Study of the light’s dazzling effect on the EEG signal of subjects performing tasks that require concentration

Tese de mestrado integrado, Engenharia Biomédica e Biofísica (Sinais e Imagens Médicas) Universidade de Lisboa, Faculdade de Ciências, 2019The objective of this work is to study the effect of luminous glare on the electroencephalographic (EEG) signals of subjects that perform concentration-based tasks. The increasing access to high-power and directional light sources (such as laser pointers, but also some flashlights) has led to a growing concern with the potential effects of its use. More than the direct damaging of the retina, the focus has been directed at the effects related to the change in states of concentration on individuals performing tasks whose concentration is critical (such as helicopter pilots or heavy vehicles drivers). This effect is known as ”dazzling” and is typically a temporary deleterious effect on the ability to see or concentrate. However, while damage to the retina can be quantified, glare effects, being indirect (based on the effect on the execution of a given task), are typically qualitative (or at least of more subjective quantification). In this context, the use of brain-computer interfaces capable of analyzing the brain response to external stimuli, opens a door towards the creation of a new tool to evaluate the effects of dazzle. Its potential was evaluated by defining a set of strategies involving the illumination process, EEG signal recording and analysis. A continuous performance task commonly used as an assessment in cognitive neuroscience (N-back) was used to test the attention under the effect of dazzling, in parallel with EEG signals acquisition. Statistical data analysis was performed with the R programming language. ANOVA statistical significant results (p<0.001) for answer scores and latency were obtained for differences between the levels of difficulty, both with or without dazzling. Tukey’s test further revealed that these statistical differences were on the 0-back/2-back and 1-back/2-back pairs (p<0.005). The differences in the pair 0-back/1-back were not significant. Peak band frequency statistical tests were not significant with or without dazzling. Statistical differences were found between dazzling conditions for the frequency band power. For the 0-back and 1-back levels, with the AF7-Fp1 electrode pair, T-student tests resulted in an alpha band frequency power increase (p<0.003, in both cases). The electrode pair AF8-Fp2 resulted in an alfa and beta frequency band increase for the 1-back level (p<0.014 and p<0.029, respectively). These results suggest that concentration is affected by dazzling and can be quantified by means of measuring the change in alpha and beta frequency band power. This technique holds potential and, if further researched and developed, may constitute an effective way of measuring the degree of loss of concentration under the effect of dazzling

Comportamento online dos portugueses e identificação dos factores de conversão

Mestrado em Econometria Aplicada e PrevisãoO presente estudo tem como objectivo a determinação de indicadores avançados que permitam identificar indivíduos susceptíveis de se converterem a um sítio online relativo aos sectores da banca e seguros. Para tal, a partir de uma amostra que contém informação comportamental online de um painel de utilizadores portugueses, foi feita uma análise descritiva aos dados, seguida da estimação de dois modelos de regressão logística respeitante a cada sector alvo de análise. A análise descritiva aos dados demonstra que variáveis demográficas, tais como idade, região, sexo e situação laboral do indivíduo, foram relevantes na distinção dos indivíduos convertidos e não convertidos. Do primeiro modelo logit estimado, relativo à banca, retiramos o motor de busca e a combinação de indicadores comportamentais com características demográficas, como as variáveis que melhor prevêem a conversão de um indivíduo no sector. Jovens com idades entre os 18 e 30 anos, recentemente pais, que passam muito tempo em casa e não estão habituados à internet, constituem um dos perfis mais destacados na probabilidade de ocorrência do evento conversão em banca. Relativamente à segunda regressão estimada, para os seguros, conclui-se que o último clique antes da conversão é o mais relevante. Um indivíduo é mais passível de se converter ao sector de seguros, partindo directamente da página de uma grande empresa. Este fenómeno está implicitamente relacionado com os funcionários que beneficiam de seguro de saúde de uma dada empresa.The present study's goal is identifying the factors that most explain the conversion of internet users in a website related to the banking and insurance sectors. From a sample containing online behaviour data about a panel of portuguese users, a descriptive analysis was done, followed by the estimation of two logistic regression models for each sector of analysis. The descriptive analysis of data showed that demographic variables such as age, sex, and the individual's work situation, were relevant to distinguish between converted and unconverted individuals. The first estimated logit model, relative to banking, points the use of search engine and a combination of behavioral indicators with demographic characteristics, as the variables that best explains the conversion in the sector. For the second logistic regression, about the insurance sector, we conclude the last click immediately before the conversion, is the most relevant to the event. There are bigger odds an internet user gets converted in the insurance sector, by jumping directly from a website regarded to a big corporation. This phenomenon is linked to employees that benefits from a health insurance service, provided by the corporation.info:eu-repo/semantics/publishedVersio

As mídias sociais no contexto da educação superior

A pesquisa aqui relatada analisou ferramentas para suporte educacional com potencial para promover práticas colaborativas e interativas e traçou um panorama quantitativo sobre as principais mídias sociais utilizadas por professores e estudantes de nível superior da macrorregião de Bauru. Este trabalho também objetivou compreender o valor e a apropriação de tais mídias no contexto educacional dos envolvidos. Para tanto, foi aplicado um Survey entre professores e estudantes do ensino superior que permitisse conhecer as preferências em relação às mídias sociais utilizadas por este público. Os resultados apontaram que a maioria dos participantes acredita que as mídias poderiam ser utilizadas como recurso didático-pedagógico (59,3%) e que são excelentes ferramentas para troca de informações entre os envolvidos no processo educacional (61,1%)

Potential biosurfactant producing endophytic and epiphytic fungi, isolated from macrophytes in the Negro River in Manaus, Amazonas, Brazil

Endophytic and epiphytic fungi isolated from Eichhornia crassipes (Mart.) Solms and Cyperus ligularis L., macrophytes collected from oil-contaminated waters, were studied to assess their potential for producing biosurfactants; the most promising ones were identified by means of the rDNA region sequencing. In the selection, in the hydrocarbonate biodegradation activity, 2.6-indophenol (DCPIP) in oil-added Bushnell-Haas (BH) medium was the indicator used. The following tests were performed to ascertain the biosurfactant, bioemulsifier activity: emulsification measurement, drop-collapse, surface tension and production slope. Of the twenty fungi isolated, six promoted DCPIP discoloration. The isolate (S31) Phoma sp. showed emulsification of diesel (1.5 cm or 52%) and reduction of the surface tension of 51.03 mN/m water identified as Phoma sp. The other five fungi were identified as Rhizopus oryzae (S24), Fusarium sp. (S32, S33, S42, S46), presenting potential for biodegradation of hydrocarbons, as well. New studies on Phoma sp. (S31), including its cultivation in different carbon sources will be necessary to improve the production of secondary compounds involved in surface tension bioemulsification and reduction.Keywords: Bioremediation, bioemulsifiers, Eichhornia, Cyperus, oil, diese

Experiências de discriminação racial e racismo contra estudantes negros no Brasil

Racial discrimination and racism are still present in everyday society, reverberating in various aspects of the lives of the black population, including in higher, secondary and primary education, where prejudice is intense and affects the permanence of this ethnic-racial group. The aim of this article is to analyze the evidence available in the scientific literature on experiences of racial discrimination and racism against black students in Brazil. This is an integrative literature review, the guiding question was based on the PICo strategy, the search for articles was carried out in the following databases: MEDLINE via PubMed, Web of Science, Scopus and LILACS. The search retrieved a total of 766&nbsp;publications, but after analyzing the inclusion and exclusion criteria and reading them in full, 12 works were included in the final sample. The main subjects covered by the works were three themes: Policies developed and implemented by the University (41.66%), Impacts of racial discrimination and racism on academic and social life (41.66%) and Manifestations of racism and discrimination and ways of coping (16.68%). Thus, racism is still present in the lives of these students, this phenomenon directly affects the academic performance and social life of students.A discriminação racial e o racismo ainda são presentes no cotidiano da sociedade, reverberando em vários aspectos na vida da população negra, inclusive no ensino superior, médio e fundamental, onde o preconceito é intenso, e afeta a permanência desse grupo étnico-racial. Diante disso, o objetivo desse artigo analisar as evidências disponíveis na literatura científica sobre experiências de discriminação racial e racismo contra estudantes negros no Brasil. Trata-se de uma revisão integrativa de literatura, a questão norteadora foi embasada pela estratégia PICo, a busca pelos artigos foi realizado nas bases de dados: MEDLINE via PubMed, Web of Science, Scopus e LILACS. Na busca, foi recuperado um quantitativo de 766 publicações, mas depois das análises dos critérios de inclusão e exclusão, e da leitura na íntegra, 12 obras foram incluídas na amostra final. As obras tinham como principais assuntos abordados três temas, sendo eles: Politicas desenvolvidas e implementadas pela a Universidade (41,66%), Impactos da discriminação racial e racismo na vida acadêmica e social (41,66%) e Manifestações de racismo e discriminação e as formas de enfrentamento (16,68%). Assim, o racismo ainda está presente na vida desses estudantes, este fenômeno afeta diretamente o desempenho acadêmico e vida social dos estudantes

Isolamento

info:eu-repo/semantics/publishedVersio

A list of land plants of Parque Nacional do Caparaó, Brazil, highlights the presence of sampling gaps within this protected area

Brazilian protected areas are essential for plant conservation in the Atlantic Forest domain, one of the 36 global biodiversity hotspots. A major challenge for improving conservation actions is to know the plant richness, protected by these areas. Online databases offer an accessible way to build plant species lists and to provide relevant information about biodiversity. A list of land plants of “Parque Nacional do Caparaó” (PNC) was previously built using online databases and published on the website "Catálogo de Plantas das Unidades de Conservação do Brasil." Here, we provide and discuss additional information about plant species richness, endemism and conservation in the PNC that could not be included in the List. We documented 1,791 species of land plants as occurring in PNC, of which 63 are cited as threatened (CR, EN or VU) by the Brazilian National Red List, seven as data deficient (DD) and five as priorities for conservation. Fifity-one species were possible new ocurrences for ES and MG states

As manifestações clínicas do portador de paralisia facial

Introdução: A paralisia facial e um sintoma de um transtorno de base resultante em imobilidade e incapacidade de executar a mímica facial e a expressão emotiva. São várias as etiologias deste acometimento, sendo a classificação em paralisia facial periférica, representada classicamente pela paralisia de Bell e a central, pelo acidente vascular encefálico, adotada para auxiliar na investigação e seguimento clínico adequado. Objetivo: Descrever sobre a paralisia facial, com foco em características clínicas que propiciem ao diagnóstico precoce, medidas terapêuticas e restauração imediata. Metodologia: Revisão narrativa que selecionou artigos disponibilizados na íntegra publicados no recorte temporal de 2008 até 2022. Resultados: Dos 10 artigos incluídos neste estudo, todos realizaram uma ampla análise sobre a temática, a qual propiciou a disseminação de informações atualizadas sobre conceito, diagnóstico diferencial entre duas condições clínicas opostas resultantes em paralisia facial, manifestações, avaliação clínica e manejo adequado. Conclusão: Estudos ainda urgem em ser feitos no intuito de orientar melhor os profissionais e a comunidade a respeito da paralisia facial e a importância que possui o acompanhamento e seguimento precoce. Destarte,