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L’estimation de l’âge à partir de pièces calcifiées est, avant tout, basée sur un processus répétitif d’interprétation de zones de croissance associant des mécanismes de perception visuelle et des connaissances biologiques. Devant la multiplicité des sources de biais et la subjectivité de certains critères d’interprétation, les sclérochronologues ont cherché à introduire une certaine objectivité à la fois dans l’acquisition des informations de base, essentiellement visuelles, et dans les sché...

Les pièces calcifiées ont des origines ontogéniques et des propriétés différentes. C’est pourquoi, dans le but d’évaluer les utilisations potentielles des otolithes, des écailles et des tissus squelettiques pour les études de sclérochronologie, il est important de bien comprendre la nature et la formation des accroissements dans ces différentes structures. Dans ce chapitre, nous décrirons la fonction, la morphologie et la structure des différentes pièces calcifiées. Puis, nous ferons une revu...

H. de Pontual, J. Panfili, P.J. Wright, H. Troadec Étymologiquement, le terme « sclérochronologie » est dérivé des racines grecques sklêros « dur », khronos « temps » et logos « étude ». Littéralement, cette science vise à reconstruire l’histoire vécue par les organismes vivants à partir de l’étude de leurs pièces calcifiées (PC). Elle couvre ainsi non seulement les problèmes d’estimation de l’âge mais aussi ceux de l’estimation de la période et de la durée d’événements marquants de l’histoir...

Les chapitres précédents ont montré que les écailles, les otolithes et les os du squelette sont utilisés pour estimer l’âge des poissons en année, en saison ou en jour. La préparation des pc nécessite une série d’étapes de traitement qui peuvent être longues et complexes. Préalablement au démarrage d’une étude de sclérochronologie, il est nécessaire d’identifier les contraintes en termes de temps et de coûts et surtout les objectifs finaux et les résultats attendus (chap. III). Le choix d’une...

Il est impossible de connaître l’âge absolu, « âge véritable », d’un poisson prélevé au hasard dans son environnement naturel. De nombreuses analyses de pêcheries dépendent cependant d’estimations exactes et fiables des structures en âge des captures. La constatation de nombreuses erreurs dans les estimations d’âge a relancé l’intérêt des méthodes de validation. « Valider » signifie qu’il faut prouver qu’une technique est exacte. Ceci peut être démontré ou estimé. Une estimation a bien sûr mo...

Contrairement aux idées reçues, la sclérochronologie, en particulier l’estimation de l’âge chez les poissons, n’est pas une science aisée. Elle implique une série de processus et de traitements de données qui sont souvent complexes et consommateurs de temps. Avant même de commencer de telles études, il est nécessaire de connaître à l’avance les contraintes sur le temps disponible et sur les coûts et, particulièrement, les objectifs de l’étude ainsi que les résultats attendus. Ce chapitre va a...

A. Introduction Depuis le début des années soixante-dix, un effort de recherche croissant a été consenti pour utiliser la composition chimique des pièces calcifiées (pc) comme source d’information permettant d’aborder un large éventail de questions en halieutique. Cette approche suppose que la composition chimique des tissus durs des poissons reflète les caractéristiques physico-chimiques de l’environnement au sein duquel ces poissons évoluent. Les otolithes en particulier ont été qualifiés d...

Background The Joint United Nations Programme on HIV/AIDS (UNAIDS) has developed an ambitious strategy to end the AIDS epidemic. After eight years of antiretroviral therapy (ART) program we assessed progress towards the UNAIDS 90–90-90 targets in Mbongolwane and Eshowe, KwaZulu-Natal, South Africa. Methods We conducted a cross-sectional household-based community survey using a two-stage stratified cluster probability sampling strategy. Persons aged 15–59 years were eligible. We used face-to-face interviewer-administered questionnaires to collect information on history of HIV testing and care. Rapid HIV testing was performed on site and venous blood specimens collected from HIV-positive participants for antiretroviral drug presence test, CD4 count and viral load. At the time of the survey the CD4 threshold for ART initiation was 350 cells/μL. We calculated progression towards the 90–90-90 UNAIDS targets by estimating three proportions: HIV positive individuals who knew their status (first 90), those diagnosed who were on ART (second 90), and those on ART who were virally suppressed (third 90). Results We included 5649/6688 (84.5%) individuals. Median age was 26 years (IQR: 19–40), 62.3% were women. HIV prevalence was 25.2% (95% CI: 23.6–26.9): 30.9% (95% CI: 29.0–32.9) in women; 15.9% (95% CI: 14.0–18.0) in men. Overall progress towards the 90–90-90 targets was as follows: 76.4% (95% CI: 74.1–78.6) knew their status, 69.9% (95% CI: 67.0–72.7) of those who knew their status were on ART and 93.1% (95% CI: 91.0–94.8) of those on ART were virally suppressed. By sex, progress towards the 90–90-90 targets was: 79%–71%–93% among women; and 68%–68%–92% among men (p-values of women and men comparisons were

The Asteraceae family is economically very important, because many of these plants are grown mainly for their food value, such as lettuce (Lactuca), chicory (Cichorium), and sunflower (Heliantus aminus). One of the typical properties of this family, which includes milk thistle (Sylibum marianum), is the richness of the oil in various compounds (flavonoids, alkaloids, tocopherols, and unsaturated fatty acids). Currently, and for the coming decades, age-related diseases, including neurodegenerative diseases, are a major public health problem. Preventing their appearance or opposing their evolution is a major objective. In this context, the cytoprotective activities of milk thistle seed oil produced in Tunisia were studied on the 158N model using 7-ketocholesterol (7KC) and 24S-hydroxycholesterol (24S) as cytotoxic agents. 7KC and 24S were used because they can be increased in the brain and body fluids of patients with major age-related neurodegenerative diseases, such as Alzheimer&rsquo, s and Parkinson&rsquo, s diseases. In order to evaluate the cytoprotective properties of milk thistle seed oil, complementary techniques of microscopy, flow cytometry, and biochemistry were used. The chemical composition of milk thistle seed oil has also been determined by various chromatography techniques. Milk thistle seed oils from different area of Tunisia are rich in tocopherols and are strongly antioxidant according to various biochemical tests (KRL (Kit Radicaux Libres), FRAP (Ferric Reducing Antioxidant Power), and DPPH (2,2-diphenyl-1-picrylhydrazyl)). The main fatty acids are linoleic acid (C18:2 n-6) and oleic acid (C18:1 n-9). The main polyphenols identified are homovanillic acid, p-coumaric acid, quercetin, and apigenin, with a predominance of vanillic acid. On 158N cells, milk thistle seed oil attenuates the cytotoxicity of 7KC and 24S including: loss of cell adhesion, increased plasma membrane permeability, mitochondrial dysfunction, overproduction of reactive oxygen species, induction of apoptosis, and autophagy. The attenuation of the cytotoxicity of 7KC and 24S observed with the milk thistle seed oil is in the order of that observed with &alpha, tocopherol used as a positive control. In the presence of nigella seed oil, considered potentially cytotoxic, no cytoprotective effects were observed. Given the chemical characteristics, antioxidant properties, and cytoprotective activities of milk thistle seed oil, our results highlight the potential benefit of this oil for human health.

International audience; Honeybee colonies are increasingly exposed to environmental stress factors, which can lead to their decline or failure. However, there are major gaps in stressor risk assessment due to the difficulty of assessing the honeybee colony state and detecting abnormal events. Since stress factors usually induce a demographic disturbance in the colony (e.g. loss of foragers, early transition from nurse to forager state), we suggest that disturbances could be revealed indirectly by measuring the age- and task-related physiological state of bees, which can be referred to as biological age (an indicator of the changes in physiological state that occur throughout an individual lifespan). We therefore estimated the biological age of bees from the relationship between age and biomarkers of task specialization (vitellogenin and the adipokinetic hormone receptor). This relationship was determined from a calibrated sample set of known-age bees and mathematically modelled for biological age prediction. Then, we determined throughout the foraging season the evolution of the biological age of bees from colonies with low (conventional apiary) or high Varroa destructor infestation rates (organic apiary). We found that the biological age of bees from the conventional apiary progressively decreased from the spring (17 days) to the fall (6 days). However, in colonies from the organic apiary, the population aged from spring (13 days) to summer (18.5 days) and then rejuvenated in the fall (13 days) after Varroa treatment. Biological age was positively correlated with the amount of brood (open and closed cells) in the apiary with low Varroa pressure, and negatively correlated with Varroa infestation level in the apiary with high Varroa pressure. Altogether, these results show that the estimation of biological age is a useful and effective method for assessing colony demographic state and likely detrimental effects of stress factors.

We combine the Leslie model and its derivatives with the classical compartmental SIRS models to build a model of transmission of infected diseases, in a population of hosts, whether opened or closed systems. We calculate the basic reproductive rate R0. Under certain conditions, when R0<1, there is a disease-free equilibrium that is locally asymptotically stable. In contrast, when R0>1, this equilibrium is unstable. Then, through an example, we show how we can define public health strategies to tackle an endemic. Finally we carry a global sensitivity analysis based on this basic reproduction rate to exhibit the most influential parameters of our model that are applied to influenza.

The age, growth, longevity, mortality and reproductive parameters were estimated forDipturus oxyrinchusfrom the Gulf of Gabès (Southern Tunisia, central Mediterranean Sea), collected monthly during 2007 from commercial fisheries. The present study provides the first data on age and growth of this species in Tunisian waters, as well as additional data on its reproduction. A total of 240 females (16.5–105 cm total length (TL)) and 280 males (15.5–95 cmTL) were examined to study the reproductive cycle. A subsample of 285 specimens (175 females and 110 males, ranging from 15.5 to 105 cmTL) were analysed to study the age and growth. The oldest female in this study was 25 yr and 105 cmTL, whereas the oldest male was 22 yr and 95 cm. The annual deposition of growth bands was verified by marginal increment and edge analysis. The von Bertalanffy growth parameters wereL∞ = 123.9 ± 2.56 cm,K = 0.08 ± 0.004 yr−1andt0 = −1.26 ± 0.04 10−1yr for females andL∞ = 102.1 ± 3.23 cm,K = 0.12 ± 0.007 10−3yr−1andt0 = −1.18 ± 0.03 10−1yr for males. Growth was not significantly different between sexes. The maturity size was 72.05 cm for males and 82.1 cm for females. The maturity age was estimated to be 11.95 and 13.96 years, respectively, for males and females. Size and age at maturity were not significantly different between sexes. The estimated longevity was 26.18 and 38.84 yr for males and females, respectively. Based on life history parameters, natural mortality was estimated at 0.53 yr−1for females and 0.41 yr−1for males.

Item does not contain fulltext Haptoglobin (Hp) levels were investigated in relation to host genotype in a malaria-endemic area in Gabon. A cross-sectional study of 1-12-year-old children was conducted in the rainy season, a period of high malaria transmission, to examine this relationship. Variables that influenced Hp levels were Hp genotype, location, and age interacting with parasite density. At low parasite densities, there was a negative correlation between Hp levels and age. At higher densities, there was a positive correlation with age. This suggests that in the presence of greater parasite-induced hemolysis, older children are capable of increased production of Hp. Sickle cell trait and ABO blood group was not associated with Hp levels in this population.

Studies with animal models have suggested the possibility of interactions between parasites during concurrent infections and have raised the question of a similar phenomenon in humans. The present survey was undertaken to assess the impact of urinary schistosomiasis on the susceptibility of children to malaria. It was carried out in Senegal between September 2001 and March 2002 among 523 children 3-15 years of age. We tested the association between Plasmodium falciparum densities and the load of Schistosoma haematobium egg excretion using a linear mixed model because data were not independent. After controlling for age, sex, and season, we showed that children lightly infected with S. haematobium (1-9 eggs/10 mL of urine) had lower P. falciparum densities than those not infected (beta = -0.34, 95% confidence interval = -0.85, -0.10), suggesting a negative interaction between both parasites.

From 1995 to 1998, outbreaks of bubonic plague occurred annually in the coastal city of Mahajanga, Madagascar. A total of 1,702 clinically suspected cases of bubonic plague were reported, including 515 laboratory confirmed by Yersinia pestis isolation (297), enzyme-linked immunosorbent assay, or both. Incidence was higher in males and young persons. Most buboes were inguinal, but children had a higher frequency of cervical or axillary buboes. Among laboratory-confirmed hospitalized patients, the case-fatality rate was 7.9%, although all Y. pestis isolates were sensitive to streptomycin, the recommended antibiotic. In this tropical city, plague outbreaks occur during the dry and cool season. Most cases are concentrated in the same crowded and insanitary districts, a result of close contact among humans, rats, and shrews. Plague remains an important public health problem in Madagascar, and the potential is substantial for spread to other coastal cities and abroad.

Stéphane Helleringer and colleagues conducted a validation study in Niakhar, Senegal to investigate whether a new approach, sibling survival calendars, improves the quality of adult mortality data collected in demographic surveys. Please see later in the article for the Editors' Summary, Background In countries with limited vital registration, adult mortality is frequently estimated using siblings' survival histories (SSHs) collected during Demographic and Health Surveys (DHS). These data are affected by reporting errors. We developed a new SSH questionnaire, the siblings' survival calendar (SSC). It incorporates supplementary interviewing techniques to limit omissions of siblings and uses an event history calendar to improve reports of dates and ages. We hypothesized that the SSC would improve the quality of adult mortality data. Methods and Findings We conducted a retrospective validation study among the population of the Niakhar Health and Demographic Surveillance System in Senegal. We randomly assigned men and women aged 15–59 y to an interview with either the DHS questionnaire or the SSC. We compared SSHs collected in each group to prospective data on adult mortality collected in Niakhar. The SSC reduced respondents' tendency to round reports of dates and ages to the nearest multiple of five or ten (“heaping”). The SSC also had higher sensitivity in recording adult female deaths: among respondents whose sister(s) had died at an adult age in the past 15 y, 89.6% reported an adult female death during SSC interviews versus 75.6% in DHS interviews (p = 0.027). The specificity of the SSC was similar to that of the DHS questionnaire, i.e., it did not increase the number of false reports of deaths. However, the SSC did not improve the reporting of adult deaths among the brothers of respondents. Study limitations include sample selectivity, limited external validity, and multiple testing. Conclusions The SSC has the potential to collect more accurate SSHs than the questionnaire used in DHS. Further research is needed to assess the effects of the SSC on estimates of adult mortality rates. Additional validation studies should be conducted in different social and epidemiological settings. Trial Registration Controlled-Trials.com ISRCTN06849961 Please see later in the article for the Editors' Summary, Editors' Summary Background Governments and international health agencies need accurate information on births and deaths in populations to help them plan health care policies and monitor the effectiveness of public health programs. The most common way of collecting information on vital statistics in an area or country is through civil registration, an administrative system used by governments to record vital events that occur in their populations. In low-to-middle-income countries that have limited resources to devote to such a system, unconventional techniques are often used to estimate mortality levels and trends. One such method is siblings' survival histories collected while conducting a health or other type of public survey. Those surveyed are asked to list all their maternal siblings by birth order and report survival status and current age (for living siblings) or age at death (for deceased siblings). Use of siblings' survival histories leaves the accuracy of the mortality record vulnerable to reporting errors and selection bias. Selection bias is a statistical prejudice that is introduced by the choice of the individuals or groups taking part in the analysis. Reporting errors occur when an individual fails to report a sibling's death, misreports the age of a sibling, or does not recall the exact date when a sibling died. Why Was This Study Done? This study was conducted to estimate whether modifying a standard siblings' survival history questionnaire could improve the accuracy of data obtained. The researchers conducted a study in Niakhar, Senegal, using a modified siblings' survival history questionnaire to incorporate some innovative techniques for assisting memory recall, such as recall cues, to help prevent omissions. The researchers also introduced an event history calendar format to help with more accurate reporting of dates. This modified questionnaire is called the siblings' survival calendar. What Did the Researchers Do and Find? The researchers randomly assigned men and women registered by the Niakhar Health and Demographic Surveillance System, aged 15–59 years old, to an interview with the basic questionnaire or the modified siblings' survival calendar. The modifications included emphasizing the importance of accurate recall before the participant started and asking respondents to list their maternal siblings in the order that they came to the mind instead of birth order. Also, the researchers used supplementary interviewing techniques designed to stimulate the recall of potentially omitted siblings and also used an event history calendar approach for collecting data on ages at, and dates of, vital events that had affected the siblings of a respondent. The researchers compared the results from the two survey instruments and precise data on adult mortality collected by continuous demographic surveillance in a small area of Senegal. They found that the calendar survey improved the sensitivity of survey data in recording adult female deaths. In addition, the modified questionnaire significantly reduced age and date heaping (the tendency of respondents to round off dates) observed with the basic questionnaire. The modified questionnaire took six minutes longer to complete on average than the basic questionnaire. What Do These Findings Mean? These findings suggest that a new approach (the siblings' survival calendar) that uses simple interview tools to improve estimates of mortality in resource-limited countries is feasible and may improve the quality of the data from siblings' survival histories, particularly in reporting female deaths. Although the study was limited by sample selectivity, limited external validity, and multiple testing, the findings suggest that this new approach has the potential to allow the collection of more accurate data from siblings' survival histories than that collected from the current questionnaire. The next step is to validate these findings in other settings. Additional Information Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001652. The World Health Organization Regional Office for Africa has a page on vital statistics Information on demographic data available in Senegal can be accessed on the website of the Agence Nationale de la Statistique et de la Démographie (in French) The UN Statistics Division has a page on their vital registration and vital statistics coverage assessment The World Mortality Report 2013 presents the latest mortality estimates developed by the Population Division of the United Nations, including the probability of dying between the ages of 15 and 60 years The Institute for Health Metrics and Evaluation has developed a visualization tool that allows one to see how siblings' survival histories are adjusted to generate estimates of adult mortality More information on Health and Demographic Surveys surveillance in Niakhar, Senegal, is available (in French) on the website of the Institut de Recherche pour le Développement

Dans cet article, nous examinons les ajustements du marché du travail aux fluctuations économiques, compte tenu des transformations structurelles en cours ainsi que des changements à court terme. Nous utilisons pour cela des données des recensements de la population ou publiées dans les annuaires statistiques de l’Office Général de la Statistique pour les séries à long terme, et les enquêtes emploi conduites entre 2007 à 2012 pour les données à court terme. Cet article souligne la profonde transformation du marché du travail au cours des dernières décennies. La population active a doublé en 25 ans et la part de l'agriculture est passée en dessous du seuil de 50 %. L’absorption de l'offre de travail a donc été l'un des principaux défis pour l'économie vietnamienne sur cette période. Le secteur des entreprises familiales agricoles et non-agricoles a été le principal pourvoyeur d'emplois au cours de ces années. Le marché du travail s'est adapté au récent ralentissement économique à travers différents canaux. Le chômage est resté stable mais le nombre de personnes inactives a augmenté. La quantité de travail a également été affectée par une réduction significative du nombre d'heures travaillées. Alors que le secteur non agricole a généré plus d'emplois pour les travailleurs qualifiés, un flux de travailleurs non-qualifiés vers l’agriculture a été observé. En raison de facteurs démographiques, l'absorption de l'offre de travail et la création de nouveaux emplois ne sont plus le principal problème. En revanche, l’évolution récente du marché du travail appelle à la mise en oeuvre de politiques structurelles en vue d’améliorer les conditions de travail, la période étant particulièrement favorable pour mener ces politiques puisque le Vietnam profite actuellement du dividende démographique.

Existing attempts to estimate the survival rate of tsetse flies from ovarian age distributions generally assume that the population is stationary. The fact that the survival rate cannot be dissociated from the growth rate by these methods poses a problem. Under the assumption of a stable age distribution, we propose a maximum likelihood method to estimate the ‘apparent survival rate’ for three categories of females: nulliparous (β0), young parous (β1) and old parous flies (β2). The rate depends both on ‘real survival rates’ a0, a1 and a2, and a growth rate λ: β0 = a0/λ, β1 = a1/λ, and β2= a2/λ. We used a matrix model, which can be parameterized if the pupal survival rate and the pupal period are known. Replacing a0, a1 and a2 by β0,λ, β1λ, and β2λin the projection matrix, the problem amounts to calculating its dominant eigen-value λ, and hence a0, a1 and a2. The application to a field population of Glossina palpalis gambiensis Vanderplank in Burkina Faso showed there was a marked difference in survival rate according to age category. The average survival rate increased with age with decreasing variability. The results suggested that sampling (by trapping) may have had an effect on the dynamics of this tsetse population by ageing it artificially. This method may be a useful tool for monitoring tsetse control.

Prolonged carriage of #Plasmodium falciparum$ in humans during the dry season is critical for parasite survival, as the infected subjects constitute a major reservoir in the absence of transmission. Yet, very little is known about the host/parasite interactions contributing to parasite persistence. In order to study the characteristics of #P. falciparum$ infections during the dry season, we have genotyped parasites collected from untreated, asymptomatic individuals during 3 cross-sectional surveys conducted during the dry season in Ndiop, a Senegalese village with seasonal, mesoendemic malaria. Monthly entomological surveillance did not detect any transmission during that period. Parasite prevalence decreased markedly in the children aged less than 7 years after 7 months of undetected transmission, but was stable in older children and adults throughout the dry season. In all chronically infected individuals, infection complexity remained stable, but there were substantial fluctuations of individual genotype(s), reflecting complex dynamics of multiple-clone infections during chronic asymptomatic parasite carriage. This fluctuation resulted in changes in the msp1 and msp2 allelic distribution within the cohort after 7 months of undetected transmission, contrasting with the stability observed during the preceding rainy season in that village. (Résumé d'auteur)

To the Editor: Coinfection with HIV and hepatitis C virus (HCV) is now a major public health concern worldwide, owing both to its high prevalence (4–5 million persons of 40 million infected by HIV) and to interactions between the 2 diseases in terms of their diagnosis, natural course, and treatment (1,2). Although Africa is the continent by far the most badly affected by both HIV and HCV infections, data on coinfection in the general population are lacking. In Cameroon, a central African country, the HCV seroprevalence is among the highest in the world (13.8%) (3). We have also reported a high seroprevalence of HIV in a general population of southern Cameroon (7.4%), and especially in young women (22.5%) (4). Here, we investigated the prevalence of HIV/HCV coinfection in this population. A population-based, cross-sectional survey was conducted in September 2001 in 3 villages of the East Province of Cameroon (250 km from Yaounde, the capital city). The study methods, the baseline characteristics of the participants, and the HIV seroprevalence have been described in detail elsewhere (4). Briefly, all inhabitants >15 years of age were eligible for the survey. After giving their informed consent, the participants were interviewed by using a standard verbal questionnaire, in French or in a local language, during door-to-door visits. Blood samples were collected by peripheral venipuncture, and serum was screened for antibodies to HCV by using an enzyme immunoassay (INNOTEST HCV Ab IV, Innogenetics, Ghent, Belgium). Samples with indeterminate results were retested. All positive and twice-indeterminate samples were confirmed with a third-generation line immunoassay (INNO-LIA HCV Ab III update, Innogenetics). Serologic screening for HIV infection was based on an enzyme immunoassay (Murex HIV-1.2.O, Abbott, Rungis, France). All positive samples were confirmed by using a line immunoassay (INNO-LIA HIV-1+2, Innogenetics). Among the 484 participants, 256 were women (52.9%), and the median age was 34 years (interquartile range 23–52 years). Most participants (93.6%) were Bantus; the remainder were pygmies. Seven persons refused venipuncture after the interview, and 1 sample could not be analyzed. These 8 persons did not differ from the rest of the study population in term of sex (50.0% women vs. 47.1% women), but they were slightly younger (median, 26.8 years vs. 34.9 years). Of the 476 available samples, respectively 19 (4.0%) had indeterminate HCV serologic results, and 5 (1.1%) had indeterminate HIV serologic results. The overall seroprevalence rates were 21.0% (95% confidence interval [CI] 17.4%–24.9%) for HCV and 7.4% (95% CI 5.2%–10.1%) for HIV. Only 3 patients (0.6%) had positive results for both infections: a man 29 years of age and 2 women ages 36 and 52 years. The Figure shows the seroprevalence rates of HCV and HIV according to sex and age. Multivariate random-effects logistic regression analyses showed different risk factors for the 2 infections. The HCV seroprevalence was associated with age (

Avec un Indice synthétique de fécondité (ISF) de 5,5 enfants par femme en 2007 (PRB, 2008), l’Afrique subsaharienne reste le continent où la fécondité est la plus élevée au monde. Toutefois l’ISF varie fortement d’un pays à l’autre. En 2007, trois pays affichent un niveau de fécondité inférieur à 3 enfants par femme. Il s’agit de l’Afrique du Sud (2,7) et de deux îles de l’océan Indien : l’île Maurice (1,7) et les Seychelles (2,1). À l’opposé, 13 pays présentent encore des indices de fécondit...

While it is widely agreed that HIV-related stigma may impede access to treatment and support, there is little evidence describing who is most likely to experience different forms of stigma and discrimination and how these affect disclosure and access to care. This study examined experiences of interpersonal discrimination, internalized stigma, and discrimination at health care facilities among HIV-positive adults aged 18 years and older utilizing health facilities in four countries in Sub-Saharan Africa (N = 536). Prevalence of interpersonal discrimination across all countries was 34.6 %, with women significantly more likely to experience interpersonal discrimination than men. Prevalences of internalized stigma varied across countries, ranging from 9.6 % (Malawi) to 45.0 % (Burkina Faso). Prevalence of health care discrimination was 10.4 % across all countries. In multiple regression analyses, we found positive, significant, and independent associations between disclosure and interpersonal discrimination and disclosure and support group utilization, and positive associations between both internalized stigma and health care discrimination and referral for medications.

A dynamic, two-sex, age-structured marriage model is presented. Part 1 focused on first marriage only and described a marriage market matching algorithm. In Part 2 the model is extended to include divorce, widowing, and remarriage. The model Produces a self-consistent set of marital states distributed by age and sex in a stable population by means of a gender-symmetric numerical method. The model is compared with empirical data for the case of Zambia. Furthermore, a dynamic marriage function for a changing population is demonstrated in simulations of three hypothetical scenarios of elevated mortality in young to middle adulthood. The marriage model has its primary application to simulation of HIV-AIDS epidemics in African countries.

Glossina or tsetse flies, the vectors of sleeping sickqess,.form a unique group of insects with remarkable characteristics. They are viviparous with a- slow !hytlynof reppduction (one larva approximately every 10 days) determined by the regular ovulation df alternate ovaries. This unusual physiology enables the age of the females to be estimated by examining the ovaries. The resulting ovarian age structure of tsetse fly populations has been used to develop research into the demography of $etse flies. Several authors have proposed methods of estimating population growth rates from ovarian age distribution data. However, such methods are applicable only when the growth rate (h) is equal to 1 (i.e. the intrinsic rate of increase ris equal to O). In fact, in this type of estimation, the adult survival rate a (or equivalently the mortality rate) cannot be dissociated from the growth rate. Other independently determined demographic parameters must be used to remove this lack of identifiability. We have built a matrix model of the dynamics of tsetse fly populations which enables the growth rate to be calculated from the pupal survival, rate, the pupal period,apd the adult survival rate. Assuming that the age-groups of the population studied have reached a stable distribution, it i calculate the probabilities for the obsed@ sample of belonging to each of the age-groups, to construct a likelihood function and thus to obtain an estimate of the ‘apparent survival rate’ s = a/h If the pupal survival rate and the pupal period are known, a and h can then be calculated from s. The application of this method to data collected for over two annual cycles in a savannah habitat (Burkina-Faso) showed a high overall stability in the populations of Glossinupalpalis gambiensis. Seasonal fluctuations could be easily interpreted as being the result of climatic changes between the dry and rainy seasons.

It is generally assumed that the daily probability of survival of mosquitoes is independent of age. To test this assumption we have conducted a three-year experimental fieldwork study (20052007) at Fortaleza-CE in Brazil, determining daily survival rates of the dengue vector Aedes aegypti (L.). Survival rates of adult Ae. aegypti may be age-dependent and the statistical analysis is a sensitive approach for comparing patterns of mosquito survival. The mosquito survival data were better fit by a Weibull survival function than by the more traditionally used Gompertz or logistic survival functions. Gompertz, Weibull, or logistic survival functions often fit the survival, and the tails of the survival curves usually appear to fall between the values predicted by the three functions. We corroborate that the mortality of Ae. aegypti in semi-natural conditions may no more be considered as a constant phenomenon during the life of adult mosquitoes but varies according to the age and environmental conditions under a tropical climate. This study estimates the variability in the survival rate of Ae. aegypti and environmental factors that are related to such variability. The statistical analysis shows that the fitting ability, concerning the hazard function, was in decreasing order: Seasonal Cox, the three-parameter Gompertz, and the three-parameter Weibull, that was similar to the three-parameter logistic. The advantage of using the Cox model is that it is convenient for exploring the relationship between survival and several explanatory variables. The Cox model has the advantage of preserving the variable in its original quantitative form and of using a maximum of information. The survival analyses indicate that mosquito mortality is both age- and environment-dependent.

Introduction Southern Mediterranean countries have experienced a marked increase in the prevalence of obesity whose consequences for gender related health inequities have been little studied. We assessed gender obesity inequalities and their environmental and socio-economic modifiers among Tunisian adults. Methods Cross-sectional survey in 2005; national, 3 level random cluster sample of 35–70 years Tunisians (women: n = 2964, men: n = 2379). Overall adiposity was assessed by BMI = weight(kg)/height(m)2 and obesity was BMI≥30, WHtR = waist circumference to height ratio defined abdominal obesity as WHtR≥0.6. Gender obesity inequality measure was women versus men Prevalence Proportion Odds-Ratio (OR); models featuring gender x covariate interaction assessed variation of gender obesity inequalities with area (urban versus rural), age, marital status or socio-economic position (profession, education, household income proxy). Results BMI was much higher among women (28.4(0.2)) versus men (25.3(0.1)), P

L’évaluation de la situation nutritionnelle d’une population d’enfants nécessite de disposer d’indicateurs dont la nature dépend des problèmes pris en compte et dont la validité est tributaire de la qualité des données recueillies. Par ailleurs, pour suivre l’évolution de la situation nutritionnelle d’une population, ou comparer celle de plusieurs populations, il est indispensable de disposer de données recueillies de manière identique. Pour toutes ces raisons, vouloir juger de l’évolution de...

Variations of the sex ratio at birth (SRB) were investigated using maternity history data collected in demographic surveys conducted in sub-Saharan Africa. Thirty-three countries were covered, totaling about 2.0 million births. The average SRB was 1.034 and varied by ethnicity, birth order, and maternal age. The effect of maternal age was significant for younger mothers (12–19 years old) and older mothers (40–49 years old), with a decline in sex ratios with increasing maternal age in both cases. The effect of birth order was significant only for the 20–39-year-old women, with a decline in sex ratio with increasing birth order. These two effects were similar for the three main population groups identified: populations from southern, eastern, and central Africa (SRB = 1.015), populations from West Africa and Sahelian countries (SRB = 1.040), and populations from Nigeria and Ethiopia (SRB = 1.087). In contrast, no effect of marital duration was found.