Dataset Information

Why do sleeping nematodes adopt a hockey-stick-like posture?

ABSTRACT: A characteristic posture is considered one of the behavioral hallmarks of sleep, and typically includes functional features such as support for the limbs and shielding of sensory organs. The nematode C. elegans exhibits a sleep-like state during a stage termed lethargus, which precedes ecdysis at the transition between larval stages. A hockey-stick-like posture is commonly observed during lethargus. What might its function be? It was previously noted that during lethargus, C. elegans nematodes abruptly rotate about their longitudinal axis. Plausibly, these "flips" facilitate ecdysis by assisting the disassociation of the old cuticle from the new one. We found that body-posture during lethargus was established using a stereotypical motor program and that body bends during lethargus quiescence were actively maintained. Moreover, flips occurred almost exclusively when the animals exhibited a single body bend, preferentially in the anterior or mid section of the body. We describe a simple biomechanical model that imposes the observed lengths of the longitudinally directed body-wall muscles on an otherwise passive elastic rod. We show that this minimal model is sufficient for generating a rotation about the anterior-posterior body axis. Our analysis suggests that posture during lethargus quiescence may serve a developmental role in facilitating flips and that the control of body wall muscles in anterior and posterior body regions are distinct.

SUBMITTER: Tramm N

PROVIDER: S-EPMC4099128 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature

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Why do sleeping nematodes adopt a hockey-stick-like posture?

Tramm Nora N Oppenheimer Naomi N Nagy Stanislav S Efrati Efi E Biron David D

PloS one 20140715 7

A characteristic posture is considered one of the behavioral hallmarks of sleep, and typically includes functional features such as support for the limbs and shielding of sensory organs. The nematode C. elegans exhibits a sleep-like state during a stage termed lethargus, which precedes ecdysis at the transition between larval stages. A hockey-stick-like posture is commonly observed during lethargus. What might its function be? It was previously noted that during lethargus, C. elegans nematodes a ...[more]

PMID: 25025212

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Project description:BackgroundThe health outcomes of men continue to be poorer than women globally. Challenges in addressing this problem include difficulties engaging men in weight loss programs as they tend to view these programs as contrary to the masculine narrative of independence and self-reliance. Researchers have been turning towards sports fans to engage men in health promotion programs as sports fans are typically male, and tend to have poor health habits.MethodsDeveloped from the highly successful gender-sensitized Football Fans in Training program, Hockey Fans in Training (Hockey FIT) recruited 80 male hockey fans of the London Knights and Sarnia Sting who were overweight or obese into a weekly, 90-minute classroom education and group exercise program held over 12 weeks; a 40-week minimally-supported phase followed. A process evaluation of the Hockey FIT program was completed alongside a pragmatic randomized controlled trial and outcome evaluation in order to fully explore the acceptability of the Hockey FIT program from the perspectives of coaches delivering and participants engaged in the program. Data sources included attendance records, participant focus groups, coach interviews, assessment of fidelity (program observations and post-session coach reflections), and 12-month participant interviews.ResultsCoaches enjoyed delivering the program and found it simple to deliver. Men valued being among others of similar body shape and similar weight loss goals, and found the knowledge they gained through the program helped them to make and maintain health behaviour changes. Suggested improvements include having more hockey-related information and activities, greater flexibility with timing of program delivery, and greater promotion of technology support tools.ConclusionsWe confirmed Hockey FIT was an acceptable "gender-sensitized" health promotion program for male hockey fans who were overweight or obese. Minor changes were required for optimization, which will be evaluated in a future definitive trial.Trial registrationNCT02396524 (Clinicaltrials.gov). Date of registration: Feb 26, 2015.

Project description:CONTEXT:Postconcussion deficits in neurocognitive performance and postural control may persist at the time of return to sport participation. How these deficits, if present, affect athletic performance is largely unknown, with prior studies showing mixed results. OBJECTIVE:To evaluate postconcussion National Hockey League player performance using advanced hockey metrics over short- (5 games), medium- (10 games), and long-term (remainder of the season) seasonal performance. DESIGN:Retrospective cohort study. PATIENTS OR OTHER PARTICIPANTS:National Hockey League players who sustained a sport-related concussion (SRC; n = 93) and returned during the same season and players (n = 51) who missed time for non-injury-related reasons. MAIN OUTCOME MEASURE(S):Six performance metrics were used: (1) points per 60 minutes, (2) Corsi percentage, (3) personal Fenwick shooting percentage, (4) scoring chances per 60 minutes, (5) penalty difference, and (6) PDO (not an acronym but sometimes referred to as SVSP% [save percentage shooting percentage]). Performance was compared using 2 (group) × 2 (time) repeated-measures analyses of variance for 3 time windows: (1) ±5 games, (2) ±10 games, and (3) the remainder of the season postconcussion. Alpha values were set at a conservative .01 to account for the lack of independence among dependent variables. RESULTS:No significant interactions were present for any of the 6 dependent variables at any of the 3 time windows. Overall, none of the secondary variables differed. CONCLUSIONS:Using advanced, sport-specific metrics, we found that National Hockey League players did not display worse seasonal performance during 3 postinjury time frames after they sustained an SRC. Whereas laboratory studies have identified lingering neurologic deficits after concussion, our results suggest that these deficits, if present, either do not translate to worse athletic performance or were not captured by these 44 metrics. Further, prospective efforts are needed to accurately quantify performance after SRC among professional hockey players.

Project description:BACKGROUND:Effective approaches that engage men in weight loss and lifestyle change are important because of worldwide increases, including in Canada, in obesity and chronic diseases. Football Fans in Training (FFIT), developed in Scotland, successfully tackled these problems by engaging overweight/obese male football fans in sustained weight loss and positive health behaviours, through program deliveries at professional football stadia. METHODS:Aims: 1) Adapt FFIT to hockey within the Canadian context and integrate with HealtheSteps™ (evidence-based lifestyle program) to develop Hockey Fans in Training (Hockey FIT); 2) Explore potential for Hockey FIT to help overweight/obese men lose weight and improve other outcomes by 12 weeks, and retain these improvements to 12 months; 3) Evaluate feasibility of recruiting and retaining overweight/obese men; 4) Evaluate acceptability of Hockey FIT; and 5) Conduct program optimization via a process evaluation. We conducted a two-arm pilot pragmatic randomized controlled trial (pRCT) whereby 80 overweight/obese male hockey fans (35-65 years; body-mass index ?28 kg/m2) were recruited through their connection to two junior A hockey teams (London and Sarnia, ON) and randomized to Intervention (Hockey FIT) or Comparator (Wait-List Control). Hockey FIT includes a 12-week Active Phase (classroom instruction and exercise sessions delivered weekly by trained coaches) and a 40-week Maintenance Phase. Data collected at baseline and 12 weeks (both groups), and 12 months (Intervention only), will inform evaluation of the potential of Hockey FIT to help men lose weight and improve other health outcomes. Feasibility and acceptability will be assessed using data from self-reports at screening and baseline, program fidelity (program observations and coach reflections), participant focus group discussions, coach interviews, as well as program questionnaires and interviews with participants. This information will be analyzed to inform program optimization. DISCUSSION:Hockey FIT is a gender-sensitive program designed to engage overweight/obese male hockey fans to improve physical activity and healthy eating choices, thereby leading to weight loss and other positive changes in health outcomes. We expect this study to provide evidence for a full-scale confirmatory pRCT. TRIAL REGISTRATION:NCT02396524 (Clinicaltrials.gov). Date of registration: Feb 26, 2015.

Project description:BackgroundIce hockey referees and linesmen are at risk for musculoskeletal injuries because of the lack of protective equipment and contact with players, sticks, pucks, the ice surface and boards.PurposeTo quantify and analyze injuries reported by officials of the International Ice Hockey Federation (IIHF).Study designDescriptive epidemiology study.MethodsA 61-question survey tool was designed by an interdisciplinary team to evaluate musculoskeletal injuries experienced by ice hockey officials. This survey was administered to 600 active IIHF referees and linesmen. Only completed survey responses were included in the statistical analysis. Continuous variables were analyzed using unpaired t-tests, while categorical data were assessed utilizing chi-square tests.ResultsOf the 600 surveys administered, 264 surveys were completed by officials from 45 countries (44% response rate). Of the respondents, 72% were male, and 28% were female, with a mean age of 31.1 ± 5.8 years. Officiating experience averaged 11.4 ± 6.0 years (6.3 ± 4.5 years with the IIHF). A total of 295 injuries were reported by 55% of the officials. Injuries occurred more frequently during games compared with training, and officials who worked year-round had more total injuries than those who took time off (P = .03). The most common injuries involved the wrist and hand (n = 64 [22%]), head and face (n = 58 [20%]), and the knee (n = 47 [16%]). Wrist and hand trauma included 23 fractures. Knee and shoulder injuries were most likely to require surgery compared with other body areas (P < .001); 30 officials underwent surgery because of an acute knee injury (10%). Injury prevention activities were effective at reducing injuries (P = .04).ConclusionMost ice hockey officials experienced musculoskeletal injuries during their career. The risk of trauma to the wrist and hand can possibly be reduced via equipment modifications including protective gloves. A greater emphasis should be placed on injury prevention programs and time away from officiating competitions.

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Why do sleeping nematodes adopt a hockey-stick-like posture?

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Why do sleeping nematodes adopt a hockey-stick-like posture?

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