Updated estimate of the duration of the meningo-encephalitic stage in gambiense human African trypanosomiasis

Background: The duration of the stages of HAT is an important factor in epidemiological studies and intervention planning. Previously, we published estimates of the duration of the haemo-lymphatic stage 1 and meningo-encephalitic stage 2 of the gambiense form of human African trypanosomiasis (HAT), in the absence of treatment. Here we revise the estimate of stage 2 duration, computed based on data from Uganda and South Sudan, by adjusting observed infection prevalence for incomplete case detection coverage and diagnostic inaccuracy. Findings: The revised best estimate for the mean duration of stage 2 is 252 days (95% CI 171–399), about half of our initial best estimate, giving a total mean duration of untreated gambiense HAT infection of approximately 2 years and 2 months. Conclusions: Our new estimate provides improved information on the transmission dynamics of this neglected tropical disease in Uganda and South Sudan. We stress that there remains considerable variability around the estimated mean values, and that one must be cautious in applying these results to other foci

A kinetic and mechanistic study on the silver (I)-catalyzed oxidation of l-alanine by cerium (IV) in sulfuric acid medium

AbstractThe kinetics and mechanism of Ag(I)-catalyzed oxidation of l-alanine by cerium (IV) in sulfuric acid media have been investigated by titrimetric technique of redox in the temperature range of 298–313K. It is found that the reaction is of first order with respect to Ce(IV) and l-alanine, and it is of a positive fractional order with respect to Ag(I). It is found that the pseudo first order ([l-alanine]≫[Ce(IV)]≫[Ag(I)]) rate constant k′ increases with the increase of[H+]. The major oxidation product of alanine has been identified as acetaldehyde by an 1H NMR and IR spectroscopy. Under the experimental conditions, the kinetically active species has been found to be Ce4+. Under nitrogen atmosphere, the reaction system can initiate the polymerization of acrylonitrile, indicating generation of free radicals. On the basis of the experimental results, a suitable mechanism has been proposed. The rate constants of the rate-determining step together with the activation parameters were evaluated

Updated estimate of the duration of the meningo-encephalitic stage in gambiense human African trypanosomiasis.

BACKGROUND: The duration of the stages of HAT is an important factor in epidemiological studies and intervention planning. Previously, we published estimates of the duration of the haemo-lymphatic stage 1 and meningo-encephalitic stage 2 of the gambiense form of human African trypanosomiasis (HAT), in the absence of treatment. Here we revise the estimate of stage 2 duration, computed based on data from Uganda and South Sudan, by adjusting observed infection prevalence for incomplete case detection coverage and diagnostic inaccuracy. FINDINGS: The revised best estimate for the mean duration of stage 2 is 252 days (95% CI 171-399), about half of our initial best estimate, giving a total mean duration of untreated gambiense HAT infection of approximately 2 years and 2 months. CONCLUSIONS: Our new estimate provides improved information on the transmission dynamics of this neglected tropical disease in Uganda and South Sudan. We stress that there remains considerable variability around the estimated mean values, and that one must be cautious in applying these results to other foci

Enhancement of Structural, Optical and Bumpy Surface Effect of Cu2O Thin Films Through Sn Doping by Modified SILAR Technique

Undoped and Sn doped Cu2-xSnxO (x = 0, 5.0, 10.0, 15.0 and 20.0) thin films have been deposited into glass substrates by hire a fee powerful method of M-SILAR (Modified-Successive Ionic Layer Adsorption and Reaction). The Sn doping level in the starting solution become numerous from 0 to 20.0 mol.% in steps of 5.0 mol.%. The deposited films were characterized for their structural, optical, morphological and topography properties with respective instrumentation. X-ray diffraction (XRD) evaluation found out the orientation of crystalline increase of Cu2-xSnxO films, and all the films showcase single crystalline. The preferential orientation was retained in favor of (111) plane even at the highest doping level. The presence of copper in the films turned into showed by way of energy dispersive X-ray spectrometer. Average optical transmittance (UV-vis-NIR and Photoluminescence (PL)) are varied with effect of doping concentration. The stretching vibrations of Cu-O, Sn-O and O-Cu-O have been showed by using Fourier transform infrared spectroscopy (FTIR). The morphological observe has been achieved by using a Field emission scanning electron microscopy (FE-SEM) has display as decrease the particle length with increase of doping concentration. From High resolution transition electron microscopy (HR-TEM) the crystalline growth of each line are excellent within the Sn doping of 10.0 mol.%. The atomic force microscopy method changed into employed to investigate the roughness of the films and the bumpy surface revealed at 10.0 mol.% of Sn doping level

Estimates of the duration of the early and late stage of gambiense sleeping sickness.

BACKGROUND: The durations of untreated stage 1 (early stage, haemo-lymphatic) and stage 2 (late stage, meningo-encephalitic) human African trypanosomiasis (sleeping sickness) due to Trypanosoma brucei gambiense are poorly quantified, but key to predicting the impact of screening on transmission. Here, we outline a method to estimate these parameters. METHODS: We first model the duration of stage 1 through survival analysis of untreated serological suspects detected during Médecins Sans Frontières interventions in Uganda and Sudan. We then deduce the duration of stage 2 based on the stage 1 to stage 2 ratio observed during active case detection in villages within the same sites. RESULTS: Survival in stage 1 appears to decay exponentially (daily rate = 0.0019; mean stage 1 duration = 526 days [95%CI 357 to 833]), possibly explaining past reports of abnormally long duration. Assuming epidemiological equilibrium, we estimate a similar duration of stage 2 (500 days [95%CI 345 to 769]), for a total of nearly three years in the absence of treatment. CONCLUSION: Robust estimates of these basic epidemiological parameters are essential to formulating a quantitative understanding of sleeping sickness dynamics, and will facilitate the evaluation of different possible control strategies.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Inelasticity effects in π-π production γ-γ collisions

The inelasticity effects in the production of pion pairs in the process γγ→ππ for real photons are investigated using the partial wave dispersion relations. The total cross sections for different photon helicities are calculated. It is observed that this process is dominated by the ππ final state interaction. A prediction for S∗(997)→γγ decay width is also made

Intermittent preventive treatment of malaria provides substantial protection against malaria in children already protected by an insecticide-treated bednet in Burkina Faso: a randomised, double-blind, placebo-controlled trial.

BACKGROUND: Intermittent preventive treatment of malaria in children (IPTc) is a promising new approach to the control of malaria in areas of seasonal malaria transmission but it is not known if IPTc adds to the protection provided by an insecticide-treated net (ITN). METHODS AND FINDINGS: An individually randomised, double-blind, placebo-controlled trial of seasonal IPTc was conducted in Burkina Faso in children aged 3 to 59 months who were provided with a long-lasting insecticide-treated bednet (LLIN). Three rounds of treatment with sulphadoxine pyrimethamine plus amodiaquine or placebos were given at monthly intervals during the malaria transmission season. Passive surveillance for malaria episodes was established, a cross-sectional survey was conducted at the end of the malaria transmission season, and use of ITNs was monitored during the intervention period. Incidence rates of malaria were compared using a Cox regression model and generalized linear models were fitted to examine the effect of IPTc on the prevalence of malaria infection, anaemia, and on anthropometric indicators. 3,052 children were screened and 3,014 were enrolled in the trial; 1,505 in the control arm and 1,509 in the intervention arm. Similar proportions of children in the two treatment arms were reported to sleep under an LLIN during the intervention period (93%). The incidence of malaria, defined as fever or history of fever with parasitaemia ≥ 5,000/µl, was 2.88 (95% confidence interval [CI] 2.70-3.06) per child during the intervention period in the control arm versus 0.87 (95% CI 0.78-0.97) in the intervention arm, a protective efficacy (PE) of 70% (95% CI 66%-74%) (p<0.001). There was a 69% (95% CI 6%-90%) reduction in incidence of severe malaria (p = 0.04) and a 46% (95% CI 7%-69%) (p = 0.03) reduction in the incidence of all-cause hospital admissions. IPTc reduced the prevalence of malaria infection at the end of the malaria transmission season by 73% (95% CI 68%-77%) (p<0.001) and that of moderately severe anaemia by 56% (95% CI 36%-70%) (p<0.001). IPTc reduced the risks of wasting (risk ratio [RR] = 0.79; 95% CI 0.65-1.00) (p = 0.05) and of being underweight (RR = 0.84; 95% CI 0.72-0.99) (p = 0.03). Children who received IPTc were 2.8 (95% CI 2.3-3.5) (p<0.001) times more likely to vomit than children who received placebo but no drug-related serious adverse event was recorded. CONCLUSIONS: IPT of malaria provides substantial protection against malaria in children who sleep under an ITN. There is now strong evidence to support the integration of IPTc into malaria control strategies in areas of seasonal malaria transmission. TRIAL REGISTRATION: ClinicalTrials.govNCT00738946. Please see later in the article for the Editors' Summary

Low Temperature Measurements by Infrared Spectroscopy in CoFe2_2O4_4 Ceramic

In this paper results of new far-infrared and middle-infrared measurements (wavenumber range of 4000cm-1 - 100cm-1) in the range of the temperature from 300K to 8K of the CoFe2O4 ceramic are presented. The bands positions and their shapes are the same in the wide temperature range. The quality of the sample was investigated by X-ray, EDS and EPMA studies. The CoFe2O4 reveals the cubic structure (Fd-3m) in the temperature range from 85K to 360 K without any traces of distortion. On the current level of knowledge the polycrystalline CoFe2O4 does not exhibit phase transition in the temperature range from 8 K to 300 K.Comment: 10 pages, 6 figure

Revising the WHO verbal autopsy instrument to facilitate routine cause-of-death monitoring.

OBJECTIVE: Verbal autopsy (VA) is a systematic approach for determining causes of death (CoD) in populations without routine medical certification. It has mainly been used in research contexts and involved relatively lengthy interviews. Our objective here is to describe the process used to shorten, simplify, and standardise the VA process to make it feasible for application on a larger scale such as in routine civil registration and vital statistics (CRVS) systems. METHODS: A literature review of existing VA instruments was undertaken. The World Health Organization (WHO) then facilitated an international consultation process to review experiences with existing VA instruments, including those from WHO, the Demographic Evaluation of Populations and their Health in Developing Countries (INDEPTH) Network, InterVA, and the Population Health Metrics Research Consortium (PHMRC). In an expert meeting, consideration was given to formulating a workable VA CoD list [with mapping to the International Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) CoD] and to the viability and utility of existing VA interview questions, with a view to undertaking systematic simplification. FINDINGS: A revised VA CoD list was compiled enabling mapping of all ICD-10 CoD onto 62 VA cause categories, chosen on the grounds of public health significance as well as potential for ascertainment from VA. A set of 221 indicators for inclusion in the revised VA instrument was developed on the basis of accumulated experience, with appropriate skip patterns for various population sub-groups. The duration of a VA interview was reduced by about 40% with this new approach. CONCLUSIONS: The revised VA instrument resulting from this consultation process is presented here as a means of making it available for widespread use and evaluation. It is envisaged that this will be used in conjunction with automated models for assigning CoD from VA data, rather than involving physicians