76 research outputs found
Utilização dos media no ensino das ciências naturais e na abordagem de temáticas ambientais em contexto de sala de aula
Dissertação de Mestrado em Educação Especialização em Supervisão Pedagógica do
Ensino da Biologia e Geologia.As questões ambientais têm estado presentes nas discussões mediáticas, no entanto,
estas mediatizações, segundo Hansen (1993), surgem ciclicamente, estando essencialmente
relacionadas com a realização de cimeiras, encontros de chefes de estado ou outra actividade à
escala global.
Aquando da abordagem destes temas pela comunicação social é natural que os alunos
se sintam particularmente interessados pela sua abordagem na sala de aula, podendo estes
temas ser percursores de um conjunto de aprendizagens significativas.
No sentido da significação das aprendizagens surgiram alguns projectos que visam a
atribuição de um carácter mais activo por parte dos alunos, entre os quais os JRA – Jovens
Repórteres para o Ambiente - que procura que os discentes estejam atentos a realidades
ambientais próximas, problematizem essa mesma realidade e assumam um carácter
interventivo na comunicação e resolução dessa questão ambiental.
Desta forma, num primeiro estudo, com o intuito de esclarecer a realidade educacional
com recurso aos media num panorama nacional, estabelecemos algumas questões que
pretendemos ver respondidas, nomeadamente perceber se os media são utilizados como
recurso na sala de aula e quais as concepções dos docentes que os utilizam. Por outro lado,
determinar a frequência de utilização, saber quais os media mais utilizados e o tipo de artigo
mediático mais explorado. Num segundo estudo, pretendemos analisar a importância da
implementação de programas de Educação Ambiental através dos media, mais concretamente
sobre o projecto dos Jovens Repórteres para o Ambiente.
Da presente investigação surgiram dados particularmente relevantes no que à Educação
em Ciências diz respeito, nomeadamente o facto dos docentes reconhecerem que os media são
importantes aliados no processo de ensino aprendizagem, sendo promotores de competências
gerais e específicas das Ciências. Quanto aos JRA, este projecto foi considerado como promotor
de aprendizagens não só ambientais, como também linguísticas, aliadas a uma educação cívica
responsável e comprometida.
Acreditamos que com estes dois estudos foi possível percepcionar a sensibilidade dos
docentes para com os meios de comunicação social e para com os JRA, no entanto, este foi um
pequeno passo para auxiliar na reestruturação do ensino das ciências, tendo em vista uma
maior significação das aprendizagens, aliado a uma superior motivação e comprometimento
pessoal e social dos alunos em temáticas científicas e ambientais.Environmental issues have become the target of widespread media coverage.
Nevertheless, this mediatization, according to Hansen (1993), is cyclic, being closely related to
political summits, meetings involving prominent public figures and other activities at a global
scale.
It is expectable that students will be particularly interested in exploring these issues in the
classroom at times of intense media coverage. Consequently, when sharing what they have
learnt about the issues explored by the media, students’ learning becomes more significant.
Some recently developed projects demand a more active role from students and have the
potential to turn the learning process more significant. An example is the Young Reporters for the
Environment (YRE), which leads students to pay more attention to their environmental realities, to
raise questions and to assume an active role in communicating and solving the problem.
This dissertation encompassed two studies. In the first study, we aimed to describe the
educational reality concerning the uses of the media in the classroom at a national level and to
analyse teachers’ perceptions concerning such uses. More specifically, we wanted to know how
often teachers use the media, which media are the most used in the classroom and which type
of news materials are the most explored.
Through a second study, we intended to analyse the importance of implementing
Environmental Educational Programs through the media, more specifically the YRE project.
The present investigation enabled us to become aware of particularly relevant facts
concerning education in Science, namely the fact that teachers do recognize the media as
important allies in the teaching and learning process, and view them as valuable means of
promoting literacy in Science.
The YRE project was considered to be a great promoter of learning, not only related to
environmental issues, but also to linguistic learning and to contribute to a responsible, civic and
engaged education.
We believe that through these two studies it was possible to understand how receptive
teachers are concerning the use of the media and the YRE project. Nonetheless, this was only a
small contribution towards the restructuring of Science teaching, as our main goal is to make
students accomplish significant learning, higher motivation, personal and social involvement in
environmental and scientific issues
Combining power electronic converters and automation to simulate solar PV systems
This paper presents a solar photovoltaic panel simulator system with the ability to perform automatic tests in different condition according to manufacture parameters. This simulator is based on three buck-boost DC-DC converters controlled by a microcontroller and supported by a Programmable Logic Controller which is responsible for the automatic tests. This solution will allow to achieve fast response, like suddenly changes in the irradiation, temperature, or load. To control the power converter, it will be used a fast and robust sliding mode controller. Therefore, with the proposed system is possible to perform the I-V curve simulation of a solar PV panel, evaluate different MPPT algorithms considering different meteorological and load variation. The main advantage of this work is the possibility to evaluate and test several MPPT algorithms and understand the operation and typical operation of solar PV panels in different conditions. Several simulations and experimental results from a laboratory prototype are presented to confirm the theoretical operation.info:eu-repo/semantics/publishedVersio
Automated Solar PV Simulation System Supported by DC–DC Power Converters
Funding Information: This work was funded by Instituto Politécnico de Lisboa, reference code: IPL/2021/ATS2SPV_ISEL. Publisher Copyright: © 2023 by the authors.Solar photovoltaic simulators are valuable tools for the design and evaluation of several components of photovoltaic systems. They can also be used for several purposes, such as educational objectives regarding operation principles, control strategies, efficiency, maintenance, and other aspects. This paper presents an automated solar photovoltaic simulation system with the capability to generate automated tests considering different parameters of solar photovoltaic panels and different operation conditions. The proposed simulator is composed of three buck-boost DC–DC power converters controlled in such a way that will behave similarly to solar photovoltaic panels. It allows to introduce additional variable loads and maximum power point tracker algorithms similar to real systems. Some converters are controlled by a DSP microcontroller connected to a single programmable logic controller which generates the automated tests. Thus, using the presented solution, it is possible to implement the I-V and P-V characteristic curves of solar photovoltaic panels and evaluate different maximum power point tracker algorithms considering different meteorological conditions and load variations, being a useful tool to teach subjects related to renewable energy sources and related applications. Several simulation results using Matlab/Simulink and experimental results are presented to validate the operation of the proposed solution. Experimental results achieve a ripple between 2% and 5% of the desired average current in MPP conditions.publishersversionpublishe
LocalEnergy: Local Resources for Multifunctional Tetrahedrite-based Energy: Harvesting Applications
info:eu-repo/semantics/publishedVersio
Recursos locais para aplicações multifuncionais de captação de energia com base em tetraedrite
CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMO: Este trabalho descreve as principais linhas de investigação que estão em curso no âmbito do projeto LocalEnergy (http://localenergy.lneg.pt). LocalEnergy é um projeto multidisciplinar de Investigação, Desenvolvimento e Inovação (I&D&I), envolvendo atividades no domínio da ciência dos materiais, da geologia e das energias renováveis. Essas atividades estão orientadas para a indústria e assentam numa abordagem disruptiva visando o desenvolvimento de materiais termoelétricos, através da utilização de materiais à base de tetraedrites naturais e sintéticas, e o desenvolvimento de novos absorsores para células solares de filmes finos, usando materiais à base de tetraedrites sintéticas. Considerando que Portugal é um dos países europeus com maior nível de irradiação de energia solar e que a tetraedrite é um recurso mineral local, presente na Zona Sul Portuguesa da Faixa Piritosa Ibérica, o projeto LocalEnergy representa uma oportunidade para o desenvolvimento de sistemas energéticos sustentáveis baseados na maximização e exploração de dois importantes recursos endógenos (energia solar e recursos minerais).ABSTRACT: This work describes the main lines of investigation that are underway within LocalEnergy project (http://localenergy.lneg.pt). LocalEnergy is a multidisciplinary Research, Development and Innovation project, involving activities in the field of materials science, geology and renewable energies. These activities are oriented towards the industry and are based on a disruptive approach aimed at the development of thermoelectric materials, through the use of materials based on natural and synthetic tetrahedrites, and the development of new absorbers for thin film solar cells, using materials based on synthetic tetrahedrites. Considering that Portugal is one of the European countries with the highest level of irradiation of solar energy and that tetrahedrite is a local mineral resource, present in the Portuguese zone of the Iberian Pyrite Belt, LocalEnergy project represents an opportunity for the development of sustainable energy systems based on the maximization and exploration of two important endogenous resources (solar energy and mineral resources).info:eu-repo/semantics/publishedVersio
Viral genetic clustering and transmission dynamics of the 2022 mpox outbreak in Portugal
Pathogen genome sequencing during epidemics enhances our ability to identify and understand suspected clusters and investigate their relationships. Here, we combine genomic and epidemiological data of the 2022 mpox outbreak to better understand early viral spread, diversification and transmission dynamics. By sequencing 52% of the confirmed cases in Portugal, we identified the mpox virus sublineages with the highest impact on case numbers and fitted them into a global context, finding evidence that several international sublineages probably emerged or spread early in Portugal. We estimated a 62% infection reporting rate and that 1.3% of the population of men who have sex with men in Portugal were infected. We infer the critical role played by sexual networks and superspreader gatherings, such as sauna attendance, in the dissemination of mpox virus. Overall, our findings highlight genomic epidemiology as a tool for the real-time monitoring and control of mpox epidemics, and can guide future vaccine policy in a highly susceptible population.info:eu-repo/semantics/publishedVersio
The basal epithelial marker P-cadherin associates with breast cancer cell populations harboring a glycolytic and acid-resistant phenotype
"BMC Cancer 2014 14:734"BACKGROUND:
Cancer stem cells are hypoxia-resistant and present a preponderant glycolytic metabolism. These characteristics are also found in basal-like breast carcinomas (BLBC), which show increased expression of cancer stem cell markers.Recently, we demonstrated that P-cadherin, a biomarker of BLBC and a poor prognostic factor in this disease, mediates stem-like properties and resistance to radiation therapy. Thus, the aim of the present study was to evaluate if P-cadherin expression was associated to breast cancer cell populations with an adapted phenotype to hypoxia.
METHODS:
Immunohistochemistry was performed to address the expression of P-cadherin, hypoxic, glycolytic and acid-resistance biomarkers in primary human breast carcinomas. In vitro studies were performed using basal-like breast cancer cell lines. qRT-PCR, FACS analysis, western blotting and confocal microscopy were used to assess the expression of P-cadherin after HIF-1a stabilization, achieved by CoCl2 treatment. siRNA-mediated knockdown was used to silence the expression of several targets and qRT-PCR was employed to evaluate the effects of P-cadherin on HIF-1a signaling. P-cadherin high and low breast cancer cell populations were sorted by FACS and levels of GLUT1 and CAIX were assessed by FACS and western blotting. Mammosphere forming efficiency was used to determine the stem cell activity after specific siRNA-mediated knockdown, further confirmed by western blotting.
RESULTS:
We demonstrated that P-cadherin overexpression was significantly associated with the expression of HIF-1a, GLUT1, CAIX, MCT1 and CD147 in human breast carcinomas. In vitro, we showed that HIF-1a stabilization was accompanied by increased membrane expression of P-cadherin and that P-cadherin silencing led to a decrease of the mRNA levels of GLUT1 and CAIX. We also found that the cell fractions harboring high levels of P-cadherin were the same exhibiting more GLUT1 and CAIX expression. Finally, we showed that P-cadherin silencing significantly decreases the mammosphere forming efficiency in the same range as the silencing of HIF-1a, CAIX or GLUT1, validating that all these markers are being expressed by the same breast cancer stem cell population.
CONCLUSIONS:
Our results establish a link between aberrant P-cadherin expression and hypoxic, glycolytic and acid-resistant breast cancer cells, suggesting a possible role for this marker in cancer cell metabolismo.This work was funded by FEDER funds through the COMPETE Program (Programa Operacional Factores de Competitividade) and by national funds through FCT (Portuguese Foundation for Science and Technology, Portugal), mainly in the context of the scientific project PTDC/SAU-GMG/120049/2010-FCOMP-01-0124-FEDER-021209, and partially by PTDC/SAU-FCF/104347/2008. FCT funded the research grants of BS (SFRH/BD/69353/2010), ASR (SFRH/BPD/75705/2011), ARN (grant from the project PTDC/SAU-GMG/120049/2010), CP (SFRH/BPD/69479/2010), AV (SFRH/BPD/90303/2012), as well as JP, with Programa Ciencia 2007 (Contratacao de Doutorados para o SCTN - financiamento pelo POPH - QREN - Tipologia 4.2 - Promocao do Emprego Cientifico, comparticipado pelo Fundo Social Europeu e por fundos nacionais do MCTES) and Programa IFCT (FCT Investigator). IPATIMUP is an Associate Laboratory of the Portuguese Ministry of Science, Technology and Higher Education and is partially supported by FCT
The institutions of archaic post-modernity and their organizational and managerial consequences: The case of Portugal
The long march of modernization of the Western societies tends to be presented as following a regular sequence: societies and institutions were pre-modern, and then they were modernized, eventually becoming post-modern. Such teleology may provide an incomplete or distorted narrative of societal evolution in many parts of the world, even in the ‘post-modern heartland’ of Western Europe, with Portugal being a case in point. The concept of archaic post-modernity has been developed by a philosopher, José Gil, to show how Portuguese institutions and organizations combine elements of pre-modernity and post-modernity. The notion of an archaic post-modernity is advanced in order to provide an alternative account of the modernization process, which enriches discussion of the varieties of capitalism. Differences in historical experiences create singularities that may be considered in the analysis of culture, management and organization
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4
While the increasing availability of global databases on ecological communities has advanced our knowledge
of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In
the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of
Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus
crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced
environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian
Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by
2050. This means that unless we take immediate action, we will not be able to establish their current status,
much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio
- …