408 research outputs found
Micromirror total internal reflection microscopy for high-performance single particle tracking at interfaces
Single particle tracking has found broad applications in the life and
physical sciences, enabling the observation and characterisation of nano- and
microscopic motion. Fluorescence-based approaches are ideally suited for
high-background environments, such as tracking lipids or proteins in or on
cells, due to superior background rejection. Scattering-based detection is
preferable when localisation precision and imaging speed are paramount due to
the in principle infinite photon budget. Here, we show that micromirror-based
total internal reflection dark field microscopy enables background suppression
previously only reported for interferometric scattering microscopy, resulting
in nm localisation precision at 6 s exposure time for 20 nm gold
nanoparticles with a 25 x 25 m field of view. We demonstrate the
capabilities of our implementation by characterizing sub-nm deterministic flows
of 20 nm gold nanoparticles at liquid-liquid interfaces. Our results approach
the optimal combination of background suppression, localisation precision and
temporal resolution achievable with pure scattering-based imaging and tracking
of nanoparticles at regular interfaces.Comment: 27 pages, 4 figure
Potential Sand and Gravel Resources of the Mansfield 30 x 60 minute quadrangle
The Ohio Department of Natural Resources (ODNR), Division of Geological Survey has completed a reconnaissance map showing areas of mineable sand and gravel resources in the Mansfield, Ohio, 30 x 60 minute (scale 1:100,000) quadrangle. The main purpose of this map was to create a reconnaissance-level map that would show the potential for mining sand and gravel in this quadrangle. The map shows areas of surficial materials in increments of 10 feet and then differentiates sand, sand and gravel, and ice-contact deposits from finer grained materials, such as glacial till, lacustrine clay and silt, and alluvial materials. The sand and sand-and-gravel units include both surficial and buried outwash and valley train deposits and ice-contact deposits, such as kames, kame terraces, and eskers. To determine if a sand-and-gravel deposit was economically viable, this map shows the total thickness or accumulation of sand and gravel in the Mansfield 30 x 60-minute quadrangle.United States Geological Survey: National Cooperative Geologic Mapping Program, Great Lakes Geologic Mapping Coalitio
Quantum Nonlocality without Entanglement
We exhibit an orthogonal set of product states of two three-state particles
that nevertheless cannot be reliably distinguished by a pair of separated
observers ignorant of which of the states has been presented to them, even if
the observers are allowed any sequence of local operations and classical
communication between the separate observers. It is proved that there is a
finite gap between the mutual information obtainable by a joint measurement on
these states and a measurement in which only local actions are permitted. This
result implies the existence of separable superoperators that cannot be
implemented locally. A set of states are found involving three two-state
particles which also appear to be nonmeasurable locally. These and other
multipartite states are classified according to the entropy and entanglement
costs of preparing and measuring them by local operations.Comment: 27 pages, Latex, 6 ps figures. To be submitted to Phys. Rev. A.
Version 2: 30 pages, many small revisions and extensions, author added.
Version 3: Proof in Appendix D corrected, many small changes; final version
for Phys. Rev. A Version 4: Report of Popescu conjecture modifie
Coherent Control of Isotope Separation in HD+ Photodissociation by Strong Fields
The photodissociation of the HD+ molecular ion in intense short- pulsed
linearly polarized laser fields is studied using a time- dependent wave-packet
approach where molecular rotation is fully included. We show that applying a
coherent superposition of the fundamental radiation with its second harmonic
can lead to asymmetries in the fragment angular distributions, with significant
differences between the hydrogen and deuterium distributions in the long
wavelength domain where the permanent dipole is most efficient. This effect is
used to induce an appreciable isotope separation.Comment: Physical Review Letters, 1995 (in press). 4 pages in revtex format, 3
uuencoded figures. Full postcript version available at:
http://chemphys.weizmann.ac.il/~charron/prl.ps or
ftp://scipion.ppm.u-psud.fr/coherent.control/prl.p
Wealth Building in Rural America: Programs, Policies, Research
Wealth Building in Rural America: Programs, Policies, Researc
Longitudinal dynamics of clonal hematopoiesis identifies gene-specific fitness effects
Clonal hematopoiesis of indeterminate potential (CHIP) increases rapidly in prevalence beyond age 60 and has been associated with increased risk for malignancy, heart disease and ischemic stroke. CHIP is driven by somatic mutations in hematopoietic stem and progenitor cells (HSPCs). Because mutations in HSPCs often drive leukemia, we hypothesized that HSPC fitness substantially contributes to transformation from CHIP to leukemia. HSPC fitness is defined as the proliferative advantage over cells carrying no or only neutral mutations. If mutations in different genes lead to distinct fitness advantages, this could enable patient stratification. We quantified the fitness effects of mutations over 12 years in older age using longitudinal sequencing and developed a filtering method that considers individual mutational context alongside mutation co-occurrence to quantify the growth potential of variants within individuals. We found that gene-specific fitness differences can outweigh inter-individual variation and, therefore, could form the basis for personalized clinical management
LSST Science Book, Version 2.0
A survey that can cover the sky in optical bands over wide fields to faint
magnitudes with a fast cadence will enable many of the exciting science
opportunities of the next decade. The Large Synoptic Survey Telescope (LSST)
will have an effective aperture of 6.7 meters and an imaging camera with field
of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over
20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with
fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a
total point-source depth of r~27.5. The LSST Science Book describes the basic
parameters of the LSST hardware, software, and observing plans. The book
discusses educational and outreach opportunities, then goes on to describe a
broad range of science that LSST will revolutionize: mapping the inner and
outer Solar System, stellar populations in the Milky Way and nearby galaxies,
the structure of the Milky Way disk and halo and other objects in the Local
Volume, transient and variable objects both at low and high redshift, and the
properties of normal and active galaxies at low and high redshift. It then
turns to far-field cosmological topics, exploring properties of supernovae to
z~1, strong and weak lensing, the large-scale distribution of galaxies and
baryon oscillations, and how these different probes may be combined to
constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at
http://www.lsst.org/lsst/sciboo
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