Os impactos da política monetária na taxa de câmbio no Brasil

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Sócio-Econômico, Programa de Pós-Graduação em Economia, Florianópolis, 2015.O presente trabalho busca analisar os efeitos da política monetária sobre a taxa de câmbio, no período de 2004-2014, considerando o problema de endogeneidade da política monetária. É utilizado um modelo de variáveis instrumentais que estima os efeitos de uma variação na taxa de juros sobre a variação da taxa de câmbio. Para tratar do problema da endogeneidade da política monetária é empregado o método de identificação via heterocedasticidade. A principal vantagem deste método é que ele se baseia no comportamento estatístico das séries, não sendo necessário realizar suposições arbitrárias de identificação. Os resultados mostram que há uma relação positiva entre a taxa de juros e a taxa de câmbio durante todo período analisado e não só em momentos de elevação da taxa de juros.Abstract : This study aims to analyze the effects of monetary policy on the exchange rate during the period of 2004-2014, taking into account the endogeneity problem of monetary policy. It used a model of instrumental variables which estimates the effects of a change in the interest rate on a change in the exchange rate. To address the problem of endogeneity of monetary policy it is used the method of identification via heteroskedasticity. The main advantage is that this method is based on the statistical behavior of the series, it is not necessary to make arbitrary assumptions of identification. The results show that there is a positive relationship between the interest rate and the exchange rate throughout the period analyzed and not only in times of high interest rates

O pass‑through da taxa de câmbio para índices de preços: análise empírica para o Brasil

O presente artigo objetiva analisar empiricamente a relação entre taxa de câmbio e preços no Brasil no período de 1999 a 2012. Adicionalmente apresenta‑se uma revisão da literatura teórica e empírica destacando os canais de transmissão do câmbio para os índices de preços tanto no âmbito micro quanto macroeconômico. Para alcançar o objetivo proposto, utilizou‑se o procedimento econométrico de séries temporais através do Vetor de Correção de Erros. Os resultados encontrados sugerem uma relação de longo prazo entre câmbio e os índices de preços domésticos em análise, embora seja possível constatar um grau de pass‑through incompleto. Observa‑se também que o repasse é maior para o índice de preços (IGPDI) com maior componente de preços por atacado

Biochemical and molecular heterogeneity in carnitine palmitoyltransferase ii deficiency

Introduction: Carnitine palmitoytransferase II (CPTII) deficiency is a recessively inherited disorder of lipid metabolism. CPT II deficiency has several clinical presentations: the adult form is characterized by episodes of rhabdomyolysis, usually triggered by extensive exercice, cold, fever or prolonged fasting and the infantile-type CPT II hepatocardiomuscular form presents as severe attacks of hypoketotic, hypoglycemia, occasionally associated with cardiac damage. Molecular analysis of CPT II gene allows not only confirmation of classical forms, with typical biochemical abnormalities, but is also key for the diagnosis of less severe forms.The authors will present biochemical and molecular findings of eight CPT II, patients. Material and methods: Acylcarnitine profiles, on dried blood spots, were done as previously reported (Vilarinho et al) Molecular analysis of CPT II gene was done by direct sequencing as reported elsewhere (Finocchiaro et al.). From the eight patients, three were detected through newborn screening and five with clinical symptoms. Results: More pronounced abnormalities in the acylcarnitine profiles are associated with neonatal forms of the disease, while the patients with late onset forms present smother alterations or completely normal profiles. This biochemical heterogeneity correlates well with genetics data. The molecular analysis revealed the presence of ten different mutations, which seven were never reported. Discussion: Our results support that newborn screening can efficiently detect infantile CPT II deficiency but is less effective in detecting adult forms, were biochemical abnormalities may only be present during acute episodes. In these cases accurate clinical characterization alongside with molecular analysis are the key for diagnosis. Bibliography: J.P. Bonnefont, F. et al (2004) Mol. Aspects Med. 25 495–520. Rashed MS, et al.(1995) Diagnosis of inborn errors of metabolism from blood spots by acylcarnitines and amino acids profiling using automated electrospray tandem mass spectrometry. Pediatr Res.38:324–331 Finocchiaro, G. et al (1991). cDNA cloning, sequence analysis, and chomosomal localization of the gene for human carnitinepalmitoyltransferase. Proc. Natl. Acad. Sci. USA 88, 661–665. K. Gempel1 et al. (2002).Screening for Carnitine Palmitoyltransferase II Deficiency by Tandem Mass Spectrometry Anichini A.et al(2011) Genotype-phenotype correlations in a large series of patients with muscle type CPT II deficiency Vilarinho et al. (2009) Four Years of Expanded Newborn Screening in Portugal with MS/M

Deep mining of oxysterols and cholestenoic acids in human plasma and cerebrospinal fluid: Quantification using isotope dilution mass spectrometry

Both plasma and cerebrospinal fluid (CSF) are rich in cholesterol and its metabolites. Here we describe in detail a methodology for the identification and quantification of multiple sterols including oxysterols and sterol-acids found in these fluids. The method is translatable to any laboratory with access to liquid chromatography – tandem mass spectrometry. The method exploits isotope-dilution mass spectrometry for absolute quantification of target metabolites. The method is applicable for semi-quantification of other sterols for which isotope labelled surrogates are not available and approximate quantification of partially identified sterols. Values are reported for non-esterified sterols in the absence of saponification and total sterols following saponification. In this way absolute quantification data is reported for 17 sterols in the NIST SRM 1950 plasma along with semi-quantitative data for 8 additional sterols and approximate quantification for one further sterol. In a pooled (CSF) sample used for internal quality control, absolute quantification was performed on 10 sterols, semi-quantification on 9 sterols and approximate quantification on a further three partially identified sterols. The value of the method is illustrated by confirming the sterol phenotype of a patient suffering from ACOX2 deficiency, a rare disorder of bile acid biosynthesis, and in a plasma sample from a patient suffering from cerebrotendinous xanthomatosis, where cholesterol 27-hydroxylase is deficient

Diagnóstico das Doenças Mitocondriais por Sequenciação de Nova Geração

Introdução e objetivos: As doenças mitocondriais constituem um importante grupo de doenças metabólicas de expressão clínica heterogénea, para as quais não existe uma terapia eficaz. Estas patologias podem ser causadas por defeitos genéticos quer no genoma mitocondrial, quer no nuclear. A sequenciação de nova geração (NGS) revolucionou o diagnóstico molecular destas doenças, uma vez que tem capacidade de gerar uma enorme quantidade de dados num curto espaço de tempo a um custo acessível. O objetivo deste estudo [Financiado pela FCT (PTDC/DTP-PIC/2220/2014) e pelo Norte 2020 (NORTE-01-0246-FEDER-000014)] é desenvolver uma estratégia de NGS para permitir o diagnóstico genético de doentes suspeitos de doenças mitocondriais.info:eu-repo/semantics/draf

SARS-CoV-2 introductions and early dynamics of the epidemic in Portugal

Genomic surveillance of SARS-CoV-2 in Portugal was rapidly implemented by the National Institute of Health in the early stages of the COVID-19 epidemic, in collaboration with more than 50 laboratories distributed nationwide. Methods By applying recent phylodynamic models that allow integration of individual-based travel history, we reconstructed and characterized the spatio-temporal dynamics of SARSCoV-2 introductions and early dissemination in Portugal. Results We detected at least 277 independent SARS-CoV-2 introductions, mostly from European countries (namely the United Kingdom, Spain, France, Italy, and Switzerland), which were consistent with the countries with the highest connectivity with Portugal. Although most introductions were estimated to have occurred during early March 2020, it is likely that SARS-CoV-2 was silently circulating in Portugal throughout February, before the first cases were confirmed. Conclusions Here we conclude that the earlier implementation of measures could have minimized the number of introductions and subsequent virus expansion in Portugal. This study lays the foundation for genomic epidemiology of SARS-CoV-2 in Portugal, and highlights the need for systematic and geographically-representative genomic surveillance.We gratefully acknowledge to Sara Hill and Nuno Faria (University of Oxford) and Joshua Quick and Nick Loman (University of Birmingham) for kindly providing us with the initial sets of Artic Network primers for NGS; Rafael Mamede (MRamirez team, IMM, Lisbon) for developing and sharing a bioinformatics script for sequence curation (https://github.com/rfm-targa/BioinfUtils); Philippe Lemey (KU Leuven) for providing guidance on the implementation of the phylodynamic models; Joshua L. Cherry (National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health) for providing guidance with the subsampling strategies; and all authors, originating and submitting laboratories who have contributed genome data on GISAID (https://www.gisaid.org/) on which part of this research is based. The opinions expressed in this article are those of the authors and do not reflect the view of the National Institutes of Health, the Department of Health and Human Services, or the United States government. This study is co-funded by Fundação para a Ciência e Tecnologia and Agência de Investigação Clínica e Inovação Biomédica (234_596874175) on behalf of the Research 4 COVID-19 call. Some infrastructural resources used in this study come from the GenomePT project (POCI-01-0145-FEDER-022184), supported by COMPETE 2020 - Operational Programme for Competitiveness and Internationalisation (POCI), Lisboa Portugal Regional Operational Programme (Lisboa2020), Algarve Portugal Regional Operational Programme (CRESC Algarve2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF), and by Fundação para a Ciência e a Tecnologia (FCT).info:eu-repo/semantics/publishedVersio

Mechanisms of early immune activation in response to hepatitis B virus.

Doutoramento em Ciências Biomédica

Identificando padrões intradiários de comunalidade na liquidez do mercado de taxas de câmbio

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Sócio-Econômico, Programa de Pós-Graduação em Economia, Florianópolis, 2019.O presente trabalho apresenta uma nova visão sobre a comunalidade na liquidez. Não interessado apenas na relação entre os pares de moedas, busca-se identificar co-movimentos entre um par de moeda e dois grupos distintos. Um grupo é composto pelas maiores e mais negociadas moedas do mercado, ou seja, um grupo de alta liquidez. O outro grupo conta com pares de moedas de países com a classificação de emergentes. O segundo grupo busca agregar países que, de forma geral, possuem características macroeconômicas em comum. Observando um componente em comum com esses grupos é possível inferir como a liquidez de uma moeda responde a liquidez geral do mercado e ao desempenho do seu grupo de países. Com o presente trabalho é possível reafirmar a existência de padrões intradiários que até então não foram explorados em profundidade para as taxas de câmbio. Considerando que o mercado de FX é um mercado contínuo, aberto 24 horas por dia, o conhecimento desses padrões é fundamental não só para estratégias de negociação, que também pode ser útil na definição de políticas, como intervenções dos bancos centrais na taxa de câmbio. A principal abordagem para a comunalidade na liquidez das taxas de câmbio ainda é linear e com algumas aplicações mais recentes de séries temporais. Neste sentido, foram realizados dois testes não lineares. O primeiro utilizou redes neurais recorrentes do tipo LSTM para verificar se o padrão intradiário é um bom preditor do comportamento futuro da séries, apresentando bons resultados nas previsões do valor médio das séries. Também foi aplicado um modelo de séries temporais baseado no TVP-VAR, com o objetivo de verificar o comportamento da comunalidade ao longo da amostra. A partir desse resultado tem-se argumentos para seguir investigando a possibilidade de que a comunalidade da liquidez entre as moedas seja uma relação não linear. No entanto, a generalização de um modelo não linear ainda necessita de mais desenvolvimentos.Abstract: This paper presents a new view on commonality in liquidity. Not only interested in the relationship between currency pairs, we seek to identify co-movements between a currency pair and two distinct groups. A group composed of the largest and most traded currencies in the market, ie a highly liquid group. The other group has currency pairs from emerging-rated countries. The second group seeks to aggregate countries that, generally, have common macroeconomic characteristics. Looking at a common component with these groups, it is possible to infer how the liquidity of a currency responds to the overall liquidity of the market and the performance of its group of countries. With the present work it is possible to reaffirm the existence of intraday patterns that until then have not been explored in depth for exchange rates. Given that the FX market is a continuous, open market 24 hours a day, knowledge of these patterns is critical not only for trading strategies but also for its usefulness in shaping policies such as central bank exchange rate interventions. . The main approach to commonality in exchange rate liquidity is still linear and with some more recent time series applications. In this sense, two nonlinear tests were performed. The first used LSTM recurrent neural networks to verify if the intraday pattern is a good predictor of the future behavior of the series, presenting good results in the prediction of the mean value of the series. A time series model based on TVP-VAR was also applied to verify the behavior of commonality throughout the sample. From this result we have arguments to continue investigating the possibility that the commonality of liquidity between currencies is a nonlinear relationship. However, the generalization of a nonlinear model still needs further development