281 research outputs found

    Nonparametric inference for competing risks current status data with continuous, discrete or grouped observation times

    Get PDF
    New methods and theory have recently been developed to nonparametrically estimate cumulative incidence functions for competing risks survival data subject to current status censoring. In particular, the limiting distribution of the nonparametric maximum likelihood estimator and a simplified naive estimator have been established under certain smoothness conditions. In this paper, we establish the large-sample behaviour of these estimators in two additional models, namely when the observation time distribution has discrete support and when the observation times are grouped. These asymptotic results are applied to the construction of confidence intervals in the three different models. The methods are illustrated on two datasets regarding the cumulative incidence of different types of menopause from a cross-sectional sample of women in the United States and subtype-specific HIV infection from a sero-prevalence study in injecting drug users in Thailan

    Nonparametric inference for competing risks current status data with continuous, discrete or grouped observation times

    Full text link
    New methods and theory have recently been developed to nonparametrically estimate cumulative incidence functions for competing risks survival data subject to current status censoring. In particular, the limiting distribution of the nonparametric maximum likelihood estimator and a simplified "naive estimator" have been established under certain smoothness conditions. In this paper, we establish the large-sample behavior of these estimators in two additional models, namely when the observation time distribution has discrete support and when the observation times are grouped. These asymptotic results are applied to the construction of confidence intervals in the three different models. The methods are illustrated on two data sets regarding the cumulative incidence of (i) different types of menopause from a cross-sectional sample of women in the United States and (ii) subtype-specific HIV infection from a sero-prevalence study in injecting drug users in Thailand.Comment: 16 pages, 3 figure

    Nonparametric inference for competing risks current status data with continuous, discrete or grouped observation times

    Get PDF
    New methods and theory have recently been developed to nonparametrically estimate cumulative incidence functions for competing risks survival data subject to current status censoring. In particular, the limiting distribution of the nonparametric maximum likelihood estimator and a simplified naive estimator have been established under certain smoothness conditions. In this paper, we establish the large-sample behaviour of these estimators in two additional models, namely when the observation time distribution has discrete support and when the observation times are grouped. These asymptotic results are applied to the construction of confidence intervals in the three different models. The methods are illustrated on two datasets regarding the cumulative incidence of different types of menopause from a cross-sectional sample of women in the United States and subtype-specific HIV infection from a sero-prevalence study in injecting drug users in Thailand

    Inconsistency of the MLE for the joint distribution of interval censored survival times and continuous marks

    Full text link
    This paper considers the nonparametric maximum likelihood estimator (MLE) for the joint distribution function of an interval censored survival time and a continuous mark variable. We provide a new explicit formula for the MLE in this problem. We use this formula and the mark specific cumulative hazard function of Huang and Louis (1998) to obtain the almost sure limit of the MLE. This result leads to necessary and sufficient conditions for consistency of the MLE which imply that the MLE is inconsistent in general. We show that the inconsistency can be repaired by discretizing the marks. Our theoretical results are supported by simulations.Comment: 27 pages, 4 figure

    Sustained data access and tools as key ingredients to strengthening EO capacities : examples from land application perspective + powerpoint

    Get PDF
    Sustainably managing agriculture and forests is key for development, in particular in Africa, and for facing global challenges such as climate change or food security, but requires reliable information. As Earth Observation (EO) satellite data can contribute to these information needs, more and more institutes integrate this technology into their daily work. Facing ever-growing and evolving EO data sources (e.g. new satellites and sensors) and access technology (both online and via EUMETCast satellite broadcast), their applications require software tools to particularly facilitate (i) the exchange of data between the analysis tools, so users can take advantage of each tool’s strengths, and (ii) the processing and analysis of time series. A first example is the Land Surface Analysis Satellite Application Facility (LSA-SAF), that entered the second part of the Continuous Development and Operations Phase (CDOP-2), under the lead of the Portuguese Institute for Sea and Atmosphere (IPMA), in 2011. VITO, joining the LSA-SAF network for the first time and building on previous experiences (e.g. http://www.metops10.vito.be), aims to contribute by producing and delivering operational, 10-daily vegetation indicators based on MetOp-AVHRR. Furthermore, a software tool is developed to aid exploitation of LSA-SAF products, provisionally called “MSG Toolbox”. A second example is the AGRICAB project, that receives funding from the European Union’s 7th Framework Programme for Research (FP7) and aims to build a comprehensive framework for strengthening capacities in the use of EO for agriculture and forestry management in Africa. This framework starts from sustained access to relevant satellite data (e.g. CBERS-3, DEIMOS) and derived products, such as those from the European Copernicus Global Land service, the 15 year time series of SPOT-VEGETATION (and its transition to PROBA-V) and Meteosat Second Generation (e.g. rainfall estimates). It combines local and EO data with tools and training into applications on crop monitoring, area statistics and yield forecasting, livestock insurance and modelling, forest and fire management, all fitted to the needs of stakeholders in the African focus countries

    Kemalettin - (Mimar) [1870-1927]

    Get PDF
    Taha Toros Arşivi, Dosya No: 134-Mimar Kemalettinİstanbul Kalkınma Ajansı (TR10/14/YEN/0033) İstanbul Development Agency (TR10/14/YEN/0033

    Long-term outcomes of slipped capital femoral epiphysis treated with in situ pinning

    Get PDF
    PURPOSE: Slipped capital femoral epiphysis (SCFE) is the commonest hip disorder in adolescents. In situ pinning is commonly performed, yet lately there has been an increase in procedures with open reduction and internal fixation. These procedures, however, are technically demanding with relatively high complication rates and unknown long-term outcomes. Nevertheless, reports on long-term results of in situ fixation are not equivocal. This study evaluates the possible higher risk of worse outcome after in situ pinning of SCFE. METHODS: All patients treated for SCFE with in situ fixation between 1980 and 2002 in four different hospitals were asked to participate. Patients were divided into three groups, based on severity of the slip. Patients were invited to the outpatient clinic for physical examination and X-rays, and to fill out the questionnaires HOOS, EQ5D, and SF36. ANOVA and chi-squared tests were used to analyze differences between groups. RESULTS: Sixty-one patients with 78 slips filled out the questionnaires. Patients with severe slips had worse scores on HOOS, EQ5D, and SF36. 75 % of patients with severe slips had severe osteoarthritis, compared to 2 % of mild and 11 % of moderate slips. CONCLUSION: Hips with mild and moderate SCFE generally had good functional and radiological outcome at a mean follow-up of 18 years, and for these hips there seems to be no indication for open procedures. However, severe slips have a significantly worse outcome, and open reduction and internal fixation could therefore be considered

    Karagöz tetkikleri

    Get PDF
    Taha Toros Arşivi, Dosya No: 176-Karagöz Sanatkarlarıİstanbul Kalkınma Ajansı (TR10/14/YEN/0033) İstanbul Development Agency (TR10/14/YEN/0033
    • …
    corecore