Influence of coral bleaching on the fauna of Tutia Reef, Tanzania

In 1998, coral reefs of Tanzania were severely affected by bleaching. The coral mortality that followed caused a concern for coral reef degradation and overall resource depletion. In this study, we investigated coral bleaching effects on the coral reef fauna at Tutia Reef in Mafia Island Marine Park, Tanzania. Corals from adjacent reef patches of the species Acropora formosa were transplanted into plots, and reef structure and associated fish assemblages were examined before and after the bleaching event. Following the coral bleaching, 88% of all corals died. A year after the event, a large proportion of the dead corals was still standing. As surviving and dead corals were from different clones, results suggested that genetic variation might influence bleaching tolerance. After the bleaching event, a change in fish community composition, with an increase in fish abundance, could be seen. Species diversity, however, was less affected. There was a correlation between structural complexity and fish densities after disturbance. This indicates that the reef may uphold an abundant fish population as long as the architectural structure is intact. The impact that the coral beaching event may have on fisheries is difficult to anticipate. The Tutia Reef supports a multi-species fishery and a variety of techniques are used. As a broad range of species are targeted, including smaller fishes, catches may not be reduced as long as the reef structure is sustained. If reef degradation follows, however, fish abundance is likely to decrease

Maximizing Laboratory Production of Aflatoxins and Fumonisins for Use in Experimental Animal Feeds

Warm and humid climatic conditions coupled with poor agricultural practices in sub-Saharan Africa favor the contamination of food and feed by Aspergillus flavus and Fusarium verticillioides fungi, which subsequently may produce aflatoxins (AFs) and fumonisins (FBs), respectively. The growth of fungi and the production of mycotoxins are influenced by physical (temperature, pH, water activity, light and aeration), nutritional, and biological factors. This study aimed at optimizing the conditions for the laboratory production of large quantities of AFs and FBs for use in the animal experiments. A. flavus and F. verticillioides strains, previously isolated from maize in Kenya, were used. Levels of AFB1 and total FBs (FB1, FB2, and FB3) in different growth substrates were screened using ELISA methods. Maize kernels inoculated with three different strains of A. flavus simultaneously and incubated at 29 degrees C for 21 days had the highest AFB1 level of 12,550 +/- 3397 mu g/kg of substrate. The highest level of total FBs (386,533 +/- 153,302 mu g/kg of substrate) was detected in cracked maize inoculated with three different strains of F. verticillioides and incubated for 21 days at temperatures of 22-25 degrees C in a growth chamber fitted with yellow light. These two methods are recommended for the mass production of AFB1 and FBs for animal feeding trials

Aflatoxin M1 survey in dairy households in Kenya

Kenya has the largest dairy herd and highest per capita milk consumption in east Africa. Kenya has also experienced multiple aflatoxicosis outbreaks in recent years, and several surveys have reported high levels of contamination in maize. When lactating cows consume feed which is contaminated with aflatoxins, they excrete a metabolite (aflatoxin M1) in their milk. This metabolite is injurious to human health, but there is no current information on the risk to human health posed by aflatoxins in milk in Kenya. To fill this gap, a risk assessment is being conducted in four agroecological zones in Kenya (semi-arid, temperate, sub-humid and humid). In 2014, we conducted a survey of households in these four zones. We surveyed 286 households in 37 villages and in each household administered a questionnaire and collected feed and milk samples. In all, 280 milk samples were analyzed using competitive ELISA. The limit of detection was 2 parts per trillion (ppt). Overall, 59 per cent of all samples had aflatoxin below the limits of detection, 32 per cent of samples had aflatoxin between 2 ppt and 50 ppt while 9 per cent exceeded the WHO/FAO limit of 50 ppt

Climate and livestock disease: assessing the vulnerability of agricultural systems to livestock pests under climate change scenarios

Livestock as a sector is extremely important to the global economy and to rural livelihoods. As of 2013, there was an estimated 38 billion livestock in the world, or five animals for every person. Most (81%) were in developing countries. Around one billion smallholder farmers keep livestock, many of them women. The burden of animal disease in developing countries is high: livestock disease probably kills 20% of ruminants and more than 50% of poultry each year causing a loss of approximately USD 300 billion per year. Climate change can exacerbate disease in livestock, and some diseases are especially sensitive to climate change. Among 65 animal diseases identified as most important to poor livestock keepers, 58% are climate sensitive. Climate change may also have indirect effects on animal disease, and these may be greater than the direct effects

Costs of aflatoxin in the Kenyan dairy value chain

Kenya's dairy industry plays an important economic role in the life of farmers, milk processors, milk traders, feed manufacturers and traders. This industry contributes 14% of the agricultural gross domestic product (GDP) and 3.5 % of the total GDP. In Kenya, the dairy sector, and especially milk production, is exposed to different risk contamination factors which will not only affect the product quality but also its innocuity. Economic costs of aflatoxin contamination could be split into two categories: direct market costs and human health costs. Using agro-ecological zones, five counties in Kenya — Kwale, Isiolo, Tharaka Nithi, Kisii, and Bungoma — were selected randomly for this study. For direct costs, questionnaires were directed to feed retailers, milk producers, milk traders and feed producers. Food and feed samples (99 dairy feed, 286 milk, 386 staples (maize, millet, sorghum groundnuts and cassava) were collected for laboratory aflatoxin analysis (ongoing) to estimate the aflatoxin daily consumption rates in people and dairy cattle. In the case of health costs, primary and secondary data are being collected to assess the estimated cost of aflatoxin in Kenya. Following Rico-Sole (2012) and introducing an additional weighting factor related to the proportion of aflatoxin provided by milk consumption, the health expenditure costs related to aflatoxin through milk will be estimated. It is possible to assess health costs using secondary data provided by the national health statistics in Kenya (health expenditure, diseases, number of the population, number of exposed population etc.) and fixing values for the remaining variables on the basis of literature review. However, the uncertainties about the actual health impacts of aflatoxin exposure in a population make it difficult to fully evaluate the burden. The approach in this study follows the risks of exposure at different steps in the dairy value chain and includes consumer surveys. This will provide increased knowledge about the risks and a basis for improved assessments of the costs

Strong pressure-energy correlations in van der Waals liquids

Strong correlations between equilibrium fluctuations of the configurational parts of pressure and energy are found in the Lennard-Jones liquid and other simple liquids, but not in hydrogen-bonding liquids like methanol and water. The correlations, that are present also in the crystal and glass phases, reflect an effective inverse power-law repulsive potential dominating fluctuations, even at zero and slightly negative pressure. In experimental data for supercritical Argon, the correlations are found to be approximately 96%. Consequences for viscous liquid dynamics are discussed.Comment: Phys. Rev. Lett., in pres