464 research outputs found
Framing The Polemics of the Intersection of Immigration and Health Care in the United States: an Ethnographic and Theoretical Contribution to a Discussion on the Biopolitics of Exclusion
The Patient Protection and Affordable Care Act (PPACA) was signed into law by President Obama on March 23, 2010 and has slowly been implemented over the past two years. If the President’s health care reform legislation continues to move forward we will see tens of millions of Americans gain health insurance and access to medical care at more affordable prices than before, yet due to some of the provisions of the ACA, almost 12 million people living in the United States will see no change to their access to health care. These habitants, most of them employed, come from outside the U.S., and therefore are defined as non-citizens by their immigration status. As a result, all undocumented immigrants and many legal residents will find themselves in a minority of American workers without the same rights and access to basic health needs. Using a multi-faceted approach to study the intersection of immigration and health care, this paper combines ethnographic interviews with immigrant small business owners in West Philadelphia with a literature review of the history of immigration reform and the theories behind the social concepts of political exclusion, framing, structural violence, and biopower. In the conclusion, explanations will be given for the continued biopolitical exclusion of immigrants in the U.S. and suggestions will be supplemented on how this country may be able to change its policy to one day have true universal health care coverage
Quantum beat spectroscopy of repulsive Bose polarons
The physics of impurities in a bosonic quantum environment is a paradigmatic
and challenging many-body problem that remains to be understood in its full
complexity. Here, this problem is investigated for impurities with strong
repulsive interactions based on Ramsey interferometry in a quantum degenerate
gas of 39K atoms. We observe an oscillatory signal that is consistent with a
quantum beat between two co-existing coherent quasiparticle states: the
attractive and repulsive polarons. The interferometric signal allows us to
extract the polaron energies for a wide range of interaction strengths,
complimenting earlier spectroscopic measurements. We furthermore identify
several dynamical regimes towards the formation of the Bose polaron in good
agreement with theory. Our results improve the understanding of quantum
impurities interacting strongly with a bosonic environment, and demonstrate how
quasiparticles as well as short-lived non-equilibrium many-body states can be
probed using Ramsey interferometry
An infrastructural account of scientific objectivity for legal contexts and bloodstain pattern analysis
Type IV pili interactions promote intercellular association and moderate swarming of Pseudomonas aeruginosa
Pseudomonas aeruginosa is a ubiquitous bacterium that survives in many environments, including as an acute and chronic pathogen in humans. Substantial evidence shows that P. aeruginosa behavior is affected by its motility, and appendages known as flagella and type IV pili (TFP) are known to confer such motility. The role these appendages play when not facilitating motility or attachment, however, is unclear. Here we discern a passive intercellular role of TFP during flagellar-mediated swarming of P. aeruginosa
that does not require TFP extension or retraction. We studied swarming at the cellular level using a combination of laboratory experiments and computational simulations to explain the resultant patterns of cells imaged from in vitro swarms. Namely, we used a computational model to simulate swarming and to probe for individual cell behavior that cannot currently be otherwise measured. Our simulations showed that TFP of swarming
P. aeruginosa should be distributed all over the cell and that TFP−TFP interactions between cells should be a dominant mechanism that promotes cell−cell interaction, limits lone cell movement, and slows swarm expansion. This predicted physical mechanism involving TFP was confirmed in vitro using pairwise mixtures of strains with and without TFP where cells without TFP separate from cells with TFP. While TFP slow swarm expansion, we show in vitro that TFP help alter collective motion to avoid toxic compounds
such as the antibiotic carbenicillin. Thus, TFP physically affect P. aeruginosa swarming by actively promoting cell-cell association and directional collective motion within motile groups to aid their survival.National Institutes of HealthIndiana Clinical and Translational Sciences Institut
Life and death of the Bose polaron
Spectroscopic and interferometric measurements complement each other in
extracting the fundamental properties of quantum many-body systems. While
spectroscopy provides precise measurements of equilibrated energies,
interferometry can elucidate the dynamical evolution of the system. For an
impurity immersed in a bosonic medium, both are equally important for
understanding the quasiparticle physics of the Bose polaron. Here, we compare
the interferometric and spectroscopic timescales to the underlying dynamical
regimes of the impurity dynamics and the polaron lifetime, highlighting the
capability of the interferometric approach to clearly resolve polaron dynamics.
In particular, interferometric measurements of the coherence amplitude at
strong interactions reveal faster quantum dynamics at large repulsive
interaction strengths than at unitarity. These observations are in excellent
agreement with a short-time theoretical prediction including both the continuum
and the attractive polaron branch. For longer times, qualitative agreement with
a many-body theoretical prediction which includes both branches is obtained.
Moreover, the polaron energy is extracted from interferometric measurements of
the observed phase velocity in agreement with previous spectroscopic results
from weak to strong attractive interactions. Finally, the phase evolution
allows for the measurement of an energetic equilibration timescale, describing
the initial approach of the phase velocity to the polaron energy.
Theoretically, this is shown to lie within the regime of universal dynamics
revealing a fast initial evolution towards the formation of polarons. Our
results give a comprehensive picture of the many-body physics governing the
Bose polaron and thus validates the quasiparticle framework for further
studies.Comment: 9 pages, 6 figure
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Development of Millimeter-Wave Velocimetry and Acoustic Time-of-Flight Tomography for Measurements in Densely Loaded Gas-Solid Riser Flow
The MFDRC was formed in 1998 to advance the state-of-the-art in simulating multiphase turbulent flows by developing advanced computational models for gas-solid flows that are experimentally validated over a wide range of industrially relevant conditions. The goal was to transfer the resulting validated models to interested US commercial CFD software vendors, who would then propagate the models as part of new code versions to their customers in the US chemical industry. Since the lack of detailed data sets at industrially relevant conditions is the major roadblock to developing and validating multiphase turbulence models, a significant component of the work involved flow measurements on an industrial-scale riser contributed by Westinghouse, which was subsequently installed at SNL. Model comparisons were performed against these datasets by LANL. A parallel Office of Industrial Technology (OIT) project within the consortium made similar comparisons between riser measurements and models at NETL. Measured flow quantities of interest included volume fraction, velocity, and velocity-fluctuation profiles for both gas and solid phases at various locations in the riser. Some additional techniques were required for these measurements beyond what was currently available. PNNL’s role on the project was to work with the SNL experimental team to develop and test two new measurement techniques, acoustic tomography and millimeter-wave velocimetry. Acoustic tomography is a promising technique for gas-solid flow measurements in risers and PNNL has substantial related experience in this area. PNNL is also active in developing millimeter wave imaging techniques, and this technology presents an additional approach to make desired measurements. PNNL supported the advanced diagnostics development part of this project by evaluating these techniques and then by adapting and developing the selected technology to bulk gas-solids flows and by implementing them for testing in the SNL riser testbed
The influence of transmitted and non-transmitted parental BMI-associated alleles on the risk of overweight in childhood
Overweight in children is strongly associated with parental body mass index (BMI) and overweight. We assessed parental transmitted and non-transmitted genetic contributions to overweight in children from the Danish National Birth Cohort by constructing genetic risk scores (GRSs) from 941 common genetic variants associated with adult BMI and estimating associations of transmitted maternal/paternal and non-transmitted maternal GRS with child overweight. Maternal and paternal BMI (standard deviation (SD) units) had a strong association with childhood overweight [Odds ratio (OR): 2.01 (95% confidence interval (CI) 1.74; 2.34) and 1.64 (95% CI 1.43; 1.89)]. Maternal and paternal transmitted GRSs (SD-units) increased odds for child overweight equally [OR: 1.30 (95% CI 1.16; 1.46) and 1.30 (95% CI 1.16; 1.47)]. However, both the parental phenotypic and the GRS associations may depend on maternal BMI, being weaker among mothers with overweight. Maternal non-transmitted GRS was not associated with child overweight [OR 0.98 (95% CI 0.88; 1.10)] suggesting no specific influence of maternal adiposity as such. In conclusion, parental transmitted GRSs, based on adult BMI, contribute to child overweight, but in overweight mothers other genetic and environmental factors may play a greater role.This article is freely available via Open Access. Click on the Publisher URL to access it via the publisher's site.WT104150/Wellcome Trust (Wellcome)published version, accepted version, submitted versio
Hanford Tank Farms Waste Certification Flow Loop Test Plan
A future requirement of Hanford Tank Farm operations will involve transfer of wastes from double shell tanks to the Waste Treatment Plant. As the U.S. Department of Energy contractor for Tank Farm Operations, Washington River Protection Solutions anticipates the need to certify that waste transfers comply with contractual requirements. This test plan describes the approach for evaluating several instruments that have potential to detect the onset of flow stratification and critical suspension velocity. The testing will be conducted in an existing pipe loop in Pacific Northwest National Laboratory’s facility that is being modified to accommodate the testing of instruments over a range of simulated waste properties and flow conditions. The testing phases, test matrix and types of simulants needed and the range of testing conditions required to evaluate the instruments are describe
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