Browsing by Issue Date, starting with "2006-11"
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- Idades U-Pb de zircões nas areias quaternárias do AlgarvePublication . Veiga-Pires, C.; Moura, Delminda; Rodrigues, Bruno; Machado, Nuno; Campo, Leif; Simonetti, AntonyO objectivo deste trabalho é realçar e quantificar a contribuição das variações geomorfológicas nas modificações da rede de drenagem através de datações de minerais detríticos que permitam a caracterização de fontes de sedimentos desde o Pliocénico.
- Aspects of the biology and fishery of the European spiny lobster (Palinurus elephas) from the SouthWest coast of PortugalPublication . Galhardo, Amelia Cristina; Serafim, Paula; Castro, MargaridaThe biology and fishery of the lobster, Palinurus elephas from the SW coast of Portugal was studied during two distinct periods 10 years apart in 1993-1994 (March 93 to March 94) and during 2003 (May to July). The landings at the port of Sagres, representing half of the catch of the country for this species, were sampled twice a week. The ovigerous season extends from September to March, with an individual incubation period of five months. Considering the ovigerous condition as an indicator of maturity in females, 50% of the females were mature at carapace length of 110 mm. Females below this size represent 95% of the population and account for 41% of the egg production. Females above 50% maturity, representing only 5% of the population, provide 59% of the eggs, showing the importance of larger individuals in the reproduction of this species. Most biological parameters estimated are within the range of values reported for this species in other areas with the exception that in our study the total length was smaller in relation to carapace length, so that females of a given carapace length carried fewer eggs. Parameters were estimated for the following relationships: total length and carapace length, weight and carapace length, weight and total length, maturity at size (carapace length) and fecundity at size (carapace length). It is suggested that a set of measures including catch control, effort control, gear control and protected areas are combined to allow the recovery of this resource.
- Bopyrid isopods do not castrate the simultaneously hermaphroditic shrimp Lysmata amboinensis (Decapoda : Hippolytidae)Publication . Calado, Ricardo; Vitorino, Antonio; Dinis, Maria TeresaThis study evaluates possible parasitic castration induced by a bopyrid isopod of the genus Parabopyrella, which parasitizes the branchial chamber of the simultaneously hermaphroditic shrimp Lysmata amboinensis. Parasitized shrimp (PS) carried embryos and produced significantly fewer larvae (mean +/- SD: 363 +/- 102; p = 0.002) than formerly parasitized shrimp (FPS) (1297 +/- 143) and unparasitized shrimp (US) paired with other US (1409 +/- 102), with PS (1362 +/- 234) or with FPS (1384 +/- 157). Starvation trials revealed no significant differences in the quality of larvae produced by PS, FPS and US paired with other US, PS and FPS. Host embryo production is only quantitatively, not qualitatively, affected, probably due to nutritional drain and/or endocrine disruption caused by the parasite. The host male sexual system remains fully functional and 'reproductive death' does not occur. The feminization of pleopods that prevents parasitized males of gonochoric species from successfully copulating seems to have no effect on L. seticaudata: pleopods are always feminized during their transition from male to simultaneous hermaphrodite phase, with adults being able to successfully fertilize broods. Parabopyrella sp. significantly affects the female sexual system of its host, but does not cause castration, as recorded for L. seticaudata parasitized by the bopyrid isopod Eophryxus lysmatae (an abdominal parasite).
- Analysis of loss networks with routingPublication . Antunes, Nelson; Fricker, Christine; Robert, Philippe; Tibi, DanielleThis paper analyzes stochastic networks consisting of finite capacity nodes with different classes of requests which move according to some routing policy. The Markov processes describing these networks do not, in general, have reversibility properties, so the explicit expression of their invariant distribution is not known. Kelly's limiting regime is considered: the arrival rates of calls as well as the capacities of the nodes are proportional to a factor going to infinity. It is proved that, in limit, the associated rescaled Markov process converges to a deterministic dynamical system with a unique equilibrium point characterized by a nonstandard fixed point equation.
- QIM, a sensory analysis-based method of determining fish qualityPublication . Esteves, E.; Aníbal, J.Presented at the FISEC Food Convention 2006, Universidade do Algarve, Campus da Penha, Faro, Novembro 2006
- Variabilidade dos Zircões de ribeiras e praias do Algarve Ocidental - dados preliminaresPublication . Rodrigues, Bruno; Moura, Delminda; Machado, Nuno; Veiga-Pires, C.O Zircão é um mineral acessório comum na maioria das rochas, possuindo um considerável interesse petrológico por ser extremamente resistente à meteorização química e de amplo uso em estudos radiométricos (Heimlich et al., 1975). Devido à sua extrema resistência à meteorização e ao transporte, o zircão possui um carácter ubíquo nos sedimentos.
- G(2)-Calogero-Moser Lax operators from reductionPublication . Fring, Andreas; Manojlovic, NenadWe construct a Lax operator for the G(2)-Calogero-Moser model by means of a double reduction procedure. In the first reduction step we reduce the A(6)-model to a B-3-model with the help of an embedding of the B-3-root system into the A(6)-root system together with the specification of certain coupling constants. The G(2)-Lax operator is obtained thereafter by means of an additional reduction by exploiting the embedding of the G(2)-system into the B-3-system. The degree of algebraically independent and non-vanishing charges is found to be equal to the degrees of the corresponding Lie algebra.
- Parathyroid hormone-related protein regulates intestinal calcium transport in sea bream (Sparus auratus)Publication . Fuentes, J.; Figueiredo, J.; Power, Deborah; Canario, Adelino V. M.Parathyroid hormone-related protein (PTHrP) is a factor associated with normal development and physiology of the nervous, cardiovascular, immune, reproductive, and musculoskeletal systems in higher vertebrates. It also stimulates whole body calcium uptake in sea bream (Sparus auratus) larvae with an estimated 60% coming from intestinal uptake in seawater. The present study investigated the role of PTHrP in the intestinal calcium transport in the sea bream in vitro. Unidirectional mucosal-to-serosal and serosal-to-mucosal 45Ca fluxes were measured in vitro in duodenum, hindgut, and rectum mounted in Ussing chambers. In symmetric conditions with the same saline, bathing apical and basolateral sides of the preparation addition of piscine PTHrP 1–34 (6 nM) to the serosal surface resulted in an increase in mucosal to serosal calcium fluxes in duodenum and hindgut and a reduction in serosal to mucosal in the rectum, indicating that different mechanisms are responsive to PTHrP along the intestine. In control asymmetric conditions, with serosal normal and mucosal bathed with a saline similar in composition to the intestinal fluid, there was a net increase in calcium uptake in all regions. The addition of 6 nM PTHrP 1–34 increased net calcium uptake two- to threefold in all regions. The stimulatory effect of PTHrP on net intestinal calcium absorption is consistent with a hypercalcemic role for the hormone. The results support the view that PTHrP, alone or in conjunction with recently identified PTH-like peptides, counteracts in vivo the hypocalcemic effects of stanniocalcin.
- Conversas pedagógicasPublication . Moura, Ana Maria da Silva; Pinheiro, Augusto Luís de Brito HenriquesThe intention of this study was to create spaces of reflection that would promote the integration and the development of teamwork. This local and specific study was developed in an educational institution with day nursery and pre-school, it was developed pointing out issues related with the dynamic and internal organization searching to promote a community of practices involving all the staff in educational and organizational issues. The purpose was not the research of causal explanations, but essentially the comprehension of the system that we investigated. The research fits in new paradigms of educational investigation that are present in the studies of investigation-action-formation. The “person” of the educator is valorised as a constructor of pedagogical knowledge. The ethnographic perspective that inspired the investigation focused on the observation, registry and interpretation of the team dynamics. Being a study with explorative characteristics, it wins sense in a fusion of horizons, of questions and answers, which enunciate themselves between conclusions and prolongations that contribute to launch new basis of understandings and knowledge among the educators that practice their profession in the day nursery and pre-school. It also opens perspectives for a work of deeper studies, of interventions with similar characteristics of the pedagogical conversations in the in-service training of the educators. The methodological procedure that we called of pedagogical conversations, integrated in the quotidian, responded to the goals of this study: to give a special attention to the comprehension of the problems from the perspective of the participants in the investigation. This procedure allowed us to approach some practices in a deeper way, through the apprehension of the senses and of the subjective state of the participants.
- Aims of education and well-being as absence of disorderPublication . Pereira, Rui Lopes Penha; Haydon, GrahamThis thesis offers an original account of what personal well-being can be. Any account of education, it is believed, has to do with and aims at personal well-being. I approach this view on well-being not in a positive but in a negative way. I put forward some items that in certain circumstances can be taken by and called sources or forms of disorder. In the absence of such forms or sources of disorder, I assume that a certain order, prudential or moral, takes place and that constitutes the well-being of the person. The concept of ‘absence of disorder’ is introduced and argued as an educationally appropriate view of personal well-being which is the central educational aim. Therefore, ‘absence of disorder’ is positioned as the central aim of education. This concept is illuminated, for practical reasoning, by a list of seven possible forms of disorder: Comparison, Corruption, Dependency, Division, Fear, Self-disintegration and Violence. As a view of personal well-being, ‘absence of disorder’ is initially rooted in informed desire satisfaction, via the introduction of the concept of entropy. Prudentially, the agent’s informed desire is satisfied by living a life with low build up of entropy or disorder. But, in a second move such a base is also provided by the Levinasinian concept of ‘disinterest’ as a root for ‘what is to be a human’. Such ‘disinterest’ is related to the concepts of love and of ‘action for its own sake’. It is at this final approach that an attempt is made towards the approximation of the ethical and the prudential aspects of social practices. Even if only to some extent successful, the argument is directed to the following conclusion: an education aiming at ‘absence of disorder’ may promote prudential well-being and give us some confidence in simultaneously favouring moral education.