440 research outputs found
Diffantom: Whole-Brain Diffusion MRI Phantoms Derived from Real Datasets of the Human Connectome Project.
Food allergies are believed to be on the rise and currently management relies on the avoidance of the food. Hen's egg allergy is after cow's milk allergy the most common food allergy; eggs are used in many food products and thus difficult to avoid. A technological process using a combination of enzymatic hydrolysis and heat treatment was designed to produce modified hen's egg with reduced allergenic potential. Biochemical (SDS-PAGE, Size exclusion chromatography and LC-MS/MS) and immunological (ELISA, immunoblot, RBL-assays, animal model) analysis showed a clear decrease in intact proteins as well as a strong decrease of allergenicity. In a clinical study, 22 of the 24 patients with a confirmed egg allergy who underwent a double blind food challenge with the hydrolysed egg remained completely free of symptoms. Hydrolysed egg products may be beneficial as low allergenic foods for egg allergic patients to extent their diet. This article is protected by copyright. All rights reserved
Optical and Infrared Photometry of the Unusual Type Ia Supernova 2000cx
We present optical and infrared photometry of the unusual Type Ia supernova
2000cx. With the data of Li et al. (2001) and Jha (2002), this comprises the
largest dataset ever assembled for a Type Ia SN, more than 600 points in
UBVRIJHK. We confirm the finding of Li et al. regarding the unusually blue B-V
colors as SN 2000cx entered the nebular phase. Its I-band secondary hump was
extremely weak given its B-band decline rate. The V minus near infrared colors
likewise do not match loci based on other slowly declining Type Ia SNe, though
V-K is the least ``abnormal''. In several ways SN 2000cx resembles other slow
decliners, given its B-band decline rate (Delta m_15(B) = 0.93), the appearance
of Fe III lines and weakness of Si II in its pre-maximum spectrum, the V-K
colors and post-maximum V-H colors. If the distance modulus derived from
Surface Brightness Fluctuations of the host galaxy is correct, we find that the
rate of light increase prior to maximum, the characteristics of the bolometric
light curve, and the implied absolute magnitude at maximum are all consistent
with a sub-luminous object with Delta m_15(B) ~ 1.6-1.7 having a higher than
normal kinetic energy.Comment: 46 pages, 17 figures, to be published in Publications of the
Astronomical Society of the Pacifi
Robust thalamic nuclei segmentation method based on local diffusion magnetic resonance properties.
The thalamus is an essential relay station in the cortical-subcortical connections. It is characterized by a complex anatomical architecture composed of numerous small nuclei, which mediate the involvement of the thalamus in a wide range of neurological functions. We present a novel framework for segmenting the thalamic nuclei, which explores the orientation distribution functions (ODFs) from diffusion magnetic resonance images at 3 T. The differentiation of the complex intra-thalamic microstructure is improved by using the spherical harmonic (SH) representation of the ODFs, which provides full angular characterization of the diffusion process in each voxel. The clustering was performed using the k-means algorithm initialized in a data-driven manner. The method was tested on 35 healthy volunteers and our results show a robust, reproducible and accurate segmentation of the thalamus in seven nuclei groups. Six of them closely matched the anatomy and were labeled as anterior, ventral anterior, medio-dorsal, ventral latero-ventral, ventral latero-dorsal and pulvinar, while the seventh cluster included the centro-lateral and the latero-posterior nuclei. Results were evaluated both qualitatively, by comparing the segmented nuclei to the histological atlas of Morel, and quantitatively, by measuring the clusters' extent and the clusters' spatial distribution across subjects and hemispheres. We also showed the robustness of our approach across different sequences and scanners, as well as intra-subject reproducibility of the segmented clusters using additional two scan-rescan datasets. We also observed an overlap between the path of the main long-connection tracts passing through the thalamus and the spatial distribution of the nuclei identified with our clustering algorithm. Our approach, based on SH representations of the ODFs, outperforms the one based on angular differences between the principle diffusion directions, which is considered so far as state-of-the-art method. Our findings show an anatomically reliable segmentation of the main groups of thalamic nuclei that could be of potential use in many clinical applications
Traffic monitoring for assuring quality of advanced services in future internet
The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-21560-5_16Services based on packet switched networks are becoming dominant in telecommunication business and both operators and service providers must evolve in order to guarantee the required quality. Increasing bandwidth is no longer a viable solution because of the business erosion for network operators which cannot expect revenues due to the large investments required to satisfy new applications demand of bandwidth. This paper presents devices and a specific architecture of services monitoring platform that allows network operators and service providers to analyze the perceived quality of service and check their service level agreements. Thus, a cost-effective service management, based on direct IP traffic measuring, can be supported on integrated monitoring systems to provide network-centric mechanisms for differentiated quality of service, security and other advanced services.This work has been partially developed in the framework of the Celtic and EUREKA initiative IPNQSIS (IP Network Monitoring for Quality of Service Intelligent Support)
The kinetics and acoustics of fingering and note transitions on the flute
Motion of the keys was measured in a transverse flute while beginner, amateur
and professional flutists played a range of exercises. The time taken for a key
to open or close is typically 10 ms when pushed by a finger or 16 ms when moved
by a spring. Delays between the motion of the fingers were typically tens of
ms, with longer delays as more fingers are involved. Because the opening and
closing of keys will never be exactly simultaneous, transitions between notes
that involve the movement of multiple fingers can occur via several possible
pathways with different intermediate fingerings. A transition is classified as
`safe' if it is possible to be slurred from the initial to final note with
little perceptible change in pitch or volume. Some transitions are `unsafe' and
possibly involve a transient change in pitch or a decrease in volume. In
transitions with multiple fingers, players, on average, used safe transitions
more frequently than unsafe transitions. Professionals exhibited smaller
average delays between the motion of fingers than did amateurs
Low angular momentum flow model of Sgr A* activity
Sgr A* is the closest massive black hole and can be observed with the highest
angular resolution. Nevertheless, our current understanding of the accretion
process in this source is very poor. The inflow is almost certainly of low
radiative efficiency and it is accompanied by a strong outflow and the flow is
strongly variable but the details of the dynamics are unknown. Even the amount
of angular momentum in the flow is an open question. Here we argue that low
angular momentum scenario is better suited to explain the flow variability. We
present a new hybrid model which describes such a flow and consists of an outer
spherically symmetric Bondi flow and an inner axially symmetric flow described
through MHD simulations. The assumed angular momentum of the matter is low,
i.e. the corresponding circularization radius in the equatorial plane of the
flow is just above the innermost stable circular orbit in pseudo-Newtonian
potential. We compare the radiation spectrum from such a flow to the broad band
observational data for Sgr A*.Comment: Proceedings of the AHAR 2008 Conference: The Universe under the
Microscope; Astrophysics at High Angular Resolution, Bad Honef
Black hole mergers: the first light
The coalescence of supermassive black hole binaries occurs via the emission
of gravitational waves, that can impart a substantial recoil to the merged
black hole. We consider the energy dissipation, that results if the recoiling
black hole is surrounded by a thin circumbinary disc. Our results differ
significantly from those of previous investigations. We show analytically that
the dominant source of energy is often potential energy, released as gas in the
outer disc attempts to circularize at smaller radii. Thus, dimensional
estimates, that include only the kinetic energy gained by the disc gas,
underestimate the real energy loss. This underestimate can exceed an order of
magnitude, if the recoil is directed close to the disc plane. We use three
dimensional Smooth Particle Hydrodynamics (SPH) simulations and two dimensional
finite difference simulations to verify our analytic estimates. We also compute
the bolometric light curve, which is found to vary strongly depending upon the
kick angle. A prompt emission signature due to this mechanism may be observable
for low mass (10^6 Solar mass) black holes whose recoil velocities exceed about
1000 km/s. Emission at earlier times can mainly result from the response of the
disc to the loss of mass, as the black holes merge. We derive analytically the
condition for this to happen.Comment: 16 pages, accepted by MNRAS. Animations of the simulations are
available at http://jilawww.colorado.edu/~pja/recoil.htm
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