1,170 research outputs found

    Testing Conditional Factor Models

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    Using nonparametric techniques, we develop a methodology for estimating conditional alphas and betas and long-run alphas and betas, which are the averages of conditional alphas and betas, respectively, across time. The tests can be performed for a single asset or jointly across portfolios. The traditional Gibbons, Ross, and Shanken (1989) test arises as a special case of no time variation in the alphas and factor loadings and homoskedasticity. As applications of the methodology, we estimate conditional CAPM and multifactor models on book-to-market and momentum decile portfolios. We reject the null that long-run alphas are equal to zero even though there is substantial variation in the conditional factor loadings of these portfolios.

    Trajectory of Change in Pain, Depression, and Physical Functioning after Physical Activity Adoption in Fibromyalgia

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    Fibromyalgia (FM) is associated with widespread pain, depression, and declines in physical functioning. The study purpose was to examine the trajectory of these symptoms over time related to physical activity adoption and maintenance via Motivational Interviewing versus Education, to increase physical activity. There were no treatment group differences, we divided the sample (n = 184) based on changes in physical activity. Repeated measures analyses demonstrated differential patterns in depression, pain, and physical functioning at 24 and 36 weeks. Findings suggest increased physical activity may serve as a multiple-target intervention that provides moderate to large, long-lasting benefits for individuals with FM

    Obesity Moderates the Effects of Motivational Interviewing Treatment Outcomes in Fibromyalgia

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    Objective: Obesity is a common comorbid condition among patients with fibromyalgia (FM). Our objective was to assess if obesity moderates the treatment benefits of exercise-based motivational interviewing (MI) for FM. Methods: This is a secondary data analysis of a completed clinical trial of 198 FM patients who were randomized to receive either MI or attention control (AC). Using body mass index (BMI) to divide participants into obese (BMI >=30 kg/m2) and non-obese (BMI <30 kg m2) groups, mixed linear models were used to determine interaction between treatment arms and obesity status with regards to the primary outcome of global FM symptom severity (Fibromyalgia Impact Questionnaire, FIQ). Secondary measures included pain intensity (Brief Pain Inventory, BPI), 6-minute walk test, and self-reported physical activity (Community Health Activities Model Program for Seniors). Results: Of the 198 participants, 91 (46%) were non-obese and 107 (54%) were obese. On global FM symptom severity (FIQ), the interaction between treatment arms and obesity status was significant (P=0.02). In the non-obese group, MI was associated with a greater improvement in FIQ than AC. In the obese group, MI participants reported less improvement in FIQ compared to AC. The interaction analysis was also significant for BPI pain intensity (P=0.01), but not for the walk test and self-reported physical activity. Discussion: This is the first study to show that obesity negatively affects the treatment efficacy of MI in patients with FM. Our findings suggest that exercise-based MI may be more effective if initiated after weight loss is achieved

    The Complex Relationship between Pain Intensity and Physical Functioning in Fibromyalgia: The Mediating Role of Depression

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    Fibromyalgia (FM) is typically associated with the experience of diffuse pain and physical impairment.Depression also commonly co-exists in patients with FM, and has been correlated with pain intensity and physical functioning.Previous research suggests an association between pain intensity and physical functioning; however, the direct causal relationship between improvements in pain intensity and in functioning is not observed in many FM patients.This may suggest that another factor such as depression is mediating this relationship. The present work examinedmediating role of depression. METHODS: 216 patients with FM completed measures of pain intensity, depression, and physical functionas part of a larger longitudinal study.Assessments were completed at baseline, 12, 24, and 36 weeks.RESULTS: Longitudinal mediational analyses indicated that depression is a partial mediator of the relationship between pain intensity and physical functioningat all four assessment points.Beta coefficients for the path from pain to physical functioning ranged from 0.18 –0.36, with attenuated path coefficients ranging from 0.03 –0.08, still showing significant but decreased associations when depression was added as a mediator. CONCLUSIONS: Clinical implication includes the importance of treating co-morbid depression in patients with fibromyalgia early in the course of treatment to prevent engagement in the cycle of disability

    Pain Coping Skills Training for Patients Who Catastrophize About Pain Prior to Knee Arthroplasty: A Multisite Randomized Clinical Trial

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    BACKGROUND: Pain catastrophizing has been identified as a prognostic indicator of poor outcome following knee arthroplasty. Interventions to address pain catastrophizing, to our knowledge, have not been tested in patients undergoing knee arthroplasty. The purpose of this study was to determine whether pain coping skills training in persons with moderate to high pain catastrophizing undergoing knee arthroplasty improves outcomes 12 months postoperatively compared with usual care or arthritis education. METHODS: A multicenter, 3-arm, single-blinded, randomized comparative effectiveness trial was performed involving 5 university-based medical centers in the United States. There were 402 randomized participants. The primary outcome was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain Scale, measured at baseline, 2 months, 6 months, and 12 months following the surgical procedure. RESULTS: Participants were recruited from January 2013 to June 2016. In 402 participants, 66% were women and the mean age of the participants (and standard deviation) was 63.2 ± 8.0 years. Three hundred and forty-six participants (90% of those who underwent a surgical procedure) completed a 12-month follow-up. All 3 treatment groups had large improvements in 12-month WOMAC pain scores with no significant differences (p > 0.05) among the 3 treatment arms. No differences were found between WOMAC pain scores at 12 months for the pain coping skills and arthritis education groups (adjusted mean difference, 0.3 [95% confidence interval (CI), -0.9 to 1.5]) or between the pain coping and usual-care groups (adjusted mean difference, 0.4 [95% CI, -0.7 to 1.5]). Secondary outcomes also showed no significant differences (p > 0.05) among the 3 groups. CONCLUSIONS: Among adults with pain catastrophizing undergoing knee arthroplasty, cognitive behaviorally based pain coping skills training did not confer pain or functional benefit beyond the large improvements achieved with usual surgical and postoperative care. Future research should develop interventions for the approximately 20% of patients undergoing knee arthroplasty who experience persistent function-limiting pain. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence

    Does Vibration Training Improve Physical Function and Quality of Life in Fibromyalgia Syndrome?

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    poster abstractExercise and physical activity recommendations are an integral component of the overall management of fibromyalgia. Unfortunately, despite the known health, fitness, and symptom relief benefits, underlying pain and fatigue prevent most from initiating (or maintaining) physical activity and exercise programs, thereby contributing to sedentary lifestyles that lead to low levels of aerobic and muscular fitness. Therefore, it is important to identify alternative approaches to exercise programming in the overall management of fibromyalgia. Vibration training is a relatively new approach to exercise that has been shown to elicit numerous benefits; however little is known about the effects of this training method in fibromyalgia. Therefore, the primary aim of this study is to evaluate the effects of vibration training in improving musculoskeletal function, balance and postural control, and health-related quality of life in patients diagnosed with fibromyalgia

    Opioid use prior to knee arthroplasty in patients who catastrophize about their pain: preoperative data from a multisite randomized clinical trial

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    Background: Opioid use rates prior to knee arthroplasty (KA) among people who catastrophize about their pain are unknown. We determined prevalence of opioid use and compared patterns of preoperative opioid use and oral morphine equivalent (OME), a measure of daily opioid dose, across varied geographic sites. We also determined which baseline variables were associated with opioid use and OME. Patients and methods: Preoperative opioid use data described type of opioid, dosage, and frequency among 397 patients scheduled for KA. Demographic, knee-related pain, and psychological distress dimensions were examined to identify variables associated with opioid use and opioid dose (OME). Opioid use prevalence and OME were compared across the four sites. A three-level censored regression determined variables associated with opioid use and OME. Results: The overall opioid use prevalence was 31.7% (95% confidence interval [CI] = 27.0, 36.3) and varied across sites from 15.9% (95% CI = 9.0, 22.8) to 51.2% (95% CI = 40.5, 61.9). After adjustment, patients using opioids were more likely to be younger, African American, and have higher self-efficacy and comorbidity scores (P < 0.05). The only variable independently associated with OME was lower depressive symptoms (P < 0.05). Conclusion: People who catastrophized prior to KA did not demonstrate increased preoperative opioid use based on current evidence, but variation in the prevalence of opioid use across study sites was substantial. Variables associated with opioid use were non-modifiable demographic and comorbidity variables

    Targeting Mesenchymal Stromal Cells/Pericytes (MSCs) With Pulsed Electromagnetic Field (PEMF) Has the Potential to Treat Rheumatoid Arthritis

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    Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic inflammation of synovium (synovitis), with inflammatory/immune cells and resident fibroblast-like synoviocytes (FLS) acting as major players in the pathogenesis of this disease. The resulting inflammatory response poses considerable risks as loss of bone and cartilage progresses, destroying the joint surface, causing joint damage, joint failure, articular dysfunction, and pre-mature death if left untreated. At the cellular level, early changes in RA synovium include inflammatory cell infiltration, synovial hyperplasia, and stimulation of angiogenesis to the site of injury. Different angiogenic factors promote this disease, making the role of anti-angiogenic therapy a focus of RA treatment. To control angiogenesis, mesenchymal stromal cells/pericytes (MSCs) in synovial tissue play a vital role in tissue repair. While recent evidence reports that MSCs found in joint tissues can differentiate to repair damaged tissue, this repair function can be repressed by the inflammatory milieu. Extremely-low frequency pulsed electromagnetic field (PEMF), a biophysical form of stimulation, has an anti-inflammatory effect by causing differentiation of MSCs. PEMF has also been reported to increase the functional activity of MSCs to improve differentiation to chondrocytes and osteocytes. Moreover, PEMF has been demonstrated to accelerate cell differentiation, increase deposition of collagen, and potentially return vascular dysfunction back to homeostasis. The aim of this report is to review the effects of PEMF on MSC modulation of cytokines, growth factors, and angiogenesis, and describe its effect on MSC regeneration of synovial tissue to further understand its potential role in the treatment of RA

    »Play it again, Sam« – Levels of Complexity in Encoding Performance Personnel

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    Capturing the personnel needed to perform a musical work in MEI metadata is straightforward with standard ensemble configurations, such as string quartets. In contrast, it can be highly complex for extensive orchestral settings, stage music, or, e.g., twentieth-century ‘Neue Musik.’ Especially in the latter case, the degree of possible variation is virtually limitless. While MEI 4.0.1 offers places within (descendants of , ) for capturing such data and provides means for quite complicated data structures through, e.g., nesting or referencing, there is still room for improvement. First of all, data structures should stay as simple and generic as possible. That is to say, that structural modification and a more detailed description of MEI's data model for the benefit of a more concise encoding should be the target, especially when envisioning a more structured encoding of more complex setups. For example, representing dependencies between performers and instruments is extremely limited in the data model for in MEI 4.0.1 (see definition of and also Gubsch & Ried, 2021). This poster takes as a starting point issues from two edition projects dealing with music from the twentieth century to illustrate philological intricacies and investigate the possibilities to encode them with MEI 4.0.1
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