3,029 research outputs found

    A simple stress test of experimenter demand effects

    Get PDF
    As a stress test of experimenter demand effects, we run an experiment where subjects can physically destroy coupons awarded to them. About one subject out of three does. Giving money back to the experimenter is possible in a separate task but is more consistent with an experimenter demand effect than an explanation based on altruism towards the experimenter. A measure of sensitivity to social pressure helps predict destruction when social information is provided

    Confirmation of low genetic diversity and multiple breeding females in a social group of Eurasian badgers from microsatellite and field data

    Get PDF
    The Eurasian badger ( Meles meles ) is a facultatively social carnivore that shows only rudimentary co-operative behaviour and a poorly defined social hierarchy. Behavioural evidence and limited genetic data have suggested that more than one female may breed in a social group. We combine pregnancy detection by ultrasound and microsatellite locus scores from a well-studied badger population from Wytham Woods, Oxfordshire, UK, to demonstrate that multiple females reproduce within a social group. We found that at least three of seven potential mothers reproduced in a group that contained 11 reproductive age females and nine offspring. Twelve primers showed variability across the species range and only five of these were variable in Wytham. The microsatellites showed a reduced repeat number, a significantly higher number of nonperfect repeats, and moderate heterozygosity levels in Wytham. The high frequency of imperfect repeats and demographic phenomena might be responsible for the reduced levels of variability observed in the badger

    The bright optical afterglow of the nearby gamma-ray burst of 29 March 2003

    Get PDF
    Many past studies of cosmological gamma-ray bursts (GRBs) have been limited because of the large distance to typical GRBs, resulting in faint afterglows. There has long been a recognition that a nearby GRB would shed light on the origin of these mysterious cosmic explosions, as well as the physics of their fireballs. However, GRBs nearer than z=0.2 are extremely rare, with an estimated rate of localisation of one every decade. Here, we report the discovery of bright optical afterglow emission from GRB 030329. Our prompt dissemination and the brilliance of the afterglow resulted in extensive followup (more than 65 telescopes) from radio through X-ray bands, as well as measurement of the redshift, z=0.169. The gamma-ray and afterglow properties of GRB 030329 are similar to those of cosmological GRBs (after accounting for the small distance), making this the nearest known cosmological GRB. Observations have already securely identified the progenitor as a massive star that exploded as a supernova, and we anticipate futher revelations of the GRB phenomenon from studies of this source.Comment: 13 pages, 4 figures. Original tex

    Three dimensional evaluation of posture in standing with the PosturePrint: an intra- and inter-examiner reliability study

    Get PDF
    Abstract Background Few digitizers can measure the complexity of upright human postural displacements in six degrees of freedom of the head, rib cage, and pelvis. Methods In a University laboratory, three examiners performed delayed repeated postural measurements on forty subjects over two days. Three digital photographs (left lateral, AP, right lateral) of each of 40 volunteer participants were obtained, twice, by three examiners. Examiners placed 13 markers on the subjects before photography and chose 16 points on the photographic images. Using the PosturePrint¼ internet computer system, head, rib cage, and pelvic postures were calculated as rotations (Rx, Ry, Rz) in degrees and translations (Tx, Tz) in millimeters. For reliability, two different types (liberal = ICC3,1 & conservative = ICC2,1) of inter- and intra-examiner correlation coefficients (ICC) were calculated. Standard error of measurements (SEM) and mean absolute differences within and between observers' measurements were also determined. Results All of the "liberal" ICCs were in the excellent range (> 0.84). For the more "conservative" type ICCs, four Inter-examiner ICCs were in the interval (0.5–0.6), 10 ICCs were in the interval (0.61–0.74), and the remainder were greater than 0.75. SEMs were 2.7° or less for all rotations and 5.9 mm or less for all translations. Mean absolute differences within examiners and between examiners were 3.5° or less for all rotations and 8.4 mm or less for all translations. Conclusion For the PosturePrint¼ system, the combined inter-examiner and intra-examiner correlation coefficients were in the good (14/44) and excellent (30/44) ranges. SEMs and mean absolute differences within and between examiners' measurements were small. Thus, this posture digitizer is reliable for clinical use

    Phase Mixing of Alfvén Waves Near a 2D Magnetic Null Point

    Get PDF
    The propagation of linear Alfvén wave pulses in an inhomogeneous plasma near a 2D coronal null point is investigated. When a uniform plasma density is considered, it is seen that an initially planar Alfvén wavefront remains planar, despite the varying equilibrium Alfvén speed, and that all the wave collects at the separatrices. Thus, in the non-ideal case, these Alfvénic disturbances preferentially dissipate their energy at these locations. For a non-uniform equilibrium density, it is found that the Alfvén wavefront is significantly distorted away from the initially planar geometry, inviting the possibility of dissipation due to phase mixing. Despite this however, we conclude that for the Alfvén wave, current density accumulation and preferential heating still primarily occur at the separatrices, even when an extremely non-uniform density profile is considered

    Impact of age on NIS2+ℱ and other non-invasive blood tests for the evaluation of liver disease and detection of at-risk MASH

    Get PDF
    \ua9 2024 The Author(s)Background & Aims: Robust performance of non-invasive tests (NITs) across ages is critical to assess liver disease among patients with metabolic dysfunction-associated liver disease (MASLD). We evaluated the impact of age on the performance of NIS2+ℱ vs. other NITs. Methods: An analysis cohort (N = 1,926) with biopsy-proven MASLD was selected among individuals screened for the phase III RESOLVE-IT clinical trial and divided into ≀45, 46–55, 56–64, and ≄65 years groups. To avoid potential confounding effects, a well-balanced cohort (n = 708; n = 177/age group) was obtained by applying a propensity score-matching algorithm to the analysis cohort. Baseline values of biomarkers and NITs were compared across age groups using one-way ANOVA, and the impact of age and histology were compared through three-way ANOVA. The impact of age on NIT performance for the detection of at-risk metabolic dysfunction-associated steatohepatitis (MASH; MASLD activity score [MAS] ≄4 and fibrosis stage [F] ≄2) was also evaluated. Results: Age did not affect the distributions of NIS2+ℱ and APRI (aspartate aminotransferase-to-platelet ratio index), but significantly (p <0.0001) impacted those of NFS (NAFLD fibrosis score), FIB-4 (Fibrosis-4 index), and Enhanced Liver Fibrosis (ELFℱ) score. NIS2+ℱ was the only NIT on which fibrosis and MAS exerted a moderate to large effect. While the impact of fibrosis on APRI was moderate, that of MAS was low. The impact of age on FIB-4 and NFS was larger than that of fibrosis. NIS2+ℱ exhibited the highest AUROC values for detecting at-risk MASH across age groups, with stable performances irrespective of cut-offs. Conclusions: NIS2+ℱ was not significantly impacted by age and was sensitive to both fibrosis and MAS grade, demonstrating a robust performance to rule in/out at-risk MASH with fixed cut-offs. Impact and Implications: While metabolic dysfunction-associated steatotic liver disease (MASLD) can affect individuals of all ages, patient age could represent an important confounding factor when interpreting non-invasive test (NIT) results, highlighting the need for reliable and efficient NITs that are not impacted by age and that could be interpreted with fixed cut-offs, irrespective of patient age. We report the impact of age on different well-established NITs – among those tested, only two panels, NIS2+ℱ and APRI, were not impacted by age and can be used and interpreted independently of patient age. NIS2+ℱ was also sensitive to both fibrosis and MAS, further confirming its efficiency for the detection of the composite endpoint of at-risk MASH and its potential as a valuable candidate for large-scale implementation in clinical practice and clinical trials

    ERCC1 expression and RAD51B activity correlate with cell cycle response to platinum drug treatment not DNA repair

    Get PDF
    Background: The H69CIS200 and H69OX400 cell lines are novel models of low-level platinum-drug resistance. Resistance was not associated with increased cellular glutathione or decreased accumulation of platinum, rather the resistant cell lines have a cell cycle alteration allowing them to rapidly proliferate post drug treatment. Results: A decrease in ERCC1 protein expression and an increase in RAD51B foci activity was observed in association with the platinum induced cell cycle arrest but these changes did not correlate with resistance or altered DNA repair capacity. The H69 cells and resistant cell lines have a p53 mutation and consequently decrease expression of p21 in response to platinum drug treatment, promoting progression of the cell cycle instead of increasing p21 to maintain the arrest. Conclusion: Decreased ERCC1 protein and increased RAD51B foci may in part be mediating the maintenance of the cell cycle arrest in the sensitive cells. Resistance in the H69CIS200 and H69OX400 cells may therefore involve the regulation of ERCC1 and RAD51B independent of their roles in DNA repair. The novel mechanism of platinum resistance in the H69CIS200 and H69OX400 cells demonstrates the multifactorial nature of platinum resistance which can occur independently of alterations in DNA repair capacity and changes in ERCC1

    Recent advances in electronic structure theory and their influence on the accuracy of ab initio potential energy surfaces

    Get PDF
    Recent advances in electronic structure theory and the availability of high speed vector processors have substantially increased the accuracy of ab initio potential energy surfaces. The recently developed atomic natural orbital approach for basis set contraction has reduced both the basis set incompleteness and superposition errors in molecular calculations. Furthermore, full CI calculations can often be used to calibrate a CASSCF/MRCI approach that quantitatively accounts for the valence correlation energy. These computational advances also provide a vehicle for systematically improving the calculations and for estimating the residual error in the calculations. Calculations on selected diatomic and triatomic systems will be used to illustrate the accuracy that currently can be achieved for molecular systems. In particular, the F+H2 yields HF+H potential energy hypersurface is used to illustrate the impact of these computational advances on the calculation of potential energy surfaces
    • 

    corecore