Connections between the Sznajd model with general confidence rules and graph theory

The Sznajd model is a sociophysics model that is used to model opinion propagation and consensus formation in societies. Its main feature is that its rules favor bigger groups of agreeing people. In a previous work, we generalized the bounded confidence rule in order to model biases and prejudices in discrete opinion models. In that work, we applied this modification to the Sznajd model and presented some preliminary results. The present work extends what we did in that paper. We present results linking many of the properties of the mean-field fixed points, with only a few qualitative aspects of the confidence rule (the biases and prejudices modeled), finding an interesting connection with graph theory problems. More precisely, we link the existence of fixed points with the notion of strongly connected graphs and the stability of fixed points with the problem of finding the maximal independent sets of a graph. We state these results and present comparisons between the mean field and simulations in Barabasi-Albert networks, followed by the main mathematical ideas and appendices with the rigorous proofs of our claims and some graph theory concepts, together with examples. We also show that there is no qualitative difference in the mean-field results if we require that a group of size q > 2, instead of a pair, of agreeing agents be formed before they attempt to convince other sites (for the mean field, this would coincide with the q-voter model).

Prevalence of influenza and adherence to the anti-flu vaccination among elderly

Introduction: The flu, a condition that can affect the elderly by increasing the risk of serious complications can be prevented through vaccination. Estimate the prevalence of signs and symptoms suggestive of influenza in a group of elderly either vaccinated or unvaccinated against influenza was the objective this study. Methods: This is a cross-sectional study performed in a Brazilian City. A structured questionnaire was employed to identify the presence of signs and symptoms of influenza in individuals aged 60 years or over. For analysis of associations between variables the prevalence ratio (PR) and its 95% confidence interval (95% CI) were used. Results: One hundred ninety-six participants were interviewed, of whom 57.7% were female. The average age was 69.7 years. About 25% of the vaccinated and 20% of the unvaccinated in 2009, and 25% of the vaccinated and 22.5% of the unvaccinated in 2010 reported having the flu. Among the vaccinated and unvaccinated in 2009 and 2010, there was no verified association between vaccination and influenza (PR=1.24; [95% CI: 0.63-2.43] and PR=1.11; [95% CI: 0.59-2.09], respectively). Conclusions: This study suggests that, among the elderly selected, the vaccination coverage for influenza is below the ideal, even with projection of the best indices for 2011 ((similar to)84%). The data on vaccination and disease protection needs further research; however, the results point to the need for measures to better clarify to this population about the disease, its complications and the benefits of vaccination, in addition to combatting the stigma related to low adherence.

Avaliação ecocardiográfica do átrio esquerdo de cães sadios por meio do modo-M convencional e do modo bidimensional

Avaliaram-se o átrio esquerdo (AE) utilizando-se o método bidimensional (2-B) (corte transverso) e a relação átrio esquerdo:aorta (AE:Ao), em um grupo de 40 cães adultos e sadios, entre um, cinco e sete anos de idade e com pesos corpóreos de 3,2kg a 38,3kg, e compararam-se esses valores aos do modo-M convencional. Observou-se diferença entre AE e Ao nos dois métodos e entre os seus respectivos índices. A correlação foi positiva alta entre peso e superfície corpórea e entre AE no modo 2-B (AEB) e AE no modo-M (AEM). Não se observou correlação entre os índices, nos dois métodos, com o peso e a superfície corpórea, isto é, os índices são independentes do peso ou da superfície corpórea. Concluiu-se que o AEB é maior do que o AEM, o índice médio para o AEB:AoB é de 1,379, e o intervalo de confiança de 1,337 a 1,422. O índice no método 2-B é, portanto, superior ao índice no modo-M.

Prevalence of excessive daytime sleepiness and associated factors in women aged 35-49 years from the "Pindamonhangaba Health Project" (PROSAPIN)

OBJETIVO: Estimar a prevalência da sonolência diurna excessiva (SDE) e identificar os fatores associados em mulheres de 35 a 49 anos de idade do "Projeto de Saúde de Pindamonhangaba" (PROSAPIN). MÉTODOS: O estudo foi observacional transversal com 372 mulheres com idade entre 35 e 49 anos selecionadas aleatoriamente da Estratégia Saúde da Família (ESF) do município de Pindamonhangaba, São Paulo, onde é desenvolvido o "Projeto de Saúde de Pindamonhangaba" (PROSAPIN). A SDE foi avaliada por entrevista utilizando a Escala de Sonolência de Epworth e os fatores associados por meio de questões que investigaram as características sócio-demográficas, a história ginecológica, a presença de comorbidades, o estilo de vida, a rotina de sono e o uso de medicamentos capazes de alterar o estado de alerta, além de mensuradas as variáveis antropométricas. Estimou-se a prevalência da SDE com intervalo de confiança de 95% (IC 95%) e foram identificados os fatores associados por meio de um modelo de regressão logística múltipla realizado no Programa Stata, versão 10.0. RESULTADOS: A prevalência da SDE foi de 18,5% (IC 95%: 14,7- 22,9) e os fatores associados foram: profissão relacionada a serviços domésticos (OR = 2,2; IC 95%: 1,1-4,3), nível de atividade física acima da média da população estudada (OR = 1,9; IC 95%: 1,1-3,4); e a presença de características sugestivas de ansiedade (OR = 1,9; IC 95%: 1,1-3,4). CONCLUSÃO: A prevalência da SDE em mulheres de 35 a 49 anos do PROSAPIN foi elevada e associada à característica sociodemográfica, à presença de comorbidades e ao estilo de vida.

Early stroke case-fatality rates in three hospital registries in the Northeast and Southeast of Brazil

Few studies have addressed early cerebrovascular lethality in Brazil. Objective: To evaluate 10 and 28-day stroke case-fatality rates in three hospitals in three Brazilian cities. Methods: We described the stroke registries in Sao Paulo, Joao Pessoa, and Natal. Results: Out of a total of 962 first-ever events (mean age, 68.1 years-old; 53% men), 83.6% (804 cases) were classified as ischemic and 16.4% (158) as hemorrhagic stroke. Overall, the case-fatality rates and 95% confidence intervals (95% CI) for hemorrhagic stroke events were higher than for ischemic events, both at 10 (12.3%; 95% CI 7.2-17.4 versus 7.0%; 95% CI 5.3-8.8) and at 28 days (19.8%; 95% CI 13.6-26.0 versus 11.1%; 95% CI 8.9-13.3). Conclusions: We did not find any substantial differences in early case-fatality rates according to stroke subtypes, when comparing the three centers.

Modified technique to increase nostril cross-sectional area after using rib and septal cartilage graft over alar nasal cartilages

PURPOSE: Describe a modified technique to increase nostril cross-sectional area using rib and septal cartilage graft over alar nasal cartilages. METHODS: A modified surgical technique was used to obtain, carve and insert cartilage grafts over alar nasal cartilages. This study used standardized pictures and measured 90 cadaveric nostril cross-sectional area using Autocad (c); 30 were taken before any procedure and 60 were taken after grafts over lateral crura (30 using costal cartilage and 30 using septal cartilage). Statistical analysis were assessed using a model for repeated measures and ANOVA (Analysis of Variance) for the variable "area". RESULTS: There's statistical evidence that rib cartilage graft is more effective than septal cartilage graft. The mean area after the insertion of septal cartilage graft is smaller than the mean area under rib graft treatment (no confidence interval for mean difference contains the zero value and all P-values are below the significance level of 5%). CONCLUSIONS: The technique presented is applicable to increase nostril cross section area in cadavers. This modified technique revealed to enhance more nostril cross section area with costal cartilage graft over lateral crura rather than by septal graft.

Satisfaction with the treatment, confidence and 'naturalness' in engaging in sexual activity in men with psychogenic erectile dysfunction: preliminary results of a randomized controlled trial of three therapeutic approaches

OBJECTIVE To assess the efficacy of group psychotherapy (GTP) and/or sildenafil for psychogenic erectile dysfunction (ED). PATIENTS AND METHODS A randomized controlled single-blind trial was performed at the Institute of Psychiatry of the Medical School of at Universidade de Sao Paulo, Sao Paulo, Brazil. In all, 30 men with mild and moderate psychogenic ED were randomized to receive for 6 months: GPT plus 50 mg sildenafil on-demand, or 50 mg sildenafil on-demand exclusively, or GPT exclusively. Changes in score from baseline for three questions of the Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS) were evaluated at endpoint and after 3-months follow-up. RESULTS Satisfaction with the treatment, confidence and 'naturalness' increased in the GPT plus sildenafil and GPT exclusively groups (P = 0.001) from baseline to endpoint. The treatment-by-time comparison was not significant at endpoint vs the 3-month follow-up, in the three groups. There was no difference in the sildenafil group in the three study periods (P > 0.05) CONCLUSION Men with mild and moderate psychogenic ED had higher treatment satisfaction, confidence and naturalness in engaging in sexual activity when receiving GPT plus sildenafil or GP exclusively, when compared with sildenafil exclusively, as assessed by these three EDITS questions after 6-months treatment.

Manifestações orais em crianças HIV, em Moçambique

O objetivo foi comparar conhecimento de homens idosos ao de adultos jovens sobre Aids, considerando escolaridade. Estudo epidemiológico, descritivo e de corte transversal, em que foram analisadas informações de 30 idosos e 62 adultos jovens sobre conceito, transmissão, prevenção, diagnóstico e tratamento de Aids, investigadas por entrevista estruturada baseada em questionário validado padronizado. Para análise de contingência e de variância, empregaram-se distribuições de frequências e testes de Qui quadrado ou exato de Fisher e teste t de Student ou Mann-Whitney em nível de significância de 0,05. Foram empregados o teste de Mantel-Haenszel, em nível de significância de 0,05, e os Odds Ratio com intervalos de confiança a 95%, para influência da escolaridade. Constataram-se percepção individual de boa saúde maior em jovens (61,3% contra 43,3% dos idosos) e atividade sexual maior em idosos (80% contra 62,9% dos jovens). Apesar disso foi menos frequente idosos afirmarem conhecimento satisfatório sobre Aids (26,7% contra 80,6% dos jovens); história de teste de HIV (13,3% contra 24,2% dos jovens) e ter recebido orientação sobre Aids (36,7% dos idosos e 98,4% dos jovens). Os idosos tinham informação insuficiente sobre HIV/Aids comparados a adultos jovens, reforçando a necessidade de maior atenção à população idosa.

A rotatividade dos servidores de confiança no governo federal brasileiro, 2010-2011

Quais fatores determinam a rotatividade dos servidores de confiança do governo federal brasileiro? Este artigo mostra que mudanças partidárias na direção dos ministérios não necessariamente se traduzem em mudanças na composição dos cargos de confiança. Funcionários de confiança com funções de policymaking são mais afetados pela mudança de ministro do que os demais. Além disso, órgãos afetados por escândalos de corrupção tiveram uma taxa de permanência de seus funcionários de confiança maior do que a dos demais órgãos. Fica evidente a necessidade de considerar a policy expertise dos funcionários, medida em tempo de serviço público, para entender a rotatividade. O artigo aponta para a pertinência de estudar as relações "Executivo-Executivo" no Brasil.

Bootstrap confidence intervals for industrial recurrent event data

Industrial recurrent event data where an event of interest can be observed more than once in a single sample unit are presented in several areas, such as engineering, manufacturing and industrial reliability. Such type of data provide information about the number of events, time to their occurrence and also their costs. Nelson (1995) presents a methodology to obtain asymptotic confidence intervals for the cost and the number of cumulative recurrent events. Although this is a standard procedure, it can not perform well in some situations, in particular when the sample size available is small. In this context, computer-intensive methods such as bootstrap can be used to construct confidence intervals. In this paper, we propose a technique based on the bootstrap method to have interval estimates for the cost and the number of cumulative events. One of the advantages of the proposed methodology is the possibility for its application in several areas and its easy computational implementation. In addition, it can be a better alternative than asymptotic-based methods to calculate confidence intervals, according to some Monte Carlo simulations. An example from the engineering area illustrates the methodology.

A cátedra UNESCO de direito à educação da Faculdade de Direito: democracia, cidadania e direito à educação

Regimes democráticos se consolidam na medida de sua aceitação pela maioria, o que supõe conhecimento e confiança nas instituições políticas e jurídicas. A educação de qualidade é relevante para a governança democrática e para a formação da cidadania, posto propiciar o acesso a ferramentas cognitivas necessárias para a participação política relevante. As interações entre a democracia, o direito à educação e as políticas públicas de educação são analisadas pela Cátedra UNESCO no projeto de pesquisa “Brasil 25 anos de democracia” sob o ângulo da função promocional do Direito à Educação da FD, em parceria com o Núcleo de Políticas Públicas da USP, com. O foco da pesquisa é a atividade do Supremo Tribunal Federal (STF), a do Superior Tribunal de Justiça (STJ) e a do Congresso Nacional, no período compreendido entre os anos 2000 e 2010.

Appropriateness of reporting statistical results in orthodontics: the dominance of P values over confidence intervals

The purpose of this study was to search the orthodontic literature and determine the frequency of reporting of confidence intervals (CIs) in orthodontic journals with an impact factor. The six latest issues of the American Journal of Orthodontics and Dentofacial Orthopedics, the European Journal of Orthodontics, and the Angle Orthodontist were hand searched and the reporting of CIs, P values, and implementation of univariate or multivariate statistical analyses were recorded. Additionally, studies were classified according to the type/design as cross-sectional, case-control, cohort, and clinical trials, and according to the subject of the study as growth/genetics, behaviour/psychology, diagnosis/treatment, and biomaterials/biomechanics. The data were analyzed using descriptive statistics followed by univariate examination of statistical associations, logistic regression, and multivariate modelling. CI reporting was very limited and was recorded in only 6 per cent of the included published studies. CI reporting was independent of journal, study area, and design. Studies that used multivariate statistical analyses had a higher probability of reporting CIs compared with those using univariate statistical analyses. Misunderstanding of the use of P values and CIs may have important implications in implementation of research findings in clinical practice.

Dose modulated retrospective ECG-gated versus non-gated 64-row CT angiography of the aorta at the same radiation dose: Comparison of motion artifacts, diagnostic confidence and signal-to-noise-ratios

To compare ECG-gated and non-gated CT angiography of the aorta at the same radiation dose, with regard to motion artifacts (MA), diagnostic confidence (DC) and signal-to-noise-ratios (SNRs).