189 research outputs found

    The Mesozoic along-strike tectono-metamorphic segmentation of Longmen Shan (eastern Tibetan plateau)

    Get PDF
    The Longmen Shan belt (eastern border of the Tibetan plateau) constitutes a tectonically active region as demonstrated by the occurrence of the unexpected 2008 Mw 7.9 Wenchuan and 2013 Mw 6.6 Lushan earthquakes in the central and southern parts of the belt respectively. These events revealed the necessity of a better understanding of the long‐term geological evolution of the belt and its effect on the present dynamics and crustal structure. New structural and thermobarometric data offer a comprehensive dataset of the paleo‐temperatures across the belt and P‐T estimates for low‐grade metamorphic domains. In the central Longmen Shan, two metamorphic jumps of 150‐200°C, 5‐6 kbar and ~50 °C, 3‐5 kbar acquired during the Early Mesozoic are observed across the Wenchuan and Beichuan faults respectively, attesting to their thrusting movement and unrevealing a major decollement between the allochtonous Songpan‐Garze metasedimentary cover (at T > 500°C) and the autochtonous units and the basement (T < 400°C). In the southern Longmen Shan, the only greenschist‐facies metamorphism is observed both in the basement (360 ± 30°C, 6 ± 2 kbar) and in the metasedimentary cover (350 ± 30°C, 3 ± 1 kbar). Peak conditions were reached at c. 80‐60 Ma in the basement and c. 55‐33 Ma in the cover, c. 50 Ma after the greenschist‐facies metamorphic overprint observed in the central Longmen Shan (c. 150‐120 Ma). This along‐strike metamorphic segmentation coincides well with the present fault segmentation and reveals that the central and southern Longmen Shan experienced different tectono‐metamorphic histories since the Mesozoic

    Commissioning of the CMS High Level Trigger

    Get PDF
    The CMS experiment will collect data from the proton-proton collisions delivered by the Large Hadron Collider (LHC) at a centre-of-mass energy up to 14 TeV. The CMS trigger system is designed to cope with unprecedented luminosities and LHC bunch-crossing rates up to 40 MHz. The unique CMS trigger architecture only employs two trigger levels. The Level-1 trigger is implemented using custom electronics, while the High Level Trigger (HLT) is based on software algorithms running on a large cluster of commercial processors, the Event Filter Farm. We present the major functionalities of the CMS High Level Trigger system as of the starting of LHC beams operations in September 2008. The validation of the HLT system in the online environment with Monte Carlo simulated data and its commissioning during cosmic rays data taking campaigns are discussed in detail. We conclude with the description of the HLT operations with the first circulating LHC beams before the incident occurred the 19th September 2008

    Comparison of new forms of creatine in raising plasma creatine levels

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Previous research has shown that plasma creatine levels are influenced by extracellular concentrations of insulin and glucose as well as by the intracellular creatine concentration. However, the form of creatine administered does not appear to have any effect although specific data on this is lacking. This study examined whether the administration of three different forms of creatine had different effects on plasma creatine concentrations and pharmacokinetics.</p> <p>Methods</p> <p>Six healthy subjects (three female and three male subjects) participated in the study. Each subject was assigned to ingest a single dose of isomolar amounts of creatine (4.4 g) in the form of creatine monohydrate (CrM), tri-creatine citrate (CrC), or creatine pyruvate (CrPyr) using a balanced cross-over design. Plasma concentration curves, determined over eight hours after ingestion, were subject to pharmacokinetic analysis and primary derived data were analyzed by repeated measures ANOVA.</p> <p>Results</p> <p>Mean peak concentrations and area under the curve (AUC) were significantly higher with CrPyr (17 and 14%, respectively) in comparison to CrM and CrC. Mean peak concentration and AUC were not significantly different between CrM and CrC. Despite the higher peak concentration with CrPyr there was no difference between the estimated velocity constants of absorption (ka) or elimination (kel) between the three treatments. There was no effect of treatment with CrPyr on the plasma pyruvate concentration.</p> <p>Conclusion</p> <p>The findings suggest that different forms of creatine result in slightly altered kinetics of plasma creatine absorption following ingestion of isomolar (with respect to creatine) doses of CrM, CrC and CrPyr although differences in ka could not be detected due to the small number of blood samples taken during the absorption phase. Characteristically this resulted in higher plasma concentrations of creatine with CrPyr. Differences in bioavailability are thought to be unlikely since absorption of CrM is already close to 100%. The small differences in kinetics are unlikely to have any effect on muscle creatine elevation during periods of creatine loading.</p

    Variability of protein level and phosphorylation status caused by biopsy protocol design in human skeletal muscle analyses

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Bergström needle biopsy is widely used to sample skeletal muscle in order to study cell signaling directly in human tissue. Consequences of the biopsy protocol design on muscle protein quantity and quality remain unclear. The aim of the present study was to assess the impact of different events surrounding biopsy protocol on the stability of the Western blot signal of eukaryotic translation initiation factor 4E binding protein 1 (4E-BP1), Akt, glycogen synthase kinase-3β (GSK-3β), muscle RING finger protein 1 (MuRF1) and p70 S6 kinase (p70 S6K). Six healthy subjects underwent four biopsies of the <it>vastus lateralis</it>, distributed into two distinct visits spaced by 48 hrs. At visit 1, a basal biopsy in the right leg was performed in the morning (R1) followed by a second in the left leg in the afternoon (AF). At visit 2, a second basal biopsy (R2) was collected from the right leg. Low intensity mobilization (3 × 20 right leg extensions) was performed and a final biopsy (Mob) was collected using the same incision site as R2.</p> <p>Results</p> <p>Akt and p70 S6K phosphorylation levels were increased by 83% when AF biopsy was compared to R1. Mob condition induced important phosphorylation of p70 S6K when compared to R2. Comparison of R1 and R2 biopsies revealed a relative stability of the signal for both total and phosphorylated proteins.</p> <p>Conclusions</p> <p>This study highlights the importance to standardize muscle biopsy protocols in order to minimize the method-induced variation when analyzing Western blot signals.</p

    A scalable monitoring for the CMS Filter Farm based on elasticsearch

    Get PDF
    A flexible monitoring system has been designed for the CMS File-based Filter Farm making use of modern data mining and analytics components. All the metadata and monitoring information concerning data flow and execution of the HLT are generated locally in the form of small documents using the JSON encoding. These documents are indexed into a hierarchy of elasticsearch (es) clusters along with process and system log information. Elasticsearch is a search server based on Apache Lucene. It provides a distributed, multitenant-capable search and aggregation engine. Since es is schema-free, any new information can be added seamlessly and the unstructured information can be queried in non-predetermined ways. The leaf es clusters consist of the very same nodes that form the Filter Farm thus providing natural horizontal scaling. A separate central" es cluster is used to collect and index aggregated information. The fine-grained information, all the way to individual processes, remains available in the leaf clusters. The central es cluster provides quasi-real-time high-level monitoring information to any kind of client. Historical data can be retrieved to analyse past problems or correlate them with external information. We discuss the design and performance of this system in the context of the CMS DAQ commissioning for LHC Run 2

    First measurements with the CMS DAQ and timing hub prototype-1

    Get PDF
    The DAQ and Timing Hub is an ATCA hub board designed for the Phase-2 upgrade of the CMS experiment. In addition to providing high-speed Ethernet connectivity to all back-end boards, it forms the bridge between the sub-detector electronics and the central DAQ, timing, and trigger control systems. One important requirement is the distribution of several high-precision, phasestable, and LHC-synchronous clock signals for use by the timing detectors. The current paper presents first measurements performed on the initial prototype, with a focus on clock quality. It is demonstrated that the current design provides adequate clock quality to satisfy the requirements of the Phase-2 CMS timing detectors

    Dynamic configuration of the CMS Data Acquisition cluster

    Get PDF
    The CMS Data Acquisition cluster, which runs around 10000 applications, is configured dynamically at run time. XML configuration documents determine what applications are executed on each node and over what networks these applications communicate. Through this mechanism the DAQ System may be adapted to the required performance, partitioned in order to perform (test-) runs in parallel, or re-structured in case of hardware faults. This paper presents the CMS DAQ Configurator tool, which is used to generate comprehensive configurations of the CMS DAQ system based on a high-level description given by the user. Using a database of configuration templates and a database containing a detailed model of hardware modules, data and control links, nodes and the network topology, the tool automatically determines which applications are needed, on which nodes they should run, and over which networks the event traffic will flow. The tool computes application parameters and generates the XML configuration documents as well as the configuration of the run-control system. The performance of the tool and operational experience during CMS commissioning and the first LHC runs are discussed
    corecore