The main goal of our cross-sectional research was to determine the current values of gross motor coordination (GMC) of Italian boys and girls between 6 and 13 years of age. Secondary goals were to ...study gender differences, and the four subtests trend with ages. Results were compared with the references proposed by KTK authors and with similar searches. Anthropometric measurements and KTK data from 2,206 schoolchildren (girls:
= 1,050; boys:
= 1,156) were collected. The KTK raw score (RS) increased with the age of the subjects (
= 0.678;
< 0.001). In 11-13-year-old subjects, the increase in results is less than in younger subjects. RS showed differences by gender (
= 5.899;
= 0.015) and age (
= 269.193;
< 0.001) without interaction gender × age. Motor quotient (MQ) tended to decrease with age (
= -0.148;
< 0.001); it showed differences by gender (
= 79.228;
< 0.001), age (
= 14.217;
< 0.001), and an interaction gender × age (
= 2.249;
< 0.05). Boys showed better performance than did girls in the raw scores of three of four subtests (JS:
= 24.529; MS:
= 9.052; HH:
= 11.105). Girls show better performances than did boys in the WB (
= 14.52). Differences between genders make us believe it appropriate to maintain a differentiated standardization. RS increased with age, and it seems reasonable, therefore, to maintain a GMC age-based normalization. On the contrary, MQ tended to decrease. All this makes us speculate that today's young people accumulate less significant motor experiences over the years compared to those achieved by their peers in the 1970s. Italian data were lower than German references and Belgian results but slightly higher than the Brazilian ones. The comparison among these four searches confirmed a worrying downward trend in GMC and its characterization by geographical and sociocultural areas. Updated parameters of the KTK can provide helpful references to improve policies to support physical activity, sport, and physical education in youth.
Gross motor coordination (GMC) development could be influenced by age, gender, weight status, geographical area, living setting, home environment, socio-economic status, sports practice.
To verify ...whether practicing sports and practicing different sports could influence children's GMC level.
A total of 295 children aged 8-11 years were involved in the study and divided into 5 groups in relation to the sport they practiced: gymnastics group (
= 67; 51F, 16M), cycling group (
= 64; 15F, 49M), athletics group (
= 47; 22F, 25M), swimming group (
= 35; 20F, 15M), control group (
= 82; 42F, 40M). The four subtests of the Körperkoordinations Test für Kinder (KTK) assessed children's GMC level. The scores from each of the four subtests were summed into the KTK total raw score (RS) and then converted into a gender- and age-specific motor quotient (MQ).
Children practicing sports showed significantly higher RS and MQ score than children of control group (203.14 ± 38.55 vs. 163.63 ± 43.50 and 98.56 ± 15.79 vs. 83.01 ± 16.71, respectively;
< 0.001). Children practicing gymnastics had a significantly higher RS and MQ than children of cycling, swimming, and control groups (
< 0.05), children of control group had a significantly lower RS and MQ than children of all other groups (
< 0.05). Children practicing gymnastics performed better walking backwards subtest than all other children's groups (
< 0.001). Children of control group performed worse jumping sideways subtest than children of gymnastics, athletics and swimming groups (
< 0.01). Children practicing gymnastics performed better moving sideways subtest than children of athletics, cycling and control groups (
< 0.01); children of control group performed worse than children of all other groups (
< 0.01). Children of control group performed worse hopping for height subtest than children of gymnastics, athletics and cycling groups (
< 0.05); children practicing gymnastics performed better than children of swimming and control groups (
< 0.05).
The performance model and therefore the specialized training that each sport discipline required, could justified the differences in children's GMC level among sports groups. Thus, coaches should plan individualized interventions and choose activity contents to support children's GMC development.
We consider a Dirichlet problem for the Poisson equation in an unbounded periodically perforated domain. The domain has a periodic structure, and the size of each cell is determined by a positive ...parameter δ, and the level of anisotropy of the cell is determined by a diagonal matrix γ with positive diagonal entries. The relative size of each periodic perforation is instead determined by a positive parameter ε. For a given value γ∼ of γ, we analyze the behavior of the unique solution of the problem as (ε,δ,γ) tends to (0,0,γ∼) by an approach which is alternative to that of asymptotic expansions and of classical homogenization theory.
We consider a nonlinear Robin problem for the Poisson equation in an unbounded periodically perforated domain. The domain has a periodic structure, and the size of each cell is determined by a ...positive parameter
δ
. The relative size of each periodic perforation is instead determined by a positive parameter
ϵ
. We prove the existence of a family of solutions which depends on
ϵ
and
δ
and we analyze the behavior of such a family as
(
ϵ
,
δ
)
tends to (0, 0) by an approach which is alternative to that of asymptotic expansions and of classical homogenization theory.
The purpose of this paper is to study a boundary value problem of Robin-transmission type for the nonlinear Darcy–Forchheimer–Brinkman and Navier–Stokes systems in two adjacent bounded Lipschitz ...domains in
R
n
(
n
∈
{
2
,
3
}
)
, with linear transmission conditions on the internal Lipschitz interface and a linear Robin condition on the remaining part of the Lipschitz boundary. We also consider a Robin-transmission problem for the same nonlinear systems subject to nonlinear transmission conditions on the internal Lipschitz interface and a nonlinear Robin condition on the remaining part of the boundary. For each of these problems we exploit layer potential theoretic methods combined with fixed point theorems in order to show existence results in Sobolev spaces, when the given data are suitably small in
L
2
-based Sobolev spaces or in some Besov spaces. For the first mentioned problem, which corresponds to linear Robin and transmission conditions, we also show a uniqueness result. Note that the Brinkman–Forchheimer-extended Darcy equation is a nonlinear equation that describes saturated porous media fluid flows.
The purpose of this paper is to study boundary value problems of Robin type for the Brinkman system and a semilinear elliptic system, called the Darcy–Forchheimer–Brinkman system, on Lipschitz ...domains in Euclidean setting. In the first part of the paper, we exploit a layer potential analysis and a fixed point theorem to show the existence and uniqueness of the solution to the nonlinear Robin problem for the Darcy–Forchheimer–Brinkman system on a bounded Lipschitz domain in
R
n
(
n
∈
{
2
,
3
}
)
with small data in
L
2
-based Sobolev spaces. In the second part, we show an existence result for the mixed Dirichlet–Robin problem for the same semilinear Darcy–Forchheimer-Brinkman system on a bounded creased Lipschitz domain in
R
3
with small
L
2
-boundary data. We also study mixed Dirichlet–Robin problems and boundary value problems of mixed Dirichlet–Robin and transmission type for Brinkman systems on bounded creased Lipschitz domains in
R
n
(
n
≥ 3). Finally, we show the well-posedness of the Navier problem for the Brinkman system with boundary data in some
L
2
-based Sobolev spaces on a bounded Lipschitz domain in
R
3
.
The purpose of this paper is to obtain existence and uniqueness results in weighted Sobolev spaces for transmission problems for the nonlinear Darcy–Forchheimer–Brinkman system and the linear Stokes ...system in two complementary Lipschitz domains in R 3 , one of them is a bounded Lipschitz domain Ω with connected boundary, and the other one is the exterior Lipschitz domain R 3 \ Ω ¯ . We exploit a layer potential method for the Stokes and Brinkman systems combined with a fixed point theorem in order to show the desired existence and uniqueness results, whenever the given data are suitably small in some weighted Sobolev spaces and boundary Sobolev spaces.
We prove the validity of a regularizing property on the boundary of the double layer potential associated with the fundamental solution of a
nonhomogeneous
second order elliptic differential operator ...with constant coefficients in Schauder spaces of exponent greater or equal to two that sharpens classical results of N.M. Günter, S. Mikhlin, V.D. Kupradze, T.G. Gegelia, M.O. Basheleishvili and T.V. Burchuladze, U. Heinemann and extends the work of A. Kirsch who has considered the case of the Helmholtz operator.
The present informal set of notes covers the material that has been presented by the author in a series of lectures for the Doctoral School in Mathematics of the Southern Federal State University of ...Rostov-on-Don in the Fall of 2020 and that develops from the first part of the notes that collect the material of the lectures of the author at the Eurasian National University, Astana, Kazakhstan in the Spring of 2012. The aim is to present some elementary classical properties of Morrey spaces and some corresponding approximation results by smooth functions.
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