777 research outputs found
Anomaly-free dark matter models with one-loop neutrino masses and a gauged U(1) symmetry
We systematically study and classify scotogenic models with a local U(1)
gauge symmetry. These models give rise to radiative neutrino masses and a
stable dark matter candidate, but avoid the theoretical problems of global and
discrete symmetries. We restrict the dark sector particle content to up to four
scalar or fermionic SU(2) singlets, doublets or triplets and use theoretical
arguments based on anomaly freedom, Lorentz and gauge symmetry to find all
possible charge assignments of these particles. The U(1) symmetry can be broken
by a new Higgs boson to a residual discrete symmetry, that still stabilizes the
dark matter candidate. We list the particle content and charge assignments of
all non-equivalent models. Specific examples in our class of models that have
been studied previously in the literature are the U(1) scotogenic and
singlet-triplet scalar models breaking to . We also briefly discuss the
new phenomenological aspects of our model arising from the presence of a new
massless dark photon or massive boson as well as the additional Higgs
boson.Comment: 23 pages, 1 figure, 5 table
The effects of vibration during maximal graded cycling exercise: A pilot study
Whole Body Vibration training is studied and used in different areas, related to sport performance and rehabilitation. However, few studies have investigated the effects of Vibration (Vib) exposure on aerobic performance through the application of this concept to cycling exercise. A specifically designed vibrating cycloergometer, the powerBIKETM, was used to compare the effects of Vib cycling exercise and normal cycling on different physiological parameters during maximal graded exercise test. Twelve recreationally active male adults (25 ± 4.8 yrs; 181.33 ± 5.47 cm; 80.66 ± 11.91 kg) performed two maximal incremental cycling tests with and without Vib in a blockrandomized order. The protocol consisted of a 4 min warm up at 70 rev·min -1 followed by incremental steps of 3 min each. Cycling cadence was increased at each step by 10 rev·min -1 until participants reached their volitional exhaustion. Respiratory gases (VO 2, VCO 2), Heart Rate, Blood Lactate and RPE were collected during the test. Paired t-tests and Correlation Coefficients were used for statistical analysis. A significantly greater (P<0.05) response in the VO 2, HR, BLa and RPE was observed during the Vib trial compare to normal cycling. No significant differences were found in the maximal aerobic power (Vib 34.32 ± 9.70 ml·kg -1·min -1; no Vib 40.11 ± 9.49 ml·kg -1·min -1). Adding Vib to cycling exercise seems eliciting a quicker energetic demand during maximal exercise. However, mechanical limitations of the vibrating prototype could have affected the final outcomes. Future studies with more comparative setting are recommended to deeply appraise this concept. © Journal of Sports Science and Medicine (2012)
Multimodal Machine Learning-based Knee Osteoarthritis Progression Prediction from Plain Radiographs and Clinical Data
Knee osteoarthritis (OA) is the most common musculoskeletal disease without a
cure, and current treatment options are limited to symptomatic relief.
Prediction of OA progression is a very challenging and timely issue, and it
could, if resolved, accelerate the disease modifying drug development and
ultimately help to prevent millions of total joint replacement surgeries
performed annually. Here, we present a multi-modal machine learning-based OA
progression prediction model that utilizes raw radiographic data, clinical
examination results and previous medical history of the patient. We validated
this approach on an independent test set of 3,918 knee images from 2,129
subjects. Our method yielded area under the ROC curve (AUC) of 0.79 (0.78-0.81)
and Average Precision (AP) of 0.68 (0.66-0.70). In contrast, a reference
approach, based on logistic regression, yielded AUC of 0.75 (0.74-0.77) and AP
of 0.62 (0.60-0.64). The proposed method could significantly improve the
subject selection process for OA drug-development trials and help the
development of personalized therapeutic plans
Sharing data-taming the beast: Barriers to meta-analyses of individual patient data (IPD) and solutions
Malalignment; a possible target for prevention of incident knee OA in middle-aged overweight and obese women
The efficacy of Tai Chi Chuan in older adults: a systematic review
OBJECTIVES: The purpose of this study was to assess the effect of Tai Chi
Chuan (TCC) on fall prevention, balance and cardiorespiratory functions in
the elderly. METHODS: A systematic review was carried out according to the
Cochrane standards. A computerized literature search was carried out.
Studies were selected when they had an experimental design; the age of the
study population was >50; one of the interventions was a form of TCC; and
when falls, balance or cardiorespiratory functions were used as an outcome
measure. A total of seven studies were included, with in total 505
participants, of whom all but 27 were healthy seniors, age between 53 and
96 years. RESULTS: In most studies, the intervention of TCC is a modified
Yang style, varying from 10 to 24 forms. The intensity of TCC varies from
1 h weekly for 10 weeks to 1 h every morning for 1 year. One study used
falls as outcome measure and reported a beneficial effect of 47% in the
TCC group. All studies mention a beneficial effect of TCC, but in most
studies this
Outcome Expectations of Total Knee Arthroplasty Patients: The Influence of Demographic Factors, Pain, Personality Traits, Physical and Psychological Status
Unfulfilled preoperative expectations have a strong influence on the outcome after total knee arthroplasty (TKA). More insight into determinants of the level of expectations is useful in identifying patients at risk for having expectations of the treatment result that are too high or too low. This information can be used in optimizing preoperative expectation management. The aim of the current study was to analyze to what extent preoperative outcome expectations of TKA patients are affected by psychological factors, demographic factors, pain, physical function, and general health status. We performed a cross-sectional analysis of 204 patients with symptomatic and radiographic knee osteoarthritis (OA), scheduled for primary TKA. Outcome expectations were measured using the hospital for special surgery knee replacement expectations survey. Independent variables included were age, sex, body mass index, and patient-reported outcome measures for pain, physical function, quality of life, anxiety, depression, catastrophizing, optimism, and pessimism. Multiple linear regression analyses were used to evaluate associations between these variables and preoperative outcome expectations. Female sex, higher age, higher depression score, and duration of complaints > 50 months showed to be significant predictors of lower expectations for the treatment outcome after TKA. Baseline pain and function scores were not related to the level of preoperative expectations. The present study aids in identifying patients at risk for having either too high or too low expectations. This knowledge can be utilized in individualized expectation management interventions
Efficacy of foot orthoses for the treatment of plantar heel pain:a systematic review and meta-analysis
BackgroundPlantar heel pain (PHP) is common. Foot orthoses are often applied as treatment for PHP, even though there is little evidence to support this.ObjectiveTo investigate the effects of different orthoses on pain, function and self-reported recovery in patients with PHP and compare them with other conservative interventions.DesignSystematic review and meta-analysis.Data sourcesA systematic literature search was conducted in MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science, CINAHL and Google Scholar up to January 2017.Eligibility criteria for selecting studiesRandomised controlled trials comparing foot orthoses with a control (defined as no intervention, sham or other type of conservative treatment) reporting on pain, function or self-reported recovery in patients with PHP.ResultsTwenty studies investigating eight different types of foot orthoses were included in the review. Most studies were of high quality. Pooled data from six studies showed no difference between prefabricated orthoses and sham orthoses for pain at short term (mean difference (MD) of 0.26 (95% CI −0.09 to 0.60)). No difference was found between sham orthoses and custom orthoses for pain at short term (MD 0.22 (95% CI −0.05 to 0.50)), nor was there a difference between prefabricated orthoses and custom orthoses for pain at short term (MD 0.03 (95% CI −0.15 to 0.22)). For the majority of other interventions, no significant differences were found.ConclusionsFoot orthoses are not superior for improving pain and function compared with sham or other conservative treatment in patients with PHP.PROSPERO registration numberCRD42015029659.</jats:sec
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