Realising a species-selective double well with multiple-radiofrequency-dressed potentials

Techniques to manipulate the individual constituents of an ultracold mixture are key to investigating impurity physics. In this work, we confine a mixture of the hyperfine ground states of Rb-87 in a double-well potential. The potential is produced by dressing the atoms with multiple radiofrequencies. The amplitude and phase of each frequency component of the dressing field are individually controlled to independently manipulate each species. Furthermore, we verify that our mixture of hyperfine states is collisionally stable, with no observable inelastic loss.Comment: 11 pages, 4 figure

Theoretical analysis of perching and hovering maneuvers

Unsteady aerodynamic phenomena are encountered in a large number of modern aerospace and non-aerospace applications. Leading edge vortices (LEVs) are of particular interest because of their large impact on the forces and performance. In rotorcraft applications, they cause large vibrations and torsional loads (dynamic stall), affecting the performance adversely. In insect flight however, they contribute positively by enabling high-lift flight. Identifying the conditions that result in LEV formation and modeling their effects on the flow is an important ongoing challenge. Perching (airfoil decelerates to rest) and hovering (zero freestream velocity) maneuvers are of special interest. In earlier work by the authors, a Leading Edge Suction Parameter (LESP) was developed to predict LEV formation for airfoils undergoing arbitrary variation in pitch and plunge at a constant freestream velocity. In this research, the LESP criterion is extended to situations where the freestream velocity is varying or zero. A point-vortex model based on this criterion is developed and results from the model are compared against those from a computational fluid dynamics (CFD) method. Abstractions of perching and hovering maneuvers are used to validate the low-order model's performance in highly unsteady vortex-dominated flows, where the time-varying freestream/translational velocity is small in magnitude compared to the other contributions to the velocity experienced by the leading edge region of the airfoil. Time instants of LEV formation, flow topologies and force coefficient histories for the various motion kinematics from the low-order model and CFD are obtained and compared. The LESP criterion is seen to be successful in predicting the start of LEV formation and the point-vortex method is effective in modeling the flow development and forces on the airfoil. Typical run-times for the low-order method are between 30-40 seconds, making it a potentially convenient tool for control/design applications

Securing Water, Sustaining Growth: Report of the GWP/OECD Task Force on Water Security and Sustainable Growth

Peer Revie

Integration of GWAS, CNV and sele ction signature reveals candidate genes for abdominal fat regulation in chickens.

Abstract: Carcass fat content is an economically important trait in commercial chickens. The use of genome-wide high density SNPs may improve the power and resolution to identify QTLs, putative candidate genes and copy number variations (CNVs), for selection programs. The main goal of this study was to identify genomic windows and putative candidate genes for carcass fat content. We checked the overlap of QTL with regions demonstrating signatures of selection and inherited CNVs identified in the same population. A total of 497 42 day-old chickens from the EMBRAPA F2 Chicken Resource Population developed for QTL studies were genotyped with the 600K SNP genotyping array (Affymetrix®), and phenotyped for carcass fat content weight (CFCW) and carcass fat content on a dry matter basis (CFCDM). After quality control, a total of 480 samples and 371,557 SNPs annotated in autosomal chromosomes (GGA1-28) based on Gallus_gallus-5.0 (NCBI) were kept for further analysis. GWAS analyses were performed with GenSel software using BayesB method (π=0.9988) to identify genomic windows associated with CFCW or CFC%. We identified 15 genomic windows associated with CFC% on GGA1, 7, 15, 20 and 28, and from those, we identified two adjacent windows on GGA7 considered as the same QTL explaining 1.31 and 2.18% of the genetic variance for CFCW and CFC%, respectively. This QTL overlapped with one regions previsiouly know to regulate abdominal fat in chickens and the QTL region encompassed two putative candidate genes overlapping with signatures of selection and inherited CNVs. Our findings are helpful to better understand the genetic regulation of fatness in chickens. Resumo: O teor de gordura na carcaça é uma característica economicamente importante em frangos comerciais. O uso de SNPs de alta densidade em todo o genoma pode melhorar o poder e a resolução para identificar QTLs, genes candidatos putativos e variações no número de cópias (CNVs), para programas de seleção. O principal objetivo deste estudo foi identificar janelas genômicas e possíveis genes candidatos para o conteúdo de gordura na carcaça. Verificamos a sobreposição de QTL com regiões demonstrando assinaturas de seleção e CNVs herdadas identificadas na mesma população. Um total de 497 galinhas com 42 dias de idade da EMBRAPA F2 Chicken Resource Population desenvolvidas para estudos QTL foram genotipadas com o arranjo de genótipos SNP 600K (Affymetrix®) e fenotipadas para peso de gordura na carcaça (CFCW) e teor de gordura na carcaça seca. matéria básica (CFCDM). Após o controle de qualidade, um total de 480 amostras e 371.557 SNPs anotados em cromossomos autossômicos (GGA1-28) baseados em Gallus_gallus-5.0 (NCBI) foram mantidos para análise posterior. As análises de GWAS foram realizadas com o software GenSel usando o método de BayesB (π = 0,9988) para identificar janelas genômicas associadas ao CFCW ou CFC%. Foram identificadas 15 janelas genômicas associadas a% CFC em GGA1, 7, 15, 20 e 28 e, a partir delas, identificamos duas janelas adjacentes em GGA7 consideradas como os mesmos QTLs explicando 1,31 e 2,18% da variância genética para CFCW e CFC% , respectivamente. Este QTL se sobrepunha a uma das regiões previsamente conhecidas para regular a gordura abdominal em frangos e a região QTL englobava dois supostos genes candidatos que se sobrepunham com assinaturas de seleção e CNVs herdadas. Nossas descobertas são úteis para entender melhor a regulação genética da gordura em frangos

Genetic parameters for concentrations of minerals in longissimus muscle and their associations with palatability traits in Angus cattle

The objective of this study was to estimate genetic parameters for concentrations of minerals in LM and to evaluate their associations with beef palatability traits. Samples of LM from 2,285 Angus cattle were obtained and fabricated into steaks for analysis of mineral concentrations and for trained sensory panel assessments. Nine minerals, including calcium, copper, iron, magnesium, manganese, phosphorus, potassium, sodium, and zinc, were quantified. Restricted maximum likelihood procedures were used to obtain estimates of variance and covariance components under a multiple-trait animal model. Estimates of heritability for mineral concentrations in LM varied from 0.01 to 0.54. Iron and sodium were highly and moderately heritable, respectively, whereas the other minerals were lowly heritable except for calcium, copper, and manganese, which exhibited no genetic variation. Strong positive genetic correlations existed between iron and zinc (0.49, P \u3c 0.05), between magnesium and phosphorus (0.88, P \u3c 0.05), between magnesium and sodium (0.68, P \u3c 0.05), and between phosphorus and potassium (0.69, P \u3c 0.05). Overall tenderness assessed by trained sensory panelists was positively associated with manganese, potassium, and sodium and negatively associated with phosphorus and zinc concentrations (P \u3c0.05). Juiciness assessed by trained sensory panelists was negatively associated with magnesium and positively associated with manganese and sodium concentrations (P \u3c 0.05). Livery or metallic flavor was not associated with any of the minerals (P \u3e 0.05). Beefy flavor was positively associated with calcium, iron, and zinc and negatively associated with sodium concentration, whereas a painty or fishy flavor was positively associated with sodium and negatively associated with calcium and potassium concentrations (P \u3c 0.05). Beef is a major contributor of iron and zinc in the human diet, and these results demonstrate sufficient genetic variation for these traits to be improved through marker-assisted selection programs without compromising beef palatability

Results of survey of stakeholders regarding knowledge of and attitudes towards feed intake, efficiency and genetic improvement concepts

Individual animal feed efficiency plays a key role in the profitability and sustainability of the US beef industry. During the growing and finishing phase of production, a 10% improvement in feed efficiency has a two-fold greater impact on profit than a 10% increase in rate of gain (Fox et al., 2001). The traits that beef producers routinely record are outputs which determine the value of product sold and not the inputs defining the cost of beef production. The inability to routinely measure feed intake and feed efficiency on large numbers of cattle has precluded the efficient application of selection despite moderate heritabilities (h2 = 0.16-0.46; Archer et al., 1999). Feed costs in calf feeding and yearling finishing systems account for approximately 66% and 77% of costs, respectively (Anderson et al., 2005).Feed costs account for approximately 65% of total beef production costs. Of the metabolizable energy required from conception to consumption of a beef animal, 72% is utilized during the cow-calf segment of production while 28% of calories are utilized in the calf growing and finishing phases of production (Ferrell and Jenkins, 1982). Of the calories consumed in the cow-calf segment, more than half are used for maintenance which presents a large selection target

Genome-wide association study of concentrations of iron and other minerals in longissimus muscle of Angus cattle1

The objective of this study was to characterize variation and identify SNP and chromosomal regions associated with mineral concentrations in LM of Angus beef cattle. Samples of LM from 2,285 Angus cattle were obtained and concentrations of seven minerals including iron, magnesium, manganese, phosphorus, potassium, sodium, and zinc were quantified. Genomic DNA extracted from the ground beef sample used for mineral composition was genotyped with the Bovine SNP50 Infinium II BeadChip and effects of SNP on each trait were estimated using the Bayes-Cπ module of GenSel software. Pedigree-based estimates of heritabilities and corresponding genetic variances indicate iron was the only mineral concentration, which could be considered a good candidate for manipulation by genomic selection. The amount of variation that could be accounted for by SNP genotypes was concordant with pedigree-based heritabilities and varied from very low for potassium and sodium (< 0.09) to medium-high (0.37) for iron. Though significant chromosomal regions were identified for all minerals analyzed in this study, further study focused on iron. Seven regions on six chromosomes (1, 2, 7, 10, 15 and 28) were identified to have major effect on iron content of LM in Angus cattle. The accuracy of direct genomic values (DGV) for iron concentration was estimated using a five-fold cross-validation strategy. The accuracy of DGV estimated as the genetic correlation between DGV and the phenotype (iron concentration) adjusted for contemporary groups was 0.59. A bivariate animal model was used to estimate genetic correlations between iron concentrations and a reduced set of economically important carcass traits: HCW, ribeye area, calculated USDA yield grade, percent KPH, and marbling score. The genetic correlations between iron concentration and HCW, percentage KPH, marbling score and ribeye area were small (-0.19 - 0.15) and non-significant. Although still weak (0.22), a positive significant genetic correlation was identified between iron content and USDA calculated yield grade. Beef is a major contributor of iron and zinc in the human diet, and this study found that iron content might be effectively manipulated through marker-assisted selection programs, without compromising other carcass and palatability traits