1,420 research outputs found
Knowledge, self-efficacy and behavioural intent towards AIDS prevention behaviours among culturally diverse secondary school pupils in South Africa
Objective: To investigate knowledge, self-efficacy, and behavioural intent towards AIDS prevention behaviours among culturally diverse secondary school pupils in South Africa.Design: Randomised study.Setting: Three urban secondary schools in Pietersburg, South Africa.Participants: Three hundred and sixty six Grade 11 secondary school pupils, comprising 150 (41%) males, and 216 (59%) females, aged 17 to 24 years (mean age 19.3 years, SD=2.6). The three cultural groups were 142 Blacks, 112 Whites and 112 Asians. Main outcome measures: The questionnaire included items on socio-economic and family background, knowledge about HIV, perceived self-efficacy and behavioural intent regarding AIDS preventive behaviours.Results: Overall, the participants showed an adequate level of AIDS knowledge. However, there was considerable inaccuracy regarding AIDS transmission myths or how AIDS cannot be transmitted. The different cultural groups generally felt most self- efficacious regardinghow to protect themselves from becoming infected (75-90%) and least self-efficacious on knowing where to go for information on AIDS (72-74%). Generally, participants reported a high behavioural intent. The Whites stand second in knowledge and more or less second inself-efficacy and behaviour intent. The Blacks stand third in knowledge and more or less second in self-efficacy and behaviour intent.Conclusion: Culturally diverse knowledge, self-efficacy and behavioural intent towards AIDS prevention was found among White, Black and Asian pupils, which should inform a culturally sensitive and appropriate AIDS health promotion programme in South Africa
Early-Onset Epileptic Encephalopathies: Ohtahara Syndrome and Early Myoclonic Encephalopathy
AbstractOhtahara syndrome and early myoclonic encephalopathy are the earliest presenting of the epileptic encephalopathies. They are typically distinguished from each other according to specific clinical and etiologic criteria. Nonetheless, considerable overlap exists between the two syndromes in terms of clinical presentation, prognosis, and electroencephalographic signature. Newer understandings of underlying etiologies of these conditions may support the previously suggested concept that they represent a single spectrum of disease rather than two distinct disorders. We review both syndromes, with particular focus on the underlying genetics and pathophysiology and implications regarding the classification of these conditions
Disorder-driven electronic localization and phase separation in superconducting Fe1+yTe0.5Se0.5 single crystals
We have investigated the influence of Fe-excess on the electrical transport
and magnetism of Fe1+yTe0.5Se0.5 (y=0.04 and 0.09) single crystals. Both
compositions exhibit resistively determined superconducting transitions (Tc)
with an onset temperature of about 15 K. From the width of the superconducting
transition and the magnitude of the lower critical field Hc1, it is inferred
that excess of Fe suppresses superconductivity. The linear and non-linear
responses of the ac-susceptibility show that the superconducting state for
these compositions is inhomogeneous. A possible origin of this phase separation
is a magnetic coupling between Fe-excess occupying interstitial sites in the
chalcogen planes and those in the Fe-square lattice. The temperature derivative
of the resistivity drho/dT in the temperature range Tc < T < Ta with Ta being
the temperature of a magnetic anomaly, changes from positive to negative with
increasing Fe. A log 1/T divergence of the resistivity above Tc in the sample
with higher amount of Fe suggests a disorder driven electronic localization.Comment: 7 page
Variations in Physical Characteristics of the Waters of Zuari Estuary
5-10Based on data collected over tidal cycles at 3 selected stations in Zuari Estuary, Goa, India, seasonal changes and temporal variations in hydrographic conditions were studied in relation to tidal currents. In general, temporal variations in different hydrographic parameters were minimum during summer and maximum during monsoon. Water temperature, in general, attained higher values ( >30° C) in summer and monsoon and lower values ( <27°C) in winter. Maximum range of salinity over a tidal cycle (about 16 % was observed during monsoon in middle and upstream regions of the estuary, the minimum range being in the mouth during summer (34.8 to 35.2%). Salinity structure indicated the transformation of the estuary from a mixed one during summer to a stratified one during monsoon. Compared to that at the suspended sediment load was generally high in middle and upstream regions of the estuary, where the maximum values encountered were of the order of 200 mg/litre in the monsoon. Tidal currents were, in general, stronger in middle and upstream regions than at the mouth. During monsoon, the pre-dominance of ebb flow bearing high sediment load, the probable flocculation due to large salinity variation in the downstream part and the reduction of current speed due to widening of the estuary appear to contribute to higher rate of siltation in the harbour area
Temporal and Spatial variations in Hydrographic Conditions of Mandovi Estuary
11-17Variations in temperature, salinity, suspended matter and currents at mouth, middle and upstream regions of Mandovi Estuary were studied in relation to tides for 3 seasons, viz. premonsoon, monsoon and postmonsoon. Waters attained maximum temperature of 31.5°C during premonsoon and minimum of 25.5°C during postmonsoon. Maximum salinity variation over a tidal cycle was in the middle region of the estuary during monsoon (2 to 34%) and minimum was at the mouth during premonsoon (34 to 36%). Horizontal gradient in salinity was maximum (2.0%/km) during monsoon and minimum (about 0.2%/km) during premonsoon. The estuary changed from a stratified type during the wettest season (monsoon) to a well-mixed type in premonsoon. The sediment load was generally low (<25 mg/litre) in the waters of the upstream region during postmonsoon. Higher values of suspended load were generally associated with strong currents. At the mid region of the estuary strong currents of about 150 cm/sec were encountered with flood during premonsoon and with ebb during monsoon
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Climate responses to anthropogenic emissions of short-lived climate pollutants
Policies to control air quality focus on mitigating emissions of aerosols and their precursors, and other short-lived climate pollutants (SLCPs). On a local scale, these policies will have beneficial impacts on health and crop yields, by reducing particulate matter (PM) and surface ozone concentrations; however, the climate impacts of reducing emissions of SLCPs are less straightforward to predict. In this paper we consider a set of idealised, extreme mitigation strategies, in which the total anthropogenic emissions of individual SLCP emissions species are removed. This provides an upper bound on the potential climate impacts of such air quality strategies.
We focus on evaluating the climate responses to changes in anthropogenic emissions of aerosol precursor species: black carbon (BC), organic carbon (OC) and sulphur dioxide (SO2). We perform climate integrations with four fully coupled atmosphere-ocean global climate models (AOGCMs), and examine the effects on global and regional climate of removing the total land-based anthropogenic emissions of each of the three aerosol precursor species.
We find that the SO2 emissions reductions lead to the strongest response, with all three models showing an increase in surface temperature focussed in the northern hemisphere high latitudes, and a corresponding increase in global mean precipitation and run-off. Changes in precipitation and run-off patterns are driven mostly by a northward shift in the ITCZ, consistent with the hemispherically asymmetric warming pattern driven by the emissions changes. The BC and OC emissions reductions give a much weaker forcing signal, and there is some disagreement between models in the sign of the climate responses to these perturbations. These differences between models are due largely to natural variability in sea-ice extent, circulation patterns and cloud changes. This large natural variability component to the signal when the ocean circulation and sea-ice are free-running means that the BC and OC mitigation measures do not necessarily lead to a discernible climate response
High Pressure Vibrational Properties of WS2 Nanotubes
We bring together synchrotron-based infrared and Raman spectroscopies, diamond anvil cell techniques, and an analysis of frequency shifts and lattice dynamics to unveil the vibrational properties of multiwall WS2 nanotubes under compression. While most of the vibrational modes display similar hardening trends, the Raman-active A1g breathing mode is almost twice as responsive, suggesting that the nanotube breakdown pathway under strain proceeds through this displacement. At the same time, the previously unexplored high pressure infrared response provides unexpected insight into the electronic properties of the multiwall WS2 tubes. The development of the localized absorption is fit to a percolation model, indicating that the nanotubes display a modest macroscopic conductivity due to hopping from tube to tube
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