Effect of Mouthguard Use on Metabolic and Cardiorespiratory Responses to Aerobic Exercise in Males

Purpose: This study investigated the physiological effects of wearing a mouthguard during submaximal treadmill exercise. Method: Twenty-four recreationally active males (M_age = 21.3 ± 2.4 years, M_height = 1.78 ± 0.06 m, M_weight = 81.9 ± 10.6 kg, M_{body mass index} = 25.8 ± 3.4 kg·m^?2) performed incremental, continuous exercise at 2, 4, 6, and 8 mph (3.2, 6.4, 9.7, 12.9 kph) for 5 min at each speed on a motor-driven treadmill on 2 separate occasions in a randomized, crossover, counterbalanced design while wearing or not wearing a self-adaptable “boil and bite” mouthguard. Respiratory rate (RR), tidal volume (V_T), ventilation (V_E), oxygen consumption (VO₂), respiratory exchange ratio (RER), and heart rate (HR) data were averaged during the last 60 s of each exercise stage; blood lactate (LA) was measured before exercise and 3 min and 10 min following exercise. Results: Repeated-measures analysis of variance revealed that mouthguard use failed to alter the response of RR, V_T, V_E, VO₂, RER, and HR to treadmill exercise (p > .05), although each variable did increase in magnitude as a result of increasing treadmill speed (p < .001). Although increasing to above resting values at both 3 min and 10 min (p < .001) after cessation of exercise, LA levels also displayed no differences with mouthguard use (p > .05). Conclusion: Despite predictable increases in respiratory, metabolic, and cardiovascular variables in response to incremental exercise, the presence of a mouthguard failed to affect the magnitude or nature of these physiological responses.     

Race,schools and opportunity hoarding: evidence from a post-war American metropolis

Opportunity hoarding is a sociological concept first introduced by Charles Tilly. This article explores its utility for historians by examining efforts to exclude different groups of people in a major American metropolis during the 1960s and seventies. This was a period of significant social change, as the racial composition of big city schools shifted dramatically and suburban school districts grew substantially. An examination two such suburban districts finds sustained and effective measures undertaken to exclude African-Americans from moving into one of them. In the neighbouring district, resistance to low-income housing was initially successful but white residents were unable to prevent relatively affluent blacks from settling there. This eventually contributed to further white flight and the transition to a predominantly African-American district. Mechanisms of exclusion are discussed, along with the utility of opportunity hoarding as a concept for historians interested in studying similar issues in other settings.     

E-Mail as Spectroscopy: Automated Discovery of Community Structure within Organizations

We describe a method for the automatic identification of communities of practice from e-mail logs within an organization. We use a betweenness centrality algorithm that can rapidly find communities within a graph representing information flows. We apply this algorithm to an initial e-mail corpus of nearly 1 million messages collected over a 2-month span, and show that the method is effective at identifying true communities, both formal and informal, within these scale-free graphs. This approach also enables the identification of leadership roles within the communities. These studies are complemented by a qualitative evaluation of the results in the field.     

Effects of Historical Story Telling on Student Understanding of Nature of Science

Science & Education - Concepts related to the nature of science (NOS) have been considered an important part of scientific literacy as reflected in its inclusion in curriculum documents. A...     

Toward instituting a chaperone policy in outpatient pediatric clinics

ObjectivesWe sought to evaluate child, parent and medical provider preferences for chaperones for outpatient encounters and to evaluate the acceptability and frequency of utilization following institution of a chaperone policy. Secondarily, we sought to understand what medical history and examinations teens consider “sensitive.”DesignWe conducted an observational study 1 month before and 1 month after institution of outpatient clinic chaperone policy. Post clinic questionnaires were used for patients ≥12 years old, parents, and clinicians. A research assistant observed chaperone use.SettingAdolescent Medicine, Urology, and Rehabilitation Clinics at a regional, tertiary-care pediatric hospital, in a major metropolitan area were studied.ParticipantsConvenience sample: 117 clinic patients during control period and 119 after policy implementation.Main outcome measuresPreferences for and satisfaction with chaperone use were documented.ResultsAlthough non-parent chaperones were usually declined (99.6%), offers were appreciated. Non-parent chaperone use increased modestly (5.3–18.1%).Most patients preferred not to have non-parent chaperones. This preference was greater among older patients (88%), than early teens (52%). After experiencing sensitive examinations, more young adolescent patients (89%) wished their parent had been present than older patients (38%). Patients’ opinions about what constitutes “sensitive” questions and examinations and chaperone preferences varied widely. Providers often did not recognize issues patients and parents considered sensitive questioning (21% agreement), but recognized sensitive physical examinations better (74% agreement). Providers felt chaperones had been a detriment to examination and exams would have gone better without one only 1% of the time.ConclusionsAlthough usually declined, offers of chaperones were appreciated and use of non-parent chaperones increased modestly. Offering chaperones for sensitive examinations may remind providers about appropriate, respectful patient encounters. Implications for children's hospitals’ patient safety and satisfaction, and institutional staff protection and costs are significant.Practice implicationsQuestions and examinations which patients consider sensitive vary widely. Asking patients for their preferences for examination chaperones may reassure them about the appropriateness of examinations, remind staff to conduct respectful examinations and protect providers from accusations of impropriety. Since most chaperone offers are declined, the cost of asking is likely to be minimal.     

The Reconciliation of Art and Psychology

The disciplines of art and experimental psychology share a number of interesting areas of overlap which are unknown and/or unconsidered by many. This purpose of this article is to elucidate topics that are of interest to both artists and psychologists in an attempt to encourage interdisciplinary collaborations. It is only on rare occasions that artists and psychologists engage in collaborative research efforts, however; here I discuss a number of topics in psychology (e.g. attention, expertise, object perception and mental representations) that would be of interest to both disciplines. The concepts that are often taught in the art studio can provide unique insight into perceptual processes that play a role in the creation and evaluation of art. However, collaborative research efforts are necessary better to understand these perceptual processes. Thus, the product of collaborative research in such areas can inform art education and psychology to mutual benefit. This article discusses topics of interest for art and psychology and poses possible research questions that can be investigated via artist–psychologist collaborations.     

Correlation between grade point averages and student evaluation of teaching scores: taking a closer look

One of the most contentious potential sources of bias is whether instructors who give higher grades receive higher ratings from students. We examined the grade point averages (GPAs) and student ratings across 2073 general education religion courses at a large private university. A moderate correlation was found between GPAs and student evaluations of teaching (SETs); however, this global correlation did not hold true for individual teachers and courses. In fact, there was a large variance in the correlations between GPAs and SETs, including some teachers with a negative correlation and a large variance between courses.     

Enhancing Communication Interventions and Evaluations through Communication Design

Communication design is first and foremost about creating, engineering, or critiquing approaches to communication that achieve specific goals or values. A design approach acts as an integrative perspective for finding the relevance of theory to a specific site of intervention. Communication design processes are illustrated through work on ombuds processes and organ donation campaigns. This research highlights four propositions related to communication design. First, design should be about both creation and critique. Second, design is complementary to, and strengthens, theory (and vice versa). Third, design can be both unique to an intervention or context and iterative from previous designs. Finally, design helps us uncover unexpected and unintended consequences, uncovering hidden properties of communication and leading to opportunities for modifying and correcting communication practices. These unintended consequences and other design successes and failures provide opportunities for learning and creating better systems. In these ways, a commitment to design processes strengthens both our research and our practice of communication across a variety of communication contexts and across different levels of communication.     

Understanding Heterogeneity in the Impact of Public Preschool Programs

We examine the North Carolina Pre-K (NC Pre-K) program to test the hypothesis that observed variation in effects resulting from exposure to the program can be attributed to interactions with other environmental factors that occur before, during, or after the pre-k year. We examine student outcomes in 5th grade and test interaction effects between NC's level of investment in public pre-k and moderating factors. Our main sample includes the population of children born in North Carolina between 1987 and 2005 who later attended a public school in that state, had valid achievement data in 5th grade, and could be matched by administrative record review (n = 1,207,576; 58% White non-Hispanic, 29% Black non-Hispanic, 7% Hispanic, 6% multiracial and Other race/ethnicity). Analyses were based on a natural experiment leveraging variation in county-level funding for NC Pre-K across NC counties during each of the years the state scaled up the program. Exposure to NC Pre-K funding was defined as the per-4-year-old-child state allocation of funds to a county in a year. Regression models included child-level and county-level covariates and county and year fixed effects. Estimates indicate that a child's exposure to higher NC Pre-K funding was positively associated with that child's academic achievement 6 years later. We found no effect on special education placement or grade retention. NC Pre-K funding effects on achievement were positive for all subgroups tested, and statistically significant for most. However, they were larger for children exposed to more disadvantaged environments either before or after the pre-k experience, consistent with a compensatory model where pre-k provides a buffer against the adverse effects of prior negative environmental experiences and protection against the effects of future adverse experiences. In addition, the effect of NC Pre-K funding on achievement remained positive across most environments, supporting an additive effects model. In contrast, few findings supported a dynamic complementarity model. Instrumental variables analyses incorporating a child's NC Pre-K enrollment status indicate that program attendance increased average 5th grade achievement by approximately 20% of a standard deviation, and impacts were largest for children who were Hispanic or whose mothers had less than a high school education. Implications for the future of pre-k scale-up and developmental theory are discussed.     

Why I do not believe in the cost-disease

Journal of Cultural Economics -