Magnitude-sensitive reaction times reveal non-linear time costs in multi-alternative decision-making

Optimality analysis of value-based decisions in binary and multi-alternative choice settings predicts that reaction times should be sensitive only to differences in stimulus magnitudes, but not to overall absolute stimulus magnitude. Yet experimental work in the binary case has shown magnitude sensitive reaction times, and theory shows that this can be explained by switching from linear to multiplicative time costs, but also by nonlinear subjective utility. Thus disentangling explanations for observed magnitude sensitive reaction times is difficult. Here for the first time we extend the theoretical analysis of geometric time-discounting to ternary choices, and present novel experimental evidence for magnitude-sensitivity in such decisions, in both humans and slime moulds. We consider the optimal policies for all possible combinations of linear and geometric time costs, and linear and nonlinear utility; interestingly, geometric discounting emerges as the predominant explanation for magnitude sensitivity

When intuition falters: repeated testing accuracy during an epidemic

Widespread, repeated testing using rapid antigen tests to proactively detect asymptomatic SARS-CoV-2 infections has been a promising yet controversial topic during the COVID-19 pandemic. Concerns have been raised over whether currently authorized lateral flow tests are sufficiently sensitive and specific to detect enough infections to impact transmission whilst minimizing unnecessary isolation of false positives. These concerns have often been illustrated using simple, textbook calculations of positivity rates and positive predictive value assuming fixed values for sensitivity, specificity and prevalence. However, we argue that evaluating repeated testing strategies requires the consideration of three additional factors: new infections continue to arise depending on the incidence rate, isolating positive individuals reduces prevalence in the tested population, and each infected individual is tested multiple times during their infection course. We provide a simple mathematical model with an online interface to illustrate how these three factors impact test positivity rates and the number of isolating individuals over time. These results highlight the potential pitfalls of using inappropriate textbook-style calculations to evaluate statistics arising from repeated testing strategies during an epidemic

The role of ECL2 in CGRP receptor activation: a combined modelling and experimental approach

The calcitonin gene-related peptide (CGRP) receptor is a complex of a calcitonin receptor-like receptor (CLR), which is a family B G-protein-coupled receptor (GPCR) and receptor activity modifying protein 1. The role of the second extracellular loop (ECL2) of CLR in binding CGRP and coupling to Gs was investigated using a combination of mutagenesis and modelling. An alanine scan of residues 271–294 of CLR showed that the ability of CGRP to produce cAMP was impaired by point mutations at 13 residues; most of these also impaired the response to adrenomedullin (AM). These data were used to select probable ECL2-modelled conformations that are involved in agonist binding, allowing the identification of the likely contacts between the peptide and receptor. The implications of the most likely structures for receptor activation are discussed.</jats:p

Defining childhood severe falciparum malaria for intervention studies.

Background Clinical trials of interventions designed to prevent severe falciparum malaria in children require a clear endpoint. The internationally accepted definition of severe malaria is sensitive, and appropriate for clinical purposes. However, this definition includes individuals with severe nonmalarial disease and coincident parasitaemia, so may lack specificity in vaccine trials. Although there is no “gold standard” individual test for severe malaria, malaria-attributable fractions (MAFs) can be estimated among groups of children using a logistic model, which we use to test the suitability of various case definitions as trial endpoints. Methods and Findings A total of 4,583 blood samples were taken from well children in cross-sectional surveys and from 1,361 children admitted to a Kenyan District hospital with severe disease. Among children under 2 y old with severe disease and over 2,500 parasites per microliter of blood, the MAFs were above 85% in moderate- and low-transmission areas, but only 61% in a high-transmission area. HIV and malnutrition were not associated with reduced MAFs, but gastroenteritis with severe dehydration (defined by reduced skin turgor), lower respiratory tract infection (clinician's final diagnosis), meningitis (on cerebrospinal fluid [CSF] examination), and bacteraemia were associated with reduced MAFs. The overall MAF was 85% (95% confidence interval [CI] 83.8%–86.1%) without excluding these conditions, 89% (95% CI 88.4%–90.2%) after exclusions, and 95% (95% CI 94.0%–95.5%) when a threshold of 2,500 parasites/μl was also applied. Applying a threshold and exclusion criteria reduced sensitivity to 80% (95% CI 77%–83%). Conclusions The specificity of a case definition for severe malaria is improved by applying a parasite density threshold and by excluding children with meningitis, lower respiratory tract infection (clinician's diagnosis), bacteraemia, and gastroenteritis with severe dehydration, but not by excluding children with HIV or malnutrition

A theory of intense-field dynamic alignment and high harmonic generation from coherently rotating molecules and interpretation of intense-field ultrafast pump-probe experiments

A theory of ultra-fast pump-probe experiments proposed by us earlier [F.H.M. Faisal et al., Phys. Rev. Lett. 98, 143001 (2007) and F.H.M. Faisal and A. Abdurrouf, Phys. Rev. Lett. 100, 123005 (2008)] is developed here fully and applied to investigate the phenomena of dynamic alignment and high harmonic generation (HHG) from coherently rotating linear molecules. The theory provides essentially analytical results for the signals that allow us to investigate the simultaneous dependence of the HHG signals on the two externally available control parameters, namely, the relative angle between the polarizations, and the delay-time between the two pulses. It is applied to investigate the characteristics of high harmonic emission from nitrogen and oxygen molecules that have been observed experimentally in a number of laboratories. The results obtained both in the time-domain and in the frequency-domain are compared with the observed characteristics as well as directly with the data and are found to agree remarkably well. In addition we have predicted the existence of a "magic" polarization angle at which all modulations of the harmonic emission from nitrogen molecule changes to a steady emission at the harmonic frequency. Among other things we have also shown a correlation between the existence of the "magic" or critical polarization angles and the symmetry of the active molecular orbitals, that is deemed to be useful in connection with the "inverse problem" of molecular imaging from the HHG data.Comment: 31 pages, 22 figures, and 140 equation

Ketamine as the anaesthetic for electroconvulsive therapy:the KANECT randomised controlled trial

C.AS. reports grants from Vifor Pharma, outside the submitted work. I.C.R. (deceased) declared personal fees from AstraZeneca, Sanofi Aventis and Sunovion, and non-financial support from Lundbeck, between 2009 and 2014 and all outside the submitted work. Volume 212, Issue 5 May 2018 , p. 323 Ketamine as the anaesthetic for electroconvulsive therapy: the KANECT randomised controlled trial – CORRIGENDUM Gordon Fernie, James Currie, Jennifer S. Perrin, Caroline A. Stewart... https://doi.org/10.1192/bjp.2018.76 Published online: 06 April 2018 Summary: This notice describes a correction to the above mentioned paper.Peer reviewedPublisher PD

Outcome measures for use in trials of paediatric otorrhoea:A systematic review

Introduction:Paediatric otorrhoea (PO) describes a middle ear infection that results in a perforation of the tympanic membrane and ear discharge, in children and young people (CYP). Prolonged infection may be associated with hearing loss and developmental delay. The current management of paediatric otorrhoea is variable, including non-invasive treatments (conservative, oral antibiotics, topical antibiotics) and surgery, reflecting the lack of a sufficiently strong evidence base. Outcome reporting is fundamental to producing reliable and meaningful evidence to inform best practice.Objectives:Primary objective: to determine which outcome measures are currently used to evaluate treatment success in studies of non-surgical treatments for paediatric otorrhoea. Secondary objectives: to identify outcome measurement instruments used in the literature and assess their applicability for use in clinical trials of PO.Methods:This systematic review was registered with PROSPERO (CRD42023407976). Database searches of EMBASE, MEDLINE and Cochrane was performed on June 6, 2023, covering from Jan 1995 to May 2023. Randomised controlled trials or study protocols involving CYP with PO were included following PRISMA guidelines. Risk of bias was assessed with Cochrane's tool.Results:Of the 377 papers identified, six were included in the systematic review. The primary outcome of five of the studies related to otorrhoea cessation; both time to cessation and proportion recovered at various time points were used as measures. Two measurement instruments were identified: Otitis Media-6 Questionnaire and the Institute for Medical Technology Assessment Productivity Cost Questionnaire. Both were shown to be applicable measurement instruments when used in clinical trials of PO.Conclusions:To promote homogeneity and facilitate meaningful comparison and combination of studies, we propose that time to cessation of otorrhoea from onset of otorrhoea should be used as the primary outcome in future studies. Further research is needed to establish if this is the most important outcome to children and their caregivers

The reflective learning continuum: reflecting on reflection

The importance of reflection to marketing educators is increasingly recognized. However, there is a lack of empirical research which considers reflection within the context of both the marketing and general business education literature. This paper describes the use of an instrument which can be used to measure four identified levels of a reflection hierarchy: habitual action, understanding, reflection and intensive reflection and two conditions for reflection: instructor to student interaction and student to student interaction. Further we demonstrate the importance of reflective learning in predicting graduates’ perception of program quality. Although the focus was on assessment of MBA level curricula, the findings have great importance to marketing education and educators