Unforeseen misuses of bed nets in fishing villages along Lake Victoria

<p>Abstract</p> <p>Background</p> <p>To combat malaria, the Kenya Ministry of Health and nongovernmental organizations (NGOs) have distributed insecticide-treated nets (ITNs) for use over beds, with coverage for children under five years of age increasing rapidly. Nevertheless, residents of fishing villages have started to use these bed nets for drying fish and fishing in Lake Victoria. This study investigated the extent of bed net misuse in fishing villages.</p> <p>Methods</p> <p>Seven fishing villages along the lake were surveyed to estimate how widely bed nets were being used for fishing and drying fish. Villagers were asked why they used the bed nets for such purposes.</p> <p>Results</p> <p>In total, 283 bed nets were being used for drying fish. Of these, 239 were long-lasting insecticidal bed nets (LLIN) and 44 were non-long-lasting insecticidal bed nets (NLLIN). Further, 72 of the 283 bed nets were also being used for fishing. The most popular reasons were because the bed nets were inexpensive or free and because fish dried faster on the nets. LLINs were preferred to NLLINs for fishing and drying fish.</p> <p>Conclusion</p> <p>There is considerable misuse of bed nets for drying fish and fishing. Many villagers are not yet fully convinced of the effectiveness of LLINs for malaria prevention. Such misuses may hamper the efforts of NGOs and governmental health organizations.</p

Predators of Anopheles gambiae sensu lato (Diptera: Culicidae) larvae in Wetlands, Western Kenya: Confirmation by polymerase chain reaction method

Polymerase chain reaction analysis was performed to determine whether mosquito predators in wetland habitats feed on Anopheles gambiae sensu lato (s.l.) larvae. Aquatic mosquito predators were collected from six wetlands near Lake Victoria in Mbita, Western Kenya. This study revealed that the whole positive rate of An. gambiae s.l. from 330 predators was 54.2%. The order of positive rate was the highest in Odonata (70.2%), followed by Hemiptera (62.8%), Amphibia (41.7%), and Coleoptera (18%). This study demonstrates that the polymerase chain reaction method can determine whether aquatic mosquito predators feed on An. gambiae s.l. larvae if the predators have undigested An. gambiae s.l. in their midgut or stomach

Poverty in Consumer Culture:Towards a Transformative Social Representation

International audienceIn this article, we consider the representations of poverty within consumer culture. We focus on four main themes – social exclusion, vulnerability, pleasure and contentment – that capture some of the associations that contemporary understandings have made with poverty. For each theme, we consider the portrayals of poverty from the perspective of key agents (such as marketers, media, politicians) and then relate this to more emic representations of poverty by drawing on a range of contemporary poverty alleviating projects from around the world. We conclude with a set of guidelines for relevant stakeholders to bear in mind when elaborating their representations of poverty. These guidelines may act as a platform to transform marginalising representations of poverty into more empowering representations

Controls on chemical weathering on a mountainous volcanic tropical island: Guadeloupe (French West Indies),

International audienceGuadeloupe Island is a natural laboratory, ideally suited to the study of biogeochemical processes in tropical and mountainous volcanic environments. The island’s east–west rainfall gradient (1200–8000 mm/yr) is superimposed on a north–south age gradient (2.7 Ma to present), providing a unique opportunity to investigate the influence of rainfall and rock age on the chemical weathering of volcanic terrains. Taking advantage of this configuration, we present the first temporal survey (2007–2013) of the geochemical composition of the dissolved load of rain and river waters in Guadeloupe. Our data demonstrate that the chemical composition of river water is influenced by rainfall abundance, hydrothermal alteration (from active or fossilized volcanic systems) and interactions between water and minerals during chemical weathering processes. The contribution of rain to the overall chemical balance is especially significant in the older northern part of the island, where the ferralitic soils are base-cation-depleted. Between 15% and 65% of the Ca or Mg riverine budgets comes from atmospheric deposits, highlighting the major role of rainfall in the geochemical budgets of small tropical and mountainous watersheds. The river water dataset indicates that different chemical weathering processes dominate the budget depending on the age of the local bedrock. In the younger, southern part of the island, a pool of easily-weatherable andesitic minerals from the bedrock dominates. The contribution from this pool decreases significantly (to 5–15 wt.% of the bulk soil) towards the older terrains in the north. The northern rivers are characterized by low Ca/Mg ratios (0.5–1.0), intermediate between those of fresh rocks (1.7–3.3) and soil (0.1). Weathering in the northern part of the island is therefore dominated by the dissolution of depleted secondary minerals into soils. The Ca/Mg ratio of the river water increases from north to south, eventually reaching values similar to those of the bedrocks, arguing for congruent dissolution of the youngest volcanic rocks. The magnesium isotopic composition of river water (δ26Mg) reflects inputs from both rain and weathering processes. In southern and central rivers, the Mg isotopic value of waters after correction for rain inputs (δ26Mgwea) is systematically depleted in heavy isotopes (mean value of −0.34‰) relative to that of the bedrock (−0.24‰ to −0.15‰). In the north, the δ26Mgwea of the river water (−0.09‰) is heavier than that of the andesitic bedrock, possibly reflecting the dissolution of 26Mg-rich secondary minerals (ferralitic soil measured around +0.13‰). The robustness of δ26Mg and Ca/Mg as proxies of the degree of soil weathering should be investigated further via more detailed sampling campaigns in the future. By combining high-frequency monitoring of river discharge with measurements of concentration–discharge relationships for a wide range of chemical elements, we estimate the mean annual chemical weathering fluxes for three rivers that belong to the OBSERA critical zone observatory. Fluxes vary from 51.7 to 91.8 t/km2/yr north to south along the bedrock age gradient, and are among the highest recorded in volcanic tropical regions. Flash floods can explain 21–31% of the annual chemical weathering fluxes. The results highlight the importance of monitoring rivers over periods of several years in order to obtain accurate estimates of chemical exports in tropical and mountainous environments