On the application of optimal wavelet filter banks for ECG signal classification

This paper discusses ECG signal classification after parametrizing the ECG waveforms in the wavelet domain. Signal decomposition using perfect reconstruction quadrature mirror filter banks can provide a very parsimonious representation of ECG signals. In the current work, the filter parameters are adjusted by a numerical optimization algorithm in order to minimize a cost function associated to the filter cut-off sharpness. The goal consists of achieving a better compromise between frequency selectivity and time resolution at each decomposition level than standard orthogonal filter banks such as those of the Daubechies and Coiflet families. Our aim is to optimally decompose the signals in the wavelet domain so that they can be subsequently used as inputs for training to a neural network classifier.

Inconclusive results in conventional serological screening for Chagas` disease in blood banks: evaluation of cellular and humoral response

To find the most reliable screening method for Trypanosoma cruzi infection in blood banks. Epidemiological data, lymphoproliferation assay, parasitological, conventional serological tests: immunofluorescence, haemagglutination, ELISA with epimastigote and trypomastigote antigens and reference serological tests: trypomastigote excreted-secreted antigens (TESA) blot and chemiluminescent ELISA assay with mucine from trypomastigote forms were applied to individuals with inconclusive serology, non-chagasic individuals and chronic chagasic patients. TESA blot had the best performance when used as a single test in all the groups. In the inconclusive group 20.5% of individuals were positive for TESA blot, 23.3% for either lymphoproliferation or TESA blot, and 17.8% for lymphoproliferation only. Positive lymphoproliferation without detectable antibodies was observed in 5.47% of all inconclusive serology cases. Analysis of six parameters (three serological assays, at least one parasitological test, one lymphoproliferation assay and epidemiological data) in the inconclusive group showed that diagnosis of Chagas` disease was probable in 15 patients who were positive by two or more serological tests or for whom three of those six parameters were positive. TESA blot is a good confirmatory test for Chagas` disease in the inconclusive group. Although lymphoproliferation suggests the diagnosis of Chagas` disease in the absence of antibodies when associated with a high epidemiological risk of acquiring Chagas` disease, the data from this study and the characteristics of the lymphoproliferation assay (which is both laborious and time-consuming) do not support its use as a confirmatory test in blood-bank screening. However, our findings underscore the need to develop alternative methods that are not based on antibody detection to improve the diagnosis when serological tests are inconclusive.

Business cycle and bank loan portfolio performance : empirical evidence from brazilian banks

Este trabalho estuda os efeitos do crescimento econômico e da taxas de juros sobre o desempenho de carteiras de empréstimo dos bancos comerciais brasileiros no período de 2000 a 2010. Os resultados empíricos mostram que o crescimento econômico é o principal "driver" para o desempenho da carteira de crédito. Não foram encontradas evidências estatísticas sginificativas de mudanças na taxa de juros sobre o desempenho das carteiras de empréstimos. Além disso, há evidências empíricas de que o impacto do crescimento econômico sobre o desempenho da carteria de crédito tem efeito defasado de 2 trimestres. Por fim, os resultados mostram que alterações de PIB impactam de forma mais significativa o desempenho da carteira de crédito dos bancos comerciais brasileiros maiores. Devido ao efeito multiplicador do mercado de crédito, quanto maior o banco, maior a expansão relativa de sua carteira de crédito e, conseqüentemente a taxa de inadimplência da carteira, que é agravada pela concentração do mercado de crédito no Brasil.

Developing a monitoring and evaluation system for Instituto Palmas: a network of community development banks in Brazil

Bancos comunitários de desenvolvimento no Brasil são instituições únicas que operam de acordo com os princípios da economia solidária em função da inclusão financeira de comunidades carentes. O Instituto Palmas, a instituição que assessora e coordena a rede destes bancos, pediu à Universidade de São Paulo e à Universidade de Columbia em Nova York para desenvolver um conjunto de indicadores que pudesse demonstrar o impacto social e o desempenho institucional dos bancos. Esse relatório apresenta os indicadores, a metodologia utilizada na sua formação, e recomendações para sua utilização. Na medida em que resultados e impacto estão analisados através do uso desses indicadores, a rede dos bancos comunitários e outros interessados terão mais clareza sobre suas funções, seu desempenho, e suas áreas que precisam ser melhoradas para cumprir sua missão – superar a pobreza urbana através da economia solidária.

Citizens vs. banks: institutional drivers of financial market litigiousness in Brazil

This article analyzes the institutional drivers of Brazil’s alarmingly high levels of litigation between clients and financial institutions. Most of the policy oriented literature that explores that phenomenon discusses the impacts of a perceived debtor-friendly bias of Brazilian courts on generating feedback loops of litigation that further increases interest rates and creates adverse selection within the pool of potential debtors. This literature therefore addresses the way courts behave once disputes reach their doorstep; conversely, we take a step back to understand the underlying reasons for why such a large number of disputes end up in courts in the first place. We accordingly attribute endemic litigation in Brazilian financial markets to a framework of political, economic and legal institutions and circumstances, which this article aims to unbound and explain.

The impact of Basel III on European banks business models

O acordo Basel III representa, em diversos aspectos, uma verdadeira mudança no paradigma regulatório. Este trabalho examina uma amostra composta por 81 bancos europeus para detectar até que ponto o impacto do Basel III é já perceptível em modelos de negócios alternativos. Descobre-se que os ajustes nos modelos de negócios causados pelo Basel III são mínimos, enquanto que as principais mudanças entre 2010 e 2013 deveram-se a outros factores exógenos, como por exemplo a crise da dívida soberana europeia. Devido à longa observação e aos períodos de transição, as maiores mudanças nos modelos de negócios como consequência do Basel III estarão ainda para acontecer.

Development banks, risk and Basle II: some assessments

The implementation of the Basle II agreement in the financial markets of world economies has been seen as a significant advance in relation to the model enforced under the first agreement (Basle I). It is generally understood that the new agreement represents a substantial advance in relation to the first because it allows banks to better deal with the risks to which they are exposed. Nevertheless, when the application of these principles to development banks is considered it can be noted that certain inconsistencies exist, notably the fact that these institutions are typically public institutions - or at least strongly dependent on public funding - and they do not operate the payment system of the economy. Therefore, the application of the Basle rules to these institutions does not make sense. This means that Basle does not represent an appropriate set of recommendations for how these institutions should deal with their risks, whether because the proposed form of dealing with risks is inadequate, or because other relevant risks for these institutions are not covered by Basle I and II.

Banks, liquidity crises and economic growth

How do the liquidity functions of banks affect investment and growth at different stages of economic development? How do financial fragility and the costs of banking crises evolve with the level of wealth of countries? We analyze these issues using an overlapping generations growth model where agents, who experience idiosyncratic liquidity shocks, can invest in a liquid storage technology or in a partially illiquid Cobb Douglas technology. By pooling liquidity risk, banks play a growth enhancing role in reducing inefficient liquidation of long term projects, but they may face liquidity crises associated with severe output losses. We show that middle income economies may find optimal to be exposed to liquidity crises, while poor and rich economies have more incentives to develop a fully covered banking system. Therefore, middle income economies could experience banking crises in the process of their development and, as they get richer, they eventually converge to a financially safe long run steady state. Finally, the model replicates the empirical fact of higher costs of banking crises for middle income economies.

Cyclicality of SME Lending and Government Involvement in Banks

Recent regulatory efforts aim at lowering the cyclicality of bank lending because of its potential detrimental effects on financial stability and the real economy. We investigate the cyclicality of SME lending by local banks with vs. without a public mandate, controlling for location, size, loan maturity, funding structure, liquidity, profitability, and credit demand-side factors. The public mandate is set by local governments and stipulates a deviation from strict profit maximization and a sustainable provision of financial services to local customers. We find that banks with a public mandate are 25 percent less cyclical than other local banks. The result is credit supply-side driven and especially strong for savings banks with high liquidity and stable deposit funding. Our findings have implications for the banking structure, financial stability and the finance-growth nexus in a local context.

Cyclicality of SME lending and government involvement in banks

Recent regulatory efforts aim at lowering the cyclicality of bank lending because of its potential detrimental effects on financial stability and the real economy. We investigate the cyclicality of SME lending by local banks with vs. without a public mandate, controlling for location, size, loan maturity, funding structure, liquidity, profitability, and credit demand-side factors. The public mandate is set by local governments and stipulates a deviation from strict profit maximization and a sustainable provision of financial services to local customers. We find that banks with a public mandate are 25 percent less cyclical than other local banks. The result is credit supply-side driven and especially strong for savings banks with high liquidity and stable deposit funding. Our findings have implications for the banking structure, financial stability and the finance-growth nexus in a local context.

Why banks want to be complex

We investigate whether and how bank complexity affects performance and systemic risk. We base the analysis on a complexity measure that captures diversification and diversity, controlling for size and other bank characteristics. We find that more complex banks exhibit a higher profitability, lower risk, and higher market share. Moreover, we show an inversely U-shaped relation between bank complexity and banks’ sensitivity to systemic shocks. The evidence challenges the view that higher bank complexity is per se bad and is consistent with theoretical models that show that diversity in the banking system is critical for financial stability.

Why join a carbon club?: a study of the banks participating in the Brazilian “Business for Climate Platform”

Why do firms that present low levels of (direct) carbon emissions participate in “carbon clubs”, which have the goal of managing and reducing greenhouse gas (GHG) emissions? In order to answer this question, we collected data from both primary and secondary sources from firms operating in the Brazilian banking sector, which are members of the Businesses for Climate Platform (Plataforma Empresas pelo Clima e EPC). We first looked for answers in the institutional theory and resource based view of the firm (RBV). By confronting the arguments presented by these streams of scientific enquiry with empirical data, we worked on theory testing. In particular, we analyzed the institutional pressures and resources and capabilities of the focus companies, in order to understand the rationales for proactive sustainability management. We found evidences of the arguments presented by both the institutional theory and the RBV. By studying an industry that is not a frequent subject to research on socio-environmental issues e for not being considered of high impact e in an emerging market economy, the research contributes to both the further development of the institutional theory and the advancement of sustainability management in corporations.

Biological aspects of the immature stages of Ceraeochrysa everes (Banks) (Neuroptera: Chrysopidae)

Para o estabelecimento de um programa de controle biológico, o conhecimento de alguns aspectos biológicos e de comportamento dos inimigos naturais é de extrema importância. Os aspectos biológicos do desenvolvimento larval e pupal do predador Ceraeochrysa everes (Banks) foram estudados. Larvas oriundas de adultos da geração F1 foram mantidas em laboratório a 25 ± 21°C, 70 ± 10 % UR e fotofase 14 horas, sendo alimentadas com ovos de Sitotroga cerealella (Olivier). A duração e viabilidade do período embrionário, estágios imaturos de desenvolvimento e o período de ovo a adulto foram avaliados. O período embrionário foi em média de 5,0 dias, enquanto que as durações médias para o primeiro, segundo e terceiro instares foram de 5,1 ± 0,03; 4,3 ± 0,05 e 4,5 ± 0,05 dias, respectivamente, com viabilidade superior a 90 %. Os estágios larval, pré-pupal e pupal apresentaram duração média de 13,9 ± 0,07; 5,7 ± 0,07 e 9,6 ± 0,12 dias, respectivamente. A duração do ciclo biológico foi de 34 ± 0,11 dias em média. Ovos de S. cerelella não foram adequados para a manutenção de C. everes em laboratório, por interferir no desenvolvimento do predador.

Psychotria hoffmansegiana (Willd ex Roem. & Schult.) Mull. Arg. and Palicourea marcagravii st. Hil. (Rubiaceae): potential for forming soil seed banks in a brazilian Cerrado

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Biologia de Polyphagotarsonemus latus (Banks) (Acari: Tarsonemidae) em limão siciliano (Citrus limon Burm)

No estudo da biologia de Polyphagotarsonemus latus em limão Siciliano, foram utilizados potes plásticos circulares com capacidade de 250 ml, contendo areia esterilizada como suporte para dois frutos novos com aproximadamente 2,0 cm de diâmetro. O ensaio foi conduzido a 27,1 ± 0,5°C, umidade relativa de 67,6 ± 1,3% e fotofase contínua. O período de ovo a adulto durou 3,7 ± 0,1 dias para fêmeas e 3,6 ± 0,1 dias para machos, com sobrevivência de 100%. Após um período de pré-oviposição de 1,0 ± 0,2 dias, as fêmeas depositaram 5,6 ± 0,5 ovos por dia durante 10,5 ± 0,9 dias, totalizando 58,9 ± 6,7 ovos por fêmea. A longevidade foi de 13,4 ± 1,0 dias para fêmeas e 12,0 ± 2,4 dias para machos. A razão intrínseca de aumento (rm) foi de 0,359, a razão finita de aumento (l) de 1,43 indivíduos por fêmea por dia, o tempo médio de uma geração (T) de 10,34 dias e a taxa líquida de reprodução (Ro) de 41,0.