The Influence of Interspecific Competition and Host Preference on the Phylogeography of Two African Ixodid Tick Species

A comparative phylogeographic study on two economically important African tick species, Amblyomma hebraeum and Hyalomma rufipes was performed to test the influence of host specificity and host movement on dispersion. Pairwise AMOVA analyses of 277 mtDNA COI sequences supported significant population differentiation among the majority of sampling sites. The geographic mitochondrial structure was not supported by nuclear ITS-2 sequencing, probably attributed to a recent divergence. The three-host generalist, A. hebraeum, showed less mtDNA geographic structure, and a lower level of genetic diversity, while the more host-specific H. rufipes displayed higher levels of population differentiation and two distinct mtDNA assemblages (one predominantly confined to South Africa/Namibia and the other to Mozambique and East Africa). A zone of overlap is present in southern Mozambique. A mechanistic climate model suggests that climate alone cannot be responsible for the disruption in female gene flow. Our findings furthermore suggest that female gene dispersal of ticks is more dependent on the presence of juvenile hosts in the environment than on the ability of adult hosts to disperse across the landscape. Documented interspecific competition between the juvenile stages of H. rufipes and H. truncatum is implicated as a contributing factor towards disrupting gene flow between the two southern African H. rufipes genetic assemblages

Diretrizes para gestão de suprimentos: análise do panorama da função compras na construção civil de uma capital Amazônica

Este artigo tem como objetivo a apresentação de um conjunto de diretrizes relacionadas ao panorama da gestão da cadeia de suprimentos (SCM), com ênfase à função compras, em pequenas, médias e grandes empresas da indústria da construção civil na cidade de Belém, localizada na Amazônia Brasileira. Para tanto, adotou conceitos teóricos relacionados à estrutura da área, seus processos, desempenho e tendências. A realização da investigação, tem como referência metodológica central um relevante estudo nacional em gestão de suprimentos, utilizando-se como ferramenta para coleta de dados um questionário fechado, em formato eletrônico, tipo survey. Constatou-se que quase a metade das empresas (44%) sequer utilizam-se da SCM em suas compras, que mais de 1/3 (36%) sofrem com atrasos muito significativos nas entregas e que a grande maioria busca a diversificação de fornecedores (92%), melhoria nas relações com eles (80%) e nos seus sistemas de Tecnologia de Informação - TI (76%). A partir destes e dos demais resultados alcançados são ressaltadas diretrizes, dentre as quais destacam-se: (1) necessidade de formalização da utilização de Indicadores de Desempenho dos Fornecedores; (2) indicação do aumento do nível de envolvimento da área de compras em decisões abrangentes; (3) configuração de uma nova postura proativa da gestão de compras. O presente estudo de caso, em um segmento específico (habitacional) de um cidade de médio porte em um país em desenvolvimento, chega à conclusões que corroboram os conceitos e as teorias existentes na literatura de gestão da cadeia de suprimentos e estratégia organizacional, em especial no setor da construção civil, e seus resultados convergem com trabalhos desenvolvidos em outros países emergentes, o que pode contribuir para o avanço e maior utilização da SCM na região amazônica e, talvez, em outras que guardem caraterísticas ou contextos similares, podendo, assim, haver importantes implicações gerenciais no setor.This article aims to present a set of guidelines related to supply management, with emphasis to procurement, in small, medium and large companies in the construction industry, building subsector in the city of Belém, located in the Brazilian Amazon. Therefore, concepts were adopted relating theories to the structural area, processes, and performance trends. To perform the research, Having as central methodological reference a relevant national study in the management of supplies we opted for the survey method, using as a tool for collecting data a closed questionnaire, in electronic format.From the great diversity of results obtained, guidelines are highlighted, among which the following stand out: (1) the need to formalize the use of supplier performance indicators; (2) the increase in the shopping area of the level of involvement in comprehensive decisions; (3) setting up a new proactive approach of purchasing management. These results contribute to the management literature of supply chain and organizational strategy as well as provide important managerial implications, especially highlighting the most usual practices found in the amazon region

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02

Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio