La présente étude propose une approche similaire à celle de Lichtenberg et Zilberman pour modéliser l'impact d'intrants qui agissent comme agents de contrôle (insecticides, fongicides, herbicides) sur la production de pomme de terre. Dans cette perspective, nous estimons, à l'aide de procédures économétriques, un système d'équations simultanées expliquant la production commercialisable de pommes de terre et trois types de dommage. Les résultats empiriques montrent que les effets des éléments fertilisants (azote, phosphore, potassium et magnésium) sur la production potentielle de pomme de terre ne sont pas statistiquement significatifs. En revanche, des impacts significatifs se retrouvent dans les fonctions de réduction des dommages pour le phosphore et le potassium. Ces derniers résultats montrent des effets antagoniques sur les pertes causées par le faible calibre des tubercules : ainsi, le phosphore contribue à les augmenter tandis que le potassium joue un rôle opposé. Plusieurs variables traduisant les pratiques culturales ont également été incorporées dans le modèle mais peu d'entre elles se sont avérées comme étant significatives.

OBJECTIVES To assess the ability of mothers in a rural area of the Republic of Guinea to identify fever in their children, and to estimate the proportion of children who received antimalarial drugs. METHODS Children under 5 years of age in 41 villages were selected by a two-step cluster sampling technique. During home visits we examined the children and questioned their mothers about the child's symptoms and treatment. FINDINGS Of 784 children examined, 23% were febrile and more than half of them also had a positive smear result for Plasmodium. Mothers reported 63% of children with a temperature > or = 37.5 degrees C as sick. Among all children reported as feverish by their mother, 55% had a normal temperature (< 37.5 degrees C). In contrast, a temperature > or = 37.5 degrees C was found in 38% of children identified as sick but afebrile by their mother and in 13% of children considered healthy. Among febrile children, 18% were given chloroquine at home or had consulted at the health centre or a dispensary. CONCLUSION In areas where malaria is endemic, recognition of fever and its presumptive treatment with antimalarial drugs is an essential part of the strategy of the World Health Organization (WHO) to reduce the morbidity due to this disease. This population study shows that mothers often failed to identify fever in their children and to consult or to provide antimalarial treatment. Without great efforts to improve home care, it is unlikely that the morbidity and mortality due to malaria in young children will be greatly reduced.

Objectif Evaluer l’aptitude des meres d’une zone rurale de Republique de Guinee a deceler la fievre chez leurs enfants, et estimer la proportion d’enfants ayant recu un traitement antipaludique. Methodes Nous avons selectionne des enfants de moins de 5 ans dans 41 villages selon une methode de sondage en grappes a deux degres. Au cours des visites a domicile, nous avons examine les enfants et interroge leur mere a propos des symptomes et du traitement. Resultats Sur 784 enfants examines, 23% etaient fievreux et plus de la moitie d’entre eux avaient egalement un prelevement de sang (goutte epaisse) positif pour Plasmodium. Les meres ont designe comme malades 63% des enfants dont la temperature etait 5 37,5 C. Parmi les enfants declares fievreux par leur mere, 55% avaient une temperature normale (<37,5 C). En revanche, 38% des enfants consideres comme malades mais non fievreux par leur mere et 13% des enfants consideres comme en bonne sante avaient une temperature 5 37,5 C. Parmi les enfants fievreux, 18% avaient recu de la chloroquine a la maison ou avaient ete conduits au centre de sante ou dans un dispensaire. Conclusion Dans les zones ou le paludisme est endemique, la detection de la fievre et son traitement presomptif par des antipaludiques est un element essentiel de la strategie de l’Organisation mondiale de la Sante (OMS) pour reduire la morbidite palustre. Cette etude en population montre que, souvent, les meres ne detectent pas la fievre chez leurs enfants et qu’elles ne consultent pas ou ne donnent pas de traitement antipaludique lorsqu’il le faudrait. Faute d’efforts importants pour ameliorer la prise en charge a domicile, il est peu probable que l’on parvienne a reduire sensiblement la morbidite et la mortalite dues au paludisme chez les jeunes enfants.

High levels of cadmium in the liver and kidneys of caribous and sea mammals of the Canadian Arctic have led to recommendations to remove such offal from the traditional diet. Blood cadmium levels have been found to be very high in samples of Inuit volunteers, hence the hypothesis that the Inuit might be exposed to cadmium through their diet. This survey of a population-based random sample of Nunavik residents (n = 518) confirms that blood cadmium of Inuit is indeed very high by comparison to published reports. Blood cadmium levels are closely associated with the current smoking status and are independent of dietary patterns among nonsmokers. Plasma omega-3 fatty acids concentrations have been used to assess the reliability of the dietary information collected by questionnaires and to test for any association of blood cadmium with the consumption of sea mammals. Blood cadmium levels are not related to the reported consumption of sea mammals. Blood cadmium levels are very high among smokers and are associated with levels of exposure to tobacco. Among nonsmoking Inuit, blood cadmium levels are comparable with those reported in nonsmokers elsewhere in the world. In reference to international standards, blood cadmium concentrations are high enough among the Inuit to warrant energetic public health interventions.

The acute toxicity of cesium given intraperitoneally (IP) as CsCl in mice is characterized by autonomic upset and by a multiphasic excitant‐depressant action on the central nervous system. The predominantly depressant action can progress to respiratory embarassment, cyanosis, spinal convulsions and death. Light microscopy of mice treated with 2.0 mEq Cs+ kg‐1 IP for 14 days showed lymphoid hyperplasia in small intestine. Measurement of tissue cesium by the proton‐induced x‐ray emission (PIXE) technique is convenient and reproducible. Cesium displays a generalized bioactivity that merits further study.