1000 resultados para PESCA MARITIMA
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La pesca es, sin duda, un sector olvidado por las investigaciones sobre la historia económica de la España moderna. Sin embargo, su importancia era relevante tanto desde el punto de vista de la movilización de capitales (barcos y equipos) como en los aspectos de ocupación de la población activa (con porcentajes nada desdeñables en la periferia peninsular), de vertebración de las economías del litoral español o de producción de alimentos imprescindibles para el consumo del conjunto de la población de un país católico. En el siglo XVIII, la incapacidad para una comercialización adecuada de los excedentes locales implicaba una dependencia para el abastecimiento de buena parte del país respecto de los mercantes extranjeros del Atlántico (singularmente de los barcos ingleses); situación que se quebraría en parte gracias a un proceso de reconversión del sector, mediante la introducción de la pesca de arrastre en gran escala, la inyección de capitales para la construcción de barcos y de otras instalaciones, así como para el establecimiento de ambiciosas compañías lejos de los puertos de atraque, la organización de redes de distribución de las capturas por todo el litoral y la implantación de una industria salazonera que permitía la conservación de la pesca.
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Ten years of demographic and genetic monitoring of Stachys maritima in Catalonia (2001-2010). Implications for a recovery plan.- Stachys maritima is a species typical of the coastal dunes, with a wide distribution within the Mediterranean Basin. In spite of this, the species shows a clear regression. In Catalonia, it has been observed an important reduction of its populations since early 20th century, where it has disappeared from several localities in which it was relatively common (Tarragonès, Barcelonès). Herein we present the results of the demographic monitoring of the species during the last 10 years (2001-2010) in the known localities in Catalonia. Besides corroborating the disappearance (northern Sant Martí d’Empúries), the re-discovering (Llobregat Delta beach) and the detection of new populations (inner dunes of the Montgrí), a large year-to-year fluctuation of the monitored populations is stated; the possible reasons are discussed. In addition, the present work also includes the results of the allozyme diversity analysis of the new detected populations as well as the rediscoveries of the period 2004-2008, which were not included in a former study of genetic diversity carried out in 2002-2003. It is necessary to emphasize that the contribution of the new populations to the genetic diversity of Stachys maritima is very small, which can be attributed to their limited population size and /or to founder effects. Despite that the species is included in the Annex 2 (“En Perill d’Extinció”) within the Catàleg de Flora Amenaçada de Catalunya (Catalogue of Endangered Flora of Catalonia), and some “soft” conservation measures have been applied at local level (signposting of the beach accesses, environmental education, etc.) coupled with other more significant measures (e.g. translocation of individuals discovered in an artificial sandbank), it would be necessary the coordinated action and the scientific support of any initiative of conservation that could be carried out. The general frame to initiate actions of conservation should be the recovery plan of Stachys maritima, whose draft and application is mandatory in accordance to the Catàleg
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Myriapods (e.g., centipedes and millipedes) display a simple homonomous body plan relative to other arthropods. All members of the class are terrestrial, but they attained terrestriality independently of insects. Myriapoda is the only arthropod class not represented by a sequenced genome. We present an analysis of the genome of the centipede Strigamia maritima. It retains a compact genome that has undergone less gene loss and shuffling than previously sequenced arthropods, and many orthologues of genes conserved from the bilaterian ancestor that have been lost in insects. Our analysis locates many genes in conserved macro-synteny contexts, and many small-scale examples of gene clustering. We describe several examples where S. maritima shows different solutions from insects to similar problems. The insect olfactory receptor gene family is absent from S. maritima, and olfaction in air is likely effected by expansion of other receptor gene families. For some genes S. maritima has evolved paralogues to generate coding sequence diversity, where insects use alternate splicing. This is most striking for the Dscam gene, which in Drosophila generates more than 100,000 alternate splice forms, but in S. maritima is encoded by over 100 paralogues. We see an intriguing linkage between the absence of any known photosensory proteins in a blind organism and the additional absence of canonical circadian clock genes. The phylogenetic position of myriapods allows us to identify where in arthropod phylogeny several particular molecular mechanisms and traits emerged. For example, we conclude that juvenile hormone signalling evolved with the emergence of the exoskeleton in the arthropods and that RR-1 containing cuticle proteins evolved in the lineage leading to Mandibulata. We also identify when various gene expansions and losses occurred. The genome of S. maritima offers us a unique glimpse into the ancestral arthropod genome, while also displaying many adaptations to its specific life history.
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Curral Velho es una comunitat tradicional, situada al nord-est de Brasil, que manté una relació directa amb els ecosistemes que la envolten. La comunitat depèn del estat de conservació del medi natura, ja que obtenen diferents serveis ecositemics. En aquest territori es desenvolupen dos tipus d’economies amb unes bases molt diferents. Una economia tradicional, desenvolupada per la pròpia comunitat, que es basa en la propietat col·lectiva del territori i en optimitzar a llarg termini els beneficis que s’obtenen del medi; y un altre com la camaronicultura, la base de la qual es la obtenció de beneficis a curt termini i amb un territori de propietat privada. Aquesta superposició de models de producció genera impactes ambientals, i un conflicte socio-ambiental entre la comunitat i els que desenvolupen la camaronicultura. L’objectiu es realitzar un estudi econòmic de la pesca artesanal de Curral Velho caracteritzant manera de viure, creant una base de dades sobre pesca artesanal i elaborant indicador de beneficis econòmics generats per la pesca artesanal. Per contextualitzar els resultats es va fer un anàlisis de les dos economies existents a la comunitat. Els resultats obtinguts en primer lloc són que l’economia d’explotació intensiva aporta més guanys per les persones de la comunitat que tenen un relació directa que les que es dediquen a la pesca artesanal, però es important no aturar-se aquí: s’ha de realitzar un anàlisis més profund. Com a conclusió, la activitat pesquera es més rentable a llarg termini ja que els recursos extrets de manera sostenible i així són il·limitats y accessibles a tota la comunitat. A diferència de la camaronicultura, la pesca artesanal no genera desigualtats socials ni vulneracions dels drets humans. Tot el contrari, genera forts vincles entre els individus de la comunitat basats en el treball en equip i l’aprenentatge vivencial e intergeneracional.
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Stemodinol, a new natural compound, together with known compounds including jaceidin, stemodin, stemodinoside B, isocrenatoside, verbascoside, crenatoside, and isoverbascoside, were isolated from Stemodia maritima Linn. The antioxidant (DPPH method) and antimicrobial activities of stemodin, stemodinoside B, and crenatoside were investigated. Among the components tested, only crenatoside isolated from the roots showed a high antioxidant power. Stemodin and stemodinoside B exhibited antibacterial activities.
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Sementes de M. maritima germinam na temperatura ótima de 25°C com valores máximos na luz, sendo o processo otimizado em temperatura alternada de 25/30°C. Escarificação mecânica promove a germinação. Em sementes nuas, a germinação é promovida e acelerada tanto na luz quanto no escuro. Temperatura de armazenamento e tempo de estocagem alteram a fotossensibilidade das sementes: sementes estocadas à temperatura ambiente por 90 dias perdem o fotoblastismo positivo enquanto que nas estocadas sob baixa temperatura (10°C) este efeito permanece. O teste do tetrazólio demonstra que aos 180 dias de estocagem 46% das sementes permaneceram viáveis. Análises topoquímicas indicam que a principal fonte de reserva destas sementes, localizada nos cotilédones, é proteica.
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Cakile maritima occurs sporadically along the southern Brazilian coast, where it is restricted to more protected sites at the base of foredunes. Somatic dimorphism in C. maritima is manifested as morphologically distinct upper and lower fruit segments (silicules). The two morphs were tested for differences in size, number of seeds, dispersal ability and natural establishment. In the C. maritima population of southern Brazil, the lower silicule has more seeds than upper silicule, and lower seeds are more likely to abort than the upper ones. Seeds from upper segments were significantly larger than those from lower ones; however, their mass ranges overlap. The mean silicule mass was not significantly different from both segments, but the silicule/seed mass ratio from upper and lower segments was significantly different. Both segments had high ability to float in sea water, more than 50% were still afloat after 70 days. Nevertheless, dispersal occurs mainly to landward due to dominant wind action. Most of the seedlings were restricted to within a one-metre radius of the mother plant, and were principally derived from lower fruit segments.
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For certain applications of the polymerase chain reaction (PCR), it may be necessary to consider the accuracy of replication. The breakthrough that made PCR user friendly was the commercialization of Thermus aquaticus (Taq) DNA polymerase, an enzyme that would survive the high temperatures needed for DNA denaturation. The development of enzymes with an inherent 3' to 5' exonuclease proofreading activity, lacking in Taq polymerase, would be an improvement when higher fidelity is needed. We used the forward mutation assay to compare the fidelity of Taq polymerase and Thermotoga maritima (ULTMA) DNA polymerase, an enzyme that does have proofreading activity. We did not find significant differences in the fidelity of either enzyme, even when using optimal buffer conditions, thermal cycling parameters, and number of cycles (0.2% and 0.13% error rates for ULTMA and Taq, respectively, after reading about 3,000 bases each). We conclude that for sequencing purposes there is no difference in using a DNA polymerase that contains an inherent 3' to 5' exonuclease activity for DNA amplification. Perhaps the specificity and fidelity of PCR are complex issues influenced by the nature of the target sequence, as well as by each PCR component.
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Tesis (Maestría en Ciencias con Especialidad en Ecología Acuática y Pesca) UANL
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Tesis (Maestría en Ciencias de Enfermería con Enfasis en Salud Comunitaria) UANL
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UANL
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UANL
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UANL