Spike Size Research Articles

Evaluation of the Spike Diversity of Seven Hexaploid Wheat Species and an Artificial Amphidiploid Using a Quadrangle Model Obtained from 2D Images

The spike shape and morphometric characteristics are among the key characteristics of cultivated cereals, being associated with their productivity. These traits are often used for the plant taxonomy and authenticity of hexaploid wheat species. Manual measurement of spike characteristics is tedious and not precise. Recently, the authors of this study developed a method for wheat spike morphometry utilizing 2D image analysis. Here, this method is applied to study variations in spike size and shape for 190 plants of seven hexaploid (2n = 6x = 42) species and one artificial amphidiploid of wheat. Five manually estimated spike traits and 26 traits obtained from digital image analysis were analyzed. Image-based traits describe the characteristics of the base, center and apex of the spike and common parameters (circularity, roundness, perimeter, etc.). Estimates of similar traits by manual measurement and image analysis were shown to be highly correlated, suggesting the practical importance of digital spike phenotyping. The utility of spike traits for classification into types (spelt, normal and compact) and species or amphidiploid is shown. It is also demonstrated that the estimates obtained made it possible to identify the spike characteristics differing significantly between species or between accessions within the same species. The present work suggests the usefulness of wheat spike shape analysis using an approach based on characteristics obtained by digital image analysis.

Real-Time Detection and Counting of Wheat Spikes Based on Improved YOLOv10

Wheat is one of the most crucial food crops globally, with its yield directly impacting global food security. The accurate detection and counting of wheat spikes is essential for monitoring wheat growth, predicting yield, and managing fields. However, the current methods face challenges, such as spike size variation, shading, weed interference, and dense distribution. Conventional machine learning approaches have partially addressed these challenges, yet they are hampered by limited detection accuracy, complexities in feature extraction, and poor robustness under complex field conditions. In this paper, we propose an improved YOLOv10 algorithm that significantly enhances the model’s feature extraction and detection capabilities. This is achieved by introducing a bidirectional feature pyramid network (BiFPN), a separated and enhancement attention module (SEAM), and a global context network (GCNet). BiFPN leverages both top-down and bottom-up bidirectional paths to achieve multi-scale feature fusion, improving performance in detecting targets of various scales. SEAM enhances feature representation quality and model performance in complex environments by separately augmenting the attention mechanism for channel and spatial features. GCNet captures long-range dependencies in the image through the global context block, enabling the model to process complex information more accurately. The experimental results demonstrate that our method achieved a precision of 93.69%, a recall of 91.70%, and a mean average precision (mAP) of 95.10% in wheat spike detection, outperforming the benchmark YOLOv10 model by 2.02% in precision, 2.92% in recall, and 1.56% in mAP. Additionally, the coefficient of determination (R2) between the detected and manually counted wheat spikes was 0.96, with a mean absolute error (MAE) of 3.57 and a root-mean-square error (RMSE) of 4.09, indicating strong correlation and high accuracy. The improved YOLOv10 algorithm effectively solves the difficult problem of wheat spike detection under complex field conditions, providing strong support for agricultural production and research.

Does ecology shape geographical parthenogenesis? Evidence from the facultatively parthenogenetic stick insect Megacrania batesii.

Closely related sexual and parthenogenetic species often show distinct distribution patterns, known as geographical parthenogenesis. Similar patterns, characterized by the existence of separate sexual and parthenogenetic populations across their natural range, can also be found in facultative parthenogens - species in which every female is capable of both sexual and parthenogenetic reproduction. The underlying mechanisms driving this phenomenon in nature remain unclear. Features of the habitat, such as differences in host-plant phenotypes or niche breadth, could favour sexual or asexual reproductive modes and thus help to explain geographical parthenogenesis in natural insect populations. Megacrania batesii is a facultatively parthenogenetic stick insect that displays geographical parthenogenesis in the wild. We aimed to explore whether sexual and parthenogenetic populations of M. batesii displayed niche differentiation or variations in niche breadth that could explain the separation of the two population types. To do this, we sampled host plants from across the range of M. batesii and quantified phenotypic traits that might affect palatability or accessibility for M. batesii, including leaf thickness, toughness, spike size and density, plant height, and chemical composition. We also quantified host-plant density, which could affect M. batesii dispersal. We found little evidence of phenotypic differences between host plants supporting sexual versus asexual M. batesii populations, and no difference in host-plant density or niche breadth between the two population types. Our results suggest that habitat parameters do not play a substantial role in shaping patterns of geographical parthenogenesis in wild populations of M. batesii. Instead, population sex ratio variation could result from interactions between the sexes or dispersal dynamics.

Identification and functional analysis of a chromosome 2D fragment harboring TaFPF1 gene with the potential for yield improvement using a late heading wheat mutant.

A chromosome fragment influencing wheat heading and grain size was identified using mapping of m406 mutant. The study of TaFPF1 in this fragment provides more insights into wheat yield improvement. In recent years, wheat production has faced formidable challenges driven by rapid population growth and climate change, emphasizing the importance of improving specific agronomic traits such as heading date, spike length, and grain size. To identify potential genes for improving these traits, we screened a wheat EMS mutant library and identified a mutant, designated m406, which exhibited a significantly delayed heading date compared to the wild-type. Intriguingly, the mutant also displayed significantly longer spike and larger grain size. Genetic analysis revealed that a single recessive gene was responsible for the delayed heading. Surprisingly, a large 46.58 Mb deletion at the terminal region of chromosome arm 2DS in the mutant was identified through fine mapping and fluorescence in situ hybridization. Thus, the phenotypes of the mutant m406 are controlled by a group of linked genes. This deletion encompassed 917 annotated high-confidence genes, including the previously studied wheat genes Ppd1 and TaDA1, which could affect heading date and grain size. Multiple genes in this region probably contribute to the phenotypes of m406. We further investigated the function of TaFPF1 using gene editing. TaFPF1 knockout mutants showed delayed heading and increased grain size. Moreover, we identified the direct upstream gene of TaFPF1 and investigated its relationship with other important flowering genes. Our study not only identified more genes affecting heading and grain development within this deleted region but also highlighted the potential of combining these genes for improvement of wheat traits.

Anatomical insights into the vascular layout of the barley rachis: implications for transport and spikelet connection.

Vascular patterning is intimately related to plant form and function. Here, using barley (Hordeum vulgare) as a model, we studied the vascular anatomy of the spike-type inflorescence. The main aim of the present work was to clarify the relationship between rachis (spike axis) vasculature and spike size, to define vascular dynamics and to discuss the implications for transport capacity and its interaction with the spikelets. We used serial transverse internode sections to determine the internode area, vascular area and number of veins along the rachis of several barley lines. Internode area and total vascular area show a clear positive correlation with spike size, whereas the number of veins is only weakly correlated. The lateral periphery of the rachis contains large mature veins of constant size, whereas the central part is occupied by small immature veins. Spikelet-derived veins entering the rachis often merge with the immature rachis veins but never merge with the mature veins. An increase in floret fertility through the conversion of a two-rowed barley into an isogenic six-rowed line, in addition to a decrease in floret fertility owing to enhanced pre-anthesis tip degeneration caused by the mutation tip sterile 2.b (tst2.b), significantly affected vein size but had limited to no effects on the number of veins or internode area. The rachis vasculature is the result of a two-step process involving an initial layout followed by size adjustment according to floret fertility/spike size. The restriction of large mature vessels to the periphery and that of small immature vessels to the centre of the rachis suggests that long-distance transport and local supply to spikelets are spatially separated processes. The identification of spikelet-derived veins entering the rachis without fusing with its vasculature indicates that a vascular continuity between rachis and spikelets might be non-essential.

Effect of Noncircular Channel on Distribution of Threshold Voltage in 3D NAND Flash Memory.

The instability in threshold voltage (VTH) and charge distributions in noncircular cells of three-dimensional (3D) NAND flash memory are investigated. Using TCAD simulation, we aim to identify the main factors influencing the VTH of noncircular cells. The key focus is on the nonuniform trapped electron density in the charge trapping layer (CTL) caused by the change in electric field between the circular region and the spike region. There are less-trapped electron (LT) regions within the CTL of programmed noncircular cells, which significantly enhances current flow. Remarkably, more than 50% of the total current flows through these LT regions when the spike size reaches 15 nm. We also performed a comprehensive analysis of the relationship between charge distribution and VTH in two-spike cells with different heights (HSpike) and angles between spikes (θ). The results of this study demonstrate the potential to improve the reliability of next-generation 3D NAND flash memory.

Genetic architecture of quantitative trait loci (QTL) for FHB resistance and agronomic traits in a hard winter wheat population

Wheat resistance to Fusarium head blight (FHB) has often been associated with some undesirable agronomic traits. To study the relationship between wheat FHB resistance and agronomic traits, we constructed a linkage map of single nucleotide polymorphisms (SNPs) using an F6:8 population from G97252W × G97380A. The two hard winter wheat parents showed contrasts in FHB resistance, plant height (HT), heading date (HD), spike length (SL), spike compactness (SC), kernel number per spike (KNS), spikelet number per spike (SNS), thousand-grain weight (TGW) and grain size (length and width). Quantitative trait locus (QTL) mapping identified one major QTL (QFhb.hwwg-2DS) on chromosome arm 2DS for the percentage of symptomatic spikelets (PSS) in the spike, deoxynivalenol (DON) content and Fusarium damaged kernel (FDK). This QTL explained up to 71.8% of the phenotypic variation for the three FHB-related traits and overlapped with the major QTL for HT, HD, SL, KNS, SNS, TGW, and grain size. QTL on chromosome arms 2AL, 2DS, 3AL and 4BS were significant for the spike and grain traits measured. G97252W contributed FHB resistance and high SNS alleles at QFhb.hwwg-2DS, high KNS alleles at the QTL on 2AL and 2DS, and high TGW and grain size alleles at QTL on 3AL; whereas G97380A contributed high TGW and grain size alleles at the QTL on 2AL and 2DS, respectively, and the high KNS allele at the 4BS QTL. Combining QFhb.hwwg-2DS with positive alleles for spike and grain traits from other chromosomes may simultaneously improve FHB resistance and grain yield in new cultivars.

Sprague-Dawley rats differ in responses to medial perforant path paired pulse and tetanic activation as a function of sex and age.

Network plasticity in the medial perforant path (MPP) of adult (5-9 mo) and aged (18-20 mo) urethane-anesthetized male and female Sprague-Dawley rats was characterized. Paired pulses probed recurrent networks before and after a moderate tetanic protocol. Adult females exhibited greater EPSP-spike coupling suggesting greater intrinsic excitability than adult males. Aged rats did not differ in EPSP-spike coupling but aged females had larger spikes at high currents than males. Paired pulses suggested lower GABA-B inhibition in females. Absolute population spike measures were larger post-tetani in female rats than male rats. Relative population spike increases were greatest in adult males relative to females and to aged males. EPSP slope potentiation was detected with normalization in some post-tetanic intervals for all groups except aged males. Tetani shortened spike latency across groups. Tetani-associated NMDA-mediated burst depolarizations were larger for the first two trains in each tetanus in adult males than other groups. EPSP slopes over 30 min post-tetani predicted spike size in female rats, but not in males. Replicating newer evidence MPP plasticity in adult males was mediated by increased intrinsic excitability. Female MPP plasticity was related to synaptic drive increases, not excitability increases. Aged male rats were deficient in MPP plasticity.SIGNIFICANCE STATEMENTThe medial perforant path (MPP)-dentate gyrus (DG) granule cell synapse was the site of discovery of long-term potentiation in the mammalian nervous system but considering the current interest in sex and aging, surprisingly few studies have directly examined these variables in relation to tetanus-induced long-term and short-term (paired pulse) plasticity. Using an interleaved current-paired pulse interval protocol and moderate tetanic protocol young (5-9mo) and old (18-20mo) male and female urethane anesthetized rats were found to differ in levels of granule cell intrinsic excitability, E-S coupling, GABA-B inhibition, and tetanic NMDA current contributions to post-tetanic population spike potentiation. This study provides a platform or future examination of sex- and age-related changes in MPP-DG function.

Effect of a native bacterial consortium on growth, yield, and grain quality of durum wheat (Triticum turgidum L. subsp. durum) under different nitrogen rates in the Yaqui Valley, Mexico

ABSTRACT A field experiment was carried out to quantify the effect of a native bacterial inoculant on the growth, yield, and quality of the wheat crop, under different nitrogen (N) fertilizer rates in two agricultural seasons. Wheat was sown under field conditions at the Experimental Technology Transfer Center (CETT-910), as a representative wheat crop area from the Yaqui Valley, Sonora México. The experiment was conducted using different doses of nitrogen (0, 130, and 250 kg N ha−1) and a bacterial consortium (BC) (Bacillus subtilis TSO9, B. cabrialesii subsp. tritici TSO2T, B. subtilis TSO22, B. paralicheniformis TRQ65, and Priestia megaterium TRQ8). Results showed that the agricultural season affected chlorophyll content, spike size, grains per spike, protein content, and whole meal yellowness. The highest chlorophyll and Normalized Difference Vegetation Index (NDVI) values, as well as lower canopy temperature values, were observed in treatments under the application of 130 and 250 kg N ha−1 (the conventional Nitrogen dose). Wheat quality parameters such as yellow berry, protein content, Sodium dodecyl sulfate (SDS)-Sedimentation, and whole meal yellowness were affected by the N dose. Moreover, the application of the native bacterial consortium, under 130 kg N ha−1, resulted in a higher spike length and grain number per spike, which led to a higher yield (+1.0 ton ha−1 vs. un-inoculated treatment), without compromising the quality of grains. In conclusion, the use of this bacterial consortium has the potential to significantly enhance wheat growth, yield, and quality while reducing the nitrogen fertilizer application, thereby offering a promising agro-biotechnological alternative for improving wheat production.

Plasmon Tunability and Field Enhancement of Gold Nanostar

Objective: The localized surface plasmon resonance (LSPR) and field enhancement of Gold nanosphere and nanostar were evaluated. Method: FDTD solutions, a product of Lumerical solutions Inc., Vancouver, Canada [17], was used to perform the electromagnetic simulations in this work. The impact of particle size and spike number on peak wavelength was studied quantitatively. Result: By altering the particle size and amount of spikes, we were able to detect a hot zone around nanostar. For Au nanostar, the peak wavelength for nanostar varies from visible to near-infrared. When compared to a nanosphere of the same dimension, the shift seen in nanostar is substantially higher, making it more suitable for biosensing applications. When the refractive index of the surrounding medium is increased, a red shift in peak wavelength is noticed, forming the basis for a plasmonic refractive index sensor. Aside from having a higher sensitivity, nanostar has a twofold hot spot system due to their unique surfaces. There is no evidence of spike aggregation in the near field pattern. As a result, it is thought to be a better nanostructure for biosensing applications. Conclusion: The LSPR and field enhancement for Au nanosphere and Nanostar were investigated using the FDTD method. The nanosphere's peak wavelength is in visible region, whereas the nanostar's range extends from visible to near-infrared, depending on the size and number of spikes. At 517 nm, the enhancement factor for a nanosphere was 102, but at 1282 nm, the enhancement factor for a nanostar with six spikes was 108.

Improving multi-scale detection layers in the deep learning network for wheat spike detection based on interpretive analysis

BackgroundDetecting and counting wheat spikes is essential for predicting and measuring wheat yield. However, current wheat spike detection researches often directly apply the new network structure. There are few studies that can combine the prior knowledge of wheat spike size characteristics to design a suitable wheat spike detection model. It remains unclear whether the complex detection layers of the network play their intended role.ResultsThis study proposes an interpretive analysis method for quantitatively evaluating the role of three-scale detection layers in a deep learning-based wheat spike detection model. The attention scores in each detection layer of the YOLOv5 network are calculated using the Gradient-weighted Class Activation Mapping (Grad-CAM) algorithm, which compares the prior labeled wheat spike bounding boxes with the attention areas of the network. By refining the multi-scale detection layers using the attention scores, a better wheat spike detection network is obtained. The experiments on the Global Wheat Head Detection (GWHD) dataset show that the large-scale detection layer performs poorly, while the medium-scale detection layer performs best among the three-scale detection layers. Consequently, the large-scale detection layer is removed, a micro-scale detection layer is added, and the feature extraction ability in the medium-scale detection layer is enhanced. The refined model increases the detection accuracy and reduces the network complexity by decreasing the network parameters.ConclusionThe proposed interpretive analysis method to evaluate the contribution of different detection layers in the wheat spike detection network and provide a correct network improvement scheme. The findings of this study will offer a useful reference for future applications of deep network refinement in this field.

Agronomic characteristics of two corn (Zea mays L.) varieties subjected to topdressing fertilization using different levels of nitrogen and potassium in Amazonas, Brazil

From the creation of new corn genomics to meet production demands, it is necessary to evaluate how these new cultivars react to the different environments that exist in Brazil. Front this, the objective of this study was to evaluate the effects of different levels of N and K used to topdressing fertilization on agronomic characteristics of two corn varieties at Amazon environmental conditions. The experimental design was randomized in block using a factorial scheme (2 x 4 x 4), with two corn varieties (BRS Caimbé and BR 5011 Sertanejo), four N dosages (0, 60, 100, and 140 kg.ha-1) and four K dosages (0, 20, 60, and 90 kg.ha-1). Each plot was constituted by five lines of 20 m of length and 2.40 m of width, with a space of 0.60 m among these, totalizing an area of 48 m2 per plot. Data collected were subjected to ANOVA and, subsequently, to Tukey test at 5% of significance. Caimbé corn variety presented higher (p < 0.05) number of plants, plant weight, and spikes per plot. High dosages of N and K provided high (p < 0.05) number of plants, plant weight, and spikes per plot. Caimbé corn variety presented higher (p < 0.05) spike weight and size. Other variables did not present significant (p > 0.05) results. High dosages of N provided high (p < 0.05) stem diameter and weight, leaf weight, spike size, and low spike weight. Lower levels of K caused low (p < 0.05) plant height, first spike height insertion, stem diameter, and spike weight.

Mechanisms leading to bursting oscillations in the system of predator–prey communities coupled by migrations

The purpose is to study the periodic regimes of the dynamics for two non-identical predator– prey communities coupled by migrations, associated with the partial synchronization of fluctuations in the abundance of communities. The combination of fluctuations in neighboring sites leads to the regimes that include both fast bursts (bursting oscillations) and slow oscillations (tonic spiking). These types of activity are characterized by a different ratio of synchronous and non-synchronous dynamics of communities in certain periods of time. In this paper, we describe scenarios of the transition between different types of burst activity. These types of dynamics differ from each other not so much in size, shape, and number of spikes in a burst, but in the order of these bursts relative to the slow-fast cycle. Methods. To study the proposed model, we use the bifurcation analysis methods of dynamic systems, as well as geometric methods based on the division of the full system into fast and slow equations (subsystems). Results. We showed that the dynamics of the first subsystem with a slow-fast limit cycle directly determines the dynamics of the second one with burst activity through a smooth dependence of regime on the number of predators and a non-smooth dependence on the number of prey. We constructed the invariant manifolds on which there are parts of dynamics with tonic (slow manifold) and burst (fast manifold) activity of the full system. Conclusion. We described the scenario for bursting with different waveforms, which are determined by the appearance of the fast invariant manifold and the location of its parts relative to the slow-fast cycle. The transitions between different types of burst are accompanied by a change in the oscillation period, the degree of synchronization, and, as a result, the dynamics becomes quasi-periodic when both communities are not synchronous with each other.

Physiological bases of cultivar differences in average grain weight in wheat: Scaling down from plot to individual grain in elite material

In recent decades, increases in wheat yield have been achieved mainly through increases in grain number per m 2 (GNM2) rather than through increases in average grain weight (AGW). Using AGW as a lever to increase yield would require avoidance of the negative relationship between GNM2 and AGW. It is usually supposed that this trade-off arises from an increase in the proportion of small grains as GNM2 rises. The proportional increase in small grains being the result either of (1) an increase in the proportion of secondary tillers in the spike population or (2) of an increase in the proportion of grains located in distal positions within each spike. Either or both of these two populational effects would tend to mask any true genotypic differences in AGW. The existence of these constitutive differences has already been proposed, but without considering the full extent of the populational confounding effects. Identification of a component of the constitutive genetic determinism of AGW - one that is truly independent of GNM2 - could contribute to cultivar developments that would lead to further increases in grain yield under future target environments. To address this question, we analysed populational effects on AGW in four, modern, well-adapted bread-wheat cultivars. The four chosen cultivars show similar grain yields but contrasting AGWs. The analysis of populational effects was carried out at three hierarchical levels (the plot, the spike and the single grain) and under two contrasting environmental conditions (well-watered vs water-deficit conditions). Regardless of the environment, no (or only slight) differences in individual spike size were observed between cultivars. Furthermore the weak relationship between spike size and AGWdemonstrates that AGW differences between cultivars cannot be attributed to spike-level populational effects. Meanwhile, the analysis of individual grain mass distributions, showed that the differences in AGW between cultivars, originated from shifts in the whole grain-mass distribution, rather than from shape changes in the grain-mass distribution. This clearly indicates that AGW differences between cultivars cannot be attributed to populational effects at the individual grain level. The analysis carried out at both spike and individual grain levels indicates that the AGW differences between cultivars are largely constitutive, so that increases in grain yield through AGW may be considered independently of the GNM2: AGW trade-off. Taken together, these findings offer a new perspective for the genetic improvement of wheat, and one that should lead to further increases in yield. • The trade-off between grain number (GNM2) and average grain weight (AGW) may limit wheat yield. • AGW differences between cultivars are not driven only by this trade-off. • AGW differences between cultivars have a constitutive nature. • Increasing AGW should be possible without negative effects on GNM2. • Increasing grain yield through AGW may be relevant to future target environments.

Soil organic carbon (SOC) prediction in Australian sugarcane fields using Vis–NIR spectroscopy with different model setting approaches

To maintain profitability in sugarcane areas of Australia, soil nutrients need to be applied to replace losses to biomass production. For example, nitrogen fertiliser requires consideration of soil organic carbon (SOC, %). However, determining SOC is time-consuming. An alternative is to use a visible–near infrared (Vis–NIR) spectroscopy library. Herein, a Vis–NIR library is developed to predict topsoil (0–0.3 m) SOC using partial least squares regression (PLSR) and machine learning (i.e., Cubist, random forest [RF] and support vector machine [SVM]) in four sugarcane districts (i.e., Mossman, Lannercost, Herbert, and Proserpine). Different approaches were compared (i.e., site-specific, site-independent, hold-out and spiking) with spike size also considered. In all comparisons, a consistent set of calibration and validation data were used. The calibration coefficient of determination (R2) was always strong (> 0.7), and generally better than the validation R2, regardless of the modelling approach, district, or spike size. For the validation, the Lin's concordance correlation coefficient (LCCC) showed PLSR (0.92, and 0.9) and Cubist (0.91 and 0.9) were close to perfect (> 0.9) for site-specific and site-independent, respectively. This was not the case for hold-out, with only strong R2 (0.71) and substantial agreement (0.80) in Herbert using Cubist and moderate overall using PLSR. Similar results were achieved in terms of the accuracy considering the ratio of performance to interquartile (RPIQ), whereby overall site-specific and site-independent approaches had excellent accuracy (> 2.5) with Cubist slightly more accurate than PLSR. Hold-out accuracy was generally very poor (< 1.4). Spiking the hold-out data sets produced mixed results with prediction R2, agreement and accuracy respectively best in Lannercost with 70 or more samples using PLSR (strong, substantial and excellent) and Hebert with 10 or more using Cubist (strong, near perfect and excellent), while in Mossman with 50 or more samples using SVM (very weak, poor and fair) and Proserpine with 30 or more samples using Cubist (weak, moderate and fair) the results were not as good. It can be concluded that either site-specific or site-independent approach to calibration and prediction using either PLSR or Cubist was best, with the use of the latter approach being more efficient and allowing for the potential to add to this spectral library when new samples from each area or new areas can be added.

Bioanalytics for Influenza Virus-Like Particle Characterization and Process Monitoring.

Virus-like particles (VLPs) are excellent platforms for the development of influenza vaccine candidates. Nonetheless, their characterization is challenging due to VLPs’ unique biophysical and biochemical properties. To cope with such complexity, multiple analytical techniques have been developed to date (e.g., single-particle analysis, thermal stability, or quantification assays), most of which are rarely used or have been successfully demonstrated for being applicable for virus particle characterization. In this study, several biophysical and biochemical methods have been evaluated for thorough characterization of monovalent and pentavalent influenza VLPs from diverse groups (A and B) and subtypes (H1 and H3) produced in insect cells using the baculovirus expression vector system (IC-BEVS). Particle size distribution and purity profiles were monitored during the purification process using two complementary technologies — nanoparticle tracking analysis (NTA) and tunable resistive pulse sensing (TRPS). VLP surface charge at the selected process pH was also assessed by this last technique. The morphology of the VLP (size, shape, and presence of hemagglutinin spikes) was evaluated using transmission electron microscopy. Circular dichroism was used to assess VLPs’ thermal stability. Total protein, DNA, and baculovirus content were also assessed. All VLPs analyzed exhibited similar size ranges (90–115 nm for NTA and 129–141 nm for TRPS), surface charges (average of −20.4 mV), and morphology (pleomorphic particles resembling influenza virus) exhibiting the presence of HA molecules (spikes) uniformly displayed on M1 protein scaffold. Our data shows that HA titers and purification efficiency in terms of impurity removal and thermal stability were observed to be particle dependent. This study shows robustness and generic applicability of the tools and methods evaluated, independent of VLP valency and group/subtype. Thus, they are most valuable to assist process development and enhance product characterization.

NUMERICAL ANALYSIS OF THE VARIOUS SIZES OF SPIKE AND SHAFTS USED ON MAIZE SHELLING MACHINE IN NIGERIA USING FINITE ELEMENT METHOD

Selection of the optimum diameter of Spikes and Shafts used on Maize sheller in Nigeria is a major problem for the local fabricators due to which they either over size those components leading to high cost of the shellers or under size them leading to failure of the shellers during operation. To determine the optimum size of the spikes and shaft to be used on Maize sheller, Finite Element Analysis (FEA) were carried out using SolidWorks Premium 2019, to determine the maximum Vonmises Stress, deflection and minimum factor of Safety of those components using the most common size of spikes and shafts used in developing Maize shellers in Bauchi State Nigeria and to recommend the most suitable sizes to be used. From the Simulation of the various sizes of the spikes, it was found that the best size of ribars to be used as the spikes for maize Shellers is either 12 or 14 mm. 12 mm will be subjected to maximum Vonmises stress of 103.092 Mpa at a factor of safety of 2.716 while 14 mm will be subjected to a Maximum stress of 76.57 Mpa at a factor of Safety of 3.66. The most suitable Size for the Shelling shaft was determined to be 20 mm which will be subjected to a maximum Vonmises Stress of 73.32 Mpa at a factor of Safety of 4.8 with a maximum deflection of 0.09 mm.

An unsupervised automatic measurement of wheat spike dimensions in dense 3D point clouds for field application

An accurate measurement of field-grown wheat traits, including spike number, dimension and volume are essential for crop phenotyping and yield analysis. A high-throughput method to image field-grown wheat in three dimensions is presented with an accompanying unsupervised measuring method to obtain individual wheat spike data. Images are captured using four structured light scanners on a field mobile platform, creating dimensionally accurate sub-millimetre resolution 3D point clouds for a 4.5 m 3 volume in less than 10 s. The unsupervised method analyses each trial plot's 3D point cloud, containing hundreds of wheat spikes, calculating the average size of the wheat spike and total spike volume per plot. The analysis utilises an adaptive k -means algorithm with dynamic perspectives, to fit each spike's shape and measures the dimensions with a random sample consensus algorithm. The method generates small cuboids to fit all the wheat spikes and estimate the total spikes volume. Experimental results show that the proposed algorithm is a reliable tool for identifying spikes from wheat crops and identifying individual spikes. Compared with the manual measurement, according to the results of five scenes, the average error rate in the number of spikes, spikes' height and spikes' width in tests were 16.27%, 5.24% and 12.38% respectively. • Laser imaging technology for automatic field phenotyping application. • High-throughput field capture platform was constructed. • Unsupervised algorithm allows for wheat dimensions measurement in 3D point clouds. • Automatic measurement can estimate wheat spike size, volume and number of spikes. • Framework was evaluated by comparing the experiment with manual measurement.

Differentiation of eiincorns by water retention capacity

Aim. On the basis of multivariate analysis, to differentiate einkorn wheat accessions by the water-holding capacity of leaves and ears and the parameters of these organs at the level of species and genotypes. Methods. The water-holding capacity was assessed by the moisture-yielding coefficient which was determined by the method of N.N. Kozhushko (Kozhushko, 1988). Differentiation of einkorn samples was carried out by the method of principal components in the interpretation of A.V. Korosov (Korosov, 1996). Results. Triticum monococcum UA0300113, Syria, and UA0300282, Hungary were characterized by the lowest specific moisture-yielding coefficients: for the second and flag leaves, respectively, (mg / cm2) 10.9, 7.0 and 11.4, 10.7; ears – the same samples as well as Triticum boeoticum UA0300401, Ukraine-Crimea: (mg / cm) 29.6, 28.2, 25.4. With an increase in the size of the lamina, there is a tendency to a decrease in its specific moisture yield. The samples of eincorn are differentiated into 4 clusters corresponding to the species. Conclusions. T. monococcum UA0300113, Syria, and UA0300282, Hungary are relatively drought tolerant. The complex of features characterizing leaf and spike size in combination with the moisture-yielding coefficients processed by the method of principal components makes it possible to differentiate einkorn oaccessions by species and genotype.&#x0D; Keywords: einkorns, moisture yield, drought resistance, leaf, ear.

On agricultural commodities\u2019 extreme price risk

We show how fat tails in agricultural commodity returns arise endogenously from productivity shocks in a standard macroeconomic model. Using nearly ninety years of data, we show that the eight agricultural commodities in our sample exhibit fat-tailed return distributions. Statistical tests confirm the heavy-tailedness of price spikes for agricultural commodities. We apply extreme value theory to estimate the size and likelihood of price spikes in agricultural commodities. Back-testing verifies the validity of our risk assessment methodology.