20 research outputs found

    Population status of olive baboon Papio anubis (lesson, 1827) in Kainji lake national park, Nigeria

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    The study assessed the population status of Olive Baboon Papio anubis in Kainji Lake National Park, in both sectors of the park. Direct count was carried out on the line transect where activities of Olive Baboon Papio anubis was observed during reconnaissance survey. It involves counting of individual or group of individual species sighted. While the indirect method involves gathering information on current locations for primate through consultation with experience Park Rangers, hunters, farmers and community leaders, counting of animal index such as feacal droppings, foot prints, calls, and feeding remnants, within each transect. These were related to relative abundance/distribution of Primates in a particular area at a particular time. Data was collected from November, 2017-August, 2019. Data was analyzed using distance software. Student t-test was used to compare between wet and dry seasons population. The results were presented in tables. The overall Population estimation revealed Papio anubis has the highest mean abundance (19 ± 0), population density (0.042 ± 0.000) and relative abundance of (6 ± 0) at Oli range and the species was not observed in the two ranges of Zugurma sector of the park. Individuals and troops recorded during the dry seasons exceeded those of the wet seasons in all the sectors during the study. The population structures (age and sex) adult female Olive Baboon has the highest mean of individual in all seasons with (140 ± 41) the least in the troop been the Sub-adult male with (32 ±6). The Olive baboons were observed to be social and a very popular attraction for park staff that resident in the Oli camp, visitors and researches alike. Keywords: Baboon, Population, status, age structure, sex structur

    Dielectric disorder in two-dimensional materials

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    Understanding and controlling disorder is key to nanotechnology and materials science. Traditionally, disorder is attributed to local fluctuations of inherent material properties such as chemical and structural composition, doping or strain. Here, we present a fundamentally new source of disorder in nanoscale systems that is based entirely on the local changes of the Coulomb interaction due to fluctuations of the external dielectric environment. Using two-dimensional semiconductors as prototypes, we experimentally monitor dielectric disorder by probing the statistics and correlations of the exciton resonances, and theoretically analyse the influence of external screening and phonon scattering. Even moderate fluctuations of the dielectric environment are shown to induce large variations of the bandgap and exciton binding energies up to the 100 meV range, often making it a dominant source of inhomogeneities. As a consequence, dielectric disorder has strong implications for both the optical and transport properties of nanoscale materials and their heterostructures

    Population Structure of Pseudomonas aeruginosa from Five Mediterranean Countries: Evidence for Frequent Recombination and Epidemic Occurrence of CC235

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    Several studies in recent years have provided evidence that Pseudomonas aeruginosa has a non-clonal population structure punctuated by highly successful epidemic clones or clonal complexes. The role of recombination in the diversification of P. aeruginosa clones has been suggested, but not yet demonstrated using multi-locus sequence typing (MLST). Isolates of P. aeruginosa from five Mediterranean countries (n = 141) were subjected to pulsed-field gel electrophoresis (PFGE), serotyping and PCR targeting the virulence genes exoS and exoU. The occurrence of multi-resistance (≥3 antipseudomonal drugs) was analyzed with disk diffusion according to EUCAST. MLST was performed on a subset of strains (n = 110) most of them had a distinct PFGE variant. MLST data were analyzed with Bionumerics 6.0, using minimal spanning tree (MST) as well as eBURST. Measurement of clonality was assessed by the standardized index of association (IAS). Evidence of recombination was estimated by ClonalFrame as well as SplitsTree4.0. The MST analysis connected 70 sequence types, among which ST235 was by far the most common. ST235 was very frequently associated with the O11 serotype, and frequently displayed multi-resistance and the virulence genotype exoS−/exoU+. ClonalFrame linked several groups previously identified by eBURST and MST, and provided insight to the evolutionary events occurring in the population; the recombination/mutation ratio was found to be 8.4. A Neighbor-Net analysis based on the concatenated sequences revealed a complex network, providing evidence of frequent recombination. The index of association when all the strains were considered indicated a freely recombining population. P. aeruginosa isolates from the Mediterranean countries display an epidemic population structure, particularly dominated by ST235-O11, which has earlier also been coupled to the spread of ß-lactamases in many countries

    Virus infection mediates the effects of elevated CO2 on plants and vectors

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    Atmospheric carbon dioxide (CO(2)) concentration has increased significantly and is projected to double by 2100. To increase current food production levels, understanding how pests and diseases respond to future climate driven by increasing CO(2) is imperative. We investigated the effects of elevated CO(2) (eCO(2)) on the interactions among wheat (cv. Yitpi), Barley yellow dwarf virus and an important pest and virus vector, the bird cherry-oat aphid (Rhopalosiphum padi), by examining aphid life history, feeding behavior and plant physiology and biochemistry. Our results showed for the first time that virus infection can mediate effects of eCO(2) on plants and pathogen vectors. Changes in plant N concentration influenced aphid life history and behavior, and N concentration was affected by virus infection under eCO(2). We observed a reduction in aphid population size and increased feeding damage on noninfected plants under eCO(2) but no changes to population and feeding on virus-infected plants irrespective of CO(2) treatment. We expect potentially lower future aphid populations on noninfected plants but no change or increased aphid populations on virus-infected plants therefore subsequent virus spread. Our findings underscore the complexity of interactions between plants, insects and viruses under future climate with implications for plant disease epidemiology and crop production
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