Theorems on existence and global dynamics for the Einstein equations

This article is a guide to theorems on existence and global dynamics of solutions of the Einstein equations. It draws attention to open questions in the field. The local-in-time Cauchy problem, which is relatively well understood, is surveyed. Global results for solutions with various types of symmetry are discussed. A selection of results from Newtonian theory and special relativity that offer useful comparisons is presented. Treatments of global results in the case of small data and results on constructing spacetimes with prescribed singularity structure or late-time asymptotics are given. A conjectural picture of the asymptotic behaviour of general cosmological solutions of the Einstein equations is built up. Some miscellaneous topics connected with the main theme are collected in a separate section.Comment: Submitted to Living Reviews in Relativity, major update of Living Rev. Rel. 5 (2002)

Theorems on existence and global dynamics for the Einstein equations

This article is a guide to theorems on existence and global dynamics of solutions of the Einstein equations. It draws attention to open questions in the field. The local in time Cauchy problem, which is relatively well understood, is surveyed. Global results for solutions with various types of symmetry are discussed. A selection of results from Newtonian theory and special relativity which offer useful comparisons is presented. Treatments of global results in the case of small data and results on constructing spacetimes with prescribed singularity structure are given. A conjectural picture of the asymptotic behaviour of general cosmological solutions of the Einstein equations is built up. Some miscellaneous topics connected with the main theme are collected in a separate section.Comment: 54 pages, submitted to Living Reviews in Relativit

Co-infecção por HIV/HCV em hospital universitário de Recife, Brasil Coinfección por HIV/HCV en hospital universitario de Recife, Brasil HIV/HCV coinfection at an university hospital in Recife, Brazil

OBJETIVO: Estimar a prevalência do vírus da hepatite C (HCV) e fatores de risco associados com a co-infecção em pessoas soropositivas para HIV. MÉTODOS: Estudo do tipo transversal, descritivo e analítico, com 343 portadores do HIV atendidos em um hospital universitário de Recife (PE), no período de março a dezembro de 2003. Os pacientes foram submetidos a um questionário padronizado sobre os fatores de risco. Nas amostras de soro foram pesquisados o anti-HCV pelo ELISA, o HCV-RNA por meio da RT-PCR e a identificação dos genótipos foi realizada no equipamento ABI377 (PE Biosystems®). As análises estatísticas utilizadas foram a univariada, a multivariada e a regressão logística múltipla. RESULTADOS: A prevalência encontrada para o HCV foi de 4,1% (14/343) pelo ELISA e de 3,2 % (11/343) quando utilizada a RT-PCR. Os genótipos mais freqüentes foram 1b (45%), 3 (33%) e 1a (22%). A faixa etária com maior proporção de co-infectados foi a de 30 a 39 anos, com predomínio do sexo masculino (64,3%). Após regressão logística múltipla, apenas a variável transfusão sangüínea permaneceu como fator de risco para o HCV (OR=4,28; IC 95%: 1,44;12,73). CONCLUSÕES: A prevalência da co-infecção HIV/HCV foi baixa, a transfusão sangüínea foi um fator de risco e o genótipo 1b do HCV foi o mais freqüente.<br>OBJETIVO: Estimar la prevalencia de virus de hepatitis C (HCV) y factores de riesgo asociados con la coinfección en personas seropositivas para HIV. MÉTODOS: Estudio de tipo transversal, descriptivo y analítico, con 343 portadores de HIV atendidos en un hospital universitario de Recife (Noreste de Brasil), en el período de marzo a diciembre de 2003. Los pacientes fueron sometidos a un cuestionario estandarizado sobre los factores de riesgo. En las muestras de suero fueron pesquisados el anti-HCV por ELISA, el HCV-RNA por medio de la RT-PCR y la identificación de los genotipos fue realizada en el equipo ABI377 (PE Biosystems®). Los análisis estadísticos utilizados fueron la univariada, la multivariada y la regresión logística múltiple. RESULTADOS: La prevalencia encontrada para el HCV fue de 4,1% (14/343) por ELISA y de 3,2% (11/343) por RT-PCR. Los genotipos mas frecuentes fueron 1b (45%), 3 (33%) y 1a (22%). El rango de edad con mayor proporción de coinfectados fue la de 30-39 años, con predominio del sexo masculino (64,3%). Posterior a la regresión logística múltiple, sólo la variable transfusión sanguínea permaneció como factor de riesgo para el HCV (OR=4,28; IC 95%: 1,44; 12,73). CONCLUSIONES: La prevalencia de la coinfección HIV/HCV fue baja, la transfusión sanguínea fue un factor de riesgo y el genotipo 1b de HCV fue el más frecuente.<br>OBJECTIVE: To estimate the prevalence of hepatitis C virus (HCV) infection and risks factors associated with coinfection in HIV-positive individuals. METHODS: A cross-sectional descriptive study was conducted with 343 HIV patients attended at a university hospital in Recife, Northeastern Brazil, from March to December 2003. A standardized questionnaire about risk factors was administered. Serum samples were analyzed for anti-HCV antibodies using enzyme-linked immunosorbent assay (ELISA), HCV-RNA using reverse transcription-polymerase chain reaction (RT-PCR), and genotyping using the ABI 377 (PE Biosystems®). Univariate and multivariate analyses and multiple logistic regression were performed. RESULTS: HCV prevalence was 4.1% (14/343) using ELISA and 3.2% (11/343) using RT-PCR. The most common genotypes were 1b (45%), 3 (33%) and 1a (22%). Co-infection was higher among those aged 30 to 39 years, and predominantly in males (64.3 %). In the multiple logistic regression, the variable blood transfusion was the single remaining risk factor for HCV (OR=4.28; 95% CI 1.44;12.73). CONCLUSIONS: The prevalence of HIV/HCV coinfection was low. Blood transfusion was a risk factor and HCV genotype 1b was the most frequently found