244 research outputs found

    Six-axis decentralized control design for spacecraft formation flying mission

    Get PDF
    This contribution addresses the control design for the three-spacecraft formation flying interferometry mission Pegase. The operational mode considered is the high-precision nulling phase. The control design has as major objective the minimization of the variance of the controlled outputs, e.g. the optical path difference. The payload performance demands are shown to be fulfilled in spite of orbital disturbances, solar radiation pressure as well as sensor and actuator noise. Furthermore, a novel iterative algorithm is proposed, capable of designing decentralized H2-suboptimal controllers. These controllers consist of a set of individual closed loops on board the different spacecraft which only use locally available measurements, forces and torques. This approach reduces communication bandwidth and enhances robustness concerning faulty communication links. Finally, the performance loss due to decentralization is investigated

    Paroles de cheminants: des gens du voyage regardent les autres suisses romands

    Get PDF
    Les « Cheminants »*, terme utilisé dans ces pages pour parler des Gens du Voyage suisses, sont présents un peu partout dans ce pays depuis des siècles. La plupart sont Yéniches, d’autres sont Manouches : ils constituent donc une minorité non pas uniquement nationale, mais aussi transnationale. Ce travail de recherche ne s’intéresse pas aux traits culturels de ce groupe, mais au regard que les Cheminants posent sur leurs compatriotes Suisses romands. Quelle image se font-ils des Suisses romands ? Cette image est-elle hétérogène ? Peut-elle s’expliquer à la lumière des relations entre ces groupes, ou alors à la lumière des mécanismes de valorisation de l’identité sociale d’un groupe ? Après une présentation de concepts à propos des perceptions et des relations intergroupes, ce travail propose une exploration de l’histoire des relations entre Cheminants et Suisses ainsi qu’un aperçu de la réalité sociale actuelle de ce groupe en Suisse. Le « cheminement » du chercheur en direction de cette minorité, ses questions, ses problèmes et ses découvertes sont présentées. Cela permettra au lecteur de prendre connaissance de la position du chercheur, mais aussi de découvrir la démarche de déconstruction que celui-ci a mené à propos des représentations qu’il associait à cette minorité. Sept entretiens approfondis avec des Cheminants figurent dans cet ouvrage sous forme de portraits. Chacun de ceux-ci est suivi par un texte destiné à résumer ainsi qu’à tenter d’analyser son contenu. Une analyse transversale des entretiens par le biais de la discussion des hypothèses est aussi proposée. Ce travail de recherche se termine sur des éléments qui questionnent et proposent des pistes non seulement aux pratiques professionnelles de l’animation socioculturelle et du travail social en général, mais aussi à tout un chacun dans sa manière de percevoir l’autre et d’être en relation avec celui-c

    Effect of Vancomycin Therapy for Osteomyelitis on Colonization by Methicillin-Resistant Staphylococcus aureus: Lack of Emergence of Glycopeptide Resistance

    Get PDF
    Abstract Background: In treating orthopedic infections, the long-term impact of vancomycin therapy on colonization by methicillin-resistant Staphylococcus aureus (MRSA) and the emergence of vancomycin-intermediate S. aureus is unknown. Design: Prospective surveillance of the effect of long-term vancomycin therapy on colonization by MRSA and the emergence of vancomycin-intermediate S. aureus. Methods: Thirty-four patients with MRSA osteomyelitis that was microbiologically documented were longitudinally observed for the emergence of vancomycin-intermediate S. aureus at 3 body sites (wound, anterior nares, and groin) during the initial period of vancomycin therapy and at the 2-month follow-up. Twenty patients received the standard dose (20 mg/kg/d) for 34 ± 6 days and 14 patients received a high dose (40 mg/kg/d) of vancomycin for 37 ± 9 days. Results: During vancomycin treatment, global MRSA carriage (all body sites) fell from 100% to 25% in the group of patients receiving the standard dose of vancomycin, and from 100% to 40% in the group receiving the high dose. During the 2-month follow-up period after vancomycin therapy, global MRSA carriage increased from 25% to 55% in the group receiving the standard dose and decreased from 43% to 36% in the group receiving the high dose. Conclusion: Therapy with a high dose of vancomycin contributes to the sustained eradication of MRSA carriage without promoting the emergence of glycopeptide resistanc

    Blunting the response to endotoxin in healthy subjects: effects of various doses of intravenous fish oil

    Get PDF
    Objective: To test the dose response effect of infused fish oil (FO) rich in n-3 PUFAs on the inflammatory response to endotoxin (LPS) and on membrane incorporation of fatty acids in healthy subjects. Design: Prospective, sequential investigation comparing three different FO doses. Subjects: Three groups of male subjects aged 26.8±3.2years (BMI 22.5±2.1). Intervention: One of three FO doses (Omegaven®10%) as a slow infusion before LPS: 0.5g/kg 1day before LPS, 0.2g/kg 1day before, or 0.2g/kg 2h before. Measurements and results: Temperature, hemodynamic variables, indirect calorimetry and blood samples (TNF-α, stress hormones) were collected. After LPS temperature, ACTH and TNF-α concentrations increased in the three groups: the responses were significantly blunted (p<0.0001) compared with the control group of the Pluess et al. trial. Cortisol was unchanged. Lowest plasma ACTH, TNF-α and temperature AUC values were observed after a single 0.2g/kg dose of FO. EPA incorporation into platelet membranes was dose-dependent. Conclusions: Having previously shown that the response to LPS was reproducible, this study shows that three FO doses blunted it to various degrees. The 0.2g/kg perfusion immediately before LPS was the most efficient in blunting the responses, suggesting LPS capture in addition to the systemic and membrane effect

    Reduction of Urinary Tract Infection and Antibiotic Use after Surgery: A Controlled, Prospective, Before-After Intervention Study

    Get PDF
    Background. Urinary tract infection is the most frequent health care—associated complication. We hypothesized that the implementation of a multifaceted prevention strategy could decrease its incidence after surgery. Methods. In a controlled, prospective, before-after intervention trial with 1328 adult patients scheduled for orthopedic or abdominal surgery, nosocomial infection surveillance was conducted until hospital discharge. A multifaceted intervention including specifically tailored, locally developed guidelines for the prevention of urinary tract infection was implemented for orthopedic surgery patients, and abdominal surgery patients served as control subjects. Infectious and noninfectious complications, adherence to guidelines, and antibiotic use were monitored before and after the intervention and again 2 years later. Results. The incidence of urinary tract infection decreased from 10.4 to 3.9 episodes per 100 patients in the intervention group (incidence-density ratio, 0.41; 95% CI, 0.20-0.79; P = .004). Adherence to guidelines was 82.2%. Both the frequency and the duration of urinary catheterization decreased following the intervention. Recourse to antibiotic therapy after surgery dropped in the intervention group from 17.9 to 15.6 defined daily doses per 100 patient-days (P < .005) because of a reduced need for the treatment of urinary tract infection (P < .001). Follow-up after 2 years revealed a sustained impact of the strategy and a subsequent low use of antibiotics, consistent with stable adherence to guidelines (80.8%). Conclusions. A multifaceted prevention strategy can dramatically decrease postoperative urinary tract infection and contribute to the reduction of the overall use of antibiotics after surger

    Video-assisted Thoracoscopic Resection of a Small Pulmonary Nodule after Computed Tomography-guided Localization with a Hook-wire System: Experience in 45 Consecutive Patients

    Get PDF
    Background: This study is a single-institution validation of video-assisted thoracoscopic (VATS) resection of a small solitary pulmonary nodule (SPN) previously localized by a CT-guided hook-wire system in a consecutive series of 45 patients. Methods: The records of all patients undergoing VATS resection for SPN preoperatively localized by CT-guided a hook-wire system from January 2002 to December 2004 were assessed with respect to failure to localize the lesion by the hook-wire system, conversion thoracotomy rate, duration of operation, postoperative complications, and histology of SPN. Results: Forty-five patients underwent 49 VATS resections, with simultaneous bilateral SPN resection performed in 4. Preoperative CT-guided hook-wire localization failed in two patients (4%). Conversion thoracotomy was necessary in two patients (4%) because it was not possible to resect the lesion by a VATS approach. The average operative time was 50 min. Postoperative complications occurred in 3 patients (6%), one hemothorax and two pneumonia. The mean hospital stay was 5 days (range: 2-18 days). Histological assessment revealed inflammatory disease in 17 patients (38%), metastasis in 17 (38%), non-small-cell lung cancer (NSCLC) in 4 (9%), lymphoma in 3 (6%), interstitial fibrosis in 2 (4%), histiocytoma in one (2%), and hamartoma in one (2%). Conclusions: Histological analysis of resected SPN revealed unexpected malignant disease in more than 50% of the patients indicating that histological clarification of SPN seems warranted. Video-assisted thoracoscopic resection of SPN previously localized by a CT-guided hook-wire system is related to a low conversion thoracotomy rate, a short operation time, and few postoperative complications, and it is well suited for the clarification of SP

    New frontiers in healthcare environmental hygiene:thoughts from the 2022 healthcare cleaning forum

    Get PDF
    Healthcare environmental hygiene (HEH) has become recognized as being increasingly important for patient safety and the prevention of healthcare-associated infections. At the 2022 Healthcare Cleaning Forum at Interclean in Amsterdam, the academic lectures focused on a series of main areas of interest. These areas are indicative of some of the main trends and avenues for research in the coming years. Both industry and academia need to take steps to continue the momentum of HEH as we transition out of the acute phase of the Covid-19 pandemic. There is a need for new ways to facilitate collaboration between the academic and private sectors. The Clean Hospitals® network was presented in the context of the need for both cross-disciplinarity and evidence-based interventions in HEH. Governmental bodies have also become more involved in the field, and both the German DIN 13603 standard and the UK NHS Cleaning Standards were analyzed and compared. The challenge of environmental pathogens was explored through the example of how P. aeruginosa persists in the healthcare environment. New innovations in HEH were presented, from digitalization to tracking, and automated disinfection to antimicrobial surfaces. The need for sustainability in HEH was also explored, focusing on the burden of waste, the need for a circular economy, and trends towards increasingly local provision of goods and services. The continued focus on and expansion of these areas of HEH will result in safer patient care and contribute to better health systems

    Patient self-reported concerns in inflammatory bowel diseases: A gender-specific subjective quality-of-life indicator.

    Get PDF
    Patient-reported disease perceptions are important components to be considered within a holistic model of quality of care. Gender may have an influence on these perceptions. We aimed to explore gender-specific concerns of patients included in a national bilingual inflammatory bowel disease cohort. Following a qualitative study, we built a questionnaire comprising 37 items of concern. Answers were collected on a visual analog scale ranging from 0 to 100. Principal axis factor analysis was used to explore concern domains. Linear multiple regressions were conducted to assess associations with patient characteristics. Of 1102 patients who replied to the survey, 54% were female and 54% had Crohn's disease. We identified six domains of concern: socialization and stigmatization, disease-related constraints and uncertainty, symptoms and their impact on body and mind, loss of body control (including sexuality), disease transmission, and long-term impact of the disease. Cancer concerns were among the highest scored by all patients (median 61.8). Severity of symptoms was the only factor associated with concerns, unrelated to dimension and gender (p&lt;0.015). In women, being &gt;40 years decreased disease-related constraints and uncertainty concerns, and being at home or unemployed increased them. Treatments were associated with increased socialization and stigmatization and with increased disease-related constraints and uncertainty concerns in men. Overall, psychosomatic characteristics were highly associated with concerns for both men and women. Depending on the concern dimensions, increased levels of concern were associated with the highest signs of anxiety in women or depression in men, as well as lower health-related quality of life in men. Patients have numerous concerns related to their illness that need to be reassessed regularly. Concerns differ between men and women, suggesting that information and communication about the disease should take gender differences and subjective perceptions of quality of life into consideration

    Associations Between Online Pornography and Sexual Behavior Among Adolescents: Myth or Reality?

    Get PDF
    This study aimed to compare the sexual behavior of adolescents who were or were not exposed to online pornography, to assess to what extent the willingness of exposure changed these possible associations, and to determine the profiles of youths who were exposed to online pornography. Data were drawn from the 2002 Swiss Multicenter Adolescent Survey on Health, a self-administered cross-sectional, paper and pencil questionnaire. From the 7529 adolescents aged 16-20years, 6054 (3283 males) used the Internet during the previous month and were eligible for our study. Males were divided into three groups (wanted exposure, 29.2%; unwanted exposure, 46.7%; no exposure, 24.1%) whereas females were divided into two groups (exposure, 35.9%; no exposure, 64.1%). The principal outcome measures were demographic characteristics, Internet use parameters and risky sexual behaviors. Risky sexual behaviors were not associated with online pornography exposure in any of the groups, except that males who were exposed (deliberately or not) had higher odds of not having used a condom at last intercourse. Bi/homosexual orientation and Internet use parameters were not associated either. Additionally, males in the wanted exposure group were more likely to be sensation-seekers. On the other hand, exposed girls were more likely to be students, higher sensation-seekers, early maturers, and to have a highly educated father. We conclude that pornography exposure is not associated with risky sexual behaviors and that the willingness of exposure does not seem to have an impact on risky sexual behaviors among adolescent
    corecore