562 research outputs found

    Particularités épidémiologiques de l'infection rétrovirale à HTLV-1 en Afrique centrale

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    L'Afrique subsaharienne est le réservoir le plus important de virus HTLV-1, mais son épidémiologie reste très mal connue. Pour y remédier, les auteurs ont étudié - de 1987 à 1990 - la situation qui prévaut dans six états d'Afrique centrale. Les modalités admises de la transmission sont effectives : voie sanguine par le biais de la transfusion au rôle à moduler selon les régions en fonction de l'importance, souvent faible, de cette pratique; voie hétérosexuelle qui ne paraît pas avoir la place essentielle supposée dans les autres régions d'endémicité du globe et transmission de la mère à l'enfant par l'allaitement au sein. Mais il semble que des facteurs environnementaux - qui restent à préciser - puissent jouer un rôle non négligeable parmi lesquels vecteurs ailés et helminthes pourraient être pris en considération. (Résumé d'auteur

    Екологія: наукова сутність, об'єкти досліджень, завдання

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    Розкрита суть чотирьох основних розділів екології: аутекології, демекології, синекології та екосистемології; описані об’єкти, предмет і завдання останньої. Визначена роль розумової і виробничої діяльности людства як зовнішнього збурювального чинника щодо живих систем і як організатора соціосфери. Обґрунтовані завдання екосистемології у теперішніх геосоціальних умовах.The matters of the four main divisions in ecology, such as autecology, demecology, synecology and ecosystemology have been uncovered. The objects, subjects and assignments of the latter were described too. A part of mankind’s mental and industrial activities, which are outside disturbing factors for biosystems and sociosphere organisers, has been determined. The assignments of ecosystemology within present geosocial condition were well grounded in the article

    Complete genome analysis of one of the earliest SIVcpzPtt strains from Gabon (SIVcpzGAB2)

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    Chimpanzees in west central Africa (Pan troglodytes troglodytes) are known to harbor simian immunodeficiency viruses (SIVcpzPtt) that represent the closest relatives of human immunodeficiency virus type 1 (HIV-1); however, the number of SIVcpzPtt strains that have been fully characterized is still limited. Here, we report the complete nucleotide sequence of SIVcpzGAB2, a virus originally identified in 1989 in a chimpanzee (P. t. troglodytes) from Gabon. Analysis of this sequence reveals that SIVcpzGAB2 is a member of the SIVcpzPtt group of viruses, but that it differs from other SIVcpzPtt strains by exhibiting a highly divergent Env V3 loop with an unusual crown (NLSPGTT) containing a canonical N-linked glycosylation site, an unpaired cysteine residue in Env V4, and two late (L) domain motifs (PTAP and YPSL) in Gag p6. Moreover, phylogenetic analyses indicate evidence of recombination during the early divergence of SIVcpzPtt strains; in particular, part of the pol gene sequence of SIVcpzGAB2 appears to be derived from a previously unidentified SIVcpz lineage ancestral to HIV-1 group O. These data indicate extensive diversity among naturally occurring SIVcpzPtt strains and provide new insight into the origin of HIV-1 group O

    A life cycle stakeholder management framework for enhanced collaboration between stakeholders with competing interests

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    This is a postprint version of the Book Chapter. Information regarding the official publication is available from the link below - Copyright @ 2011 SpringerImplementation of a Life Cycle Sustainability Management (LCSM) strategy can involve significant challenges because of competing or conflicting objectives between stakeholders. These differences may, if not identified and managed, hinder successful adoption of sustainability initiatives. This article proposes a conceptual framework for stakeholder management in a LCSM context. The framework identifies the key sustainability stakeholder groups and suggests strategic ambiguity as a management tool to harness dysfunctional conflict into constructive collaboration. The framework is of practical value as it can be used as a guideline by managers who wish to improve collaboration with stakeholders along the supply chain. The article also fills a gap in the academic literature where there is only limited research on sustainability stakeholder management through strategic ambiguity

    An improvement of the Berry--Esseen inequality with applications to Poisson and mixed Poisson random sums

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    By a modification of the method that was applied in (Korolev and Shevtsova, 2009), here the inequalities ρ(Fn,Φ)0.335789(β3+0.425)n\rho(F_n,\Phi)\le\frac{0.335789(\beta^3+0.425)}{\sqrt{n}} and ρ(Fn,Φ)0.3051(β3+1)n\rho(F_n,\Phi)\le \frac{0.3051(\beta^3+1)}{\sqrt{n}} are proved for the uniform distance ρ(Fn,Φ)\rho(F_n,\Phi) between the standard normal distribution function Φ\Phi and the distribution function FnF_n of the normalized sum of an arbitrary number n1n\ge1 of independent identically distributed random variables with zero mean, unit variance and finite third absolute moment β3\beta^3. The first of these inequalities sharpens the best known version of the classical Berry--Esseen inequality since 0.335789(β3+0.425)0.335789(1+0.425)β3<0.4785β30.335789(\beta^3+0.425)\le0.335789(1+0.425)\beta^3<0.4785\beta^3 by virtue of the condition β31\beta^3\ge1, and 0.4785 is the best known upper estimate of the absolute constant in the classical Berry--Esseen inequality. The second inequality is applied to lowering the upper estimate of the absolute constant in the analog of the Berry--Esseen inequality for Poisson random sums to 0.3051 which is strictly less than the least possible value of the absolute constant in the classical Berry--Esseen inequality. As a corollary, the estimates of the rate of convergence in limit theorems for compound mixed Poisson distributions are refined.Comment: 33 page

    Effect of inoculation with plant growth promoting bacteria in corn plants (Zea mays L.)

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    A pesar de que existen numerosos estudios de la interacción entre plantas de maíz (Zea mays) con Azospirillum brasilense, los reportes de la interacción con Gluconacetobacter diazotrophicus son escasos. El objetivo de este trabajo fue evaluar el efecto de la inoculación con microorganismos promotores del crecimiento vegetal correspondientes a las especies bacterianas de A. brasilense REC3 y G. diazotrophicus PAL5 sobre el desarrollo de plantas de maíz. Se implementaron ensayos en los que los microorganismos fueron inoculados en forma individual y conjunta en plantas de la variedad Leales 25 de maíz, las cuales fueron sembradas en dos suelos con distintos grados de fertilidad. Las variables medidas en las plantas fueron los valores relativos de SPAD (Soil Plant Analysis Development) y la longitud y superficie radicular. Los resultados obtenidos revelaron que A. brasilense REC3 y G. diazotrophicus PAL5 tuvieron efectos superiores a los tratamientos control y mezcla, y que sólo A. brasilense REC3 generó incrementos significativos en la biomasa en las plantas de maíz respecto a los demás tratamientos en ambos tipos de suelos.Although there are numerous studies of the interaction between corn plants (Zea mays) with Azospirillum brasilense, reports about the interaction with Gluconacetobacter diazotrophicus are scarce. The aim of this work was to evaluate the effect of inoculation with microorganisms that promote plant growth corresponding to the bacterial species of A. brasilense REC3 and G. diazotrophicus PAL5 on the development of maize plants. Trials were carried out in which the microorganisms were inoculated individually or in combination in corn plants of the variety Leales 25, which were sowed in two soils with different degrees of fertility. Variables measured in plants were relative values ​of Soil Plant Analysis Development (SPAD) and length and root surface. Results revealed that A. brasilense REC3 and G. diazotrophicus PAL5 had superior effects than the control. Only A. brasilense REC3 generated a significant increment in biomass of corn plants compared to other treatments in both types of soils.Fil: Lovaisa, Nadia Carolina. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Guevara, E. E.. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; ArgentinaFil: Delaporte Quintana, Paola Adriana Georgina. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Elias, J.. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Arroyo, J.. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; ArgentinaFil: Salazar, Sergio Miguel. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Tucuman-Santiago del Estero. Estación Experimental Agropecuaria Famaillá; Argentina. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; Argentin
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