179 research outputs found
Peacock's "History of Arithmetic", an Attempt to reconcile empiricism to universality
When the Whig Anglican algebraist Rev. George Peacock (1791-1858) conceived of his new abstract view of Symbolical Algebra in the 1830s, he had already written an impressive little known « History of Arithmetic » for the Encyclopaedia Metropolitana, eventually published in 1845, back in the 1820s. This paper studies why this « History of Arithmetic » was conceived and how it reinforced Peacock's general view of algebra as a symbolizing process. As a fellow, tutor and lecturer at Trinity College since 1814, Peacock was already involved in the renewal of mathematics curriculum and mathematical research in Cambridge, as well as in the cultivation and the diffusion of science. As a reformer, Peacock along with his colleagues in Cambridge, faced the Industrial Revolution, its varied pressures on the country's academic institutions, and its concern with transformation processes. As soon as the 1820s, Peacock sought out a universal genesis from arithmetic to algebra, founded on the mathematical language of operations, and he launched his « History of Arithmetic » as a large inquiry into the vocabulary that all known tribes and nations used for elementary computations. In this way, he supported a moderate empiricist approach to science, deeply rooted in Locke's philosophy of human understanding. With a comparative and philological approach to numeral languages in hand, Peacock presented first arithmetic and then algebra as the progressive developments of asbtract calculating languages,.symbolising algorithmical processes. This view accounted for the special place he gave to Indian and Arabic arithmetics in his exposition of contemporaneous knowledge on numbers.Lorsque l'algĂ©briste Whig anglican George Peacock (1791-1858) prĂ©sente sa nouvelle conception de l'algĂšbre symbolique en 1830, il a dĂ©jĂ Ă©crit une "History of Arithmetic", impressionnante mais peu connue, publiĂ©e dans l'Encyclopaedia Metropolitana en 1846. Cet article analyse les orientations philosophiques qui nourrissent cette "History of Arithmetic", et en quoi elles affirment dĂ©jĂ sa conception de l'algĂšbre comme une Ă©tape dans le processus de symbolisation des opĂ©rations. En tant que tuteur, "lecturer" et "fellow" de Trinity College depuis 1814, Peacock, tout comme ses collĂšgues Ă Cambridge, est directement impliquĂ© dans le renouvellement des Ă©tudes et de la recherche en mathĂ©matiques, ainsi que dans le renforcement du rĂŽle de la science en Grande-Bretagne. En tant que rĂ©formateur, il est directement confrontĂ© aux effets de la rĂ©volution industrielle, notamment sur les institutions universitaires et les sociĂ©tĂ©s savantes, et sur l'importance qu'elle insuffle aux processus de transformation. DĂšs les annĂ©es 1820, Peacock envisage un mode universel de dĂ©veloppement de l'arithmĂ©tique, puis de l'algĂšbre, fondĂ© sur l'expĂ©rience des opĂ©rations, et perçu Ă travers le vocabulaire qui les reprĂ©sente. L'"History of Arithmetic" est structurĂ©e comme une vaste enquĂȘte sur le langage littĂ©ral et numĂ©rique qu'utilisent les diffĂ©rentes tribus et nations du monde connu pour reprĂ©senter les calculs Ă©lĂ©mentaires. Peacock soutient ainsi un empirisme modĂ©rĂ©, profondĂ©ment enracinĂ© dans la philosophie de Locke sur l'entendement humain. Cette approche comparatiste et philologique des langages sur les opĂ©rations permet d'envisager l'arithmĂ©tique, puis l'algĂšbre, comme Ă©tapes successives du processus de symbolisation des opĂ©rations, conçues comme algorithmiques. L'importance accordĂ©e aux arithmĂ©tiques dĂ©veloppĂ©es en Inde et dans le monde arabe prend ici tout son sens
RĂ©cit de lâĂ©dification dâune Ă©quipe de recherche interdisciplinaire pour aborder la problĂ©matique de la situation de handicap au travail
Depuis lâannĂ©e 2000, une Ă©quipe quĂ©bĂ©coise de chercheurs se sont alliĂ©s afin dâapprofondir et de mieux comprendre les diffĂ©rents facteurs, tant biomĂ©caniques quâorganisationnels, qui permettraient de cerner de façon plus efficace la problĂ©matique de la prĂ©vention des situations de handicap au travail. La crĂ©ation de cette Ă©quipe de chercheurs rĂ©sulte en fait dâune transformation de la comprĂ©hension de lâobjet de recherche passant dâun modĂšle mĂ©dical plutĂŽt monolithique Ă un modĂšle personne-environnement oĂč les contributions des systĂšmes extĂ©rieurs sont considĂ©rĂ©es. Bien que la littĂ©rature actuelle souligne la grandeur et les vertus du travail interdisciplinaire en recherche, peu dâauteurs se sont attardĂ©s aux processus, aux conditions et aux enjeux individuels de ce type de collaboration. Cet article veut dans un premier temps illustrer briĂšvement les connaissances qui appuient le nouveau paradigme dâincapacitĂ© au travail puis dĂ©gager quelques-uns des processus qui ont permis la construction de cette Ă©quipe interdisciplinaire pour finalement indiquer ce qui nous a semblĂ© reprĂ©senter les conditions gagnantes pour rĂ©ussir cet arrimage.In the year 2000, a team of researchers was formed in the province of Quebec to study the multiple biomechanical and organizational factors that may be involved in the prevention of work-related disability. In fact, the creation of the new team resulted from a better understanding of the research problem, with a shift from a monolithic medical model to a person-environment model within which the contribution of external systemic factors was considered. Although the recent literature underlines the importance of interdisciplinary work in research, few authors have examined the processes, conditions and individual issues of interdisciplinary collaboration. This article offers a brief presentation of the work disability paradigm and its characteristics, describes the process used to build the interdisciplinary team, and discusses the winning strategies for successful team development.Desde el año 2000, se ha formado un equipo de investigadores para profundizar y conocer mĂĄs los diferentes factores, tanto biomecĂĄnicos como organizacionales, que permitirĂan definir de manera mĂĄs eficaz la problemĂĄtica de la prevenciĂłn de las situaciones de discapacidad en el trabajo. De hecho, la creaciĂłn de este equipo de investigadores resulta de una transformaciĂłn de la comprensiĂłn del objeto de investigaciĂłn pasando de un modelo mĂ©dico mĂĄs bien monolĂtico a un modelo persona-ambiente en el cual se consideran las contribuciones de los sistemas exteriores. Aunque la literatura actual subraya la grandeza y las virtudes del trabajo interdisciplinario en la investigaciĂłn, pocos autores han estudiado los procesos, las condiciones y los desafĂos individuales de este tipo de colaboraciĂłn. Primero, este artĂculo ilustra brevemente los conocimientos que apoyan el nuevo paradigma de discapacidad en el trabajo, luego destacan algunos de los procesos que han permitido la construcciĂłn de este equipo interdisciplinario para finalmente indicar lo que nos pareciĂł representar las condiciones favorables para el Ă©xito de este desafĂo
Le regard français de Charles Babbage (1791-1871)sur le « déclin de la science en Angleterre »
Dans lâimagerie classique des informaticiens, Charles Babbage (1791-1871) est souvent considĂ©rĂ© comme le « pĂšre » ou le « pionnier » de lâordinateur : les plans de sa « machine analytique » sont en effet ceux dâune calculatrice automatique et mĂ©canique Ă programme externe, susceptible de calculer aussi bien sur des nombres que sur des symboles. Cette imagerie conforte lâhistoire hagiographique des gĂ©nies isolĂ©s, puisque dâaprĂšs cette perspective, il faut attendre un siĂšcle, essentiellement autour dâAlan Turing (1912-1954) et de John von Neumann (1903-1957), pour voir se concrĂ©tiser la rĂ©alisation de ce nouveau type de machines. Mon propos est de restituer cet apport de Babbage dans un contexte plus vaste que ne le dessine une histoire strictement conceptuelle. Babbage Ă©tait en effet un mathĂ©maticien fascinĂ© Ă la fois par le dĂ©veloppement industriel de son pays, et par la rĂ©organisation des institutions du savoir en France, issue de la RĂ©volution Française. Câest fort de cette volontĂ© rĂ©formatrice quâil sâattaque Ă ce quâil qualifie en 1830 de « dĂ©clin de la science anglaise ». En dĂ©pit de la finesse prospective de ses analyses et de ses projets, il demeure cependant un « gentleman amateur », travaillant dans son atelier personnel Ă lâĂ©laboration de ses machines. Confronter les diffĂ©rentes facettes du projet de Babbage Ă la situation effective des relations entre science et industrie, tant en France quâen Angleterre, peut permettre dâĂ©clairer lâĂ©volution de cette situation jusquâĂ la rĂ©alisation effective de lâ« analyseur harmonique » de Lord Kelvin (1824-1907) en 1876.Traditional accounts of computing view Charles Babbage (1791-1871) as the âfatherâ or âpioneerâ of the computer. Actually, Babbageâs planned âanalytical engineâ corresponds to an automatic mechanical computing machine with an external program that works using both symbols and numbers. This traditionalist view reinforces the hagiographic history of isolated geniuses in the history of science. Such histories suggest that in the century following Babbageâs death, relatively little occurred in âcomputingâ until Alan Turing (1912-1954) and John von Neumann (1903-1957) works. My research situates Babbage within his context and broadens the account by extending beyond a mere history of ideas. Babbage, as a mathematician, was fascinated both by the industrial development of Britain as well as the post-Revolutionary organisation of institutions of knowledge in France. Babbage looked at what he termed âthe decline of English scienceâ from this view, though he himself continued to behave as a âgentleman amateurâ, working on his machines in his personal workshop. In addition, situating Babbageâs analytical designs within the context of relationships emerging between science and industry in France and England in the 19th century helps to better highlight the deeply industrial context within which Lord Kelvin (1824-1907) built his own harmonic analyzer in 1876
La transformation de la rĂ©adaptation au travail dâune perspective parcellaire Ă une perspective systĂ©mique
Les troubles musculo-squelettiques associĂ©s au travail sont extrĂȘmement courants. Habituellement, ce problĂšme de santĂ© est de courte durĂ©e. Cependant, dans un petit nombre de cas, il gĂ©nĂšre des coĂ»ts sociaux importants et affecte la productivitĂ© des entreprises. Les Ă©vidences actuelles dĂ©montrent que les causes de lâincapacitĂ© ne sont pas uniquement reliĂ©es aux caractĂ©ristiques de lâindividu blessĂ©, mais proviennent aussi de lâenvironnement du travailleur : le milieu de travail, le systĂšme de compensation et mĂȘme le systĂšme de prise en charge mĂ©dical. Une revue des Ă©tudes portant sur les interventions qui ont eu un effet positif sur le retour au travail supporte dâune part, lâutilisation du milieu de travail naturel comme contexte de rĂ©entraĂźnement et dâautre part, renforce la nĂ©cessitĂ© de lâimplication des diffĂ©rents partenaires dans le processus. Cet article dĂ©crira la structure dâun programme dâintervention basĂ©e sur les plus rĂ©centes Ă©vidences scientifiques. Lâimplantation de ce programme demande des changements profonds dans les rĂŽles des partenaires impliquĂ©s mais apparaĂźt prometteuse Ă long terme pour Ă©viter lâincapacitĂ© prolongĂ©e chez les travailleurs.Musculoskeletal disorders are an extremely common short-term but recurring health problem that, in a small number of cases, generates major societal costs and affects the productivity of companies. Recent evidence has shown that the causes of disability are not only related to the patientâs characteristics, but also originate from the workerâs environment : the workplace, the compensation system, and even the healthcare delivery system. A review of studies on interventions that had a positive effect on returning to work supports, on the one hand, the use of the natural workplace as a context for retraining, and on the other, the need for the involvement of the different partners in the process. This article describes the structure of an intervention program based on the most recent scientific evidence. The implementation of this program requires major changes in the roles of the stakeholders but seems promising over the long term for avoiding prolonged disability in workers.Los tratornos musculoesquelĂ©ticos asociados al trabajo son muy frecuentes. Normalmente, ese problema de salud es de corta duraciĂłn. Sin embargo, en pocos casos, genera costos sociales importantes y afecta la productividad de las empresas. Las tendencias actuales demuestran que las causas de la incapacidad no solamente estĂĄn vinculadas con las caracterĂsticas del individuo herido, sino tambiĂ©n con el medio ambiente del trabajador : el lugar de trabajo, el sistema de compensaciĂłn e incluso el sistema de cuidado mĂ©dico. Una revista de los estudios tratando de las intervenciones que han tenido un efecto positivo sobre la vuelta al trabajo, soporta por una parte, la utilizaciĂłn del ambiente de trabajo natural como contexto de reintegraciĂłn y por otra parte, reforza la necesidad de la implicaciĂłn de los diferentes socios en el proceso. Este artĂculo describe la estructura de un programa de intervenciĂłn basado en las evidencias cientĂficas mĂĄs recientes. La implantaciĂłn de este programa requiere cambios profundos en los papeles de los socios implicados pero aparece prometedora a largo plazo para evitar la incapacidad prolongada con los trabajadores
New Concepts in the Evaluation of Biodegradation/Persistence of Chemical Substances Using a Microbial Inoculum
The European REACH Regulation (Registration, Evaluation, Authorization of CHemical substances) implies, among other things, the evaluation of the biodegradability of chemical substances produced by industry. A large set of test methods is available including detailed information on the appropriate conditions for testing. However, the inoculum used for these tests constitutes a âblack box.â If biodegradation is achievable from the growth of a small group of specific microbial species with the substance as the only carbon source, the result of the test depends largely on the cell density of this group at âtime zero.â If these species are relatively rare in an inoculum that is normally used, the likelihood of inoculating a test with sufficient specific cells becomes a matter of probability. Normally this probability increases with total cell density and with the diversity of species in the inoculum. Furthermore the history of the inoculum, e.g., a possible pre-exposure to the test substance or similar substances will have a significant influence on the probability. A high probability can be expected for substances that are widely used and regularly released into the environment, whereas a low probability can be expected for new xenobiotic substances that have not yet been released into the environment. Be that as it may, once the inoculum sample contains sufficient specific degraders, the performance of the biodegradation will follow a typical S shaped growth curve which depends on the specific growth rate under laboratory conditions, the so called F/M ratio (ratio between food and biomass) and the more or less toxic recalcitrant, but possible, metabolites. Normally regulators require the evaluation of the growth curve using a simple approach such as half-time. Unfortunately probability and biodegradation half-time are very often confused. As the half-time values reflect laboratory conditions which are quite different from environmental conditions (after a substance is released), these values should not be used to quantify and predict environmental behavior. The probability value could be of much greater benefit for predictions under realistic conditions. The main issue in the evaluation of probability is that the result is not based on a single inoculum from an environmental sample, but on a variety of samples. These samples can be representative of regional or local areas, climate regions, water types, and history, e.g., pristine or polluted. The above concept has provided us with a new approach, namely âProbabio.â With this approach, persistence is not only regarded as a simple intrinsic property of a substance, but also as the capability of various environmental samples to degrade a substance under realistic exposure conditions and F/M ratio
Bacterial Bioluminescent Biosensor Characterisation for On-line Monitoring of Heavy Metals Pollutions in Waste Water Treatment Plant Effluents
International audienc
Trajectoires des travailleurs recevant un programme de retour au travail : Ă©tude exploratoire des discussions dâune Ă©quipe interdisciplinaire
Sujet : Cette Ă©tude exploratoire a pour objectif de dĂ©crire diffĂ©rents types de trajectoires de travailleurs prĂ©sentant des troubles musculo-squelettiques pendant un programme de rĂ©adaptation. Les trajectoires sont tracĂ©es Ă partir des visions dâune Ă©quipe interdisciplinaire.MĂ©thode : Le devis de recherche est une mĂ©thode de cas unique oĂč lâunitĂ© dâanalyse principale est une Ă©quipe interdisciplinaire. Cette Ă©quipe a discutĂ© de la progression de 18 travailleurs, durant un programme de rĂ©adaptation. Les analyses des discussions ont Ă©tĂ© inspirĂ©es par la phĂ©nomĂ©nologie. Toutes les discussions de lâĂ©quipe ont Ă©tĂ© enregistrĂ©es et retranscrites. Lâanalyse de contenu a Ă©tĂ© effectuĂ©e par deux chercheurs. RĂ©sultats : Quatre types de trajectoires ont Ă©mergĂ©Â : 1) trajectoires de retour au travail sans obstacle ; 2) trajectoires de retour au travail avec obstacles ; 3) trajectoires de non-retour au travail avec Ă©pisodes de progression et 4) trajectoires de non-retour au travail sans progression. Trois facteurs clefs ont Ă©mergĂ© de ces analyses comme dĂ©terminant au processus de retour au travail : 1) la complaisance des travailleurs face au programme de rĂ©adaptation, 2) les diffĂ©rentes façons dont le travailleur aborde et vit la premiĂšre exposition au travail et 3) la collaboration avec les diffĂ©rents partenaires. Les rĂ©sultats de cette Ă©tude suggĂšrent aussi que lâabsence de message unique entre les professionnels de la santĂ© face au travailleur peut entraĂźner de la confusion et devenir un frein Ă la reprise des activitĂ©s.Conclusions : Les rĂ©sultats soulignent encore une fois la complexitĂ© pour les cliniciens de la prise en charge en rĂ©adaptation au travail de travailleurs en phase chronique. Cette intervention doit agir Ă la fois sur le travailleur et Ă©galement sur les interactions entre les travailleurs et les diffĂ©rents partenaires concernĂ©s. Aussi, cette Ă©tude souligne le processus non linĂ©aire de la rĂ©adaptation au travail pour des individus prĂ©sentant des incapacitĂ©s prolongĂ©es dâorigine musculo-squelettique, tel que dĂ©crit par une Ă©quipe interdisciplinaire.Purpose : Based on the viewpoint of an interdisciplinary team, this exploratory study aimed to identify different types of trajectories followed by workers with musculoskeletal disorders and the factors contributing to them.Methods : The research design used a single-case study in which the main unit of analysis was an interdisciplinary work team. This team discussed eighteen workersâ progression during a work rehabilitation programme. Analytical methods were based on phenomenology. All team discussions were audiotaped and transcribed, and two researchers completed the content analysis.Results : Four types of trajectories emerged : (1) return-to-work trajectories without obstacles ; (2) return-to-work trajectories with obstacles ; (3) non-return-to-work trajectories with episodes of progression ; and (4) non-return-to-work trajectories without progression. Moreover, three outlines emerged from the data analysis : (1) the workerâs compliance with the programme ; (2) the way the worker coped with exposure to work ; and (3) stakeholder collaboration. The results of this study also suggested that the absence of a single consistent message among participating health professionals could create confusion for workers and pose a major impediment to the resumption of their activities.Conclusion : The results underscore, for clinicians, the complexity in managing this type of chronic work rehabilitation population, related to both the worker and the workerâs interactions with the stakeholders. Also, this study casts light on the non-linear work rehabilitation processes of individuals with prolonged disabilities of musculoskeletal origin, as described by an interdisciplinary team.Tema : Este estudio exploratorio se propone identificar diferentes tipos de trayectorias de trabajadores que presentan lesiones mĂșsculo-esquelĂ©ticas en el marco de un programa de readaptaciĂłn. Las trayectorias se definen a partir de las visiones de un equipo interdisciplinar.MĂ©todo : El mĂ©todo utilizado, llamado « devis de investigaciĂłn » es un mĂ©todo basado en el estudio de casos y en el cual la unidad de anĂĄlisis principal es un equipo interdisciplinar. En este caso, el equipo ha intercambiado opiniones acerca de la progresiĂłn de dieciocho trabajadores durante un programa de readaptaciĂłn. El anĂĄlisis de los intercambios ha seguido un enfoque fenomenolĂłgico. Todas las discusiones del equipo han sido grabadas y desgrabadas posteriormente. El anĂĄlisis del contenido ha sido efectuado por dos investigadores.Resultados : Cuatro tipos de trayectorias han emergido : 1) trayectorias de reinsecion laboral sin obstaculos ; 2) Trayectorias de reinserciĂłn laboral con obstĂĄculos ; 3) trayectorias sin reinserciĂłn laboral y con episodios de progresiĂłn ; y 4) trayectorias sin reinserciĂłn laboral y sin progresiĂłn. Tres factores clave han emergido de estos anĂĄlisis en tanto determinates del proceso de reinserciĂłn laboral : 1) el hecho de que los trabajadores respeten el programa de readaptaciĂłn, 2) las diferentes formas en las que el trabajador aborda y vive su primera exposiciĂłn al trabajo, 3) la colaboracion con los diferentes compañeros de trabajo. Los resultados de este estudio sugieren tambien que la ausencia de unidad en los mensajes enviados por los profesionales de la salud al trabajador puede generar confusiĂłn y transformarse en un freno en el proceso de retorno a la actividad.Conclusiones : Los resultados obtenidos resaltan una vez mĂĄs la complejidad que significa, desde un enfoque clĂnico, el hacerce cargo de la readaptaciĂłn del trabajador en fase crĂłnica. Esta intervenciĂłn debe actuar a la vez sobre el trabajador y sobre las interacciones entre los trabajadores y las diferentes personas implicadas. Asimismo, este estudio subraya la no linealidad de la readaptaciĂłn laboral para los individuos que presentan incapacidades prolongadas de origen musculoesquelĂ©tico, tal como lo describe un equipo interdisciplinar
Ecotoxicity tests and ecoscores to improve soil management : case of a secondary lead smelter plant
International audienceriginally located on the outskirts of cities, numerous industrial sites, sometimes abandoned, are now in urban areas and are therefore likely to have environmental and health risks to surrounding populations. Currently, rehabilitation of the sites frequently entails excavation of polluted soils. Excavated soils can thus follow two different ways: landfilling, expensive and energy intensive, or reuse/recycling, integrated to sustainable development. The choice of a specific track mainly depends on total and leachable concentrations of the pollutant in the soil. Among the numerous pollutants observed in urban and peri-urban areas, trace metals are often present in soils; atmosphere emissions by smelters being one of the main anthropogenic source. MTE speciation and compartmentalization in soils can modify their impact on living organisms
Ecotoxicity tests and ecoscores to improve soil management : case of a secondary lead smelter plant
International audienceriginally located on the outskirts of cities, numerous industrial sites, sometimes abandoned, are now in urban areas and are therefore likely to have environmental and health risks to surrounding populations. Currently, rehabilitation of the sites frequently entails excavation of polluted soils. Excavated soils can thus follow two different ways: landfilling, expensive and energy intensive, or reuse/recycling, integrated to sustainable development. The choice of a specific track mainly depends on total and leachable concentrations of the pollutant in the soil. Among the numerous pollutants observed in urban and peri-urban areas, trace metals are often present in soils; atmosphere emissions by smelters being one of the main anthropogenic source. MTE speciation and compartmentalization in soils can modify their impact on living organisms
Lipidomic approach in young adult triathletes: effect of supplementation with a polyphenols-rich juice on neuroprostane and F2-dihomo-isoprostane markers
The aim of the this study was to determine the effect of a polyphenols-rich juice (aronia-citrus juice, ACJ) on F4-neuroprostanes and F2-dihomo-isoprostanesâmarkers of oxidative stress associated with the central nervous system (CNS)âin 16 elite triathletes under a controlled diet for triathlon training (145 days). In the triathletes, a decrease of the lipid peroxidation markers after ACJ intake, associated with neuronal membrane degradation (10-epi-10-F4t-neuroprostane and 10-F4t-neuroprostane), was observed when compared with placebo stage values. Regarding the F2-dihomo-isoprostanes, a significant decrease of the neuromotor system damage biomarkers (17-F2t-dihomo-isoprostane) with an increase of training load during the study was observed, although the decrease of the load training at the last stage showed a significant increase of the values of ent-7-(RS)-7-F2t-dihomo-IsoP, suggesting a possible role in adaptation post-training. On the other hand, the changes in the excretion of 17-epi-17-F2t-dihomo-IsoP provided a positive connection between physical exercise and ACJ intake. Thus, the results showed in this clinical study in young triathletes will help to elucidate novel interactions and mechanisms between the excretion of lipid peroxidation metabolites from CNS, supplementation of polyphenols-rich juice in the diet and physical exercise during a training season.This study was supported by the project AGL2011-23690 (CICYT) (Spanish Ministry of Economy and Competitiveness). This work has been partially funded by the âFundaciĂłn SĂ©neca de la RegiĂłn de Murciaâ Grupo de Excelencia 19900/GERM/15. LAGF was granted a pre-doctoral FPI fellowship (BES2012-060185) by the Spanish government
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