421 research outputs found
Rules, Discretion, and Central Bank Independence: The German Experience 1880 - 1989
Theories of rules and discretion have become a corner stone in the formulation of macroeconomic policy. They suggest that monetary policy rules are first best in terms of social welfare. However, if commitment is not feasible, delegating monetary policy to an independent and conservative central bank can be second best. Monetary policy in Germany during the past one hundred years provides an excellent case to assess the empirical evidence on the use of rules and central bank independence in monetary policy making. Since the creation of a central monetary authority in 1876, Germany has participated in four monetary regimes: the pre-war gold standard, the inter-war gold standard, the Bretton Woods system, and the floating exchange rate regime. With the exception of the two world war periods German monetary policy was geared primarily towards maintaining price stability and characterized by a high degree of formal and practical central bank independenc
Performance of the EUDET-type beam telescopes
Test beam measurements at the test beam facilities of DESY have been
conducted to characterise the performance of the EUDET-type beam telescopes
originally developed within the EUDET project. The beam telescopes are equipped
with six sensor planes using MIMOSA26 monolithic active pixel devices. A
programmable Trigger Logic Unit provides trigger logic and time stamp
information on particle passage. Both data acquisition framework and offline
reconstruction software packages are available. User devices are easily
integrable into the data acquisition framework via predefined interfaces.
The biased residual distribution is studied as a function of the beam energy,
plane spacing and sensor threshold. Its standard deviation at the two centre
pixel planes using all six planes for tracking in a 6\,GeV
electron/positron-beam is measured to be
(2.88\,\pm\,0.08)\,\upmu\meter.Iterative track fits using the formalism of
General Broken Lines are performed to estimate the intrinsic resolution of the
individual pixel planes. The mean intrinsic resolution over the six sensors
used is found to be (3.24\,\pm\,0.09)\,\upmu\meter.With a 5\,GeV
electron/positron beam, the track resolution halfway between the two inner
pixel planes using an equidistant plane spacing of 20\,mm is estimated to
(1.83\,\pm\,0.03)\,\upmu\meter assuming the measured intrinsic resolution.
Towards lower beam energies the track resolution deteriorates due to increasing
multiple scattering. Threshold studies show an optimal working point of the
MIMOSA26 sensors at a sensor threshold of between five and six times their RMS
noise. Measurements at different plane spacings are used to calibrate the
amount of multiple scattering in the material traversed and allow for
corrections to the predicted angular scattering for electron beams
Rules, Discretion, and Central Bank Independence: The German Experience 1880-1989
Theories of rules and discretion suggest that monetary policy rules are first best in terms of social welfare. However, if commitment is not feasible, delegating monetary policy to an independent and conservative central bank can be second best. Monetary policy in Germany during the past one hundred years provides an excellent case to assess the empirical evidence on the use of rules and central bank independence in monetary policy making. Since the creation of a central monetary authority in 1876, Germany has participated in four monetary regimes: the pre-war gold standard, the inter-war gold standard, the Bretton-Woods system, and the floating exchange rate regime. The bottom line of our analysis is that monetary policy in Germany was always geared toward maintaining price stability with the exception of the two world war periods. Germany relied both on rules and discretion with central bank independence to achieve the goal of price stability. A comparison of the Classical Gold Standard regime with the floating exchange rate regime suggests that society under the floating exchange rate regime with central bank independence was better off. However, this comparison ignores the historical difference in output shocks and the possibility that society became more inflation averse over time.
SymmetryĂą Directed SelfĂą Assembly of a Tetrahedral Protein Cage Mediated by de NovoĂą Designed Coiled Coils
The organization of proteins into new hierarchical forms is an important challenge in synthetic biology. However, engineering new interactions between protein subunits is technically challenging and typically requires extensive redesign of proteinĂą protein interfaces. We have developed a conceptually simple approach, based on symmetry principles, that uses short coiledĂą coil domains to assemble proteins into higherĂą order structures. Here, we demonstrate the assembly of a trimeric enzyme into a wellĂą defined tetrahedral cage. This was achieved by genetically fusing a trimeric coiledĂą coil domain to its C terminus through a flexible polyglycine linker sequence. The linker length and coiledĂą coil strength were the only parameters that needed to be optimized to obtain a high yield of correctly assembled protein cages.Geometry lesson: A modular approach for assembling proteins into largeĂą scale geometric structures was developed in which coiledĂą coil domains acted as Ăą twist tiesĂą to facilitate assembly. The geometry of the cage was specified primarily by the rotational symmetries of the coiled coil and building block protein and was largely independent of protein structural details.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138862/1/cbic201700406_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138862/2/cbic201700406.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138862/3/cbic201700406-sup-0001-misc_information.pd
Chancengerechtigkeit durch Bildung â Chancengerechtigkeit in der Bildung (Auszug)
Der hier mit freundlicher Genehmigung des AWO Bundesverbands abgedruckte Text ist ein Auszug aus der BroschĂŒre: Arbeiterwohlfahrt Bundesverband (Hrsg.): Standpunkte 2006. Chancengerechtigkeit durch Bildung â Chancengerechtigkeit in der Bildung, Bonn 2006. Unser Bildungssystem fĂŒr die Kinder im Alter von 6 bis 16 Jahren wird den Herausforderungen der Zukunft nicht gerecht. Ein Umsteuern ist dringend notwendig, da ohne Bildung der Wandel in die Wissensgesellschaft nicht zu bewĂ€ltigen ist. Bildung, Qualifikation und Kompetenzen und das Erlernen von Diskurs- und KonfliktfĂ€higkeit entscheiden ĂŒber die beruflichen und gesellschaftlichen Chancen eines jeden Menschen und davon abhĂ€ngig ĂŒber seine Zukunftschancen. Bildung bedeutet Entwicklung der Persönlichkeit, der IdentitĂ€t. Bildung bedeutet aber auch, die gemeinschaftsfĂ€hige Persönlichkeit zu gestalten. Und somit bekommt Bildung gerade in der Lebensphase der 6- bis 16-JĂ€hrigen ĂŒber die eher traditionelle Dimension hinaus auch einen emanzipatorischen Charakter. Wenn Bildung also fĂŒr den Einzelnen diese entscheidende Rolle spielt, dann bekommt die öffentliche Verantwortung fĂŒr dieses Bildungswesen eine ganz zentrale Bedeutung. (DIPF/Orig.
Virtual reality surgery simulation: A survey on patient specific solution
For surgeons, the precise anatomy structure and its dynamics are important in the surgery interaction, which is critical for generating the immersive experience in VR based surgical training applications. Presently, a normal therapeutic scheme might not be able to be straightforwardly applied to a specific patient, because the diagnostic results are based on averages, which result in a rough solution. Patient Specific Modeling (PSM), using patient-specific medical image data (e.g. CT, MRI, or Ultrasound), could deliver a computational anatomical model. It provides the potential for surgeons to practice the operation procedures for a particular patient, which will improve the accuracy of diagnosis and treatment, thus enhance the prophetic ability of VR simulation framework and raise the patient care. This paper presents a general review based on existing literature of patient specific surgical simulation on data acquisition, medical image segmentation, computational mesh generation, and soft tissue real time simulation
Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR
Substantial experimental and theoretical efforts worldwide are devoted to
explore the phase diagram of strongly interacting matter. At LHC and top RHIC
energies, QCD matter is studied at very high temperatures and nearly vanishing
net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was
created at experiments at RHIC and LHC. The transition from the QGP back to the
hadron gas is found to be a smooth cross over. For larger net-baryon densities
and lower temperatures, it is expected that the QCD phase diagram exhibits a
rich structure, such as a first-order phase transition between hadronic and
partonic matter which terminates in a critical point, or exotic phases like
quarkyonic matter. The discovery of these landmarks would be a breakthrough in
our understanding of the strong interaction and is therefore in the focus of
various high-energy heavy-ion research programs. The Compressed Baryonic Matter
(CBM) experiment at FAIR will play a unique role in the exploration of the QCD
phase diagram in the region of high net-baryon densities, because it is
designed to run at unprecedented interaction rates. High-rate operation is the
key prerequisite for high-precision measurements of multi-differential
observables and of rare diagnostic probes which are sensitive to the dense
phase of the nuclear fireball. The goal of the CBM experiment at SIS100
(sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD
matter: the phase structure at large baryon-chemical potentials (mu_B > 500
MeV), effects of chiral symmetry, and the equation-of-state at high density as
it is expected to occur in the core of neutron stars. In this article, we
review the motivation for and the physics programme of CBM, including
activities before the start of data taking in 2022, in the context of the
worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal
Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at = 5.02 TeV
Two-particle angular correlations between unidentified charged trigger and
associated particles are measured by the ALICE detector in p-Pb collisions at a
nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum
range 0.7 5.0 GeV/ is examined,
to include correlations induced by jets originating from low
momen\-tum-transfer scatterings (minijets). The correlations expressed as
associated yield per trigger particle are obtained in the pseudorapidity range
. The near-side long-range pseudorapidity correlations observed in
high-multiplicity p-Pb collisions are subtracted from both near-side
short-range and away-side correlations in order to remove the non-jet-like
components. The yields in the jet-like peaks are found to be invariant with
event multiplicity with the exception of events with low multiplicity. This
invariance is consistent with the particles being produced via the incoherent
fragmentation of multiple parton--parton scatterings, while the yield related
to the previously observed ridge structures is not jet-related. The number of
uncorrelated sources of particle production is found to increase linearly with
multiplicity, suggesting no saturation of the number of multi-parton
interactions even in the highest multiplicity p-Pb collisions. Further, the
number scales in the intermediate multiplicity region with the number of binary
nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/161
Multi-particle azimuthal correlations in p-Pb and Pb-Pb collisions at the CERN Large Hadron Collider
Measurements of multi-particle azimuthal correlations (cumulants) for charged
particles in p-Pb and Pb-Pb collisions are presented. They help address the
question of whether there is evidence for global, flow-like, azimuthal
correlations in the p-Pb system. Comparisons are made to measurements from the
larger Pb-Pb system, where such evidence is established. In particular, the
second harmonic two-particle cumulants are found to decrease with multiplicity,
characteristic of a dominance of few-particle correlations in p-Pb collisions.
However, when a gap is placed to suppress such correlations,
the two-particle cumulants begin to rise at high-multiplicity, indicating the
presence of global azimuthal correlations. The Pb-Pb values are higher than the
p-Pb values at similar multiplicities. In both systems, the second harmonic
four-particle cumulants exhibit a transition from positive to negative values
when the multiplicity increases. The negative values allow for a measurement of
to be made, which is found to be higher in Pb-Pb collisions at
similar multiplicities. The second harmonic six-particle cumulants are also
found to be higher in Pb-Pb collisions. In Pb-Pb collisions, we generally find
which is indicative of a Bessel-Gaussian
function for the distribution. For very high-multiplicity Pb-Pb
collisions, we observe that the four- and six-particle cumulants become
consistent with 0. Finally, third harmonic two-particle cumulants in p-Pb and
Pb-Pb are measured. These are found to be similar for overlapping
multiplicities, when a gap is placed.Comment: 25 pages, 11 captioned figures, 3 tables, authors from page 20,
published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/87
EUDAQ - A data acquisition software framework for common beam telescopes
EUDAQ is a generic data acquisition software developed for use in conjunction with common beam telescopes at charged particle beam lines. Providing high-precision reference tracks for performance studies of new sensors, beam telescopes are essential for the research and development towards future detectors for high-energy physics. As beam time is a highly limited resource, EUDAQ has been designed with reliability and ease-of-use in mind. It enables flexible integration of different independent devices under test via their specific data acquisition systems into a top-level framework. EUDAQ controls all components globally, handles the data flow centrally and synchronises and records the data streams. Over the past decade, EUDAQ has been deployed as part of a wide range of successful test beam campaigns and detector development applications
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