The Independent Party Panacea?

In this commentary, Daniel M. Shea considers whether the addition of another party would redeem our faith in elections and cure the ills of governance

Blade tip rubbing stress prediction

A linear analysis was performed to determine the dynamic response of a turbine blade to intermittent rubbing against a tip seal. The response analysis consisted of a parametric study where the rubbing friction force was assumed to vary as a half sine wave over a preselected contact arc. The length of the contact arc, as well as the pump speed, was varied to determine the effects of each. Results show that for a given contact arc there are distinct critical speeds at which the blade response becomes a maximum

Patterns of introduced species interactions affect multiple aspects of network structure in plant-pollinator communities

Species introductions have the potential to affect the functionality and stability of ecological communities, but because little is known about how introduced species form novel interactions, these impacts are difficult to predict. We quantified the impacts of species introductions on species interaction networks using five different model scenarios of how a novel species might form plant–pollinator interactions. The network structure was based on experimental manipulations on a community of plants and pollinators and shows that the community was more diverse, ordered, and compartmentalized, but less complex when an invasive plant generalist was present. Our models of species introductions reliably predicted several aspects of novel network structure in the field study. We found that introduced species that become incorporated into the community as generalists (both in the number and frequency of their interactions) have a much larger impact on the structure of plant–pollinator communities than introduced species that integrate into the community with few interactions. Average degree is strongly affected by the number of interactions the novel species forms and whether it competes for interactions, whereas connectance is affected by whether the novel species competes for interactions or adds new interaction partners. The number and size of compartments in the network change only when the novel species adds new interaction partners, while modularity and nestedness respond most to the number of interactions formed by the novel species. We provide a new approach for understanding the impacts of introduced and invasive species on plant–pollinator communities and demonstrate that it is critical to evaluate multiple structural characters simultaneously, as large changes in the fundamental structure of the community may be disguised

The Evolution of Endurance Running and the Tyranny of Ethnography: A Reply to Pickering and Bunn (2007)

Endurance running (ER) poses a conundrum for paleoanthropologists. As summarized in Bramble and Lieberman (2004), human ER capabilities, which are unique among primates, either match or exceed those of mammals adapted for running (cursors), including dogs and equids. Because many of the biomechanical and physiological challenges of human ER are so different from those of walking, we can conclude that human ER capabilities did not arise merely as a by-product of selection for walking. Instead, the available evidence suggests that an array of features that improve ER performance were selected in the genus Homo, and they were probably present to some extent by the appearance of Homo erectus at approximately 1.9 Ma. Yet, ER is no longer necessary for human survival, even among extant foragers such as the Hadza or the Bushmen. Thus, a puzzle that paleoanthropologists must solve is identifying what past behaviors - behaviors no longer common among living foragers - favored the evolution of ER. Pickering and Bunn’s (2007) criticisms of the ER hypothesis center on two issues: first, that early Homo lacked the tracking abilities necessary for successful pursuit hunts, and second, that recent ethnographic evidence suggests that modern hunter-gatherers rarely use ER to either hunt or scavenge. These arguments are based on a presumptive link between modern human- like cognition and tracking abilities, as well as the notion that the modern ethnographic record provides an adequate reflection of past behaviors. Both of these assumptions are flawed. Although tracking is complex, there is little evidence to suggest that early hominids lacked the tracking abilities of much less encephalized carnivores. Additionally, as noted by Marlowe (2005), comparatively recent inventions, such as the bow and arrow, the spear thrower, nets, and even the spear point, fundamentally altered how humans hunt and scavenge. A strict reliance on the recent ethnographic record, what Wobst (1978) termed the ‘‘tyranny of ethnography,’’ is a fundamentally problematic way of testing hypotheses of past hunting behavior. Even so, a review of the ethnographic evidence reveals errors in Pickering and Bunn’s contentions.Anthropolog

Gender equality predicts leisure-time physical activity: benefits for both sexes across 34 countries

Although countries’ gender equality is associated with important health outcomes, especially for females, it remains unclear whether gender equality is associated with leisure-time physical activity (LTPA). Data from 34 countries was acquired from the International Social Survey Program, the Pew Research Forum, the United Nations, and the World Bank. Separate analyses were conducted for 21,502 males and 26,652 females. Hierarchal nonlinear Bernoulli modeling was used to examine the association between gender equality and participation in LTPA. Both males and females residing in countries’ with higher gender equality were more likely (twice and three times more likely, respectively) to report weekly LTPA than those residing in countries characterized by low gender equality. These effects persisted even when controlling for individual (i.e. age, education) and country-level (i.e. population, gross domestic product) covariates. However, significant variation in LTPA persisted at the country level, suggesting the need for further research. These findings provide novel evidence that both males and females benefit from gender equality. To explain these findings, we hypothesize that increased gender equality decreases the average number of offspring and, in turn, allows mothers more time for leisure, and to invest more resources in both male and female offspring, which may increase LTPA

How Do Collegiate Sport Clubs Achieve Organizational Effectiveness?

A greater understanding of the organizational processes of sport clubs can inform strategies to improve clubs’ organizational effectiveness. This study examined whether sport club capacity and activities influence the organizational effectiveness of collegiate sport clubs. Sport club members (n = 201) completed a questionnaire, with secondary data collected from the university. Regression analysis found club operations, club fiscal responsibility, frequency of club practice, and frequency of competitions significantly, positively predict organizational effectiveness. Comparatively, club human capital and facility quality significantly, negatively predict organizational effectiveness. These results have implications relating to club training, mentorship, resource allocation, and club activities

Utilization and Impact of Career Services Among Collegiate Athletes

Career readiness is a concern within the American educational system, particularly among student-athletes that must manage intense time commitments both on and off the field. Student services have emerged in higher education to support career preparation, but the utilization and impact of these services for collegiate athletes is largely unknown. The systems-theory framework (STF) of career development identifies a multitude of internal and external factors that influence individual career development. Guided by STF, the purpose of this study was to predict the factors that influence collegiate athletes\u27 utilization of career services and resulting perceived career skills. An online questionnaire was distributed to collegiate athletes at a Division I university, resulting in 143 collegiate athletes completing the questionnaire. Multiple regression analysis demonstrated collegiate athletes’ familiarity with career services significantly predicted their utilization of career services. In turn, utilization of only four of nine career services investigated (i.e., Careers Online, Career Fairs, Career Workshops, and Athletic Academic Advisor) significantly predicted perceived career skills positively. Implications for the design and marketing of career services for collegiate athletes are discussed

Timing of ibuprofen use and musculoskeletal adaptations to exercise training in older adults

AbstractProstaglandins (PGs) increase in bone in response to mechanical loading and stimulate bone formation. Inhibition of cyclooxygenase (COX), the enzyme responsible for PG synthesis, by non-steroidal anti-inflammatory drugs (NSAIDs) impairs the bone formation response to loading in animals when administered before, but not after, loading. The aim was to determine whether the timing of ibuprofen use (400mg before versus after exercise sessions) is a significant determinant of the adaptive response of BMD to exercise training in older adults. We hypothesized that taking ibuprofen before exercise would attenuate the improvements in total hip and lumbar spine BMD in response to 36weeks of training when compared with placebo or with ibuprofen use after exercise. Untrained women and men (N=189) aged 60 to 75years were randomly assigned to 1 of 3 treatment arms: placebo before and after exercise (PP); ibuprofen before and placebo after exercise (IP); and placebo before and ibuprofen after exercise (PI).The difference between groups in the change in BMD was not significant when IP was compared with either PP (hip, −0.5% (−1.4, 0.4); spine, 0.1% (−0.9, 1.2)) or PI (hip, 0.3% (−0.6, 1.2); spine, 0.5% (−0.5, 1.5)). Ibuprofen use appeared to have more adverse effects on BMD in women than men. The study demonstrated that ibuprofen use did not significantly alter the BMD adaptations to exercise in older adults, but this finding should be interpreted cautiously. It had been expected that the inhibition of bone formation by ibuprofen would be more robust in men than in women, but this did not appear to be the case and may have limited the power to detect the effects of ibuprofen. Further research is needed to understand whether NSAID use counteracts, in part, the beneficial effects of exercise on bone