55 research outputs found

    The USDA Barley Core Collection:Genetic Diversity, Population Structure, and Potential for Genome-Wide Association Studies

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    New sources of genetic diversity must be incorporated into plant breeding programs if they are to continue increasing grain yield and quality, and tolerance to abiotic and biotic stresses. Germplasm collections provide a source of genetic and phenotypic diversity, but characterization of these resources is required to increase their utility for breeding programs. We used a barley SNP iSelect platform with 7,842 SNPs to genotype 2,417 barley accessions sampled from the USDA National Small Grains Collection of 33,176 accessions. Most of the accessions in this core collection are categorized as landraces or cultivars/breeding lines and were obtained from more than 100 countries. Both STRUCTURE and principal component analysis identified five major subpopulations within the core collection, mainly differentiated by geographical origin and spike row number (an inflorescence architecture trait). Different patterns of linkage disequilibrium (LD) were found across the barley genome and many regions of high LD contained traits involved in domestication and breeding selection. The genotype data were used to define 'mini-core' sets of accessions capturing the majority of the allelic diversity present in the core collection. These 'mini-core' sets can be used for evaluating traits that are difficult or expensive to score. Genome-wide association studies (GWAS) of 'hull cover', 'spike row number', and 'heading date' demonstrate the utility of the core collection for locating genetic factors determining important phenotypes. The GWAS results were referenced to a new barley consensus map containing 5,665 SNPs. Our results demonstrate that GWAS and high-density SNP genotyping are effective tools for plant breeders interested in accessing genetic diversity in large germplasm collections

    Do board secretaries influence management earnings forecasts?

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    The role of board secretaries is a unique institutional feature in China. Individuals in this senior executive role are responsible for coordinating information disclosure. We study the impact of board secretaries on management earnings forecasts and find that their legal expertise, accounting expertise and foreign experience help improve management earnings forecast quality. The quality of forecasts, as indicated by their occurrence, frequency, precision and accuracy, is also positively associated with the role duality (e.g. board director, CFO or other senior executive role) and equity holdings of board secretaries and negatively associated with their political connection. The quality of forecasts is found to increase the compensation of board secretaries. Finally, we show that the equity holding of board secretaries reduces litigation risks and increases corporate philanthropic giving

    The cold-shock response in mammalian cells: investigating the HeLa cell cold-shock proteome

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    In recent years there have been a number of reports that suggest the sub-physiological (< 37 degrees C) temperature in vitro culturing of mammalian cells can result in enhanced heterologous protein production. Despite these reports, the mechanisms by which mammalian cells respond to such conditions are largely unknown. We therefore set out to use a model in vitro culture HeLa cell system to begin investigating the cold-shock response in mammalian cell systems. Sub-physiological temperature cultivation resulted in reduced growth and proliferation and a lower total cell protein content. Proteomic analysis confirmed that HeLa cells actively respond to sub-physiological temperature by up-regulating a number of proteins and immunoblot analysis confirmed that specific proteins are indeed up-regulated in a time and temperature dependent manner. Additional work is likely to improve our understanding of the cold-shock response in mammalian cells and identify candidate target proteins for cell engineering to further enhance heterologous protein production at sub-physiological temperatures

    Multicenter Study of Robotic Thyroidectomy: Short-Term Postoperative Outcomes and Surgeon Ergonomic Considerations

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    BACKGROUND: Robotic thyroidectomy (RT) has recently emerged as a viable approach to thyroid surgery, resulting in better functional and cosmetic outcomes than afforded by open thyroidectomy (OT). The present multicenter study assessed the perioperative outcomes of RT and compared physician perspectives on the musculoskeletal ergonomic parameters associated with OT, endoscopic thyroidectomy (ET), and RT. MATERIALS AND METHODS: We reviewed the medical records of 2014 consecutive patients who underwent RT, conducted by 7 surgeons, at 4 centers between October 2007 and June 2010. Patient characteristics, perioperative clinical results, complications, and pathologic outcomes were analyzed. Moreover, surgeons were surveyed to gather data on musculoskeletal discomfort experienced during OT, ET, and RT. RESULTS: Of the 2014 patients, 740 underwent total and 1274 subtotal thyroidectomy. Mean tumor diameter was 0.8 cm, and the mean number of retrieved central lymph nodes was 4.5 ± 3.9 (range 0-28). The rates of permanent recurrent laryngeal nerve injury and permanent hypocalcemia were 0.4 and 0.05%, respectively. Neck and/or back pain after OT, ET, and RT was experienced by 100, 85.7, and 28.6% of surgeons, respectively. When surgeons ranked the operative approaches in decreasing order of associated pain, 57.1% indicated ET > OT > RT, 28.6% selected OT > ET > RT, and 14.3% responded ET > RT > OT. CONCLUSION: RT is a feasible and safe procedure that may facilitate radical cervical lymph node dissection. Moreover, for surgeons, the RT resulted in less musculoskeletal discomfort than did OT or ET. A larger prospective study, with a longer follow-up, is needed to determine whether RT offers real benefits for both patients and surgeons
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