The Increase in Hemoglobin Concentration With Altitude Differs Between World Regions and Is Less in Children Than in Adults

To compensate for decreased oxygen partial pressure, high-altitude residents increase hemoglobin concentrations [Hb]. The elevation varies between world regions, posing problems in defining cutoff values for anemia or polycythemia. The currently used altitude adjustments (World Health Organization [WHO]), however, do not account for regional differences. Data from The Demographic and Health Survey (DHS) Program were analyzed from 32 countries harboring >4% of residents at altitudes above 1000 m. [Hb]-increase, (ΔHb/km altitude) was calculated by linear regression analysis. Tables show 95% reference intervals (RIs) for different altitude ranges, world regions, and age groups. The prevalence of anemia and polycythemia was calculated using regressions in comparison to WHO adjustments. The most pronounced Δ[Hb]/km was found in East Africans and South Americans while [Hb] increased least in South/South-East Asia. In African regions and Middle East, [Hb] was decreased in some altitude regions showing inconsistent changes in different age groups. Of note, in all regions, the Δ[Hb]/km was lower in children than in adults, and in the Middle East, it was even negative. Overall, the Δ[Hb]/km from our analysis differed from the region-independent adjustments currently suggested by the WHO resulting in a lower anemia prevalence at very high altitudes. The distinct patterns of Δ[Hb] with altitude in residents from different world regions imply that one single, region-independent correction factor for altitude is not be applicable for diagnosing abnormal [Hb]. Therefore, we provide regression coefficients and reference-tables that are specific for world regions and altitude ranges to improve diagnosing abnormal [Hb]

Artemisinin versus Nonartemisinin Combination Therapy for Uncomplicated Malaria: Randomized Clinical Trials from Four Sites in Uganda

BACKGROUND: Drug resistance in Plasmodium falciparum poses a major threat to malaria control. Combination antimalarial therapy including artemisinins has been advocated recently to improve efficacy and limit the spread of resistance, but artemisinins are expensive and relatively untested in highly endemic areas. We compared artemisinin-based and other combination therapies in four districts in Uganda with varying transmission intensity. METHODS AND FINDINGS: We enrolled 2,160 patients aged 6 mo or greater with uncomplicated falciparum malaria. Patients were randomized to receive chloroquine (CQ) + sulfadoxine-pyrimethamine (SP); amodiaquine (AQ) + SP; or AQ + artesunate (AS). Primary endpoints were the 28-d risks of parasitological failure either unadjusted or adjusted by genotyping to distinguish recrudescence from new infections. A total of 2,081 patients completed follow-up, of which 1,749 (84%) were under the age of 5 y. The risk of recrudescence after treatment with CQ + SP was high, ranging from 22% to 46% at the four sites. This risk was significantly lower (p < 0.01) after AQ + SP or AQ + AS (7%–18% and 4%–12%, respectively). Compared to AQ + SP, AQ + AS was associated with a lower risk of recrudescence but a higher risk of new infection. The overall risk of repeat therapy due to any recurrent infection (recrudescence or new infection) was similar at two sites and significantly higher for AQ + AS at the two highest transmission sites (risk differences = 15% and 16%, p< 0.003). CONCLUSION: AQ + AS was the most efficacious regimen for preventing recrudescence, but this benefit was outweighed by an increased risk of new infection. Considering all recurrent infections, the efficacy of AQ + SP was at least as efficacious at all sites and superior to AQ + AS at the highest transmission sites. The high endemicity of malaria in Africa may impact on the efficacy of artemisinin-based combination therapy. The registration number for this trial is ISRCTN67520427 (http://www.controlled-trials.com/isrctn/trial/|/0/67520427.html)

A Highly Emissive Surface Layer in Mixed-Halide Multication Perovskites.

Mixed-halide lead perovskites have attracted significant attention in the field of photovoltaics and other optoelectronic applications due to their promising bandgap tunability and device performance. Here, the changes in photoluminescence and photoconductance of solution-processed triple-cation mixed-halide (Cs0.06 MA0.15 FA0.79 )Pb(Br0.4 I0.6 )3 perovskite films (MA: methylammonium, FA: formamidinium) are studied under solar-equivalent illumination. It is found that the illumination leads to localized surface sites of iodide-rich perovskite intermixed with passivating PbI2 material. Time- and spectrally resolved photoluminescence measurements reveal that photoexcited charges efficiently transfer to the passivated iodide-rich perovskite surface layer, leading to high local carrier densities on these sites. The carriers on this surface layer therefore recombine with a high radiative efficiency, with the photoluminescence quantum efficiency of the film under solar excitation densities increasing from 3% to over 45%. At higher excitation densities, nonradiative Auger recombination starts to dominate due to the extremely high concentration of charges on the surface layer. This work reveals new insight into phase segregation of mixed-halide mixed-cation perovskites, as well as routes to highly luminescent films by controlling charge density and transfer in novel device structures

Tau Lepton Physics: Theory Overview

The pure leptonic or semileptonic character of tau decays makes them a good laboratory to test the structure of the weak currents and the universality of their couplings to the gauge bosons. The hadronic tau decay modes constitute an ideal tool for studying low-energy effects of the strong interactions in very clean conditions; a well-known example is the precise determination of the QCD coupling from tau-decay data. New physics phenomena, such as a non-zero tau-neutrino mass or violations of (flavour / CP) conservation laws can also be searched for with tau decays.Comment: 20 pages, latex, 5 Postscript figures, uses espcrc2.sty, Invited Talk at the Fourth International Workshop on Tau Lepton Physics (TAU96), Colorado, September 199

Performance and usefulness of the Hexagon rapid diagnostic test in children with asymptomatic malaria living in the Mount Cameroon region

<p>Abstract</p> <p>Background</p> <p>Rapid and correct diagnosis of malaria is considered an important strategy in the control of the disease. However, it remains to be determined how well these tests can perform in those who harbour the parasite, but are asymptomatic, so that rapid diagnostic tests (RDTs) could be used in rapid mass surveillance in malaria control programmes.</p> <p>Methods</p> <p>Microscopic and immunochromatographic diagnosis of malaria were performed on blood samples from the hyperendemic Mount Cameroon region. Thin and thick blood films were stained with Giemsa and examined under light microscopy for malaria parasites. The RDT was performed on the blood samples for the detection of <it>Plasmodium </it>species. In addition, the performance characteristics of the test were determined using microscopy as gold standard.</p> <p>Results</p> <p>Results revealed 40.32% to be positive for microscopy and 34.41% to be positive for the RDT. Parasites were detected in a greater proportion of samples as the parasite density increase. <it>Plasmodium falciparum </it>was the predominant <it>Plasmodium </it>species detected in the study population either by microscopy or by the RDT. Overall, the test recorded a sensitivity and specificity of 85.33% and 95.05% respectively, and an accuracy of 91.40%. The sensitivity and specificity of the RDT increased as parasite densities increased.</p> <p>Conclusion</p> <p>The Hexagon Malaria Combi™ test showed a high sensitivity and specificity in diagnosing malaria in asymptomatic subjects and so could be suitable for use in mass surveillance programmes for the management and control of malaria.</p

Cognitive and social functioning correlates of employment among people with severe mental illness

We assess how social and cognitive functioning is associated to gaining employment for 213 people diagnosed with severe mental illness taking part in employment programs in Andalusia (Spain). We used the Repeatable Battery for the Assessment of Neuropsychological Status and the Social Functioning Scale and conducted two binary logistical regression analyses. Response variables were: having a job or not, in ordinary companies (OCs) and social enterprises (SEs), and working in and OC or not. There were two variables with significant adjusted odds ratios for having a job: “attention” and “Educational level”. There were five variables with significant odds ratios for having a job in an OC: “Sex”, “Educational level”, “Attention”, “Communication”, and “Independence-competence”. The study looks at the possible benefits of combining employment with support and social enterprises in employment programs for these people and underlines how both social and cognitive functioning are central to developing employment models