Secure referee selection for fair and responsive peer-to-peer gaming

Peer-to-Peer (P2P) architectures for Massively Multiplayer Online Games (MMOG) provide better scalability than Client/Server (C/S); however, they increase the possibility of cheating. Recently proposed P2P protocols use trusted referees that simulate/validate the game to provide security equivalent to C/S. When selecting referees from untrusted peers, selecting non-colluding referees becomes critical. Further, referees should be selected such that the range and length of delays to players is minimised (maximising game fairness and responsiveness). In this paper we formally define the referee selection problem and propose two secure referee selection algorithms, SRS-1 and SRS-2, to solve it. Both algorithms ensure the probability of corrupt referees controlling a zone/region is below a predefined limit, while attempting to maximise responsiveness and fairness. The trade-off between responsiveness and fairness is adjustable for both algorithms. Simulations of three different scenarios show the effectiveness of our algorithms

Potential Drug Development Candidates for Human Soil-Transmitted Helminthiases

There are few drugs - none ideal - for the treatment and control of gastrointestinal helminths (soil-transmitted nematodes) which, as chronic infections jeopardize children's growth, learning and ultimately individual, community and country development. Drugs for helminths are not attractive in human medicine, but are lucrative in animal health. Traditionally, investment in veterinary medicines has benefited humans for these diseases. With modern regulations an approved veterinary medicine can be tested in humans with little adaptation, reducing time and cost of development. We searched for products that could easily be transitioned into humans, having the necessary characteristics for use in communities exposed to these infections. A limited number of candidates met the main criteria for selection. We provide here a detailed analysis of two veterinary products, emodepside and monepantel, and nitazoxanide, which is approved for human use. In addition we include a less detailed analysis of all products examined, and the criteria on which the analysis was based. It is clear that the pipeline of easily obtainable human anthelminthics remains extremely limited, and further efforts are needed to find replacements for the inadequate number of products available today

Melanocortin-1 Receptor, Skin Cancer and Phenotypic Characteristics (M-SKIP) Project: Study Design and Methods for Pooling Results of Genetic Epidemiological Studies

Background: For complex diseases like cancer, pooled-analysis of individual data represents a powerful tool to investigate the joint contribution of genetic, phenotypic and environmental factors to the development of a disease. Pooled-analysis of epidemiological studies has many advantages over meta-analysis, and preliminary results may be obtained faster and with lower costs than with prospective consortia. Design and methods: Based on our experience with the study design of the Melanocortin-1 receptor (MC1R) gene, SKin cancer and Phenotypic characteristics (M-SKIP) project, we describe the most important steps in planning and conducting a pooled-analysis of genetic epidemiological studies. We then present the statistical analysis plan that we are going to apply, giving particular attention to methods of analysis recently proposed to account for between-study heterogeneity and to explore the joint contribution of genetic, phenotypic and environmental factors in the development of a disease. Within the M-SKIP project, data on 10,959 skin cancer cases and 14,785 controls from 31 international investigators were checked for quality and recoded for standardization. We first proposed to fit the aggregated data with random-effects logistic regression models. However, for the M-SKIP project, a two-stage analysis will be preferred to overcome the problem regarding the availability of different study covariates. The joint contribution of MC1R variants and phenotypic characteristics to skin cancer development will be studied via logic regression modeling. Discussion: Methodological guidelines to correctly design and conduct pooled-analyses are needed to facilitate application of such methods, thus providing a better summary of the actual findings on specific fields

Análise das internações por doenças respiratórias em Tangará da Serra - Amazônia Brasileira Analysis of hospitalizations for respiratory diseases in Tangará da Serra, Brazil

OBJETIVO: Analisar as internações hospitalares por doenças respiratórias em menores de 15 anos de idade em uma área com elevados níveis de poluição ambiental. MÉTODOS: Estudo transversal da morbidade hospitalar por doenças respiratórias de residentes no município de Tangará da Serra (MT) na Amazônia brasileira, no período de 2000 a 2005, através de dados de internações hospitalares do Sistema Único de Saúde brasileiro e de estimativas populacionais do Instituto Brasileiro de Geografia e Estatística. RESULTADOS: Em 2005, a taxa de internações por doenças respiratórias em menores de 15 anos foi de 70,1/1.000 crianças na microrregião de Tangará da Serra. Entre 2000 a 2005 ocorreram, no município de Tangará da Serra, 12.777 internações de crianças, das quais 8.142 (63,7%) por doenças respiratórias. No período da seca (maio a outubro) houve 10% mais internações por doenças respiratórias que no período da chuva (novembro a abril). As principais causas de internação foram: pneumonias (90,7%) e insuficiência respiratória (8,5%). Em menores de 5 anos de idade, as internações por pneumonia foram mais de 4 vezes o esperado para o município. Os menores de 12 meses de idade foram mais frequentemente internados, com incremento médio de 32,4 internações por 1.000 crianças a cada ano. CONCLUSÕES: Tangará da Serra tem apresentado elevado número de internações por doenças respiratórias, portanto, é coerente considerá-lo como área prioritária para investigação e monitoramento dos fatores de risco ambientais para tais doenças.<br>OBJECTIVE: To analyze hospitalizations for respiratory diseases among children under 15 years of age in an area with high levels of environmental pollution. METHODS: A cross-sectional study of hospitalizations due to respiratory diseases of patients residing in the city of Tangará da Serra, located in the state of Mato Grosso (Brazilian Amazon region), from 2000 to 2005. Data on hospital admissions were obtained from the Brazilian Unified Health Care System and from Brazilian Institute of Geography and Statistics population estimates. RESULTS: In 2005, the rate of hospitalization for respiratory diseases among children under 15 years of age in the microregion of Tangará da Serra was 70.1/1,000 children. Between 2000 and 2005, there were 12,777 such admissions, of which 8,142 (63.7%) were for respiratory diseases. During the dry season (May to October), the rate of admissions for respiratory diseases was 10% higher than during the rainy season (November to April). The principal causes of admission included pneumonia (90.7%) and respiratory insufficiency (8.5%). Admissions of children under 5 years of age for pneumonia were 4 times the expected number for the city. Children under 12 months of age were the most frequently hospitalized, with an average increase of 32.4 admissions per 1,000 children per year. CONCLUSIONS: Tangará da Serra presented a high number of pediatric admissions for respiratory diseases. Therefore, it is logical to consider it a priority area for investigation and monitoring of the environmental risk factors for such diseases