294 research outputs found
Optimization of Elastic Cloud Brokerage Mechanisms for Future Telecommunication Service Environments
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugĂ€nglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Cloud computing mechanisms and cloud-based services are currently revolutionizing Web as well as telecommunication service platforms and service offerings. Apart from providing infrastructures, platforms and software as a service, mechanism for dynamic allocation of compute and storage resources on-demand, commonly termed as âelastic cloud computingâ account for the most important cloud computing functionalities.
Resource elasticity allows not only for efficient internal compute and storage resource consumption, but also, through so called hybrid cloud computing mechanisms, for dynamic utilization of external resources on-demand. This capability is especially useful in order to cost-efficiently cope with peakworkloads, allowing service providers to significantly reduce usually required over-provisioned service infrastructures, allowing for âpay-per-useâ cost models.
With a steadily growing number of cloud providers and with the proliferation of unified cloud computing interfaces, service providers are given free choice of flexibly selecting and utilizing cloud resources from different cloud providers. Cloud brokering systems allow for dynamic selection and utilization of cloud computing resources based on functional (e.g. QoS, SLA, energy consumption) as well as nonfunctional criteria (e.g. costs).
The presented work focuses on enhanced cloud brokering mechanisms for telecommunication service platforms, enabling quality telecommunication service assurance, still optimizing cloud resources consumption, i.e. saving costs and energy.
Furthermore this work shows that by combining cloud brokering mechanisms with standardized telecommunication service brokering mechanisms an even greater benefit for telecommunication service providers can be achieved as this enables an even better cost-efficiency since different user segments can seamlessly be served by allocating different cloud resources to them in a policy-driven manner
Characterization of a Rn source for low-energy electronic recoil calibration of the XENONnT detector
Low-background liquid xenon detectors are utilized in the investigation of
rare events, including dark matter and neutrinoless double beta decay. For
their calibration, gaseous Rn can be used. After being introduced into
the xenon, its progeny isotope Pb induces homogeneously distributed,
low-energy ( keV) electronic recoil interactions. We report on the
characterization of such a source for use in the XENONnT experiment. It
consists of four commercially available Th sources with an activity of
55 kBq. These sources provide a high Rn emanation rate of about 9 kBq.
We find no indication for the release of the long-lived Th above 1.7
mBq. Though an unexpected Rn emanation rate of about 3.6 mBq is
observed, this source is still in line with the requirements for the XENONnT
experiment.Comment: 8 pages, 5 figure
A Planar FiveâMembered Aromatic Ring Stabilized by Only Two ÏâElectrons
Many chemicals known today are partially or fully aromatic, since a ring framework experiences additional stabilization through the delocalization of Ïâelectrons. While aromatic rings with equal numbers of Ïâelectrons and ring atoms such as benzene are particularly stable, those with the minimally required two Ïâelectrons are very rare and yet remain limited to threeâ and fourâmembered rings if not stabilized in the coordination sphere of heavy metals. Here we report the facile synthesis of a dipotassium cyclopentagallene, a unique example of a fiveâmembered aromatic ring stabilized by only two Ïâelectrons. Singleâcrystal Xâray diffraction revealed a planar Ga5 ring with almost equal galliumâgallium bond lengths, which together with computational and spectroscopic data confirm its aromatic character. Our results prove that aromatic stabilization goes far beyond what has previously been assumed as minimum Ïâelectron count in a fiveâatom ring fragment.Deutsche Forschungsgemeinschaft
http://dx.doi.org/10.13039/501100001659Verband der Chemischen Industrie
http://dx.doi.org/10.13039/100007215Peer Reviewe
A multi-temporal hyperspectral camouflage detection and transparency experiment
Hyperspectral sensors are used to measure the electromagnetic spectrum in hundreds of narrow and contiguous
spectral bands. The recorded data exhibits characteristic features of materials and objects. For tasks within
the security and defense domain, this valuable information can be gathered remotely using drones, airplanes
or satellites. In 2021, we conducted an experiment in Ettlingen, Germany, using a drone-borne hyperspectral
sensor to record data of various camouflage setups. The goal was the inference of camouflage detection limits
from typical hyperspectral data evaluation approaches for different scenarios. The experimental site is a natural
strip of vegetation between two corn fields. Our main experiment was a camouflage garage that covered different
target materials and objects. The distance between the targets and the roof of the camouflage garage was
modified during the experiment. Together with the target variations, this was done to determine the material
dependent detection limits and the transparency of the camouflage garage. Another experiment was carried
out using two different types of camouflage nets in various states of occlusion by freshly cut vegetation. This
manuscript contains a detailed experiment description, as well as, the first results of the camouflage transparency
and occlusion experiment. We show that it is possible to determine the target inside the camouflage garage and
that vegetation cover is not suitable additional camouflage for hyperspectral sensors
Cryogenics in high-current busbars and multistage cooled current leads
The use of high-temperature superconductors (HTS) has big advantages especially in high direct current applications. Relevant industrial applications can be found in chlorine, zinc or copper electrolysis and aluminum plants. We developed a superconducting busbar for 20 kA based on YBCO tapes including two novel multistage cooled current leads at the ends. The special characteristic of the system is the closed-loop operation evaporating no cryogens after initial cool down. This feature is advantageous particularly with regard to industrial application. A 25 m long demonstrator will be installed in a chlorine plant at BASF in Ludwigshafen under real industrial conditions within the scope of government-granted 3S project. In high current busbars the major cooling demand is generated in the current leads. To minimize these current lead losses we increased the efficiency by installing common cooling machines for three different temperature stages.
To reduce the required quantity of high temperature superconductors, the superconductors inside the busbar are cooled by sub-cooled liquid nitrogen at a temperature between 65 and 70 K. The need of superconductor is further minimized by increasing the distance between the single HTS tapes. Both technical measures create high demands on the supporting structure plus the pipe cryostat elements and their cooling system. Test results of the current lead and busbar sections will be presented
Nachhaltigkeitsaspekte bei Kaufentscheidungen von Lebensmitteln
Kaufentscheidungen im Sinne des Leitbildes einer nachhaltigen ErnÀhrung werden von Konsumenten unter verschiedenen Einflussbedingungen getroffen. Dabei verlassen sie sich auf ein möglichst transparentes Informationsspektrum. Besonders deutlich wird dies bei der Wahl von Bioprodukten und regionalen Produkten, die hÀufig mit dem Nachhaltigkeitsgedanken verbunden werden. (DIPF/Orig.
Nowcasting in a pandemic using non-parametric mixed frequency VARs
This paper develops Bayesian econometric methods for posterior inference in non-parametric mixed frequency VARs using additive regression trees. We argue that regression tree models are ideally suited for macroeconomic nowcasting in the face of extreme observations, for instance those produced by the COVID-19 pandemic of 2020. This is due to their exibility and ability to model outliers. In an application involving four major euro area countries, we find substantial improvements in nowcasting performance relative to a linear mixed frequency VAR
Predisposing and precipitating risk factors for delirium in gastroenterology and hepatology: Subgroup analysis of 718 patients from a hospital-wide prospective cohort study
BACKGROUND AND AIMS
Delirium is the most common acute neuropsychiatric syndrome in hospitalized patients. Higher age and cognitive impairment are known predisposing risk factors in general hospital populations. However, the interrelation with precipitating gastrointestinal (GI) and hepato-pancreato-biliary (HPB) diseases remains to be determined.
PATIENTS AND METHODS
Prospective 1-year hospital-wide cohort study in 29'278 adults, subgroup analysis in 718 patients hospitalized with GI/HPB disease. Delirium based on routine admission screening and a DSM-5 based construct. Regression analyses used to evaluate clinical characteristics of delirious patients.
RESULTS
Delirium was detected in 24.8% (178/718). Age in delirious patients (median 62 years [IQR 21]) was not different to non-delirious (median 60 years [IQR 22]), p = 0.45). Dementia was the strongest predisposing factor for delirium (OR 66.16 [6.31-693.83], p < 0.001). Functional impairment, and at most, immobility increased odds for delirium (OR 7.78 [3.84-15.77], p < 0.001). Patients with delirium had higher in-hospital mortality rates (18%; OR 39.23 [11.85-129.93], p < 0.001). From GI and HPB conditions, cirrhosis predisposed to delirium (OR 2.11 [1.11-4.03], p = 0.023), while acute renal failure (OR 4.45 [1.61-12.26], p = 0.004) and liver disease (OR 2.22 [1.12-4.42], p = 0.023) were precipitators. Total costs were higher in patients with delirium (USD 30003 vs. 10977; p < 0.001).
CONCLUSION
Delirium in GI- and HPB-disease was not associated with higher age per se, but with cognitive and functional impairment. Delirium needs to be considered in younger adults with acute renal failure and/or liver disease. Clinicians should be aware about individual risk profiles, apply preventive and supportive strategies early, which may improve outcomes and lower costs
The Actin Targeting Compound Chondramide Inhibits Breast Cancer Metastasis via Reduction of Cellular Contractility
Background: A major player in the process of metastasis is the actin cytoskeleton as it forms key structures in both invasion mechanisms, mesenchymal and amoeboid migration. We tested the actin binding compound Chondramide as potential anti-metastatic agent. Methods: In vivo, the effect of Chondramide on metastasis was tested employing a 4T1-Luc BALB/c mouse model. In vitro, Chondramide was tested using the highly invasive cancer cell line MDA-MB-231 in Boyden-chamber assays, fluorescent stainings, Western blot and Pull down assays. Finally, the contractility of MDA-MB-231 cells was monitored in 3D environment and analyzed via PIV analysis. Results: In vivo, Chondramide treatment inhibits metastasis to the lung and the migration and invasion of MDA-MB-231 cells is reduced by Chondramide in vitro. On the signaling level, RhoA activity is decreased by Chondramide accompanied by reduced MLC-2 and the stretch induced guanine nucleotide exchange factor Vav2 activation. At same conditions, EGF-receptor autophosphorylation, Akt and Erk as well as Rac1 are not affected. Finally, Chondramide treatment disrupted the actin cytoskeleton and decreased the ability of cells for contraction. Conclusions: Chondramide inhibits cellular contractility and thus represents a potential inhibitor of tumor cell invasion
Antibodies Produced by CLL Phenotype B Cells in Patients With Myasthenia Gravis Are Not Directed Against Neuromuscular Endplates
BACKGROUND AND OBJECTIVES
Myasthenia gravis (MG) can in rare cases be an autoimmune phenomenon associated with hematologic malignancies such as chronic lymphocytic leukemia (CLL). It is unclear whether in patients with MG and CLL, the leukemic B cells are the ones directly driving the autoimmune response against neuromuscular endplates.
METHODS
We identified patients with acetylcholine receptor antibody-positive (AChR) MG and CLL or monoclonal B-cell lymphocytosis (MBL), a precursor to CLL, and described their clinical features, including treatment responses. We generated recombinant monoclonal antibodies (mAbs) corresponding to the B-cell receptors of the CLL phenotype B cells and screened them for autoantigen binding.
RESULTS
A computational immune cell screen revealed a subgroup of 5/38 patients with MG and 0/21 healthy controls who displayed a CLL-like B-cell phenotype. In follow-up hematologic flow cytometry, 2 of these 5 patients were diagnosed with an MBL. An additional patient with AChR MG as a complication of manifest CLL presented at our neuromuscular clinic and was successfully treated with the anti-CD20 therapy obinutuzumab plus chlorambucil. We investigated the specificities of expanding CLL-like B-cell clones to assess a direct causal link between the 2 diseases. However, we observed no reactivity of the clones against the AChR, antigens at the neuromuscular junction, or other common autoantigens.
DISCUSSION
Our study suggests that AChR autoantibodies are produced by nonmalignant, polyclonal B cells The new anti-CD20 treatment obinutuzumab might be considered in effectively treating AChR MG.
CLASSIFICATION OF EVIDENCE
This is a single case study and provides Class IV evidence that obinutuzumab is safe to use in patients with MG
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