Children's eating behaviours: The importance of the family setting

Childhood obesity has become a major public health challenge. Whilst it is accepted that the aetiology of obesity is complex, there is very little that targets the home environment and specifically looks at the family setting and how this influences children's eating behaviours. This research aimed to redress the balance by alerting people to the importance of the family environment as a contributory factor for childhood obesity. Using a grounded theory approach, 'Ordering of eating' highlights the importance of the family setting and demonstrates how micro and macro order influences the development of children's eating behaviours. © Journal compilation © 2008 Royal Geographical Society (with the Institute of British Geographers)

In a World of its Own: How Operative Closure Limits the Law's Ability to Protect Children from Maltreatment.

New Zealand's figures for child maltreatment are consistently amongst the highest in the OECD. The purpose of this thesis is to understand what the legal system can do to protect children in New Zealand from maltreatment and why legal responses to child maltreatment often appear to be ineffectual or of limited effect. This thesis uses the theories of Luhman and Teubner to argue that the law's ability to protect children from maltreatment is limited because the legal system creates and responds to its own abstract world. This process arises from the functional requirements of the law and its operation as an autopoietic system of power that produces its own abstract knowledge about the world. The legal system's function within New Zealand society is to stabilise behavioural expectations and maintain society's coherence and it does so by reducing the complexity of subjective human existence into binary alternatives. However, this process of reducing complexity limits the way in which the law produces its knowledge about the world and controls how power is distributed within the law's abstract world to such an extent that the legal system is closed from the world of subjective experience. This closure from the world outside the legal system limits the law's ability to regulate and reform that outside world and protect the children who live within it. By identifying these limits, this thesis will contribute to an understanding of the limits of the law's ability to protect children from maltreatment and thereby improve the effectiveness of New Zealand society's attempts to protect its children

The evolution of body size and sexual size dimorphism in primates

Primates vary widely in respect to body mass, as well as sexual size dimorphism. Despite largely being considered the result of sexual selection, the processes that give rise to sexual size dimorphism are still widely debated, with a number of alternative theories having been and still being proposed. Relatively recent studies have found that allometric relationships among primates follow two prominent and widely cited “rules” of evolutionary biology, Rensch’s rule and Cope’s rule. Using phylogenetic comparative methods that enable the detection of long-term trends from extant data, and by looking at male and female evolutionary history independently, I test the idea that sexual selection for increased male size is not only the primary mechanism behind sexual size dimorphism in primates, but also the observed trends of Cope’s and Rensch’s rule. I find that although multiple processes may lead to sexual size dimorphism in primates, the most extreme cases, those observed in the catarrhines, are most likely the result of selection for larger males. The most notable example of this occurred early on in catarrhine evolution, with several lineages subsequently undergoing further selection on male size. I also find that selection for increased male size in catarrhines as the most likely cause behind the pattern of Rensch’s rule and Cope’s rule observed in primates, suggesting that these “rules” should not in fact be considered allometric rules, but are instead trends that result directly from sexual selection for larger male size. I also find that species adopting polygynous and polygynandrous mating systems are significantly more sexually dimorphic in size than monogamous and polyandrous species. These results open up intriguing new avenues of future study in which the relative roles of natural selection and sexual selection in the evolution of morphological traits can be teased apart, and further light shed on questions that have pervaded evolutionary biology for centuries

The kinematics of batting against fast bowling in cricket

In cricket, batting against a fast bowler is thought to be one of the most challenging tasks a player must undertake. Despite this, minimal research exists investigating the techniques used by batsmen, with the majority of research focussed on injury mechanisms and pace generation in fast bowlers. The aim of this study was to investigate the techniques used by elite and amateur batsmen in a training environment, such that key aspects of batting technique relating to success could be extracted, and recommendations for future coaching practice and player development could be made. A novel methodology was developed for the collection of full body three-dimensional kinematic data of cricket batsmen in a realistic training environment. Kinematic and high-speed video (250 Hz) data were collected for 31 batsmen, and a three-dimensional full body biomechanical model was developed. Batsmen performed forward drive and pull shots against different delivery methods. Key events and kinematic parameters were defined, and used to produce detailed biomechanical descriptions of the forward drive and pull shots. A curve fitting methodology was developed and validated to determine the impact location of the ball on the bat face, and used to investigate the effects of impact location on shot outcome during a range hitting task. Impacts further from the sweetspot were found to generate lower ball speeds and decrease shot accuracy through bat twist. [Continues.

How children eat may contribute to rising levels of obesity children's eating behaviours: An intergenerational study of family influences

The term ‘obesogenic environment’ is rapidly becoming part of common phraseology. However, the influence of the family and the home environment on children's eating behaviours is little understood. Research that explores the impact of this micro environment and intergenerational influences affecting children's eating behaviours is long overdue. A qualitative, grounded theory approach, incorporating focus groups and semi-structured interviews, was used to investigate the family environment and specifically, the food culture of different generations within families. What emerged was a substantive theory based on ‘ordering of eating’ that explains differences in eating behaviours within and between families. Whereas at one time family eating was highly ordered and structured, typified by the grandparent generation, nowadays family eating behaviours are more haphazard and less ordered, evidenced by the way the current generation of children eat. Most importantly, in families with an obese child eating is less ordered compared with those families with a normal weight child. Ordering of eating' is a unique concept to emerge. It shows that an understanding of the eating process is crucial to the development and improvement of interventions targeted at addressing childhood obesity within the family context

The effects of different delivery methods on the movement kinematics of elite cricket batsmen in repeated front foot drives

The aim of this paper was to examine differences in delivery characteristics and the resulting response exhibited by ten elite cricket batsmen when hitting repeated front foot drives against three different ball delivery methods; a bowling machine, a Sidearm™ ball thrower and a bowler. Synchronous three-dimensional Vicon motion capture technology and high-speed video were used to track batsman, bat and ball motion, and a range of discrete timing and kinematic variables were extracted from the resulting biomechanical model. Results showed significant differences in speed and ball release-to-impact time between the three delivery methods, thus questioning the validity of the bowling machine and Sidearm™ in the way they are currently used as true representations of batting against a real life bowler. Findings from the timing and kinematics of the subjects’ movements suggest a different technical response is also exhibited when facing the different delivery methods; for example batters were found to initiate movement earlier and have a lower maximum bat speed against the bowling machine, but initiate and complete their front foot stride earlier as well as moving their COM further forward in the Sidearm™ trials. © 2014 The Authors. Published by Elsevier Ltd

RELATIONSHIPS BETWEEN HITTING TECHNIQUE AND BALL CARRY DISTANCE IN CRICKET

The aim of this study was to identify the technique parameters characterising batsmen who generate large carry distances, ball launch speeds, and bat speeds during a range hitting task in cricket. Kinematic data were collected for 20 batsmen, and a series of ball launch, impact, and technique parameters were calculated for each trial. A regression analysis found impact location relative to the sweetspot and bat speed together to explain 70% of the observed variation in ball speed. A further regression analysis found the maximum X-factor (the separation between the pelvis and thorax segments in the transverse plane), front elbow extension, and wrist uncocking during the downswing explained 66% of the observed variation in bat speed. These findings will be useful in coaching more effective hitters, and in assessing the mechanics of generating bat speed

The effects of different delivery methods on the movement kinematics of elite cricket batsmen in repeated front foot drives

The aim of this paper was to examine differences in delivery characteristics and the resulting response exhibited by ten elite cricket batsmen when hitting repeated front foot drives against three different ball delivery methods; a bowling machine, a Sidearm™ ball thrower and a bowler. Synchronous three-dimensional Vicon motion capture technology and high-speed video were used to track batsman, bat and ball motion, and a range of discrete timing and kinematic variables were extracted from the resulting biomechanical model. Results showed significant differences in speed and ball release-to-impact time between the three delivery methods, thus questioning the validity of the bowling machine and Sidearm™ in the way they are currently used as true representations of batting against a real life bowler. Findings from the timing and kinematics of the subjects’ movements suggest a different technical response is also exhibited when facing the different delivery methods; for example batters were found to initiate movement earlier and have a lower maximum bat speed against the bowling machine, but initiate and complete their front foot stride earlier as well as moving their COM further forward in the Sidearm™ trials. © 2014 The Authors. Published by Elsevier Ltd

Clinical Correlates and Prognostic Significance of the Ventilatory Response to Exercise in Chronic Heart Failure

AbstractObjectives. This study sought to investigate the clinical characteristics of patients with chronic heart failure and an increased ventilatory response to exercise and to examine the prognostic usefulness of this response.Background. The ventilatory response to exercise is increased in many patients with chronic heart failure and may be characterized by the regression slope relating minute ventilation to carbon dioxide output (V̇e–V̇co2slope) during exercise.Methods. One hundred seventy-three consecutive patients (155 men; mean [±SD] age 59.8 ± 11.5 years; radionuclide left ventricular ejection fraction [LVEF] 28.4 ± 14.6%) underwent cardiopulmonary exercise testing (peak oxygen consumption 18.5 ± 7.3 ml/kg per min; V̇e–V̇co2slope 34.8 ± 10.6) over a 2-year period. Using 1.96 standard deviations above the mean V̇e–V̇co2slope of 68 healthy age-matched subjects (mean slope 26.3 ± 4.1), we defined a high ventilatory response to exercise as a slope >34.Results. Eighty-three patients (48%) had an increased V̇e–V̇co2slope (mean 43.1 ± 8.9). There was a difference in age (62.2 vs. 57.3 years, p = 0.005), New York Heart Association functional class (2.9 vs. 2.1, p < 0.001), LVEF (24.7 vs. 31.9%, p = 0.0016), peak oxygen consumption (14.9 vs. 21.7 ml/kg per min, p < 0.0001) and radiographic cardiothoracic ratio (0.58 vs. 0.55, p = 0.002) between these patients and those with a normal slope. In the univariate Cox proportional hazards model, the V̇e–V̇co2slope was an important prognostic factor (p < 0.0001). In the multivariate Cox analyses using several variables (age, peak oxygen consumption, V̇e–V̇co2slope and LVEF), the V̇e–V̇co2slope gave additional prognostic information (p = 0.018) beyond peak oxygen consumption (p = 0.022). Kaplan-Meier survival curves at 18 months demonstrated a survival rate of 95% in patients with a normal V̇e–V̇co2slope compared with 69% in those with a high slope (p < 0.0001).Conclusions. A high V̇e–V̇co2slope selects patients with more severe heart failure and is an independent prognostic marker. The V̇e–V̇co2slope may be used as a supplementary index in the assessment of patients with chronic heart failure.(J Am Coll Cardiol 1997;29:1585–90