931 research outputs found
Solution to the problem of tomographic scanning of objects by small area X-Ray detectors
Standard X-Ray tomographic setups basically consist of 3 parts: radiation source, mechanics for mounting a sample and detector system. Each part of tomographic setup in one way or another contributes into the quality of reconstructed images. Detector system is responsible for data acquisition process. Development of detectors improves them in terms of resolution, acquisition speed, dark current etc. Such improvements increases costs for producing of detectors as well as their final price. Tomographic scanning of long objects requires using detectors of corresponding size. It makes tomographic setups expensive, because the price of detectors also increases with increasing of their size. Presented work proposes to solve this problem by shifting detector along the longest dimension of the sample and applying optimized filtered backprojection algorithm
Real Time Global Tests of the ALICE High Level Trigger Data Transport Framework
The High Level Trigger (HLT) system of the ALICE experiment is an online
event filter and trigger system designed for input bandwidths of up to 25 GB/s
at event rates of up to 1 kHz. The system is designed as a scalable PC cluster,
implementing several hundred nodes. The transport of data in the system is
handled by an object-oriented data flow framework operating on the basis of the
publisher-subscriber principle, being designed fully pipelined with lowest
processing overhead and communication latency in the cluster. In this paper, we
report the latest measurements where this framework has been operated on five
different sites over a global north-south link extending more than 10,000 km,
processing a ``real-time'' data flow.Comment: 8 pages 4 figure
Prader-Willi Syndrome Is Associated with Activation of the Innate Immune System Independently of Central Adiposity and Insulin Resistance
Background: Subjects with Prader-Willi syndrome (PWS) have a reduced life expectancy due to cardiovascular disease. Increased systemic low-grade inflammation is postulated as a contributor, despite reported lower visceral fat mass and increased insulin sensitivity. Objectives: Our aim was to compare inflammatory markers and arterial stiffness in PWS and adiposity-matched obese control subjects. Design: We conducted a cross-sectional cohort study comparing 12 PWS subjects, 12 obese subjects matched for percentage body fat and central abdominal fat mass, and 10 healthy normal-weight subjects. Main Outcome Measures: Dual-energy x-ray absorptiometry was used to assess body composition, flow cytometry to quantify activation markers on immune cells, and ELISA for measurement of C-reactive protein, adiponectin, and IL-6. Insulin resistance was estimated by homeostasis model assessment and arterial stiffness by applanation tonometry. Results: PWS and obese subjects had similarly increased homeostasis model assessment and arterial stiffness. Nevertheless, PWS subjects showed significantly higher IL-6 (4.9 ± 1.0 vs. 2.5 ± 0.4 pg/ml; P = 0.02) and nonsignificantly higher C-reactive protein (10.5 ± 3.2 vs. 4.0 ± 1.0 ng/ml; P = 0.08). Neutrophil activation markers CD66b and CD11b were higher in PWS compared to obese subjects (P < 0.01), reflecting an activated innate immune system. These markers were positively related to central adiposity in lean and obese subjects (r = 0.49; P < 0.05), but not in PWS subjects. Conclusions: PWS subjects compared to adiposity-matched obese subjects demonstrate similar insulin resistance but increased low-grade inflammation. The dissociation of inflammation and central adiposity suggests that activation of innate immunity may be either a specific genetic feature of PWS or linked to the commonly associated obstructive sleep apnea syndrome, and might offer a treatment target to reduce cardiovascular disease
Intersectionality: Social Marginalisation and Self-Reported Health Status in Young People.
BACKGROUND:The aim of this study was to measure young people's health status and explore associations between health status and belonging to one or more socio-culturally marginalised group. METHODS:part of the Access 3 project, this cross-sectional survey of young people aged 12-24 years living in New South Wales, Australia, oversampled young people from one or more of the following groups: Aboriginal and or Torres Strait Islander; living in rural and remote areas; homeless; refugee; and/or, sexuality and/or gender diverse. This paper reports on findings pertaining to health status, presence of chronic health conditions, psychological distress, and wellbeing measures. RESULTS:1416 participants completed the survey; 897 (63.3%) belonged to at least one marginalised group; 574 (40.5%) to one, 281 (19.8%) to two and 42 (3.0%) to three or four groups. Belonging to more marginalised groups was significantly associated with having more chronic health conditions (p = 0.001), a greater likelihood of high psychological distress (p = 0.001) and of illness or injury related absence from school or work (p < 0.05). CONCLUSIONS:increasing marginalisation is associated with decreasing health status. Using an intersectional lens can to be a useful way to understand disadvantage for young people belonging to multiple marginalised groups
Raman microprobe observation of intercalate contraction in graphite intercalation compounds
Raman microprobe spectra of SbCl5, Br2, and FeCl3 graphite intercalation compounds have been obtained with a spatial resolution of 2 m. Depletion of the intercalate was observed within 10 m of the sample edge in the SbCl5-graphite samples, and this observation is found to be consistent with a model in which the intercalate contracts thermally as the sample is cooled after the intercalation reaction is completed. No depletion was observed in the Br2 and FeCl3 graphite intercalation compounds, consistent with the low intercalation temperature of the former and the small thermal expansion coefficient of the latter
Gain of chromosome 3q defines the transition from severe dysplasia to invasive carcinoma of the uterine cervix.
AMBIT RESTful web services: an implementation of the OpenTox application programming interface
The AMBIT web services package is one of the several existing independent implementations of the OpenTox Application Programming Interface and is built according to the principles of the Representational State Transfer (REST) architecture. The Open Source Predictive Toxicology Framework, developed by the partners in the EC FP7 OpenTox project, aims at providing a unified access to toxicity data and predictive models, as well as validation procedures. This is achieved by i) an information model, based on a common OWL-DL ontology ii) links to related ontologies; iii) data and algorithms, available through a standardized REST web services interface, where every compound, data set or predictive method has a unique web address, used to retrieve its Resource Description Framework (RDF) representation, or initiate the associated calculations
Calculation of magnetic anisotropy energy in SmCo5
SmCo5 is an important hard magnetic material, due to its large magnetic
anisotropy energy (MAE). We have studied the magnetic properties of SmCo5 using
density functional theory (DFT) calculations where the Sm f-bands, which are
difficult to include in DFT calculations, have been treated within the LDA+U
formalism. The large MAE comes mostly from the Sm f-shell anisotropy, stemming
from an interplay between the crystal field and the spin-orbit coupling. We
found that both are of similar strengths, unlike some other Sm compounds,
leading to a partial quenching of the orbital moment (f-states cannot be
described as either pure lattice harmonics or pure complex harmonics), an
optimal situation for enhanced MAE. A smaller portion of the MAE can be
associated with the Co-d band anisotropy, related to the peak in the density of
states at the Fermi energy. Our result for the MAE of SmCo5, 21.6 meV/f.u.,
agrees reasonably with the experimental value of 13-16 meV/f.u., and the
calculated magnetic moment (including the orbital component) of 9.4 mu_B agrees
with the experimental value of 8.9 mu_B.Comment: Submitted to Phys. Rev.
Self-consistent calculation of total energies of the electron gas using many-body perturbation theory
The performance of many-body perturbation theory for calculating ground-state properties is investigated. We present fully numerical results for the electron gas in three and two dimensions in the framework of the GW approximation. The overall agreement with very accurate Monte Carlo data is excellent, even for those ranges of densities for which the GW approach is often supposed to be unsuitable. The latter seems to be due to the fulfillment of general conservation rules. These results open further prospects for accurate calculations of ground-state properties circumventing the limitations of standard density-functional theory
Diagrammatic self-energy approximations and the total particle number
There is increasing interest in many-body perturbation theory as a practical tool for the calculation of ground-state properties. As a consequence, unambiguous sum rules such as the conservation of particle number under the influence of the Coulomb interaction have acquired an importance that did not exist for calculations of excited-state properties. In this paper we obtain a rigorous, simple relation whose fulfilment guarantees particle-number conservation in a given diagrammatic self-energy approximation. Hedin's G(0)W(0) approximation does not satisfy this relation and hence violates the particle-number sum rule. Very precise calculations for the homogeneous electron gas and a model inhomogeneous electron system allow the extent of the nonconservation to be estimated
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