635 research outputs found
Disability Pension Rates Among Immigrants in Norway
Immigrants from low-income countries are more likely than ethnic Norwegians to receive disability pensions. In a previous study in Oslo, we showed that occupational position probably accounted for all of this difference. The present article presents a study of the total population, with data on education and age at receipt of pension. Census and social security data for all persons living in Norway from 1992 to 2003 were used to identify new disability pensions to those aged 30–55 years and eligible in 1992, comprising 15.9% females and 11.4% males. Age-adjusted relative risk was 2.03 (95% CI 1.97–2.08) for non-Western males and 1.30 (1.26–1.36) for non-Western females compared with Westerners, and more than three times higher for males from North Africa/the Middle East. Education did not explain any of the risk differences, but when adjusting for age at pension receipt the differences disappeared completely. This is probably due to their being in predominantly unskilled occupations where there is also a low pension age among ethnic Norwegians
Analysis of the loop length distribution for the negative weight percolation problem in dimensions d=2 through 6
We consider the negative weight percolation (NWP) problem on hypercubic
lattice graphs with fully periodic boundary conditions in all relevant
dimensions from d=2 to the upper critical dimension d=6. The problem exhibits
edge weights drawn from disorder distributions that allow for weights of either
sign. We are interested in in the full ensemble of loops with negative weight,
i.e. non-trivial (system spanning) loops as well as topologically trivial
("small") loops. The NWP phenomenon refers to the disorder driven proliferation
of system spanning loops of total negative weight. While previous studies where
focused on the latter loops, we here put under scrutiny the ensemble of small
loops. Our aim is to characterize -using this extensive and exhaustive
numerical study- the loop length distribution of the small loops right at and
below the critical point of the hypercubic setups by means of two independent
critical exponents. These can further be related to the results of previous
finite-size scaling analyses carried out for the system spanning loops. For the
numerical simulations we employed a mapping of the NWP model to a combinatorial
optimization problem that can be solved exactly by using sophisticated matching
algorithms. This allowed us to study here numerically exact very large systems
with high statistics.Comment: 7 pages, 4 figures, 2 tables, paper summary available at
http://www.papercore.org/Kajantie2000. arXiv admin note: substantial text
overlap with arXiv:1003.1591, arXiv:1005.5637, arXiv:1107.174
MSX versus IRAS Two-Color Diagrams and the CSE-Sequence of Oxygen-Rich Late-Type Stars
We present MSX two-color diagrams that can be used to characterize
circumstellar environments of sources with good quality MSX colors in terms of
IRAS color regions for oxygen-rich stars. With these diagrams we aim to provide
a new tool that can be used to study circumstellar environments and to improve
detection rates for targeted surveys for circumstellar maser emission similar
to the IRAS two-color diagram. This new tool is especially useful for regions
in the sky where IRAS was confused, in particular in the Galactic plane and
bulge region. Unfortunately, using MSX colors alone does not allow to
distinguish between carbon-rich and oxygen-rich objects. An application of this
tool on 86 GHz SiO masers shows that for this type of masers an instantaneous
detection rate of 60% to 80% can be achieved if target sources are selected
according to MSX color (region).
Our investigations may have revealed an error in the MSX point source catalog
version 2.3. That is, the photometry of the 21.3 m (MSX E filter) band for
most weak 8.28 m (or MSX A filter) band sources seems off by about a
factor two (0.5--1 magnitude too bright).Comment: accepted to Astrophysical Journal, 11 pages, 11 figs of which 1 in
colo
A highly-collimated SiO jet in the HH212 protostellar outflow
We mapped the HH212 Class 0 outflow in SiO(2--1, 5--4) and continuum using
the PdBI in its extended configurations. The unprecedented angular resolution
(down to 0.34") allows accurate comparison with a new, deep H2 image obtained
at the VLT. The SiO emission is confined to a highly-collimated bipolar jet
(width 0.35") along the outflow axis. The jet can be traced down to within 500
AU of the protostar, in a region that is heavily obscured in H2 images. Where
both species are detected, SiO shows the same overall kinematics and structure
as H2, indicating that both molecules are tracing the same material. We find
that the high-velocity SiO gas near the protostar is not tracing a wide-angle
wind but is already confined to a flow inside a narrow cone of half-opening
angle < 6 deg.Comment: Astronomy and Astrophysics Letter, in pres
The magnetic field of IRAS 16293-2422 as traced by shock-induced H2O masers
Shock-induced H2O masers are important magnetic field tracers at very high
density gas. Water masers are found in both high- and low-mass star-forming
regions, acting as a powerful tool to compare magnetic field morphologies in
both mass regimes. In this paper, we show one of the first magnetic field
determinations in the low-mass protostellar core IRAS 16293-2422 at volume
densities as high as 10^(8-10) cm^-3. Our goal is to discern if the collapsing
regime of this source is controlled by magnetic fields or other factors like
turbulence. We used the Very Large Array (VLA) to carry out
spectro-polarimetric observations in the 22 GHz Zeeman emission of H2O masers.
From the Stokes V line profile, we can estimate the magnetic field strength in
the dense regions around the protostar. A blend of at least three maser
features can be inferred from our relatively high spatial resolution data set
(~ 0.1"), which is reproduced in a clear non-Gaussian line profile. The
emission is very stable in polarization fraction and position angle across the
channels. The maser spots are aligned with some components of the complex
outflow configuration of IRAS 16293-2422, and they are excited in zones of
compressed gas produced by shocks. The post-shock particle density is in the
range of 1-3 x 10^9 cm^-3, consistent with typical water masers pumping
densities. Zeeman emission is produced by a very strong line-of-sight magnetic
field (B ~ 113 mG). The magnetic field pressure derived from our data is
comparable to the ram pressure of the outflow dynamics. This indicates that the
magnetic field is energetically important in the dynamical evolution of IRAS
16293-2422.Comment: 7 pages, 6 figures, accepted for publication in A&
Memory difference control of unknown unstable fixed points: Drifting parameter conditions and delayed measurement
Difference control schemes for controlling unstable fixed points become
important if the exact position of the fixed point is unavailable or moving due
to drifting parameters. We propose a memory difference control method for
stabilization of a priori unknown unstable fixed points by introducing a memory
term. If the amplitude of the control applied in the previous time step is
added to the present control signal, fixed points with arbitrary Lyapunov
numbers can be controlled. This method is also extended to compensate arbitrary
time steps of measurement delay. We show that our method stabilizes orbits of
the Chua circuit where ordinary difference control fails.Comment: 5 pages, 8 figures. See also chao-dyn/9810029 (Phys. Rev. E 70,
056225) and nlin.CD/0204031 (Phys. Rev. E 70, 046205
Pulmonary Hypertension in Patients with Chronic Fibrosing Idiopathic Interstitial Pneumonias
Background Pulmonary hypertension (PH) is a common finding in patients with chronic fibrosing idiopathic interstitial pneumonias (IIP). Little is known about the response to pulmonary vasodilator therapy in this patient population. COMPERA is an international registry that prospectively captures data from patients with various forms of PH receiving pulmonary vasodilator therapies. Methods We retrieved data from COMPERA to compare patient characteristics, treatment patterns, response to therapy and survival in newly diagnosed patients with idiopathic pulmonary arterial hypertension (IPAH) and PH associated with IIP (PH-IIP). Results Compared to patients with IPAH (n = 798), patients with PH-IIP (n = 151) were older and predominantly males. Patients with PH-IIP were treated predominantly with phosphodiesterase-5 inhibitors (88% at entry, 87% after 1 year). From baseline to the first follow-up visit, the median improvement in 6MWD was 30 m in patients with IPAH and 24.5 m in patients with PH-IIP (p = 0.457 for the difference between both groups). Improvements in NYHA functional class were observed in 22.4% and 29.5% of these patients, respectively (p = 0.179 for the difference between both groups). Survival rates were significantly worse in PH-IIP than in IPAH (3-year survival 34.0 versus 68.6%; p<0.001). Total lung capacity, NYHA class IV, and mixed-venous oxygen saturation were independent predictors of survival in patients with PH-IIP. Conclusions Patients with PH-IIP have a dismal prognosis. Our results suggest that pulmonary vasodilator therapy may be associated with short-term functional improvement in some of these patients but it is unclear whether this treatment affects survival
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