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Metabolomic analysis of longissimus from underperforming piglets relative to piglets with normal preweaning growth

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Journal of Animal science and Biotechnology 2018年第3期9卷 630-638页

作者： Timothy G.Ramsay Margo J.stoll Amy E.shannon Le Ann Blomberg Animal Biosciences and Biotechnology Laboratory U.S.Department of Agriculture Agricultural Research Service

Background: Recent increases in intra-litter variability in weaning weight have raised swine production costs. A contributor to this variability is the normal birth weight pig that grows at a slower rate than littermates of similar birth weight. The goal of this study was to interrogate biochemical profiles manifested in skeletal muscle originating from slow growing(sG) and faster growing littermates(control), with the aim of identifying differences in metabolic pathway utilization between skeletal muscle of the sG pig relative to its littermates. samples of longissimus muscle from littermate pairs of pigs were collected at 21 d of age for metabolomic ***: Birth weights did not differ between littermate pairs of sG and Control pigs(P > 0.05). Weaning weights differed by 1.51 ± 0.19 kg(P st(RF) analysis was effective at segregating the metabolome of muscle samples by growth rate, resulting in a predictive accuracy of 81% versus random segregation(50%).Decreases in sugars in the pentose phosphate pathway(PPP) in the longissimus of sG pigs were detected(P ses were also apparent in glycolytic intermediates(glycerol-3-phosphate and lactate) and key glycolysis-derived intermediates(glucose-6-phosphate and fructose-6-phosphate; P sG pigs had increased levels of phospholipids, lysolipids, diacylglycerols, and sphingolipids(P sis identified a cluster of molecules associated with muscle and collagen/extracellular matrix breakdown that are increased in the sG pig(glutamate, 3-methylhistidine and hydroxylated proline moieties; P sm was altered in sG pigs, resulting in a 78% decrease in the nicotinamide adenine dinucleotide pool(P usions: These metabolomic data provide the first evidence for biochemical mechanisms that should be investigated to determine if they have a potential role in the slow growth in some normal birth weight piglets that contribute to inc

关键词： Growth rate Longissimus Metabolome Neonate swine

Flow near a model spur dike with a fixed scoured bed

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International Journal of sediment Research 2013年第3期28卷 349-357页

作者： Roger KuHNLE Carlos ALONsO National sedimentation Laboratory U.S.Department of AgricultureAgricultural Research Service

Three-dimensional flow velocities were measured using an acoustic Doppler velocimeter at a closely spaced grid over a fixed scoured bed with a submerged spur ***-dimensional flow velocities were measured at 3,484 positions around the trapezoidal shaped submerged model spur *** velocity distributions and detailed near field flow structures were revealed by the *** differences were revealed between flow over fixed flat and scoured *** lateral flows were the dominant cause of the observed local *** stresses were higher for the scoured bed than in the flat bed *** rates of scour as the scour hole developed were attributed to increases in critical shear stress in the scour holes caused by the increase in the length and magnitude of adverse slopes associated with the two main scour holes.

关键词： submerged spur dike 3-dimensional flow Velocity measurements Free surface flow Hydraulic structure

Genetic characterization of melon accessions in the u.s. National Plant Germplasm system and construction of a melon core collection

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Molecular Horticulture 2021年第1期1卷 72-84页

作者： Xin Wang Kaori Ando shan Wu umesh K.Reddy Prabin Tamang Kan Bao sue A.Hammar Rebecca Grumet James D.McCreight Zhangjun Fei Boyce Thompson Institute Cornell UniversityIthacaNY 14853USA u.s.department of agriculture-Agricultural Research service Crop Improvement and Protection Research UnitSalinasCA 93905USA Nunhems usA IncAcampoCA 95220USA Gus R.Douglass Institute and department of Biology West Virginia State UniversityInstituteWV 25112USA u.s.department of agriculture-Agricultural Research service Natural Products Utilization Research UnitThad Cochran Research CenterP.O.Box 1848OxfordMS 38677USA department of Horticulture Michigan State UniversityEast LansingMI 48824USA u.s.department of agriculture-Agricultural Research service Robert W.Holley Center for Agriculture and HealthIthacaNY 14853USA.

Melon(*** L.)is an economically important vegetable crop cultivated *** melon collection in the *** Plant Germplasm system(NPGs)is a valuable resource to conserve natural genetic diversity and provide novel traits for melon *** we use the genotyping-by-sequencing(GBs)technology to characterize 2083 melon accessions in the NPGs collected from major melon production areas as well as regions where primitive melons *** structure and genetic diversity analyses suggested that *** *** was firstly introduced from the centers of origin,Indian and Pakistan,to Central and West Asia,and then brought to Europe and *** *** from East Asia was likely derived from *** *** in India and Pakistan and displayed a distinct genetic background compared to the rest of *** accessions from other geographic *** developed a core collection of 383 accessions capturing more than 98%of genetic variation in the germplasm,providing a publicly accessible collection for future research and genomics-assisted breeding of ***-five morphological characters investigated in the core collection indicated high variability of these characters across accessions in the ***-wide association studies using the core collection panel identified potentially associated genome regions related to fruit quality and other horticultural *** study provides insights into melon origin and domestication,and the constructed core collection and identified genome loci potentially associated with important traits provide valuable resources for future melon research and breeding.

关键词： Melon C.melo Germplasm Genetic characterization Core collection Genome-wide association study

sensing grain and seed moisture and density from dielectric properties

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International Journal of Agricultural and Biological Engineering 2011年第1期4卷 75-81页

作者： stuart O.Nelson D.sc.samir Trabelsi u.s.department of agriculture Agricultural Research ServiceRussell Research CenterAthensGeorgiaU.S.A.

The importance of moisture measurement in grain and seed is discussed,and a brief history of the development of moisture sensing instruments,based on sensing of dielectric properties of these materials,is *** are presented graphically on the permittivities or dielectric properties of grain and seed showing their variation with frequency,moisture content,temperature,and bulk density,and references are cited for further *** recent developments on microwave measurements for moisture content and bulk density sensing are briefly described,and numerous studies are cited providing sources of information on these newer techniques.

关键词： sensing dielectric properties moisture content density permittivity cereal grain oilseed

Male Burmese pythons follow female scent trails and show sex-specific behaviors

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Integrative Zoology 2019年第5期14卷 460-469页

作者： shannon A.RICHARD Eric A.TILLMAN John s.HuMPHREY Michael L.AVERY M.Rockwell PARKER department of Biology James Madison UniversityHarrisonburgVirginiaUSA National Wildlife Research Center Florida Field StationU.S.Department of AgricultureGainesvilleFloridaUSA

Animals communicate with potential mates using species-specific signals,and pheromones are powerful sexual signals that modify conspecific behavior to facilitate mate *** the vertebrates,snakes are especially adept in mate searching via chemical trailing,which is particularly relevant given that many snake species are invasive outside their native *** signals used in mate choice are,thus,potentially valuable tools for management of invasive snake *** Burmese python(Python bivittatus)is an invasive snake in the Florida Everglades where it is negatively impacting native *** this study,we sought to:(i)determine if males can follow conspecific chemical trails in a Y-maze;and(ii)describe the mate searching behaviors exhibited by males while *** males consistently followed a single female scent trail in the maze,but when only a male scent trail was present they did not discriminate between the male and blank *** of tongue-flicking,a proxy for chemosensory sampling,was also marginally higher when males were following female versus male scent ***,when both female and male scent trails were simultaneously present in the Y-maze,males did not show a preference for the female arm,although the tongue-flick rate was higher in the female-only trial compared to female versus *** of multiple male behaviors individually and using an ethogram revealed that behaviors were more frequent and complex in the female-only trials compared to male-only *** behavioral trials are needed to determine if an effective pheromonal approach to Burmese python management is possible.

关键词： chemical ecology invasive species pheromone snake trailing

Elevated temperature intensity,timing,and duration of exposure affect soybean internode elongation,mainstem node number,and pod number per plant

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The Crop Journal 2018年第2期6卷 148-161页

作者： Leon Hartwell Allen Jr. Lingxiao Zhang Kenneth J.Boote Bernard A.Hauser u.s.department of agriculture-Agricultural Research service GainesvilleFL 32608USA department of Agronomy University of FloridaGainesvilleFL 32611USA department of Biology University of FloridaGainesvilleFL 32611USA

A study was conducted in four compartments of a polycarbonate greenhouse at Gainesville,FL, usA to investigate how a soybean(Glycine max L. Merr.) cultivar, Maverick(maturity group III, indeterminate), responded to three elevated temperatures, ELT,(day/night of 34/26 °C, 38/30 °C, and 42/34 °C) in comparison to a control growth temperature(30/22 °C).Carbon dioxide(CO_2) concentration was maintained at 700 μmol mol^(-1) in each compartment by a processor controlled air-sampling and CO_2-injection system. Three sequential experiments were conducted at different times of year(summer, autumn, and early spring)to investigate the effect of intensity, timing, and duration of ELT on soybean node number,internode elongation, mainstem length, and number of pods set per plant. At the control temperature, the soybean plants grown in the polycarbonate greenhouse were taller than field-grown plants. When plants were grown under continuous ELT applied soon after sowing or at initial flowering, the number of nodes increased with increasing ELT intensity,whereas the length of individual internodes decreased. When ELT treatment was applied during the beginning of flowering stage(R1–R2) or earlier, more nodes were produced and the length of affected internodes was decreased. When the ELT was imposed later at reproductive stage R5+ just before the beginning of seed filling, effects on node numbers and internode lengths were negligible. short-term(10-day) duration of ELT applied at four stages from V3 to R5+ did not significantly affect final mean numbers of nodes or mean mainstem lengths. Possible mechanisms of elevated temperature effects on soybean internode elongation and node number(internode number) are discussed. Total pod numbers per plant increased linearly with mainstem node numbers and mainstem ***, total pod numbers per plant were greatest at 34/26 °C rather than at the control temperature of 30/22 °C(and remained high at 38/30 °C). Mild increases in temperatu

关键词： Elevated temperature Internode elongation Node number Pod yield soybean phenology

Large-scale forest inventories of the united states and China reveal positive effects of biodiversity on productivity

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Forest Ecosystems 2015年第4期2卷 272-287页

作者： James V Watson Jingjing Liang Patrick C Tobin Xiangdong Lei James s Rentch Catherine E Artis Davis College of agriculture Natural Resources and DesignWest Virginia University Forest service U.S.Department of AgricultureNorthern Research Station school of Environmental and Forest sciences University of Washington Research Institute of Forest Resource Information Techniques Chinese Academy of Forestry

Background： With the loss of species worldwide due to anthropogenic factors, especially in forested ecosystems, it has become more urgent than ever to understand the biodiversity-ecosystem functioning relationship （BEFR）. BEFR research in forested ecosystems is very limited and thus studies that incorporate greater geographic coverage and structural complexity are needed. Methods： We compiled ground-measured data from approx, one half million forest inventory sample plots across the contiguous united states, Alaska, and northeastern China to map tree species richness, forest stocking, and productivity at a continental scale. Based on these data, we investigated the relationship between forest productivity and tree species diversity, using a multiple regression analysis and a non-parametric approach to account for spatial autocorrelation. Results： In general, forests in the eastern united states consisted of more tree species than any other regions in the country. The highest forest stocking values over the entire study area were concentrated in the western united states and Central Appalachia. Overall, 96.4 % of sample plots （477,281） showed a significant positive effect of species richness on site productivity, and only 3.6 % （17,349） had an insignificant or negative effect. Conclusions： The large number of ground-measured plots, as well as the magnitude of geographic scale, rendered overwhelming evidence in support of a positive BEFR. This empirical evidence provides insights to forest management and biological conservation across different types of forested ecosystems. Forest timber productivity may be impaired by the loss of species in forests, and biological conservation, due to its potential benefits on maintaining species richness and productivity, can have profound impacts on the functioning and services of forested ecosystems.

关键词： Tree species diversity Forest management Biological conservation Continental map of forest diversity spatial autocorrelation Bootstrap

Ecohydrological processes and ecosystem services in the Anthropocene: a review

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Ecological Processes 2017年第1期6卷 364-372页

作者： Ge sun Dennis Hallema Heidi Asbjornsen Eastern Forest Environmental Threat Assessment Center Southern Research StationU.S.Department of Agriculture Forest Service920 Main Campus Dr.Suite 300RaleighNC 27606USA Oak Ridge Institute for science and Education U.S.Department of EnergyOak RidgeTN 37830USA Institute for the study of Earth Oceansand SpaceUniversity of New HampshireDurhamNHUSA

The framework for ecosystem services has been increasingly used in integrated watershed ecosystem management practices that involve scientists,engineers,managers,and policy *** objective of this review is to explore the intimate connections between ecohydrological processes and water-related ecosystem services in human-dominated ecosystems in the *** synthesize current literature to illustrate the importance of understanding the ecohydrological processes for accurately quantifying ecosystem services under different environmental and socioeconomic settings and *** synthesis focuses on managed ecosystems that are dominated by humans and explores how ecological processes affect the tradeoffs and synergies of multiple ecosystem *** identify research gaps in studying ecological processes mainly including energy,carbon,water,and nutrient balances to better assess and quantify ecosystem services that are critical for sustaining natural resources for future *** better assess ecosystem services,future ecohydrological studies need to better account for the scaling effects of natural and anthropogenic stressors exerted on evapotranspiration and other water supply and demand *** studies should focus on the bidirectional interactions between hydrological functions and services and human actions to solve real world problems such as water shortages,ecological degradation,and climate change adaptation.

关键词： watershed services ecosystem

Magnetocaloric effect of Pr_2Fe_(17-x)Mn_x alloys

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Rare Metals 2014年第5期33卷 552-555页

作者： Xi-Chun Zhong Zhong-Wu Liu De-Chang Zeng Karl A.Gschneidner Jr. Vitalij K.Pecharsky school of Materials science and Engineering South China University of Technology Ames Laboratory U.S.Department of Energy and Department of Materials Science and Engineering Iowa State University

Polycrystalline Pr2Fe17-xMnx（x = 0, 1, and 2）alloys were studied by X-ray diffraction（XRD）, heat capacity, ac susceptibility, and isothermal magnetization measurements. All the alloys adopt the rhombohedral Th2Zn17-type structure. The Curie temperature increases from 283 K at x = 0 to 294 K at x = 1, and then decreases to 285 K at x = 2. The magnetic phase transition at the Curie temperature is a typical second-order paramagnetic–ferromagnetic transition. For an applied field change from0 to 5 T, the maximum-△sM for Pr2Fe17-xMnxalloys with x = 0, 1, and 2 are 5.66, 5.07, and 4.31 J·kg^-1·K^-1,respectively. The refrigerant capacity（RC） values range from 458 to 364 J·kg^-1, which is about 70 %–89 % that of Gd. The large, near room temperature △sM and RC values,chemical stability, and a high performance-to-cost ratio make Pr2Fe17-xMnxalloys be selectable materials for room temperature magnetic refrigeration applications.

关键词： Pr2Fe17-xMnx alloys Magnetocaloric effect Magnetic entropy change