Equivalence between supersymmetric self-dual and Maxwell-Chern-Simons models coupled to a matter spinor superfield

We study the duality of the supersymmetric self-dual and Maxwell-Chern-Simons theories coupled to a fermionic matter superfield, using a master action. This approach evades the difficulties inherent to the quartic couplings that appear when matter is represented by a scalar superfield. The price is that the spinorial matter superfield represents a unusual supersymmetric multiplet, whose main physical properties we also discuss.Comment: v2, 16 pages, elsarticle.cls, accepted for publication in PL

Accretion, Outflows, and Winds of Magnetized Stars

Many types of stars have strong magnetic fields that can dynamically influence the flow of circumstellar matter. In stars with accretion disks, the stellar magnetic field can truncate the inner disk and determine the paths that matter can take to flow onto the star. These paths are different in stars with different magnetospheres and periods of rotation. External field lines of the magnetosphere may inflate and produce favorable conditions for outflows from the disk-magnetosphere boundary. Outflows can be particularly strong in the propeller regime, wherein a star rotates more rapidly than the inner disk. Outflows may also form at the disk-magnetosphere boundary of slowly rotating stars, if the magnetosphere is compressed by the accreting matter. In isolated, strongly magnetized stars, the magnetic field can influence formation and/or propagation of stellar wind outflows. Winds from low-mass, solar-type stars may be either thermally or magnetically driven, while winds from massive, luminous O and B type stars are radiatively driven. In all of these cases, the magnetic field influences matter flow from the stars and determines many observational properties. In this chapter we review recent studies of accretion, outflows, and winds of magnetized stars with a focus on three main topics: (1) accretion onto magnetized stars; (2) outflows from the disk-magnetosphere boundary; and (3) winds from isolated massive magnetized stars. We show results obtained from global magnetohydrodynamic simulations and, in a number of cases compare global simulations with observations.Comment: 60 pages, 44 figure

Using Physical Activity Trackers in Arthritis Self-Management:A Qualitative Study of Patient and Rehabilitation Professional Perspectives

Objective: To compare and contrast the perspectives of patients with arthritis and those of rehabilitation professionals regarding starting and sustaining use of physical activity trackers (PATs). Methods: We conducted focus group sessions with patients, physiotherapists, and occupational therapists in Ontario, Alberta, or British Columbia, Canada. To be eligible, patients must have self-reported a diagnosis of inflammatory or osteoarthritis. Rehabilitation professionals reported that at least 40% of their caseload was dedicated to arthritis care. Participants had any level of experience with PATs. A thematic analytic approach was used. Results: The following 3 themes were identified: 1) anticipating sharing objective measures of physical activity. Participants agreed that use of PATs had the potential to improve consultations between patients with arthritis and rehabilitation professionals but were uncertain how to achieve this potential; 2) perceived or experienced barriers to start or continue using a PAT. Participants shared doubts about whether existing PATs would meet specific needs of patients with arthritis and expressed concerns about possible negative impacts; and 3) bolstering motivation? Although there was agreement that use of PATs could bolster the motivation of patients who were already active, patients and rehabilitation professionals had different opinions regarding whether use of PATs alone would motivate patients to start increasing activity levels. Conclusion: Our study highlights similarities and differences between the perspectives of patients and rehabilitation professionals regarding the potential value and risks of integrating PATs into arthritis self-management. Despite agreement about the potential of PATs, participants were uncertain how to effectively incorporate these tools to enhance patient–clinician consultations and had differing views about whether use of PATs would support a patient's motivation to be active. © 2018, American College of Rheumatolog

Effects of a 12-Week Multifaceted Wearable-Based Program for People with Knee Osteoarthritis:Randomized Controlled Trial

Background: Current guidelines emphasize an active lifestyle in the management of knee osteoarthritis (OA), but up to 90% of patients with OA are inactive. In a previous study, we demonstrated that an 8-week physiotherapist (PT)-led counseling intervention, with the use of a Fitbit, improved step count and quality of life in patients with knee OA, compared with a control. Objective: This study aimed to examine the effect of a 12-week, multifaceted wearable-based program on physical activity and patient outcomes in patients with knee OA. Methods: This was a randomized controlled trial with a delay-control design. The immediate group (IG) received group education, a Fitbit, access to FitViz (a Fitbit-compatible app), and 4 biweekly phone calls from a PT over 8 weeks. Participants then continued using Fitbit and FitViz independently up to week 12. The delay group (DG) received a monthly electronic newsletter in weeks 1 to 12 and started the same intervention in week 14. Participants were assessed in weeks 13, 26, and 39. The primary outcome was time spent in daily moderate-to-vigorous physical activity (MVPA; in bouts ≥10 min) measured with a SenseWear Mini. Secondary outcomes included daily steps, time spent in purposeful activity and sedentary behavior, Knee Injury and OA Outcome Score, Patient Health Questionnaire-9, Partners in Health Scale, Theory of Planned Behavior Questionnaire, and Self-Reported Habit Index. Results: We enrolled 51 participants (IG: n=26 and DG: n=25). Compared with the IG, the DG accumulated significantly more MVPA time at baseline. The adjusted mean difference in MVPA was 13.1 min per day (95% CI 1.6 to 24.5). A significant effect was also found in the adjusted mean difference in perceived sitting habit at work (0.7; 95% CI 0.2 to 1.2) and during leisure activities (0.7; 95% CI 0.2 to 1.2). No significant effect was found in the remaining secondary outcomes. Conclusions: A 12-week multifaceted program with the use of a wearable device, an app, and PT counseling improved physical activity in people with knee OA