Efficient Yield Curve Estimation and Forecasting in Brazil

Term Structure of the Interest Rate, Yield Curve, State-Space Model, Kalman Filter.

Bio-Optical Modeling in a Tropical Hypersaline Lagoon Environment

In this chapter, we attempted to present an overview of the use of remote sensing to monitor water quality parameters, mainly chlorophyll-a (chl-a) and turbidity. We summarized the main concepts of bio-optical modeling and presented a case study of the application of the Hyperspectral Imager for the Coastal Ocean (HICO) for the monitoring of water quality in a tropical hypersaline aquatic environment. Using HICO, we evaluated a set of different semi-empirical bio-optical algorithms for chl-a and turbidity estimation developed for inland and oceanic waters in the Araruama Lagoon, RJ, Brazil, which is an extreme environment due to its high salinity values. We also developed an empirical algorithm for both water quality parameters and compared the performances. Results showed that for chl-a estimation all models have a low performance with a normalized root mean square error (NRMSE) varying from 24.13 to 30.46. For turbidity, the bio-optical algorithms showed a better performance with the NRMSE between 15.49 and 28.04. Overall, these results highlight the importance of including extreme environments, such as the Araruama Lagoon, on the validation of bio-optical algorithms as well as the need for new orbital hyperspectral sensors which will improve the development of the field

Basic Income with Digital Community Currency: Digital Platforms for Public Policies Implementation During Pandemic Crisis

This short paper presents a research-in-progress that discusses how basic income policies can be implemented using digital currency platforms and the implications of this approach in the context of the pandemic. We analyze the case of Banco Mumbuca, a non-profit organization that uses a community currency on a digital payment platform, E-Dinheiro, to deliver the basic income program of the Brazilian town of Maricá. This city program became one of the largest in the world during the COVID-19 pandemic, considering both the amount of money transferred to municipal beneficiaries and the adoption rate of a community currency by citizens and the local commerce. We adopt the Design Science Research (DSR) approach to analyze the case, considering this implementation as two entangled sub-artifacts: the public policy and the digital community currency. These sub-artifacts will be analyzed from the perspective of the problems they intend to solve, the particular aspects of the designed solution, the evaluation of the solution by actors involved, and the discussion of the achieved outcomes. This study intends to contribute to the basic income discussion that emerged as a solution for economic recovery from the COVID-19, the strategies for scaling up community currencies, and the DSR as a strategy for producing impactful research in the ICT4D field

Ondaietas e previsão de séries de tempo: uma análise empírica

This paper presents three case studies in time series forecasting. We try to compare the use of traditional ARIMA models with an alternative method that combines of ARIMA and Wavelets models. Two different approaches are applied. In the first one, Wavelets are used to fraction the original time series, so that ARIMA forecasting is performed on the ffactioned series. The fractioned forecasting is then jointed to obtain the original series forecasting. The second alternative method consist in using Wavelets to smooth the original series before using traditional ARIMA forecasting

COST of PNEUMONIA HOSPITALIZATION in ELDERLY PEOPLE FROM TWO LARGE BRAZILIAN HOSPITALS

Universidade Federal de São Paulo, São Paulo, BrazilAxia Bio Consulting, São Paulo, BrazilSanofi Aventis Brasil, São Paulo, BrazilSanofi Pasteur, Lyon 07, FranceUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc

Estudo preliminar dos microfósseis (ostracodes, radiolários e foraminíferos) do Cretáceo Superior da porção noroeste da Ilha James Ross, Antártica

Estudos micropaleontológicos para a porção noroeste da Ilha James Ross são raros e revestem-se de grande importância para a compreensão e a evolução geológica da Península Antártica. A Bacia James Ross foi formada por diversos eventos extensivos de bacias de retro-arco, durante o meso-Mesozóico ao neo-Cenozóico. A seção estudada está inserida nas unidades litológicas Formação Whisky Bay (Albiano ao Coniaciano) e Formação Santa Marta (Santoniano ao Campaniano). Foram analisadas 159 amostras oriundas de afloramentos, coletadas durante o verão de 2007 pelo Museu Nacional/RJ. As amostras são constituídas de rochas sedimentares clásticas finas a grossas. Para sua preparação foram utilizados os métodos usuais com peróxido de hidrogênio (H2O2) e a posterior separação em quatro diferentes frações. O objetivo desse trabalho é a identificação taxonômica da microfauna recuperada que inclui ostracodes, radiolários e foraminíferos. Os ostracodes pertencem aos gêneros Bythocypris, Cytherella, Majungaella e Paracypris característicos de uma fauna marinha e de idade campaniana. Em relação aos radiolários foram encontrados espumelários e nasselários, pertencentes às espécies Archaeodictyomitra squinaboli Pessagno, Praeconocaryomma californiensis? Pessagno, Stichomitra livermorensis? Campbell e Clark, Stichomitra sp., Pseudoaulophacus sp., Pseudodictyomitra sp., Paronaella sp. e Cryptamphorella sphaerica? White. A fauna de radiolários caracteriza-se pela presença de espécies consideradas cosmopolitas e espumelários esféricos esponjosos indeterminados. As espécies identificadas como Archaeodictyomitra squinaboli Pessagno e Praeconocaryomma californiensis? Pessagno são restritas ao Cretáceo Superior. Os foraminíferos apresentaram-se mais abundantes nas amostras, tendo sido recuperadas as espécies bentônicas Pyrgo sp., Fissurina sp., Lenticulina sp., Textularia sp. e Ammodiscus sp. A associação dos foraminíferos bentônicos bem como dos ostracodes encontrados, permite inferir um ambiente plataforma externa para a regiãoSimposio VI: Microfósiles del Mesozoico y Cenozoico de América del Sur y Antártida. Nuevas aplicaciones y problemáticas asociadasFacultad de Ciencias Naturales y Muse

Determination of the acidity of MCM-41 with different Si/Al ratios by the temperature programmed Desorption of Pyridine

Mesoporous catalysts of MCM-41 type with different Si/Al ratios were synthesized by the hydrothermal method and characterized by X-ray diffraction, nitrogen adsorption and thermogravimetric analysis. Their acidic properties were determined via the temperature programmed desorption of pyridine. Vyazovkin kinetic models were used to correlate the total acidity as a function of the Si/Al ratio with the apparent activation energy for pyridine desorption. The results obtained indicated that the catalysts possessed weak and medium acidic sites. An increase in the Si/Al ratio led to an increase in the activation energy for pyridine desorption

Patterns of viral load in chronic hepatitis B

ABSTRACT Serum hepatitis B virus (HBV) DNA level is a predictor of the development of cirrhosis and hepatocellular carcinoma in chronic hepatitis B patients. Nevertheless, the distribution of viral load levels in chronic HBV patients in Brazil has yet to be described. This cross-sectional study included 564 participants selected in nine Brazilian cities located in four of the five regions of the country using the database of a medical diagnostics company. Admission criteria included hepatitis B surface antigen seropositivity, availability of HBV viral load samples and age ≥ 18 years. Males comprised 64.5% of the study population. Mean age was 43.7 years. Most individuals (62.1%) were seronegative for the hepatitis B e antigen (HBeAg). Median serum ALT level was 34 U/L. In 58.5% of the patients HBV-DNA levels ranged from 300 to 99,999 copies/mL; however, in 21.6% levels were undetectable. Median HBV-DNA level was 2,351 copies/mL. Over 60% of the patients who tested negative for HBeAg and in whom ALT level was less than 1.5 times the upper limit of the normal range had HBV-DNA levels > 2,000 IU/mL, which has been considered a cut-off point for indicating a liver biopsy and/or treatment. In conclusion, HBV-DNA level identified a significant proportion of Brazilian individuals with chronic hepatitis B at risk of disease progression. Furthermore, this tool enables those individuals with high HBV-DNA levels who are susceptible to disease progression to be identified among patients with normal or slightly elevated ALT