3,008 research outputs found
Generation of N00N-like interferences with two thermal light sources
Measuring the th-order intensity correlation function of light emitted by
two statistically independent thermal light sources may display N00N-like
interferences of arbitrary order . We show that via a particular
choice of detector positions one can isolate -photon quantum paths where
either all photons are emitted from the same source or photons are
collectively emitted by both sources. The latter superposition displays
N00N-like oscillations with which may serve, e.g., in astronomy, for
imaging two distant thermal sources with -fold increased resolution. We
also discuss slightly modified detection schemes improving the visibility of
the N00N-like interference pattern and present measurements verifying the
theoretical predictions.Comment: 9 pages, 6 figure
Job search monitoring, inactivity and reservation wages
"German unemployed who turned 58 and were registered in the Public Employment Service had until the end of 2007 the option to avoid job-search monitoring without sanction if they agreed to retire as soon as they were eligible for an old age pension. In this study we analyze the impact of job search monitoring on reservation wages of older welfare benefit recipients using as identification strategy age discontinuity in the eligibility rule to participate in the program. Our results indicate that participation in the program increases reservation wages. However, the question whether this has an effect on unemployment duration remains open for further research." (author´s abstract
Creation of orbital angular momentum states with chiral polaritonic lenses
Controlled transfer of orbital angular momentum to exciton-polariton
Bose-Einstein condensate spontaneously created under incoherent, off-resonant
excitation conditions is a long-standing challenge in the field of microcavity
polaritonics. We demonstrate, experimentally and theoretically, a simple and
efficient approach to generation of nontrivial orbital angular momentum states
by using optically-induced potentials -- chiral polaritonic lenses.Comment: 5 pages, 5 figure
Sharing is CAIRing: Characterizing Principles and Assessing Properties of Universal Privacy Evaluation for Synthetic Tabular Data
Data sharing is a necessity for innovative progress in many domains,
especially in healthcare. However, the ability to share data is hindered by
regulations protecting the privacy of natural persons. Synthetic tabular data
provide a promising solution to address data sharing difficulties but does not
inherently guarantee privacy. Still, there is a lack of agreement on
appropriate methods for assessing the privacy-preserving capabilities of
synthetic data, making it difficult to compare results across studies. To the
best of our knowledge, this is the first work to identify properties that
constitute good universal privacy evaluation metrics for synthetic tabular
data. The goal of such metrics is to enable comparability across studies and to
allow non-technical stakeholders to understand how privacy is protected. We
identify four principles for the assessment of metrics: Comparability,
Applicability, Interpretability, and Representativeness (CAIR). To quantify and
rank the degree to which evaluation metrics conform to the CAIR principles, we
design a rubric using a scale of 1-4. Each of the four properties is scored on
four parameters, yielding 16 total dimensions. We study the applicability and
usefulness of the CAIR principles and rubric by assessing a selection of
metrics popular in other studies. The results provide granular insights into
the strengths and weaknesses of existing metrics that not only rank the metrics
but highlight areas of potential improvements. We expect that the CAIR
principles will foster agreement among researchers and organizations on which
universal privacy evaluation metrics are appropriate for synthetic tabular
data
RNase A Inhibits Formation of Neutrophil Extracellular Traps in Subarachnoid Hemorrhage
Background: Subarachnoid hemorrhage (SAH) caused by rupture of an intracranial aneurysm, is a life-threatening emergency that is associated with substantial morbidity and mortality. Emerging evidence suggests involvement of the innate immune response in secondary brain injury, and a potential role of neutrophil extracellular traps (NETs) for SAH-associated neuroinflammation. In this study, we investigated the spatiotemporal patterns of NETs in SAH and the potential role of the RNase A (the bovine equivalent to human RNase 1) application on NET burden.
Methods: A total number of n=81 male C57Bl/6 mice were operated utilizing a filament perforation model to induce SAH, and Sham operation was performed for the corresponding control groups. To confirm the bleeding and exclude stroke and intracerebral hemorrhage, the animals received MRI after 24h. Mice were treated with intravenous injection of RNase A (42 mu g/kg body weight) or saline solution for the control groups, respectively. Quadruple-immunofluorescence (IF) staining for cell nuclei (DAPI), F-actin (phalloidin), citrullinated H3, and neurons (NeuN) was analyzed by confocal imaging and used to quantify NET abundance in the subarachnoid space (SAS) and brain parenchyma. To quantify NETs in human SAH patients, cerebrospinal spinal fluid (CSF) and blood samples from day 1, 2, 7, and 14 after bleeding onset were analyzed for double-stranded DNA (dsDNA) via Sytox Green.
Results: Neutrophil extracellular traps are released upon subarachnoid hemorrhage in the SAS on the ipsilateral bleeding site 24h after ictus. Over time, NETs showed progressive increase in the parenchyma on both ipsi- and contralateral site, peaking on day 14 in periventricular localization. In CSF and blood samples of patients with aneurysmal SAH, NETs also increased gradually over time with a peak on day 7. RNase application significantly reduced NET accumulation in basal, cortical, and periventricular areas.
Conclusion: Neutrophil extracellular trap formation following SAH originates in the ipsilateral SAS of the bleeding site and spreads gradually over time to basal, cortical, and periventricular areas in the parenchyma within 14days. Intravenous RNase application abrogates NET burden significantly in the brain parenchyma, underpinning a potential role in modulation of the innate immune activation after SAH
New Constraints on Cosmic Reionization from the 2012 Hubble Ultra Deep Field Campaign
Understanding cosmic reionization requires the identification and
characterization of early sources of hydrogen-ionizing photons. The 2012 Hubble
Ultra Deep Field (UDF12) campaign has acquired the deepest infrared images with
the Wide Field Camera 3 aboard Hubble Space Telescope and, for the first time,
systematically explored the galaxy population deep into the era when cosmic
microwave background (CMB) data indicates reionization was underway. The UDF12
campaign thus provides the best constraints to date on the abundance,
luminosity distribution, and spectral properties of early star-forming
galaxies. We synthesize the new UDF12 results with the most recent constraints
from CMB observations to infer redshift-dependent ultraviolet (UV) luminosity
densities, reionization histories, and electron scattering optical depth
evolution consistent with the available data. Under reasonable assumptions
about the escape fraction of hydrogen ionizing photons and the intergalactic
medium clumping factor, we find that to fully reionize the universe by redshift
z~6 the population of star-forming galaxies at redshifts z~7-9 likely must
extend in luminosity below the UDF12 limits to absolute UV magnitudes of
M_UV\sim -13 or fainter. Moreover, low levels of star formation extending to
redshifts z~15-25, as suggested by the normal UV colors of z\simeq7-8 galaxies
and the smooth decline in abundance with redshift observed by UDF12 to
z\simeq10, are additionally likely required to reproduce the optical depth to
electron scattering inferred from CMB observations.Comment: Version accepted by ApJ (originally submitted Jan 5, 2013). The UDF12
website can be found at http://udf12.arizona.ed
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