Institution
University of Hohenheim
Education•Stuttgart, Germany•
About: University of Hohenheim is a education organization based out in Stuttgart, Germany. It is known for research contribution in the topics: Population & Soil water. The organization has 8585 authors who have published 16406 publications receiving 567377 citations.
Papers published on a yearly basis
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TL;DR: CV with data from three QTL studies reported in the literature yielded similar results as those obtained with maize testcrosses, and is recommended for obtaining asymptotically unbiased estimates of p and consequently a realistic assessment of the prospects of MAS.
Abstract: Cross validation (CV) was used to analyze the effects of different environments and different genotypic samples on estimates of the proportion of genotypic variance explained by QTL (p). Testcrosses of 344 F(3) maize lines grown in four environments were evaluated for a number of agronomic traits. In each of 200 replicated CV runs, this data set was subdivided into an estimation set (ES) and various test sets (TS). ES were used to map QTL and estimate p for each run (p(ES)) and its median (p(ES)) across all runs. The bias of these estimates was assessed by comparison with the median (p(TS.ES)) obtained from TS. We also used two independent validation samples derived from the same cross for further comparison. The median p(ES) showed a large upward bias compared to p(TS.ES). Environmental sampling generally had a smaller effect on the bias of p(ES) than genotypic sampling or both factors simultaneously. In independent validation, p(TS.ES) was on average only 50% of p(ES). A wide range among p(ES) reflected a large sampling error of these estimates. QTL frequency distributions and comparison of estimated QTL effects indicated a low precision of QTL localization and an upward bias in the absolute values of estimated QTL effects from ES. CV with data from three QTL studies reported in the literature yielded similar results as those obtained with maize testcrosses. We therefore recommend CV for obtaining asymptotically unbiased estimates of p and consequently a realistic assessment of the prospects of MAS.
357 citations
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Beth Israel Deaconess Medical Center1, University of Hohenheim2, Broad Institute3, Icahn School of Medicine at Mount Sinai4, University of Oxford5, Vanderbilt University Medical Center6, University of Geneva7, Wellcome Trust Sanger Institute8, Harvard University9, University of Melbourne10, Baylor College of Medicine11, Boston Children's Hospital12, University of California, San Francisco13, National Institutes of Health14, Howard Hughes Medical Institute15, University of Washington16, University of Cambridge17
TL;DR: Progress is described in the study of human genetics, in which rapid advances in technology, foundational genomic resources and analytical tools have contributed to the understanding of the mechanisms responsible for many rare and common diseases and to preventative and therapeutic strategies for many of these conditions.
Abstract: A primary goal of human genetics is to identify DNA sequence variants that influence biomedical traits, particularly those related to the onset and progression of human disease. Over the past 25 years, progress in realizing this objective has been transformed by advances in technology, foundational genomic resources and analytical tools, and by access to vast amounts of genotype and phenotype data. Genetic discoveries have substantially improved our understanding of the mechanisms responsible for many rare and common diseases and driven development of novel preventative and therapeutic strategies. Medical innovation will increasingly focus on delivering care tailored to individual patterns of genetic predisposition.
356 citations
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TL;DR: Dusts blown into the Sahara-Sahel Dust Corridor from sub-Saharan Africa during the summer monsoon source from deeply chemically weathered terrains and are therefore likely to be more kaolinitic and stripped of mobile elements, but retain immobile and resistant elements.
355 citations
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TL;DR: This work has shown that the utilization of soil nutrients may depend more on efficient uptake of phosphate, nitrate, and ammonium from the soil solution even at low supply concentrations than on mobilization processes in the hyphosphere.
Abstract: Colonization of plant roots by arbuscular mycorrhizal fungi can greatly increase the plant uptake of phosphorus and nitrogen. The most prominent contribution of arbuscular mycorrhizal fungi to plant growth is due to uptake of nutrients by extraradical mycorrhizal hyphae. Quantification of hyphal nutrient uptake has become possible by the use of soil boxes with separated growing zones for roots and hyphae. Many (but not all) tested fungal isolates increased phosphorus and nitrogen uptake of the plant by absorbing phosphate, ammonium, and nitrate from soil. However, compared with the nutrient demand of the plant for growth, the contribution of arbuscular mycorrhizal fungi to plant phosphorus uptake is usually much larger than the contribution to plant nitrogen uptake. The utilization of soil nutrients may depend more on efficient uptake of phosphate, nitrate, and ammonium from the soil solution even at low supply concentrations than on mobilization processes in the hyphosphere. In contrast to ectomy...
352 citations
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TL;DR: In vivo studies with transgenic plants expressing FTs showed fructan accumulation and an associated improvement in freezing and/or chilling tolerance, suggesting the water-soluble nature of fructans may allow their rapid adaptation as cryoprotectants in order to give optimal membrane protection.
Abstract: Plants are sessile and sensitive organisms known to possess various regulatory mechanisms for defending themselves under stress environments. Fructans are fructose-based polymers synthesized from sucrose by fructosyltransferases (FTs). They have been increasingly recognized as protective agents against abiotic stresses. Using model membranes, numerous in vitro studies have demonstrated that fructans can stabilize membranes by direct H-bonding to the phosphate and choline groups of membrane lipids, resulting in a reduced water outflow from the dry membranes. Inulin-type fructans are flexible random-coiled structures that can adopt many conformations, allowing them to insert deeply within the membranes. The devitrification temperature (Tg) can be adjusted by their varying molecular weights. In addition, above Tg their low crystallization rates ensure prolonged membrane protection. Supporting, in vivo studies with transgenic plants expressing FTs showed fructan accumulation and an associated improvement in freezing and/or chilling tolerance. The water-soluble nature of fructans may allow their rapid adaptation as cryoprotectants in order to give optimal membrane protection. One of the emerging concepts for delivering vacuolar fructans to the extracellular space for protecting the plasma membrane is vesicle-mediated, tonoplast-derived exocytosis. It should, however, be noted that natural stress tolerance is a very complex process that cannot be explained by the action of a single molecule or mechanism.
352 citations
Authors
Showing all 8665 results
Name | H-index | Papers | Citations |
---|---|---|---|
Robert J. Lefkowitz | 214 | 860 | 147995 |
Patrick O. Brown | 183 | 755 | 200985 |
Mark Stitt | 132 | 456 | 60800 |
Wolf B. Frommer | 105 | 345 | 30918 |
Muhammad Imran | 94 | 3053 | 51728 |
Muhammad Farooq | 92 | 1341 | 37533 |
Yakov Kuzyakov | 87 | 667 | 37050 |
Werner Goebel | 85 | 367 | 26106 |
Ismail Cakmak | 84 | 249 | 25991 |
Reinhold Carle | 84 | 418 | 24858 |
Michael Wink | 83 | 938 | 32658 |
Albrecht E. Melchinger | 83 | 398 | 23140 |
Tilman Grune | 82 | 479 | 30327 |
Volker Römheld | 79 | 231 | 20763 |
Klaus Becker | 79 | 320 | 27494 |