•The primary finding of this analysis is that quality of life improved after virtual reality-based exercise in older adults aged 60 years or over.•Virtual reality-based exercise caused improvements ...in depressive symptoms in older adults.•Some of the balance tests revealed significant improvement following virtual reality-based exercise.
The objective of this study was to investigate the impact of virtual reality-based exercise on the quality of life, some balance variables, and depression among older adults aged 60 years or older.
We systematically searched five electronic databases.
Twenty-seven articles met our inclusion criteria. Meta-analysis revealed that exercise using virtual reality had a significant positive effect on overall quality of life (p = 0.05), mental (p = 0.001) and physical component scores (p = 0.01), social relation (p = 0.0002), psychological health(p = 0.01), physical health(p = 0.04), and environmental health (p = 0.04). Additionally, depression significantly improved following virtual reality-based exercise (p = 0.01). However, there were significant improvements in the balance berg scale (p<0.00001) and ABC scale (p<0.00001) but not in timed-up-and-go(TUG) or 8-foot-up-and-go(8-FUG).
Virtual reality-based exercise has a positive impact on various aspects of quality of life, BBS and ABC scores, and depression. More studies with larger sample sizes and less heterogeneity in design and assessments are required.
•Stochastic and deterministic models both describe motor-driven filament transport.•Comparing stochastic and deterministic forms assesses the impact of intrinsic noise.•Discrepancies between ...multi-stable deterministic and stochastic models emerge.•Intrinsic noise helps coordinate polarized transport of filament ensemble.•In biological systems, motor binding properties are a major regulatory mechanism.
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Noise affects all biological processes from molecules to cells, organisms and populations. Although the effect of noise on these processes is highly variable, evidence is accumulating which shows natural stochastic fluctuations (noise) can facilitate biological functions. Herein, we investigate the effect of noise on the transport of intermediate filaments in cells by comparing the stochastic and deterministic formalizations of the bidirectional transport of intermediate filaments, long elastic polymers transported along microtubules by antagonistic motor proteins (Dallon et al., 2019; Portet et al., 2019). By numerically exploring discrepancies in timescales and attractors between both formalizations, we characterize the impact of stochastic fluctuations on the individual and ensemble transport. Biologically, we find that noise promotes the collective movement of intermediate filaments and increases the efficiency of its regulation by the biochemical properties of motor-cargo interactions. While stochastic fluctuations reduce the impact of the initial distributions of motor proteins in cells, the number of binding sites and the affinity of motor-cargo interactions are the key parameters controlling transport efficiency and efficacy.
TUG-OF-WAR AND THE INFINITY LAPLACIAN PERES, YUVAL; SCHRAMM, ODED; SHEFFIELD, SCOTT ...
Journal of the American Mathematical Society,
01/2009, Letnik:
22, Številka:
1
Journal Article
Recenzirano
Odprti dostop
We prove that every bounded Lipschitz function
F
F
on a subset
Y
Y
of a length space
X
X
admits a
tautest
extension to
X
X
, i.e., a unique Lipschitz extension
u
:
X
→
R
u:X \rightarrow \mathbb {R}
...for which
Lip
U
u
=
Lip
∂
U
u
\operatorname {Lip}_U u =\operatorname {Lip}_{\partial U} u
for all open
U
⊂
X
∖
Y
U \subset X\smallsetminus Y
. This was previously known only for bounded domains in
R
n
\mathbb {R}^n
, in which case
u
u
is
infinity harmonic
; that is, a viscosity solution to
Δ
∞
u
=
0
\Delta _\infty u = 0
, where
\
Δ
∞
u
=
|
∇
u
|
−
2
∑
i
,
j
u
x
i
u
x
i
x
j
u
x
j
.
\Delta _\infty u = |\nabla u|^{-2} \sum _{i,j} u_{x_i} u_{x_ix_j} u_{x_j}.
\
We also prove the first general uniqueness results for
Δ
∞
u
=
g
\Delta _{\infty } u = g
on bounded subsets of
R
n
\mathbb {R}^n
(when
g
g
is uniformly continuous and bounded away from
0
0
) and analogous results for bounded length spaces. The proofs rely on a new game-theoretic description of
u
u
. Let
u
ε
(
x
)
u^\varepsilon (x)
be the value of the following two-player zero-sum game, called
tug-of-war
: fix
x
0
=
x
∈
X
∖
Y
x_0=x\in X \smallsetminus Y
. At the
k
t
h
k^{\mathrm {th}}
turn, the players toss a coin and the winner chooses an
x
k
x_k
with
d
(
x
k
,
x
k
−
1
)
>
ε
d(x_k, x_{k-1})> \varepsilon
. The game ends when
x
k
∈
Y
x_k \in Y
, and player
I
’s payoff is
F
(
x
k
)
−
ε
2
2
∑
i
=
0
k
−
1
g
(
x
i
)
F(x_k) - \frac {\varepsilon ^2}{2}\sum _{i=0}^{k-1} g(x_i)
. We show that
‖
u
ε
−
u
‖
∞
→
0
\|u^\varepsilon - u\|_{\infty } \to 0
. Even for bounded domains in
R
n
\mathbb {R}^n
, the game theoretic description of infinity harmonic functions yields new intuition and estimates; for instance, we prove power law bounds for infinity harmonic functions in the unit disk with boundary values supported in a
δ
\delta
-neighborhood of a Cantor set on the unit circle.
Timed Up and Go (TUG) test is one of the most popular clinical tools aimed at the assessment of functional mobility and fall risk in older adults. The automation of the analysis of TUG movements is ...of great medical interest not only to speed up the test but also to maximize the information inferred from the subjects under study. In this context, this article describes a dataset collected from a cohort of 69 experimental subjects (including 30 adults over 60 years), during the execution of several repetitions of the TUG test. In particular, the dataset includes the measurements gathered with four wearables devices embedding four sensors (accelerometer, gyroscope magnetometer and barometer) located on four body locations (waist, wrist, ankle and chest). As a particularity, the dataset also includes the same measurements recorded when the young subjects repeat the test while wearing a commercial geriatric simulator, consisting of a set of weighted vests and other elements intended to replicate the limitations caused by aging. Thus, the generated dataset also enables the investigation into the potential of such tools to emulate the actual dynamics of older individuals.
The transverse upper gracilis (TUG) flap provides a good alternative to the gold standard DIEP in breast reconstruction. However, flap volume estimates are subjective, making preoperative planning ...potentially challenging.
To derive a reliable, accurate, and reproducible mathematical algorithm for the preoperative calculation of TUG flap volumes.
Nineteen consecutive patients with 30 TUG flaps were prospectively included. On the assumption that the TUG flap resembles two isosceles prisms, the formula of the volume of a prism was used to calculate their preoperative flap weights. These were then intraoperatively compared to the actual flap weights. A regression equation was calculated from the correlation analysis of 10 random flaps. This was then applied to the remaining 20 flaps to assess for improved reliability and weight prediction accuracy.
The prism volume equation used to clinically calculate flap volumes was: Geometric flap weight = (h1bT)/2+ (h2bT)/2, (h = height, b = base, T = flap thickness); all in centimetres. Geometric and actual flap weights were found to be significantly correlated (r2 = 0.977) generating the following regression formula: predicted TUG weight = 0.924 × geometric weight + 26.601. When this was applied to the remaining 20 flaps, no significant difference was found (p = 0.625) between predicted and actual flap weights, demonstrating an increased accuracy of predicting flap volume.
The proposed formula provides the clinician with a more accurate and reliable estimation of available TUG flap volume and may potentially aid with preoperative planning and patient consultations.
Particle motion at the microscale is an incessant tug-of-war between thermal fluctuations and applied forces on one side and the strong resistance exerted by fluid viscosity on the other. Friction is ...so strong that completely neglecting inertia--the overdamped approximation--gives an excellent effective description of the actual particle mechanics. In sharp contrast to this result, here we show that the overdamped approximation dramatically fails when thermodynamic quantities such as the entropy production in the environment are considered, in the presence of temperature gradients. In the limit of vanishingly small, yet finite, inertia, we find that the entropy production is dominated by a contribution that is anomalous, i.e., has no counterpart in the overdamped approximation. This phenomenon, which we call an entropic anomaly, is due to a symmetry breaking that occurs when moving to the small, finite inertia limit. Anomalous entropy production is traced back to futile phase-space cyclic trajectories displaying a fast downgradient sweep followed by a slow upgradient return to the original position.
•Tug scheduling for hinterland transportation of barging cargos.•Mixed-integer programming model that captures realistic factors.•Tailor branch-and-price algorithm with accelerating techniques.
In a ...hinterland barge transport system, barges are usually not self-propelled and need to be towed or pushed by tugs. This study investigates a tug-scheduling problem at a seaport that is located at a river mouth and that connects the hinterland ports along the river with the global maritime transportation network. A mixed-integer programming model is proposed to optimize the assignment of barges to tugs as well as the time when the tugs depart from the seaport and go to the hinterland ports. Some properties of the model are also investigated. Moreover, an exact solution method based on a branch-and-price approach is developed to solve the proposed model. Numerical experiments are also conducted to validate the effectiveness of the proposed model and the efficiency of the proposed solution method.
In this paper, we study value functions of time-dependent tug-of-war games. We first prove the existence and uniqueness of value functions and verify that these game values satisfy a dynamic ...programming principle. Using the arguments in the proof of existence of game values, we can also deduce asymptotic behavior of game values when T→∞. Furthermore, we investigate boundary regularity for game values. Thereafter, based on the regularity results for value functions, we deduce that game values converge to viscosity solutions of the normalized parabolic p-Laplace equation.
Resumo Com o intuito de verificar a compreensão de gráficos cinemática de um grupo de estudantes de ensino médio, é recomendável utilizar um instrumento que possua tanto uma validade de conteúdo por ...parte de especialistas, quanto uma validação estatística. Nesse sentido, foi escolhida a nova versão do Test of Understanding Graphs in Kinematics (TUG-K), proposta em 2017 por Zavala e originalmente criado por Beichner, em 1994. O TUG-K foi elaborado para medir o conhecimento de gráficos em cinemática de alunos universitários, majoritariamente. Logo, para que possa ser usado na educação básica, é preciso saber se possui validade estatística nesse contexto. Portanto, foi realizada uma análise estatística do teste, após ser aplicado em dois momentos distintos, em estudantes de ensino médio de uma escola federal do Rio de Janeiro. Os parâmetros medidos foram os mesmos utilizados por Zavala. O principal resultado deste artigo foi demonstrar a validação do TUG-K nesse grupo. Como complemento, mostrou-se que o ganho de aprendizagem normalizado de Hake desses estudantes submetidos a aulas expositivas de cinemática foi de 17%, valor esperado para o ensino tradicional. A perspectiva subjacente é difundir e incentivar o uso do TUG-K no ensino médio.
Abstract In order to verify the kinematics graphs comprehension for a group of high school students, it is recommended to use an instrument that has a content valid by experts and a statistical validation. In this sense, was chosen the updated version of Test of Understanding Graphs in Kinematics (TUG-K), proposed in 2017 by Zavala and originally created by Beichner, in 1994. The TUG-K was elaborated to measure the understanding of graphs in kinematics of university students, mostly. Therefore, for this test to be used in basic education, it is necessary to know if it has statistical validity in this context. Consequently, a statistical analysis of the test was performed, after being applied at two different moments, with upper secondary level students of a federal school in Rio de Janeiro. The measured parameters were the same used by Zavala. The main result of this article was to demonstrate that TUG-K validity in this group. As a complement, it was shown that Hake's normalized learning gain from this group of students exposed to kinematics lectures was 17%, a value that is expected to be in traditional teaching. The underlying perspective is to disseminate and encourage the use of TUG-K in high school.
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