7,870 research outputs found
American Anthem: Modern American History
This Teacher\u27s Edition of American Anthem: Modern American History covers the United States Before 1898 and with emphasis on the nation becoming a world power, the First World War, from war to peace, the roaring twenties, the Great Depression, the New Deal, World War II, the Cold War, post-war America, the Civil Rights Movement, the Vietnam War, a conservative era, and into the twenty-first century.https://scholarship.richmond.edu/bookshelf/1282/thumbnail.jp
Recent amplification of an alpha satellite DNA in humans.
A repeat sequence 682 base pairs (bp) long produced by cleavage of human DNA with Xba I restriction enzyme is composed of four tandemly arranged subunits with lengths of 171, 170, 171, and 170 bp each. The sequence organization of the 682 bp Xba I repeat bears a striking resemblance to other complex satellite DNAs of primates, including the Eco RI human alpha satellite family which also occurs as a 170 bp repeat. The Eco RI tetramer and the 682 bp Xba I repeat show a sequence divergence of 21%. The 682 bp Xba I repeat sequence is restricted to humans and is only distantly related to the previously reported 340 bp Xba human repeated DNA sequence. These finding are consistent with the concept of occasional amplifications of members or groups of members of alpha satellite DNA during human evolution. Amplifications apparently occurred after humans, apes and gibbons diverged from Old World monkeys (Eco RI satellite), after humans and apes diverged from gibbons (340 bp Xba I satellite) and after humans diverged from the great apes (682 bp Xba I satellite)
Mapping the 3-D dark matter with weak lensing in COMBO-17
We present a 3-dimensional lensing analysis of the z=0.16 supercluster
A901/2, resulting in a 3-D map of the dark matter distribution within a 3 X
10^{5} [Mpc]^3 volume from the COMBO-17 survey. We perform a chi^2-fit of
isothermal spheres to the tangential shear pattern around each cluster as a
function of redshift to estimate the 3-D positions and masses of the main
clusters in the supercluster from lensing alone. We then present the first 3-D
map of the dark matter gravitational potential field, Phi, using the
Kaiser-Squires (1993) and Taylor (2001) inversion methods. These maps clearly
show the potential wells of the main supercluster components, including a new
cluster behind A902, and demonstrates the applicability of 3-D dark matter
mapping and projection free-mass-selected cluster finding to current data.
Finally, we develop the halo model of dark matter and galaxy clustering and
compare this with the auto-and cross-correlation functions of the 3-D
gravitational potential, galaxy number densities and galaxy luminosity
densities measured in the A901/2 field. We find significant anti-correlations
between the gravitational potential field and the galaxy number density and
luminosities, as expected due to baryonic infall into dark matter
concentrations. We find good agreement with the halo model for the number
densities and luminosity correlation functions.Comment: Submitted to MNRAS; 21 pages, 18 figure
Cosmological constraints from COMBO-17 using 3D weak lensing
We present the first application of the 3D cosmic shear method developed in
Heavens et al. (2006) and the geometric shear-ratio analysis developed in
Taylor et al. (2006), to the COMBO-17 data set. 3D cosmic shear has been used
to analyse galaxies with redshift estimates from two random COMBO-17 fields
covering 0.52 square degrees in total, providing a conditional constraint in
the (sigma_8, Omega_m) plane as well as a conditional constraint on the
equation of state of dark energy, parameterised by a constant w= p/rho c^2. The
(sigma_8, Omega_m) plane analysis constrained the relation between sigma_8 and
Omega_m to be sigma_8(Omega_m/0.3)^{0.57 +- 0.19}=1.06 +0.17 -0.16, in
agreement with a 2D cosmic shear analysis of COMBO-17. The 3D cosmic shear
conditional constraint on w using the two random fields is w=-1.27 +0.64 -0.70.
The geometric shear-ratio analysis has been applied to the A901/2 field, which
contains three small galaxy clusters. Combining the analysis from the A901/2
field, using the geometric shear-ratio analysis, and the two random fields,
using 3D cosmic shear, w is conditionally constrained to w=-1.08 +0.63 -0.58.
The errors presented in this paper are shown to agree with Fisher matrix
predictions made in Heavens et al. (2006) and Taylor et al. (2006). When these
methods are applied to large datasets, as expected soon from surveys such as
Pan-STARRS and VST-KIDS, the dark energy equation of state could be constrained
to an unprecedented degree of accuracy.Comment: 10 pages, 4 figures. Accepted to MNRA
International multicenter, multiplatform study to validate Taipan snake venom time as a lupus anticoagulant screening test with ecarin time as the confirmatory test: communication from the ISTH SSC subcommittee on Lupus Anticoagulant/Antiphospholipid antibodies
Background
Lupus anticoagulant (LA) assays are compromised in anticoagulated patients, and existing strategies to overcome the interferences have limitations. The prothrombin-activating Taipan snake venom time (TSVT) screening test and ecarin time (ET) confirmatory test are innately insensitive to vitamin K antagonists (VKA) and direct factor Xa inhibitors (DFXaI).
Objectives
Validate standardised TSVT/ET reagents for LA detection, in a multi-centre, multi-platform study.
Patients/Methods
Six centres from four countries analysed samples with TSVT/ET from 81 non-anticoagulated patients with LA, patients with established antiphospholipid syndrome (APS) and proven persistent LA who were either not anticoagulated (n=120) or were anticoagulated with VKAs (n=180) or DFXaIs (n=71). Additionally, 339 non-anticoagulated LA-negative patients, and 575 anticoagulated non-APS patients (172 VKA, 403 DFXaI) were tested. Anticoagulant spiking experiments were performed and 112 samples containing potential interferences (i.e. direct thrombin inhibitors) were tested. Results were evaluated against locally derived cut-offs. Imprecision was evaluated.
Results
Cut-offs were remarkably similar despite use of different analysers and donor populations. Cut-offs for TSVT ratio, ET ratio, percent correction and normalised TSVT ratio/ET ratio ranged between 1.08-1.10, 1.09-1.12, 9.3%-14.8% and 1.10-1.15 respectively. Coefficients of variation for TSVT and ET ratios were â¤5.0%. TSVT/ET exhibited sensitivity, specificity, negative and positive predictive values of 78.2%/95.0%/86.3%/91.5% respectively with established APS as the LA-positive population, and 86.9%/95.0%/76.8%/97.4% respectively with triple-positive APS. Interference was seen with direct thrombin inhibitors, unfractionated heparin and low molecular weight heparins, but not VKAs or DFXaIs.
Conclusions
TSVT/ET are validated for LA detection in non-anticoagulated patients and those on VKAs or DFXaIs
The effect of flight line spacing on radioactivity inventory and spatial feature characteristics of airborne gamma-ray spectrometry data
Airborne Gamma Spectrometry (AGS) is well suited to the mapping of radioactivity in the environment. Flight parameters (e.g. speed and line spacing) directly affect the rate of area coverage, cost, and data quality of any survey. The influences of line spacing have been investigated for data from interâtidal, coastal and upland environments with a range of <sup>137</sup>Cs activity concentrations and depositional histories. Estimates of the integrated <sup>137</sup>Cs activity (âinventoryâ) within specified areas and the shapes of depositional features were calculated for subsets of the data at different line spacings. Features with dimensions greater than the line spacing show variations in inventory and area of less than 3%, and features with dimensions less than the line spacing show larger variations and a decreased probability of detection. The choice of line spacing for a task is dependent on the dimensions of the features of interest and required edge definition. Options for line spacing for different tasks are suggested. It is noted that for regional mapping, even 5â10 km line spacing can produce useful data
Theoretical studies of the historical development of the accounting discipline: a review and evidence
Many existing studies of the development of accounting thought have either been atheoretical or have adopted Kuhn's model of scientific growth. The limitations of this 35-year-old model are discussed. Four different general neo-Kuhnian models of scholarly knowledge development are reviewed and compared with reference to an analytical matrix. The models are found to be mutually consistent, with each focusing on a different aspect of development. A composite model is proposed. Based on a hand-crafted database, author co-citation analysis is used to map empirically the entire literature structure of the accounting discipline during two consecutive time periods, 1972â81 and 1982â90. The changing structure of the accounting literature is interpreted using the proposed composite model of scholarly knowledge development
Documenting the NICU design dilemma: comparative patient progress in open-ward and single family room units
Objective:To test the efficacy of single family room (SFR) neonatal intensive care unit (NICU) designs, questions regarding patient medical progress and relative patient safety were explored. Addressing these questions would be of value to hospital staff, administrators and designers alike. Study Design:This prospective study documented, by means of Institution Review Board-approved protocols, the progress of patients in two contrasting NICU designs. Noise levels, illumination and air quality measurements were included to define the two NICU physical environments. Result:Infants in the SFR unit had fewer apneic events, reduced nosocomial sepsis and mortality, as well as earlier transitions to enteral nutrition. More mothers sustained stage III lactation, and more infants were discharged breastfeeding in the SFR. Conclusion:This study showed the SFR to be more conducive to family-centered care, and to enhance infant medical progress and breastfeeding success over that of an open ward
Oxidative stability of sunflower oil bodies
This study investigates the oxidative stability of sunflower oil body suspensions (10 wt-% lipid). Two washed suspensions of oil bodies were evaluated over 8 days at three temperatures (5, 25 and 45 °C) against three comparable sunflower oil emulsions stabilized with dodecyltrimethylammonium bromide (DTAB), polyoxyethylene-sorbitan monolaurate (Tween 20) and sodium dodecyl sulfate (SDS) (17 mM). The development of oxidation was monitored by measuring the presence of lipid hydroperoxides and the formation of hexanal. Lipid hydroperoxide concentrations in the DTAB, SDS and Tween 20 emulsions were consistently higher than in the oil body suspensions; furthermore, hexanal formation was not detected in the oil body emulsions, whereas hexanal was present in the headspace of the formulated emulsions. The reasons for the extended resistance to oxidation of the oil body suspensions are hypothesized to be due to the presence of residual seed proteins in the continuous phase and the presence of a strongly stabilized lipid-water interface. Š 2008 Wiley-VCH Verlag GmbH & Co. KGaA
Male Circumcision at Different Ages in Rwanda: A Cost-Effectiveness Study
Agnes Binagwaho and colleagues predict that circumcision of newborn boys would be effective and cost-saving as a long-term strategy to prevent HIV in Rwanda
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