Development and standardization of a protocol for sperm cryopreservation of two important commercial oyster species

Dissertação de mestrado, Aquacultura e Pescas, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015Aquaculture activities have a huge contribution for the world food production and their development is extremely necessary to answer to the lack of resources, especially to the demand for seafood. Bivalve production, especially Crassostrea angulata (Portuguese oyster) has been practiced from long ago, and although its production suffered several constraints, in recent years it has been increasing the interests in recovering production and in preserving nature populations. In this sense, new research needs to guarantee an efficient and economically viable production, contributing to a relatively new environmental concern: wild population restoration. Nowadays, pure wild populations of Crassostrea angulata are rare to find due to multiple factors that affected this oyster industry. Cryopreservation technology could promote alternative techniques to contribute for the resource management efficiency of the Portuguese oyster and associated economic activity. In this sense, standardization of procedures is important for Crassostrea genus. At the present there are no cryopreservation reports on Crassostrea angulata sperm, and therefore, one of the objectives of this work is to design a cryopreservation protocol for this species, testing the more adequate cryoprotectant solution, its ideal concentration, different freezing rates and types of containers. In parallel, this stablished protocol was applied in Crassostrea gigas and compared to other previously published for this species. Analysis of motility, viability, agglutination and fertilizations were used as guides for the establishment of the protocol in C. angulata. Moreover, ATP content, DNA fragmentation and lipid peroxidation were done in order to standardize the same protocol for both species. Movement analysis were assessed by CASA system, viability through common staining techniques and flow cytometer, agglutination was quantified according to the scale developed by Dong et al., (2007), ATP content determined by bioluminescence, Comet assay was performed to quantify the DNA fragmentation and lipid peroxidation determined spectrophotometrically by measuring the absorbance of the malondialdehyde (MDA). Significant differences were observed (p<0.05) for lipid peroxidation and fertilization trials whereas ATP content and fragmentation of DNA of the cryopreserved samples did not differ significantly from the control. In C. gigas, the same analysis were performed and did not reveal post-thaw quality differences in the samples cryopreserved with 10% DMSO. The established protocol revealed to be effective and with a low degree of cellular damage on C. angulata sperm and, at the same time, viable to apply in other species, such as Crassostrea gigas

Intelligent Integrated Management for Telecommunication Networks

As the size of communication networks keeps on growing, faster connections, cooperating technologies and the divergence of equipment and data communications, the management of the resulting networks gets additional important and time-critical. More advanced tools are needed to support this activity. In this article we describe the design and implementation of a management platform using Artificial Intelligent reasoning technique. For this goal we make use of an expert system. This study focuses on an intelligent framework and a language for formalizing knowledge management descriptions and combining them with existing OSI management model. We propose a new paradigm where the intelligent network management is integrated into the conceptual repository of management information called Managed Information Base (MIB). This paper outlines the development of an expert system prototype based in our propose GDMO+ standard and describes the most important facets, advantages and drawbacks that were found after prototyping our proposal

La calidad de los servicios en la sociedad de la información y la formación de los futuros profesionales.

Sin resume

La migración como factor que determina la duración de los cuidados parentales durante el periodo de dependencia en rapaces: el caso del alimoche (Neophron percnopterus) en las Islas Baleares

Sedentary Egyptian vulture population was studied during their post-fledging dependence period in Balearic Islands (Spain) compared with a migratory population in northern Iberian Peninsula. Fledging age, independence age and length of postfledging dependence period are similar in these two populations. Some studies are indicated that length of post-fledging dependence period are determinate by the necessity of migrant species begin his migration, and this migrant species would show length post-fledging dependence period more shorts. Our results show that sedentary populations have similar post-fledging dependence period that migration population.Se ha estudiado el periodo de dependencia en una rapaz carroñera sedentaria, el alimoche (Neophron percnopterus) en las Islas Baleares, comparando con los datos obtenidos en una población migrante del noroeste de la Península Ibérica. La fecha de primer vuelo, la edad de independencia y la duración del periodo de dependencia no han variado entre estas dos poblaciones. Diversos autores han manifestado que la duración del periodo de dependencia puede venir determinado por la necesidad de que especies migrantes deban iniciar su migración, por lo que estas poblaciones deberían mostrar periodos de dependencia más cortos. Nuestros datos no apuntan en esa dirección mostrando que una población sedentaria tiene periodos de dependencia iguales a los que ocurren en otra población migrante

Población reproductora, productividad y distribución espacial de una población insular de cuervo, Corvus corax (Menorca, Islas Baleares)

Se ha llevado a cabo, en la isla de Menorca (Islas Baleares), un estudio sobre la población reproductora de cuervo (Corvus corax), centrándose en estimar su población, la productividad y su distribución espacial sobre la superficie insular. Los datos obtenidos muestran que la población de la isla de Menorca, estimada en 40 parejas reproductoras, parece encontrase en un estado de conservación desfavorable. Unas densidades de parejas reproductoras bajas (5.6 parejas/100 km2), distribución espacial irregular (G= 0.53), existencia de perturbaciones humanas (venenos y electrocuciones), asociados con una alta productividad (3.1 pollos/pareja territorial), gran cantidad de lugares para la cría disponibles y un importante aporte de alimento basado en actividades agrícolas-ganaderas apuntan en esa dirección, a pesar de no disponer de censos históricos que la corroboren