Background The impact of the emergence drug-resistance mutations on mortality is not well characterized in antiretroviral-naïve patients first starting highly active antiretroviral therapy (HAART). Patients may be able to sustain immunologic function with resistant virus, and there limited evidence that reduced sensitivity antiretrovirals leads rapid disease progression or death. We undertook present analysis characterize determinants a prospective cohort study median nearly 5 y follow-up....

One explanation for animal personality is that different behavioural types derive from life-history strategies. Highly productive individuals, with high growth rates and fecundity, are assumed to live life at a fast pace showing levels of boldness risk taking, compared less individuals. Here, we investigate among-individual differences in mean (the inverse the latency recover startling stimulus) consistency boldness, male hermit crabs relation two aspects investment. We assessed aerobic...

Summary Recent developments in the Cormack–Jolly–Seber (CJS) model for analyzing capture–recapture data have focused on allowing capture and survival rates to vary between individuals. Several methods been developed which are functions of auxiliary variables that may be discrete, constant over time, or apply population as a whole, but problem has not solved continuous covariates with both time individual. This article proposes new method handle such by modeling changes via diffusion process...

Summary Mark–recapture models are valuable for assessing diverse demographic and behavioural parameters, yet the precision of traditional estimates is often constrained by sparse empirical data. Bayesian inference explicitly recognizes estimation uncertainty, hierarchical Bayes has proven particularly useful dealing with sparseness combining information across data sets. We developed a general multi‐state mark–recapture model, tested its performance on simulated sets applied it to real...

Time varying, individual covariates are problematic in experiments with marked animals because the covariate can typically only be observed when each animal is captured. We examine three methods to incorporate time of survival probabilities into analysis data from mark-recapture-recovery experiments: deterministic imputation, a Bayesian imputation approach based on modeling joint distribution and capture history, conditional considering events for which associated completely (the trinomial...

Abstract Summary Non‐invasive marks, including pigmentation patterns, acquired scars, and genetic markers, are often used to identify individuals in mark‐recapture experiments. If animals a population can be identified from multiple, non‐invasive marks then some may counted twice the observed data. Analyzing histories without accounting for these errors will provide incorrect inference about dynamics. Previous approaches this problem include modeling data only one mark combining estimators...

Summary Human‐induced land‐use changes are among the primary causes of ecosystem degradation and biodiversity loss. Across central Appalachia (USA), mountaintop removal mining valley filling (MTR/VF) is prevailing form change represents a stressor to stream ecosystems. Salamanders dominant vertebrate in Appalachian headwater streams. Thus, we addressed question: Is salamander occupancy conditional abundance reduced streams impacted by MTR/VF? We conducted repeated counts adult larval...

Animals select resources to maximize fitness but associated costs and benefits are spatially temporally variable. Differences in wetland management influence resource availability for ducks mortality risk from duck hunting. The local distribution of the Mallard (Anas platyrhynchos) is affected by this heterogeneity variable Regional conservation strategies primarily focus on how waterfowl distributions food during nonbreeding season. To test if selection was related abundance resources,...

Summary Hair snares have become an established method for obtaining mark‐recapture data population size estimation of Ursids and recently been used to study other species including carnivores, small mammals ungulates. However, bias due a behavioural response capture in the presence missing has only recognized no statistical methodology exists accommodate it. In hair snare experiment, can be if animals encounter without leaving sample, poor‐quality samples are not genotyped, fraction all...

Generalist predators are capable of selective foraging, but predicted to feed in close proportion prey availability maximize energetic intake especially when overall is low. By extension, they also expected a more frequency-dependent manner during winter compared the favourable foraging conditions spring, summer and fall seasons. For 18 months, we observed patterns forest-dwelling wolf spiders from genus Schizocosa (Araneae: Lycosidae) using PCR-based gut-content analysis simultaneously...

Pathogenic fungi are increasingly associated with epidemics in wildlife populations. Snake fungal disease (SFD, also referred to as Ophidiomycosis) is an emerging threat snakes, taxa that elusive and difficult sample. Thus, assessments of the effects SFD on populations have rarely occurred. We used a field technique enhance detection, Passive Integrated Transponder (PIT) telemetry, multi-state capture-mark-recapture model assess short-term (within-season) survival, movement, surface activity...

Although the impact of Aboriginal status on HIV incidence, disease progression, and access to treatment has been investigated previously, little is known about relationship between ethnicity outcomes associated with highly active antiretroviral therapy (HAART). We undertook present analysis determine if non-Aboriginal persons respond differently HAART by measuring plasma viral load response, CD4 cell response time all-cause mortality.A population-based a cohort naïve HIV-positive men women...

Summary Petersen-type mark–recapture experiments are often used to estimate the number of fish or other animals in a population moving along set migration route. A first sample individuals is captured at one location, marked, and returned population. second then farther route, inferences derived from numbers marked unmarked found this sample. Data such stratified by time (day week) allow for possible changes capture probabilities, previous methods analysis fail take advantage temporal...

Abstract The aim of this study was to quantify the level employment at one-year and determine potential predictors future among HIV-positive persons on highly active antiretroviral therapy (HAART) in province British Columbia. Of 392 individuals that were initially unemployed baseline 63 (16.1%) found a job over subsequent year. Factors associated with becoming employed included income $10 000, having long-term disability or unemployment insurance as an source, higher CD4 cell counts, better...

Summary Estimating abundance from mark–recapture data is challenging when capture probabilities vary among individuals. Initial solutions to this problem were based on fitting conditional likelihoods and estimating as a derived parameter. More recently, B ayesian methods using full have been implemented via reversible jump M arkov chain onte C arlo sampling ( RJMCMC ) or augmentation DA ). The latter approach easily in available software has applied fit models that allow for heterogeneity...

The latent multinomial model (LMM) of Link et al. [Biometrics 66 (2010) 178–185] provides a framework for modelling mark-recapture data with potential identification errors. Key is Markov chain Monte Carlo (MCMC) scheme sampling configurations the counts true capture histories that could have generated observed data. Assuming linear map between and counts, MCMC algorithm uses vectors from basis kernel to move Schofield Bonner 71 (2015) 1070–1080] shows this sufficient some models within but...

Abstract A key area of research in ecological statistics involves combining data sources from multiple streams to improve population estimates. One such model attempts integrate capture–recapture and presence–absence estimate the size Eurasian lynx Jura Mountains, eastern France. This has been observed underestimate sizes. We conducted an extensive simulation study evaluate model's performance. describe our methods for generation simultaneous demonstrate that is flawed. Finally, we give...

Link et al. (2010, Biometrics 66, 178-185) define a general framework for analyzing capture-recapture data with potential misidentifications. In this framework, the observed vector of counts, y, is considered as linear function latent x, such that y=Ax, x assumed to follow multinomial distribution conditional on model parameters, θ. Bayesian methods are then applied by sampling from joint posterior both and particular, (2010) propose Metropolis-Hastings algorithm sample full where new...