Evolving team compositions by agent swapping

Optimizing collective behavior in multiagent systems requires algorithms to find not only appropriate individual behaviors but also a suitable composition of agents within a team. Over the last two decades, evolutionary methods have emerged as a promising approach for the design of agents and their compositions into teams. The choice of a crossover operator that facilitates the evolution of optimal team composition is recognized to be crucial, but so far, it has never been thoroughly quantified. Here, we highlight the limitations of two different crossover operators that exchange entire agents between teams: restricted agent swapping (RAS) that exchanges only corresponding agents between teams and free agent swapping (FAS) that allows an arbitrary exchange of agents. Our results show that RAS suffers from premature convergence, whereas FAS entails insufficient convergence. Consequently, in both cases, the exploration and exploitation aspects of the evolutionary algorithm are not well balanced resulting in the evolution of suboptimal team compositions. To overcome this problem, we propose combining the two methods. Our approach first applies FAS to explore the search space and then RAS to exploit it. This mixed approach is a much more efficient strategy for the evolution of team compositions compared to either strategy on its own. Our results suggest that such a mixed agent-swapping algorithm should always be preferred whenever the optimal composition of individuals in a multiagent system is unknown.

Patients satisfaction in an academic walk-in centre: a new model of residents training achieved by family doctors.

BACKGROUND: Walk-in centres may improve access to healthcare for some patients, due to their convenient location and extensive opening hours, with no need for an appointment. Herein, we describe and assess a new model of walk-in centre, characterised by care provided by residents and supervision achieved by experienced family doctors. The main aim of the study was to assess patients' satisfaction about the care they received from residents and their supervision by family doctors. The secondary aim was to describe walk-in patients' demographic characteristics and to identify potential associations with satisfaction. METHODS: The study was conducted in the walk-in centre of Lausanne. Patients who consulted between 11th and 31st April were automatically included and received a questionnaire in French. We used a five-point Likert scale, ranging from "not at all satisfied" to "very satisfied", converted from values of 1 to 5. We focused on the satisfaction regarding residents' care and supervision by a family doctor. The former was divided in three categories: "Skills", "Treatment" and "Behaviour". A mean satisfaction score was calculated for each category and a multivariable logistic model was applied in order to identify associations with patients' demographics. RESULTS: The overall response rate was 47% [184/395]. Walk-in patients were more likely to be women (62%), young (median age 31), with a high education level (40% of University degree or equivalent). Patients were "very satisfied" with residents' care, with a median satisfaction score between 4.5 and 5, for each category. Over 90% of patients were "satisfied" or "very satisfied" that a family doctor was involved in the consultation. Age showed the greatest association with satisfaction. CONCLUSION: Patients were highly satisfied with care provided by residents and with the involvement of a family doctor in the consultation. Older age showed the greatest positive association with satisfaction with a positive impact. The high level satisfaction reported by walk-in patients supports this new model of walk-in centre.

Une équipe mobile en psychiatrie de l'âge avancé [A crisis team in the field of old age psychiatry]

In the context of demographic evolution, psychiatric care needs increase steadily in most western countries. Given the financial limitations, it is mandatory to establish appropriate care priorities in order to avoid psychiatric hospitalisations by assisting care providers, general practionners and nurses, at home or in the nursing homes. A crisis team has been established 18 months ago within the Division of old age psychiatry in Lausanne. The care program included immediate assistance in the community, assessement, crisis counseling, medication consultation and referral for psychiatric services providing an alternative to hospitalization. The first results indicate that this intervention is well accepted by the users and correspond to a real need.

High-dose therapy and autologous hematopoietic stem cell transplantation in T-cell lymphoma : a single centre experience

Le diagnostic de lymphome représente 4% de tous les cancers et a une incidence particulièrement élevée dans les pays industrialisés. La proportion de lymphomes T, évaluée en Europe et aux Etats Unis, représente environ 5 à 10% des lymphomes. Alors que des progrès très sensibles ont été apportés dans la prise en charge et le pronostic des lymphomes B agressifs durant ces dernières décennies et en particulier depuis le début des années 2000 avec l'utilisation des anticorps anti-CD20 associés à la chimiothérapie, le pronostic des lymphomes T reste très décevant. La survie globale des lymphomes T à 5 ans est estimée entre 28% et 38%. Le bénéfice réel d'une chimiothérapie intensive suivie d'une autogreffe de cellules souches hématopoïétiques périphériques au terme d'un traitement de chimiothérapie d'induction dans le lymphome T périphérique reste débattu. Les résultats des rares études prospectives et des études rétrospectives à disposition sont discordants. Nous avons donc analysé rétrospectivement 43 patients successifs de mars 2000 à mars 2011, atteints de lymphome T, issus de notre base de données du programme autogreffe lausannois. Nos analyses statistiques permettent, sur la base d'un suivi médian de 63 mois, une estimation à 12 ans, de la survie globale de nos patients à 40%, de la survie sans progression à 34% et de la survie sans événement à 30%. Ces chiffres s'inscrivent parfaitement dans les résultats des études prospectives qui montrent un bénéfice de l'autogreffe dans le lymphome T. Parmi les différents paramètres pronostiques habituellement évalués, l'âge et l'absence de symptômes B au diagnostic sont les seuls paramètres statistiquement significatifs en analyse univariée dans notre cohorte. En effet, Les patients de moins de 50 ans et ceux qui ne présentent pas de symptômes B au diagnostic ont un meilleur pronostic. Nous concluons de cette analyse que les patients traités par chimiothérapie intensive et autogreffe de cellules souches hématopoïétiques périphériques ont une survie moyenne supérieure aux résultats rapportés dans la littérature avec des traitements de chimiothérapie conventionnelle de type CHOP. En effet, on estime à environ 50% les patients répondant à une chimiothérapie conventionnelle de type CHOP.

Is trauma in Switzerland any different? epidemiology and patterns of injury in major trauma - a 5-year review from a Swiss trauma centre.

Switzerland, the country with the highest health expenditure per capita, is lacking data on trauma care and system planning. Recently, 12 trauma centres were designated to be reassessed through a future national trauma registry by 2015. Lausanne University Hospital launched the first Swiss trauma registry in 2008, which contains the largest database on trauma activity nationwide. METHODS: Prospective analysis of data from consecutively admitted shock room patients from 1 January 2008 to 31 December 2012. Shock room admission is based on physiology and mechanism of injury, assessed by prehospital physicians. Management follows a surgeon-led multidisciplinary approach. Injuries are coded by Association for the Advancement of Automotive Medicine (AAAM) certified coders. RESULTS: Over the 5 years, 1,599 trauma patients were admitted, predominantly males with a median age of 41.4 years and median injury severity score (ISS) of 13. Rate of ISS >15 was 42%. Principal mechanisms of injury were road traffic (40.4%) and falls (34.4%), with 91.5% blunt trauma. Principal patterns were brain (64.4%), chest (59.8%) and extremity/pelvic girdle (52.9%) injuries. Severe (abbreviated injury scale [AIS] score ≥ 3) orthopaedic injuries, defined as extremity and spine injuries together, accounted for 67.1%. Overall, 29.1% underwent immediate intervention, mainly by orthopaedics (27.3%), neurosurgeons (26.3 %) and visceral surgeons (13.9%); 43.8% underwent a surgical intervention within the first 24 hours and 59.1% during their hospitalisation. In-hospital mortality for patients with ISS >15 was 26.2%. CONCLUSION: This is the first 5-year report on trauma in Switzerland. Trauma workload was similar to other European countries. Despite high levels of healthcare, mortality exceeds published rates by >50%. Regardless of the importance of a multidisciplinary approach, trauma remains a surgical disease and needs dedicated surgical resources.

Centre de la prostate: une approche multidisciplinaire pour une prise en charge globale du patient [Prostate cancer center: a multidisciplinary approach to accurately manage patients with prostate cancer]

The prostate cancer is a complex pathology involving oncological, functional and psychosocial items. The prostate's center of CHUV harmonize the know-how of urologists, oncologist, radiotherapists and clinical nurses to offer a global management to patients attempts by prostate cancer, from diagnosis to therapy and follow-up.

The role of the radiotherapy technologist in gamma knife radiosurgery within a multidisciplinary team: the Lausanne experience

Objective: Integration of the radiotherapy technologist "know-how" in the Gamma Knife treatment processMaterials and Methods: Gamma Knife (GK) treatments started in July 2010 at the GK Center in C.H.U.V. with the Leksell Gamma KnifeR Perfexion?(Elekta AB, Sweden). The multidisciplinary GK team involves neurosurgeons, radio-oncologists, physicists, neuroradiologists, nurses and technologists, aiming at a full integration for optimal patient management.Results: Between July and December 2010, 60 patients have been treated. Required stereotactic imaging involves IRM, CT scan (and angiography for AVM). All the steps in the treatment process (Leksell coordinate frame fixation, imaging, planning, treatment) are supervised by the members of the multidisciplinary team. In our experience, radiotherapy technologist (RTT) have acquired an important role in the multidisciplinary team communication and integration. Specifically, the RTT are responsible of: supervision of the image acquisition, performing the Gamma Knife unit control tests, patient setup, and patient surveillance during treatment.Conclusion: RTT have a fundamental role in the communication within the team, between the team and the patient and also to assure the patient security. Our experience shows that it is possible and required to involve RTT in all steps of the GK treatment process, to guarantee the best GK treatment possible.

Accuracy of prehospital triage of trauma patients by emergency physicians: a retrospective study in western Switzerland.

OBJECTIVE: Accurate identification of major trauma patients in the prehospital setting positively affects survival and resource utilization. Triage algorithms using predictive criteria of injury severity have been identified in paramedic-based prehospital systems. Our rescue system is based on prehospital paramedics and emergency physicians. The aim of this study was to evaluate the accuracy of the prehospital triage performed by physicians and to identify the predictive factors leading to errors of triage.METHODS: Retrospective study of trauma patients triaged by physicians. Prehospital triage was analyzed using criteria defining major trauma victims (MTVs, Injury Severity Score >15, admission to ICU, need for immediate surgery and death within 48 h). Adequate triage was defined as MTVs oriented to the trauma centre or non-MTV (NMTV) oriented to regional hospitals.RESULTS: One thousand six hundred and eighti-five patients (blunt trauma 96%) were included (558 MTV and 1127 NMTV). Triage was adequate in 1455 patients (86.4%). Overtriage occurred in 171 cases (10.1%) and undertriage in 59 cases (3.5%). Sensitivity and specificity was 90 and 85%, respectively, whereas positive predictive value and negative predictive value were 75 and 94%, respectively. Using logistic regression analysis, significant (P<0.05) predictors of undertriage were head or thorax injuries (odds ratio >2.5). Predictors of overtriage were paediatric age group, pedestrian or 2 wheel-vehicle road traffic accidents (odds ratio >2.0).CONCLUSION: Physicians using clinical judgement provide effective prehospital triage of trauma patients. Only a few factors predicting errors in triage process were identified in this study.

Rewarding civil service performance through team bonuses : findings, analysis and recommendations

Performance-related pay within public organizations is continuing to spread. Although it can help to strengthen an entrepreneurial spirit in civil servants, its implementation is marred by technical, financial, managerial and cultural problems. This article identifies an added problem, namely the contradiction that exists between a managerial discourse that emphasizes the team and collective performance, on the one hand, and the use of appraisal and reward tools that are above all individual, on the other. Based on an empirical survey carried out within Swiss public organizations, the analysis shows that the team is currently rarely taken into account and singles out the principal routes towards an integrated system for the management and rewarding of civil servants.

Hematopoietic stem cell transplantation in Switzerland: a comprehensive quality control report on centre effect.

Interest groups advocate centre-specific outcome data as a useful tool for patients in choosing a hospital for their treatment and for decision-making by politicians and the insurance industry. Haematopoietic stem cell transplantation (HSCT) requires significant infrastructure and represents a cost-intensive procedure. It therefore qualifies as a prime target for such a policy. We made use of the comprehensive database of the Swiss Blood Stem Cells Transplant Group (SBST) to evaluate potential use of mortality rates. Nine institutions reported a total of 4717 HSCT - 1427 allogeneic (30.3%), 3290 autologous (69.7%) - in 3808 patients between the years 1997 and 2008. Data were analysed for survival- and transplantation-related mortality (TRM) at day 100 and at 5 years. The data showed marked and significant differences between centres in unadjusted analyses. These differences were absent or marginal when the results were adjusted for disease, year of transplant and the EBMT risk score (a score incorporating patient age, disease stage, time interval between diagnosis and transplantation, and, for allogeneic transplants, donor type and donor-recipient gender combination) in a multivariable analysis. These data indicate comparable quality among centres in Switzerland. They show that comparison of crude centre-specific outcome data without adjustment for the patient mix may be misleading. Mandatory data collection and systematic review of all cases within a comprehensive quality management system might, in contrast, serve as a model to ascertain the quality of other cost-intensive therapies in Switzerland.

Le choix de vivre en ville-centre : interactions entre mobilité quotidienne et mobilité résidentielle

Cet article s'insère dans un double débat : celui de l'influence des formes urbaines sur les pratiques modales et celui relatif au regain d'attractivité des villes pour les classes moyennes supérieures. Il aborde les interactions entre mobilité quotidienne et mobilité résidentielle dans un nouveau quartier d'une ville de taille moyenne. Les choix résidentiels étudiés se basent en grande partie sur la valorisation de la proximité. Toutefois, plusieurs styles de mobilité coexistent au sein de ce même contexte territorial en fonction notamment des parts modales des transports publics et de l'automobile.

Dépression, suicide assisté et vieillissement: cas clinique et commentaires = Depression, assisted suicide and ageing: case report and comments

L'hôpital de jour de psychiatrie de l'âge avancé du centre hospitalier universitaire Vaudois (CHUV), en Suisse, prend en charge ambulatoirement les personnes âgées souffrant de troubles psychiatriques. Cet article relate la première expérience de notre équipe d'une patiente qui est décédée à domicile via l'assistance au suicide alors qu'elle était suivie dans notre service pour un épisode dépressif sévère, de probables troubles cognitifs et un trouble de la personnalité émotionnellement labile de type borderline. Cette pratique d'assistance au suicide, autorisée par la loi suisse sous certaines conditions, est reprécisée et quelques directives médicoéthiques professionnelles sont présentées, avec un accent sur la capacité de discernement. © 2010 Elsevier Masson SAS. Tous droits réservés. The old age psychiatric daycare hospital of the Vaud University Hospital (CHUV), in Switzerland, follows up on elderly ambulatory patients with psychiatric disease. This article relates our team's first time experience with a patient who, while she was being treated in our unit for severe depression, cognitive symptoms and a borderline personality disorder, died at home via a suicide organization. Assisted suicide, allowed by the Swiss law, is also discussed in this article and, in addition, a few professional medico-ethics directives, with an emphasis on decision-making capacity are presented. © 2010 Elsevier Masson SAS. All rights reserved.

Profiling safety of intravitreal injections for retinoblastoma using an anti-reflux procedure and sterilisation of the needle track.

BACKGROUND: The preservation of globe integrity has always been a major concern during the treatment of retinoblastoma for fear of extraocular or metastatic spread. Intravitreal chemotherapy has been attempted as a desperate salvage therapy only for eyes with refractory retinoblastoma. Published data on the safety and efficacy of this route are, however, limited. METHODS: A modified technique of intravitreal injection in eyes with retinoblastoma is described. All children with retinoblastoma who received one or more intravitreal injections using this technique were retrospectively reviewed concerning ocular complications of the injection procedure as well as clinical or histopathological evidence of tumour spread. RESULTS: 30 eyes of 30 children with retinoblastoma received a total of 135 intravitreal injections, with a median follw-up duration of 13.5 months. No extraocular spread was seen on clinical follow-up in any patients and there was no tumour contamination of the retrieved entry sites histopathologically analysed among the five enucleated eyes. No significant ocular side effects were observed except transient localised vitreous haemorrhage (3/135). CONCLUSION: This technique is potentially safe and effective at a low cost and may play a promising role, especially in the treatment of recurrent and/or resistant vitreous disease in retinoblastoma, as an alternative to enucleation and/or external beam radiotherapy. However, this treatment should not replace the primary standard of care of retinoblastoma and should not be considered in group E eyes. Its application should be approved by an ophthalmological-oncological team and it should be performed by an experienced eye surgeon in a tertiary referral centre after careful selection of a tumour-free injection site.

Expression of MYC, IgM, As Well As Non-Germinal Centre B-Cell Like Immunophenotype and Positive Immunofish Index Predict a Worse Progression Free Survival and Overall Survival in a Series of 670 De Novo Diffuse Large B-Cell Lymphomas Included in Clinical Trials: A GELA Study of the 2003 Program

Introduction: Diffuse large B-cell lymphomas (DLBCL) represent a heterogeneous disease with variable clinical outcome. Identifying phenotypic biomarkers of tumor cells on paraffin sections that predict different clinical outcome remain an important goal that may also help to better understand the biology of this lymphoma. Differentiating non-germinal centre B-cell-like (non-GCB) from Germinal Centre B-cell-like (GCB) DLBCL according to Hans algorithm has been considered as an important immunohistochemical biomarker with prognostic value among patients treated with R-CHOP although not reproducibly found by all groups. Gene expression studies have also shown that IgM expression might be used as a surrogate for the GCB and ABC subtypes with a strong preferential expression of IgM in ABC DLBCL subtype. ImmunoFISH index based on the differential expression of MUM-1, FOXP1 by immunohistochemistry and on the BCL6 rearrangement by FISH has been previously reported (C Copie-Bergman, J Clin Oncol. 2009;27:5573-9) as prognostic in an homogeneous series of DLBCL treated with R-CHOP. In addition, oncogenic MYC protein overexpression by immunohistochemistry may represent an easy tool to identify the consequences of MYC deregulation in DLBCL. Our aim was to analyse by immunohistochemistry the prognostic relevance of MYC, IgM, GCB/nonGCB subtype and ImmunoFISH index in a large series of de novo DLBCL treated with Rituximab (R)-chemotherapy (anthracyclin based) included in the 2003 program of the Groupe d'Etude des Lymphomes de l'Adulte (GELA) trials. Methods: The 2003 program included patients with de novo CD20+ DLBCL enrolled in 6 different LNH-03 GELA trials (LNH-03-1B, -B, -3B, 39B, -6B, 7B) stratifying patients according to age and age-adjusted IPI. Tumor samples were analyzed by immunohistochemistry using CD10, BCL6, MUM1, FOXP1 (according to Barrans threshold), MYC, IgM antibodies on tissue microarrays and by FISH using BCL6 split signal DNA probes. Considering evaluable Hans score, 670 patients were included in the study with 237 (35.4%) receiving intensive R-ACVBP regimen and 433 (64.6%) R-CHOP/R-mini-CHOP. Results: 304 (45.4%) DLBCL were classified as GCB and 366 (54.6%) as non-GCB according to Hans algorithm. 337/567 cases (59.4%) were positive for the ImmunoFISH index (i.e. two out of the three markers positive: MUM1 protein positive, FOXP1 protein Variable or Strong, BCL6 rearrangement). Immunofish index was preferentially positive in the non-GCB subtype (81.3%) compared to the GCB subtype (31.2%), (p<0.001). IgM was recorded as positive in tumor cells in 351/637 (52.4%) DLBCL cases with a preferential expression in non-GCB 195 (53.3%) vs GCB subtype 100(32.9%), p<0.001). MYC was positive in 170/577 (29.5%) cases with a 40% cut-off and in 44/577 (14.2%) cases with a cut-off of 70%. There was no preferential expression of MYC among GCB or non-GCB subtype (p>0.4) for both cut-offs. Progression-free Survival (PFS) was significantly worse among patients with high IPI score (p<0.0001), IgM positive tumor (p<0.0001), MYC positive tumor with a 40% threshold (p<0.001), ImmunoFISH positive index (p<0.002), non-GCB DLBCL subtype (p<0.0001). Overall Survival (OS) was also significantly worse among patients with high IPI score (p<0.0001), IgM positive tumor (p=0.02), MYC positive tumor with a 40% threshold (p<0.01), ImmunoFISH positive index (p=0.02), non-GCB DLBCL subtype (p<0.0001). All significant parameters were included in a multivariate analysis using Cox Model and in addition to IPI, only the GCB/non-GCB subtype according to Hans algorithm predicted significantly a worse PFS among non-GCB subgroup (HR 1.9 [1.3-2.8] p=0.002) as well as a worse OS (HR 2.0 [1.3-3.2], p=0.003). This strong prognostic value of non-GCB subtyping was confirmed considering only patients treated with R- CHOP for PFS (HR 2.1 [1.4-3.3], p=0.001) and for OS (HR 2.3 [1.3-3.8], p=0.002). Conclusion: Our study on a large series of patients included in trials confirmed the relevance of immunohistochemistry as a useful tool to identify significant prognostic biomarkers for clinical use. We show here that IgM and MYC might be useful prognostic biomarkers. In addition, we confirmed in this series the prognostic value of the ImmunoFISH index. Above all, we fully validated the strong and independent prognostic value of the Hans algorithm, daily used by the pathologists to subtype DLBCL.