Seasonality of suicide in the city of Sao Paulo, Brazil, 1979-2003 Sazonalidade do suicídio na cidade de São Paulo, Brasil, 1979-2003

OBJECTIVE: To evaluate suicide seasonality in the city of São Paulo within an urban area and tropical zone. METHOD: Suicides were evaluated using the chi-square test and analysis of variance (ANOVA) by comparing monthly, quarterly and half-yearly variations, differentiating by gender. Analyses of time series were carried out using the autocorrelation function and periodogram, while the significance level for seasonality was confirmed with the Fisher's test. RESULTS: The suicides of the period between 1979 and 2003 numbered 11,434 cases. Differences were observed in suicides occurring in Spring and Autumn for the total sample (ANOVA: p-value = 0.01), and in the male sample (ANOVA: p-value = 0.02). For the analysis of time series, seasonality was significant only for the period of 7 months in the male sample (p-value = 0.04). DISCUSSION: In this study, no significant seasonal differences were observed in the occurrences of suicides, with the exception of the male sample. The differences observed did not correspond with the pattern described in studies carried out in temperate zones. Some of the climatic particularities of the tropical zone might explain the atypical pattern of seasonality of suicides found in large populations within an urban area and tropical zone.<br>OBJETIVO: Avaliar a sazonalidade do suicídio na cidade de São Paulo, uma área urbana em zona tropical. MÉTODO: Os suicídios foram avaliados pelo teste de qui-quadrado e análise de variância (ANOVA), comparando variações mensais, trimestrais e semestrais, diferenciando por gênero. Também foi realizada a análise de séries temporais, utilizando a função de autocorrelação e periodograma, além da confirmação, com o teste de Fisher de significância para sazonalidade. RESULTADOS: Os suicídios do período entre 1979 e 2003 totalizaram 11.434 casos. Foram observadas diferenças apenas nos suicídios ocorridos na primavera e outono na amostra total (ANOVA: p-valor = 0,01), e na amostra para o sexo masculino (ANOVA: p-valor = 0,02). Pela análise de séries temporais, a sazonalidade foi significativa apenas para o período de sete meses, na amostra para o sexo masculino (p-valor = 0,04). DISCUSSÃO: Neste estudo não foram observadas diferenças sazonais significativas na ocorrência de suicídios, com exceção da amostra masculina. Tais diferenças não correspondem ao padrão descrito nos estudos realizados em zona temperada. Algumas das particularidades climáticas da zona tropical poderiam explicar o padrão atípico de sazonalidades de suicídios em uma grande população de área urbana e zona tropical

Influence of the Alkali Promoter on the Activity and Stability of Transition Metal (Cu, Co, Fe) Based Structured Catalysts for the Simultaneous Removal of Soot and NOx

Structured catalysts prepared by means of coating cordierite monoliths with alumina-based suspensions containing transition metals such as Cu, Co and Fe and alkali/alkali-earth promoters such as K and Ba. Textural and structural features of these catalysts were analyzed by means of N2 adsorption and SEM. Their activity in the simultaneous removal of soot and NOx was assayed in a lab-scale installation, using a carbon black as diesel surrogate. Catalysts exhibited significant activity in deNOx and soot oxidation. K and Ba enhanced both NOx adsorption and soot–catalyst contact. However Ba contributed to a greater extent to the adsorption of N-species, which moreover presented higher thermal stability than on K-catalysts, and K showed higher mobility than Ba. Thus, Ba-containing catalysts showed increased activity towards NOx reduction but shifted to higher temperatures in comparison to K-catalysts, which on the other hand resulted more active towards soot oxidation than Ba-ones. Fe-based catalyst turned out to be less active both in soot oxidation and NOx reduction than Co and Cu-based ones. Intensive calcination of the catalysts at 800 °C for 5 h resulted in substantial loss of K and Ba. Loss of promoter depends, however, on the metal contained in the catalyst. In this sense Fe-containing catalysts showed higher stability. Calcination has a substantial effect on catalytic activity. Catalyst significantly lost their NOx adsorption capacity and showed similar activity than a catalyst prepared in absence of promoter, pointing to a substantial change in reaction mechanism and reaction predominantly occurring on metallic sites upon the loss of alkali/alkali-earth compound

Detailed Modeling of Carbon Oxidation

The kinetics of low-temperature oxidation of a synthetic carbon black material, i.e. Printex- U, by gaseous oxygen is modeled via conventional mean-field treatment of various detailed reaction schemes as well as lumped models. The significance of different elementary steps is elucidated by comparing predicted CO and CO2 formation during temperature programmed and isothermal carbon oxidation with the corresponding experimental data. In specific the connection between oxidation rate and surface coverages of reaction intermediates is demonstrated. The results suggest that activation of the carbon surface by oxygen adsorption is a key-step for further carbon oxidation and that gas phase oxygen plays a direct role in the formation of CO and CO2. Furthermore, the results suggest that Printex-U is preferably modeled as spherical shaped particles, especially at high conversion stages

Cuidando de quem não tem família: percepção de mães acolhedoras sobre esta experiência

Objetivou-se apreender os sentimentos de mães em relação à experiência de acolher temporariamente uma criança no seio familiar e as mudanças ocorridas em decorrência desta experiência. Trata-se de estudo descritivo, de natureza qualitativa, realizado com sete mães acolhedoras. Os dados foram coletados em junho de 2012 por meio de entrevistas semi-estruturadas e submetidos à Análise de Conteúdo. Os resultados mostram que a experiência de acolher uma criança é decorrente da conscientização sobre a importância desta atividade, que o vínculo com a mesma surge naturalmente, toda a família é envolvida em seu cuidado e a rotina familiar é adaptada às suas necessidades. As famílias experimentam sentimentos de alegria e satisfação decorrente da convivência com a criança e preocupação e tristeza quando ela vai embora. Conclui-se que acolher traz benefícios para as crianças e também famílias, entretanto, estas necessitam de acompanhamento profissional para que esta atividade não prejudique a saúde da unidade familiar