Defining and quantifying fatigue in the rugby codes

The rugby codes (i.e., rugby union, rugby league, rugby sevens [termed 'rugby']) are teamsports that impose multiple complex physical, perceptual, and technical demands on players which leads to substantial player fatigue post-match. In the post-match period, fatigue manifests through multiple domains and negatively influences recovery. There is, however, currently no definition of fatigue contextualised to the unique characteristics of rugby (e.g., locomotor and collision loads). Similarly, the methods and metrics which practitioners consider when quantifying the components of post-match fatigue and subsequent recovery are not known. The aims of this study were to develop a definition of fatigue in rugby, to determine agreement with this common definition of fatigue, and to outline which methods and metrics are considered important and feasible to implement to quantify post-match fatigue. Subject matter experts (SME) undertook a two-round online Delphi questionnaire (round one; n = 42, round two; n = 23). SME responses in round one were analysed to derive a definition of fatigue, which after discussion and agreement by the investigators, obtained 96% agreement in round two. The SME agreed that fatigue in rugby refers to a reduction in performance- related task ability which is underpinned by time-dependent negative changes within and between cognitive, neuromuscular, perceptual, physiological, emotional, and technical/tactical domains. Further, there were 33 items in the neuromuscular performance, cardio-autonomic, or self-report domains achieved consensus for importance and/or feasibility to implement. Highly rated methods and metrics included countermovement jump force/power (neuromuscular performance), heart rate variability (cardio-autonomic measures), and soreness, mood, stress, and sleep quality (self-reported assessments). A monitoring system including highly-rated fatigue monitoring objective and subjective methods and metrics in rugby is presented. Practical recommendations of objective and subjective measures, and broader considerations for testing and analysing the resulting data in relation to monitoring fatigue are provided.</p

Effect of Block Design on Swimming Relay Start Performance

Starting blocks used in competitive swimming often incorporate a wedge for the rear foot to push against when performing flat starts. In most competitions, this wedge cannot be removed so relay starts must be performed with the wedge in place despite the common addition of an approach step during a relay starts. The presence of the wedge constrains the length of the approach step but does provide an inclined surface from which to push which may improve propulsive force development. PURPOSE: The purpose of this study was to evaluate the effect of using a wedge in relay start performance. METHODS: Eight collegiate swimmers (177.69 + 8.73 cm, 74.7 + 9.11 kg, 19.59 + 0.59 years) provided informed consent and completed eight maximal effort relay starts, four with the wedge in place and four without. For all starts, participants were instructed to maintain a streamline position upon entering the water and to glide as far as possible. A relay judging platform was installed on the block and used with an in-water touch pad to measure the exchange time for the relay start. Two synchronized cameras captured movements at 60 Hz above and below water. A 16-point model of the body was used to compute center of mass position for above water movements. Takeoff velocity and angle were defined using the horizontal and vertical velocity of the whole body center of mass. Time to 7m was measured as the time needed for the wrist to reach a point 7m from the pool wall. Paired t-tests were used to compare dependent measures between start conditions. RESULTS: Exchange time (t(7) = 0.11, p = 0.99), takeoff angle (t(7)= 0.60, p = 0.57), and time to 7 m (t(7) = 0.69, p = 0.51) were not different when using the wedge as compared to not using the wedge (Table 1). However, takeoff velocity without the wedge was 2.4% faster (t(7) = 2.48, p = 0.04) than with the wedge on the block (p\u3c0.05). This difference was characterized by a moderate effect size (Cohen d = 0.46). CONCLUSION: Presence of the wedge on the block had a minimal effect on relay start performance. It adversely affected start performance by decreasing takeoff velocity however no other kinematic variables were affected. Having the wedge on the block may constrain the step length of the swimmer during the relay start, which might explain the decrease in velocity

The Effect of Kipping on the Performance of a Pull-up

The high prevalence of obesity and sedentary lifestyle contribute to the growing burden of health care costs, incidence of disease, and mortality, making a lifestyle that includes regular physical activity increasingly important. Low intensity resistance training has been studied as a possible intervention to increase physical activity in inactive individuals. To determine the effects of a weighted vest treatment (WV) on steady state VO2, O2 deficit, VO2max, body mass index (BMI), and resting blood pressure (RBP). Fourteen college age women participated in a 4 week trial and completed both pre and posttest evaluations. These evaluations included a submaximal exercise bout, a maximal graded exercise test, determination of BMI, and measurement of RBP. Seven participants wore a weighted vest, fitted with 10% of their body weight, during normal daily activities for a minimum of 10 hours a day, 5 days each week. The remaining 7 participants served as a control group. ANCOVAs, with pretest measures serving as the covariates, were conducted to determine the effect of WV on posttest responses. Mean (sd) pre-test O2 deficit values were 0.64 (0.18) and 0.68 (0.18) for the control and WV groups, respectively. Mean (sd) post-test O2 deficit values were 0.62 (0.15) and 0.38 (0.17) for the control and WV groups, respectively. Results of the ANCOVA revealed a significant effect of WV on O2 deficit with O2 deficit values being lower following WV (F(1,11) = 7.30, p = 0.02). Further, WV accounted for about 40% of the change observed in posttest O2 deficit values (ηp2 = 0.40). However, no significant effect of WV was seen on steady state VO2, VO2 max, BMI, or RBP. WV resulted in lower O2 deficit values suggesting that it could elicit training effects related to improved aerobic function. Possible explanations for the lack of effects on other variables could be related to the limitations imposed by the relatively small sample size and trial length. Future studies designed with larger sample sizes and longer trial periods might prove more effective in evaluating the effect of WV on eliciting health related benefits

Influences on academics' approaches to development: voices from below

The purpose of this qualitative case study research was to explore faculty-based academics’ views on what influences their behaviours and attitudes towards their development. Informed by critical realist ontology, the data collection was carried out through narrative interviews with academics in two contrasting English Universities. Findings, or areas for reflection, have emerged about the constraints and enablements academics perceive in respect of their professional development. In particular, themes such as the significance of professional status; misaligned initiatives and priorities; the influence of supportive networks; and emergent personal, individual concerns have surfaced. The conclusion is drawn that the significance of agency raises the importance of responding to the ‘voices from below’

Transcatheter interatrial shunt device for the treatment of heart failure with preserved ejection fraction (REDUCE LAP-HF I [Reduce Elevated Left Atrial Pressure in Patients With Heart Failure]): A phase 2, randomized, sham-controlled trial

Background -In non-randomized, open-label studies, a transcatheter interatrial shunt device (IASD, Corvia Medical) was associated with lower pulmonary capillary wedge pressure (PCWP), less symptoms, and greater quality of life and exercise capacity in patients with heart failure (HF) and mid-range or preserved ejection fraction (EF ≥ 40%). We conducted the first randomized, sham-controlled trial to evaluate the IASD in HF with EF ≥ 40%. Methods -REDUCE LAP-HF I was a phase 2, randomized, parallel-group, blinded multicenter trial in patients with New York Heart Association (NYHA) class III or ambulatory class IV HF, EF ≥ 40%, exercise PCWP ≥ 25 mmHg, and PCWP-right atrial pressure gradient ≥ 5 mmHg. Participants were randomized (1:1) to the IASD vs. a sham procedure (femoral venous access with intracardiac echocardiography but no IASD placement). The participants and investigators assessing the participants during follow-up were blinded to treatment assignment. The primary effectiveness endpoint was exercise PCWP at 1 month. The primary safety endpoint was major adverse cardiac, cerebrovascular, and renal events (MACCRE) at 1 month. PCWP during exercise was compared between treatment groups using a mixed effects repeated measures model analysis of covariance that included data from all available stages of exercise. Results -A total of 94 patients were enrolled, of which n=44 met inclusion/exclusion criteria and were randomized to the IASD (n=22) and control (n=22) groups. Mean age was 70±9 years and 50% were female. At 1 month, the IASD resulted in a greater reduction in PCWP compared to sham-control (P=0.028 accounting for all stages of exercise). Peak PCWP decreased by 3.5±6.4 mmHg in the treatment group vs. 0.5±5.0 mmHg in the control group (P=0.14). There were no peri-procedural or 1-month MACCRE in the IASD group and 1 event (worsening renal function) in the control group (P=1.0). Conclusions -In patients with HF and EF ≥ 40%, IASD treatment reduces PCWP during exercise. Whether this mechanistic effect will translate into sustained improvements in symptoms and outcomes requires further evaluation. Clinical Trial Registration -URL: http://clinicaltrials.gov. Unique identifier: NCT02600234

Quantifying Fatigue in the Rugby Codes: The Interplay Between Collision Characteristics and Neuromuscular Performance, Biochemical Measures, and Self-Reported Assessments of Fatigue

Locomotor and collision actions that rugby players complete during match-play often lead to substantial fatigue, and in turn, delays in recovery. The methods used to quantify post-match fatigue and recovery can be categorised as subjective and objective, with match-related collision characteristics thought to have a primary role in modulating these recovery measures. The aim of this review was to (1) evaluate how post-match recovery has been quantified in the rugby football codes (i.e., rugby league, rugby union, and rugby sevens), (2) to explore the time-course of commonly used measures of fatigue post-match, and (3) to investigate the relationships between game-related collisions and fatigue metrics. The available evidence suggests that upper-, and lower-body neuromuscular performance are negatively affected, and biomarkers of muscular damage and inflammation increase in the hours and days following match-play, with the largest differences being at 12–36 h post-match. The magnitude of such responses varies within and between neuromuscular performance (Δ ≤ 36%, n = 13 studies) and tissue biomarker (Δ ≤ 585%, n = 18 studies) measures, but nevertheless appears strongly related to collision frequency and intensity. Likewise, the increase in perceived soreness in the hours and days post-match strongly correlate to collision characteristics across the rugby football codes. Within these findings, there are specific differences in positional groups and recovery trajectories between the codes which relate to athlete characteristics, and/or locomotor and collision characteristics. Finally, based on these findings, we offer a conceptual model of fatigue which details the multidimensional latent structure of the load to fatigue relationship contextualised to rugby. Research to date has been limited to univariate associations to explore relationships between collision characteristics and recovery, and multivariate methods are necessary and recommended to account for the latent structures of match-play external load and post-match fatigue constructs. Practitioners should be aware of the typical time windows of fatigue recovery and utilise both subjective and objective metrics to holistically quantify post-match recovery in rugby

Comportamiento de híbridos de maíz y aptitud combinatoria de líneas con caracteres contrastantes.

Se identificaron doce líneas con mazorca larga y doce líneas con mazorca gruesa. Las cruzas simples fueron evaluadas bajo un diseño de látice simple 12 x 12 en cinco ambientes duran-te 1995. Estimaciones de aptitud combinatoria general (ACG) y específica (ACE) para rendimiento de grano se calcularon con análisis de línea x probador. La línea Pob.21xPob.43 registró el valor más alto de ACG (0,58 t/ha) dentro de líneas con mazorca larga, mientras que en el grupo de líneas con mazorca gruesa el valor más alto de ACG (0,48 t/ha) fue para la línea 19 (Pob.25). El más alto rendimiento (8,35 t/ha) fue para la cruza 4 x 22 (Pob.21xPob.43) x (Pob.32). Se muestra la importancia de considerar el uso de líneas con caracteres contrastantes y su patrón heterótico en el desarrollo de híbridos para maximizar el comportamiento de la Fl

Filling the void: an optimized polymicrobial interkingdom biofilm model for assessing novel antimicrobial agents in endodontic infection

There is a growing realization that endodontic infections are often polymicrobial, and may contain Candida spp. Despite this understanding, the development of new endodontic irrigants and models of pathogenesis remains limited to mono-species biofilm models and is bacterially focused. The purpose of this study was to develop and optimize an interkingdom biofilm model of endodontic infection and use this to test suitable anti-biofilm actives. Biofilms containing Streptococcus gordonii, Fusobacterium nucleatum, Porphyromonas gingivalis, and Candida albicans were established from ontological analysis. Biofilms were optimized in different media and atmospheric conditions, prior to quantification and imaging, and subsequently treated with chlorhexidine, EDTA, and chitosan. These studies demonstrated that either media supplemented with serum were equally optimal for biofilm growth, which were dominated by S. gordonii, followed by C. albicans. Assessment of antimicrobial activity showed significant effectiveness of each antimicrobial, irrespective of serum. Chitosan was most effective (3 log reduction), and preferentially targeted C. albicans in both biofilm treatment and inhibition models. Chitosan was similarly effective at preventing biofilm growth on a dentine substrate. This study has shown that a reproducible and robust complex interkingdom model, which when tested with the antifungal chitosan, supports the notion of C. albicans as a key structural component

Cranial nerve outcomes in regionally recurrent head & neck melanoma after sentinel lymph node biopsy

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/156007/1/lary28243.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/156007/2/lary28243_am.pd