The immediate effects of an acute bout of moderate physical activity on cognitive processing in children.

This study examined the effect of acute physical activity on cognitive tasks of 37, 7th and 8th grade females. Subjects' cognitive performance following acute physical activity was hypothesized to be significantly better on five tasks (choice reaction time, probed memory, dual task, vigilance, executive function) used in the study, with no significant difference in performance hypothesized for the sixth (simple reaction time). The study assessed cognitive tasks twice, following a 30 minute sedentary period and 30 minutes of physical activity. The within subject design compared the independent variable of physical activity level (activity or none) on the dependent variables simple reaction time, choice reaction time, dual task-tracking and simple reaction time, vigilance, probed memory, and executive function.Results indicated that for the simple reaction time task subjects demonstrated significantly faster (reaction and movement) times following acute physical activity. For choice reaction time the percent of correct responses was significantly higher following sedentary behavior, while for choice reaction and movement time, subjects were significantly faster following acute physical activity. Analysis of probed memory reported no significance between the scores following the two activity sessions. Analysis of dual task reported no significance for two subcomponents, however a significant difference was reported for the third subcomponent.Analysis of vigilance reported subjects demonstrated significantly improved performance on two subcomponents following physical activity. Analysis of the third subcomponent did not report significance. Performance on the executive function task was mixed with no significance reported for subjects between the following physical activity and following sedentary behavior scores, while significance was reported with regard to time to complete the task.Levels of significance were not reached for every task, however there was a trend consistent with expectations for those that did not reach significance (With the exception of choice reaction time percentage of correct responses.), following physical activity, performance was better

Navigating the medical physics education and training landscape

PurposeThe education and training landscape has been profoundly reshaped by the ABR 2012/2014 initiative and the MedPhys Match. This work quantifies these changes and summarizes available reports, surveys, and statistics on education and training.MethodsWe evaluate data from CAMPEP‐accredited program websites, annual CAMPEP graduate and residency program reports, and surveys on the MedPhys Match and Professional Doctorate degree (DMP).ResultsFrom 2009–2015, the number of graduates from CAMPEP‐accredited graduate programs rose from 210 to 332, while CAMPEP‐accredited residency positions rose from 60 to 134. We estimate that approximately 60% of graduates of CAMPEP‐accredited graduate programs intend to enter clinical practice, however, only 36% of graduates were successful in acquiring a residency position in 2015. The maximum residency placement percentage for a graduate program is 70%, while the median for all programs is only 22%. Overall residency placement percentage for CAMPEP‐accredited program graduates from 2011–2015 was approximately 38% and 25% for those with a PhD and MS, respectively. The disparity between the number of clinically oriented graduates and available residency positions is perceived as a significant problem by over 70% of MedPhys Match participants responding to a post‐match survey. Approximately 32% of these respondents indicated that prior knowledge of this situation would have changed their decision to pursue graduate education in medical physics.ConclusionThese data reveal a substantial disparity between the number of residency training positions and graduate students interested in these positions, and a substantial variability in residency placement percentage across graduate programs. Comprehensive data regarding current and projected supply and demand within the medical physics workforce are needed for perspective on these numbers. While the long‐term effects of changes in the education and training infrastructure are still unclear, available survey data suggest that these changes could negatively affect potential entrants to the profession.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139957/1/acm212202.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139957/2/acm212202_am.pd

Reducing the Risk of Invasive Pathogens to Wildlife Health in the United States

Call to Action In keeping with action items 4.3.1 and 4.3.2 of the 2016–2018 National Invasive Species Council (NISC) Management Plan, the Wildlife Health Task Team of the Invasive Species Advisory Committee (ISAC) was charged with: 1) identifying the major areas of vulnerability to native wildlife from the introduction and spread of invasive pathogens, and 2) making recommendations to address these vulnerabilities, including through potential changes in statute, regulation, policy, or practice of the relevant agencies

The Impossibility of a Perfectly Competitive Labor Market

Using the institutional theory of transaction cost, I demonstrate that the assumptions of the competitive labor market model are internally contradictory and lead to the conclusion that on purely theoretical grounds a perfectly competitive labor market is a logical impossibility. By extension, the familiar diagram of wage determination by supply and demand is also a logical impossibility and the neoclassical labor demand curve is not a well-defined construct. The reason is that the perfectly competitive market model presumes zero transaction cost and with zero transaction cost all labor is hired as independent contractors, implying multi-person firms, the employment relationship, and labor market disappear. With positive transaction cost, on the other hand, employment contracts are incomplete and the labor supply curve to the firm is upward sloping, again causing the labor demand curve to be ill-defined. As a result, theory suggests that wage rates are always and everywhere an amalgam of an administered and bargained price. Working Paper 06-0

Geochemical proxies of North American freshwater routing during the Younger Dryas cold event

The Younger Dryas cold interval represents a time when much of the Northern Hemisphere cooled from ≈12.9 to 11.5 kiloyears B.P. The cause of this event, which has long been viewed as the canonical example of abrupt climate change, was initially attributed to the routing of freshwater to the St. Lawrence River with an attendant reduction in Atlantic meridional overturning circulation. However, this mechanism has recently been questioned because current proxies and dating techniques have been unable to confirm that eastward routing with an increase in freshwater flux occurred during the Younger Dryas. Here we use new geochemical proxies (ΔMg/Ca, U/Ca, and ⁸⁷Sr/⁸⁶Sr) measured in planktonic foraminifera at the mouth of the St. Lawrence estuary as tracers of freshwater sources to further evaluate this question. Our proxies, combined with planktonic δ¹⁸Oseawater and δ¹³C, confirm that routing of runoff from western Canada to the St. Lawrence River occurred at the start of the Younger Dryas, with an attendant increase in freshwater flux of 0.06 ± 0.02 Sverdrup (1 Sverdrup = 10⁶ m³·s⁻¹). This base discharge increase is sufficient to have reduced Atlantic meridional overturning circulation and caused the Younger Dryas cold interval. In addition, our data indicate subsequent fluctuations in the freshwater flux to the St. Lawrence River of ≈0.06–0.12 Sverdrup, thus explaining the variability in the overturning circulation and climate during the Younger Dryas.Keywords: abrupt climate change, paleoclimate, Atlantic meridional overturning circulatio

Urban meadows as an alternative to short mown grassland: Effects of composition and height on biodiversity

There are increasing calls to provide greenspace in urban areas, yet the ecological quality, as well as quantity, of greenspace is important. Short mown grassland designed for recreational use is the dominant form of urban greenspace in temperate regions but requires considerable maintenance and typically provides limited habitat value for most taxa. Alternatives are increasingly proposed, but the biodiversity potential of these is not well understood. In a replicated experiment across six public urban greenspaces we used nine different perennial meadow plantings to quantify the relative roles of floristic diversity and height of sown meadows on the richness and composition of three taxonomic groups – plants, invertebrates and soil microbes. We found that all meadow treatments were colonised by plant species not sown in the plots, suggesting that establishing sown meadows does not preclude further locally determined grassland development if management is appropriate. Colonising species were rarer in taller and more diverse plots, indicating competition may limit invasion rates. Urban meadow treatments contained invertebrate and microbial communities that differed from mown grassland. Invertebrate taxa responded to changes in both height and richness of meadow vegetation, but most orders were more abundant where vegetation height was longer than mown grassland. Order richness also increased in longer vegetation and Coleoptera family richness increased with plant diversity in summer. Microbial community composition seems sensitive to plant species composition at the soil surface (0–10 cm), but in deeper soils (11–20 cm) community variation was most responsive to plant height, with bacteria and fungi responding differently. In addition to improving local residents’ satisfaction, native perennial meadow plantings can produce biologically diverse grasslands that support richer and more abundant invertebrate communities, and restructured plant, invertebrate and soil microbial communities compared with short mown grassland. Our results suggest that diversification of urban greenspace by planting urban meadows in place of some mown amenity grassland is likely to generate substantial biodiversity benefits, with a mosaic of meadow types likely to maximise such benefits

Texas Lifestyle Limits Transmission of Dengue Virus

Urban dengue is common in most countries of the Americas, but has been rare in the United States for more than half a century. In 1999 we investigated an outbreak of the disease that affected Nuevo Laredo, Tamaulipas, Mexico, and Laredo, Texas, United States, contiguous cities that straddle the international border. The incidence of recent cases, indicated by immunoglobulin M antibody serosurvey, was higher in Nuevo Laredo, although the vector, Aedes aegypti, was more abundant in Laredo. Environmental factors that affect contact with mosquitoes, such as air-conditioning and human behavior, appear to account for this paradox. We conclude that the low prevalence of dengue in the United States is primarily due to economic, rather than climatic, factors

'To live and die [for] Dixie': Irish civilians and the Confederate States of America

Around 20,000 Irishmen served in the Confederate army in the Civil War. As a result, they left behind, in various Southern towns and cities, large numbers of friends, family, and community leaders. As with native-born Confederates, Irish civilian support was crucial to Irish participation in the Confederate military effort. Also, Irish civilians served in various supporting roles: in factories and hospitals, on railroads and diplomatic missions, and as boosters for the cause. They also, however, suffered in bombardments, sieges, and the blockade. Usually poorer than their native neighbours, they could not afford to become 'refugees' and move away from the centres of conflict. This essay, based on research from manuscript collections, contemporary newspapers, British Consular records, and Federal military records, will examine the role of Irish civilians in the Confederacy, and assess the role this activity had on their integration into Southern communities. It will also look at Irish civilians in the defeat of the Confederacy, particularly when they came under Union occupation. Initial research shows that Irish civilians were not as upset as other whites in the South about Union victory. They welcomed a return to normalcy, and often 'collaborated' with Union authorities. Also, Irish desertion rates in the Confederate army were particularly high, and I will attempt to gauge whether Irish civilians played a role in this. All of the research in this paper will thus be put in the context of the Drew Gilpin Faust/Gary Gallagher debate on the influence of the Confederate homefront on military performance. By studying the Irish civilian experience one can assess how strong the Confederate national experiment was. Was it a nation without a nationalism

“There was something very peculiar about Doc…”: Deciphering Queer Intimacy in Representations of Doc Holliday

This is an Accepted Manuscript of an article published by Taylor & Francis in American Nineteenth-Century History on 8-12-14, available online: http://dx.doi.org/10.1080/14664658.2014.971481This essay discusses representations of male intimacy in life-writing about consumptive gunfighter John Henry “Doc” Holliday (1851-1887). I argue that twentieth-century commentators rarely appreciated the historical specificity of Holliday’s friendships in a frontier culture that not only normalized but actively celebrated same-sex intimacy. Indeed, Holliday lived on the frayed edges of known nineteenth-century socio-sexual norms, and his interactions with other men were further complicated by his vicious reputation and his disability. His short life and eventful afterlife exposes the gaps in available evidence – and the flaws in our ability to interpret it. Yet something may still be gleaned from the early newspaper accounts of Holliday. Having argued that there is insufficient evidence to justify positioning him within modern categories of hetero/homosexuality, I analyze the language used in pre-1900 descriptions of first-hand encounters with Holliday to illuminate the consumptive gunfighter’s experience of intimacy, if not its meaning