1,721,004 research outputs found
Fylogeografie a genetická diverzita populací druhu Gobius niger (Gobiiformes: Gobiidae)
Full text linkHlaváči (Gobiiformes: Gobiidae) jsou nejpočetnější rybí čeledí a nejvíce zastoupenou skupinou ryb obývající evropské pobřeží. Genetická diverzita evropských hlaváčů byla doposud studována pouze u několika málo druhů. Ačkoli se mořské prostředí jeví jako homogenní, existují zde bariéry bránící genovému toku, například v podobě průlivů či mořských proudů. Hlaváč černý (Gobius niger) obývá pobřežní vody Evropy, severní Afriky a také středozemní a černomořské pobřeží Blízkého východu. Jedná se o bentický druh hlaváče, který má v rámci životního cyklu planktonní larvální stadia. V rámci této práce byli studovaní jedinci z 28 lokalit napříč areálem rozšíření, s cílem studia vnitrodruhové genetické diverzity. Analýza dvou mitochondriálních genů (cytochrom b a D loop) odhalila komplexní populační strukturu a výraznou vnitrodruhovou diverzitu (maximální p-distance 6,1 %). Populace je rozčleněna na čtyři velmi rozdílné haplotypové skupiny, s neočekávaným geografickým rozložením. Zatímco populace obývající Atlantský oceán a Severní moře je geneticky homogenní a všichni studovaní jedinci nesou haplotypy patřící do stejné haplotypové skupiny, středomořská populace je velmi komplexní, a vykazuje přítomnost čtyř haplotypových skupin, z nichž některé jsou sdílené i mezi vzdálenějšími regiony. V západním středomoří...Gobies (Gobiiformes: Gobiidae) are the most speciose fish family and the most abundant fish group of the European seas. Yet, the population genetic diversity has been studied in only a few European goby species. Although the ocean is seemingly a continuous habitat, there are barriers to gene flow in marine environment in form of e.g. straits or marine currents. The black goby (Gobius niger) is a demersal marine fish with planktonic larvae, inhabiting the coastal waters of Europe, north Africa and the Mediterranean and Black Sea coast of the Middle East. The current work examined individuals from 28 localities across the distribution range of the species in order to study the population genetic diversity. The analyses of two mitochondrial markers (cytochrome b and D loop) revealed a complex structuring of the population and a pronounced intraspecific diversity (maximum uncorrected p-distance 6.1 %). The population is divided into four very diverse haplotype groups, with unexpected geographic pattern. While the population inhabiting the Atlantic Ocean and the North Sea is generally genetically homogeneous, with all examined individuals bearing haplotypes belonging to a single haplotype group, the Mediterranean population is very complex, displaying a presence of four haplotype groups, some of which...Katedra ekologieDepartment of EcologyPřírodovědecká fakultaFaculty of Scienc
Phylogeography and genetic diversity of the populations of Gobius niger (Gobiiformes: Gobiidae)
No full textGobies (Gobiiformes: Gobiidae) are the most speciose fish family and the most abundant fish group of the European seas. Yet, the population genetic diversity has been studied in only a few European goby species. Although the ocean is seemingly a continuous habitat, there are barriers to gene flow in marine environment in form of e.g. straits or marine currents. The black goby (Gobius niger) is a demersal marine fish with planktonic larvae, inhabiting the coastal waters of Europe, north Africa and the Mediterranean and Black Sea coast of the Middle East. The current work examined individuals from 28 localities across the distribution range of the species in order to study the population genetic diversity. The analyses of two mitochondrial markers (cytochrome b and D loop) revealed a complex structuring of the population and a pronounced intraspecific diversity (maximum uncorrected p-distance 6.1 %). The population is divided into four very diverse haplotype groups, with unexpected geographic pattern. While the population inhabiting the Atlantic Ocean and the North Sea is generally genetically homogeneous, with all examined individuals bearing haplotypes belonging to a single haplotype group, the Mediterranean population is very complex, displaying a presence of four haplotype groups, some of which..
Phylogenetic, Biogeographic and Taxonomic investigations within the freshwater fish Family Nemacheilidae (Cypriniformes: Cobitoidea)
No full textWith over 800 species, the family Nemacheilidae is one of the biggest families of primary freshwater fishes. Distributed nearly across whole Eurasia and with two species in northeast Africa, the family offers a rich subject for phylogenetic, biogeographic and taxonomic investigations. This doctoral thesis aims to untangle phylogenetic relationships within Nemacheilidae at multiple taxonomic levels. The thesis comprises five articles published in peer-reviewed journals and one preprint currently undergoing revision. The main article presented here as a preprint provides the most comprehensive phylogenetic overview of the family Nemacheilidae to date and first extensive reconstruction of its biogeographic history. The study covers most of the distribution area of the family and significant portion of its taxonomic diversity, including 36 of the 49 recognized genera and over 250 species. The results of the phylogenetic analyses reveal several polyphyletic species and genera and several undescribed taxa. Six major clades were identified within the family. The reconstructed biogeographic history highlights the influence of local as well as global tectonic, geological, geographical and climatic events on the evolutionary history of Nemacheilidae. Three of the five published articles are focused on the..
Lamprehuela – Cobitis calderoni Băcescu, 1962
No full textPeces - Orden Cypriniformes - Familia Cobitidae en la Enciclopedia Virtual de Vertebrados Españoles, http://www.vertebradosibericos.org/.A comprehensive review of the natural history
of the Northern Iberian spined-loach Cobitis calderoni in Spain.Peer reviewe
La Sociedad Ibérica de Ictiología (SIBIC). Proyecto Life INVASAQUA
No full textSeminarioEspecies exóticas invasoras de agua dulce y sistemas estuarinos: sensibilización y prevención en la Península Ibérica. La diversidad natural en ríos, lagos y estuarios en España y Portugal está seriamente amenazada por la presencia de Especies Exóticas Invasoras (EEI). Después de la destrucción del hábitat, son la principal causa de la pérdida de biodiversidad y causan graves perjuicios en la economía y en la salud humana. LIFE INVASAQUA es un proyecto europeo cuya finalidad es concienciar al público en general y a los sectores interesados e involucrados en la problemática de las EEI sobre los ecosistemas acuáticos de la Península Ibérica. Contribuirá a mejorar la gestión y reducir los impactos de las EEI aumentando la difusión de información y el intercambio de conocimientos sobre soluciones y prácticas ambientales exitosas. Pretende apoyar y facilitar la puesta en marcha de la normativa europea sobre EEI. También aumentar y mejorar la capacidad de España y Portugal para la detección temprana y gestión de EEI acuáticas mediante la sensibilización y formación de grupos clave. Además busca sensibilizar al público en general sobre los impactos ambientales, socioeconómicos y sanitarios causados por EEI acuáticas
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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