Thermal Optimization of Injection Molds Produced by Layered Manufacturing Techniques

Producing injection tooling with cooling channels of almost any form seems to be one of the most promising advantages of Layered Manufacturing Techniques (like Selective Laser Sintering). It could be efficiently exploited to achieve higher productivity or better quality parts in injection molding. Unfortunately, at the present time, the lack of data-processing tools to design optimal cooling systems still prevents us from fully benefiting from this new potential. The first objective of this paper is to present a methodology for the optimal design of cooling systems in three-dimensional injection molds. Our optimization process is based on a finite element model of the mold and on the standard gradient method. In the second part of this paper, we compare a conventional mold and a mold equipped with a cooling system optimized by means of the proposed methodology. The comparison is carried out thanks to an appropriate protocol. The conclusion is that the optimization of the cooling system doubled the productivity of the mold.Mechanical Engineerin

On the singular status of the human voice : tomorrow’s eve and the cultural series of talking machines

Diffusé avec l’accord des Éditions Amsterdam University Press, détentrices des droits d’auteur sur ce texte

The social imaginary of telephony : fictional dispositives in Albert Robida’s Le vingtième siècle and the archeology of "Talking Cinema"

Diffusé avec l’accord des Éditions Amsterdam University Press, détentrices des droits d’auteur sur ce texte

Comorbidity between counnunicable and non-communicable diseases : the example of the dual burden of tuberculosis and diabetes in Dar es Salaam, Tanzania

Background Although recognized for centuries, the association between tuberculosis (TB) and diabetes mellitus (DM) was forgotten with the discovery of efficient treatments. In the last decade, the prevalence of DM has dramatically increased, particularly in low- and middle-income countries experiencing a high burden of TB, leading to a new interest in this association. DM increases TB risk while TB, as an infectious disease, leads to hyperglycemia. The relationship between TB and DM has been poorly studied in Sub-Saharan Africa, where the high incidence of TB is associated with HIV infection. Concentration of vitamin D is inversely associated with TB and DM, and it has been suggested that low vitamin D could mediate some of the association between TB and DM. DM affects the immune response to TB, but the precise mechanisms underlying this association are not clear. To address this issue of high public health relevance, we undertook a project on the association between TB, DM and HIV in Tanzania. The project had three major components: (1) Assessing the association of TB and its outcome with the presence and persistence of hyperglycemia in Tanzania, using three different DM screening tests. (2) Describing the association between vitamin D, TB and DM. (3) Studying the immunological features underlying TB and DM comorbidity in sub-Saharan Africa and testing the hypothesis of delayed adaptive immune response with increasing glycemia. The overall aim of the project was to improve knowledge on the dynamic interaction between TB and DM in an African setting with high HIV prevalence by integrating a longitudinal component into the case-control study. Methods A case-control study with longitudinal follow-up of cases was conducted in Dar es Salaam. Consecutive adults with new active TB were included and followed up for five months after the start of anti-TB treatment. Healthy controls, matched by age and sex to TB cases, were recruited among volunteering adults accompanying patients to the outpatient departments of the same hospitals. Exclusion criteria were a biological relationship to TB case, TB history, symptoms or signs of TB, other acute infection or major trauma within the last three months. All underwent 25-hydroxyvitamin D (25(OH)D) measurement and DM screening tests (fasting glucose (FCG), 2-hour capillary glucose after standard oral glucose tolerance test (2h-CG) and glycated hemoglobin (HbA1c)) at enrolment and TB patients were again tested after five months of TB treatment. Data on the outcome of TB (treatment failure, death, lost to follow-up) were collected. For the nested immunological study, four groups of HIV negative patients were included: i) active TB without DM, ii) active TB with DM, iii) latent TB patients without DM and iv) latent TB patients with DM. Latent TB patients were selected among the healthy volunteering adults, as well as among diabetic patients attending the DM clinic in the participating hospitals. Exclusion criteria for groups iii and iv were past TB history and symptoms or signs of active TB. Peripheral blood mononuclear cells were stimulated with Mycobacterium tuberculosis (Mtb)-specific peptide pools and live Mycobacterium bovis BCG and then analysed by polychromatic flow cytometry for Th1, Th2, Th9 and Th17 cytokine production. Cell culture supernatants were analysed by Luminex® for 34 cytokines and chemokines. Findings At enrolement, DM prevalence was significantly higher among TB patients (N=539; FCG>7mmol/L: 4.5%, 2-hCG>11mmol/L: 6.8% and HbA1c>6.5%: 9.3%) compared to controls (N=496; 1.2%, 3.1% and 2.2%). However, the association between hyperglycemia and TB disappeared after TB treatment (aOR(95% CI) at enrolment vs follow-up: FCG 9.6(3.7-24.7) vs 2.4(0.7-8.7); 2-hCG 6.6(4.0-11.1) vs 1.6(0.8-2.9); HbA1c 4.2(2.9-6.0) vs 1.4(0.9-2.0)). FCG hyperglycemia at enrolment was associated with TB treatment failure or death (aOR(95%CI) 3.3(1.2-9.3). The prevalence of 25(OH)D insufficiency (25(OH)D<75nmol/l) was not statistically different between TB patients and controls (25.8% versus 31.0%; p=0.22). But the association between 25(OH)D insufficiency and TB was modified by hyperglycemia (pinteraction=0.01). Patient with vitamin D insufficiency were only at higher risk for TB in the presence of underlying hyperglycemia. The OR (95%CI) for TB risk in patients with vitamin D insufficiency and hyperglycemia was 4.94(1.16-21.0) versus 0.68(0.39-1.17) for patients with vitamin D insufficiency and normoglycemia where normoglycemia and normal vitamin D were the reference category. Patients with active TB and DM had a lower frequency of INF-γ CD4+ T cells and a lower proportion of CD4+ T cells producing both TNF-α and IFN-γ after live M. bovis BCG but not after Mtb-specific peptide pool stimulation, compared to normoglycemic TB patients. A negative correlation between INF-γ or TNF-α CD4+ T cell frequency and increasing glycemia was observed in the context of live M. bovis BCG stimulation only. Conclusions Transient hyperglycemia is frequent during TB, and DM needs confirmation after TB treatment. However, DM screening at TB diagnosis gives the opportunity to detect patients at risk of adverse outcome. 25(OH)D insufficiency seams to increase the risk of TB only if associated with hyperglycemia. DM patients living in high TB burden settings might benefit from preventive vitamin D supplementation. The immunological findings suggest that DM might affect Mtb-specific CD4+ T cell immune responses at the level of reduced antigen processing and presentation, a defect that could be compensated by metformin. The results of the study are of public health and clinical utility. First, they lend support to the integration of care between TB and DM programs. Second, they imply that, at the time of TB diagnosis, patients should be screened for hyperglycemia using cost-effective fasting glucose tests. Treatment of hyperglycemia should be initiated to improve TB outcome. Third, before initiation of long-term DM treatment, DM diagnosis must be confirmed after the resolution of TB. Finally, in the absence of evidence for a strong contribution of DM to TB risk in this African setting with high HIV prevalence, DM patients should not be screened for TB with expensive test. DM physicians and patients should rather be trained for recognizing TB symptoms and signs as a cost-effective way to recognize TB early

La formation professionnelle des jeunes en situation de handicap mental léger: comparaison entre des institutions grecques et l'Orif Sion

Cette recherche détermine la formation suivie et l’expérience du personnel grec encadrant, le type de formations données, ainsi que leur cahier des charges. le type de handicap et l’origine des bénéficiaires sont également des thèmes abordés, de même que les infras-tructures et les moyens à disposition. Les méthodes utilisées sont des entretiens réalisés auprès de personnes vivant en Suisse mais connaissant bien la situation en Grèce, puis dans trois institutions grecques. Cette partie d’entretiens est complétée par une recherche documentaire et des éléments biblio-graphiques en lien avec le sujet traité

Analyse de faisabilité d'une plateforme de prise de rendez-vous en ligne pour les professionnels du bien-être et de la santé

Mon désir est de faire gagner du temps autant aux professionnels qu’aux personnes voulant prendre rendez-vous. C’est pourquoi j’ai pensé à un système de prise de rendez-vous en ligne pour le secteur du bien-être et de la santé. iReserve a donc pour but de fournir un site internet permettant aux professionnels de la santé et du bien-être de s’inscrire, afin de proposer à leurs clients la possibilité de prendre rendez-vous via internet, sans passer par le téléphone. Concernant le besoin en ressources humaines, la société a besoin d’un informaticien à temps complet, afin de gérer la programmation des pages web, tandis que moi-même je m’occupe du côté analyse des besoins. À partir de la deuxième année, deux personnes supplémentaires rejoindront l’équipe. Grâce à des sondages quantitatifs et qualitatifs, je constate un intérêt auprès des professionnels quant à une prise de rendez-vous en ligne, ainsi qu’auprès de la population, car 72% se disent prêts à utiliser le système. Chez les professionnels, je constate également une envie de personnalisation. Le service comprend un élément de base, c’est-à-dire la page web avec l’agenda en ligne. Le professionnel peut choisir des modules supplémentaires, afin de personnaliser sa page web. Il peut également prendre le module de synchronisation de son agenda personnel avec l’agenda en ligne. Ce module est l’avantage concurrentiel de la société. Durant la première année d’exploitation, les actions marketing sont ciblées sur les professionnels avec des publications dans le journal de l’Association des Médecins de Genève, ainsi qu’avec une participation à des salons. À partir de la deuxième année, les actions sont orientées vers les preneurs de rendez-vous avec des spots radios ou des flyers dans les transports publics genevois. Concernant l’aspect financier, malgré l’enregistrement d’une perte lors de la première année, dès la deuxième année des bénéfices sont à prévoir. Grâce à une tarification basée sur des abonnements mensuels, à partir de la quatrième année, la société peut faire des bénéfices sans avoir de nouveaux clients

Political Agroecology in Senegal: Historicity and Repertoires of Collective Actions of an Emerging Social Movement

Agroecology has become an ideological foundation for social and environmental transformation in sub-Saharan Africa. In Senegal, agroecological advocacy coalitions, made up of farmers’ organizations, scientists, NGOs, and IOs, are using agroecology as an umbrella concept for proposing policy changes at multiple scales. We describe the history of the agroecological movement in Senegal in the context of the constitution of a national advocacy coalition. We then examine the “repertoires of collective action” mobilized by the coalition. Four repertoires are identified: technical support and knowledge co-production, territorial governance, alternative food networks, and national policy dialogue. Our analysis highlights the potential that these multi-level approaches have to sustainably transform the current food systems in sub-Saharan Africa. However, our research also reveals the limited agency of farmer organizations and the limitations of a movement that is strongly dependent on NGOs and international donors, leading to a “projectorate” situation in which contradictory policy actions can overlap. We further argue that, although the central government has formally welcomed some of the principles of agroecology into their policy discourse, financial and political interests in pursuing a Green Revolution and co-opting agroecology are pending. This leads to a lack of political and financial autonomy for grassroots farmers’ organizations, limiting the development of counter-hegemonic agroecology. We discuss the conditions under which territorial approaches, and the three other repertoires of collective action, can have significant potential to transform Sub-Saharan Africa in the coming years