Strategies For Yield Improvement Research Articles

Mutation of KAP, which encodes a keratin-associated protein, affects grain size and yield production in rice.

Grain size and shape are critical agronomic traits that directly impact rice grain yield. Identifying genes that control these traits can provide new strategies for yield improvement. In this study, we characterized a rice mutant, reduced grain length (rgl), which exhibited decreased grain length due to reduced cell proliferation. Map-based cloning identified a base deletion in OsRGL2, a gene encoding a keratin-associated protein (KAP), as the cause of the mutant phenotype. CRISPR-Cas9-generated OsRGL2 knockout mutants also displayed reduced grain length, confirming its role. OsRGL2 transcripts were detected in various tissues, with relative higher gene expression in young panicles, and OsRGL2 was localized to the plasma membrane. Overexpression of OsRGL2 increased grain size by promoting cell proliferation in the spikelet hull and significantly enhanced grain yield per plant. Importantly, OsRGL2 was found to interact with RGB1, indicating that OsRGL2 positively regulates grain size and yield through its interaction with RGB1. Additionally, OsRGL2 regulated the expression of cell cycle-related genes, further elucidating its role in grain development. These findings demonstrate that OsRGL2 is a positive regulator of grain size in rice, and manipulating its expression may offer a novel strategy for enhancing rice grain yield.

RNA-seq reveals multifaceted gene expression response to Fab production in Escherichia coli fed-batch processes with particular focus on ribosome stalling

BackgroundEscherichia coli is a cost-effective expression system for production of antibody fragments like Fabs. Various yield improvement strategies have been applied, however, Fabs remain challenging to produce. This study aimed to characterize the gene expression response of commonly used E. coli strains BL21(DE3) and HMS174(DE3) to periplasmic Fab expression using RNA sequencing (RNA-seq). Two Fabs, Fabx and FTN2, fused to a post-translational translocation signal sequence, were produced in carbon-limited fed-batch cultivations.ResultsProduction of Fabx impeded cell growth substantially stronger than FTN2 and yields of both Fabs differed considerably. The most noticeable, common changes in Fab-producing cells suggested by our RNA-seq data concern the cell envelope. The Cpx and Psp stress responses, both connected to inner membrane integrity, were activated, presumably by recombinant protein aggregation and impairment of the Sec translocon. The data additionally suggest changes in lipopolysaccharide synthesis, adjustment of membrane permeability, and peptidoglycan maturation and remodeling. Moreover, all Fab-producing strains showed depletion of Mg2+, indicated by activation of the PhoQP two-component signal transduction system during the early stage and sulfur and phosphate starvation during the later stage of the process. Furthermore, our data revealed ribosome stalling, caused by the Fabx amino acid sequence, as a contributor to low Fabx yields. Increased Fabx yields were obtained by a site-specific amino acid exchange replacing the stalling sequence. Contrary to expectations, cell growth was not impacted by presence or removal of the stalling sequence. Considering ribosome rescue is a conserved mechanism, the substantial differences observed in gene expression between BL21(DE3) and HMS174(DE3) in response to ribosome stalling on the recombinant mRNA were surprising.ConclusionsThrough characterization of the gene expression response to Fab production under industrially relevant cultivation conditions, we identified potential cell engineering targets. Thereby, we hope to enable rational approaches to improve cell fitness and Fab yields. Furthermore, we highlight ribosome stalling caused by the amino acid sequence of the recombinant protein as a possible challenge during recombinant protein production.

From Sequencing to Genome Editing in Cucurbitaceae: Application of Modern Genomic Techniques to Enhance Plant Traits

The availability of genome-sequencing and genome-editing techniques has increased the applicability of innovative solutions, opening up revolutionary prospects for developments in horticultural plant breeding. The Cucurbitaceae family is a group of plants of great importance in horticulture due to their high nutritional and economic value. These plants serve as important models for elucidating the principles of plant development and refining yield improvement strategies. While traditional breeding approaches have made significant contributions to the production of cucurbits, they have also been limited by the reduced genetic diversity and lower rates of variation inherent in these species. This comprehensive review summarises the latest developments in genome editing in cucurbits. It covers various aspects of enhancing plant traits to resist biotic stresses such as pathogenic fungi and viruses, as well as abiotic stresses such as adverse climate change, especially stresses caused by drought and salinity. This study focused on improvements in plant quality and on the optimisation of plant architecture, sex determination of flowers and fruit features. This review provides insights that may hold great promise for the future of horticultural crop improvement and serves as an important reference for the advancement of genome-sequencing and gene-editing technologies in cucurbits.

Analysis of Genetic Diversity in Adzuki Beans (Vigna angularis): Insights into Environmental Adaptation and Early Breeding Strategies for Yield Improvement.

Adzuki beans are widely cultivated in East Asia and are one of the earliest domesticated crops. In order to gain a deeper understanding of the genetic diversity and domestication history of adzuki beans, we conducted Genotyping by Sequencing (GBS) analysis on 366 landraces originating from Korea, China, and Japan, resulting in 6586 single-nucleotide polymorphisms (SNPs). Population structure analysis divided these 366 landraces into three subpopulations. These three subpopulations exhibited distinctive distributions, suggesting that they underwent extended domestication processes in their respective regions of origin. Phenotypic variance analysis of the three subpopulations indicated that the Korean-domesticated subpopulation exhibited significantly higher 100-seed weights, the Japanese-domesticated subpopulation showed significantly higher numbers of grains per pod, and the Chinese-domesticated subpopulation displayed significantly higher numbers of pods per plant. We speculate that these differences in yield-related traits may be attributed to varying emphases placed by early breeders in these regions on the selection of traits related to yield. A large number of genes related to biotic/abiotic stress resistance and defense were found in most quantitative trait locus (QTL) for yield-related traits using genome-wide association studies (GWAS). Genomic sliding window analysis of Tajima's D and a genetic differentiation coefficient (Fst) revealed distinct domestication selection signatures and genotype variations on these QTLs within each subpopulation. These findings indicate that each subpopulation would have been subjected to varied biotic/abiotic stress events in different origins, of which these stress events have caused balancing selection differences in the QTL of each subpopulation. In these balancing selections, plants tend to select genotypes with strong resistance under biotic/abiotic stress, but reduce the frequency of high-yield genotypes to varying degrees. These biotic/abiotic stressors impact crop yield and may even lead to selection purging, resulting in the loss of several high-yielding genotypes among landraces. However, this also fuels the flow of crop germplasms. Overall, balancing selection appears to have a more significant impact on the three yield-related traits compared to breeder-driven domestication selection. These findings are crucial for understanding the impact of domestication selection history on landraces and yield-related traits, aiding in the improvement of adzuki bean varieties.

Multivariate analysis for various agro-morphological traits of turmeric (Curcuma longa L.)

Turmeric is one of the potential spice crops having importance in culinary, colouring in textiles and therapeutic in pharmaceutical industries. The present investigation was carried out to estimate the genetic diversity of 21 turmeric genotypes representing different geographical locations of India. The principal component (PC) analysis indicated that the most of the variation among the genotypes was contributed by the first two principal components (61.38%), which were largely governed by plant height, number of leaves per plant, leaf lamina length, leaf area, total leaf area, collar girth and weight of the mother rhizomes per clump. These traits showed high positive correlation with first two PCs and influenced significantly for grouping. Based on PC correlation analysis, it is evident that morphological and yield attributing traits of PC1 and PC2 are influenced and contributed for most of the variation among the genotypes. The cluster analysis revealed that the 21 genotypes fall into five clusters, and among them most divergent with distinct genotypes were cluster I, III and cluster IV. However, IISR Pragati, Rajendra Sonali and NDH 8 were found superior for fresh rhizome yield and Acc. 849 was found unique with robust mother rhizome. The present study contributes to the knowledge of genetic diversity and defining strategies for yield improvement in turmeric.

A 30% reduction in switchgrass rhizome reserves did not decrease biomass yield

AbstractA long‐standing question in perennial grass breeding and physiology is whether yield improvement strategies could compromise winter survival. Since perennial grasses rely on stored carbohydrates for winter maintenance and spring regrowth, yield improvement strategies could reduce winter survival if they increase biomass and grain yields at the expense of carbon allocation to storage. Therefore, it is crucial to comprehend the dependence of regrowth on storage reserves. We experimentally depleted switchgrass (Panicum virgatum L.) rhizome reserves by storing rhizomes for 2 weeks at 5°C (control treatment) and 25°C (reserve‐depleted treatment). During the storage period rhizome respiration was 5.3× higher at 25°C (0.010 μmol CO2 g−1 min−1 at 5°C vs. 0.054 μmol CO2 g−1 min−1 at 25°C; p < 0.0001) and the starch content was depleted by 30% by the end of storage. Surprisingly, reserve‐depleted switchgrass had 60% larger leaf area (LA; LAcontrol = 149 cm2 pot−1 vs. LAdepleted = 239 cm2 pot−1; p = 0.013) and produced ~40% more aboveground biomass than control plants (9.46 g pot−1 vs. 6.63 g pot−1; p = 0.112). In addition, reserve‐depleted switchgrass restored its rhizome starch reserves to pre‐storage levels. Switchgrass showed a large plasticity among its source‐sink components to buffer the imposed reserve depletion. It increased plant photosynthesis by increasing the photosynthetic leaf area while keeping photosynthesis constant on a leaf area basis and readjusted the timing and activity of sink organs. These results suggest that switchgrass, and potentially other perennial grasses, largely over‐invest in storage reserves. Therefore, current breeding strategies in perennial grasses aimed to extend the aboveground growing season should not compromise crop persistence. Our study also has implications on long‐term yield dynamics as it highlights sink limitations as potential driver of the yield decline commonly observed in perennial grasses 5+ years after cultivation.

Correlation and Path Coefficients Analysis for Yield and its Contributing Traits in Rice (Oryza sativa L.) under Sodic Soil

Yield is the complex trait that depends on various attributes. Therefore, the knowledge about the relationship of different attributes to yield is crucial for making efficient selection strategy. The grain yield per plant exhibited highly significant and positive association with biological yield per plant followed by panicle bearing tillers per plant, spikelets per panicle, grains per panicle, chlorophyll content in F1 s at both genotypic and phenotypic level. Highest positive direct effect on grain yield per plant was exerted by biological yield per plant and harvest-index in F1 s at both genotypic and phenotypic level. Therefore, biological yield per plant and harvest index should be utilized in making selection strategy for yield improvement in rice.

Carpel-specific down-regulation of GhCKXs in cotton significantly enhances seed and fiber yield.

Cytokinin is considered to be an important driver of seed yield. To increase the yield of cotton while avoiding the negative consequences caused by constitutive overproduction of cytokinin, we down-regulated specifically the carpel genes for cytokinin oxidase/dehydrogenase (CKX), a key negative regulator of cytokinin levels, in transgenic cotton. The carpel-specific down-regulation of CKXs significantly enhanced cytokinin levels in the carpels. The elevated cytokinin promoted the expression of carpel- and ovule-development-associated genes, GhSTK2, GhAG1, and GhSHP, boosting ovule formation and thus producing more seeds in the ovary. Field experiments showed that the carpel-specific increase of cytokinin significantly increased both seed yield and fiber yield of cotton, without resulting in detrimental phenotypes. Our study details the regulatory mechanism of cytokinin signaling for seed development, and provides an effective and feasible strategy for yield improvement of seed crops.

On the large‐scale production of a new vaccine

Large‐scale production of a new vaccine, such as the COVID‐19 vaccine, is characterized by evolving demand and production yield uncertainties. Further, following its FDA approval for efficacy and safety, a vaccine may not even be manufacturable due to its low production yield and the resulting lack of profitability. To deal with those challenges in practice, a vaccine manufacturer can (stochastically) increase the uncertain yield of a vaccine prior to launching large‐scale production by learning through small‐scale, experimental production runs about manufacturing conditions that are conducive to raising that yield. After starting large‐scale production and receiving revenues from the sale of the vaccine, the manufacturer can continue to stochastically improve vaccine yield by acquiring knowledge from real‐time production data. The two key decisions faced by a vaccine manufacturer concern the optimal timing and capacity of the vaccine's large‐scale production. To determine the structure of vaccine manufacturer's optimal decisions, we formulate and solve a stochastic, multiperiod, sequential‐decision model, while incorporating the dynamic evolution of vaccine yield uncertainty under those two yield improvement strategies. We establish the optimality of a threshold stopping policy for the timing of the large‐scale vaccine production. This policy depends in a fundamental way on the relative stochastic rates of the two yield improvement strategies. We characterize the manufacturer's optimal capacity decision and identify conditions under which optimal capacity and production yield become substitutes. We analyze the implications of our results for rendering a new vaccine large‐scale manufacturable, and bringing it to the market sooner during a pandemic period.

Genetic analysis of introgression lines of Oryza rufipogon for improvement of low phosphorous tolerance in indica rice

Soil phosphorus (P) deficiency is one of the major challenges for rice cultivation. The present study was carried out under low soil P condition (available P, < 2 kg ha-1) to study the genetic variability, correlation, path and principal component analysis (PCA) in a set of 40 introgression lines derived from Samba Mahsuri (Oryza sativa ssp. indica) × Oryza rufipogon. High genotypic coefficient of variation and phenotypic coefficient of variation was recorded for productive tillers (PT), seed weight (SW), and grain yield (GY). High heritability coupled with high genetic advance was recorded for plant height (PH), PT, SW, number of spikelets/panicle (SPP), spikelet fertility, and GY. Correlation analysis revealed that grain yield had a significant positive association with PH, PT, panicle length, SPP, and SW. Regression analysis revealed that the grain yield was mainly influenced by PT and SW. This was confirmed by path analysis, wherein PT and SW exerted the highest direct positive effect on grain yield. The PCA revealed that the first two PCs contribute to maximum variability, which together accounted for 60% of the total variability. The traits PT and SW contributed the maximum to load/variance the total variability. Thus, the selection of introgression lines with a greater number of PT and higher SW would be the most appropriate strategy for yield improvement under low soil P condition in rice. Cluster analysis grouped introgression lines along with checks into three clusters. Overall, the study revealed the pattern genetic variability for low P tolerance in the introgression lines. This further helps in designing appropriate breeding strategies for the improvement of rice cultivars for low P tolerance.

Yield and leakage current of organic thin-film transistor logic gates toward reliable and low-power operation of large-scale logic circuits for IoT nodes

This paper reports on a strategy for yield improvement and static leakage current reduction by a standard cell design for large-scale organic thin-film transistor (OTFT) circuits. Printable or flexible devices are suitable for IoT nodes, and digital OTFT circuits comprise the peripheral circuits of such devices. Sufficiently high yields and low static power consumptions are essential for battery operations of IoT nodes having functional digital circuits. Our design method to address the weak n-type OTFT on-current results in improved logic gate yields without any cell area increase. We improved the yield of the inverter, NAND, and NOR gates using a standard cell design, and achieved a 100% yield for the inverter and NOR gates and 88% yield for the NAND gates. Signal propagations with the rail-to-rail operation were measured on test chips. Leakage currents of 585 pA and 2.94 nA were achieved for the inverter and NOR gates, respectively.

Exploring teff yield variability related with farm management and soil property in contrasting agro-ecologies in Ethiopia

CONTEXTTeff is an important food-security crop for millions of people in Ethiopia. The demand for teff products is also increasing globally due to its health benefits as a gluten-free grain. However, teff productivity is low compared with other cereals. Crop yields vary widely among farms in rainfed production system. Identifying the key crop management practices and soil properties responsible for these variations will help to raise crop productivity through informed decision making by farmers, experts, researchers, and policy makers. OBJECTIVESThe objectives of this study were to assess the characteristics of the Ethiopian teff-cropping system, quantify the variability of grain yields among farms, and identify the impacts of different crop management practices and soil fertility parameters on yield variability. METHODSThe study examined 82 teff farms at three sites representing different teff-growing agro-ecologies in Ethiopia. Practices used to manage crops and soil on each farm were assessed. Composite topsoil samples were collected from farms at each site and analyzed for selected physical and chemical parameters. Grain and straw yields were quantified when crops were matured. Descriptive statistics, and factor analysis followed by multiple regression analysis was performed to identify the factors that caused the variability of yields among farms. RESULTS AND CONCLUSIONSTeff yields were highly variable within and across different agro-ecologies. The crop management factors that greatly affected yields were N and P application rates and days to harvesting. The most important soil characteristics were total nitrogen, texture and micronutrients. Poor teff yields were attributable to failure to implement improved agronomic practices, poor soil fertility, and inefficient production systems. Teff production system is a low-yielding, less-profitable, and resource-intensive enterprise. The observed variations in yields among farms indicated that there is a big opportunity to improve teff productivity. The high frequency of tillage, monocropping, and complete removal of crop residues were major causes of the low soil fertility. SIGNIFICANCEUnderstanding teff yield variability among farms helps to design appropriate yield improvement strategies. The use of low-cost crop-intensification options such as planting of improved cultivars using improved sowing methods, reduced tillage, incorporation of crop residues and legume-based crop rotation could sustainably improve productivity and restore soil fertility with minimal increases of costs in rainfed teff production system.

Yield improvement of enediyne yangpumicins in Micromonospora yangpuensis through ribosome engineering and fermentation optimization.

Yangpumicins (YPMs), for example, YPM A, F, and G, are newly discovered enediynes from Micromonospora yangpuensis DSM 45577, which could be exploited as promising payloads of antibody-drug conjugates. However, the low yield of YPMs in the wild-type strain (∼1mg L-1 ) significantly hampers their further drug development. In this study, a combined ribosome engineering and fermentation optimization strategy has been used for yield improvement of YPMs. One gentamicin-resistant M. yangpuensis DSM 45577 strain (MY-G-1) showed higher YPMs production (7.4± 1.0mg L-1 ), while it exhibits delayed sporulation and slender mycelium under scanning electron microscopy. Whole genome re-sequencing of MY-G-1 reveals several deletion and single nucleotide polymorphism mutations, which were confirmed by PCR and DNA sequencing. Further Box-Behnken experiment and regression analysis determined that the optimal medium concentrations of soluble starch, D-mannitol, and pharmamedia for YPMs production in shaking flasks (10.0± 0.8mg L-1 ). Finally, the total titer of YPM A/F/G in MY-G-1 reached to 15.0± 2.5mg L-1 in 3 L fermenters, which was about 11-fold higher than the original titer of 1.3± 0.3mg L-1 in wild-type strain. Our study may be instrumental to develop YPMs into a clinical anticancer drug, and inspire the use of these multifaceted strategies for yield improvement in Micromonospora species. GRAPHICAL ABSTRACT LAY SUMMARY: ???

Optimizing Planting Density and Impact of Panicle Types on Grain Yield and Microclimatic Response Index of Hybrid Rice (Oryza sativa L.)

The architecture of rice plant represents important and complex agronomic traits, such as panicles morphology, which directly influence the microclimate of rice population and consequently grain yield. To enhance yield, modification of plant architecture to create new hybrid cultivars is considered a sustainable approach. The current study includes an investigation of yield and microclimate response index under low to high plant density of two indica hybrid rice R498 (curved panicles) and R499 (erect panicles), from 2017 to 2018. The split-plot design included planting densities of 11.9–36.2 plant/m2. The results showed that compared with R498, R499 produced a higher grain yield of 8.02–8.83 t/ha at a higher planting density of 26.5–36.2 plant/m2. The response index of light intensity and relative humidity to the planting density of R499 was higher than that of R498 at the lower position of the rice population. However, the response index of temperature to the planting density of R499 was higher at the upper position (0.2–1.4%) than at the lower position. Compared with R498, R499 at a high planting density developed lower relative humidity (78–88%) and higher light intensity (9900–15,916 lx) at the lower position of the rice population. Our finding suggests that erect panicles are highly related to grain yield microclimatic contributors under a highly dense rice population, such as light intensity utilization, humidity, and temperature. The application of erect panicle rice type provides a potential strategy for yield improvement by increasing microclimatic conditions in rice.

Genetic variability and association of yield and yield components among bread wheat genotypes under drought-stressed conditions

Drought is one of the major constraints to wheat production and productivity globally. Developing drought-adapted wheat cultivars is paramount to increase wheat productivity under variable rainfall conditions. Understanding the genetic variability and trait association is key to the development of improved wheat cultivars. The objective of this study was to determine the extent of the genetic parameters and associations of yield and yield components of bread wheat genotypes, in order to design appropriate breeding strategies for yield improvement in wheat. One hundred and twenty genotypes were evaluated at five test sites in the 2018/19 cropping season using a 10 x 12 alpha lattice design with two replications. Different sowing dates were used to impose contrasting drought stress levels based on the onset of the main seasonal rains at each site. Data were recorded on agronomic traits such as days to heading (DH), days to maturity (DM), plant height (PH), spike length (SL), spikelet per spike (SS), kernel per spike (KS), 1000 kernel weight (TKW) and grain yield (GY). There was significant (p<0.01) genetic variation for all agronomic traits studied under both drought-stressed and non-stressed conditions. The highest estimates for genetic variance were obtained for DH (54.0%), followed by SL (38.3%). The high heritability estimated for DH (94.4%), SL (90.2%) and SS (85.2%), coupled with a high rate of genetic advance, suggest that direct selection for these traits would be effective under drought-stressed conditions. GY exhibited low genetic advance (9%) and heritability (41.5%) estimates, which were concomitant with its polygenic and complex inheritance pattern. Correlation and path analyses revealed that TKW was the most important contributing trait for improving grain yield under drought-stressed conditions

Radiation Interception, Conversion and Partitioning Efficiency in Potato Landraces: How Far Are We from the Optimum?

Crop efficiencies associated with intercepted radiation, conversion into biomass and allocation to edible organs are essential for yield improvement strategies that would enhance genetic properties to maximize carbon gain without increasing crop inputs. The production of 20 potato landraces—never studied before—was analyzed for radiation interception (), conversion () and partitioning () efficiencies. Additionally, other physiological traits related to senescence delay (normalized difference vegetation index (NDVI)), tuberization precocity (), photosynthetic performance and dry tuber yield per plant (TY) were also assessed. Vegetation reflectance was remotely acquired and the efficiencies estimated through a process-based model parameterized by a time-series of airborne imageries. The combination of and , closely associated with an early tuber maturity and a NDVI explained 39% of the variability grouping the most productive genotypes. TY was closely correlated to senescence delay (r = 0.74), indicating the usefulness of remote sensing methods for potato yield diversity characterization. About 89% of TY was explained by the first three principal components, associated mainly to , and , respectively. When comparing potato with other major crops, its is very close to the theoretical maximum. These findings suggest that there is room for improving and to enhance potato production.

Hot sparing for lifetime-chip-performance and cost improvement in application specific SIMT processors

Redundancy is a well-known technique for replacing components with manufacturing defects, improving yield and reducing cost. Previously, most yield improvement strategies utilized redundant components only when another component had failed (i.e., cold spares). However, utilizing hot spares is becoming popular in commercial products (e.g., the NVIDIA Ti GPU series). Hot spares address manufacturing cost when the components are defective; otherwise, they can be used to improve performance in the field. In this paper, we investigate the effect of hot spares on lifetime-chip-performance (LCP) in multi-core single-instruction, multiple-thread (SIMT) processors. We observe that hot sparing is outstandingly effective for specific types of SIMT processor configurations (small and medium systems) and applications (FFT and FILTER), while improving cost and LCP over other configurations and applications as well. For example, hot-sparing can improve LCP more than 75% compared with conventional methods (i.e., cold sparing), on average, for applications that experience significant performance improvement when adding hot spares (e.g., FFT and FILTER). In particular, microarchitectural hot redundant resources (e.g., hot spare lanes) achieve better LCP improvement than conventional architectural redundancies (e.g., hot spare cores).

Optimal Timing of Influenza Vaccine Production Under Yield-Improving and Knowledge Acquisition Strategies

We consider a manufacturer of a new vaccine, such as the COVID-19 vaccine, characterized by evolving demand and production yield uncertainties. At the beginning of the time horizon, a vaccine may not be manufacturable due to its low production yield and the resulting lack of profitability. Prior to launching large-scale production, the manufacturer stochastically increases the uncertain yield of the vaccine by learning through small-scale experimental production runs about manufacturing conditions that are conducive to raising that yield, thus forsaking, in the process, immediate profits but raising future ones. After starting large-scale production and receiving revenues from the sale of the vaccine, the manufacturer can continue to stochastically improve vaccine yield by acquiring knowledge from real-time production data. The two key decisions faced by the vaccine manufacturer who seeks to maximize his total expected profit over the time horizon concern the optimal timing and capacity of the vaccine’s large-scale production. We formulate and solve a stochastic, multi-period, sequential-decision model to determine the structure of the vaccine’s manufacturer’s optimal decisions, while incorporating the dynamic evolution of vaccine yield uncertainty under those two yield improvement strategies. In particular, we establish the optimality of a threshold stopping policy for the timing of the large-scale vaccine production. This policy is found to depend in a fundamental way on the relative stochastic rates of the two yield improvement strategies. We also characterize the manufacturer’s optimal capacity decision and identify conditions under which, for a new vaccine, optimal capacity and production yield become substitutes. We analyze the implications of our results and underlying yield improvement strategies for rendering a new vaccine large-scale manufacturable, and bringing it to the market sooner in the time horizon.

Characterizing the Effectiveness of Hot Sparing on Cost and Performance-per-Watt in Application Specific SIMT

Adding redundant components is a well-known technique in the industry for replacing defective components, which results in yield improvement, and consequently, manufacturing cost reduction. Previously, most yield improvement strategies utilized redundant components only when another component had failed (i.e., cold spares). However, utilizing hot spares is becoming popular in commercial products (e.g., NVIDIA Ti GPU series). Hot spares address manufacturing cost when the components are defective; otherwise, they can be used to improve performance in the field. In this paper, we investigate the performance improvement of hot spares to see if it can be used to improve performance per watt (PPW) in multi-core single-instruction, multiple-thread (SIMT) processors over different applications. Also, we investigate the cost and PPW implications of employing different types of hot spares in SIMT processors. Then, we study optimal solutions in the cost-PPW design space to see what kind of redundancy improves cost and PPW the most. However, since evaluating individual design points (different SIMT processor configurations with redundancy) is time consuming, we adapt a design space exploration algorithm to find near-optimal solutions without evaluating the design space exhaustively, which finds approximated optimal solutions three times better than conventional methods. We observe that hot sparing is effective for specific types of SIMT processor configurations (small and medium sized). On these configurations, it can improve PPW more than 16%, on average, for applications that experience significant performance improvement by adding hot spares (e.g., FFT and FILTER). Furthermore, we show that hot sparing's PPW improvement on these applications is comparable with the results of conventional techniques (e.g., voltage scaling) and can be utilized together with them to more effectively improve PPW in the systems. Also, we observed that microarchitectural hot redundant resources (e.g., hot shared-spare lanes) achieve better PPW improvement than conventional architectural redundancies (e.g., hot spare cores).CCS Concepts: • Hardware → Yield and cost optimization; Application specific processors; Redundancy;

A reductionist approach to dissecting grain weight and yield in wheat.

Grain yield is a highly polygenic trait that is influenced by the environment and integrates events throughout the life cycle of a plant. In wheat, the major grain yield components often present compensatory effects among them, which alongside the polyploid nature of wheat, makes their genetic and physiological study challenging. We propose a reductionist and systematic approach as an initial step to understand the gene networks regulating each individual yield component. Here, we focus on grain weight and discuss the importance of examining individual sub‐components, not only to help in their genetic dissection, but also to inform our mechanistic understanding of how they interrelate. This knowledge should allow the development of novel combinations, across homoeologs and between complementary modes of action, thereby advancing towards a more integrated strategy for yield improvement. We argue that this will break barriers in terms of phenotypic variation, enhance our understanding of the physiology of yield, and potentially deliver improved on‐farm yield.