163 research outputs found
Stochastic Reaction-diffusion Equations Driven by Jump Processes
We establish the existence of weak martingale solutions to a class of second
order parabolic stochastic partial differential equations. The equations are
driven by multiplicative jump type noise, with a non-Lipschitz multiplicative
functional. The drift in the equations contains a dissipative nonlinearity of
polynomial growth.Comment: See journal reference for teh final published versio
Regularity of Ornstein-Uhlenbeck processes driven by a L{\'e}vy white noise
The paper is concerned with spatial and time regularity of solutions to
linear stochastic evolution equation perturbed by L\'evy white noise "obtained
by subordination of a Gaussian white noise". Sufficient conditions for spatial
continuity are derived. It is also shown that solutions do not have in general
\cadlag modifications. General results are applied to equations with fractional
Laplacian. Applications to Burgers stochastic equations are considered as well.Comment: This is an updated version of the same paper. In fact, it has already
been publishe
Development and psychometric properties of a belief-based Physical Activity Questionnaire for Diabetic Patients (PAQ-DP)
<p>Abstract</p> <p>Background</p> <p>This study carried out to develop a scale for assessing diabetic patients' perceptions about physical activity and to test its psychometric properties (The Physical Activity Questionnaire for Diabetic Patients-PAQ-DP).</p> <p>Methods</p> <p>An item pool extracted from the Theory of Planned Behavior literature was generated. Then an expert panel evaluated the items by assessing content validity index and content validity ratio. Consequently exploratory factor analysis (EFA) was performed to indicate the scale constructs. In addition reliability analyses including internal consistency and test-retest analysis were carried out.</p> <p>Results</p> <p>In all a sample of 127 women with diabetes participated in the study. Twenty-two items were initially extracted from the literature. A six-factor solution (containing 19 items) emerged as a result of an exploratory factor analysis namely: instrumental attitude, subjective norm, perceived behavioral control, affective attitude, self-identity, and intention explaining 60.30% of the variance observed. Additional analyses indicated satisfactory results for internal consistency (Cronbach's alpha ranging from 0.54 to 0.8) and intraclass correlation coefficients (ranging from 0.40 to 0.92).</p> <p>Conclusions</p> <p>The Physical Activity Questionnaire for Diabetic Patients (PAQ-DP) is the first instrument that applies the Theory of Planned Behavior in its constructs. The findings indicated that the PAQ-DP is a reliable and valid measure for assessing physical activity perceptions and now is available and can be used in future studies.</p
Personality factors in exercise addiction: a pilot study exploring the role of narcissism, extraversion, and agreeableness
Despite the increased evidence and acceptance of exercise being classed as a behavioral addiction, there is limited research examining personality characteristics within exercise addicts. The purpose of this study was to examine three personality traits (narcissism, extraversion, and agreeableness) and to examine their role in exercise addiction. The sample comprised 114 voluntary participants (74 females and 40 males) who completed the (i) Exercise Addiction Inventory, (ii) Narcissistic Personality Inventory, and (iii) Ten-Item Personality Inventory, as well as demographic questions and questions concerning their engagement and intensity levels of exercise. Results indicated a low incidence of individuals who were classed as at risk of exercise addiction (7%), but a high incidence of symptomatic individuals (75%). Results suggested that extraversion and narcissism may be underlying factors in exercise addiction with no effect for agreeableness. Exercise engagement and intensity were also related to exercise addiction. Further research examining the relationship between personality types and exercise addiction may be useful in identifying individuals at risk for developing exercise addiction
Eating disorders in sport : current status and future directions in the study of the psychological factors
Este trabalho procura atingir dois objetivos. Em primeiro lugar, apresenta-se a situação atual da investigação sobre desordens alimentares no desporto. Neste caso, salientam-se as linhas de investigação dedicadas ao estudo da prevalĂȘncia destes problemas no desporto e analisam-se as diferenças entre atletas e modalidades desportivas. Dadas as dificuldades destas linhas de investigação na compreensĂŁo dos comportamentos alimentares de risco nos atletas, sĂŁo avançadas outras possibilidades de desenvolvimento da investigação. Assim, e enquanto segundo objetivo deste artigo, salientamos a necessidade dos estudos se dirigirem para a compreensĂŁo dos fatores psicolĂłgicos associados aos comportamentos alimentares de risco e implicados no desenvolvimento das desordens alimentares. Esta abordagem tem como vantagem adicional ajudar a prevenir estes problemas atravĂ©s da promoção das competĂȘncias mentais dos atletas no sentido de resistirem melhor aos possĂveis efeitos nocivos da prĂĄtica desportiva, onde se inserem os problemas com a alimentação.This paper focuses on two main goals. In first place, we present the current status on the
research about eating disorders in sport contexts. In this case, we point out studies dedicated to the
analysis of the incidence of eating disorders in sport and studies that observe the differences between athletes and different sports in the tendency for these problems. Second, we proposed new research
directions on this subject, namely the need of analysing the psychological factors that are related with
the development of eating disorders on athletes. This research approach has the advantage of helping
the prevention of eating disorders on athletes through the promotion of psychological skills that protect
athletes from the negative effects of sport practicing, where are included maladaptive eating behaviors.(undefined
Nonlinear Stochastic Partial Differential Equations of hyperbolic type driven by LĂ©vy-type noises
Nonlinear stochastic evolution equations of second order with damping
Convergence of a full discretization of a second order stochastic evolution
equation with nonlinear damping is shown and thus existence of a solution is
established. The discretization scheme combines an implicit time stepping
scheme with an internal approximation. Uniqueness is proved as well.Comment: This is the version of the article accepted for publication. The
final publication is available at http://link.springer.co
Atividade fĂsica, qualidade de vida e depressĂŁo durante a gravidez
This study examines physical activity patterns among women, from pre-pregnancy to the second trimester of pregnancy, and the relationship between physical activity status based on physical activity guidelines and health-related quality of life (HRQoL) and depression over pregnancy. 56 healthy pregnant women self reported physical activity, HRQoL and depression at 10-15 and 19-24 weeks of pregnancy and physical activity before pregnancy. Whereas vigorous leisure physical activity decreased after conception, moderate leisure physical activity and work related physical activity remained stable over time. The prevalence of recommended physical activity was 39.3% and 12.5% in the 1st and 2nd trimesters of pregnancy respectively, and 14.3% pre-pregnancy. From the 1st to the 2nd pregnancy trimester, most
physical HRQoL dimensions scores decreased and only mental component increased, independently
of physical activity status. No changes in mean depression scores were observed. These data suggest
that physical activity patterns change with pregnancy and that physical and mental components
are differentially affected by pregnancy course, independently of physical activity status.Este estudo examina os padrĂ”es de atividade fĂsica antes
da concepção até o segundo trimestre de gravidez
e a relação entre o nĂvel de atividade fĂsica, com base
nas recomendaçÔes de atividade fĂsica, a qualidade de
vida relacionada Ă saĂșde (QVRS) e depressĂŁo ao longo
da gravidez. Cinquenta e seis grĂĄvidas saudĂĄveis reportaram
nĂvel de atividade fĂsica, QVRS e depressĂŁo
às 10-15 e 19-24 semanas de gravidez, além de atividade
fĂsica antes da concepção. Enquanto a atividade
fĂsica vigorosa no lazer diminuiu depois da concepção,
as atividades fĂsicas moderadas no lazer e no trabalho
mantiveram-se estĂĄveis. A prevalĂȘncia de atividade fĂ-
sica recomendada foi de 39,3%, 12,5% e 14,3% antes,
no primeiro e no segundo trimestres de gravidez, respectivamente.
Independentemente do estatuto de atividade
fĂsica, a maior parte dos escores nas dimensĂ”es
fĂsicas da QVRS diminui do primeiro para o segundo
trimestre de gestação, e apenas o componente mental
aumenta. Não se verificaram alteraçÔes nos escores
médios de depressão. Estes dados sugerem que, com a
gravidez, hĂĄ alteração nos padrĂ”es de atividade fĂsica;
alĂ©m disso, os componentes fĂsico e mental sĂŁo diferentemente
afetados pelo curso da gestação, independentemente
do nĂvel de atividade fĂsica
Meta-Analysis of the Reasoned Action Approach (RAA) to Understanding Health Behaviors
YesBackground: Reasoned action approach (RAA) includes subcomponents of attitude (experiential/instrumental), perceived norm (injunctive/descriptive), and perceived behavioral control (capacity/autonomy) to predict intention and behavior. Purpose: To provide a meta-analysis of the RAA for health behaviors focusing on comparing the pairs of RAA subcomponents and differences between health protection and health-risk behaviors. Methods: The present research reports a meta-analysis of correlational tests of RAA subcomponents, examination of moderators, and combined effects of subcomponents on intention and behavior. Regressions were used to predict intention and behavior based on data from studies measuring all variables. Results: Capacity and experiential attitude had large, and other constructs had small-medium-sized correlations with intention; all constructs except autonomy were significant independent predictors of intention in regressions. Intention, capacity, and experiential attitude had medium-large, and other constructs had small-medium-sized correlations with behavior; intention, capacity, experiential attitude, and descriptive norm were significant independent predictors of behavior in regressions. Conclusions: The RAA subcomponents have utility in predicting and understanding health behaviors
Now you see it, Now you donât: compulsive exercise in adolescents with an eating disorder
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