1,598 research outputs found

    Influencia del liderazgo sobre el clima organizacional

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    ResumenEl objetivo central de este artículo es analizar la influencia del liderazgo sobre el clima organizacional. Se hace una revisión de los antecedentes del liderazgo, sus conceptos y las diferentes teorías propuestas por varios autores. Se estudia el clima organizacional, sus dimensiones y factores y se determina la influencia que tiene el liderazgo en el clima organizacional y como esto conlleva al desempeño de los trabajadores en la organización. También se revisan estudios empíricos que confirmen la relación entre las variables mencionadas y se concluye que el liderazgo es el desencadenante para un gran desempeño laboral a través de la construcción de un buen clima organizacional en base a las percepciones provocadas por el líder.AbstractThe central aim of this paper is to analyze the influence of leadership on organizational climate. A review of the history of leadership concepts and the different theories proposed by several authors is made. The organizational climate dimensions and factors and through a deep analysis the influence of leadership on organizational climate and how it leads to the performance of employees in the organization is determined is studied. Empirical studies confirm the relationship between these variables and concludes that leadership is the trigger for a big job performance through the construction of a good organizational climate based on perceptions caused by the leader are also reviewed

    Electron-phonon renormalization of the absorption edge of the cuprous halides

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    Compared to most tetrahedral semiconductors, the temperature dependence of the absorption edges of the cuprous halides (CuCl, CuBr, CuI) is very small. CuCl and CuBr show a small increase of the gap E0E_0 with increasing temperature, with a change in the slope of E0E_0 vs. TT at around 150 K: above this temperature, the variation of E0E_0 with TT becomes even smaller. This unusual behavior has been clarified for CuCl by measurements of the low temperature gap vs. the isotopic masses of both constituents, yielding an anomalous negative shift with increasing copper mass. Here we report the isotope effects of Cu and Br on the gap of CuBr, and that of Cu on the gap of CuI. The measured isotope effects allow us to understand the corresponding temperature dependences, which we also report, to our knowledge for the first time, in the case of CuI. These results enable us to develop a more quantitative understanding of the phenomena mentioned for the three halides, and to interpret other anomalies reported for the temperature dependence of the absorption gap in copper and silver chalcogenides; similarities to the behavior observed for the copper chalcopyrites are also pointed out.Comment: 14 pages, 5 figures, submitted to Phys. Rev.

    A comparison of electrochemical degradation of phenol on boron doped diamond and lead dioxide anodes

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    This work compares two electrode materials used to mineralize phenol contained in waste waters. Two disks covered with either boron doped diamond (BDD) or PbO2 were used as anodes in a one compartment flow cell under the same hydrodynamic conditions. Efficiencies of galvanostatic electrolyses are compared on the basis of measurements of Total Organic Carbon (TOC) and Chemical Oxygen Demand (COD). Galvanostatic electrolyses were monitored by analysis of phenol and of its oxidation derivatives to evaluate the operating time needed for complete elimination of toxic aromatics. The experimental current efficiency is close to the theoretical value for the BDD electrode. Other parameters being equal, phenol species disappeared at the same rate using the two electrode materials but the BDD anode showed better efficiency to eliminate TOC and COD. Moreover, during the electrolysis less intermediates are formed with BDD compared to PbO2 whatever the current density. A comparison of energy consumption is given based on the criterion of 99% removal of aromatic compounds

    Human Mas-related G protein-coupled receptors-X1 induce chemokine receptor 2 expression in rat dorsal root ganglia neurons and release of chemokine ligand 2 from the human LAD-2 mast cell line

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    Primate-specific Mas-related G protein-coupled receptors-X1 (MRGPR-X1) are highly enriched in dorsal root ganglia (DRG) neurons and induce acute pain. Herein, we analyzed effects of MRGPR-X1 on serum response factors (SRF) or nuclear factors of activated T cells (NFAT), which control expression of various markers of chronic pain. Using HEK293, DRG neuron-derived F11 cells and cultured rat DRG neurons recombinantly expressing human MRGPR-X1, we found activation of a SRF reporter gene construct and induction of the early growth response protein-1 via extracellular signal-regulated kinases-1/2 known to play a significant role in the development of inflammatory pain. Furthermore, we observed MRGPR-X1-induced up-regulation of the chemokine receptor 2 (CCR2) via NFAT, which is considered as a key event in the onset of neuropathic pain and, so far, has not yet been described for any endogenous neuropeptide. Up-regulation of CCR2 is often associated with increased release of its endogenous agonist chemokine ligand 2 (CCL2). We also found MRGPR-X1-promoted release of CCL2 in a human connective tissue mast cell line endogenously expressing MRGPR-X1. Thus, we provide first evidence to suggest that MRGPR-X1 induce expression of chronic pain markers in DRG neurons and propose a so far unidentified signaling circuit that enhances chemokine signaling by acting on two distinct yet functionally co-operating cell types. Given the important role of chemokine signaling in pain chronification, we propose that interruption of this signaling circuit might be a promising new strategy to alleviate chemokine-promoted pain

    Education can improve the negative perception of a threatened long-lived scavenging bird, the Andean condor

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    Human-wildlife conflicts currently represent one of the main conservation problems for wildlife species around the world. Vultures have serious conservation concerns, many of which are related to people's adverse perception about them due to the belief that they prey on livestock. Our aim was to assess local perception and the factors influencing people's perception of the largest scavenging bird in South America, the Andean condor. For this, we interviewed 112 people from Valle Fértil, San Juan province, a rural area of central west Argentina. Overall, people in the area mostly have an elementary education, and their most important activity is livestock rearing. The results showed that, in general, most people perceive the Andean condor as an injurious species and, in fact, some people recognize that they still kill condors. We identified two major factors that affect this perception, the education level of villagers and their relationship with livestock ranching. Our study suggests that conservation of condors and other similar scavengers depends on education programs designed to change the negative perception people have about them. Such programs should be particularly focused on ranchers since they are the ones who have the worst perception of these scavengers. We suggest that highlighting the central ecological role of scavengers and recovering their cultural value would be fundamental to reverse their persecution and their negative perception by people.Fil: Cailly Arnulphi, Verónica Beatríz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; ArgentinaFil: Lambertucci, Sergio Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Borghi, Carlos Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; Argentin

    Spin Caloritronics

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    This is a brief overview of the state of the art of spin caloritronics, the science and technology of controlling heat currents by the electron spin degree of freedom (and vice versa).Comment: To be published in "Spin Current", edited by S. Maekawa, E. Saitoh, S. Valenzuela and Y. Kimura, Oxford University Pres

    PRESENCIA DE Neospora caninum EN LLAMAS DE UNA EMPRESA GANADERA DE LA SIERRA CENTRAL

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    El Neospora caninum es un protozoo implicado como agente causal de abortos y muerte neonatal, principalmente en el ganado bovino. El presente estudio se llevó a cabo para determinar la seroprevalencia a Neospora caninum en llamas de la zona central del país. Se evaluaron 175 sueros de llamas hembras en edad reproductiva, pertenecientes a la empresa Sociedad Agraria de Interés Social (SAIS) Pachacútec, del departamento de Junín, mediante la técnica de inmunofluorescencia indirecta (IFI). Los resultados confirman la presencia del Neospora caninum en llamas de la sierra central, aunque con una seroprevalencia reducida (2.9 ± 2.5%).The Neospora caninum is a protozoan that causes abortion, especially in cattle. Thepresent study was carried out to determine the seroprevalence to Neospora caninum inllamas of the central zone of the country. A total of 175 serum samples of breeding femalellamas of the Agrarian Cooperative Pachacútec were analyzed by the immunofluorescentantibody test (IFAT). The results confirmed the presence of Neospora caninum in llamasof the Central Sierra, but the seroprevalence was low (2.9 ± 2.5 %)

    p16 Overexpression: A Potential Early Indicator of Transformation in Ovarian Carcinoma

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    Objective: The recently cloned gene p16 (MST 1) has been identified as a putative tumor suppressor gene that binds to CDK4 and CDK6 (cyclin-dependent kinases), preventing their interaction with cyclin D1 and thereby preventing cell cycle progression at the G1 stage. In addition, the p16 gene has been shown to have a high frequency of mutation in some tumor cell lines; however, it has also been shown that a much lower frequency of mutation occurs in primary tumors. This study investigated the mRNA expression level and mutation status of the p16 gene in ovarian tumors. Methods: We performed quantitative polymerase chain reaction and direct cDNA sequencing analysis. To confirm the p16 protein level in ovarian tumors, Western blotting and immunohistochemical staining were performed. Expression levels of mRNA for the p16 gene relative to the β-tubulin gene were examined in 32 ovarian tumors (24 carcinomas, six low malignant potential tumors, and two benign tumors) and six normal ovaries. Results: The mRNA expression level of p16 was significantly elevated in 28 ovarian tumors (22 carcinomas, five low malignant potential tumors, and one benign tumor) compared with that of normal ovaries. Western blotting analysis and immunohistochemical staining confirmed elevated p16 protein levels in ovarian tumor samples. Among 32 ovarian tumors, cDNA sequencing of the p16 gene showed no p16 mutation resulting in a coding error, although one silent mutation and three polymorphisms were found. Conclusions: Although p16 is seldom mutated in ovarian tumors, the overexpression of p16 in most ovarian tumor cases indicates a dysfunction in the regulatory complex for G1 arrest. Therefore, overexpression of p16 may be an important early event in the neoplastic transformation of the ovarian epithelium.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68382/2/10.1177_107155769700400209.pd

    Phylogenetic Relationships of Tribes Within Harpalinae (Coleoptera: Carabidae) as Inferred from 28S Ribosomal DNA and the Wingless Gene

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    Harpalinae is a large, monophyletic subfamily of carabid ground beetles containing more than 19,000 species in approximately 40 tribes. The higher level phylogenetic relationships within harpalines were investigated based on nucleotide data from two nuclear genes, wingless and 28S rDNA. Phylogenetic analyses of combined data indicate that many harpaline tribes are monophyletic, however the reconstructed trees showed little support for deeper nodes. In addition, our results suggest that the Lebiomorph Assemblage (tribes Lebiini, Cyclosomini, Graphipterini, Perigonini, Odacanthini, Lachnophorini, Pentagonicini, Catapiesini and Calophaenini), which is united by a morphological synapomorphy, is not monophyletic, and the tribe Lebiini is paraphyletic with respect to members of Cyclosomini. Two unexpected clades of tribes were supported: the Zuphiitae, comprised of Anthiini, Zuphiini, Helluonini, Dryptini, Galeritini, and Physocrotaphini; and a clade comprised of Orthogoniini, Pseudomorphini, and Graphipterini. The data presented in this study represent a dense sample of taxa to examine the molecular phylogeny of Harpalinae and provide a useful framework to examine the origin and evolution of morphological and ecological diversity in this group
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