Development and validation of the body shape scale (BOSHAS) for assessing body shape perception in African populations.

BACKGROUND: As a consequence of 'Western' acculturation, eating disorders and body image disturbances, such as fatness phobia and body dysmorphic disorders towards musculature and body shape, are emerging in Africa, with young people the most affected. It is therefore important to accurately assess perceptions of body shape. However, the existing body image assessment scales lack sufficient accuracy and validity testing to compare body shape perception across different African populations. The purpose of this study was to develop and validate the Body Shape Scale (BOSHAS) to evaluate body shape perceptions related body image disorders in African populations. METHODS: To develop the BOSHAS, anthropometric measures of 80 Cameroonians and 81 Senegalese (both sexes included; 40.1% females overall) were taken for three body shape criteria: somatotype components, body mass index (BMI) and waist-to-hip ratio. Subjects were selected to cover a wide variability in body shape and were photographed in full face and profile positions. To validate the BOSHAS, the scale was administered twice (2 weeks apart) to 106 participants (aged 31.2 ± 12.6 years) to assess its reliability. In addition, a questionnaire measuring different aspects of body shape (e.g. musculature) was also administered (n = 597; aged 36.7 ± 15.6 years) to assess its convergent validity. RESULTS: The BOSHAS includes two sex-specific subscales of 10 photographs each. Most participants were able to repeat their BOSHAS preference order. Test-retest reliability was also consistent in estimating Current Body Shape (CBS), Desired Body Shape and Ideal Body Shape for participants and their partners. CBS was correlated with BMI, and different BOSHAS indices were consistent with declarations obtained by questionnaire. CONCLUSIONS: The BOSHAS is the first sex-specific scale of real African models photographed in face and profile, including large body shape variability. The validation protocol showed good validity and reliability for evaluating body shape perceptions and dissatisfaction of Africans.

Biocultural determinants of overweight and obesity in the context of nutrition transition in Senegal: a holistic anthropological approach.

Senegal is experiencing a rising obesity epidemic, due to the nutrition transition occurring in most African countries, and driven by sedentary behaviour and high-calorie dietary intake. In addition, the anthropological local drivers of the social valorization of processed high-calorie food and large body sizes could expose the population to obesity risk. This study aimed to determine the impact of these biocultural factors on the nutritional status of Senegalese adults. A mixed methods approach was used, including qualitative and quantitative studies. Between 2011 and 2013, fourteen focus group discussions (n=84) and a cross-sectional quantitative survey (n=313 women; n=284 men) of adults in three different socio-ecological areas of Senegal (rural: n=204; suburban: n=206; urban: n=187) were conducted. Dietary intake (Dietary Diversity Scores), physical activity (International Physical Activity Questionnaire), body weight norms (Body Size Scale), weight and health statuses (anthropometric measures and blood pressure) were measured. Middle-aged and older Senegalese women were found to value overweight/obesity more than younger Senegalese in all regions. In addition, young urban/suburban adults had a tendency for daily snacking whilst urban/suburban adults tended to be less physically active and had higher anthropometric means. A binary logistic regression model showed that being female, older, living in urban/suburban areas and valuing larger body size were independently associated with being overweight/obese, but not high-calorie diet. Univariate analyses showed that lower physical activity and higher socioeconomic status were associated with being overweight/obese. Finally, overweight/obesity, which is low in men, is associated with hypertension in the total sample. The nutrition transition is currently underway in Senegal's urban/suburban areas, with older women being more affected. Since several specific biocultural factors jointly contribute to this phenomenon, the study's findings suggest the need for local public health interventions that target women and which account for the anthropological specificities of the Senegalese population.

[Mothers' responses to teething in children in Ferlo, Senegal]. / Réponses thérapeutiques des mères face à l'éruption dentaire chez les enfants du Ferlo au Sénégal.

INTRODUCTION: Tooth eruption is a process that begins in infancy and continues throughout childhood and adolescence. This complex phenomenon induces systemic disorders requiring specific management. The objective of this study was to identify the therapeutic responses to teething in children in Ferlo, Senegal. METHODS: This qualitative study focused on mothers of teething children (infants and young children). Information was collected by individual interviews (20 persons) and two focus groups (six persons/group) concerning the symptoms and signs of teething, the first-line solution in the presence of such signs, the type and form of prevention and the mother's psychological aspects during this period. RESULTS: The methods used by mothers to treat signs of teething were incantations on strings of knots, amulets, plants and various hard objects such as coins, cowry shells, or wild donkey teeth. CONCLUSION: These methods responded to the mothers' concerns to prevent and treat the signs accompanying teething. However, mass communication sessions may be necessary to encourage visits to the dentist to improve the management of complications.

The relevance of the side-view in body image scales for public health: an example from two African populations.

BACKGROUND: Body size scales are a common method for diagnosing body image disturbances and assessing the cultural valorisation of stoutness, a phenomenon that plays a role in the development of overweight, especially among African populations. Traditionally, body size scales present a front view. In this study, we evaluated a complementary model of representing body shape: the side view of body outlines. In particular, we examined the association between the side-view and a set of bio-anthropometric indices in men and women. METHODS: To cover the inter-ethnic variability in the Niger-Congo area, we selected a balanced sex-ratio sample of 80 Cameroonians and 81 Senegalese. Individuals wearing close-fitting clothes were photographed from the front-and side-view, and measured following a bio-anthropometric protocol synthesizing body shape variation: Body Mass Index, percentage body fat, somatotype profile, waist circumference, waist-to-hip ratio, mean blood pressure and glycaemia. The shape of each front and side body outline was extracted and characterised by Normalized Elliptic Fourier Descriptors (NEFD). Finally, we assessed associations between NEFD and bio-anthropometric indices. RESULTS: Variation in the shape of both front and side body outlines was associated with all bio-anthropometrics for at least one sex-population combination. Overall, the side view best captured body shape variation related to changes in almost all bio-anthropometrics in both sexes and populations, with the exceptions of female mesomorphy, male blood pressure and glycaemia (in both sexes). We found that the details of the relationship between bio-anthropometrics and body shape differed between the two male populations, a finding that was reflected in side-views for all criteria, but not front-views. CONCLUSIONS: Variation in body shape assessed by several bio-anthropometrics related to health and nutritional status was larger for side than front body outlines. Integrating side views in body size scales would improve the accuracy of body size assessment and thus, the assessment of behaviours leading to overweight, as well as symptoms of body image disturbances, in Africa and potentially in other populations.

Socio-cultural aspects of oral health among the Fulani in Ferlo (Senegal): a qualitative study.

OBJECTIVES: Health is a subjective concept that considers the social, cultural, environmental and behavioural problems of the individual. This study was conducted with the objective of better understanding the sociocultural aspects related to the oral health of the Fulani populations of Ferlo, Senegal. METHODS: The study was qualitative and based in the area of the Great Green Wall (GGW) in the region known as Ferlo, northern Senegal. Data were collected by semi-structured interviews in a sample of the population and through discussions with a focus group. It concerned health and aesthetics of the teeth, care and traditional herbal recipes, teeth and superstitions. RESULTS: It appears that people were using the toothpick, the chewing stick and/or charcoal to clean their teeth. Confusion persisted with respect to the types of food consumed that were implicated in the occurrence of dental caries: tea, rice, 'jumbo' (a seasoning spice) and tobacco. 'Borom bop', which means 'master of the head', was the most commonly reported cause of caries. Healthy, beautiful teeth were attributes of beauty and elegance, enhanced by tattoos and crafted crowns in the Fulani. Their health problems were generally managed by healers or traditional practitioners who based their practices on empirical and 'handed down' knowledge. Socio-anthropological meanings were given to children with neonatal teeth. CONCLUSIONS: It is therefore important to consider the sociocultural aspects in oral health projects and programmes; the place of herbal medicine in dentistry should be recognized and maybe researched in the region of the Great Green Wall.

Migration and hypertension in Dakar, Senegal.

This article examines social and environmental influences on the development of hypertension in a sample of 568 adults (290 men; 278 women) aged 20 years and older from Dakar, Senegal. We test the hypothesis that more recent immigrants to the city of Dakar will have lower blood pressure and lower rates of hypertension than those who have lived there longer. Cross-sectional sociodemographic, anthropometric and blood pressure data were collected during 2009. The overall prevalence of hypertension was 27.1% (95% CI: 25.2-29.0). Hypertension rates were not significantly associated with place of birth; however, length of residence in Dakar was a significant predictor, with those living in the city for less than 10 years having reduced risks of developing hypertension (OR = 0.25; P = 0.003). Other important correlates of blood pressure and hypertension risk in this sample were age and body mass index. These findings suggest that length of exposure to the urban environment-and associated changes in lifestyle-are linked to hypertension. Public health officials should thus pay particular attention to this phenomenon, and future anthropological research should include measures of both environmental and biological characteristics to study hypertension in Senegal.

Gender and population history: sex bias revealed by studying genetic admixture of Ngazidja population (Comoro Archipelago).

The peopling of Comoro Archipelago is defined by successive waves of migration from three main areas: the East African Coast (Bantu-speaking populations), the Persia and Arabian Peninsula, and Southeast Asia (especially Indonesia). It follows an apparent classic trihybrid admixture model. To better understand the Comorian population admixture dynamics, we analyzed the contributions of these three historical parental components to its genetic pool. To enhance accuracy and reliability, we used both classical and molecular markers. Samples consist of published data: blood group frequencies, 14 KIR genes, 19 mitochondrial DNA SNPs (to highlight female migrations), 14 Y chromosome SNPs (male migrations). We revealed distinct admixture patterns for autosomal and uniparental markers. KIR gene frequencies had never been used to estimate admixture rates, this being a first assessment of their informative power in admixture studies. To avoid major methodological and statistical bias, we determined admixture coefficients through nine well-tried estimators and their associated software programs (ADMIX95, ADMIX, admix 2.0, LEA, LEADMIX, and Mistura). Results from mtDNA and Y chromosome markers point to an important sex-bias in the admixture event. The original Bantu gene pool received a predominant male-mediated contribution from the Arabian Peninsula and Persia, and a female-mediated contribution from Southeast Asia. Admixture rates estimated from autosomal KIR gene markers point also to an unexpected elevated Austronesian contribution.

[Blood donation in foreign populations in Marseille]. / Le don de sang des populations étrangères et d'origine étrangère à Marseille.

Blood donations by populations from the Maghreb and Sub-Saharan Africa are a public health necessity for reasons of genetic polymorphism. This article aims to determine whether blood donors' social characteristics ? i.e. greater socio-economic integration and a strong sense of citizenship ? constitute deterrents to blood donation among foreign populations. Results show that donors from the Maghreb and Sub-Saharan Africa are not better integrated than non-donors from the same areas. However, blood donors express a significantly greater sense of citizenship than non-donors. Donors from the Maghreb and Sub-Saharan Africa feel a greater sense of citizenship than non-donors from the same areas. The study of blood donation in these categories of population has two major implications. In biological terms, blood donation by foreign populations constitutes a response to transfusion needs. In cultural terms, blood donation is used by populations from the Maghreb and Sub-Saharan Africa as an active means of expressing their sense of citizenship.

Assessing health impacts of an environmental pan-African development project: A migration perspective.

The general objective of this article is to analyze to what extent the implementation of the Great Green Wall project is likely to disrupt migratory movements towards the rural environment and, consequently, the socio-economic structures and health status of local populations. This study was carried out in 2015 on a population sample of 500 individuals living in the municipality of Tessekere, constructed using the quota method. Socioeconomic and demographic characteristics, migratory status and self-rated health of individuals were collected during face-to-face interviews. Statistical analyses used were Chi-square tests, student and binary logistic regressions. Results show that internal migrants in the municipality of Tessekere represent 13.40% of the study population. Migrants more often work as civil servants, artisans, craft workers or traders than the region's native population, who are generally livestock breeders or jobless. While place of birth does not play a significant role, it appears that the length of residence of migrants in rural areas influences health status: migrants residing in the municipality of Tessekere for less than 10 years are less likely to report poor health, regardless of their sex, age, occupation, material well-being and perceived stress. In conclusion, an environmental requirement (combating desertification), addressed by an international political project - the Great Green Wall - and then applied at the national level, has transformed the demographic, economic and health structure of a local population. In conclusion, our study showed that (1) an examination of migration can offer a means of interpreting the impact of development projects and the local changes they entail, and (2) migration is a unique prism through which one can study how exposure to a new physical and social environment influences the health of populations.

The effect of socio-economic status and area of residence on household food variety in Morocco.

BACKGROUND: In Morocco, few studies have specifically addressed the association between food variety and household socio-economic status and area of residence. AIM: The study's objective was to obtain a qualitative description of food consumption in samples of Moroccan households and to examine the influence of socio-economic factors and area of residence on their food variety. SUBJECTS AND METHODS: A qualitative food frequency questionnaire was administered by adolescent school pupils in their own households between March 2005 and March 2006 in 526 households in the regions of Marrakesh north of the High Atlas range and Ouarzazate to the south. We calculated the Food Variety Index (FVI) based on 183 food items and compared scores for advantaged/disadvantaged and urban/rural households. RESULTS: Mean FVI scores for all individuals and total food groups differ significantly between the area of residence, urban and peri-urban Marrakesh and urban Ouarzazate having the highest scores. The mean total FVI scores, presented according to the household's socio-economic status from highest to lowest, are 123.8 +/- 17.1 for urban Marrakesh, 107.6 +/- 21.6 for urban Ouarzazate, 92.0 +/- 22.4 for rural Skoura, 110.5 +/- 21.5 for peri-urban Marrakesh and 89.9 +/- 10.8 for rural Iguerferouane (F-test = 26.7, p < 0.001). Advantaged households have significantly greater variety than disadvantaged households for all variables only in the two urban samples. In peri-urban Marrakesh and rural Skoura, there are no significant differences between advantaged and disadvantaged households. CONCLUSION: In our Moroccan sample, food variety is distributed according to two patterns: One based on area of residence, urban areas having greater variety than rural areas, and the other on socio-economic factors, with advantaged households having higher FVI values but only in urban areas. The limited availability of certain foods and food preferences by the populations mean that not all households are able to diversify their diets.

Perception of age stereotypes and self-perception of aging: a comparison of French and Moroccan populations.

The objective of this study was threefold: (1) assess the general perceptions of age stereotypes among older French and Moroccan adults, (2) analyze discourse associated with these different perceptions, and (3) compare aging self-perception scores of French and Moroccan (rural/urban) older adults and investigate the sociodemographic and health indicators likely to be associated with these self-perceptions. One-to-one structured interviews were conducted with 260 older French adults living in Marseille and 239 older Moroccans (123 living in Marrakech and 116 living in a Berber village). The same questionnaire comprising multiple-choice and short-answer questions was used in both countries. This methodology allowed us to perform quantitative and qualitative analyses. Participants averaged 73 years of age in both samples. The French and Moroccan older adults perceived positive and negative age stereotypes within their societies, but the Moroccan ones more often perceived positive stereotypes toward older adults. Moreover, almost as many Moroccan people living in Marrakech as French people perceived negative stereotypes toward older adults. The qualitative analysis allowed us to demonstrate that some notions associated with the status of older adults are shared in France and Morocco-such as respect is due to older adults-whereas other notions differ between these societies-such as the association between aging and affection/love in Morocco. Finally, this study also tended to show that the Attitudes Toward Own Aging Scale focuses mainly on the mental/physical domain of old age.

Genetic polymorphisms with erythrocyte traits in malaria endemic areas of Mali.

African populations are characterized by high degree of genetic diversity. This high genetic diversity could result from the natural selection pressure. Several studies have described an association between some genetic diversities and difference of susceptibility to infectious diseases like malaria. It seems therefore important to consider genetic diversity impact when interpreting results of clinical trials in malaria endemic areas. This study aimed to determine the genetic polymorphism with erythrocyte traits in different populations of malaria endemic area in Mali. The cross-sectional surveys were carried out in different ethnic groups living in malaria endemic areas in Mali. Six milliliters of whole blood were collected in EDTA vials from each participant after informed consent has been obtained. The ABO, RH, Kell, MNSs, Kidd and Duffy systems phenotypes were assessed by the technique of gel filtration. A total of 231 subjects were included from six villages. The blood groups phenotypes O (40.7%) and A (31.2%) were more frequent with respective allele frequencies of 0.65 and 0.21. In the RH system the haplotypes R0 (0.55), r (0.20) and R1 (0.13) were the most frequent. Seven percent (7%) of Duffy positive and 4% of Glycophorin B deficiency (S-s-) were observed among participants. All participants were Kell negative. ABO and RH systems were polymorphic in these ethnic groups in Mali. Their implication in susceptibility to malaria should be taken into account in clinical trials interpretation, and for prevention of blood transfusion risks during anemia frequently caused by malaria in children.

Stature, economy and migration during the 19th century: comparative analysis of Haute-Vienne and Hautes-Alpes, France.

Data sources are achieved records of men workers' passbooks and registry for work permits in two rural parts of Southern France. We obtained three samples: masons from Rancon, a Limousin village, local sedentary alpine workers and Italian immigrants. The results obtained provide two types of information. The first concerns adult height, which is thought to be a result of both a growth pattern and environmental factors. The second concerns growth rates at the end of adolescence. The results seem to contradict the statements made above concerning the relationships between misery, elevation and height. While the alpine inhabitants are shorter, the Limousin inhabitants are taller in sprite they live in a miserable environment. It appears that taller individuals select themselves into migration. Thus, this model would contradict the idea of a regional genetic base.

The One Health Concept: 10 Years Old and a Long Road Ahead.

Over the past decade, a significant increase in the circulation of infectious agents was observed. With the spread and emergence of epizootics, zoonoses, and epidemics, the risks of pandemics became more and more critical. Human and animal health has also been threatened by antimicrobial resistance, environmental pollution, and the development of multifactorial and chronic diseases. This highlighted the increasing globalization of health risks and the importance of the human-animal-ecosystem interface in the evolution and emergence of pathogens. A better knowledge of causes and consequences of certain human activities, lifestyles, and behaviors in ecosystems is crucial for a rigorous interpretation of disease dynamics and to drive public policies. As a global good, health security must be understood on a global scale and from a global and crosscutting perspective, integrating human health, animal health, plant health, ecosystems health, and biodiversity. In this study, we discuss how crucial it is to consider ecological, evolutionary, and environmental sciences in understanding the emergence and re-emergence of infectious diseases and in facing the challenges of antimicrobial resistance. We also discuss the application of the "One Health" concept to non-communicable chronic diseases linked to exposure to multiple stresses, including toxic stress, and new lifestyles. Finally, we draw up a list of barriers that need removing and the ambitions that we must nurture for the effective application of the "One Health" concept. We conclude that the success of this One Health concept now requires breaking down the interdisciplinary barriers that still separate human and veterinary medicine from ecological, evolutionary, and environmental sciences. The development of integrative approaches should be promoted by linking the study of factors underlying stress responses to their consequences on ecosystem functioning and evolution. This knowledge is required for the development of novel control strategies inspired by environmental mechanisms leading to desired equilibrium and dynamics in healthy ecosystems and must provide in the near future a framework for more integrated operational initiatives.

Type 2 diabetes in a Senegalese rural area.

AIM: To estimate the prevalence of diabetes in the rural population of Tessekere (Senegal) and investigate associated risk factors. METHODS: Data from a 2015 survey of 500 individuals age 20 and over representative of the population of the municipality of Tessekere were used. Sociodemographic characteristics, health related variables, capillary whole blood glucose, and weight and height measurements of individuals were collected during face-to-face interviews. Statistical analyses used were bivariate tests and binary logistic regressions. RESULTS: The percentage of individuals having impaired fasting glucose (IFG) is 6.6%. Those with fasting blood glucose (FBG) levels ≥ 126 mg/dL and/or currently being treated for diabetes is 4.2%. Only mean body mass index (BMI) is significantly higher among diabetic individuals and among those having FBG levels ≥ 110 mg/dL. After adjustment for sex, age, educational level, BMI and hypertension, only BMI is associated with diabetes. CONCLUSION: Prevalence of diabetes and IFG in our study correspond to the high range of rural sub-Saharan Africa prevalence. Diabetes is thus becoming a pressing public health concern, even in rural areas. But the risk factors identified in Tessekere suggest that the diabetes epidemic is still in the early stages, such that concerted action would make it possible to contain the devastating impact of this chronic condition.

Self-rated health in Senegal: A comparison between urban and rural areas.

INTRODUCTION: Although the relationship between mortality and self-rated health has been demonstrated in sub-Saharan Africa, information in this area is rudimentary. In Senegal, no study has been undertaken comparing self-rated health between urban and rural areas. The objective of this study is therefore to compare self-rated health and its main predictors in Dakar and in a rural isolated area, Tessekere municipality, taking into account socio-demographic and economic factors, social relations, as well as measures of physical and mental health. MATERIAL AND METHODS: This study was carried out in 2015 on a population sample of 1000 individuals living in Dakar and 500 individuals living in the municipality of Tessekere, constructed using the quota method. Self-rated health, health variables, psychosocial, sociodemographic and economic characteristics were collected during face-to-face interviews. Statistical analyses used were Chi-square tests and binary logistic regressions. RESULTS: Results show that self-rated health in Senegalese urban area (Dakar) is better than in rural area (Tessekere), but the determinants of self-rated health partly differ between these two environments. Age and gender play a fundamental role in self-rated health as much in Dakar as in Tessekere but diabetes and social support play a role in self-rated health only in urban environment, whereas economic well-being is associated to self-rated health only in rural area. CONCLUSION: The analyses carried out in these two environments show that despite the existence of common determinants (age, gender, stress), the determinants for formulating an answer to the question of self-rated health differ. People's social and cultural environments thus play a fundamental role in the process of rating one's health and, in the short and long term, in the mortality rate.

Prevalence of obesity and body size perceptions in urban and rural Senegal: new insight on the epidemiological transition in West Africa.

BACKGROUND: The objectives of this study were to assess the prevalence of obesity in Dakar and in Tessekere, a rural municipality in northern Senegal, and to compare ideal body size between these populations. METHODS: A cross-sectional survey was carried out in 2015 on a representative sample of 1 000 adults, aged 20 years and older in Dakar, and 500 adults of the same age in Tessekere. RESULTS: The prevalence of obesity and overweight was higher in Dakar than in Tessekere. However, overweight and obesity rates of young women living in this rural area were close to those of young women in Dakar. At a body mass index of 27.5 kg/m2, less than 40% of the men in Dakar and Tessekere found themselves too fat, compared to 50% of urban women and 30% of rural women. CONCLUSION: This study explains how and why obesity is becoming a rural health problem in Senegal.

Hypertension in the Ferlo (Northern Senegal): prevalence, awareness, treatment and control.

INTRODUCTION: The aim of this article is to assess prevalence, awareness, treatment and control of hypertension in rural Senegal (Sahelian Ferlo region). METHODS: This study was carried out in 2015 on a population sample of 500 individuals living in the municipality of Tessekere, constructed using the quota method. Sociodemographic characteristics, hypertension, hypertension awareness, treatment and control, and body mass index of individuals were collected during face-to-face interviews. Statistical analyses used were Chi-square tests and binary logistic regressions. RESULTS: Prevalence of hypertension was 31.40%. Prevalence of awareness, treatment and control among hypertensives, were 43.31%, 24.84% and 11.46% respectively. Logistic regression showed that the prevalence and awareness of hypertension increased with age. Overweight and obese subjects were more often hypertensive, but did not differ from others in awareness and treatment. CONCLUSION: Given the very high prevalence of hypertension in the region, a strategic approach to prevent and control hypertension is critically needed.

[The international man-media Tessékéré (OHMi) Observatory: a research tool to study the complexity of arid ecosystems in Sahel]. / L'Observatoire hommes-milieux international Tessékéré (OHMi) : un outil de recherche pour étudier la complexité des écosystèmes arides du Sahel.

In the Sahelian zone, the drought phenomenon, combined with anthropic factors (monoculture, bush fires, defect or deficit of manure, overgrazing, etc.), has seriously affected ecological great balances, involving a degradation of the natural resources as well as a fall in agricultural productions, pointing to a process of desertification. To face these challenges, in the course of the 8th ordinary session of the conference of the Heads of States of the African Union held in January 2007 in Addis Ababa (Ethiopia), 11 countries adopted the Panafrican project called the Green Great Wall (GGW). The total objective of the GGW is to contribute i) to the fight against the desert's advance, ii) to the development of the Saharan-Sahelian zones toward a durable management of the natural resources, and iii) to the fight against poverty. It deals with the construction of a set of zones of afforestation crossing the whole African continent in the long term (7000km of which are in the west). Even if some decisions in the launching phase the GGW must be taken quickly, one cannot do without investment in interdisciplinary research. In particular, associating fundamental research and applied research will allow us to ensure the success in the medium and long term of such a large-scale reforestation project. Research segmented in compartmentalized knowledge fields needed to get adequate tools, among which OHMi Tessékéré, initiated by INNEE (Centre national de la recherche scientifique [CNRS]), in partnership with UCAD, constitutes an example. This suitable scientific tool, capable of action flexibility, of self-financing capacity, anchored in civil society, ready to implement a pragmatic and local interdisciplinarity founded currently on the concept of socio-ecological system (SES), is the one we chose to conduct our studies on the Ferlo arid ecosystems.

Genetic diversity on the Comoros Islands shows early seafaring as major determinant of human biocultural evolution in the Western Indian Ocean.

The Comoros Islands are situated off the coast of East Africa, at the northern entrance of the channel of Mozambique. Contemporary Comoros society displays linguistic, cultural and religious features that are indicators of interactions between African, Middle Eastern and Southeast Asian (SEA) populations. Influences came from the north, brought by the Arab and Persian traders whose maritime routes extended to Madagascar by 700-900 AD. Influences also came from the Far East, with the long-distance colonisation by Austronesian seafarers that reached Madagascar 1500 years ago. Indeed, strong genetic evidence for a SEA, but not a Middle Eastern, contribution has been found on Madagascar, but no genetic trace of either migration has been shown to exist in mainland Africa. Studying genetic diversity on the Comoros Islands could therefore provide new insights into human movement in the Indian Ocean. Here, we describe Y chromosomal and mitochondrial genetic variation in 577 Comorian islanders. We have defined 28 Y chromosomal and 9 mitochondrial lineages. We show the Comoros population to be a genetic mosaic, the result of tripartite gene flow from Africa, the Middle East and Southeast Asia. A distinctive profile of African haplogroups, shared with Madagascar, may be characteristic of coastal sub-Saharan East Africa. Finally, the absence of any maternal contribution from Western Eurasia strongly implicates male-dominated trade and religion as the drivers of gene flow from the North. The Comoros provides a first view of the genetic makeup of coastal East Africa.