16 research outputs found

    Stability of trapped Bose-Einstein condensates

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    In three-dimensional trapped Bose-Einstein condensate (BEC), described by the time-dependent Gross-Pitaevskii-Ginzburg equation, we study the effect of initial conditions on stability using a Gaussian variational approach and exact numerical simulations. We also discuss the validity of the criterion for stability suggested by Vakhitov and Kolokolov. The maximum initial chirp (initial focusing defocusing of cloud) that can lead a stable condensate to collapse even before the number of atoms reaches its critical limit is obtained for several specific cases. When we consider two- and three-body nonlinear terms, with negative cubic and positive quintic terms, we have the conditions for the existence of two phases in the condensate. In this case, the magnitude of the oscillations between the two phases are studied considering sufficient large initial chirps. The occurrence of collapse in a BEC with repulsive two-body interaction is also shown to be possible.Comment: 15 pages, 11 figure

    Effects on short term outcome of non-invasive ventilation use in the emergency department to treat patients with acute heart failure: A propensity score-based analysis of the EAHFE Registry

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    Objective: To assess the effects of non-invasive ventilation (NIV) in emergency department (ED) patients with acute heart failure (AHF) on short term outcomes. Methods: Patients from the EAHFE Registry (a multicenter, observational, multipurpose, cohort-designed database including consecutive AHF patients in 41 Spanish EDs) were grouped based on NIV treatment (NIV+ and NIV–groups). Using propensity score (PS) methodology, we identified two subgroups of patients matched by 38 covariates and compared regarding 30-day survival (primary outcome). Interaction was investigated for age, sex, ischemic cardiomyopathy, chronic obstructive pulmonary disease, AHF precipitated by an acute coronary syndrome (ACS), AHF classified as hypertensive or acute pulmonary edema (APE), and systolic blood pressure (SBP). Secondary outcomes were intensive care unit (ICU) admission; mechanical ventilation; in-hospital, 3-day and 7-day mortality; and prolonged hospitalization (>7 days). Results: Of 11, 152 patients from the EAHFE (age (SD): 80 (10) years; 55.5% women), 718 (6.4%) were NIV+ and had a higher 30-day mortality (HR = 2.229; 95%CI = 1.861–2.670) (p 85 years, p < 0.001), AHF associated with ACS (p = 0.045), and SBP < 100 mmHg (p < 0.001). No significant differences were found in the secondary endpoints except for more prolonged hospitalizations in NIV+ patients (OR = 1.445; 95%CI = 1.122–1.862) (p = 0.004). Conclusion: The use of NIV to treat AHF in ED is not associated with improved mortality outcomes and should be cautious in old patients and those with ACS and hypotension

    Modeling and Analysis of Thread-Pools in an Industrial Communication Platform

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    Abstract. Thread pools are often used as a pattern to increase the throughput and responsiveness of software systems. Implementations of thread pools may differ considerably from each other, which urges the need to analyze these differences in a formal manner. We use an object-oriented paradigm to model different thread pools in the context of the ASK system, an industrial communication platform. We use be-havioral interfaces, high-level behavioral specifications for the objects, as a starting-point for analysis. Based on these behavioral interfaces, func-tional aspects are modeled in Creol, a high-level modeling language for concurrent objects. We use Uppaal to create real-time models and to perform schedulability analysis with respect to the behavioral interfaces. We finally check conformance between the real-time and Creol models using test-cases generated from the behavioral interfaces.

    Decision-making on preimplantation genetic diagnosis and prenatal diagnosis: a challenge for couples with hereditary breast and ovarian cancer

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    How do couples with a BRCA1/2 mutation decide on preimplantation genetic diagnosis (PGD) and prenatal diagnosis (PND) for hereditary breast and ovarian cancer syndrome (HBOC)? BRCA couples primarily classify PGD and/or PND as reproductive options based on the perceived severity of HBOC and moral considerations, and consequently weigh the few important advantages of PGD against numerous smaller disadvantages. Awareness of PGD is generally low among persons at high risk for hereditary cancers. Most persons with HBOC are in favour of offering PGD for BRCA1/2 mutations, although only a minority would consider this option for themselves. Studies exploring the motivations for using or refraining from PGD among well-informed BRCA carriers of reproductive age are lacking. We studied the reproductive decision-making process by interviewing a group of well-informed, reproductive aged couples carrying a BRCA1/2 mutation, regarding their decisional motives and considerations. This exploratory, qualitative study investigated the motives and considerations taken into account by couples with a BRCA1/2 mutation and who have received extensive counselling on PGD and PND and have made a well-informed decision regarding this option. Eighteen couples took part in focus group and dyadic interviews between January and September 2012. Semi-structured focus groups were conducted containing two to four couples, assembled based on the reproductive method the couple had chosen: PGD (n 6 couples) or conception without testing (n 8 couples). Couples who had chosen PND for BRCA (n 4) were interviewed dyadically. Two of the women, of whom one had chosen PND and the other had chosen no testing, had a history of breast cancer. None of the couples who opted for PGD or conception without testing found the use of PND, with possible pregnancy termination, acceptable. PND users chose this method because of decisive, mainly practical reasons (natural conception, high chance of favourable outcome). Motives and considerations regarding PGD largely overlapped between PGD users, PND users and non-users, all mentioning some significant advantages (e.g. protecting the child and family from the mutation) and many smaller disadvantages (e.g. the necessity of in vitro fertilization (IVF), low chance of pregnancy by IVF/PGD). For female carriers, the safety of hormonal stimulation and the time required for PGD before undergoing preventive surgeries were important factors in the decision. Non-users expressed doubts about the moral justness of their decision afterwards and emphasized the impact the decision still had on their lives. The interviewed couples were at different stages in their chosen trajectory, up to 3 years after completion. This may have led to recall bias of original motives and considerations. Couples who did not actively seek information about PGD were excluded. Therefore the results may not be readily generalizable to all BRCA couples. The perceived severity of HBOC and, for female carriers, the safety of hormonal stimulation and the time frames for PGD planning before preventive surgeries are essential items BRCA couples consider in reproductive decision-making. The emotional impact of this decision should not be underestimated; especially non-users may experience feelings of doubt or guilt up to several years afterwards. PGD counselling with tailored information addressing these items and decisional support in order to guarantee well-informed decision-making is needed. This study was funded by the Dutch breast cancer foundation Stichting Pink Ribbon, grant number 2010.PS11.C74. None of the authors have competing interests to declare. Not applicable

    PERTINENT - PERindopril-Thrombosis, InflammatioN, endothelial dysfunction and neurohormonal activation trial: A sub-study of the EUROPA study

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    BACKGROUND: Markers of thrombosis, inflammation, endothelial dysfunction and neurohumoral activation such as fibrinogen, D-dimer, C-reactive protein, von Willebrand factor, tumour necrosis factor-alpha and chromogranin-A are reported to be linked to the increase of cardiovascular risk for atherosclerosis progression and events in patients with cardiovascular diseases. METHODS: EUROPA is a double blind, placebo-controlled trial on 12,231 patients that evaluates the effect of an angiotensin converting enzyme inhibitor--perindopril--on prevention of cardiovascular events in patients with coronary artery disease. PERTINENT is a sub-study of EUROPA that evaluates (a) in Part A (300 patients): the influence of perindopril vs. placebo on fibrinogen, D-dimer, C-reactive protein, von Willebrand factor, tumour necrosis factor-alpha and chromogranin-A. In addition, NOS expression and induction of apoptosis on human umbilical vein endothelial cells and angiotensin converting enzyme levels are also studied; (b) in Part B (about 1200 patients): the predictive role of plasma levels of C-reactive protein and von Willebrand factor on the occurrence of cardiovascular events. To this end, matched case-control analyses are planned (patients with vs. patients without events). STATUS OF PERTINENT: Blood analyses are in progress in four specialised laboratories: (a) Gaubius Laboratory, Leiden, TNO-PG, The Netherlands; (b) University Department of Medicine, Birmingham, UK; (c) University of Pavia, Italy; (d) Fondazione Salvatore Maugeri, Cardiovascular Research Centre, Gussago, Italy. CONCLUSIONS: The PERTINENT sub-study might help elucidating the phenomena contributing to the pathophysiology of cardiovascular events in patients with coronary artery disease and the role of perindopril in such context

    Atrial fibrillation history impact on catheter ablation outcome. Findings from the ESC-EHRA Atrial Fibrillation Ablation Long-Term Registry

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    Background Atrial fibrillation (AF) promotes atrial remodeling that in turn promotes AF perpetuation. The aim of our study is to investigate the impact of AF history length on 1-year outcome of AF catheter ablation in a cohort of patients enrolled in the Atrial Fibrillation Ablation Registry. Methods We described the real-life clinical epidemiology, therapeutic strategies, and the short- and mid-term outcomes of 1948 patients (71.9% with paroxysmal AF) undergoing AF ablation procedures, stratified according to AF history duration (= 2 years). Results The mean AF history duration was 46.2 +/- 57.4 months, 592 patients had an AF history duration = 2 years (mean 75.5 +/- 63.5 months) (P = 2 years (34.0%) (P = 0.037). AF history duration >= 2 years, overall ablation procedure duration, hypertension, and chronic kidney disease were all predictors of recurrences after the blanking period. Conclusions In this multicenter registry, performing catheter ablation in patients with an AF history >= 2 years was associated with higher rates of AF recurrences at 1 year. Since cumulative time in AF in not necessarily equivalent to AF history, its role remains to be clarified.Cardiolog
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