936 resultados para Direct effect


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We investigate the impact of foreign direct investment on the productivity of domestic firms, using sectoral data for Portugal. An improved analysis takes into account the most appropriate interval for the technological gap between foreign and domestic firms. Sectoral variation of spillovers, idiosyncratic sectoral factors and the search for inter-sectoral effects provide new insights on the subject. Significant spillovers require a proper technology differential between the foreign and domestic producers and favourable sectoral characteristics. Broadly, they occur in modern industries in which foreign firms have a clear, but not too sharp, edge on the domestic ones. Agglomeration effects are also identified as pertinent specific influences.

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In this dissertation, we investigate the effect of foreign capital participations in Brazilians companies’ performance. To carry out this analysis, we constructed two sets of model based on EBITDA margin and return on equity. Panel data analysis is used to examine the relationship between foreign capital ownership and Brazilian firms’ performance. We construct a cross-section time-series sample of companies listed on the BOVESPA index from 2006 to 2010. Empirical results led us to validate two hypotheses. First, foreign capital participations improve companies’ performance up to a certain level of participation. Then, joint controlled or strategic partnership between a Brazilian company and a foreign investor provide high operating performance.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The objective of the present study was to investigate the effect of data structure on estimated genetic parameters and predicted breeding values of direct and maternal genetic effects for weaning weight (WW) and weight gain from birth to weaning (BWG), including or not the genetic covariance between direct and maternal effects. Records of 97,490 Nellore animals born between 1993 and 2006, from the Jacarezinho cattle raising farm, were used. Two different data sets were analyzed: DI_all, which included all available progenies of dams without their own performance; DII_all, which included DI_all + 20% of recorded progenies with maternal phenotypes. Two subsets were obtained from each data set (DI_all and DII_all): DI_1 and DII_1, which included only dams with three or fewer progenies; DI_5 and DII_5, which included only dams with five or more progenies. (Co)variance components and heritabilities were estimated by Bayesian inference through Gibbs sampling using univariate animal models. In general, for the population and traits studied, the proportion of dams with known phenotypic information and the number of progenies per dam influenced direct and maternal heritabilities, as well as the contribution of maternal permanent environmental variance to phenotypic variance. Only small differences were observed in the genetic and environmental parameters when the genetic covariance between direct and maternal effects was set to zero in the data sets studied. Thus, the inclusion or not of the genetic covariance between direct and maternal effects had little effect on the ranking of animals according to their breeding values for WW and BWG. Accurate estimation of genetic correlations between direct and maternal genetic effects depends on the data structure. Thus, this covariance should be set to zero in Nellore data sets in which the proportion of dams with phenotypic information is low, the number of progenies per dam is small, and pedigree relationships are poorly known. (c) 2012 Elsevier B.V. All rights reserved.

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The aim of this work was to evaluate the direct protective action of oral fatty acid supplementation against the deleterious effect of hyperglycemia on maternal reproductive outcomes; fetal growth and development on female Wistar rats. The animals were distributed into four experimental groups: G1= non-diabetic without supplementation (Control group); G2= non-diabetic treated with linoleic (LA) and gammalinolenic acid (GLA) (1 mL of Gamaline-V/day); G3= diabetic without supplementation and G4= diabetic treated with LA and GLA. Diabetes was induced by streptozotocin (40 mg/kg). At day 21 of pregnancy, the gravid uterus was weighed and dissected to count the dead and live fetuses, resorption, implantation, and corpora lutea numbers. The fetuses were analyzed for external and internal anomalies. The treatment with Gamaline-V supplementation to diabetic rats interfered in the maternal reproductive outcome (reduced number of live fetuses and embryonic implantation); however, it protected the deleterious on the incidence of congenital anomalies caused by hyperglycemia.

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The aim of this study was to evaluate the viability in the effect of open pulled straw (OPS) vitrification procedure of sheep embryos after direct transference. Embryos were produced in vivo and cryopreserved in slow freezing or OPS vitrification. The survival rates of cryopreserved embryos were compared to non-frozen standard pattern. In a first set of experiments, embryos at morula and blastocyst stages were dived in ethylene glycol (1.5 M) and frozen in an automatic freezer. After being thawed, they were directly or indirectly transferred to ewes recipient. A second group of embryos were drawn into OPS and plunged into liquid nitrogen after being exposed at room temperature for 1 min and 45 s in 10% EG plus 10% dimethyl sulphoxide (DMSO), then again for 30 s in 20% EG + 20% DMSO + 0.5 M sucrose. After being warmed, embryos were also directly transferred using a French mini straw as the catheter for the transplantation process or after in vitro dilution of cryoprotectants (two-step-process). No significant difference was observed among fresh, frozen or vitrified embryos on pregnancy rate (50.0%, 38.6% and 55.8%). However, when we evaluated only the direct transference, the pregnancy rate of OPS vitrified embryos was higher than that of frozen embryos (57.1% vs 34.8%) (p = 0.07). In addition, vitrified morulae had a higher pregnancy rate than the one with frozen embryos (64.0% vs 38.9%) (p = 0.07). Finally, our results indicate that OPS vitrification technique in association with direct transference improves the viability of sheep embryos with potential applications to field conditions.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Objective. This study evaluated transenamel and transdentinal cytotoxic effects of a bleaching gel on the MDPC-23 cell line.Study design. Discs obtained from bovine incisors were placed in a metallic device to simulate an in vivo pulp chamber. Groups were formed according to the enamel surface treatment: G1: 35% H(2)O(2) bleaching gel; G2: 35% H2O2 bleaching gel + halogen light; G3: halogen light; and G4: control. Cell metabolism was evaluated by the methyltetrazolium assay and cell morphology by scanning electron microscopy.Results. Cell metabolism decreased by 31.7%, 41.6%, and 11.5% in G1, G2, and G3, respectively. Cytotoxic effects observed in G2 were significantly more severe compared with G3 and G4. In G1 and G2, a smaller number of viable cells with major morphologic alterations remained adhered to dentin.Conclusion. The bleaching gel associated with light presented transenamel and transdentinal cytotoxic effects characterised by direct damage to odontoblasts and decrease of their metabolic activity. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009; 108: 458-464)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Histamine release induced by plant lectins was studied with emphasis on the carbohydrate specificity, external calcium requirement, metal binding sites, and mast cell heterogeneity and on the importance of antibodies bound to the mast cell membrane to the lectin effect. Peritoneal mast cells were obtained by direct lavage of the rat peritoneal cavity and guinea pig intestine and hamster cheek pouch mast cells were obtained by dispersion with collagenase type IA. Histamine release was induced with concanavalin A (Con A), lectins from Canavalia brasiliensis, mannose-specific Cymbosema roseum, Maackia amurensis, Parkia platycephala, Triticum vulgaris (WGA), and demetallized Con A and C. brasiliensis, using 1-300 µg/ml lectin concentrations applied to Wistar rat peritoneal mast cells, peaking on 26.9, 21.0, 29.1, 24.9, 17.2, 10.7, 19.9, and 41.5%, respectively. This effect was inhibited in the absence of extracellular calcium. The lectins were also active on hamster cheek pouch mast cells (except demetallized Con A) and on Rowett nude rat (animal free of immunoglobulins) peritoneal mast cells (except for mannose-specific C. roseum, P. platycephala and WGA). No effect was observed in guinea pig intestine mast cells. Glucose-saturated Con A and C. brasiliensis also released histamine from Wistar rat peritoneal mast cells. These results suggest that histamine release induced by lectins is influenced by the heterogeneity of mast cells and depends on extracellular calcium. The results also suggest that this histamine release might occur by alternative mechanisms, because the usual mechanism of lectins is related to their binding properties to metals from which depend the binding to sugars, which would be their sites to bind to immunoglobulins. In the present study, we show that the histamine release by lectins was also induced by demetallized lectins and by sugar-saturated lectins (which would avoid their binding to other sugars). Additionally, the lectins also released histamine from Rowett nude mast cells that are free of immunoglobulins.

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This study analyzed the effects of noise levels and number of visitors on the behaviors of a mother puma and her daughter in a zoo environment with respect to the time of day. The study monitored visitation (noise and number) over two 1-week periods (4 weeks between periods) and frequency of various puma behaviors (videorecorded). The study analyzed videotaped behavior of the pumas based on the time of day and visitors number and noise levels. There was a direct association of puma behaviors with visitors number and noise levels. The daughter puma was the most affected and behavioral changes of both pumas correlated more strongly with the noise level than the number of visitors. The noise level and number of visitors affected the behavior of the mother and her daughter only in the morning. The results of this study indicate that both noise level and number of visitors affected these pumas but revealed the noise as predominant. Moreover, the response of these pumas to visitors depended on the time of the day.

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Contamination with cadmium compounds poses high potential risk for the health of populations and for this reason the treatment of their toxic effects should urgently be established. The present study was carried out to determine whether or-tocopherol intake can protect tissues against damage induced by cadmium, and to clarify the contribution of superoxide radicals (O-2(-)) in this process. Cadmium chloride was tested for tissue damage by a single intraperitoneal injection of Cd2+ ions (2 mg Kg(-1)). To determine the potential therapeutic effect of Vitamin E, a group of Cd2+-treated rats received a drinking solution of or-tocopherol (40 mg l(-1)) for 15 days. Cadmium induced increased serum creatinine and total lactate dehydrogenase, reflecting renal and cardiac damage. The increased lipoperoxide and decreased Cu-Zn superoxide dismutase levels indicated the generation of superoxide radicals in cadmium-treated rats. Tocopherol induced increased serum high-density lipoprotein and depressed the toxic effects of Ca2+ alone, since creatinine and lactate dehydrogenase determinations were recovered to the control values. Tocopherol decreased lipoperoxide and led the superoxide dismutase activities to approach those of the control values. We concluded that superoxide radicals are produced as mediators of cadmium toxicity. Tocopherol possesses a significant anti-radical activity and inhibits the cadmium effect on superoxide dismutase activity. Tocopherol also protected tissues from the toxic effects of cadmium by a direct antioxidant action which decreased lipoperoxide formation.

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OBJETIVO: Nosso objetivo foi investigar se o uso do solo do ambiente terrestre adjacente influencia a estrutura das assembleias fitoplanctônicas (composição, riqueza, diversidade e abundância) e biomassa (clorofila-a) em um riacho de Cerrado durante diferentes períodos do ano. MÉTODOS: Os trabalhos de campo foram realizados trimestralmente durante dois anos. RESULTADOS: As variáveis físico-químicas que melhor indicaram as diferenças nas condições da água foram condutividade, oxigênio dissolvido e transparência. Também houve um notável aumento na concentração de nitrogênio, fósforo e material em suspensão na água durante o verão devido aos efeitos da pluviosidade. As assembleias fitoplanctônicas foram compostas por 64 espécies. Cryptophyceae foi o grupo mais abundante, seguido por Bacillariophyceae. Para ambos os anos, a riqueza e a diversidade foram maiores durante a primavera e no outono, enquanto que a abundância do fitoplâncton e a concentração de clorofila-a foram mais elevados durante o outono e verão. A análise de agrupamento e a analise de correspondência canônica mostraram que a sazonalidade e o uso do solo são fatores importantes na estruturação das assembleias ao longo do ano. As alterações nas assembleias fitoplanctônicas ocorreram provavelmente em função da variação na intensidade e freqüência da mistura da água e da entrada de nutrientes oriundo do sistema terrestre adjacente para o aquático. CONCLUSÃO: A estrutura das assembleias fitoplanctônicas mostrou ser altamente influenciada pelo uso do solo, corroborando com a hipótese inicial do trabalho.