13,306 research outputs found
Effect of the channel and interference phenomena in the two-pion transitions of charmonia and bottomonia
The basic shape of di-pion mass spectra in the two-pion transitions of both
charmonia and bottomonia states is explained by an unified mechanism based on
contributions of the , and coupled channels
including their interference. The role of the individual resonances in
shaping the di-pion mass distributions in the charmonia and bottomonia decays
is considered.Comment: 8 pages, 4 figures, Talk at the XXIII International Baldin Seminar on
High Energy Physics Problems "Relativistic Nuclear Physics \& Quantum
Chromodynamics" (Dubna, Russia, 19--24 September 2016). arXiv admin note:
text overlap with arXiv:1610.0789
The interference effects of multi-channel pion-pion scattering contributions to the final states of - and -meson family decays
It is shown that the basic shape of dipion mass distributions in the two-pion
transitions of both charmonia and bottomonia states are explained by an unified
mechanism based on the contribution of the , and
coupled channels including their interference.Comment: 5 pages, 3 figures, talk at the14th International Workshop on Meson
Production, Properties and Interaction (Krakow, Poland, 2nd - 7th June 2016
All-weather ice information system for Alaskan arctic coastal shipping
A near real-time ice information system designed to aid arctic coast shipping along the Alaskan North Slope is described. The system utilizes a X-band Side Looking Airborne Radar (SLAR) mounted aboard a U.S. Coast Guard HC-130B aircraft. Radar mapping procedures showing the type, areal distribution and concentration of ice cover were developed. In order to guide vessel operational movements, near real-time SLAR image data were transmitted directly from the SLAR aircraft to Barrow, Alaska and the U.S. Coast Guard icebreaker Glacier. In addition, SLAR image data were transmitted in real time to Cleveland, Ohio via the NOAA-GOES Satellite. Radar images developed in Cleveland were subsequently facsimile transmitted to the U.S. Navy's Fleet Weather Facility in Suitland, Maryland for use in ice forecasting and also as a demonstration back to Barrow via the Communications Technology Satellite
A causal statistical family of dissipative divergence type fluids
In this paper we investigate some properties, including causality, of a
particular class of relativistic dissipative fluid theories of divergence type.
This set is defined as those theories coming from a statistical description of
matter, in the sense that the three tensor fields appearing in the theory can
be expressed as the three first momenta of a suitable distribution function. In
this set of theories the causality condition for the resulting system of
hyperbolic partial differential equations is very simple and allow to identify
a subclass of manifestly causal theories, which are so for all states outside
equilibrium for which the theory preserves this statistical interpretation
condition. This subclass includes the usual equilibrium distributions, namely
Boltzmann, Bose or Fermi distributions, according to the statistics used,
suitably generalized outside equilibrium. Therefore this gives a simple proof
that they are causal in a neighborhood of equilibrium. We also find a bigger
set of dissipative divergence type theories which are only pseudo-statistical,
in the sense that the third rank tensor of the fluid theory has the symmetry
and trace properties of a third momentum of an statistical distribution, but
the energy-momentum tensor, while having the form of a second momentum
distribution, it is so for a different distribution function. This set also
contains a subclass (including the one already mentioned) of manifestly causal
theories.Comment: LaTex, documentstyle{article
Vascular endothelial growth factor directly inhibits primitive neural stem cell survival but promotes definitive neural stem cell survival
There are two types of neural stem cells (NSCs). Primitive NSCs [leukemia inhibitory factor (LIF) dependent but exogenous fibroblast growth factor (FGF) 2 independent] can be derived from mouse embryonic stem (ES) cells in vitro and from embryonic day 5.5 (E5.5) to E7.5 epiblast and E7.5-E8.5 neuroectoderm in vivo. Definitive NSCs (LIF independent but FGF2 dependent) first appear in the E8.5 neural plate and persist throughout life. Primitive NSCs give rise to definitive NSCs. Loss and gain of functions were used to study the role of vascular endothelial growth factor (VEGF)-A and its receptor, Flk1, in NSCs. The numbers of Flk1 knock-out mice embryo-derived and ES cell-derived primitive NSCs were increased because of the enhanced survival of primitive NSCs. In contrast, neural precursor-specific, Flk1 conditional knock-out mice-derived, definitive NSCs numbers were decreased because of the enhanced cell death of definitive NSCs. These effects were not observed in cells lacking Flt1, another VEGF receptor. In addition, the cell death stimulated by VEGF-A of primitive NSC and the cell survival stimulated by VEGF-A of definitive NSC were blocked by Flk1/Fc-soluble receptors and VEGF-A function-blocking antibodies. These VEGF-A phenotypes also were blocked by inhibition of the downstream effector nuclear factor kappa B (NF-kappa B). Thus, both the cell death of primitive NSC and the cell survival of definitive NSC induced by VEGF-A stimulation are mediated by bifunctional NF-kappa B effects. In conclusion, VEGF-A function through Flk1 mediates survival (and not proliferative or fate change) effects on NSCs, specifically
INVESTIGATION OF SOME FUNCTIONAL AND NUTRITIVE PROPERTIES OF CEREAL GERM PROTEINS
Proteins, protein concentrates and isolates were prepared frolll wheat, rye, barley, rice
and maize germs. after defatting with hexane or supercritical carbon dioxide, by alkaline extraction (NaOH, pH=10) and acid precipitation (0.1 mol/l HCI). The chemical composition, amino acid composition and functional properties (emulsifying properties, foam activity and stability, water , and oil absorption, solubility) were determined. The digestibility and biological value of protein preparations were also calculated.
Protein isolates had a high protein content (75.8 - 94.3%). The oil content was low, except in maize germ protein isolates, obtained after defatting with supercritical carbon dioxide. High digestibility (83 - 90%) and moderate biological value (63 - 7,5 FAO/WHO index) was characteristic of all isolates. Methionine and cysteine were the limiting amino acids.
Ivlaize germ protein isolates showed the best functional properties, being comparable with those of soy protein isolates. Other germ protein isolates also had acceptable properties. No significant. differences were observed bet ween the functional properties of isolates prepared after defatting with hexane or supercritical carbon dioxide, except the foaming properties. The latter were adversely affected by supercritical fluid extraction
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