HIV-1 and HIV-2 antibodies in pregnant women in the City of Maputo, Mozambique. A comparative study between 1982/1983 and 1990

The seroprevalence of HIV-1 and HIV-2 among pregnant women in Maputo, the capital of Mozambique, was compared between the years 1982/83, 1988 and 1990. None of the 432 serum samples collected in 1982/83 was positive for HIV antibodies whereas in 1988 the HIV-1 and HIV-2 seroprevalence was 0.4% (2/500) and 0.6% (3/500), respectively, and in 1990 0.6% (12/2014) and 0.2% (4/2014), respectively. These results indicate that HIV infection has been introduced recently in Maputo and is spreading at a slow rate among women.     

Spatial soliton-induced guiding by cross-phase modulation

The authors show that spatial solitons are able to induce the stable guiding of a weak probe beam in a homogeneous Kerr-type nonlinear media through cross-phase modulation (XPM). The modes of the induced waveguide are derived from the propagation equation of the probe. Experiments have been performed in Kerr liquid CS₂, with beams of picosecond duration at infrared and visible wavelengths. Stable guiding of a green probe induced by an IR soliton beam has been demonstrated in several different experimental situations. Induced antiguiding and beam splitting are also reported for pump and probe of perpendicular polarizations. All results are in excellent agreement with numerical simulations of the propagation     

Measurement of synchronous machine rotor angle from analysis ofzero sequence harmonic components of machine terminal voltage

Generator rotor angle measurement is useful in identification of electric machine parameters in the d and q axes and as an indicator of stability of the operating condition. Rotor angle measurements with the appropriate bandwidth are also very useful in observation of rotor torsional oscillations both for monitoring and protection against undamped torsional modes, and for use in control schemes designed to damp torsional oscillations. A method of measurement of synchronous machine rotor angle from an analysis of the phase angle of zero sequence harmonic components of terminal voltage is presented     

Assessment of bog-body tissue preservation by pyrolysis-gas chromatography/mass spectrometry

Flash pyrolysis-gas chromatography/mass spectrometry (py-GC/MS) was used to assess the quality and mechanism of protein preservation in the tissue of Iron Age bog bodies from Lindow, UK, and south-eastern Drenthe, The Netherlands. Abundant pyrolysis products of the fresh skin tissue, including 2,5-diketopiperazines of Pro-Gly, Pro-Ala, Pro-Val, Pro-Pro and Hyp, were readily assigned to specific amino acid or dipeptide moieties. Comparison of the pyrolysates of the bog-body tissues with that of modern samples revealed qualitative similarities suggesting good preservation of the collagen and non-collagenous proteins in the ancient tissues. Examination of the pyrolysates of samples of fresh calf skin, which had been treated with various vegetable tanning agents, clearly revealed markers of non-hydrolysable tannins including 1,2-benzenediol, 1,3-benzenediol and 1,2,3-benzenetriol, although chromatographic quality inevitably diminished with increasing functionalization of the compounds. Such markers were not detected in the pyrolysates of the bog-body tissues. Instead 4-isopropenylphenol, a characteristic pyrolysis product of Sphagnum moss, was detected in both solvent-extracted and base-treated samples of tissue. The presence of 4-isopropenylphenol in the pyrolysates of the bog-body tissues provides evidence that their preservation involves reactions of amino acids with sphagnum acid, and possibly other agents derived from the peat. The study constitutes the first chemical characterization of the pyrolysis products of modern and ancient collagen.     

Ischemia‐reperfusion injury. A phenomenon,that also occurs in the bone

Ischemia‐reperfusion injury of the bone occurs due to traumatic and non‐traumatic alterations affecting blood supply to the bone. It is likely to occur also upon insertion of an implant. Ischemia‐reperfusion injury of the bone has been studied by interruption of blood supply in situ, in limb replantation/transplantation models, in revascularized bone grafts and non‐vascularized bone fragments, as well as in isolated cultured cells. All cells of the bone are affected, including osteoblasts, osteocytes, osteoclasts, chondrocytes, and bone marrow cells. Critical ischemia times for induction of bone cell death, either in the ischemic period or following reperfusion, are in the range of 3 to 7 h. These critical ischemia times are significantly increased by decreasing the temperature from 37 °C to 0–4 °C. Anoxia is the most likely trigger of cell injury in the ischemic phase. In the reperfusion phase, reactive oxygen species are decisively involved in the injurious process. In general, however, the available information on the mechanism of ischemia‐reperfusion injury of the bone is relatively sparse. On the other hand, there are clear similarities to the mechanisms of ischemia‐reperfusion injury known from other organs, and there is a clear potential for protection against ischemia‐reperfusion injury of the bone.     

Flood risk mapping at European scale.

The aim of this article is to illustrate a framework for flood risk mapping at pan-European scale produced by the Weather-Driven Natural Hazards (WDNH) action of the EC-JRC-IES. Early results are presented in the form of flood risk index maps. We assess several flood risk factors that contribute to the occurrence of flood disasters. Among the causal factors of a flood disaster one is triggering a natural event in the form of extreme precipitation and consequently extreme river discharge and extreme flood water levels. The threatening natural event represents the hazard component in our assessment. Furthermore exposure and vulnerability are anthropogenic factors that contribute also to flood risk. In the proposed approach, flood risk is considered on the light of exposure, vulnerability and hazard. We use a methodology with a marked territorial approach for the assessment of the flood risk. Hence, based on mathematical calculations, risk is the product of hazard, exposure and vulnerability. Improvements on datasets availability and spatial scale are foreseen in the next phases of this study. This study is also a contribution to the discussion about the need for communication tools between the natural hazard scientific community and the political and decision making players in this field.     

Longitudinal analysis of semiconductor lasers with low reflectivity facets

An analysis is made of longitudinal effects in semiconductor lasers with low facet reflectivities. For this purpose, a self-consistent model is used based on the beam propagation method, which takes into account both the lateral and longitudinal dimension. The calculations show that longitudinal effects have a significant influence on the output fields in the laser.     

Adjuvant arthritis: influence of the adjuvant volume and composition on the non-specific inflammation

Adjuvant-induced arthritis is an animal model of chronic inflammatory disease widely used in anti-inflammatory and immunosuppressive drugs testing. When the development and the inhibition of the induced arthritis are measured by the injected paw oedema, it is difficult to delineate the immunological contribution from the persistent non-specific primary section. To study the influence of volume and composition of the injected adjuvant upon the primary non-specific inflammation, we devised a 3X4 factorial experiment on a strain of inbred rats with a low susceptibility to adjuvant-induced arthritis. The injection of mineral oil alone produces a persistent oedema. The injection of mycobacteriae in suspension in saline induces a rapid inflammatory response followed by a fast decrease of the oedema. When complete adjuvant is used, there is always a very strong interaction between the effects of the two components of the adjuvant, i.e. the measured oedemas are much greater than the calculated values, For a given injected volume, the inflammation is maximum when the concentration of mycobacteriae is 2.5 mg/ml. All the rats injected with complete adjuvant present a transient oedema of the non-injected hind paw. This oedema is very small and proportional to the amount of mycobacteria injected.