1,072 research outputs found
The common data acquisition platform in the Helmholtz Association
Various centres of the German Helmholtz Association (HGF) started in 2012 to developa modular data acquisition (DAQ) platform, covering the entire range from detector readout todata transfer into parallel computing environments. This platform integrates generic hardwarecomponents like the multi-purpose HGF-Advanced Mezzanine Card or a smart scientific cameraframework, adding user value with Linux drivers and board support packages. Technically the scopecomprises the DAQ-chain from FPGA-modules to computing servers, notably frontend-electronicsinterfaces, microcontrollers and GPUs with their software plus high-performance data transmissionlinks. The core idea is a generic and component-based approach, enabling the implementationof specific experiment requirements with low effort. This so called DTS-platform will supportstandards like MTCA.4 in hard- and software to ensure compatibility with commercial components.Its capability to deploy on other crate standards or FPGA-boards with PCI express or Ethernetinterfaces remains an essential feature.Competences of the participating centres are coordinated in order to provide a solid technological basis for both research topics in the Helmholtz Programme “Matter and Technology”:“Detector Technology and Systems” and “Accelerator Research and Development”. The DTSplatform aims at reducing costs and development time and will ensure access to latest technologiesfor the collaboration. Due to its flexible approach, it has the potential to be applied in other scientificprograms
Using the classical model for structured expert judgment to estimate extremes: a case study of discharges in the Meuse River
Accurate estimation of extreme discharges in rivers, such as the Meuse, is crucial for effective flood risk assessment. However, hydrological models that estimate such discharges often lack transparency regarding the uncertainty in their predictions. This was evidenced by the devastating flood that occurred in July 2021, which was not captured by the existing model for estimating design discharges. This article proposes an approach to obtain uncertainty estimates for extremes with structured expert judgment using the classical model (CM). A simple statistical model was developed for the river basin, consisting of correlated generalized extreme value (GEV) distributions for discharges from upstream tributaries. The model was fitted to seven experts' estimates and historical measurements using Bayesian inference. Results were fitted only to the measurements were solely informative for more frequent events, while fitting only to the expert estimates reduced uncertainty solely for extremes. Combining both historical observations and estimates of extremes provided the most plausible results. The classical model reduced the uncertainty by appointing the most weight to the two most accurate experts, based on their estimates of less extreme discharges. The study demonstrates that with the presented Bayesian approach that combines historical data and expert-informed priors, a group of hydrological experts can provide plausible estimates for discharges and potentially also other (hydrological) extremes with relatively manageable effort.</p
Cardiac left atrium CT image segmentation for ablation guidance
Catheter ablation is an increasingly important curative procedure for atrial fibrillation. Knowledge of the local wall thickness is essential to determine the proper ablation energy. This paper presents the first semi-automatic atrial wall thickness measurement method for ablation guidance. It includes both endocardial and epicardial atrial wall segmentation on CT image data. Segmentation is based on active contours, Otsu's multiple threshold method and hysteresis thresholding. Segmentation results were compared to contours manually drawn by two experts, using repeated measures analysis of variance. The root mean square differences between the semi-automatic and the manually drawn contours were comparable to intra-observer variation (endocardium: p = 0.23, epicardium: p = 0.18). Mean wall thickness difference is significant between one of the experts on one side, and the presented method and the other expert on the other side (
How needs and preferences of employees influence participation in health promotion programs: A six-month follow-up study
Background: Low participation in health promotion programs (HPPs) might hamper their effectiveness. A potential reason for low participation is disagreement between needs and preferences of potential participants and the actual HPPs offered. This study aimed to investigate employees' need and preferences for HPPs, whether these are matched by what their employers provide, and whether a higher agreement enhanced participation. Methods: Employees of two organizations participated in a six-month follow-up study (n = 738). At baseline, information was collected on employees' needs and preferences for the topic of the HPP (i.e. physical activity, healthy nutrition, smoking cessation, stress management, general health), whether they favored a HPP via their employer or at their own discretion, and their preferred HPP regarding three components with each two alternatives: mode of delivery (individual vs. group), intensity (single vs. multiple meetings), and content (assignments vs. information). Participation in HPPs was assessed at six-month
CO carbonylation and first evaluation as a P-gp tracer in rats
BACKGROUND: At present, several positron emission tomography (PET) tracers are in use for imaging P-glycoprotein (P-gp) function in man. At baseline, substrate tracers such as R-[(11)C]verapamil display low brain concentrations with a distribution volume of around 1. [(11)C]phenytoin is supposed to be a weaker P-gp substrate, which may lead to higher brain concentrations at baseline. This could facilitate assessment of P-gp function when P-gp is upregulated. The purpose of this study was to synthesize [(11)C]phenytoin and to characterize its properties as a P-gp tracer. METHODS: [(11)C]CO was used to synthesize [(11)C]phenytoin by rhodium-mediated carbonylation. Metabolism and, using PET, brain pharmacokinetics of [(11)C]phenytoin were studied in rats. Effects of P-gp function on [(11)C]phenytoin uptake were assessed using predosing with tariquidar. RESULTS: [(11)C]phenytoin was synthesized via [(11)C]CO in an overall decay-corrected yield of 22 ± 4%. At 45 min after administration, 19% and 83% of radioactivity represented intact [(11)C]phenytoin in the plasma and brain, respectively. Compared with baseline, tariquidar predosing resulted in a 45% increase in the cerebral distribution volume of [(11)C]phenytoin. CONCLUSIONS: Using [(11)C]CO, the radiosynthesis of [(11)C]phenytoin could be improved. [(11)C]phenytoin appeared to be a rather weak P-gp substrate
Array-based DNA methylation profiling of primary lymphomas of the central nervous system
<p>Abstract</p> <p>Background</p> <p>Although primary lymphomas of the central nervous system (PCNSL) and extracerebral diffuse large B-cell lymphoma (DLBCL) cannot be distinguished histologically, it is still a matter of debate whether PCNSL differ from systemic DLBCL with respect to their molecular features and pathogenesis. Analysis of the DNA methylation pattern might provide further data distinguishing these entities at a molecular level.</p> <p>Methods</p> <p>Using an array-based technology we have assessed the DNA methylation status of 1,505 individual CpG loci in five PCNSL and compared the results to DNA methylation profiles of 49 DLBCL and ten hematopoietic controls.</p> <p>Results</p> <p>We identified 194 genes differentially methylated between PCNSL and normal controls. Interestingly, Polycomb target genes and genes with promoters showing a high CpG content were significantly enriched in the group of genes hypermethylated in PCNSL. However, PCNSL and systemic DLBCL did not differ in their methylation pattern.</p> <p>Conclusions</p> <p>Based on the data presented here, PCNSL and DLBCL do not differ in their DNA methylation pattern. Thus, DNA methylation analysis does not support a separation of PCNSL and DLBCL into individual entities. However, PCNSL and DLBCL differ in their DNA methylation pattern from non- malignant controls.</p
Épica, crónicas y genealogías. En torno a la historicidad de la Leyenda de los infantes de Lara
[ES] Este trabajo analiza la historicidad de la narración épica conocida como Leyenda de los Infantes de Lara. Frente a la visión tradicional, que atribuía a este relato una gran fidelidad a los hechos históricos, se sugiere una imagen más compleja, que mezcla elementos nuevos y más antiguos: 1) Un posible núcleo histórico consistente en la historia de Ruy Velázquez; 2) Una parte más compacta formada por la trama de la
venganza de sangre, que enlaza la traición con la venganza de Mudarra. Frente a la idea tradicional de que la venganza es una
completa ficción elaborada mucho tiempo después, se sugiere que traición y venganza constituyen una unidad lógica, aunque no
se relacione con hechos históricos concretos. Es muy probable que el núcleo central de la leyenda, tal y como nos ha llegado, sea más bien un conjunto amplio de temas y motivos entretejidos con hechos
históricos más o menos desfigurados.
Finalmente, todas estas piezas cobran sentido en su contexto geográfico: la leyenda parece estar reflejando un
conflicto entre Lara y Salas, leído desde el punto de vista de Salas, con una clara
hostilidad hacia Lara.Peer reviewe
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Validation of the Athletic Identity Measurement Scale in Youth Academy Soccer Players
The Athletic Identity Measurement Scale (AIMS) is a popular measure of Athletic Identity (AI). The purpose of the present study was to investigate the factor structure (7-item single factor and 3 factor model; Social Identity, Exclusivity and Negative Affectivity) of the AIMS within youth academy soccer players. A total of 259 male youth academy soccer players aged 12-18 years completed the AIMS. A series of confirmatory factor analyses, independent cluster modelling indicated support for the 7-item single-factor (AI) and the three-factor models but not within the same analysis. The results support the use of AIMS for the measurement of AI in elite male youth soccer players. Practitioners seeking to explore AI in youth soccer populations should use the three-factor model to glean further insight from the three subscales to support the design of more specific interventions where appropriate
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