3 resultados para Bodiversity hotspots

em Repositório Científico da Universidade de Évora - Portugal


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Nineteen areas on the island of Hispaniola (Haiti and the Dominican Republic) were studied with the aim of determining the distribution pattern of the endemic flora in these areas, and their variability with altitude. The main concentration of endemic species occurs in mountains with a medium altitude and in certain mountain sites (palaeo-islands), which coincide with hotspots; a lower number of endemics are found in low-lying areas (coldspots), due to the degradation of their habitats. A total of 1,582 endemic species were studied and were distributed in 19 areas. The whole island is of outstanding interest for its richness in endemics; it has 2,050 endemic species, representing 34.16% of its total flora. The territory in the study is home to 1,284 genera of which 31 are endemic to the island, including monotypical genera such as Tortuella abietifolia Urb. & Ekman, and endemic genera such as Hottea, containing seven endemic species. The sites with the highest rate of endemics are area A16 in the central range with a total of 440 endemic species, of which 278 are exclusive to the territory; and the Sierra de Bahoruco, la Selle, La Hotte and Tibur on in area A12, where we found 699 plants of which 482 are endemic and exclusive to the area; and A13 with 173 and 129 respectively. This work highlights the exceptional floristic diversity in endemic species and genera and analyses their distribution patterns as a tool for conservation in this area of the world, whose high endemicity rate makes it one of the most significant hotspots in the Caribbean.

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Esta tese consiste no estudo, implementação e desenvolvimento da infra-estrutura para o projecto SEMCABO-WIFI. Este projecto está inserido na empresa Sem¬ Cabo, com o objectivo de levar a Internet aos clientes sob a forma de hotspots ou no acesso à ultima milha (Last Míle Access) à casa dos residentes. O projecto também deu origem à própria empresa, levando esta a ISP desde Setembro de 2007. Numa primeira fase, é feita abordagem a Sistemas de Authentícatíon, Authorization e Ac­countíng para ISPs, na vertente WI-FI e apresentadas possíveis soluções comercias e open source. Em seguida, é apresentado a empresa SemCabo, vertente comercial e tecnológica. O sistema base da SemCabo é referido, contemplando a tecnologia de suporte, rede, equipamentos activos, módulos de emissão de sinal WI-FI, segurança, monitorização e portal de autenticação. Os servidores base são indicados posteriormente, sendo efectuado a apresentação de todos os servidores com suporte ao projecto, incluindo alguns pormenores de configuração. São apresentados equipa­ mentos e sistemas utilizados para controlo de acesso à rede (NAS), sendo igualmente descritos pormenores de configuração. ABSTRACT; This thesis is about the study, implementation and development of the infrastructure created for the SEMCABO-WIFI project. This project is inserted in the company SemCabo, with the objective to bring the Internet to costumers in the form of hots­pots or access in last mile to the house of residents. The project also originated the company and led the company to ISP since September 2007. ln the first fase, the approach is about Systems Authentication, Authorization and Accounting for WISPs and presented possible commercial and open source solutions. ln next, the SemCabo company is presented and described their technological and commercial aspects. The base system of the SemCabo is refered, considering the support technology, network equipment, modules emission signal WI-FI, security, monitoring and portal authentication module. Base servers of the SemCabo project are shown, a presentation of all the servers that support the project is made, including some details of the configuration. The equipment and systems used to control network access (NAS) are presented, details of configuration are also described.

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By definition, the domestication process leads to an overall reduction of crop genetic diversity. This lead to the current search of genomic regions in wild crop relatives (CWR), an important task for modern carrot breeding. Nowadays massive sequencing possibilities can allow for discovery of novel genetic resources in wild populations, but this quest could be aided by the use of a surrogate gene (to first identify and prioritize novel wild populations for increased sequencing effort). Alternative oxidase (AOX) gene family seems to be linked to all kinds of abiotic and biotic stress reactions in various organisms and thus have the potential to be used in the identification of CWR hotspots of environment-adapted diversity. High variability of DcAOX1 was found in populations of wild carrot sampled across a West-European environmental gradient. Even though no direct relation was found with the analyzed climatic conditions or with physical distance, population differentiation exists and results mainly from the polymorphisms associated with DcAOX1 exon 1 and intron 1. The relatively high number of amino acid changes and the identification of several unusually variable positions (through a likelihood ratio test), suggests that DcAOX1 gene might be under positive selection. However, if positive selection is considered, it only acts on some specific populations (i.e. is in the form of adaptive differences in different population locations) given the observed high genetic diversity. We were able to identify two populations with higher levels of differentiation which are promising as hot spots of specific functional diversity.