Sensitivity of muscle force estimates to variations in muscle-tendon properties

The aim of this study was to determine the sensitivity of muscle force estimates to changes in some of the parameters which are commonly used to describe models of muscle-tendon actuation. The sensitivity analysis was performed on three parameters: optimal muscle-fiber length, muscle physiological cross-sectional area (PCSA), and tendon rest length. The muscles selected for the analysis were posterior gluteus medius/minimus, vasti, soleus, and sartorius. Each parameter was perturbed from its nominal value, and an optimization problem was solved to determine the relative influence of each parameter on the calculated values of muscle force. Muscle forces were calculated for a simulated cycle of normal walking. Parameter sensitivity was quantified using two new metrics: an integrated sensitivity ratio, which quantified the effect of changing a single parameter for any muscle on the time history of force developed by that muscle; and a summed cross-sensitivity ratio, which quantified the effect of changing one parameter for any muscle on the time histories of forces developed by all of the other muscles. The results showed that muscle force estimates for walking are most sensitive to changes in tendon rest length and least sensitive to changes in muscle PCSA. For soleus, for example, the integrated sensitivity ratios for tendon rest length were an order of magnitude greater than those for muscle-fiber length and PCSA. For vasti, the integrated sensitivity ratios for tendon rest length were twice as large as those for muscle-fiber length and nearly an order of magnitude greater than those for PCSA. Overall, changes in the tendon rest lengths of vasti and soleus and changes in the fiber length of vasti were most critical to model estimates of muscle force. Our results emphasize the importance of obtaining accurate estimates of tendon rest length and muscle-fiber length, particularly for those actuators that function as prime movers during locomotion (gluteus maximus, gluteus medius/minimus, vasti, soleus, and gastrocnemius).     

The Resurgence of Anti-Semitism on American College Campuses

Few American college campuses have witnessed the number and intensity of anti-Semitic incidents reported at San Francisco State University, Columbia University, and the University of California at Irvine (2000–2005), however, dozens of American campuses every year experience at least some manifestation of this ugly problem, which is now undoubtedly national in scope. The Anti-Defamation League (ADL) documents nearly 100 anti-Semitic incidents on American college campuses in 2005 alone. Most incidents are probably not reported to the ADL. The United States Commission on Civil Rights monitors anti-Semitic incidents on college campuses and will continue to do so.     

Jurors Report that Risk Measure Scores Matter in Sexually Violent Predator Trials,but that Other Factors Matter More

After deliberating to a verdict, jurors (N = 462) from 40 sexually violent predator (SVP) trials completed a questionnaire asking them to rate the extent to which risk measure scores, diagnoses, expert witness testimony, and offender characteristics described during the trials influenced their commitment decisions. Jurors reported that offenders' sexual offending history, failure to change, and lack of remorse had the strongest influence on their commitment decisions. They reported that testimony about risk instrument scores (e.g., Static-99) and psychopathy had less influence on their decisions, but those who did report being influenced by instrument results were especially likely to view the offender as being at a high risk for reoffending. Overall, findings suggest that SVP jurors view risk measure results as important, but not as important as other offender, offense, and testimony characteristics, including some that have limited relevance to recidivism risk. Thus, findings also suggest that experts may need to better educate jurors regarding factors that do and do not relate to recidivism risk. Copyright © 2015 John Wiley & Sons, Ltd.     

Disorders of Eating in the Elderly

The most common eating disorder in the elderly in both community and hospital settings is food refusal. This may lead to weight loss and malnutrition with all the adverse consequences on independence and function. The management of disorders of eating in the elderly is a diagnostic and therapeutic challenge, requiring the combined skills of the medical and nursing staff. The causes are often multifactorial and require careful and repeated assessment of the patient's social, psychological, and medical history. Approach to treatment involves these factors, as well as ethical and cultural considerations. Eating is the most basic biological drive for survival in nature. In human societies there are additional cultural and social aspects that may override this instinct, as in the case of hunger strikes for political motives. In the elderly, food is one of the major sources of possible pleasure and it is the challenge for health providers to try and give this enjoyment to their patients for as long as possible.     

Preference or ability: Exploring the relations between risk preference,personality, and cognitive abilities

Key issues in the behavioral sciences are if there exist stable risk preferences that generalize across domains and if these are best measured by revealed risk preference (RRP) in behavioral decision tasks or by surveys eliciting stated risk preference (SRP). We applied network analysis to data from a representative Swedish sample to investigate the relations between RRP, SRP, personality characteristics, and cognitive abilities, using in total over 70 measurements. The results showed that different measures of RRP were poorly intercorrelated and formed a community together with measures of numerical and cognitive abilities. Measures of SRP were weakly correlated with measures of RRP and identified in a distinctly separate community, along with personality characteristics and gender. The ensuing analyses provided support for a model suggesting that RRPs are contaminated by demands on numerical and cognitive abilities. RRPs may thus suffer from poor construct validity, whereas SRPs may better capture people's everyday risk preferences because they are related to more stable traits.