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Influence of the dopaminergic system, CREB, and transcription factor-κB on cocaine neurotoxicity

Planeta, Cleopatra da Silva; Lepsch, L. B.; Alves, R.; Scavone, Cristoforo
Fonte: Associação Brasileira de Divulgação Científica; São Paulo Publicador: Associação Brasileira de Divulgação Científica; São Paulo
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
55.37%
Cocaine is a widely used drug and its abuse is associated with physical, psychiatric and social problems. Abnormalities in newborns have been demonstrated to be due to the toxic effects of cocaine during fetal development. The mechanism by which cocaine causes neurological damage is complex and involves interactions of the drug with several neurotransmitter systems, such as the increase of extracellular levels of dopamine and free radicals, and modulation of transcription factors. The aim of this review was to evaluate the importance of the dopaminergic system and the participation of inflammatory signaling in cocaine neurotoxicity. Our study showed that cocaine activates the transcription factors NF-κB and CREB, which regulate genes involved in cellular death. GBR 12909 (an inhibitor of dopamine reuptake), lidocaine (a local anesthetic), and dopamine did not activate NF-κB in the same way as cocaine. However, the attenuation of NF-κB activity after the pretreatment of the cells with SCH 23390, a D1 receptor antagonist, suggests that the activation of NF-κB by cocaine is, at least partially, due to activation of D1 receptors. NF-κB seems to have a protective role in these cells because its inhibition increased cellular death caused by cocaine. The increase in BDNF (brain-derived neurotrophic factor) mRNA can also be related to the protective role of both CREB and NF-κB transcription factors. An understanding of the mechanisms by which cocaine induces cell death in the brain will contribute to the development of new therapies for drug abusers...

Effects of inhibition gastric acid secretion on arterial acid-base status during digestion in the toad Bufo marinus

Andersen, J. B.; Andrade, D. V.; Wang, T.
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 425-433
ENG
Relevância na Pesquisa
55.33%
Digestion affects acid-base status, because the net transfer of HCl from the blood to the stomach lumen leads to an increase in HCO3- levels in both extra- and intracellular compartments. The increase in plasma [HCO3-], the alkaline tide, is particularly pronounced in amphibians and reptiles, but is not associated with an increased arterial pH, because of a concomitant rise in arterial Pco(2) caused by a relative hypoventilation. In this study, we investigate whether the postprandial increase in Paco(2) of the toad Bufo marinus represents a compensatory response to the increased plasma [HCO3-] or a state-dependent change in the control of pulmonary ventilation. To this end, we successfully prevented the alkaline tide, by inhibiting gastric acid secretion with omeprazole, and compared the response to that of untreated toads determined in our laboratory during the same period. In addition, we used vascular infusions of bicarbonate to mimic the alkaline tide in fasting animals. Omeprazole did not affect blood gases, acid-base and haematological parameters in fasting toads, but abolished the postprandial increase in plasma [HCO3-] and the rise in arterial Pco(2) that normally peaks 48 h into the digestive period. Vascular infusion of HCO3-...

In vitro effects of calcium hydroxide and polymyxin B on endotoxins in root canals

Oliveira, L. D.; Leao, MVP; Carvalho, CAT; Camargo, CHR; Valera, M. C.; Jorge, AOC; Unterkircher, C. S.
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 107-114
ENG
Relevância na Pesquisa
55.39%
Objectives. To evaluate the effects of intracanal medicaments on endotoxins in root canals.Methods. Seventy-five freshly extracted maxillary incisors were used in this study. The crowns of teeth were sectioned near the CEJ in order to standardize the root length to 14 mm. The root canals were instrumented to an apical size #50 file and irrigated with 1% sodium hypochlorite solution and sterilized with 60 Co gamma irradiation. Standardized suspension containing Escherichia coli endotoxin was inoculated into the 60 root canals. The specimens were randomly assigned to 5 groups (n=15), according to the intracanal medicament used: (G1) calcium hydroxide; (G2) polymyxin B; (0) combination neomycin-potymyxin B-hydrocortisone; (G4) positive control (no intracanal medicament); (G5) negative control (no endotoxin and no intracanal medicament). After 7 days, the detoxification of endotoxin was evaluated by Limulus lysate assay and antibody production in B-tymphocytes culture.Results. Groups 1, 2 and 5 presented the best results by Limulus lysate and were significantly different to groups 3 and 4 (p<0.05). Stimulation of antibodies production in cell culture by groups 1 and 6 was smaller and statistically different than groups 2, 3, 4 and 5 (p<0.05). Groups 2 and 5 induced a small increase in the antibodies production in relation to the groups 1 and 6. Groups 3 and 4 induced a significant increase of antibodies production (p<0.05).Conclusions. The calcium hydroxide and polymyxin B intracanal medicaments detoxified endotoxin in root canals and altered the properties of LPS to stimulate the antibody production by B-Lymphocytes. The combination neomycin-polymyxin B-hydrocortisone did not detoxified endotoxin. (C) 2004 Elsevier Ltd. All rights reserved.

New physics in B-s(0) -> J/psi phi decays?

El-Bennich, B.; de Melo, J. P. B. C.; Leitner, O.; Loiseau, B.; Dedonder, J-P
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 395-400
ENG
Relevância na Pesquisa
55.38%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Processo FAPESP: 09/53351-0; Processo FAPESP: 09/51296-1; Processo FAPESP: 10/05772-3; After a brief review of B-s(0)-(B) over bar (0)(s) oscillations, we discuss the weak decays B-s(0) -> J/psi phi and B-s(0) -> J/psi f(0)(980) and the ratio R-f0/phi of their decay rates in the light of recent measurements by the LHCb, D(sic) and CDF Collaborations. We point out that the experimental values for R-f0/phi, impose tight limits on new physics contributions to both decay channels. (C) 2012 Elsevier B.V. All rights reserved.

b-Jet identification in the D0 experiment

Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T.; Aguilo, E.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Alves, G. A.; Anastasoaie, M.; Ancu, L. S.; Aoki, M.; Arnoud, Y.; Arov, M.; Askew, A.; Asman, B.; Atramentov,
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 490-517
ENG
Relevância na Pesquisa
55.38%
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Algorithms distinguishing jets originating from b quarks from other jet flavors are important tools in the physics program of the D0 experiment at the Fermilab Tevatron p (p) over bar collider. This article describes the methods that have been used to identify b-quark jets, exploiting in particular the long lifetimes of b-flavored hadrons, and the calibration of the performance of these algorithms based on collider data. (C) 2010 Elsevier B.V. All rights reserved.

Search for the rare decay B-s(0) -> mu(+)mu(-)

Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Alves, G. A.; Ancu, L. S.; Aoki, M.; Arnoud, Y.; Arov, M.; Askew, A.; Asman, B.; Atramentov, O.; Avila, C.; BackusMayes, J
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 539-544
ENG
Relevância na Pesquisa
55.38%
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); We present the results of a search for the flavor changing neutral current decay B-s(0) -> mu(+)mu(-) using 6.1 fb(-1) of p (p) over bar collisions at root s = 1.96 TeV collected by the D0 experiment at the Fermilab Tevatron Collider. The observed number of B-s(0) candidates is consistent with background expectations. The resulting upper limit on the branching fraction is B(B-s(0) -> mu(+)mu(-)) < 5.1 x 10(-8) at the 95% C.L. This limit is a factor of 2.4 better than that of the previous do analysis and the best limit to date. Published by Elsevier B.V.

Effects of apolipoprotein B-100 on the metabolism of a lipid microemulsion model in rats

Hirata, RDC; Hirata, M. H.; Mesquita, C. H.; Cesar, T. B.; Maranhao, R. C.
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 53-62
ENG
Relevância na Pesquisa
55.4%
In previous studies, it was shown that lipid microemulsions resembling LDL (LDE) but not containing protein, acquire apolipoprotein E when injected into the bloodstream and bind to LDL receptors (LDLR) using this protein as ligand. Aiming to evaluate the effects of apolipoprotein (apo) B-100 on the catabolism of these microemulsions, LDE with incorporated apo B-100 (LDE-apoB) and native LDL, all labeled with radioactive lipids were studied after intraarterial injection into Wistar rats. Plasma decay curves of the labels were determined in samples collected over 10 h and tissue uptake was assayed from organs excised from the animals sacrificed 24 h after injection. LDE-apo B had a fractional clearance rate (FCR) similar to native LDL (0.40 and 0.33, respectively) but both had FCR pronouncedly smaller than LDE (0.56, P<0.01). Liver was the main uptake site for LDE, LDE-apoB, and native LDL, but LDE-apoB and native LDL had lower hepatic uptake rates than LDE. Pre-treatment of the rats with 17 alpha-ethinylestradiol, known to upregulate LDLR, accelerated the removal from plasma of both LDE and LDE-apoB, but the effect was greater upon LDE than LDE-apoB. These differences in metabolic behavior documented in vivo can be interpreted by the lower affinity of LDLR for apo B-100 than for apo E...

Swimming training exacerbates pathological cardiac hypertrophy in kinin B(2) receptor-deficient mice

Batista, Elice C.; Batista, Eliza C.; Ramalho, Joao D. S.; Reis, Felipe C. G.; Barros, Carlos C.; Moraes, Milton R.; Pesquero, Jorge L.; Bacurau, Reury F. P.; Pesquero, Joao B.; Araujo, Ronaldo C.
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 271-275
ENG
Relevância na Pesquisa
55.38%
Kallikrein-kinin system exerts cardioprotective effects against pathological hypertrophy. These effects are modulated mainly via B(2) receptor activation. Chronic physical exercise can induce physiological cardiac hypertrophy characterized by normal organization of cardiac structure. Therefore, the aim of this work was to verify the influence of kinin B(2) receptor deletion on physiological hypertrophy to exercise stimulus. Animals were submitted to swimming practice for 5 min or for 60 min, 5 days a week, during 1 month and several cardiac parameters were evaluated. Results showed no significantly difference in heart weight between both groups, however an increased left ventricle weight and myocyte diameter were observed after the 60 min swimming protocol, which was more pronounced in B(2)(-/-) mice. In addition, sedentary B(2)(-/-) animals presented higher left ventricle mass when compared to wild-type (WT) mice. An increase in capillary density was observed in exercised animals, however the effect was less pronounced in B(2)(-/-) mice. Collagen, a marker of pathological hypertrophy, was increased in B(2)(-/-) mice submitted to swimming protocol, as well as left ventricular thickness, suggesting that these animals do not respond with physiological hypertrophy for this kind of exercise. In conclusion...

Influence of the dopaminergic system, CREB, and transcription factor-B on cocaine neurotoxicity

Planeta, Cleopatra da Silva; Lepsch, L.b.; Alves, R.; Scavone, C.
Fonte: Associação Brasileira de Divulgação Científica (ABRADIC) Publicador: Associação Brasileira de Divulgação Científica (ABRADIC)
Tipo: Artigo de Revista Científica Formato: 909-915
ENG
Relevância na Pesquisa
55.37%
Cocaine is a widely used drug and its abuse is associated with physical, psychiatric and social problems. Abnormalities in newborns have been demonstrated to be due to the toxic effects of cocaine during fetal development. The mechanism by which cocaine causes neurological damage is complex and involves interactions of the drug with several neurotransmitter systems, such as the increase of extracellular levels of dopamine and free radicals, and modulation of transcription factors. The aim of this review was to evaluate the importance of the dopaminergic system and the participation of inflammatory signaling in cocaine neurotoxicity. Our study showed that cocaine activates the transcription factors NF-κB and CREB, which regulate genes involved in cellular death. GBR 12909 (an inhibitor of dopamine reuptake), lidocaine (a local anesthetic), and dopamine did not activate NF-κB in the same way as cocaine. However, the attenuation of NF-κB activity after the pretreatment of the cells with SCH 23390, a D1 receptor antagonist, suggests that the activation of NF-κB by cocaine is, at least partially, due to activation of D1 receptors. NF-κB seems to have a protective role in these cells because its inhibition increased cellular death caused by cocaine. The increase in BDNF (brain-derived neurotrophic factor) mRNA can also be related to the protective role of both CREB and NF-κB transcription factors. An understanding of the mechanisms by which cocaine induces cell death in the brain will contribute to the development of new therapies for drug abusers...

Acceso a la información y la producción de conocimiento científico: la b-on y un análisis bibliométrico

Costa, Teresa; Vaz, Francisco
Fonte: ICE. Universidad de Oviedo Publicador: ICE. Universidad de Oviedo
Tipo: Artigo de Revista Científica
SPA
Relevância na Pesquisa
65.37%
En los últimos años han sido desarrolladas iniciativas para promover el acceso universal a la Sociedad de la Información y del Conocimiento. Es, en esta dinámica que surge en el año 2004 en Portugal, la Biblioteca de Conocimientos en Línea (b-on). Con ésta resultó más fácil el acceso al contenido de texto completo en una amplia gama de publicaciones científicas internacionales. Este estudio es parte de un proyecto de investigación doctoral y tiene como objetivo presentar y analizar algunos de los principales indicadores estadísticos/bibliométricos de la Producción Científica Portuguesa buscando asociarlos con la b-on. Se analizó desde 2007 hasta 2011, el uso de los recursos por las universidades miembros del consorcio, habiendo sido seleccionadas como muestra las cinco con más descargas por FTE (full time equivalent). Además de los datos de uso del consorcio, se utilizó la Web of Science en la cual se identificó a los artículos indexados con afiliación institucional en las universidades portuguesas. A partir de éstos, se identificó a los autores con mayor número de artículos indexados. Posteriormente, se analizaron otros datos como: producción científica por área científica, cooperación internacional...

The impact of the Online Knowledge Library: its use and impact on the production of the Portuguese academic and scientific community (2000-2010)

Costa, Teresa; Vaz, Francisco; Lopes, Carlos
Fonte: 5th Qualitative and Quantitative Methods in Libraries International Conference Publicador: 5th Qualitative and Quantitative Methods in Libraries International Conference
Tipo: Aula
ENG
Relevância na Pesquisa
55.38%
In recent years several initiatives have taken place to promote universal access to the Information and Knowledge Society. It was in this context that in 2004 the Online Knowledge Library (b-on) was launched in Portugal. With it, it became easier to get access to full text international scientific publications. This study aims to present and analyse some of the statistical and bibliometric indicators of the Portuguese scientific output seeking to evaluate its link it with b-on. It was analysed the usage of b-on resources by the public universities members of the consortium from 2004 to 2010, and we chose as sample the five universities with more downloads per FTE (full time equivalent).In addition to the usage data of the consortium, we used the Web of Science (WoS) from which we identified the articles indexed by the five Portuguese universities affiliated between 2000-2010.Thus, and through a quantitative methodology, we identified the scientific production per subject area, international cooperation and scientific journals with the highest number of published articles, among others. We conclude that the availability and access to electronic resources contributes to the increased of the scientific productivity of the universities and that the study and analysis of its use and output are essential.

Acceso a la información y la producción de conocimiento científico: la b-on y un análisis bibliométrico

Costa, Teresa; Amante, Mª João; Vaz, Francisco
Fonte: Universidad de Oviedo: Instituto de Ciencias de la Educación Publicador: Universidad de Oviedo: Instituto de Ciencias de la Educación
Tipo: Artigo de Revista Científica
Publicado em //2012 SPA
Relevância na Pesquisa
65.37%
En los últimos años han sido desarrolladas iniciativas para promover el acceso universal a la Sociedadde la Información y del conocimiento. Es, en esta dinámica que surge en el año 2004 en Portugal, la Biblioteca de Conocimientos en Línea (b-on). Con ésta resultó más fácil el acceso al contenido de texto completo en una amplia gama de publicaciones científicas internacionales. Este estudio es parte de un proyecto de investigación doctoral y tiene como objetivo presentar y analizar algunos de los rincipales indicadores estadísticos /bibliométricos de la Producción Científica Portuguesa buscando asociarlos con la b-on. Se analizó desde 2007 hasta 2011, el uso de los recursos por las universidades miembros del consorcio, habiendo sido seleccionadas como muestra las cinco con más descargas por FTE (full time equivalent). Además de los datos de uso del consorcio, se utilizó la Web of Science en la cual se identificó a los artículos indexados con afiliación institucional en las universidades portuguesas. A partir de éstos, se identificó a los autores con mayor número de artículos indexados. Posteriormente, se analizaron otros datos como: producción científica por área científica, cooperación internacional...

Influence of the dopaminergic system, CREB, and transcription factor-B on cocaine neurotoxicity

Planeta,C.S.; Lepsch,L.B.; Alves,R.; Scavone,C.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2013 EN
Relevância na Pesquisa
55.37%
Cocaine is a widely used drug and its abuse is associated with physical, psychiatric and social problems. Abnormalities in newborns have been demonstrated to be due to the toxic effects of cocaine during fetal development. The mechanism by which cocaine causes neurological damage is complex and involves interactions of the drug with several neurotransmitter systems, such as the increase of extracellular levels of dopamine and free radicals, and modulation of transcription factors. The aim of this review was to evaluate the importance of the dopaminergic system and the participation of inflammatory signaling in cocaine neurotoxicity. Our study showed that cocaine activates the transcription factors NF-κB and CREB, which regulate genes involved in cellular death. GBR 12909 (an inhibitor of dopamine reuptake), lidocaine (a local anesthetic), and dopamine did not activate NF-κB in the same way as cocaine. However, the attenuation of NF-κB activity after the pretreatment of the cells with SCH 23390, a D1 receptor antagonist, suggests that the activation of NF-κB by cocaine is, at least partially, due to activation of D1 receptors. NF-κB seems to have a protective role in these cells because its inhibition increased cellular death caused by cocaine. The increase in BDNF (brain-derived neurotrophic factor) mRNA can also be related to the protective role of both CREB and NF-κB transcription factors. An understanding of the mechanisms by which cocaine induces cell death in the brain will contribute to the development of new therapies for drug abusers...

Biochemical studies on the effect of Clostridium difficile toxin B on actin in vivo and in vitro.

Mitchell, M J; Laughon, B E; Lin, S
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /07/1987 EN
Relevância na Pesquisa
55.42%
We describe a simplified procedure for purification of Clostridium difficile toxin B. In this procedure, cytotoxicity is associated with a single protein band with a molecular mass of 230 kilodaltons. We used direct fluorescent staining of actin filaments to study the effect of this toxin on cultured cells. Morphologic changes were preceded by a decrease in the number and length of stress fibers followed by their disappearance with condensation of cellular actin around the nucleus. We then showed that cells treated with either cytochalasin B or toxin B had a significant increase in the monomeric actin pool as quantitated by DNase I inhibition. In contrast to the cytochalasins, toxin B had no direct effect on the rate or extent of actin polymerization or network formation in vitro. Cytoplasmic extracts of toxin B-treated cells had a significantly lower level of modulating activity on actin assembly and interactions in vitro compared with extracts of untreated cells. These results suggest that the action of toxin B on cells is due to direct or indirect effects on cellular proteins involved in controlling the state of actin assembly in the cells.

Calmodulin protects Aurora B on the midbody to regulate the fidelity of cytokinesis

Mallampalli, Rama K.; Glasser, Jennifer R.; Coon, Tiffany A.; Chen, Bill B.
Fonte: Landes Bioscience Publicador: Landes Bioscience
Tipo: Artigo de Revista Científica
Publicado em 15/02/2013 EN
Relevância na Pesquisa
55.4%
Aurora B kinase is an integral regulator of cytokinesis as it stabilizes the intercellular canal within the midbody to ensure proper chromosomal segregation during cell division. Here we identified an E3 ligase subunit, F box protein FBXL2, that by recognizing a calmodulin binding signature within Aurora B, ubiquitinates and removes the kinase from the midbody. Calmodulin, by competing with the F box protein for access to the calmodulin binding signature, protected Aurora B from FBXL2. Calmodulin co-localized with Aurora B on the midbody, preserved Aurora B levels in cells, and stabilized intercellular canals during delayed abscission. Genetic or pharmaceutical depletion of endogenous calmodulin significantly reduced Aurora B protein levels at the midbody resulting in tetraploidy and multi-spindle formation. The calmodulin inhibitor, calmidazolium, reduced Aurora B protein levels resulting in tetraploidy, mitotic arrest, and apoptosis of tumorigenic cells and profoundly inhibiting tumor formation in athymic nude mice. These observations indicate molecular interplay between Aurora B and calmodulin in telophase and suggest that calmodulin acts as a checkpoint sensor for chromosomal segregation errors during mitosis.

O impacto da biblioteca do conhecimento online (B-on) sobre a utilização e a produção científica portuguesas (2000-2010)

Costa, Teresa
Fonte: Universidade de Évora Publicador: Universidade de Évora
Tipo: Tese de Doutorado
POR
Relevância na Pesquisa
65.46%
Nos últimos anos, têm sido várias as iniciativas realizadas para promover o acesso universal à Sociedade da Informação e do Conhecimento. Foi neste contexto que, em 2004, a Biblioteca do Conhecimento Online (b-on) foi lançada em Portugal celebrando este ano o seu 10 º aniversário. Com a b-on, tornou-se mais fácil ter acesso ao texto integral de publicações científicas internacionais. Este estudo tem como objetivo apresentar e analisar alguns dos indicadores estatísticos e bibliométricos da produção científica portuguesa relacionando- -os com a b-on. Procurámos conhecer o impacto da b-on quer ao nível da utilização quer ao nível da produção científica. Para tal analisámos o uso dos recursos eletrónicos disponibilizados pela b-on por parte das universidades públicas membros do consórcio, entre 2004 e 2010, tendo escolhido como amostra as cinco universidades com maior número de downloads por FTE (full time equivalent). Analisámos a evolução do número de downloads, os fornecedores de conteúdos mais utilizados, os títulos com maior utilização. Para além dos dados de utilização do consórcio, utilizámos a Web of Science (WoS) a partir da qual identificámos os artigos indexados com afiliação Portuguesa e nas cinco universidades que constituem a nossa amostra entre 2000-2010. Posteriormente...

Dez anos de b-on segundo os investigadores portugueses: impacto e consequências

Costa, Teresa; CIDEHUS - Centro Interdisciplinar de História, Culturas e Sociedades da Universidade de Évora e FCT|FCCN – Fundação para a Ciência e Tecnologia, Unidade de Computação Científica Nacional
Fonte: Actas do Congresso Nacional de Bibliotecários, Arquivistas e Documentalistas Publicador: Actas do Congresso Nacional de Bibliotecários, Arquivistas e Documentalistas
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; article Formato: application/pdf
Publicado em 16/07/2015 POR
Relevância na Pesquisa
65.46%
ResumoÉ sabido que com a difusão e propagação do uso dos recursos científicos eletrónicos as práticas de consulta e de leitura dos investigadores mudaram, não só ao nível do tempo que dedicam à pesquisa, mas sobretudo pela quantidade e variedade de conteúdos que consultam muito mais facilmente e rapidamente. Com o surgimento da b-on em abril de 2004 a quantidade e a qualidade dos conteúdos disponíveis aos investigadores aumentaram significativamente.Quisemos, então, perceber se este aumento gradual no acesso a conteúdos científicos teve impacto nas suas rotinas e práticas profissionais, bem como ao nível da sua produção científica.Assim, entre Dezembro de 2013 e Fevereiro de 2014 aplicámos um inquérito online a 500 investigadores de modo a aferir qual o uso que faziam dos recursos disponibilizados pela b-on e em que medida é que esta Biblioteca lhes trouxe mudanças à sua prática profissional. IntroduçãoTendo a b-on completado 10 anos de existência em 2014, era altura de conhecer a opinião dos investigadores nacionais, de modo a perceber não só se usavam a b-on, mas o que é que esta trouxe de novo às suas rotinas e práticas de investigação, não só ao nível do acesso, mas também em termos da sua produção científica. Como refere Deng (2010) para melhorar os serviços e apoio aos utilizadores é fundamental compreender e conhecer as suas expectativas...

A b-on e a preservação digital de periódicos eletrónicos: o projeto Portico

Costa, Teresa; Moreira, João; FCT|FCCN
Fonte: Actas do Congresso Nacional de Bibliotecários, Arquivistas e Documentalistas Publicador: Actas do Congresso Nacional de Bibliotecários, Arquivistas e Documentalistas
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; article Formato: application/pdf
Publicado em 16/07/2015 POR
Relevância na Pesquisa
65.43%
ResumoO número de periódicos científicos em formato digital tem vindo a aumentar significativamente na última década. Existem cada vez mais conteúdos a transitar para o digital ou até mesmo a nascer em formato digital, não tendo, por isso, uma cópia “física”. No mundo do papel, a responsabilidade da preservação estava vinculada ao proprietário e era tradicionalmente uma função das bibliotecas e dos arquivos. Na era digital, o vínculo entre o proprietário, a preservação e o acesso foi alterado. A escala e a complexidade da infraestrutura tecnológica exigida, os conhecimentos especializados e os processos de controlo de qualidade necessários à preservação de recursos eletrónicos são extremamente exigentes e dispendiosos.Tendo a b-on recursos exclusivamente eletrónicos esta é uma questão fundamental, pelo que foram analisadas várias soluções tendo a escolha recaído sobre o Portico.IntroduçãoOs periódicos científicos têm desempenhado um papel fundamental no sistema de comunicação científica. Com a migração do impresso para o ambiente digital, a comunicação científica deixou de ser possível sem o acesso a informação do passado, pelo que a preservação dos periódicos científicos eletrónicos se tornou numa das principais preocupações dos bibliotecários.Muitos dos stakeholders da publicação científica perceberam a importância e urgência de tomarem medidas que garantissem a preservação e o acesso a este tipo de conteúdo de forma eficaz.Sendo a b-on e-only tem naturalmente como preocupação a manutenção do acesso aos conteúdos subscritos por parte de todas as suas instituições...

O impacto da Biblioteca do Conhecimento Online (b-on) no acesso à informação e produção científica nacional : Resultados de um inquérito

Costa, Teresa; Lopes, Carlos Alberto; Vaz, Francisco
Fonte: Universidad Complutense Publicador: Universidad Complutense
Tipo: Conferência ou Objeto de Conferência
Publicado em //2015 POR
Relevância na Pesquisa
65.4%
O surgimento das novas tecnologias e da Internet contribuiu para o surgimento na Europa de consórcios e redes de bibliotecas académicas. Os profissionais destas bibliotecas perceberam a necessidade de trabalharem em cooperação, de uma forma estruturada, através da criação de infraestruturas que permitissem a cooperação e a partilha de recursos. É, pois, neste contexto que surgiu, a Biblioteca do Conhecimento Online, b-on, que permite, desde 2004, o acesso a milhares de publicações eletrónicas de editoras de referência internacional nas principais áreas de investigação científica e académica e que constitui um instrumento essencial de acesso e disseminação da informação científica. É sabido que com a difusão e propagação do uso dos recursos científicos eletrónicos as práticas de consulta e de leitura dos investigadores mudaram, não só ao nível do tempo que dedicam à pesquisa, mas sobretudo pela quantidade e variedade de conteúdos que consultam muito mais facilmente e rapidamente. Quisemos perceber se este aumento gradual no acesso a conteúdos científicos estava a ter algum impacto ao nível da produção científica nacional. Assim, entre Dezembro de 2013 e Fevereiro de 2014 aplicámos um inquérito online a 500 investigadores de modo a aferir qual o uso que faziam dos recursos disponibilizados pela b-on e em que medida é que esta Biblioteca lhes trouxe mudanças à sua prática profissional.; ABSTRACT: The emergence of new technologies and Internet has contributed to the appearance in Europe of consortia and academic libraries networks. The professionals of these libraries have realised the need to work in collaboration...

B-on’s evolution and its contribution to the development of Portuguese science

Costa, Teresa; Vaz, Francisco; Lopes, Carlos
Fonte: ACM Publicador: ACM
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
55.38%
In recent years several initiatives have taken place to promote universal access to the Information and Knowledge Society. It was in this context that in 2004 the Online Knowledge Library (b-on) was launched in Portugal. With it, it became easier to get access to full text international scientific publications. This study aims to present and analyze some bibliometric indicators of the Portuguese scientific output seeking to evaluate its link it with b-on. It was analyzed the usage of b-on resources by the public universities members of the consortium from 2004 to 2010, and we chose as sample the five universities with more downloads per FTE (full time equivalent).In addition to the usage data of the consortium, we used the Web of Science (WoS) and Scopus from which we identified the articles indexed with Portuguese affiliation and by the five Portuguese universities between 2000-2010. In WoS we found 79.192 articles indexed with at least one Portuguese author, published in the years under analysis, 40.413 have affiliation at least in one of the five universities considered in this study (51%). In Scopus the number of articles is similar, 62.634 articles for Portugal from which 33.417 have affiliation in at least one of the five universities (54%).We identified the research areas with the largest number of articles. The national scientific production concerning the scientific areas is relatively diverse in accordance with both databases: Chemistry...