5,000 research outputs found
Amplifier clamping circuit for horizon scanner Patent
Clamped amplifier circuit for horizon scanner enabling amplification and accurate measurement of specified parameter
Attitude control system Patent
Development of attitude control system for spacecraft orientatio
Base composition of intact nucleic acid oligomers
Base composition of intact nucleic acid oligomer
Repetitions in the polypeptide sequence of cytochromes
Protein evolution from peptides, gene duplications and deletions in polypeptides and cytochrome
Cyclic Universe and Infinite Past
We address two questions about the past for infinitely cyclic cosmology. The
first is whether it can contain an infinite length null geodesic into the past
in view of the Borde-Guth-Vilenkin (BGV) "no-go" theorem, The second is
whether, given that a small fraction of spawned universes fail to cycle, there
is an adequate probability for a successful universe after an infinite time. We
give positive answers to both questions then show that in infinite cyclicity
the total number of universes has been infinite for an arbitrarily long time.Comment: 7 pages. Clarification in discussion of infinite pas
Design of a single axis simulator for satellite control system testing and for low torque measurement
Single axis simulator design for satellite control system testing and low torque measuremen
Analysis of Accordion DNA Stretching Revealed by The Gold Cluster Ruler
A promising new method for measuring intramolecular distances in solution
uses small-angle X-ray scattering interference between gold nanocrystal labels
(Mathew-Fenn et al, Science, 322, 446 (2008)). When applied to double stranded
DNA, it revealed that the DNA length fluctuations are strikingly strong and
correlated over at least 80 base pair steps. In other words, the DNA behaves as
accordion bellows, with distant fragments stretching and shrinking concertedly.
This hypothesis, however, disagrees with earlier experimental and computational
observations. This Letter shows that the discrepancy can be rationalized by
taking into account the cluster exclusion volume and assuming a moderate
long-range repulsion between them. The long-range interaction can originate
from an ion exclusion effect and cluster polarization in close proximity to the
DNA surface.Comment: 9 pages, 4 figures, to appear in Phys. Rev.
The Impact of State Dependent Coverage Expansions on Young Adult Insurance Status: Further Analysis
Outlines how state initiatives to expand dependent coverage affected young adults' rates of uninsurance and of employer-sponsored coverage. Considers differential time effects and implications for national reform provisions to expand coverage to age 26
Stretching of a single-stranded DNA: Evidence for structural transition
Recent experiments have shown that the force-extension (F-x) curve for
single-stranded DNA (ssDNA) consisting only of adenine [poly(dA)] is
significantly different from thymine [poly(dT)]. Here, we show that the base
stacking interaction is not sufficient to describe the F-x curves as seen in
the experiments. A reduction in the reaction co-ordinate arising from the
formation of helix at low forces and an increase in the distance between
consecutive phosphates of unstacked bases in the stretched state at high force
in the proposed model, qualitatively reproduces the experimentally observed
features. The multi-step plateau in the F-x curve is a signature of structural
change in ssDNA.Comment: 10 pages, 4 figure
Dependent Coverage Expansions: Estimating the Impact of Current State Policies
Presents preliminary findings on common provisions in state regulations of dependent health coverage and discusses the analytic approach to estimating the impact of state policy changes on young adults
- …