21,571 research outputs found
On Quillen's calculation of graded -theory
We adapt Quillen's calculation of graded K-groups of
Z-graded rings with support in N to graded
K-theory, allowing gradings in a product Z \times G with G an arbitrary
group. This in turn allows us to use inductions and calculate graded K-theory
of Z^m-graded rings. Here Z is the ring of integers and N positive natural
numbers
A note on the graded K-theory of certain graded rings
Following ideas of Quillen it is shown that the graded K-theory of a
Z^n-graded ring with support contained in a pointed cone is entirely determined
by the K-theory of the subring of degree-0 elements.Comment: 4 page
A microscopic description of sound absorption in the atmosphere
The various mechanisms which contribute to sound absorption in the atmosphere are identified and a technique for computing the contribution from each is presented. The similarities between sound absorption, laser fluorescence measurements, and the opto-acoustic effect are discussed. Finally, experimental sound absorption results are compared to predictions to test the microscopic energy transfer approach
The Impact of a Clinical Faculty Institute on Participants\u27 Skills for Mentoring Novice Teachers, Grades K-8
A seven-day Clinical Faculty Institute was implemented to increase the skills of mentor teachers and to develop a cadre of Clinical Faculty for the four participating colleges and universities. The 128 participants entered with some confidence in their ability to mentor novice teachers in areas typically taught in methods courses; whereas, they displayed minimal confidence in skills typically taught in supervisory courses. By the end of the Institute, participants showed significant changes in their self-perceptions of skills in twenty areas, with post-scores clustering between 3.5 and 3.9 on a four-point scale. Future institutes should focus on supervisory skills and then emphasize more reflection upon the congruence of teaching, with the best practices articulated in national standards
Nucleus-nucleus collisions at high baryon densities
We study central collision of Pb+Pb at 20, 40, 80 and 160 AGeV within the
UrQMD transport approach and compare rapidity distributions of pi-, K+, K- and
Lambda with the recent measurements from the NA49 Collaboration at 40, 80 and
160 AGeV. It is found that the UrQMD model reasonably describes the data,
however, systematically overpredicts the pi- yield by about 20%, whereas the K+
yield is underestimated by about 15%. The K- yields are in a good agreement
with the experimental data, the Lambda yields are also in a reasonable
correspondence with the data for all energies. We find that hadronic flavour
exchange reactions largely distort the information about the initial
strangeness production mechanism at all energies considered.Comment: 9 pages, including 3 eps figures, submitted to Phys. Lett.
Splittings of generalized Baumslag-Solitar groups
We study the structure of generalized Baumslag-Solitar groups from the point
of view of their (usually non-unique) splittings as fundamental groups of
graphs of infinite cyclic groups. We find and characterize certain
decompositions of smallest complexity (`fully reduced' decompositions) and give
a simplified proof of the existence of deformations. We also prove a finiteness
theorem and solve the isomorphism problem for generalized Baumslag-Solitar
groups with no non-trivial integral moduli.Comment: 20 pages; hyperlinked latex. Version 2: minor change
PEDIATRÍA: Recientes progresos en el conocimiento de las enfermedades infecciosas en la infancia
Can Momentum Correlations Proof Kinetic Equilibration in Heavy Ion Collisions at 160 AGeV?
We perform an event-by-event analysis of the transverse momentum distribution
of final state particles in central Pb(160AGeV)+Pb collisions within a
microscopic non-equilibrium transport model (UrQMD). Strong influence of
rescattering is found. The extracted momentum distributions show less
fluctuations in A+A collisions than in p+p reactions. This is in contrast to
simplified p+p extrapolations and random walk models.Comment: 9 pages, 3 eps figures, submitted to Phys. Lett.
Azimuthal correlations of pions in relativistic heavy ion collisions at 1 GeV/nucl.
Triple differential cross sections of pions in heavy ion collisions at 1
GeV/nucl. are studied with the IQMD model. After discussing general properties
of resonance and pion production we focus on azimuthal correlations:
At projectile- and target-rapidities we observe an anticorrelation in the
in-plane transverse momentum between pions and protons. At c.m.-rapidity,
however, we find that high pions are being preferentially emitted
perpendicular to the event-plane. We investigate the causes of those
correlations and their sensitivity on the density and momentum dependence of
the real and imaginary part of the nucleon and pion optical potential.Comment: 40 pages, 18 eps-figures, uses psfig.sty; complete postscript file
available at ftp://th.physik.uni-frankfurt.de/pub/bass/GSI-preprint_95-7.ps.
Organization of the telencephalon in the channel catfish, Ictalurus punctatus
The cytoarchitectonics of the telencephalon of the channel catfish, Ictalurus punctatus , are described as a basis for experimental analysis of telencephalic afferents and efferents. The olfactory bulb comprises: (1) an outer layer of olfactory nerve fibers, (2) a glomerular layer, (3) an external cell layer, (4) an inner fiber layer, and (5) an internal cell layer. The telencephalic hemispheres comprise the areas ventralis and dorsalis telencephali. The area ventralis consists of: (1) a precommissural, periventricular zone including nucleus 'nother (Vn), the ventral nucleus (Vv), and the dorsal nucleus (Vd); (2) a precommissural, migrated zone of central (Vc) and lateral (VI) nuclei; (3) a supracommissural nucleus (Vs); (4) a caudal commissural zone of postcommissural (Vp) and intermediate (Vi) nuclei; and (5) a preoptic area (PP). The area dorsalis comprises: (1) medial (DM), (2) dorsal (Dd), (3) lateral [DL, containing dorsal (DLd), ventral (DLv), and posterior (DLp) regions], (4) posterior (DP), and (5) central (DC-1, -2, -3) areas. Nucleus taeniae (NT) is transitional between areas dorsalis and ventralis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50274/1/1051690107_ftp.pd
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