How to measure post-error slowing: The case of pre-error speeding

Post-error slowing is one of the most widely employed measures to study cognitive and behavioral consequences of error commission. Several methods have been proposed to quantify the post-error slowing effect, and we discuss two main methods: The traditional method of comparing response times in correct post-error trials to response times of correct trials that follow another correct trial, and a more recent proposal of comparing response times in correct post-error trials to the corresponding correct pre-error trials. Based on thorough re-analyses of two datasets, we argue that the latter method provides an inflated estimate by also capturing the (partially) independent effect of pre-error speeding. We propose two solutions for improving the assessment of human error processing, both of which highlight the importance of distinguishing between initial pre-error speeding and later post-error slowing.

A Critical Analysis of the Literature on Time-to-Antibiotics in Suspected Sepsis

The Surviving Sepsis Campaign recommends immediate antibiotics for all patients with suspected sepsis and septic shock, ideally within 1 hour of recognition. Immediate antibiotic treatment is lifesaving for some patients, but a substantial fraction of patients initially diagnosed with sepsis have noninfectious conditions. Aggressive time-to-antibiotic targets risk promoting antibiotic overuse and antibiotic-associated harms for this subset of the population. An accurate understanding of the precise relationship between time-to-antibiotics and mortality for patients with possible sepsis is therefore critical to finding the best balance between assuring immediate antibiotics for those patients who truly need them versus allowing clinicians some time for rapid investigation to minimize the risk of overtreatment and antibiotic-associated harms for patients who are not infected. More than 30 papers have been published assessing the relationship between time-to-antibiotics and outcomes, almost all of which are observational cohort studies. Most report significant associations but all have important limitations. Key limitations include focusing just on the sickest subset of patients (only patients requiring intensive care and/or patients with septic shock), blending together mortality estimates from patients with very long intervals until antibiotics with patients with shorter intervals and reporting a single blended (and thus inflated) estimate for the average increase in mortality associated with each hour until antibiotics, and failure to control for large potential confounders including patients’ presenting signs and symptoms and granular measures of comorbidities and severity of illness. In this study, we elaborate on these potential sources of bias and try to distill a better understanding of what the true relationship between time-to-antibiotics and mortality may be for patients with suspected sepsis or septic shock.

Nestling immune response to phytohaemagglutinin is not heritable in collared flycatchers

The response to intradermally injected phytohaemagglutinin (PHA-response) is a commonly used quantification of avian immunocompetence (the ability to resist pathogens). Parasite-mediated sexual selection requires heritable immunocompetence, but evidence for heritability of PHA-response in birds largely stems from full-sib comparisons. Using an animal model approach, we quantified the narrow-sense heritability of PHA-response in 1626 collared flycatcher ( Ficedula albicollis ) nestlings from 332 families, most of which were cross-fostered. Nestling PHA-response was not significantly heritable ( h 2 =0.06±0.10), but was subject to non-heritable nest-of-origin effects (10% of variation). Our findings illustrate that full-sib comparisons of immunological measures may lead to an inflated estimate of heritability and also reveal a limited role of nestling PHA-response for sexual selection in this population.

Water contact observations in Kenyan communities endemic for schistosomiasis: methodology and patterns of behaviour

SUMMARYA descriptive analysis of observed water contact activities in seven Kenyan (Akamba) communities is presented. The patterns of contact with time of day, month of year, type of activity, degree of immersion, use of soap, use of ‘kithima’ and day of week are all considered, with particular attention given to how these vary with age and sex. It is noted that (a) patterns of contact vary dramatically between these culturally rather similar communities, (b) contact usually peaks in the second decade of life, (c) generally females, especially young women, spend more time at the water than males and (d) simple (unweighted) total observed duration of contact gives a relatively inflated estimate of exposure in adults, especially young women. The methodology of observation and data handling is described in some detail.