8,753 research outputs found
Do Markets Respond More to More Reliable Labor Market Data? A Test of Market Rationality
Since 1979, the Bureau of Labor Statistics (BLS) has nearly quadrupled the size of the sample used to estimate monthly employment changes. Although first-reported employment estimates are still noisy, the magnitude of sampling variability has declined in proportion to the increase in the sample size. A model of rational Bayesian updating predicts that investors would assign more weight to the BLS employment survey as it became more precise. However, a regression analysis of changes in interest rates on the day the employment data are released finds no evidence that the bond marketâs reaction to employment news intensified in the late 1980s or 1990s; indeed, in the late 1990s and early 2000s the bond markets hardly reacted to unexpected employment news. For the time period as a whole, an unexpected increase of 200,000 jobs is associated with about a 6 basis point increase in the interest rate on 30 year Treasury bonds, and an 8 basis point increase in the interest rate on 3 month bills, all else equal. Additionally, unexpected changes in the unemployment rate and revisions to past monthsâ employment estimates have statistically insignificant effects on long-term interest rates.
Simulation study of a highly efficient, high resolution X-ry sensor based on self-organizing aluminum oxide
State of the art X-ray imaging sensors comprise a trade-off between the
achievable efficiency and the spatial resolution. To overcome such limitations,
the use of structured and scintillator filled aluminum oxide (AlOx) matrices
has been investigated. We used Monte-Carlo (MC) X-ray simulations to determine
the X-ray imaging quality of these AlOx matrices. Important factors which
influence the behavior of the matrices are: filling factor (surface ratio
between channels and 'closed' AlOx), channel diameter, aspect ratio, filling
material etc. Therefore we modeled the porous AlOx matrix in several different
ways with the MC X-ray simulation tool ROSI [1] and evaluated its properties to
investigate the achievable performance at different X-ray spectra, with
different filling materials (i.e. scintillators) and varying channel height and
pixel readout. In this paper we focus on the quantum efficiency, the spatial
resolution and image homogeneity
Experimental observation of the 'Tilting Mode' of an array of vortices in a dilute Bose-Einstein Condensate
We have measured the precession frequency of a vortex lattice in a
Bose-Einstein condensate of 87Rb atoms. The observed mode corresponds to a
collective motion in which all the vortices in the array are tilted by a small
angle with respect to the z-axis (the symmetry axis of the trapping potential)
and synchronously rotate about this axis. This motion corresponds to excitation
of a Kelvin wave along the core of each vortex and we have verified that it has
the handedness expected for such helical waves, i.e. precession in the opposite
sense to the rotational flow around the vortices. The experimental method used
to excite this collective mode closely resembles that used to study the
scissors mode and excitation of the scissors mode for a condensate containing a
vortex array was used to determine the angular momentum of the system. Indeed,
the collective tilting of the array that we have observed has previously been
referred to as an `anomalous' scissors mode.Comment: 5 pages, 7 figures to be published in PR
Alefacept therapy produces remission for patients with chronic plaque psoriasis
Background âAlefacept, human LFA-3/IgG 1 fusion protein, is a novel biological agent currently being developed for the treatment of chronic plaque psoriasis. Alefacept selectively reduces the memory-effector T cells that have been implicated in the pathogenesis of the disease; as a result, alefacept is classified as a therapy that induces remission (so-called âremittiveâ therapy). In a previously published randomized, placebo-controlled phase II study of intravenous alefacept in 229 patients with chronic plaque psoriasis, clinical improvement was observed during dosing as well as in the postdosing follow-up period. Objectives âTo assess the remission period following alefacept therapy. Methods âThe time before re-treatment was required was measured in patients who were âclearâ or âalmost clearâ of disease according to a physician global assessment at the end of the follow-up phase. Results âIn these patients, responses were sustained for a median of 10âmonths, and for up to 18âmonths. No patient reported disease rebound after cessation of alefacept. Conclusions âAlefacept is a biological agent for the treatment of chronic plaque psoriasis that provides disease-free intervals and time off drug therapy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75170/1/j.1365-2133.2003.05239.x.pd
Effect of Ferulic Acid Esterase Enzyme Application on the \u3ci\u3ein Vitro\u3c/i\u3e Digestibility and \u3ci\u3ein Situ\u3c/i\u3e Rumen Degradability of Tropical Grasses
Tropical grasses are the primary staple diet of most of the domesticated ruminants in the tropical and subtropical regions of the world. However, dry matter (DM) digestibility (DMD) and intake levels of these C4 grasses are considerably low, partly because of high lignin contents. Ferulic acid also impedes fibre digestion in such forages due to formation of cross linkages with digestible xylans. Certain esterase enzymes have been shown to cleave ferulic acid cross linkages in wheat bran but no studies have examined whether such enzymes can be used to increase the digestion of tropical grasses. Therefore, the objective of this work was to evaluate the effect of a ferulic acid esterase preparation applied at different rates on the digestibility of C4 grasses
Room-temperature near-infrared silicon carbide nanocrystalline emitters based on optically aligned spin defects
Bulk silicon carbide (SiC) is a very promising material system for
bio-applications and quantum sensing. However, its optical activity lies beyond
the near infrared spectral window for in-vivo imaging and fiber communications
due to a large forbidden energy gap. Here, we report the fabrication of SiC
nanocrystals and isolation of different nanocrystal fractions ranged from 600
nm down to 60 nm in size. The structural analysis reveals further fragmentation
of the smallest nanocrystals into ca. 10-nm-size clusters of high crystalline
quality, separated by amorphization areas. We use neutron irradiation to create
silicon vacancies, demonstrating near infrared photoluminescence. Finally, we
detect, for the first time, room-temperature spin resonances of these silicon
vacancies hosted in SiC nanocrystals. This opens intriguing perspectives to use
them not only as in-vivo luminescent markers, but also as magnetic field and
temperature sensors, allowing for monitoring various physical, chemical and
biological processes.Comment: 5 pages, 4 figure
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