Effects of Ambient Particulate Matter on Aerobic Exercise Performance

Background/Objective: Wintertime thermal inversions in narrow mountain valleys create a ceiling effect, increasing concentration of small particulate matter (PM2.5). Despite potential health risks, many people continue to exercise outdoors in thermal inversions. This study measured the effects of ambient PM2.5 exposure associated with a typical thermal inversion on exercise performance, pulmonary function, and biological markers of inflammation. Methods: Healthy, active adults (5 males, 11 females) performed two cycle ergometer time trials outdoors in a counterbalanced design: 1) low ambient PM2.5 concentrations (/m3 ), and 2) an air quality index (AQI) ranking of “yellow.” Variables of interest were exercise performance, exhaled nitric oxide (eNO), c-reactive protein (CRP), forced vital capacity (FVC), and forced expiratory volume in 1 s (FEV1). Results: Despite a significant difference in mean PM2.5 concentration of 9.3 ± 3.0 mg/m3 between trials (p \u3c .001), there was no significant difference (p = .424) in the distance covered during low PM2.5 conditions (9.9 ± 1.7 km) compared to high PM2.5 conditions (10.1 ± 1.5 km). There were no clinically significant differences across time or between trials for eNO, CRP, FVC, or FEV1. Additionally, there were no dose-response relationships (p \u3e .05) for PM2.5 concentration and the measured variables. Conclusion: An acute bout of vigorous exercise during an AQI of “yellow” did not diminish exercise performance in healthy adults, nor did it have a negative effect on pulmonary function or biological health markers. These variables might not be sensitive to small changes from acute, mild PM2.5 exposur

The role of temporal and spectral cues in the temporal integration of pitch and in pitch-based segregation of sound sources

The auditory nerve conveys spectral information, reflecting the location of maximum vibration along the frequency-tuned basilar membrane, and also information reflecting the timing of peaks in the vibrations at each location. Debate continues as to whether pitch is extracted based on the available temporal or spectral representations of tonal stimuli, or both. The aim of the current work was to determine the roles of temporal and spectral harmonicity cues for pitch, under important conditions for understanding speech in multi-talker environments. Two such conditions are the temporal integration of pitch and pitch-based segregation of sound sources. Pitch information in running speech changes over time. Therefore, pitch-extraction mechanisms must be able to follow these changes to enhance intelligibility, particularly when listening in modulated backgrounds such as competing speech. However, the temporal resolution of pitch has received little attention. In the first three chapters, the roles of temporal and spectral cues on the temporal resolution of pitch extraction were determined by measuring pitch-domain temporal modulation transfer functions and gap-detection thresholds. Temporal resolution was shown to be unaffected by the availability of spectral cues, and similarly unaffected by the overall pitch strength of the stimulus. However, the system was much more sluggish in response to changes in pitch information in stimuli presented in high-frequency regions compared to low-frequency regions. This processing strategy may reflect the progressive loss of accurate temporal information towards higher frequencies imposed by transduction processes in the auditory periphery. To understand speech in noise, the ability of the auditory system to integrate pitch information over long periods is equally important as its ability to detect rapid changes in pitch. In Chapter 4, discrimination thresholds for pitch value and pitch strength were measured in the presence and absence of spectral cues as a function of stimulus duration. The assumption was that discrimination thresholds would reach asymptote at the stimulus duration corresponding to the length of the pitch integration window. However, the pitch-strength discrimination data revealed integration was only limited by the stimulus duration, suggesting that this task may reflect the rate of decrease in the variance of internal pitch-value and pitch-strength estimates with increasing stimulus duration, but not the total integration capacity of the system. In multi-talker environments, listeners have to process multiple simultaneous tonal sound sources. The fifth study showed that temporal interactions between simultaneous tonal stimuli could aid detection in the absence of spectral cues. In contrast, harmonic resolvability is thought to be a prerequisite for pitch-based simultaneous grouping. However, data from a second experiment showed that listeners were able to perceptually segregate tonal sounds in the absence of spectral cues

The role of temporal and spectral cues in the temporal integration of pitch and in pitch-based segregation of sound sources

The auditory nerve conveys spectral information, reflecting the location of maximum vibration along the frequency-tuned basilar membrane, and also information reflecting the timing of peaks in the vibrations at each location. Debate continues as to whether pitch is extracted based on the available temporal or spectral representations of tonal stimuli, or both. The aim of the current work was to determine the roles of temporal and spectral harmonicity cues for pitch, under important conditions for understanding speech in multi-talker environments. Two such conditions are the temporal integration of pitch and pitch-based segregation of sound sources. Pitch information in running speech changes over time. Therefore, pitch-extraction mechanisms must be able to follow these changes to enhance intelligibility, particularly when listening in modulated backgrounds such as competing speech. However, the temporal resolution of pitch has received little attention. In the first three chapters, the roles of temporal and spectral cues on the temporal resolution of pitch extraction were determined by measuring pitch-domain temporal modulation transfer functions and gap-detection thresholds. Temporal resolution was shown to be unaffected by the availability of spectral cues, and similarly unaffected by the overall pitch strength of the stimulus. However, the system was much more sluggish in response to changes in pitch information in stimuli presented in high-frequency regions compared to low-frequency regions. This processing strategy may reflect the progressive loss of accurate temporal information towards higher frequencies imposed by transduction processes in the auditory periphery. To understand speech in noise, the ability of the auditory system to integrate pitch information over long periods is equally important as its ability to detect rapid changes in pitch. In Chapter 4, discrimination thresholds for pitch value and pitch strength were measured in the presence and absence of spectral cues as a function of stimulus duration. The assumption was that discrimination thresholds would reach asymptote at the stimulus duration corresponding to the length of the pitch integration window. However, the pitch-strength discrimination data revealed integration was only limited by the stimulus duration, suggesting that this task may reflect the rate of decrease in the variance of internal pitch-value and pitch-strength estimates with increasing stimulus duration, but not the total integration capacity of the system. In multi-talker environments, listeners have to process multiple simultaneous tonal sound sources. The fifth study showed that temporal interactions between simultaneous tonal stimuli could aid detection in the absence of spectral cues. In contrast, harmonic resolvability is thought to be a prerequisite for pitch-based simultaneous grouping. However, data from a second experiment showed that listeners were able to perceptually segregate tonal sounds in the absence of spectral cues

Copper-catalysed C-H functionalisation gives access to 2-aminobenzimidazoles

This paper describes the development, optimisation and exemplification of a copper-catalysed C–H functionalisation to form pharmaceutically relevant 2-aminobenzimidazoles from aryl-guanidines. High throughput screening was used as a tool to identify a catalytically active copper source, DoE was used for reaction optimisation and a range of aryl-guanidines were prepared and exposed to the optimum conditions to afford a range of 2-aminobenzimidazoles in moderate to good yields. The methodology has been applied to the synthesis of Emedastine, a marketed anti-histamine pharmaceutical compound, with the key cyclisation step performed on a gram-scale

Abstract 482: Differences in Ground Reaction Forces and Chest Compression Release Velocity in Professional and Lay Rescuers With and Without the Use of Real-Time CPR Feedback

Purpose: Chest compression release velocity (CCRV) has been associated with survival and favorable neurological outcome after cardiac resuscitation. Both complete chest release and high CCRV contribute to improved venous return during CPR. Differences in compression forces delivered by professional and lay rescuers are reported, which may contribute to differences in CCRV. The aim of this pilot study was to investigate differences in ground reaction force (GRF) and CCRV between professional and lay rescuers during CPR performed on a manikin with and without real-time feedback. Methods: Professional (n = 5) and lay rescuers (n = 11) performed two minutes of continuous compressions on a manikin positioned over a force plate for two trials. CPR feedback provided by a defibrillator was disabled in the first trial and enabled in the second. CPR pads containing an accelerometer were used to calculate individual compression characteristics. Relative maximum and minimum GRFs were calculated for each compression cycle and averaged over each trial. Paired and independent sample t tests and Pearson correlations were conducted in STATA 15.1. Results: CCRV was higher in professionals vs. lay rescuers with feedback disabled and enabled (p\u3c0.05). Professionals had greater maximal and lower minimum forces than lay rescuers without feedback (p\u3c0.05), though there were no differences between groups with feedback enabled (Table 1). CCRV was associated with minimum force (r = -0.63, p\u3c0.01) and force range (r = 0.78, p\u3c0.01) in all rescuers. Analysis of GRFs by CCRV for all rescuers indicated lower force minimum (9.71 + 3.16 N, p\u3c0.05) with CCRV \u3e400 mm/s in comparison to CCRV 300-400 mm/s (39.73 + 8.91 N) and CCRV 200-300 mm/s (63.82 + 16.98 N). Conclusions: CPR feedback attenuated differences in GRF between professional and lay rescuers. CCRV was greater in professionals and was associated with measures of GRF, and thus may serve as an indicator of both velocity and amount of chest release

Kinematic differences between professional and lay rescuers with and without the use of real-time cpr feedback

Purpose: Guideline-compliant cardiopulmonary resuscitation (CPR) performance can be achieved with training and use of real-time feedback. Kinematic differences are reported between experts and novices in various motor tasks. The aim of this pilot study was to investigate differences in kinematics between professional and lay rescuers during CPR performed on a manikin with and without feedback. Methods: Professional (n = 5) and lay rescuers (n = 11) performed two minutes of continuous chest compressions on a manikin for two trials. Real-time CPR feedback provided by a defibrillator was disabled in the first trial and enabled in the second. CPR pads containing an accelerometer were used to calculate individual compression characteristics. Participants were instrumented for electromyography (EMG) and inertial motion capture and a motion capture marker was placed on the top hand. Paired and independent-sample t-tests and Pearson correlations were conducted in STATA 15.1. Results: CPR feedback increased compression depth in lay rescuers (p \u3c 0.05) to achieve guideline compliance. Lower bilateral hip range of motion (ROM) was recorded in lay rescuers compared with professionals without feedback (p \u3c 0.05), but hip ROM was increased in lay rescuers with feedback enabled (p \u3c 0.05). Hip ROM was associated with compression depth on both right (r = 0.61, p \u3c 0.01) and left sides (r = 0.65, p \u3c 0.01) for all rescuers. Greater left shoulder flexion was measured in lay rescuers both with (p \u3c 0.05) and without feedback (p \u3c 0.05). Lower extremity muscle coactivation indexes (CI) indicate greater hip extensor activity in professionals with feedback on both left (1.42 ± 0.17 vs. 0.87 ± 0.12, p \u3c 0.05) and right sides (1.33 ± 0.16 vs. 0.99 ± 0.07, p \u3c 0.05)

The Grizzly, January 22, 1991

Student Activism Rises Across the Country • Caught in the Crossfire: Iraqi Speaks on the War • What to Look for in the Gulf War • Taking War to Heart • Limerick Prepared • Saddam Hussein Must be Stopped • Ruminations of a Confused Mind • How has the War Affected You?https://digitalcommons.ursinus.edu/grizzlynews/1267/thumbnail.jp

Sensitivity of Prescribing High-Intensity, Interval Training Using the Critical Power Concept

International Journal of Exercise Science 8(3): 202-212, 2015. The critical power (CP) concept enables the calculation of time to exhaustion (tLIM) for a given power output above CP using the equation of tLIM = W’/(power – CP), where W’ is the curvature constant, and CP is the asymptote for the power-tLIM relationship. The CP concept offers great promise for prescribing high-intensity interval training (HIIT); however, knowledge on the concept’s sensitivity is lacking (i.e., how much of a difference in W’ expenditure is needed to evoke different metabolic responses). We tested if two different power-tLIM configurations expending identical proportions of W’ would evoke different end-exercise oxygen uptake (VO2) and heart rate (HR) values. Five men and five women completed a graded exercise test, 3-min all-out exercise tests, and intervals prescribed to deplete either 70 or 80% of W’ on separate visits. Consistency statistics of intraclass correlation (ICC a), standard error of measure (SEM), and coefficient of variation (CV) were calculated on end-exercise values. End-exercise VO2 were similar for the 3.5- and 5-min bouts, depleting 70% of W’ (ICC a = 0.91, SEM = 3.23 mL·kg-1·min-1, CV = 8.1%) and similar for the 4- and 5-min bouts, depleting 80% of W’ (ICC a = 0.95, SEM = 2.34 mL·kg-1·min-1, CV = 8.1%). No VO2 differences were observed between trials or conditions (p = 0.58). Similarly, HR values (~181 b·min-1) did not differ between trials or conditions (p = 0.45). Use of the CP concept for HIIT prescriptions of different power-tLIM configurations evokes similar end-exercise VO2 values on a given day. Our findings indicate that \u3e10% W’ depletion is necessary to evoke different metabolic responses to HIIT

Surgical approach to limiting skin contracture following protractor myectomy for essential blepharospasm

Purpose: To report our experience with protractor myectomy in patients with benign essential blepharospasm who did not respond to serial botulinum toxin injection, and to describe intra- and postoperative techniques that limited skin contracture while also providing excellent functional and cosmetic results. Methods: The medical records of patients with isolated, benign, essential blepharospasm who underwent protractor myectomy from 2005 to 2008 by a single surgeon were reviewed retrospectively. The technique entailed operating on a single eyelid during each procedure, using a complete en bloc resection of all orbicularis tissue, leaving all eyelid skin intact at the time of surgery, and placing the lid under stretch with Frost suture and applying a pressure dressing for 5-7 days. Results: Data from 28 eyelids in 7 patients were included. Average follow-up was 21.5 months (range, 4-76 months). Of the 28 eyelids, 20 (71.4%) showed postoperative resolution of spasm, with no further need for botulinum toxin injections. In the 8 eyelids requiring further injections, the average time to injection after surgery was 194 days (range, 78-323 days), and the average number of injections was 12 (range, 2-23 injections). All but one eyelid had excellent cosmetic results, without signs of contracture; one eyelid developed postoperative skin contracture following premature removal of the Frost suture and pressure dressing because of concerns over increased intraocular pressure. Conclusions: In our patient cohort, this modified technique resulted in excellent cosmetic and functional results and limited postoperative skin contracture