1,893 research outputs found

    Investigations of rate and multi-hit capability of multi-gap resistive plate chambers

    Get PDF
    The application of multi-gap resistive plate chambers (MRPC) for time-of-flight (TOF) measurements in future high-rate heavy-ion-collision experiments like CBM (Compressed Baryonic Matter) at FAIR is constrained by both challenging particle-flux and multi-hit conditions on the counter surface. Towards the center of the 120 mÂČ TOF wall of CBM, fluxes of up to 25 kHz/cmÂČ in gold-on-gold collisions at 10 MHz and 11 A GeV (SIS100) are handled by detectors with special low-resistive glass. At the periphery, common-glass counters are used for cost reasons. In this work, test-beam results for corresponding prototypes obtained in a multi-hit environment under moderate particle fluxes of 1–2 kHz/cmÂČ at CERN/SPS are systematically analyzed for rate and interference effects on counter performance. For a reproduction in simulations, a novel parametrization of the MRPC response function is introduced which models both the impact of sustained irradiation on detection capability in time and the distortion of reconstructed hits by interfering induced signals. An envisaged qualitative agreement is achieved between real and simulated observations. While only the common-glass counter shows an expected performance degradation due to rate, the response evaluation of both prototypes via correlations on adjacent detectors is significantly complicated by multi-hit effects. The new response model provides a reliable simulation reference for further investigations on this matter

    [P4H]+[Al(OTeF5)4]−: protonation of white phosphorus with the Brþnsted superacid H[Al(OTeF5)4](solv)

    Get PDF
    A sustainable transformation of white phosphorus (P4) into chemicals of higher value is one of the key aspects in modern phosphorus research. Even though the chemistry of P4 has been investigated for many decades, its chemical reactivity towards the simplest electrophile, the proton, is still virtually unknown. Based on quantum-chemical predictions, we report for the first time the successful protonation of P4 by the Brþnsted acid H[Al(OTeF5)4](solv). Our spectroscopic results are in agreement with acid-mediated activation of P4 under protonation of an edge of the P4-tetrahedron and formation of a three-center two-electron P–H–P bond. These investigations are of fundamental interest as they permit the activation of P4 with the simplest electrophile as a new prototype reaction for this molecule

    Low-Frequency Oscillations Code Speech during Verbal Working Memory

    Get PDF
    Item does not contain fulltextThe way the human brain represents speech in memory is still unknown. An obvious characteristic of speech is its evolvement over time. During speech processing, neural oscillations are modulated by the temporal properties of the acoustic speech signal, but also acquired knowledge on the temporal structure of language influences speech perception-related brain activity. This suggests that speech could be represented in the temporal domain, a form of representation that the brain also uses to encode autobiographic memories. Empirical evidence for such a memory code is lacking. We investigated the nature of speech memory representations using direct cortical recordings in the left perisylvian cortex during delayed sentence reproduction in female and male patients undergoing awake tumor surgery. Our results reveal that the brain endogenously represents speech in the temporal domain. Temporal pattern similarity analyses revealed that the phase of frontotemporal low-frequency oscillations, primarily in the beta range, represents sentence identity in working memory. The positive relationship between beta power during working memory and task performance suggests that working memory representations benefit from increased phase separation.SIGNIFICANCE STATEMENT Memory is an endogenous source of information based on experience. While neural oscillations encode autobiographic memories in the temporal domain, little is known on their contribution to memory representations of human speech. Our electrocortical recordings in participants who maintain sentences in memory identify the phase of left frontotemporal beta oscillations as the most prominent information carrier of sentence identity. These observations provide evidence for a theoretical model on speech memory representations and explain why interfering with beta oscillations in the left inferior frontal cortex diminishes verbal working memory capacity. The lack of sentence identity coding at the syllabic rate suggests that sentences are represented in memory in a more abstract form compared with speech coding during speech perception and production

    Mittelfristige Prognose der österreichischen Wirtschaft 2014 – 2018: WachstumskrĂ€fte stĂ€rken – Reformen umsetzen

    Get PDF
    Die vergangenen fĂŒnf Jahre waren durch die „große Rezession‟ und die Krise im Euroraum geprĂ€gt. Mit der Erholung der internationalen Konjunktur sollte sich die österreichische Wirtschaft im Prognosezeitraum wieder beleben. Das Institut erwartet fĂŒr den Zeitraum 2014 bis 2018 ein durchschnittliches Wachstum der österreichischen Volkswirtschaft von 1.9 %. Die positive Wirtschaftsentwicklung fĂŒhrt zu einer Stabilisierung am Arbeitsmarkt, mit 7.5 % am Ende des Prognosezeitraums bleibt die Arbeitslosenquote gemĂ€ĂŸ nationaler Definition jedoch auf einem sehr hohen Niveau. Das Ziel eines annĂ€hernd ausgeglichenen öffentlichen Haushalts bis zum Jahr 2016 ist bei strikter Budgetdisziplin erreichbar. Notwendig sind weitere fiskalische und regulatorische Reformschritte, um das Wachstumspotenzial der österreichischen Wirtschaft zu stĂ€rken

    Study of exclusive one-pion and one-eta production using hadron and dielectron channels in pp reactions at kinetic beam energies of 1.25 GeV and 2.2 GeV with HADES

    Get PDF
    We present measurements of exclusive ensuremathπ+,0 and η production in pp reactions at 1.25GeV and 2.2GeV beam kinetic energy in hadron and dielectron channels. In the case of π+ and π0 , high-statistics invariant-mass and angular distributions are obtained within the HADES acceptance as well as acceptance-corrected distributions, which are compared to a resonance model. The sensitivity of the data to the yield and production angular distribution of Δ (1232) and higher-lying baryon resonances is shown, and an improved parameterization is proposed. The extracted cross-sections are of special interest in the case of pp → pp η , since controversial data exist at 2.0GeV; we find \ensuremathσ=0.142±0.022 mb. Using the dielectron channels, the π0 and η Dalitz decay signals are reconstructed with yields fully consistent with the hadronic channels. The electron invariant masses and acceptance-corrected helicity angle distributions are found in good agreement with model predictions

    Bioenergy production and sustainable development: Science base for policymaking remains limited

    Get PDF
    The possibility of using bioenergy as a climate change mitigation measure has sparked a discussion of whether and how bioenergy production contributes to sustainable development. We undertook a systematic review of the scientific literature to illuminate this relationship and found a limited scientific basis for policymaking. Our results indicate that knowledge on the sustainable development impacts of bioenergy production is concentrated in a few well‐studied countries, focuses on environmental and economic impacts, and mostly relates to dedicated agricultural biomass plantations. The scope and methodological approaches in studies differ widely and only a small share of the studies sufficiently reports on context and/or baseline conditions, which makes it difficult to get a general understanding of the attribution of impacts. Nevertheless, we identified regional patterns of positive or negative impacts for all categories – environmental, economic, institutional, social and technological. In general, economic and technological impacts were more frequently reported as positive, while social and environmental impacts were more frequently reported as negative (with the exception of impacts on direct substitution of GHG emission from fossil fuel). More focused and transparent research is needed to validate these patterns and develop a strong science underpinning for establishing policies and governance agreements that prevent/mitigate negative and promote positive impacts from bioenergy production

    A randomized multi-center phase II trial of the angiogenesis inhibitor Cilengitide (EMD 121974) and gemcitabine compared with gemcitabine alone in advanced unresectable pancreatic cancer

    Get PDF
    BACKGROUND: Anti-angiogenic treatment is believed to have at least cystostatic effects in highly vascularized tumours like pancreatic cancer. In this study, the treatment effects of the angiogenesis inhibitor Cilengitide and gemcitabine were compared with gemcitabine alone in patients with advanced unresectable pancreatic cancer. METHODS: A multi-national, open-label, controlled, randomized, parallel-group, phase II pilot study was conducted in 20 centers in 7 countries. Cilengitide was administered at 600 mg/m(2 )twice weekly for 4 weeks per cycle and gemcitabine at 1000 mg/m(2 )for 3 weeks followed by a week of rest per cycle. The planned treatment period was 6 four-week cycles. The primary endpoint of the study was overall survival and the secondary endpoints were progression-free survival (PFS), response rate, quality of life (QoL), effects on biological markers of disease (CA 19.9) and angiogenesis (vascular endothelial growth factor and basic fibroblast growth factor), and safety. An ancillary study investigated the pharmacokinetics of both drugs in a subset of patients. RESULTS: Eighty-nine patients were randomized. The median overall survival was 6.7 months for Cilengitide and gemcitabine and 7.7 months for gemcitabine alone. The median PFS times were 3.6 months and 3.8 months, respectively. The overall response rates were 17% and 14%, and the tumor growth control rates were 54% and 56%, respectively. Changes in the levels of CA 19.9 went in line with the clinical course of the disease, but no apparent relationships were seen with the biological markers of angiogenesis. QoL and safety evaluations were comparable between treatment groups. Pharmacokinetic studies showed no influence of gemcitabine on the pharmacokinetic parameters of Cilengitide and vice versa. CONCLUSION: There were no clinically important differences observed regarding efficacy, safety and QoL between the groups. The observations lay in the range of other clinical studies in this setting. The combination regimen was well tolerated with no adverse effects on the safety, tolerability and pharmacokinetics of either agent

    The identification of economically relevant health and social care services for mental disorders in the PECUNIA project

    Get PDF
    Background: Health economic research is still facing significant problems regarding the standardization and international comparability of health care services. As a result, comparative effectiveness studies and cost-effectiveness analyses are often not comparable. This study is part of the PECUNIA project, which aimed to improve the comparability of economic evaluations by developing instruments for the internationally standardized measurement and valuation of health care services for mental disorders. The aim of this study was to identify internationally relevant services in the health and social care sectors relevant for health economic studies for mental disorders. Methods: A systematic literature review on cost-of-illness studies and economic evaluations was conducted to identify relevant services, complemented by an additional grey literature search and a search of resource use measurement (RUM) questionnaires. A preliminary long-list of identified services was explored and reduced to a short-list by multiple consolidation rounds within the international research team and an external international expert survey in six European countries. Results: After duplicate removal, the systematic search yielded 15,218 hits. From these 295 potential services could be identified. The grey literature search led to 368 and the RUM search to 36 additional potential services. The consolidation process resulted in a preliminary list of 186 health and social care services which underwent an external expert survey. A final consolidation step led to a basic list of 56 services grouped into residential care, daycare, outpatient care, information for care, accessibility to care, and self-help and voluntary care. Conclusions: The initial literature searches led to an extensive number of potential service items for health and social care. Many of these items turned out to be procedures, interventions or providing professionals rather than services and were removed from further analysis. The resulting list was used as a basis for typological coding, the development of RUM questionnaires and corresponding unit costs for international mental health economic studies in the PECUNIA project.</p

    Epidemic Microclusters of Blood-Culture Proven Sepsis in Very-Low-Birth Weight Infants: Experience of the German Neonatal Network

    Get PDF
    INTRODUCTION: We evaluated blood culture-proven sepsis episodes occurring in microclusters in very-low-birth-weight infants born in the German Neonatal Network (GNN) during 2009-2010. METHODS: Thirty-seven centers participated in GNN; 23 centers enrolled ≄50 VLBW infants in the study period. Data quality was approved by on-site monitoring. Microclusters of sepsis were defined as occurrence of at least two blood-culture proven sepsis events in different patients of one center within 3 months with the same bacterial species. For microcluster analysis, we selected sepsis episodes with typically cross-transmitted bacteria of high clinical significance including gram-negative rods and Enterococcus spp. RESULTS: In our cohort, 12/2110 (0.6%) infants were documented with an early-onset sepsis and 235 late-onset sepsis episodes (≄72 h of age) occurred in 203/2110 (9.6%) VLBW infants. In 182/235 (77.4%) late-onset sepsis episodes gram-positive bacteria were documented, while coagulase negative staphylococci were found to be the most predominant pathogens (48.5%, 95%CI: 42.01-55.01). Candida spp. and gram-negative bacilli caused 10/235 (4.3%, 95%CI: 1.68% -6.83%) and 43/235 (18.5%) late-onset sepsis episodes, respectively. Eleven microclusters of blood-culture proven sepsis were detected in 7 hospitals involving a total 26 infants. 16/26 cluster patients suffered from Klebsiella spp. sepsis. The median time interval between the first patient's Klebsiella spp. sepsis and cluster cases was 14.1 days (interquartile range: 1-27 days). First patients in the cluster, their linked cases and sporadic sepsis events did not show significant differences in short term outcome parameters. DISCUSSION: Microclusters of infection are an important phenomenon for late-onset sepsis. Most gram-negative cluster infections occur within 30 days after the first patient was diagnosed and Klebsiella spp. play a major role. It is essential to monitor epidemic microclusters of sepsis in surveillance networks to adapt clinical practice, inform policy and further improve quality of care
    • 

    corecore