927 resultados para Host Institution
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An integrated whole-rock petrographic and geochemical study has been carried out on kamafugites and kimberlites of the Late Cretaceous Alto Paranaiba igneous province, in Brazil, and their main minerals, olivine, clinopyroxene, perovskite, phlogopite, spinels and ilmenite. Perovskite is by far the dominant repository for light lanthanides, Nb, Ta, Th and U, and occasionally other elements, reaching concentrations up to 3.4 x 10(4) chondrite values for light lanthanides and 105 chondrite for Th. A very strong fractionation between light and heavy lanthanides (chondrite-normalized La/Yb from similar to 175 to similar to 2000) is also observed. This is likely the first comprehensive dataset on natural perovskite. Clinopyroxene has variable trace-element contents. likely due to the different position of this phase in the crystallization sequence; Sc reaches values as high as 200 ppm whereas the lanthanides show very variable enrichment in light over heavy REE, and commonly show a negative Eu anomaly. The olivine, phlogopite (and tetra-ferriphlogopite), Cr-Ti oxide and ilmenite are substantially barren minerals for lanthanides and most other trace elements, with the exception of Ba, Cs and Rb in mica, and V, Nb and Ta in ilmenite. Estimated mineral/whole-rock partition coefficients for lanthanides in perovskite are similar to previous determinations, though much higher than those calculated in experiments with synthetic compositions, testifying once more to the complex behavior of these elements in a natural environment. The enormous potential for exploitation of lanthanides, Th, U and high-field-strength elements in the Brazilian kamafugites, kimberlites and related rocks is clearly shown.
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This study aimed to evaluate the potential of soybean-promoted acidic nitrite reduction and to correlate this activity with the content of phenolics and with the bactericidal activity against Escherichia coli O157:H7. Extracts of embrionary axes and cotyledons enriched in phenolics increased (center dot)NO formation at acidic pH at values that were 7.1 and 4.5 times higher, respectively, when compared to the reduction of the nonenriched extracts. Among the various phenolics accumulated in the soybean extracts, five stimulated nitrite reduction in the following decreasing order of potency: epicatechin gallate, chlorogenic acid, caffeic acid, galic acid and p-coumaric acid. Extracts of embrionary axes presented higher contents of epicatechin gallate and caffeic acid, compared to that of cotyledons, indicating a positive correlation between activity of the extracts and content of phenolics with regard to nitrite reducing activity. Soybean extracts enriched in phenolics interacted synergistically with acidified nitrite to prevent E. coli O157:H7 growth. The results suggest that soybean phenolics may interfere with the metabolism of (center dot)NO in an acidic environment by accelerating the reduction of nitrite, with a potential antimicrobial effect in the stomach.
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Trypanosoma cruzi is a protozoan parasite that infects vertebrates, causing in humans a pathological condition known as Chagas` disease. The infection of host cells by T. cruzi involves a vast collection of molecules, including a family of 85 kDa GPI-anchored glycoproteins belonging to the gp85/trans-sialidase superfamily, which contains a conserved cell-binding sequence (VTVXNVFLYNR) known as FLY, for short. Herein, it is shown that BALB/c mice administered with a single dose (1 mu g/animal, intraperitoneally) of FLY-synthetic peptide are more susceptible to infection by T. cruzi, with increased systemic parasitaemia (2-fold) and mortality. Higher tissue parasitism was observed in bladder (7.6-fold), heart (3-fold) and small intestine (3.6-fold). Moreover, an intense inflammatory response and increment of CD4(+) T cells (1.7-fold) were detected in the heart of FLY-primed and infected animals, with a 5-fold relative increase of CD4(+)CD25(+)FoxP3(+) T (Treg) cells. Mice treated with anti-CD25 antibodies prior to infection, showed a decrease in parasitaemia in the FLY model employed. In conclusion, the results suggest that FLY facilitates in vivo infection by T. cruzi and concurs with other factors to improve parasite survival to such an extent that might influence the progression of pathology in Chagas` disease.
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Photoluminescence and electroluminescence of PVK films doped with fac-[ClRe(CO)(3)(bpy)], bpy=2,2`-bipyridine, are investigated. Photoluminescence spectra of spin-coated PVK films (lambda(exc)=290 nm) exhibit a broad band centered at 405 nm. As the concentration of dopant increases, the polymer emission is quenched and a band at 555 nm appears (isosbestic point at 475 nm). In OLEDs with ITO/PEDOT:PSS/PVK/butylPBD/Al architecture doped with fac-[ClRe(CO)(3)(bpy)], the polymer host emission is completely quenched even at the lowest concentration of dopant. The electroluminescence spectra of the devices show that there is an efficient energy transfer from the host to the dopant, which exhibits a very intense emission at 580 nm. (C) 2009 Elsevier B.V. All rights reserved.
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The interaction of 4-nerolidylcatechol (4-NRC), a potent antioxidant agent, and 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD) was investigated by the solubility method using Fourier transform infrared (FTIR) methods in addition to UV-Vis, (1)H-nuclear magnetic resonance (NMR) spectroscopy and molecular modeling. The inclusion complexes were prepared using grinding, kneading and freeze-drying methods. According to phase solubility studies in water a B(S)-type diagram was found, displaying a stoichiometry complexation of 2:1 (drug:host) and stability constant of 6494 +/- A 837 M(-1). Stoichiometry was established by the UV spectrophotometer using Job`s plot method and, also confirmed by molecular modeling. Data from (1)H-NMR, and FTIR, experiments also provided formation evidence of an inclusion complex between 4-NRC and HP-beta-CD. 4-NRC complexation indeed led to higher drug solubility and stability which could probably be useful to improve its biological properties and make it available to oral administration and topical formulations.
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The aim of this project is to provide an explanation for recently obtained binding constants for two similar guest molecules, NDMG and N-MAP, with a p-sulfonatocalix[6]arene host in ammonium acetate buffer. This work was done primarily using pressure perturbation calorimetry, which is a technique that determines the coefficient of thermal expansion, α, which is in turn related to the solute molecule's effect on the order of the surrounding water molecules. A series of experiments were designed to test the effects of suspected confounding variables on the validity of PPC data. PPC was then used to study NDMG and N-MAP in ammonium acetate buffer. NDMG exhibited a minimum in α as function of temperature, while N-MAP did not. This difference was theorized to be due to the formation of an intramolecular hydrogen bond in monocationic NDMG that would lower the heat capacity of the molecule and better distribute the molecule's charge. Computational work and nuclear magnetic resonance spectroscopy confirmed that monocationic, ring-closed NDMG has less concentrated charge and more constrained motion than monocationic, ring-open NDMG. This evidence supports the theory that monocationic NDMG forms an intramolecular hydrogen bond and that this may be responsible for the minimum in α. This difference may explain the differences in binding constants between NDMG and N-MAP.
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Institutions continue to face increasing pressure from faculty, students, and other concerned constituents to divest endowment holdings from perceived social injustices. In this report, investment officers and advisory committee members offer insight into institutional practices used to respond to these concerns through the adoption of socially responsible investment policies and other socially responsible investment options. Contacts offer recommendations on balancing the administration’s fiduciary responsibility to ensure maximum endowment returns with the social concerns of institutional constituents.
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O Crescimento Econômico é Quase que Invariavelmente o Resultado de uma Estratégia Nacional De Desenvolvimento. o Efetivo Desenvolvimento Econômico Ocorre Historicamente Quando a Nação é Uma Nação Forte, e as Diferentes Classes Sociais são Capazes de Cooperar e Formular uma Efetiva Estratégia Para Promover o Crescimento e Enfrentar a Competição Internacional. uma Estratégia Nacional De Desenvolvimento é Essencialmente uma Instituição ou um Conjunto de Instituições que Estimulam A Acumulação de Capital e o Progresso Técnico. Segue uma Discussão das Principais Características de Tais Estratégias. o Artigo Finaliza com uma Análise dos Conflitos ou Tensões Envolvidos nas Estratégias Nacionais de Desenvolvimento.
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The aim of this study is to analyze the profile of today’s manager, according to the classical management literature, working on internationalized higher education institute. This paper draws together knowledge about the manager’s profile in a corporate environment and how it can be appreciated in a higher education institute all of this taking into consideration the environment that nowadays exists in these institutions. Data were collected through semi-structured interviews, with professors of the Fundacao Getulio Vargas, more specific on their Public and Business Administration School (EBAPE), which had active roles on its development, internationalization and during some point in time their management. The findings obtained where analyzed under the perspective brought by the theoretical reference framework, and, based on this approach is represented the manager whom could have a better perspective to administrate a higher education institute.
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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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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Few studies have been performed with parasites of marine and estuarine fish in southern Brazil. In the present study, unpublished results show the ways of parasitism of juvenile mullet by parasites. The toxicity of formaldehyde and the effectiveness of this chemotherapy in controlling parasites in reared juvenile mullet Mugil liza were also studied. Juvenile mullets (1 +/- 0.26 g; 4.1 +/- 0.4 cm) were exposed to different concentrations of 37% formaldehyde: control group and five formaldehyde concentrations which were tested: T1 (13.5), T2 (21.6), T3 (40.5), T4 (81) and T5 (135) mg L-1 with 8 fish per repetition in triplicate. To verify the drug effectiveness in parasitic control, juvenile mullets were exposed to 1 h prophylactic bath of 37% formaldehyde with a control group and five formaldehyde concentrations: T1 (67.5), T2 (135), T3 (270), T4 (405) and T5 (540) mg L-1, 8 fish per repetition in triplicate. Ligophorus cf. uruguayensis (Monogenoidea: Ancyrocephalidae) and Solostamenides cf. platyorchis (Monogenoidea: Microcotylidae) were identified in the gills. Digenea and Nematoda were observed in the intestines. This is the first occurrence of S. cf. platyorchis in Brazil. During the toxicity test, the LC50-96 h was estimated at 20.77 mg L-1 of formaldehyde. During the 1 h formaldehyde prophylactic bath, all parasites were eliminated in formaldehyde concentrations between 135 and 540 mg L-1. High survival rate was observed in all treatments. Values of prevalence and intensity of infestation observed in this study showed the potential damage caused by Monogenoidea to mullet. Formaldehyde baths with 135 mg L-1 are recommended to control Monogenoidea in mullet and the safe limits for formaldehyde use were presented. Besides, the endoparasites were tolerant to formaldehyde exposure. (C) 2012 Elsevier B.V. All rights reserved.
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Several Alternaria cassiae isolates were recovered from diseased sicklepod plants (Senna obtusifolia) in the southern regions of Brazil. A representative isolate (Cenargen CG593) was tested for its host range under greenhouse conditions. The fungus promoted symptoms in sicklepod, cassava (Manihot dulce), tomato (Lycopersicon esculentum) and eggplant (Solanum melongena) when tested at a spore concentration of 10(6) spores ml(-1). When the plants were inoculated with a suspension of 10(5) spores ml(-1) and held at a dew period of 12 h (cassava) or 18 h (tomato and eggplant), the plants showed symptoms of the disease, but they recovered and continued their normal vegetative growth. These results show that the fungus A. cassiae is safe to use for the control of S. obtusifolia under Brazilian conditions, because it did not cause excessive damage in the three plants tested.