225 research outputs found
A three-year follow-up survey of demographic changes in a Ugandan town on the trans-African highway with high HIV-1 seroprevalence
A 1991 serosurvey in a Ugandan trading town on the trans-African highway reported a 40 per cent HIV-1 prevalence in adults. Three years later in a repeat survey of the 531 adults resident in 1991, 279 (53%) were still present, 196 (37%) had left and 56 (11%) had died. There were 138 new residents and 46 children had become adults, making a total of 463 adults in 1994, 13 per cent less than 1991. Most immigrants (91%) came from the surrounding rural district whereas 38 per cent of emigrants went to an urban area. A significant inverse association between wealth and seropositivity was found for women but not men. Of the original residents 157 were known to be HIV-1 positive in 1991; 31 (20%) had died compared to 10 (4%) of the 232 known to be seronegative, representing an HIV-1 attributable mortality fraction of 60 per cent
The Bright and the Dark Side of Malin 1
Malin 1 has long been considered a prototype giant, dark matter dominated Low
Surface Brightness galaxy. Two recent studies, one based on a re-analysis of
VLA HI observations and the other on an archival Hubble I-band image, throw a
new light on this enigmatic galaxy and on its dark/luminous matter properties.Comment: 4 pages, 3 figures, to appear in the Proceedings of the 41st ESLAB
Symposium "The Impact of HST on European Astronomy", 29 May to 1 June 2007,
ESTEC, Noordwijk, N
The UV tube: a family-shared water disinfection system in rural Sri Lanka
The UV tube: a family-shared water disinfection system in rural Sri Lank
Vulnérabilité des ressources halieutiques et aquacoles du Pacifique tropical face au changement climatique : résumé à l'intention des Etats et Territoires insulaires océaniens
En complĂ©ment de l'ouvrage intitulĂ© "Vulnerability of tropical Pacific fisheries and aquaculture to climate change", qui analyse de maniĂšre exhaustive les effets possibles du changement climatique sur les plans visant Ă maximiser les avantages Ă©conomiques et sociaux tirĂ©s de la pĂȘche et de l'aquaculture en OcĂ©anie, le prĂ©sent document fait la synthĂšse des conclusions de cette Ă©valuation de la vulnĂ©rabilitĂ© climatique rĂ©gionale en ce qui concerne les Territoires français du Pacifique. Les mesures d'adaptation, les politiques et les investissements prĂ©conisĂ©s devraient permettre Ă chaque Territoire de rĂ©duire les menaces que fait peser le changement climatique sur la pĂȘche et l'aquaculture, tout en tirant le meilleur parti des dĂ©bouchĂ©s qui en dĂ©coulent. Les recommandations formulĂ©es rĂ©pondent directement aux prĂ©occupations de toutes les parties prenantes et de leurs partenaires dans le dĂ©veloppement. (RĂ©sumĂ© d'auteur
Vulnerability of tropical Pacific fisheries and aquaculture to climate change : summary for Pacific island countries and territories
The purpose of this summary is to present the main results from the regional vulnerability assessment as they apply to each country and territory, making the information easily to use.
The practical adaptations, policies and investments described here are needed to maintain the economic and social benefits of fisheries and aquaculture in the face of climate change. They are essential planning tools
Effect of deformation schedule on the microstructure and mechanical properties of a thermomechanically processed C-Mn-Si transformation-induced plasticity steel
Thermomechanical processing simulations were performed using a hot-torsion machine, in order to develop a comprehensive understanding of the effect of severe deformation in the recrystallized and nonrecrystallized austenite regions on the microstructural evolution and mechanical properties of the 0.2 wt pct C-1.55 wt pct Mn-1.5 wt pct Si transformation-induced plasticity (TRIP) steel. The deformation schedule affected all constituents (polygonal ferrite, bainite in different morphologies, retained austenite, and martensite) of the multiphased TRIP steel microstructure. The complex relationships between the volume fraction of the retained austenite, the morphology and distribution of all phases present in the microstructure, and the mechanical properties of TRIP steel were revealed. The bainite morphology had a more pronounced effect on the mechanical behavior than the refinement of the microstructure. The improvement of the mechanical properties of TRIP steel was achieved by variation of the volume fraction of the retained austenite rather than the overall refinement of the microstructure. <br /
Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy
We review HB stars in a broad astrophysical context, including both variable
and non-variable stars. A reassessment of the Oosterhoff dichotomy is
presented, which provides unprecedented detail regarding its origin and
systematics. We show that the Oosterhoff dichotomy and the distribution of
globular clusters (GCs) in the HB morphology-metallicity plane both exclude,
with high statistical significance, the possibility that the Galactic halo may
have formed from the accretion of dwarf galaxies resembling present-day Milky
Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the
second-parameter problem is presented. A technique is proposed to estimate the
HB types of extragalactic GCs on the basis of integrated far-UV photometry. The
relationship between the absolute V magnitude of the HB at the RR Lyrae level
and metallicity, as obtained on the basis of trigonometric parallax
measurements for the star RR Lyrae, is also revisited, giving a distance
modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are
studied. Finally, the conductive opacities used in evolutionary calculations of
low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and
Space Scienc
An Overview of the Lightning - Atmospheric Chemistry Aspects of the Deep Convective Clouds and Chemistry (DC3) Experiment
Some of the major goals of the DC3 experiment are to determine the contribution of lightning to NO(x) in the anvils of observed thunderstorms, examine the relationship of lightning NO(x) production to flash rates and to lightning channel lengths, and estimate the relative production per flash for cloud-to-ground flashes and intracloud flashes. In addition, the effects of lightning NO(x) production on photochemistry downwind of thunderstorms is also being examined. The talk will survey the observation types that were conducted during DC3 relevant to these goals and provide an overview of the analysis and modeling techniques which are being used to achieve them. NO(x) was observed on three research aircraft during DC3 (the NCAR G-V, the NASA DC-8, and the DLR Falcon) in flights through storm anvils in three study regions (NE Colorado, Central Oklahoma to West Texas, and northern Alabama) where lightning mapping arrays (LMAs) and radar coverage were available. Initial comparisons of the aircraft NOx observations in storm anvils relative to flash rates have been conducted, which will be followed with calculations of the flux of NO(x) through the anvils, which when combined with observed flash rates can be used to estimate storm-average lightning NOx production per flash. The WRF-Chem model will be run for cloud-resolved simulations of selected observed storms during DC3. Detailed lightning information from the LMAs (flash rates and flash lengths as a function of time and vertical distributions of flash channel segments) will be input to the model along with assumptions concerning NO(x) production per CG flash and per IC flash. These assumptions will be tested through comparisons with the aircraft NOx data from anvil traverses. A specially designed retrieval method for lightning NO2 column amounts from the OMI instrument on NASA fs Aura satellite has been utilized to estimate NO2 over the region affected by selected DC3 storms. Combined with NO(x) to NO2 ratios from the aircraft data and WRF-Chem model and observed flash rates, average NO(x) production per flash can be estimated. Ozone production downwind of observed storms can be estimated from the WRF-Chem simulations and the specific downwind flights
Measurement of and charged current inclusive cross sections and their ratio with the T2K off-axis near detector
We report a measurement of cross section and the first measurements of the cross section
and their ratio
at (anti-)neutrino energies below 1.5
GeV. We determine the single momentum bin cross section measurements, averaged
over the T2K -flux, for the detector target material (mainly
Carbon, Oxygen, Hydrogen and Copper) with phase space restricted laboratory
frame kinematics of 500 MeV/c. The
results are and $\sigma(\nu)=\left( 2.41\
\pm0.022{\rm{(stat.)}}\pm0.231{\rm (syst.)}\ \right)\times10^{-39}^{2}R\left(\frac{\sigma(\bar{\nu})}{\sigma(\nu)}\right)=
0.373\pm0.012{\rm (stat.)}\pm0.015{\rm (syst.)}$.Comment: 18 pages, 8 figure
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