Contribution à l’étude de la radioactivité gamma du sable des plages de Ramena et d’Orangea, Antsiranana, Madagascar

Les familles de l’Uranium -238, de l’Uranium -235, du Thorium -232 et du Potassium -40 sont d’origines telluriques et contribuent de manière générale aux expositions internes et externes d’un individu. Ce travail a pour objectif de mesurer la radioactivité du sable de deux plages de la baie de Diego-Suarez, à savoir celles de ramena et d’orangea. Différents échantillons ont été collectés pour avoir une représentation fidèle de ces sites. Les analyses par spectrométrie gamma de ces échantillons nous permettent de déterminer les activités des familles de l’Uranium -238, du Thorium -232 et du Potassium -40. Les analyses effectuées avec le détecteur NaI (Tl) de marque ORTEC et de modèle 905-4 série ont donné des résultats fiables. En effet, les activités varient de (66 ± 22) Bq.kg-1 à (180 ± 32) Bq.kg-1 pour la famille de l’Uranium-238, de (54 ± 14) Bq.kg-1 à (95 ± 16) Bq.kg-1 pour celle du Thorium-232 et de (107 ± 22) Bq.kg-1 à (321 ± 49) Bq.kg-1 pour le Potassium -40. Ainsi le radium équivalent varie de (174 ± 26) Bq.kg-1 à (319±37) Bq.kg-1 avec une moyenne de (235 32) Bq.kg-1.Mots-clés: radioactivité, spectrométrie gamma, radium équivalent.Contribution of the Measurements of beach sand radioactivities of Ramena and Orangea in Antsiranana, Madagascar Uranium -238, uranium -235 and Thorium -232 series are from telluric elements and with Potassium -40, they contribute to the internal and external exposure of the public. This work is essentially based on the measurement of beach sand radioactivities of Ramena and Orangea in Antsiranana. Enough samples have been collected in such way to have a good image of the two areas of interest. The samples analyses by gamma spectrometry system using ORTEC NaI(Tl) detector, 905-4 serie, allow us to determine the activities of Uranium -238, Thorium -232 series and the Potasium -40. The results show that the uranium -238, the thorium-232 series and the potassium-40 activities ranges are respectively from (66±22) Bq.kg-1 to (180 ± 32) Bq.kg-1, from (54 ± 14) Bq.kg-1 to (95 ± 16) Bq.kg-1 and from (107 ± 22) Bq.kg-1 to (321 ± 49) Bq.kg-1. Thus, the estimated radium equivalent ranges are between (174 ± 26) Bq.kg-1 to (319 ± 37) Bq.kg-1, with an average for about (235 32) Bq.kg-1.Keywords: radioactivity, gamma spectrometry, radium equivalent

Contribution à l’étude de dose due à la radioactivité gamma du sol sur la rive de la baie des Français, Antsiranana, Madagascar

Le but de ce travail est d’étudier la radioactivité gamma des sols sur la rive de la baie des français et de déterminer l’impact dosimétrique sur la population locale dans les localités d’Ankorikihely, de betahitry et de Lazaret-Nord. Des échantillons du sol ont été prélevés et analysés pour identifier les activités spécifiques du potassium-40, des familles de l’Uranium-238 et du Thorium-232. Ces échantillons ont été analysés sur une chaine de spectrométrie gamma, muni d’un détecteur NaI(Tl) et du logiciel Scinti-vision. Le traitement des spectres a été réalisé en utilisant la méthode de Rybach. Après mesures, les résultats suivants ont été obtenus : les activités spécifiques du potassium-40 varient de 112 ± 34 Bq.kg-1 à 565 ± 50Bq.kg-1, avec une moyenne de 313 Bq.kg-1. Cette dernière est inferieure à la valeur moyenne mondiale, qui est 400 Bq.kg-1.Les activités spécifiques de la famille de l’uranium-238 varient de 87 ± 32 Bq.kg-1 à 190 ± 46Bq.kg-1, avec une moyenne de 139 Bq.kg-1. Cette valeur moyenne est quatre fois supérieure à la valeur moyenne mondiale, qui est de 35 Bq.kg-1. Les activités spécifiques de la famille du thorium-232 varient de 81 ± 20 Bq.kg-1 à 161 ± 23 Bq.kg-1, avec une moyenne de 126 Bq.kg-1. Cette valeur moyenne est quatre fois plus que la valeur moyenne mondiale, qui est de 30 Bq.kg-1. Les débits de dose absorbée à 1m au-dessus de la surface de sol varient entre 89 ± 14 nGy.h-1 et 209± 29 nGy.h-1 avec une moyenne de 153 nGy.h-1. Les doses efficaces annuelles sont comprises entre 0,14 ± 0,02 mSv.a-1 et 0,25 ± 0,03 mSv.a-1. Ces valeurs annuelles sont bien en-dessous de la valeur limite acceptable pour le public qui est de 1 mSv.a-1.Mots-clés: radioactivite, spectrométrie gamma, dose absorbée, dose efficace annuelle. Study of the dosimetric impact due to the gamma radioactivity of the soil in the border of the “baie des français”, Antsiranana, MadagascarThe aim of this work is to study gamma radioactivity of the soil in the border of the “baie des français” and then to determine the dosimetric impact to the local population of Ankorikihely, betahitry and Lazaret-Nord. Samples have been collected to identify the specific activities of the potassium-40, Uranium-238 series and Thorium-232.series. These samples have been analyzed by gamma spectrometry system, with NaI(Tl) detector using ScintiVision software. The spectrum processing has been done by using the method developed by Rybach. The results show that:The potassium-40 activity ranges are from 112 ± 34 Bq.kg-1 to 565 ± 50 Bq.kg-1, with an average of 313Bq.kg-1. This latter is below the work average value of 400 Bq.kg-1. The uranium-238 activity varies between 87 ± 32 Bq.kg-1 and 190 ± 46Bq.kg-1, with an average of 139 Bq.kg-1. This average value is 4 times higher than the world average value of 35 Bq.kg-1. The thorium-232 activity varies from 81 ± 20 Bq.kg-1 to (161 ± 23) Bq.kg-1, with an average of 126 Bq.kg-1. This average value is 4 times higher than the world average value of 30 Bq.kg-1. The absorbed dose rate at 1m above soil surface varies between 89 ± 14nGy.h-1and 209± 29 nGy.h-1, with an average of 153nGy.h-1. The annual effective dose ranges from 0.14 ± 0.02mSv.y-1to 0.25 ± 0.03mSv.y-1. The estimated annual effective doses are below 1mSv.y-1, the limit value for the public.Keywords: radioactivity, gamma spectrometry, absorbed dose rate, annual effective dose

mspire: mass spectrometry proteomics in Ruby

Summary: Mass spectrometry-based proteomics stands to gain from additional analysis of its data, but its large, complex datasets make demands on speed and memory usage requiring special consideration from scripting languages. The software library ‘mspire’—developed in the Ruby programming language—offers quick and memory-efficient readers for standard xml proteomics formats, converters for intermediate file types in typical proteomics spectral-identification work flows (including the Bioworks .srf format), and modules for the calculation of peptide false identification rates

Experience of primary care for people with HIV: a mixed-method analysis

Background Advances in treatment have transformed HIV into a long-term condition (LTC), presenting fresh challenges for health services, HIV specialists and general practitioners (GPs). Aim To explore the experience of people living with HIV (PLHIV) regarding using their GPs. Design and setting A mixed-method analysis using data from two sources: a nationally-representative survey of PLHIV and a qualitative study with London-based PLHIV. Methods Univariate logistic regression for quantitative data and Framework analysis for qualitative data. Results The survey had 4,422 participants; the qualitative study included 52 participants. In both studies, GP registration and HIV status disclosure were high. Similar to general population trends, recent GP use was associated with poor self-rated health status, co-morbidities, older age and lower socioeconomic status. Two-thirds reported a good experience with GPs; a lower proportion felt comfortable asking HIV-related questions. Actual or perceived HIV stigma were consistently associated with poor satisfaction. In the interviews, participants with additional LTCs valued sensitive and consistent support from GPs. Some anticipated, and sometimes experienced, problems relating to HIV status, GPs’ limited experience and time to manage their complex needs. Sometimes they took their own initiatives to facilitate coordination and communication. For PLHIV, a ‘good’ GP offered continuity and took time to know and accept them without judgement. Conclusion We suggest clarification of roles and provision of relevant support to build confidence in GPs and primary care staff to care for PLHIV. As PLHIV population ages, there is a strong need to develop trusting patient/GP relationships and HIV-friendly GP practices

On the Sensitivity and Specificity of Postmortem Upper Respiratory Tract Testing for SARS-CoV-2

Background Postmortem testing can improve our understanding of the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) if sufficiently sensitive and specific. Methods We investigated the postmortem sensitivity and specificity of reverse transcriptase polymerase chain reaction (PCR) testing on upper respiratory swabs using a dataset of everyone tested for SARS-CoV-2 before and after death in England, 1 March to 29 October 2020. We analyzed sensitivity in those with a positive test before death by time to postmortem test. We developed a multivariate model and conducted time-to-negativity survival analysis. For specificity, we analyzed those with a negative test in the week before death. Results Postmortem testing within a week after death had a sensitivity of 96.8% if the person had tested positive within a week before death. There was no effect of age, sex, or specimen type on sensitivity, but individuals with coronavirus disease 2019 (COVID-19)–related codes on their death certificate were 5.65 times more likely to test positive after death (95% confidence interval, 2.31–13.9). Specificity was 94.2%, increasing to 97.5% in individuals without COVID-19 on the death certificate. Conclusion Postmortem testing has high sensitivity (96.8%) and specificity (94.2%) if performed within a week after death and could be a useful diagnostic tool

An ALM model for pension funds using integrated chance constraints

We discuss integrated chance constraints in their role of short-term risk constraints in a strategic ALM model for Dutch pension funds. The problem is set up as a multistage recourse model, with special attention for modeling short-term risk prompted by the development of new guidelines by the regulating authority for Dutch pension funds. The paper concludes with a numerical illustration of the importance of such short-term risk constraints

Mortality and causes of death in people diagnosed with HIV in the era of highly active antiretroviral therapy compared with the general population: an analysis of a national observational cohort

BACKGROUND: Deaths in HIV-positive people have decreased since the introduction of highly active antiretroviral therapy (HAART) in 1996. Fewer AIDS-related deaths and an ageing cohort have resulted in an increase in the proportion of HIV patients dying from non-AIDS-related disorders. Here we describe mortality and causes of death in people diagnosed with HIV in the HAART era compared with the general population. METHODS: In this observational analysis, we linked cohort data collected by Public Health England (PHE) for individuals aged 15 years and older, diagnosed with HIV in England and Wales from 1997 to 2012, to the Office for National Statistics (ONS) national mortality register. Cohort inclusion began at diagnosis with follow-up clinical information collected every year from all 220 National Health Service (NHS) HIV outpatient clinics nationwide. To classify causes of death we used a modified Coding Causes of Death in HIV (CoDe) protocol, which uses death certificate data and clinical markers. We applied Kaplan-Meier analysis for survival curves and mortality rate estimation and Cox regression to establish independent predictors of all-cause mortality, adjusting for sex, infection route, age at diagnosis, region of birth, year of diagnosis, late diagnosis, and history of HAART. We used standardised mortality ratios (SMRs) to make comparisons with the general population. FINDINGS: Between 1997 and 2012, 88 994 people were diagnosed with HIV, contributing 448 839 person-years of follow up. By the end of 2012, 5302 (6%) patients had died (all-cause mortality 118 per 10 000 person-years, 95% CI 115–121). In multivariable analysis, late diagnosis was a strong predictor of death (hazard ratio [HR] 3·50, 95% CI 3·13–3·92). People diagnosed more recently had a lower risk of death (2003–07: HR 0·66, 95% CI 0·62–0·70; 2008–12: HR 0·65, 95% CI 0·60–0·71). Cause of death was determinable for 4808 (91%) of 5302 patients; most deaths (2791 [58%] of 4808) were attributable to AIDS-defining illnesses. Cohort mortality was significantly higher than the general population for all causes (SMR 5·7, 95% CI 5·5–5·8), particularly non-AIDS infections (10·8, 9·8–12·0) and liver disease (3·7, 3·3–4·2). All-cause mortality was highest in the year after diagnosis (SMR 24·3, 95% CI 23·4–25·2). INTERPRETATION: Despite the availability of free treatment and care in the UK, AIDS continues to account for the majority of deaths in HIV-positive people, and mortality remains higher in HIV-positive people than in the general population. These findings highlight the importance of prompt diagnosis, care engagement, and optimum management of comorbidities in reducing mortality in people with HIV

Modeling peptide fragmentation with dynamic Bayesian networks for peptide identification

Motivation: Tandem mass spectrometry (MS/MS) is an indispensable technology for identification of proteins from complex mixtures. Proteins are digested to peptides that are then identified by their fragmentation patterns in the mass spectrometer. Thus, at its core, MS/MS protein identification relies on the relative predictability of peptide fragmentation. Unfortunately, peptide fragmentation is complex and not fully understood, and what is understood is not always exploited by peptide identification algorithms