12,600 research outputs found
A new Determination of the Extragalactic Background of Diffuse Gamma Rays taking into account Dark Matter Annihilation
The extragalactic background (EGB) of diffuse gamma rays can be determined by
subtracting the Galactic contribution from the data. This requires a Galactic
model (GM) and we include for the first time the contribution of dark matter
annihilation (DMA), which was previously proposed as an explanation for the
EGRET excess of diffuse Galactic gamma rays above 1 GeV.
In this paper it is shown that the newly determined EGB shows a
characteristic high energy bump on top of a steeply falling soft contribution.
The bump is shown to be compatible with a contribution from an extragalactic
DMA signal from weakly interacting massive particles (WIMPs) with a mass
between 50 and 100 GeV in agreement with the EGRET excess of the Galactic
diffuse gamma rays and in disagreement with earlier analysis. The remaining
soft contribution of the EGB is shown to resemble the spectra of the observed
point sources in our Galaxy.Comment: 7 pages, 4 figures. Accepted by A&A, made Fig. 4 and table 1
consisten
Mass spectrometry in structural and stereochemical problems. Part 178 - The electron-impact promoted fragmentation of 1,2-cyclohexene oxide
Mass spectra of 1,2-cyclohexane oxide and three deuterium labeled analog
Parameterization of the Angular Distribution of Gamma Rays Produced by p-p Interaction in Astronomical Environment
We present the angular distribution of gamma rays produced by proton-proton
interactions in parameterized formulae to facilitate calculations in
astrophysical environments. The parameterization is derived from Monte Carlo
simulations of the up-to-date proton-proton interaction model by Kamae et al.
(2005) and its extension by Kamae et al. (2006). This model includes the
logarithmically rising inelastic cross section, the diffraction dissociation
process and Feynman scaling violation. The extension adds two baryon resonance
contributions: one representing the Delta(1232) and the other representing
multiple resonances around 1600 MeV/c^2. We demonstrate the use of the formulae
by calculating the predicted gamma-ray spectrum for two different cases: the
first is a pencil beam of protons following a power law and the second is a
fanned proton jet with a Gaussian intensity profile impinging on the
surrounding material. In both cases we find that the predicted gamma-ray
spectrum to be dependent on the viewing angle.Comment: 8 pages, 7 figures, figure 7 updated, accepted for publication in
ApJ, text updated to match changes by the editor, two refs updated from
preprints to full journal
INDICATIONS OF TISSUE SPECIFICITY IN A TRANSPLANTABLE SARCOMA
1. A sarcoma of the mouse which has proved to be transplantable to a great variety of strains of mice does not furnish an exception to the theory that transplantability is controlled by genetic factors, since this tumor possesses some characteristics that are more than probably genetic. 2. The phenomenon of the assumption of tissue specificity on the part of the host may possibly be of genetic origin. 3. The evidence suggests that the gonads have some influence on the assumption of tissue specificity on the part of the host. 4. The growth rate of the transplanted tumor may possibly be correlated with the genetic constitution of the host
An experimental study of tonal pattern training and learning modalities on the pitch accuracy of first grade students
The purpose of this study was to investigate the use of the body scale in the tonal pattern training of first grade students. The problem of this study was to determine the comparative effects of tonal pattern instruction with and without the use of the body scale on the singing accuracy of first-grade students among auditory, visual, and kinesthetic learners.
Sixty-seven first grade students in four intact classes were used as the sample in this study. Two of the classes were randomly assigned to serve as the control group and two classes were assigned to serve as the experimental group. All subjects were pretested for pitch accuracy and learning modality preference.
During the 12 weeks of treatment, students in both the control and experimental groups received similar tonal pattern instruction. The main difference existed in that the control group received tonal pattern training without a body scale while the experimental group received tonal pattern training that included a body scale.
At the conclusion of the 12 weeks of treatment, students were individually tape-recorded singing a rote song and their performances were judged by two independent music teachers. Interjudge reliabilities for the pretest and posttest were .67 and .70, respectively. The researcher failed to find statistically significant differences for the interaction and main effects.
Based on the data acquired from this study, it cannot yet be concluded that the use of a body scale during tonal pattern instruction among students with various learning styles (auditory, visual, kinesthetic) has an effect on the singing accuracy of those young children in first grade
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