检索结果-南通市图书馆

Survival of boll weevil （Coleoptera： Curculionidae） adults after feeding on pollens from various sources

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Insect Science 2007年第6期14卷 503-510页

作者： SHOIL M. GREENBERG GRETCHEN D. j.NES FRANK EISCHEN RANDY j. COLEMAN john j. ADAMCZYK, j.. TONG-XIAN LIU MAMOUDOU SETAMOU USDA-ARS KSARC-BIRU Weslaco USDA-ARS APMRU College Station USDA-ARS KSARC-Honey Bee Research Unit Department of Entomology Texas AgriLife Research Texas A&M University System Texas A&M University Kingsville Citrus Center Weslaco Texas USA

The survival of overwintering boll weevil, Anthonomus grandis grandis （Boheman）, adults on non-cotton hosts in the Lower Rio Grande Valley （LRGV） of Texas was examined from 2001 to 2006. The success of the Boll Weevil Eradication Program, which was reintroduced into the LRGV in 2005, depends on controlling overwintering boll weevil populations. Laboratory studies were conducted using boll weevil adults that were captured in pheromone traps from September through March. The number of adults captured per trap declined significantly in the field from fall to the beginning of spring （3.5-7.0-fold）. The proportion of trapped males and females did not differ significantly. The mean weight of boll weevil adults captured in September was 13.3 mg, while those of captured adults from November to February were significantly lower and ranged from 6.7 to 7.8 mg. Our results show that boll weevil adults can feed on different plant pollens. The highest longevity occurred when adults were fed almond pollen or mixed pollens （72.6 days and 69.2 days, respectively） and the lowest when they fed on citrus pollen or a non-food source （9.7 days or 7.4 days, respectively）. The highest adult survival occurred on almond and mixed pollens [88.0%-97. 6% after 1st feeding period （10 days）, 78.0%-90.8% after 3rd feeding period （10 days）, 55. 0%-83.6% after 5th feeding period （10 days）, and 15.2%-32.4% after lOth feeding period （10 days）]. The lowest adult survival occurred on citrus pollen [52.0%-56.0% after 1st feeding period （10 days）, 13.3% after 3rd and 5th feeding periods （10 days）, and 0 after 6th feeding period （10 days）]. Pollen feeding is not a behavior restricted to adult boll weevils of a specific sex or physiological state. Understanding how boll weevil adults survive in the absence of cotton is important to ensure ultimate success of eradicating this pest in the subtropics.

关键词： boll weevil Anthonomus grandis grandis Curculionidae subtropics pollen

Did natural fission of^(235)U in the earth lead to formation of the supercontinent Columbia?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2012年第4期3卷 369-374页

作者： john j.W.Rogers Department of Geological Sciences University of North Carolina at Chapel HillChapel HillNC 27599-3315USA

Steady decline in the percentage of 235U in terrestrial uranium made natural fission impos- sible after about 1.8 Ga. Fission before 1.8 Ga disturbed the lead isotope system at various places world- wide, such as Oklo, Gabon, and may have caused the first lead isotope paradox. Fission in areas of high uranium concentration may also have generated enough heat to localize sparse Archean and Paleoproter- ozoic UHT belts. The oldest widespread orogenic systems formed at approximately 2.0-1.8 Ga after fission stopped contributing to the earth＇s heat flow. These early orogenic systems partly created the supercontinent Columbia.

关键词： Natural fission Archean Paleoproterozoic Columbia supercontinent Tectonics

Hyponatremia in cirrhosis:Pathophysiology and management

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

World j.urnal of Gastroenterology 2015年第11期21卷 3197-3205页

作者： Savio john Paul j.Thuluvath Division of Gastroenterology Department of MedicineSUNY Upstate Medical University University of Maryland School of Medicine and Mercy Medical Center

Hyponatremia is frequently seen in patients with ascites secondary to advanced cirrhosis and portal *** development of ascites in patients with cirrhosis is *** hypertension and the associated systemic vasodilation lead to activation of the sodium-retaining neurohumoral mechanisms which include the renin-angiotensin-aldosterone system,sympathetic nervous system and antidiuretic hormone(ADH).The net effect is the avid retention of sodium and water to compensate for the low effective circulatory volume resulting in the development of *** not apparent in the early stages of cirrhosis,the progression of cirrhosis and ascites leads to impairment of the kidneys to eliminate solutefree *** leads to additional compensatory mechanisms including non-osmotic secretion of ADH,also known as arginine vasopressin,further worsening excess water retention and thereby *** is associated with increased morbidity and mortality in patients with cirrhosis,and is an important prognostic marker both before and after liver *** management of hyponatremia in this setting is a challenge as conventional therapy for hyponatremia including fluid restriction and loop diuretics are frequently *** this review,we discuss the pathophysiology and various treatment modalities,including selective vasopressin receptor antagonists,for the management of hyponatremia in patients with cirrhosis.

关键词： Hyponatremia in cirrhosis Dilutional hypo-natremia

Metabolomic Profiling in Selaginella lepidophylla at Various Hydration States Provides New Insights into the Mechanistic Basis of Desiccation Tolerance

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Molecular Plant 2013年第2期6卷 369-385页

作者： Abou Yobi Bernard W.M. Wone Wenxin Xu Danny C. Alexander Lining Guo john A. Ryals Melvin j. Oliver john C. Cushman Department of Biochemistry and Molecular Biology University of Nevada Reno NV 89557-0330 USA Department of Biological Sciences University of Nevada Reno NV 89557-0314 USA Metabolon Inc. 800 Capitola Drive Suite 1 Durham NC 27713 USA US Department of Agriculture-Agricultural Research Service Plant Genetic Research Unit University of Missouri Columbia MI 65211 USA

Selaginella lepidophylla is one of only a few species of spike mosses （Selaginellaceae） that have evolved des-iccation tolerance （DT） or the ability to ＇resurrect＇ from an air-dried state. In order to understand the metabolic basis of DT, S, lepidophylla was subj.cted to a five-stage, rehydration/dehydration cycle, then analyzed using non-biased, global metabolomics profiling technology based on GC/MS and UHLC/MS/MS2 platforms. A total of 251 metabolites including 167 named （66.5%） and 84 （33.4%） unnamed compounds were characterized. Only 42 （16.7%） and 74 （29.5%） of compounds showed significantly increased or decreased abundance, respectively, indicating that most compounds were produced con-stitutively, including highly abundant trehalose, sucrose, and glucose. Several glycolysis/gluconeogenesis and tricarboxylic acid （TCA） cycle intermediates showed increased abundance at 100% relative water content （RWC） and 50% RWC. Vanillate, a potent antioxidant, was also more abundant in the hydrated state. Many different sugar alcohols and sugar acids were more abundant in the hydrated state. These polyols likely decelerate the rate of water loss during the drying process as well as slow water absorption during rehydration, stabilize proteins, and scavenge reactive oxygen species （ROS）. In contrast, nitrogen-rich and y-glutamyl amino acids, citrulline, and nucleotide catabolism products （e.g. allantoin） were more abundant in the dry states, suggesting that these compounds might play important roles in nitrogen remobilization during rehydration or in ROS scavenging. UV-protective compounds such as 3-（3-hydroxyphenyl）propionate, apigenin, and naringenin, were more abundant in the dry states. Most lipids were produced constitutively, with the exception of choline phosphate, which was more abundant in dry states and likely plays a role in membrane hydration and stabilization. In contrast, several poly- unsaturated fatty acids were more abundant in the hydrated states, suggestin

关键词： abiotic/environmental stress mass spectrometry metabolomics oxidative/photooxidative stress desiccationtolerance Selaginella.

Magnetic resonance studies of j.ts in a gas-solid fluidised bed

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2012年第2期10卷 161-169页

作者： Meenal Pore Thusara C. Chandrasekera Daniel j. Holland Aining Wang Fei Wang Qussai Marashdeh Michael D. Mantle Andrew j. Sederman Liang-Shih Fan Lynn F. Gladden john S. Dennis Department of Chemical Engineering and Biotechnology University of Cambridge Pembroke Street Cambridge CB2 3RA United Kingdom The William G. Lowrie Department of Chemical and Biomolecular Engineering Ohio State University Columbus OH 43210 USA

Magnetic resonance imaging （MRI） has been used to study the behaviour Of j.ts at the distributor of a 50 mm diameter fluidised bed of 0.5 mm diameter poppy seeds. Two perforated-plate distributors were examined, containing either 10 or 14 holes, each 1 mm diameter. Ultra-fast MR imaging was able to show the transient nature of the upper parts of the j.ts, where discrete bubbles are formed. Imaging in 3D showed that the central j.ts were the longest for flow rates below minimum fluidisation. Above minimum fluidisation, the outer j.ts, nearest the wall of the fluidised bed, arched inward towards the central axis. In this latter case, interpretation of the time-averaged 3D image required the use of ultra-fast MR imaging to identify the approximate height above the distributor at which discrete bubbles were formed. The apparently continuous void extending along the central axis above this height in the time-averaged 3D image was thus identified, using ultra-fast MR imaging, as representing the averaged paths of released bubbles. Time-averaged MR velocity mapping was also used to identify dead zones of stationary particles resting on the distributor between the j.ts. The dead zones could be observed when the superficial velocity of the gas approached minimum fluidisation, but they were smaller than those observed at lower gas superficial velocity. Comparable images of a single j.t through 1.2 mm diameter poppy seeds from MRI and electrical capacitance volume tomography （ECVT） are also demonstrated.

关键词： Fluidised bedMRIECVTj.tsDistributor design

Proteomic changes in mammalian spermatozoa during epididymal maturation

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Asian j.urnal of Andrology 2007年第4期9卷 554-564页

作者： R. john Aitken Brett Nixon Minj.e Lin Adam j. Koppers Yun H. Lee Mark A. Baker The ARC Centre of Excellence in Biotechnology and Development University of Newcastle Newcastle NSW 2308Australia Discipline of Biological Sciences University of Newcastle Newcastle NSW 2308 Australia

Epididymal maturation is associated with the activation of a cAMP-induced tyrosine phosphorylation cascade, which is ultimately associated with the expression of capacitation-dependent sperm functions, such as hyperactivated movement and acrosomal exocytosis. As spermatozoa progress through the epididymis they first acquire the capacity to phosphorylate tyrosine on targets on the principal piece, followed by the midpiece. By the time these cells have reached the cauda epididymidis they can phosphorylate the entire tail from neck to endpiece. This particular pattern of phosphorylation is associated with the ontogeny of fully functional spermatozoa that are capable of fertilizing the oocyte. Proteomic analyses indicate that this change is associated with the phosphorylation of several mitochondrial proteins, creation of a mitochondrial membrane potential and activation of mitochondrial free radical generation. At least in rodent species, activation of sperm mitochondria appears to be a particularly important part of epididymal maturation. （Asian j.Androl 2007 j.ly; 9： 554-564）

关键词： epididymis mitochondria spermatozoa tyrosine phosphorylation

The effect of social context and social scale on the perception of relationships in monk parakeets

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2015年第1期61卷 55-69页

作者： Elizabeth A. HOBSON Darlene j. john Tiffany L. MCINTOSH Michael L. AVERY Timothy F. WRIGHT National Institute for Mathematical and Biological Synthesis University of Tennessee Knoxville TN 37996-3410 USA Department of Biology New Mexico State University Las Cruces NM 88003USA USDA Wildlife Services National Wildlife Research Center Gainesville FL 32641USA

Social relationships formed within a network of interacting group members can have a profound impact on an indi- vidual＇s behavior and fitness. However, we have little understanding of how individuals perceive their relationships and how this perception relates to our external measures of interactions. We investigated the perception of affiliative and agonistic relation- ships at both the dyadic and emergent social levels in two captive groups of monk parakeets （Myiopsitta monachus, n = 21 and 19） using social network analysis and playback experiments. At the dyadic social scale, individuals directed less aggression to- wards their strong affiliative partners and more aggression towards non-partner *** the emergent social scale, there was no association between relationships in different social contexts and an individual＇s dominance rank did not correlate with its popularity rank. Playback response pattems were mainly driven by relationships in affiliative social contexts at the dyadic scale. In both groups, individual responses to playback experiments were significantly affected by strong affiliative relationships at the dyadic social scale, albeit in different directions in the two groups. Response pattems were also affected by affiliative relation- ships at the emergent social scale, but only in one of the two groups. Within affiliative relationships, those at the dyadic social scale were perceived by individuals in both groups, but those at the emergent social scale only affected responses in one group. These results provide preliminary evidence that relationships in affiliative social contexts may be perceived as more important than agonistic relationships in captive monk parakeet groups. Our approach could be used in a wide range of social species and comparative analyses could provide important insight into how individuals perceive relationships across social contexts and social scales [Current Zoology 61 （1）： 55-69, 2015].

关键词： Affiliative Agonistic Dominance Eigenvector centrality Emergent social property Myiopsitta monachus Parrot Popularity Rank Social network analysis

The Hardy-Weinberg principle and its applications in modern population genetics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers in Biology 2010年第4期5卷 348-353页

作者： john j.CHEN Department of Preventive Medicine State University of New York at Stony BrookStony BrookNY 11794-8036USA

The discovery of the Hardy-Weinberg principle marked the beginning of the field of population *** the past hundred years,it has provided a starting point for many population genetic *** this review,the Hardy-Weinberg principle,its statistical testing,and several of its applications in various modern population genetic research areas,including allelic variability and selection in the human leukocyte antigen region,microsatellite genotyping error detection,and accuracy of haplotype estimation,are discussed.

关键词： the Hardy-Weinberg principle statistical testing population genetics human leukocyte antigens microsatellite genotyping haplotype estimation

嗜酸性粒细胞性食管炎：管理进展及面临的困惑

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

英国医学杂志中文版 2018年第7期21卷 388-401页

作者： j.an W Chen john Y kao 夏志伟(译) Division of Gastroenterology and Hepatology Department of Internal Medicine University of Michigan Ann Arbor M148109-5362 USA 北京大学第三医院消化内科

嗜酸性粒细胞性食管炎是由过敏原驱动、免疫介导的慢性疾病。近年来，大家逐步认识到该病是成人和儿童发生吞咽困难及上消化道症状的重要原因。时该病的遗传及环境因素、相关的炎症背景、食管改变的远期并发症等方面的资料逐步丰富。本... 详细信息

嗜酸性粒细胞性食管炎是由过敏原驱动、免疫介导的慢性疾病。近年来，大家逐步认识到该病是成人和儿童发生吞咽困难及上消化道症状的重要原因。时该病的遗传及环境因素、相关的炎症背景、食管改变的远期并发症等方面的资料逐步丰富。本文主要总结了成人嗜酸性粒细胞性食管炎的最新进展，讨论通过微侵入的方法替代反复活检来判断疾病的活动程度的尝试，对采用现有方法如阻抗和腔内成像等技术检测黏膜完整性及食管功能改变的研究进行总结，探讨质子泵抑制剂时嗜酸性粒细胞性炎症的疗效差异。一临床治疗研究仍然支持应用局部糖皮质激素和食物剔除疗法作为该病的一线治疗方法。本文还将讨论优化食物剔除疗法以缩短饮食限制时间并降低饮食限制的程度。展望未来，目前对嗜酸性粒细胞性食管炎发病机制的理解已有可能支持进一步研发特异性的生物治疗。

关键词：管理食道曙红