COOPERATION AND OPPORTUNISM IN VENTURE CAPITAL FINANCED COMPANIES

This study investigates cooperation and opportunism in interdependent relationships and, in particular, the influence of differing managerial time horizons on the collaborative behavior of interdependent parties. Interdependent relationships are a common aspect of business organizations and the attainment of business objectives frequently requires the combined efforts of people in different roles both within and external to the organization. The context for this study is the relationship between venture capital firms and the management of their portfolio companies. This context was selected two reasons. Firstly, venture capital provides money and expertise to help establish new ventures that are critical to the growth and development of the economy. Secondly, the success rate of venture capital investments is equivocal at best. Using survey data collected from CEOs of venture capital financed companies, I find a strong association between perceived alignment and differences in managerial time horizons and cooperative and opportunistic behavior. I also find evidence that perception of negative interdependence mediates the relationship between perceived differences in managerial time horizons and opportunistic behavior

Functional Movement Deficits In Relation to Sport-Related Concussion

The objective of this dissertation was to identify tandem gait dynamic balance deficits and assess dynamic functional movement in recreational athletes with and without a history of concussion within the past 18 months. We recruited a convenience sample of 30 college-aged recreational athletes. There were two groups (15 participants per group): 1) Recent concussion group (median time since concussion 126 days, range 28-432 days), and 2) Matched control group with no recent concussions. Control participants were matched to injured participants based on sex, age (±1 year), mass (±10%), and height (±5%). We measured center of pressure outcomes under 4 tandem gait (heel-to-toe walking) conditions: 1) Tandem gait (eyes open, no cognitive distraction), 2) Tandem gait, eyes closed (no cognitive distraction), 3) Tandem gait, eyes open, cognitive distraction (Brooks Visuospatial Task), and 4) Tandem gait, eyes closed, cognitive distraction (Brooks Visuospatial Task). We investigated joint kinematics and reaction time during 3 movement tasks: 1) Jump-landing, 2) Anticipated-cut, and 3) Unanticipated-cut. The recently concussed group demonstrated slower velocity during tandem gait compared to the control group (4.0 cm/s difference; F1,27=4.26; p=0.049; ES=0.38). Greater dual-task cost was observed for center of pressure speed (F3,26=5.13; p=0.032) such that the concussion group (23.5%) reduced their center of pressure speed to a greater extent than the control group (16.3%) during the eyes closed dual-task condition as compared to the eyes closed, no cognitive task condition. There were no between-group differences in reaction time during cutting tasks, but the control group displayed better reaction time cost (-10.7%) than the concussed group (-0.8%) during anticipated cutting (F2, 25=5.26; p=0.030). The concussed group displayed greater trunk flexion compared to the control group during anticipated cut towards the non-dominant side (5.1° difference; F2, 27=5.89; p=0.022; ES=0.63). There may be subtle movement differences that are detectable more than a month after return-to-activity following concussion, but the clinical meaning of these findings is unclear. Limitations include a lack of baseline data and a relatively small sample size. Longitudinal investigations should identify acute movement deficits after concussion in comparison with recovery on traditional concussion assessment tools while also recording musculoskeletal injury outcomes.Doctor of Philosoph

Concussion management in soccer

Brain injuries in sports drew more and more public attentions in recent years. Brain injuries vary by name, type, and severity in the athletic setting. It should be noted, however, that these injuries are not isolated to only the athletic arena, as non-athletic mechanisms (e.g., motor vehicle accidents) are more common causes of traumatic brain injuries (TBI) among teenagers. Notwithstanding, as many as 1.6 to 3.8 million TBI result from sports and recreation each year in the United States alone. These injuries are extremely costly to the global health care system, and make TBI among the most expensive conditions to treat in children. This article serves to define common brain injuries in sport describe their prevalence, what happens to the brain following injury, how to recognize and manage these injuries, and what you can expect as the athlete recovers. Some return-to-activity considerations for the brain-injured athlete will also be discussed

The Influence of Network Topology on Sound Propagation in Granular Materials

Granular materials, whose features range from the particle scale to the force-chain scale to the bulk scale, are usually modeled as either particulate or continuum materials. In contrast with either of these approaches, network representations are natural for the simultaneous examination of microscopic, mesoscopic, and macroscopic features. In this paper, we treat granular materials as spatially-embedded networks in which the nodes (particles) are connected by weighted edges obtained from contact forces. We test a variety of network measures for their utility in helping to describe sound propagation in granular networks and find that network diagnostics can be used to probe particle-, curve-, domain-, and system-scale structures in granular media. In particular, diagnostics of meso-scale network structure are reproducible across experiments, are correlated with sound propagation in this medium, and can be used to identify potentially interesting size scales. We also demonstrate that the sensitivity of network diagnostics depends on the phase of sound propagation. In the injection phase, the signal propagates systemically, as indicated by correlations with the network diagnostic of global efficiency. In the scattering phase, however, the signal is better predicted by meso-scale community structure, suggesting that the acoustic signal scatters over local geographic neighborhoods. Collectively, our results demonstrate how the force network of a granular system is imprinted on transmitted waves.Comment: 19 pages, 9 figures, and 3 table

Static and dynamic single leg postural control performance during dual-task paradigms

ABSTRACTCombining dynamic postural control assessments and cognitive tasks may give clinicians a more accurate indication of postural control under sport-like conditions compared to single-task assessments. We examined postural control, cognitive and squatting performance of healthy individuals during static and dynamic postural control assessments in single- and dual-task paradigms. Thirty participants (female = 22, male = 8; age = 20.8 ± 1.6 years, height = 157.9 ± 13.0 cm, mass = 67.8 ± 20.6 kg) completed single-leg stance and single-leg squat assessments on a force plate individually (single-task) and concurrently (dual-task) with two cognitive assessments, a modified Stroop test and the Brooks Spatial Memory Test. Outcomes included centre of pressure speed, 95% confidence ellipse, squat depth and speed and cognitive test measures (percentage of correct answers and reaction time). Postural control performance varied between postural control assessments and testing paradigms. Participants did not squat..

Descriptive Epidemiology of Non–Time-Loss Injuries in Collegiate and High School Student-Athletes

CONTEXT: Research on non-time-loss (NTL) injuries, which result in less than 24 hours of restriction from participation, is limited. OBJECTIVE: To describe the epidemiology of NTL injuries among collegiate and high school student-athletes. DESIGN: Descriptive epidemiology study. SETTING: Aggregate injury and exposure data collected from a convenience sample of National College Athletic Association varsity teams and 147 high schools in 26 states. PATIENTS OR OTHER PARTICIPANTS: Collegiate and high school student-athletes participating in men's and boys' baseball, basketball, football, lacrosse, soccer, and wrestling and women's and girls' basketball, field hockey, lacrosse, soccer, softball, and volleyball during the 2009-2010 through 2013-2014 and the 2011-2012 through 2013-2014 academic years, respectively, participated. Collegiate student-athletes participating in men's and women's ice hockey were also included. MAIN OUTCOME MEASURE(S): Injury data from the National Collegiate Athletic Association Injury Surveillance Program and the National Athletic Treatment, Injury and Outcomes Network were analyzed. Injury counts, rates per 1000 athlete-exposures (AEs), and rate ratios were reported with 95% confidence intervals (CIs). RESULTS: A total of 11 899 and 30 122 NTL injuries were reported in collegiate and high school student-athletes, respectively. The proportion of NTL injuries in high school student-athletes (80.3%) was 1.61 times greater than that of collegiate student-athletes (49.9%; 95% CI = 1.59, 1.63). The NTL injury rate in high school student-athletes (8.75/1000 athlete-exposures [AEs]) was 2.18 times greater than that of collegiate student-athletes (4.02/1000 AEs; 95% CI = 2.13, 2.22). Men's ice hockey (5.27/1000 AEs) and boys' football (11.94/1000 AEs) had the highest NTL injury rates among collegiate and high school athletes, respectively. Commonly injured body parts in collegiate and high school student-athletes were the hip/thigh/upper leg (17.5%) and hand/wrist (18.2%), respectively. At both levels, contusions, sprains, and strains were the most frequent diagnoses. Contact with another player was the most cited injury mechanism (college = 38.0%, high school = 46.3%). CONCLUSIONS: Non-time-loss injuries compose large proportions of collegiate and high school sports injuries. However, the NTL injury rate was higher in high school than in collegiate student-athletes. Tracking NTL injuries will help to better describe the breadth of injuries sustained by athletes and managed by athletic trainers