2,188 research outputs found
Automated urinalysis technique determines concentration of creatine and creatinine by colorimetry
Continuous urinalysis technique is useful in the study of muscle wastage in primates. Creatinine concentration in urine is determined in an aliquot mixture by a color reaction. Creatine is determined in a second aliquot by converting it to creatinine and measuring the difference in color intensity between the two aliquots
Low temperature behavior of the heavy Fermion Ce3Co4Sn13
The compound Ce3Co4Sn13 is an extremely heavy cubic heavy fermion system with
a low temperature electronic specific heat of order ~4 J/mol-K2. If the
compound is nonmagnetic, it would be one of the heaviest nonmagnetic Ce-based
heavy fermions reported to date and therefore would be expected to lie
extremely close to a quantum critical point. However, a broad peak of unknown
origin is observed at 0.8 K in the specific heat and magnetic susceptibility,
suggesting the possibility of antiferromagnetic order. We present neutron
diffraction data from polycrystalline samples which do not show any sign of
magnetic scattering below 0.8 K. In addition, we present inelastic neutron
scattering data from a single crystal sample which is consistent with the 1.2 K
energy scale for Kondo spin fluctuations determined from specific heat
measurements.Comment: 4 pages, 2 figures, submitted to J. Mag. Mag. Mater. for ICM 200
The site of ribonucleic acid synthesis in the isolated nucleus
There is still controversy concerning the primary site of RNA synthesis in the cell.(1) When tissues are radioautographed after administration of radioactive inorganic phosphorus or radioactive RNA(2) precursors such as tritiated uridine or cytidine, it is commonly observed that radioactivity appears in the nucleus first and in the cytoplasm later. It has furthermore been shown that isolated nuclei of both animal(3) and plant(4) material are able to synthesize RNA in vitro but that enucleated cytoplasm is unable to carry on such synthesis.(5) Although the problem of whether or not RNA is synthesized in both nucleus and cytoplasm is not completely understood,(6-8) there is increasing cytological evidence that a substantial portion of the cytoplasmic RNA is synthesized in the nucleus (9-17) and subsequently migrates to the cytoplasm
Incorporation of tritiated cytidine into ribonucleic acid by isolated pea nuclei
A new method for the isolation of the nuclei from plant tissue has been devised. This method consists in passing the plant tissue through a set of spring-loaded, counter-rotating rollers and collecting the liberated nuclei in sucrose solution containing calcium ions. A semi-automatic machine which couples the rollers with a special tissue chopping device has been constructed. It has been shown that nuclei obtained in this way actively incorporate cytidine-H3 into RNA. This incorporation is increased in the presence of nucleoside triphosphates and an energy-regenerating system
Nonabelian Berry Phases in Baryons
We show how generic nonabelian gauge fields can be induced in baryons when a
hierarchy of fast degrees of freedom is integrated out. We identify them with
nonabelian Berry potentials and discuss their role in transmuting quantum
numbers in bag and soliton models of baryons. The resulting baryonic spectra
for both light and heavy quark systems are generic and resemble closely the
excitation spectrum of diatomic molecules. The symmetry restoration in the
system, i.e., the electronic rotational invariance in diatomic molecules, the
heavy-quark symmetry in heavy baryons etc. is interpreted in terms of the
vanishing of nonabelian Berry potentials that otherwise govern the hyperfine
splitting.Comment: Latex 35 pages (2 figures not added, will be faxed if requested),
NTG-92-2
Neutrino Interactions In Color-Flavor-Locked Dense Matter
At high density, diquarks could condense in the vacuum with the QCD color
spontaneously broken. Based on the observation that the symmetry breaking
pattern involved in this phenomenon is essentially the same as that of the
Pati-Salam model with broken electroweak--color SU(3) group, we determine the
relevant electroweak interactions in the color-flavor locked (CFL) phase in
high density QCD. We briefly comment on the possible implications on the
cooling of neutron stars.Comment: 13 pages. LaTeX. Talk given at the First KIAS Workshop on
Astrophysics, Seoul, May 2000; V2. references added. comments on cooling
change
The Gluon Spin in the Chiral Bag Model
We study the gluon polarization contribution at the quark model
renormalization scale to the proton spin, , in the chiral bag model. It
is evaluated by taking the expectation value of the forward matrix element of a
local gluon operator in the axial gauge . It is shown that the confining
boundary condition for the color electric field plays an important role. When a
solution satisfying the boundary condition for the color electric field, which
is not the conventionally used but which we favor, is used, the has a
positive value for {\it all} bag radii and its magnitude is comparable to the
quark spin polarization. This results in a significant reduction in the
relative fraction of the proton spin carried by the quark spin, which is
consistent with the small flavor singlet axial current measured in the EMC
experiments.Comment: Corrections to figure
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