Institution
Texas A&M University
Education•College Station, Texas, United States•
About: Texas A&M University is a education organization based out in College Station, Texas, United States. It is known for research contribution in the topics: Population & Finite element method. The organization has 72169 authors who have published 164372 publications receiving 5764236 citations.
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TL;DR: Understanding mechanisms of abiotic stress tolerance in endophyte-infected grasses is essential for continued improvement and persistence of grasses for a range of applications, e.g., forage for semi-arid areas or cover plants for soil renovation.
Abstract: Cool-season grasses infected with Neotyphodium spp. endophytes have an extraordinary impact on the ecology and economy of pasture and turf. A range of adaptations of endophyte-infected grasses to biotic and abiotic stresses has been identified but mechanisms of these adaptations are not clearly understood. In this review, we present recent research progress on endophyte-related mechanisms affecting abiotic (drought, mineral) and selected aspects of biotic stress tolerance in cool-season grasses. Endophytes induce mechanisms of drought avoidance (morphological adaptations), drought tolerance (physiological and biochemical adaptations), and drought recovery in infected grasses. Mineral nutrition (nitrogen, phosphorus, calcium) affects production of ergot alkaloids, thus understanding mechanisms involved in mineral economy of endophyte-infected grasses will help in developing management practices to reduce forage toxicity to livestock. Previous research resolved the role of endophyte in nitrogen (N) economy of tall fescue. We identified two endophyte-related mechanisms in tall fescue operating in response to phosphorus (P) deficiency. The mechanisms are altered root morphology (reduced root diameters and longer root hairs) and chemical modification of the rhizosphere resulting from exudation of phenolic-like compounds. These mechanisms were shown to benefit endophyte-infected plants grown under P deficiency. We also report a mechanism of aluminum (Al) sequestration on root surfaces in endophyte-infected tall fescue, which appears to be related to exudation of phenolic-like compounds with Al-chelating activity. Understanding mechanisms of abiotic stress tolerance in endophyte-infected grasses is essential for continued improvement and persistence of grasses for a range of applications, e.g., forage for semi-arid areas or cover plants for soil renovation.
741 citations
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University of Potsdam1, Université Paris-Saclay2, Purdue University3, Japan Agency for Marine-Earth Science and Technology4, University of California, Berkeley5, University of Southern California6, Pennsylvania State University7, Northwestern University8, Columbia University9, University of Nantes10, University of Washington11, Technische Universität München12, California Institute of Technology13, University of Colorado Boulder14, Texas A&M University15, ETH Zurich16
TL;DR: In this paper, the authors review the factors and processes that are known to influence the hydrogen-isotopic compositions of lipids from photosynthesizing organisms, and provide a framework for interpreting their D/H ratios from ancient sediments and identify future research opportunities.
Abstract: Hydrogen-isotopic abundances of lipid biomarkers are emerging as important proxies in the study of ancient environments and ecosystems. A decade ago, pioneering studies made use of new analytical methods and demonstrated that the hydrogen-isotopic composition of individual lipids from aquatic and terrestrial organisms can be related to the composition of their growth (i.e., environmental) water. Subsequently, compound-specific deuterium/hydrogen (D/H) ratios of sedimentary biomarkers have been increasingly used as paleohydrological proxies over a range of geological timescales. Isotopic fractionation observed between hydrogen in environmental water and hydrogen in lipids, however, is sensitive to biochemical, physiological, and environmental influences on the composition of hydrogen available for biosynthesis in cells. Here we review the factors and processes that are known to influence the hydrogen-isotopic compositions of lipids-especially n-alkanes-from photosynthesizing organisms, and we provide a framework for interpreting their D/H ratios from ancient sediments and identify future research opportunities.
740 citations
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TL;DR: This work has shown that on a surface, the formation of a heteronuclear metal-metal bond induces a flow of electron density toward the element with the larger fraction of empty states in its valence band, which is completely contrary to that observed in bulk alloys.
Abstract: The formation of a surface metal-metal bond can produce large perturbations in the electronic, chemical, and catalytic properties of a metal. Recent studies indicate that charge transfer is an important component in surface metal-metal bonds that involve dissimilar elements. The larger the charge transfer, the stronger the cohesive energy of the bimetallic bond. On a surface, the formation of a heteronuclear metal-metal bond induces a flow of electron density toward the element with the larger fraction of empty states in its valence band. This behavior is completely contrary to that observed in bulk alloys, indicating that the nature of a heteronuclear metal-metal bond depends strongly on the structural geometry of the bimetallic system.
740 citations
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TL;DR: In this article, an amended low-latitude (tropical and subtropical) Cenozoic planktonic foraminiferal zonation is presented, based on the first appearance dates of Globigerinatheka kugleri and Hantkenina singanoae.
739 citations
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TL;DR: In the last decade, there has been a great deal of correlational research on the relationships between perceived role ambiguity and role conflict and a host of hypothesized antecedents (such as tenure, formalization, boundary spanning) and consequences as discussed by the authors.
Abstract: The correlational literature concerning the relationships of role conflict and ambiguity to numerous hypothesized antecedents and consequences is still somewhat unclear after a decade of research Schmidt-Hunter meta-analysis procedures were applied to the results of 43 past studies in an effort to draw valid conclusions about the magnitude and direction of these relationships in the population For some correlates, apparently inconsistent research results could be ascribed largely to statistical artifacts. For other correlates, it seems that moderator research may be needed to explain conflicting results across samples In the last 12 years, there has been a great deal of correlational research on the relationships between perceived role ambiguity and role conflict and a host of hypothesized antecedents (such as tenure, formalization, boundary spanning) and consequences (such as job satisfaction, job involvement, performance, tension, propensity to leave the job). Although nearly all studies have been crosssectional, one laboratory study did find that role conflict caused a host of dysfunctional affective and behavioral outcomes (Manning, Ismail, & Sherwood, 1981) Thus, the consequences of these two types of role stress have potentially important cost implications for organizations. Whereas the costs of turnover and substandard performance are obvious, the true cost of attitudinal variables is just beginning to be understood (Cascio, 1982; Mirvis & Lawler, 1977). Therefore, efforts to obtain a better understanding of role conflict, role ambiguity, and their correlates are certainly justified.
739 citations
Authors
Showing all 72708 results
Name | H-index | Papers | Citations |
---|---|---|---|
Yi Chen | 217 | 4342 | 293080 |
Scott M. Grundy | 187 | 841 | 231821 |
Evan E. Eichler | 170 | 567 | 150409 |
Yang Yang | 164 | 2704 | 144071 |
Martin Karplus | 163 | 831 | 138492 |
Robert Stone | 160 | 1756 | 167901 |
Philip Cohen | 154 | 555 | 110856 |
Claude Bouchard | 153 | 1076 | 115307 |
Jongmin Lee | 150 | 2257 | 134772 |
Zhenwei Yang | 150 | 956 | 109344 |
Vivek Sharma | 150 | 3030 | 136228 |
Frede Blaabjerg | 147 | 2161 | 112017 |
Steven L. Salzberg | 147 | 407 | 231756 |
Mikhail D. Lukin | 146 | 606 | 81034 |
John F. Hartwig | 145 | 714 | 66472 |