2,913 research outputs found
Poverty and income maintenance in old age: A cross-national view of low income older women
Great strides have been made in reducing poverty amongst the elderly in most rich countries over the past forty years. But pensioner poverty has not been eradicated, especially in the English-speaking nations. Poverty rates amongst older women are much higher than those for older men and much higher in the United States compared to other nations. In general, poverty rates rise with both age and changes in living arrangements though living alone has a larger effect for women. Poverty rates among older women are highest amongst the divorced, widowed and never- married, groups whose prevalence within the elder population will rise significantly over the next decades. The challenge for policy makers is to design systems of retirement benefits that guarantee minimum standards of living for all elderly women while also preserving incentives for self-financed retirement
Superfield algorithm for higher order gauge field theories
We propose an algorithm for the construction of higher order gauge field
theories from a superfield formulation within the Batalin-Vilkovisky formalism.
This is a generalization of the superfield algorithm recently considered by
Batalin and Marnelius. This generalization seems to allow for non-topological
gauge field theories as well as alternative representations of topological
ones. A five dimensional non-abelian Chern-Simons theory and a topological
Yang-Mills theory are treated as examples.Comment: 17 pages in LaTeX, improved text, published versio
Autocrine production of extracellular catalase prevents apoptosis of the human CEM T-cell line in serum-free medium.
CCRF-CEM is a human T-cell line originally isolated from a child with acute lymphoblastic leukemia. At cell densities > 2 x 10 cells per ml, CEM cells grow in serum-free medium, but at lower cell densities the cultures rapidly undergo apoptosis, or programmed cell death. The viability of lowdensity CEM cells could be preserved by supplementing the serum-free medium with "conditioned" medium from highdensity CEM cultures, but a variety of known growth factors and lymphokines were ineffective. Fractionation ofconditioned medium by sequential chromatography on DEAE-cellulose, propyl agarose, chromatofocusing, and hydrophobic-interaction HPLC resulted in the isolation of a 60-kDa protein capable of sustaining CEM growth in the absence ofserum. The active protein was identified as human catalase based on its amino acid sequence and composition and was subsequently shown to exhibit catalase activity and to be replaceable by human erythrocyte catalase or bovine liver catalase. Comparison of the level of intracellular catalase activity with the amount released into the culture medium demonstrated that the latter accounted for <3% of the total catalase activity present in the cell culture. These findings show that, despite its low amount, the catalase released by CEM cells, and perhaps by T cells in general, provides a critical rust Ilne of defense against hydrogen peroxide (11202) present in the extracellular milieu. Originally published Proceedings of the National Academy of Sciences, Vol. 90, No. 10, May 199
The Small Magellanic Cloud Investigation of Dust and Gas Evolution (SMIDGE): The Dust Extinction Curve from Red Clump Stars
We use Hubble Space Telescope (HST) observations of red clump stars taken as
part of the Small Magellanic Cloud Investigation of Dust and Gas Evolution
(SMIDGE) program to measure the average dust extinction curve in a ~ 200 pc x
100 pc region in the southwest bar of the Small Magellanic Cloud (SMC). The
rich information provided by our 8-band ultra-violet through near-infrared
photometry allows us to model the color-magnitude diagram of the red clump
accounting for the extinction curve shape, a log-normal distribution of
, and the depth of the stellar distribution along the line of sight. We
measure an extinction curve with = 2.65
0.11. This measurement is significantly larger than the equivalent values
of published Milky Way = 3.1 () and SMC Bar =
2.74 () extinction curves. Similar extinction curve offsets in
the Large Magellanic Cloud (LMC) have been interpreted as the effect of large
dust grains. We demonstrate that the line-of-sight depth of the SMC (and LMC)
introduces an apparent "gray" contribution to the extinction curve inferred
from the morphology of the red clump. We show that no gray dust component is
needed to explain extinction curve measurements when a full-width half-max
depth of 10 2 kpc in the stellar distribution of the SMC (5 1 kpc
for the LMC) is considered, which agrees with recent studies of Magellanic
Cloud stellar structure. The results of our work demonstrate the power of
broad-band HST imaging for simultaneously constraining dust and galactic
structure outside the Milky Way.Comment: 16 pages, 12 figures, 5 tables. Accepted for publication in Ap
Predicting musically induced emotions from physiological inputs: linear and neural network models
Listening to music often leads to physiological responses. Do these physiological responses contain sufficient information to infer emotion induced in the listener? The current study explores this question by attempting to predict judgments of ?felt? emotion from physiological responses alone using linear and neural network models. We measured five channels of peripheral physiology from 20 participants?heart rate (HR), respiration, galvanic skin response, and activity in corrugator supercilii and zygomaticus major facial muscles. Using valence and arousal (VA) dimensions, participants rated their felt emotion after listening to each of 12 classical music excerpts. After extracting features from the five channels, we examined their correlation with VA ratings, and then performed multiple linear regression to see if a linear relationship between the physiological responses could account for the ratings. Although linear models predicted a significant amount of variance in arousal ratings, they were unable to do so with valence ratings. We then used a neural network to provide a non-linear account of the ratings. The network was trained on the mean ratings of eight of the 12 excerpts and tested on the remainder. Performance of the neural network confirms that physiological responses alone can be used to predict musically induced emotion. The non-linear model derived from the neural network was more accurate than linear models derived from multiple linear regression, particularly along the valence dimension. A secondary analysis allowed us to quantify the relative contributions of inputs to the non-linear model. The study represents a novel approach to understanding the complex relationship between physiological responses and musically induced emotion
The Structure of a Low-Metallicity Giant Molecular Cloud Complex
To understand the impact of low metallicities on giant molecular cloud (GMC)
structure, we compare far infrared dust emission, CO emission, and dynamics in
the star-forming complex N83 in the Wing of the Small Magellanic Cloud. Dust
emission (measured by Spitzer as part of the S3MC and SAGE-SMC surveys) probes
the total gas column independent of molecular line emission and traces
shielding from photodissociating radiation. We calibrate a method to estimate
the dust column using only the high-resolution Spitzer data and verify that
dust traces the ISM in the HI-dominated region around N83. This allows us to
resolve the relative structures of H2, dust, and CO within a giant molecular
cloud complex, one of the first times such a measurement has been made in a
low-metallicity galaxy. Our results support the hypothesis that CO is
photodissociated while H2 self-shields in the outer parts of low-metallicity
GMCs, so that dust/self shielding is the primary factor determining the
distribution of CO emission. Four pieces of evidence support this view. First,
the CO-to-H2 conversion factor averaged over the whole cloud is very high 4-11
\times 10^21 cm^-2/(K km/s), or 20-55 times the Galactic value. Second, the
CO-to-H2 conversion factor varies across the complex, with its lowest (most
nearly Galactic) values near the CO peaks. Third, bright CO emission is largely
confined to regions of relatively high line-of-sight extinction, A_V >~ 2 mag,
in agreement with PDR models and Galactic observations. Fourth, a simple model
in which CO emerges from a smaller sphere nested inside a larger cloud can
roughly relate the H2 masses measured from CO kinematics and dust.Comment: 17 pages, 10 figures (including appendix), accepted for publication
in the Astrophysical Journa
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