The effects of exercise-induced muscle damage on pacing strategy during time-trial performance

Previous research has suggested that resistance training can improve endurance performance by improving muscle strength, power and speed whilst maintaining endurance capacity. However, a consequence of unaccustomed resistance training is the prolonged appearance of exercise induced muscle damage. This study examined the effects of a single bout of resistance exercise designed to elicit muscle damage on cycling performance when pacing in the first 60 seconds of a 5-minute time-trial, which was either controlled by the experimenter or self-paced by the individual. Seventeen cyclists/triathletes were randomly assigned to either a paced group (n= 8) or a self-paced group (n=9). Measurements of perceived muscle soreness, peak isokinetic strength and Creatine kinase were recorded as markers of muscle damage taken before and 48 h after muscle damage protocol. Measurements of , heart rate, rate of perceived exertion and power output were recorded throughout the 5-minute time-trial, conducted before and 48 h after muscle damage. Total distance covered, peak isokinetic torque, blood lactate were reduced for both groups as well as no significant differences were seen between the groups for , heart rate, RPE and power output, during time-trial, 48 h after muscle damage protocol (P>0.05). A trend is seen whereby participants in the paced group are able to match the performance during the first minute as that of their baseline measurement. Participants in the paced group then continue to cycle with a lower decrement in power output compared to those in the self- paced group. It could be speculated that a reduced central drive is the mechanism for a downward regulation of power output seen in the self-paced group and not peripheral factors affecting performance as the paced group are able to maintain a similar peak power output following muscle damage protocol to baseline values

Smoothing nodal Calabi-Yau n-folds

Let X be an n-dimensional Calabi-Yau with ordinary double points, where n is odd. Friedman showed that for n=3 the existence of a smoothing of X implies a specific type of relation between homology classes on a resolution of X. (The converse is also true, due to work of Friedman, Kawamata and Tian.) We sketch a more topological proof of this result, and then extend it to higher dimensions. For n>3 the "Yukawa product" on the middle dimensional (co)homology plays an unexpected role. We also discuss a converse, proving it for nodal Calabi-Yau hypersurfaces in projective space.Comment: Included missing torsion in Lemma 2.5. Results unchanged. 20 page

Composite flight-control actuator development

The composite actuator is 'jam resistant', satisfying a survivability requirement for the Navy. Typically, the push-pull force needed to drive through the wound area of the composite actuator is 73 percent less than that of an all-metal actuator. In addition to improving the aircraft's combat survivability, significant weight savings were realized. The current design of the survivable, composite actuator cylinder is 36 percent lighter than that of the production steel cylinder, which equates to a 15 percent overall actuator weight savings

The physiological, perceptual and neuromuscular responses of team sport athletes to a running and cycling high intensity interval training session

This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: http://dx.doi.org/10.1007/s00421-022-05053-8Purpose: The acute physiological, perceptual and neuromuscular responses to volume-matched running and cycling high intensity interval training (HIIT) were studied in team sport athletes. Methods: In a randomized cross-over design, 11 male team sport players completed 3 x 6 min (with 5 min between sets) repeated efforts of 15 s exercising at 120% speed (s"V" ̇O2max) or power (p"V" ̇O2max) at VO2max followed by 15 s passive recovery on a treadmill or cycle ergometer, respectively. Results: Absolute mean "V" ̇O2 (ES [95%CI] = 1.46 [0.47-2.34], p 90% VO2max during the HIIT was higher for running compared to cycling (ES [95%CI] = 1.21 [0.26-2.07], p = 0.015). Overall differential RPE (dRPE) (ES [95%CI] = 0.55 [-0.32-1.38], p = 0.094) and legs dRPE (ES [95%CI] = -0.65 [-1.48-0.23], p = 0.111) were similar whereas breathing dRPE (ES [95%CI] = 1.01 [0.08-1.85], p = 0.012) was higher for running. Maximal isometric knee extension force was unchanged after running (ES [95%CI] = -0.04 [-0.80-0.8], p = 0.726) compared to a moderate reduction after cycling (ES [95%CI] = -1.17 [-2.02- -0.22], p = 0.001). Conclusion: Cycling HIIT in team sport athletes is unlikely to meet the requirements for improving run-specific metabolic adaptation but might offer a greater lower limb neuromuscular load

Service tough composite structures using the Z-direction reinforcement process

Foster-Miller has developed a new process to provide through thickness reinforcement of composite structures. The process reinforces laminates locally or globally on-tool during standard autoclave processing cycles. Initial test results indicate that the method has the potential to significantly reduce delamination in carbon-epoxy. Laminates reinforced with the z-fiber process have demonstrated significant improvements in mode 1 fracture toughness and compression strength after impact. Unlike alternative methods, in-plane properties are not adversely affected

Bott Periodicity and Realizations of Chiral Symmetry in Arbitrary Dimensions

We compute the chiral symmetries of the Lagrangian for confining "vector-like" gauge theories with massless fermions in $d$-dimensional Minkowski space and, under a few reasonable assumptions, determine the form of the quadratic fermion condensates which arise through spontaneous breaking of these symmetries. We find that for each type (complex, real, or pseudoreal) of representation of the gauge group carried by the fermions, the chiral symmetries of the Lagrangian, as well as the residual symmetries after dynamical breaking, exactly follow the pattern of Bott periodicity as the dimension changes. The consequences of this for the topological features of the low-energy effective theory are considered.Comment: v2: Small additions and clarifications. To appear in Physics Letters

Correlation of Urinary Engrailed-2 Levels to Tumour Volume and Pathological Stage in Men Undergoing Radical Prostatectomy

yesThe aim of this study was to assess the relationship between pre-prostatectomy urinary Engrailed-2 (EN2), a transcription factor secreted by prostate cancer cells, with tumour volume and pathological characteristics in resected prostate specimens. First pass urine samples (10 ml) without prior prostatic massage were collected and stored at –80°C. EN2 levels were measured using an enzyme-linked immunoabsorbent assay. Tumour volume in the prostatectomy specimens was determined histologically. 57 men undergoing RP in one urological cancer network were evaluated. EN2 was detected in 85% of RP patients. EN2 correlated with tumour volume (but not total prostatic volume) in a linear regression analysis, with increasing pathological T stage and margin positivity. Using three “cutoff levels” of tumour volume (0.5 ml, 1.3 ml and 2.5 ml) to define “significant disease”, men with “significant disease” had markedly higher levels of urinary EN2 (p < 0.001 for each cut off level). Levels of urinary EN2 may be useful in predicting tumour volume in men with prostate cancer by potentially identifying men with small volume “insignificant” disease. This study justifies a larger multicentre evaluation of urinary EN2 levels as a biomarker of PC significance using cancer volume, pathological and PSA criteria

Crystal melting on toric surfaces

We study the relationship between the statistical mechanics of crystal melting and instanton counting in N=4 supersymmetric U(1) gauge theory on toric surfaces. We argue that, in contrast to their six-dimensional cousins, the two problems are related but not identical. We develop a vertex formalism for the crystal partition function, which calculates a generating function for the dimension 0 and 1 subschemes of the toric surface, and describe the modifications required to obtain the corresponding gauge theory partition function.Comment: 30 pages; v2: references adde

Surfactants for heterogeneous processes in liquid or supercritical CO.sub.2

Heterogeneous polymer mixtures comprising a polymer in liquid or supercritical CO.sub.2 are stabilized by employing a poly(propylene oxide) or poly(butylene oxide) based surfactant. These surfactants are especially well suited for stabilizing heterogeneous polymer mixtures formed by micronizing techniques as well as by precipitation of a compressed fluid antisolvent applications.Board of Regents, University of Texas Syste

Bi-exponential modelling of W ′ reconstitution kinetics in trained cyclists

From Springer Nature via Jisc Publications RouterHistory: received 2021-06-21, accepted 2021-12-10, registration 2021-12-11, pub-electronic 2021-12-18, online 2021-12-18, pub-print 2022-03Publication status: PublishedAbstract: Purpose: The aim of this study was to investigate the individual W′ reconstitution kinetics of trained cyclists following repeated bouts of incremental ramp exercise, and to determine an optimal mathematical model to describe W′ reconstitution. Methods: Ten trained cyclists (age 41 ± 10 years; mass 73.4 ± 9.9 kg; V˙O2max 58.6 ± 7.1 mL kg min−1) completed three incremental ramps (20 W min−1) to the limit of tolerance with varying recovery durations (15–360 s) on 5–9 occasions. W′ reconstitution was measured following the first and second recovery periods against which mono-exponential and bi-exponential models were compared with adjusted R2 and bias-corrected Akaike information criterion (AICc). Results: A bi-exponential model outperformed the mono-exponential model of W′ reconstitution (AICc 30.2 versus 72.2), fitting group mean data well (adjR2 = 0.999) for the first recovery when optimised with parameters of fast component (FC) amplitude = 50.67%; slow component (SC) amplitude = 49.33%; time constant (τ)FC = 21.5 s; τSC = 388 s. Following the second recovery, W′ reconstitution reduced by 9.1 ± 7.3%, at 180 s and 8.2 ± 9.8% at 240 s resulting in an increase in the modelled τSC to 716 s with τFC unchanged. Individual bi-exponential models also fit well (adjR2 = 0.978 ± 0.017) with large individual parameter variations (FC amplitude 47.7 ± 17.8%; first recovery: (τ)FC = 22.0 ± 11.8 s; (τ)SC = 377 ± 100 s; second recovery: (τ)FC = 16.3.0 ± 6.6 s; (τ)SC = 549 ± 226 s). Conclusions: W′ reconstitution kinetics were best described by a bi-exponential model consisting of distinct fast and slow phases. The amplitudes of the FC and SC remained unchanged with repeated bouts, with a slowing of W′ reconstitution confined to an increase in the time constant of the slow component