An exploration into response validity

Objectives: Performance validity tests (PVTs) and symptom validity tests (SVTs) have been recommended by the British Psychological Society to assist clinicians in validating assessment data. The current study aimed to explore the base rate of PVT failure in an NHS neuropsychology service, a setting relatively unexplored. A secondary aim was to investigate the relationship between PVT and SVT performance. Lastly, group differences in those passing and failing PVTs were explored in terms of demographics, and psychological functioning. Method: Archival test data (n=127) was drawn from an NHS outpatient neuropsychology service. Participants completed one stand-alone PVT (the Test of Memory Malingering [TOMM]), one embedded PVT (Digit Span age-corrected scaled score [DS-SS]), and one SVT (the Personality Assessment Inventory [PAI]). Results: The base rate of failure on any one PVT was 26%. The rate of TOMM failure was 12% and 6% additionally failed an embedded PVT. A significant relationship was found between PVT and SVT performance. Significantly elevated Paranoia, Anxiety-Related Disorders, and Schizophrenia PAI scales, as well as lower Full Scale IQ scores, were found in those who failed PVTs compared to those who passed. No other group differences on demographics were found, including reported financial incentive. Conclusions: Findings suggest that PVT failure occurs in a sizable minority of NHS ABI outpatients, which is unlikely to be simply explained by malingering for material gain. Elevations in reported psychopathological symptoms may be related to emotional and cognitive sequalae resulting from the ABI itself. Careful interpretation of neuropsychological test data is endorsed

Efficacy of crustal superfluid neutrons in pulsar glitch models

In order to assess the ability of purely crust-driven glitch models to match the observed glitch activity in the Vela pulsar, we conduct a systematic analysis of the dependence of the fractional moment of inertia of the inner crustal neutrons on the stiffness of the nuclear symmetry energy at saturation density $L$. We take into account both crustal entrainment and the fact that only a fraction $Y_{\rm g}$ of the core neutrons may couple to the crust on the glitch-rise timescale. We use a set of consistently-generated crust and core compositions and equations-of-state which are fit to results of low-density pure neutron matter calculations. When entrainment is included at the level suggested by recent microscopic calculations and the core is fully coupled to the crust, the model is only able to account for the Vela glitch activity for a 1.4$M_{\odot}$ star if the equation of state is particularly stiff $L>100$ MeV. However, an uncertainty of about 10\% in the crust-core transition density and pressure allows for the Vela glitch activity to be marginally accounted for in the range $L\approx30-60$MeV consistent with a range of experimental results. Alternatively, only a small amount of core neutrons need be involved. If less than 50\% of the core neutrons are coupled to the crust during the glitch, we can also account for the Vela glitch activity using crustal neutrons alone for EOSs consistent with the inferred range of $L$. We also explore the possibility of Vela being a high-mass neutron star, and of crustal entrainment being reduced or enhanced relative to its currently predicted values.Comment: 10 pages, 6 figure

On Some Species of Impatiens from Indo-China and the Malayan Peninsula

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Helpful Homework in Geometry: A Redesigned Circles Unit

Homework has been part of the educational system for many decades. During this time, public opinion has varied greatly on its usefulness in the classroom. Much of the more recent research has focused on the idea that homework can be valuable to students when the assignments are meaningful, as opposed to homework that is assigned with little or no purpose. This research was analyzed to find patterns in the various definitions of meaningful homework. It was found that meaningful homework generally contains the following qualities: brevity, choice, defined purpose, real-world connections, hands-on components, rigor through synthesis, the integration of technology or web-based activities, opportunities for family involvement, and the substantial incorporation of previously taught topics. Based on these findings, a Geometry unit on circles was redesigned to combine these elements into practical lessons, as an example to educators of how to begin making homework more constructive in the mathematics classroom

Listen up, health officials – here’s how to reduce ‘Ebolanoia’

An epidemic disease such as Ebola brings suffering to more than those who get ill or die. Social and economic threats can actually outstrip the medical ones. The outbreaks of SARS in 2003, for example, cost the world economy some US$40 billion, partly as a result of highly disputed travel bans. Epidemic diseases nearly always also lead to stigmatisation and ill treatment of groups associated with the disease. And because there are always people who are especially scared, epidemic diseases can cause social disruption by people who do such things as flee cities, swamp doctors and health services while well, and stockpile food or medicines. We can’t entirely eliminate these costs, but we can minimise “Ebolanoia” by addressing fears and directing people to positive actions. Here are some of the risk communication lessons our health officials and political leaders should be mindful of when they engage with the public about Ebola