996 resultados para 11-106
Resumo:
Esta dissertação trata do que se entende como terrorismo após os atentados de setembro de 2001, seja como lógica de ação ou como método de ação. A partir desta data, o terrorismo alcançou enorme projeção e passou a figurar como tema central tanto na imprensa cotidiana quanto em reuniões internacionais de cúpula. O fenômeno era, muitas vezes, historicamente circunscrito às nações que enfrentavam esse problema. Após o Onze de Setembro, o debate expandiu-se e as políticas, e a propaganda, antiterroristas incidiram sobre a sociedade, modificando comportamentos individuais e coletivos. A associação entre Islamismo e terrorismo foi frequente e a Guerra Contra ao Terror (GCT), promovida pela política externa norte-americana de George W. Bush, contribuiu para difundir uma percepção do terrorismo como uma lógica de ação afeita à violência em si. Isso contrasta com a percepção quanto a grupos terroristas de momentos históricos anteriores, cujo recurso ao terrorismo era compreendido como método de ação com valor instrumental para alcançar objetivos políticos diversos, como a emancipação nacional e a desestabilização de regimes políticos estabelecidos. O estudo de caso da Organização de Xangai (OCX) visa demonstrar que a identificação entre terrorismo e Islã leva ao equívoco de compreender os grupos terroristas contemporâneos islâmicos, com lógicas próprias, como uma fenômeno só o que leva à imprecisão de atribuir ao terrorismo o caráter de primeiro fenômeno macro-securitizado. Este breve histórico da ascensão do terrorismo na agenda política contemporânea, mediante a análise do processo securitizador tanto na GCT quanto na Organização de Cooperação de Xangai, serve como referência para as análises contidas no trabalho que o leitor tem em mãos, uma vez que o sentido atribuído ao terrorismo só pode ser entendido em termos dos atores políticos envolvidos na sua definição e no contexto em qual o fazem. Na OCX, o verificou-se o entendimento do terrorismo como método de ação de grupos separatistas, o que não corresponde à ideia do terrorismo como lógica de ação contida na GCT.
Resumo:
Sistemas deslizantes com interface formada com aços baixa liga e polímeros variados são vastamente utilizados na indústria automotiva em sistemas de transmissão de torque submetidas à carregamento axial. Geralmente esses sistemas são acoplados aos sistemas de direção e interagem quase diretamente com o usuário final do veículo. Para conhecer as condições de desgaste mais severas as quais esses sistemas são submetidos e tentar minimiza-las, foi proposta a análise tribológica, em tribômetro do tipo pino-no-disco, da interface aço SAE 1020 com poliamida 11 em água destilada, solução aquosa com 5% em massa de cloreto de sódio e solução aquosa com 184,21 g/l. de areia natural, de acordo com as normas técnicas automotivas VW PV1210:2010-02 e VW PV2982:2013-07. Os ensaios foram realizados em frequências de 3,0 Hz e 1,5 Hz com quantidade fixada em 10.000 ciclos de rotação. O potencial de corrosão em circuito aberto foi monitorado ao longo dos ensaios e a taxa de desgaste foi calculada. Foram evidenciados maiores coeficientes de atrito, maiores taxas de desgaste e maiores amplitudes de potencial de corrosão nas amostras ensaiadas em solução de areia; com valores mais brandos para as amostras ensaiadas em água destilada e valores intermediários para as amostras ensaiadas em solução de cloreto de sódio.
Resumo:
本文通过对五味子科及其近缘类群植物的形态性状、叶表皮解剖特征、木材解剖特征、细胞学以及分支系统学研究,发现了一些重要的新性状,提出了新的五味子属的次级划分,阐明了南五味子属与五味子属的属间系统学关系,以及它们与近缘类群间的系统学关系,最后对这两属进行了分类学修订。主要内容包括: 1.形态性状分析 我们在查阅大量国内外馆藏标本和野外居群观察的基础上,对五味子科植物及部分近缘类群的形态性状和变异式样进行了详细地比较分析,重新评价了各性状的分类学价值,认为习性、茎有无棱翅、叶有无毛被、花雄蕊群特征及果实和种子形态等性状具有系统学意义,而叶片形状和大小、毛被多少、花被片颜色等特征在种内变化较大,不宜作为种的划分依据,至少不能作为主要的或唯一的依据。 2.叶表皮形态解剖学 在光学显微镜和扫描电镜下,分别观察了南五味子属全属11种共92个样品、五味子属全属10种共136个样品和八角属2种共15个样品的叶表皮形态特征。结果发现南五味子属和五味子属植物的叶表皮性状,包括表皮细胞形状、气孔类型、保卫细胞形状及叶表皮细胞表面的角质纹饰、表皮毛的有无等在种内稳定且在种间有明显差异,对研究属内和属间关系有重要系统学意义。 在南五味子属中,发现了一个新的分类学性状:叶表皮表面具脊状网纹,该性状支持将南五味子属分为离蕊南五味子亚属Subg. Cosbaea和南五味子亚属Subg. Kadsura,且根据叶表皮形态特征和性状分析,支持将南五味子亚属分为南五味子组Sect. Kadsura和肉蕊组Sect. Sarcocarpon,同时支持R. M. K. Saunders和林祁对某些种的归并处理。 在五味子属中发现一新的分类学性状:气孔器外拱盖,表明该属常绿类群的气孔具有双层外拱盖,而落叶类群的气孔具有单层外拱盖。这一性状支持前人将五味子属根据习性和雄蕊群特征划分为两个亚属的观点,这一观点同样得到了包括形态学和分子系统学证据的支持。此外,还发现在全为常绿习性的南五味子属中,气孔都具双层外拱盖,一方面说明五味子属的常绿类群与南五味子属有一定的相似性,亲缘关系密切,这同样得到分子证据的支持;另一方面表明五味子科植物生长习性与气孔器特征有一定相关性。 通过比较南五味子属与五味子属以及近缘的八角属叶表皮形态特征,认为这三个属的叶表皮形态特征非常相似,只是南五味子属在叶表皮形态特征上比五味子属和八角属具有更多的复杂或次生性状状态,此外,研究结果不支持将五味子科从八角目中分出而成立五味子目的观点。 3.比较木材解剖学 在光学显微镜下观察了南五味子属7种21个样品和五味子属8种16个样品的木材解剖特征,结果表明次生木质部的导管分子类型、导管-射线间纹孔的排列方式、射线类型、射线细胞形状等性状特征在科的水平上很稳定,这些共同特征都支持五味子科是比较自然的类群。在五味子科中发现木材导管单生、具梯状穿孔板、导管壁具梯形排列的纹孔以及木射线异型等原始性状,支持五味子科在被子植物中的原始地位。此外,该科木材还具有单穿孔板导管、导管次生壁具螺纹加厚、具分隔纤维等较为特化的性状状态,这种性状进化水平的异等级现象,使五味子科表现出不同进化水平性状的镶嵌组合。根据木材解剖性状对五味子科进行UPGMA聚类分析,结果显示南五味子属和五味子属在木材解剖特征方面有一定的交叉和重叠,这与分子系统学的结论一致,表明这两个属关系密切,可能起源于共同的祖先。通过比较五味子科与八角科的木材解剖特征,进一步证明两个科的亲缘关系很近,同样不支持将五味子科从八角目中独立出来成立五味子目的观点。 4. 细胞分类学 对五味子属铁箍散Schisandra propinqua(Wall.)Baill进行了细胞学研究,首次报道该种植物的染色体核型。核型分析的结果表明染色体数目为2n = 28,核型公式为2n = 2x = 20m+8sm, 染色体相对长度组成2n = 2L+14M2+8M1+4S,核型不对称系数0.59,核型为2B型,未发现次缢痕和随体。通过与该属其它种类的核型进行比较,发现具常绿习性的铁箍散其核型不对称性系数比该属落叶种类高,表明该种在五味子属中处于较进化的地位,这与我们根据该属其它性状得出的结论一致。 5. 分支系统学研究 对五味子属33个形态学性状进行了分支系统学研究,得到5棵同等最简约树,树长为53步,一致性指数(CI)= 0.7740, 保留性指数(RI)= 0.7740。在最简约树(MP)的严格一致树中,内类群形成两大支,一支包括所有落叶习性的类群,另一支包括具有常绿习性的类群,两支的支持率都非常高, 在一定程度上能反映五味子属内各种间的系统学关系。根据五味子属分支系统学分析的结果,对该属属下分类系统进行了调整。 在补充了包括叶表皮形态解剖学和木材解剖学等新性状的基础上,对五味子科42个形态学性状进行了分支系统学分析,分别计算得到了MP树和邻接树(N-J)。简约分析得到三棵同等最简约树,树长106步,一致性指数(CI)= 0.4910,保留性指数(RI)= 0.7450。严格一致树显示:五味子科分为五个并列的分支,其中南五味子属被分为三支,五味子属被分为两支,虽然这些分支的支持率都不是很高,但是一些种类间的亲缘关系还是得到很好的体现。用距离法建立的N-J树中,将该科分为两大支,五味子属所有落叶种类聚为一支,南五味子属和五味子属具常绿习性的类群聚为一支,这与分子系统学分析的结果一致,但是由于在N-J树上,五味子属两个常绿种与南五味子属构成的分支支持率较低,所以两属之间的关系还尚待讨论。 6. 分类学修订 在应用上述性状分析结果及查阅国内外大量标本的基础上,重新修订了南五味子属和五味子属的概念,包括新性状的补充,对两属植物进行了分类学修订。确定了南五味子属目前包括2亚属2组11种;五味子属目前包括2亚属4组10种,指定了Embelia valbrayi H. Léveillé的后选模式,提出一个新等级组。描述了每个种的性状特征、变异情况、地理分布、相关的分类学处理及其与近缘种的关系,并列出所研究的标本,最后讨论了南五味子属和五味子属的系统关系。
Resumo:
苔藓是高等植物(有胚植物或陆地植物)中最原始的一类,但种类却丰富多样,其形态和生长环境的多样化程度高于蕨类和裸子植物,且对极端环境的忍耐力更强,分布范围也更广。“特有”是一个地理概念,它是相对广布而言,当一个类群的分布范围有一定的限制时即为特有现象。“东亚特有”是指分布范围主要局限于中国,朝鲜,日本和蒙古等,向北可及俄罗斯远东地区,少数可分布至中国南部相邻地区的植物类群。东亚地区主要以温带植物区系为主,但也包含一些热带植物区系成分,还因为第四纪以来受冰川活动影响较少,因此植物种类非常丰富。东亚地区也是苔藓植物的多样性中心之一,这里有较多的特有成分。在我国总共分布有苔藓植物东亚特有属35属,其中苔类5属,藓类30属。长期以来,特有成分始终引起人们的极大关注,不仅是因为其在植物地理学上的重要性,还因为特有类群中包含了孓遗类群,往往系统位置比较关键,此外,大部分特有类群对人为干扰比较敏感,对其保护就愈加重要,因为它在这个地区的消失就意味着一个类群的灭绝。 我国对苔藓植物东亚特有类群已有较好的认识,在前人知识积累的基础之上,我们期望通过分子系统学的方法,开展对东亚特有苔藓属的研究,逐步揭开特有属植物的神秘面纱,最终在系统树上找到它们各自应该属于自己的位置。 在本次研究中,我们总共得到十一个苔藓植物东亚特有属的新鲜材料。在实验室中我们对这十一个特有属叶绿体和核的六个基因(叶绿体atpB, rbcL, cp-SSU, cp-LSU 和核18S,26S rDNA)进行了测序,并在此基础之上,构建了来自苔藓植物106个属上述六个基因的联合矩阵,并对它们进行了系统学分析。本文所选十一个特有属中除三个苔类属和一个线齿藓类的属之外,其它七个特有属都属于侧蒴藓类。根据近几年的研究结果,侧蒴藓类中灰藓目被认为是起源自一次快速辐射演化,灰藓目各科之间的关系以及各科的范围都很难确定。即便本实验测序一万多bp,这一支之内的关系仍不能解决。 在以上结果的基础上,本文对线齿藓类的树发藓属(Microdendron)进行了较为详细的研究,我们用最大简约法分析了金发藓目15属,33种的18S, rbcL和trnL-F序列的联合矩阵。对树发藓属的微形态进行了电镜扫描。形态和分子数据的分析结果表明,这个特有属在属级水平是不成立的,它仅是小金发藓属的一个种。此结果支持将这个东亚特有属降为种的等级。此外,本文还对囊绒苔属(Trichocoleopsis)和新绒苔属(Neotrichocolea)的系统位置做了比较详细的研究。我们分别分析了一个苔类植物57属的四基因(cp-SSU, cp-LSU, atpB and rbcL)矩阵和一个苔类植物24属的九基因(cp-SSU, cp-LSU, atpB, psbA, rps4, rbcL, 18S, 26S and nad5)联合矩阵,结果显示囊绒苔属和新绒苔属互为姐妹群关系,而毛叶苔属(Ptilidium)又是它们二者的姐妹群。研究结果支持了囊绒苔属和新绒苔属组成新绒苔科(Neotrichocoleaceae),而不同于前人的观点:将上述两属放置于毛叶苔科(Ptilidiaceae)、绒苔科(Trichocoleaceae)或多囊苔科(Lepidolaenaceae)。另外值得注意的是这两个特有属和毛叶苔属组成的一支位于叶苔类(Leafy liverwort)中“Leafy I”和“Leafy II”两大支之间,但这一支确切的系统位置没有解决,仍有待于进一步研究。 除此之外,本文还利用GenBank中的数据对东亚特有属日鳞苔属(Nipponolejeunea)和耳坠苔属(Ascidiota)(未获得实验材料)进行了初步的系统学分析。结果表明传统上放在细鳞苔科的日鳞苔属与毛耳苔科的毛耳苔属(Jubula)为姐妹群关系,建议将日鳞苔属置于毛耳苔科;耳坠苔属是光萼苔科的成员,属的分类等级是合理的。 最后本文利用罚分似然法,选取多个化石作为标定点,对来自苔藓植物主要类群及其它陆地植物共115个类群5个基因(atpB, rbcL, cp-SSU, cp-LSU, 18S)的矩阵进行了分子钟的分析,初步估算11个东亚特有属的分化时间。
Resumo:
The spatial and temporal occurrence of Atlantic bottlenose dolphins (Tursiops truncatus) in the coastal and estuarine waters near Charleston, SC were evaluated. Sighting and photographic data from photo-identification (ID), remote biopsy, capture-release and radio-tracking studies, conducted from 1994 through 2003, were analyzed in order to further delineate residence patterns of Charleston area bottlenose dolphins. Data from 250 photo-ID, 106 remote biopsy, 15 capture-release and 83 radio-tracking surveys were collected in the Stono River Estuary (n = 247), Charleston Harbor (n = 86), North Edisto River (n = 54), Intracoastal Waterway (n = 26) and the coastal waters north and south of Charleston Harbor (n = 41). Coverage for all survey types was spatially and temporally variable, and in the case of biopsy, capture-release and radio-tracking surveys, data analyzed in this report were collected incidental to other research. Eight-hundred and thirty-nine individuals were photographically identified during the study period. One-hundred and fifteen (13.7%) of the 839 photographically identified individuals were sighted between 11-40 times, evidence of consistent occurrence in the Charleston area (i.e., site fidelity). Adjusted sighting proportions (ASP), which reflect an individual’s sighting frequency in a subarea relative to other subareas after adjusting for survey effort, were analyzed in order to evaluate dolphin spatial occurrence. Forty-three percent (n = 139) of dolphins that qualified for ASP analyses exhibited a strong subarea affiliation while the remaining 57% (n = 187) showed no strong subarea preference. Group size data were derived from field estimates of 2,342 dolphin groups encountered in the five Charleston subareas. Group size appeared positively correlated with degree of “openness” of the body of water where dolphins were encountered; and for sightings along the coast, group size was larger during summer months. This study provides valuable information on the complex nature of bottlenose dolphin spatial and temporal occurrence near Charleston, SC. In addition, it helps us to better understand the stock structure of dolphins along the Atlantic seaboard.
Resumo:
This cruise report is a summary of a field survey conducted along a portion of the U.S. continental shelf in northwestern Gulf of Mexico (GOM), at navigable depths along the coastline seaward to the shelf break (~100m) from about 89°30' W to 95°28' W longitude, August 8 – 16, 2011 on NOAA Ship Nancy Foster Cruise NF-11-07-RACOW. Synoptic sampling of multiple ecological indicators was conducted at each of 34 stations throughout these waters using a random probabilistic sampling design. The original study design consisted of 50 stations extending from the Mississippi delta all the way to the U.S./Mexican border, but vessel failures precluded sampling at 16 stations within the western-most portion of the study area. At each station samples were collected for the analysis of benthic community structure and composition; concentrations of chemical contaminants in sediments and target demersal biota; sediment toxicity; nutrient and chlorophyll levels in the water column; and other basic habitat characteristics such as salinity, temperature, dissolved oxygen, turbidity, pH, sediment grain size, and organic carbon content. Other indicators, from a human-dimension perspective, were also recorded, including presence of vessels, oil rigs, surface trash, visual oil sheens in sediments or water, marine mammals, or noxious/oily sediment odors. The overall purpose of the survey was to collect data to assess the status of ecosystem condition and potential stressor impacts throughout the region, based on these various indicators and corresponding management thresholds, and to provide this information as a baseline for determining how such conditions may be changing with time. While sample analysis is still ongoing, some preliminary results and observations are reported here. A final report will be completed once all data have been processed.
Resumo:
We present prevalence of Bartonella spp. for multiple cohorts of wild and captive cetaceans. One hundred and six cetaceans including 86 bottlenose dolphins (71 free-ranging, 14 captive in a facility with a dolphin experiencing debility of unknown origin, 1 stranded), 11 striped dolphins, 4 harbor porpoises, 3 Risso's dolphins, 1 dwarf sperm whale and 1 pygmy sperm whale (all stranded) were sampled. Whole blood (n = 95 live animals) and tissues (n = 15 freshly dead animals) were screened by PCR (n = 106 animals), PCR of enrichment cultures (n = 50 animals), and subcultures (n = 50 animals). Bartonella spp. were detected from 17 cetaceans, including 12 by direct extraction PCR of blood or tissues, 6 by PCR of enrichment cultures, and 4 by subculture isolation. Bartonella spp. were more commonly detected from the captive (6/14, 43%) than from free-ranging (2/71, 2.8%) bottlenose dolphins, and were commonly detected from the stranded animals (9/21, 43%; 3/11 striped dolphins, 3/4 harbor porpoises, 2/3 Risso's dolphins, 1/1 pygmy sperm whale, 0/1 dwarf sperm whale, 0/1 bottlenose dolphin). Sequencing identified a Bartonella spp. most similar to B. henselae San Antonio 2 in eight cases (4 bottlenose dolphins, 2 striped dolphins, 2 harbor porpoises), B. henselae Houston 1 in three cases (2 Risso's dolphins, 1 harbor porpoise), and untyped in six cases (4 bottlenose dolphins, 1 striped dolphin, 1 pygmy sperm whale). Although disease causation has not been established, Bartonella species were detected more commonly from cetaceans that were overtly debilitated or were cohabiting in captivity with a debilitated animal than from free-ranging animals. The detection of Bartonella spp. from cetaceans may be of pathophysiological concern.