• A2 milk enhances dynamic muscle function following repeated sprint exercise, a possible ergogenic aid for a1-protein intolerant athletes?

      Kirk, Ben; Mitchell, Jade; Jackson, Matthew; Amirabdollahian, Farzad; Alizadehkhaiyat, Omid; Clifford, Tom; School of Health Sciences, Liverpool Hope University, Hope Park, Liverpool L16 9JD, UK. kirkb@hope.ac.uk. (MDPI, 2017-01-28)
      Hyperaminoacidemia following ingestion of cows-milk may stimulate muscle anabolism and attenuate exercise-induced muscle damage (EIMD). However, as dairy-intolerant athletes do not obtain the reported benefits from milk-based products, A2 milk may offer a suitable alternative as it lacks the A1-protein. This study aimed to determine the effect of A2 milk on recovery from a sports-specific muscle damage model. Twenty-one male team sport players were allocated to three independent groups: A2 milk (n = 7), regular milk (n = 7), and placebo (PLA) (n = 7). Immediately following muscle-damaging exercise, participants consumed either A2 milk, regular milk or PLA (500 mL each). Visual analogue scale (muscle soreness), maximal voluntary isometric contraction (MVIC), countermovement jump (CMJ) and 20-m sprint were measured prior to and 24, 48, and 72 h post EIMD. At 48 h post-EIMD, CMJ and 20-m sprint recovered quicker in A2 (33.4 ± 6.6 and 3.3 ± 0.1, respectively) and regular milk (33.1 ± 7.1 and 3.3 ± 0.3, respectively) vs. PLA (29.2 ± 3.6 and 3.6 ± 0.3, respectively) (p < 0.05). Relative to baseline, decrements in 48 h CMJ and 20-m sprint were minimised in A2 (by 7.2 and 5.1%, respectively) and regular milk (by 6.3 and 5.2%, respectively) vs. PLA. There was a trend for milk treatments to attenuate decrements in MVIC, however statistical significance was not reached (p = 0.069). Milk treatments had no apparent effect on muscle soreness (p = 0.152). Following muscle-damaging exercise, ingestion of 500 mL of A2 or regular milk can limit decrements in dynamic muscle function in male athletes, thus hastening recovery and improving subsequent performance. The findings propose A2 milk as an ergogenic aid following EIMD, and may offer an alternative to athletes intolerant to the A1 protein.
    • Acute and short-term effects of secondhand smoke on lung function and cytokine production.

      Flouris, Andreas D.; Metsios, Giorgos S.; Carrillo, A. E.; Jamurtas, Athanasios Z.; Gourgoulianis, K.; Kiropoulos, Theodoros; Tzatzarakis, M. N.; Tsatsakis, A. M.; Koutedakis, Yiannis (American Thoracic Society, 2009)
      RATIONALE: The acute effect of secondhand smoke (SHS) on lung function and the duration of system disruption remain unknown. OBJECTIVES: To assess the SHS effects and their duration on lung function and inflammatory markers. METHODS: In a randomized single-blind crossover experiment data were obtained from 16 (8 women) nonsmoking adults at baseline and at 0, 1, and 3 hours after a 1-hour SHS exposure set at bar/restaurant SHS levels. MEASUREMENTS AND MAIN RESULTS: Serum and urine cotinine, lung function, and cytokines IL-4, IL-5, IL-6, tumor necrosis factor (TNF)-alpha, and IFN-gamma. At 0 hours most lung function parameters were significantly reduced (indicative: FEV(1), 4.3 +/- 0.4 vs. 3.8 +/- 0.3 L; FEV(1)/FVC, 0.9 +/- 0.1 vs. 0.8 +/- 0.1; P < 0.05) but at 3 hours they were at baseline levels. In contrast, cotinine (serum, 8.9 +/- 3.2 vs. 35.5 +/- 10.2 ng x ml(-1)), IL-4 (41.3 +/- 5.8 vs. 44.2 +/- 4.5 pg x ml(-1)), IL-5 (36.1 +/- 3.2 vs. 60.1 +/- 7.0 pg x ml(-1)), IL-6 (2.5 +/- 0.3 vs. 7.6 +/- 1.4 pg x ml(-1)) and IFN-gamma (0.3 +/- 0.2 vs. 0.6 +/- 0.2 IU x ml(-1)) at 3 hours were higher than at baseline (P < 0.05). IL-4 and TNF-alpha increased only in men, whereas IL-5, IL-6, and IFN-gamma were different between sexes after exposure (P < 0.05). Regression analyses revealed inverse associations of FEV(1) and FEV(1)/FVC ratio with IL-5 (P < 0.05) in men and with IL-5 (P = 0.01), IL-6 (P < 0.001), IFN-gamma (P = 0.034) and serum cotinine (P < 0.001) in women. CONCLUSIONS: We conclude that 1 hour of SHS exposure at bar/restaurant levels is accompanied by significant decrements on lung function and marked increases in inflammatory cytokines, particularly in men. More importantly, whereas most smoke-induced effects on lung function appear to recede within 60 minutes, inflammatory cytokines remain elevated for at least 3 hours after exposure to SHS.
    • Ankle and foot contributions to extreme plantar- and dorsiflexion in female ballet dancers.

      Russell, Jeffrey A.; Shave, Ruth M; Kruse, David W.; Koutedakis, Yiannis; Wyon, Matthew A. (American Orthopaedic Foot and Ankle Society, Inc., 2011)
      Background: Female ballet dancers require extreme ankle motion. The objective of this study was to quantify the relative contributions of the ankle and various foot joints to extreme plantarflexion (PF) and dorsiflexion (DF) in female ballet dancers using an X-ray superimposition technique and digital graphics software. Materials and Methods: One asymptomatic ankle was studied in each of seven experienced female ballet dancers. Three lateral weightbearing X-rays were taken of each ballet dancer's ankle: en pointe (maximum PF), in neutral position, and in demi-plié (maximum DF). Using graphics software, a subject's three X-ray images were superimposed and the tali were aligned. On each image the tibia, navicular, intermediate cuneiform, and first metatarsal were marked. Positional differences of a bone's line among the three images demonstrated angular movement of the bone in degrees. The neutral position was the reference from which both PF and DF of the bones were calculated. Results: The talocrural joint contributed the most motion of any pair of bones evaluated for both PF and DF, with mean movements of 57.6 ± 5.2 degrees en pointe and 24.6 ± 9.6 degrees in demi-plié. Approximately 70% of total PF and DF were attributable to the talocrural joint, with the remaining 30% coming from motion between adjacent pairs of the studied foot bones. Conclusion: Superimposed X-rays for assessing ankle and foot contributions to the extreme positions required of female ballet dancers offer insight into how these positions are attained that is not available via goniometry. Clinical Relevance: Functional information gained from this study may assist clinicians in assessessing ankle and foot pain in these individuals.
    • Anthropometric indicators of adiposity related to body weight and body shape as cardiometabolic risk predictors in British young adults: Superiority of waist-to-height ratio

      Amirabdollahian, Farzad; Haghighatdoost, Fahimeh; School of Health Sciences, Liverpool Hope University, Hope Park, Liverpool, UK. (Hindawi, 2018-11-01)
      Frequently reported poor dietary habits of young adults increase their risk of metabolic syndrome (MetS). Excess adiposity is the most established predictor of MetS, and numerous anthropometric measures have been proposed as proxy indicators of adiposity. We aimed to assess prevalence of MetS in young adult population and to make comparison between weight- and shape-oriented measures of adiposity to identify the best index in association with measured body fat and as a risk predictor for MetS. Healthy males and females aged 18-25 years from the Northwest of England were recruited using convenience sampling (<i>n</i>=550). As part of the assessment of the overall health of young adults, the biochemical variables and adiposity measures BMI, waist circumference (WC), waist-to-height ratio (WHtR), waist-to-hip ratio (WHR), new BMI, Body Adiposity Index (BAI), Clinica Universidad de Navarra-Body Adiposity Estimator (CUN-BAE), and A Body Shape Index (ABSI) were assessed. Linear regression analysis was used to investigate the association between the proxy indices of adiposity and measured percentage body fat. The odds ratio with 95% confidence interval was used to investigate the relationship between cardiometabolic (CM) risk factors and proxy measures of adiposity. The discriminatory power of these measures for diagnosis of MetS was investigated using area under the receiver operating characteristic curve. Body weight-related indicators of adiposity, particularly CUN-BAE, had stronger association with measured body fat compared with body shape-related indices. In relation with MetS, body shape-related indices, particularly elevated WC and WHtR, had stronger associations with CM risk compared with body weight-related measures. Amongst all indices, the best predictor for CM risk was WHtR, while ABSI had the weakest correlation with body fat, MetS, and CM risk. Indices directly associated with WC and specifically WHtR had greater diagnostic power in detection of CM risk in young adults.
    • Anthropometry, somatotypes, and aerobic power in ballet, contemporary dance, and dancesport

      Liiv, Helena; Wyon, Matthew A; Jürimäe, Toivo; Saar, Meeli; Mäestu, Jarek; Jürimäe, Jaak (Science & Medicine, 2013-12)
      This study compared anthropometric variables, somatotypes, and aerobic capacity between three groups of dancers: classical ballet dancers (M 33, F 56), contemporary dancers (M 28, F 109), and dancesport dancers (M 30, F 30). The assumption was that different functional requirements should produce differences in the anthropometric and aerobic capacity variables among the three groups. Anthropometric data for body mass index (BMI) and somatotypes were measured. Body fat percentage was measured by dual-energy x-ray absorptiometry. Maximal oxygen consumption and aerobic power were measured during an incremental treadmill test until exhaustion. Dancesport athletes were taller compared with same gender contemporary dancers (p<0.05). Female ballet dancers had a lower body mass and BMI compared with their contemporary dance and dancesport equivalents (p<0.001). There was significant difference between dance styles in endomorphy (F2,221 = 8.773, p<0.001) and mesomorphy (F2,221 = 21.458, p<0.001) scores. Dancesport dancers had significantly greater VO2max values (p<0.01). It was concluded that female contemporary dancers are generally more muscular than their ballet counterparts, while dancesport dancers are taller and heavier, less muscular, with slightly greater adioposity compared to the classical ballet dancers. Ballet dancers had the lowest body fat percentage, weight, and BMI values. Dancesport dancers had greater aerobic capacity than the ballet dancers. Based on this study, we conclude that dancers in these three styles differ in some aspects of anthropometric variables, somatotypes, and aerobic capacity, but we cannot say is it because of the training or selection or both.
    • Ballet injuries: injury incidence and severity over 1 year.

      Allen, Nick; Nevill, Alan; Brooks, John; Koutedakis, Yiannis; Wyon, Matthew (Lippincott, Williams & Wilkin, 2012-09)
      STUDY DESIGN: Prospective, descriptive single-cohort study. OBJECTIVE: To assess the incidence and severity of injuries to a professional ballet company over 1 year. METHODS: Data for an elite-level ballet company of 52 professional dancers were collected by an in-house medical team using a time-loss injury definition. RESULTS: A total of 355 injuries were recorded, with an overall injury incidence of 4.4 injuries per 1000 hours (female, 4.1; male, 4.8; P>.05) and a mean of 6.8 injuries per dancer (female, 6.3; male, 7.3; P>.05). Mean injury severity was 7 days (female, 4; male, 9; P<.05). Most injuries were classified as overuse (64%; female, 68%; male, 60%; P>.05); mean severity of injury was 3 days for females and 9 days for males (P<.05). The percentage of traumatic injuries was 32% for females and 40% for males (P<.05); the corresponding severity was 6 and 10 days, respectively (P<.05). CONCLUSION: The relatively high number of injuries reported and the resulting loss of dance time support the need to introduce interventions to reduce the risk of injury in professional dancers.
    • Bilateral differences in peak force, power, and maximum plié depth during multiple grande jetés.

      Wyon, Matthew; Harris, Julie; Brown, Derrick; Clark, Frances (Science & Medicine, 2013-03)
      A lateral bias has been previously reported in dance training. The aim of this study was to investigate whether there are any bilateral differences in peak forces, power, and maximum knee flexion during a sequence of three grand jetés and how they relate to leg dominance. A randomised observational design was selected for the study. Volunteers consisted of 20 female dancers in the last year of pre-professional training. All volunteers completed three different tests to determine leg dominance prior to completing a three grande jeté sequence. The lead leg for the jump sequence was randomised. Peak take-off power, relative landing force (BW), and maximum knee flexion angles were measured using a Myotest accelerometer and integrated goniometer. Results indicated that 90% of dancers reported right leg dominance. A significant difference was noted in peak take-off power among the jumps (p<0.01); post hoc test indicated jump 3 was significantly greater than jump 1. Mean maximum take-off knee angles increased over the three-jump sequence with the left leg having a significantly deeper plié than the right (p<0.01). Landing data showed an increase in peak force and a decrease in maximum knee angles across the jump sequence. The present data indicate different bilateral strategies during take-off and landing during grand jetés in female dancers resulting in increased forces during the jumps on the non-dominant side. These differences need to be addressed by incorporating appropriate modifications in training methodology that eliminates the observed bilateral differences.
    • Body mass index, nutritional knowledge, and eating behaviors in elite student and professional ballet dancers.

      Wyon, Matthew; Hutchings, Kate M; Wells, Abigail; Nevill, Alan M (Wolters Kluwer Health, 2014-09)
      Objective: It is recognized that there is a high esthetic demand in ballet, and this has implications on dancers' body mass index (BMI) and eating behaviors. The objective of this study was to examine the association between BMI, eating attitudes, and nutritional knowledge of elite student and professional ballet dancers. Design: Observational design. Setting: Institutional. Participants: One hundred eighty-nine participants from an elite full-time dance school (M = 53, F = 86) and from an elite ballet company (M = 16, F = 25) volunteered for the study. There were no exclusion criteria. Interventions: Anthropometric data (height and mass), General Nutrition Knowledge Questionnaire (GNKQ), and the Eating Attitude Test—26 (EAT-26) were collected from each participant. Main Outcome Measures: Univariate analysis of variance was used to examine differences in gender and group for BMI, GNKQ, and EAT-26. Regression analyses were applied to examine interactions between BMI, GNKQ, and EAT-26. Results: Professional dancers had significantly greater BMI than student dancers (P < 0.001), and males had significantly higher BMI scores than females (P < 0.05). Food knowledge increased with age (P < 0.001) with no gender difference. Student dancers had a significant interaction between year group and gender because of significantly higher EAT-26 scores for females in years 10 and 12. Regression analysis of the subcategories (gender and group) reported a number of significant relationships between BMI, GNKQ, and EAT-26. Conclusions: The findings suggest that dancers with disordered eating also display lower levels of nutritional knowledge, and this may have an impact on BMI. Female students' eating attitudes and BMI should especially be monitored during periods of adolescent development.
    • A cross-over experiment to investigate possible mechanisms for lower BMIs in people who habitually eat breakfast

      Reeves, S; Huber, JW; Halsey, LG; Villegas-Montes, M; Elgumati, J; Smith, T; Department of Life Sciences, University of Roehampton, London, UK. (Springer Science and Business Media LLC, 2015-01-07)
      © 2015 Macmillan Publishers Limited. The body mass index (BMI) of breakfast eaters is frequently reported to be lower compared with that of breakfast skippers. This is not explained by differences in energy intakes, indicating there may be other mechanisms serving to drive this paradoxical association between breakfast and BMI. This study aimed to investigate the effect of eating breakfast versus morning fasting on measures predominantly of metabolism in lean and overweight participants who habitually eat or skip breakfast.Subjects/Methods:Participants (n=37) were recruited into four groups on the basis of BMI (lean and overweight) and breakfast habit (breakfast eater and breakfast skipper). Participants were randomly assigned to a breakfast experimental condition, breakfast eating or no breakfast, for 7 days and then completed the alternative condition. At the end of each breakfast experimental condition, measurements were made before and after a high carbohydrate breakfast of 2274±777 kJ or a rest period. Resting metabolic rate, thermic effect of food (TEF), blood glucose, insulin and leptin levels were recorded. Hunger and 'morningness' were assessed and pedometers worn.Results:Lean participants had lower fasting insulin levels (P=0.045) and higher insulin concentrations following breakfast (P=0.001). BMI and breakfast habit did not interact with the experimental breakfast condition, with the exception of hunger ratings; breakfast eaters were hungrier in the mornings compared with breakfast skippers in the no breakfast condition (P=0.001).Conclusions:There is little evidence from this study for a metabolic-based mechanism to explain lower BMIs in breakfast eaters.
    • Decay uncovered in nonverbal short-term memory.

      Mercer, Tom; McKeown, Denis (Springer, 2014-02)
      Decay theory posits that memory traces gradually fade away over the passage of time unless they are actively rehearsed. Much recent work exploring verbal short-term memory has challenged this theory, but there does appear to be evidence for trace decay in nonverbal auditory short-term memory. Numerous discrimination studies have reported a performance decline as the interval separating two tones is increased, consistent with a decay process. However, most of this tone comparison research can be explained in other ways, without reference to decay, and these alternative accounts were tested in the present study. In Experiment 1, signals were employed toward the end of extended retention intervals to ensure that listeners were alert to the presence and frequency content of the memoranda. In Experiment 2, a mask stimulus was employed in an attempt to distinguish between a highly detailed sensory trace and a longer-lasting short-term memory, and the distinctiveness of the stimuli was varied. Despite these precautions, slow-acting trace decay was observed. It therefore appears that the mere passage of time can lead to forgetting in some forms of short-term memory.
    • Development of an accelerometer-based multivariate model to predict free-living energy expenditure in a large military cohort.

      Horner, Fleur; Bilzon, James L; Rayson, Mark; Blacker, Sam; Richmond, Victoria; Carter, James; Wright, Anthony; Nevill, Alan M. (2013)
      This study developed a multivariate model to predict free-living energy expenditure (EE) in independent military cohorts. Two hundred and eighty-eight individuals (20.6 ± 3.9 years, 67.9 ± 12.0 kg, 1.71 ± 0.10 m) from 10 cohorts wore accelerometers during observation periods of 7 or 10 days. Accelerometer counts (PAC) were recorded at 1-minute epochs. Total energy expenditure (TEE) and physical activity energy expenditure (PAEE) were derived using the doubly labelled water technique. Data were reduced to n = 155 based on wear-time. Associations between PAC and EE were assessed using allometric modelling. Models were derived using multiple log-linear regression analysis and gender differences assessed using analysis of covariance. In all models PAC, height and body mass were related to TEE (P < 0.01). For models predicting TEE (r (2) = 0.65, SE = 462 kcal · d(-1) (13.0%)), PAC explained 4% of the variance. For models predicting PAEE (r (2) = 0.41, SE = 490 kcal · d(-1) (32.0%)), PAC accounted for 6% of the variance. Accelerometry increases the accuracy of EE estimation in military populations. However, the unique nature of military life means accurate prediction of individual free-living EE is highly dependent on anthropometric measurements.
    • Do increases in selected fitness parameters affect the aesthetic aspects of classical ballet performance?

      Twitchett, Emily A; Angioi, Manuela; Koutedakis, Yiannis; Wyon, Matthew A. (2011-03)
      Research has indicated that classical ballet dancers tend to have lower fitness levels and increased injury rates compared to other athletes with similar workloads. The aim of the current study was to examine the effects of a specifically tailored fitness training programme on the incidence of injury and the aesthetic quality of performance of classical ballet dancers compared to a control group. Proficiency in performance was evaluated at the beginning and end of the intervention period for both groups through a 4-min dance sequence using previously ratified marking criteria. The intervention group (n = 8) partook in a weekly 1-hr training session that included aerobic interval training, circuit training, and whole body vibration. All dancers' performance proficiency scores increased from pre-intervention testing to post-intervention. The intervention group's overall performance scores demonstrated a significantly greater increase (p = 0.03) than the equivalent for the control group. It was concluded that supplementary fitness training has a positive effect on aspects related to aesthetic dance performance as studied herein; further research is recommended on a larger and more varied sample. Practical applications from this study suggest that supplemental training should be part of a ballet dancer's regime, and minimal intervention time is required to have observable effects.
    • The effects of muscle damage on walking biomechanics are speed-dependent.

      Tsatalas, Themistoklis; Giakas, Giannis; Spyropoulos, Giannis; Paschalis, Vassilis; Nikolaidis, Michalis G.; Tsaopoulos, Dimitrios E; Theodorou, Anastasios A.; Jamurtas, Athanasios Z.; Koutedakis, Yiannis (Springer-Verlag, 2010)
      The purpose of the present study was to examine the effects of muscle damage on walking biomechanics at different speeds. Seventeen young women completed a muscle damage protocol of 5 × 15 maximal eccentric actions of the knee extensors and flexors of both legs at 60°/s. Lower body kinematics and swing-phase kinetics were assessed on a horizontal treadmill pre- and 48 h post-muscle damaging exercise at four walking speeds. Evaluated muscle damage indices included isometric torque, delayed onset muscle soreness, and serum creatine kinase. All muscle damage indices changed significantly after exercise, indicating muscle injury. Kinematic results indicated that post-exercise knee joint was significantly more flexed (31-260%) during stance-phase and knee range of motion was reduced at certain phases of the gait cycle at all speeds. Walking post-exercise at the two lower speeds revealed a more extended knee joint (3.1-3.6%) during the swing-phase, but no differences were found between pre- and post-exercise conditions at the two higher speeds. As speed increased, maximum dorsiflexion angle during stance-phase significantly decreased pre-exercise (5.7-11.8%), but remained unaltered post-exercise across all speeds (p > 0.05). Moreover, post-exercise maximum hip extension decreased (3.6-18.8%), pelvic tilt increased (5.5-10.6%), and tempo-spatial differences were found across all speeds (p < 0.05). Limited effects of muscle damage were observed regarding swing-phase kinetics. In conclusion, walking biomechanics following muscle damage are affected differently at relatively higher walking speeds, especially with respect to knee and ankle joint motion. The importance of speed in evaluating walking biomechanics following muscle damage is highlighted.
    • The effects of pre-game carbohydrate intake on running performance and substrate utilisation during simulated Gaelic football match play

      O'Brien, Luke; Collins, Kieran; Webb, Richard; Davies, Ian; Doran, Dominic; Amirabdollahian, Farzad; School of Health Sciences, Liverpool Hope University, Liverpool L16 9JD, UK. (MDPI, 2021-04-21)
      Previous research has reported that elite Gaelic football players' carbohydrate (CHO) intakes are sub-optimal, especially, in the lead up to competitive matches. Despite clear decrements in running performance across elite Gaelic football matches, there are no studies that have investigated nutrition interventions on match-related Gaelic football performance. The aim of this study was to determine whether a higher-CHO diet in line with sports nutrition guidelines can improve Gaelic football-related performance compared to lower CHO intakes previously observed in Gaelic footballers. Twelve Gaelic football players completed a Gaelic football simulation protocol (GFSP) on two occasions after consuming a high-CHO diet (7 g·kg-1) (HCHO) or an energy-matched lower-CHO diet (3.5 g·kg-1) (L-CHO) for 48 h. Movement demands and heart rate were measured using portable global positioning systems devices. Countermovement jump height (CMJ) and repeated-sprint ability (RSA) were measured throughout each trial. Expired respiratory gases were collected throughout the trial using a portable gas analyser. Blood samples were taken at rest, half-time, and post-simulation. There was no significant difference in total distance (p = 0.811; η2 = 0.005) or high-speed running distance (HSRD) covered between both trials. However, in the second half of the HCHO trial, HSRD was significantly greater compared to the second half of the LCHO trial (p = 0.015). Sprint distance covered during GFSP was significantly greater in HCHO (8.1 ± 3.5 m·min-1) compared with LCHO (6.4 ± 3.2 m·min-1) (p = 0.011; η2 = 0.445). RSA performance (p < 0.0001; η2 = 0.735) and lower body power (CMJ) (p < 0.0001; η2 = 0.683) were significantly greater during the HCHO trial compared to LCHO. Overall CHO oxidation rates were significantly greater under HCHO conditions compared to LCHO (3.3 ± 0.5 vs. 2.7 ± 0.6 g·min-1) (p < 0.001; η2 = 0.798). Blood lactate concentrations were significantly higher during HCHO trial versus LCHO (p = 0.026; η2 = 0.375). There were no significant differences in plasma glucose, non-esterified fatty acids (NEFAs), and glycerol concentration between trials. In both trials, all blood metabolites were significantly elevated at half-time and post-trial compared to pre-trial. These findings indicate that a higher-CHO diet can reduce declines in physical performance during simulated Gaelic football match play.
    • Effects of self-esteem on the association between negative life events and suicidal ideation in adolescents

      Wan, Yuhui; Chen, Ruoling; Wang, Shan-Shan; Orton, Sophie; Wang, Danni; Zhang, Shichen; Sun, Ying; Tao, Fangbiao; Department of Maternal, Child & Adolescent Health, School of Public Health, Anhui Medical University, Hefei 230032, China. (MDPI AG, 2019-08-09)
      © 2019 by the authors. Licensee MDPI, Basel, Switzerland. Negative life events (NLEs) increase the risk of suicidal ideation (SI) in adolescents. However, it is not known whether the association between NLEs and SI can be moderated by self-esteem and varies with gender. The aim of the current paper was to examine gender differences in the association of SI with NLEs in adolescents, and assess the effects of self-esteem on the association and their gender variations. We conducted a school-based health survey in 15 schools in China between November 2013 and January 2014. A total of 9704 participants aged 11–19 years had sociodemographic data reported and self-esteem (Rosenberg self-esteem scale), NLEs, and SI measured. Multivariate-adjusted logistic regression was used to calculate the odds ratio (OR) of having SI in relation to NLEs. Increased risk of SI was significantly associated with NLEs (adjusted OR 2.19, 95%CI 1.94–2.47), showing no gender differences (in females 2.38, 2.02–2.80, in males 1.96, 1.64–2.36, respectively). The association was stronger in adolescents with high esteem (2.93, 2.34–3.68) than those with low esteem (2.00, 1.65–2.42) (ORs ratio 1.47, p = 0.012). The matched figures in females were 3.66 (2.69–4.99) and 2.08 (1.61–2.70) (1.76, p = 0.006), while in males these figures were 2.27(1.62–3.19) and 1.89 (1.41–2.53) (1.20, p = 0.422), respectively. Self-esteem had moderate effects on the association between NLEs and SI in adolescents, mainly in females. NLEs, self-esteem, and gender need to be incorporated into future intervention programs to prevent SI in adolescents.
    • Effects of supplemental training on fitness and aesthetic competence parameters in contemporary dance: a randomised controlled trial.

      Angioi, Manuela; Metsios, George; Twitchett, Emily A; Koutedakis, Yiannis; Wyon, Matthew A. (Science & Medicine, Inc., 2012-03)
      Within aesthetic sports such as figure skating and rhythmic gymnastics, physical fitness has been shown to have positive benefits on performance outcomes. Presently the link between physical fitness and aesthetic contemporary dance performance has not been demonstrated within an intervention study. In this study, 24 females engaged in contemporary dance (age 27 ± 5.9 yrs; height 165.3 ± 4.8 cm; weight 59.2 ± 7.6 kg) were recruited and randomly assigned to either an exercise (n = 12) or a control group (n = 12). Three dancers withdrew during the study. The intervention group completed a 6-week conditioning programme comprising two 1-hr sessions of circuit and vibration training per week. The circuit training focused on local muscular endurance and aerobic conditioning and vibration training protocol concentrated on power. Repeated measures ANOVA revealed significant increases for the conditioning group in lower body muscular power (11%), upper body muscular endurance (22%), aerobic fitness (11%), and aesthetic competence (12%) (p < 0.05). The control group reported decreases in all the fitness parameters with the exception of aerobic fitness as well as a decrease in aesthetic competence (7%). A 6-week circuit and vibration training programme, which supplemented normal dance commitments, revealed significant increases in selected fitness components and a concomitant increase in aesthetic competence in contemporary professional and student dancers.
    • Fit to dance survey: a comparison with dancesport injuries

      Riding McCabe, Teri; Ambegaonkar, Jatin; Redding, Emma; Wyon, Matthew (Science & Medicine, 2014-06)
      The Fit to Dance survey has been conducted twice previously, in 1993 and 2002, without dancesport participants. The purpose of this present online survey was to supplement a comparison of dancesport against the earlier results. The current study had a greater percentage of male respondents than previous studies (43% vs 24% and 26%). The dancesport participants were older (28% at 40+ yrs vs 3% and 1%) and more likely to have normal (69% vs 57%) to overweight BMI (18% vs 2%). Dancesport participants spent more time in various non-dancing conditioning activities than previous surveys (5.2 ± 3.9 hrs SD vs 1.9 ± 2.5 and 2.2 ± 2.7). Muscles and joints were the most common type of injury in all the surveys. The knee was the top injury site in this survey, with lower back in previous surveys. The main perceived cause of injury was repetitive movements, whereas fatigue and overwork were cited in the previous surveys. Physiotherapists were the most common type of medical professionals from whom the dancers sought treatment for their injuries in all surveys. The first survey included recommendations that the present survey results agree with, including: dancers should be physically fit, dancers should warm up and cool down, dancers should never have to work in unsuitable environments, and dancers should receive immediate high-quality treatment for injuries.
    • Identification of candidate tumour suppressor genes frequently methylated in renal cell carcinoma

      Morris, MR; Ricketts, C; Gentle, D; Abdulrahman, M; Clarke, N; Brown, M; Kishida, T; Yao, M; Latif, F; Maher, ER; et al. (Springer Nature, 2010-02-15)
      Promoter region hyermethylation and transcriptional silencing is a frequent cause of tumour suppressor gene (TSG) inactivation in many types of human cancers. Functional epigenetic studies, in which gene expression is induced by treatment with demethylating agents, may identify novel genes with tumour-specific methylation. We used high-density gene expression microarrays in a functional epigenetic study of 11 renal cell carcinoma (RCC) cell lines. Twenty-eight genes were then selected for analysis of promoter methylation status in cell lines and primary RCC. Eight genes (BNC1, PDLIM4, RPRM, CST6, SFRP1, GREM1, COL14A1 and COL15A1) showed frequent (30% of RCC tested) tumour-specific promoter region methylation. Hypermethylation was associated with transcriptional silencing. Re-expression of BNC1, CST6, RPRM and SFRP1 suppressed the growth of RCC cell lines and RNA interference knock-down of BNC1, SFRP1 and COL14A1 increased the growth of RCC cell lines. Methylation of BNC1 or COL14A1 was associated with a poorer prognosis independent of tumour size, stage or grade. The identification of these epigenetically inactivated candidate RCC TSGs can provide insights into renal tumourigenesis and a basis for developing novel therapies and biomarkers for prognosis and detection. © 2010 Macmillan Publishers Limited.
    • Instruments to assess secondhand smoke exposure in large cohorts of never smokers: The smoke scales

      Misailidi, M; Tzatzarakis, MN; Kavvalakis, MP; Koutedakis, Y; Tsatsakis, AM; Flouris, AD; FAME Laboratory, Centre for Research and Technology Hellas, Trikala, Greece ; Department of Exercise Sciences, University of Thessaly, Trikala, Greece ; Regional Directorate of Primary and Secondary Education of Western Greece, Patras, Greece. (Public Library of Science (PLoS), 2014-01-21)
      The objectives of this study were to: (i) to develop questionnaires that can identify never-smoking children and adults experiencing increased exposure to secondhand smoke (SHS+), (ii) to determine their validity against hair nicotine, and (iii) assess their reliability. A sample of 191 children (85 males; 106 females; 7-18 years) and 95 adult (23 males; 72 females; 18- 62 years) never-smokers consented to hair nicotine analysis and answered a large number of questions assessing all sources of SHS. A randomly-selected 30% answered the questions again after 20-30 days. Prevalence of SHS+ in children and adults was 0.52±0.07 and 0.67±0.10, respectively (p<0.05). The Smoke Scale for Children (SS-C) and the Smoke Scale for Adults (SS-A) were developed via factor analysis and included nine questions each. Positivity criteria for SS-C and SS-A via receiver operating characteristics curve analysis were identified at >16.5 and >16, respectively. Significant Kappa agreement (p<0.05) was confirmed when comparing the SS-C and SS-A to hair nicotine concentration. Reliability analyses demonstrated that the SS-C and SS-A scores obtained on two different days are highly correlated (p<0.001) and not significantly different (p>0.05). Area under the curve and McNemar's Chi-square showed no pair-wise differences in sensitivity and specificity at the cutoff point between the two different days for SS-C and SS-A (p>0.05). We conclude that the SS-C and the SS-A represent valid, reliable, practical, and inexpensive instruments to identify children and adult never-smokers exposed to increased SHS. Future research should aim to further increase the validity of the two questionnaires. © 2014 Misailidi et al.
    • Internet gamblers: a latent class analysis of their behaviours and health experiences.

      Lloyd, Joanne; Doll, Helen; Hawton, Keith; Dutton, William H; Geddes, John R; Goodwin, Guy M; Rogers, Robert D (Springer Link, 2010-09)
      In order to learn about the behaviours and health experiences of people who gamble on the Internet, we conducted an international online survey with respondents recruited via gambling and gambling-related websites. The mean (SD) age of the 4,125 respondents completing the survey was 35.5 (11.8) years, with 79.1% being male and 68.8% UK residents. Respondents provided demographic details and completed validated psychometric screening instruments for problem gambling, mood disturbances, as well as alcohol and substance misuse, and history of deliberate self harm. We applied latent class analysis to respondents' patterns of regular online gambling activities, and identified subgroups of individuals who used the Internet to gamble in different ways (L (2) = 44.27, bootstrap P = 0.07). We termed the characteristic profiles as 'non-to-minimal gamblers'; 'sports bettors'; 'casino & sports gamblers'; 'lottery players'; and 'multi-activity gamblers'. Furthermore, these subgroups of respondents differed on other demographic and psychological dimensions, with significant inter-cluster differences in proportion of individuals scoring above threshold for problem gambling, mood disorders and substance misuse, and history of deliberate self harm (all Chi (2)s > 23.4, all P-values <0.001). The 'casino & sports' and 'multi-activity-gamblers' clusters had the highest prevalence of mental disorder. Internet gamblers appear to be heterogeneous but composed of several subgroups, differing markedly on both demographic and clinical characteristics.