400 research outputs found

    Infertilitat masculina per un "error de càlcul" cromosòmic

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    Durant el procés de divisió cel·lular conegut com a meiosi, poden tenir lloc errors en la segregació cromosòmica, donant gàmetes amb un nombre erroni de cromosomes, que poden ser l'origen d'infertilitat masculina, avortaments espontanis o de descendència afectada. Aquest treball descriu, per primera vegada, la separació prematura de cromàtides germanes -ja detectada en oòcits- en la formació de gàmets masculins (espermatogènesi).Durante el proceso de división celular conocido como meiosis, pueden ocurrir errores en la segregación cromosómica que dan lugar a gametos con un número erróneo de cromosomas, causando infertilidad masculina, abortos espontáneos o descendencia afectada. Este trabajo describe por primera vez la separación prematura de cromátidas hermanas -ya detectada en ovocitos- en la formación de gametos masculinos (espermatogénesis).During meiosis, errors in chromosome segregation lead to aneuploid gametes (with an erroneous number of chromosomes) which might result in male infertility, spontaneous abortions or affected offspring. This work describes for the first time in human spermatogenesis the premature separation of sister chromatids, previously detected in oocytes

    Population status of the endangered limpet Patella ferruginea (Mollusca: Patellidae) in the Peñón de Vélez de la Gomera (south-west Mediterranean Sea)

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    The population of the endangered limpet Patella ferruginea in the Peñón de Vélez de la Gomera, a small Spanish peninsula located on the North African coast (south-west Mediterranean) was evaluated by surveys carried out in June and October 2012. Overall, 567 specimens were recorded along the entire coastline (about 1320 m) of this enclave (169 individuals measured >30 mm in maximum diameter of the shell, likely adults, and 398 specimens were <30 mm, likely immature individuals). In this site an average 0.13 adults/m was registered, and the maximum density observed was 0.90 adults/m in some zones. This points out the importance of this enclave among the present known populations existing in Spanish territories of this highly endangered limpet, but particularly highlights the role of the adjacent North African coastal protected areas in the conservation of this speciesOur work has been partly funded by the project ‘Action plan for Proposals viability of the endangered limpet, Patella ferruginea ’ (Project Zero—Endangered Species of the Fundacion General CSIC)Peer Reviewe

    Corallium rubrum

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    Existen 31 especies descritas de la familia Corallidae (corales rojos y rosas) asignadas a dos géneros diferentes: Corallium y Paracorallium . Casi todas ellas son de aguas profundas y la mayoría se distribuyen por los océanos Índico y Pacífico. En el Atlántico oriental además de C. rubrum se conocen otras dos especies: C. niobe Bayer, 1964, descrita en el área caribeña pero que también está presente desde el Golfo de Vizcaya hasta las costas de Marruecos, y C. tricolor Jonson, 1899, sólo conocida en Madeira y CanariasPeer Reviewe

    Crisilla morenoi Templado & Rolán, 1994

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    Catálogo do Museo de Historia Natural USC. n. inventario 10016

    The mitochondrial genome of Ifremeria nautilei and the phylogenetic position of the enigmatic deep-sea Abyssochrysoidea (Mollusca: Gastropoda)

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    The complete nucleotide sequence of the mitochondrial (mt) genome of the deep-sea vent snail Ifremeria nautilei (Gastropoda: Abyssochrysoidea) was determined. The double stranded circular molecule is 15,664 pb in length and encodes for the typical 37 metazoan mitochondrial genes. The gene arrangement of the Ifremeria mt genome is most similar to genome organization of caenogastropods and differs only on the relative position of the trnW gene. The deduced amino acid sequences of the mt protein coding genes of Ifremeria mt genome were aligned with orthologous sequences from representatives of the main lineages of gastropods and phylogenetic relationships were inferred. The reconstructed phylogeny supports that Ifremeria belongs to Caenogastropoda and that it is closely related to hypsogastropod superfamilies. Results were compared with a reconstructed nuclear-based phylogeny. Moreover, a relaxed molecular-clock timetree calibrated with fossils dated the divergence of Abyssochrysoidea in the Late Jurassic-Early Cretaceous indicating a relatively modern colonization of deep-sea environments by these snails. © 2014 Elsevier B.V.This work was supported by the Spanish Ministry of Science and Innovation (CGL2007-60954 and CGL2010-18216 to RZ; BES-2008-009562 to DO).Peer Reviewe

    Catálogo nacional de los moluscos marinos de las aguas españolas

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    A checklist of marine Mollusca recorded in Spanish jurisdictional waters is presented, based on a thorough literature search and a limited input of recent field work. The list is detailed according to the five demarcations of the Marine Strategy Framework Directive (NOR, Spanish north coast; SUR, Spanish coast of the Gulf of Cádiz; ESAL, Strait of Gibraltar and Alboran Sea; LEBA, East coast of Spain and Balearic Islands; CAN, the Canary Islands). The list differentiates coastal species living from the supralittoral zone to the shelf break, deep-sea benthic or demersal species, and holoplanktonic species, and also distinguishes between non-indigenous species and species endemic to a particular demarcation. A total of 2466 marine Mollusca species have been reported from Spanish waters, of which 1126 are recorded only from waters surrounding the Iberian Peninsula, 498 are recorded from the Canaries only, and 842 are shared. That total number represents around 5.5% of the global marine molluscan richness. Shore and shelf species are the most numerous (1837), followed by deep-sea benthic species (490) and pelagic species (139), but the contribution of the deep-sea species is most noteworthy in NOR. All eight molluscan classes were represented, but solenogastres and scaphopods were notably more represented than usual in NOR. Species richness in SUR and ESAL was higher than would be expected from their areas, supporting the claim that Andalusian waters have an exceptionally diverse molluscan fauna. Thirteen species collected from INDEMARES cruises are here reported for the first time in Spanish waters. The species recorded in Spanish seas represent more than half of the 4340 species of Mollusca recorded within the scope of the European Register of Marine Species, making this the highest species count in European seas. The Canary Islands demarcation holds by far the largest number of endemic species (127), but special mention is needed regarding the ca. 20 species endemic to the Strait of Gibraltar, a highly anomalous chorotype in the marine realm. The number of non-indigenous species (38) is surprisingly low compared with that of species known in the Mediterranean Sea, amounting to hardly 1.5% of the total and supporting the view that a high number of native species tends to reduce invasion success. The list is seen as a much needed tool for the identification of priority areas for biodiversity conservation, but requires permanent attention and curating in order to remain up-to-date.Se presenta el catálogo actualizado de los moluscos marinos citados en las aguas jurisdiccionales españolas, basado en una exhaustiva revisión bibliográfica y en los hallazgos de campañas recientes. La lista se detalla para las cinco demarcaciones de la Directiva Marco sobre la Estrategia Marina (NOR: costas del norte de España; SUR: costas españolas del golfo de Cádiz, ESAL: estrecho de Gibraltar y mar de Alborán; LEBA: costas del este de España e islas Baleares; CAN: islas Canarias). En la lista se diferencia entre las especies costeras (las que viven desde la zona supralitoral hasta el borde de la plataforma continental), las especies bentónicas o demersales de aguas profundas y las especies holoplanctónicas, y también se indican las especies alóctonas y las que son endémicas para cada una de las demarcaciones. En total, se han citado 2.466 especies de moluscos marinos en aguas españolas, de las cuales 1.126 se conocen sólo en aguas peninsulares y baleares, 498 sólo en aguas canarias, mientras que 842 comparten ambas áreas. Ese número total representa alrededor del 5,5% de la riqueza específica global de moluscos marinos. Las especies costeras y de la plataforma continental son las más numerosas (1.837), seguidas de las especies de aguas profundas (490) y pelágicas (139), pero la contribución de las especies profundas es especialmente notable en NOR. Están representadas las ocho clases que comprende el filo Mollusca, con una destacable representación de los solenogastros y escafópodos en NOR. La riqueza de especies en SUR y ESAL es superior a la que cabría esperar de sus respectivas áreas, lo que apoya la afirmación de que las costas y aguas andaluzas albergan una malacofauna especialmente diversa. Trece especies recogidas en campañas del proyecto INDEMARES se citan aquí por primera vez en aguas españolas. Las especies registradas en los mares españoles suponen más de la mitad de las 4.340 especies de moluscos registradas en el ámbito geográfico del Registro Europeo de Especies Marinas, lo que supone el mayor número de especies de los países europeos. La demarcación de las islas Canarias es la que contiene con diferencia el mayor número de endemismos (127), pero merecen una mención especial las cerca de 20 especies endémicas del área del estrecho de Gibraltar, un corotipo muy anómalo en el medio marino. El número de especies alóctonas (38) es sorprendentemente bajo si lo comparamos con el número de especies que se consideran introducidas en el mar Mediterráneo, y representa apenas un 1,5 % del total, lo que apoya la idea de que un alto número de especies nativas tiende a reducir el éxito de las invasiones. La lista de especies que aquí se presenta constituye una herramienta muy necesaria para la identificación de áreas prioritarias de conservación de la biodiversidad, pero requiere una constante atención y actualización

    El partido de acción republicana, 1925-1934

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    Tesis inédita de la Universidad Complutense de Madrid, Facultad de Derecho, leída en 1978.ProQuestFac. de DerechoTRUEpu

    Biogeographical homogeneity in the eastern Mediterranean Sea - I: the opisthobranchs (Mollusca: Gastropoda) from Lebanon

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    A reviewed knowledge of the opisthobranch species from Lebanon (eastern Mediterranean Sea), based on literature records (scattered throughout various papers published over a period of more than 150 years) and recently collected material (1999-2002 within the CEDRE framework and other samples), is presented, yielding a total number of 35 taxa recorded from the Lebanese shores identified to species level. Special emphasis has mainly been given to the alien species, for which scattered notes are also given. The known opisthobranch biota is composed of 22 native (~ 63%), 12 alien (~ 34%) and one cryptogenic (~ 3%) taxa. Eleven of these (Berthella aurantiaca, B. ocellata, Aplysia fasciata, Felimare picta, Felimida britoi, F. luteorosea, F. purpurea, Phyllidia flava, Dendrodoris grandiflora, D. limbata and Aeolidiella alderi) constitute new records for the Lebanese fauna, whilst the examined material of a further seven species (Elysia grandifolia, Pleurobranchus forskalii, Aplysia dactylomela, Bursatella leachii, Syphonota geographica, Goniobranchus annulatus, Flabellina rubrolineata) anecdotally cited from Lebanon on the basis of the samples here studied, is here first explained. One additional taxon belonging to the genus Haminoea has been identified to genus level only. Despite the searching effort poning the basis of the material analyzed here, data reported clearly suggest that strong investments are still needed for a better understanding of the eastern Mediterranean opisthobranch fauna
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