Porastom osviještenosti čovjeka o negativnim učincima Sunčeva zračenja znatno se povećala proizvodnja i uporaba krema za sunčanje. Posljedica toga je akumulacija UV zaštitnih filtara, aktivnih ...sastojaka krema za sunčanje, u vodenom okolišu. Istraživanja su pokazala da su UV filtri, osobito organski filtri poput oksibenzona, oktinoksata i 4-MBC-a opasnost za čitav niz različitih organizama. Odabrana istraživanja u ovom radu usredotočena su na toksični učinak navedenih spojeva na morske i slatkovodne organizme te ukazuju na to da njihova prisutnost u vodenom okolišu rezultira inhibicijom rasta i fotosinteze, reproduktivnim i razvojnim poremećajima, izbjeljivanjem pa čak i smrću ispitivanih organizama. Anorganski UV filtri, čiji su predstavnici nanočestični oblici TiO2 i ZnO, u provedenim ispitivanjima ekotoksičnosti pokazuju slabo toksičan ili gotovo nikakav učinak na ispitivane organizme. Međutim, u istraživanjima u kojima su se pokazali slabo toksičnima, ta toksičnost nije uzrokovana samo prisutnošću nanočestica nego i stvaranjem reaktivnih vrsta kisika, što kod pojedinih organizama izaziva inhibiciju rasta, izbjeljivanje, abnormalnu embriogenezu i oksidativni stres. Daljnja istraživanja nužna su za bolje shvaćanje toksičnog učinka tih spojeva i precizniju procjenu rizika za vodeni okoliš te čitav ekosustav.
Although defining normative values of cardiorespiratory fitness have been the topic of many Western societies, little evidence has been provided for less developed countries like Croatia. Since ...cardiorespiratory fitness rapidly declines in Croatian children and adolescents, the newly established normative values would help health-related professionals and physical education teachers to detect 'talented' groups and direct them towards sport and 'risky' groups for planning special interventions. Therefore, the main purpose of the study was to determine normative reference values of cardiorespiratory fitness. A total of 1,612 children and adolescents aged 7-14 years (mean±SD; age 9.7±2.4 years; stature 151.0±17.6 cm; body mass 45.1±19.1 kg; 52.5% girls) participated in this cross-sectional study. Cardiorespiratory fitness was assessed by the Maximal multistage 20-m shuttle run test and the performance was expressed as the number of stages. Maximal oxygen uptake (VO2max) was estimated by equations. Smoothed percentile curves were calculated. Boys outperformed girls in the maximal number of levels achieved after the 20-m shuttle run test and in the VO2max values at each age category. In boys, a gradually higher level of performance between ages 11 and 14 was observed, while in girls the values started to rise after the age of 8. Our study provides one of the first sex- and age-specific normative values for cardiorespiratory fitness assessed by the 20-m shuttle run test in Croatian children and adolescents.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The goal of this research was to determine cardiorespiratory fitness (CRF) among primary school male and female pupils and its association with their anthropometric characteristics. The sample ...consisted of 112 boys and 136 girls, primary school pupils, aged 7 to 10. The Eurofit test battery was used to evaluate anthropometric characteristics (body height, body mass, body mass index (BMI)) and CRF (Beep test to estimate maximal oxygen uptake). The results indicate stagnation in the CRF with chronological age, in both sexes. A statistically significant association (p = 0.001) was shown for all CRF variables and anthropometric variables except for body height, which was not significantly associated with CRF. An increase in body mass and BMI was associated with a significant (p = 0.001) decrease in male and female pupils' CRF.
Although evidence suggests that functional endurance capacity is the most important component associated with future health, little is known of how it is associated with multiple other physical ...fitness components. Since various physical fitness aspects do not change the same as functional endurance capacity during childhood, it is necessary to establish possible associations between functional endurance capacity and other physical fitness components in children. Therefore, the main purpose of the study was to test the associations between functional endurance capacity with other physical fitness components in 7-14-year-old children, stratified by gender.
In this cross-sectional study, we recruited 1612 children mean age ± standard deviation (SD) = 9.72 ± 2.37 years; 52.5% girls). Health-related physical fitness components included: 1) body-mass index (kg/m
) calculated from height and weight (measure of body size), 2) sit-and-reach test (measure of flexibility), 3) standing broad jump (measure of explosive strength of lower extremities), 4) sit-ups in 30 s (measure of repetitive strength of the trunk), 5) 10 × 5 shuttle run test (measure of agility) and 6) 20-m shuttle run test (measure of functional endurance capacity). The associations were performed using generalized estimating equations with beta (β) coefficients.
After adjusting for age, functional endurance capacity was associated with sit-and-reach test (β = 0.13, p < 0.001), standing broad jump (β = 0.59, p < 0.001), sit-ups in 30 s (β = 0.53, p < 0.001) and 10 × 5 shuttle run test (β = - 0.56, p < 0.001) in boys. In girls, functional endurance capacity was associated with body-mass index (β = - 0.12, p < 0.001), sit-and-reach test (β = 0.21, p < 0.001), standing broad jump (β = 0.25, p < 0.001), sit-ups in 30 s (β = 0.36, p < 0.001) and 10 × 5 shuttle run test (β = - 0.40, p < 0.001). No significant associations between functional endurance capacity and body-mass index in boys were observed.
Although significant, functional endurance capacity is weakly to moderately associated with other physical fitness components, pointing out that such measure should be tested separately from other aspects of physical fitness in school-aged children.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Physical inactivity is the fourth major cause of mortality in the world, so the World Health Organisation advises for children and adolescents to accumulate moderate physical activity at least 60 ...minutes a day with the aim to preserve health and prevent the occurrence of various chronic diseases. Elevated overweight and obesity, besides in adulthood, occur increasingly more in childhood. The aim of the research is to determine the level of nutrition and physical activity of younger school children, as well as the differences between girls and boys. The results obtained on a sample of 265 participants of a younger school age show that girls and boys have a normal nutritional level in the first and third grade, while for girls and boys of the second and fourth grade an elevated level of the body mass index (BMI) was noticed. Results show that most girls and boys of a younger school age do sports in their free time, and that they spend approximately 2 to 3 hours a day outdoors. Boys usually train three times a week, girls train two times a week, while the average boys' training lasts 60, and the girls' training 75 minutes.
The main purpose of the study was to define optimal criterion-referenced cut-points for cardiorespiratory fitness (CRF) associated with overweight/obesity. In this cross-sectional study, participants ...were 1,612 children aged 7-14 years (mean age ± SD = 9.7 ± 2.4 years; 52.5% girls). CRF was assessed by the Maximal multistage 20-m shuttle run test, from which maximal oxygen uptake (VO
max) was estimated. Anthropometric indices included body-mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR). Receiver operating characteristic (ROC) curves were performed to determine cut-off points. In boys, the optimal cut-off points of CRF in defining overweight/obesity for BMI, WC, and WHtR were 44.6, 46.4, and 46.9 mlO
/kg/min. The areas under the curves (AUC) were 0.83 (95% CI 0.78-0.88,
< 0.001), 0.77 (95% CI 0.71-0.83,
< 0.001), and 0.90 (95% CI 0.86-0.93,
< 0.001). In girls, the optimal cut-off points were 41.0, 40.8, and 40.7 mlO
/kg/min for BMI, WC, and WHtR, with the AUCs of 0.86 (95% CI 0.82-0.90,
< 0.001), 0.83 (95% CI 0.79-0.88), and 0.88 (95% CI 0.84-0.93,
< 0.001). In conclusion, our newly developed cut-off points for CRF assessed by the Maximal multistage 20-m shuttle run test may adequately detect primary school-aged boys and girls with general and abdominal obesity.
The Nagorno-Karabakh conflict began in 1988 after the regional Supreme Council declared the transfer of the region from the Azerbaijani SSR to the Armenian SSR. The full-scale war started in 1992 ...after the dissolution of the USSR and ended with the May 1994 armistice. In the following quarter century, a peaceful resolution of the conflict was mediated by OSCE’s Minsk Group in a form of facilitative mediation. The warring sides have never reached a final solution and a new war started in the autumn of 2020. This paper examines how facilitative mediation was conducted by the Minsk Group and why it eventually failed. The conclusion of this paper is that the combination of the weak mandate and the co-chairs’ separate and incongruous interests in the Caucasus resulted in the failure of the conflict resolution in Nagorno-Karabakh.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The topic of this paper are the material working conditions in Physical Education as a very important part of the educational process which is successfully conducted with appropriate exercising ...equipment, props and premises in which exercising takes place. The aim of this paper was to study the state of material working conditions in all primary schools in Pula. The research was conducted among 99 primary education teachers using an anonymous questionnaire that consisted of 14 variables. It examined the opinions of the teachers, their agreements and disagreements through a five-degree Likert scale. Based on the obtained results, it can be concluded that the main problem in primary schools in Pula is a lack of exercising equipment and props needed to work in Physical Education. Furthermore, gyms are not sufficiently available for classroom teachers because subject teaching has precedence over them.
Although defining normative values of cardiorespiratory fitness have been the topic of many Western societies, little evidence has been provided for less developed countries like Croatia. Since ...cardiorespiratory fitness rapidly declines in Croatian children and adolescents, the newly established normative values would help health-related professionals and physical education teachers to detect 'talented' groups and direct them towards sport and 'risky' groups for planning special interventions. Therefore, the main purpose of the study was to determine normative reference values of cardiorespiratory fitness. A total of 1,612 children and adolescents aged 7-14 years (mean±SD; age 9.7±2.4 years; stature 151.0±17.6 cm; body mass 45.1±19.1 kg; 52.5% girls) participated in this cross-sectional study. Cardiorespiratory fitness was assessed by the Maximal multistage 20-m shuttle run test and the performance was expressed as the number of stages. Maximal oxygen uptake (VO2max) was estimated by equations. Smoothed percentile curves were calculated. Boys outperformed girls in the maximal number of levels achieved after the 20-m shuttle run test and in the VO2max values at each age category. In boys, a gradually higher level of performance between ages 11 and 14 was observed, while in girls the values started to rise after the age of 8. Our study provides one of the first sex- and age-specific normative values for cardiorespiratory fitness assessed by the 20-m shuttle run test in Croatian children and adolescents.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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