Ecologists often assume that dispersing individuals experience increased predation risk owing to increased exposure to predators while moving. To test the hypothesis that predation risk is a function of movement distance or rate of movement, we used radio-telemetry data collected from 193 ruffed grouse (Bonasa umbellus) during 1996– 1999 in southeastern Ohio. Cox’s proportional hazards model wa...

Probabilistic models for biological sequences (DNA and proteins) have many useful applications in bioinformatics. Normally, the values of parameters of these models have to be estimated from empirical data. However, even for the most common estimates, the maximum likelihood (ML) estimates, properties have not been completely explored. Here we assess the uniform accuracy of the ML estimates for ...

Excess female mortality during childhood is a distinct and unrelieved phenomenon in India, particularly in the two northern Indian states— Punjab and Haryana. This paper investigates the basic facts of sex differentials in child mortality in a very comprehensive manner using the three rounds of NFHS data sets from 1992 to 2006. More specifically, this paper examines the following three basic qu...

We consider methods for evaluating repeated markers to be used as a substitute for a clinical examination or to predict an outcome, in our case progression of breast cancer. We propose a deenition of speciicity and sensitivity for this setting and describe nonparametric estimators for these parameters. We then derive the theory required to obtain conndence intervals for the speciicity and sensi...

Bias variance decomposition of the expected error defined for regression and classification problems is an important tool to study and compare different algorithms, to find the best areas for their application. Here the decomposition is introduced for the survival analysis problem. In our experiments, we study bias -variance parts of the expected error for two algorithms: original Cox proportio...

Survival analysis is applied to records for length of productive life of Angus cows, fitting several proportional hazards models. It is shown that a piece-wise Weibull model with a time-dependent stage effect can model the distinct annual culling pattern reasonably well. Analyses fitting a sire model suggest some genetic variability, with heritability estimates on the logarithmic scale ranging ...

We obtain a fermionic coset realization of the primaries of minimal unitary models and show how their four-point functions may be calculated by the use of a reduction formula. We illustrate the construction for the Ising model, where we obtain an explicit realization of the energy operator, Onsager fermions, as well as of the order and disorder operators realizing the dual algebra, in terms of ...

In this paper, we describe a new Stata command, stlh, which estimates and tests for the significance of the time-varying regression coefficients in Aalen’s linear hazards model; see Aalen (1989). We see two potential uses for this command. One may use it as an alternative to a proportional hazards or other nonlinear hazards regression model analysis to describe the effects of covariates on surv...