Impact of dependent left truncation in semiparametric competing risks methods: A simulation study

In this study, we investigated the robustness of the methods that account for independent left truncation when applied to competing risks settings with dependent left truncation. We specifically focused on the methods for the proportional cause-specific hazards model and the Fine–Gray model. Simulation experiments showed that these methods are not in general robust against dependent left truncation. The magnitude of the bias was analogous to the strength of the association between left truncation and failure times, the effect of the covariate on the competing cause of failure, and the baseline hazard of left truncation time

The prison of Regina Coeli : a laboratory of identity in the Post-Risorgimento Italy

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Architecture, 2006.Includes bibliographical references (leaves 97-104).In my thesis I am studying the prison of Regina Coeli in Rome. Completed in 1892, it occupies the space of the convent after which it was named: the convent of Santa Maria Regina Coeli. The particular prison was built in the aftermath of the Italian unification when national identity was still formulated and the economy industrialized. At the same period, the discussion on prison architecture was shifting from an interest in the panopticon-centered structures to the architecture of the cell. Penitentiaries were transformed from sites of mere constrain, to sites of correction, to later develop into laboratories of identity. Along with the research on the typical cell, the field of criminology was objectifying the criminal body, in pursuit of the delinquent type. Although rarely documented, Regina Coeli was built in this transition before modernity appeared in the structure of the penitentiary institutions.(cont.) I explore the particular prison not only as the product of this multiple transition, but also as the vehicle to forge it. Being the main custodial prison of the Kingdom of Italy, Regina Coeli constituted the portal to the Italian penitentiary network. The convicts awaiting trial, executing the last part of their sentence or pending transfer to other prisons or penal colonies were situated in the prison. In my thesis the issues of national identity, architectural historiography and identity politics are addressed through the study of the prison of Regina Coeli.by Olga Touloumi.S.M

The Efficacy of OWL and DL on User Understanding of Axioms and Their Entailments

OWL is recognized as the de facto standard notation for on- tology engineering. The Manchester OWL Syntax (MOS) was developed as an alternative to symbolic description logic (DL) and it is believed to be more e ective for users. This paper sets out to test that belief from two perspectives by evaluating how accurately and quickly people understand the informational content of axioms and derive inferences from them. By conducting a between-group empirical study, involving 60 novice participants, we found that DL is just as e ective as MOS for people's understanding of axioms. Moreover, for two types of inference problems, DL supported signi cantly better task performance than MOS, yet MOS never signi cantly outperformed DL. These surprising results suggest that the belief that MOS is more e ective than DL, at least for these types of task, is unfounded. An outcome of this research is the suggestion that ontology axioms, when presented to non-experts, may be better presented in DL rather than MOS. Further empirical studies are needed to explain these unexpected results and to see whether they hold for other types of task

Neuroprotection from inflammation: Experimental allergic encephalomyelitis facilitates traumatic spinal cord injury recovery

Passive immunization with T cells activated against central nervous system (CNS) - associated myelin antigens has been found to provide neuroprotection following CNS trauma, leading to the concept of protective autoimmunity. However, limited research exists about whether actively induced CNS autoimmunity may offer any similar benefit. In this study, the kinetics and the effect of endogenously anti-myelin activated T cells following spinal cord injury (SCI), were investigated. Experimental allergic encephalomyelitis (EAE) was actively induced in Lewis rats following immunization with myelin basic protein (MBP). In vivo 5-Bromo-2-deoxyuridine (BrdU) incorporation from activated T cells was used as a marker of T cell- proliferation. BrdU was injected on 5th, 6th and 7th day post-induction (DPI) at all EAE-animals. On DPI 8, spinal cord compressive injury was induced by a transient extradural application of an aneurysm clip at the T8 spinal level. SCI resulted in spastic paralysis of hindlimbs, in all but sham-injured animals. Recovery from SCI was significantly better in EAE-animals. Activated mononuclear cells were selectively accumulated at the site of the injury. Axonal loss was less in the EAE group following SCI. Our findings indicate that actively induced autoimmunity against CNS myelin antigens may protect spinal cord pathways from mechanical injury

Towards standardized definitions for monitoring the continuum of HIV care in Europe

International audienceThe continuum of HIV care is a simple conceptual framework for monitoring HIV programmes, comprising a series of stages that people living with HIV (PLHIV) pass through to access antiretroviral treatment (ART) and achieve viral suppression [1,2]. Individual benefits of suppression include reduced risk of morbidity and mortality. At the population level, viral suppression reduces the risk of onward transmission and enables epidemic containment [3]. Transmission risk may be further reduced by lowering the number of undiagnosed PLHIV [4,5]. Complete continua are, therefore, constructed beginning with the total number of PLHIV in a given population and ending with the number virally suppressed. Intervening stages have included the numbers diagnosed, linked to HIV care, retained in care, eligible for ART, on ART and adhering to ART. Although people can move between stages, the continuum is typically conceptualized as a ‘snapshot’ at one time-point

Effects of air pollution and meteorological parameters on human health in the city of Athens, Greece

The impact of air pollution (CO, NO, NO2, SO2, O3) and meteorological parameters (air temperature, humidity and atmospheric pressure) on three indicators of human morbidity (circulatory, respiratory and skin diseases) is quantified, while the sensitivity of the results to different model specifications is tested. Findings indicate that higher SO2 and CO levels significantly increase circulatory and skin diseases, respectively, while higher NO and O3 concentrations increase respiratory diseases. Air temperature is significantly associated with all human health indicators. This work highlights the need for lower air pollution standards for the city of Athens and a wider climate change policy

Determining the likely place of HIV acquisition for migrants in Europe combining subject-specific information and biomarkers data

In most HIV-positive individuals, infection time is only known to lie between the time an individual started being at risk for HIV and diagnosis time. However, a more accurate estimate of infection time is very important in certain cases. For example, one of the objectives of the Advancing Migrant Access to Health Services in Europe (aMASE) study was to determine if HIV-positive migrants, diagnosed in Europe, were infected pre- or post-migration. We propose a method to derive subject-specific estimates of unknown infection times using information from HIV biomarkers' measurements, demographic, clinical, and behavioral data. We assume that CD4 cell count (CD4) and HIV-RNA viral load trends after HIV infection follow a bivariate linear mixed model. Using post-diagnosis CD4 and viral load measurements and applying the Bayes' rule, we derived the posterior distribution of the HIV infection time, whereas the prior distribution was informed by AIDS status at diagnosis and behavioral data. Parameters of the CD4-viral load and time-to-AIDS models were estimated using data from a large study of individuals with known HIV infection times (CASCADE). Simulations showed substantial predictive ability (e.g. 84% of the infections were correctly classified as pre- or post-migration). Application to the aMASE study ( n = 2009) showed that 47% of African migrants and 67% to 72% of migrants from other regions were most likely infected post-migration. Applying a Bayesian method based on bivariate modeling of CD4 and viral load, and subject-specific information, we found that the majority of HIV-positive migrants in aMASE were most likely infected after their migration to Europe