Summary1. Many capture-recapture surveys of wildlife populations operate in continuous time, but detections are typically aggregated into occasions for analysis, even when exact detection times are available. This discards information and introduces subjectivity, in the form of decisions about occasion definition. 2. We develop a spatiotemporal Poisson process model for spatially explicit capture-recapture (SECR) surveys that operate continuously and record exact detection times. We show that, except in some special cases (including the case in which detection probability does not change within occasion), temporally aggregated data do not provide sufficient statistics for density and related parameters, and that when detection probability is constant over time, our continuous-time (CT) model is equivalent to an existing model based on detection frequencies. We use the model to estimate jaguar density from a camera-trap survey and conduct a simulation study to investigate the properties of a CT estimator and discrete-occasion estimators with various levels of temporal aggregation. This includes investigation of the effect on the estimators of spatiotemporal correlation induced by animal movement. 3. The CT estimator is found to be unbiased and more precise than discrete-occasion estimators based on binary capture data (rather than detection frequencies) when there is no spatiotemporal correlation. It is also found to be only slightly biased when there is correlation induced by animal movement, and to be more robust to inadequate detector spacing, while discrete-occasion estimators with binary data can be sensitive to occasion length, particularly in the presence of inadequate detector spacing. 4. Our model includes as a special case a discrete-occasion estimator based on detection frequencies, and at the same time lays a foundation for the development of more sophisticated CT models and estimators. It allows modelling within-occasion changes in detectability, readily accommodates variation in detector effort, removes subjectivity associated with user-defined occasions and fully utilizes CT data. We identify a need for developing CT methods that incorporate spatiotemporal dependence in detections and see potential for CT models being combined with telemetry-based animal movement models to provide a richer inference framework.

Exposure to violence puts children at risk for developing a variety of problems, including depression, anxiety, and conduct problems. The extent to which children's individual, family, school, and peer group characteristics influence resilient responses to violence exposure was investigated amongst Grade 6 students living in a high-violence community in Cape Town. The majority (68.44%) reported both witnessing and being a victim of violence. Both witnessing and victimisation by violence were found to be positively associated with anxiety and depression, but only victimisation was positively associated with conduct problems. Peer delinquency was positively associated with both depres sion and conduct problems. Involvement in conventional after-school activities was negatively asso ciated with anxiety, and school support was negatively associated with both depression and conduct problems. No association was identified between parent support and any of anxiety, depression, or conduct problems. However, this latter finding may be related to measurement problems, or to participants' reports that they were most likely to be victimised in their homes (rather than at school or in the neighbourhood). While this study is limited by its cross-sectional nature, it implies that key sites for intervention are after-school activities, school support, peer delinquency, and home life.Around the world, children's exposure to community violence has been identified as a widespread problem (Raviv et al., 2001;Schwab-Stone et al., 1999;

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The global decline of large carnivores demands effective and efficient methods to monitor population status, particularly using non-invasive methods. Density is among the most useful metrics of population status because it is directly comparable across space and time. Unfortunately, density is difficult to measure reliably, especially for mobile, cryptic species. Recently, efforts have turned to approximating density based on its relationship to more readily estimable indices of occurrence. However, the relationship between density and such indices is contingent on several key assumptions that field studies often violate. Recent research has shown that these relationships are unreliable where sampling units are not independent, as is often the case when estimating density or occurrence of large carnivores. Here, we use the largest data set thus far collected for leopards (Panthera pardus)-88 camera-trap surveys undertaken in 24 protected areas between 2013 and 2018-to explore how density and other population characteristics relate to parameter estimates in occupancy and Royle-Nichols abundance models. We show how home-range size confounds underlying relationships, with larger home ranges inflating the proportion of area used (PAU) and resulting in double counting in abundance models. Relativizing estimates of occupancy and abundance by home-range size improved their relationship with density, but the relationship remained weak and largely uninformative for management. Our findings illustrate the pitfalls of using the PAU or abundance as implicit proxies for density and highlight the challenges of assessing population status for wide-ranging, cryptic species across fragmented landscapes.

Survival was influenced by the severity of liver failure, with most deaths occurring in Child-Pugh grade C patients. Patients with AVH and encephalopathy, ascites, bilirubin levels >51 mmol/l, INR >2.3, albumin <25 g/l and who require balloon tube tamponade are at increased risk of dying within the first 6 weeks. Bilirubin levels >51 mmol/l and transfusion of >6 units of blood were predictors of variceal rebleeding.