1,567 research outputs found
Histamine modulates dopaminergic neuronal survival by boosting microglial activity
As células microgliais são os principais intervenientes na resposta inflamatória inata no cérebro adulto. Num contexto de lesão cerebral, a resposta das células da microglia envolve mecanismos de fagocitose de neurónios mortos ou danificados, libertação de fatores tróficos e/ou inflamatórios, e a produção de espécies reativas de oxigénio (ROS).
A histamina é uma amina encontrada em grandes quantidades em mastócitos, neurónios histaminérgicos, e leucócitos. No Sistema Nervoso Central (SNC), a histamina também é libertada por células da microglia e exerce as suas funções através da ativação de quatro subtipos de recetores acoplados a proteínas G: H1, H2, H3 e H4. Previamente, mostramos que a histamina modula a motilidade microglial e a libertação de citocinas. Os principais objetivos deste trabalho foram: i) avaliar o papel da histamina na atividade fagocítica microglial e na produção de ROS; e ii) explorar as consequências da inflamação microglial induzida pela histamina na sobrevivência neuronal dopaminérgica.
Inicialmente, verificamos que a histamina, através da ativação do recetor H1R, induziu um aumento de fagocitose na linha celular N9 de microglia, quando comparada com a condição controlo. Este efeito foi acompanhado por um rearranjo do citoesqueleto microglial monitorizado através da imunomarcação para a faloidina e a tubulina acetilada. A histamina também induziu um aumento da produção de ROS através da ativação dos recetores H1R e do H4R. A apocinina, um inibidor do NADPH oxidase, foi capaz de inibir totalmente a fagocitose e a produção de ROS mediada pela histamina. A incubação com lipopolissacarídeo (LPS), utilizado como controlo positivo, também induziu um aumento significativo de fagocitose e produção de ROS, quando comparado com culturas controlo.
Por outro lado, a injeção estereotáxica de histamina ou LPS na substancia nigra de murganhos adultos da estirpe C57BL/6 durante 7 dias, induziu um aumento da reatividade glial e uma diminuição robusta na sobrevivência neuronal dopaminérgica. Tanto a apocinina como a anexina V (usada como inibidor de fagocitose induzida pela fosfatidilserina) inibiram completamente a toxicidade dos neurónios dopaminérgicos induzida pela histamina.
Surpreendentemente, valores semelhantes à condição controlo, nos parâmetros avaliados invitro (fagocitose e produção de ROS) e in vivo (sobrevivência neuronal dopaminérgica), foram encontrados quando se procedeu à co-administração de histamina e LPS.
Em geral, os nossos resultados sugerem que a histamina induz a reatividade da microglia e que este efeito pode modular a sobrevivência neuronal dopaminérgica. Histamina per se atua principalmente como um agente pro-inflamatório induzindo neurotoxicidade. Contudo, na presença de LPS, a histamina pode exercer atividade anti-inflamatória e neuroprotetora
The COVID - 19 pandemic’s impact on the behavioural trends in the use of printed book or e-book a case study in Portugal and Brazil
Abstract:In a time of serious health crisis worldwide, this study is the extension of a case study already started (in February and March 2020) about the issue, reading behaviors, and preferences between the use of books and e-books. The COVID-19 pandemic came to impose social distancing in the world, closing universities, schools, and other services. The implementation of Internet services has presented itself as a valid response to the change that has so brutally arisen. Naturally, everyone had to adapt to it. In this context, the question about the preferences in using books or e-books is now even more relevant. This paper analyses the impact of COVID-19 in the behavioral trends in the use of scientific information from printed books and e-books in Portugal and Brazil. To this end, a survey was conducted on a user sample from various Portuguese and Brazilian higher education schools and public libraries. The first part focused on the characterization of the respondents, which includes data on gender and qualifications attended. In the second part, we obtained viewpoints about the advantages and disadvantages of each medium, frequency of use, choice of medium according to the purpose of reading, and devices used. The results let us examine the factors that influence and change the behaviors of users concerning their choice. Research such as this is beneficial to support the decision not only in selecting the information resources to be bought or pondering user preferences, but also to define strategies for advocating the use of various media that, rather than competitors, should be complimentary.This work is funded by national funds through the Foundation for Science and Technology, under the project UIDB/00057/2020
Challenged by academic social networks: a case study inside University of Lisbon’ institutional repository
This communication reflects on the challenges brought by academic social networks to institutional repositories. The study reveals the practices of academics from the Faculties of Dental Medicine, Psychology and the Institute of Education on the issue of the visibility of scientific information in academic social networks and in institutional repositories. The data were obtained by analysing the profiles of professors and researchers in a professional social network, ResearchGate, crossed with the documents of the Institutional Repository of the University of Lisbon (Repositório.UL), related to the studied schools. Statistical methods and quantitative data were used to compare the behaviours of the teachers and the researchers concerning their preferences on scientific document dissemination throughout the World Wide Web.info:eu-repo/semantics/publishedVersio
Guidelines, recommendations, and near future for university libraries
In the current context, library associations around the globe seek to present perspectives for the future, supporting professionals to develop strategies, projects, and skills. In Portugal, the Recommendations for Higher Education Libraries have given impetus to the work of professionals to face changes and continue their intervening and active role. At the same time, they aim to serve as a focus, creating national congruence in the areas of activity, and as an inspiration for action, motivating a convergence of information professionals, to contribute to greater unity and coherence of Higher Education Libraries in Portugal. This is the basis for this exploratory study. To this end, a literature review that embases a case study is carried out to understand the librarian's professional strategies that have been used throughout the Portuguese academic community. How do institutions and their professionals position themselves to support and develop actions around future challenges? How is being developed the support for teaching and learning, specifically in promoting information literacy skills and fostering digital fluency and user empowerment? How is addressed the support for research activities and the scientific publication, especially in the context of Open Science? How is professional and organizational development that places the librarian at the center of processes and institutions as aggregators of synergies for continuous improvement actions? And finally, how are being taken projects to the design and provision of services and partnerships that facilitate and enhance the creation of networks for cultural expression, including the preservation and dissemination of documentary heritage? It is concluded that the preparation and planning based on guidelines work as stabilizers, which anchor the actions developed, at the same time that the winds of change allow the exploration of new paths and practices, thus enhancing a virtuous context of action.info:eu-repo/semantics/publishedVersio
Guidelines, recommendations, and near future for university libraries
In the current context, library associations around the globe seek to present perspectives for the future, supporting professionals to develop strategies, projects, and skills. In Portugal, the Recommendations for Higher Education Libraries have given impetus to the work of professionals to face changes and continue their intervening and active role. At the same time, they aim to serve as a focus, creating national congruence in the areas of activity, and as an inspiration for action, motivating a convergence of information professionals, to contribute to greater unity and coherence of Higher Education Libraries in Portugal. This is the basis for this exploratory study. To this end, a literature review that embases a case study is carried out to understand the librarian's professional strategies that have been used throughout the Portuguese academic community. How do institutions and their professionals position themselves to support and develop actions around future challenges? How is being developed the support for teaching and learning, specifically in promoting information literacy skills and fostering digital fluency and user empowerment? How is addressed the support for research activities and scientific publication, especially in the context of Open Science? How is professional and organizational development that places the librarian at the center of processes and institutions as aggregators of synergies for continuous improvement actions? And finally, how are being taken projects to the design and provision of services and partnerships that facilitate and enhance the creation of networks for cultural expression, including the preservation and dissemination of documentary heritage.It is concluded that the preparation and planning based on guidelines work as stabilizers, which anchor the actions developed, at the same time that the winds of change allow the exploration of new paths and practices, thus enhancing a virtuous context of action
Influencia de las reformas pensionales en el presupuesto de rentas de la nación para el periodo 1990-2016
Trabajo de investigaciónEsta investigación realiza un análisis de las reformas pensionales que ha tenido Colombia desde 1990 hasta el 2016, resaltando las más importantes, mostrando una identificación, descripción y análisis de todas estas reformas, el objetivo que perseguían, adicional a eso se va a verificar los principales aporte del presupuesto para las pensiones en el mismo rango de tiempo relacionado de igual manera los aportes que se realizaron referente a las reformas, y por qué se dieron los respectivos cambios.1. INTRODUCCIÓN
2. PLANTEAMIENTO DEL PROBLEMA
3. JUSTIFICACIÓN
4. ANTECEDENTES
5. CAPITULO 1 REFORMAS PENSIONALES EN COLOMBIA 1990-2016
6. CAPITULO 2 PARTICIPACIÓN PRESUPUESTAL DE LAS PENSIONES 7. CAPITULO 3. RELACIÓN REFORMAS PENSIONALES CON EL PRESUPUESTO
8. CONCLUSIONES
9. BIBLIOGRAFÍAPregradoEconomist
The training of health professionals in hearing health: a systematic review
O objetivo deste trabalho foi avaliar a capacitação de profissionais da saúde sobre saúde auditiva por meio da revisão sistemática. O levantamento bibliográfico foi conduzido em base eletrônica de dados (Lilacs, SciELO, Medline, Scopus, Embase, Science Direct Online e Web of Science), revistas online da área de audiologia, anais de congressos nacionais e bibliotecas de universidades brasileiras, com busca bibliográfica padronizada, utilizando-se palavras-chave específicas procurando todos os resumos de estudos pertinentes à questão proposta. Para a seleção e avaliação dos estudos científicos levantados na busca foram estabelecidos critérios, contemplando os aspectos: tipo de estudo, participantes, intervenção adotada e avaliação dos resultados. Dos títulos obtidos a partir desta busca foram selecionados apenas aqueles cujo resumo ou corpo do artigo tivesse relação com o objeto do presente estudo. Após a leitura do texto completo, os mesmos foram resenhados de acordo com ficha protocolar e classificados com relação ao nível de evidência e grau de recomendação. Como resultado cinco estudos foram incluídos na revisão sistemática. Existe uma escassez de estudos com este enfoque, contudo os resultados obtidos demonstraram que a capacitação dos profissionais em saúde auditiva é efetiva, aumentando o conhecimento dos mesmos sobre o tema e, consequentemente, identificando e encaminhando os indivíduos com sinais de distúrbios auditivos para os serviços de referência.The aim of this study was to evaluate the training of health professionals regarding hearing health, through a systematic literature review. The bibliographic search was carried out in scientific database (Lilacs, SciELO, Medline, Scopus, Embase, Science Direct Online and Web of Science), online journals on audiology, proceedings from Brazilian conventions, and libraries from Brazilian universities, using specific keywords in order to find all the possible studies matching the proposed question. The studies that matched these criteria were selected and evaluated according to the following aspects: type of study, participants, intervention adopted and outcomes evaluation. After reading the selected manuscripts, they were summarized in a protocol and classified according to level of evidence and recommendation degree. Five studies were included in the systematic review. The results showed a shortage of researches that emphasize this topic, but the analysis of the articles demonstrated that the training of health professionals in hearing health is effective, increasing their knowledge on the theme and, consequently, enabling them to identify patients at risk for hearing loss and to refer these individuals to specific evaluation
Assessing the economic value of academic libraries: a case study in the University of Lisbon
The assessment of academic libraries is an important management issue of the services and of Library Advocacy. Determining the monetary value of the services may be an interesting element at a time when there are constraints on the budgets of the institutions. The main aim of this paper is to calculate the tangible value in monetary terms of certain services of two libraries of the University of Lisbon. In this task we use six statistical indicators: document loans, accesses to the Internet; accesses to computers, accesses to journals, training, and interlibrary loans. The method to calculate the monetary value for specialized quality service is to verify the current market value of the service, ie., the current price of the service that can be bought or sold in the free market (ISO16439:2014). According to this investigation, we calculate the monetary values for these indicators. The cost-benefit value is also calculated, that is, the return on investment, the relationship between the total economic benefit of these indicators and the total resources invested in the library according to these indicators.info:eu-repo/semantics/publishedVersio
Choosing readings: Portuguese academic library users' preferences for printed books or e-books
The emergence of e-books as resources of scientific information in university libraries has been
imposing at the pace of technology, with advantages such as portability, cost or accessibility,
assuming that e-reading is being well received and appropriated by library users, who can access
scientific information from anywhere. However, recent studies from prior to the COVID-19
pandemic, pointed to the resurgence of paper reading preferences. This study analyses the
behavioural trends in the use of scientific information from these two media: printed books and ebooks and the way university libraries users choose to use it, particularly in the pandemic context.
To this end, a survey is conducted on a sample of users from various Portuguese higher education
schools. The first part focuses on the characterization of respondents, which includes data on
gender, area of knowledge, academic level they attend. In the second part we seek the opinion
about advantages and disadvantages of each medium, frequency of use, choice of medium
according to the purpose of reading, devices used, acquisition suggestions for the library. The
results allow us to observe the factors that influence and affect the behaviours of users regarding
this choice. Studies such as these are important to support the decision in choosing the
information resources to be purchased, taking into account user preferences, but also to outline strategies for promoting the use of various media.FCT- Foundation for Science
and Technology, under the projects UIDB/00057/2020
and UIDB/04107/202
Choosing Readings: Portuguese Academic Library Users' Preferences for Printed Books or e-Books
The emergence of e-books as resources of scientific information in university libraries has been imposing at the pace of technology, with advantages such as portability, cost or accessibility, assuming that e-reading is being well received and appropriated by library users, who can access scientific information from anywhere. However, recent studies from prior to the COVID-19 pandemic, pointed to the resurgence of paper reading preferences. This study analyses the behavioural trends in the use of scientific information from these two media: printed books and e-books and the way university libraries users choose to use it, particularly in the pandemic context. To this end, a survey is conducted on a sample of users from various Portuguese higher education schools. The first part focuses on the characterization of respondents, which includes data on gender, area of knowledge, academic level they attend. In the second part we seek the opinion about advantages and disadvantages of each medium, frequency of use, choice of medium according to the purpose of reading, devices used, acquisition suggestions for the library. The results allow us to observe the factors that influence and affect the behaviours of users regarding this choice. Studies such as these are important to support the decision in choosing the information resources to be purchased, taking into account user preferences, but also to outline strategies for promoting the use of various media.info:eu-repo/semantics/publishedVersio
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