Showing papers by "University of Mons published in 1986"

Morphological alterations in distal and collecting tubules of the rat renal cortex after aminoglycoside administration at low doses.

Abstract: Ultrastructural alterations in the cortical, distal and collecting tubules have been examined in female Sprague-Dawley rats treated with various aminoglycosides in clinical use. Gentamicin, dibekacin (10 mg/ kg-day), netilmicin, tobramycin (4 or 10 mg/kg · day) or amikacin (37.5 mg/kg · day) were administered intraperitoneally twice a day over different periods of time, extending from 4 to 14 days. The kidney cortex was examined after 4, 7, 10 or 14 days of aminoglycoside administration by light (semithin sections) and electron microscopy. After 7 or more days of treatment, lysosomes in collecting tubular cells (and to a lesser extent in distal tubular cells) contained concentric lamellar material (myeloid bodies), an ultrastructural alteration typical of drug-induced lysosomal phospholipidosis. Although this alteration appeared qualitatively similar to that observed in proximal tubular cells, it was less conspicuous and occurred later during treatment. In addition, distal tubular cells occasionally showed marked vacuolization and disruption of the basal cell architecture. The possible relationship between these alterations and the urine hypo-osmolality characteristic of aminoglycoside-induced renal dysfunction is discussed.

Investigation of the Mg XII 8.42 Å doublet in solar flare spectra

Abstract: The intensity ratio of the components of the Mg xii 8.42 A (1s2S1/2 − 2p2P1/2, 3/2) doublet in solar flare spectra has been investigated using observations recorded from the Intercosmos 7 satellite. The observed values of the ratio fall within the interval 0.38–0.66 and have been compared with recent theoretical predictions based on an optically thin collisional-radiative model. It has been found that for the flare plasma the low values of the ratio cannot be explained since they fall below the smallest theoretical value. The highest values on the other hand require that an unacceptably high electron density be postulated. It is suggested that both high and low values may be caused by the resonance line scattering of the Mg xii quanta in the flare volume, provided that the volume is elongated and not spherical.

Gaussian quantization,ON theory and the goldstone theorem

Abstract: A Gaussian variational principle for anON-invariant self-interacting theory is formulated. The conditions for spontaneous symmetry breaking and the limits of validity of the approximation are analysed in detail.

Evolution of an Aphasic Child after the Introduction of NVCDs

Abstract: Acquired aphasia is the loss of language as a result of a brain lesion. The prognosis for recovery from childhood aphasia is variable and is determined by at least four factors: etiology, location of lesion, age at time of lesion, and associated disturbances (Woods, 1982). The goal of therapy for aphasic children is different from that in adults: not only must former language abilities be recovered, but further language acquisition must also be continued.

Synthesis and Future Perspectives

Abstract: During the 1983 conference many papers were presented (they can be found in the conference proceedings), but the discussion sessions cannot be found anywhere. Therefore, we thought that it would be worthwhile to summarize them here. The organizers purposely chose a program structure in which it was possible to rediscuss a paper presented on the first day of the conference on the final day. Such a program structure favours discussion, even if it makes an independent presentation of each discussion session impossible. We will thus make a global synthesis.

Conformational changes of amino acids monitored by deuterium nuclear relaxation rate

Abstract: As an extension of previous work on simple amino acids, deuterium nuclear relaxation rates were used to study the molecular dynamics of γ-2,2-[2H2]aminobutyric acid, d,l-2-[2H1]glutamic acid and d,l-2-[2H1]lysine, and also model compounds 2,2,2-[2H3]acetic acid and 1,1-[2H2]butylamine. This study was carried out in aqueous solution in the pH range ca 0–14. From the observed rotational correlation times and solution viscosities, molecular volumes of various ionic forms were calculated using the Gierer and Wirtz model. The results obtained are in good agreement with conformational changes expected in the pH range investigated.

The Ob-Serving Computer

Abstract: Lowenthal (1978) defined, some years ago, what is now known as “Non-verbal communication devices” (NVCD). A detailed definition and a long discussion concerning the relevance of the concept NVCD can be found in another paper (Lowenthal, this volume). Since 1978, much research concerning the use of NVCDs by several kinds of subjects, has been led in the NVCD lab at the University of Mons. This research shows the importance of this kind of approach (Lowenthal, 1980, 1984). A new research trend has been recently described (Harmegnies and Lowenthal, 1984) which will enable us to extend previous research and to study aspects of NVCDs which were not studied before. In order to reach our aim, we will use new means and we will place our investigations in a framework differing from the one previously used. On the one hand, we will use computerized NVCDs with children: the computer will give (or “serve”) information; on the other hand we will focus on new research topics which could not be studied without having recourse to informatics: the computer will “observe” children.

Non-Verbal Communication Devices: Their Relevance, Their Use and the Mental Processes Involved

Abstract: Non-verbal communication devices have been defined in previous papers (Lowenthal, 1978a, 1982). We want to show here, by means of examples, in what ways they are similar to and how they differ from any known verbal language; what makes them useful either for introducing new concepts in a teaching situation, or for creating a situation where the subject’s behaviour can easily be observed and analyzed. Finally we will describe what mental processes are involved, according to us, when children are confronted with NVCDs. This can be illustrated by descriptions of experiments carried out with children (Lowenthal, 1979, 1984a). Two of these experiments are presented in this book (the first one concerns the use of NVCDs in a teaching situation and the second one concerns the use of an NVCD used to observe the behaviour of children solving a logical problem).