207 resultados para China travel and tourism
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The Sichuan golden monkey (Rhinopithecus roxellana) is a famous and beautiful endangered primate. Owing to the dearth of samples and technical limitations, previous studies could not adequately assess the levels of genetic polymorphisms in the species. To
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Premise of the study: Microsatellite markers were developed for Pinus koraiensis to characterize its genetic diversity and understand its population structure. Methods and Results: Using the Fast Isolation by AFLP of Sequences COntaining (FIASCO) Repeats protocol, 20 primer sets were developed in Chinese populations of P. koraiensis. Three of the markers showed polymorphism with two alleles per locus when assessed in a sample of two populations of P. koraiensis from the Changbai Mountain in the Jilin Province of China. Five and three loci were successfully amplified in P. taiwanensis and P. massoniana, respectively. The amplification size of these loci matches those in P. koraiensis. Conclusions: These markers may be useful for further investigation of population genetics of P. koraiensis.
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Pancreatic RNase genes implicated in the adaptation of the colobine monkeys to leaf eating have long intrigued evolutionary biologists since the identification of a duplicated RNASE1 gene with enhanced digestive efficiencies in Pygathrix nemaeus. The recent emergence of two contrasting hypotheses, that is, independent duplication and one-duplication event hypotheses, make it into focus again. Current understanding of Colobine RNASE1 gene evolution of colobine monkeys largely depends on the analyses of few colobine species. The present study with more intensive taxonomic and character sampling not only provides a clearer picture of Colobine RNASE1 gene evolution but also allows to have a more thorough understanding about the molecular basis underlying the adaptation of Colobinae to the unique leaf-feeding lifestyle. The present broader and detailed phylogenetic analyses yielded two important findings: 1) All trees based on the analyses of coding, noncoding, and both regions provided consistent evidence, indicating RNASE1 duplication occurred after Asian and African colobines speciation, that is, independent duplication hypothesis; 2) No obvious evidence of gene conversion in RNASE1 gene was found, favoring independent evolution of Colobine RNASE1 gene duplicates. The conclusion drawn from previous studies that gene conversion has played a significant role in the evolution of Colobine RNASE1 was not supported. Our selective constraint analyses also provided interesting insights, with significant evidence of positive selection detected on ancestor lineages leading to duplicated gene copies. The identification of a handful of new adaptive sites and amino acid changes that have not been characterized previously also provide a necessary foundation for further experimental investigations of RNASE1 functional evolution in Colobinae.
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Human perception of speed declines with age. Much of the decline is probably mediated by changes in the middle temporal (MT) area, an extrastriate area whose neural activity is linked to the perception of speed. In the present study, we used random-dot pa
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Bats (Chiroptera) are the second-most abundant mammalian order in the world, occupying a diverse range of habitats and exhibiting many different life history traits. In order to contribute to this highly underrepresented group we describe the sleep architecture of two species of frugivorous bat, the greater short-nosed fruit bat (Cynopterus sphinx) and the lesser dawn fruit bat (Eonycteris spelaea). Electroencephalogram (EEG) and electromyogram (EMG) data were recorded from multiple individuals (>= 5) by telemetry over a 72-h period in a laboratory setting with light/dark cycles equivalent to those found in the wild. Our results show that over a 24-h period both species spent more time asleep than awake (mean 15 h), less than previous reported for Chiroptera (20 h). C sphinx spent significantly more of its non-rapid eye movement sleep (NREM) and rapid eye movement sleep (REM) quotas during the light phase, while E. spelaea divided its sleep-wake architecture equally between both light and dark phases. Comparing the sleep patterns of the two species found that C. sphinx had significantly fewer NREM and REM episodes than E. spelaea but each episode lasted for a significantly longer period of time. Potential hypotheses to explain the differences in the sleep architecture of C. sphinx with E. spelaea, including risk of predation and social interaction are discussed. (C) 2010 Published by Elsevier B.V.
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Recurrence is a key characteristic in the development of epilepsy. It remains unclear whether seizure recurrence is sensitive to postseizure stress. Here, tonic-clonic seizures were induced with a convulsive dose of pentylenetetrazole (PTZ), and acute seizure recurrence was evoked with a subconvulsive dose of the drug. We found that stress inhibited seizure recurrence when applied 30 minutes or 2 hours, but not 4 hours, after the tonic-clonic seizure. The time-dependent anti-recurrence effect of stress was mimicked by the stress hormone corticosterone and blocked by co-administration of mineralocorticoid and glucocorticoid receptor antagonists. Furthermore, in a PTZ-induced epileptic kindling model, corticosterone administered 30 minutes after each seizure decreased the extent of seizures both during the kindling establishment and in the following challenge test. These results provide novel insights into both the mechanisms of and therapeutic strategies for epilepsy. (C) 2010 Elsevier Inc. All rights reserved.
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通过对采自云南程海和珠江、闽江、长江、辽河、松花江等水系蛇ju标本的形态、度量特征进行仔细分析和比较,认为蛇ju程海种群是蛇ju的1个新亚种,命名为程海蛇ju(Saurogobio dabryi chenghaiensis)。程海蛇ju的特征为:吻皮发达,盖过上唇;上下唇布满发达的乳突;体及尾柄极细长,体高为体长的12.7%-15.0%,尾柄高为体长的5.5%-6.1%、为尾柄长的31.8%-39.1%;沿体侧中轴自鳃孔上方至尾鳍基具一浅色暗纹,其上布有6-11个大型棒状黑斑(黑斑长为宽的2-4倍);肛门位于腹鳍长度的中点之后;尾鳍最长鳍条为其最短鳍条的2倍以上;仅分布于云南程海。
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To explore the possible abnormal resting-state activity in patients with obsessive-compulsive disorder (OCD), the regional homogeneity (ReHo) of 22 pairs of patients and well-matched healthy controls was calculated. Compared with controls, the patients showed higher ReHo in the left anterior cingulate cortex, but lower ReHo in the left inferior temporal gyrus. These findings supported the abnormal resting-state brain activity in drug-naive OCD patients. No significant correlations between ReHo value and four clinical characteristics were found, suggesting that abnormal ReHo might be trait-related in OCD. NeuroReport 21:786-790 (C) 2010 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.
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介绍了黄连山自然保护区非人灵长类的现状。利用现有统计资料中隐含的生态信息 对自然保护区中的非人灵长类的生存威胁因素作了分析。农村人口与农民收入、粮食面积、粮 食产量、茶叶产量、水果产量和紫胶产量呈正相关;农民收入与粮食产量、茶叶产量、水果产量、 紫胶产量和橡胶面积呈正相关。农村人口、农业发展和偷猎行为是保护区非人灵长类的威胁 因素;提高农业生产效率和加强保护区管理是改善非人灵长类现状的关键。
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鳃暴露在水环境中,增加了对疾病的易感性。为了研究稀有鮈鲫人工感染草鱼呼肠孤病毒过程中鳃部先天性免疫反应机制,我们克隆了抗病毒效应分子Mx基因的部分序列,用适时荧光定量PCR检测双链RNA的模式识别受体(Toll-like receptor3,TLR3)及I型干扰素指示基因Mx的表达。TLR3和Mx基因的表达在注射病毒后12h显著升高(p<0.05),TLR3的表达水平在注射后48h恢复到正常水平(p>0.05),而Mx的高水平表达一直持续到实验结束(p<0.05)。结果表明在GCRV感染中,鳃能发生局部免
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本文以长江三峡干流河岸植物群落为研究对象,对群落的物种组成、物种多样性进行了分析,并利用TWINSPAN和DCA对植物群落进行等级式划分。结果表明:河岸植物区系组成较为复杂,以温带成分为主,有着较高比率的世界分布成分。灌、草丛群落之间的物种多样性差异不显著,但部分草丛的不同层次间存在较大差异。TWINSPAN 和DCA分析显示,河岸植物群落呈现沿湿度梯度方向的分布格局。图2表3参8。
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Because of the obvious importance of P as a nutrient that often accelerates growth of phytoplankton (including toxic cyanobacteria) and therefore worsens water quality, much interest has been devoted to P exchange across the sediment-water interface. Generally, the release mode of P from the sediment differed greatly between shallow and deep lakes, and much of the effort has been focused on iron and oxygen, and also on the relevant environmental factors, for example, turbulence and decomposition, but a large part of the P variation in shallow lakes remains unexplained. This paper reviews experimental and field studies on the mechanisms of P release from the sediment in the shallow temperate (in Europe) and subtropical (in the middle and lower reaches of the Yangtze River in China) lakes, and it is suggested that pH rather than DO might be more important in driving the seasonal dynamics of internal P loading in these shallow lakes, i.e., intense photosynthesis of phytoplankton increases pH of the lake water and thus may increase pH of the surface sediment, leading to enhanced release of P (especially iron-bound P) from the sediment. Based on the selective pump of P (but not N) from the sediment by algal blooms, it is concluded that photosynthesis which is closely related to eutrophication level is the driving force for the seasonal variation of internal P loading in shallow lakes. This is a new finding. Additionally, the selective pump of P from the sediment by algal blooms not only explains satisfactorily why both TP and PO4-P in the hypereutrophic Lake Donghu declined significantly since the mid-1980s when heavy cyanobacterial blooms were eliminated by the nontraditional biomanipulation (massive stocking of the filter-feeding silver and bighead carps), but also explains why TP in European lakes decreased remarkably in the spring clear-water phase with less phytoplankton during the seasonal succession of aquatic communities or when phytoplankton biomass was decreased by traditional biomanipulation. Compared with deep lakes, wax and wane of phytoplankton due to alternations in the ecosystem structure is also able to exert significant influences on the P exchange at the sediment-water interface in shallow lakes. In other words, biological activities are also able to drive P release from sediments, and such a static P release process is especially more prominent in eutrophic shallow lakes with dense phytoplankton.