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The market for amino acids: understanding supply and demand of substrate for more efficient milk protein synthesis

Journal of Animal Science and Biotechnology 2021年第1期12卷 37-48页

作者： virginia l.pszczolkowski Sebastian I.Arriola Apelo Department of Animal and Dairy Sciences University of Wisconsin-MadisonMadisonWIUSA Endocrinology and Reproductive Physiology Graduate Training Program University of Wisconsin-MadisonMadisonWIUSA

For dairy production systems, nitrogen is an expensive nutrient and potentially harmful waste product. With three quarters of fed nitrogen ending up in the manure, significant research efforts have focused on understanding and mitigating lactating dairy cows' nitrogen losses. Recent changes proposed to the Nutrient Requirement System for Dairy Cattle in the US include variable efficiencies of absorbed essential AA for milk protein production. This first separation from a purely substrate-based system, standing on the old limiting AA theory, recognizes the ability of the cow to alter the metabolism of AA. In this review we summarize a compelling amount of evidence suggesting that AA requirements for milk protein synthesis are based on a demand-driven system. Milk protein synthesis is governed at mammary level by a set of transduction pathways, including the mechanistic target of rapamycin complex 1(mTORC1), the integrated stress response(ISR), and the unfolded protein response(UPR). In tight coordination, these pathways not only control the rate of milk protein synthesis, setting the demand for AA, but also manipulate cellular AA transport and even blood flow to the mammary glands, securing the supply of those needed nutrients. These transduction pathways, specifically mTORC1, sense specific AA, as well as other physiological signals, including insulin, the canonical indicator of energy status. Insulin plays a key role on mTORC1 signaling, controlling its activation, once AA have determined mTORC1 localization to the lysosomal *** on this molecular model, AA and insulin signals need to be tightly coordinated to maximize milk protein synthesis rate. The evidence in lactating dairy cows supports this model, in which insulin and glucogenic energy potentiate the effect of AA on milk protein synthesis. Incorporating the effect of specific signaling AA and the differential role of energy sources on utilization of absorbed AA for milk protein synthesis seems like

关键词： Amino acids Blood flow Insulin Mammary uptake Milk proteins mTORC1 Nitrogen efficiency Splanchnic tissues

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Pharmacologic inhibition of mTORC1 mimics dietary protein restriction in a mouse model of lactation

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Journal of Animal Science and Biotechnology 2021年第2期12卷 729-738页

作者： virginia l.pszczolkowski Steven J.Halderson Emma J.Meyer Amy lin Sebastian I.Arriola Apelo Department of Animal and Dairy Sciences University of Wisconsin-MadisonMadisonWIUSA Endocrinology and Reproductive Physiology Graduate Training Program University of Wisconsin-MadisonMadisonWIUSA

Background:Understanding the mechanisms of N utilization for lactation can lead to improved requirement estimates and increased efficiency,which modern dairy diets currently fail to *** mechanistic target of rapamycin complex 1(mTORC1)is a central hub of translation regulation,processing extra-and intra-cellular signals of nutrient availability and physiological state,such as amino acids and *** hypothesized that dietary amino acids regulate lactation through mTORC1,such that inhibition of mTORC1 will lead to decreased lactation performance when amino acids are not *** objectives were to assess lactation performance in lactating mice undergoing dietary and pharmacologic interventions designed to alter mTORC1 ***:First lactation mice(N=18;n=6/treatment)were fed an adequate protein diet(18%crude protein),or an isocaloric protein-restricted diet(9%crude protein)from the day after parturition until lactation 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)intraperitoneally,with the first two groups treated with vehicle as *** and pups were weighed daily,and feed intake was recorded every other *** production was measured every other day beginning on lactation day 4 by the weigh-suckle-weigh *** were collected after fasting and ***:Milk production and pup weight were similarly 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(Plation of mTORC1’s downstream targets were decreased by protein restriction and rapamycin treatment(Ple very little effect was observed in the liver of rapamycin treated mice,and none by protein ***:Overall,sufficient supply of dietary amino acids was unable to maintain lactation performance status in mice with pharmacologically reduced mam

关键词： Amino acids lactation Mammary Mouse model mTORC1 Rapamycin

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Pressure-dependent phase transition of 2D layered silicon telluride(Si2le3)and manganese intercalated silicon telluride

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Nano Research 2019年第9期12卷 2373-2377页

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

Two-dimensional(2D)layered silicon telluride(SizTes)nanocrystals were compressed to 12 GPa using diamond anvil cell *** measurements show a color change from transparent red to opaque black indicating a semiconductor-to-metal phase *** scattering was used to observe the stiffening of the crystal lattice and subsequent phase behavior.A possible phase transition was *** 9.5±0.5 GPa evidenced by the disappearance of the Atg stretching *** was intercalated with elemental manganese to^1 at.%.Intercalation lowers the pressure of the proposed phase transition to 7.5±1 *** modes show both phonon stiffening and phonon softening,suggesting negative linear *** results provide fundamental insight into the high-pressure optical phonon behavior of silicon telluride and illuminate how a specific electron-donating intercalant can chemically alter pressure-dependent optical phonon behavior.

关键词： silicon telluride Si2Te3 high pressure diamond anvil cell two-dimensional(2D)layered material

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Assessing display variability in wild brown anoles Anolis sagrei using a mechanical lizard model

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Current Zoology 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 Psychology University of South Florida St. Petersburg FL 33701 USA

Signals used for species identity ought to be highly stereotyped so as to facilitate immediate recognition by conspecifics. It is surprising therefore to find variability in putative species signature displays. The brown anole Anolis sagrei has a high degree of variability in its signature bobbing display. In this study we collected descriptive data on variability in the temporal structure of wild brown anole bobbing patterns, finding that no two displays analyzed had the same temporal structure, and we also tested whether wild brown anoles prefer the signature display over an alternate display pattern by using mechanical robot playbacks in the field. As a response metric we assessed whether or not the lizards showed social responses （pushup, dewlap extension, or head-nod） in response to the robotic presentations. We found that the lizards responded slightly more to the signature than to the alternate pattern, providing support for the idea that despite the variability seen in displays, the signature pattern is meaningful to them. We tested two other independent variables： speed of the display and elevation of the robot during its display, neither of which was significant. Dewlap extensions were given predominantly by adult males and were more likely to be given in the breeding season than the nonbreeding season. Pushups and head-nods were given equally by males and a combined class of females and juveniles, and were not seasonal. Head-nods increased after the robot turned off, suggesting that they may be used in a conversational turn-taking style during communication .

关键词： Species recognition Ethorobotics Visual signals Territoriality Signature display Sex differences

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OPTIMAl INVERSE lQG CONTROl FOR CERTAIN ODE AND PDE STATIONARY PROCESSES

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Journal of Systems Science & Complexity 2010年第3期23卷 584-599页

作者： David l.RUSSEll Department of Mathematics Virginia Tech

Following work carried out earlier on linear-quadratic optimal control for linear finitedimensional stationary systems we report,in this article,on extension of some of those results to certaininfinite dimensional systems;in particular a class of PDE systems of elliptic *** systems arestudied in the now familiar framework developed by *** and ***,specialized to asubclass of such systems important in a variety of *** an extended example this paperstudies an optimal redistribution problem in a groundwater flow system governed by Darcy's equation,presenting both analytic and computational work related to such problems.

关键词： Elliptic PDE linear feedback control stationary system.

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Effects of Spent Craft Brewers’ Yeast on Fermentation and Methane Production by Rumen Microorganisms

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Advances in Microbiology 2016年第9期6卷 716-723页

作者： virginia l. pszczolkowski Robert W. Bryant Brittany E. Harlow Glen E. Aiken langdon J. Martin Michael D. Flythe Department of Chemistry Warren Wilson College Asheville NC USA Asheville Flavor Innovations LLC Asheville NC USA Forage-Animal Production Research Unit Agricultural Research Service USDA Lexington KY USA Department of Animal and Food Sciences University of Kentucky Lexington KY USA

Saccharomyces cerevisiae is a key component of beer brewing and a major by-product. The leftover, spent brewers’ yeast from large breweries has been used as a protein supplement in cattle;however the possible advantages of spent yeast from smaller craft breweries, containing much higher levels of bioactive hop acids, have not been evaluated. Hops secondary metabolites from the hops (Humulus lupulus l.) used to make beer are concentrated in the yeast during brewing, and have antimicrobial activity against Gram-positive bacteria. Uncultivated suspensions of bovine rumen microorganisms produced less methane during fructose fermentation when exposed to inactivated, and freeze-dried spent craft brewers’ yeast than a bakers’ yeast control. The experiment was repeated with caprine rumen microorganisms and ground grass hay as the substrate. likewise, in the presence of craft brewers’ yeast less methane was produced (2.7% vs. 6.9% CH4). Both experiments also revealed a decrease in acetic acid production, but not propionic acid production, when craft brewers’ yeast was included. These results indicated that spent yeast could represent a co-product for craft breweries, and a feed supplement for ruminants that has a favorable impact on methane production.

关键词： Antimicrobials Brewing Co-Product Feed Supplement Feed Efficiency Hops Acids Humulus lupulus Plant Secondary Metabolite Phytochemicals

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

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Journal of Plant Ecology 2012年第4期5卷 366-375页

作者： Philip A.Fay H.Wayne Polley virginia l.Jin Michael J.Aspinwall USDA-ARS Grassland Soil and Water Research laboratory 808 E Blackland RdTempleTX 76502USA USDA-ARS Agroecosystem Management Research 137 Keim HallUniversity of Nebraska-LincolnLincolnNE 68583USA Section of Integrative Biology 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-limited perennial grasslands,in part by reducing stomatal conductance and transpiration,thereby reducing depletion of soil ***,the benefits of CO_(2) enrichment for ANPP will vary with soil type and may be reduced if water limitation is *** is known about CO_(2) effects on ANPP of Panicum virgatum,a perennial C4 tallgrass and potential bioenergy *** hypothesized that if water limitation is minimized,(i)CO_(2) enrichment would not increase *** ANPP because photosynthetic rates of this C4 grass would not increase and because decreased transpiration at elevated CO_(2) would provide little additional benefit in increased soil moisture and(ii)soil type will have little effect on *** CO_(2) responses because of high overall soil *** Growth and leaf physiology of *** cv.‘Alamo’were studied as plants established for 4 years on silty clay and clay soils along a 250 to 500 ll l-1 gradient in atmospheric CO_(2) located in central Texas,*** were watered to replace evapotranspiration,fertilized with NO_(3)NH_(4) and P_(2)O_(5) and clipped to standard height during *** Findings ANPP increased through the third year of *** moisture(0–20 cm),ANPP,tiller numbers and leaf area index were 8–18%higher on the clay than on the silty clay *** did not increase with CO_(2) except in the planting ***,biomass removed with clipping strongly increased with CO_(2) in years 2 and 3,suggesting that CO_(2) enrichment increased the early-to mid-season growth of establishing *** but not later regrowth or that of fully established ***,CO_(2) enrichment differentially affected two components of ANPP in years 2 and 3,increasing tiller mass and reducing tiller *** reallocation of resources in clipped *** suggested increased meristem limitation of productivi

关键词： switchgrass bioenergy resource allocation tillering meristem limitation

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Anuran forelimb muscle tendinous structures and their relationship with locomotor modes and habitat use

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Current Zoology 2019年第5期65卷 599-608页

作者： Silvia DE OlIVEIRA-lAGOA Felix B.CRUZ Debora l.Moreno AZOCAR Esteban O.lAVIllA virginia ABDAlA Facultad de Ciencias Exactas y Naturales-Universidad Nacional de Asuncion San LorenzoParaguay Instituto de Investigaciones en Biodiversidad y Medioambiente INIBIOMA(CONICET-UNCOMA)Quintral Bariloche Rio NegroArgentina Instituto de Herpetologia UEL(Fundacion Miguel Lillo-CONICET)TucumanArgentina dlnstituto de Biodiversidad Neotropical(UNT-CONICET)Horco Molle 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 imply divergent morphology of locomotor systems;thus,detecting which morphological traits are conservative across lineages and which ones vary under environmental pressure is important in evolutionary *** studied internal and external morphology in 28 species of Neotropical *** aim was to determine if internal morphology(muscle and tendons)shows lower phylogenetic signal than external *** addition,we wanted to know if morphology varies in relation to the habitat use and if there are different functional *** found differences in the degree of phylogenetic signal on the groups of ***,postaxial regions of the forelimb are evolutionarily more labile than the preaxial *** plots show that arboreal(jumpers and graspers)and swimmer frogs cluster based on length of fingers and the lack of sesamoid,also reflected by the use of *** functional clusters are also related to *** and flexor plate dimensions together with digit tendons showed to be important to discriminate functional groups as well as use of habitat *** results allow us to identify a"grasping syndrome"in the hand of these frogs,where palmar sesamoid and flexor plate are absent and a third metacarpal with a bony knob are ***,a lighter skeleton,long fingers and a prensile hand may be key for arboreality.

关键词： comparative analyses ecomorphology neotropical frogs function habits phylogeny

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Inflammatory bowel disease and celiac disease:Overlaps and differences

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World Journal of Gastroenterology 2014年第17期20卷 4846-4856页

作者： virginia Pascual Romina Dieli-Crimi Natalia lópez-Palacios Andrés Bodas luz María Medrano Concepción Nú?ez UGC de Inmunología Hospital Clínico San CarlosInstituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC)28040 MadridSpain Servicio de Digestivo Hospital Clínico San CarlosInstituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC)28040 MadridSpain Servicio de Pediatría Hospital Clínico San CarlosInstituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC)28040 MadridSpain

Recent findings demonstrate the common genetic basis for many immune-mediated diseases, and consequently, the partially shared pathogenesis. We collected these findings and reviewed the extension of these overlaps to other disease characteristics. Two autoimmune diseases were selected that also share the specific target organ, the bowel. The etiology and immunopathogenesis of both conditions characterized by chronic intestinal inflammation, inflammatory bowel disease (IBD) and celiac disease (CeD), are not completely understood. Both are complex diseases with genetics and environment contributing to dysregulation of innate and adaptive immune responses, leading to chronic inflammation and disease. CeD constitutes a particular disease because the main environmental and genetic triggers are largely known. IBD comprises two main clinical forms, Crohn’s disease and ulcerative colitis, which most likely involve a complex interplay between some components of the commensal microbiota and other environmental factors in their origin. These multifactorial diseases encompass a broad spectrum of clinical phenotypes and ages of onset, although the clinical presentation often differs depending on childhood or adult onset, with greater heterogeneity commonly observed in adults.

关键词： Disease susceptibility Gene-environment interaction Immune system Inflammation Microbiota Inflammatory bowel disease

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Gelatin-biofermentative unsulfated glycosaminoglycans semi-interpenetrating hydrogels via microbial-transglutaminase crosslinking enhance osteogenic potential of dental pulp stem cells

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Regenerative Biomaterials 2021年第3期8卷 110-123页

作者： Annalisa la Gatta virginia Tirino Marcella Cammarota Marcella la Noce Antonietta Stellavato Anna virginia Adriana Pirozzi Marianna Portaccio Nadia Diano luigi laino Gianpaolo Papaccio Chiara Schiraldi Dipartimento di Medicina Sperimentale Universita`della Campania“Luigi Vanvitelli”via L.De Crecchio 7Naples 80138Italy Dipartimento Multidisciplinare di Specialita’Medico-Chirurgiche e Odontoiatriche via Luigi De Crecchio6Napoli 80138Italy

Gelatin hydrogels by microbial-transglutaminase crosslinking are being increasingly exploited for tissue engineering,and proved high potential in bone *** study aimed to evaluate,for the first time,the combination of enzymatically crosslinked gelatin with hyaluronan and the newly developed biotechnological chondroitin in enhancing osteogenic *** enzymatic crosslinking was carried out in the presence of hyaluronan or of a hyaluronan–chondroitin mixture,obtaining semi-interpenetrating *** latter proved lower swelling extent and improved stiffness compared to the gelatin matrix alone,whilst maintaining high *** heteropolysaccharides were retained for 30 days in the hydrogels,thus influencing cell response over this *** evaluate the effect of hydrogel composition on bone regeneration,materials were seeded with human dental pulp stem cells and osteogenic differentiation was *** expression of osteocalcin(OC)and osteopontin(OPN),both at gene and protein level,was evaluated at 7,15 and 30 days of *** electron microscopy(SEM)and two-photon microscope observations were performed to assess bone-like extracellular matrix(ECM)deposition and to observe the cell penetration *** the presence of the heteropolysaccharides,OC and OPN expression was upregulated and a higher degree of calcified matrix formation was *** with hyaluronan and chondroitin improved both the biophysical properties and the biological response of enzymatically crosslinked gelatin,fastening bone deposition.

关键词： hydrogels gelatin hyaluronan biotechnological chondroitin bone regeneration human dental pulp stem cells

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