2,782 research outputs found
Building valoristaion strategies for biodiverse products - the approach
The market valorisation of âdiverse food productsâ is crucial to increase diversity in farming systems. It involves multiple actors, from the field to the table, and requires an integrated approach to take into account several dimensions involved
Building Valorisation Strategies for Biodiverse Products - Case Studies
The market valorisation of âdiverse food productsâ is crucial to promote agrobiodiversity. Despite the differences due to the specific contexts, valorisation strategies show relevant common features
What does anticipated monetary policy do?
Forward rate guidance, which has been used with increasing regularity by monetary policymakers, relies on the manipulation of expectations of future short-term interest rates. We identify shocks to these expectations at short and long horizons since the early 1980s and examine their effects on contemporaneous macroeconomic outcomes. Our identification uses sign restrictions on survey forecasts incorporated in a structural VAR model to isolate expected deviations from the monetary- policy rule. We find that expectations of future policy easing that materialize over the subsequent four quarters - similar to those generated by credible forward guidance - .have immediate and persistent stimulative effects on output, inflation, and employment. The effects are larger than those produced by an identical shift in the policy path that is not anticipated. Our results are broadly consistent with the mechanism underlying forward guidance in New Keynesian models, but they suggest that those models overstate the persistence of the inflation response. Further, we find that changes in short-rate expectations farther in the future have weaker macroeconomic effects, the opposite of what most New Keynesian models predict
Entanglement distribution for a practical quantum-dot-based quantum processor architecture
We propose a quantum dot (QD) architecture for enabling universal quantum information processing. Quantum registers, consisting of arrays of vertically stacked self-assembled semiconductor QDs, are connected by chains of in-plane self-assembled dots. We propose an entanglement distributor, a device for producing and distributing maximally entangled qubits on demand, communicated through in-plane dot chains. This enables the transmission of entanglement to spatially separated register stacks, providing a resource for the realization of a sizeable quantum processor built from coupled register stacks of practical size. Our entanglement distributor could be integrated into many of the present proposals for self-assembled QD-based quantum computation (QC). Our device exploits the properties of simple, relatively short, spin-chains and does not require microcavities. Utilizing the properties of self-assembled QDs, after distribution the entanglement can be mapped into relatively long-lived spin qubits and purified, providing a flexible, distributed, off-line resource. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft
The formation of helium lines in the spectrum of COM J1740-5340
The He I 5876A absorption line recently discovered in the spectrum of the
companion to the millisecond pulsar PSR J1740-5340 is tentatively attributed to
electron impact excitations due to the irradiation of its atmosphere by
gamma-rays emitted by the pulsar's magnetosphere. Numerical calculations,
similar to those carried out previously for Type Ib SNe, indicate that a pulsar
beam with photon energies ~ 1 MeV gives rise to a 5876A line of the observed
strength if the beam's spin-down conversion efficiency approaches 1%. However,
a significant difficulty for the proposed mechanism is the strength of the
singlet line at 6678A. Compared to the corresponding triplets, singlet lines
are weak because of the loss of excitation when photons emitted in decays to
the ground state ionize hydrogen atoms, an effect absent in the hydrogen-free
atmospheres of Type Ib SNe.Comment: Accepted for publication in A&
First In-Orbit Experience of TerraSAR-X Flight Dynamics Operations
TerraSAR-X is an advanced synthetic aperture radar satellite system for scientific and commercial applications that is realized in a public-private partnership between the German Aerospace Center (DLR) and the Astrium GmbH. TerraSAR-X was launched at June 15, 2007 on top of a Russian DNEPR-1 rocket into a 514 km sun-synchronous dusk-dawn orbit with an 11-day repeat cycle and will be operated for a period of at least 5 years during which it will provide high resolution SAR-data in the X-band. Due to the objectives of the interferometric campaigns the satellite has to comply to tight orbit control requirements, which are formulated in the form of a 250 m toroidal tube around a pre-flight determined reference trajectory (see [1] for details). The acquisition of the reference orbit was one of the main and key activities during the Launch and Early Orbit Phase (LEOP) and had to compensate for both injection errors and spacecraft safe mode attitude control thruster activities. The paper summarizes the activities of GSOC flight dynamics team during both LEOP and early Commissioning Phase, where the main tasks have been 1) the first-acquisition support via angle-tracking and GPS-based orbit determination, 2) maneuver planning for target orbit acquisition and maintenance, and 3) precise orbit and attitude determination for SAR processing support. Furthermore, a presentation on the achieved results and encountered problems will be addressed
The 69 ms Radio Pulsar Near the Supernova Remnant RCW 103
We report the detection of the radio pulsar counterpart to the 69 ms X-ray
pulsar discovered near the supernova remnant RCW 103 (G332.4-0.4). Our
detection confirms that the pulsations arise from a rotation-powered neutron
star, which we name PSR J1617-5055. The observed barycentric period derivative
confirms that the pulsar has a characteristic age of only 8 kyr, the sixth
smallest of all known pulsars. The unusual apparent youth of the pulsar and its
proximity to a young remnant requires that an association be considered.
Although the respective ages and distances are consistent within substantial
uncertainties, the large inferred pulsar transverse velocity is difficult to
explain given the observed pulsar velocity distribution, the absence of
evidence for a pulsar wind nebula, and the symmetry of the remnant. Rather, we
argue that the objects are likely superposed on the sky; this is reasonable
given the complex area. Without an association, the question of where is the
supernova remnant left behind following the birth of PSR J1617-5055 remains
open. We also discuss a possible association between PSR J1617-5055 and the
gamma-ray source 2CG 333+01. Though an association is energetically plausible,
it is unlikely given that EGRET did not detect 2CG 333+01.Comment: 18 pages, 2 encapsulated Postscript figures, uses AAS LaTeX style
files. Accepted for publication in The Astrophysical Journal Letter
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