Spatial and Temporal Dynamics of Human–Wildlife Conflicts in the Kenya Greater Tsavo Ecosystem

Biodiversity conservation in developing countries is faced with many and mounting challenges, including increasing human–wildlife conflicts (HWCs). In Africa and other developing countries, increasing HWCs, particularly those adjacent to protected areas, can adversely affect local stakeholder perceptions and support for conservation. We analyzed HWC reports for multiple wildlife species compiled \u3e23 years (1995–2017) from the Greater Tsavo Ecosystem (GTE) in Kenya to determine HWC trends. The GTE is the largest protected area in Kenya, covering 22,681 km2. Overall, 39,022 HWC incidents were reported in 6 GTE regions (i.e., Taveta, Mutomo, Kibwezi, Rombo, Galana, Bachuma). The 5 wildlife species most often implicated in HWC incidents were the African elephant (Loxodonta africana, 61.6%, n = 24,032), nonhuman primates (11.5%, n = 4,480), buffalo (Syncerus caffer, 6.2%, n = 2,432 ), African lion (Panthera leo, 4.2%, n = 1,645), and the hippopotamus (Hippopotamus amphibius, 3.8%, n = 1,497). The HWC reports also revealed spatial distinctions across the 6 GTE regions. More human–elephant conflicts (HECs; 43.3%, n = 10,427) were reported in the Taveta region than other regions. The Mutomo region was the epicenter of primate, snake, and python (Python spp.) conflicts. More large carnivore depredations on livestock were reported in the Taveta, Rombo, and Mutomo regions. Lions, spotted hyenas (Crocuta crocuta), and leopards (P. pardus) were implicated in more livestock depredations than other carnivores. The number of HWCs reported varied by year and season and were related to similar variations in the availability, quality, and distribution of food and water governed by rainfall fluctuations. Reported HECs were positively and linearly related to human, elephant, and livestock population densities. The Kenya Wildlife Service responded to \u3e90% of the reported HWCs. In general, the number of HWCs and trends reported were higher in the regions that also exhibited the highest human population growth rates and densities. Sustainable biodiversity conservation in human-dominated landscapes is contingent upon communities deriving meaningful benefits from wildlife conservation. Far-sighted measures and different conservation approaches are required to mitigate HWCs in communities neighboring protected areas

Certainty of Knowledge and Performance of Physics among Secondary School Students in Tharaka-Nithi County, Kenya

The study aimed to investigate the extent to which students’ epistemological beliefs in the dimension of certainty of knowledge acquisition relate to performance in physics. The study used a mixed-methods research approach that included philosophical analysis, a descriptive survey, and a correlational analysis. The sample size comprised 310 form two students, 60 physics teachers, and 20 heads of the science department. Quantitative data was analyzed using descriptive and inferential statistics. Qualitative data was analyzed through a thematic approach. The study revealed a positive correlation between sophisticated beliefs in the certainty of knowledge and performance in physics. The researcher concluded that sophisticated beliefs in certainty of knowledge contribute towards better performance in physics. The study suggests the implementation of strategies aimed at fostering the development and adoption of sophisticated epistemological beliefs in the certainty of knowledge among students to enhance their performance in physics. The outcome of this study can inform educational policymakers, curriculum developers, and teachers in Kenya to design interventions that promote the development of students’ epistemological beliefs in certainty of knowledge to stimulate performance in physics. Keywords: Certainty of knowledge, Epistemological belief, Knowledge acquisition, Physics performance, Secondary school DOI: 10.7176/JEP/14-28-02 Publication date:October 31st 202

Conceptualisation d’une nouvelle approche méthodologique pour l’évaluation de la vulnérabilité des ressources en eau

Water resources are under increasing pressure worldwide. The complexity of the water resource system with multiple components affecting it makes problem analysis more difficult and complex. This paper proposes a new methodological approach for the assessment of water resource vulnerability. The conceptual framework for vulnerability assessment is multi-dimensional and takes into account physiographic, socio-economic, and institutional and governance components, as well as eco-environmental aspects and water quality. This approach involves four (4) main steps: the selection of factors or parameters, the weighting of factors, the normalization of factor values into sub-indices, and the aggregation of the sub-indices into a composite index. The result of the vulnerability assessment is expected to be displayed in a Geographic Information System (GIS) environment, followed by a sensitivity analysis, and a scenario of the future vulnerability of water resources based on current vulnerability. Keywords: Water resources, Vulnerability factors, Vulnerability index, MoroccoLes ressources en eau sont soumises à de nombreuses pressions partout dans le monde. La complexité du système de ressources en eau et les multiples composantes l’affectant rend les analyses des problèmes plus difficiles et complexes. Cette présente étude propose une nouvelle approche méthodologique pour l’évaluation de la vulnérabilité des ressources en eau. Le cadre conceptuel de l’évaluation de la vulnérabilité est multidimensionnel et tient compte des composantes physiographiques, socioéconomiques, institutionnelles et de gouvernance, et des composantes écoenvironnementales et la qualité de l’eau. Dans cette approche, quatre (4) étapes principales sont nécessaires : le choix des facteurs ou des paramètres, la pondération des facteurs, la normalisation des valeurs des facteurs en sous-indices, et l’agrégation des sous-indices en un indice composite. Le résultat de l’évaluation de la vulnérabilité est représenté sous un environnement du système d’information géographique (SIG), suivi d’une analyse de sensibilité, et d’une simulation de la vulnérabilité future des ressources en eau à partir de la vulnérabilité actuelle. Mots clés: Ressources en eau, Facteurs de vulnérabilité, Indice de vulnérabilité, Maro

Short-term effect of adrenalin on S-100b and N-CAM level in the different rat brain areas

The level of adrenalin grows under stress conditions, sense of danger, anxiety, fear, trauma, burns and shock. In high concentrations adrenaline increases the speed of protein catabolism. Working through the circulatory system, adrenaline affects almost all the functions of organs, causing the body mobilization to counter stressful situations. Due to ELISA the astrocytes-specific protein (S-100b) and neural cell adhesion molecule (N-CAM) were studied. S-100b is produced mainly by astrocytes іn the brain and depending on the concentration it causes trophic or toxic effect on the neurons and glial cells.Strong stress and ischemia induce re-distribution of calcium-binding protein S-100b and elevation of its level. Quantitative changes of S-100b under the influence of various factors on the body which lead to the metabolic disorder in the brain are considered today as a sign of brain damage (cortical, ischemic one, etc.). Fluctuations in the concentration of S-100b in the brain are not always accompanied by marked deterioration of the physical condition of animals, but they can also lead to a number of violations of integrative functions of the brain depending on over-production of this protein. Most N-CAM are transmembrane proteins that cross the plasma membraneonce; intracellular domains have different size and it is thought they are involved in binding to cytoskeleton or cell signaling. Violation of N-CAM functions leads to disruption of nerve sprouts. Data obtained in our study showed no serious re-distribution of S-100b and N-CAM level in the different areas of rat brain (cerebral cortex, hippocampus and thalamus) under effect of adrenalin administered to the animals (under skin) in dosage of 0.45–0.60 mg per rat, 1 time per day during 10 days, probably because of the type of injection and/or short time of adrenalin action. Increased dosage of adrenaline 1 hour before decapitation leads to the decrease of level of total protein in membrane fraction extracted from brain tissue without changing the level of S-100b and N-CAM

A Trial of Early Antiretrovirals and Isoniazid Preventive Therapy in Africa

BACKGROUND: In sub-Saharan Africa, the burden of human immunodeficiency virus (HIV)-associated tuberculosis is high. We conducted a trial with a 2-by-2 factorial design to assess the benefits of early antiretroviral therapy (ART), 6-month isoniazid preventive therapy (IPT), or both among HIV-infected adults with high CD4+ cell counts in Ivory Coast. METHODS: We included participants who had HIV type 1 infection and a CD4+ count of less than 800 cells per cubic millimeter and who met no criteria for starting ART according to World Health Organization (WHO) guidelines. Participants were randomly assigned to one of four treatment groups: deferred ART (ART initiation according to WHO criteria), deferred ART plus IPT, early ART (immediate ART initiation), or early ART plus IPT. The primary end point was a composite of diseases included in the case definition of the acquired immunodeficiency syndrome (AIDS), non-AIDS-defining cancer, non-AIDS-defining invasive bacterial disease, or death from any cause at 30 months. We used Cox proportional models to compare outcomes between the deferred-ART and early-ART strategies and between the IPT and no-IPT strategies. RESULTS: A total of 2056 patients (41% with a baseline CD4+ count of ≥500 cells per cubic millimeter) were followed for 4757 patient-years. A total of 204 primary end-point events were observed (3.8 events per 100 person-years; 95% confidence interval [CI], 3.3 to 4.4), including 68 in patients with a baseline CD4+ count of at least 500 cells per cubic millimeter (3.2 events per 100 person-years; 95% CI, 2.4 to 4.0). Tuberculosis and invasive bacterial diseases accounted for 42% and 27% of primary end-point events, respectively. The risk of death or severe HIV-related illness was lower with early ART than with deferred ART (adjusted hazard ratio, 0.56; 95% CI, 0.41 to 0.76; adjusted hazard ratio among patients with a baseline CD4+ count of ≥500 cells per cubic millimeter, 0.56; 95% CI, 0.33 to 0.94) and lower with IPT than with no IPT (adjusted hazard ratio, 0.65; 95% CI, 0.48 to 0.88; adjusted hazard ratio among patients with a baseline CD4+ count of ≥500 cells per cubic millimeter, 0.61; 95% CI, 0.36 to 1.01). The 30-month probability of grade 3 or 4 adverse events did not differ significantly among the strategies. CONCLUSIONS: In this African country, immediate ART and 6 months of IPT independently led to lower rates of severe illness than did deferred ART and no IPT, both overall and among patients with CD4+ counts of at least 500 cells per cubic millimeter. (Funded by the French National Agency for Research on AIDS and Viral Hepatitis; TEMPRANO ANRS 12136 ClinicalTrials.gov number, NCT00495651.)

Mycolactone-dependent depletion of endothelial cell thrombomodulin is strongly associated with fibrin deposition in Buruli ulcer lesions

A well-known histopathological feature of diseased skin in Buruli ulcer (BU) is coagulative necrosis caused by the Mycobacterium ulcerans macrolide exotoxin mycolactone. Since the underlying mechanism is not known, we have investigated the effect of mycolactone on endothelial cells, focussing on the expression of surface anticoagulant molecules involved in the protein C anticoagulant pathway. Congenital deficiencies in this natural anticoagulant pathway are known to induce thrombotic complications such as purpura fulimans and spontaneous necrosis. Mycolactone profoundly decreased thrombomodulin (TM) expression on the surface of human dermal microvascular endothelial cells (HDMVEC) at doses as low as 2ng/ml and as early as 8hrs after exposure. TM activates protein C by altering thrombin's substrate specificity, and exposure of HDMVEC to mycolactone for 24 hours resulted in an almost complete loss of the cells' ability to produce activated protein C. Loss of TM was shown to be due to a previously described mechanism involving mycolactone-dependent blockade of Sec61 translocation that results in proteasome-dependent degradation of newly synthesised ER-transiting proteins. Indeed, depletion from cells determined by live-cell imaging of cells stably expressing a recombinant TM-GFP fusion protein occurred at the known turnover rate. In order to determine the relevance of these findings to BU disease, immunohistochemistry of punch biopsies from 40 BU lesions (31 ulcers, nine plaques) was performed. TM abundance was profoundly reduced in the subcutis of 78% of biopsies. Furthermore, it was confirmed that fibrin deposition is a common feature of BU lesions, particularly in the necrotic areas. These findings indicate that there is decreased ability to control thrombin generation in BU skin. Mycolactone's effects on normal endothelial cell function, including its ability to activate the protein C anticoagulant pathway are strongly associated with this. Fibrin-driven tisischemia could contribute to the development of the tissue necrosis seen in BU lesions