71,932 research outputs found
An Incomes Policy for the Professions: the Dutch Experience
In 1951 the United States began moving toward an incomes policy, an attempt to end postwar wage and price inflation by linking changes in these prices to gains in productivity. Other countries later followed suit; some countries had already adopted wage and price control policies. The Netherlands moved toward an incomes policy immediately after World War II. Initially, the Dutch program involved wages only, but in the 1970s it became an accepted principle that private professional income should be comparable with the salaries of government officials and civil servants with comparable training and responsibilities. In the Netherlands (as in the United States and, before medicine was socialized, the United Kingdom) health professionals operate on a fee-for-service basis and their incomes escalated as a result of both inflation and monopoly power. So they were subjected to the incomes policy. The policy's effectiveness in curbing income escalation cannot be determined with certainty—reliable data are lacking. However, the evidence indicates that the policy failed to achieve its original purpose.Incomes policy, Netherlands
First Detection of Molecular Gas in the Shells of CenA
Shells are faint arc-like stellar structures, which have been observed around
early type galaxies and are thought to be the result of an interaction. HI gas
has recently been detected in shells, a surprising result in view of the
theoretical predictions that most of the gas should decouple from stars and
fall into the nucleus in such interactions. Here we report the first detection
of molecular gas (CO) in shells, found 15kpc away from the center of NGC5128
(CenA), a giant elliptical galaxy that harbors an active nucleus (AGN). The
ratio between CO and HI emission in the shells is the same as that found in the
central regions, which is unexpected given the metallicity gradient usually
observed in galaxies. We propose that the dynamics of the gas can be understood
within the standard picture of shell formation if one takes into account that
the interstellar medium is clumpy and hence not highly dissipative. The
observed metal enrichment could be due to star formation induced by the AGN jet
in the shells. Furthermore our observations provide evidence that molecular gas
in mergers may be spread out far from the nuclear regions.Comment: Accepted for publication in Astronomy & Astrophysics Letters, (Vol.
356), 4 pages + 1 color figur
Hansenula polymorpha: An attractive model organism for molecular studies of peroxisome biogenesis and function
In wild-type Hansenula polymorpha the proliferation of peroxisomes is induced by various unconventional carbon- and nitrogen sources. Highest induction levels, up to 80% of the cytoplasmic volume, are observed in cells grown in methanol-limited chemostat cultures. Based on our accumulated experience, we are now able to precisely adjust both the level of peroxisome induction as well as their protein composition by specific adaptations in growth conditions.
During the last few years a series of peroxisome-deficient (per) mutants of H. polymorpha have been isolated and characterized. Phenotypically these mutants are characterized by the fact that they are not able to grow on methanol. Three mutant phenotypes were defined on the basis of morphological criteria, namely: (a) mutants completely lacking peroxisomes (Per-; 13 complementation groups); (b) mutants containing few small peroxisomes which are partly impaired in the peroxisomal import of matrix proteins (Pim-; five complementation groups); and (c) mutants with aberrations in the peroxisomal substructure (Pss-; two complementation groups). In addition, several conditional Per-, Pim- and Pss- mutants have been obtained. In all cases the mutant phenotype was shown to be caused by a recessive mutation in one gene. However, we observed that different mutations in one gene may cause different morphological mutant phenotypes. A detailed genetic analysis revealed that several PER genes, essential for peroxisome biogenesis, are tightly linked and organized in a hierarchical fashion.
The use of both constitual and conditional per mutants in current and future studies of the molecular mechanisms controlling peroxisome biogenesis and function is discussed.
Multinucleon Mechanisms in (,N) and (,NN) Reactions
The similarities in the experimental indications for multinucleon mechanisms
in and processes are pointed out. For both types of
reactions, the substantial role of two-nucleon emission processes for
transitions to high excitation energies in the residual nucleus is stressed. A
microscopic model for the calculation of the two-body knockout contributions to
the inclusive reaction is presented. It is based on an
unfactorized formalism for the calculation of electromagnetically induced
two-nucleon emission cross sections. The model is shown to yield a reasonable
description of the overall behaviour of the C and
C data at high excitation energies in the residual nucleus.
In the calculations effects from non-resonant and resonant pion exchange
currents are included. Photoabsorption on these currents are predicted to
produce the major contributions to the exclusive OO
process at photonenergies above the pion threshold. Double differential cross
sections for photon induced and emission from O are calculated
and compared with the data.Comment: 18 pages, Revtex 3.0, 13 figures (available upon request),
SSF93-10-0
A deep learning approach to diabetic blood glucose prediction
We consider the question of 30-minute prediction of blood glucose levels
measured by continuous glucose monitoring devices, using clinical data. While
most studies of this nature deal with one patient at a time, we take a certain
percentage of patients in the data set as training data, and test on the
remainder of the patients; i.e., the machine need not re-calibrate on the new
patients in the data set. We demonstrate how deep learning can outperform
shallow networks in this example. One novelty is to demonstrate how a
parsimonious deep representation can be constructed using domain knowledge
Population synthesis of classical low-mass X-ray binaries in the Galactic Bulge
Aims. We model the present-day population of 'classical' low-mass X-ray
binaries (LMXBs) with neutron star accretors, which have hydrogen-rich donor
stars. Their population is compared with that of hydrogen-deficient LMXBs,
known as ultracompact X-ray binaries (UCXBs). We model the observable LMXB
population and compare it to observations. Methods. We combine the binary
population synthesis code SeBa with detailed LMXB evolutionary tracks to model
the size and properties of the present-day LMXB population in the Galactic
Bulge. Whether sources are persistent or transient, and what their
instantaneous X-ray luminosities are, is predicted using the thermal-viscous
disk instability model. Results. We find a population of ~2.1 x 10^3 LMXBs with
neutron star accretors. Of these about 15 - 40 are expected to be persistent
(depending on model assumptions), with luminosities higher than 10^35 erg s^-1.
About 7 - 20 transient sources are expected to be in outburst at any given
time. Within a factor of two these numbers are consistent with the observed
population of bright LMXBs in the Bulge. This gives credence to our prediction
of the existence of a population of ~1.6 x 10^3 LMXBs with low donor masses
that have gone through the period minimum, and have present-day mass transfer
rates below 10^-11 Msun yr^-1. Conclusions. Even though the observed population
of hydrogen-rich LMXBs in the Bulge is larger than the observed population of
(hydrogen-deficient) UCXBs, the latter have a higher formation rate. While
UCXBs may dominate the total LMXB population at the present, the majority would
be very faint, or may have become detached and produced millisecond radio
pulsars. In that case UCXBs would contribute significantly more to the
formation of millisecond radio pulsars than hydrogen-rich LMXBs. [abridged]Comment: 8 pages, 10 figures. Accepted for publication in Astronomy and
Astrophysics. v2: minor language correction
The exclusive (e,ep) reaction at high missing momenta
The reduced (e,ep) cross section is calculated for kinematics that probe
high missing momenta. The final-state interaction is handled within a
non-relativistic many-body framework. One- and two-body nuclear currents are
included. Electron distortion effects are treated in an exact distorted wave
calculation. It is shown that at high missing momenta the calculated (e,ep)
cross sections exhibit a pronounced sensitivity to ground-state correlations of
the RPA type and two-body currents. The role of these mechanisms is found to be
relatively small at low missing momenta.Comment: 15 pages in REVtex with embedded psfigure
Universality check of Abelian Monopoles
We study the Abelian projected SU(2) lattice gauge theory after gauge fixing
to the maximally Abelian gauge (MAG). In order to check the universality of the
Abelian dominance we employ the tadpole improved tree level (TI) action. We
show that the density of monopoles in the largest cluster (the IR component) is
finite in the continuum limit which is approximated already at relatively large
lattice spacing. The value itself is smaller than in the case of Wilson action.
We present results for the ratio of the Abelian to non-Abelian string tension
for both Wilson and TI actions for a number of lattice spacings in the range
0.06 fm < a < 0.35 fm. These results show that the ratio is between 0.9 and
0.95 for all considered values of lattice couplings and both actions. We
compare the properties of the monopole clusters in two gauges - in MAG and in
the Laplacian Abelian gauge (LAG). Whereas in MAG the infrared component of the
monopole density shows a good convergence to the continuum limit, we find that
in LAG it is even not clear whether a finite limit exists.Comment: 18 pages, 11 figure
Large cone angle magnetization precession of an individual nanomagnet with dc electrical detection
We demonstrate on-chip resonant driving of large cone-angle magnetization
precession of an individual nanoscale permalloy element. Strong driving is
realized by locating the element in close proximity to the shorted end of a
coplanar strip waveguide, which generates a microwave magnetic field. We used a
microwave frequency modulation method to accurately measure resonant changes of
the dc anisotropic magnetoresistance. Precession cone angles up to are
determined with better than one degree of resolution. The resonance peak shape
is well-described by the Landau-Lifshitz-Gilbert equation
Control of recollision wave packets for molecular orbital tomography using short laser pulses
The tomographic imaging of arbitrary molecular orbitals via high-order
harmonic generation requires that electrons recollide from one direction only.
Within a semi-classical model, we show that extremely short phase-stabilized
laser pulses offer control over the momentum distribution of the returning
electrons. By adjusting the carrier-envelope phase, recollisions can be forced
to occur from mainly one side, while retaining a broad energy spectrum. The
signatures of the semi-classical distributions are observed in harmonic spectra
obtained by numerical solution of the time-dependent Schr\"{o}dinger equation.Comment: 8 pages, 4 figures; v2: Added some extra clarifications; v3: minor
grammatical change
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