76 research outputs found

    Addicions a la flora algològica del Principat de Catalunya

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    In a sandy-bed near Arenys de Mar (Barcelona, Spain) some algal species were collected, using scuba-diving techniques, at 25-32 m depth. Three of them were for the first time found in the catalan coast: Halymenia latifolia Crouan & Crouan, Halymenia floresia (Clemente) C. Agardh var. pinnata Codomier and Carpomitra costata (Stackhouse) Batters var. mediterranea Feldmann

    On the presence of fertile gametophytes of <i>Padina pavonica</i> (Dictyotales, Phaeophyceae) from the Iberian coasts

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    The gametophytes of <em>Padina pavonica</em> (L.) Thivy have received little attention in literature. Both female and predominantly male monoecious gametophytes of <em>P. pavonica</em> are recorded for the first time in the Iberian Peninsula. A detailed description of the morphology and the disposition of oogonia and antheridia is presented. In addition, a comparison with literature data on this and other <em>Padina</em> species is carried out.<br><br>Los gametófitos de <em>Padina pavonica</em> (L.) Thivy han sido escasamente reseñados en la bibliografía. En este trabajo se señala por primera vez en las costas de la Península Ibérica la presencia de gametófitos fértiles de <em>P. pavonica</em>, tanto femeninos como monoicos predominantemente masculinos. Se presenta una detallada descripción de la disposición y la morfología de los oogonios y anteridios. Asimismo, se realiza una comparación con los datos bibliográficos de esta especie y con los de otras especies de <em>Padina</em

    Nuevas citas para la flora algológica de Baleares

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    In the study that we are carrying out about the algological flora of Mallorca, two new species for the Balearic islands have been determined: they are Hypnea cervicornis J. Agardh and Galaxaura oblongata (Ellis and Solander) Lamouroux, two tipically tropical species.En el estudio que estamos llevando a cabo sobre la flora algológica de Mallorca, se han determinado dos especies nuevas para las Baleares. Son Hypnea cervicornis J. Agardh y Galaxaura oblongata (Ellis and Solander) Lamouroux, especies típicamente tropicales

    Sobre la presencia de gametófitos fértiles de Padina pavonica (Dictyotales, Phaeophyceae) en las costas ibéricas

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    The gametophytes of Padina pavonica (L.) Thivy have received little attention in literature. Both female and predominantly male monoecious gametophytes of P. pavonica are recorded for the first time in the Iberian Peninsula. A detailed description of the morphology and the disposition of oogonia and antheridia is presented. In addition, a comparison with literature data on this and other Padina species is carried out.Los gametófitos de Padina pavonica (L.) Thivy han sido escasamente reseñados en la bibliografía. En este trabajo se señala por primera vez en las costas de la Península Ibérica la presencia de gametófitos fértiles de P. pavonica, tanto femeninos como monoicos predominantemente masculinos. Se presenta una detallada descripción de la disposición y la morfología de los oogonios y anteridios. Asimismo, se realiza una comparación con los datos bibliográficos de esta especie y con los de otras especies de Padin

    Nuclear DNA content variation in life history phases of the Bonnemaisoniaceae (Rhodophyta)

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    Nuclear DNA content in gametophytes and sporophytes or the prostrate phases of the following species of Bonnemaisoniaceae (Asparagopsis armata, Asparagopsis taxiformis, Bonnemaisonia asparagoides, Bonnemaisonia clavata and Bonnemaisonia hamifera) were estimated by image analysis and static microspectrophotometry using the DNA-localizing fluorochrome DAPI (4′, 6-diamidino-2-phenylindole, dilactate) and the chicken erythrocytes standard. These estimates expand on the Kew database of DNA nuclear content. DNA content values for 1C nuclei in the gametophytes (spermatia and vegetative cells) range from 0.5 pg to 0.8 pg, and for 2C nuclei in the sporophytes or the prostrate phases range from 1.15-1.7 pg. Although only the 2C and 4C values were observed in the sporophyte or the prostrate phase, in the vegetative cells of the gametophyte the values oscillated from 1C to 4C, showing the possible start of endopolyploidy. The results confirm the alternation of nuclear phases in these Bonnemaisoniaceae species, in those that have tetrasporogenesis, as well as those that have somatic meiosis. The availability of a consensus phylogenetic tree for Bonnemaisoniaceae has opened the way to determine evolutionary trends in DNA contents. Both the estimated genome sizes and the published chromosome numbers for Bonnemaisoniaceae suggest a narrow range of values consistent with the conservation of an ancestral genome

    ‘Restricted’ and ‘General’ Complexity Perspectives on Social Bilingualisation and Language Shift Processes

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    Historical processes exert an influence on the current state and evolution of situations of language contact, brought to bear from different domains, the economic and the political, the ideological and group identities, geo-demographics, and the habits of inter-group use. Clearly, this kind of phenomenon requires study from a complexical and holistic perspective in order to accommodate the variety of factors that belong to different levels and that interrelate with one another in the evolving dynamic of human languaging. Therefore, there is a need for the restricted and general complexity approaches to come to a meeting of the minds, and take steps toward a mutual integration based on the acceptance of the shortcomings of each approach, achieving progress through a non-contradictory complementarity of perspectives. It must be conceded that the practical and methodological applications of basic complexical ideas need to be developed much farther in order to apply them to specific research. At the same time, the limits of complex adaptive systems as computational strategies must be accepted in the pursuit of a better understanding of the dynamic and evolutionary processes typical of human beings. New tools for the conception, apprehension and treatment of the data will need to be devised to complement existing ones and to enable us to make headway toward practices that better fit complexical perspectives. It seems obvious that human complexics must be seen as multi-methodological, insofar as necessary combining quantitative-computation methodologies and more qualitative methodologies aimed at understanding the historical mental and emotional world of people

    Current status and trends of biological invasions in the Lagoon of Venice, a hotspot of marine NIS introductions in the Mediterranean Sea

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    This paper provides an updated account of the occurrence and abundance of non-indigenous species (NIS) in an area of high risk of introduction: the Lagoon of Venice (Italy). This site is a known hotspot of NIS introductions within the Mediterranean Sea, hosting all the most important vectors of introduction of marine NIS—shipping, recreational boating, shellfish culture and live seafood trade. The recent literature demonstrates that the number of NIS in Venice is continuously changing, because new species are being introduced or identified, and new evidence shows either an exotic origin of species previously believed to be native, or a native origin of formerly believed ‘‘aliens’’, or demonstrates the cryptogenic nature of others. The number of NIS introduced in the Venetian lagoon currently totals 71, out of which 55 are established. This number exceeds those displayed by some nations like Finland, Portugal or Libya. Macroalgae are the taxonomic group with the highest number of introduced species (41 % of NIS): the most likely vector for their introduction is shellfish culture. The source region of NIS introduced to Venice is mainly represented by other Mediterranean or European sites (76 %). The Lagoon of Venice represents a sink but also a source of NIS in the Mediterranean Sea, as it is the site of first record of several NIS, which have since further spread elsewhere.This paper provides an updated account of the occurrence and abundance of non-indigenous species (NIS) in an area of high risk of introduction: the Lagoon of Venice (Italy). This site is a known hotspot of NIS introductions within the Mediterranean Sea, hosting all the most important vectors of introduction of marine NIS-shipping, recreational boating, shellfish culture and live seafood trade. The recent literature demonstrates that the number of NIS in Venice is continuously changing, because new species are being introduced or identified, and new evidence shows either an exotic origin of species previously believed to be native, or a native origin of formerly believed "aliens", or demonstrates the cryptogenic nature of others. The number of NIS introduced in the Venetian lagoon currently totals 71, out of which 55 are established. This number exceeds those displayed by some nations like Finland, Portugal or Libya. Macroalgae are the taxonomic group with the highest number of introduced species (41 % of NIS): the most likely vector for their introduction is shellfish culture. The source region of NIS introduced to Venice is mainly represented by other Mediterranean or European sites (76 %). The Lagoon of Venice represents a sink but also a source of NIS in the Mediterranean Sea, as it is the site of first record of several NIS, which have since further spread elsewhere

    Passat, present i perspectives de l'algologia als Països Catalans

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