检索结果-南通市图书馆

Integrative Zoology 2011年第3期6卷 290-296页

作者： Ronald R.SWAISGOOD Fuwen WeI William J.MCSHeA david e.wildt Andrew J.KOUBA Zejun ZHANG San Diego Zoo Institute for Conservation Research EscondidoCaliforniaUSA Institute of Zoology Chinese Academy of ScienceBeijingChina Conservation&Research Center Smithsonian’s National Zoological ParkFront RoyalVirginiaUSA Memphis Zoo MemphisTennesseeUSA Institute of Rare Animals and Plants China West Normal UniversityNanchongSichuanChina

The giant panda(Ailuropoda melanoleuca david,1869)is an iconic species for global conservation,yet field research has only recently advanced to the point where adaptive management is ***,we review recent developments in giant panda conservation science and propose a strategic plan for moving panda conservation *** of scientific,funding,political,and logistical hurdles,few endangered species management programs have embraced adaptive management,wherein management decisions are shaped iteratively by targeted scientific *** threats,such as habitat destruction,anthropogenic disturbance and fragmented nonviable populations,need to be addressed simultaneously by researchers,managers and policy-makers working in concert to understand and overcome these obstacles to species *** the backing of the Chinese Govern-ment and the conservation community,the giant panda can become a high-profile test species for this much touted,but rarely implemented,approach to conservation management.

关键词： adaptive management conservation policy endangered species giant panda strategic conservation plan

大熊猫冷冻精液解冻速度和解冻液中添加Pentyoxyfilline对其解冻后活力的影响

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

兽类学报 2004年第4期24卷 286-292页

作者：黄炎王鹏彦 Rebecca e.Spindler JoGayle Howard 张和民 david e.wildt 中国保护大熊猫研究中心 Conservation & Research Center Smithsonian National Zoological Park 1500 Remount Road Front Royal VA 22630USA

建立大熊猫的精子库,进行远距离圈养大熊猫种群间的人工授精和遗传物质的转运,维持遗传多样性,是目前大熊猫遗传管理的优先方法。要成为最有效的工具,精子库保存的精子解冻后的活力必须很好。本文对大熊猫冷冻精液的解冻速度和解冻液中... 详细信息

建立大熊猫的精子库,进行远距离圈养大熊猫种群间的人工授精和遗传物质的转运,维持遗传多样性,是目前大熊猫遗传管理的优先方法。要成为最有效的工具,精子库保存的精子解冻后的活力必须很好。本文对大熊猫冷冻精液的解冻速度和解冻液中添加化学激活剂Pentyoxyfilline(PF)后的精子活力进行了试验。试验用的精液采自11只成年大熊猫,精液冷冻速度为每分钟-40℃～-100℃。试验Ⅰ:将冷冻精液放入3种不同温度的水浴中解冻:(1)22℃(慢速解冻);(2)37℃(中速解冻)(3)50℃(快速解冻)。将冷冻前精子活力(78 1±2 9%)和解冻后的平均精子活力进行比较,快速解冻后的精子活力(57 5±5 4%)显著地降低(P0 05)。在1mMPF中孵育24h的精子活力没有变化(P>0 05)。在5mM和10mMPF中孵育过的精子活力(5mM:24 0±4 7%;10mM19 5±3 6%)比没有加PF的对照组的精子活力(38 3±5 2%)显著地低(P<0 05)。而且。

关键词：大熊猫冷冻精液解冻速度解冻液精子活力人工授精

解冻速度和添加Pentyoxyfilline来提高大熊猫冷冻精液解冻后活力的研究

在线全文

学校读者我要写书评

暂无评论

解冻速度和添加Pentyoxyfilline来提高大熊猫冷冻精液解冻后活力...

Mitochondrial recruitment in myelin:an anchor for myelin dynamics and plasticity?

四川省动物学会第八次会员代表大会暨第九次学术年会

作者：黄炎王鹏彦 Rebecca e.Spindler JoGayle Howard 张和民 david e.wildt 中国保护大熊猫研究中心斯密史苏尼安国家公园保护研究中心

建立大熊猫的精子库,可以进行远距离圈养大熊猫种群间的人工授精和遗传物质的转运,以维持遗传多样性,这是目前大熊猫遗传管理的优先方法。要成为最有效的工具,精子库保存的精子解冻后的活力必须是最好的。本项研究包括:1)不同解冻速度...

建立大熊猫的精子库,可以进行远距离圈养大熊猫种群间的人工授精和遗传物质的转运,以维持遗传多样性,这是目前大熊猫遗传管理的优先方法。要成为最有效的工具,精子库保存的精子解冻后的活力必须是最好的。本项研究包括:1)不同解冻速度对解冻后精子的影响;2)使用化学试剂Pentyoxyfilline(PF)对解冻后精子活率和活力的影响。试验用的精液采自11只成年大熊猫,精液冷冻速度为-40--100℃/min。试验口:把冷冻精液放入3种不同温度的水浴中解冻:(1)22℃(慢速解冻);(2)37℃(中速解冻)和(3)50℃(快速解冻)。把冷冻前(78.1±2.9%)和解冻后的平均精子活力进行比较,快速解冻后的精子活力(57.5±5.4%)显著地降低(P0.05)。在1mMPF中孵育24h的精子活力没有变化(P>0.05)。在5和10mM PF中孵育过的精子活力(5mM:24.0±4.7;10mM 19.5±3.6%)比没有加PF的对照组的精子活力(38.3±5.2%)显著地低(P<0.05)。而且,在10mM PF孵育4小时的精子的顶体正常率(56.3±2.8)也比对照组的顶体正常率低(71.0±3.3%P<0.05)。这两个大熊猫精子的试验表明大熊猫精子通过快速冷冻制成的颗粒冻精在解冻时用慢速解冻的效果更好。虽然,大熊猫精子对常用激活剂PF是敏感的,但激活是短暂的,几小时后反而会降低精子的活力,在高浓度下还会损坏精子的顶体。

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第7期19卷 1401-1402页

作者： Jean-david M.Gothié Timothy e.Kennedy Department of Neurology and Neurosurgery Montreal Neurological InstituteMcGill UniversityMontrealQCCanada

Optimal propagation of neuronal electrical impulses depends on the insulation of axons by myelin,produced in the central nervous system by *** is an extension of the oligodendrocyte plasma membrane,which wraps around an axon to form a compact multi-layered *** is composed of a substantially higher proportion of lipids compared to other biological membranes and enriched in a small number of specialized proteins.

关键词： plasticity insulation dynamics

A systematic scoping review of study methodology for randomized controlled trials investigating probiotics in athletic and physically active populations

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 61-71页

作者： Alex e.Mohr david B.Pyne Geovana Silva Fogaça Leite Deborah Akins Jamie Pugh College of Health Solutions Arizona State UniversityPhoenixAZ 85004USA Research Institute for Sport and exercise University of CanberraCanberraACT 2617Australia Laboratory of Functional Fermented Food Faculty of Pharmaceutical SciencesUniversity of São PauloSão Paulo 05508-030Brazil Research Institute for Sport and exercise Sciences Liverpool John Moores UniversityLiverpool L33AFUK

Background:The purported ergogenic and health effects of probiotics have been a topic of great intrigue among researchers,practitioners,and the lay public *** has also been an increased research focus within the realm of sports science and exercise medicine on the athletic gut ***,compared to other ergogenic aids and dietary supplements,probiotics present unique study *** objectives of this systematic scoping review were to identify and characterize study methodologies of randomized controlled trials investigating supplementation with probiotics in athletes and physically active ***:Four databases(MeDLINe,CINAHL,Cochrane CeNTRAL,and Cochrane Database of Systematic Reviews)were searched for randomized controlled studies involving healthy athletes or physically active *** intervention with probiotics and inclusion of a control and/or placebo group were *** peer-reviewed articles in english were considered,and there were no date *** were extracted and presented in tabular form to detail study protocols,characteristics,and *** in randomized controlled trials was determined with the RoB 2.0 ***:A total of 45 studies were included in the review,with 35 using a parallel group design and 10 using a cross-over *** half the studies used a single probiotic and the other half a multi-strain *** probiotic dose ranged from 2×10^(8)to 1×10^(11)colony forming units daily,and the length of intervention was between 7 and 150 *** than half the studies directly assessed gastrointestinal symptoms,gut permeability,or the gut *** sex ratio of participants was heavily weighted toward males,and only 3 studies exclusively investigated ***-level adverse events were reported in only 2 studies,although the methodology of reporting varied *** risk of bias was generally low,although details on randomization were lacking in some s

关键词： exercise experimental methodology Gastrointestinal symptoms Gut microbiota Probiotic supplementation

Instance Segmentation of Characters Recognized in Palmyrene Aramaic Inscriptions

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in engineering & Sciences 2024年第9期140卷 2869-2889页

作者： Adéla Hamplová Alexey Lyavdansky TomášNovák Ondrej Svojše david Franc Arnošt Veselý Czech University of Life Sciences in Prague(CULS) Faculty of Economics and ManagementDepartment of Information EngineeringPrague16500Czech Republic National Research University Higher School of economics(HSe) Faculty of HumanitiesInstitute for Oriental and Classical StudiesMoscow101000The Russian Federation

This study presents a single-class and multi-class instance segmentation approach applied to ancient Palmyrene inscriptions,employing two state-of-the-art deep learning algorithms,namely YOLOv8 and Roboflow *** goal is to contribute to the preservation and understanding of historical texts,showcasing the potential of modern deep learning methods in archaeological *** research culminates in several key findings and scientific *** comprehensively compare the performance of YOLOv8 and Roboflow 3.0 in the context of Palmyrene character segmentation—this comparative analysis mainly focuses on the strengths and weaknesses of each algorithm in this *** also created and annotated an extensive dataset of Palmyrene inscriptions,a crucial resource for further research in the *** dataset serves for training and evaluating the segmentation *** employ comparative evaluation metrics to quantitatively assess the segmentation results,ensuring the reliability and reproducibility of our findings and we present custom visualization tools for predicted segmentation *** study advances the state of the art in semi-automatic reading of Palmyrene inscriptions and establishes a benchmark for future *** availability of the Palmyrene dataset and the insights into algorithm performance contribute to the broader understanding of historical text analysis.

关键词： Optical character recognition instance segmentation Palmyrene ancient languages computer vision

Kerogen Kinetic Distributions and Simulations Provide Insights into Petroleum Transformation Fraction (TF) Profiles of Organic-Rich Shales

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 earth Science 2024年第3期35卷 747-757页

作者： david A.Wood DWA energy Limited Lincoln LN59JPUnited Kingdom

Two hundred and fifty single first-order Arrhenius reactions are simulated to generate S2 pyrograms at three heating rates 25,15,and 5°C·*** activation energy(e)and pre-exponential factor(A)of the reactions simulated follow a long-established trend of those variable values displayed by shales and *** characteristics of the transformation fraction(TF)profiles(product generation window temperatures)of the simulated single reactions are compared to the TF profiles of recorded shale pyrograms generated by multiple reactions with different e-A values lying near the defined e-A *** similarities and differences are observed between the TF profile values of the two *** similarities support the spread of e-A values involved in shale pyrogram best *** differences are most likely explained by the complexity of the multiple kerogen first-order and second-order reactions contributing to the recorded shale pyrograms versus the simplicity and crispness of the single first-order reactions *** results also justify the validity of using the previously described“variable e-A pyrogram-fitting method”of multi-heating-rate shale pyrograms enabling optimizers to choose multiple reactions from an unlimited range of e-A *** contrast,further doubt is cast on the validity of the constant-A pyrogram-fitting method used by the easy%Ro technique,in that a distribution of reactions with a single A value is unlikely to represent the complex variety of kerogen macerals observed in shale *** profiles generated by the variable e-A pyrogram-fitting method lie close to the established e-A trend and are likely to provide more realistic TF generation window temperatures than TF profiles generated by the constant-A pyrogram-fitting method.

关键词： transformation fraction profiles simulated S2 pyrograms multiple heating rates kerogen/shale kinetics S2 pyrogram fitting techniques kerogen petroleum research.

Association between baseline levels of muscular strength and risk of stroke in later life:The Cooper Center Longitudinal Study

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5期13卷 642-649页

作者： Stephen W.Farrell david Leonard Qing Li Carolyn e.Barlow Kerem Shuval Jarett D.Berry Andjelka Pavlovic Laura F.DeFina Research Division The Cooper InstituteDallasTX 75230USA Department of Internal Medicine University of Texas at Tyler School of MedicineTylerTX 75799USA

Background:Muscular strength is an important component of physical *** evaluated the relationship between baseline muscular strength and risk of stroke among adults who were aged≥65 years during ***:We included 7627 healthy adults(mean age=43.9 years,86.0%male)underwent a baseline physical examination between 1980 and *** strength was determined by 1-repetition maximum measures for bench press and leg press and categorized into age-and sex-specific tertiles for each *** fitness(CRF)was assessed via a maximal treadmill exercise *** enrolled in fee-for-service Medicare from 1999 to 2019 were included in the *** between baseline strength and stroke outcomes were estimated using a modified Cox proportional hazards *** a secondary analysis,we examined stroke risk by categories of CRF where Quintile 1=low,Quintiles 2-3=moderate,and Quintiles 4-5=high CRF based on age and ***:After 70,072 person-years of Medicare follow-up,there were 1211 earliest indications of incident *** multivariable analyses,the hazard ratio(95%confidence interval(95%CI))for stroke across bench press categories were 1.0(referent),0.96(0.83-1.11),and 0.89(0.77-1.04),respectively(p trend=0.14).The trend across categories of leg press was also non-significant(p trend=0.79).Adjusted hazard ratio(95%CI)for stroke across ordered CRF categories were 1.0(referent),0.90(0.71-1.13),and 0.72(0.57-0.92)(p trende meeting public health guidelines for muscular strengthening activities is likely to improve muscular strength as well as many health outcomes in older adults,performing such activities may not be helpful in preventing ***,meeting guidelines for aerobic activity is likely to improve CRF and lower stroke risk.

关键词： Cardiorespiratory fitness Medicare Muscular strength Stroke

Role of climatic variability in shaping intraspecific variation of thermal tolerance in Mediterranean water beetles

在线全文

学校读者我要写书评

暂无评论

Insect Science 2024年第1期31卷 285-298页

作者： Susana Pallarés david Garoffolo Belén Rodríguez david Sánchez-Fernández Department of Zoology University of SevilleSevilleSpain Faculty of Biology Department of Ecology and HydrologyUniversity of MurciaCampus EspinardoMurciaSpain

The climatic variability hypothesis(CVH)predicts that organisms in more thermally variable environments have wider thermal breadths and higher thermal plasticity than those from more stable ***,due to evolutionary trade-offs,taxa with greater absolute thermal limits may have little plasticity of such limits(trade-off hypothesis).The CVH assumes that climatic variability is the ultimate driver of thermal tolerance variation across latitudinal and altitudinal gradients,but average temperature also varies along such *** explored intraspecific variation of thermal tolerance in three typical Mediterranean saline water beetles(families Hydrophilidae and Dytiscidae).For each species,we compared two populations where the species coexist,with similar annual mean temperature but contrasting thermal variability(continental *** population).We estimated thermal limits of adults from each population,previously acclimated at 17,20,or 25℃.We found species-specific patterns but overall,our results agree with the CVH regarding thermal ranges,which were wider in the continental(more variable)*** the two hydrophilid species,this came at the cost of losing plasticity of the upper thermal limit in this population,supporting the trade-off hypothesis,but not in the dytiscid *** results support the role of local adaptation to thermal variability and trade-offs between basal tolerance and physiological plasticity in shaping thermal tolerance in aquatic ectotherms,but also suggest that intraspecific variation of thermal tolerance does not fit a general pattern among aquatic *** such intraspecific variation could lead to inaccurate predictions of the vulnerability of aquatic insects to global warming.

关键词： acclimation capacity aquatic insects climate change heat coma temperature supercooling point thermal plasticity

Lipid nanoparticles deliver mRNA to the blood-brain barrier

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第10期17卷 9126-9134页

作者： Yanina Kuzminich Avraham Shakked Randi Calkins Sebastian Rudden Camille Jones Jessie Doan Bora Jang elisa Schrader echeverri Ryan Zenhausern Liming Lian david Loughrey Hannah e.Peck Rachelle Wiese Dorothy Koveal Philip J.Santangelo James e.Dahlman George C.Woodruff School of Mechanical engineering Georgia Institute of TechnologyAtlantaGA 30332USA Parker H.Petit Institute for Bioengineering and Biosciences Georgia Institute of TechnologyAtlantaGA 30332USA Wallace H.Coulter Department of Biomedical engineering Emory University School of Medicine and Georgia Institute of TechnologyAtlantaGA 30332USA

Lipid nanoparticles(LNPs)have delivered RNA to hepatocytes in patients after intravenous *** clinical data support efforts to design LNPs that transfect cells in the central nervous system(CNS).However,delivery to the CNS has been difficult,in large part because quantifying on-target delivery alongside common off-target cell types in adult mice remains *** we report methods to isolate different cell types from the CNS,and subsequently present mRNA delivery readouts using a liver-detargeted *** data suggest that LNPs without targeting ligands can transfect cerebral endothelial cells in mice after intravenous *** the difficulty of crossing the blood-brain barrier,they also underscore the value of quantifying delivery in the CNS with cell-type resolution instead of whole-tissue resolution.

关键词： lipid nanoparticle mRNA nanomedicine central nervous system blood-brain barrier