appear in the spring: shoots have shortened, swollen internodes and their tips sometimes die, and leaves have irregular, yellowish mottling between the veins. Grapevines are also sensitive to too much boron. Toxicity is common on the west side of the San Joaquin Valley, where most soils are derived from marine sedimentary and metasedimentary parent material that is rich in easily weathered boron minerals. Symptoms of boron toxicity include leaves that are cupped downward in the spring and that develop brown spots adjacent to the leaf margin in middle or late summer, intensifying and leading to necrosis as boron accumulates.

Yields are reduced, the result of diminished vine vigor and canopy development. When foliar boron sprays are applied in excess in the spring, juvenile leaves become cupped within 2 weeks; however, vines quickly recover and yields are usually unaffected. Toxicity also occurs when boron fertilizer is applied in excess, regardless of the soil type, and this can lead to yield loss. Over-fertilization is the sole reason for boron toxicity on the east side of the San Joaquin Valley, so it is critical to establish how much boron fertilizer can be applied safely and effectively. Our research investigated the uptake of boron by grapevines when fertilizer was applied with a drip-irrigation system.Research was conducted from 1998 to 2001 in a mature ‘Thompson Seedless’ raisin vineyard near Woodlake in Tulare County. The vineyard was planted in Cajon sandy loam on a recent alluvial fan associated with the Kaweah River. This soil is derived from granitic parent materials, and the surface soil is highly micaceous with a slight to moderate amount of lime. The underlying soil has a coarse, sandy texture. At the onset of this study, the vineyard’s boron status was in the questionable range for deficiency. The vine’s leaf petioles and blades contained about 30 ppm boron. While the foliage had no symptoms of boron deficiency, in the past the grower had observed sticking caps and pumpkin-shaped shot berries, which are indicative of boron deficiency. During the course of the research, the vineyard was drip-irrigated from April through October. The vineyard canopy covered 60% of the land surface during summer months and about 20 inches of water was applied during the season. Boron treatments consisted of applying fertilizer in varying amounts 3 weeks prior to bloom on May 18, 1998, and then again 3 weeks prior to bloom the following year, on May 3, 1999. Growers who fertigate grapevines with a drip system generally inject material into the irrigation water over a 45-to- 60-minute period at the beginning of an irrigation set. We simulated fertigation by applying Solubor, a soluble boron product , to a shovel-sized hole beneath drippers during the first hour of the irrigation set. By doing this, precise amounts of boron could be applied to each plot and plot size could be reduced. This technique has been used successfully in previous research with other nutrients . The experiment was designed as a randomized complete block with five treatments, five blocks and five vine plots . To evaluate the rate of boron uptake and accumulation in tissue with consecutive years of fertilization, grape tissue samples were collected in 1998 and 1999 at bloom and then again about 6 weeks later during veraison. Veraison is the stage of development where berries begin to soften and/or color. To evaluate carryover, leaf tissue samples were also collected at this Tulare County site at both bloom and veraison in 2001, 2 years after the fertilization was discontinued. In each case, 100 petioles and 50 blades were sampled per plot from the center three vines. Petioles and blades were taken opposite inflorescences during bloom, and recently matured leaves were sampled at veraison. Samples were oven-dried, ground in a Wiley mill and sent to the UC Davis DANR Analytical Laboratory for analysis of total boron. Statistical analysis was by ANOVA using least significance difference to separate treatment means. A second experiment was conducted in 1998 in Fresno County near Selma, in a mature Thompson Seedless raisin vineyard planted on Pollaski sandy loam and drip-irrigated.

We describe a microscopic model, an extended Hubbard model on the diamond lattice that, within a mean field treatment, leads to this phase. The order parameter supports a number of topological defects. In particular, a vortex like line defect occurs, but with a Z2 charge. This line defect in the STI is found to be associated with a pair of gapless fermionic excitations that travel along its length. These modes are topologically stable against moderate perturbations such as impurities and interactions as long as time reversal symmetry is intact. This is the main result of the chapter – an analytical derivation is provided which relies on the properties of the Dirac equation on a two-dimensional curved surface. We now contrast our results with other recent work. In Chapter 2 we have shown similar exotic behavior also occurs in TIs, along crystal defects such as dislocations. Gapless fermionic excitations emerge there when a Z2 parameter formed by the product of the dislocation Burgers vector and three WTI indices is nonzero – which in principle can occur inboth the weak and strong TI. In contrast, in the present chapter, the fermionic modes along the line defect are solely determined by the more elusive strong index. They are absent in the case of the WTI. Thus far, the characterization of the TI phase has relied on the surface behavior. This result provides a route to identifying the strong TMI via a bulk property. Similar modes have been identified propagating along a solenoid of π flux, inserted into a STI. Here, the 2π rotation of the electron spin around the line defect leads to a Berry’s phase, plastic potting pots providing a physical realization of the π flux. Analogous phenomena occur in the context of line defects in superfluid He3-B.

In most solids where electron-electron interactions are important tend to have some degree of SOIs – which will confine the defects. Hence, we propose realizations of this physics in optical lattices of ultracold atoms, utilizing molecules with multipole moments to obtain the proposed extended Hubbard models. Realizing the three-dimensional case is more challenging, however molecules with electric quadrupole moments confined in optical lattice can realize some of the key ingredients required. This chapter is organized as the following: In Section 3.2, we will present the order parameter manifold and the line modes’ Z2 dependence on the winding number; in Section 3.3, we will justify our claim with numerical and analytical results; another texture Shankar monopole will be discussed in Section 3.4; in Section 3.5, we will establish our model Hamiltonian on a diamond lattice and show the mean field stability of TMI phases; we give two possible experimental realizations in cold atom systems in Section 3.6; we conclude the main result of this chapter in the Section 3.7. Hereafter we use σ and τ for the spin and sublattice degree of freedom, respectively. This chapter incorporates materials previously published in Ref. .An experimental realization of the TMI phase must contend with two challenges. First, the system should have weak intrinsic spin-orbit coupling, but strong interactions. Next, the further neighbour repulsion should be substantial compared to the nearest neighbor interactions. We believe these difficulties can be overcome in cold atom system, where intrinsic spin orbit couplings are irrelevant, if particles with electric multipole moments are confined to optical lattice sites. We first discuss a two-dimensional example involving electric dipoles, for which a fairly definite experimental setup can be constructed.

Although the phase realized here is two-dimensional and does not break SRS completely spin rotation remains unbroken, it illustrates how the necessary ingredients can be assembled.Subsequently we discuss ideas for realizing the three-dimensional TMI, the main subject of this chapter, using electric quadrupole moments. Two-dimensional Case: Electric Dipoles on a diamond lattice layer Dipole-dipole interactions between hetero-nuclear polar molecules, such as Rb87 and K40 have already been shown to be stron. Consider a fermionic spin 1/2 molecule, with an electric dipole moment confined to the sites of an optical lattice. We note here that the diamond lattice has a special property that if the dipole-moment is along the directions, then the nearest neighbor interaction V1 vanishes. Thus, the second nearest neighbor interaction V2 becomes dominant. However, the difficulty is that within the twelve second nearest neighbors, only interactions between neighbors within a plane perpendicular to the dipole moment are repulsive. This problem can be solved if we restrict the molecules within a two-dimensional layer of the diamond lattice , as the sites circled in Figure 3.4. Then if the dipole moment is perpendicular to the plane all possible nearest neighbor interactions are repulsive. We solve for the mean field phase diagram of this model, as was done previously for the three-dimensional case. Note, since the lattice is essentially the honeycomb lattice, this is essentially the model studied in Ref. . There exists a two-dimensional TMI phase at the center of the U − V2 phase diagram . Note this phase diagram differs from the same model in Ref. which has an extended two-dimensional TMI phase. This is because we also allow for the second nearest neighbor CDW that the authors neglected. Though frustrated, this order will dominate at large V2.One of the many advantages of Drosophila flies as model organisms for life science research has long been their benign relationship to our own species, allowing strains and transgenic stocks to be widely shared without the fear of jeopardizing either human endeavours or the natural environment.

The potential for conflict with humans was highlighted, however, following the 2008 identification of Drosphila suzukii in California. In sharp contrast to the vast majority of Drosophila species, which feed on rotting fruit and other decaying vegetation, D. suzukii, a species that is native to east Asia and had not previously been identified on the US mainland, is capable of puncturing the skin of intact, ripening fruit to lay its eggs. Over the past 5 years, D. suzukii has spread widely across North America and Europe, causing extensive agricultural damage. Today, it ranks with the lionfish infestation of the western Atlantic as one of the more severe ongoing biological invasions of the Western Hemisphere. While there has been a proliferation of recent studies on the ecology and pest management of D. suzukii , this work has often been divorced from the broader context of Drosophila evolution. The ability of D. suzukii to lay its eggs in ripening fruit has been attributed to the unusual appearance of its ovipositor, but little research has been carried out on either the morphology or evolutionary origin of this structure. The evolutionary context, however, is critical from the perspective of both basic and applied science. From the vantage point of evolutionary theory, the derived ovipositor is an example of a putative key innovation, conferring an adaptive advantage by allowing D. suzukii to exploit a new ecological niche: young, undamaged fruit that is inaccessible to the larvae of other Drosophila species. From the applied science perspective, it is critical to know the extent to which other relatives of D. suzukii could behave as pests in a similar manner, raspberry container growing in the hope of preventing their spread before they are established. Indeed, popular guides have referred to D. suzukii as ‘spotted wing Drosophila’ but this description applies to a number of flies in this species group and it is not clear how many of them are potentially harmful to agriculture. We carried out a comparative study of fruit susceptibility to D. suzukii and three of its closest relatives, and combined this work with a morphological analysis of their ovipositors. In our experiments, only D. suzukii and D. subpulchrella , the two species with ovipositors that carry enlarged bristles, punctured the intact skin of raspberries and cherries. However, while the number and morphology of enlarged bristles does not differ between these species, only D. suzukii punctured the tough skin of grapes. The shape of the D. suzukii ovipositor differs from the three other species, suggesting that changes in ovipositor shape evolved after the evolution of enlarged bristles. Our results show that D. subpulchrella could be a significant threat to the raspberry and cherry industries, while suggesting that other closely related species, including one with a spotted wing , are unlikely to be harmful.The susceptibility of four varieties of fruit to flies of four species was assayed. All flies were cultured on standard laboratory media. Bottles of flies containing pupae ready to eclose were emptied of all adults. Five to 7 days later, any adults that had emerged from the pupae were transferred to separate bottles and were aged for another 6–7 days. This process ensured that all flies were between 6 and 14 days old prior to the start of the experiment. For each experiment, three female flies of each of the four species were placed in separate plastic bottles with foam plugs, with each bottle containing one raspberry, cherry, red grape or Thompson grape. 

Only fresh fruits were used. After 24 h of exposure to the fruit, flies were removed and each fruit was analysed under dissecting microscopes by two raters. In some cases, particularly for D. mimetica, we observed that flies had died during the 24 h period. Eggs in the exposed region of the fruit were counted separately from eggs found in the intact region of the skin, inserted through punctures generated by the fly . The identification of eggs was facilitated by the presence of protruding filaments . Punctures without eggs were counted in a separate tally. In cases where the raters failed to reach a consensus, the mean value of the two counts was used. Ten to 11 simultaneous replicates of each experiment were carried out. Only D. suzukii flies laid eggs in the intact region of Thompson grapes , and these were very rare. Therefore, in order to have enough punctures with eggs to make meaningful comparisons with the punctures without eggs , we carried out a separate experiment where we placed 6–10 D. suzukii female flies per bottle. We measured the area of a total of 18 randomly selected punctures with egg filaments and compared the results to 14 punctures without filaments from the same experiment.Two strains of each of the four species were used for the morphological analysis . Ten ovipositor plates from each strain, each from a separate fly, were analysed, and the total number of bristles on each plate was determined . Some of the ovipositor bristles on D. subpulchrella and D. suzukii are modified, being enlarged and heavily pigmented. These modified bristles were counted and the location of each bristle was recorded . Outlines of the ovipositor plates were generated manually from photographs. In a manner analogous to a study of the posterior lobe of the male genitalia, a horizontalline was drawn at the base of the ovipositor plate where the pigmentation fades and the structure merges with the abdomen . The area and length to width ratio of each plate outline were calculated using the program IMAGEJ. The same program was also used to calculate puncture area and wing area . Although the flies we studied are all closely related, the ovipositors do not contain easily identifiable landmarks that are invariant across species, making it difficult to employ standard landmark-based morphometric techniques. We decided, therefore, to use elliptical Fourier analysis, which does not require the identification of landmarks. The technique uses a series of contours, described by Fourier harmonics, to approximate a shape. Each harmonic is specified by four Fourier coefficients. Following the example of previous studies, we decided to use 25 harmonics. We conducted the EFA on the distal half of the ovipositorplates , because this is the portion that comes into contact with the fruit. As it is difficult to compare outlines on a large number of Fourier coefficients , principal component analysis is typically used to reduce the data to an orthogonal set of variables ordered according to the proportion of variation explained. As the interpretation of the principal components , however, is not immediately clear, we reconstructed the outlines explained by each PC using the inverse Fourier transform . The software package SHAPE was used for the EFA and PCA.All statistical analyses were carried out using the programming language R. The fruit experiments were designed specifically to compare the susceptibility of the exposed and intact region of each type of fruit across the four species. We therefore tested the following model: number of eggs ¼ f, considering each fruit and skin condition separately.

A direct approach for identifying predators is visual identification of prey remains in predators’ guts or feces . While visual identification of prey gut contents can sometimes yield the necessary taxonomic resolution to identify insect pests, the necessary inspection labor is considerable and sampling techniques often result in high mortality rates among study subjects. Molecular identification techniques, however, offer great potential to yield insight into predator–prey interactions . These techniques often rely on targeting and sequencing a standardized DNA region across species to facilitate identifications . Applications of this approach are diverse; for example, detecting diet shifts in ancient humans , characterizing biological communities in hydrothermal vents , identifying illegal trade in endangered species , and surveying rare mammals with DNA from leeches . Similarly, molecular identification in feces,regurgitate, and stomach contents from carnivores, insectivores, and herbivores of diverse taxa has been used to infer diet . While the application of molecular diet analysis is becoming widespread, the technique is not without limitations. First, predators vary in gut retention times and digestion processes, which may affect detection rates and complicate comparisons among species . Second, DNA assays can misattribute diet in the presence of intraguild predation— that is, if the DNA of the prey of an intermediate predator is found in the fecal samples of a top predator . Finally, digestion degrades prey DNA, making fecal analysis more sensitive than other PCR procedures to DNA quantity . Despite these shortcomings, large pots plastic several studies have used molecular techniques to identify suites of pest predators, largely through DNA analysis of arthropod predators’ gut contents .

Less work has focused on vertebrate insectivores, despite their great potential to control pest infestations . Those that have studied vertebrate predators of insect pests tend to analyze single predator species rather than communities . Further, analyses have neglected the biologically diverse, tropical countries that may stand to benefit most from conservation-minded pest-management plans . We used molecular fecal analysis to identify bird predators of coffee’s most damaging insect pest— the coffee berry borer beetle . Coffee is cultivated across the tropics, with a total export value over US$20 billion and twenty million households involved in its production . The borer has invaded almost every coffee-producing country in recent years. In fact, the borer invaded Costa Rica in 2000 and our study sites in 2005. It spends the majority of its life cycle within coffee berries, overwintering in unharvested berries and undergoing a major dispersal event several months after the first rains . Previous exclusion experiments have shown that birds consume the borer, likely during the primary dispersal event or secondary movements to adjacent berries throughout the year . The borer’s small size makes directly witnessing predation unlikely . Our work builds on Karp et al. , which used exclosures to quantify bird-mediated borer control. Here, we sought to characterize more completely which species are borer predators, supplementing their analysis with an additional 961 fecal samples and 33 bird species . In addition, we verified this approach through feeding trials with three insectivorous bird species. Finally, we compiled a database of bird conservation and functional traits to make a preliminary determination of the traits associated with borer consumption and to assess whether species that important for controlling damaging insect pests are also conservation targets.

We assessed whether confirmed borer predators shared functional traits through compiling a trait database for birds in our study area, focusing on resource and acquisition traits that may affect pest-control provision . We used measurements from birds we captured, and a bird population dynamics dataset collected at 18 nearby sites . Wing chord length and mass were obtained from the population dynamics dataset. We also calculated the total number of captures for each species. We collected bill width , bill length , and tarsus length from species that we trapped during fecal sample collection. Body lengths were obtained from literature . We gathered behavioral traits from literature . We translated foraging stratum into an ordinal scale , and calculated the average foraging stratum for each species. We quantified diet breadth as the number of food categories consumed . From literature and conversations with local ornithologists , we also identified species that consumed insects and the subset that specialized strictly on insects.Ecosystem-service management necessitates identifying service providers, especially in the many agricultural systems that are rapidly expanding and intensifying . Our analysis of ~1500 fecal samples documented that six Costa Rican bird species consume coffee’s most damaging insect pest. Still, detection rates were very low: only 0.7% of analyzed samples contained borer DNA. We offer several explanations for low detection. First, we sampled the entire bird community, including frugivores which do not likely consume the borer. Second, borer abundance is low in our study system. Only 2.5% of berries across plantations are currently infested with borers, whereas infestation has soared above 90% in other countries . Third, detection windows may be narrow. We detected borer DNA in only one sample defecated within 30 min of feeding. Insect DNA could be detected in Carrion Crow feces 30 minutes to 4 hours after consumption .

Borers disperse most often and hence are most vulnerable to predation in the afternoon . Because tropical weather constraints precluded afternoon sampling, a mismatch in sampling and consumption could have depressed detections. Finally, feeding trials demonstrated that false negatives are regular. Models predicted that a positive detection was ~20 times more likely when birds were fed 8 borers and defecated 0.1 g versus 2 borers and 0.01 g. In addition to DNA degradation in the gut, our extraction and PCR procedures may be prone to false negatives. First, PCR inhibitors can persist through extraction and impede DNA amplification from fecal pellets . Second, unlike the primers developed by Jaramillo et al. , the primers that we developed were not specific to the berry borer, meaning the primers could have amplified DNA from any one of the many species of insects that a bird had recently consumed. Moreover, iterant non-specific PCR binding of either primer set could generate chimeric sequences of multiple species. Accordingly, only 10 of the 57 samples that yielded PCR products of the expected size range were identified as borer DNA after sequencing. Future work could utilize a post-PCR sorting method such as next generation sequencing or cloning to help reduce the frequency of false negatives . Low detection rates suggest that there are other species that consume the borer that we did not identify. The species we did identify, however, shared traits that may be characteristic of these other predators. All identified borer predators except the nectarivorous White-tailed Emerald were strict insectivores. Unsurprising given the borer’s size , borer predators had narrow bills. Additionally, these species had short wings, ideal for navigating the dense coffee understory . It is possible that functional traits would change with a larger sample of predators; however, confirmed borer predators in Jamaican coffee plantations shared many of these traits , supporting our hypothesis that they may help predict other predators . A key difference between our studies, however, is that only one of the species that we identified as a borer predator is migratory . We collected our fecal samples during the period of maximum borer dispersal , a time when most migratory species are absent from Costa Rica. Because migratory species could consume borers during their secondary dispersals that occur throughout the year, square planter pots future work should temporally expand sampling effort to ensure that migratory species are well represented. Our work yielded the critical management insight that managing the predators of crop pests may require looking beyond traditional conservation targets. The six documented borer predators were not rare, endemic, or listed on the IUCN red list. Traditional conservation efforts for threatened species often center on delineating large protected areas. Focusing conservation explicitly in agricultural landscapes could benefit species involved in providing critical ecosystem services to farmers . By confirming that birds consume pests, our work could thus help change attitudes towards biodiversity in human-dominated landscapes by fostering greater recognition of its role in supporting human well being. Species interactions play a pivotal role in many ecologically and economically important ecosystem processes. Uncovering the basic relationships between animals and their food is critical for managing pest control, pollination, seed dispersal, and sanitation . Molecular methods can provide us with a window into these interactions, in some instances for the very first time. Our results demonstrate how identifying just a few key interactions between predators and their prey can yield potential insights for management. Indeed, managing nature to enhance both biodiversity and human wellbeing requires diverse approaches.

Techniques and practices have already been borrowed from fields as diverse as agronomy, economics, hydrology, psychology, and sociology. Our results indicate that molecular biology offers ecologists the ability to expand their toolkit in key dimensions and, in turn, advance ecosystem service management.California is the leading producer of table grapes. In 2019 table grapes accounted for 130,000 acres of the 918,000 acres of grapes grown in the state, with 6,588 acres grown with the variety Redglobe . The cultivar Redglobe is a variety popular for export markets, including China and Mexico, because of its flavor and long shelf life . Brown spot can cause major post harvest fruit loss in Redglobe and other late-harvest cultivars such as Crimson Seedless and Autumn King . No reliable control of brown spot has been found. A study by Swett et al. showed 100% of Redglobe clusters collected from a commercial field in Delano, in the San Joaquin Valley, had latent infections of Cladosporium species responsible for brown spot disease. Redglobe clusters may be stored for 2 to 3 months before they are shipped to Asia. When symptomless berries are in cold storage conditions for long periods, brown spot disease begins to emerge and spread . While initial infections occurin the field, once in post-harvest, infection can also easily spread from berry to berry through epidermis contact with no wounding necessary and in temperatures as low as −2°C . Attempts to manage brown spot have relied on strategies developed for the control of gray mold, a severe post harvest disease caused by the fungus Botrytis cinerea . Gray mold and brown spot have similar biology, such as infection timing, occurrence of a latency period and timing of symptoms expression . However, the common practice of using 100 to 200 parts per million per hour sulfur dioxide treatments used to control gray mold during cold storage and during transport has not been effective for the control of brown spot . Brown spot has been attributed to several species of the Cladosporium herbarum species complex and C. cladosporioides . As described by Swett et al. , typically a fluffy, light green to white mycelial mat will form where infection has taken place on the berry epidermis. A mycelial callus can form under the epidermis as a result of an internal infection, creating a scab and a brown spot on the underside of the epidermis. As the infection progresses, the scab will encompass the seed of the grape, forming a fungal fruiting body that eventually replaces the grape seed placenta, and prolific sporulation will occur on the seed . In the last 20 years, a total utilization technique for fumigant applications of SO2 during cold storage has been established for table grapes; it increases efficiency, reduces environmental pollution and protects operators . An important step of the technique is to apply the first SO2 treatment during the initial forced-air cooling of the grapes after harvest, which is then followed by weekly applications during cold storage with homogenous air distribution . The total utilization technique system uses ~ 10 times less SO2 than the previous standard fumigation system, but it requires uniform room air distribution for the treatment to be effective . The total utilization technique was based on laboratory studies that revealed that at least 100 ppm-h SO2 was necessary to kill B. cinerea conidia and inactivate exposed mycelia at 0°C . Even less than 100 ppm-h was effective at warm temperatures to cause the death of conidia and mycelium of B. cinerea on grape . These latter studies confirmed that SO2 applied at 200 ppm-30 min, 400 ppm-15 min, 50 ppm-2 h or 25 ppm-4 h was as effective as the 100 ppm-h treatment .

The wines made from control and sort treatments are more closely associated with each of the significant attributes; this trend generally matches the results from the chemical analyses. Both the wines made from control and sort treatments were higher in ethanol content, which can explain their greater association with “alcohol hotness” when compared to reject treatment wines. It is possible that the higher ethyl ester concentration in the control and sort treatment wines could explain why they are rated significantly higher in the “apple” aroma. Most ethyl esters have fruity aromas which the judges could have rated as “apple”. Curiously, the control and sort treatment wines are rated significantly higher in “sweet” as well despite the residual sugar content of all wines being less than 1 g/L , which is below the sensory threshold . All three significant attributes for the CS panel were rated similarly between control and sort treatment wines. This suggests that these wines made from these treatments had similar sensory properties.Analysis of wine color revealed that there were perceivable differences among treatments for all three varieties . For BA the reject treatments were rated lighter in color compared to the control and sort treatments, whereas a similar trend was observed in the CS treatments. This was expected because berries with less color were removed by the optical sorter and included in the reject fermentations. This agrees with results from Table 6; the rejected treatments were significantly lower in anthocyanin content for BA and CS, plastic gutter which can explain the difference in color perception. For GN wines, the control treatment was perceived to be slightly darker than the sort and reject treatments.

Although fermentations were prepared to have similar solid-to-juice ratios in the must among treatments, it is possible that variations between replicates may have resulted in the control treatments being slightly more concentrated, which could provide an explanation for this result. Color perception from the panelists matches well with the wine color determined in the CIELAB color space . It can be concluded that optical sorting was generally successful in removing berries with less color; however, this did not lead to a large difference in the final color of the wines between the sort and control treatments.Multiple Factor Analysis was performed for each variety using all sensory attributes and only volatile compounds that differed significantly among treatments . This was done to observe the association, if any, of the significant volatile compounds and sensory attributes. For GN wines, the only significant attribute was “SO2”. From Figure 7, isobutanol, which can impart a solventlike aroma in wine, is grouped closely with “SO2”. It is possible that wines with a higher isobutanol concentration were perceived to be higher in “SO2” aroma. For BA wines, there does not appear to be a trend among sensory attributes and volatile compounds . For CS wines, “apple” is grouped closely with ethyl esters , which provides evidence that this may have caused the increased perception of this attribute in the control and sort treatments .Overall, optical sorting had minimal impact on the sensory properties of the three varieties tested. It is possible that the chemical differences noted earlier were too small to result in consistent differences by descriptive analysis.

Even though the wines made from reject material contained significantly higher concentrations of higher alcohols, it did not result in a difference in sensory perception. Higher alcohols have a relatively high sensory threshold . It is possible that the concentration of these compounds in the reject wines was below the sensory threshold.The purpose of this study was to determine what effects, if any, optical berry sorting had on wine made from different red grape varieties, and to investigate the potential to use optical sorters to sort for different ripeness levels using color as a main criterion. Given the observed differences in Brix and final ethanol content, optical sorting seemed to be successful in removing underripe berries for CS and possibly for BA; however, this did not result in a significant difference in the final ethanol content between the sort and control treatments. The removal of underripe berries was also evident by the difference in color among treatments. For BA, the rejected treatments were significantly lighter in color; however, the color of the sort and control treatments was very similar, whereas a similar trend was observed in the CS treatments. Wines made from GN generally did not follow these trends; possibly because sorting parameters were too aggressive for this cultivar, resulting in a high percent rejection of optimal berries. This may have minimized potential differences between reject wine with the other treatments. Another possibility is that color differences in the GN fruit did not correspond to differences in sugar content. From these results, it may be concluded that, when using color as a criterion, optical sorting based on ripeness level was successful but may be dependent on variety and fruit variability. Additionally, the impact on the resulting wine is likely dependent on the initial variability in grape ripeness.

The optical sorter was successful in removing MOG. Thisresult was reflected in the phenolic analyses; reject treatments were generally higher in total phenolics and tannin, most likely due to the greater proportion of MOG included in the must. The decrease in anthocyanins is likely due to the higher percentage of green, underripe berries in the reject treatment musts. A study that made wine with the addition of MOG found that this addition significantly increased the phenolic and tannin content in the resulting wines. Despite the differences observed in the phenolic composition of the reject wines, the control and sort treatments were very similar for all three varieties. This is in contrast with some previous studies that have found wine made from optical sorted fruit had significantly different levels of phenolics. One study found that optical sorting led to wines with higher levels of total phenolics. It should be mentioned that the researchers here did whole cluster pressing for their control wines , whereas the sorted wines were destemmed. It is possible that higher levels of phenolics were extracted due to the damage caused by the destemming process on the seeds and skins. Another study found that wine made from optically sorted grapes that were machine harvested generally had lower levels of phenolics; levels that were similar to the same wines made from a handpick treatment. Given that the rejects were, in general, significantly higher in total phenolics and tannin than the control and sort treatments, it can be suggested that optical sorting has the potential to decrease the phenolic content in wine; however, there was not enough MOG to show a large impact in the current study. Optical sorting likely has a greater impact on mechanically harvest fruit due to generally higher levels of MOG observed from this harvest method. Some differences were found among treatments in the aroma profiles of the wines. Few compounds differed significantly between sort and control treatment and, in general, the reject treatments had greater concentrations of higher alcohols and control and sort treatments had greater concentrations of ethyl esters. The higher ethanol content of the sort and control treatments as well as their lower pH can lead to a higher production of esters. In general, blueberry container reject treatments contained significantly more suspended solids then the control and sort treatments for all varieties studied. Research has shown that high levels of suspended solids during fermentation can lead to greater production of higher alcohols. Descriptive analysis indicated only one significantly different attribute among GN treatments and only two significantly different attributes among BA treatments. BA control and sort wines were associated with the “alcohol” descriptor which correlated with the higher ethanol levels in these treatments compared to the reject treatment. Similarly, there were only three significant attributes among the CS treatments. “Alcohol hotness” related to ethanol content as previously described. The control and sort treatments were also rated significantly higher in “apple” and “sweet” aromas compared to the reject treatment. Some studies have shown that higher levels of ethanol can increase the perception of sweetness in a wine. However, as King et al. noted, there is disagreement in this regard, as other studies have shown that ethanol content can either decrease or have no effect on the perception of sweetness. Thus, this may not be a sufficient explanation as to why the control and sort wines were rated significantly higher in sweetness. Perhaps the higher concentration of total phenolics and tannin in reject wines could explain the difference given that phenolics in wine contribute to bitterness and astringency. From the PCA in Figure 6, it can be noted that “bitter” and “drying” are more associated with reject wines. Although these attributes are not significantly different among the treatments there appears to be a trend which could impact the perception of sweetness. One study found that increasing bitterness in coffee decreased the perception of sweetness. It is possible that reject wines were rated lower in “sweet” due to the higher concentration of phenolic compounds thus decreasing the perception of sweetness. The higher perception of sweetness in the control and sort wines may also be attributed to the higher intensity of the “apple” aroma, which the judges could have associated with a sweet taste.

One study found that retronasal aromaperception of fruity compounds increased with an increasing level of sweetness in a model wine solution. The authors also noted several other studies which found that aroma compounds can enhance the perception of sweetness in different foods and beverages. Another study found that samples described as “fruity” were also often associated with a “sweet” aroma. This provides further evidence that the judges in the current study may have associated these attributes together. The overall sensory differences were minimal, and the wines were determined to be similar. The results from this study largely agree with results from previous studies investigating the effects of optical sorters. It is possible that there was not enough variation in the starting material of the current study for optical sorting to have a large impact. Optical sorters may be used to greater effect during vintages with inconsistent ripening, issues with raisining, or large amounts of berry damage, possibly caused by either birds and/or fungal infections. Future research should investigate the impact of optical sorters in these scenarios.Grapevine has indeterminate growth habits compared to other perennial fruit crops. Latent growth of the dormant grapevine bud may be induced by favorable conditions with little to no dormancy period required . Therefore, semi-tropical regions may raise two crops a year, and in fact, it is not uncommon for the latent bud to produce some fruit when correlative inhibition is removed in temperate regions. Furthermore, the grape berry does not have the same fruit abscission mechanism as apple or peach revealed under carbon starvation. It is therefore possible for grapevine canopy size and crop level manipulations leading to a wider range of source or sink limiting conditions within a growing season. The number and size of the flower primordia is associated with number of clusters and berries per cluster through the formation flowers and fruit set . However, fruit set is largely variable among years, weather, location, and cultivars . Poor fruit set may be a limitation to crop yield, although weather is often considered to be the leading cause. However, the mechanism of poor fruit set is not fully understood. Carbon supply or mineral nutrition are related to the amount of fruit set , which is an acclimation mechanism to unfavorable conditions. Ultimately, yield of grapevine is affected by berry size, and within the berry, pulp enlargement is the largest contributor to yield gain rather than skin or seed biomass . Conversely, vegetative growth is far less influenced by latent bud formation, as competition amongst growing buds tends to buffer the impact of growing shoot tips on its length and total leaf area . This is likely due to the great limiting effect of nitrogen among other nutrients or hydraulic pressure . The ratio between leaf area and fruit mass is closely related to the amount of carbohydrates accumulated in the must . Thus, an excessive crop level or less than ideal canopy size may result in over cropping and may lead to delayed ripening .