A note on weak ∞-Chichilnisky rules

 There does not exist a weak ∞-Chichilnisky rule as defined in Candeal et al. (1992). Received: 5 November 1992/Accepted: 22 April 1996     

Investigating the correlation structure of quadrivariate udder infection times through hierarchical Archimedean copulas

The correlation structure imposed on multivariate time to event data is often of a simple nature, such as in the shared frailty model where pairwise correlations between event times in a cluster are all the same. In modeling the infection times of the four udder quarters clustered within the cow, more complex correlation structures are possibly required, and if so, such more complex correlation structures give more insight in the infection process. In this article, we will choose a marginal approach to study more complex correlation structures, therefore leaving the modeling of marginal distributions unaffected by the association parameters. The dependency of failure times will be induced through copula functions. The methods are shown for (mixtures of) the Clayton copula, but can be generalized to mixtures of Archimedean copulas for which the nesting conditions are met (McNeil in J Stat Comput Simul 6:567–581, 2008; Hofert in Comput Stat Data Anal 55:57–70, 2011).     

No overall effect of urbanization on nest-dwelling arthropods of great tits (Parus major).

Urbanization has been shown to strongly affect community composition of various taxa with potentially strong shifts in ecological interactions, including those between hosts and parasites. We investigated the effect of urbanization on the composition of arthropods in nests of great tits in Flanders, Belgium. These nests contain taxonomically and functionally diverse arthropod communities including parasites, predators, detritivores and accidental commensals. Using a standardized hierarchical sampling design with subplots (200 m?×?200 m) nested in plots (3 km?×?3 km) of varying urbanization levels, we collected arthropods from nests of resident great tits after the young had fledged. Arthropods were extracted, identified to Primary Taxonomical Groups (PTG) and counted. Using generalized linear mixed models (GLMMs) we found diverging effects of urbanization on PTG occurrences and abundances at various levels, but we did not find an overall signal in arthropod diversity or richness. Also, visual inspection of non-metric multidimensional scaling (NMDS) plots did not reveal any community differences between urbanization levels at plot or subplot scales. Land use and environmental variables at different distances around nestboxes did not contribute much to the variation between communities. Our results indicate that arthropod nestbox communities are generally not adversely affected by urbanization, and even city gardens and parks harbor comparable communities to forests and suburban areas. We thus found no evidence for a parasite release effect due to urbanization, nor an increased risk of parasitism in human-dominated environments.

     

Identity Styles and Interpersonal Behavior in Emerging Adulthood: The Intervening Role of Empathy

This study examined the intervening role of empathy in the relations between identity styles (i.e., information‐oriented, normative, and diffuse‐avoidant styles), and inter‐personal behaviors (i.e., prosocial behavior, self‐ and other‐oriented helping, and physical and relational aggression). In a sample of 341 emerging adults, it was found that an information‐oriented style relates to a more adaptive pattern of interpersonal behaviors whereas a normative or a diffuse‐avoidant identity style relate to a more maladaptive pattern of interpersonal behaviors. Empathy played an intervening role between the information‐oriented style and interpersonal behavior, and between the diffuse‐avoidant style and interpersonal behavior. However, empathy did not intervene between the normative style and interpersonal behavior. Implications for future research are discussed.