Mindfulness-based cognitive therapy for prevention and time to depressive relapse: Systematic review and network meta-analysis.

OBJECTIVE: To perform a network meta-analysis (NMA) to compare the long-term effectiveness of mindfulness-based cognitive therapy (MBCT) with available strategies for prevention and time to depressive relapse. METHODS: Seven electronic databases were searched up to June 2019. Studies evaluated MBCT for the management of depression-related outcomes and follow-up assessments occurred at 12 months or longer. RESULTS: Twenty-three publications were included, 17 of which were randomised controlled trials (RCTs). Data from 14 RCTs including 2077 participants contributed to meta-analysis (MA) and NMA to assess relapse of depression and 13 RCTs with 2017 participants contributed to MA and NMA for time to relapse of depression. NMAs showed statistically significant advantages for MBCT over treatment as usual (TAU) for relapse of depression (RR = 0.73, 95% CI 0.54 to 0.98) and for MBCT over TAU and placebo for time to relapse of depression (MBCT vs TAU: HR = 0.57, 95% CI 0.37 to 0.88; MBCT vs placebo: HR = 0.23, 95% CI 0.08 to 0.67). Subgroup meta-analysis of relapse of depression by previous number of depressive episodes showed similar results between subgroups. Subgroup meta-analysis by the use or not of booster sessions suggests these may lead to improved effectiveness. CONCLUSIONS: MBCT is more effective than TAU in the long-term in preventing relapse of depression and has statistically significant advantages over TAU and placebo for time to relapse of depression. No statistically significant differences were observed between MBCT and active treatment strategies for rate of relapse or time to relapse of depression.

Mathematics of Zernike polynomials: a review.

Monochromatic aberrations of the eye principally originate from the cornea and the crystalline lens. Aberrometers operate via differing principles but function by either analysing the reflected wavefront from the retina or by analysing an image on the retina. Aberrations may be described as lower order or higher order aberrations with Zernike polynomials being the most commonly employed fitting method. The complex mathematical aspects with regards the Zernike polynomial expansion series are detailed in this review. Refractive surgery has been a key clinical application of aberrometers; however, more recently aberrometers have been used in a range of other areas ophthalmology including corneal diseases, cataract and retinal imaging.

Lyapunov exponents for multi-parameter tent and logistic maps.

The behaviour of logistic and tent maps is studied in cases where the control parameter is dependent on iteration number. Analytic results for global Lyapunov exponent are presented in the case of the tent map and numerical results are presented in the case of the logistic map. In the case of a tent map with N control parameters, the fraction of parameter space for which the global Lyapunov exponent is positive is calculated. The case of bi-parameter maps of period N are investigated.

New design and development of a manual wheelchair for India.

PURPOSE: The most common methods of delivering assistive technology in developing countries are charitable donation and workshops. This describes a new approach to solving the problem, a collaboration undertaken by a US-based lab and a manufacturer in India to produce quality wheelchairs. One goal is to publicize the design free of charge to manufacturers and interested parties world-wide. The process, a demonstration of a new technology transfer method, and the product, an adult manual wheelchair, are described. METHOD: An iterative process occurred over four years to design and produce the wheelchair. This consisted of prototypes, small production runs, ANSI/RESNA testing, hardness and tensile testing and informal user testing. RESULTS: The design is a manual folding cross-brace design with several points of adjustability. Final pre-production prototypes experienced fastener failures during durability testing. Higher grade bolts were specified. Trial-run production has begun. An ANSI/RESNA wheelchair test lab was constructed in India. Subsequent projects include power and pediatric tilt-in-space wheelchairs. CONCLUSIONS: The approach seems promising as a method to improve the quality of assistive technology available in India and begin to meet the vast need in India. Pitfalls encountered throughout the collaboration are described in this paper along with solutions to remedy these problems for future projects.

Towards the development of an effective technology transfer model of wheelchairs to developing countries.

PURPOSE: And estimated 20-100 million wheelchairs are needed in developing countries. Efforts to provide wheelchairs either through donations or by starting small-scale workshops have been made for decades, but estimates suggest that less than 1 million wheelchairs have been provided. We undertook this study to better understand why these efforts have not met the need, and to investigate if other technology transfer models may be successful for wheelchair provision. METHODS: We performed a literature review, discussed our own experiences with wheelchair technology transfer, and used our expertise to develop a model for wheelchair technology transfer. RESULTS: Previous efforts have not met the need because: (1) donated wheelchairs were typically inappropriate for the user, and (2) small-scale workshops are not easily scalable for the large-scale production needed. Three additional technology transfer models exist-manufacturing, globalization, and multi-modal-that have not been widely demonstrated or discussed in the literature. Our experience with the manufacturing model suggests that it could potentially provide the large volumes of appropriate wheelchairs needed in certain regions. Lastly, we present a framework comparing the important characteristics of each model: required input, sustainability, appropriateness, and the potential impact. CONCLUSIONS: While most efforts to provide wheelchairs to developing countries are helpful, we show that expansion of the manufacturing and globalization model to provide wheelchairs may be necessary if the supply will meet the demand.