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Transient [3,3] Cope rearrangement of 3,3-dicyano-1,5-dienes: computational analysis and 2-step synthesis of arylcycloheptanes.
A simple and modular route to arylcycloheptene scaffolds is reported. The two-step route from Knoevenagel adducts and allylic electrophiles is made possible through the design of a Cope rearrangement that utilizes a "traceless" activating group to promote an otherwise thermodynamically unfavorable transformation. Experimentally, the [3,3] rearrangement occurrs transiently at room temperature with a computed barrier of 19.5 kcal mol-1, which ultimately allows for three-component bis-allylation. Ring-closing metathesis delivers the arylcycloheptane and removes the activating group. This report describes the design and optimization of the methodology, scope and mechanistic studies, and computational analysis
Post-license Education for Novice Drivers: Evaluation of a Training Programme implemented in Spain
Introduction: This study evaluated the implementation of a 2nd phase training programme for novice drivers in Spain, which puts the primary focus of the training on the higher hierarchical levels of driver behaviour. Method: Two hundred and sixty-three participants took part throughout the study, which was implemented as an experimental design with the test and control groups assessed before and after the one day safety training. Measurement of the impact of the training program focused on the participantsÂż self-evaluation and self reporting of some driving behaviour indicators related to accident risk. Results: Data analysis showed a change in the expected direction in the scale related to the skills for careful driving, but not for the other four scales considered. A feedback survey about the training course offered some important input for evaluating the organization, contents, tuition, and results of the three parts of the training programme (discussion group, on-road and track training) as reported by the participants in the test group. Conclusions and suggestions: The results of the experiment show that using a one day driver safety course, it is possible to change some of the driversÂż evaluations connected to safe driving style into safe direction. The follow-up period was exceptionally long (9 months) and the design (randomly divided experimental and control groups with before and after measurements) was reliable. More effort should be devoted to improving the on-road part of the training, which was often perceived as a typical driving lesson rather than a feedback drive
Local and Global Distinguishability in Quantum Interferometry
A statistical distinguishability based on relative entropy characterises the
fitness of quantum states for phase estimation. This criterion is employed in
the context of a Mach-Zehnder interferometer and used to interpolate between
two regimes, of local and global phase distinguishability. The scaling of
distinguishability in these regimes with photon number is explored for various
quantum states. It emerges that local distinguishability is dependent on a
discrepancy between quantum and classical rotational energy. Our analysis
demonstrates that the Heisenberg limit is the true upper limit for local phase
sensitivity. Only the `NOON' states share this bound, but other states exhibit
a better trade-off when comparing local and global phase regimes.Comment: 4 pages, in submission, minor revision
Peak Speeds of Professional Football Players During Bouts of Non-curved, Manual Treadmill Sprints
Purpose: Speed training and short distance sprints have become an essential component of preparation for professional football players. Current trends in speed training have included the application of non-curved, manual treadmills, as they may enhance peak speeds with less biomechanical stress. A lack of data currently exists in regards to the effectiveness of different settings and peak speed response. Therefore, we proposed to compare peak speeds during different settings of non-curved, manual treadmills. It was hypothesized that as resistance/incline increased, peak sprinting speeds would decrease and vice versa. Methods: Fourteen male professional football players (27.14 ± 3.11 yrs., 183.93 ± 8.52 cm, 100.36 ± 15.60 kg) sprinted at peak speeds during four different incline/resistance bouts. Paired samples T-tests examined differences between bouts, and significance was set at p ≤ 0.008. Results: A significant difference (p \u3c 0.001) existed for peak speeds between each incline/resistance bout (i.e. INC15R8, INC15R5, INC20R3, INC20R1). Conclusions: The observed data differences existed between all bouts, indicating that as resistance and/or incline increased, peak speed decreased. This also indicated that as resistance and/or incline decreased, peak speed increased during sprint bouts in professional football players
Aerobic Capacity is Related to Repeated Sprint Ability with Sprint Distances Less Than 40 Meters.
International Journal of Exercise Science 10(2): 197-204, 2017 Research is inconclusive regarding the association between aerobic fitness (objectively measured VO2max) and repeated sprint performance when the sprints are less than 40 meters. Soccer athletes must be able to repeat sprints without significant decreases in speed and strength and conditioning coaches need to better understand if aerobic fitness is related to repeated sprint ability (RSA). Twenty (10 male, 10 female) Division I soccer athletes first completed a graded maximal treadmill test to measure VO2max. Then on a separate day, athletes completed the RSA test. The RSA test consisted of 10, 30-meter sprints which athletes repeated every 30 seconds. There were significant negative correlations (r ≤ -0.69, P \u3c 0.001) between VO2max and all 10-sprint times and average sprint time. More aerobically fit Division I soccer athletes were faster at all time points during the RSA test. Aerobic fitness is associated with faster sprint times during a more anaerobic RSA test when sprint distances are less than 40 meters
Weight loss and competition weight in Ultimate Fighting Championship (UFC) athletes
Previous research has demonstrated that professional mixed martial arts (MMA) athletes employ a variety of weight manipulation strategies to compete at given weight classes. Although there is much literature demonstrating weight manipulation methods, minimal research exists analyzing how much weight MMA athletes lose prior to the official weigh-in. Moreover, there is minimal research examining how much weight professional MMA athletes gain between the official weigh-in and competition. Therefore, the purpose of the current study was to analyze weight loss/regain in professional MMA athletes. Data collected from 616 professional MMA athletes (31.1 ± 4.0 yrs. ; 177.1 ± 4.7 cm) competing for the Ultimate Fighting Championship (UFC) between 2020 and 2022 were used for the study. The athlete’s weight was obtained 72 h, 48 h, and 24 h prior to the official weigh-in, at the official weigh-in, and prior to competition. Random effects analysis was utilized to compare weight at a variety of time points between different weight classes. All statistics were analyzed, and significance was set at p ≤ 0.05. There is a significant (p ≤ 0.05) difference between weight classes and time points in professional MMA. MMA athletes decrease body weight significantly prior to the official weigh-in. MMA athletes increase body weight significantly between official weigh-in and competition. Based on these data, it appears that MMA athletes average a weight loss of nearly 7 % within 72 h prior to the official weigh-in. The data also suggest that athletes gain nearly 10 % of total weight between the official weigh-in and competition
The Effects of Cold and Lower Body Negative Pressure on Cardiovascular Effects
Purpose. The purpose of this study is to determine how cold exposure and lower body negative pressure effected cardiovascular variables. Methods. Eleven males (20.3 years ± 2.7) underwent two 20-minute exposures to LBNP. During the 2 trials, the subjects were exposed to cold air (10°C) (COLD) and to ambient temperature (23°C) (AMB). The trials consisted of a 100-minute pre-LBNP period followed by a 20-minute exposure to LBNP and then a 15-minute recovery period. Cardiovascular variables were recorded every 30 minutes using bioimpedance. Results. When LBNP was applied during the AMB trials, stroke volume immediately decreased. During the COLD trial, there was a five-minute delay before the decrease in stroke volume. Heart rate increased immediately after LBNP initiation during the AMB trials but there was a delay in the increase during the COLD trials. That same pattern was followed with mean arterial blood pressures. Cerebral oxygenation was significantly lower throughout the COLD trial as compared to the AMB trials. Six subjects reported symptoms of syncope or presyncope during the AMB trials but there were no reports of symptoms during the COLD trials. Conclusion. From analysis of this data, cold improved the subject’s tolerance to LBNP
The Physiologic and Behavioral Implications of Playing Active and Sedentary Video Games in a Seated and Standing Position
International Journal of Exercise Science 7(3) : 194-201, 2014. Previous studies have assessed physiologic response while playing video games per manufacturer instructions with participants standing during active video game play and seated during sedentary game play. It is not known whether an assigned seated or standing position affects positional preference and oxygen consumption (VO2) while gaming. The purpose of the study was to assess VO2 and preference of playing active and sedentary video games in a seated and standing position. VO2 was assessed in 25 participants during four, 20-minute conditions; resting, PlayStation 2 Madden NFL Football 2011, Nintendo Wii-Sports Boxing and Nintendo Wii Madden NFL Football 2011. Each condition was divided into two positional conditions (10 minutes seated, 10 minutes standing) and each participant indicated their positional preference after each 20-minute condition. Standing VO2 (4.4 ± 0.2 ml•kg-1•min-1 PS2, 4.6 ± 0.1 ml•kg-1•min-1 Wii Madden, 6.8 ± 0.3 ml•kg-1•min-1Wii Boxing) was significantly (p ≤ 0.001) greater than seated VO2 (4.0 ± 0.1 ml•kg-1•min-1 PS2, 4.2 ± 0.1 ml•kg-1•min-1 Wii Madden, 6.1 ± 0.3 ml•kg-1•min-1Wii Boxing) for each gaming condition. Participants preferred (p ≤ 0.001) to sit for all gaming conditions except Wii Boxing. Playing video games while standing increases VO2 to a greater extent than playing the same games in a seated position. Standing was only preferred for the most physiologically challenging game, Wii Boxing. Gaming position should be considered when assessing the physiologic and behavioral outcomes of playing video games
A Submaximal Field Test of Aerobic Capacity does not Accurately Reflect VO2max in Career Firefighters
International Journal of Exercise Science 15(4): 221-230, 2022. Adequate aerobic capacity is crucial to maintaining firefighter safety. The purpose of this study was to compare predicted VO2max scores from a submaximal and maximal step test. Eighteen career male firefighters from a medium sized urban municipality completed both a submaximal Forestry step test and a maximal laboratory WFI step test. A lack of association (p = .017) and low level of agreement (p = .015) was determined between step test protocols producing a mean bias of ± 5.61 mL.kg-1/min-1 with most scores being overestimated. Use of the Forestry step test to predict true VO2max in firefighters should be used with caution when classifying firefighter fitness
An Acute Bout of Self-Myofascial Release in the Form of Foam Rolling Improves Performance Testing
International Journal of Exercise Science 7(3) : 202-211, 2014. Recent developments in the strength and conditioning field have shown the incorporation of foam rolling self-myofascial release in adjunct with a dynamic warm-up. This is thought to improve overall training performance; however, minimal research exists supporting this theory. Therefore, determining if an acute bout of foam rolling self-myofascial release in addition to a dynamic warm-up could influence performance is of importance. In order to do so, eleven athletically trained male subjects participated in a two condition, counterbalanced, crossover within-subjects study comparing two particular warm-up routines. The two warm-up routines compared were a total-body dynamic warm-up (DYN) and a total-body dynamic warm-up in adjunct with a self-myofascial release, total-body foam rolling session (SMR). Following each warm-up condition, subjects performed tests of flexibility, power, agility, strength, and speed. Paired samples T-tests were utilized to determine if there were any significant differences in test results between conditions (DYN vs. SMR). The data indicated that SMR was effective at improving power, agility, strength, and speed when compared to DYN (P ≤ 0.024). A warm-up routine consisting of both a dynamic warm-up and a self-myofascial release, total-body foam rolling session resulted in overall improvements in athletic performance testing
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