218 research outputs found
Monitoring of 17B-estradiol in raw and treated samples of wastewater treatment plants
Mestrado de dupla diplomação com a FUMECAquatic environment pollution is a keen subject in the most important discussions surrounding global issues. With the increase of industrialization, globalization and urbanization, as consequence, there is an increase in production of high-level pollutants. Emerging pollutants (EP’s) are compounds which are, usually, not found in natural water sources. Data concerning the occurrence and concentrations of some pharmaceuticals in effluents from WWTPs and surface waters, shows that EP concentrations in effluents fluctuate widely, most probably due to inconsistent efficiency of wastewater treatment.
Endocrine disrupting compounds (EDCs), are an important group of EP’s, considering they are often found in different aquatic matrices. Nowadays, monitoring the concentration levels of estrogens in treated wastewaters of wastewater treatment plants (WWTP) is an environmental mandatory task to minimize or eliminate water pollution.
The present work is divided in two main experimental stages. First, an SPE/HPLC-UV experimental methodology is optimized to detect and quantify 17β-Estradiol (E2) present in aqueous samples. The HPLC-UV operating conditions were selected by performing a screening between 10 different mobile phase compositions. A pure methanol composition was selected based in the lower retention time and the highest UV detector signal. The solid phase extraction optimization involves a three-level Box-Behnken experimental design with four factors (sample volume, sample pH, adsorbent drying time and solvent composition used for the washing step), combined with a response surface methodology. The implementation of the optimized experimental methodology occurred by the monitoring of estradiol in a wastewater influent and effluent samples. E2 was detected and quantified in three different samples collected from three distinct point of a WWTP. Sample 1 was collected from the entrance point, sample 2 was collected from the activated sludge aeration tank and sample 3 was the completely treated effluent. The concentration of E2 found in three points was higher than what was anticipated, but coherent with other works.A poluição do ambiente aquático é um assunto importante nas discussões mais importantes em torno de questões globais. Com o aumento da industrialização, globalização e urbanização, como consequência, há um aumento na produção de poluentes de alto nível. Poluentes emergentes (PE) são compostos que, geralmente, não são encontrados em fontes naturais de água. Dados relativos à ocorrência e concentração de alguns produtos farmacêuticos em efluentes de ETARs e águas superficiais, mostram que as concentrações de PE em efluentes variam amplamente, muito provavelmente devido à eficiência inconsistente do tratamento de águas residuais.
Compostos desreguladores endócrinos (CDEs), são um importante grupo de PE, considerando que são freqüentemente encontrados em diferentes matrizes aquáticas. Atualmente, monitorar os níveis de concentração de estrogênios em águas residuárias tratadas de estações de tratamento de efluentes (ETE) é uma tarefa ambiental de suma importância para minimizar ou eliminar a poluição da água.
O presente trabalho está dividido em duas etapas experimentais principais. Primeiro, uma metodologia experimental SPE/HPLC-UV é otimizada para detectar e quantificar o 17β-estradiol (E2) presente em amostras aquosas. As condições operacionais de HPLC-UV foram selecionadas realizando uma triagem entre 10 composições de fase móvel diferentes. Uma composição de metanol puro foi selecionada com base no menor tempo de retenção e no maior sinal do detector de UV. A otimização da extração em fase sólida envolve um projeto experimental Box-Behnken de três níveis com quatro fatores (volume da amostra, pH da amostra, tempo de secagem do adsorvente e composição do solvente usado para a etapa de lavagem), combinado com uma metodologia de superfície de resposta. A implementação da metodologia experimental otimizada ocorreu por meio do monitoramento do estradiol em uma amostra de efluente e afluente de água residuária. O E2 foi detectado e quantificado em três diferentes amostras coletadas em três pontos distintos de uma ETAR. A amostra 1 foi coletada do ponto de entrada, a amostra 2 foi coletada do tanque de aeração de lodo ativado e a amostra 3 foi o efluente completamente tratado. A concentração de E2 encontrada em três pontos foi maior do que o previsto, mas coerente com outros trabalhos
Violence and birth outcomes: evidence from homicides in Brazil
This paper uses microdata from Brazilian natality and mortality vital statistics between 2000 and 2010 to estimate the impact of in-utero exposure to local violence - measured by homicide rates - on birth outcomes. The estimates shows that exposure to violence during the first trimester of pregnancy leads to a small but precisely estimated increase in the risk of low birthweight and prematurity. Effects are found in both rural areas, where homicides are rare, and in urban areas, where violence is endemic. Our estimates imply that homicides in Brazil are responsible for at least 0.5 percent of the incidence of low birthweight (<=2.5 kg) and 3 percent of the incidence of extremely low birthweight (<=1 kg)
Essays on Human Capital in Brazil.
PhDThis thesis consists of three independent chapters on human capital in Brazil.
Chapter one examines the effect of the introduction of automatic grade promotion on student performance in 1,993 public primary schools in the Brazilian state of Minas Gerais. A difference-in-differences approach that exploits variation over time in the adoption of the policy allows the identification of the treatment effect of automatic promotion. I find a negative and significant effect of about 6% of a standard deviation. I provide evidence from quantile regression DiD estimates consistent with an interpretation of the findings as disincentive effect on student effort associated with the introduction of automatic grade promotion; additional evidence on student and teacher behaviour supports this interpretation.
Chapter two provides a novel way of identifying peer group effects in Brazil. Students in Brazil are typically assigned to classes based on the age ranking in their cohort. I exploit this rule to estimate the effects on maths achievement of being in class with older peers for students in fifth grade using a regression discontinuity design. I provide evidence that heterogeneity in age (and in other characteristics) is an important factor for student performance. Information on teaching practices and student behaviour sheds light on how class heterogeneity may harm learning.
Chapter three uses microdata from Brazilian vital statistics natality and mortality data between 2000 and 2010 to estimate the impact of in-utero exposure to local violence - measured by homicide rates - on birth outcomes. Focusing on small communities, for which it is more credible that local homicide rates reflect actual exposure to violence, the analysis shows that exposure to violence during pregnancy leads to deterioration in birth outcomes: one extra homicide during the first trimester of pregnancy increases the probability of low birthweight by around 6 percent
Secondary School Enrolment and Teenage Childbearing: Evidence from Brazilian Municipalities
This article investigates whether increasing secondary education opportunities influences childbearing among young women in Brazil. We examine a novel dataset reflecting the vast expansion of secondary education in Brazil between 1997 and 2009 and exploit variation in the introduction of schools across 4,884 municipalities to instrument for school enrolment. Our most conservative estimate suggests that for every 9.7 students enrolled there is one fewer teenage births. These findings are robust to a number of specifications and sensitivity tests. Our estimates imply that Brazil’s secondary school expansion accounts for 34% of the substantial decline in teenage childbearing observed over the same period. We further look at heterogeneous effects across a number of municipal characteristics and discuss what these results suggest about the mechanisms underlying the school-childbearing relationship
AS PARALELAS QUE SE ENCONTRAM: ELUCUBRAÇÕES ACERCA DA LEITURA DE “SARGENTO GARCIA”, DE CAIO FERNANDO ABREU
The article undertakes the analysis of a text from the perspective of the homoerotic gaze. In terms of language, homoeroticism expresses a poetic look through suggestive forms, the dance of gestures and in the possibility of the encounter. The translation of these deictics for fiction is the ultimate step taken by Caio Fernando Abreu: his desire for expression through words. The present rereading of his text seeks to take advantage of the image of an impossibility: the meeting of two parallel lines, in order to speak about the limitless possibilities of interpretation which a text raises.O artigo pressupõe a análise de um texto, sob a perspectiva do olhar homoerótico. Em termos de linguagem, o homoerotismo manifesta uma poética do olhar, na insinuação de formas, na dança dos gestos e na possibilidade do encontro. A tradução desses dêiticos para a ficção é o passo a mais dado por Caio Fernando Abreu: sua expressão para os desejos por meio de palavras. A releitura que aqui se apresenta busca tirar proveito da imagem de uma impossibilidade: o encontro de duas retas paralelas, para falar da “infinitude” de possibilidades de leitura que um texto suscita
Too big to fail? : estudo de caso do setor bancário português
Dissertação de mestrado em Economia Monetária, Bancária e FinanceiraEste estudo investiga se a percepção de uma política de salvamentos too big to fail afeta o comportamento dos depositantes portugueses, no período entre 2001 e 2010. Nele buscou-se examinar se o comportamento dos depositantes é melhor explicado pelos fundamentos de gestão e estabilidade bancária ou pela percepção de uma política, mesmo que implícita, de salvamentos too big to fail.
Esta analise é baseada no estudo realizado por Oliveira, Schiozer e Barros (2010) com foco no mercado bancário brasileiro e apresentado no EFMA de 2011 realizado na Universidade do Minho.
Foi utilizado um conjunto de dados em painel com um total de 140 observações, de uma amostra de 14 bancos universais para um período de 10 anos. Estes bancos foram selecionados de acordo com o papel que desempenham no mercado português.
E os resultados sugerem que em Portugal não é consistente afirmar que o comportamento dos depositantes seja influenciado pela percepção de uma política de salvamentos too big to fail.This study investigates if the perception of a too big to fail policy affects depositor behavior in Portugal, for the period 2001 – 2010. It tries to examine if depositor behavior is better explained by Banks’ fundamentals or by the perception of an implicit too big to fail policy.
Our analysis is based at the Oliveira, Schiozer and Barros (2011) study for the Brazilian banking market, presented at EFMA in 2011.
Here were used a panel data of 140 observations, in a sample of 14 universal banks for a period of 10 years. Banks were selected according with their function in the Portuguese banking market.
Results suggest that in Portugal it is not consistent to say that depositors ran from smaller banks to the largest banks because they believed the largest banks were too big to fail
Optimization of estradiol monitoring in raw and treated wastewater samples by response surface methodology
The ever-increasing use of endocrine disruptors compounds (EDCs), through
pharmaceuticals such as synthetic estrogens, both in humans as well as in animals, are raising its
concentration in the environment. Estradiol, also designed as 17β-Estradiol (see Fig. 1), belongs
to the pharmaceutical class of steroid estrogens and was included in the “Watch List” since 2013
the Directive 2013/39/EU due to its potential risk to human health and environment. The low
removal efficiency of estrogens by the conventional wastewater treatment plants (WWTPs),
becomes a major source of their release into different aquatic matrices. Therefore, the
occurrence and, more importantly, the destination of these compounds are matters of utmost
importance towards a better public health.
The aim of this work is the optimization of solid phase extraction/high performance liquid
chromatography (SPE/HPLC) using the response surface methodology (RSM) to detect and
quantify 17β-Estradiol in WWTPs effluents.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support
through national funds FCT/MCTES (PIDDAC) to CIMO (UIDB/00690/2020, UIDP/00690/2020 and
EXPL2021CIMO_05-REMPHARM) and SusTEC (LA/P/0007/2021). J.L. Diaz De Tuesta acknowledges the
financial support of “Comunidad de Madrid” (Spain) for the individual research grant 2020-T2/AMB-19836.info:eu-repo/semantics/publishedVersio
Understanding access barriers to public services : lessons from a randomized domestic violence intervention
We study the effect of decreasing barriers to accessing non-police services on the demand for police services in cases of police-reported domestic violence. Variation comes from a large case-level randomised control trial designed to assist victims in accessing non-police services. Our data link information from local and national police administrative records, and a survey of victims. The intervention led to a robust 21% decrease in the demand for police services, as measured by the provision of a statement by victims. Despite a strong correlation between statements and criminal sanctions against perpetrators, we do not find a corresponding effect of the intervention on perpetrator arrest, charges or sentencing. This suggests that the victims who do not provide a statement because of treatment had a relatively low statement effectiveness. Consistent with this result, we find treatment group statements are significantly less likely to be withdrawn than are control group statements
Monitoring of 17 β-Estradiol in raw and treated waters of wastewater treatment plants
Nowadays, there has been a growing concern regarding the possible consequences of exposure to estrogens through its direct or indirect consumptioninfo:eu-repo/semantics/publishedVersio
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