1,875 research outputs found
Survey of children accessing HIV services in a high prevalence setting: time for adolescents to count?
OBJECTIVE: To establish the proportion of adolescents among children infected with human immunodeficiency virus (HIV) in Zimbabwe who receive HIV care and support, and what clinic staff perceives to be the main problems faced by HIV-infected children and adolescents. METHODS: In July 2008, we sent a questionnaire to all 131 facilities providing HIV care in Zimbabwe. In it we requested an age breakdown of the children (aged 0-19 years) registered for care and asked what were the two major problems faced by younger children (0-5 years) and adolescents (10-19 years). FINDINGS: Nationally, 115 (88%) facilities responded. In 98 (75%) that provided complete data, 196 032 patients were registered and 24 958 (13%) of them were children. Of children under HIV care, 33% were aged 0-4 years; 25%, 5-9 years; 25%, 10-14 years; and 17%, 15-19 years. Staff highlighted differences in the problems most commonly faced by younger children and adolescents. For younger children, such problems were malnutrition and lack of appropriate drugs (cited by 46% and 40% of clinics, respectively); for adolescents they concerned psychosocial issues and poor drug adherence (cited by 56% and 36%, respectively). CONCLUSION: Interventions for the large cohort of adolescents who are receiving HIV care in Zimbabwe need to target the psychosocial concerns and poor drug adherence reported by staff as being the main concerns in this age group
Geometrical effects on the optical properties of quantum dots doped with a single magnetic atom
The emission spectra of individual self-assembled quantum dots containing a
single magnetic Mn atom differ strongly from dot to dot. The differences are
explained by the influence of the system geometry, specifically the in-plane
asymmetry of the quantum dot and the position of the Mn atom. Depending on both
these parameters, one has different characteristic emission features which
either reveal or hide the spin state of the magnetic atom. The observed
behavior in both zero field and under magnetic field can be explained
quantitatively by the interplay between the exciton-manganese exchange
interaction (dependent on the Mn position) and the anisotropic part of the
electron-hole exchange interaction (related to the asymmetry of the quantum
dot).Comment: 5 pages, 5 figures, to be published in Phys. Rev. Let
The social fabric of Jeans': Assessing the social: Coupling social simulation and assessment methods
International audienceThe culture and manufacturing of the cotton fabric used to make your Jeans’ may have implied the use of fertilizers or pesticides polluting a water basin, have led to relocating people and even of children labour at different stages of its fabrication. As a consumer you probably didn’t take all these consequences into account (for your sake most of the information is not available, or value-wise you feel unconcerned) and you surely preferred to buy the cheapest one or to follow the fashion trend. Basically, every economic or public activity has repercussions directly, or through a chain of consequences on the environment and the society. In order to try and measure those impacts, or to valuate one choice (Jeans’ L) compared to another (Jeans’ P&J), several assessment methods have been developed and are frequently used. As a self-evident truth, assessment methods are instruments used to evaluate something. These could include measuring a performance on a specific case. In terms of evaluating policies and strategies, their possible outcomes are intended to evaluate their potential impacts. This refers to impact assessment in which past (already implemented actions) or future (ex-ante analysis) performances are studied
Acquired epidermodysplasia verruciformis due to multiple and unusual HPV infection among vertically-infected, HIV-positive adolescents in Zimbabwe.
BACKGROUND: We have previously described the presentation of epidermodysplasia verruciformis (EV)-like eruptions in almost a quarter of hospitalized adolescents with vertically-acquired human immunodeficiency virus (HIV) infection in Harare, Zimbabwe, a region with a high prevalence of HIV infection. METHODS: We performed a clinical case note review and skin biopsy from affected sites in 4 HIV-infected adolescents with EV-like lesions in Harare. Biopsies were processed for histology and for human papillomavirus (HPV) typing. RESULTS: All patients had long-standing skin lesions that pre-dated the diagnosis of HIV by several years. The histology of skin biopsies from all patients was consistent with EV. In each biopsy, EV-associated β-HPV type 5 was identified (additionally, type 19 was found in 1 biopsy). Cutaneous wart-associated HPV types 1 and 2 were detected in all biopsies, together with genital lesion-associated HPV types 6, 16, and 52, (as well as ≥3 other genital lesion-associated HPV types). Despite immune reconstitution with combination antiretroviral therapy (cART), there was no improvement in EV-like lesions in any patient. CONCLUSIONS: EV is a disfiguring and potentially stigmatizing condition among this patient group and is difficult to treat; cART appears to have no impact on the progression of skin disease. Among adolescents with longstanding HIV-induced immunosuppression and with high levels of sun exposure, close dermatological surveillance for potential skin malignancy is required
Observation of strong-coupling effects in a diluted magnetic semiconductor (Ga,Fe)N
A direct observation of the giant Zeeman splitting of the free excitons in
(Ga,Fe)N is reported. The magnetooptical and magnetization data imply the
ferromagnetic sign and a reduced magnitude of the effective p-d exchange energy
governing the interaction between Fe^{3+} ions and holes in GaN, N_0 beta^(app)
= +0.5 +/- 0.2 eV. This finding corroborates the recent suggestion that the
strong p-d hybridization specific to nitrides and oxides leads to significant
renormalization of the valence band exchange splitting.Comment: 4 pages, 2 figure
Observation of Fragile-to-Strong Dynamic Crossover in Protein Hydration Water
At low temperatures proteins exist in a glassy state, a state which has no
conformational flexibility and shows no biological functions. In a hydrated
protein, at and above 220 K, this flexibility is restored and the protein is
able to sample more conformational sub-states, thus becomes biologically
functional. This 'dynamical' transition of protein is believed to be triggered
by its strong coupling with the hydration water, which also shows a similar
dynamic transition. Here we demonstrate experimentally that this sudden switch
in dynamic behavior of the hydration water on lysozyme occurs precisely at 220
K and can be described as a Fragile-to-Strong dynamic crossover (FSC). At FSC,
the structure of hydration water makes a transition from predominantly
high-density (more fluid state) to low-density (less fluid state) forms derived
from existence of the second critical point at an elevated pressure.Comment: 6 pages (Latex), 4 figures (Postscript
Inverse problem and Bertrand's theorem
The Bertrand's theorem can be formulated as the solution of an inverse
problem for a classical unidimensional motion. We show that the solutions of
these problems, if restricted to a given class, can be obtained by solving a
numerical equation. This permit a particulary compact and elegant proof of
Bertrand's theorem.Comment: 11 pages, 3 figure
Magneto-optical spectroscopy of (Ga,Mn)N epilayers
We report on the magneto-optical spectroscopy and cathodoluminescence of a
set of wurtzite (Ga,Mn)N epilayers with a low Mn content, grown by molecular
beam epitaxy. The sharpness of the absorption lines associated to the Mn
internal transitions allows a precise study of its Zeeman effect in both
Faraday and Voigt configurations. We obtain a good agreement if we assume a
dynamical Jahn-Teller effect in the 3d configuration of Mn, and we
determine the parameters of the effective Hamiltonians describing the
and levels, and those of the spin Hamiltonian in the
ground spin multiplet, from which the magnetization of the isolated ion can be
calculated. On layers grown on transparent substrates, transmission close to
the band gap, and the associated magnetic circular dichroism, reveal the
presence of the giant Zeeman effect resulting from exchange interactions
between the Mn ions and the carriers. The spin-hole interaction is found
to be ferromagnetic
Did Ebola emerge in West Africa by a policy-driven phase change in agroecology? Ebola's social context
SCOPUS: no.jinfo:eu-repo/semantics/publishe
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