Teachers studying, teachers eesearching: a possible role of doctoral training in the professional development of educators

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Regulation of gap junction function; the role of nitric oxide.

Myocardial ischemia resulting from sudden occlusion of a coronary artery is one of the major causes in the appearance of severe, often life-threatening ventricular arrhythmias. Although the underlying mechanisms of these acute arrhythmias are many and varied, there is no doubt that uncoupling of gap junctions (GJs) play an important role especially in arrhythmias that are generated during phase Ib, and often terminate in sudden cardiac death. In the past decades considerable efforts have been made to explore mechanisms which regulate the function of GJs, and to find new approaches for protection against arrhythmias through the modulation of GJs. These investigations led to the development of GJ openers and inhibitors. The pharmacological modulation of GJs, however, resulted in conflicting results. It is still not clear whether opening or closing of GJs would be advantageous for the ischemic myocardium. Both maneuvers can result in protection, depending on the models, endpoints and the time of opening and closing of GJs. Furthermore, although there is substantial evidence that preconditioning decreases or delays the uncoupling of GJs, the precise mechanisms by which this attains have not yet been elucidated. In our own studies in anesthetized dogs preconditioning suppressed the ischemia and reperfusion-induced ventricular arrhythmias, and this protection was associated with the preservation of GJ function, manifested in less marked changes in electrical impedance, as well as in the maintenance of GJ permeability and phosphorylation of connexin43. Since we have substantial previous evidence that nitric oxide (NO) is an important trigger and mediator of the preconditioning-induced antiarrhythmic protection, we hypothesized that NO, among its several effects, may lead to this protection by influencing cardiac GJs. The hypotheses and theories relating to the pharmacological modulation of GJs will be discussed with particular attention to the role of NO

The mental lexicon: Results of some word association experiments

There are numerous hypotheses concerning the structure, size, and strategies of adults’ mental lexicon. This is the first time, however, that children’s mental vocabularies are analysed using the technique of free word associations (with the participation of two hundred 12-year-old and two hundred 13-year-old pupils). The analysis focuses on both quantitative and qualitative characteristics of the data like types of associations, lexical representations, distribution of word categories or semantic analysis of words. Comparisons are also made with a very similar material found in the Hungarian literature that provides a unique opportunity to look at the differences of the mental lexicon after 60 years. The discussion concerns (i) the patterns of the tested children’s mental lexicon (including the individual performances) and (ii) vocabulary changes seen as a multifactorial consequence of the progress of time. The hypothesis about the speed of lexical access being a definitive factor in the development of the mental lexicon has been confirmed and may be applied to other languages as well