141 research outputs found
Coevolution of exploiter specialization and victim mimicry can be cyclic and saltational
Darwin’s Principle of Divergence explains sympatric speciation as gradual and directional. Contradicting evidence suggests that species’ traits evolve saltationally. Here, we model coevolution in exploiter-victim systems. Victims (resource population) have heritable, mutable cue phenotypes with different levels of defense. Exploiters have heritable, mutable perceptual phenotypes. Our simulations reveal coevolution of victim mimicry and exploiter specialization in a saltational and reversible cycle. Evolution is gradual and directional only in the specialization phase of the cycle thereby implying that specialization itself is saltational in such systems. Once linked to assortative mating, exploiter specialization provides conditions for speciation
Selection against Accumulating Mutations in Niche-Preference Genes Can Drive Speciation
Our current understanding of sympatric speciation is that it occurs primarily through disruptive selection on ecological genes driven by competition, followed by reproductive isolation through reinforcement-like selection against inferior intermediates/heterozygotes. Our evolutionary model of selection on resource recognition and preference traits suggests a new mechanism for sympatric speciation. We find speciation can occur in three phases. First a polymorphism of functionally different phenotypes is established through evolution of specialization. On the gene level, regulatory functions have evolved in which some alleles are conditionally switched off (i.e. are silent). These alleles accumulate harmful mutations that potentially may be expressed in offspring through recombination. Second mating associated with resource preference invades because harmful mutations in parents are not expressed in the offspring when mating assortatively, thereby dividing the population into two pre-zygotically isolated resource-specialist lineages. Third, silent alleles that evolved in phase one now accumulate deleterious mutations over the following generations in a Bateson-Dobzhansky-Muller fashion, establishing a post-zygotic barrier to hybridization
Marine nature-based solutions: Where societal challenges and ecosystem requirements meet the potential of our oceans
Nature-Based Solutions (NbS), a concept introduced in the late 2000s, has developed rapidly during the last years and is now frequently appearing in a broad spectrum of policies developed within the European Union. Its role in marine policies and research programmes is however still limited, but is likely to increase as NbS are adopted as key terminology in both biodiversity strategies and the EU taxonomy for sustainable financing. This will enhance the need for scientific advisory institutions to provide evidence-based advice on potential impacts of various combinations of marine NbS. To facilitate a critical debate about the prospects and pitfalls related to the operationalisation of marine NbS in an EU context, this paper provides an analysis of core definitions, potential categories of marine NBS and a suite of case studies. Coastal waters, shelf and open oceans present multiple options for testing new and scaling up known NbS, which could support both environmental restoration simultaneously with addressing multiple societal challenges, paving the way for a new level of ecosystem-based management. However, as the acceptance of NbS types will depend on ecosystem state and thus history, it will be a significant task to consistently communicate why some solutions may count as a NbS in some areas, while not in others. To conclude, the paper therefore raises a set of research priorities and policy advice aimed at ensuring the successful advice and deployment of marine NBS in support of multiple societal goals
Estilos Gerenciales y Clima Organizacional en la Municipalidad Distrital de Ascensión. Huancavelica – 2019
En la investigación titulada: “Los Estilos Gerenciales y el Clima Organizacional en la Municipalidad Distrital de Ascensión, Huancavelica - año 2019”, su “objetivo general fue: Establecer la relación de los Estilos Gerenciales y el Clima Organizacional en la Municipalidad Distrital de Ascensión, Huancavelica - 2019.El problema en la investigación fue conocer la relación que existe entre los estilos gerenciales y el clima organizacional en la Municipalidad Distrital de Ascensión, Huancavelica - 2019. La investigación se empleó como base estructural el cual es el método científico, que orienta como efectuar una investigación del tipo: Inductivo – Deductivo. El tipo de investigación es básica, el nivel de investigación es correlacional y el diseño de la investigación es no experimental – corte trasversal. La población estuvo constituida por 67 colaboradores. La recolección de datos se realizó mediante la aplicación de la técnica de la encuesta y el instrumento utilizado fue el cuestionario, el cual constaba de 36 preguntas. La conclusión obtenida sobre la base de los resultados se ha establecido que, sabiendo que el coeficiente tau b es τ = 0.603 y significación bilateral de p=0.000, bajo esta evidencia se establece que la relación que, entre los estilos gerenciales y el clima organizacional en la Municipalidad Distrital de Ascensión, Huancavelica – 2019, es considerable. Se concluye, que existe una relación significativa entre los estilos gerenciales y el clima organizacional en la Municipalidad Distrital de” Ascensión, Huancavelica – 2019
Brote urbano de aguda adquirida por vía oral la enfermedad de Chagas en el estado Táchira, Venezuela
Aguda por vía oral adquirió la enfermedad de Chagas (AOACD) se ha convertido en una amenaza importante en algunos países de América del Sur [1,2]. Hasta marzo de 2013, al menos cuatro han reportado brotes de la enfermedad de Chagas aguda adquirida por vía oral, en concreto Brasil [3], Venezuela [4], Colombia [5] y Bolivia [6]. Los brotes también se están produciendo probablemente en Argentina y Ecuador, según algunos informes antiguos [2]. En Venezuela, ha habido por lo menos tres informes epidemiológicos conocidos de AOACD, la primera en 2007 en Caracas (Chacao) [4], el segundo en 2009 a Vargas [7] y la tercera en 2010 en Caracas (Antímano) [ 8]. Una característica común de estos brotes es que han afectado principalmente a los niños y han dado lugar a una alta tasa de mortalidad entre los casos confirmados. Los informes que describen la investigación de estos brotes son de gran importancia científica y epidemiológica, sin embargo, la información sólo en el primer brote se ha publicado [4]. Por estas razones, se reportan los resultados del cuarto brote de AOACD que ocurrió en Venezuela, en el estado de Táchira.Acute orally acquired Chagas disease (AOACD) has emerged as a significant threat in some countries
of South America [1,2]. Until March 2013, at least
four have reported outbreaks of acute orally acquired Chagas disease, specifically Brazil [3], Venezuela [4], Colombia [5] and Bolivia [6]. Outbreaks are also likely occurring in Argentina and Ecuador, according to some old reports [2]. In Venezuela, there have been at least three well-known epidemiological reports of AOACD, the first in 2007 at Caracas (Chacao) [4], the second in 2009 at Vargas [7] and the third in 2010 at
Caracas (Antimano) [8]. A common feature of these
outbreaks is that they have affected predominantly
children and have led to a high fatality rate among confirmed cases. Reports describing the investigation of these outbreaks are of high scientific and epidemiological significance; however, information on only the first outbreak has been published [4]. For these reasons we report the findings of the fourth outbreak of AOACD that occurred in Venezuela, in Táchira state
Proyecto de construcción de “Edificio Barcelona 209”
El presente trabajo tesis tiene como objetivo mostrar los procesos de: Inicio, planificación, ejecución, monitoreo y control y cierre de los entregables de gestión y construcción dentro del proyecto inmobiliario, Edificio Barcelona 209.
El esquema de desarrollo de la tesis se ejecutará en cinco capítulos en los que se pasa por todas los procesos la Guía del PMBOK 5ª edición, partiendo de la configuración del Caso de negocio del proyecto desde el marco referencial de la empresa; marco conceptual en el que se exponen las bases que rigen la dirección de proyectos basada en la Guía del PMBOK 5ª edición; identificando la documentación en los grupos de proceso de: inicio, planificación, ejecución control y cierre y por último se cierra con las conclusiones y recomendaciones.
Esta tesis servirá de guía para los proyectos de la empresa aumentando los activos de procesos de la organización.Tesi
DIFICULDADES NA CONTRATAÇÃO DA MÃO DE OBRA OPERACIONAL NAS INDÚSTRIAS METAL-MECÂNICAS
Na busca do bom andamento das atividades da empresa, cada qual com suas particularidades, estabelecem-se métodos e procedimentos a serem seguidos. Assim, considerando que o capital mais valioso de uma organização são as pessoas, deve sempre haver o equilíbrio entre os interesses da empresa e de seus empregados. Para isso, existe a área de recursos humanos, a qual se torna responsável por ser essa “ponte intermediária” na relação entre o empregado e o empregador. Esse método deve ser aplicado principalmente no momento de contratar os novos colaboradores, pois observa-se que cada vez mais, as empresas estão enfrentando grandes dificuldades de encontrar profissionais capazes de atender a todas as exigências da organização e que permaneçam no trabalho. Portanto, com o objetivo de aprofundar o entendimento em relação ao apagão de mão de obra que as empresas estão vivendo atualmente, buscou-se abordar a realidade vivida pelas indústrias do ramo metal-mecânico localizadas nas cidades de Herval d’ Oeste, Joaçaba e Luzerna, região Meio-oeste catarinense, identificando e analisando as dificuldades encontradas na contratação da mão de obra dos setores de produção. Contatou-se que, devido a tantos obstáculos enfrentados para contratar profissionais desse ramo, 76,5% das indústrias pesquisadas consideram mais interessante manter os funcionários que já atuam em seu quadro laboral.Palavras-chave: Indústria metal-mecânica. Mão de obra operacional. Dificuldades de contratação
Тенденции использования венгерской орфографии в русинском языке
One characteristic feature of the vocabulary of Rusyn language which makes it different from the vocabulary of other East Slavic languages is the presence of Hungarian loanwords in it. From the middle of the 19th to the early 20th century, certain Rusyn authors wrote their Rusyn works using the Latin alphabet based on the Hungarian orthography. The paper is devoted to this phenomenon which remained almost unnoticed by the researchers
HRP2 and pLDH-Based Rapid Diagnostic Tests, Expert Microscopy, and PCR for Detection of Malaria Infection during Pregnancy and at Delivery in Areas of Varied Transmission: A Prospective Cohort Study in Burkina Faso and Uganda.
BACKGROUND: Intermittent screening and treatment (IST) of malaria during pregnancy has been proposed as an alternative to intermittent preventive treatment in pregnancy (IPTp), where IPTp is failing due to drug resistance. However, the antenatal parasitaemias are frequently very low, and the most appropriate screening test for IST has not been defined. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a multi-center prospective study of 990 HIV-uninfected women attending ANC in two different malaria transmission settings at Tororo District Hospital, eastern Uganda and Colsama Health Center in western Burkina Faso. Women were enrolled in the study in the second or third trimester of pregnancy and followed to delivery, generating 2,597 blood samples for analysis. Screening tests included rapid diagnostic tests (RDTs) targeting histidine-rich protein 2 (HRP2) and parasite lactate dehydrogenase (pLDH) and microscopy, compared to nPCR as a reference standard. At enrolment, the proportion of pregnant women who were positive for P. falciparum by HRP2/pan pLDH RDT, Pf pLDH/pan pLDH RDT, microscopy and PCR was 38%, 29%, 36% and 44% in Uganda and 21%, 16%, 15% and 35% in Burkina Faso, respectively. All test positivity rates declined during follow-up. In comparison to PCR, the sensitivity of the HRP2/pan pLDH RDT, Pf pLDH/pan pLDH RDT and microscopy was 75.7%, 60.1% and 69.7% in Uganda, 55.8%, 42.6% and 55.8% in Burkina Faso respectively for all antenatal visits. Specificity was greater than 96% for all three tests. Comparison of accuracy using generalized estimating equation revealed that the HRP2- detecting RDT was the most accurate test in both settings. CONCLUSIONS/SIGNIFICANCE: The study suggests that HRP2-based RDTs are the most appropriate point-of-care test currently available for use during pregnancy especially for symptomatic women, but will still miss some PCR-positive women. The clinical significance of these very low density infections needs to be better defined
Report of the Inter-benchmark Process on Herring (Clupea harengus) in the Gulf of Bothnia (IBPCluB)
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