Ambulatory measurement of ankle kinetics for clinical applications.

This study aimed to design and validate the measurement of ankle kinetics (force, moment, and power) during consecutive gait cycles and in the field using an ambulatory system. An ambulatory system consisting of plantar pressure insole and inertial sensors (3D gyroscopes and 3D accelerometers) on foot and shank was used. To test this system, 12 patients and 10 healthy elderly subjects wore shoes embedding this system and walked many times across a gait lab including a force-plate surrounded by seven cameras considered as the reference system. Then, the participants walked two 50-meter trials where only the ambulatory system was used. Ankle force components and sagittal moment of ankle measured by ambulatory system showed correlation coefficient (R) and normalized RMS error (NRMSE) of more than 0.94 and less than 13% in comparison with the references system for both patients and healthy subjects. Transverse moment of ankle and ankle power showed R>0.85 and NRMSE<23%. These parameters also showed high repeatability (CMC>0.7). In contrast, the ankle coronal moment of ankle demonstrated high error and lower repeatability. Except for ankle coronal moment, the kinetic features obtained by the ambulatory system could distinguish the patients with ankle osteoarthritis from healthy subjects when measured in 50-meter trials. The proposed ambulatory system can be easily accessible in most clinics and could assess main ankle kinetics quantities with acceptable error and repeatability for clinical evaluations. This system is therefore suggested for field measurement in clinical applications.

Multi-stage oligopoly models with nested logit demand structures: A simplifying approach

Solving multi-stage oligopoly models by backward induction can easily become a com- plex task when rms are multi-product and demands are derived from a nested logit frame- work. This paper shows that under the assumption that within-segment rm shares are equal across segments, the analytical expression for equilibrium pro ts can be substantially simpli ed. The size of the error arising when this condition does not hold perfectly is also computed. Through numerical examples, it is shown that the error is rather small in general. Therefore, using this assumption allows to gain analytical tractability in a class of models that has been used to approach relevant policy questions, such as for example rm entry in an industry or the relation between competition and location. The simplifying approach proposed in this paper is aimed at helping improving these type of models for reaching more accurate recommendations.

Innovation or Imitation? The effect of spillovers and competitive pressure on firms' R&D strategy choice

This article provides a theoretical and empirical analysis of a firm's optimal R&D strategy choice. In this paper a firm's R&D strategy is assumed to be endogenous and allowed to depend on both internal firms. characteristics and external factors. Firms choose between two strategies, either they engage in R&D or abstain from own R&D and imitate the outcomes of innovators. In the theoretical model this yields three types of equilibria in which either all firms innovate, some firms innovate and others imitate, or no firm innovates. Firms'equilibrium strategies crucially depend on external factors. We find that the efficiency of intellectual property rights protection positively affects firms'incentives to engage in R&D, while competitive pressure has a negative effect. In addition, smaller firms are found to be more likely to become imitators when the product is homogeneous and the level of spillovers is high. These results are supported by empirical evidence for German .rms from manufacturing and services sectors. Regarding social welfare our results indicate that strengthening intellectual property protection can have an ambiguous effect. In markets characterized by a high rate of innovation a reduction of intellectual property rights protection can discourage innovative performance substantially. However, a reduction of patent protection can also increase social welfare because it may induce imitation. This indicates that policy issues such as the optimal length and breadth of patent protection cannot be resolved without taking into account specific market and firm characteristics. Journal of Economic Literature Classification Numbers: C35, D43, L13, L22, O31. Keywords: Innovation; imitation; spillovers; product differentiation; market competition; intellectual property rights protection.

Influence of inter-electrode distance, contraction type, and muscle on the relationship between the sEMG power spectrum and contraction force.

INTRODUCTION: Spectral frequencies of the surface electromyogram (sEMG) increase with contraction force, but debate still exists on whether this increase is affected by various methodological and anatomical factors. This study aimed to investigate the influence of inter-electrode distance (IED) and contraction modality (step-wise vs. ramp) on the changes in spectral frequencies with increasing contraction strength for the vastus lateralis (VL) and vastus medialis (VM) muscles. METHODS: Twenty healthy male volunteers were assessed for isometric sEMG activity of the VM and VL, with the knee at 90° flexion. Subjects performed isometric ramp contractions in knee extension (6-s duration) with the force gradually increasing from 0 to 80 % MVC. Also, subjects performed 4-s step-wise isometric contractions at 10, 20, 30, 40, 50, 60, 70, and 80 % MVC. Interference sEMG signals were recorded simultaneously at different IEDs: 10, 20, 30, and 50 mm. The mean (F mean) and median (F median) frequencies and root mean square (RMS) of sEMG signals were calculated. RESULTS: For all IEDs, contraction modalities, and muscles tested, spectral frequencies increased significantly with increasing level of force up to 50-60 % MVC force. Spectral indexes increased systematically as IED was decreased. The sensitivity of spectral frequencies to changes in contraction force was independent of IED. The behaviour of spectral indexes with increasing contraction force was similar for step-wise and ramp contractions. CONCLUSIONS: In the VL and VM muscles, it is highly unlikely that a particular inter-electrode distance or contraction modality could have prevented the observation of the full extent of the increase in spectral frequencies with increasing force level.

CoLaus: diabète et dyslipidémie, il y a toujours du nouveau ! [CoLaus: diabetes and dyslipidemia, there is always something to new !].

Résumé : Les maladies cardiovasculaires restent la première cause de mortalité dans notre pays. Elles sont associées à des facteurs de risque (FRCV) bien connus comme le diabète ou la dyslipidémie. Nous résumons ici les principaux résultats de l'étude CoLaus concernant d'une part la prévalence du diabète et de la dyslipidémie et certaines caractéristiques de leur prise en charge.Les découvertes récentes concernant de nouveaux déterminants génétiques impliqués dans ces FRCV sont présentées de manière succincte. La contribution de ces données génétiques est également discutée dans une perspective de prise en charge clinique.[Abstract] Cardiovascular diseases remain the first cause of mortality in our country. They are associated with well known risk factors such as diabetes and dyslipidemia. Herein we summarize main results of the CoLaus study regarding, first the prevalence and characteristics of the treatment of these risk factors.Then we present recent discoveries of new genetic determinants associated with these risk factors. Finally, we discuss whether this knowledge changes our current clinical management of our patients.

An outbreak of gastroenteritis associated with astrovirus serotype 1 in a day care center, in Rio de Janeiro, Brazil

Between June 4th and June 20th1996 rotavirus, adenovirus, and astrovirus (HAstrV) were investigated in fecal samples from 27 children under three years old with acute diarrhea, attending the Bertha Lutz day care center, in Rio de Janeiro. All fecal samples were analyzed by polyacrylamide gel electrophoresis (PAGE), reverse transcriptase polymerase chain reaction (RT-PCR), enzyme immunoassays (EIA), and electron microscopy (EM). Nine of them (33%) showed positive results for HAstrV by at least one of the employed methodologies. Eight were positive by RT-PCR and EIA, and six by EM. All positive samples were inoculated onto HT-29 (human colon adenocarcinoma) cultured cells for HAstrV isolation and seven were positive after three passages. The sequencing analysis of eight RT-PCR products (449 bp) from gene that codifies VP2 protein, showed a total nucleotide identity among them and 98% with HAstrV-1 (strain Oxford type 1). This is the first report of a gastroenteritis outbreak associated with HAstrv-1 in a day care center in Rio de Janeiro and it reinforces the importance of this virus in association with infantile acute gastroenteritis.

Médecine sociale en 2013 : quand la précarité précède la pauvreté [Social medicine : does it still make sense in 2013?]

Social medicine is a medicine that seeks to understand the impact of socio-economic conditions on human health and diseases in order to improve the health of a society and its individuals. In this field of medicine, determining the socio-economic status of individuals is generally not sufficient to explain and/or understand the underlying mechanisms leading to social inequalities in health. Other factors must be considered such as environmental, psychosocial, behavioral and biological factors that, together, can lead to more or less permanent damages to the health of the individuals in a society. In a time where considerable progresses have been made in the field of the biomedicine, does the practice of social medicine in a primary care setting still make sense? La médecine sociale est une médecine qui cherche à comprendre l'impact des conditions socio-économiques sur la santé humaine et les maladies, dans la perspective d'améliorer l'état de santé d'une société et de ses individus. Dans ce domaine, la détermination du statut socio-économique des individus ne suffit généralement pas à elle seule pour expliquer et comprendre les mécanismes qui sous-tendent les inégalités sociales de santé. D'autres facteurs doivent être pris en considération, tels que les facteurs environnementaux, psychosociaux, comportementaux et biologiques, facteurs qui peuvent conduire de manière synergique à des atteintes plus ou moins durables de l'état de santé des individus d'une société. A une époque où les connaissances, les compétences et les moyens à disposition en biomédecine ont fait des progrès considérables, la pratique de la médecine sociale en cabinet a-t-elle encore sa place en 2013?

Dépistage organisé du cancer colorectal: défis et enjeux pour un essai pilote en Suisse. [Organized screening for colorectal cancer: challenges and issues for a Swiss pilot study].

Colorectal cancer is among the three most common and lethal neoplasms in Switzerland (about 4,000 new cases and 1,600 deaths per year, respectively). Several screening modalities are available. The effectiveness of colorectal cancer screening on mortality is established. The implementation of a successful screening intervention shall follow specified phases and conditions, and abide with global principles: pooling and coordinating efforts from all partners, setting goals and priorities, and identifying action plans. A feasibility (pilot) study is needed to verify requirements for quality, effectiveness, efficiency and innocuousness. Endeavours towards implementing a pilot programme for colorectal cancer screening in the Vaud canton (Switzerland) are presented and discussed.

Evaluation globale et prise en charge gériatriques: quel intérêt ?: revue Cochrane pour le praticien.

Cet article présente les résultats de la revue systématique: Ellis G, Whitehead MA, O'Neill D, Langhorne P, Robinson D. Comprehensive geriatric assessment for older adults admitted to hospital. Cochrane Database Syst Rev. 2011 Jul 6;(7):CD006211. PMID: 21735403.

Gériatrie [Review in geriatric medicine 2013].

Physical activity appears once again as the single most effective preventative intervention in older persons to delaying functional decline, avoiding falls, and mitigating the odds of developing dementia. Integrated care that promotes interdisciplinary collaboration among healthcare professionals is a major avenue to improve care coordination in polymorbid older patients. A study depicts the large gap between physicians and nurses' views about their respective skills and role in such a collaboration. On the cognitive side, while several studies show that new cohorts of older persons appear to age in better cognitive shape, results of trials of semagestat, a gamma-secretase inhibitor, and post-menopausal estrogenic therapy were disappointing. Finally, a study challenges the benefits of hydration in terminally ill patients.

Adaptations des recommandations pour la pratique clinique: l'exemple du Programme cantonal Diabète de Vaud [Adaptation of clinical practice guidelines--the example of cantonal Diabetes Program].

With the growing number of scientific publications, practitioners can use scientific knowledge synthesis, including Clinical Practice Guidelines (CPG). The practical use of a CPG implies considering the context, that is the local healthcare system and the patient. Thus, the CPG can never replace the expertise of the practitioner! Diabetes is a wide public health issue and the canton of Vaud established the cantonal Diabetes Program (cDP), to optimize the care of diabetic patients. The cDP has many projects including the adaptation of reliable CPG to local needs. We present the pros and cons of the CPG in the cDP and the methods to adapt it to the regional healthcare context, and also at an individual level.

Prévention primaire et dépistage chez l'adulte: mise a jour 2014 [Primary prevention and screening in adults: update 2014].

Cet article propose une mise à jour des recommandations pour le bilan de santé et la prévention primaire et secondaire de nombreuses maladies cardiovasculaires et oncologiques. Les nouveautés pour le dépistage des cancers concernent essentiellement les cancers colorectal, du poumon et de la prostate. Pour la prévention des maladies cardiovasculaires, le dépistage de la sténose de l'artère carotidienne n'est toujours pas recommandé. Les preuves de la littérature sont insuffisantes pour recommander le dépistage de l'artériopathie coronarienne ou périphérique chez les patients asymptomatiques. Le partage de l'information et de la décision entre le médecin et le patient est à privilégier lorsqu'il existe une incertitude quant à l'efficacité d'une intervention. This article provides an update on the recommendations for the routine check-up and the primary and secondary prevention of cancer and cardiovascular disease. Changes for cancer screening affect mainly colorectal, lung and prostate cancers. In the area of cardiovascular disease prevention, screening for carotid artery stenosis is still not recommended. The current evidence is insufficient to recommend screening for coronary heart disease or peripheral artery disease in asymptomatic patients. Shared information and decision making between physician and patient is recommended when there is uncertainty regarding the effectiveness of an intervention.

Addictions [Addiction].

Les nouveautés en médecine 2012 pour les dépendances sont présentées sur trois axes d'actualité : tout d'abord dans le champ des neurosciences avec les travaux sur les processus d'extinction de la mémoire addictive. Puis dans le champ clinique avec une réflexion sur le traitement des addictions à l'hôpital psychiatrique. Enfin, dans le domaine de l'enseignement, un développement d'e-learning avec un patient virtuel présente un grand intérêt en psychiatrie de l'addiction. This year, the actuality about addiction is on psychopharmacology, in the controversy about the prescription of baclofene to reduce the craving for alcohol. More results from controlled studies are expected. The development of smartphones to access toe-Health skills is questionable, especially in matterofevaluation of these programs. Despite of encouraging results, open questions are remaining for clinicians, to be compared with clinical practice. Finally, it is necessary to keep in touch with translational neurosciences; in fact, research is showing that populations of addicts present a deficit in matter of empathy. This is the cause of a handicap in the social relationships. At a lower level, a difficulty to take the other's place could be the cause of this deficit at a higher level. Rehabilitation perspectives could come out of this discovery.

Contribution de l'étude CoLaus à l'élucidation des déterminants de l'acide urique sérique. [Contribution of the CoLaus study to decipher the determinants of serum uric acid].

Asymptomatic hyperuricemia affects one in five adults in the general population and is associated with elevated cardiovascular risk. It is however not clear whether asymptomatic hyperuricemia is a cause or simply a marker of conditions associated with high cardiovascular risk. Sex, age, obesity, renal function and selected drugs are major determinants of serum uric acid. Moreover, recent genome-wide association studies have identified new genes involved in the control of serum uric acid levels, in particular SLC2A9, which encodes a urate transporter located in the kidney. A genetic score based on several genetic variants associated with serum uric acid is strongly associated with the risk of gout, but not with cardiovascular events so far.