934 resultados para vascular flora


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This report presents an overview of the land-based biodiversity of the St Martin's Island, based on field visits during October 2014 and from historical data.

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Vascular endothelial growth factor (VEGF) plays an important role in normal and pathological angiogenesis. VEGF receptors (VEGFRs, including VEGFR-1, VEGFR-2, and VEGFR-3) and neuropilins (NRPs, including NRP-1 and NRF-2) are high-affinity receptors for V

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A great part of Uganda is endowed with water bodies in the forms of rivers and open water lakes. These bodies are never alone. They are either flanked or associated with plants, which are adapted to the wet conditions. They are so characteristic that they are part and parcel of the aquatic ecosystems. They occupy various positions depending on the amount of water in the relevant habitats.

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At present, acute vascular rejection (AVR) remains a primary obstacle inhibiting long-term graft survival in the pig-to-non-human primate transplant model. The present study was undertaken to determine whether repetitive injection of low dose Yunnan-cobra venom factor (Y-CVF), a potent complement inhibitor derived from the venom of Naja kaouthia can completely abrogate hemolytic complement activity and subsequently improve the results in a pig-to-rhesus monkey heterotopic heart transplant model. Nine adult rhesus monkeys received a heterotopic heart transplant from wild-type pigs and the recipients were allocated into two groups: group 1 (n = 4) received repetitive injection of low dose Y-CVF until the end of the study and group 2 (n = 5) did not receive Y-CVF. All recipients were treated with cyclosporine A (CsA), cyclophosphamide (CyP) and steroids. Repetitive Y-CVF treatment led to very dramatic fall in CH50 and serum C3 levels (CH50 < 3 units/C3 remained undetectable throughout the experiment) and successfully prevented hyperacute rejection (HAR), while three of five animals in group 2 underwent HAR. However, the continuous suppression of circulating complement did not prevent AVR and the grafts in group 1 survived from 8 to 13 days. Despite undetectable C3 in circulating blood, C3 deposition was present in these grafts. The venular thrombosis was the predominant histopathologic feature of AVR. We conclude that repetitive injection of low dose Y-CVF can be used to continuously suppress circulating complement in a very potent manner and successfully prevent HAR. However, this therapy did not inhibit complement deposition in the graft and failed to prevent AVR. These data suggest that using alternative pig donors [i.e. human decay accelerating factor (hDAF)-transgenic] in combination with the systemic use of complement inhibitors may be necessary to further control complement activation and improve survival in pig-to-non-human primate xenotransplant model.

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横断山地区是一个十分自然的植物区系地区,在中国植物区系分区中是作为泛北极植物区中国-喜马拉雅亚区中的一个地区,其种子植物区系具有丰富的科、属、种,地理成分复杂,特有现象和替代现象明显。该地区作为植物区系和生物多样性的研究热点地区,长期以来极受中外植物学家关注。横断山脉东缘是中国-喜马拉雅和中国-日本植物区系的交汇过渡区域,北部的岷江流域以及南部的金沙江流域,孕育了该区丰富的物种资源和植被资源。而岷江干热河谷和金沙江干热河谷的相似性和相关性,更为该区的植物区系和生物多样性南北的对比研究提供了有利的条件。 本研究选择的九顶山西坡和龙肘山分别位于横断山区北部和南部,九顶山属岷江流域而龙肘山属金沙江流域。本研究结合植物区系研究和生物多样性研究,对该区的植物资源进行调查。通过样带调查和样线踏查结合,大量详实的野外样方调查和标本采集,进行传统的区系研究和生物多样性研究。研究该区物种多样性的海拔梯度格局及其潜在的影响影子,并利用新的区系评估质量方法对九顶山西坡的植物区系质量进行定量的研究,以期能更为深刻的理解该区的植物资源,为该区的资源保护和利用提供合理可行的建议。主要研究结论如下: 1)九顶山西坡植物区系的性质和特点 经鉴定和统计,九顶山西坡共有1707 种维管植物,分属617 属和140 科,其中种子植物1616 种,分属572 属117 科。就科的分布区成分构成而言,该区系的热带成分与温带成分相当,热带成分略占优势,表明九顶山西坡的植物区系与热带植物区系有较强的联系。但是,在九顶山西坡属的分布区类型所占的比例上,温带成分远远超过了热带成分,本区的种子植物分布表现出明显的温带性质。且温带分布类型的许多物种组成了九顶山西坡植被的建群种和优势种,是本区系最重要的成分,充分体现了本区系的温带性质。 2)九顶山西坡不同植被带的生物多样性海拔梯度格局 基于对土门-断头崖、茶山-九顶山、雁门沟-光光山三条垂直植被样带的调查,我们发现九顶山西坡的生物多样性沿海拔梯度的变化呈现出一定的规律性,不同样带之间有一定差异。就三条样带的物种组成相似性来看,虽然土门-断头崖样带属于涪江水系,而茶山-九顶山样带和雁门沟-光光山样带属于岷江水系,但不同水系对该区物种组成的影响并不明显。三条样带中,草本层物种丰富度均远远大于灌木层和乔木层,而以乔木层物种丰富度最低;α-多样性指数随着海拔梯度的变化在土门-断头崖样带中呈现单一下降趋势,在茶山-九顶山样带表现为双峰模型,而在雁门沟-光光山样带则表现为不显著波动变化;均匀度指数在土门-断头崖样带呈现出单一下降的趋势,在雁门沟-光光山样带表现为凹形曲线,而在茶山-九顶山样带却无明显的变化规律。β-多样性指数在土门-断头崖样带和茶山-九顶山样带呈现出明显的波动状态,植被类型替代现象明显;而在雁门沟-光光山样带却并未有十分显著的转折点,因其水平植被带受到干扰,同海拔替代现象不显著。 3)九顶山西坡维管植物丰富度的海拔梯度格局 我们考察了九顶山西坡和两条垂直样带(土门-断头崖和雁门沟-光光山样带)的不同分类等级(包括科、属、种)和不同生活型物种(乔木、灌木、禾草、蕨类和其它草本)的丰富度沿着海拔梯度的分布。结果发现,物种的丰富度海拔梯度格局具有不同的模式,单一下降和中间膨胀格局依然是其主流。不同生活型的物种具有不同的丰富度格局,但是对于环境需求相似的类型具有较相似的丰富度格局。不同的丰富度格局可能由多因素导致,包括:气候,海拔跨度,面积,人为干扰等等。 4)九顶山西坡区系质量评估 我们尝试使用传统的区系质量评估方法对九顶山西坡的区系质量进行评估,并尝试使用一种新的区系质量评估体系对该区的区系进行评价。在九顶山西坡随着海拔梯度的上升,平均保守性系数在各条植被带中均呈现出逐渐上升的趋势。区系质量指数随着海拔的升高都表现为双峰模型,在植被交错区区系质量指数相对较高,而在海拔的两极,区系质量指数都很低。大部分地区使用新方法计算所得的加权平均保守性系数和区系质量指数都比传统方法计算的平均保收性系数和区系质量指数要高,说明在九顶山西坡的三条样带中,大部分地区都是那些保守性系数较高的物种占据优势,同时也表明九顶山西坡具有很高质量的区系和自然植被。 5)龙肘山种子植物区系的性质和特点 龙肘山种子植物区系的物种较为丰富,共有154 科,544 属,1156 种。科的优势十分明显,单种属和寡种属数量众多,说明本区系植物成分较为复杂、起源古老、物种多样性指数较高。地理成分复杂,分布类型多样,其中热带成分在总数量上高于温带成分,但是许多温带成分的属是该区植被的重要建群类群和优势类群,表现出明显的亚热带性质。 6)龙肘山生物多样性的现状和特点 在海拔梯度上,龙肘山地区无论是科、属、种的数量,还是不同等级分类单元之间的数量比,均呈现先升后降的趋势,并在中海拔地区达到峰值。物种多样性指数从总体上来说变化幅度不大,略有先升后降的趋势,在中海拔梯度物种多样性最高。乔、灌、草三层的多样性指数表现出乔木层<灌木层<草本层的特征;乔木层均匀度的变化很大,而灌木层和草本层均匀度的变化较小;灌木层均匀度的波动又强于草本层。β-多样性指数呈现单峰模式,中海拔地区最高。就龙肘山东、西坡物种多样性相比较而言,两者虽然在数值上交替上升,但是却体现出了较为一致的趋势,但西坡因受到干热河谷气候的影响,其平均气温要高于东坡,导致了东坡植物群落和物种的分布比西坡要低。在区系成分构成上,低山区的相同海拔段,西坡的热带亚热带成分所占的比例要比东坡高,这是因为西坡的平均气温比东坡稍高,导致了热带、亚热带物种分布更多。而随着海拔的上升,东、西两坡的气候、土壤等条件趋于一致,其植物区系成分的构成格局也趋于一致。 The Hengduan Mountain region is a very natural floristic region; it belongs toChina-Himalaya sub-region of Holarctic region in floristic subarea of China. The flora in this areais rich in family, genus and species; has a very complex composition of geographical elements;especially with high richness of endemic species and obvious substitution phenomenon. Thisregion as a hot-spot area of floristic and biodiversity, has fascinated biologists in the world for along time. The eastern range of Hengduan Mountain is the transition zone of China – Himalayaforest sub-region and China-Japan forest sub-region in floristic. The water systems are quitedifferent, Minjiang River in the north and Jishajiang River in the south grow quit different but alsoabundant plant species and vegetation resources. The similarity and correlativity of Minjiang River dry valleys and Jinshajiang River dry valleys have provided advantageous condition tocontrast flora and biodiversity between north and south. In the present study, the Jiuding Mountainlies in the north of Hengduan Mountain and belongs to Minjiang River, and the LongzhouMountain lies in the south of Hengduan Mountain and belongs to Jinshajiang River. In our study, we combined the methods of floristic research and biodiversity investigation toexplore the resources of plant species and vegetations; sampled with transects along the altitudinalgradients and also with transverse straps with similar elevation; collected the vascular plant specimen with sampling plots of ecology. We explored the plant species richness patterns alongaltitudinal gradients and discussed the underlying factors aroused these patterns; and used a novelmethod to assess the quality of Jiuding Mountain’s flora. All for a deeper comprehension of the plant recourses of this region; and provided feasible and reasonable suggestion for the protectionof resources. The results were as follows: 1 The characteristic of the flora of the west slope of Jiuding Mountain We had collected 1707 species of vascular plants belonging to 617 genera in 140 families inthe west slope of Jiuding Mountain,in which included 1616 seed plant species belonging to 572genera and 117 families. As for the composition of the areal types of the Families of seed plants,tropic components and temperate components are well-balanced, and percentage of tropicscomponents is higher than that of temperate ones for a litter bit. This shows the flora in the westslope of Jiuding Mountain has strong relationship with the tropic flora. But for the composition ofthe areal types of genera, temperate components have far exceeded the tropics ones, indicated thewhole flora with a conspicuous temperate character. Temperate components possess maximumproportion in the west slope of Jiuding Mountain, and many of them belong to constructivespecies and dominant species in the vegetation, are most important components in JiudingMountain’s Flora, also have embodied the temperate character of this area sufficiently. 2 Biodiversity patterns along altitudinal gradients in different vegetation transects in the westslope of Jiuding Mountain Based on the investigation of three vegetation transects (including Tumen-Duantouya transect,Chashan-Jiudingshan transect and Yanmengou-Guangguangshan Transect) in the west slope ofJiuding Mountain, we found the change of biodiversity along the altitude gradients displayedcertain regularity, but have differences among different transects. The three transects belong todifferent water systems; the Tumen-Duantouya transect belongs to Fujiang River, and the othertwo belong to Minjiang River. From the similarity of species compositions of different transects,we found different water system didn’t show obvious impact on the species composition. In all thethree transects, the species richness of herb layer was remarkably higher than shrub and tree layer,and the species richness of tree layer was the lowest one. With the increasing of the altitude, theline of α-diversity was monotonically decreasing curve in Tumen-Duantouya transect, andbimodal curve in Chashan-Jiudingshan transect, but in Yanmengou-Guangguangshan transectshowed a wave-like curve although not very obvious. Species evenness showed monotonicallydecreasing trends in Tumen-Duantouya transect, and very low at mid-altitude in Yanmengou-Guangguangshan transect, but in Chashan-Jiudingshan transect changed irregularly. Changes inβ-diversity corresponded with the transition of vegetation in the Tumen-Duantouya transect andChashan-Jiudingshan transect, and the curve of β-diversity along altitude had obvious turningpoint; but in Yanmengou-Guangguangshan transect had no obvious turning point, and thesubstitution phenomenon was not obvious, transverse vegetation straps distributed interlaced. 3 Richness patterns of vascular plant species along altitude in the west slope of Jiuding Mountain Direct gradient analysis and regression methods were used to describe the species richnesspatterns along the altitudinal for Mt. Jiuding, as well as separately for Tumen-Duantouya Transectand Yanmengou-Guangguangshan Transect. Altitudinal gradient of diversity of units at differenttaxonomic level (including Family, Genus and Species) and at different life form (including tree,shrub, pteridophyte, grass and other herb) were tested to find differences among the richnesspattern. We found altitudinal richness also shows different patterns, and both monotonicallydecreasing pattern and hump-shaped pattern can be founded in vascular species richness. Speciesin different life forms show different altitudinal patterns, but those species with similarrequirements to environmental conditions show similar richness patterns along altitudinalgradients. Different richness patterns can be aroused by different climate, different altitudinal span,area factor, anthropogenic factor and so on. 4 Floristic quality assessments in the west slope of Jiuding Mountain We used both the conventional method broadly adopted in the USA and the new one toassess the floristic quality in the west slope of Jiuding Mountain. The Mean Coefficient ofConservatism (MC) had the trend of increment along the altitudinal gradients. The FloristicQuality Index (FQI) was a bimodal curve with increasing of elevation; FQI got maximum valuesin the transition zones of different vegetations in the middle altitude, and had very low values atthe two end of elevation. In most areas of the west slope of the Jiuding Mountain, the resultscalculated using the new methods were higher than those using the conventional method. Thisindicated the dominant species of the communities had very high coefficients of conservatism inmost areas of Jiuding Mountain, and the communities are relatively kept pristine and the habitats very integrative. 5 The characteristic of the flora of Longzhou Mountain The flora of Longzhou Mountain has very abundant in species composition; there are about1156 species of seed plants belonging to 544 genera in 154 families. In which, twelve families with more than 20 species include totally 232 genera and 532 species, and form the majority of itsflora. The origin of its flora is old, monospecific genera and oligotypic genera amounts to 510 innumber, which constitute 93.75% of total number of genera. The geographical components arevarious in Longzhou Mountain, the majority of flora are temperate and pantropic ones. The tropiccomponents overtopped temperate components on genera quantity, but many temperatecomponents belong to constructive species and dominant species in the vegetation, and the wholeflora shows an obvious subtropical character. 6 Current situation and characteristic of biodiversity in Longzhou Mountain With the increasing of altitude, the number of species, genus, family and the ratios ofdifferent taxonomic levels all displayed a trend of descending after rising first, and peaked atmiddle height area. The change of α-diversity was not very acutely, with the trend of descendingafter rising first in some degree, the middle height area had highest α-diversity. As studying thetree layer, shrub layer and herb layer respectively, the Shannon-Wiener index was in followingorder: tree layer < shrub layer < herb layer; the change of evenness was more complicatedly thanthat of diversity, the tree layer changed acutely, but the shrub layer and herb layer fluctuatedsmoothly. Changes in β-diversity also showed the trend of descending after rising first. TheJaccard index and Cody index all peaked at the middle height forest area. As for the comparison ofplant diversity and evenness between the west and east slope, the numerical values ascendedalternatively, but the trend of changing was similar. The distribution of similar plant communitiesand species in east slope were lower than the west slope for the influence of Jinsha River DryValley. As for the composition of different floristic components, in lower altitude area of westslope, the tropic and sub-tropic plants had higher ratio than east slope’s and even could be equal tothe temperate plants. With the increasing of elevation, the floristic composition become morelikely between the east and west slope and temperate plants dominated the flora.

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The usage of RNA interference for gene knockdown in zebrafish through expression of the small interfering RNA mediators from DNA vectors has created a lot of excitement in the research community. In this work, the ability of human cytomegalovirus immediate early promoter (CMV promoter)-driven short hairpin RNA (shRNA) expression vector to induce shRNA against vascular endothelial growth factor (VEGF) gene in zebrafish was tested, and its effects on VEGF-mediated vasculogenesis and angiogenesis were evaluated. Altogether four vectors targeting various locations of VEGF gene were constructed, and pSI-V4 was proven to be the most effective one. Microinjection of pSI-V4 into the zebrafish embryos resulted in defective vascular formation and down regulation of VEGF expression. In situ hybridization analysis indicated that silencing VEGF gene expression by pSI-V4 resulted in down regulation of neuropilin-1 (NRP1), a potent VEGF receptor. Knockdown of VEGF expression by morpholino gave the same result. This provided evidence that the VEGF-mediated angiogenesis in zebrafish was in part dependent on NRP1 expression. The results contributed to a better understanding of molecular mechanisms of cardiovascular development and provided a potential promoter for making inducible knockdown in zebrafish.

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Zebrafish has been generally considered as an excellent model in case of drug screening, disease model establishment, and vertebrate embryonic development study. In this work, the ability of human cytomegalovirus immediate early promoter (CMV promoter)-driven short hairpin RNA (shRNA) expression vector to induce shRNA against VEGF gene in zebrafish was tested, and its effect on vascular development was assed, too. Using RT-qPCR, blood vessel staining, and in situ hybridization, we confirmed certain transcriptional activity and down regulation of gene expression by the vector. In situ hybridization analysis indicated selective inhibition of NRP1 expression in the VEGF gene loss of function model, which might imply in turn that VEGF could not only activate endothelial cells directly but also could contribute to stimulating angiogenesis in vivo by a mechanism that involved up-regulation of its cognate receptor expression in zebrafish. This contributed to a better understanding of molecular mechanisms of cardiovascular development. The system improved the success rate in making inducible knockdown and widened the possibilities for better therapeutic targets in zebrafish.

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The diatom flora in a 164 cm long sediment core obtained from Jiaozhou Bay (Yellow Sea, China) was analyzed in order to trace the response of diatoms to environmental changes over the past 100 years. The sediment core was dated by Pb-210 and Cs-137 and represented approximately 100 years (1899-2001 A.D.). The flora was mainly composed of centric diatoms (59-96%). The concentration of diatoms declined sharply above 30 cm (after similar to 1981 A.D.), while the dominant species changed from Thalassiosira anguste-lineatus, Thalassiosira eccentria, Coscinodiscus excentricus, Coscinodiscus concinnus and Diploneis gorjanovici to Cyclotella stylorum and Paralia sulcata. Species richness decreased slightly, and the cell abundance of warm-water species increased. We argue that these floral changes were probably caused by climate change in combination with eutrophication resulting from aquaculture and sewage discharge. (c) 2007 Elsevier B.V. All rights reserved.

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When Oryzopsis is confined to the type species, Chinese species are placed in Achnatherum and Piptatherum. This necessitates the following new combinations: Piptatherum grandispiculum, Piptatherum aequiglume var. ligulatum, Piptatherum tibeticum var. psilolepis.. Piptatherum. munroi var. parviflorum, Achnatherum henryi. and Achnatherum henryi var. acutum. Achnatherum henryi is lectotypified. The new name Piptatherum kuoi replaces the illegitimate name Piptatherum obtusum, and this species is lectotypified. Hierochloe potaninii is transferred to Anthoxanthum as A. potaninii, as Hierochloe is regarded as a synonym of Anthoxanthum. All the grass taxa (Poaceae) listed are endemic to China.

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The following new species, new variety, new name, and four new combinations are published for the forthcoming account of Saxifraga L. in the Flora of China, Volume 8: S. epiphylla Gornall & H. Ohba, sp. nov., S. gemmigera Engler var. gemmuligera (Engler) J. T. Pan & Gornall, comb. nov., S. heterotricha Marquand & Airy-Shaw var. anadena (H. Smith) J. T. Pan & Gornall, comb. et stat, nov., S. hypericoides Franchet var. aurantiascens (Engler & Irmscher) J. T. Pan & Gornall, comb. nov., S. hypericoides var. rockii (Mattfeld) J. T. Pan & Gornall, comb. et stat. nov., S. sinomontana J. T. Pan & Gornall, nom. nov., and S. sinomontana var. amabilis H. Smith ex J. T. Pan, var. nov. In addition, the names S. mengtzeana Engler & Irmscher and S. mengtzeana var. cordatifolia Engler & Irmscher are lectotypified here.

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2001

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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas

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Dissertação apresentada à Universidade Fernando Pessoa como parte dos requisitos para a obtenção do grau de Mestre em Psicologia, ramo de Psicologia Clínica e da Saúde

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High intensity focused ultrasound (HIFU) can be used to control bleeding, both from individual blood vessels as well as from gross damage to the capillary bed. This process, called acoustic hemostasis, is being studied in the hope that such a method would ultimately provide a lifesaving treatment during the so-called "golden hour", a brief grace period after a severe trauma in which prompt therapy can save the life of an injured person. Thermal effects play a major role in occlusion of small vessels and also appear to contribute to the sealing of punctures in major blood vessels. However, aggressive ultrasound-induced tissue heating can also impact healthy tissue and can lead to deleterious mechanical bioeffects. Moreover, the presence of vascularity can limit one’s ability to elevate the temperature of blood vessel walls owing to convective heat transport. In an effort to better understand the heating process in tissues with vascular structure we have developed a numerical simulation that couples models for ultrasound propagation, acoustic streaming, ultrasound heating and blood cooling in Newtonian viscous media. The 3-D simulation allows for the study of complicated biological structures and insonation geometries. We have also undertaken a series of in vitro experiments, in non-uniform flow-through tissue phantoms, designed to provide a ground truth verification of the model predictions. The calculated and measured results were compared over a range of values for insonation pressure, insonation time, and flow rate; we show good agreement between predictions and measurements. We then conducted a series of simulations that address two limiting problems of interest: hemostasis in small and large vessels. We employed realistic human tissue properties and considered more complex geometries. Results show that the heating pattern in and around a blood vessel is different for different vessel sizes, flow rates and for varying beam orientations relative to the flow axis. Complete occlusion and wall- puncture sealing are both possible depending on the exposure conditions. These results concur with prior clinical observations and may prove useful for planning of a more effective procedure in HIFU treatments.