994 research outputs found
The Urban Unbanked In Mexico And The United States
This paper examines the ways in which lower-income households obtain basic financial services in urban communities in Mexico and the United States. And it discusses the efforts that private sector and government organizations are making to lower the cost or improve the quality of those services. The paper summarizes available information on these issues and assesses the rationale and challenges facing the strategies that both countries are using to improve the financial services available to lower-income households, giving particular attention to unbanked households, meaning households that do not have deposit accounts with any regulated deposit-taking institution, and also to lower-income households in large urban areas. In comparing the experiences of the two countries, the paper reviews the extent to which lower-income households are unbanked, their use of non-bank financial services, and strategies for improving financial services to the unbanked. The underlying differences between the countries\u27 typical household incomes-national income per capita in Mexico in 2002 was US35,060 in the United States (World Bank 2003)-may also influence the difference in percentage of unbanked-9.1 percent of families in the United States compared with 76.4 percent found in a recent study in Mexico City
Scanning detection of mutations in human ornithine transcarbamoylase by chemical mismatch cleavage.
Cloning and expression of a mammalian peptide chain release factor with sequence similarity to tryptophanyl-tRNA synthetases
The termination of protein synthesis is encoded by in-frame nonsense (stop) codons. Most organisms use three nonsense codons: UGA, UAG, and UAA. In contrast to sense codons, which are decoded by specific tRNAs, nonsense codons are decoded by proteins called release factors (RFs). Here we report the cloning of a mammalian RF cDNA by the use of monoclonal antibodies specific for rabbit RF. Functional studies showed that, when expressed in Escherichia coli, the protein encoded by this cDNA has in vitro biochemical characteristics similar to those of previously characterized mammalian RFs. DNA sequencing of this eukaryotic RF cDNA revealed a remarkable sequence similarity to bacterial and mitochondrial tryptophanyl-tRNA synthetases, with the greatest similarity confined to the synthetase active site, and no obvious similarity to bacterial RFs
Laying the groundwork at the AGS: Recent results from experiment E895
The E895 Collaboration at the Brookhaven AGS has performed a systematic
investigation of Au+Au collisions at 2-8 AGeV, using a large-acceptance Time
Projection Chamber. In addition to extensive measurements of particle flow,
spectra, two-particle interferometry, and strangeness production, we have
performed novel hybrid analyses, including azimuthally-sensitive pion HBT,
extraction of the six-dimensional pion phasespace density, and a first
measurement of the Lambda-proton correlation function.Comment: Presented at Quark Matter 2001, 8 pages, 5 figure
Longitudinal Flow of Protons from 2-8 AGeV Central Au+Au Collisions
Rapidity distributions of protons from central Au + Au
collisions measured by the E895 Collaboration in the energy range from 2 to 8
AGeV at the Brookhaven AGS are presented. Longitudinal flow parameters derived
using a thermal model including collective longitudinal expansion are extracted
from these distributions. The results show an approximately linear increase in
the longitudinal flow velocity, , as a function of the
logarithm of beam energy.Comment: 5 Pages, including 3 figures, 1 tabl
Charged Pion Production in 2 to 8 AGeV Central Au+Au Collisions
Momentum spectra of charged pions over nearly full rapidity coverage from
target to beam rapidity have been measured in the 0-5% most central Au+Au
collisions in the beam energy range from 2 to 8 AGeV by the E895 Experiment.
Using a thermal parameterization to fit the transverse mass spectra, rapidity
density distributions are extracted. The observed spectra are compared with
predictions from the RQMD v2.3 cascade model and also to a thermal model
including longitudinal flow. The total 4 yields of the charged pions are
used to infer an initial state entropy produced in the collisions.Comment: 13 pgs, 19 figs, accepted by Phys. Rev. C. Data tables available at
http://nuclear.ucdavis.edu/~e895/published_spectra.htm
Near-threshold production of the multi-strange hyperon
The yield for the multi-strange hyperon has been measured in 6 AGeV
Au+Au collisions via reconstruction of its decay products and
, the latter also being reconstructed from its daughter tracks of
and p. The measurement is rather close to the threshold for
production and therefore provides an important test of model predictions. The
measured yield for and are compared for several
centralities. In central collisions the yield is found to be in
excellent agreement with statistical and transport model predictions,
suggesting that multi-strange hadron production approaches chemical equilibrium
in high baryon density nuclear matter.Comment: Submitted to PR
Three-layer model with absorption for conservative estimation of the maximum acoustic transmission coefficient through the human skull for transcranial ultrasound stimulation.
Transcranial ultrasound stimulation (TUS) has been shown to be a safe and effective technique for non-invasive superficial and deep brain stimulation. Safe and efficient translation to humans requires estimating the acoustic attenuation of the human skull. Nevertheless, there are no international guidelines for estimating the impact of the skull bone. A tissue independent, arbitrary derating was developed by the U.S. Food and Drug Administration to take into account tissue absorption (0.3 dB/cm-MHz) for diagnostic ultrasound. However, for the case of transcranial ultrasound imaging, the FDA model does not take into account the insertion loss induced by the skull bone, nor the absorption by brain tissue. Therefore, the estimated absorption is overly conservative which could potentially limit TUS applications if the same guidelines were to be adopted. Here we propose a three-layer model including bone absorption to calculate the maximum pressure transmission through the human skull for frequencies ranging between 100Â kHz and 1.5Â MHz. The calculated pressure transmission decreases with the frequency and the thickness of the bone, with peaks for each thickness corresponding to a multiple of half the wavelength. The 95th percentile maximum transmission was calculated over the accessible surface of 20 human skulls for 12 typical diameters of the ultrasound beam on the skull surface, and varies between 40% and 78%. To facilitate the safe adjustment of the acoustic pressure for short ultrasound pulses, such as transcranial imaging or transcranial ultrasound stimulation, a table summarizes the maximum pressure transmission for each ultrasound beam diameter and each frequency
Model-independent source imaging using two-pion correlations in 2 to 8A GeV Au + Au collisions
We report a particle source imaging analysis based on two-pion correlations
in high multiplicity Au + Au collisions at beam energies between 2 and 8A GeV.
We apply the imaging technique introduced by Brown and Danielewicz, which
allows a model-independent extraction of source functions with useful accuracy
out to relative pion separations of about 20 fm. The extracted source functions
have Gaussian shapes. Values of source functions at zero separation are almost
constant across the energy range under study. Imaging results are found to be
consistent with conventional source parameters obtained from a multidimensional
HBT analysis.Comment: 4 pages, 3 figure
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