A longitudinal view of factors that influence the emotional well-being of family caregivers to individuals with heart failure.

Objectives: Caring for community-residing patients with heart failure can affect caregivers' emotional wellbeing. However, few studies have examined caregivers' well-being longitudinally, or identified factors associated with positive and negative outcomes. The objective of this longitudinal cohort study was to examine changes in caregivers' well-being over time, and to identify patient and caregiver factors associated with positive and negative outcomes.

Restricted participation in stroke caregivers: who is at risk?

Objective: To identify caregiver-, stroke survivor-, and caregiving situation-related factors that are associated with caregivers' restriction from participation in their normative activities (ie, participation restriction) over the first 2 years poststroke.

Design: Longitudinal cohort study.

Setting: Acute care facilities and community.

Stroke survivors', caregivers', and health care professionals' perspectives on the weekend pass to facilitate transition home.

Objective: To explore stroke survivors', caregivers', and health care professionals' perceptions of weekend passes offered during inpatient rehabilitation and its role in facilitating the transition home.

Design: Qualitative descriptive.

Subjects: Sixteen stroke survivors, 15 caregivers, and 20 health care professionals' from a rehabilitation hospital.

Dispersal network structure and infection mechanism shape diversity in a coevolutionary bacteria-phage system.

Resource availability, dispersal and infection genetics all have the potential to fundamentally alter the coevolutionary dynamics of bacteria-bacteriophage interactions. However, it remains unclear how these factors synergise to shape diversity within bacterial populations. We used a combination of laboratory experiments and mathematical modeling to test how the structure of a dispersal network affects host phenotypic diversity in a coevolving bacteria-phage system in communities of differential resource input.

Case definitions for acute myocardial infarction in administrative databases and their impact on in-hospital mortality rates.

Objective: To identify validated ICD-9-CM/ICD-10 coded case definitions for acute myocardial infarction (AMI).

Data Sources: Ovid Medline (1950-2010) was searched to identify studies that validated acute myocardial infarction (AMI) case definitions. Hospital discharge abstract data and chart data were linked to validate identified AMI definitions.

Evolutionary history, immigration history, and the extent of diversification in community assembly.

During community assembly, species may accumulate not only by immigration, but also by in situ diversification. Diversification has intrigued biologists because its extent varies even among closely related lineages under similar ecological conditions. Recent research has suggested that some of this puzzling variation may be caused by stochastic differences in the history of immigration (relative timing and order of immigration by founding populations), indicating that immigration and diversification may affect community assembly interactively.

Predation and the evolutionary dynamics of species ranges.

Gene flow that hampers local adaptation can constrain species distributions and slow invasions. Predation as an ecological factor mainly limits prey species ranges, but a richer array of possibilities arises once one accounts for how predation alters the interplay of gene flow and selection. We extend previous single-species theory on the interplay of demography, gene flow, and selection by investigating how predation modifies the coupled demographic-evolutionary dynamics of the range and habitat use of prey.

Psychiatric outcomes of epilepsy surgery: a systematic review.

Purpose: The objective of this systematic review was to identify: (1) prevalence and severity of psychiatric conditions before and after resective epilepsy surgery, (2) incidence of postsurgical psychiatric conditions, and (3) predictors of psychiatric status after surgery.

Methods: A literature search was conducted using PubMed, EmBase, and the Cochrane database as part of a larger project on the development of an appropriateness and necessity rating tool to identify patients of all ages with potentially resectable focal epilepsy. The search yielded 5,061 articles related to epilepsy surgery and of the 763 articles meeting the inclusion criteria and reviewed in full text, 68 reported psychiatric outcomes.

An integrative approach to understanding microbial diversity: from intracellular mechanisms to community structure.

Trade-offs have been put forward as essential to the generation and maintenance of diversity. However, variation in trade-offs is often determined at the molecular level, outside the scope of conventional ecological inquiry. In this study, we propose that understanding the intracellular basis for trade-offs in microbial systems can aid in predicting and interpreting patterns of diversity.

Ecological feedbacks and the evolution of resistance.

1. The idea that parasites can affect host diversity is pervasive, and the possibility that parasites can increase host diversity is of particular interest. In this review, we focus on diversity in the resistance of hosts to their parasites, and on the different ways in which parasites can increase or decrease this resistance diversity.

Understanding the limits to generalizability of experimental evolutionary models.

Given the difficulty of testing evolutionary and ecological theory in situ, in vitro model systems are attractive alternatives; however, can we appraise whether an experimental result is particular to the in vitro model, and, if so, characterize the systems likely to behave differently and understand why? Here we examine these issues using the relationship between phenotypic diversity and resource input in the T7-Escherichia coli co-evolving system as a case history. We establish a mathematical model of this interaction, framed as one instance of a super-class of host-parasite co-evolutionary models, and show that it captures experimental results. By tuning this model, we then ask how diversity as a function of resource input could behave for alternative co-evolving partners (for example, E.

Ecology and evolution in microbial systems: the generation and maintenance of diversity in phage-host interactions.

Insights gained from studying the interactions between viruses and bacteria have important implications for the ecology and evolution of virus-host interactions in many environments and for pathogen-host and predator-prey interactions in general. Here, we focus on the generation and maintenance of diversity, highlighting recent laboratory and field experiments with microorganisms.

Coevolution drives temporal changes in fitness and diversity across environments in a bacteria-bacteriophage interaction.

Coevolutionary interactions are thought to play a crucial role in diversification of hosts and parasitoids. Furthermore, resource availability has been shown to be a fundamental driver of species diversity. Yet, we still do not have a clear understanding of how resource availability mediates the diversity generated by coevolution between hosts and parasitoids over time.

A meta-analysis of factors affecting local adaptation between interacting species.

Adaptive divergence among populations can result in local adaptation, whereby genotypes in native environments exhibit greater fitness than genotypes in novel environments. A body of theory has developed that predicts how different species traits, such as rates of gene flow and generation times, influence local adaptation in coevolutionary species interactions. We used a meta-analysis of local-adaptation studies across a broad range of host-parasite interactions to evaluate predictions about the effect of species traits on local adaptation.

Gene flow reverses an adaptive cline in a coevolving host-parasitoid interaction.

Many natural populations are characterized by clinal patterns of adaptation, but it is unclear how gene flow and environmental gradients interact to drive such clines. We addressed this question by directly manipulating dispersal and productivity in an experimental landscape containing a microbial parasitoid, the bacteriophage T7, and its host, the bacterium Escherichia coli. We observed that the adaptation of parasitoids increased on hosts originating from lower-productivity communities in the absence of gene flow.

Big questions, small worlds: microbial model systems in ecology.

Although many biologists have embraced microbial model systems as tools to address genetic and physiological questions, the explicit use of microbial communities as model systems in ecology has traditionally been more restricted. Here, we highlight recent studies that use laboratory-based microbial model systems to address ecological questions. Such studies have significantly advanced our understanding of processes that have proven difficult to study in field systems, including the genetic and biochemical underpinnings of traits involved in ecological interactions, and the ecological differences driving evolutionary change.

Adaptation varies through space and time in a coevolving host-parasitoid interaction.

One of the central challenges of evolutionary biology is to understand how coevolution organizes biodiversity over complex geographic landscapes. Most species are collections of genetically differentiated populations, and these populations have the potential to become adapted to their local environments in different ways. The geographic mosaic theory of coevolution incorporates this idea by proposing that spatial variation in natural selection and gene flow across a landscape can shape local coevolutionary dynamics.