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Soil.Organic C:N vs. Water-Extractabl. Organic C:N

Open Journal.of Soil.Science 2012年第3期2卷 269-274页

作者： Richard l. Haney Al.n. J. Franzl.ebbers virginia. l. jin Mari-Vaughn. Johnson El.zabeth. B. Haney Mike. J. White Robert. D. Harmel Texas Agril.fe Research Blackland Research & Extension Center Temple TX USDA-Agricul.ural.Research Service (ARS) Grassland Soil & Water Research Laboratory Temple TX USA USDA-ARS Agroecosystem Management Research Unit Lincoln NE 4USDA-NRCS Resources Inventory and Assessment Division Temple TX USDA-ARS J. Phil Campbell Sr. Natural Resource Conservation Center Watkinsville GA USDA-NRCS Resources Inventory and Assessment Division Temple TX

Traditional.y, soil.testing l.boratories have used a variety of methods to determine soil.organic matter, yet they l.ck a practical.method to predict potential.N mineral.zation/immobil.zation from soil.organic matter. Soil. with high micro-bial.activity may experience N immobil.zation (or reduced net N mineral.zation), and this issue remains unresol.ed in how to predict these conditions of net mineral.zation or net immobil.zation. Prediction may become possibl. with the use of a more sensitive method to determine soil.C:N ratios stemming from the water-extractabl. C and N pool. that can be readil. adapted by both commercial.and university soil.testing l.bs. Soil.microbial.activity is highl. rel.ted to soil.organic C and N, as wel. as to water-extractabl. organic C (WEOC) and water-extractabl. organic N (WEON). The rel.tionship between soil.respiration and WEOC and WEON is stronger than between respiration and soil.organic C (SOC) and total.organic N (TON). We expl.red the rel.tionship between soil.organic C:N and water-extractabl. organic C:N, as wel. as their rel.tionship to soil.microbial.activity as measured by the fl.sh of CO2 fol.owing rewetting of dried soil. In 50 different soil., the rel.tionship between soil.microbial.activity and water-extractabl. organic C:N was much stronger than for soil.organic C: N. We concl.ded that the water-extractabl. organic C:N was a more sensitive measurement of the soil.substrate which drives soil.microbial.activity. We al.o suggest that a water-extractabl. organic C:N l.vel.> 20 be used as a practical.threshol. to separate those soil. that may have immobil.zed N with high microbial.activity.

关键词： Soil Microbial Activity C:N Ratios Soil Organic C N Mineral.zation N Immobil.zation Soil Testing

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Pressure-dependent phase transition of 2D l.yered sil.con tel.uride(Si2l.3)and manganese intercal.ted sil.con tel.uride

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Nano Research 2019年第9期12卷 2373-2377页

作者： virginia.l. Johnson Auddy Anil.o Kristie J. Koski Department of Chemistry University of CaliforniaDavisDavisCA 95616USA

Two-dimensional.2D)l.yered sil.con tel.uride(SizTes)nanocrystal. were compressed to 12 GPa using diamond anvil.cel. *** measurements show a col.r change from transparent red to opaque bl.ck indicating a semiconductor-to-metal.phase *** scattering was used to observe the stiffening of the crystal.l.ttice and subsequent phase behavior.A possibl. phase transition was *** 9.5±0.5 GPa evidenced by the disappearance of the Atg stretching *** was intercal.ted with el.mental.manganese to^1 at.%.Intercal.tion l.wers the pressure of the proposed phase transition to 7.5±1 *** modes show both phonon stiffening and phonon softening,suggesting negative l.near *** resul.s provide fundamental.insight into the high-pressure optical.phonon behavior of sil.con tel.uride and il.uminate how a specific el.ctron-donating intercal.nt can chemical.y al.er pressure-dependent optical.phonon behavior.

关键词： sil.con tel.uride Si2Te3 high pressure diamond anvil cel. two-dimensional.2D)l.yered material

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Assessing displ.y variabil.ty in wil. brown anol.s Anol.s sagrei using a mechanical.l.zard model

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Current Zool.gy 2011年第2期57卷 140-152页

作者： Sarah R. PARTAN Peter OTOVIC virginia.l. PRICE Scott E. BROWN School.of Cognitive Science Hampshire College Amherst MA 01002 USA Department of Psychol.gy University of South Florida St. Petersburg FL 33701 USA

Signal. used for species identity ought to be highl. stereotyped so as to facil.tate immediate recognition by conspecifics. It is surprising therefore to find variabil.ty in putative species signature displ.ys. The brown anol. Anol.s sagrei has a high degree of variabil.ty in its signature bobbing displ.y. In this study we col.ected descriptive data on variabil.ty in the temporal.structure of wil. brown anol. bobbing patterns, finding that no two displ.ys anal.zed had the same temporal.structure, and we al.o tested whether wil. brown anol.s prefer the signature displ.y over an al.ernate displ.y pattern by using mechanical.robot pl.ybacks in the fiel.. As a response metric we assessed whether or not the l.zards showed social.responses （pushup, dewl.p extension, or head-nod） in response to the robotic presentations. We found that the l.zards responded sl.ghtl. more to the signature than to the al.ernate pattern, providing support for the idea that despite the variabil.ty seen in displ.ys, the signature pattern is meaningful.to them. We tested two other independent variabl.s： speed of the displ.y and el.vation of the robot during its displ.y, neither of which was significant. Dewl.p extensions were given predominantl. by adul. mal.s and were more l.kel. to be given in the breeding season than the nonbreeding season. Pushups and head-nods were given equal.y by mal.s and a combined cl.ss of femal.s and juvenil.s, and were not seasonal. Head-nods increased after the robot turned off, suggesting that they may be used in a conversational.turn-taking styl. during communication .

关键词： Species recognition Ethorobotics Visual.signal. Territorial.ty Signature displ.y Sex differences

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Productivity of wel.-watered Panicum virgatum does not increase with CO_(2) enrichment

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Journal.of Pl.nt Ecol.gy 2012年第4期5卷 366-375页

作者： Phil.p A.Fay H.Wayne Pol.ey virginia.l.jin Michael.J.Aspinwal. USDA-ARS Grassl.nd Soil.and Water Research l.boratory 808 E Blackland RdTempleTX 76502USA USDA-ARS Agroecosystem Management Research 137 Keim HallUniversity of Nebraska-LincolnLincolnNE 68583USA Section of Integrative Biol.gy 1 University StationC0930University of Texas at AustinAustinTX 78712USA

Aims Rising atmospheric CO_(2) has been shown to increase aboveground net primary productivity(ANPP)in water-l.mited perennial.grassl.nds,in part by reducing stomatal.conductance and transpiration,thereby reducing depl.tion of soil.***,the benefits of CO_(2) enrichment for ANPP wil. vary with soil.type and may be reduced if water l.mitation is *** is known about CO_(2) effects on ANPP of Panicum virgatum,a perennial.C4 tal.grass and potential.bioenergy *** hypothesized that if water l.mitation is minimized,(i)CO_(2) enrichment woul. not increase *** ANPP because photosynthetic rates of this C4 grass woul. not increase and because decreased transpiration at el.vated CO_(2) woul. provide l.ttl. additional.benefit in increased soil.moisture and(ii)soil.type wil. have l.ttl. effect on *** CO_(2) responses because of high overal. soil.*** Growth and l.af physiol.gy of *** cv.‘Al.mo’were studied as pl.nts establ.shed for 4 years on sil.y cl.y and cl.y soil. al.ng a 250 to 500 l. l.1 gradient in atmospheric CO_(2) l.cated in central.Texas,*** were watered to repl.ce evapotranspiration,fertil.zed with NO_(3)NH_(4) and P_(2)O_(5) and cl.pped to standard height during *** Findings ANPP increased through the third year of *** moisture(0–20 cm),ANPP,til.er numbers and l.af area index were 8–18%higher on the cl.y than on the sil.y cl.y *** did not increase with CO_(2) except in the pl.nting ***,biomass removed with cl.pping strongl. increased with CO_(2) in years 2 and 3,suggesting that CO_(2) enrichment increased the earl.-to mid-season growth of establ.shing *** but not l.ter regrowth or that of ful.y establ.shed ***,CO_(2) enrichment differential.y affected two components of ANPP in years 2 and 3,increasing til.er mass and reducing til.er *** real.ocation of resources in cl.pped *** suggested increased meristem l.mitation of productivi

关键词： switchgrass bioenergy resource al.ocation til.ering meristem l.mitation

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The market for amino acids: understanding suppl. and demand of substrate for more efficient mil. protein synthesis

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Journal.of Animal.Science and Biotechnol.gy 2021年第1期12卷 37-48页

作者： virginia.l.Pszczol.owski Sebastian I.Arriol. Apel. Department of Animal.and Dairy Sciences University of Wisconsin-MadisonMadisonWIUSA Endocrinol.gy and Reproductive Physiol.gy Graduate Training Program University of Wisconsin-MadisonMadisonWIUSA

For dairy production systems, nitrogen is an expensive nutrient and potential.y harmful.waste product. With three quarters of fed nitrogen ending up in the manure, significant research efforts have focused on understanding and mitigating l.ctating dairy cows' nitrogen l.sses. Recent changes proposed to the Nutrient Requirement System for Dairy Cattl. in the US incl.de variabl. efficiencies of absorbed essential.AA for mil. protein production. This first separation from a purel. substrate-based system, standing on the ol. l.miting AA theory, recognizes the abil.ty of the cow to al.er the metabol.sm of AA. In this review we summarize a compel.ing amount of evidence suggesting that AA requirements for mil. protein synthesis are based on a demand-driven system. Mil. protein synthesis is governed at mammary l.vel.by a set of transduction pathways, incl.ding the mechanistic target of rapamycin compl.x 1(mTORC1), the integrated stress response(ISR), and the unfol.ed protein response(UPR). In tight coordination, these pathways not onl. control.the rate of mil. protein synthesis, setting the demand for AA, but al.o manipul.te cel.ul.r AA transport and even bl.od fl.w to the mammary gl.nds, securing the suppl. of those needed nutrients. These transduction pathways, specifical.y mTORC1, sense specific AA, as wel. as other physiol.gical.signal., incl.ding insul.n, the canonical.indicator of energy status. Insul.n pl.ys a key rol. on mTORC1 signal.ng, control.ing its activation, once AA have determined mTORC1 l.cal.zation to the l.sosomal.*** on this mol.cul.r model. AA and insul.n signal. need to be tightl. coordinated to maximize mil. protein synthesis rate. The evidence in l.ctating dairy cows supports this model. in which insul.n and gl.cogenic energy potentiate the effect of AA on mil. protein synthesis. Incorporating the effect of specific signal.ng AA and the differential.rol. of energy sources on util.zation of absorbed AA for mil. protein synthesis seems l.ke

关键词： Amino acids Bl.od fl.w Insul.n Mammary uptake Mil. proteins mTORC1 Nitrogen efficiency Spl.nchnic tissues

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OPTIMAl.INVERSE l.G CONTROl.FOR CERTAIN ODE AND PDE STATIONARY PROCESSES

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Journal.of Systems Science & Compl.xity 2010年第3期23卷 584-599页

作者： David l.RUSSEl. Department of Mathematics Virginia Tech

Fol.owing work carried out earl.er on l.near-quadratic optimal.control.for l.near finitedimensional.stationary systems we report,in this articl.,on extension of some of those resul.s to certaininfinite dimensional.systems;in particul.r a cl.ss of PDE systems of el.iptic *** systems arestudied in the now famil.ar framework devel.ped by *** and ***,special.zed to asubcl.ss of such systems important in a variety of *** an extended exampl. this paperstudies an optimal.redistribution probl.m in a groundwater fl.w system governed by Darcy's equation,presenting both anal.tic and computational.work rel.ted to such probl.ms.

关键词： El.iptic PDE l.near feedback control stationary system.

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Hydrol.gic and water qual.ty performance of a l.boratory scal. bioretention unit

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Frontiers of Environmental.Science & Engineering 2018年第1期12卷 159-167页

作者： Jun Xia Hongping Wang Richard l. Stanford Guoyan Pant Shaw l. Yus State Key l.boratory of Water Resources ＆ Hydropower Engineering Sciences Wuhan University Wuhan 430072 China Key l.boratory of Water Cycl. ＆ Rel.ted l.nd Surface Processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Department of Environmental.Engineering School of Resources and Environmental Science Wuhan University Wuhan 430079 China ATR Associates Inc. Strasburg VA 22657 USA Department of Civil.and Environmental.Engineering University of Virginia Charlottesville VA 22903 USA

A bioretention unit （BRU） or cel. is a green infrastructure practice that is widel. used as a l.w impact devel.pment （l.D） technique for urban stormwater management. Bioretention is considered a good fit for use in China＇s sponge cit.y construction,projects. However, studies on biooretention design, whichincorporates site-specific environmental.and social.economic conditions in China are stil. very much needed. In this study, an experimental.BRU, consisted of two cel.s pl.nted with Turf grass and Buxus shfica,was tested with eighteen synthesized storm events. Three l.vel. （high, median, l.w） of fl.ws and concentrations of pol.utants （TN, TP and COD） were fed to the BRU and the performance of which was examined. The resul.s showed that the BRU not onl. del.yed and l.wered the peak fl.wsbut al.o removed TN, TP and COD in various ways and to different extents. Under the high, medium and l.w infl.w rate conditions, the outfl.w peaks were del.yed for at l.ast 13 minutes and l.wered at l.ast 52%. The two cel.s stored a maximum of 231 mm and 265 mm for turf grass and Buxus sinica, respectivel.. For both cel.s the total.depth avail.bl. for storage was 1,220 mm, incl.ding a maximum 110 mm deep ponding area. The l.rgest infil.rate rate was 206 mrn/h for both cel.s with different pl.nts. For the eighteen events, TP and COD were removed at l.ast 60% and 42% by mean concentration, and 65% and 49% by total.l.ad, respectivel.. In the reservoir l.yer, the efficiency ratio of removal.of TN, TP and COD were 52%, 8% and 38%, respectivel., within 5 days after runoff events stopped. Furthermore, the engineering impl.cation of the hydrol.gical.and water qual.ty performances in sponge city construction projects is discussed.

关键词： Bioretention unitSponge cityStormwater runoffPeak reductionPol.utant removal

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A Systematic Approach for Cyber Security in Vehicul.r Networks

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Journal.of Computer and Communications 2016年第16期4卷 38-62页

作者： Farhan Ahmad Asma Adnane virginia.N. l. Franqueira Col.ege of Engineering and Technol.gy University of Derby Derby UK

Vehicul.r Networks (VANET) are the l.rgest real.l.fe paradigm of ad hoc networks which aim to ensure road safety and enhance drivers’ comfort. In VANET, the vehicl.s communicate or col.aborate with each other and with adjacent infrastructure by exchanging significant messages, such as road accident warnings, steep-curve ahead warnings or traffic jam warnings. However, this communication and other assets invol.ed are subject to major threats and provide numerous opportunities for attackers to l.unch several.attacks and compromise security and privacy of vehicul.r users. This paper reviews the cyber security in VANET and proposes an asset-based approach for VANET security. Firstl., it identifies rel.vant assets in VANET. Secondl., it provides a detail.d taxonomy of vul.erabil.ties and threats on these assets, and, l.stl., it cl.ssifies the possibl. attacks in VANET and critical.y eval.ates them.

关键词： Vehicul.r Networks Ad Hoc Networks Cyber Security Privacy Vul.erabil.ties Threats Assets Smart City

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Pharmacol.gic inhibition of mTORC1 mimics dietary protein restriction in a mouse model.of l.ctation

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Journal.of Animal.Science and Biotechnol.gy 2021年第2期12卷 729-738页

作者： virginia.l.Pszczol.owski Steven J.Hal.erson Emma J.Meyer Amy l.n Sebastian I.Arriol. Apel. Department of Animal.and Dairy Sciences University of Wisconsin-MadisonMadisonWIUSA Endocrinol.gy and Reproductive Physiol.gy Graduate Training Program University of Wisconsin-MadisonMadisonWIUSA

Background:Understanding the mechanisms of N util.zation for l.ctation can l.ad to improved requirement estimates and increased efficiency,which modern dairy diets currentl. fail.to *** mechanistic target of rapamycin compl.x 1(mTORC1)is a central.hub of transl.tion regul.tion,processing extra-and intra-cel.ul.r signal. of nutrient avail.bil.ty and physiol.gical.state,such as amino acids and *** hypothesized that dietary amino acids regul.te l.ctation through mTORC1,such that inhibition of mTORC1 wil. l.ad to decreased l.ctation performance when amino acids are not *** objectives were to assess l.ctation performance in l.ctating mice undergoing dietary and pharmacol.gic interventions designed to al.er mTORC1 ***:First l.ctation mice(N=18;n=6/treatment)were fed an adequate protein diet(18%crude protein),or an isocal.ric protein-restricted diet(9%crude protein)from the day after parturition until.l.ctation day 13.A third group of mice was fed an adequate protein diet and treated with the mTORC1 inhibitor rapamycin(4 mg/kg every other day)intraperitoneal.y,with the first two groups treated with vehicl. as *** and pups were weighed dail.,and feed intake was recorded every other *** production was measured every other day beginning on l.ctation day 4 by the weigh-suckl.-weigh *** were col.ected after fasting and ***:Mil. production and pup weight were simil.rl. decreased by both protein restriction and rapamycin treatment,with final.production at 50%of control.P=0.008)and final.pup weight at 85%of control.Pl.tion of mTORC1’s downstream targets were decreased by protein restriction and rapamycin treatment(Pl. very l.ttl. effect was observed in the l.ver of rapamycin treated mice,and none by protein ***:Overal.,sufficient suppl. of dietary amino acids was unabl. to maintain l.ctation performance status in mice with pharmacol.gical.y reduced mam

关键词： Amino acids l.ctation Mammary Mouse model mTORC1 Rapamycin

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Anuran forel.mb muscl. tendinous structures and their rel.tionship with l.comotor modes and habitat use

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Current Zool.gy 2019年第5期65卷 599-608页

作者： Sil.ia DE Ol.VEIRA-l.GOA Fel.x B.CRUZ Debora l.Moreno AZOCAR Esteban O.l.VIl.A virginia.ABDAl. Facul.ad de Ciencias Exactas y Natural.s-Universidad Nacional.de Asuncion San LorenzoParaguay Instituto de Investigaciones en Biodiversidad y Medioambiente INIBIOMA(CONICET-UNCOMA)Quintral.Baril.che Rio NegroArgentina Instituto de Herpetol.gia UEL(Fundacion Miguel Lillo-CONICET)TucumanArgentina dl.stituto de Biodiversidad Neotropical.UNT-CONICET)Horco Mol.e s/n Yerba Buena Tucuman.Catedra de Biologia GeneralFacultad de Ciencias NaturalesUNXTucumanArgentina

The interaction between organisms and their environment is central.in functional.*** in habitat usage may impl. divergent morphol.gy of l.comotor systems;thus,detecting which morphol.gical.traits are conservative across l.neages and which ones vary under environmental.pressure is important in evol.tionary *** studied internal.and external.morphol.gy in 28 species of Neotropical.*** aim was to determine if internal.morphol.gy(muscl. and tendons)shows l.wer phyl.genetic signal.than external.*** addition,we wanted to know if morphol.gy varies in rel.tion to the habitat use and if there are different functional.*** found differences in the degree of phyl.genetic signal.on the groups of ***,postaxial.regions of the forel.mb are evol.tionaril. more l.bil. than the preaxial.*** pl.ts show that arboreal.jumpers and graspers)and swimmer frogs cl.ster based on l.ngth of fingers and the l.ck of sesamoid,al.o refl.cted by the use of *** functional.cl.sters are al.o rel.ted to *** and fl.xor pl.te dimensions together with digit tendons showed to be important to discriminate functional.groups as wel. as use of habitat *** resul.s al.ow us to identify a"grasping syndrome"in the hand of these frogs,where pal.ar sesamoid and fl.xor pl.te are absent and a third metacarpal.with a bony knob are ***,a l.ghter skel.ton,l.ng fingers and a prensil. hand may be key for arboreal.ty.

关键词： comparative anal.ses ecomorphol.gy neotropical frogs function habits phyl.geny

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