6,822 research outputs found
The Hand in the Brew: Judges and Their Communities
Reviewing: Paul W. Kahn, Making the Case: The Art of the Judicial Opinion (Yale University Press 2016); Douglas E. Edlin, Common Law Judging: Subjectivity, Impartiality, and the Making of Law (University of Michigan Press 2016)
Coupling Strategies for the Synthesis of Peptide-Oligonucleotide Conjugates for Patterned Synthetic Biomineralization
This work describes preparation strategies for peptide-oligonucleotide conjugates that combine the self-assembling behavior of DNA oligonucleotides with the molecular recognition capabilities of peptides. The syntheses include a solution-phase fragment coupling reaction and a solid-phase fragment coupling strategy where the oligonucleotide has been immobilized on DEAE Sepharose. The yield of four coupling reagents is evaluated, two reagents in water, EDC (1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride) and DMTMM (4-(4,6-dimethoxy[1,3,5]triazin-2-yl)-4-methyl-morpholinium chloride), and two in dimethylformamide (DMF), PyBOP ((Benzotriazol-1-yloxy) tripyrrolidinophosphonium hexafluorophosphate) and HBTU (O-benzotriazole-N,N,N′,N′-tetramethyluronium hexafluorophosphate), while the oligonucleotide fragment is either in solution or immobilized on DEAE. These coupling strategies rely on an unprotected 5′ amino linker on the oligonucleotide reacting with the peptide C-terminus. The peptide, selected from a combinatorial library for its gold-binding behavior, was 12 amino acids long with an N-terminus acetyl cap. Formation of the conjugates was confirmed by gel electrophoresis and mass spectrometry while molecular recognition functionality of the peptide portion was verified using atomic force microscopy. Solution-phase yields were superior to their solid-phase counterparts. EDC resulted in the highest yield for both solution-phase (95%) and solid-phase strategies (24%), while the DMF-based reagents, PyBOP and HBTU, resulted in low yields with reduced recovery. All recoverable conjugates demonstrated gold nanoparticle templating capability
Stress-life relation of the rolling-contact fatigue spin rig
The rolling-contact fatigue spin rig was used to test groups of SAE 52100 9.16-inch-diameter balls lubricated with a mineral oil at 600,000-, 675,000-, and 750,000-psi maximum Hertz stress. Cylinders of AISI M-1 vacuum and commercial melts and MV-1 (AISI M-50) were used as race specimens. Stress-life exponents produced agree closely with values accepted in industry. The type of failure obtained in the spin rig was similar to the subsurface fatigue spells found in bearings
Post-Newtonian expansion for Gauss-Bonnet Gravity
The Parametrized Post-Newtonian expansion of gravitational theories with a
scalar field coupled to the Gauss-Bonnet invariant is performed and
confrontation of such theories with Solar system experiments is discussed.Comment: 4 pages; typos corrected, published versio
Globular Cluster Populations in Four Early-Type Poststarburst Galaxies
We present a study of the globular cluster systems of four early-type
poststarburst galaxies using deep g and I-band images from the ACS camera
aboard the Hubble Space Telescope (HST). All the galaxies feature shells
distributed around their main bodies and are thus likely merger remnants. The
color distribution of the globular clusters in all four galaxies shows a broad
peak centered on g-I ~ 1.4, while PGC 6240 and PGC 42871 show a significant
number of globular clusters with g-I ~ 1.0. The latter globular clusters are
interpreted as being of age ~ 500 Myr and likely having been formed in the
merger. The color of the redder peak is consistent with that expected for an
old metal-poor population that is very commonly found around normal galaxies.
However, all galaxies except PGC 10922 contain several globular clusters that
are significantly brighter than the maximum luminosity expected of a single old
metal-poor population. To test for multiple-age populations of overlapping g-I
color, we model the luminosity functions of the globular clusters as composites
of an old metal-poor subpopulation with a range of plausible specific
frequencies and an intermediate-age subpopulation of solar metallicity. We find
that three of the four sample galaxies show evidence for the presence of an
intermediate-age (~ 1 Gyr) globular cluster population, in addition to the old
metal-poor GC population seen in normal early-type galaxies. None of the
galaxies show a significant population of clusters consistent with an old,
metal-rich red cluster population that is typically seen in early-type
galaxies.Comment: 41 pages, 13 figures, accepted for publication in AJ. Some figues
have been downgraded to reduce their size
Rurality or distance to care and the risk of homelessness among Afghanistan and Iraq veterans
INTRODUCTION:
To date, no studies have examined the relationship of rurality and distance to nearest VA facility to risk of homelessness.
METHODS:
We examined differences in the rate of homelessness within a year of a Veteran's first encounter with the VA following last military separation based on rurality and distance to the nearest VA facility using multivariable log-binomial regressions.
RESULTS:
In our cohort of 708,120 Veterans, 73% were determined to have a forwarding address in urban areas, 59.2% and 86.7% lived within 40 miles of the nearest VA medical center (VAMC), respectively. Veterans living in a rural area and those living between 20+ miles away from the nearest VAMC were at a lower risk for homelessness.
CONCLUSIONS:
Our unique dataset allowed us to explore the relationship between geography and homelessness. These results are important to policy makers in understanding the risk factors for homelessness among Veterans and planning interventions
Liquid-gas phase transition in nuclear matter including strangeness
We apply the chiral SU(3) quark mean field model to study the properties of
strange hadronic matter at finite temperature. The liquid-gas phase transition
is studied as a function of the strangeness fraction. The pressure of the
system cannot remain constant during the phase transition, since there are two
independent conserved charges (baryon and strangeness number). In a range of
temperatures around 15 MeV (precise values depending on the model used) the
equation of state exhibits multiple bifurcates. The difference in the
strangeness fraction between the liquid and gas phases is small when they
coexist. The critical temperature of strange matter turns out to be a
non-trivial function of the strangeness fraction.Comment: 15 pages, 7 figure
On wormholes with arbitrarily small quantities of exotic matter
Recently several models of traversable wormholes have been proposed which
require only arbitrarily small amounts of negative energy to hold them open
against self-collapse. If the exotic matter is assumed to be provided by
quantum fields, then quantum inequalities can be used to place constraints on
the negative energy densities required. In this paper, we introduce an
alternative method for obtaining constraints on wormhole geometries, using a
recently derived quantum inequality bound on the null-contracted stress-energy
averaged over a timelike worldline. The bound allows us to perform a simplified
analysis of general wormhole models, not just those with small quantities of
exotic matter. We then use it to study, in particular, the models of Visser,
Kar, and Dadhich (VKD) and the models of Kuhfittig. The VKD models are
constrained to be either submicroscopic or to have a large discrepancy between
throat size and curvature radius. A recent model of Kuhfittig is shown to be
non-traversable. This is due to the fact that the throat of his wormhole flares
outward so slowly that light rays and particles, starting from outside the
throat, require an infinite lapse of affine parameter to reach the throat.Comment: 30 pages, 2 figure
Cost Structures of Information Technology Products and Digital Products and Services Firms: Implications for Financial Analysis
Effects of acute exercise on cutaneous thermal sensation
The aim of this study was to assess the effect of exercise intensity on thermal sensory function of active and inactive limbs. In a randomised and counterbalanced manner 13 healthy young male participants (25±6 yr, 1.8±0.1 m, 77±6 kg) conducted; 1) 30 minutes low (50% heart rate maximum, HRmax; LOW) intensity, 2) 30 minutes high (80% HRmax; HIGH) intensity cycling exercise and 3) 30 minutes seated rest (CONTROL). Before, immediately and 1-hour after each intervention thermal sensory function of the non-dominant dorsal forearm and posterior calf were examined by increasing local skin temperature (1°C/s) to assess perceptual heat sensitivity and pain thresholds. Relative to pre-exercise, forearm heat sensitivity thresholds were increased immediately and 1-hr after HIGH but there were no changes after LOW exercise or during CONTROL (main effect of trial; P=0.017). Relative to pre-exercise, calf heat sensitivity thresholds were not changed after LOW or HIGH exercise or during CONTROL (main effect of trial; P=0.629). There were no changes in calf (main effect of trial; P=0.528) or forearm (main effect of trial; P=0.088) heat pain thresholds after exercise in either LOW or HIGH or CONTROL. These results suggest that cutaneous thermal sensitivity function of an inactive limb is only reduced after higher intensity exercise but is not changed in a previously active limb after exercise. Exercise does not affect heat pain sensitivity in either active or inactive limbs
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