检索结果-南通市图书馆

Long-term monitoring of cycles in Clethrionomys rutilus in the Yukon boreal forest

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Integrative Zoology 2024年第1期19卷 27-36页

作者： Charles j.KREBS Alice j.KENNEY B.scott GILBERT Rudy BOONSTRA Department of Zoology University of British ColumbiaVancouverBritish ColumbiaCanada Renewable Resources Management Program Yukon UniversityWhitehorseYukonCanada Department of Biological Sciences University of Toronto ScarboroughTorontoOntarioCanada

Baseline studies of small rodent populations in undisturbed ecosystems are *** report here 50 years of mon-itoring and experimentation in Yukon of a dominant rodent species in the North American boreal forest,the red-backed vole Clethrionomys *** voles breed in summer,weigh 20–25 g,and reach a maximum density of 20 to 25 per *** populations have shown consistent 3–4-year cycles for the last 50 years with the only change being that peak densities averaged 8/ha until 2000 and 18/ha since that *** the last 25 years,we have measured food resources,predator numbers,and winter weather,and for 1-year social interactions,to estimate their contribution to changes in the rate of summer increase and the rate of overwinter *** these potential limiting factors could contribute to changes in density,and we measured their relative contributions statistically with multiple *** rate of winter decline in density was related to both food supply and winter *** rate of summer increase was related to summer berry crops and white spruce cone *** measure of predator numbers was related to winter or summer changes in vole *** was a large signal of climate change effects in these *** is no density dependence in summer population growth and only a weak one in winter population *** of our results provide a clear understanding of what generates 3–4-year cycles in these voles,and the major missing piece may be an understanding of social interactions at high density.

关键词： boreal forest climate change density dependence population cycles predation winter severity

Adaptation in brain structure and respiratory and olfactory structures across environmental gradients in African and North American muroid rodents

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Integrative Zoology 2024年第1期19卷 165-181页

作者： Peter j.TAYLOR Aluwani NENGOVHELA Christiane DENYS Graham R.scott Catherine M.IVY Department of Zoology School of Natural and Mathematical SciencesUniversity of VendaThohoyandouSouth Africa Afromontane Unit Department of Zoology and EntomologyUniversity of the Free StatePhuthaditjhabaSouth Africa Department of Mammalogy National MuseumBloemfonteinSouth Africa Institut de Systématique EvolutionBiodiversité(ISYEB)Muséum National d’Histoire NaturelleCNRSSorbonne UniversitéEPHEUniversitéDes AntillesParisFrance Department of Biology McMaster UniversityHamiltonOntarioCanada Guglielmo and Shoemaker Labs Advanced Facility for Avian ResearchUniversity of Western OntarioLondonOntarioCanada

Morphometric studies of 3D micro CT-scanned images can provide insights into the evolution of the brain and sensory structures but such data are still scarce for the most diverse mammalian order of *** reviewed and new data,we tested for convergence to extreme aridity and high elevation in the sensory and brain morphology of rodents,from morphometric data from micro-CT X-ray scans of 174 crania of 16 species of three distantly re-lated African murid(soft-furred mice,Praomyini,laminate-toothed rats,Otomyini,and gerbils,Gerbillinae)clades and one North American cricetid(deer mice and white-footed mice,Peromyscus)*** studies demon-strated convergent evolution acting on the oval window area of the cochlea(enlarged in extremely arid-adapted species of Otomyini and Gerbillinae)and on endocranial volume(reduced in high elevation taxa of Otomyini and Peromyscus).However,contrary to our predictions,we did notfind evidence of convergence in brain struc-ture to aridity,or in the olfactory/respiratory system(turbinate bones)to high *** structure differed,particularly in the petrosal lobules of the cerebellum and the olfactory bulbs,between Otomyini and Gerbillinae,with extreme arid-adapted species in each clade being highly divergent(not convergent)from other species in the same *** observed greater“packing”of the maxillary turbinate bones,which have important respiratory functions,in Peromyscus mice from high and low elevations compared to the high-elevation African Praomyini,but more complex patterns within Peromyscus,probably related to trade-offs in respiratory physiology and heat exchange in the nasal epithelium associated with high-elevation adaptation.

关键词： 3D morphometrics Africa brain size North America Rodentia sensory evolution

Quantitative Applications of Weather Satellite Data for Nowcasting:Progress and Challenges

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

journal of Meteorological Research 2024年第3期38卷 399-413页

作者： jun LI jing ZHENG Bo LI Min MIN Yanan LIU Chian-Yi LIU Zhenglong LI WPaul MENZEL Timothy j.SCHMIT john L.CINTINEO scott LINDSTROM scott BACHMEIER Yunheng XUE Yayu MA Di DI Han LIN Innovation Centre for Fengyun Meteorological Satellite(FYSIC) National Satellite Meteorological CentreChina Meteorological AdministrationBeijing100081China School of Atmospheric Sciences and Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies Sun Yat-sen University and Southern Laboratory of Ocean Science and EngineeringZhuhai519082China Key Laboratory of Geographic Information Science(Ministry of Education) East China Normal UniversityShanghai200241China Research Center for Environmental Changes Academia SinicaTaipei11529China Cooperative Institute for Meteorological Satellite Studies University of Wisconsin-MadisonMadisonWI53706USA Sensors and Calibration Branch STAR/NESDISMadisonWI53706USA Wuxi University Wuxi214105China School of Computer Science Chengdu University of Information TechnologyChengdu610225China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing210044China Key Laboratory of Spatial Data Mining and Information Sharing of Ministry of Education National and Local Joint Engineering Research Center of Satellite Geospatial Information TechnologyFuzhou UniversityFuzhou350108China

Monitoring and predicting highly localized weather events over a very short-term period,typically ranging from minutes to a few hours,are very important for decision makers and public *** these events usually relies on radar observations through monitoring and *** advanced high-resolution imaging and sounding observations from weather satellites,nowcasting can be enhanced by combining radar,satellite,and other data,while quantitative applications of those data for nowcasting are advanced through using machine learning *** applications include monitoring the location,impact area,intensity,water vapor,atmospheric instability,precipitation,physical properties,and optical properties of the severe storm at different stages(pre-convection,initiation,development,and decaying),identification of storm types(wind,snow,hail,etc.),and predicting the occurrence and evolution of the *** observations can provide information on the environmental characteristics in the preconvection stage and are very useful for situational awareness and storm *** paper provides an overview of recent progress on quantitative applications of satellite data in nowcasting and its challenges,and future perspectives are also addressed and discussed.

关键词： weather satellite quantitative applications nowcasting pre-convection

EZH2 inhibitors promote β-like cell regeneration in young and adult type 1 diabetes donors

在线全文

学校读者我要写书评

暂无评论

Signal Transduction and Targeted Therapy 2024年第2期9卷 679-692页

作者： Keith Al-Hasani Safiya Naina Marikar Harikrishnan Kaipananickal scott Maxwell jun Okabe Ishant Khurana Thomas Karagiannis julia j.Liang Lina Mariana Thomas Loudovaris Thomas Kay Assam El-Osta Epigenetics in Human Health and Disease Program Baker Heart and Diabetes Institute75 Commercial RoadMelbourne 3004 VICAustralia Department of Diabetes Central Clinical SchoolMonash UniversityMelbourne 3004 VICAustralia Epigenetics in Human Health and Disease Laboratory Central Clinical SchoolMonash UniversityMelbourne 3004 VICAustralia School of Science STEM CollegeRMIT UniversityMelbourne 3001 VICAustralia Immunology and Diabetes Unit St Vincent’s Institute of Medical ResearchFitzroy 3065 VICAustralia Department of Medicine and Therapeutics The Chinese University of Hong KongSha TinHong Kong SAR Hong Kong Institute of Diabetes and Obesity Prince of Wales HospitalThe Chinese University of Hong Kong3/F Lui Che Woo Clinical Sciences Building30-32-Ngan Shing StreetSha TinHong Kong SAR Li Ka Shing Institute of Health Sciences The Chinese University of Hong KongSha TinHong Kong SAR Biomedical Laboratory Science Department of TechnologyFaculty of HealthUniversity College CopenhagenCopenhagenDenmark

β-cells are a type of endocrine cell found in pancreatic islets that synthesize,store and release *** type 1 diabetes(T1D),T-cells of the immune system selectively destroy the insulin-producingβ-*** of these cells leads to a lifelong dependence on exogenous insulin administration for ***,there is an urgent need to identify novel therapies that stimulateβ-cell growth and induceβ-cell *** and others have shown that pancreatic ductal progenitor cells are a promising source for regeneratingβ-cells for T1D owing to their inherent differentiation *** transcriptional suppression is refractory to exocrine reaction and tightly controls the regenerative potential by the EZH2 *** the present study,we show that transient stimulation of exocrine cells,derived from juvenile and adult T1D donors to the FDAapproved EZH2 inhibitors GSK126 and Tazemetostat(Taz)influence a phenotypic shift towards aβ-like cell *** transition from repressed to permissive chromatin states are dependent on bivalent H3K27me3 and H3K4me3 chromatin *** EZH2 is fundamental toβ-cell regenerative *** pancreatic ductal cells exhibit insulin production and secretion in response to a physiological glucose challenge ex *** pre-clinical studies underscore the potential of small molecule inhibitors as novel modulators of ductal progenitor differentiation and a promising new approach for the restoration ofβ-like cell function.

关键词： EZH2 struction inhibitors

HI in High Gas-phase Metallicity Dwarf Galaxy WISEA j230615.06+143927.9

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第1期24卷 292-299页

作者： Yan Guo C.Sengupta T.C.scott P.Lagos Y.Luo Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China School of Astronomy and Space Sciences University of Science and Technology of ChinaHefei 230026China Institute of Astrophysics and Space Sciences(IA Porto) Rua das Estrelas4150-762PortoPortugal

We present resolved Giant Metrewave Radio Telescope H I observations of the high gas-phase metallicity dwarf galaxy WISEA j230615.06+143927.9(z = 0.005)(hereafter j2306) and investigate whether it could be a Tidal Dwarf Galaxy(TDG) candidate. TDGs are observed to have higher metallicities than normal dwarfs. j2306 has an unusual combination of a blue g-r color of 0.23 mag, irregular optical morphology and high-metallicity(12 +log(O/H) = 8.68 ± 0.14), making it an interesting galaxy to study in more detail. We find j2306 to be an H I rich galaxy with a large extended, unperturbed rotating H I disk. Using our H I data we estimated its dynamical mass and found the galaxy to be dark matter(DM) dominated within its H I radius. The quantity of DM, inferred from its dynamical mass, appears to rule out j2306 as an evolved TDG. A wide area environment search reveals j2306 to be isolated from any larger galaxies which could have been the source of its high gas metallicity. Additionally, the H I morphology and kinematics of the galaxy show no indication of a recent merger to explain the *** detailed optical spectroscopic observations of j2306 might provide an answer to how a seemingly ordinary irregular dwarf galaxy achieved such a high level of metal enrichment.

关键词： galaxies:abundances galaxies:dwarf galaxies:irregular radio lines:galaxies radio lines:ISM

Older Adult Compendium of Physical Activities:Energy costs of human activities in adults aged 60 and older

在线全文

学校读者我要写书评

暂无评论

journal of Sport and Health Science 2024年第1期13卷 13-17,F0003页

作者： Erik A.Willis Stephen D.Herrmann Mary Hastert Chelsea L.Kracht Tiago V.Barreira john M.Schuna jr. Zhenghua Cai Minghui Quan scott A.Conger Wendy j.Brown Barbara E.Ainsworth Center for Health Promotion and Disease Prevention University of North Carolina at Chapel HillChapel HillNC 27599USA Kansas Center for Metabolism and Obesity Research The University of Kansas Medical CenterKansas CityKS 66160USA Division of Physical Activity and Weight Management Department of Internal MedicineUniversity of Kansas Medical CenterKansas CityKS 66160USA Clinical Science Division Pennington Biomedical Research CenterBaton RougeLA 70808USA Exercise Science Department Syracuse UniversitySyracuseNY 13244USA School of Exercise&Sport Science Oregon State UniversityCorvallisOR 97331USA School of Exercise and Health Shanghai University of SportShanghai 200438China Department of Kinesiology Boise State UniversityBoiseID 83725USA School of Human Movement and Nutrition Sciences The University of QueenslandSt.LuciaQLD 4072Australia Faculty of Health Sciences and Medicine Bond UniversityGold CoastQLD 4229Australia College of Health Solutions Arizona State UniversityPhoenixAZ 85003USA

Purpose:To describe the development of a Compendium for estimating the energy costs of activities in adults>60 years(OA Compendium).Methods:Physical activities(PAs)and their metabolic equivalent of task(MET)values were obtained from a systematic search of studies published in 4 sport and exercise databases(PubMed,Embase,SPORTDiscus(EBSCOhost),and Scopus)and a review of articles included in the 2011 Adult Compendium that measured PA in older *** values were computed as the oxygen cost(VO_(2),mL/kg/min)during PA divided by 2.7 m L/kg/min(MET_(60+))to account for the lower resting metabolic rate in older ***:We identified 68 articles and extracted energy expenditure data on 427 *** these,we derived 99 unique Specific Activity codes with corresponding MET_(60+)values for older *** developed a website to present the OA Compendium MET_(60+)values:https://***:The OA Compendium uses data collected from adults>60 years for more accurate estimation of the energy cost of PAs in older *** is an accessible resource that will allow researchers,educators,and practitioners to find MET_(60+)values for older adults for use in PA research and practice.

关键词： Energy expenditure Exercise MET Older adults

Tantalum pentoxide:a new material platform for high-performance dielectric metasurface optics in the ultraviolet and visible region

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第1期13卷 142-152页

作者： Cheng Zhang Lu Chen Zhelin Lin junyeob Song Danyan Wang Moxin Li Okan Koksal Zi Wang Grisha Spektor David Carlson Henri j.Lezec Wenqi Zhu scott Papp Amit Agrawal School of Optical and Electronic Information&Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhanHubei 430074China National Institute of Standards and Technology GaithersburgMD 20899USA University of Maryland College ParkMD 20742USA National Institute of Standards and Technology BoulderCO 80305USA

Dielectric metasurfaces,composed of planar arrays of subwavelength dielectric structures that collectively mimic the operation of conventional bulk optical elements,have revolutionized the field of optics by their potential in constructing high-efficiency and multi-functional optoelectronic systems on *** performance of a dielectric metasurface is largely determined by its constituent material,which is highly desired to have a high refractive index,low optical loss and wide bandgap,and at the same time,be fabrication ***,we present a new material platform based on tantalum pentoxide(Ta2O5)for implementing high-performance dielectric metasurface optics over the ultraviolet and visible spectral *** wide-bandgap dielectric,exhibiting a high refractive index exceeding 2.1 and negligible extinction coefficient across a broad spectrum,can be easily deposited over large areas with good quality using straightforward physical vapor deposition,and patterned into high-aspect-ratio subwavelength nanostructures through commonly-available fluorine-gas-based reactive ion *** implement a series of highefficiency ultraviolet and visible metasurfaces with representative light-field modulation functionalities including polarization-independent high-numerical-aperture lensing,spin-selective hologram projection,and vivid structural color generation,and the devices exhibit operational efficiencies up to 80%.Our work overcomes limitations faced by scalability of commonly-employed metasurface dielectrics and their operation into the visible and ultraviolet spectral range,and provides a novel route towards realization of high-performance,robust and foundry-manufacturable metasurface optics.

关键词： dielectric optics ultraviolet

Oxidative Stress in Collegiate Cross Country Skiers in Mid- and Post-Seasons

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

journal of Biosciences and Medicines 2024年第5期12卷 99-110页

作者： scott P. jerome Kriya L. Dunlap Ava M. Parrish Matthew L. Lowman Emily M. Shipman Lawrence K. Duffy Arleigh j. Reynolds Department of Chemistry & Biochemistry University of Alaska Fairbanks Fairbanks AK USA Institute of Arctic Biology University of Alaska Fairbanks Fairbanks AK USA Department of Biology & Wildlife University of Alaska Fairbanks Fairbanks AK USA Department of Veterinary Medicine University of Alaska Fairbanks Fairbanks AK USA

Purpose: The oxidative stress (OS) hypothesis of overtraining syndrome argues that increased production of free radicals through exercise cause muscle fatigue and damage resulting in lower athletic performance. Several studies have investigated OS immediately before and after exercise bouts in a training macrocycle. Our study aimed to compare OS of endurance athletes between a competition macrocycle and the immediate post-season recovery macrocycle. In addition, we aimed to identify athletes who experienced an unexplainable drop in athletic performance during the competition season in order to compare their OS to those who experienced no drop in performance. Methods: Fifteen members of the University of Alaska Fairbanks cross country ski team volunteered for this study. Blood samples were taken in early February (“mid-season”) and late April (“post-season”). Participants completed questionnaires regarding physical activity and athletic performance at the time of the blood draws. Plasma was analyzed for 4-hydroxynonenal (HNE), nitrotyrosine, nitric oxide (NOX), and superoxide dismutase (SOD). Significance was determined by Wilcoxon and Mann-Whitney tests. Results: Participants displayed significantly higher (p Conclusion: Signs of oxidative stress and mitigation during the post-season recovery macrocycle were higher in athletes who reported experiencing a drop in athletic performance during the competition season macrocycle.

关键词： Oxidative Stress 4-Hydroxynonenal Superoxide Dismutase Athletic Performance Training Macrocycle

Effects of structural characterizations on fragility functions of bridges subject to seismic shaking and lateral spreading

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2008年第4期7卷 369-382页

作者： scott j.Brandenberg Pirooz Kashighandi Department of Civil and Environmental Engineering University of California

This paper evaluates the seismic vulnerability of different classes of typical bridges in California when subjected to seismic shaking or liquefaction-induced lateral spreading. The detailed structural configurations in terms of superstructure type, connection, continuity at support and foundation type, etc. render different damage resistant capability. Six classes of bridges are established based on their anticipated failure mechanisms under earthquake shaking. The numerical models that are capable of simulating the complex soil-structure interaction effects, nonlinear behavior of columns and connections are developed for each bridge class. The dynamic responses are obtained using nonlinear time history analyses for a suite of 250 earthquake motions with increasing intensity. An equivalent static analysis procedure is also implemented to evaluate the vulnerability of the bridges when subjected to liquefaction-induced lateral spreading. Fragility functions for each bridge class are derived and compared for both seismic shaking （based on nonlinear dynamic analyses） and lateral spreading （based on equivalent static analyses） for different performance states. The study finds that the fragility functions due to either ground shaking or lateral spreading show significant correlation with the structural characterizations, but differences emerge for ground shaking and lateral spreading conditions. Structural properties that will mostly affect the bridges＇ damage resistant capacity are also identified.

关键词： fragility functions bridge seismic response liquefaction lateral spreading structural characterization