Characterizing the evolution of defense in a tripartite marine symbiosis using adaptive dynamics.

The evolution and maintenance of symbiotic systems remains a fascinating puzzle. While the coevolutionary dynamics of bipartite (host-symbiont) systems are well-studied, the dynamics of more complex systems have only recently garnered attention with increasing technological advances. We model a tripartite system inspired by the marine symbiotic relationship between the alga sp.

Rate of nosocomial MRSA transmission evaluated via contact screening.

Background: The prevention of methicillin-resistant S. aureus (MRSA) transmission in the healthcare setting is a priority in Infection Control practices. A cornerstone of this policy is contact tracing of nosocomial contacts after an unexpected MRSA finding.

Relative abundance data can misrepresent heritability of the microbiome.

Background: Host genetics can shape microbiome composition, but to what extent it does, remains unclear. Like any other complex trait, this important question can be addressed by estimating the heritability (h) of the microbiome-the proportion of variance in the abundance in each taxon that is attributable to host genetic variation. However, unlike most complex traits, microbiome heritability is typically based on relative abundance data, where taxon-specific abundances are expressed as the proportion of the total microbial abundance in a sample.

Closing the gap in the Janzen-Connell hypothesis: What determines pathogen diversity?

The high tree diversity in tropical forests has long been a puzzle to ecologists. In the 1970s, Janzen and Connell proposed that tree species (hosts) coexist due to the stabilizing actions of specialized enemies. This Janzen-Connell hypothesis was subsequently supported by theoretical studies.

Hosts, microbiomes, and the evolution of critical windows.

The absence of microbial exposure early in life leaves individuals vulnerable to immune overreaction later in life, manifesting as immunopathology, autoimmunity, or allergies. A key factor is thought to be a "critical window" during which the host's immune system can "learn" tolerance, and beyond which learning is no longer possible. Animal models indicate that many mechanisms have evolved to enable critical windows, and that their time limits are distinct and consistent.

Reducing Inappropriate Urinary Catheter Use by Involving Patients Through the Participatient App: Before-and-After Study.

Background: The risk of urinary tract infections is increased by the inappropriate placement and unnecessary prolongation of the use of indwelling urinary catheters. Sustained behavior change in infection prevention could be promoted by empowering patients through a smartphone app.

Objective: The aim of this study is to assess the feasibility and efficacy of implementation actions on patients' use of the Participatient app on a clinical ward and to compare 3 survey methods for urinary catheter use.

Natural selection for imprecise vertical transmission in host-microbiota systems.

How and when the microbiome modulates host adaptation remains an evolutionary puzzle, despite evidence that the extended genetic repertoire of the microbiome can shape host phenotypes and fitness. One complicating factor is that the microbiome is often transmitted imperfectly across host generations, leading to questions about the degree to which the microbiome contributes to host adaptation. Here, using an evolutionary model, we demonstrate that decreasing vertical transmission fidelity can increase microbiome variation, and thus phenotypic variation, across hosts.

The microbiome extends host evolutionary potential.

The microbiome shapes many host traits, yet the biology of microbiomes challenges traditional evolutionary models. Here, we illustrate how integrating the microbiome into quantitative genetics can help untangle complexities of host-microbiome evolution. We describe two general ways in which the microbiome may affect host evolutionary potential: by shifting the mean host phenotype and by changing the variance in host phenotype in the population.

Variation in SARS-CoV-2 outbreaks across sub-Saharan Africa.

A surprising feature of the SARS-CoV-2 pandemic to date is the low burdens reported in sub-Saharan Africa (SSA) countries relative to other global regions. Potential explanations (for example, warmer environments, younger populations) have yet to be framed within a comprehensive analysis. We synthesized factors hypothesized to drive the pace and burden of this pandemic in SSA during the period from 25 February to 20 December 2020, encompassing demographic, comorbidity, climatic, healthcare capacity, intervention efforts and human mobility dimensions.

Borderline oxacillin-resistant Staphylococcus aureus carriage among healthcare workers at neonatal intensive care unit and paediatric ward.

Background: During a meticillin-resistant Staphylococcus aureus contact tracing and screening investigation, two borderline oxacillin-resistant Staphylococcus aureus (BORSA)-positive screening cultures were encountered among neonatal intensive care unit (NICU) healthcare workers (HCWs). This finding led to further investigations.

Aim: To assess the likelihood of an outbreak with direct transmission among HCWs.

The Evolution of Variance Control.

Genetically identical individuals can be phenotypically variable, even in constant environmental conditions. The ubiquity of this phenomenon, known as 'intra-genotypic variability', is increasingly evident and the relevant mechanistic underpinnings are beginning to be understood. In parallel, theory has delineated a number of formal expectations for contexts in which such a feature would be adaptive.

Demographic responses underlying eco-evolutionary dynamics as revealed with inverse modelling.

Changes in population dynamics due to interacting evolutionary and ecological processes are the direct result of responses in vital rates, that is stage-specific growth, survival and fecundity. Quantifying through which vital rates population fitness is affected, instead of focusing on population trends only, can give a more mechanistic understanding of eco-evolutionary dynamics. The aim of this study was to estimate the underlying demographic rates of aphid (Myzus persicae) populations.

Surviving in a Cosexual World: A Cost-Benefit Analysis of Dioecy in Tropical Trees.

Dioecy has a demographic disadvantage compared with hermaphroditism: only about half of reproductive adults produce seeds. Dioecious species must therefore have fitness advantages to compensate for this cost through increased survival, growth, and/or reproduction. We used a full life cycle approach to quantify the demographic costs and benefits associated with dioecy while controlling for demographic differences between dioecious and hermaphroditic species related to other functional traits.

Extended-spectrum β-lactamase-producing enterobacteriaceae among travelers from the Netherlands.

A prospective cohort study was performed among travelers from the Netherlands to investigate the acquisition of carbapenemase-producing Enterobacteriaceae (CP-E) and extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) and associated risk factors. Questionnaires were administered and rectal swab samples were collected and tested before and after traveler return. Of 370 travelers, 32 (8.