2 resultados para Hospitality and Administration and Management

em Universidad de Alicante


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Optic neuritis is an inflammation of the optic nerve and may be related to different systemic conditions. The clinical presentation of this pathology usually includes sudden loss of visual acuity (VA) which may be unilateral or bilateral, visual field restriction, pain with eye movements, dyschromatopsia, a relative afferent pupillary defect and optic disk swelling. Optic neuritis in children has specific clinical features and a better prognosis than in adulthood. Although usually appears an underlying viral disease, the main concern for practitioners is the relationship of optic neuritis with multiple sclerosis. In addition to the classical techniques as magnetic resonance imaging (MRI), current tendencies of diagnosis for eye practitioners include new imaging devices as optical coherence tomography (OCT), useful to show a thinning of the retinal fibers layer (RFL) after the inflammatory episode. Regarding the management of these patients, short-term intravenous steroid dosages seem to be the best option to treat acute attacks characterized by a very poor bilateral VA.

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Frequently, population ecology of marine organisms uses a descriptive approach in which their sizes and densities are plotted over time. This approach has limited usefulness for design strategies in management or modelling different scenarios. Population projection matrix models are among the most widely used tools in ecology. Unfortunately, for the majority of pelagic marine organisms, it is difficult to mark individuals and follow them over time to determine their vital rates and built a population projection matrix model. Nevertheless, it is possible to get time-series data to calculate size structure and densities of each size, in order to determine the matrix parameters. This approach is known as a “demographic inverse problem” and it is based on quadratic programming methods, but it has rarely been used on aquatic organisms. We used unpublished field data of a population of cubomedusae Carybdea marsupialis to construct a population projection matrix model and compare two different management strategies to lower population to values before year 2008 when there was no significant interaction with bathers. Those strategies were by direct removal of medusae and by reducing prey. Our results showed that removal of jellyfish from all size classes was more effective than removing only juveniles or adults. When reducing prey, the highest efficiency to lower the C. marsupialis population occurred when prey depletion affected prey of all medusae sizes. Our model fit well with the field data and may serve to design an efficient management strategy or build hypothetical scenarios such as removal of individuals or reducing prey. TThis This sdfsdshis method is applicable to other marine or terrestrial species, for which density and population structure over time are available.