986 resultados para Biology, Ecology|Biology, Oceanography|Biogeochemistry


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A conservation priority in the marine environment is the establishment of ecologically coherent reserve networks. Since these networks will integrate existent reserves, an understanding of spatial genetic diversity and genetic connectivities between areas is necessary. Using Strangford Lough marine nature reserve (MNR) as a model, spatial genetic analyses were employed to evaluate the function of the lough. Samples of the marine gastropod Nucella lapillus (L.) from 7 locations in the reserve and adjacent areas were screened at 6 microsatellites. Genetic variation was temporally stable. Significant genetic structuring (F-ST = 0.133) was observed among samples. Genetic divergence and isolation by distance indicated reduced gene flow between the marine reserve and coastal samples relative to that between adjacent coastal samples. Partitioning of genetic variation between the reserve and coast was significant (AMOVA, 7.45%, p

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Bio art, understood as the convergence of the relations between art, biology and technology, constitutes a useful case study to discuss the meaning of interdisciplinarity in the artistic field. This paper explores different discourses around interdisciplinarity in order to challenge certain generic approaches for their ineffectiveness when assessing artistic practices. It is proposed that the analysis of interdisciplinarity must address the singular connections produced in the artistic practice itself, considering the impossibility of reducing the complexity of interdisciplinary dialogues into generic considerations. Taking bioart as a case study, different kinds of relationships between the artist and the lab are identified and analyzed, ranging from the use of the lab as a true atelier and as a resource for materials and techniques, to the rejection of the lab by proposing amateurism as an alternative. estrategias amateur, pasando por su utilización como fuente de técnicas y materiales.

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We know considerably more about what makes cells and tissues resistant or sensitive to radiation than we did 20 years ago. Novel techniques in molecular biology have made a major contribution to our understanding at the level of signalling pathways. Before the “New Biology” era, radioresponsiveness was defined in terms of physiological parameters designated as the five Rs. These are: repair, repopulation, reassortment, reoxygenation and radiosensitivity. Of these, only the role of hypoxia proved to be a robust predictive and prognostic marker, but radiotherapy regimens were nonetheless modified in terms of dose per fraction, fraction size and overall time, in ways that persist in clinical practice today. The first molecular techniques were applied to radiobiology about two decades ago and soon revealed the existence of genes/proteins that respond to and influence the cellular outcome of irradiation. The subsequent development of screening techniques using microarray technology has since revealed that a very large number of genes fall into this category. We can now obtain an adequately robust molecular signature, predicting for a radioresponsive phenotype using gene expression and proteomic approaches. In parallel with these developments, functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) can now detect specific biological molecules such as haemoglobin and glucose, so revealing a 3D map of tumour blood flow and metabolism. The key to personalised radiotherapy will be to extend this capability to the proteins of the molecular signature that determine radiosensitivity.

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Epibiotic foraminifers selectively settle on the most food-rich area of the host substrate, even when the species acts as a facultative ectoparasite in later life stages. In 398 specimens examined of the deep-sea chiton Leptochiton arcticus from Iceland, 46% show evidence of infestation by foraminifers, with many showing extensive shell damage from present and past bioeroding epibionts. Disturbances to the inner layer of the host shell are indicative of parasitism, as evidenced both by wound healing calcification and protrusions of the foraminiferan tubules. The epibionts employ different feeding strategies at different stages of their life cycle, taking advantage of nutrient availability from the posterior respiration currents and excrement of the chitons as juveniles, and feeding parasitically as adults. Epibiont persistence on individual hosts-through successive generations, or long-term continuous bioerosion by epibionts-allow larger adult parasitic foraminifers of Hyrrokkin sarcophaga to penetrate the thick tail valve of a chiton and feed parasitically on the host tissue. The proportion of chitons infested increases with host size, indicating that epibionts are accumulated through a chiton's life, seemingly without major detriment to host survivorship.

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Jellyfish are increasingly topical within studies of marine food webs. Stable isotope analysis represents a valuable technique to unravel the complex trophic role of these long-overlooked species. In other taxa, sample preservation has been shown to alter the isotopic values of species under consideration, potentially leading to misinterpretation of trophic ecology. To identify potential preservation effects in jellyfish, we collected Aurelia aurita from Strangford Lough (54(o)22'44.73aEuro(3)N, 5(o)32'53.44aEuro(3)W) during May 2009 and processed them using three different methods prior to isotopic analysis (unpreserved, frozen and preserved in ethanol). A distinct preservation effect was found on delta N-15 values: furthermore, preservation also influenced the positive allometric relationship between individual size and delta N-15 values. Conversely, delta C-13 values remained consistent between the three preservation methods, conflicting with previous findings for other invertebrate, fish and mammalian species. These findings have implications for incorporation of jellyfish into marine food webs and remote sampling regimes where preservation of samples is unavoidable.