The Barometer

(This discussion is in reply to Mr. Neil Sheehan\u27s article titled The Role of the Press published in the February issue.

Circulations and the Entanglements of Citizenship Formation

Citizenship is given form, meaning, and power through the transactions and circulations that constitute it. Our focus in this article is the ways in which circulations through networks and institutions that extend beyond nation-states are enacted and encouraged through pedagogies and practices that moor habits of citizenship in daily lives. Although there has been significant attention to those practices at national and local levels, there has been relatively little attention to the ways that floating sites of citizenship formation are entwined with, but also seem to be suspended above, other sites. There are at least three ways in which circulations both construct those sites and are entwined in citizenship formation: They are the reason that the seeming contradiction between cosmopolitanism and efforts to moor citizens to place becomes unremarkable; they enable and shape the modes of interaction that conjoin politics and emotional geographies; and they are part of the way in which a common understanding of active citizenship is accepted almost without question. We use the examples of two international conferences for young citizen-activists to illustrate our arguments regarding the circulations of ideas, norms, and practice that are central to citizenship formation

A global analysis of bird plumage patterns reveals no association between habitat and camouflage

Evidence suggests that animal patterns (motifs) function in camouflage. Irregular mottled patterns can facilitate concealment when stationary in cluttered habitats, whereas regular patterns typically prevent capture during movement in open habitats. Bird plumage patterns have predominantly converged on just four types-mottled (irregular), scales, bars and spots (regular)-and habitat could be driving convergent evolution in avian patterning. Based on sensory ecology, we therefore predict that irregular patterns would be associated with visually noisy closed habitats and that regular patterns would be associated with open habitats. Regular patterns have also been shown to function in communication for sexually competing males to stand-out and attract females, so we predict that male breeding plumage patterns evolved in both open and closed habitats. Here, taking phylogenetic relatedness into account, we investigate ecological selection for bird plumage patterns across the class Aves. We surveyed plumage patterns in 80% of all avian species worldwide. Of these, 2,756 bird species have regular and irregular plumage patterns as well as habitat information. In this subset, we tested whether adult breeding/non-breeding plumages in each sex, and juvenile plumages, were associated with the habitat types found within the species' geographical distributions. We found no evidence for an association between habitat and plumage patterns across the world's birds and little phylogenetic signal. We also found that species with regular and irregular plumage patterns were distributed randomly across the world's eco-regions without being affected by habitat type. These results indicate that at the global spatial and taxonomic scale, habitat does not predict convergent evolution in bird plumage patterns, contrary to the camouflage hypothesis.</p

Characterising pressure and bruising in apple fruit

A large percentage of apples are wasted each year due to damage such as bruising. The apple journey from orchard to supermarket is very complex and apples are subjected to a variety of static and dynamic loads that could result in this damage occurring. The aim of this work was to use a novel ultrasonic technique to study apple contact areas and stresses under static loading that may occur, for example, in bulk storage bins used during harvesting. These results were used to identify load thresholds above which unacceptable damage occurs. They were also used to validate output from a finite element model, which will ultimately be developed into a packaging design tool to help reduce the likelihood of apple damage occurring

Generalized Drinfeld-Sokolov Reductions and KdV Type Hierarchies

Generalized Drinfeld-Sokolov (DS) hierarchies are constructed through local reductions of Hamiltonian flows generated by monodromy invariants on the dual of a loop algebra. Following earlier work of De Groot et al, reductions based upon graded regular elements of arbitrary Heisenberg subalgebras are considered. We show that, in the case of the nontwisted loop algebra $\ell(gl_n)$, graded regular elements exist only in those Heisenberg subalgebras which correspond either to the partitions of $n$ into the sum of equal numbers $n=pr$ or to equal numbers plus one $n=pr+1$. We prove that the reduction belonging to the grade $1$ regular elements in the case $n=pr$ yields the $p\times p$ matrix version of the Gelfand-Dickey $r$-KdV hierarchy, generalizing the scalar case $p=1$ considered by DS. The methods of DS are utilized throughout the analysis, but formulating the reduction entirely within the Hamiltonian framework provided by the classical r-matrix approach leads to some simplifications even for $p=1$.Comment: 43 page

Extensions of the matrix Gelfand-Dickey hierarchy from generalized Drinfeld-Sokolov reduction

The $p\times p$ matrix version of the $r$-KdV hierarchy has been recently treated as the reduced system arising in a Drinfeld-Sokolov type Hamiltonian symmetry reduction applied to a Poisson submanifold in the dual of the Lie algebra $\widehat{gl}_{pr}\otimes {\Complex}[\lambda, \lambda^{-1}]$. Here a series of extensions of this matrix Gelfand-Dickey system is derived by means of a generalized Drinfeld-Sokolov reduction defined for the Lie algebra $\widehat{gl}_{pr+s}\otimes {\Complex}[\lambda,\lambda^{-1}]$ using the natural embedding $gl_{pr}\subset gl_{pr+s}$ for $s$ any positive integer. The hierarchies obtained admit a description in terms of a $p\times p$ matrix pseudo-differential operator comprising an $r$-KdV type positive part and a non-trivial negative part. This system has been investigated previously in the $p=1$ case as a constrained KP system. In this paper the previous results are considerably extended and a systematic study is presented on the basis of the Drinfeld-Sokolov approach that has the advantage that it leads to local Poisson brackets and makes clear the conformal ($\cal W$-algebra) structures related to the KdV type hierarchies. Discrete reductions and modified versions of the extended $r$-KdV hierarchies are also discussed.Comment: 60 pages, plain TE

Complex transboundary movements of marine megafauna in the Western Indian Ocean

Transboundary marine species have an increased risk of overexploitation as management regimes and enforcement can vary among states. The complex geopolitical layout of exclusive economic zones (EEZs) in the Western Indian Ocean (WIO) introduces the potential for migratory species to cross multiple boundaries, consequently a lack of scientific data could complicate regional management. In the current study, we highlight both the relative lack of spatial data available in the WIO, and the prevalence of transboundary movements in species that have previously been studied in the region. Five tiger sharks Galeocerdo cuvier were tracked with near real‐time positioning (SPOT) satellite tags to determine individual shark movements relative to EEZs within the WIO. Concurrently, a literature search was performed to identify all satellite telemetry studies conducted to date in the WIO for marine megafaunal species, and the results compared to global satellite telemetry effort. Finally, the satellite tracks of all marine species monitored in the WIO were extracted and digitized to examine the scale of transboundary movements that occur in the region. Tiger sharks exhibited both coastal and oceanic movements, with one individual crossing a total of eight EEZs. Satellite telemetry effort in the WIO has not matched the global increase, with only 4.7% of global studies occurring in the region. Species in the WIO remained within the EEZ in which they were tagged in only three studies, while all other species demonstrated some level of transboundary movement. This study demonstrates the lack of spatial data available for informed regional management in an area where transboundary movements by marine megafauna are highly prevalent. Without more dedicated funding and research, the rich biodiversity of the WIO is at risk of overexploitation from the diverse threats present within the various political regions

Relationship between concussion history and concussion knowledge, attitudes, and disclosure behavior in high school athletes

Objective: Examine the association between self-reported concussion history and measures of concussion knowledge, attitude, and disclosure behavior. Design: Cross-sectional survey. Setting: Classroom. Participants: A convenience sample of high school athletes (n = 167; mean age = 15.7 years) from multiple sports completed a validated survey. Independent Variables: Concussion history (main predictor) was defined as the number of self-recalled concussions during participants' high school career. Main Outcome Measures: The outcomes were recalled concussion disclosure behavior (3 measures) and scales assessing both concussion knowledge and concussion attitude. Results: A greater number of previous concussions was associated with worse attitude to concussion and negative concussion disclosure behavior. For every 3 additional self-recalled concussions, there was a mean decrease of 7.2 points (range of possible scores = 14-98) in concussion attitude score (P = 0.002), a 48% decrease in the self-reported proportion of concussion events disclosed (P = 0.013), and an increased prevalence of self-reported participation in games (67%) and practices (125%) while experiencing signs and symptoms of concussion (P < 0.001). Increased concussion history did not affect concussion knowledge score (P = 0.333). Conclusions: Negative trends in concussion disclosure behavior were identified in youth athletes with a positive history of concussion. Improving disclosure in this subgroup will require targeted efforts addressing negative attitude to concussion

Demographic, parental, and personal factors and youth athletes' concussion-related knowledge and beliefs

Context: Currently, significant attention is focused on improving care for patients with concussions through legislative mandates that include educational interventions. Few researchers have examined young athletes' concussion knowledge and the factors that may influence their knowledge. Objective: To use the socioecological model to examine demographic, parental, and personal factors associated with youth athletes' knowledge of concussion. Our ultimate goal is to inform the planning and implementation of youth sport concussion-related interventions. Design: Cross-sectional survey. Setting: Gymnasium and classroom. Patients or Other Participants: North Carolina and Arizona youth athletes (n ¼ 225; age ¼ 8 to 15 years) active in football, boys' or girls' soccer, boys' or girls' ice hockey, or boys' or girls' lacrosse in 2012-2013. Main Outcome Measure(s): Participants completed a validated, self-administered survey. The intention and belief measures were guided by the theory of planned behavior. Perceptions of concussion and intention to seek care were examined using descriptive statistics. Athletes' concussion knowledge was modeled using linear regressions and generalized estimating equations, with child demographic and personal factors and parental knowledge and attitudes about concussion as predictors. Results: Geography, sport, parental attitudes toward concussion, and athlete age were associated with athlete knowledge in the univariable analyses (P, .10). In the multivariable model, geographic location (North Carolina versus Arizona, mean difference [MD] ¼ 2.2, 95% confidence interval [CI] ¼ 1.1, 3.2), sport (girls' soccer versus girls' lacrosse, MD ¼ 2.2, 95% CI ¼ 0.7, 3.6), more favorable parental attitudes toward concussion (MD ¼ 1.2 for a 2-standard deviation shift; 95% CI ¼ 0.3, 2.1), and older age (.12 years, MD ¼ 1.6; 95% CI ¼ 0.5, 2.6) were associated with better knowledge about concussion. Conclusions: Geographic location, sport, parental attitudes about concussion, and athlete's age influenced athletes' concussion-related perceptions, indicating the need to address multiple levels of the socioecological model when targeting youth sport interventions. Parental interventions that translate to an improved culture of youth sport by improving youth athletes' perceptions and experiences are key areas for future work

The first decade of web-based sports injury surveillance: Descriptive epidemiology of injuries in us high school girls' volleyball (2005-2006 through 2013-2014) and national collegiate athletic association women's volleyball (2004-2005 Through 2013-2014)

Context: The advent of Web-based sports injury surveillance via programs such as the High School Reporting Information Online system and the National Collegiate Athletic Association Injury Surveillance Program has aided in the acquisition of girls' and women's volleyball injury data. Objective: To describe the epidemiology of injuries sustained in high school girls' volleyball in the 2005-2006 through 2013-2014 academic years and collegiate women's volleyball in the 2004-2005 through 2013-2014 academic years using Webbased sports injury surveillance. Design: Descriptive epidemiology study. Setting: Online injury surveillance from high school girls' (annual average=100) and collegiate women's (annual average = 50) volleyball teams. Patients or Other Participants: Girls' and women's volleyball players who participated in practices and competitions during the 2005-2006 through 2013-2014 academic years in high school and the 2004-2005 through 2013-2014 academic years in college. Main Outcome Measure(s): Athletic trainers collected timeloss (≥24 hours) injury and exposure data. Injury rates per 1000 athlete-exposures (AEs), injury rate ratios (IRRs) with 95% confidence intervals (CIs), and injury proportions by body site and diagnosis were calculated. Results: The High School Reporting Information Online system documented 1634 time-loss injuries during 1 471 872 AEs; the National Collegiate Athletic Association Injury Surveillance Program documented 2149 time-loss injuries during 563 845 AEs. The injury ratewas higher in college than in high school (3.81/ 1000 versus 1.11/1000 AEs; IRR=3.43; 95%CI=3.22, 3.66), and higher in high schools with ≤1000 students than in those with >1000 students (IRR=1.35; 95% CI=1.23, 1.49). Injury rates did not vary by collegiate division. The injury rate was higher during competitions than practices for high school (IRR=1.23; 95% CI= 1.12, 1.36) but not for college (IRR= 1.01; 95% CI= 0.92, 1.10). Ankle sprains were common in both the high school and collegiate setting. However, liberos had a high incidence of concussion. Conclusions: Injury rates were higher among collegiate than high school players. However, injury rates differed by event type in high school, unlike college. Concussion injury patterns among liberos varied from those for other positions. These findings highlight the need for injury-prevention interventions specific to setting and position