Shot noise limited detection of OH using the technique of laser induced fluorescence

Nearly shot-noise limited detection of OH using the technique of laser-induced fluorescence is reported. A LIDAR configuration is used to excite fluorescence in a large volume and a narrow-bandwidth interference filter provides spectral discrimination. This arrangement alleviates the effect of ozone interference and facilitates image processing at relatively close distances. The detection limit is determined mainly by the shot-noise of the solar background. Ground-based measurements in Dearborn indicate a detection limit of better than 1 x 10 to the 6th power OH/cubic cm over a forty-minute acquisition period. Under favorable conditions, a comparable detection limit was also observed for airborne measurements

Assessing a Monitoring Scale of Physiological Health and Risk Assessment Among Those Exposed to Heated Environments: A Brief Report

Background: Prevention of heat illness is of considerable medical interest within the field of occupational work. There are many established methods of perceptual health assessment; however, many are rather unpractical and timely. The objective was to improve the practicality and timeliness of perceptual physiological monitoring; a Heat Thermal Sensation scale has been developed. The usefulness of the scale was assessed on its ability to monitor physiological variable. Materials and Methods: Ten apparently healthy individuals performed physically exerting activity while exposed to 37 °C. Sensation and physiology were measured throughout. Results: The perceptual monitoring scale demonstrated weak positive correlations with human physiological variables including cardiorespiratory stresses. It demonstrated no correlation with thermoregulation stress. Conclusion: The scale needs further development to better improve heat illness practices to those commonly exposed in extreme heat during occupational work

Crossing borders: new teachers co-constructing professional identity in performative times

This paper draws on a range of theoretical perspectives on the construction of new teachers’ professional identity. It focuses particularly on the impact of the development in many national education systems of a performative culture of the management and regulation of teachers’ work. Whilst the role of interactions with professional colleagues and school managers in the performative school has been extensively researched, less attention has been paid to new teachers’ interactions with students. This paper highlights the need for further research focusing on the process of identity co-construction with students. A key theoretical concept employed is that of liminality, the space within which identities are in transition as teachers adjust to the culture of a new professional workplace, and the nature of the engagement of new teachers, or teachers who change schools, with students. The authors argue that an investigation into the processes of this co-construction of identity offers scope for new insights into the extent to which teachers might construct either a teacher identity at odds with their personal and professional values, or a more ‘authentic’ identity that counters performative discourses. These insights will in turn add to our understanding of the complex range of factors impacting on teacher resilience and motivation

Improving cognitive function following exercise-induced dehydration: Role of sports drink supplementation

Objective: While brief bouts of exercise improve cognitive function, more prolonged exercise can suppress attention and executive function. Dehydration and heat exposure are known contributors to these deficits, though the role of blood sugar changes during exercise in cognitive dysfunction is less understood at this time. The current study sought to clarify the independent contribution of blood glucose levels to cognitive function following demanding exercise. Method: Healthy adult males (N= 10, age= 21.9 +/- 1.97 years) presented for two counterbalanced experimental trials in a 100 degrees F heated chamber. Each experimental trial consisted of BASELINE glucose and cognitive function assessments, as measured by the Logical Relations (LR) and Running Memory Continuous Performance Task (RMCPT) subtests of the Automated Neuropsychological Assessment Metrics- 4th Edition (ANAM4). Participants then completed 120 minutes of exercise on a cycle ergometer, with glucose and cognitive function measured POST-EXERCISE. Next, participants rehydrated with a zero-sugar or full-sugar sports beverage, with measures of glucose and cognitive function repeated immediately POST-REHYDRATION. Finally, after a 15-minute recovery period during which the participants rested while not permitted to drink, they completed experimental measures an additional time, at POST-RECOVERY. Results: Physiological response to the experimental trials was similar across conditions. Participants demonstrated significantly reduced blood glucose levels (F(1,9)=16.93, p<0.01) and lost an average of 2.57% of their body weight following exercise. Contrary to hypotheses, repeated measures ANOVA showed performance on LR did not change from BASELINE to POST-EXERCISE and actually declined from POST-EXERCISE to POST-REHYDRATION (F(1,9)=9.44, p=0.01). Performance on RMCPT improved from BASELINE to POST-EXERCISE (F(19)=5.43, p<0.05) and the zero-sugar condition produced gains from POST-REHYDRATION to POST-RECOVERY (F(1,9)=6.45, p=0.03) relative to the full-sugar condition. Conclusion: Contrary to past studies, cognitive function did not universally decline with strenuous exercise, despite reduced blood glucose levels. Performances on an attention measure increased following exercise and were unexpectedly better at POST-RECOVERY for the zero- versus the full-sugar condition. However, executive functioning was stable to POST-EXERCISE and declined following rehydration. The exact mechanisms responsible for this pattern of findings are unclear, but likely involve a combination of limited core temperature increase and dehydration level, reactivity to blood sugar fluctuations, and multiple possible variables not assessed in the current study such as neurotransmitter and blood lactate levels, brain temperature, physiological arousal, and task engagement. Future studies are needed to better understand the inconsistent findings across the literature, as a significant number of individuals engage in strenuous and prolonged exercise regularly, including those involved in service positions (i.e., military personnel and firefighters). Articulating the mechanisms at play in this phenomenon may increase safety and improve performance

The non-equivalent circulant D-optimal designs for n = 90

An exhaustive search was carried out to find all 1358 non-equivalent circulant D-optimal designs for n = 90. A sample of 30 of these designs, presented in a table in the form of the corresponding non-equivalent supplementary difference sets, is given. All these designs are new, except one found by J.H.E. Cohn (Bull. London Math. Soc. 21 (1989), 36-42)

The Nonequivalent Circulant D-Optimal Designs for n=2 mod 4, n<=54, n=66

AbstractAll non-equivalent circulant D-optimal designs for n ≡ 2 mod 4, n ⩽ 54 and n = 66 are given and were found by an exhaustive search. There is a unique non-equivalent circulant design for each value of n ⩽ 18, 3 for n = 26 and n = 30, 8 for n = 38, 31 for n = 42, 17 for n = 46, 39 for n = 50, 48 for n = 54, and 1025 for n = 66. These are presented in tables in the form of the corresponding non-equivalent supplementary difference sets. Most of the given designs are new