1,561 research outputs found

    Resilience–Recovery Factors in Post-traumatic Stress Disorder Among Female and Male Vietnam Veterans: Hardiness, Postwar Social Support, and Additional Stressful Life Events

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    Structural equation modeling procedures were used to examine relationships among several war zone stressor dimensions, resilience-recovery factors, and post-traumatic stress disorder symptoms in a national sample of 1,632 Vietnam veterans (26% women and 74% men). A 9-factor measurement model was specified on a mixed-gender subsample of the data and then replicated on separate subsamples of female and male veterans. For both genders, the structural models supported strong mediation effects for the intrapersonal resource characteristic of hardiness, postwar structural and functional social support, and additional negative life events in the postwar period. Support for moderator effects or buffering in terms of interactions between war zone stressor level and resiliencerecovery factors was minimal

    Charge-ice dynamics in the negative thermal expansion material Cd(CN)2_2

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    We use variable-temperature (150--300\,K) single-crystal X-ray diffraction to re-examine the interplay between structure and dynamics in the ambient phase of the isotropic negative thermal expansion (NTE) material Cd(CN)2_2. We find strong experimental evidence for the existence of low-energy vibrational modes that involve off-centering of Cd2+^{2+} ions. These modes have the effect of increasing network packing density---suggesting a mechanism for NTE that is different to the generally-accepted picture of correlated Cd(C/N)4_4 rotation modes. Strong local correlations in the displacement directions of neighbouring cadmium centres are evident in the existence of highly-structured diffuse scattering in the experimental X-ray diffraction patterns. Monte Carlo simulations suggest these patterns might be interpreted in terms of a basic set of `ice-rules' that establish a mapping between the dynamics of Cd(CN)2_2 and proton ordering in cubic ice VII.Comment: 5 pages, 5 figures, submitted to PR

    Measurement of the Hyperfine Structure and Isotope Shifts of the 3s23p2 3P2 to 3s3p3 3Do3 Transition in Silicon

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    The hyperfine structure and isotope shifts of the 3s23p2 3P2 to 3s3p3 3Do3 transition in silicon have been measured. The transition at 221.7 nm was studied by laser induced fluorescence in an atomic Si beam. For 29Si, the hyperfine A constant for the 3s23p2 3P2 level was determined to be -160.1+-1.3 MHz (1 sigma error), and the A constant for the 3s3p3 3Do3 level is -532.9+-0.6 MHz. This is the first time that these constants were measured. The isotope shifts (relative to the abundant isotope 28Si) of the transition were determined to be 1753.3+-1.1 MHz for 29Si and 3359.9+-0.6 MHz for 30Si. This is an improvement by about two orders of magnitude over a previous measurement. From these results we are able to predict the hyperfine structure and isotope shift of the radioactive 31Si atom, which is of interest in building a scalable quantum computer

    Development of a German version of the Oswestry Disability Index. Part 1: cross-cultural adaptation, reliability, and validity

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    Patient-orientated assessment methods are of paramount importance in the evaluation of treatment outcome. The Oswestry Disability Index (ODI) is one of the condition-specific questionnaires recommended for use with back pain patients. To date, no German version has been published in the peer-reviewed literature. A cross-cultural adaptation of the ODI for the German language was carried out, according to established guidelines. One hundred patients with chronic low-back pain (35 conservative, 65 surgical) completed a questionnaire booklet containing the newly translated ODI, along with a 0-10 pain visual analogue scale (VAS), the Roland Morris Disability Questionnaire, and Likert scales for disability, medication intake and pain frequency [to assess ODI's construct (convergent) validity]. Thirty-nine of these patients completed a second questionnaire within 2weeks (to assess test-retest reliability). The intraclass correlation coefficient for the test-retest reliability of the questionnaire was 0.96. In test-retest, 74% of the individual questions were answered identically, and 21% just one grade higher or lower. The standard error of measurement (SEM) was 3.4, giving a "minimum detectable change” (MDC95%) for the ODI of approximately 9 points, i.e. the minimum change in an individual's score required to be considered "real change” (with 95% confidence) over and above measurement error. The ODI scores correlated with VAS pain intensity (r=0.78, P<0.001) and Roland Morris scores (r=0.80, P<0.001). The mean baseline ODI scores differed significantly between the surgical and conservative patients (P<0.001), and between the different categories of the Likert scales for disability, medication use and pain frequency (in each case P<0.001). Our German version of the Oswestry questionnaire is reliable and valid, and shows psychometric characteristics as good as, if not better than, the original English version. It should represent a valuable tool for use in future patient-orientated outcome studies in German-speaking land

    Development of a German version of the Oswestry Disability Index. Part 2: sensitivity to change after spinal surgery

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    When functional scales are to be used as treatment outcome measures, it is essential to know how responsive they are to clinical change. This information is essential not only for clinical decision-making, but also for the determination of sample size in clinical trials. The present study examined the responsiveness of a German version of the Oswestry Disability Index version 2.1 (ODI) after surgical treatment for low back pain. Before spine surgery 63 patients completed a questionnaire booklet containing the ODI, along with a 0-10 pain visual analogue scale (VAS), the Roland Morris disability questionnaire, and Likert scales for disability, medication intake and pain frequency. Six months after surgery, 57 (90%) patients completed the same questionnaire booklet and also answered Likert-scale questions on the global result of surgery, and on improvements in pain and disability. Both the effect size for the ODI change score 6months after surgery (0.87) and the area under the receiver operating characteristics (ROC) curve for the relative improvement in ODI score in relation to global outcome 6months after surgery (0.90) indicated that the ODI showed good responsiveness. The ROC method revealed that a minimum reduction of the baseline (pre-surgery) ODI score by 18% (equal to a mean 8-point reduction in this patient group) represented the cut-off for indicating a "good” individual outcome 6months after surgery (sensitivity 91.4% and specificity 82.4%). The German version of the ODI is a sensitive instrument for detecting clinical change after spinal surgery. Individual improvements after surgery of at least an 18% reduction on baseline values are associated with a good outcome. This figure can be used as a reliable guide for the determination of sample size in future clinical trials of spinal surger

    Rehabilitation following surgery for lumbar spinal stenosis: a Cochrane review

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    Study Design A systematic review of randomised controlled trials (RCTs) Objective To determine the effects of active rehabilitation on functional outcome following lumbar spinal stenosis surgery when compared with 'usual postoperative care'. Summary of background data Surgery rates for lumbar spinal stenosis have risen, yet outcomes remain suboptimal. Post-operative rehabilitation has been suggested as a tool to improve post-operative function but, to date, there is limited evidence to support its use. Methods CENTRAL (The Cochrane Library), the Cochrane Back Review Group Trials Register, MEDLINE, EMBASE, CINAHL and PEDro electronic databases were searched. Randomised controlled trials (RCTs) comparing the effectiveness of active rehabilitation with usual care in adults with lumbar spinal stenosis who had undergone primary spinal decompression surgery were included. Two authors independently selected studies, assessed the risk of bias, and extracted the data in line with the recommendations of the Cochrane Back Review Group. Study results were pooled in a meta-analysis when appropriate using functional status as the primary outcome, with secondary outcomes including measures of leg pain, low back pain, and global improvement/general health. The GRADE approach was used to assess the quality of the evidence. Results Our searches yielded 1,726 articles, of which three studies (N = 373 participants) were suitable for inclusion in meta-analysis. All included studies were deemed to have low risk of bias; no study had unacceptably high dropout rates. There was moderate evidence suggesting that active rehabilitation was more effective than usual care in improving both short- and long-term functional status following surgery. Similar findings were noted for secondary outcomes, including short-term improvement in low back pain and long-term improvement in both low back pain and leg pain. Conclusions We obtained moderate-quality evidence indicating that postoperative active rehabilitation after decompression surgery for lumbar spinal stenosis is more effective than usual care. Further work is required particularly with respect to the cost effectiveness of such interventions

    Perform a gyro test of general relativity in a satellite and develop associated control technology

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    The progress accomplished in the Stanford Gyro Relativity program during the period November 1974 to October 1975 was described. Gyro developments were continued in the main laboratory dewar, concentrating on the operation of a three axis gyro readout and on improvements to the methods of canceling trapped fields in the rotor; these efforts culminated in the first successful observation of the London moment in the spinning gyro rotor in March 1975. Following a review meeting at that time, a new goal was formulated for the next 12 to 18 months, namely to operate a gyroscope in the new ultra-low field facility with readout resolution approaching 1 arc-second. The following other tasks were also completed: (1) sputtering work, (2) magnetometry, (3) construction and installation of the North Star simulator, (4) analysis of torques on the gyro, especially in inclined orbits, (5) equivalence principle accelerometer, and (6) analysis of a twin-satellite test of relativity

    Universal amplitude ratios from numerical studies of the three-dimensional O(2) model

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    We investigate the three-dimensional O(2) model near the critical point by Monte Carlo simulations and calculate the major universal amplitude ratios of the model. The ratio U_0=A+/A- is determined directly from the specific heat data at zero magnetic field. The data do not, however, allow to extract an accurate estimate for alpha. Instead, we establish a strong correlation of U_0 with the value of alpha used in the fit. This numerical alpha-dependence is given by A+/A- = 1 -4.20(5) alpha + O(alpha^2). For the special alpha-values used in other calculations we find full agreement with the corresponding ratio values, e. g. that of the shuttle experiment with liquid helium. On the critical isochore we obtain the ratio xi+/xi-_T=0.293(9), and on the critical line the ratio xi_T^c/xi_L^c=1.957(10) for the amplitudes of the transverse and longitudinal correlation lengths. These two ratios are independent of the used alpha or nu-values.Comment: 34 pages, 19 Ps-figures, Latex2e, revised version, to be published in J. Phys.

    Alcohol Use and Trauma Exposure Among Male and Female Veterans Before, During, and After Military Service

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    Background: The present study examined lifespan and combat-related trauma exposure as predictors of alcohol use among male and female veterans. Posttraumatic stress and depressive symptoms were examined as mediators of the effects of trauma exposure on alcohol use. Methods: Data were examined from 1825 (1450 male, 375 female) veterans and active duty service members who took part in a multi-site research study conducted through the Department of Veterans Affairs Mid-Atlantic Mental Illness Research, Education and Clinical Center (VISN 6 MIRECC). Results: For both men and women, depressive symptoms significantly mediated the effects of non-combat trauma exposure experienced before, during and after the military, as well as combat-exposure, on alcohol use. With posttraumatic stress symptoms, the models for men and women differed. For men, the effects of non-combat trauma exposure during and after military service, and combat exposure, on alcohol use were mediated by PTSD symptoms; however, for women, PTSD symptoms did not mediate these relationships. Conclusion: Findings are discussed in the context of potential gender differences in response to trauma such as use of alcohol to cope with traumatic events

    ISSLS PRIZE in Clinical Science 2023: comparison of degenerative MRI features of the intervertebral disc between those with and without chronic low back pain. An exploratory study of two large female populations using automated annotation

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    Objectives The relationship of degeneration to symptoms has been questioned. MRI detects apparently similar disc degeneration and degenerative changes in subjects both with and without back pain. We aimed to overcome these problems by re-annotating MRIs from asymptomatic and symptomatics groups onto the same grading system. Methods We analysed disc degeneration in pre-existing large MRI datasets. Their MRIs were all originally annotated on different scales. We re-annotated all MRIs independent of their initial grading system, using a verified, rapid automated MRI annotation system (SpineNet) which reported degeneration on the Pfirrmann (1–5) scale, and other degenerative features (herniation, endplate defects, marrow signs, spinal stenosis) as binary present/absent. We compared prevalence of degenerative features between symptomatics and asymptomatics. Results Pfirrmann degeneration grades in relation to age and spinal level were very similar for the two independent groups of symptomatics over all ages and spinal levels. Severe degenerative changes were significantly more prevalent in discs of symptomatics than asymptomatics in the caudal but not the rostral lumbar discs in subjects  Conclusions We confirmed age and disc level are significant in determining imaging differences between asymptomatic and symptomatic populations and should not be ignored. Automated analysis, by rapidly combining and comparing data from existing groups with MRIs and information on LBP, provides a way in which epidemiological and ‘big data’ analysis could be advanced without the expense of collecting new groups. Level of evidence I Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding
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