Xavier Schmitz | HEC-ULg - Academia.edu (original) (raw)
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Papers by Xavier Schmitz
Fear of falling (FoF) is a real public health problem among elders. Indeed, this multi-determined... more Fear of falling (FoF) is a real public health problem among elders. Indeed, this multi-determined phenomenon is highly prevalent in the elderly and leads to several negative physical and psychological consequences. Therefore, identify elders at risk of experiencing this fear is essential. By means of a two-year longitudinal study, we examined the relationships between different variables (i.e., sociodemographic, physical, psychological and cognitive variables) and FoF among 92 elders aged 65 and over. All participants were assessed twice (i.e., at the beginning and at the end of the study) with besides quarterly calls in order to report falls. We conducted univariate and multivariate logistic regression analyses. As expected, our multivariate model showed that a prior history of falls is a significant predictor of FoF. We also pointed out a higher tendency among women to experience FoF than among men. Furthermore, we showed, through univariate analyses, significant relationships bet...
Kitaev's quantum double models in 2D provide some of the most commonly studied examples of topolo... more Kitaev's quantum double models in 2D provide some of the most commonly studied examples of topological quantum order. In particular, the ground space is thought to yield a quantum error-correcting code. We offer an explicit proof that this is the case for arbitrary finite groups. Actually a stronger claim is shown: any two states with zero energy density in some contractible region must have the same reduced state in that region. Alternatively, the local properties of a gauge-invariant state are fully determined by specifying that its holonomies in the region are trivial. We contrast this result with the fact that local properties of gauge-invariant states are not generally determined by specifying all of their non-Abelian fluxes-that is, the Wilson loops of lattice gauge theory do not form a complete commuting set of observables. We also note that the methods developed by P. Naaijkens (PhD thesis, 2012) under a different context can be adapted to provide another proof of the error correcting property of Kitaev's model. Finally, we compute the topological entanglement entropy in Kitaev's model, and show, contrary to previous claims in the literature, that it does not depend on whether the "log dim R" term is included in the definition of entanglement entropy.
American Journal of Speech-language Pathology, 2012
Purpose: According to the Procedural Deficit Hypothesis (PDH), difficulties in the Procedural Lea... more Purpose: According to the Procedural Deficit Hypothesis (PDH), difficulties in the Procedural Learning (PL) system may contribute to the language difficulties observed in children with Specific Language Impairment (SLI). Method: Fifteen children with SLI and their typically developing (TD) peers were compared on visual PL tasks: specifically, deterministic Serial Reaction Time (SRT) tasks. In a first experiment, children with SLI and their TD peers performed the classical SRT task using a keyboard as response mode. In a second experiment, they performed the same SRT task but gave their responses through a touchscreen (instead of a keyboard) to reduce the motor and cognitive demands of the task. Results: Although in Experiment 1, children with SLI demonstrated learning, they were slower and made more errors than their TD peers. Nevertheless, these relative weaknesses disappeared when the nature of the response mode changed (Experiment 2). Conclusions: This study reports that children...
For half the subjects a small part of the form is first administered, and then the missing elemen... more For half the subjects a small part of the form is first administered, and then the missing elements are added little by little (Errorless condition). The other 1. In the learning phase, we observe a lower error rate in the errorless condition. We observe an advantage for the errorless condition only for AD patients with low scores in working memory (F=5,01, p=.04) and motor inhibition (F=4,02, p=.06).
European Geriatric Medicine, 2015
Conclusions: To the best of our knowledge this is the first study that presents data on the relat... more Conclusions: To the best of our knowledge this is the first study that presents data on the relationship between smoking and life satisfaction of older people in EU countries living independently. Non-smoking older people report a higher level of life satisfaction compared to smoking older people. The relation between smoking behaviour, diseases, disabilities and life satisfaction is complicated because smoking is related to diseases with a high mortality rate and sometimes a relatively short period with disabilities before death.
European Geriatric Medicine, 2015
Fear of falling (FoF) is a real public health problem among elders. Indeed, this multi-determined... more Fear of falling (FoF) is a real public health problem among elders. Indeed, this multi-determined phenomenon is highly prevalent in the elderly and leads to several negative physical and psychological consequences. Therefore, identify elders at risk of experiencing this fear is essential. By means of a two-year longitudinal study, we examined the relationships between different variables (i.e., sociodemographic, physical, psychological and cognitive variables) and FoF among 92 elders aged 65 and over. All participants were assessed twice (i.e., at the beginning and at the end of the study) with besides quarterly calls in order to report falls. We conducted univariate and multivariate logistic regression analyses. As expected, our multivariate model showed that a prior history of falls is a significant predictor of FoF. We also pointed out a higher tendency among women to experience FoF than among men. Furthermore, we showed, through univariate analyses, significant relationships bet...
Kitaev's quantum double models in 2D provide some of the most commonly studied examples of topolo... more Kitaev's quantum double models in 2D provide some of the most commonly studied examples of topological quantum order. In particular, the ground space is thought to yield a quantum error-correcting code. We offer an explicit proof that this is the case for arbitrary finite groups. Actually a stronger claim is shown: any two states with zero energy density in some contractible region must have the same reduced state in that region. Alternatively, the local properties of a gauge-invariant state are fully determined by specifying that its holonomies in the region are trivial. We contrast this result with the fact that local properties of gauge-invariant states are not generally determined by specifying all of their non-Abelian fluxes-that is, the Wilson loops of lattice gauge theory do not form a complete commuting set of observables. We also note that the methods developed by P. Naaijkens (PhD thesis, 2012) under a different context can be adapted to provide another proof of the error correcting property of Kitaev's model. Finally, we compute the topological entanglement entropy in Kitaev's model, and show, contrary to previous claims in the literature, that it does not depend on whether the "log dim R" term is included in the definition of entanglement entropy.
American Journal of Speech-language Pathology, 2012
Purpose: According to the Procedural Deficit Hypothesis (PDH), difficulties in the Procedural Lea... more Purpose: According to the Procedural Deficit Hypothesis (PDH), difficulties in the Procedural Learning (PL) system may contribute to the language difficulties observed in children with Specific Language Impairment (SLI). Method: Fifteen children with SLI and their typically developing (TD) peers were compared on visual PL tasks: specifically, deterministic Serial Reaction Time (SRT) tasks. In a first experiment, children with SLI and their TD peers performed the classical SRT task using a keyboard as response mode. In a second experiment, they performed the same SRT task but gave their responses through a touchscreen (instead of a keyboard) to reduce the motor and cognitive demands of the task. Results: Although in Experiment 1, children with SLI demonstrated learning, they were slower and made more errors than their TD peers. Nevertheless, these relative weaknesses disappeared when the nature of the response mode changed (Experiment 2). Conclusions: This study reports that children...
For half the subjects a small part of the form is first administered, and then the missing elemen... more For half the subjects a small part of the form is first administered, and then the missing elements are added little by little (Errorless condition). The other 1. In the learning phase, we observe a lower error rate in the errorless condition. We observe an advantage for the errorless condition only for AD patients with low scores in working memory (F=5,01, p=.04) and motor inhibition (F=4,02, p=.06).
European Geriatric Medicine, 2015
Conclusions: To the best of our knowledge this is the first study that presents data on the relat... more Conclusions: To the best of our knowledge this is the first study that presents data on the relationship between smoking and life satisfaction of older people in EU countries living independently. Non-smoking older people report a higher level of life satisfaction compared to smoking older people. The relation between smoking behaviour, diseases, disabilities and life satisfaction is complicated because smoking is related to diseases with a high mortality rate and sometimes a relatively short period with disabilities before death.
European Geriatric Medicine, 2015