578 research outputs found

    A Reforma de Córdoba de 1918 e a internacionalização universitária na América Latina

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    A internacionalização é uma tendência que, nas últimas duas décadas, tem-se instalado com força no âmbito universitário latino-americano. Contudo, argumenta-se neste artigo que ela é parte de um processo histórico que vem se constituindo dentro da região com características lhe são próprias. Por isso, este trabalho tem como objetivo identificar as contribuições da Reforma de Córdoba de 1918 para a análise do processo de internacionalização universitária na América Latina. Realizou-se uma pesquisa bibliográfica e documental, com um conteúdo de cunho histórico. Aponta-se como resultado que o legado da reforma, no que se refere à integração regional e ao conceito de autonomia universitária, contribui para uma visão da internacionalização enraizada no contexto latino-americano

    Evaluation des traits de vie d'une espèce endémique du Maroc (Salmo trutta macrostigma, Dumeril, 1858) dans une rivière du Moyen Atlas du Maroc: Oued Sidi Rachid

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    Cette étude a pour objectif la contribution à la détermination de la qualité physicochimique des eaux de l'Oued Sidi Rachid au Moyen Atlas où vit une espèce endémique du Maroc : la truite de rivière (Salmo trutta macrostigma, Duméril, 1858). L'étude des paramètres essentiels pour la vie de ce salmonidé au cours de la période comprise entre le mois de mai 2007 et le mois d'avril 2008 montre que la température, le potentiel Hydrogène (pH) et les concentrations des nitrites témoignent de la bonne qualité des eaux de l'Oued Sidi Rachid et permettent de classer ce site parmi les sites à vocation salmonicole. Les concentrations des orthophosphates sont très faibles et ne témoignent d'aucune source de pollution organique. Les concentrations des indicateurs de la dureté reflètent la nature géologique (carbonatée) de la région. Les résultats obtenus montrent bien que les eaux de l'Oued Sidi Rachid assurent à la truite de rivière un bon habitat écologique favorable à son développement et à sa reproduction.Mots clés: Qualité physicochimique, Truite de rivière, Oued Sidi Rachid, Maro

    ANALGESIC EFFECT AND ANTI-INFLAMMATORY ACTIVITY OF AQUEOUS EXTRACT OF BOSWELLIA DALZIELII (BURSERACEAE) STEM BARK

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    Objective: To evaluate the analgesic effect and anti-inflammatory properties of Boswellia dalzielii (Burseraceae), a medicinal plant commonly used in northern Nigeria as an anti-diarrhoeal, antipyretic, analgesic and anti-inflammatory agent.Methods: Three doses (25 mg/kg, 50 mg/kg and 100 mg/kg) of the crude aqueous extract of Boswellia dalzielii were evaluated for analgesic and anti-inflammatory activities using the acetic acid-induced writhing test, formalin-induced nociception and formalin-induced hind paw oedema in rats. The acute oral toxicity was carried out using the up and down procedure as described by the OECD guidelines.Results: All doses (25, 50 and 100 mg/kg) of the extract tested were effective against acetic acid induced abdominal constrictions producing a percentage inhibition of (55.43, 69.56 and 71.73%) respectively. A percentage inhibition of the formalin-induced nociception of (7.31, 31.70 and 48.78%-early phase) and (12.82, 21.79 and 48.71%-late phase) respectively was also produced. For the acetic acid writhing test, the percentage inhibition obtained at the dose of 50 and 100 mg/kg (69.56 and 71.73%) were higher than that of the standard drug (Piroxicam, 10 mg/kg) (59.78%). For formalin-induced nociception, the test extract at 100 mg/kg showed a higher percentage inhibition compared to Piroxicam, in early (48.78 and 43.90%) and late phase (48.71 and 39.74 %) respectively. The extract, however, did not show a significant activity against formalin-induced paw oedema at all the doses used.Conclusion: The present study demonstrated that Boswellia dalzielii has significant analgesic properties comparable to that of the standard drug (10% Piroxicam), thus validating the traditional claim of its antinociceptive property

    R-Estimates vs. GMM: A Theoretical Case Study of Validity and Efficiency

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    What role should assumptions play in inference? We present a small theoretical case study of a simple, clean case, namely the nonparametric comparison of two continuous distributions using (essentially) information about quartiles, that is, the central information displayed in a pair of boxplots. In particular, we contrast a suggestion of John Tukey—that the validity of inferences should not depend on assumptions, but assumptions have a role in efficiency—with a competing suggestion that is an aspect of Hansen’s generalized method of moments—that methods should achieve maximum asymptotic efficiency with fewer assumptions. In our case study, the practical performance of these two suggestions is strikingly different. An aspect of this comparison concerns the unification or separation of the tasks of estimation assuming a model and testing the fit of that model. We also look at a method (MERT) that aims not at best performance, but rather at achieving reasonable performance across a set of plausible models

    Contribution a l’étude physicochimique de l’écosystème lacustre Dayet Aoua au Maroc

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    L’étude consiste à la détermination de la qualité physicochimique des eaux du lac Dayet Aoua situé dans le Moyen Atlas au Maroc juste après son dernier desséchement survenu en été 2002. Les résultats d’analyse obtenus au cours de la période d’étude comprise entre février et juillet 2005, montrent que les eaux du lac sont bicarbonatées calciques et magnésiennes, dures à très dures. La dureté dépend essentiellement des ions magnésium. Les analyses des formes azotées et des orthophosphates des eaux du lac donnent des valeurs très faibles, et ne décèlent aucune sorte de pollution de type organique pouvant engendrer son eutrophisation, ce qui permet de le classeractuellement parmi les lacs oligotrophes.Mots-clés : lac, physico-chimie, pollution organique, oligotrophe

    Improving the Time Resolution of Large-Area LaBr3:Ce Detectors with SiPM Array Readout

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    LaBr3:Ce crystals have good scintillation properties for X-ray spectroscopy. Initially, they were introduced for radiation imaging in medical physics with either a photomultiplier or SiPM readout, and they found extensive applications in homeland security and gamma-ray astronomy. We used 1 inch round LaBr3:Ce crystals to realize compact detectors with the SiPM array readout. The aim was a good energy resolution and a fast time response to detect low-energy X-rays around 100 keV. A natural application was found inside the FAMU experiment, at RIKEN RAL. Its aim is a precise measurement of the proton Zemach radius with impinging muons, to contribute to the solution to the so-called proton radius puzzle. Signals to be detected are characteristic X-rays around 130 KeV. A limit for this type of detector, as compared to the ones with a photomultiplier readout, is its poorer timing characteristics due to the large capacity of the SiPM arrays used. In particular, long signal falltimes are a problem in experiments such as FAMU, where a prompt background component must be separated from a delayed one (after 600 ns) in the signal X-rays to be detected. Dedicated studies were pursued to improve the timing characteristics of the used detectors, starting from hybrid ganging of SiPM cells; then developing a suitable zero pole circuit with a parallel ganging, where an increased overvoltage for the SiPM array was used to compensate for the signal decrease; and finally designing ad hoc electronics to split the 1 inch detector SiPM array into four quadrants, thus reducing the involved capacitances. The aim was to improve the detectors timing characteristics, especially falltime, while keeping a good FWHM energy resolution for low-energy X-ray detection

    Protein kinase C and cancer: what we know and what we do not

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    Since their discovery in the late 1970s, protein kinase C (PKC) isozymes represent one of the most extensively studied signaling kinases. PKCs signal through multiple pathways and control the expression of genes relevant for cell cycle progression, tumorigenesis and metastatic dissemination. Despite the vast amount of information concerning the mechanisms that control PKC activation and function in cellular models, the relevance of individual PKC isozymes in the progression of human cancer is still a matter of controversy. Although the expression of PKC isozymes is altered in multiple cancer types, the causal relationship between such changes and the initiation and progression of the disease remains poorly defined. Animal models developed in the last years helped to better understand the involvement of individual PKCs in various cancer types and in the context of specific oncogenic alterations. Unraveling the enormous complexity in the mechanisms by which PKC isozymes have an impact on tumorigenesis and metastasis is key for reassessing their potential as pharmacological targets for cancer treatment.Centro de Investigaciones Inmunológicas Básicas y Aplicada

    On the Extension of the Eddy Viscosity Model to Compressible Flows

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    In the paper the authors examine the extension of the eddy viscosity modeling approach to compressible large eddy simulation. On the basis of formal algebraic relations among the generalized central moments and the filtered Favre terms, a new compressible eddy viscosity formulation is derived

    PROJECTION OF CRITERIA AIR POLLUTANTS EMISSION FROM ON-ROAD VEHICLES IN THE MEGACITY OF LAGOS, NIGERIA

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    The increase in the mode of transportation has become a serious environmental threat that has resulted in the emission of criteria air pollutants (CAPs) into the atmosphere. These CAPs are sulphur oxides (SOx), particulate matter (PM), lead (Pb), carbon monoxide (CO), and nitrogen oxides (NOx). This study examined the emission of CAPs from road traffic use in Lagos State. Data for the inventories of the production of these five sources were taken from 1997–2011 and were used to forecast CAPs emissions from 2012–2030. The petroleum products consumption data were sourced from the Nigerian National Petroleum Corporation (NNPC). Five categories of CAPs were studied and their corresponding emissions from 1997–2011 were computed as follows: SOx: 209–15,358t, NOx: 2,038–25,692t, CO: 24,996–186,202t, PM: 155–995t, Pb: 0.8 4.5t. Projection and forecasting of CAPs emissions from 2012 to 2030 were carried out using the Box Jenkins ARIMA method. There were close similarities between the observed and forecast values. The predicted CAPs emissions between 2012 to 2030 will be 309t for SOx, 22,600 – 41,300t for NOx, 100,000 – 300,000t for CO, 414t for PM, and 0.7t for Pb. The study concluded that there is tendency for these CAPs emissions to increase if the authorities and stakeholders do nothing. Several mitigation measures aimed towards reducing future CAPs emissions in Lagos State were recommended for the various sources

    The cancer gene WWOX behaves as an inhibitor of SMAD3 transcriptional activity via direct binding

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    Background: The WW domain containing protein WWOX has been postulated to behave as a tumor suppressor in breast and other cancers. Expression of this protein is lost in over 70% of ER negative tumors. This prompted us to investigate the phenotypic and gene expression effects of loss of WWOX expression in breast cells. Methods: Gene expression microarrays and standard in vitro assays were performed on stably silenced WWOX (shRNA) normal breast cells. Bioinformatic analyses were used to identify gene networks and transcriptional regulators affected by WWOX silencing. Co-immunoprecipitations and GST-pulldowns were used to demonstrate a direct interaction between WWOX and SMAD3. Reporter assays, ChIP, confocal microscopy and in silico analyses were employed to determine the effect of WWOX silencing on TGFβ-signaling. Results: WWOX silencing affected cell proliferation, motility, attachment and deregulated expression of genes involved in cell cycle, motility and DNA damage. Interestingly, we detected an enrichment of targets activated by the SMAD3 transcription factor, including significant upregulation of ANGPTL4, FST, PTHLH and SERPINE1 transcripts. Importantly, we demonstrate that the WWOX protein physically interacts with SMAD3 via WW domain 1. Furthermore, WWOX expression dramatically decreases SMAD3 occupancy at the ANGPTL4 and SERPINE1 promoters and significantly quenches activation of a TGFβ responsive reporter. Additionally, WWOX expression leads to redistribution of SMAD3 from the nuclear to the cytoplasmic compartment. Since the TGFβ target ANGPTL4 plays a key role in lung metastasis development, we performed a meta-analysis of ANGPTL4 expression relative to WWOX in microarray datasets from breast carcinomas. We observed a significant inverse correlation between WWOX and ANGPTL4. Furthermore, the WWOXlo/ANGPTL4hi cluster of breast tumors is enriched in triple-negative and basal-like sub-types. Tumors with this gene expression signature could represent candidates for anti-TGFβ targeted therapies. Conclusions: We show for the first time that WWOX modulates SMAD3 signaling in breast cells via direct WW-domain mediated binding and potential cytoplasmic sequestration of SMAD3 protein. Since loss of WWOX expression increases with breast cancer progression and it behaves as an inhibitor of SMAD3 transcriptional activity these observations may help explain, at least in part, the paradoxical pro-tumorigenic effects of TGFβ signaling in advanced breast cancer.Fil: Ferguson, Brent W.. University of Texas; Estados UnidosFil: Gao, Xinsheng. University of Texas; Estados UnidosFil: Zelazowski, Maciej J.. University of Texas; Estados UnidosFil: Lee, Jaeho. University of Texas; Estados UnidosFil: Jeter, Collene R.. University of Texas; Estados UnidosFil: Abba, Martín Carlos. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Inmunológicas Básicas y Aplicadas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Aldaz, Claudio Marcelo. University of Texas; Estados Unido
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