2,838 research outputs found
Federal Reserve control of credit
In the early days of the Federal Reserve, changes in the discount rate were the principal instrument through which the central bank exercised control over credit conditions. In this -address, Strong explains the use of discount rate changes as a means of controlling the volume of credit and influencing interest rate movements. He considers criteria for discount rate changes, concluding that in the absence of gold movements under a reestablished gold standard, policy makers have no option but to look to general economic conditions.Discount ; Federal Reserve banks ; Credit control ; Federal Reserve System - History
The formation of the Federal Reserve System
Federal Reserve System ; Federal Reserve System - History
Continuum Halos in Nearby Galaxies -- an EVLA Survey (CHANG-ES) -- I: Introduction to the Survey
We introduce a new survey to map the radio continuum halos of a sample of 35
edge-on spiral galaxies at 1.5 GHz and 6 GHz in all polarization products. The
survey is exploiting the new wide bandwidth capabilities of the Karl G. Jansky
Very Large Array (i.e. the Expanded Very Large Array, or EVLA) in a variety of
array configurations (B, C, and D) in order to compile the most comprehensive
data set yet obtained for the study of radio halo properties. This is the first
survey of radio halos to include all polarization products.
In this first paper, we outline the scientific motivation of the survey, the
specific science goals, and the expected improvements in noise levels and
spatial coverage from the survey. Our goals include investigating the physical
conditions and origin of halos, characterizing cosmic ray transport and wind
speed, measuring Faraday rotation and mapping the magnetic field, probing the
in-disk and extraplanar far-infrared - radio continuum relation, and
reconciling non-thermal radio emission with high-energy gamma-ray models. The
sample size allows us to search for correlations between radio halos and other
properties, including environment, star formation rate, and the presence of
AGNs. In a companion paper (Paper II) we outline the data reduction steps and
present the first results of the survey for the galaxy, NGC 4631.Comment: 17 pages, 1 figure, accepted to the Astronomical Journal, Version 2
changes: added acknowledgement to NRA
Factors Associated with Marburg Hemorrhagic Fever:
Background. Reliable on-site polymerase chain reaction (PCR) testing for Marburg hemorrhagic fever (MHF)
is not always available. Therefore, clinicians triage patients on the basis of presenting symptoms and contact history.
Using patient data collected in Uige, Angola, in 2005, we assessed the sensitivity and specificity of these factors
to evaluate the validity of World Health Organization (WHO)–recommended case definitions for MHF.
Methods. Multivariable logistic regression was used to identify independent predictors of PCR confirmation
of MHF. A data-derived algorithm was developed to obtain new MHF case definitions with improved sensitivity
and specificity.
Results. A MHF case definition comprising (1) an epidemiological link or (2) the combination of myalgia or
arthralgia and any hemorrhage could potentially serve as an alternative to current case definitions. Our dataderived
case definitions maintained the sensitivity and improved the specificity of current WHO-recommended
case definitions.
Conclusions. Continued efforts to improve clinical documentation during filovirus outbreaks would aid in
the refinement of case definitions and facilitate outbreak control
Physical Properties and Galactic Distribution of Molecular Clouds identified in the Galactic Ring Survey
We derive the physical properties of 580 molecular clouds based on their 12CO
and 13CO line emission detected in the University of Massachusetts-Stony Brook
(UMSB) and Galactic Ring surveys. We provide a range of values of the physical
properties of molecular clouds, and find a power-law correlation between their
radii and masses, suggesting that the fractal dimension of the ISM is around
2.36. This relation, M = (228 +/- 18) R^{2.36+/-0.04}, allows us to derive
masses for an additional 170 GRS molecular clouds not covered by the UMSB
survey. We derive the Galactic surface mass density of molecular gas and
examine its spatial variations throughout the Galaxy. We find that the
azimuthally averaged Galactic surface density of molecular gas peaks between
Galactocentric radii of 4 and 5 kpc. Although the Perseus arm is not detected
in molecular gas, the Galactic surface density of molecular gas is enhanced
along the positions of the Scutum-Crux and Sagittarius arms. This may indicate
that molecular clouds form in spiral arms and are disrupted in the inter-arm
space. Last, we find that the CO excitation temperature of molecular clouds
decreases away from the Galactic center, suggesting a possible decline in the
star formation rate with Galactocentric radius. There is a marginally
significant enhancement in the CO excitation temperature of molecular clouds at
a Galactocentric radius of about 6 kpc, which in the longitude range of the GRS
corresponds to the Sagittarius arm. This temperature increase could be
associated with massive star formation in the Sagittarius spiral arm
Recommended from our members
Autoreactivity and Exceptional CDR Plasticity (but Not Unusual Polyspecificity) Hinder Elicitation of the Anti-HIV Antibody 4E10
The broadly-neutralizing anti-HIV antibody 4E10 recognizes an epitope in the membrane-proximal external region of the HIV envelope protein gp41. Previous attempts to elicit 4E10 by vaccination with envelope-derived or reverse-engineered immunogens have failed. It was presumed that the ontogeny of 4E10-equivalent responses was blocked by inherent autoreactivity and exceptional polyreactivity. We generated 4E10 heavy-chain knock-in mice, which displayed significant B cell dysregulation, consistent with recognition of autoantigen/s by 4E10 and the presumption that tolerance mechanisms may hinder the elicitation of 4E10 or 4E10-equivalent responses. Previously proposed candidate 4E10 autoantigens include the mitochondrial lipid cardiolipin and a nuclear splicing factor, 3B3. However, using carefully-controlled assays, 4E10 bound only weakly to cardiolipin-containing liposomes, but also bound negatively-charged, non-cardiolipin-containing liposomes comparably poorly. 4E10/liposome binding was predominantly mediated by electrostatic interactions rather than presumed hydrophobic interactions. The crystal structure of 4E10 free of bound ligands showed a dramatic restructuring of the combining site, occluding the HIV epitope binding site and revealing profound flexibility, but creating an electropositive pocket consistent with non-specific binding of phospholipid headgroups. These results strongly suggested that antigens other than cardiolipin mediate 4E10 autoreactivity. Using a synthetic peptide library spanning the human proteome, we determined that 4E10 displays limited and focused, but unexceptional, polyspecificity. We also identified a novel autoepitope shared by three ER-resident inositol trisphosphate receptors, validated through binding studies and immunohistochemistry. Tissue staining with 4E10 demonstrated reactivity consistent with the type 1 inositol trisphosphate receptor as the most likely candidate autoantigen, but is inconsistent with splicing factor 3B3. These results demonstrate that 4E10 recognition of liposomes competes with MPER recognition and that HIV antigen and autoepitope recognition may be distinct enough to permit eliciting 4E10-like antibodies, evading autoimmunity through directed engineering. However, 4E10 combining site flexibility, exceptional for a highly-matured antibody, may preclude eliciting 4E10 by conventional immunization strategies
Assessing health and well-being among older people in rural South Africa
Background: The population in developing countries is ageing, which is likely to increase the burden of noncommunicable diseases and disability.
Objective: To describe factors associated with self-reported health, disability and quality of life (QoL) of older people in the rural northeast of South Africa.
Design: Cross-sectional survey of 6,206 individuals aged 50 and over. We used multivariate analysis to examine relationships between demographic variables and measures of self-reported health (Health Status), functional ability (WHODASi) and quality of life (WHOQoL).
Results: About 4,085 of 6,206 people eligible (65.8%) completed the interview. Women (Odds Ratio (OR)
1.30, 95% CI 1.09, 1.55), older age (OR2.59, 95% CI 1.97, 3.40), lower education (OR1.62, 95% CI 1.31,2.00), single status (OR1.18, 95% CI 1.01, 1.37) and not working at present (OR1.29, 95% CI 1.06, 1.59) were associated with a low health status. Women were also more likely to report a higher level of disability (OR1.38, 95% CI 1.14, 1.66), as were older people (OR2.92, 95% CI 2.25, 3.78), those with no education (OR1.57, 95% CI 1.26, 1.97), with single status (OR1.25, 95% CI 1.06, 1.46) and not working at present (OR1.33, 95% CI 1.06, 1.66). Older age (OR1.35, 95% CI 1.06, 1.74), no education (OR1.39, 95% CI
1.11, 1.73), single status (OR1.28, 95% CI 1.10, 1.49), a low household asset score (OR1.52, 95% CI 1.19,
1.94) and not working at present (OR1.32; 95% CI 1.07, 1.64) were all associated with lower quality of life.
Conclusions: This study presents the first population-based data from South Africa on health status, functional ability and quality of life among older people. Health and social services will need to be restructured to provide effective care for older people living in rural South Africa with impaired functionality and other health problems
Obesity inhibits the osteogenic differentiation of human adipose-derived stem cells
Additional file 3: Figure S3. No observable differences in lnASCs and obASCs during early bone regeneration. Critical size calvarial defects were created in the parietal bone of nude mice and assessed after 2 weeks. (A) Representative images of microCT scanning. (B) Quantification of microCT. Scale bar represents 1 mm. Bars, Âą SEM
Unveiling the molecular environment of the ring nebula RCW 78
We present a study of the ionized, neutral atomic, and molecular gas
associated with the ring nebula RCW 78 around the WR star HD 117688 (= WR 55).
We based our study on CO observations carried out with the SEST and NANTEN
telescopes. We report the detection of molecular gas with velocities in the
range -56 to -33 km/s. The CO emission is mainly connected to the western
section, with a total molecular mass of 1.3 x 10^5 solar masses. The analysis
of the HI gas distribution reveals the HI envelope of the molecular cloud,
while the radio continuum emission shows a ring-like structure, which is the
radio counterpart of the optical nebula. The gas distribution is compatible
with the western section of RCW 78 having originated in the photodissociation
and ionization of the molecular gas by HD 117688, and with the action of the
stellar winds of the WR star. A number of infrared point sources classified as
YSO candidates showed that stellar formation activity is present in the
molecular gas linked to the nebula. The fact that the expansion of the bubble
have triggered star formation in this region can not be discarded.Comment: 15 pages, 11 Postscript figures, to be published in A&
Spatial distribution of interstellar gas in the innermost 3 kpc of our Galaxy
We review the present observational knowledge on the spatial distribution and
the physical state of the different (molecular, atomic and ionized) components
of the interstellar gas in the innermost 3 kpc of our Galaxy -- a region which
we refer to as the interstellar Galactic bulge, to distinguish it from its
stellar counterpart. We try to interpret the observations in the framework of
recent dynamical models of interstellar gas flows in the gravitational
potential of a barred galaxy. Finally, relying on both the relevant
observations and their theoretical interpretation, we propose a model for the
space-averaged density of each component of the interstellar gas in the
interstellar Galactic bulge.Comment: 19 pages, 11 figure
- …
