24 research outputs found
Good to be bad : should we be worried by the sharing economy?
We develop the notion of a legitimacy tipping point to demonstrate how informal economy practices are being utilized by innovative sharing economy ventures to gain a competitive advantage that is subsequently leveraged to reconfigure formal institutional arrangements. Companies who are able to scale rapidly can afford to contravene regulations, provided they have public support. When they reach a certain size, in terms of investment and customer numbers, regulators are forced into a reactive position where novel business models are legitimized. This raises an important question for regulators and entrepreneurs as to whether subverting business regulation is being viewed as a viable source of competitive advantage by scaling firms
Description of the registry of patients with ankylosing spondylitis in Turkey: TRASD-IP
PubMedID: 20711591A web-based application patient follow-up program was developed to create a registry of patients with ankylosing spondylitis (AS) by the Turkiye Romatizma Arastirma Savas Dernegi (TRASD) AS Study Group. This study describes the methodological background and patient characteristics. The patient follow-up program is a web-based questionnaire, which contains sections on socio-demographic data, anamnesis, personal and family history, systemic and musculoskeletal examination, laboratory and imaging data and treatment. Between October 1, 2007 and February 28, 2009, 1,381 patients from 41 centers were included in the registry (1,038 males [75.2%]; mean age 39.5 ± 10.7 years). Mean disease duration was 12.1 ± 8.5 years, and mean time from initial symptom to diagnosis was 5 ± 6.8 years (median 2 years). HLA-B27 positivity was detected in 73.7% of 262 patients tested. Manifestations of extraarticular involvement were anterior uveitis (13.2%), psoriasis and other skin and mucous membrane lesions (6%) and inflammatory bowel disease (3.8%). The prevalence of peripheral arthritis was 11.2%. In 51.7% of patients, the Bath AS Disease Activity Index was ?4. But since our patients consisted of the ones with more severe disease who referred to the tertiary centers and needed a regular follow-up, they may not represent the general AS population. Disease-modifying anti-rheumatic drugs were being used by 41.9% of patients, with 16.4% using anti-TNF agents. TRASD-IP (Izlem Programi: Follow-up program) is the first AS registry in Turkey. Such databases are very useful and provide a basis for data collection from large numbers of subjects. TRASD-IP gives information on the clinical and demographic profiles of patients, and the efficacy and safety of anti-TNF drugs, examines the impact on quality of life, and provides real-life data that may be used in cost-effectiveness analyses. © 2010 Springer-Verlag
High bone mineral density in loaded skeletal regions of former professional football (soccer) players: what is the effect of time after active career?
Objectives: Physical exercise is an important factor in the acceleration and maintenance of bone mineral density (BMD). Football is an impact loading sport and some studies demonstrate its site specific, bone mass increasing effect. We compared BMD at different skeletal regions in a group of former professional football players and in normal control subjects and evaluated the effect of demographic factors and time after active career on BMD. Methods: Twenty four former football players <70 years old who had retired from professional football at least 10 years previously and 25 non-athletic controls were recruited. The demographic characteristics, activity levels, and dietary habits of all subjects and the chronological history of the footballers' professional careers were noted. BMD was measured by DEXA at the calcaneus and distal tibia and at the lumbar spine, proximal femur, and distal and proximal radius, and compared between groups. Stepwise multiple linear regression analysis was used to determine the probable predictors of BMD in former football players. Results: In former players BMD values were found to be significantly higher at the lumbar spine, femur neck, femur trochanter, distal tibia, and calcaneus, but not at Ward's triangle (femur) or the distal and proximal radius regions compared with controls. Time after active career was the only independent predictor of BMD at the lumbar spine, proximal femur (neck, trochanter, and Ward's triangle), and distal tibia. Conclusions: Former footballers had higher BMD at weight loaded sites and time after active career seemed to be an important factor in determining BMD
High-order integral nodal discontinuous Gegenbauer-Galerkin method for solving viscous Burgers' equation
Sharing Economy
The sharing economy can be understood as a web of markets in which individuals exchange goods and services. Market exchange is typically based on transactions mediated by a digital platform operated by an organization (Mair and Reischauer 2017). The multiple legal forms, orientations, and modes of compensation these organizations adopt combined with the broad range of markets including food, tool, and ride-sharing exemplify the potential of the sharing economy to nurture alternative forms of organizing with social purpose (Mair and Rathert forthcoming) to affect the economy, society, and the environment in new ways (Frenken and Schor 2017)
Structure preserving integration and model order reduction of skew-gradient reaction–diffusion systems
Translation and validation of the Turkish version of the Ankylosing Spondylitis Quality of Life (ASQOL) questionnaire
WOS: 000325962100002PubMed ID: 23765201The Ankylosing Spondylitis Quality of Life (ASQoL) questionnaire is a disease-specific measure of needs-based quality of life developed in the UK and the Netherlands. This study describes translation, validation, and reliability of the scale into Turkish population. The ASQoL was translated into Turkish using the dual-panel process. Content validity was assessed via cognitive debriefing interviews with ankylosing spondylitis (AS) patients. Patients with AS according to modified New York criteria were recruited into the study from 12 hospitals of all part of Turkey. Psychometric and scaling properties were assessed via a two administration survey involving the ASQoL, the Nottingham Health Profile (NHP), Bath AS Functional Index (BASFI), and Bath AS Disease Activity Index (BASDAI). Classical psychometrics assessed reliability, convergent validity (correlation of ASQoL with NHP, BASFI, and BASDAI) and discriminative validity (correlation of ASQoL with perceived AS-severity and general health). Cognitive debriefing showed the new Turkish ASQoL to be clear, relevant, and comprehensive. Completed survey questionnaires were received from 277 AS patients (80 % Male, mean age 42.2/SD 11.6, mean AS duration 9.4 years/SD 9.4). Test-retest reliability was excellent (0.96), indicating low random measurement error for the scale. Correlations of ASQoL with NHP sections were low to moderate (NHP Sleep 0.34; NHP Emotional Reactions 0.83) suggesting the measures assess related but distinct constructs. The measure was able to discriminate between patients based on their perceived disease severity (p < 0.0001) and self-reported general health (p < 0.0001). The Turkish version of ASQoL has good reliability and validity properties. It is practical and useful scale to assess the quality of life in AS patients in Turkish population