275 research outputs found
Adjoint-Based Error Estimation and Mesh Adaptation for Hybridized Discontinuous Galerkin Methods
We present a robust and efficient target-based mesh adaptation methodology,
building on hybridized discontinuous Galerkin schemes for (nonlinear)
convection-diffusion problems, including the compressible Euler and
Navier-Stokes equations. Hybridization of finite element discretizations has
the main advantage, that the resulting set of algebraic equations has globally
coupled degrees of freedom only on the skeleton of the computational mesh.
Consequently, solving for these degrees of freedom involves the solution of a
potentially much smaller system. This not only reduces storage requirements,
but also allows for a faster solution with iterative solvers. The mesh
adaptation is driven by an error estimate obtained via a discrete adjoint
approach. Furthermore, the computed target functional can be corrected with
this error estimate to obtain an even more accurate value. The aim of this
paper is twofold: Firstly, to show the superiority of adjoint-based mesh
adaptation over uniform and residual-based mesh refinement, and secondly to
investigate the efficiency of the global error estimate
A Comparison of Hybridized and Standard DG Methods for Target-Based hp-Adaptive Simulation of Compressible Flow
We present a comparison between hybridized and non-hybridized discontinuous
Galerkin methods in the context of target-based hp-adaptation for compressible
flow problems. The aim is to provide a critical assessment of the computational
efficiency of hybridized DG methods. Hybridization of finite element
discretizations has the main advantage, that the resulting set of algebraic
equations has globally coupled degrees of freedom only on the skeleton of the
computational mesh. Consequently, solving for these degrees of freedom involves
the solution of a potentially much smaller system. This not only reduces
storage requirements, but also allows for a faster solution with iterative
solvers. Using a discrete-adjoint approach, sensitivities with respect to
output functionals are computed to drive the adaptation. From the error
distribution given by the adjoint-based error estimator, h- or p-refinement is
chosen based on the smoothness of the solution which can be quantified by
properly-chosen smoothness indicators. Numerical results are shown for
subsonic, transonic, and supersonic flow around the NACA0012 airfoil.
hp-adaptation proves to be superior to pure h-adaptation if discontinuous or
singular flow features are involved. In all cases, a higher polynomial degree
turns out to be beneficial. We show that for polynomial degree of approximation
p=2 and higher, and for a broad range of test cases, HDG performs better than
DG in terms of runtime and memory requirements
RobotKube: Orchestrating Large-Scale Cooperative Multi-Robot Systems with Kubernetes and ROS
Modern cyber-physical systems (CPS) such as Cooperative Intelligent Transport
Systems (C-ITS) are increasingly defined by the software which operates these
systems. In practice, microservice architectures can be employed, which may
consist of containerized microservices running in a cluster comprised of robots
and supporting infrastructure. These microservices need to be orchestrated
dynamically according to ever changing requirements posed at the system.
Additionally, these systems are embedded in DevOps processes aiming at
continually updating and upgrading both the capabilities of CPS components and
of the system as a whole. In this paper, we present RobotKube, an approach to
orchestrating containerized microservices for large-scale cooperative
multi-robot CPS based on Kubernetes. We describe how to automate the
orchestration of software across a CPS, and include the possibility to monitor
and selectively store relevant accruing data. In this context, we present two
main components of such a system: an event detector capable of, e.g.,
requesting the deployment of additional applications, and an application
manager capable of automatically configuring the required changes in the
Kubernetes cluster. By combining the widely adopted Kubernetes platform with
the Robot Operating System (ROS), we enable the use of standard tools and
practices for developing, deploying, scaling, and monitoring microservices in
C-ITS. We demonstrate and evaluate RobotKube in an exemplary and reproducible
use case that we make publicly available at
https://github.com/ika-rwth-aachen/robotkube .Comment: 7 pages, 2 figures, 2 tables; Accepted to be published as part of the
26th IEEE International Conference on Intelligent Transportation Systems
(ITSC), Bilbao, Spain, September 24-28, 202
Digitale Selbstbestimmung
Die fortschreitende Digitalisierung verĂ€ndert die Gesellschaft und viele Lebensbereiche grundlegend. Beachtlichen Nutzungspotenzialen der sich stetig weiterentwickelnden Sammlung, Auswertung und Verwendung von personenbezogenen Daten steht die Gefahr gegenĂŒber, dass die Entscheidungs- und Handlungsfreiheit der Menschen eingeschrĂ€nkt wird. FĂŒr Nutzer digitaler Medien wird es zunehmend schwieriger, selbstbestimmt zu handeln. Ein Konzept der âdigitalen Selbstbestimmungâ sowie verwandte Begriffe wie etwa âdigitale Autonomieâ werden daher in der öffentlichen und wissenschaftlichen Diskussion immer bedeutsamer. Es fehlt bisher jedoch ein ausgearbeitetes theoretisches Konzept, welches âdigitale Selbstbestimmungâ als normativen Begriff klĂ€rt und empirische Bedingungen fĂŒr die Möglichkeit digitaler Selbstbestimmung systematisiert.
Ausgehend von der Leitfrage âWas ist âdigitale Selbstbestimmungâ?â wird in dieser Studie anhand einer explorativen Literaturrecherche und einer philosophischen Begriffsanalyse ein Konzept der digitalen Selbstbestimmung entwickelt. Dieses Konzept expliziert digitale Selbstbestimmung anhand der sieben Begriffskomponenten Kompetenz, Informiertheit, Werte, Wahlmöglichkeit, Freiwilligkeit, Willensbildung und Handlung. DarĂŒber hinaus werden technische, soziokulturelle und personenbezogene Determinanten identifiziert, d.h. Bedingungen und Faktoren, welche empirisch mitbestimmen, inwieweit eine Person digital selbstbestimmt ist.
Der empirische Teil der Studie stellt Erkenntnisse ĂŒber die Einstellungen von deutschen Nutzerinnen und Nutzer hinsichtlich des Umgangs mit personenbezogenen Daten vor. Die reprĂ€sentative sozialwissenschaftliche Erhebung wurde mit Hilfe eines standardisierten Fragebogens durchgefĂŒhrt, der auf der Basis des theoretischen Konzeptes entwickelt wurde. Es wird deutlich, dass die Sicherheit persönlicher Daten im Internet angezweifelt wird, dass die Möglichkeiten, sich ĂŒber gespeicherte persönliche Daten und ihre Weitergabe zu informieren, als unzureichend beurteilt werden, und dass Nutzer sich eine stĂ€rkere Einflussnahme auf die Speicherung und Verwendung persönlicher Daten wĂŒnschen.
Ein mittel- bis langfristiges Ziel der Studie ist es, die wissenschaftliche Erforschung von digitaler Selbstbestimmung zu stimulieren und letztlich zur Förderung digitaler Selbstbestimmung beizutragen
ECOG and BMI as preoperative risk factors for severe postoperative complications in ovarian cancer patients: results of a prospective study (RISC-GYNâtrial)
Background: Accompanying co-morbidities in patients with ovarian cancer are of major relevance for scheduling debulking surgery, especially in the anesthesiological consultations. Aim of this study was to evaluate the impact of co-morbidities and patient characteristics on postoperative complications.
Methods: Patients undergoing maximal cytoreductive surgery were prospectively enrolled from October 2015 to January 2017. Various variables were recorded, such as the Charlson comorbidity index, Eastern cooperative oncology group scale of performance status (ECOG PS) and the American society of anesthesiologists physical status classification system (ASA PS). Surgical complications were graded using the Clavien-Dindo criteria. Logistic regression models were used to analyze risk factors for severe postoperative complications.
Results: Of 106 enrolled patients, 19 (17.9%) developed severe postoperative complications grade >= IIIb according to Clavien-Dindo criteria. In the multivariable regression analysis impaired (ECOG PS) > 1 (odds ratio OR) 13.34, 95% confidence interval (CI) 1.74-102.30, p = 0.01), body mass index (BMI) > 25 kg/m(2) (OR 10.48, 95% CI 2.38-46.02, p = 0.002) along with the use of intraoperative norepinephrine > 0.11 mu g/kg/min (OR 4.69, 95% CI 1.13-19.46, p = 0.03) and intraoperative fresh frozen plasma (FFP) > 17 units (OR 4.11, 95% CI 1.12-15.14, p = 0.03) appeared as significant predictors of severe postoperative complications.
Conclusion: We demonstrated that neither the presence of a certain comorbidity nor the summation of the co-morbidities were associated with adverse outcome. Patient characteristics, such as ECOG PS > 1 and obesity (BMI > 25 kg/m(2)), are highly predictive factors for severe postoperative complications. The analysis of intraoperative data showed that the need for more than > 0.11 mu g/kg/min of norepinephrine and transfusions of FFPs more than 17 units were strongly associated with severe postoperative complications
Entwicklungen in der PrÀnataldiagnostik: verÀndertes Erleben der Schwangerschaft und Auswirkungen bei pathologischem fetalen Befund
'Die Weiterentwicklung der PrĂ€nataldiagnostik hat die Betreuung schwangerer Frauen stetig verĂ€ndert, und auch von den Frauen wird eine Schwangerschaft heute völlig anders erlebt als noch vor wenigen Jahrzehnten. Trotz erheblicher Fortschritte in der medizinischen Versorgung sind aber noch lĂ€ngst nicht alle Erkrankungen des Kindes therapeutisch zu beeinflussen; insbesondere nach Feststellung einer genetisch bedingten Erkrankung oder Behinderung des Kindes stellt sich fĂŒr die Frauen und ihre Partner oft die Frage danach, ob sie die Schwangerschaft fortsetzen können. Betroffene Frauen bzw. Paare reagieren auf solche Situationen nicht selten mit einer Schock-Reaktion, und auch langfristig können sich psychische Probleme einstellen, unabhĂ€ngig davon, ob die Schwangerschaft ausgetragen oder wegen einer medizinischen Indikation gemÀà Paragraf 218a Abs. 2 StGB abgebrochen wurde. Um die Betroffenen in einer solchen Krisensituation zu unterstĂŒtzen und sie auch im Entscheidungsprozess zu begleiten wurde an drei Modellstandorten (Bonn, DĂŒsseldorf und Essen) eine psychosoziale Beratung etabliert, wobei diese psychosoziale Beratung zusĂ€tzlich zur Ă€rztlichen Beratung unabhĂ€ngig von konfessioneller oder nicht-konfessioneller Ausrichtung ergebnisoffen erfolgt. Die wissenschaftliche Evaluation von insgesamt 512 Erstberatungen und die Verlaufsuntersuchung ĂŒber zwei Jahre zeigte eine hohe Akzeptanz der Beratung von Seiten der Betroffenen. Viele Argumente sprechen dafĂŒr, eine solche Beratung als Regelangebot im Kontext von PrĂ€natalmedizin zu etablieren.' (Autorenreferat)'The further development of prenatal diagnosis has led to changes in the care for pregnant women. Also, pregnant women nowadays experience pregnancy in a way very different from that a few decades ago. Despite of impressive medical progress, it is still not possible to have an therapeutic impact on all diseases of the foetus and the child. In particular, when a genetic disorder is diagnosed, the question arises whether or not the pregnancy should be continued. More often than not, women or couples, respectively, display a shock reaction following this disclosure. In the long run, psychological problems may evolve, regardless of the continuation of the pregnancy or its termination (abortion) on grounds of article 218a, 2 StGB (German Criminal Code) for medical reasons. For providing support to these women in crisis and for accompanying the decision-making process, psychosocial counselling has been established in three demonstration sites (Bonn, DĂŒsseldorf and Essen). This counselling had been offered in addition to the medical counselling and has been performed in an unbiased manner, regardless of the denominational orientation of the responsible body. The assessment of 512 first-time counselling sessions as well as the accompanying two-year evaluation study show that this kind of counselling has been widely accepted by the affected women. There are striking arguments for establishing psychosocial counselling as a scheduled part of counselling in prenatal diagnosis.' (author's abstract)
Enhancing Lidar-based Object Detection in Adverse Weather using Offset Sequences in Time
Automated vehicles require an accurate perception of their surroundings for
safe and efficient driving. Lidar-based object detection is a widely used
method for environment perception, but its performance is significantly
affected by adverse weather conditions such as rain and fog. In this work, we
investigate various strategies for enhancing the robustness of lidar-based
object detection by processing sequential data samples generated by lidar
sensors. Our approaches leverage temporal information to improve a lidar object
detection model, without the need for additional filtering or pre-processing
steps. We compare different neural network architectures that process
point cloud sequences including a novel augmentation strategy introducing a
temporal offset between frames of a sequence during training and evaluate the
effectiveness of all strategies on lidar point clouds under adverse weather
conditions through experiments. Our research provides a comprehensive study of
effective methods for mitigating the effects of adverse weather on the
reliability of lidar-based object detection using sequential data that are
evaluated using public datasets such as nuScenes, Dense, and the Canadian
Adverse Driving Conditions Dataset. Our findings demonstrate that our novel
method, involving temporal offset augmentation through randomized frame
skipping in sequences, enhances object detection accuracy compared to both the
baseline model (Pillar-based Object Detection) and no augmentation.Comment: Published as part of the III. International Conference on Electrical,
Computer and Energy Technologies (ICECET 2023), Cape Town, South Africa,
November 16-17, 202
NVX-CoV2373-induced T- and B-cellular immunity in immunosuppressed people with multiple sclerosis that failed to respond to mRNA and viral vector SARS-CoV-2 vaccines
Importance: Immunological response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination is important, especially in people with multiple sclerosis (pwMS) on immunosuppressive therapies.
Objective: This study aims to determine whether adjuvanted protein-based vaccine NVX-CoV2373 is able to induce an immune response to SARS-CoV-2 in pwMS with inadequate responses to prior triple mRNA/viral vector vaccination.
Design, setting, and participants: We conducted a single-center, prospective longitudinal cohort study at the MS Center in Dresden, Germany. In total, 65 participants were included in the study in accordance with the following eligibility criteria: age > 18 years, immunomodulatory treatment, and insufficient T-cellular and humoral response to prior vaccination with at least two doses of SARS-CoV-2 mRNA (BNT162b2, mRNA-1273) or viral vector vaccines (AZD1222, Ad26.COV2.S).
Interventions: Intramuscular vaccination with two doses of NVX-CoV2373 at baseline and 3 weeks of follow-up.
Main outcomes and measures: The development of SARS-CoV-2-specific antibodies and T-cell responses was evaluated.
Results: For the final analysis, data from 47 patients on stable treatment with sphingosine-1-phosphate receptor (S1PR) modulators and 17 on ocrelizumab were available. The tolerability of the NVX-CoV2373 vaccination was overall good and comparable to the one reported for the general population. After the second NVX-CoV2373 vaccination, 59% of S1PR-modulated patients developed antispike IgG antibodies above the predefined cutoff of 200 binding antibody units (BAU)/ml (mean, 1,204.37 [95% CI, 693.15, 2,092.65] BAU/ml), whereas no clinically significant T-cell response was found. In the subgroup of the patients on ocrelizumab treatment, 23.5% developed antispike IgG > 200 BAU/ml (mean, 116.3 [95% CI, 47.04, 287.51] BAU/ml) and 53% showed positive spike-specific T-cellular responses (IFN-gamma release to antigen 1: mean, 0.2 [95% CI, 0.11, 0.31] IU/ml; antigen 2: mean, 0.24 [95% CI, 0.14, 0.37]) after the second vaccination.
Conclusions: Vaccination with two doses of NVX-CoV2373 was able to elicit a SARS-CoV-2-specific immune response in pwMS lacking adequate immune responses to previous mRNA/viral vector vaccination. For patients receiving S1PR modulators, an increase in anti-SARS-CoV-2 IgG antibodies was detected after NVX-CoV2373 vaccination, whereas in ocrelizumab-treated patients, the increase of antiviral T-cell responses was more pronounced. Our data may impact clinical decision-making by influencing the preference for NVX-CoV2373 vaccination in pwMS receiving treatment with S1PR modulation or anti-CD20 treatment
Gender differences of health literacy in persons with a migration background: a systematic review and meta-analysis
Objective: To investigate gender differences of health literacy in individuals with a migration background.
Design: Systematic review and meta-analysis. OVID/MEDLINE, PsycINFO and CINAHL were searched in March 2018 and July 2020.
Setting: Studies had to provide health literacy data for adult women and men with a migration background, collected with a standardised instrument, or report results that demonstrated the collection of such data. Health literacy data were extracted from eligible studies or requested from the respective authors. Using a random-effects model, a meta-analysis was conducted to assess standardised mean differences (SMDs) of health literacy in men and women. Two researchers independently assessed risk of bias for each included study using the Appraisal Tool for Cross-Sectional Studies.
Results: Twenty-four studies were included in this systematic review. Thereof, 22 studies (8012 female and 5380 male participants) were included in the meta-analyses. In six studies, gender-specific health literacy scores were reported. The authors of additional 15 studies provided their data upon request and for one further study data were available online. Women achieved higher health literacy scores than men: SMD=0.08, 95% CI 0.002 to 0.159, p=0.04, I2=65%. Another 27 studies reported data on female participants only and could not be included due to a lack of comparable studies with male participants only. Authors of 56 other eligible studies were asked for data, but without success.
Conclusion Men with a migration backgroundâwhile being much less frequently examinedâmay have lower health literacy than women. As heterogeneity between studies was high and the difference became statistically insignificant when excluding studies with a high risk of bias, this result must be interpreted with caution. There is a paucity of research on the social and relational aspects of gender in relation to health literacy among people with a migration background, especially for men
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