Brucellosis in dairy herds: a public health concern in the milk supply chains of West and Central Africa

Ten herd-level cross-sectional studies were conducted in peri-urban dairy production areas of seven West and Central African countries (Burkina Faso, Burundi, Cameroon, Mali, Niger, Senegal and Togo). The objectives were to estimate herd level Brucella spp. seroprevalence and identify risk factors for seropositivity. In each of the ten study areas, herds (between 52 and 142 per area, total = 965) were selected probabilistically and a structured questionnaire was administered to gather information on their structure and management. A bulk milk sample from each herd was tested by indirect ELISA for Brucella spp. For each area, herd seroprevalence estimates were obtained after adjusting for the assumed performance of the diagnostic test. Herd level risk factors for Brucella spp. seropositivity were identified by means of stratified logistic regression, with each peri-urban zone as a stratum. Area-specific models were also explored. Estimated herd seroprevalences were: Lomé (Togo) 62.0% (95% CI:55.0-69.0), Bamako (Mali) 32.5% (95% CI:28.0-37.0), Bujumbura (Burundi) 14.7% (95%CI:9.4-20.8), Bamenda (Cameroon) 12.6% (95% CI:7.6-21.9), Ouagadougou (Burkina Faso) 3.0% (95% CI:1.0-9.1), Ngaoundere (Cameroon) 2.3% (95% CI:1.0-7.0), Thies (Senegal) 1.3% (95% CI:0.1, 5.3), Niamey (Niger) 1.2% (95% CI:0.08-5.3), Dakar (Senegal) 0.2% (95% CI:0.01-1.7) and Niakhar (Senegal) <0.04%. Logistic regression modelling revealed transhumant herds to be at lower risk of infection (adjusted OR: 0.25, 95% CI: 0.13 - 0.5) and in one of the areas (Bamenda), regular purchase of new animals was found to be strongly associated with Brucella spp. seropositivity (adjusted OR = 5.3, 95% CI: 1.4-25.9). Our findings confirm that Brucella spp. circulates among dairy cattle supplying milk to urban consumers in West and Central Africa, posing a serious public health concern. Control programs are urgently needed in areas such as Lomé or Bamako, where more than 30% of the herds show evidence of infection

Estuaries of Australia in 2050 and beyond: a synthesis

This book "Estuaries of Australia in 2050 and Beyond" in the series "Estuaries of the World" addresses the question: Is Australia's growing human population and economy environmentally sustainable for its estuaries and coasts by 2050? To answer this question, this chapter summarises detailed studies of a number of iconic Australian estuaries and bays. They can be divided in three types based on the human impact, namely (1) estuaries that bore the full pressure of the historical developments, (2) estuaries being degraded, and (3) estuaries that are still relatively pristine. For type (1) the case studies focus on Sydney Estuary, the Coorong/Murray-Darling Estuary, Port Philip Bay, and the Tamar Estuary. For type (2) the case studies focus on the Gold Coast Broadwater, the Hawkesbury Estuary, the Burdekin flood plains, Moreton Bay, the Ord River estuary, Brisbane peri-urban estuaries, South Australia gulfs, Hervey Bay, and Darwin Harbour. For type (3) the case studies focus on the Mary River estuary and floodplains in the Northern Territory and Deluge Inlet in Queensland. In addition, summaries are also provided of the state of the environment and the management strategy for a number of other estuaries and coastal waters. Overall, this chapter synthesises multidisciplinary scientific knowledge in time and space across Australia to suggest what Australian estuaries may look like in 2050 based on socio-economic decisions that are made now, and the changes that are needed to ensure sustainability

Introduction: Reclaiming and Rewilding River Cities for Outdoor Recreation

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Exploitation des ressources en bivalves de la Baie de Somme. Aménagement de la pêche à pied et état de la ressource en coques

The present survey of the cockle (Cerastoderma edule) beds of the "baie of Somme" (France) was carried out in 1985-1986 and brought to light initial account for the decline in the landings of the edible cockle from the main French fishery area. The survey of the benthic fa un a from 1981 onwards enabled a European intersite comparison to be included to back up the cockle study. Comprehensive and novel methodologies allowed a quick and reliable assessment of fishable stocks covering large areas, particular attention being paid to the biology of the species and its population dynamics (reproduction, recruitment, growth, mortality). The speed of the biosedimentary changes was demonstrated in what is considered as a typical and threatened estuarine habitat. The steady population survey pointed out that biotic and abiotic antagonistic  environmental factors are manifold. The fisheries collapse and the difficulties of the cockle populations to recover were attributed to this comple ity. Short-term instructions for exploitation are suggested and the present investigations should be regarded as a baseline study to be used for commercial fisheries management. The cockle, being considered as a sensitive species indicatif of pollution, induced change in the milieu ; simulation models of the mollusc growth and dynamics will be initiated in 1987 and are expected to complete this approachCette étude du gisement de coques (Cerastoderma edule) de la baie de Somme (France), réalisée en 1985-1986, apporte les premières explications de la crise de production du principal site national d'exploitation de ce bivalve, confortées par le suivi de la faune benthique mené, depuis 1981, dans un contexte européen. Des méthodologies appropriées, souvent originales, ont, d'une part, permis une évaluation rapide et fiable d'une ressource très étendue, d'autre part, fourni une meilleure connaissance des caractéristiques dynamiques de l'espèce et du stock (reproduction, recrutement, croissance, mortalité), et enfin mis en évidence la rapidité de l'évolution biosédimentaire d'un milieu estuarien typique et menacé. Le suivi régulier des populations a montré la multiplicité des facteurs antagonistes, tant biotiques qu'abiotiques, de l'environnement qui expliquent la crise mais aussi les difficultes que connaît aujourd'hui le gisement pour retrouver son équilibre. Ce travail, qui propose des recommandations d'exploitation à court terme, constitue une approche de la gestion d'un gisement naturel qui sera facilitée par la modélisation entreprise en 1987 sur la croissance et la dynamique de la coque, cette dernière étant devenue espèce-témoin de la qualité du milieu estuarien

Reclaiming and Rewilding River Cities for Outdoor Recreation

International audienceThe introduction of sports and recreational facilities into natural environments calls for reflection on their impact on fragile ecosystems. This book is unique in providing an interdisciplinary approach to the ecological restoration of urban and industrial degraded habitats and their use by nearby city-dwellers. For the first time ecologists, sociologists and anthropologists have worked together on particularly sensitive ecosystems such as rivers and estuaries to propose recovery strategies that allow their basic ecological functions to be restored, and which can benefit local populations through nature activities.Nonetheless, the use of natural spaces calls for the building of sustainable towns. This is why this book is distinctive in considering quality of life and well-being as stated objectives of modern river towns. Recently, leisure time has become a part of urban rhythms. In order to favour personal development, an extensive palette of leisure activities is considered by the authors: bird watching entertainment sports cultureMany aspects including physical and psychological attributes in relation to the contemporary socio-political fabric are dealt with.While creating areas of freedom, landscaping also induces certain forms of practice and encourages certain social skills. Conversely, the book questions certain types of management based on mass consumption. Don’t they, in the end, aim to satisfy needs that are impermanent and shallow?The image of the contemporary town relies on urban planning projects which, in a global economy, seek to capture the interest of tourists and local populations. How can suitable, diligent planning be successfully combined with both creative design and ecological care? This book demonstrates how biology and sociology can (and should) work in harmony in order to promote an ecosystem approach to environmental management

Bio-sedimentary indicators for estuaries: a critical review

The rational management of the marine environment relies on the measurement of selected attributes and the detection of changes in carefully chosen parameters as the result of human activities. Following that detection, integrated management relies on actions being predefined in order to minimise harmful effects. This book undertakes an analysis of the indicators available for detecting change in the sedimentary part of the marine system in coastal and estuarine areas.It covers intertidal and subtidal habitats. As such, it includes indicators on sedimentary conditions and biological indicators based on benthic plants, seaweeds and invertebrates. Organisms and populations are considered as well as molecular biomarkers and sublethal indicators, as well as biophysical indicators. As studies of the habitat level lead into functional ecology then the book further deals with integrated and multicriteria approaches.An assessment of the applicability of existing indicators helps to identify where modifications might be appropriate and to identify significant gaps. It appears that most of the available indicators are rather well suited to showing the structure of systems (and in the case of the European Water Framework Directive have been encouraged to be so by the wording in the Directive). However, their applicability to enclosed estuarine ecosystems remains problematic as most of such indicators were designed in relation to organic matter enrichment.Very few of them are adequate to show the functioning of transitional ecosystems. This is particularly important given the high reliance by ecological objectives and contributory objectives for the marine environment on functional aspects. This book was written as an attempt to clarify the current situation with regard to the use of indicators in environmental management of estuaries and coasts. As such, it will be of interest to any researcher involved in monitoring coastal environments.More specifically, it targets students, practitioners and policy makers who often find themselves overwhelmed by the huge amount of information to be dealt with when approaching the subject. It is not intended as a comprehensive review of all indicators, but more as a compendium to be used as a guide when confronted to concrete cases

The occurrence of abnormal embryos in two ovoviviparous barnacle-dwelling littorinids

The occurrence of developmental abnormalities in two ovoviviparous littorinids (Littorina neglecta and a barnacle-dwelling form of L. saxatilis) inhabiting the barnacle zone at Peak Steel, Ravenscar on the north-east coast of England was investigated. In general developmental abnormalities appeared to be a rare occurrence in both taxa. However, L. neglecta was found to have a significantly greater proportion of deformed embryos in their brood pouches than L. saxatilis B (Figure 1). A distinct seasonal variation in the number of developmental abnormalities was observed in L. neglecta, and it is suggested this is a result of broods developing outside of the main reproductive season being more prone to deformity

Rôle de la compétition intraspécifique dans la régulation du recrutement chez la coque, <I>Cerastoderma edule</I> (L)

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