1,277 research outputs found
Doubly heavy quark baryon spectroscopy and semileptonic decay
Working in the framework of a nonrelativistic quark model we evaluate the
spectra and semileptonic decay widths for the ground state of doubly heavy
and baryons. We solve the three-body problem using a variational
ansatz made possible by the constraints imposed by heavy quark spin symmetry.
In order to check the dependence of our resultson the inter-quark interaction
we have used five different quarkquark potentials which include Coulomb and
hyperfine terms coming fromone-gluon exchange, plus a confining term. Our
results for the spectra are in good agreement with a previous calculation done
using a Faddeev approach. For the semileptonic decay our results for the total
decay widths are in a good agreement with the ones obtained within a
relativistic quark model in the quark-diquark approximation.Comment: Talk given at the IVth International Conference on Quarks an Nuclear
Physics (QNP06), Madrid, June 5th-10th 200
Comprehensive evaluation of extracellular small RNA isolation methods from serum in high throughput sequencing
Supplementary Tables S1-S9. (XLSX 576Â kb
Heavy quark symmetry constraints on semileptonic form factors and decay widths of doubly heavy baryons
We show how heavy quark symmetry constraints on doubly heavy baryon
semileptonic decay widths can be used to test the validity of different quark
model calculations. The large discrepancies in the results observed between
different quark model approaches can be understood in terms of a severe
violation of heavy quark spin symmetry constraints by some of those models.Comment: 10 LaTex pages, 3 figures, 6 tables. Corrected and enlarged versio
Decay Constants of Heavy Meson of State in Relativistic Salpeter Method
The decay constants of pseudoscalar heavy mesons of state are computed
by means of the relativistic (instantaneous) Salpeter equation. We solved the
full Salpeter equation without making any further approximation, such as
ignoring the small component wave function. Therefore, our results for the
decay constants include the complete relativistic contributions from the light
and the heavy quarks. We obtain , , , , and MeV.Comment: 9 pages, 1 figur
Wind Power Forecasting Error Distributions: An International Comparison
Wind power forecasting is essential for greater penetration of wind power into electricity systems. Because no wind forecasting system is perfect, a thorough understanding of the errors that may occur is a critical factor for system operation functions, such as the setting of operating reserve levels. This paper provides an international comparison of the distribution of wind power forecasting errors from operational systems, based on real forecast data. The paper concludes with an assessment of similarities and differences between the errors observed in different locations.QC 20130116Elektra 36141: Korttidsplanering av vatten-värmekraftsystem vid stora mängder vindkraft: System-perspektive
Iron oxide nanoparticles induce human microvascular endothelial cell permeability through reactive oxygen species production and microtubule remodeling
<p>Abstract</p> <p>Background</p> <p>Engineered iron nanoparticles are being explored for the development of biomedical applications and many other industry purposes. However, to date little is known concerning the precise mechanisms of translocation of iron nanoparticles into targeted tissues and organs from blood circulation, as well as the underlying implications of potential harmful health effects in human.</p> <p>Results</p> <p>The confocal microscopy imaging analysis demonstrates that exposure to engineered iron nanoparticles induces an increase in cell permeability in human microvascular endothelial cells. Our studies further reveal iron nanoparticles enhance the permeability through the production of reactive oxygen species (ROS) and the stabilization of microtubules. We also showed Akt/GSK-3β signaling pathways are involved in iron nanoparticle-induced cell permeability. The inhibition of ROS demonstrate ROS play a major role in regulating Akt/GSK-3β – mediated cell permeability upon iron nanoparticle exposure. These results provide new insights into the bioreactivity of engineered iron nanoparticles which can inform potential applications in medical imaging or drug delivery.</p> <p>Conclusion</p> <p>Our results indicate that exposure to iron nanoparticles induces an increase in endothelial cell permeability through ROS oxidative stress-modulated microtubule remodeling. The findings from this study provide new understandings on the effects of nanoparticles on vascular transport of macromolecules and drugs.</p
Local Group Dwarf Galaxies: Nature And Nurture
We investigate the formation and evolution of dwarf galaxies in a high
resolution, hydrodynamical cosmological simulation of a Milky Way sized halo
and its environment. Our simulation includes gas cooling, star formation,
supernova feedback, metal enrichment and UV heating. In total, 90 satellites
and more than 400 isolated dwarf galaxies are formed in the simulation,
allowing a systematic study of the internal and environmental processes that
determine their evolution. We find that 95% of satellite galaxies are gas-free
at z=0, and identify three mechanisms for gas loss: supernova feedback, tidal
stripping, and photo-evaporation due to re-ionization. Gas-rich satellite
galaxies are only found with total masses above ~ 5x10^9 solar masses. In
contrast, for isolated dwarf galaxies, a total mass of ~ 10^9 solar masses
constitutes a sharp transition; less massive galaxies are predominantly
gas-free at z=0, more massive, isolated dwarf galaxies are often able to retain
their gas. In general, we find that the total mass of a dwarf galaxy is the
main factor which determines its star formation, metal enrichment, and its gas
content, but that stripping may explain the observed difference in gas content
between field dwarf galaxies and satellites with total masses close to 10^9
solar masses. We also find that a morphological transformation via tidal
stripping of infalling, luminous dwarf galaxies whose dark matter is less
concentrated than their stars, cannot explain the high total mass-light ratios
of the faint dwarf spheroidal galaxies.Comment: 18 pages, 13 figures, submitted to MNRA
Mass models of the Milky Way
We present a simple method for fitting parametrized mass models of the Milky
Way to observational constraints. We take a Bayesian approach which allows us
to take into account input from photometric and kinematic data, and
expectations from theoretical modelling. This provides us with a best-fitting
model, which is a suitable starting point for dynamical modelling. We also
determine a probability density function on the properties of the model, which
demonstrates that the mass distribution of the Galaxy remains very uncertain.
For our choices of parametrization and constraints, we find disc scale lengths
of 3.00 \pm 0.22 kpc and 3.29 \pm 0.56 kpc for the thin and thick discs
respectively; a Solar radius of 8.29 \pm 0.16 kpc and a circular speed at the
Sun of 239 \pm 5 km/s; a total stellar mass of 6.43 \pm 0.63 * 10^10 M_sun; a
virial mass of 1.26 \pm 0.24 * 10^12 M_sun and a local dark matter density of
0.40 \pm 0.04 GeV/cm^3. We find some correlations between the best-fitting
parameters of our models (for example, between the disk scale lengths and the
Solar radius), which we discuss. The chosen disc scale-heights are shown to
have little effect on the key properties of the model.Comment: 13 pages, 5 figures, 4 tables. Accepted by MNRA
Report on the BTAS 2016 Video Person Recognition Evaluation
© 2016 IEEE. This report presents results from the Video Person Recognition Evaluation held in conjunction with the 8th IEEE International Conference on Biometrics: Theory, Applications, and Systems (BTAS). Two experiments required algorithms to recognize people in videos from the Point-and-Shoot Face Recognition Challenge Problem (PaSC). The first consisted of videos from a tripod mounted high quality video camera. The second contained videos acquired from 5 different handheld video cameras. There were 1,401 videos in each experiment of 265 subjects. The subjects, the scenes, and the actions carried out by the people are the same in both experiments. An additional experiment required algorithms to recognize people in videos from the Video Database of Moving Faces and People (VDMFP). There were 958 videos in this experiment of 297 subjects. Four groups from around the world participated in the evaluation. The top verification rate for PaSC from this evaluation is 0.98 at a false accept rate of 0.01 - a remarkable advancement in performance from the competition held at FG 2015
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