Systems control theory applied to natural and synthetic musical sounds

Systems control theory is a far developped field which helps to study stability, estimation and control of dynamical systems. The physical behaviour of musical instruments, once described by dynamical systems, can then be controlled and numerically simulated for many purposes. The aim of this paper is twofold: first, to provide the theoretical background on linear system theory, both in continuous and discrete time, mainly in the case of a finite number of degrees of freedom ; second, to give illustrative examples on wind instruments, such as the vocal tract represented as a waveguide, and a sliding flute

Endogenous N-nitroso compounds, and their precursors, present in bacon, do not initiate or promote aberrant crypt foci in the colon of rats

Processed meat intake is associated with increased risk of colorectal cancer. This association may be explained by the endogenous formation of N-nitroso compounds (NOC). The hypothesis that meat intake can increase fecal NOC levels and colon carcinogenesis was tested in 175 Fischer 344 rats. Initiation was assessed by the number of aberrant crypt foci (ACF) in the colon of rats 45 days after the start of a high-fat bacon-based diet. Promotion was assessed by the multiplicity of ACF (crypts per ACF) in rats given experimental diets for 100 days starting 7 days after an azoxymethane injection. Three promotion studies were done, each in 5 groups of 10 rats, whose diets contained 7%, 14%, or 28% fat. Tested meats were bacon, pork, chicken, and beef. Fecal and dietary NOC were assayed by thermal energy analysis. Results show that feces from rats fed bacon-based diets contained 10-20 times more NOC than feces from control rats fed a casein-based diet (all p < 0.0001 in 4 studies). In bacon-fed rats, the amount of NOC input (diet) and output (feces) was similar. Rats fed a diet based on beef, pork, or chicken meat had less fecal NOC than controls (most p < 0.01). No ACF were detected in the colon of bacon-fed uninitiated rats. After azoxymethane injection, unprocessed but cooked meat-based diets did not change the number of ACF or the ACF multiplicity compared with control rats. In contrast, the bacon-based diet consistently reduced the number of large ACF per rat and the ACF multiplicity in the three promotion studies by 12%, 17%, and 20% (all p < 0.01). Results suggest that NOC from dietary bacon would not enhance colon carcinogenesis in rats

L’intervention de type criminologique à l’aune de la Collaboration Cochrane

Dans les échelles d’appréciation de la qualité scientifique des recherches, les essais randomisés contrôlés (ERC) figurent en haut de la liste. En termes de crédibilité, dans le courant des pratiques fondées sur des données probantes (Evidence Based Practice [EBP]), les résultats qu’ils obtiennent ont la priorité sur les autres. Les recensions Cochrane, qui portent généralement sur l’efficacité d’interventions médicales, s’intéressent aussi aux interventions de type criminologique. À notre connaissance, aucune étude ne s’est encore penchée sur les conclusions dégagées par la Collaboration Cochrane sur ce type d’intervention. Dans le présent article, le contenu de la revue électronique Cochrane Database of Systematic Reviews a été analysé, pour la période allant de 2000 à 2008. Les résultats montrent que 33 recensions Cochrane ont traité d’interventions de type criminologique. Privilégiant les ERC, ces recensions n’ont retenu en moyenne que 2 % de toutes les études publiées dans différents champs d’intervention. Un tel résultat permet de discuter de la pertinence de la méthode Cochrane pour évaluer l’efficacité d’interventions à caractère plus social. Les questions posées concernent la représentativité des milieux où sont implantées les interventions, la concomitance et la complexité des problèmes à résoudre, les apports et limites des « protocoles » d’intervention, ainsi que les risques de retard, voire de paralysie, dans l’implantation d’approches innovantes.In reviews of scientific quality of studies, randomized controlled trials (RCT) are typically regarded as having the highest methodological rigour. Although the Cochrane Reviews are best known for their analysis of the effects of treatment in healthcare settings, they also investigate the effectiveness of criminological interventions. To our knowledge, no study has ever examined the conclusions of the Cochrane Reviews for this type of intervention. In this study, our analysis of the Cochrane Database of Systematic Reviews between 2000 and 2008 found 33 Cochrane Reviews of criminological interventions. Not surprisingly, given its weight on RCT, on average only 2 % of these studies were assessed as having high methodological quality. These results raise questions about the appropriateness of the Cochrane Reviews to evaluate the scientific quality of social type interventions. Issues such as the representativeness of the environment where interventions are implemented, the concomitance and complexity of social problems, the contributions and limits of intervention protocols and the risks of delay, even paralysis, in the implementation of innovative approaches are not part of their scientific quality examinations.Los estudios randomizados controlados (ERC) figuran a la cabeza de las escalas de evaluación de la calidad científica de las investigaciones. En términos de credibilidad, sus resultados tienen prioridad en la corriente de prácticas basadas en la evidencia (Evidence Based Practice). Las revisiones sistemáticas Cochrane, que por lo general tratan sobre la eficacia de las intervenciones médicas, se usan también en las intervenciones de tipo criminológico. Hasta donde sabemos, ningún estudio se ha detenido aún en las conclusiones de la Colaboración Cochrane sobre la intervención de tipo criminológico. En este artículo hemos analizado el contenido de la revista electrónica Cochrane Database of Systematic Reviews de 2000 a 2008 ; los resultados muestran que 33 revisiones sistemáticas Cochrane tratan sobre intervenciones de tipo criminológico. Privilegiando los ERC, estas revisiones no han retenido en promedio más que el 2 % del total de estudios publicados en ésta u otra área de intervención. Este resultado permite discutir la pertinencia del método Cochrane para evaluar la eficacia de intervenciones de índole más social. Las cuestiones planteadas conciernen la representatividad de los medios en que se han implantado las intervenciones, la concomitancia y complejidad de problemas por resolver, los aportes y límites de los protocolos de intervención y el riesgo de retraso, e incluso parálisis, en la instrumentación de enfoques innovadores

One hundred years of forensic sciences in Quebec: the evolution of scientific techniques since 1914

In 2014, Quebec's forensic science laboratory (Laboratoire de sciences judiciaires et de medicine légale) is celebrating its 100th anniversary. Since its foundation by Dr. Derome in 1914, scientific techniques in the various areas of forensic science have greatly evolved. Not only was the Laboratory the first forensic science institution in North America, it has been a pioneer for several analytical methods. The early days of the Laboratory as well as the specific evolution of the departments and divisions of biology, chemistry, arson and explosion, questioned documents, forensic pathology, odontology and anthropology, toxicology and administration will be reviewed here

Approche systémique de l’intégration des TIC dans l’éducation : enjeux, actions et perspectives à l’horizon 2020

En Belgique francophone, diverses initiatives ont vu le jour durant ces quinze dernières années dans le but de développer un usage réfléchi des TIC en éducation. Parmi celles-ci épinglons les « Plans TIC", la mise au point d’un curriculum de formation relatif aux usages et aux apports des médias et des TIC en enseignement destiné aux futurs enseignants, la mise en réseau d’enseignants du supérieur, la constitution de communautés d’apprenants supportées par les TIC. Plans d’équipement des écoles, projets-pilotes, formation initiale et continuée des enseignants en matière de TICE, réseaux de partage… convergent vers un même objectif : développer, expérimenter et diffuser des activités d’apprentissage à hautes plus-values. Des scénarios pédagogiques exploitant différents types d’outils/services technologiques et supports (ordinateurs, tablettes, tableaux interactifs…) et leurs plus-values sont mis au point afin de développer les savoirs, savoir-faire et savoir-être des apprenants, non seulement en rapport aux apprentissages scolaires, mais aussi dans l’optique d’un transfert dans la vie quotidienne, citoyenne et professionnelle. Certaines de ces initiatives seront présentées en les situant dans une approche systémique. Nous mettrons l’accent sur ce qui les unit, les facteurs facilitateurs et les obstacles rencontrés lors de leur implémentation sur le terrain et proposerons quelques recommandations

Alginate Scaffolds for Mesenchymal Stem Cell Cardiac Therapy: Influence of Alginate Composition

Despite the success of alginate scaffolds and mesenchymal stem cells (MSCs) therapy in cardiac failure treatment, the impact of the physicochemical environment provided by alginate matrices on cell behavior has never been investigated. The purpose of this work was double: to determine the alginate composition influence on (1) encapsulated rat MSC viability, paracrine activity, and phenotype in vitro and (2) cardiac implantability and in vivo biocompatibility of patch shape scaffolds. Two alginates, differing in composition and thus presenting different mechanical properties when hydrogels, were characterized. In both cases, encapsulated MSC viability was maintained at around 75%, and their secretion characteristics were retained 28 days postencapsulation. In vivo study revealed a high cardiac compatibility of the tested alginates: cardiac parameters were maintained, and rats did not present any sign of infection. Moreover, explanted hydrogels appeared surrounded by a vascularized tissue. However, scaffold implantability was highly dependent on alginate composition. G-type alginate patches, presenting higher elastic and Young moduli than M-type alginate patches, showed a better implantation easiness and were the only ones that maintained their shape and morphology in vivo. As a consequence of alginate chemical composition and resulting hydrogel structuration, G-type alginate hydrogels appear to be more adapted for cardiac implantation

EvaSylv: A user-friendly software to evaluate forestry scenarii including natural risk

Forest management relies on the evaluation of silviculture practices. The increase in natural risk due to climate change makes it necessary to consider evaluation criteria that take natural risk into account. Risk integration in existing software requires advanced programming skills.We propose a user-friendly software to simulate even-aged and monospecific forest at the stand level, in order to evaluate and optimize forest management. The software gives the possibility to run management scenarii with or without considering the impact of natural risk. The control variables are the dates and rates of thinning and the cutting age.The risk model is based on a Poisson processus. The Faustmann approach, including tree damage risk, is used to evaluate future benefits, economic or ecosystem services. It relies on the calculation of expected values, for which a dedicated mathematical development has been done. The optimized criteria used to evaluate the various scenarii are the Faustmann value and the Averaged yield value.We illustrate the approach and the software on two case studies: economic optimization of a beech stand and carbon sequestration optimization of a pine stand.Software interface makes it easy for users to write their own (growth-tree damage-economic) models without advanced programming skills. The possibility to run management scenarii with/without considering the impact of natural risk may contribute improving silviculture guidelines and adapting them to climate change. We propose future lines of research and improvement

Polyethylene glycol and prevalence of colorectal adenomas : Population-based study of 1165 patients undergoing colonoscopy

Background and aim — Dietary polyethylene glycol (PEG) is extraordinarily potent in the chemoprevention of experimental colon carcinogenesis. PEG is used to treat constipation in France and in the USA. French laxatives include Forlax® (PEG4000), Movicol® and Transipeg® (PEG3350), and Idrocol® (pluronic F68). This study tests the hypothesis that use of a PEG-based laxative might reduce the prevalence of colorectal tumors. Methods — In this population-based study, consecutive patients attending for routine total colonoscopy were enrolled during four months by the gastroenterologists of Indre-et-Loire. They were asked if they had previously taken a laxative or a NSAID. Age, gender, previous polyps, family history of colorectal cancer, constipation, digestive symptoms were also recorded. Tumors found during colonoscopy were categorized histologically. Results — Records from 1165 patients fulfilled the inclusion criteria, 607 women and 498 men, mean age 58.3. Among those, 813 had no tumor, 329 had adenomas, and 23 had carcinomas. In a univariate analysis, older age, male gender, lack of digestive symptom, and previous polyps were more common in patients with colorectal tumors. In contrast, previous Forlax® intake was more common in tumor-free patients (odds ratio (OR) any use/no use, 0.52; 95% confidence interval, 0.27-0.94). More people used Forlax®, which contains a higher dose of PEG than the other PEGlaxatives, whose ORs were smaller than one, but did not reach significance. In multivariate analysis, older age and male gender were associated with higher risk, and NSAIDs use with lower risk, of colorectal tumors. Conclusion — Forlax® users had a halved risk of colorectal tumors in univariate analysis, which suggests that PEG may prevent carcinogenesis