135 research outputs found
Misleading pustular plaques of the lower limbs during Crohn's disease: two case reports
<p>Abstract</p> <p>Background</p> <p>Extraintestinal manifestations of Crohn's disease may involve the skin, the eyes, the genital mucosa, and the joints. Dermatoses associated with Crohn's disease include neutrophilic dermatoses, erythema nodosum, granulomatous dermatitis, blistering dermatoses, and non-specific skin manifestations. Cutaneous Crohn's disease is characterized by skin non-caseating epithelioid granulomatas with giant cells, remote from the gastrointestinal tract. We report herein two new cases.</p> <p>Observations</p> <p>On both patients, differential diagnosis of neutrophilic dermatoses and infectious disease were evoked, and antimicrobial agents were introduced in one of them. Given the atypical presentation, the final diagnosis of cutaneous Crohn's disease could only be made with histological examination. In patient 1, the plaques decreased in size and infiltration by more than 75% after 3 weeks of treatment with bethametasone dipropionate 0.05% cream. In patient 2, the plaques decreased by more than 50% after 6 weeks of treatment with prednisolone (45 mg/day) and azathioprine (100 mg/day).</p> <p>Discussion</p> <p>Cutaneous Crohn's disease may present as dusky, erythematous, infiltrated, and ulcerated plaques and nodules. Female-to-male sex ratio is about 2, and the mean age at onset is 35. Recurrently, the hypothesis of a skin mycobacterial or fungal infection greatly delays proper treatment. Rarity of cutaneous Crohn's disease hampers therapeutic assessment in controlled trials. Thus, available literature is limited to case reports and sparse small series, with contradictory results. These reports are subject to publication bias, and no definite evidence-based recommendations can be made on the most adequate therapeutic strategy.</p
High-fidelity quantum driving
The ability to accurately control a quantum system is a fundamental
requirement in many areas of modern science such as quantum information
processing and the coherent manipulation of molecular systems. It is usually
necessary to realize these quantum manipulations in the shortest possible time
in order to minimize decoherence, and with a large stability against
fluctuations of the control parameters. While optimizing a protocol for speed
leads to a natural lower bound in the form of the quantum speed limit rooted in
the Heisenberg uncertainty principle, stability against parameter variations
typically requires adiabatic following of the system. The ultimate goal in
quantum control is to prepare a desired state with 100% fidelity. Here we
experimentally implement optimal control schemes that achieve nearly perfect
fidelity for a two-level quantum system realized with Bose-Einstein condensates
in optical lattices. By suitably tailoring the time-dependence of the system's
parameters, we transform an initial quantum state into a desired final state
through a short-cut protocol reaching the maximum speed compatible with the
laws of quantum mechanics. In the opposite limit we implement the recently
proposed transitionless superadiabatic protocols, in which the system perfectly
follows the instantaneous adiabatic ground state. We demonstrate that
superadiabatic protocols are extremely robust against parameter variations,
making them useful for practical applications.Comment: 17 pages, 4 figure
Production of Two Non-Conjugate Leptoquarks in Collisions
We study the production of scalar and vector leptoquarks in
scattering. We use the most general couplings to the known fermions which are
dimensionless, baryon and lepton number conserving, and invariant. Expressions are presented for production
cross sections and predictions are given for future linear colliders.Comment: 14 page
Personalised Tweeting: the emerging practices of journalists on Twitter
This study focuses on an in-depth case study of regional news outlet the Bournemouth Daily Echo and the role of Twitter within its editorial team. It is based upon two comparative studies conducted in 2011 and 2013 involving interviews with reporters, photographers and senior editorial staff, a discussion of the company Twitter guidelines and a content analysis of 27 Twitter accounts. During the research timeframe Twitter use increased dramatically amongst journalists leading to a clearer set of emerging practices. The data suggests that types of Twitter use are diverse but routine practices are forming in the areas of news gathering and live reporting causing a shift in traditional gatekeeping and verification conventions. The notion that journalists primarily use Twitter to drive traffic to their legacy platforms is not supported but there is evidence of personal branding and journalists presenting a personalised - but not personal - account of their job via their tweets
Determination of alphaS from Hadronic Event Shapes in e+e- Annihilation at 192 < sqrt(s) < 208 GeV
Results are presented from a study of the structure of high energy hadronic
events recorded by the L3 detector at sqrt(s)>192 GeV. The distributions of
several event shape variables are compared to resummed O(alphaS^2) QCD
calculations. We determine the strong coupling constant at three average
centre-of-mass energies: 194.4, 200.2 and 206.2 GeV. These measurements,
combined with previous L3 measurements at lower energies, demonstrate the
running of alphaS as expected in QCD and yield alphaS(mZ) = 0.1227 +- 0.0012 +-
0.0058, where the first uncertainty is experimental and the second is
theoretical
Measurement of the Photon Structure Function at High Q^2 at LEP
The structure functions of real and virtual photons are derived from cross
section measurements of the reaction e^+e^ -> e^+e^- + hadrons at LEP. The
reaction is studied at \sqrt{s} ~ 91 GeV with the L3 detector. One of the final
state electrons is detected at a large angle relative to the beam direction,
leading to Q^2 values between 40 GeV^2 and 500 GeV^2. The other final state
electron is either undetected or it is detected at a four-momentum transfer
squared P^2 between 1 GeV^2 and 8 GeV^2. These measurements are compared with
predictions of the Quark Parton Model and other QCD based models
Monetary Policy and Long-Term Real Rates
Abstract Changes in monetary policy have surprisingly strong effects on forward real rates in the distant future. A 100 basis-point increase in the 2-year nominal yield on an FOMC announcement day is associated with a 42 basis-point increase in the 10-year forward real rate. This finding is at odds with standard macro models based on sticky nominal prices, which imply that monetary policy cannot move real rates over a horizon longer than that over which all prices in the economy can readjust. Rather, the responsiveness of long-term real rates to monetary shocks appears to reflect changes in term premia. One mechanism that may generate such variation in term premia is based on demand effects coming from "yield-oriented" investors. We find some evidence supportive of this channel. * We thank John Campbell, Gene Fama, Emmanuel Farhi, Robin Greenwood, Anil Kashyap, David Scharfstein, Larry Summers, Adi Sunderam, Paul Tucker, Luis Viceira, and seminar participants at Harvard University for helpful comments. The analysis and conclusions set forth are those of the authors and do not indicate concurrence by other members of the Board of Governors.
Monetary Policy and Long-Term Real Rates
Abstract Changes in monetary policy have surprisingly strong effects on forward real rates in the distant future. A 100 basis point increase in the two-year nominal yield on a Federal Open Markets Committee announcement day is associated with a 42 basis point increase in the ten-year forward real rate. This finding is at odds with standard macro models based on sticky nominal prices, which imply that monetary policy cannot move real rates over a horizon longer than that over which all prices in the economy can readjust. Instead, the responsiveness of long-term real rates to monetary shocks appears to reflect changes in term premia. One mechanism that could generate such variation in term premia is based on demand effects due to the existence of what we call yield-oriented investors. We find some evidence supportive of this channel. JEL classification: E43, E52, G12, G1
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