Collective elaboration of care for safety in radiotherapy: cooperative management of patient variability

International audienceThis research is about collective production of radiotherapy care involved in cancer treatment. The aim of this research is to characterize the communicative process between actors to highlight the safety practices carried out to build, and to implement, a safe treatment. We focus here on the radiographers' activity and in particular the function of the diversity of informal exchanges between these actors who are present at the both ends of the treatment chain. Observations have been carried out to understand the work practices of each professional category. Five radiographers at simulation station and five radiographers at the treatment station were interviewed. Informal communications outlined illustrate cooperation between radiographers at the both ends of the chain. Their objective is to share specific information related to the treatment and related to the patient that may affect the treatment session. These strategies for safety production imply to manage the variability related to the patient and are achieved by anticipation between the posts promoting temporal conditions for the reproducibility and immobility of positioning the patient

Une approche multidimensionnelle de la participation dans les communautés de développement de logiciels libres

National audienceNotre étude vise à analyser les formes de participation dans les communautés de développement de logiciels libres. Nous proposons une approche méthodologique multidimensionnelle de la participation dans ces communautés, en nous basant sur le concept de rôle. On considère le rôle en tant que phénomène émergeant de l'interaction. Ce concept est développé selon plusieurs dimensions : une dimension sociale, une dimension cognitive et une dimension interactive. Notre approche se base sur l'exploitation et l'analyse des interactions dans trois espaces d'activités (discussion, documentation, implémentation) ainsi que sur les interactions conjointes dans ces espaces d'activités

Interactions in an online community in ergonomics: from sharing information to comparing practices?

International audienceThe goal of our research is to characterize practices shared in an online community dedicated to ergonomics in order to understand how these online discussions are a means to construct co-elaborated knowledge about ergonomics and its practices. This communication presents a preliminary study of the nature (purpose of interactions, topics) and structure (relations between participants, purposes and topics) of exchanges on Ergoliste, a French speaking online mailing list dedicated to ergonomics. We show that the mailing list is mostly dominated by ergonomists (consultants, ergonomists working in private companies, institutions, students) seeking and sharing resources: information about jobs and resources (documentation, literature, etc.) and experiences about various topics (methodology, trades of ergonomics, specific tools or work settings...). It also opens some prospects for more longitudinal investigations of the contents of the list, to analyze more deeply how the list can be viewed as an efficient tool to co-elaborate knowledge about ergonomics and its development

Vers la modélisation des processus sociotechniques : analyse du processus collectif de conception des procédures d'une entreprise

International audienceCe papier présente l'analyse d'un processus collectif de conception de documents procéduraux en contexte industriel. Nous mobilisons un outil de modélisation qui permet de synthétiser la structure organisationnelle globale du processus sociotechnique et d'interpréter les rôles individuels des acteurs qui y participent. En pratique, la modélisation proposée est basée sur la traduction de la procédure générale définissant le processus de mise à jour des procédures de l'entreprise. Notre modèle est une traduction des actions de ce processus, sous la forme de nœuds et de liens qui définissent un graphe. Les résultats permettent de montrer que cette modélisation est un outil puissant pour l'analyse du processus étudié. Les entités participant au processus sont clairement définies. Leurs relations dans la chaîne d'action qui compose le processus sont explicitées. Leurs positions structurales sont établies sur la base d'une méthode algorithmique validée. Sur la base de ces résultats, nous concluons sur des perspectives possibles à ce travail

The role of argumentation in online epistemic communities: the anatomy of a conflict in Wikipedia

International audienceThis research aims to investigate the processes by which knowledge objects — in this case Wikipedia pages on astronomy — are elaborated, in online communities, focussing on the role of argumentative interactions

Non evaporable getter thin film coatings for vacuum applications

LAUREA MAGISTRALETra i requisiti piu` stringenti da soddisfare nella costruzione di un acceleratore di particelle o di un sincrotrone, c’`e sicuramente il raggiungimento di condizioni di ultra alto vuoto (UHV). Per il pompaggio di alcune sezioni del Large Hadron Collider (LHC), per esempio, si `e scelto di usare i materiali Non-Evaporable Getter (NEG), in particolare il Ti30Zr30V40. Durante lavori di manutenzione di LHC si `e presentata la necessit`a di esporre le camere rivestite di NEG all’atmosfera del tunnel. Si `e quindi deciso di intraprendere uno studio sistematico degli effetti che l’esposizione pu`o avere sulle propriet`a di pompaggio dei film. Nella prima parte del presente lavoro di tesi sono presentati i risultati ottenuti; sei camere rivestite di un fin sottile di Ti30Zr30V40 sono state esposte per diversi periodi e in diversi punti del tunnel. Misure di velocit`a di pompaggio per l’idrogeno e misure di saturazione per il monossido di carbonio sono state effettuate. I risultati ottenuti suggeriscono che l’esposizione all’atmosfera del tunnel di LHC non condizioni i rivestimenti interni di NEG delle camere a vuoto. Tuttavia, si sono riscon- trati problemi dell’attivazione di alcune camere dovuti all’apparato sperimentale usato. Sono necessarie quindi ulteriori studi. Esistono elementi che potrebbero essere adatti al rivestimento delle camere da vuoto; in par- ticolare si `e alla ricerca di materiali che possano essere depositati come film sottili ed abbiano caratteristiche simili a quelle del TiZrV: basse temperature di attivazione e grandi velocit`a di pompaggio. In questo lavoro di tesi sono state testate tre diverse leghe metalliche: ZrV , HfV e TiZrHfV . Piu` di 30 camere di acciaio inossidabile sono state rivestite e completamente carat- terizzate, sia da un punto di vista macroscopico (velocit`a di pompaggio e sticking probability), sia da una punto di vista microscopico (analisi di composizione chimica superficiale, analisi mor- fologiche e di cristallinit`a). Dai risultati ottenuti `e possibile concludere che per tutte le leghe la temperature di attivazione `e legata alla cristallinit`a del film: solo film nano-cristallini presentano basse temperature di attivazione. La dimensione dei grani cristallini di un film `e influenzata dalla composizione della lega: `e necessaria una certa percentuale di vanadio per ottenere grani piu` piccoli di 5 nm. Le caratteristiche di pompaggio sono invece legate alla morfologia superficiale e agli elementi presenti in lega; film rugosi, porosi e con strutture superficiali simili al TiZrV hanno sticking probability e capacit`a superficiali elevate.Among the most challenging requisites for the design of an accelerator or a synchrotron there is the reaching of Ultra High Vacuum (UHV) conditions. This goal is reached in the Large Hadron Collider (LHC) coating the internal surface of some beam pipe sections with Ti30Zr30V40 Non- Evaporable Getter (NEG) thin film. During the Long Shutdown 1 (LS1), started in February 2013, some of the NEG coated vacuum chambers were exposed to the air of the LHC tunnel because of maintenance. It has been decided to study in details if the exposure to tunnel atmosphere for long periods affects the pumping properties of a NEG coated vacuum chamber. In the first part of this work the results obtained are presented; six Ti30Zr30V40 coated vacuum chambers have been exposed for different periods and in different points of the tunnel. H2 pumping speed and CO saturation measurements have been performed. The results obtained suggest that the exposition at the LHC tunnel atmosphere does not affect the the pumping properties of the NEG coating. However, there have been prob- lems in the activation of some chambers due to the experimental set-up. Further investigations are needed. Other alloy, with properties close to those of TiZrV, exist and are suitable to becoming NEG thin film coating for vacuum applications; low activation temperatures and high pumping speed are looked for. In the present work three alloys have been tested: ZrV , HfV e TiZrHfV . More than 30 stainless steel chambers have been coated and fully characterized: pumping speed and sticking probability have been evaluated, surface elemental chemical composition, morphology and crystallinity have been checked. The obtained results suggest that the activation temper- ature is liked to the nano-crystallinity: only nano-crystal samples have activation temperature compatible with the bake-out temperature of the vacuum chambers structural materials. The film crystallinity is affected by the composition: a certain percentage of vanadium is needed for having grains smaller than 5 nm. The pumping properties depends on the surface morphology and the from the elements present in the alloy

How I treat warm autoimmune hemolytic anemia

Warm autoimmune hemolytic anemia (wAIHA) is caused by increased erythrocyte destruction by immunoglobulin G (IgG) autoantibodies, with or without complement activation. Antibody-dependent cell-mediated cytotoxicity by macrophages/activated lymphocytes occurs in the lymphoid organs and spleen (extravascular hemolysis). The ability of the bone marrow (BM) to compensate determines clinical severity. The different pathogenic mechanisms, their complex interplay, and changes over time may explain wAIHA's great clinical heterogeneity and unpredictable course. The disease may be primary, drug induced, or associated with lymphoproliferative neoplasms, autoimmune and infectious diseases, immunodeficiencies, solid tumors, or transplants. Therapeutic interventions include steroids, splenectomy, immunosuppressants, and rituximab; the latter is increasingly used in steroid-refractory cases based on evidence from the literature and a few prospective trials. We present 5 patient case studies highlighting important issues: (1) the diagnosis and proper use of steroid therapy, (2) the concerns about the choice between rituximab and splenectomy in second-line treatment, (3) the need of periodical re-evaluation of the disease to assess the possible evolution of relapsed/refractory cases in myelodysplastic and BM failure syndromes, and (4) the difficulties in managing cases of severe/acute disease that are at high risk of relapse. Incorporating novel targeted therapies into clinical practice will be an exciting challenge in the future

Autoimmune Hemolytic Anemias: Challenges in Diagnosis and Therapy

Background: Autoimmune hemolytic anemia (AIHA) is a rare disease due to increased destruction of erythrocytes by autoantibodies, with or without complement activation. Summary: AIHA is usually classified in warm AIHA (wAIHA) and cold agglutinin disease (CAD), based on isotype and thermal amplitude of the autoantibody. The direct antiglobulin test (DAT) or Coombs test is the cornerstone of AIHA diagnosis, as it is positive with anti-IgG in wAIHA, and with anti-C3d/IgM antisera plus high titer cold agglutinins in CAD. Therapy is quite different, as steroids and rituximab are effective in the former, but have a lower response rate and duration in the latter. Splenectomy, which is still a good option for young/fit wAIHA, is contraindicated in CAD, and classic immunosuppressants are moving to further lines. Several new drugs are increasingly used or are in trials for relapsed/refractory AIHAs, including B-cell (parsaclisib, ibrutinib, rilzabrutinib), and plasma cell target therapies (bortezomib, daratumumab), bispecific agents (ianalumab, obexelimab, povetacicept), neonatal Fc receptor blockers (nipocalimab), and complement inhibitors (sutimlimab, riliprubart, pegcetacoplan, iptacopan). Clinically, AIHAs are highly heterogeneous, from mild/compensated to lifethreatening/ fulminant, and may be primary or associated with infections, neoplasms, autoimmune diseases, transplants, immunodeficiencies, and drugs. Along with all these variables, there are rare forms like mixed (wAIHA plus CAD), atypical (IgA or warm IgM driven), and DAT negative, where the diagnosis and clinical management are particularly challenging. Key Messages: This article covers the classic clinical features, diagnosis, and therapy of wAIHA and CAD, and focuses, with the support of clinical vignettes, on difficult diagnosis and refractory/relapsing cases requiring novel therapies

Clinical Applications of Hemolytic Markers in the Differential Diagnosis and Management of Hemolytic Anemia

Several hemolytic markers are available to guide the differential diagnosis and to monitor treatment of hemolytic conditions. They include increased reticulocytes, an indicator of marrow compensatory response, elevated lactate dehydrogenase, a marker of intravascular hemolysis, reduced haptoglobin, and unconjugated hyperbilirubinemia. The direct antiglobulin test is the cornerstone of autoimmune forms, and blood smear examination is fundamental in the diagnosis of congenital membrane defects and thrombotic microangiopathies. Marked increase of lactate dehydrogenase and hemosiderinuria are typical of intravascular hemolysis, as observed in paroxysmal nocturnal hemoglobinuria, and hyperferritinemia is associated with chronic hemolysis. Prosthetic valve replacement and stenting are also associated with intravascular and chronic hemolysis. Compensatory reticulocytosis may be inadequate/absent in case of marrow involvement, iron/vitamin deficiency, infections, or autoimmune reaction against bone marrow-precursors. Reticulocytopenia occurs in 20-40% of autoimmune hemolytic anemia cases and is a poor prognostic factor. Increased reticulocytes, lactate dehydrogenase, and bilirubin, as well as reduced haptoglobin, are observed in conditions other than hemolysis that may confound the clinical picture. Hemoglobin defines the clinical severity of hemolysis, and thrombocytopenia suggests a possible thrombotic microangiopathy or Evans' syndrome. A comprehensive clinical and laboratory evaluation is advisable for a correct diagnostic and therapeutic workup of the different hemolytic conditions

Immune Phenomena in Myeloid Neoplasms : An “Egg or Chicken” Question

Immune phenomena are increasingly reported in myeloid neoplasms, and include autoimmune cytopenias/diseases and immunodeficiency, either preceding or complicating acute myeloid leukemia, myelodysplastic syndromes (MDS), chronic myeloproliferative neoplasms, and bone marrow failure (BMF) syndromes. Autoimmunity and immunodeficiency are the two faces of a dysregulated immune tolerance and surveillance and may result, along with contributing environmental and genetic factors, in an increased incidence of both tumors and infections. The latter may fuel both autoimmunity and immune activation, triggering a vicious circle among infections, tumors and autoimmune phenomena. Additionally, alterations of the microbiota and of mesenchymal stem cells (MSCs) pinpoint to the importance of a permissive or hostile microenvironment for tumor growth. Finally, several therapies of myeloid neoplasms are aimed at increasing host immunity against the tumor, but at the price of increased autoimmune phenomena. In this review we will examine the epidemiological association of myeloid neoplasms with autoimmune diseases and immunodeficiencies, and the pivotal role of autoimmunity in the pathogenesis of MDS and BMF syndromes, including the paroxysmal nocturnal hemoglobinuria conundrum. Furthermore, we will briefly examine autoimmune complications following therapy of myeloid neoplasms, as well as the role of MSCs and microbiota in these settings