Integration of aerobic power into the morphological-motor system in children aged 7-11 years

The aim of the study was to analyze integration of aerobic power into other dimensions evaluated. For this purpose, predictor relations of the morphological-motor variables were analyzed with a 3-minute run as a criterion (according to school grade and sex). Four morphological and 6 motor variables covering the morphological-motor system were used in a sample of 4,440 children of both sexes aged 7-11 years, elementary school first- to four-graders from the Primorje-Gorski Kotar County, Republic of Croatia, divided into 8 groups. Data were processed by use of regression analysis. Study results clearly showed the values of the criterion variable to rise and criterion prediction using the set of predictor variables to improve with age. Also, the number of predictors included in power run prediction was observed to significantly increase with age. Strength factors with a predominance of explosive strength and repetitive strength in boys and girls, respectively, were the best criterion predictors. It is emphasized that development of the morphological-motor system and thus functioning of the body as a whole are influenced by aerobic power upgrading. Appropriate systematic kinesiologic activities accelerate the process of aerobic power integration in the morphological-motor system. As indicated by study results, this integration occurred at a faster rate and was more intensive in girls than in boys.     

Development of biomotor characteristics and sprint and throw athletic abilities in six- to eight-year-old girls

The aim of the study was to assess the effect of programmed physical education on biomotor changes in girls, and the impact of these changes on relations between the set of morphological and motor variables, and athletic variables evaluating the sprint and throw abilities. Study sample included 310 six- to eight-year-old girls, elementary school first-graders from the Split area, divided into control group (n = 138) attending regular physical education classes and experimental group (n = 172) attending programmed physical education classes based on the elements of athletics, apparatus gymnastics, games and general preparatory exercises. Relations between the predictor set of variables consisting of 4 morphological measures and 6 motor tests, and the sprint and ball throw criteria were determined by regression correlation analysis at the beginning and at the end of the academic year. Both groups achieved favorable quantitative result improvement between the two measurement points, however, the improvement was considerably more pronounced in experimental group, especially in the motor abilities of coordination, flexibility, movement frequency, and explosive, repetitive and static strength. On final measurement, the number of significant predictors for the criterion variables of sprint and ball throw increased from the initial measurement in both experimental and control group of subjects. In control group, trunk strength, explosive strength and movement frequency as motor abilities and body height as a morphological characteristic were found to be the best result predictors in sprint. In experimental group, coordination, flexibility, static arm strength and trunk strength as motor abilities were the best result predictors in sprint. In the study sample as a whole, explosive strength and trunk strength were identified as the best predictors of ball throw as a criterion variable. In experimental group, it was accompanied by muscle mass development and adipose tissue reduction. Based on comparison of these results and those obtained in previous studies, a new model of work in the athletics events of sprint and throw in elementary school physical education is proposed.     

Effects of biomotor structures on performance of competitive gymnastics elements in elementary school female sixth-graders

In order to identify biomotor systems that determine performance of competitive gymnastics elements in elementary school female sixth-graders, factor structures of morphological characteristics and basic motor abilities were determined first, followed by relations of the morphological-motor system factors obtained with a set of criterion variables evaluating specific motor skills in competitive gymnastics in 126 female children aged 12 years +/- 3 months. Factor analysis of 17 morphological measures yielded three morphological factors: factor of mesoendomorphy and/or adipose body voluminosity; factor of longitudinal body dimensionality; and factor of transverse arm dimensionality. Factor analysis of 16 motor variables produced four motor factors: general motoricity factor (motor system); general speed factor; factor of explosive strength of throwing type (arm explosiveness); and factor of arm and leg flexibility. Three significant canonical correlations, i.e. linear combinations, explained the association between the set of seven latent variables of the morphological and basic motor system, and five variables evaluating the knowledge in competitive gymnastics. The first canonical linear combination was based on a favorable and predominant impact of the general motor factor (a system integrating whole body coordination, leg explosiveness, relative arm strength, arm movement frequency and body flexibility) on performance of gymnastics elements, cartwheel, handstand and backward pullover mount in particular, and to a lesser extent front scale and double leg pirouette for 180 degrees. The relation of the second pair of canonical factors additionally explained the role of transverse dimensionality of arm skeleton, arm flexibility and explosiveness in performing cartwheel and squat vault, whereas the relation of the third pair of canonical factors explained the unfavorable impact of adipose voluminosity on the performance of squat vault and backward pullover mount.     

Biomotor development in 1992 and 2002 samples of seven-year-old children

The aim of the study was to determine quantitative and qualitative differences in the morphological-motor status between elementary school first-graders of both sexes in 1992 and 2002. A standard set of 11 variables currently used in the Croatian school system to evaluate the morphological, motor and functional status of school children was employed at the beginning of academic years in a sample of 635 children (325 male and 310 female) in 1992 and a sample of 850 children (430 male and 420 female) in 2002. The mean age of study children was 7 years (+/- 2 months). Results of canonic discriminative analysis revealed the male children enrolled in elementary school first grade in 2002 to show better performance on the tests of aerobic endurance, static strength and explosive strength, and to have greater mass of muscle tissue and less adipose tissue, while achieving poorer results on the test of movement frequency than their 1992 counterparts. Female children tested in 2002 showed better results on the test of aerobic endurance and all tests of strength factors, with greater mass of muscle tissue and less adipose tissue, while yielding poorer results on the tests of flexibility, coordination and movement frequency as compared with their 1992 counterparts. Factor analysis in the morphological-motor system isolated three varimax factors each in children of both sexes tested in 1992 and 2002. First factor showed a pattern of a general morphological factor predominantly defined by body weight and volume in the children of both sexes from both study years. Second factor showed a pattern of a general motoricity factor predominantly defined by explosive strength, coordination and speed in children tested in 1992, whereas in their 2002 counterparts the general motoricity factor was predominantly defined by the factors of strength and endurance. Third factor was defined by flexibility in both 1992 and 2002 children. In female children tested in 1992, second factor mostly defined energy regulation with predominance of explosive and static strength, followed by coordination, whereas third factor was defined by movement frequency and aerobic endurance. In female children tested in 2002, second factor mostly defined energy regulation with predominance of explosive and repetitive strength, followed by aerobic endurance and coordination, whereas third factor was defined by movement frequency followed by muscle tone regulation.     

Sex differences in motor characteristics of elementary school children included/not included in swimming training

The aim of the study was to assess the development of motor abilities in elementary school fifth- to eighth-graders (age 11-14 years) according to sex, age and physical activity. Study sample included 312 subjects divided according to age and sex into four groups: male subjects aged 11-12 (n = 93) and 13-14 years (n = 84); and female subjects aged 11-12 (n = 65) and 13-14 years (n = 70). Then, differences in basic motor abilities between children included (experimental group) and those not included (control group) in swimming training were analyzed. In male fifth- and sixth-graders, experimental group was superior to control group in the variables of trunk repetitive strength, sprint, flexibility and coordination, while in male seventh- and eighth-graders experimental group showed better performance than control group in agility, aerobic endurance and explosive throw and jump strength. In female fifth- and sixth-graders, experimental group proved superior to control group in the variables of explosive strength, coordination, trunk strength and aerobic endurance, whereas in female seventh- and eighth-graders experimental group had better performance in coordination, endurance, explosive strength, speed and flexibility. Discriminative analysis of motor variables between male and female subjects revealed male subjects to be superior in explosive strength, throw strength in particular, coordination and aerobic endurance, whereas female subjects showed better performance in the variables of flexibility and movement frequency, leg movement in particular. Study results showed the formation of appropriate motor system determining achievement of top results in swimming to be influenced by swimming training from age 11 to 14. In male children, motor system was found to integrate coordination/agility, aerobic endurance and explosive strength, whereas in female children it integrated coordination in terms of cortical movement regulation, aerobic endurance, explosive strength and psychomotor speed.     

Effects of biomotor structures on performance of competitive gymnastics elements in elementary school male sixth-graders

In order to identify the biomotor systems that determine performance of competitive gymnastics elements in elementary school male sixth-graders, factor structures of morphological characteristics and basic motor abilities were determined first, followed by relations of the morphological-motor system factors obtained with a set of criterion variables evaluating specific motor skills in competitive gymnastics in 110 male children aged 12 years +/- 3 months. Factor analysis of 17 morphological measures produced three morphological factors: factor of mesoectoendomorphy (general morphological factor) and factor of pronounced endomorphy, i.e. excessive adipose tissue, along with low skeleton longitudinality. Factor analysis of 16 motor variables yielded four motor factors: factor of general motoricity; factor integrating leg flexibility and arm explosiveness; factor juxtaposing body flexibility and repetitive leg strength; and factor predominantly defining leg movement frequency. Three significant canonical correlations, i.e. linear combinations, explained the association between the set of six latent variables of the morphological and basic motor system, and five variables assessing the knowledge in competitive gymnastics. The first canonical linear combination was based on the favorable and predominant impact of the general motor factor (a system integrating leg explosiveness, whole body coordination, relative arm and trunk strength, and arm movement frequency), along with unfavorable effect of morphological factors on the gymnastics elements performance, squat vault and handstand in particular The relation of the second pair of canonical factors pointed to the effects of leg flexibility and arm explosiveness on the cartwheel and backward pullover mount performance, whereas the relation of the third pair of canonical factors showed a favorable impact of the general morphological factor and leg movement frequency regulator on the forward shoulderkip from increase, cartwheel and handstand performance.     

The mechanisms of morphological-motor functioning in elementary school female first- to fourth-graders

Four morphological and 7 motor variables were assessed in a sample of 2,235 female children (subdivided into 4 groups) aged 7-11 years, elementary school first- to fourth-graders from the Primorje-Gorski Kotar County, Republic of Croatia. The study objective was to analyze the morphological-motor structures according to age. Factor analysis was done for each of the four subject groups. Results clearly showed the morphological-motor functioning of the girls to change with age. Developmental processes lead to the formation of a general morphological factor defined as ectomesomorph and two general mechanisms responsible for motor efficiency in the form of strength regulation and speed regulation. The results obtained were found to be consistent with the existing relevant models related to the morphological, motor, functional and cognitive systems. The more so, these results allow for a supramodel to design, which will integrate relevant elements of all these models to define the function of the body as a whole.     

Development of biomotor characteristics and athletic abilities of sprint and throw in boys aged six to eight years

The aim of this research was to examine the influences of specially programmed physical education lessons on biomotor development in boys, as well as the influence of those changes on relations between the set of morphological and motor variables and athletic variables for the assessment of sprint and throw abilities. For this purpose, an overall sample of 325 primary school first grade pupils from the city of Split area, aged 6-8 years, was divided into control group of subjects (N=140) attending regular physical education lessons and experimental group attending specially programmed lessons based on athletics, sports gymnastics and games elements as well as on general preparatory exercises. The relations between the predictor set of variables composed of 4 morphological measurements and 6 motor tests with the criteria of sprint and ball throwing were established by the regression correlation analysis at the beginning and at the end of the academic year Both groups of subjects achieved positive quantitative resultant shift between the two points of measurements, whereas this shift was more significant in the experimental group in relation to the control group, especially in motor abilities coordination of flexibility, movement frequency and of explosive, repetitive and static strength. The number of significant predictors for criteria variables of sprint and ball throwing increased in the final measurement in relation to the first one in both groups of subjects. While in the control group the best results predictor in sprint were the motor abilities of explosive strength and trunk strength, the best results predictor in sprint in the experimental group were coordination, trunk strength, flexibility and explosive strength. As far as the morphological characteristics are concerned muscle mass has a positive and body mass a negative effect on the sprint result. The best results predictor in ball throwing are explosive strength and trunk strength which, in the experimental group of pupils are additionally followed by coordination development as well as the overall body mass development. By comparison of these and the earlier obtained results, a new work model for the disciplines of sprint and throws within the athletic sport school, has been proposed.     

Motor abilities at belly dance in elementary female schoolers

The aim of the study was to determine the relation between motor abilities and belly dance performance in elementary school fifth- and sixth-grade female students. A battery of 19 motor tests was used in a sample of 96 students twice, i.e. at the beginning (initial measurement) and at the end (final measurement) of the academic year. On initial measurement, five factors were isolated by the motor space factor analysis: first factor of muscular-aerobic endurance; second factor integrating the strength of legs, coordination of foot and hand movement, and agility; third factor integrating explosive strength of the arms with speed and body coordination; fourth factor defined by flexibility (muscle tone regulation); and fifth factor integrating explosive strength of legs with equilibrium. On final measurement, five factors were isolated as well: first factor as a general one integrating coordination abilities, explosive strength of legs and flexibility; second factor defined by repetitive strength of the trunk and legs; third factor defined by rhythm coordination accompanied by flexibility; fourth factor predominantly defined by equilibrium (accompanied by explosive strength of throwing type and speed); and fifth factor predominantly defined by static strength of arms and legs (accompanied by arm movement frequency). On initial measurement, fourth factor responsible for muscle tone regulation and second factor integrating the strength of legs, coordination of movement frequency of arms and legs, and agility were found to be the best predictors of belly dance performance. In this setting, the tests of forward bow (flexibility) and sit-ups (repetitive strength of abdominal musculature) proved superior in differentiating high performance students and those less successful in belly dance. On final measurement, third factor named rhythm coordination (accompanied by muscle tone regulation) and second factor defined by repetitive strength of the trunk and legs were the best predictors of belly dance performance. In this setting, the tests of rhythm coordination, flexibility tests, tests of repetitive strength of the trunk and legs, and test of aerobic endurance proved superior in differentiating high performance and less successful students in belly dance.     

A new model of selection in women's handball

The aim of the study was to assess the basic motor abilities that determine top performance in women's handball, and to identify test panel for primary selection at handball school. The study included 155 female attendants of the Split Handball School, mean age 12.5 years. Differences in the basic motor abilities between the subjects that developed into elite handball players after 7-year training process and those that abandoned handball for being unable to meet the competition criteria were evaluated by use of discriminative analysis. The former were found to have also been superior initially in all variables analyzed, and in arm coordination, overall body coordination, throw and jump explosive strength, arm movement frequency and repetitive trunk strength in particular. Motor superiority based on the abilities of coordination, explosive strength and speed determines performance in women's handball, qualifying these abilities as reliable selection criteria. Based on this study results, a new model of selection in women's handball, with fine arm coordination as the major limiting factor of performance, has been proposed.     

Motor abilities in dance structure performance in female students

The aim of the study was to analyze the relation between motor abilities and performance in folk dances originating from the island of Hvar and modern social dances. Two groups of variables were used in a sample of 78 female students of the Teacher Training College from Split: 7 motor variables as a battery of predictors, and performance evaluation of 4 dances (2 folk dances, i.e. ciciliona and pasavijen, and 2 social dances, i.e. cha-cha-cha and rock-'n'-roll) as criterion variables. Canonical correlation analysis between the groups of variables yielded two canonical correlations of 0.94 and 0.73, with a level of significance of p<0.001. The first canonical correlation was based on marked determination of coordination and ciciliona dance, and the second one on explosive strength of the running type with below-average coordination and the cha-cha-cha, rock-'n'-roll and pasavijen dances. Regression analysis indicated the battery of motor variables used to be a good predictor of performance in all study dances, with multiple correlation of 0.93 in ciciliona, 0.84 in pasavijen, 0.75 in rock-'n'-roll and 0.73 in cha-cha-cha. In ciciliona and pasavijen, the latent dance structure is predominantly explained by coordination, in rock-'n'-roll by explosive strength, and in cha-cha-cha by explosive strength and speed. Discriminative analysis revealed the general dance performance to mostly depend on coordination, then on explosive strength, and to a lesser extent on speed (movement frequency). Dance is an irreplaceable educational tool in kinesiologic education of female students, among others for its considerable contribution to the development and maintenance of basic motor abilities.     

Relationships between cognitive and motor abilities in female children aged 10-14 years

The aim of the study was to determine cognitive and motor status factors in female children aged 10-14 years and to identify developmental and/or integration functions according to age. The study included a sample of 162 female schoolchildren aged 10-14 years divided into two groups: 84 girls aged 10-12 (X 11.26, SD 0.68) years and 78 girls aged 13-14 (X 13.52, SD 0.63) years. Study results showed a statistically significant between-group difference in the overall system of variables (MANOVA), with the level of significance determined for each individual variable (ANOVA). The older group of subjects showed significantly superior results in comparison with the younger group in the motor tests assessing flexibility, agility, psychomotor speed, explosive strength of throwing type and repetitive strength of the trunk, as well as in the test assessing cognitive functioning. Qualitative differences between the two age groups (prepubertal and pubertal) were determined by use of the matrix of variable inter-correlations factorized by the procedure of principal components that were then transformed to promax solution. The results thus obtained indicated cognitive functioning to take significant part in the motor efficacy of girls aged 10-14 years. In the younger age group (10-12 years), cognitive functioning was related to the motor system that integrates muscle tone regulation and agility/coordination. In the older age group (13-14 years), cognitive functioning was involved in the formation of the first and third factor isolated, i.e. in the factor regulating coordination and intensity of energy mobilization of lower extremities (general motor efficiency) and, to a lesser extent, in third factor regulation the intensity of energy mobilization of upper extremities and trunk strength.     

The effect of physical activity on serum IL-6 and vaspin levels in late elementary school children

[Purpose]

This study investigates the effects of physical activity on serum IL-6 and vaspin in late elementary school children.

[Methods]

Those who (n = 220) completed the 7-day physical activity monitoring underwent a second round of measurements including body fat, serum glucose and insulin, and serum IL-6 and vaspin. One way ANOVAs followed by LSD post hoc tests were used to test for significant differences in dependent variables across incremental physical activity levels at p=0.05. Multivariate stepwise linear regression analyses were used to determine significant predictors for serum IL-6 and vaspin levels at p=0.05.

[Results]

The results showed significant inverse linear trends for body fat parameters across incremental physical activity levels (from low to high); the lower the body fat, the higher the physical activity levels. On the other hand, there were no significant linear trends for insulin resistance markers or dietary intake across incremental physical activity levels. Multiple stepwise linear regression analyses were used to determine significant predictors for individual variations in serum IL-6 and vaspin in the study population. We found that body mass index (p=0.002) and low- and moderate-intensity physical activities (p=0.002 and p=0.0045, respectively) were significant determinants of serum IL-6. In addition, low- and moderate-intensity physical activities (p=0.01 & p=0.022, respectively) were significant determinants of serum vaspin levels in this study population.

[Conclusion]

In summary, the findings of the current study suggest that promotion of physical activity along with a healthy diet should be key components of lifestyle interventions to improve serum cytokine profiles associated with insulin resistance syndrome in late elementary school children.     

Adaptive significance of small body size: strength and motor performance of school children in Mexico and Papua New Guinea

The postulated superior functional efficiency in association with reduced body size under conditions of chronic protein-energy undernutrition was considered in school children from rural Mexico and coastal Papua New Guinea. Grip strength and three measures of motor performance were measured in cross-sectional samples of children 6-16 years of age from a rural agricultural community in Oaxaca, Mexico, and from the coastal community Pere on Manus Island, Papua New Guinea. The strength and performance of a mixed-longitudinal sample of well nourished children from Philadelphia was used as a reference. The Oaxaca and Pere children are significantly shorter and lighter and are not as strong as the well nourished children. Motor performances of Pere children compare favorably to those of the better-nourished Philadelphia children, whereas those of the Oaxaca children are poorer. Throwing performance is more variable. When expressed relative to body size, strength is similar in the three samples, but the running and jumping performances of Pere children per unit body size are better than the relative performances of Oaxaca and Philadelphia children. Throwing performance per unit body size is better in the undernourished children. The influence of age, stature, and weight on the performance of Oaxaca and Pere children is generally similar to that for well nourished children. These results suggest that the hypothesized adaptive significance of small body size for the functional efficiency of populations living under conditions of chronic undernutrition varies between populations and with performance tasks.     

Effect of motor abilities on performing the Hvar folk dance cicilion in 11-year-old girls

A battery of 21 motor tests as predictor variables and evaluation of motor performance of cicilion, a Croatian folk dance from the island of Hvar as a criterion variable, were used in a sample of 101 female fifth-grade students aged 11 years. Regression analysis showed the changed group of motor variables to be a good predictor of success in performing the cicilion folk dance with multiple correlation of 0.63. The flexibility variable of astride trunk bending forwards and frequency variable of hand tapping had greatest impact on the criterion. A considerable favorable impact was also recorded for the variables for assessment of rhythmic coordination, balance, agility on ground, and repetitive strength of the trunk.     

The effect of motor abilities on karate performance

The aim of the study was to identify the motor structures that determine achievement of top results in karate. The study included a sample of 85 karateka aged 18-29 years, competing as senior category athletes of the Croatian Karate Society. Fourteen motor tests (9 basic motor tests and 5 specific motor tests) were used to assess technical efficiency; fighting efficiency was estimated on the basis of results achieved at a number of contests. Factorial analysis of the basic set of motor variables indicated the presence of three major factors of coordination, explosive strength, and movement frequency. Factorial analysis of pooled basic and specific motor variables also pointed to three major factors of speed (basic and specific), controlled power (explosive strength and specific agility), and basic coordination. Regression analysis showed the isolated basic factors to significantly determine both technical and fighting efficiency of the karateka, with the major role of the factor of explosive strength (power). Regression analysis of pooled basic and specific factors revealed the factors of controlled speed and controlled power to predominantly determine the karateka fighting and technical efficiency. In the set of tests used to assess specific motor abilities in karate, the speed of blockade, the speed of moving in multiple directions, and frequency of foot kicking were found to be the best predictors of technical efficiency, whereas the speed of moving in multiple directions, the speed of blockade, and frequency of foot kicking were the best predictors of fighting efficiency.     

Augmented Backward Elimination: A Pragmatic and Purposeful Way to Develop Statistical Models

Statistical models are simple mathematical rules derived from empirical data describing the association between an outcome and several explanatory variables. In a typical modeling situation statistical analysis often involves a large number of potential explanatory variables and frequently only partial subject-matter knowledge is available. Therefore, selecting the most suitable variables for a model in an objective and practical manner is usually a non-trivial task. We briefly revisit the purposeful variable selection procedure suggested by Hosmer and Lemeshow which combines significance and change-in-estimate criteria for variable selection and critically discuss the change-in-estimate criterion. We show that using a significance-based threshold for the change-in-estimate criterion reduces to a simple significance-based selection of variables, as if the change-in-estimate criterion is not considered at all. Various extensions to the purposeful variable selection procedure are suggested. We propose to use backward elimination augmented with a standardized change-in-estimate criterion on the quantity of interest usually reported and interpreted in a model for variable selection. Augmented backward elimination has been implemented in a SAS macro for linear, logistic and Cox proportional hazards regression. The algorithm and its implementation were evaluated by means of a simulation study. Augmented backward elimination tends to select larger models than backward elimination and approximates the unselected model up to negligible differences in point estimates of the regression coefficients. On average, regression coefficients obtained after applying augmented backward elimination were less biased relative to the coefficients of correctly specified models than after backward elimination. In summary, we propose augmented backward elimination as a reproducible variable selection algorithm that gives the analyst more flexibility in adopting model selection to a specific statistical modeling situation.     

Biomotor status and kinesiological education of students aged 13 to 15 years - example: karate

The aim of this paper was to obtain information relevant for efficient selection in karate, based on comparison of biomotor status of male/female 7th and 8th grade students in primary school "Bija?i" from Kastel Novi and karate practitioners and non-practitioners (cadets) in Croatia. For this purpose, a sample was drawn of 352 primary school students (150 males and 152 females) and 50 karate practitioners (25 males and 25 females), all aged 13 to 15 years, and 2 morphological measures (body height and body mass) and a battery of 6 motor tests was used. A biomotor system which determines the situation efficacy in male and female karate practitioners was defined based on the comparison of test results of students from Kastela, Croatian karateka and Croatian standards, factor analysis of applied variables and discriminant analysis of those variables between karate athletes and students from Kastela. In male karate athletes, general motor efficacy in karate is based on explosive strength of jumping type, repetitive strength of the trunk and coordination, followed by flexibility, static strength of the arms, and movement frequency speed. In female karate athletes, integration of force, coordination, muscle tone regulation and speed is dominant for achieving success in karate. Female karate athletes use speed and fine muscle tone regulation in motor functioning more than male karate athletes, who use basic strength more.     

Evaluation of Circulating Proteins and Hemodynamics Towards Predicting Mortality in Children with Pulmonary Arterial Hypertension

Background

Although many predictors have been evaluated, a set of strong independent prognostic mortality indicators has not been established in children with pediatric pulmonary arterial hypertension (PAH). The aim of this study was to identify a combination of clinical and molecular predictors of survival in PAH.

Methods

This single-center, retrospective cohort study was performed from children with PAH between 2001 and 2008 at Children''s Hospital Colorado. Blood samples from 83 patients (median age of 8.3 years-old) were obtained. We retrospectively analyzed 46 variables, which included 27 circulating proteins, 7 demographic variables and 12 hemodynamic and echocardiographic variables for establishing the best predictors of mortality. A data mining approach was utilized to evaluate predictor variables and to uncover complex data structures while performing variable selection in high dimensional problems.

Results

Thirteen children (16%) died during follow-up (median; 3.1 years) and survival rates from time of sample collection at 1 year, 3 years and 5 years were 95%, 85% and 79%, respectively. A subset of potentially informative predictors were identified, the top four are listed here in order of importance: Tissue inhibitors of metalloproteinases-1 (TIMP-1), apolipoprotein-AI, RV/LV diastolic dimension ratio and age at diagnosis. In univariate analysis, TIMP-1 and apolipoprotein-AI had significant association with survival time (hazard ratio [95% confidence interval]: 1.25 [1.03, 1.51] and 0.70 [0.54–0.90], respectively). Patients grouped by TIMP-1 and apolipoprotein-AI values had significantly different survival risks (p<0.01).

Conclusion

Important predictors of mortality were identified from a large number of circulating proteins and clinical markers in this cohort. If confirmed in other populations, measurement of a subset of these predictors could aid in management of pediatric PAH by identifying patients at risk for death. These findings also further support a role for the clinical utility of measuring circulating proteins.     

Relations of the morphological characteristic latent structure and body posture indicators in children aged seven to nine years

With the aim of determining the connection between the indicators of body posture and latent structure of morphological variables in children aged 7 and 8 years, first and second grade of primary school, a set of 17 morphological measures and 12 body posture indicators were longitudinally applied to a sample of 110 boys and 114 girls. The latent structure of morphological variables in both sexes was defined by three factors but at a different order of significance: in boys, the order was longitudinal dimensionality, voluminosity, mass and subcutaneous fat tissue and transverse dimensionality, whereas in girls the order was voluminosity, mass and subcutaneous fat tissue, longitudinal dimensionality and transverse dimensionality. The latent structure of torax body posture indicator was defined by two factors, the status of body posture of the rear part of the thorax, and status of the body posture of the front part of the thorax. The results obtained by canonical correlation analysis between predictive variables, morphological latent structure and criterion variables, latent structure of thorax body posture indicators with two posture indicators of the chest and one of the foot status, showed two important pairs of canonical roots on each measurement, suggesting a significant association between these two sets of parameters.