237 research outputs found
The Transmission of German Monetary Policy in the Pre-Euro Period
A small macroeconomic model is constructed to study the transmission of the monetary policy conducted by the Deutsche Bundesbank (DBB) since the middle of the 1970s. For this purpose quarterly, seasonally unadjusted data for the period from 1975 to 1998 are used, that is, the period until the introduction of the Euro is considered. A vector error correction model is constructed for the German monetary sector based on M3, GNP, an inflation rate, a long-term interest rate and a short-term rate which represents the policy variable of the DBB. Moreover, import price inflation is included as an exogenous variable to capture foreign effects. An impulse response analysis highlights the effects of changes in the short-term interest rate and shows the interaction of the main variables of the monetary sector.cointegration analysis, impulse response analysis, monetary policy, money demand, structural vector error correction model
The HERA-B database services: for detector configuration, calibration, alignment, slow control and data classification
Abstract The database services for the distributed application environment of the HERA-B experiment are presented. Achieving the required 10 6 trigger reduction implies that all reconstruction, including calibration and alignment procedures, must run online, making extensive usage of the database systems. The associations from the events to the database objects are carefully introduced considering efficiency and flexibility. The challenges of managing the slow control information were addressed by introducing data and update objects used in special processing on dedicated servers. The system integrates the DAQ client/server protocols with customized active database servers and relies on a high-performance database support toolkit. For applications that required complex selection mechanisms, as in the data-quality databases, the relevant data is replicated using a relational database management system
Muon Array with RPCs for Tagging Air showers (MARTA)
We discuss the concept of an array with Resistive Plate Chambers (RPC) for muon detection in ultra-high energy cosmic ray (UHECR) experiments. RPC have been used in particle physics experiments due to their fast timing properties and spatial resolution. The operation of a ground array detector poses challenging demands, as the RPC must operate remotely under extreme en- vironments, with limited power and minimal maintenance. In its baseline configuration, each MARTA unit includes one 1.5x1.2 m 2 RPC, with 64 pickup electrodes (pads). The DAQ sys- tem is based on an ASIC, allowing one to read out the high number of channels with low power consumption. Data are recorded using a dual technique: single particle counting with a simple threshold on the signal from each pad and charge integration for high occupancy. The RPC, DAQ, High Voltage and monitoring systems are enclosed in an aluminum-sealed case, providing a com- pact and robust unit suited for outdoor environments, which can be easily deployed and connected. The RPCs developed at LIP-Coimbra are able to operate using very low gas flux, which allows running them for few years with a small gas reservoir. Several full-scale units are already installed and taking data in several locations and with different configurations, proving the viability of the MARTA concept. By shielding the detector units with enough slant mass to absorb the electro- magnetic component in the air showers, a clean measurement of the muon content is allowed, a concept to be implemented in a next generation of UHECR experiments. The specificities of a MARTA unit are presented, which include particle counting with high efficiency, time resolu- tion and spatial segmentation. The potential of the MARTA concept for muon measurements in air showers is assessed, as well as tentative methods for calibration and cross-calibrations with existing detectors.Peer Reviewe
Deletion of SERF2 in mice delays embryonic development and alters amyloid deposit structure in the brain
In age-related neurodegenerative diseases, like Alzheimer's and Parkinson's, disease-specific proteins become aggregation -prone and form amyloid-like deposits. Depletion of SERF pro-teins ameliorates this toxic process in worm and human cell models for diseases. Whether SERF modifies amyloid pathology in mammalian brain, however, has remained unknown. Here, we generated conditional Serf2 knockout mice and found that full -body deletion of Serf2 delayed embryonic development, causing premature birth and perinatal lethality. Brain-specific Serf2 knockout mice, on the other hand, were viable, and showed no major behavioral or cognitive abnormalities. In a mouse model for amyloid-beta aggregation, brain depletion of Serf2 altered the binding of structure-specific amyloid dyes, previously used to distinguish amyloid polymorphisms in the human brain. These results suggest that Serf2 depletion changed the structure of amyloid deposits, which was further supported by scanning transmission electron microscopy, but further study will be required to confirm this observation. Altogether, our data reveal the pleiotropic functions of SERF2 in embryonic development and in the brain and support the existence of modifying factors of amyloid deposition in mammalian brain, which offer possi-bilities for polymorphism-based interventions
Deletion of SERF2 in mice delays embryonic development and alters amyloid deposit structure in the brain
In age-related neurodegenerative diseases, like Alzheimer's and Parkinson's, disease-specific proteins become aggregation-prone and form amyloid-like deposits. Depletion of SERF proteins ameliorates this toxic process in worm and human cell models for diseases. Whether SERF modifies amyloid pathology in mammalian brain, however, has remained unknown. Here, we generated conditional Serf2 knockout mice and found that full-body deletion of Serf2 delayed embryonic development, causing premature birth and perinatal lethality. Brain-specific Serf2 knockout mice, on the other hand, were viable, and showed no major behavioral or cognitive abnormalities. In a mouse model for amyloid-β aggregation, brain depletion of Serf2 altered the binding of structure-specific amyloid dyes, previously used to distinguish amyloid polymorphisms in the human brain. These results suggest that Serf2 depletion changed the structure of amyloid deposits, which was further supported by scanning transmission electron microscopy, but further study will be required to confirm this observation. Altogether, our data reveal the pleiotropic functions of SERF2 in embryonic development and in the brain and support the existence of modifying factors of amyloid deposition in mammalian brain, which offer possibilities for polymorphism-based interventions. </p
A compilation of charged-particle induced thermonuclear reaction rates
Low-energy cross section data for 86 charged-particle induced reactions involving light (1 less than or equal to Z less than or equal to 14), mostly stable, nuclei are compiled. The corresponding Maxwellian-averaged thermonuclear reaction rates of relevance in astrophysical plasmas at temperatures in the range from 10(6) K to 10(10) K are calculated. These evaluations assume either that the target nuclei are in their ground state, or that the target states are thermally populated following a Maxwell-Boltzmann distribution, except in some cases involving isomeric states. Adopted values complemented with lower and upper limits of the rates are presented in tabular form. Analytical approximations to the adopted rates, as well as to the inverse/direct rate ratios, are provided. (C) 1999 Elsevier Science B.V. All rights reserved
Measurement of meson production in jets from pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
This paper reports a measurement of D*+/- meson production in jets from proton-proton collisions at a center-of-mass energy of sqrt(s) = 7 TeV at the CERN Large Hadron Collider. The measurement is based on a data sample recorded with the ATLAS detector with an integrated luminosity of 0.30 pb^-1 for jets with transverse momentum between 25 and 70 GeV in the pseudorapidity range |eta| D0pi+, D0 -> K-pi+, and its charge conjugate. The production rate is found to be N(D*+/-)/N(jet) = 0.025 +/- 0.001(stat.) +/- 0.004(syst.) for D*+/- mesons that carry a fraction z of the jet momentum in the range 0.3 < z < 1. Monte Carlo predictions fail to describe the data at small values of z, and this is most marked at low jet transverse momentum.Peer Reviewe
Search for events with large missing transverse momentum, jets, and at least two tau leptons in 7 TeV proton–proton collision data with the ATLAS detector
A search for events with large missing transverse momentum, jets, and at least two tau leptons has been performed using 2 fb^-1 of proton-proton collision data at sqrt(s) = 7 TeV recorded with the ATLAS detector at the Large Hadron Collider. No excess above the Standard Model background expectation is observed and a 95% CL visible cross section upper limit for new phenomena is set. A 95% CL lower limit of 32 TeV is set on the GMSB breaking scale Lambda independent of tan(beta). These limits provide the most stringent tests to date in a large part of the considered parameter space.Peer Reviewe
Jet energy measurement with the ATLAS detector in proton-proton collisions at TeV
The jet energy scale (JES) and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of sqrt(s) = 7 TeV corresponding to an integrated luminosity of 38 inverse pb. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0.4 or R=0.6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pt > 20 GeV and pseudorapidities eta 50 GeV after a dedicated correction for this effect. The JES is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pt, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pt jets recoiling against a high-pt jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, providing an improved jet energy resolution and a reduced flavour dependence of the jet response. The JES systematic uncertainty determined from a combination of in situ techniques are consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pt jets.Peer Reviewe
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