Isoprene nitrates: preparation, separation, identification, yields, and atmospheric chemistry

Isoprene is an important atmospheric volatile organic compound involved in ozone production and NO<sub>x</sub> (NO+NO<sub>2</sub>) sequestration and transport. Isoprene reaction with OH in the presence of NO can form either isoprene hydroxy nitrates ("isoprene nitrates") or convert NO to NO<sub>2</sub> which can photolyze to form ozone. While it has been shown that isoprene nitrate production can represent an important sink for NO<sub>x</sub> in forest impacted environments, there is little experimental knowledge of the relative importance of the individual isoprene nitrate isomers, each of which has a different fate and reactivity. In this work, we have identified the 8 individual isomers and determined their total and individual production yields. The overall yield of isoprene nitrates at atmospheric pressure and 295 K was found to be 0.070(+0.025/−0.015). Three isomers, representing nitrates resulting from OH addition to a terminal carbon, represent 90% of the total IN yield. We also determined the ozone rate constants for three of the isomers, and have calculated their atmospheric lifetimes, which range from ~1–2 h, making their oxidation products likely more important as atmospheric organic nitrates and sinks for nitrogen

Psychological Responses Prior to a Strenuous Task Involving an Injured Joint

Injuries are an inherent risk of sport participation. Roughly 68% of athletes experience an athletic injury during their college career, with over half being injuries to the lower extremity (Hootman, Dick & Agel, 2007). While much attention has been given to the physical effects of an injury, the psychological ramifications can also affect an athlete’s recovery from injury. According to Quinn & Fallon (2008), an athlete can physically recover from an injury however they may not attain a complete psychological recovery. An athlete’s performance can be affected negatively if they return to sport participation without recovering psychologically from their injury, which can also lead to a risk of re-injury or receiving additional injuries (Quinn & Fallon, 2008). Two variables related to psychological recovery include re-establishment of confidence and a decrease in fear of re-injury (Magyar & Duda, 2000; Walker & Heaney, 2013). Additionally, an athlete may feel reluctance to perform skills that require the site of injury to be used which affects subsequent performance. An athlete’s fear of re-injury can negatively affect athletes’ performance by undermining an athlete’s confidence in obtaining their pre-injury sport performance (Arden, Taylor, Feller & Webster, 2012). The purpose of this study was to determine how psychological responses to injury, namely sport resumption confidence, fear of re-injury, and injury perception change throughout the rehabilitation process. These variables were examined in relation to performing a strenuous isokinetic dynamometer task on an injured joint (e.g., knee, ankle). Participants (N=21; 62% female) completed psychometrically sound measures designed to assess confidence, fear and injury perception across three groups of athletes: healthy (n = 9), injured (n = 6), and rehabilitated (n = 6). All subjects were told they would be completing a maximal isokinetic contraction task on the lower extremity that had been injured before completing the survey. Only healthy and rehabilitated athletes actually performed the task at the completion of the survey. ANOVA was utilized to compare group differences on study variables. There was a significant difference between groups with regard to fear (healthy=1.62 ± 0.03; injured=4.09 ± 0.10; rehabilitated=3.17 ± 0.61; p \u3c .05) and confidence (healthy=5.82 ± 0.68; injured=2.99 ± 0.06; rehabilitated=4.06 ± 0.58; p \u3c .01) where healthy athletes reported the highest confidence and lowest fear across groups. Additionally, injured athletes reported the lowest confidence and highest fear across groups. There were no group differences found with regard to injury perception (healthy=0.00 ± 0.00; injured=1.01 ± 0.41; rehabilitated=0.07 ± 0.09). This study extends the current sport injury research base by identifying changes in key psychological variables across the healthy-injured-rehabilitated continuum of the collegiate sport experience

Controlled Cold Water and Water Slushy Ingestion, and Heat Performance in Subjects of Average Fitness

Fluid ingestion is known to improve exercise performance and could lead to a heat sink effect, if cold enough. While research has been conducted on the influence of hydration in exercise performance, little has been done which consider beverages’ temperature during controlled consumption. PURPOSE: To examine the effect of controlled consumption of water at different temperatures on heat performance in subjects of average fitness. METHODS: Fifteen males, ages 18-29, with no prior heat illness were recruited. Subjects were tested for body composition and peak oxygen consumption (VO2peak) prior to testing. All subjects underwent three experimental trials [cold water (CD=4̊C), water slushy (SL=-1̊C), room temperature water (RM=22̊C)] in a balanced crossover design. Subjects were required to exercise on a cycle ergometer at intensity 70% VO2peak (vigorous exercise) in the heat (34.0±0.6̊C, 41.7±2.7% RH, 3.6 km∙hr∙-1 wind speed) until volitional maximum. Subjects were required to consume a controlled volume (2.5 g∙kgBodyMass-1) of one of the treatments (CD, SL, RM) every 10 minutes each trial. Measurements for maximum exercise time (ExT), pre-/post-core body temperature change (ΔTc), heart rate (HR), mean skin temperature (MTsk), sweat rate (SR), and RPE were recorded. One-way (beverage) or two-way (beverage x time) ANOVA with repeated measures was used (α=0.05). RESULTS: ExT did not differ significantly between treatments (CD=33.8±9.4 min; SL=35.0±9.8 min; RM=31.5±8.6 min) but a trend (p=0.0680) was seen where SL&CD\u3eRM, which was supported by all subjects having their longest bouts during CD (n=10) and SL (n=5) trials. Neither ΔTc (CD=0.69±0.36˚C, SL=0.64±0.43˚C, RM=0.77±0.45˚C), or SR (CD=1545±1109 ml·hr-1; SL=1837±692 ml·hr-1; RM=1891±489 ml·hr-1), differed (p\u3e0.05) between treatments. A main effect for beverage was seen in HR (CD=157±16 bpm; SL=153±18 bpm; RM=160±17 bpm)(p\u3c0.05) where SLsk or RPE (p\u3e0.05). A main effect for time (p\u3c0.05) was see in HR (T20=161±18 bpm\u3eT10=153±16 bpm), MTsk (T20=36.2±0.3˚C\u3eT10=35.9±0.3˚C), and RPE (T20=5.8±2.1 (0-10)\u3eT10=3.3±1.4 (0-10)). A trend towards significant beverage x time interaction was seen for HR (p=0.0900) but treatments did not respond differently over time for MTsk or RPE (p\u3e0.05). HR at volitional maximum differed between treatments (CD=168±20 bpm; SL=165±20 bpm; RM=173±20 bpm)(p\u3c0.05), specifically SLsk or RPE (p\u3e0.05). CONCLUSION: SL appeared to improve performance over RM, but not CD. There may be a point where colder beverage temperature does not yield a greater heat sink effect or, results could have been due to shorter exercise time in subjects of average fitness

Anthropogenic Control over Wintertime Oxidation of Atmospheric Pollutants

Anthropogenic air pollutants such as nitrogen oxides (NO(x) = NO + NO(2)), sulfur dioxide (SO(2)), and volatile organic compounds (VOC), among others, are emitted to the atmosphere throughout the year from energy production and use, transportation, and agriculture. These primary pollutants lead to the formation of secondary pollutants such as fine particulate matter (PM(2.5)) and ozone (O(3)) and perturbations to the abundance and lifetimes of short-lived greenhouse gases. Free radical oxidation reactions driven by solar radiation govern the atmospheric lifetimes and transformations of most primary pollutants and thus their spatial distributions. During winter in the mid and high latitudes, where a large fraction of atmospheric pollutants are emitted globally, such photochemical oxidation is significantly slower. Using observations from a highly instrumented aircraft, we show that multi-phase reactions between gas-phase NO(x) reservoirs and aerosol particles, as well as VOC emissions from anthropogenic activities, lead to a suite of atypical radical precursors dominating the oxidizing capacity in polluted winter air, and thus, the distribution and fate of primary pollutants on a regional to global scale

Mechanical deformation induces depolarization of neutrophils

The transition of neutrophils from a resting state to a primed state is an essential requirement for their function as competent immune cells. This transition can be caused not only by chemical signals but also by mechanical perturbation. After cessation of either, these cells gradually revert to a quiescent state over 40 to 120 min. We use two biophysical tools, an optical stretcher and a novel microcirculation mimetic, to effect physiologically relevant mechanical deformations of single nonadherent human neutrophils. We establish quantitative morphological analysis and mechanical phenotyping as label-free markers of neutrophil priming. We show that continued mechanical deformation of primed cells can cause active depolarization, which occurs two orders of magnitude faster than by spontaneous depriming. This work provides a cellular-level mechanism that potentially explains recent clinical studies demonstrating the potential importance, and physiological role, of neutrophil depriming in vivo and the pathophysiological implications when this deactivation is impaired, especially in disorders such as acute lung injury.We acknowledge financial support by the Cambridge Commonwealth Trust (to A.E.E.), the European Research Council (Starting Grant “Light Touch” to J.G.), and the National Institute for Health Research Cambridge Biomedical Research Centre (to E.R.C.). C.S. is a Wellcome Trust Postdoctoral Clinical Research Fellow (101692MA), and C.F. is a Medical Research Council Clinical Training Fellow

80,000,000 hooligans. Discourses of resistance to racism and xenophobia in German punk lyrics 1991-1994

The late eighties and early nineties in Germany were not only marked by the fall of the Wall and German unification, but also by the dramatization of the political issue of asylum, resulting in outbreaks of xenophobic violence. In the context of the asylum debate of the early nineties, a number of punk bands produced songs between 1991 and 1994 which criticise the xenophobic climate created by the asylum debate and undermine an exculpatory official discourse about the violent attacks. The lyrics of these songs will be analysed as instances of counter-discourse emerging from a subcultural sphere that nurtures a critical distance towards hegemonic public and political discourse, arguing that Critical Discourse Analysis should pay more attention to defiance of hegemonic discourse

Ghosts of other stories: a synthesis of hauntology, crime and space

Criminology has long sought to illuminate the lived experience of those at the margins. More recently, there has been a turn toward the spatial in the discipline. This paper sets out an analytical framework that synthesizes spatial theory with hauntology. We demonstrate how a given space's violent histories can become embedded in the texts that constitute it and the language that describes it. The art installation ‘Die Familie Schneider’ is used as an example of how the incorporation of social trauma can lead to the formation of a spatial “crypt”. Cracking open this “crypt” allows us to draw out Derrida's notion of the specter within the context of a “haunted” city space