10,318 research outputs found
Full Open Population Capture-Recapture Models with Individual Covariates
Traditional analyses of capture-recapture data are based on likelihood
functions that explicitly integrate out all missing data. We use a complete
data likelihood (CDL) to show how a wide range of capture-recapture models can
be easily fitted using readily available software JAGS/BUGS even when there are
individual-specific time-varying covariates. The models we describe extend
those that condition on first capture to include abundance parameters, or
parameters related to abundance, such as population size, birth rates or
lifetime. The use of a CDL means that any missing data, including uncertain
individual covariates, can be included in models without the need for
customized likelihood functions. This approach also facilitates modeling
processes of demographic interest rather than the complexities caused by
non-ignorable missing data. We illustrate using two examples, (i) open
population modeling in the presence of a censored time-varying individual
covariate in a full robust-design, and (ii) full open population multi-state
modeling in the presence of a partially observed categorical variable
Follow-up services for improving long-term outcomes in intensive care unit (ICU) survivors
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
Our main objective is to assess the effectiveness of follow-up services for ICU survivors that aim to identify and address unmet health needs related to the ICU period. We aim to assess the effectiveness in relation to health-related quality of life, mortality, depression and anxiety, post-traumatic stress disorder, physical function, cognitive function, ability to return to work or education and adverse events.
Our secondary objectives are, in general, to examine both the various ways that follow-up services are provided and any major influencing factors. Specifically, we aim to explore: the effectiveness of service organisation (physician versus nurse led, face to face versus remote, timing of follow-up service); possible differences in services related to country (developed versus developing country); and whether participants had delirium within the ICU setting
Data Catalog Series for Space Science and Applications Flight Missions
The main purpose of the data catalog series is to provide descriptive references to data generated by space science flight missions. The data sets described include all of the actual holdings of the Space Science Data Center (NSSDC), all data sets for which direct contact information is available, and some data collections held and serviced by foreign investigators, NASA and other U.S. government agencies. This volume contains narrative descriptions of data sets from geostationary and high altitude scientific spacecraft and investigations. The following spacecraft series are included: Mariner, Pioneer, Pioneer Venus, Venera, Viking, Voyager, and Helios. Separate indexes to the planetary and interplanetary missions are also provided
Extending the Latent Multinomial Model with Complex Error Processes and Dynamic Markov Bases
The latent multinomial model (LMM) model of Link et al. (2010) provided a
general framework for modelling mark-recapture data with potential errors in
identification. Key to this approach was a Markov chain Monte Carlo (MCMC)
scheme for sampling possible configurations of the counts true capture
histories that could have generated the observed data. This MCMC algorithm used
vectors from a basis for the kernel of the linear map between the true and
observed counts to move between the possible configurations of the true data.
Schofield and Bonner (2015) showed that a strict basis was sufficient for some
models of the errors, including the model presented by Link et al. (2010), but
a larger set called a Markov basis may be required for more complex models. We
address two further challenges with this approach: 1) that models with more
complex error mechanisms do not fit easily within the LMM and 2) that the
Markov basis can be difficult or impossible to compute for even moderate sized
studies. We address these issues by extending the LMM to separately model the
capture/demographic process and the error process and by developing a new MCMC
sampling scheme using dynamic Markov bases. Our work is motivated by a study of
Queen snakes (Regina septemvittata) in Kentucky, USA, and we use simulation to
compare the use of PIT tags, with perfect identification, and brands, which are
prone to error, when estimating survival rates
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