High-field magnetoresistance of Fe/GaAs/Fe tunnel junctions

We investigate transport through 6 to 10 nm thin epitaxial GaAs(001) barriers sandwiched between polycrystalline iron films. Apart from a pronounced tunneling magnetoresistance effect (TMR) at low magnetic fields we observe a distinct negative magnetoresistance (MR) at low and a positive MR at higher temperatures. We show that the negative MR contribution is only observed for the ferromagnetic iron contacts but is absent if iron is replaced by copper or gold electrodes. Possible explanations of the negative MR involve suppression of spin-flip scattering or Zeeman splitting of the tunneling barrier.Comment: 12 pages, 4 figures, submitted to Appl. Phys. Let

Cylindrical, periodic surface lattice — theory, dispersion analysis, and experiment

A two-dimensional surface lattice of cylindrical topology obtained via perturbing the inner surface of a cylinder is considered. Periodic perturbations of the surface lead to observation of high-impedance, dielectric-like media and resonant coupling of surface and non-propagating volume fields. This allows synthesis of tailored-for-purpose "coating" material with dispersion suitable, for instance, to mediate a Cherenkov type interaction. An analytical model of the lattice is discussed and coupled-wave equations are derived. Variations of the lattice dispersive properties with variation of parameters are shown, illustrating the tailoring of the structure's electromagnetic properties. Experimental results are presented showing agreement with the theoretical model

Validation of the Patient-Doctor-Relationship Questionnaire (PDRQ-9) in a representative cross-sectional German population survey

The patient-doctor relationship (PDR) as perceived by the patient is an important concept in primary care and psychotherapy. The PDR Questionnaire (PDRQ-9) provides a brief measure of the therapeutic aspects of the PDR in primary care. We assessed the internal and external validity of the German version of the PDRQ-9 in a representative cross-sectional German population survey that included 2,275 persons aged≥14 years who reported consulting with a primary care physician (PCP). The acceptance of the German version of this questionnaire was good. Confirmatory factor analysis demonstrated that the PRDQ-9 was unidimensional. The internal reliability (Cronbach's α) of the total score was .95. The corrected item-total correlations were≥.94. The mean satisfaction index of persons with a probable depressive disorder was lower than that of persons without a probable depressive disorder, indicating good discriminative concurrent criterion validity. The correlation coefficient between satisfaction with PDR and satisfaction with pain therapy was r = .51 in 489 persons who reported chronic pain, indicating good convergent validity. Despite the limitation of low variance in the PDRQ-9 total scores, the results indicate that the German version of the PDRQ-9 is a brief questionnaire with good psychometric properties to assess German patients' perceived therapeutic alliance with PCPs in public health research

U.S. SPACE FORCE (USSF) ACQUISITION OCCUPATIONAL COMPETENCY INTEGRATION INTO A TALENT OPERATIONS PLATFORM

The idea of using competencies as a vehicle for effective talent management has been an idea explored by many organizations. Recently all service components across the Department of Defense (DOD) have begun a revolution within talent management, particularly with job placement. The DOD’s newest component, the United States Space Force (USSF), actively seeks to implement a competency-based process as dictated by the Guardian Ideal. This capstone report provides USSF with recommendations on effectively integrating a scalable competency-driven system into a talent operations platform that manages Guardian talent during assignment placement. The team evaluated civilian and governmental talent operations systems and processes through interviews with relevant talent management personnel within the DOD and industry. This qualitative analysis fueled the team’s development of a simulation model to identify the effects of competency integration on the system and its interaction with external variables. Throughout the research, the team confirmed that all services desire the effective integration of competencies but lack the implementation of accountable competencies by a validation method. The team recommends Space Force develop a way to validate and input competency assessments by implementing the competency framework within a software system in terms of a scoring algorithm to provide a clear picture for Guardians and Commanders to determine the best fit for vacant billets.Space Force Talent Management Office (ETMO)Major, United States ArmyCaptain, United States ArmyCaptain, United States ArmyCaptain, United States ArmyCaptain, United States ArmyApproved for public release. Distribution is unlimited

Genomic selection in aquaculture: application, limitations and opportunities with special reference to marine shrimp and pearl oysters

Within aquaculture industries, selection based on genomic information (genomic selection) has the profound potential to change genetic improvement programs and production systems. Genomic selection exploits the use of realized genomic relationships among individuals and information from genome-wide markers in close linkage disequilibrium with genes of biological and economic importance. We discuss the technical advances, practical requirements, and commercial applications that have made genomic selection feasible in a range of aquaculture industries, with a particular focus on molluscs (pearl oysters, Pinctada maxima) and marine shrimp (Litopenaeus vannamei and Penaeus monodon). The use of low-cost genome sequencing has enabled cost-effective genotyping on a large scale and is of particular value for species without a reference genome or access to commercial genotyping arrays. We highlight the pitfalls and offer the solutions to the genotyping by sequencing approach and the building of appropriate genetic resources to undertake genomic selection from first-hand experience. We describe the potential to capture large-scale commercial phenotypes based on image analysis and artificial intelligence through machine learning, as inputs for calculation of genomic breeding values. The application of genomic selection over traditional aquatic breeding programs offers significant advantages through being able to accurately predict complex polygenic traits including disease resistance; increasing rates of genetic gain; minimizing inbreeding; and negating potential limiting effects of genotype by environment interactions. Further practical advantages of genomic selection through the use of large-scale communal mating and rearing systems are highlighted, as well as presenting rate-limiting steps that impact on attaining maximum benefits from adopting genomic selection. Genomic selection is now at the tipping point where commercial applications can be readily adopted and offer significant short- and long-term solutions to sustainable and profitable aquaculture industries

A first-generation integrated tammar wallaby map and its use in creating a tammar wallaby first-generation virtual genome map.

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.BACKGROUND: The limited (2X) coverage of the tammar wallaby (Macropus eugenii) genome sequence dataset currently presents a challenge for assembly and anchoring onto chromosomes. To provide a framework for this assembly, it would be a great advantage to have a dense map of the tammar wallaby genome. However, only limited mapping data are available for this non-model species, comprising a physical map and a linkage map. RESULTS: We combined all available tammar wallaby mapping data to create a tammar wallaby integrated map, using the Location DataBase (LDB) strategy. This first-generation integrated map combines all available information from the second-generation tammar wallaby linkage map with 148 loci, and extensive FISH mapping data for 492 loci, especially for genes likely to be located at the ends of wallaby chromosomes or at evolutionary breakpoints inferred from comparative information. For loci whose positions are only approximately known, their location in the integrated map was refined on the basis of comparative information from opossum (Monodelphis domestica) and human. Interpolation of segments from the opossum and human assemblies into the integrated map enabled the subsequent construction of a tammar wallaby first-generation virtual genome map, which comprises 14336 markers, including 13783 genes recruited from opossum and human assemblies. Both maps are freely available at http://compldb.angis.org.au. CONCLUSIONS: The first-generation integrated map and the first-generation virtual genome map provide a backbone for the chromosome assembly of the tammar wallaby genome sequence. For example, 78% of the 10257 gene-scaffolds in the Ensembl annotation of the tammar wallaby genome sequence (including 10522 protein-coding genes) can now be given a chromosome location in the tammar wallaby virtual genome map.Peer Reviewe

Interpretable Modeling and Reduction of Unknown Errors in Mechanistic Operators

Prior knowledge about the imaging physics provides a mechanistic forward operator that plays an important role in image reconstruction, although myriad sources of possible errors in the operator could negatively impact the reconstruction solutions. In this work, we propose to embed the traditional mechanistic forward operator inside a neural function, and focus on modeling and correcting its unknown errors in an interpretable manner. This is achieved by a conditional generative model that transforms a given mechanistic operator with unknown errors, arising from a latent space of self-organizing clusters of potential sources of error generation. Once learned, the generative model can be used in place of a fixed forward operator in any traditional optimization-based reconstruction process where, together with the inverse solution, the error in prior mechanistic forward operator can be minimized and the potential source of error uncovered. We apply the presented method to the reconstruction of heart electrical potential from body surface potential. In controlled simulation experiments and in-vivo real data experiments, we demonstrate that the presented method allowed reduction of errors in the physics-based forward operator and thereby delivered inverse reconstruction of heart-surface potential with increased accuracy.Comment: 11 pages, Conference: Medical Image Computing and Computer Assisted Interventio

A comparative integrated gene-based linkage and locus ordering by linkage disequilibrium map for the Pacific white shrimp, Litopenaeus vannamei

The Pacific whiteleg shrimp, Litopenaeus vannamei, is the most farmed aquaculture species worldwide with global production exceeding 3 million tonnes annually. Litopenaeus vannamei has been the focus of many selective breeding programs aiming to improve growth and disease resistance. However, these have been based primarily on phenotypic measurements and omit potential gains by integrating genetic selection into existing breeding programs. Such integration of genetic information has been hindered by the limited available genomic resources, background genetic parameters and knowledge on the genetic architecture of commercial traits for L. vannamei. This study describes the development of a comprehensive set of genomic gene-based resources including the identification and validation of 234,452 putative single nucleotide polymorphisms in-silico, of which 8,967 high value SNPs were incorporatedm into a commercially available Illumina Infinium ShrimpLD-24 v1.0 genotyping array. A framework genetic linkage map was constructed and combined with locus ordering by disequilibrium methodology to generate an integrated genetic map containing 4,817 SNPs, which spanned a total of 4552.5 cM and covered an estimated 98.12% of the genome. These gene-based genomic resources will not only be valuable for identifying regions underlying important L. vannamei traits, but also as a foundational resource in comparative and genome assembly activities

A second-generation anchored genetic linkage map of the tammar wallaby (Macropus eugenii)

Background: \ud The tammar wallaby, Macropus eugenii, a small kangaroo used for decades for studies of reproduction and metabolism, is the model Australian marsupial for genome sequencing and genetic investigations. The production of a more comprehensive cytogenetically-anchored genetic linkage map will significantly contribute to the deciphering of the tammar wallaby genome. It has great value as a resource to identify novel genes and for comparative studies, and is vital for the ongoing genome sequence assembly and gene ordering in this species.\ud \ud Results: \ud A second-generation anchored tammar wallaby genetic linkage map has been constructed based on a total of 148 loci. The linkage map contains the original 64 loci included in the first-generation map, plus an additional 84 microsatellite loci that were chosen specifically to increase coverage and assist with the anchoring and orientation of linkage groups to chromosomes. These additional loci were derived from (a) sequenced BAC clones that had been previously mapped to tammar wallaby chromosomes by fluorescence in situ hybridization (FISH), (b) End sequence from BACs subsequently FISH-mapped to tammar wallaby chromosomes, and (c) tammar wallaby genes orthologous to opossum genes predicted to fill gaps in the tammar wallaby linkage map as well as three X-linked markers from a published study. Based on these 148 loci, eight linkage groups were formed. These linkage groups were assigned (via FISH-mapped markers) to all seven autosomes and the X chromosome. The sex-pooled map size is 1402.4 cM, which is estimated to provide 82.6% total coverage of the genome, with an average interval distance of 10.9 cM between adjacent markers. The overall ratio of female/male map length is 0.84, which is comparable to the ratio of 0.78 obtained for the first-generation map.\ud \ud Conclusions: \ud Construction of this second-generation genetic linkage map is a significant step towards complete coverage of the tammar wallaby genome and considerably extends that of the first-generation map. It will be a valuable resource for ongoing tammar wallaby genetic research and assembling the genome sequence. The sex-pooled map is available online at http://compldb.angis.org.au/