Cetacean research in Senegal 1995-97, an overview. Scientific Committee document SC/49/SM10, International Whaling Commission, Bournemouth, UK

Historically Senegal is the West-African nation with the best kept faunistical records for cetaceans. We found verifiable evidence for at least 18 species, but limited life history data. Quantified information on interactions with soaring coastal fisheries is wanting. Here we present preliminary results of recent field work in central and central-south Senegal, which aim was to help design a long-term research plan with Senegalese scientists, offer training and reinitiate data collecting.With limited monitoring we encountered evidence of dolphin by-catches but no wide-spread directed dolphin fishery. However the presence of tell-tale conditions including spreading acceptance for consumption of dolphin meat and indications of overexploitation of some fish stocks are known warning signs. Future efforts should cover larger areas and generally be more intensive. Three carcasses of Atlantic hump-backed dolphin Sousa teuszii found on Sangomar island had rope tied around the tailstock. Fishermen at Djifer and Joal-Fadiouth confirmed regular incidental takes and landings. In the Siné-Saloum delta, inshore S. teuszii and T. truncatus are probably the most affected species. Senegal’s EEZ waters support large industrial fisheries which may constitute an additional source of by-caught small cetaceans. We here document 21 new specimen records and a series of sightings. Dolphins occurring in the Casamance river and upstream in the salt-water canals of the Saloum delta are identified as T. truncatus

Redistribution with Performance Pay

Half of the jobs in the U.S. feature pay-for-performance. We study nonlinear income taxation in a model where such contracts arise in private labor markets that are constrained by moral hazard frictions. We derive novel formulas for the incidence of arbitrarily nonlinear reforms of any given tax code on both the mean of earnings and their sensitivity to performance. We show theoretically and quantitatively that, follow- ing an increase in tax progressivity, the higher performance-sensitivity caused by the crowding-out of insurance provided by firms is almost fully offset by a countervailing performance-pay effect driven by labor supply responses. As a result, earnings risk is hardly affected by policy. We then turn to the normative analysis of a government that levies taxes and transfers to redistribute income across workers with different levels of uninsurable productivity. We find that setting taxes without accounting for the endogeneity of private insurance is close to optimal. Thus, the common concern that standard models of taxation underestimate the cost of redistribution is, in the context of performance-based compensation, overblown

Compression medullaire lente secondaire a un lymphome de Burkitt intra - rachidien

Le lymphome de Burkitt (LB) appartient au groupe des lymphomes malins non hodgkiniens (LMNH) à cellules B. Il sévit de façon endémique chez l’enfant africain en région intertropicale. La rareté des localisations neuro-méningées dont médullaires a été rapportée. Nous rapportons le cas d’un jeune garçon présentant une localisation médullaire secondaire de LB maxillo-facial. Il avait présenté de façon lentement progressive dans un contexte d’amaigrissement et de tumeur maxillo-faciale, un syndrome de compression médullaire dorsale dont le diagnostic a été confirmé au myéloscanner dorsal. L’histologie de la tumeur maxillo faciale après biopsie révélait un LB. Une chimiothérapie a permis une disparition complète de la tumeur maxillo-faciale à la fin du 1er mois et une récupération neurologique au bout d’un an. La localisation secondaire intra rachidienne d’un LB bien que rare doit être présente à l’esprit surtout en face d’une compression médullaire lente survenue dans un contexte de tumeur maxillo-faciale chez l’enfant

Preserving soil quality under irrigation in the Senegal River Valley

Soil quality under irrigation in the Senegal River Valley may become affected by salinization (Delta) and alkalinization (Middle Valley) processes. The salinity status of 158 irrigated rice fields in the Delta was measured with an electromagnetic conductivity meter. Double-cropped fields (two rice crops per year on the same field) were least saline (average horizontal reading: 0.6 dS/m), followed by single-cropped drained fields (1.6 dS/m), single-cropped non-drained fields (2.5 dS/m), non-cropped sites outside irrigation schemes (4.7 dS/m) and abandoned fields (5.7 dS/m). Results illustrated that when cultivating rice in the delta, the ponded water on the soil surface blocks capillary rise of salt from the water table. In the valley, the difference in the total amount of carbonates in 1:50 soil extracts between cultivated and non-cultivated sites was used as an indicator for alkalinization risk in 27 irrigation schemes. Highest rates of carbonate accumulation (0.65 meq HCO3-/(kg soil) per cropping season) and, therefore, greatest soil degradation risk were observed in schemes without drainage, compared to 0.10 meq HCO3-/(kg soil) per cropping season in schemes with good irrigation and drainage facilities. Plot and scheme level recommendations that may preserve soil quality under irrigation are presented