Analysing mark-recapture-recovery data in the presence of missing covariate data via multiple imputation

We consider mark–recapture–recovery data with additional individual time-varying continuous covariate data. For such data it is common to specify the model parameters, and in particular the survival probabilities, as a function of these covariates to incorporate individual heterogeneity. However, an issue arises in relation to missing covariate values, for (at least) the times when an individual is not observed, leading to an analytically intractable likelihood. We propose a two-step multiple imputation approach to obtain estimates of the demographic parameters. Firstly, a model is fitted to only the observed covariate values. Conditional on the fitted covariate model, multiple “complete” datasets are generated (i.e. all missing covariate values are imputed). Secondly, for each complete dataset, a closed form complete data likelihood can be maximised to obtain estimates of the model parameters which are subsequently combined to obtain an overall estimate of the parameters. Associated standard errors and 95 % confidence intervals are obtained using a non-parametric bootstrap. A simulation study is undertaken to assess the performance of the proposed two-step approach. We apply the method to data collected on a well-studied population of Soay sheep and compare the results with a Bayesian data augmentation approach. Supplementary materials accompanying this paper appear on-line.Publisher PDFPeer reviewe

Acadian French and Linguistic Theory

This article identifies some profitable areas of research for Acadian linguistics, in particular, research in sociolinguistics and in grammatical theory. The value of Acadian French data for the testing of theories of language change and for the study of syntactic variation within generative grammar is explored

'Quite' in Acadian French : a variety of Scalar Focus

This paper discusses the properties of the 'quite de' construction in the Baie Sainte-Marie, Nova Scotia variety of Acadian French in examples such as le/un quite de souper 'quite the/a supper' which have a hyperbolic connotation. Unlike epithet nouns and other binominals of French (and Romance more generally), we argue that this Acadian French construction contains a complex DP with a unique N but an expanded left nominal periphery (cf. Giusti 2005, 2006, 2012). In order to unify its syntactic and semantic properties, we propose an analysis where [Adv quite] is a scalar Focus head (following Kayne's 1998 treatment of scalar only), with a null M(easurement) Op(erator) (Rett 2008, 2011) in its specifier. This M-op is associated with a degree argument (i.e. N) bound by existential closure, which forces its linearization within the predicate domain (cf. Diesing 1992). Lastly, we show that de in the AF 'quite de' construction cannot be construed as a linker (pace den Dikken 2004, 2006) or as a P category (pace Kayne 1994), but is best analysed as a nominal functor (cf. Ihsane 2013) at the Comp-Infl interface whose role is to recategorize a referential DP into a property denoting DP

Student Perceptions of Online Homework Grading Software

Accounting students used homework-grading software and were generally happy with it but its use did not improve their grades unless they had used similar software previously. These are the results of a longitudinal study regarding their perceptions of use of the software. Even though the homework counted for 20% of their grade and they had unlimited attempts to make 100% each week, very few of them took advantage of the opportunity. They would work until they were satisfied with their grade and stop or they world start working late and run out of time before they finished. They knew it was useful and they intended to use it, but 80% of them stopped before making 100% on each assignment. Student responses also reflected the instructor had significantly more “power” at the beginning of the term but by the end, their peer’s influence had increased while the teacher’s influence had waned

The role of anterior cingulate cortex in the affective evaluation of conflict

An influential theory of anterior cingulate cortex (ACC) function argues that this brain region plays a crucial role in the affective evaluation of performance monitoring and control demands. Specifically, control-demanding processes such as response conflict are thought to be registered as aversive signals by ACC, which in turn triggers processing adjustments to support avoidance learning. In support of conflict being treated as an aversive event, recent behavioral studies demonstrated that incongruent (i.e., conflict inducing), relative to congruent, stimuli can speed up subsequent negative, relative to positive, affective picture processing. Here, we used fMRI to investigate directly whether ACC activity in response to negative versus positive pictures is modulated by preceding control demands, consisting of conflict and task-switching conditions. The results show that negative, relative to positive, pictures elicited higher ACC activation after congruent, relative to incongruent, trials, suggesting that ACC's response to negative (positive) pictures was indeed affectively primed by incongruent (congruent) trials. Interestingly, this pattern of results was observed on task repetitions but disappeared on task alternations. This study supports the proposal that conflict induces negative affect and is the first to show that this affective signal is reflected in ACC activation