Field Studies on the Behaviour of Sea-Ducklings

During the summer of 1959 the writer was engaged in studies on the behaviour of sea-ducklings in the Belcher Islands, Hudson Bay. This work is centred on an ethological study of eider ducklings (Somateria mollissima) with comparative observations on ducklings of oldsquaw (Clangula hyemalis) and redbreasted merganser (Mergus serratus); it had been begun in the False River area, Ungava in the summer of 1958. Once again Mr. C.W. Nicol gave able assistance. The objective of this work is to build up as complete an account as possible of the behaviour of the normal eider duckling in its natural environment, beginning shortly before hatching and ending with fledging. It is hoped that an account of the basic behaviour of this species will provide a sound foundation on which to plan analytical studies. The approach to this work is largely that of the present European vertebrate ethologists, but it is planned to develop the more "psychological" aspects of the work in future studies. The most obvious single comment to be made about the behaviour of the eider duckling is that it is extremely complex, more so than has previously been recognized. This complexity is partly due to the mixture of innate and learned processes, which together enable the duckling to survive the difficulties of the pre-adult stages. One of the present aims therefore is to describe the part played by innate mechanisms and to correlate learning processes with them. A brief summary of the results to date follows. ..

Teaching of Energy Issues: A debate proposal for a GLobal Reorientation

The growing awareness of serious difficulties in the learning of energy issues has produced a great deal of research, most of which is focused on specific conceptual aspects. In our opinion, the difficulties pointed out in the literature are interrelated and connected to other aspects (conceptual as well as procedural and axiological), which are not sufficiently taken into account in previous research. This paper aims to carry out a global analysis in order to avoid the more limited approaches that deal only with individual aspects. From this global analysis we have outlined 24 propositions that are put forward for debate to lay the foundations for a profound reorientation of the teaching of energy topics in upper high school courses, in order to facilitate a better scientific understanding of these topics, avoid many students' misconceptions and enhance awareness of the current situation of planetary emergency

A História da Alimentação: balizas historiográficas

Os M. pretenderam traçar um quadro da História da Alimentação, não como um novo ramo epistemológico da disciplina, mas como um campo em desenvolvimento de práticas e atividades especializadas, incluindo pesquisa, formação, publicações, associações, encontros acadêmicos, etc. Um breve relato das condições em que tal campo se assentou faz-se preceder de um panorama dos estudos de alimentação e temas correia tos, em geral, segundo cinco abardagens Ia biológica, a econômica, a social, a cultural e a filosófica!, assim como da identificação das contribuições mais relevantes da Antropologia, Arqueologia, Sociologia e Geografia. A fim de comentar a multiforme e volumosa bibliografia histórica, foi ela organizada segundo critérios morfológicos. A seguir, alguns tópicos importantes mereceram tratamento à parte: a fome, o alimento e o domínio religioso, as descobertas européias e a difusão mundial de alimentos, gosto e gastronomia. O artigo se encerra com um rápido balanço crítico da historiografia brasileira sobre o tema

PHOTOTHERMAL DEGRADATION OF BLACK CHROME - A POSSIBLE CONTRIBUTING FACTOR

Une revue du processus par moyen duquel s'accomplit le dépôt du chrome noir a permis l'identification d'un facteur, auparavant inconnu, qui contribue à la dégradation photothermique du chrome noir. Des méthodes sont proposées pour réduire ou éliminer les effets des éléments sensibles à la stimulation photothermique.By a review of the electrochemistry of the electrodeposition of black chrome, it has been possible to identify a previously unrecognised factor which is almost certain to contribute to the photothermal degradation of black chrome. Methods have been proposed for reducing or eliminating the effects of these photothermally sensitive constituents

Sol-gel phosphate-based glass for drug delivery applications

Development of controlled, targeted drug delivery systems represents one of the frontier areas of biomaterials science, where a multidisciplinary approach is of direct benefit to human healthcare. We demonstrate herein the potential of sol-gel derived phosphate-based glass for use in drug delivery applications. Our low-temperature sol-gel synthesis of phosphate-based glasses has made it possible to incorporate relatively unstable functional molecules for controlled release. We demonstrate the potential of this approach by incorporating the chemotherapy agent cisplatin in a CaO-Na2O-P2O5 glass. X-ray absorption spectroscopy is used to show that the chlorine ligands of cisplatin undergo exchange with oxygen during the synthesis, consistent with binding to the phosphate groups of the sol-gel. UV-visible spectroscopy reveals the subsequent release of cisplatin into an aqueous medium