891 resultados para Boundaries


Relevância:

20.00% 20.00%

Publicador:

Resumo:

This thesis is developed in the contest of Ritmare project WP1, which main objective is the development of a sustainable fishery through the identification of populations boundaries in commercially important species in Italian Seas. Three main objectives are discussed in order to help reach the main purpose of identification of stock boundaries in Parapenaeus longirostris: 1 -Development of a representative sampling design for Italian seas; 2 -Evaluation of 2b-RAD protocol; 3 -Investigation of populations through biological data analysis. First of all we defined and accomplished a sampling design which properly represents all Italian seas. Then we used information and data about nursery areas distribution, abundance of populations and importance of P. longirostris in local fishery, to develop an experimental design that prioritize the most important areas to maximize the results with actual project funds. We introduced for the first time the use of 2b-RAD on this species, a genotyping method based on sequencing the uniform fragments produced by type IIB restriction endonucleases. Thanks to this method we were able to move from genetics to the more complex genomics. In order to proceed with 2b-RAD we performed several tests to identify the best DNA extraction kit and protocol and finally we were able to extract 192 high quality DNA extracts ready to be processed. We tested 2b-RAD with five samples and after high-throughput sequencing of libraries we used the software “Stacks” to analyze the sequences. We obtained positive results identifying a great number of SNP markers among the five samples. To guarantee a multidisciplinary approach we used the biological data associated to the collected samples to investigate differences between geographical samples. Such approach assures continuity with other project, for instance STOCKMED, which utilize a combination of molecular and biological analysis as well.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study focused on the role of oceanographic discontinuities and the presence of transitional areas in shaping the population structure and the phylogeography of the Raja miraletus species complex, coupled with the test of the effective occurrence of past speciation events. The comparisons between the Atlantic African and the North-Eastern Atlantic-Mediterranean geographic populations were unravelled using both Cytochrome Oxidase I and eight microsatellite loci. This approach guaranteed a robust dataset for the identification of a speciation event between the Atlantic African clade, corresponding to the ex Raja ocellifera nominal species, and the NE Atlantic-Mediterranean R. miraletus clade. As a matter of fact, the origin of the Atlantic Africa and the NE Atlantic-Mediterranean deep split dated about 11.74MYA and was likely due to the synergic influence currents and two upwelling areas crossing the Western African Waters. Within the Mediterranean Sea, particular attention was also paid to the transitional area represented by Adventura and Maltese Bank, that might have contributed in sustaining the connectivity of the Western and the Eastern Mediterranean geographical populations. Furthermore, the geology of the easternmost part of Sicily and the geo-morphological depression of the Calabrian Arc could have driven the differentiation of the Eastern Mediterranean Sea. Although bathymetric and oceanographic discontinuity could represent barriers to dispersal and migration between Eastern and Western Mediterranean samples, a clear and complete genetic separation among them was not detected. Results produced by this work identified a speciation event defining Raja ocellifera and R. miraletus as two different species, and describing the R. miraletus species complex as the most ancient cryptic speciation event in the family Rajidae, representing another example of how strictly connected the environment, the behavioural habits and the evolutionary and ecologic drivers are.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper explores the politics of community making at the India-Bangladesh border by examining the public and private narratives of history and belonging in a Bangladeshi enclave-a sovereign piece of Bangladesh completely territorially surrounded by India. Drawing on framings of political society, this paper argues that understanding populations at the margins of South Asia and beyond requires attention to two processes: first, to the ways that para-legal activities are part and parcel of daily life; and second, to the strategies through which these groups construct themselves as moral communities deserving of inclusion within the state. Border communities often articulate narratives of dispossession, exceptionality, and marginalization to researchers and other visitors-narratives that are often unproblematically reproduced in academic treatments of the border. However, such articulations mask both the complicated histories and quotidian realities of border life. This paper views these articulations as political projects in and of themselves. By reading the more hidden histories of life in this border enclave, this article reconstructs the notion of borders as experienced by enclave residents themselves. It shows the ways that the politics of the India-Bangladesh border are constitutive of (and constituted by) a range of fractures and internal boundaries within the enclave. These boundaries are as central to forging community-to articulating who belongs and why-as are more public narratives that frame enclave residents as victims of confused territorial configurations. (C) 2012 Elsevier Ltd. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Druze community in Israel is a distinct religious community currently undergoing important ethnolinguistic shifts. The government's implementation of an official policy has led to the deconstruction and reshaping of the Druze political and national identity to one that differs substantially from that of the Palestinian minority in Israel. In this study, I argue that the visibility, vitality and appreciation of Hebrew in the Druze linguistic landscape are indicative of new ethnolinguistic boundaries of the Druze identity in Israel. The fact that the Druze in Israel are dispersed throughout the Galilee and Mount Carmel area and experience varying levels of language contact as well as divergent economic relations with their Palestinian–Israeli and Jewish–Israeli neighbors suggests that one cannot expect uniformity in the Druze linguistic markets or the processes of social, cultural and linguistic identification. This study will show that Hebrew has become a dominant component of the linguistic repertoire and social identity of the Druze in the Mount Carmel area since it has become the first choice of communication as the linguistic landscape indicates.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Speech is typically a multimodal phenomenon, yet few studies have focused on the exclusive contributions of visual cues to language acquisition. To address this gap, we investigated whether visual prosodic information can facilitate speech segmentation. Previous research has demonstrated that language learners can use lexical stress and pitch cues to segment speech and that learners can extract this information from talking faces. Thus, we created an artificial speech stream that contained minimal segmentation cues and paired it with two synchronous facial displays in which visual prosody was either informative or uninformative for identifying word boundaries. Across three familiarisation conditions (audio stream alone, facial streams alone, and paired audiovisual), learning occurred only when the facial displays were informative to word boundaries, suggesting that facial cues can help learners solve the early challenges of language acquisition.