17 research outputs found

    Design procedures for sustainable structural concretes using wastes and industrial by-products

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    The protection of the environment must be a priority in our society, and the construction sector can contribute significantly to this goal. Construction, being one of the industrial sectors that is more demanding in terms of raw materials, must reinforce its effort to implement, in a more profound and systematic way, the paradigm of the circular economy. In this sense, in recent years several studies have been trying to contribute solutions aimed at reintroducing industrial by-products or residues in new products for the construction industry. It should be noted that nowadays it is increasingly important to introduce a higher percentage of recycled materials in concrete. In this context, the present work addresses the appropriateness of a design procedure proposed to maximize the content of electric arc furnace slag (EAFS) and include recycled tire steel fibers (RTSF) in the production of more sustainable structural concretes. For this, the properties of various concrete mixtures at the fresh and hardened state, obtained by the substantial substitution of coarse and fine natural aggregates by EAFS and fly ash (FA), were investigated. The design of EAFS mixtures was based on two conventional reference mixtures (REF1 and REF2), and by using the modified Andreasen and Andersen particle packing model, these were optimized to achieve maximum packing density. Compressive strength, modulus of elasticity behavior, and fresh and physical properties were assessed in order to define the best mix proportions with respect to the predefined requirements of ordinary mixtures. Untreated recycled tire steel fibers (RTSF) were included in the developed sustainable concrete to perform a comparison of the physical properties with unreinforced concretes developed with natural aggregates (REF2) and with EAFS aggregates (EAFS8D1). This incorporation was intended to improve the physical behavior of unreinforced concretes with EAFS aggregates. Mixtures with high percentages of waste aggregates up to 70% (in weight), and 10% (in weight) of FA were obtained, showing competitive mechanical behavior compared to REF1 and REF2. These concrete compositions showed minimum and maximum compressive strengths between 9 MPa and 37 MPa, respectively. This study coverd the two major classes of concrete used as structural material, namely structural concrete and fiber reinforced concrete.This research was funded by Fundação para a Ciência e a Tecnologia grant number SFRH/BD/135790/2018) and projects with references POCI-01-0247-FEDER-033834, NORTE-01-0145-FEDER-000032.The first author would also like to thank FCT (Fundação para a Ciência e a Tecnologia) for the funding through the PhD grant SFRH/BD/135790/2018. The authors would like to thank DST company, the project RENEw, POCI-01-0247-FEDER-033834, funded by Fundo Europeu de Desenvolvimento Regional (FEDER) and Programa Operacional da Competitividade e Internacionalização do Portugal 2020 (COMPETE 2020), “Next generation monitoring of coastal ecosystems in a scenario of global change”, NORTE-01-0145-FEDER-000032, funded by Fundo Europeu de Desenvolvimento Regional (FEDER) and Programa Operacional Regional do Norte (NORTE2020), and “CirMat: CIRcular aggregates for sustainable road and building MATerials” is funded by Iceland, Liechtenstein and Norway through the EEA Grants and Norway Grants, operationalized by the Portuguese Office of the Secretary of State for the Environment. They are also very grateful to the companies SECIL and SIKA for the material provided that contributed to the realization of this study

    Determinants of HIV-1 Late Presentation in Patients Followed in Europe

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    To control the Human Immunodeficiency Virus (HIV) pandemic, the World Health Organization (WHO) set the 90-90-90 target to be reached by 2020. One major threat to those goals is late presentation, which is defined as an individual presenting a TCD4+ count lower than 350 cells/mm3 or an AIDS-defining event. The present study aims to identify determinants of late presentation in Europe based on the EuResist database with HIV-1 infected patients followed-up between 1981 and 2019. Our study includes clinical and socio-demographic information from 89,851 HIV-1 infected patients. Statistical analysis was performed using RStudio and SPSS and a Bayesian network was constructed with the WEKA software to analyze the association between all variables. Among 89851 HIV-1 infected patients included in the analysis, the median age was 33 (IQR: 27.0–41.0) years and 74.4% were males. Of those, 28,889 patients (50.4%) were late presenters. Older patients (>56), heterosexuals, patients originated from Africa and patients presenting with log VL >4.1 had a higher probability of being late presenters (p < 0.001). Bayesian networks indicated VL, mode of transmission, age and recentness of infection as variables that were directly associated with LP. This study highlights the major determinants associated with late presentation in Europe. This study helps to direct prevention measures for this population

    Serological screening in a large-scale municipal survey in Cascais, Portugal, during the first waves of the COVID-19 pandemic: lessons for future pandemic preparedness efforts

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    BackgroundSerological surveys for SARS-CoV-2 were used early in the COVID-19 pandemic to assess epidemiological scenarios. In the municipality of Cascais (Portugal), serological testing combined with a comprehensive socio-demographic, clinical and behavioral questionnaire was offered to residents between May 2020 and beginning of 2021. In this study, we analyze the factors associated with adherence to this municipal initiative, as well as the sociodemographic profile and chronic diseases clinical correlates associated to seropositivity. We aim to contribute with relevant information for future pandemic preparedness efforts.MethodsThis was a cross-sectional study with non-probabilistic sampling. Citizens residing in Cascais Municipality went voluntarily to blood collection centers to participate in the serological survey. The proportion of participants, stratified by socio-demographic variables, was compared to the census proportions to identify the groups with lower levels of adherence to the survey. Univariate and multivariate logistic regression were used to identify socio-demographic, clinical and behavioral factors associated with seropositivity.ResultsFrom May 2020 to February 2021, 19,608 participants (9.2% of the residents of Cascais) were included in the study. Based on the comparison to census data, groups with lower adherence to this survey were men, the youngest and the oldest age groups, individuals with lower levels of education and unemployed/inactive. Significant predictors of a reactive (positive) serological test were younger age, being employed or a student, and living in larger households. Individuals with chronic diseases generally showed lower seroprevalence.ConclusionThe groups with low adherence to this voluntary study, as well as the socio-economic contexts identified as more at risk of viral transmission, may be targeted in future pandemic situations. We also found that the individuals with chronic diseases, perceiving higher risk of serious illness, adopted protective behaviors that limited infection rates, revealing that health education on preventive measures was effective for these patients

    Determinants of HIV-1 Late Presentation in Patients Followed in Europe.

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    To control the Human Immunodeficiency Virus (HIV) pandemic, the World Health Organization (WHO) set the 90-90-90 target to be reached by 2020. One major threat to those goals is late presentation, which is defined as an individual presenting a TCD4+ count lower than 350 cells/mm3 or an AIDS-defining event. The present study aims to identify determinants of late presentation in Europe based on the EuResist database with HIV-1 infected patients followed-up between 1981 and 2019. Our study includes clinical and socio-demographic information from 89851 HIV-1 infected patients. Statistical analysis was performed using RStudio and SPSS and a Bayesian network was constructed with the WEKA software to analyze the association between all variables. Among 89,851 HIV-1 infected patients included in the analysis, the median age was 33 (IQR: 27.0–41.0) years and 74.4% were males. Of those, 28,889 patients (50.4%) were late presenters. Older patients (>56), heterosexuals, patients originated from Africa and patients presenting with log VL >4.1 had a higher probability of being late presenters (p < 0.001). Bayesian networks indicated VL, mode of transmission, age and recentness of infection as variables that were directly associated with LP. This study highlights the major determinants associated with late presentation in Europe. This study helps to direct prevention measures for this population.Depto. de MedicinaFac. de MedicinaTRUEpu

    Data_Sheet_1_Serological screening in a large-scale municipal survey in Cascais, Portugal, during the first waves of the COVID-19 pandemic: lessons for future pandemic preparedness efforts.pdf

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    BackgroundSerological surveys for SARS-CoV-2 were used early in the COVID-19 pandemic to assess epidemiological scenarios. In the municipality of Cascais (Portugal), serological testing combined with a comprehensive socio-demographic, clinical and behavioral questionnaire was offered to residents between May 2020 and beginning of 2021. In this study, we analyze the factors associated with adherence to this municipal initiative, as well as the sociodemographic profile and chronic diseases clinical correlates associated to seropositivity. We aim to contribute with relevant information for future pandemic preparedness efforts.MethodsThis was a cross-sectional study with non-probabilistic sampling. Citizens residing in Cascais Municipality went voluntarily to blood collection centers to participate in the serological survey. The proportion of participants, stratified by socio-demographic variables, was compared to the census proportions to identify the groups with lower levels of adherence to the survey. Univariate and multivariate logistic regression were used to identify socio-demographic, clinical and behavioral factors associated with seropositivity.ResultsFrom May 2020 to February 2021, 19,608 participants (9.2% of the residents of Cascais) were included in the study. Based on the comparison to census data, groups with lower adherence to this survey were men, the youngest and the oldest age groups, individuals with lower levels of education and unemployed/inactive. Significant predictors of a reactive (positive) serological test were younger age, being employed or a student, and living in larger households. Individuals with chronic diseases generally showed lower seroprevalence.ConclusionThe groups with low adherence to this voluntary study, as well as the socio-economic contexts identified as more at risk of viral transmission, may be targeted in future pandemic situations. We also found that the individuals with chronic diseases, perceiving higher risk of serious illness, adopted protective behaviors that limited infection rates, revealing that health education on preventive measures was effective for these patients.</p

    Ichthyoplankton distribution and abundance in the northern Todos os Santos and Camamu Bays, Bahia State - Brazil

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    The occurrence, distribution and abundance of ichthyoplankton in Todos os Santos and Camamu Bays were analyzed based on four samplings (winter 2003, summer 2003, winter 2004 and summer 2005). Samples were obtained by surface horizontal hauls, using a 200-µm mesh conical-cylinder plankton net. The distribution and abundance of eggs indicate a remarkable seasonal and annual variation of spawning activity in the region, especially when the two summer campaigns are compared. In summer 2003 the highest quantitative values were recorded, especially for Camamu, where the maximum reached 106.56 eggs.m-3, with an overall average of 43.46 eggs.m-3 for the two areas. In summer 2005 values were relatively low, the overall average being 3.49 eggs.m-3. The larval taxonomic composition is characterized by the predominance of gobiids, with small variation from summer to winter. Considering all the campaigns and samplings undertaken in both areas, larvae of 11 families were identified: Engraulidae, Clupeidae, Mugilidae, Atherinopsidae, Hemiramphidae, Syngnathidae, Blenniidae, Carangidae, Gobiidae, Achiridae and Tetraodontidae.<br>O ictioplâncton coletado ao norte da baía de Todos os Santos e na baía de Camamu (Inverno 2003, Verão 2003, Inverno 2004 e Verão 2005) é analisado de forma comparativa. As amostras foram obtidas com redes de plâncton do tipo cônica-cilíndrica de 200 µm de malhagem, em arrastos horizontais de subsuperfície. Os resultados sobre a distribuição e abundância de ovos de peixes sugerem uma ampla variação sazonal e anual da desova. Entre os verões as diferenças foram especialmente visíveis, sendo observados no primeiro verão (dez/03) os maiores valores quantitativos do projeto (máximo = 106,56 ovos.m-3; média = 43,46 ovos.m-3), enquanto que no segundo verão (jan/05) os valores foram em geral baixos (média geral = 3,49 ovos.m-3). A composição taxonômica é caracterizada pela predominância de gobiídeos, com pequenas variações entre o verão e o inverno. Considerando-se todas as campanhas e as duas áreas, foram identificadas larvas de 11 famílias: Engraulidae, Clupeidae, Mugilidae, Atherinopsidae, Hemiramphidae, Syngnathidae, Blenniidae, Carangidae, Gobiidae, Achiridae e Tetraodontidae

    Dance Is the new metal: Adolescent music preferences and substance use across Europe

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    Item does not contain fulltextThis study examined relationships between music preferences and substance use (tobacco, alcohol, cannabis) among 18,103 fifteen-year-olds from 10 European countries. In 2005-2006, across Europe, preferences for mainstream Pop (pop chart music) and Highbrow (classical music and jazz) were negatively associated with substance use, while preferences for Dance (house/trance and techno/hardhouse) were associated positively with substance use. In three countries, links were identified between liking Rock (rock, heavy metal punk/hardcore, and gothic) and substance use; associations between Urban (hip-hop and R&B) and substance use were mixed. No substantial gender differences emerged in these patterns, and controlling for relevant covariates did not attenuate the predictive value of substance use. The findings are consistent with the conclusion that music is a robust marker of adolescent substance use.13 p
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