517 research outputs found

    Shedding Light on the Matter of Abell 781

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    The galaxy cluster Abell 781 West has been viewed as a challenge to weak gravitational lensing mass calibration, as Cook and dell'Antonio (2012) found that the weak lensing signal-to-noise in three independent sets of observations was consistently lower than expected from mass models based on X-ray and dynamical measurements. We correct some errors in statistical inference in Cook and dell'Antonio (2012) and show that their own results agree well with the dynamical mass and exhibit at most 2.2--2.9σ\sigma low compared to the X-ray mass, similar to the tension between the dynamical and X-ray masses. Replacing their simple magnitude cut with weights based on source photometric redshifts eliminates the tension between lensing and X-ray masses; in this case the weak lensing mass estimate is actually higher than, but still in agreement with, the dynamical estimate. A comparison of lensing analyses with and without photometric redshifts shows that a 1--2σ\sigma chance alignment of low-redshift sources lowers the signal-to-noise observed by all previous studies which used magnitude cuts rather than photometric redshifts. The fluctuation is unexceptional, but appeared to be highly significant in Cook and dell'Antonio (2012) due to the errors in statistical interpretation.Comment: 7 pages, submitted to MNRA

    Use of the Adult Myopathy Assessment Tool as a predictor of functional abilities in people with multiple sclerosis

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    Background: People with multiple sclerosis (PwMS) are at greater risk for decreased muscle performance which may lead to decreased functional abilities. The Kurtzke Expanded Disability Status Scale (EDSS) is commonly used as a disability status rating scale in PwMS. Nevertheless, the EDSS is largely comprised of neurological tests and may not best reflect functional performance. A functional battery such as The Adult Myopathy Assessment Tool (AMAT) may better reflect functional performance. The AMAT was designed to assess both functional strength and endurance in clinical settings. However, the AMAT has not been validated for the assessment of PwMS. Objective: The purpose of the study was to determine the comparative association of the AMAT and EDSS with measures of strength, fatigability, and functional performance. Methods: Twenty-nine people (mean age 48.6 ±11.2), with a history of MS (EDSS \u3c 7.0) were recruited. Participants completed functional testing (5 times sit to stand and gait speed) and an assessment of disability and functional status using the EDSS and AMAT, respectively. Muscle performance was assessed via a 60 s maximal volitional isometric contraction (MVIC) of the knee extensors using an isokinetic dynamometer, and expressed as fatigability (exhaustion time to 60% of MVIC), peak torque, and peak torque scaled to body weight. Results:The participants exhibited moderate levels of disability (EDSS, 3.6 ±1.4) and function (AMAT total score, 36.1 ±7.6; AMAT function subscale, 18.2 ±3.3). Peak force was 70.1 kg ±22.0 kg, exhaustion time was 38.4 s ±17.4 s, gait speed was 1.3 m/s ±0.3 m/s, and five time sit to stand was 11.4 s ±4.1 s. The AMAT function subscale was associated with scaled peak torque (r=0.426, p=.021), gait speed (r=0.825, p=0.00), and 5 time sit to stand (r=-0.632, p Conclusions: The AMAT was more strongly associated with scaled peak torque and functional measures in comparison to the EDSS. This may reflect the observation that relative strength is a better predictor of functional abilities than unadjusted strength measures. Whereas, the stronger association of the EDSS with fatigability may be explained by the pyramidal systems measures within the tool and the well-known association of MS-related fatigue with disability. Based on the results of the study, we suggest clinicians administer the AMAT in addition to the EDSS, to gain insight into functional impairments and assist with formulating a comprehensive plan of care

    Course and predictors of posttraumatic stress and depression longitudinal symptom profiles in refugees:A latent transition model

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    Exposure to potentially traumatic events and post-migration living difficulties (PMLDs) may explain the high rates of posttraumatic stress disorder (PTSD) and depression in resettled refugees. Latent class analyses (LCAs) in refugees have identified subgroups that differ in symptom profiles of PTSD and comorbid symptoms. However, knowledge on longitudinal symptom profiles in refugees is sparse. Examining longitudinal PTSD and depression symptom profiles could provide information on risk factors underlying worsening of symptoms post-resettlement. Self-rated PTSD (Posttraumatic Diagnostic Scale) and depression (Patient Health Questionnaire-9) symptoms were assessed among 613 refugees who had resettled in Australia up to two years previously (W1) and at 6 months follow-up (W2). PTSD and depression symptom profiles were identified using LCAs for W1 and W2 separately. Latent transition analysis was used to examine (predictors of) changes in symptom profiles, including gender, age, trauma exposure, and PMLDs. Four classes were identified that were consistent across timepoints: a No symptoms (W1 61%; W2 68%), Low PTSD/Moderate depression (W1 16%; W2 10%), Moderate PTSD/depression (W1 16%; W2 14%), and High symptoms class (W1 7%; W2 7%). Higher levels of problems with PMLDs, including being discrimination and family separation, predicted movements out of the No symptom class at W1 to classes with psychopathology at W2. To conclude, most participants did not develop PTSD or depression symptoms. The risk of developing these symptoms seems higher when problems with interpersonal PMLDs increased, pointing to the need for considering these stressors when addressing the mental health needs in this population

    An overview of the PubChem BioAssay resource

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    The PubChem BioAssay database (http://pubchem.ncbi.nlm.nih.gov) is a public repository for biological activities of small molecules and small interfering RNAs (siRNAs) hosted by the US National Institutes of Health (NIH). It archives experimental descriptions of assays and biological test results and makes the information freely accessible to the public. A PubChem BioAssay data entry includes an assay description, a summary and detailed test results. Each assay record is linked to the molecular target, whenever possible, and is cross-referenced to other National Center for Biotechnology Information (NCBI) database records. ‘Related BioAssays’ are identified by examining the assay target relationship and activity profile of commonly tested compounds. A key goal of PubChem BioAssay is to make the biological activity information easily accessible through the NCBI information retrieval system-Entrez, and various web-based PubChem services. An integrated suite of data analysis tools are available to optimize the utility of the chemical structure and biological activity information within PubChem, enabling researchers to aggregate, compare and analyze biological test results contributed by multiple organizations. In this work, we describe the PubChem BioAssay database, including data model, bioassay deposition and utilities that PubChem provides for searching, downloading and analyzing the biological activity information contained therein

    Effectiveness of a single-session early psychological intervention for children after road traffic accidents: a randomised controlled trial

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    BACKGROUND: Road traffic accidents (RTAs) are the leading health threat to children in Europe, resulting in 355,000 injuries annually. Because children can suffer significant and long-term mental health problems following RTAs, there is considerable interest in the development of early psychological interventions. To date, the research in this field is scarce, and currently no evidence-based recommendations can be made. METHODS: To evaluate the effectiveness of a single-session early psychological intervention, 99 children age 7-16 were randomly assigned to an intervention or control group. The manualised intervention was provided to the child and at least one parent around 10 days after the child's involvement in an RTA. It included reconstruction of the accident using drawings and accident-related toys, and psychoeducation. All of the children were interviewed at 10 days, 2 months and 6 months after the accident. Parents filled in questionnaires. Standardised instruments were used to assess acute stress disorder (ASD), posttraumatic stress disorder (PTSD), depressive symptoms and behavioural problems. RESULTS: The children of the two study groups showed no significant differences concerning posttraumatic symptoms and other outcome variables at 2 or at 6 months. Interestingly, analyses showed a significant intervention x age-group effect, indicating that for preadolescent children the intervention was effective in decreasing depressive symptoms and behavioural problems. CONCLUSIONS: This study is the first to show a beneficial effect of a single-session early psychological intervention after RTA in preadolescent children. Therefore, an age-specific approach in an early stage after RTAs may be a promising way for further research. Younger children can benefit from the intervention evaluated here. However, these results have to be interpreted with caution, because of small subgroup sizes. Future studies are needed to examine specific approaches for children and adolescents. Also, the intervention evaluated here needs to be studied in other groups of traumatised children. TRIAL REGISTRATION: Clinical Trial Registry: ClinicalTrials.gov: NCT00296842

    The Ganzflicker experience:High probability of seeing vivid and complex pseudo-hallucinations with imagery but not aphantasia

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    There are considerable individual differences in visual mental imagery ability across the general population, including a “blind” mind's eye, or aphantasia. Recent studies have shown that imagery is linked to differences in perception in the healthy population, and clinical work has found a connection between imagery and hallucinatory experiences in neurological disorders. However, whether imagery ability is associated with anomalous perception–including hallucinations–in the general population remains unclear. In the current study, we explored the relationship between imagery ability and the anomalous perception of pseudo-hallucinations (PH) using rhythmic flicker stimulation (“Ganzflicker”). Specifically, we investigated whether the ability to generate voluntary imagery is associated with susceptibility to flicker-induced PH. We additionally explored individual differences in observed features of PH. We recruited a sample of people with aphantasia (aphants) and imagery (imagers) to view a constant red-and-black flicker for approximately 10 min. We found that imagers were more susceptible to PH, and saw more complex and vivid PH, compared to aphants. This study provides the first evidence that the ability to generate visual imagery increases the likelihood of experiencing complex and vivid anomalous percepts

    Unraveling the New England orocline, east Gondwana accretionary margin

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    The New England orocline lies within the Eastern Australian segment of the Terra Australis accretionary orogen and developed during the late Paleozoic to early Mesozoic Gondwanide Orogeny (310–230 Ma) that extended along the Pacific margin of the Gondwana supercontinent. The orocline deformed a pre-Permian arc assemblage consisting of a western magmatic arc, an adjoining forearc basin and an eastern subduction complex. The orocline is doubly vergent with the southern and northern segments displaying counter-clockwise and clockwise rotation, respectively, and this has led to contrasting models of formation. We resolve these conflicting models with one that involves buckling of the arc system about a vertical axis during progressive northward translation of the southern segment of the arc system against the northern segment, which is pinned relative to cratonic Gondwana. Paleomagnetic data are consistent with this model and show that an alternative model involving southward motion of the northern segment relative to the southern segment and cratonic Gondwana is not permissible. The timing of the final stage of orocline formation (~270–265 Ma) overlaps with a majorgap in magmatic activity along this segment of the Gondwana margin, suggesting that northward motion and orocline formation were driven by a change from orthogonal to oblique convergence and coupling between the Gondwana and Pacific plates

    Designing the Macrocyclic Dimension in Main Group Chemistry

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    Outside the confines and well-established domain of organic chemistry, the systematic building of large macromolecular arrangements based on non-carbon elements represents a significant and exciting challenge. Our aim in the past two decades has been to develop robust synthetic methods to construct new types of main group architectures in a methodical way, principles of design that parallel those used in the organic arena. This concept article addresses the fundamental thermodynamic and kinetic problems involved in the design and synthesis of main group macrocycles and looks to future developments of macromolecules in this area, as well as new applications in coordination chemistry.ERC. Grant Number: 291280 EU. Grant Number: RYC-2015-1903
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