Seasonal movements and habitat use of African buffalo in Ruaha National Park, Tanzania.

BACKGROUND:Assessing wildlife movements and habitat use is important for species conservation and management and can be informative for understanding population dynamics. The African buffalo (Syncerus caffer) population of Ruaha National Park, Tanzania has been declining, and little was known about the movement, habitat selection, and space use of the population, which is important for understanding possible reasons behind the decline. A total of 12 African buffalo cows from four different herds were collared with satellite transmitters. Movements were assessed over 2 years from 11 animals. RESULTS:The space use of the individual collared buffaloes as an approximation of the 95% home range size estimated using Brownian bridge models, ranged from 73 to 601 km2. The estimated home ranges were larger in the wet season than in the dry season. With the exception of one buffalo all collared animals completed a wet season migration of varying distances. A consistent pattern of seasonal movement was observed with one herd, whereas the other herds did not behave the same way in the two wet seasons that they were tracked. Herd splitting and herd switching occurred on multiple occasions. Buffaloes strongly associated with habitats near the Great Ruaha River in the dry season and had little association to permanent water sources in the wet season. Daily movements averaged 4.6 km (standard deviation, SD = 2.6 km), with the longest distances traveled during November (mean 6.9 km, SD = 3.6 km) at the end of the dry season and beginning of the wet season. The shortest daily distances traveled occurred in the wet season in April-June (mean 3.6 km, SD = 1.6-1.8 km). CONCLUSION:The Great Ruaha River has experienced significant drying in the last decades due to water diversions upstream, which likely has reduced the suitable range for buffaloes. The loss of dry season habitat due to water scarcity has likely contributed to the population decline of the Ruaha buffaloes

Improvement in real time detection and selectivity of phthalocyanine gas sensors dedicated to oxidizing pollutants evaluation

International audienceA sensor microsystem prototype, using copper phthalocyanine thin film as sensitive layer, and dedicated to ozone evaluation, was developed. The methodology implemented is based on cyclic sensor recalibrations by thermal cleaning of the sensitive membrane, and on pollutant concentration quantification according to the kinetics of sensor response. Results of laboratory experiments for various NO2 and O3 concentrations, in the range of 10–200 ppb, illustrate the selectivity of CuPc sensors towards ozone, obtained by our methodology. We have shown that ozone selectivity is especially improved for short time of exposure (few minutes) and for phthalocyanine layer maintained at low temperature (80 °C). For optimal conditions, our microsystem exhibits a threshold lower than 10 ppb, a resolution lower than 10 ppb, and good reproducibility of measurements. Performances obtained in real urban atmosphere are satisfying to ensure real time evaluation of ozone during several days. Long-term stability and the detection of NO2 by associating chemical filters to our microsystem will be also discussed

Health and demographics of African buffalo (Syncerus caffer) in Ruaha National Park, Tanzania

Presented at the 9th international wildlife ranching symposium: wildlife - the key to prosperity for rural communities, held on 12-16 September 2016 at Hotel Safari & the Safari Court, Windhoek, Namibia in conjuction with the IUCN 2nd African Buffalo Symposium.The African buffalo (Syncerus caffer) population of Ruaha National Park may be in decline. Seasonal drying of the park's water source due to upstream irrigation may have caused loss of dry season habitat, increased pressure on remaining water sources, and possibly increased contact between wildlife and livestock at the park borders. The Health for Animals and Livelihood Improvement (HALI) project and Ruaha National Park are collaborating to investigate the health and population status of the African buffaloes. Between 2011 and 2015, this partnership resulted in testing 30 young and 25 adult African buffaloes for bovine tuberculosis (2011, 2014-15), conducting 4 dry season demographic surveys and herd level parasite screenings (2011, 2013-15), and conducting one aerial population survey in collaboration with the Tanzania Wildlife Research Institute (2013). In 2014-15, 12 adult female buffaloes were collared with satellite GPS collars to learn more about the seasonal movements, habitat preferences, and herd dynamics of Ruaha's buffalo herds. The research has shown that bovine tuberculosis and brucellosis is present in the buffalo population, that the population number appear to be reduced since the last total count in 2004, that the herd composition and seasonal movements may be influenced by rainfall, and the herd level gastrointestinal parasite counts generally are low. The data generated in this study will be used to inform management and conservation of Ruaha National Park's buffaloes

Educating pastoralists and extension officers on diverse livestock diseases in a changing environment in Tanzania

East African pastoralists and their livestock are vulnerable to alterations in resource availability and disease transmission and frequently face poor access to livestock health services. Government veterinarians tasked with guiding health services must prioritize livestock health risks and allocate limited resources across disparate ecosystems with different disease threats. To identify livestock diseases of concern and strategies for improving herd health and resilience, we conducted community focus groups with pastoralists and interviewed pastoralist household leaders, village extension officers, and government veterinary officials in south-central Tanzania, an area experiencing rapid population growth and environmental change. All participants discussed pastoralist access to livestock health services, livestock disease priorities, and means to improve livestock health. Perceptions of diseases of importance differed among pastoralists, extension officers, and government veterinarians. Spatial differences in diseases of concern among study area pastoralists emphasized the need for locally adaptable livestock health service delivery. Although pastoralist strategies to improve livestock health differed by ethnic group, many pastoralists as well as extension officers and government veterinarians identified livestock health education and training for pastoralists and extension officers as a critical need. Policies designed at the regional, rather than the local, level may not reflect the disease concerns of the entire area. To effectively address veterinary health problems and make livestock herds more resilient to environmental change, conditions at the local level must be considered. Education targeted to pastoralist households and extension officers could achieve greater flexibility in the livestock health system and provide more reliable information about local conditions for governmental policymakers

les peupleuments de Fourmis et les peuplements d'Acridiens du Mont Ventoux. II. Les peuplements de Fourmis

The composition of the ant communities and the relative frequency of each species are described, as well as their ecological and altitudinal amplitudes. The richness and/or the composition of the communities differs from one vegetation zone to another. All the communities show a very hierarchical structure. The Shannon' eaver index of evenness is roughly equal in all communities. The communities are very varied, but three species are predominant over the mountain : Lasiw; niger, Tetramorium caespitum and Formica lemani. Of the environmental features, temperature is the most important, producing a marked altitudinal zonation of species and communities. The effects of aridity are important among certain species, leading to vertical discontinuities in their ranges. The vegetation caver affects species dependant on particular plants ; these species have been considerably affected by reafforestation, especially on the lower parts of the southern slopes, leading to a notable increase in L. niger. At the summit, the main limiting factor is temperature on the northern slope ; and the dessicating effects of the winds on the southern slopes

Naphthoquinone Derivatives Exert Their Antitrypanosomal Activity via a Multi-Target Mechanism

BACKGROUND AND METHODOLOGY: Recently, we reported on a new class of naphthoquinone derivatives showing a promising anti-trypanosomatid profile in cell-based experiments. The lead of this series (B6, 2-phenoxy-1,4-naphthoquinone) showed an ED(50) of 80 nM against Trypanosoma brucei rhodesiense, and a selectivity index of 74 with respect to mammalian cells. A multitarget profile for this compound is easily conceivable, because quinones, as natural products, serve plants as potent defense chemicals with an intrinsic multifunctional mechanism of action. To disclose such a multitarget profile of B6, we exploited a chemical proteomics approach. PRINCIPAL FINDINGS: A functionalized congener of B6 was immobilized on a solid matrix and used to isolate target proteins from Trypanosoma brucei lysates. Mass analysis delivered two enzymes, i.e. glycosomal glycerol kinase and glycosomal glyceraldehyde-3-phosphate dehydrogenase, as potential molecular targets for B6. Both enzymes were recombinantly expressed and purified, and used for chemical validation. Indeed, B6 was able to inhibit both enzymes with IC(50) values in the micromolar range. The multifunctional profile was further characterized in experiments using permeabilized Trypanosoma brucei cells and mitochondrial cell fractions. It turned out that B6 was also able to generate oxygen radicals, a mechanism that may additionally contribute to its observed potent trypanocidal activity. CONCLUSIONS AND SIGNIFICANCE: Overall, B6 showed a multitarget mechanism of action, which provides a molecular explanation of its promising anti-trypanosomatid activity. Furthermore, the forward chemical genetics approach here applied may be viable in the molecular characterization of novel multitarget ligands

The Earth BioGenome Project 2020: Starting the clock

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