Does the Framing of Progress Towards Virtual Rewards Matter? - Empirical Evidence from an Online Community

A natural experiment on a popular German Question & Answer community is used to find out whether the small-area hypothesis applies to user activation by means of a virtual reward in the form of badges. Koo and Fishbach’s small-area hypothesis posits that individuals in pursuit of a goal are more highly motivated when focusing on the smaller percentage of progress towards their goal, irrespective of whether this figure represents the actions already completed or those still remaining. Consistent with the authors’ theoretical predictions, the study finds empirical evidence for the small-area effect and its activating power, translated here into increased online user contributions. Besides contributing to the literature with an empirical study anchored in theory, the findings have direct practical implications for designers of online virtual reward systems by suggesting more effective (and motivating) ways of framing user progress towards virtual rewards

CHALLENGE ACCEPTED! - THE IMPACT OF GOAL ACHIEVEMENT ON SUBSEQUENT USER EFFORT AND THE IMPLICATIONS OF A GOAL’S DIFFICULTY

We empirically investigate the impact of successful goal achievement on future effort to attain the next goal in a recurring goal framework. We use data from a popular German Question & Answer commu-nity where goals are represented in the form of badges. In particular, our analysis of this data hinges on the fact, that in this Question & Answer community, badges in a hierarchical badge system are in-creasingly challenging to attain up to a certain badge. After this certain badge, the difficulty level sud-denly drops and remains constant throughout up to the last badge in the hierarchy. Our findings indicate that after successful badge achievement users increase their subsequent effort to attain the next badge, but only as long as badges represent a challenge to the user. According to our analysis, we identify self-learning to be the key driver of this behavior

Muscle Degeneration Induced by Sequential Release and Denervation of the Rotator Cuff Tendon in Sheep

Background In a sheep rotator cuff model, tenotomy predominantly induces fatty infiltration, and denervation induces mostly muscle atrophy. In clinical practice, myotendinous retraction after tendon tear or lateralization after tendon repair tear may lead to traction injury of the nerve. Purpose/Hypothesis To analyze whether an additional nerve lesion during rotator cuff repair leads to further degeneration of the rotator cuff muscle in the clinical setting. We hypothesized that neurectomy after tendon tear would increase atrophy as well as fatty infiltration and that muscle paralysis after neurectomy would prevent myotendinous retraction after secondary tendon release. Study Design Controlled laboratory study. Methods Twelve Swiss alpine sheep were used for this study. For the 6 sheep in the tenotomy/neurectomy (T/N) group, the infraspinatus tendon was released; 8 weeks later, the suprascapular nerve was transected. For the 6 sheep in the neurectomy/tenotomy (N/T) group, neurectomy was performed, and the infraspinatus was tenotomized 8 weeks later. All sheep were sacrificed after 16 weeks. Magnetic resonance imaging (MRI) was performed before the first surgery (baseline) and then after 8 and 16 weeks. The MRI data were used to assess muscle volume, fat fraction, musculotendinous retraction, pennation angle, and muscle fiber length of the infraspinatus muscle. Results Three sheep (2 in the T/N and 1 in the N/T group) had to be excluded because the neurectomy was incomplete. After 8 weeks, muscle volume decreased significantly less in the T/N group (73% ± 2% of initial volume vs 52% ± 7% in the N/T group; P < .001). After 16 weeks, the mean intramuscular fat increase was higher in the T/N group (36% ± 9%) than in the N/T group (23% ± 6%), without reaching significance (P = .060). After 16 weeks, the muscle volumes of the N/T (52% ± 8%) and T/N (49% ± 3%) groups were the same (P = .732). Conclusion Secondary neurectomy after tenotomy of a musculotendinous unit increases muscle atrophy. Tenotomy of a denervated muscle is associated with substantial myotendinous retraction but not with an increase of fatty infiltration to the level of the tenotomy first group. Clinical Relevance Substantial retraction, which is associated with hitherto irrecoverable fatty infiltration, should be prevented, and additional neurogenic injury during repair should be avoided to limit the development of further atrophy

Methodology description for detection of cellular uptake of PVA coated superparamagnetic iron oxide nanoparticles (SPION) in synovial cells of sheep

The detection of superparamagnetic iron oxide nanoparticles (SPION) in synoviocytes is reported. Synoviocytes were incubated for 2, 12, 24 and 48 h with 1.5 mg/ml of PVA coated SPION under the influence of magnets (12 h). Particles were well tolerated by the synoviocytes, were easily detected using the Turnbulls and Prussian blue reactions between 12 and 24 h