1,581 research outputs found

    Cross-sectional evidence on the relation between monetary policy, macroeconomic conditions and low-frequency inflation uncertainty

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    We examine how the interaction between monetary policy and macroeconomic conditions affects inflation uncertainty in the long-term. The unobservable inflation uncertainty is quantified by means of the slowly evolving long-term variance component of inflation in the framework of the Spline-GARCH model (Engle and Rangel, 2008). For a cross-section of 13 developed economies, we find that long-term inflation uncertainty is high if central bank governors are perceived as less inflation-averse and if the conduct of monetary policy is ad-hoc rather than rule-based

    Glockenbecherzeitliche Gräber in Nordwestsachsen: Vom Becher(-n) zur Tasse

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    Folgender Artikel stellt die nach der politischen Wende in Sachsen gefundenen und bisher nur aus Vorberichten bekannten Glockenbechergräber vor. Die archäologisch-kulturelle Zuordnung der Gräber steht im Vordergrund, da einige Gräber keine oder kulturunspezifische Beigaben enthielten. Durch die Analyse eines internen und externen Grabkontextes kann der Großteil der Gräber der archäologischen Kultur mit Glockenbecher zugeordnet und die mit den Gräbern in Beziehung stehenden Befunde interpretiert werden. Weiterhin wird die Beziehungen zwischen den archäologischen Kulturen Glockenbecher und Aunjetitz thematisiert und auf besondere Aspekte der Glockenbecherbestattungssitte in Nordwestsachsen eingegangen.This article presents the Bell Beaker graves found in Northwest Saxony after 1989. Because some of the burials contained none or only culturally non-specific grave goods, the overall analysis focused on the cultural classification of the graves. Investigation of the internal and external grave context allowed to classify the majority as graves of the Bell Beaker Culture and subsequently to interpret the features related to the graves. Furthermore the relationship between the Bell Beaker and Únetice Culture is discussed and special regional aspects of Bell Beaker burial customs are described in detail

    Synthetic communication signals influence wild harbour porpoise (Phocoena phocoena) behaviour

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    We used our novel and programmable Porpoise Alarm (PAL, patd.) to synthesize life-like, electronic harbour porpoise communication signals based on those described for captive animals. In the Little Belt, Denmark, we employed PAL (source level 158 ± 1 dB p–p re 1 μPa@1 m; centroid frequency 133 ± 8.5 kHz) to synthesize three aggressive click train types termed “A”, “F3” and “M1” to naive, free-living harbour porpoises. Via theodolite tracking (372 h of total visual effort spread over 10 expeditions) we found that, depending on signal type, porpoises either avoid or become attracted to PAL: Signal types “A” and “F3” are slight deterrents, porpoises increasing minimum range (+23 to 32 m, respectively), whereas “M1” attracts porpoises, reducing range (by − 29 m). As determined via archival acoustic detectors (AADs), both signals “F3” and “M1” led the animals to significantly intensify their click rate (by +10% and 68%, respectively) while signal “A” led to a significant reduction ( − 59%). We propose that equipping fishing gear with PAL emitting signal “F3” could potentially reduce porpoise by-catch by increasing (1) awareness through enhanced echolocation and (2) distance to the nets. Detection probability and radius of PAL/AAD tandems could be improved by emitting signal “M1” to focus porpoise echolocation signals on the AAD. The signal may also be useful in luring animals away from hazards, which may be helpful for conservation measures prior to the onset of harmful acoustic activities such as pile-driving, seismic exploration or ammunition clearance

    Innovative Dam Monitoring Tools Based on Distributed Temperature Measurement

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    Distributed fibreoptic measurements contain a number of particular features. Even though they are nowadays used for strain measurements, actually the most interesting parameter to be monitored by distributed fibreoptic measurements in dams is temperature. Due to their enormous mass, large structures such as dams usually show very slow behaviour in terms of temperature changes. It is well known that temperature measurements have to be carried out in concrete dams in order to observe the development of the heat of hydration. Furthermore, seepage flows affect the temperature field within the dams and their foundations. The Distributed Fibre Optic Temperature DFOT measurement was identified to be ideally suited for monitoring the temperature fields of dams, both for leakage detection and for the observation of concrete temperatures. For almost one decade, DFOT measurement has proven to be a powerful tool to detect and locate leakage in hydraulic structures. Leakage detection by means of DFOT measurements has been typically implemented through two major approaches: the gradient method, which employs the temperature as a tracer to detect anomalies in the flow field; and the heat-up method, which allows detecting the presence and movement of water by evaluating the thermal response after external heat is induced. In the past years more and more DFOT projects are under progress. As for today, the DFOT measurement has to be considered as a state of the art tool in dam monitoring. Nevertheless, especially in the field of leakage detection, there is still an enormous potential to improve effectiveness. New additional applications will be developed and important parameters as the seepage velocity in soil material will be measured with DFOT technology in the future. Being robust and gaining a high density of in-situ information out of the dam, DFOT technology has to be considered as one of the key technologies in tomorrow’s dam monitoring

    Prediction contribution of the cranial collateral circulation to the clinical and radiological outcome of ischemic stroke

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    Background and Aim: The extent of penumbra tissue and outcome in stroke patients depend on the collateral cranial vasculature. To provide optimal individualized care for stroke patients in the emergency room setting we investigated the predictive capability of a stringent evaluation of the collateral vessels in ischemic stroke on clinical outcome and infarct size. Methods: We retrospectively studied uniform clinical and radiological data of 686 consecutive patients admitted to the emergency department with suspected acute ischemic stroke. Cranial collateral vasculature status was graded using the initial CT-angiography. Outcome was measured by mRS, NIHSS and final infarct size at hospital discharge. All data were used to build a linear regression model to predict the patients´ outcome. Results: Univariate and multivariate analyses showed significant effects of the whole brain collateral vessel score on all outcome variables. Atherosclerosis and piale collateral status were associated with the final infarct volume (FIV). Atherosclerosis and age were associated with the NIHSS at discharge. The presence of atherosclerosis, glucose level on admission and age were associated with the mRS at discharge. The multivariate models were able to predict 29% of the variance of the mRS at discharge, 24% of the variance in FIV and 17% of the variance of the NIHSS at discharge. The whole brain collateral status and the presence of atherosclerosis were the most relevant predictors for the clinical and radiological outcome. Conclusion: The whole brain collateral vasculature status is clearly associated with clinical and radiological outcome but in a multivariate model seems not sufficiently predictive for FIV, mRS and NIHSS outcome at discharge in non-preselected patients admitted to the emergency department with ischemic stroke

    In Vivo Localization of the Human Velocity Storage Mechanism and Its Core Cerebellar Networks by Means of Galvanic-Vestibular Afternystagmus and fMRI.

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    Humans are able to estimate head movements accurately despite the short half-life of information coming from our inner ear motion sensors. The observation that the central angular velocity estimate outlives the decaying signal of the semicircular canal afferents led to the concept of a velocity storage mechanism (VSM). The VSM can be activated via visual and vestibular modalities and becomes manifest in ocular motor responses after sustained stimulation like whole-body rotations, optokinetic or galvanic vestibular stimulation (GVS). The VSM has been the focus of many computational modelling approaches; little attention though has been paid to discover its actual structural correlates. Animal studies localized the VSM in the medial and superior vestibular nuclei. A significant modulation by cerebellar circuitries including the uvula and nodulus has been proposed. Nevertheless, the corresponding neuroanatomical structures in humans have not been identified so far. The aim of the present study was to delineate the neural substrates of the VSM using high-resolution infratentorial fMRI with a fast T2* sequence optimized for infratentorial neuroimaging and via video-oculography (VOG). The neuroimaging experiment (n=20) gave first in vivo evidence for an involvement of the vestibular nuclei in the VSM and substantiate a crucial role for cerebellar circuitries. Our results emphasize the importance of cerebellar feedback loops in VSM most likely represented by signal increases in vestibulo-cerebellar hubs like the uvula and nodulus and lobule VIIIA. The delineated activation maps give new insights regarding the function and embedment of Crus I, Crus II, and lobule VII and VIII in the human vestibular system

    Influence of relative NK-DC abundance on placentation and its relation to epigenetic programming in the offspring

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    Normal placentation relies on an efficient maternal adaptation to pregnancy. Within the decidua, natural killer (NK) cells and dendritic cells (DC) have a critical role in modulating angiogenesis and decidualization associated with pregnancy. However, the contribution of these immune cells to the placentation process and subsequently fetal development remains largely elusive. Using two different mouse models, we here show that optimal placentation and fetal development is sensitive to disturbances in NK cell relative abundance at the fetal–maternal interface. Depletion of NK cells during early gestation compromises the placentation process by causing alteration in placental function and structure. Embryos derived from NK-depleted dams suffer from intrauterine growth restriction (IUGR), a phenomenon that continued to be evident in the offspring on post-natal day 4. Further, we demonstrate that IUGR was accompanied by an overall reduction of global DNA methylation levels and epigenetic changes in the methylation of specific hepatic gene promoters. Thus, temporary changes within the NK cell pool during early gestation influence placental development and function, subsequently affecting hepatic gene methylation and fetal metabolism.Fil: Freitag, Nancy. Medicine University of Berlin; AlemaniaFil: Zwier, M. V.. University of Groningen; Países BajosFil: Barrientos, Gabriela Laura. Medicine University of Berlin; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tirado González, Irene. Medicine University of Berlin; AlemaniaFil: Conrad, Melanie L.. Medicine University of Berlin; AlemaniaFil: Rose, Matthias. Medicine University of Berlin; AlemaniaFil: Scherjon, S. A.. University of Groningen; Países BajosFil: Plösch, T.. University of Groningen; Países BajosFil: Blois, Sandra M.. Medicine University of Berlin; Alemani

    Input beam matching and beam dynamics design optimizations of the IsoDAR RFQ using statistical and machine learning techniques

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    This work was supported by NSF grants PHY-1505858 and PHY-1626069 and funding from the Bose Foundation and the Heising-Simons Foundation.We present a novel machine learning-based approach to generate fast-executing virtual radiofrequency quadrupole (RFQ) particle accelerators using surrogate modelling. These could potentially be used as on-line feedback tools during beam commissioning and operation, and to optimize the RFQ beam dynamics design prior to construction. Since surrogate models execute orders of magnitude faster than corresponding physics beam dynamics simulations using standard tools like PARMTEQM and RFQGen, the computational complexity of the multi-objective optimization problem reduces significantly. Ultimately, this presents a computationally inexpensive and time efficient method to perform sensitivity studies and an optimization of the crucial RFQ beam output parameters like transmission and emittances. Two different methods of surrogate model creation (polynomial chaos expansion and neural networks) are discussed and the achieved model accuracy is evaluated for different study cases with gradually increasing complexity, ranging from a simple FODO cell example to the full RFQ optimization. We find that variations of the beam input Twiss parameters can be reproduced well. The prediction of the beam with respect to hardware changes, e.g., the electrode modulation, are challenging on the other hand. We discuss possible reasons for that and elucidate nevertheless existing benefits of the applied method to RFQ beam dynamics design.Publisher PDFPeer reviewe
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