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151.
Pääsuke M Ereline J Gapeyeva H Joost K Mõttus K Taba P 《Journal of aging and physical activity》2004,12(4):511-524
The lower extremity performance in elderly female patients with mild to moderate Parkinson's disease (PD; n = 12) and controls (n = 16) was compared. Isometric dynamometry and force-plate measurements were used. PD patients had lower (p < .05) bilateral (BL) maximal isometric leg-extension force (MF), BL isometric MF relative to body mass, and maximal rate of isometric force development than control participants. BL strength deficit was greater (p < .05) in PD patients than in controls. A significantly longer chair-rise time and lower maximal rate of vertical-ground-reaction-force development while rising from a chair was found in PD patients than in controls. These findings suggest that elderly women with PD have lowered voluntary isometric force-generation capacity of the leg-extensor muscles. Reduced BL leg-extension strength might contribute to the difficulty of individuals with PD to rise from a chair. 相似文献
152.
Research on disparities in health and services should include a critical examination of how social, cultural, and contextual factors affect the connection between symptoms and psychiatric disorders. Systematic differences in this connection by these factors will mean that clinicians using a universalist approach to disorders may make more diagnostic errors for certain patients (e.g., ethnic minorities, the poor). Based on the literature on normative clinical decision-making, this study tests for whether the effect of specific psychiatric disorders on key symptoms is the same for certain groups of the population. The data come from the National Comorbidity Survey. Conditional probabilities of disorders and symptoms, the elements feeding into clinical decision-making, are calculated and tested for equivalence across various racial/ethnic, educational, income, and gender groups. We find some significant differences in the relation of key symptoms to disorders across groups. These findings should encourage testing relativistic frameworks in diagnostic nosology as a step to improve clinical decision-making and reduce diagnostic and treatment disparities in mental health services. 相似文献
153.
Literature on ambidexterity emphasizes the need for both exploration and exploitation. Large firms usually choose to implement structural ambidexterity to separate both activities. We here focus on an extreme case of such structural partitioning implemented as a secret skunkworks project in a large French automotive company. A qualitative survey using both primary and secondary data shows that the major basic and initial characteristics of a skunkworks (i.e. secrecy, urgency, and autonomy) created favorable conditions for the technological exploration. However, exploitation failed due to precisely those same characteristics coupled with the fact that the project did not respond to a specific market demand: The skunkworks suffered from what we call the "Robinson Crusoe effect." We therefore contribute to the literature on skunkworks, which have remained understudied in the academic literature, as well as on ambidexterity, by showing how the interrelation between different factors is crucial for structural ambidexterity to be successful 相似文献
154.
Rafael Pino-Mejías Mercedes Carrasco-Mairena Antonio Pascual-Acosta María-Dolores Cubiles-De-La-Vega Joaquín Muñoz-García 《Journal of applied statistics》2008,35(3):233-244
The main models of machine learning are briefly reviewed and considered for building a classifier to identify the Fragile X Syndrome (FXS). We have analyzed 172 patients potentially affected by FXS in Andalusia (Spain) and, by means of a DNA test, each member of the data set is known to belong to one of two classes: affected, not affected. The whole predictor set, formed by 40 variables, and a reduced set with only nine predictors significantly associated with the response are considered. Four alternative base classification models have been investigated: logistic regression, classification trees, multilayer perceptron and support vector machines. For both predictor sets, the best accuracy, considering both the mean and the standard deviation of the test error rate, is achieved by the support vector machines, confirming the increasing importance of this learning algorithm. Three ensemble methods - bagging, random forests and boosting - were also considered, amongst which the bagged versions of support vector machines stand out, especially when they are constructed with the reduced set of predictor variables. The analysis of the sensitivity, the specificity and the area under the ROC curve agrees with the main conclusions extracted from the accuracy results. All of these models can be fitted by free R programs. 相似文献
155.
In this article, we explore the impacts that education expansion and increased levels in educational homogamy have had on couples’ isolated illiteracy rates, defined as the proportion of illiterates in union that are married to an illiterate partner. First, we develop the methodology to decompose isolated illiteracy rates into two main components: one related to level of homogamy among illiterates, and the other related to the educational distribution of the spouses. Second, we use harmonized international census microdata from IPUMS and DHS data for 73 countries and 217 samples to investigate which of the two components is more important in shaping the level of isolated illiteracy. Our results indicate that the expansion of literacy has been more powerful than the increases in the tendency toward homogamy in its impact on isolated illiteracy rates. As the percentage of illiterates decreases over time, an increasingly large proportion of them marry literate individuals, showing that opportunities for intermarriage among illiterates expand despite the strengthening of homogamy. 相似文献
156.
C. B. García J. García Pérez J. R. van Dorp 《Statistical Methods and Applications》2011,20(4):463-486
A prevalence of heavy-tailed, peaked and skewed uncertainty phenomena have been cited in literature dealing with economic,
physics, and engineering data. This fact has invigorated the search for continuous distributions of this nature. In this paper
we shall generalize the two-sided framework presented in Kotz and van Dorp (Beyond beta: other continuous families of distributions
with bounded support and applications. World Scientific Press, Singapore, 2004) for the construction of families of distributions with bounded support via a mixture technique utilizing two generating
densities instead of one. The family of Elevated Two-Sided Power (ETSP) distributions is studied as an instance of this generalized
framework. Through a moment ratio diagram comparison, we demonstrate that the ETSP family allows for a remarkable flexibility
when modeling heavy-tailed and peaked, but skewed, uncertainty phenomena. We shall demonstrate its applicability via an illustrative
example utilizing 2008 US income data. 相似文献
157.
Angela María Estrada Carolina Ibarra Estefanía Sarmiento 《Community, Work & Family》2007,10(3):257-281
A qualitative study was carried out in four municipalities in four different conflict zones in Colombia. Intrafamilial violence and gender violence are studied through the testimonies of the people interviewed. The impact was analysed in terms of the exercise of control over the civilian population by paramilitaries in relation to subjectivity, the family, social networks and the prevailing moral order. In effect, the strengthening of barriers between traditional gender identities has enabled a de-structuring of traditional masculinity through moral co-optation, the reinforcement of traditional feminine identity and the objectification of the sexuality of young women, at the same time as they are manipulated sexually and emotionally. In general, strong legitimation of the model of the armed fighter as a paradigm of masculinity is found in children. In addition, the de-structuring of the family and its manipulation as a means of influence over civil society is one of the strategies employed for the installation of a regime of terror that fractures social networks. It does this through the erosion of confidence and the legitimation and mystification of the power of an actor whose mediation in inter-family and micro-social conflicts has been legitimated, instrumentalizing and scaling up traditional violence, taking advantage of the power vacuum and moral weaknesses in local culture. 相似文献
158.
This paper provides an analysis of the Minimal Overlap Rule, a solution for bankruptcy problems introduced by O’Neill (1982). We point out that this rule can be understood as a composition
of Ibn Ezra’s proposal and the recommendation given by the Constrained Equal Loss Rule. Following an interpretation of bankruptcy problems in terms of TU games, we show that the Minimal Overlap Value is the unique solution for bankruptcy games which satisfies Anonymity and Core Transition Responsiveness. 相似文献
159.
Influence diagnostics in the capital asset pricing model under elliptical distributions 总被引:1,自引:0,他引:1
In this paper we consider the Capital Asset Pricing Model under Elliptical (symmetric) Distributions. This class of distributions, which contains the normal distribution, t, contaminated normal and power exponential, among others, offers a more flexible framework for modelling asset prices or returns. In order to analyze the sensibility to possible outliers and/or atypical returns of the maximum likelihood estimators, the local influence method was implemented. The results are illustrated by using a set of shares from companies who trade in the Chilean Stock Market. Our main conclusion is that symmetric distributions having heavier tails than those of the normal distribution, especially the t distribution with small degrees of freedom, show a better fit and allow the reduction of the influence of atypical returns in the maximum likelihood estimators. 相似文献
160.