34,464 research outputs found
Costs of publicly provided maternity services in Rosario, Argentina
This material is posted here with permission of the publishers, Instituto Nacional de Salud Pública. Internal or personal use of this material is permitted. However, permission to reprint/republish this material must be obtained from the Publisher.Objective. This study estimates the costs of maternal health services in Rosario, Argentina. Material and Methods. The rovider costs (US114.62. The average cost of a caesarean section (105.61). A normal delivery costs less at the general
hospital and a c-section less at the aternity hospital. The average cost of an antenatal visit is 4.70. Direct costs are minimal compared to indirect costs of travel and waiting time. Conclusions. These results suggest the potential for increasing the efficiency of resource use by promoting antenatal care visits at the primary level. Women could also benefit from reduced travel and waiting time. Similar benefits could accrue to the provider by encouraging normal delivery at general hospitals, and complicated deliveries at specialised maternity hospitals.Josephine Borghi is funded by the Department for International Development through the Maternal Health Programme at the London School of Hygiene and Tropical Medicine. This project was conducted for and funded by the Human Reproduction Programme at WHO, Geneva
Optical monitoring system
Instrument can measure optical transmission, reflectance, and scattering. This information can be used to identify changes in optical properties or deviations from required optical standards. Device consists of monochromatic source, photo detector, transfer mirror, and hemiellipsoid. System might be used to measure optical properties of thin film
Indeterminacy of Spatiotemporal Cardiac Alternans
Cardiac alternans, a beat-to-beat alternation in action potential duration
(at the cellular level) or in ECG morphology (at the whole heart level), is a
marker of ventricular fibrillation, a fatal heart rhythm that kills hundreds of
thousands of people in the US each year. Investigating cardiac alternans may
lead to a better understanding of the mechanisms of cardiac arrhythmias and
eventually better algorithms for the prediction and prevention of such dreadful
diseases. In paced cardiac tissue, alternans develops under increasingly
shorter pacing period. Existing experimental and theoretical studies adopt the
assumption that alternans in homogeneous cardiac tissue is exclusively
determined by the pacing period. In contrast, we find that, when calcium-driven
alternans develops in cardiac fibers, it may take different spatiotemporal
patterns depending on the pacing history. Because there coexist multiple
alternans solutions for a given pacing period, the alternans pattern on a fiber
becomes unpredictable. Using numerical simulation and theoretical analysis, we
show that the coexistence of multiple alternans patterns is induced by the
interaction between electrotonic coupling and an instability in calcium
cycling.Comment: 20 pages, 10 figures, to be published in Phys. Rev.
Comment on ``Creating Metastable Schroedinger Cat States''
After a careful analysis of the feedback model recently proposed by Slosser
and Milburn [Phys. Rev. Lett. 75, 418 (1995)], we are led to the conclusion
that---under realistic conditions---their scheme is not significantly more
effective in the production of linear superpositions of macroscopically
distinguishable quantum states than the usual quantum-optical Kerr effect.Comment: 1 page, RevTeX, 1 eps figure (fig_1.eps), accepted for publication in
Physical Review Letters [Phys. Rev. Lett. 77 (9) (1996)
Influence of alloying elements on the oxidation behavior of NbAl3
NbAL3 is one candidate material for advanced aeropropulsion systems because of its high melting point, low density, and good oxidation resistance. Although NbAl3 has the lowest oxidation rate among the binary Nb-Al alloys, it does not form exclusive layers of protective Al2O3 scales. Recently Perkin et al., have shown the feasibility of forming alumina scales on Nb-Al alloys at greatly reduced Al contents. However, the objective was to maintain the high Al content, and hence low density, while achieving the capability of growing protective alumina scales. Alloy development followed approaches similar to those used successfully for superalloys and oxidation resistant MCrAlY coatings. Among the three elements examined (Ti, Si, and Cr) as ternary additions to Nb-Al3, Cr was the most effective in favoring the selective oxidation of Al. Nb-41Al-8Cr formed exclusive layers of alumina and had a k sub p value of 0.22 mg squared/cm (sup 4)/hr at 1200 C. The addition of 1 wt percent Y to this alloy was also beneficial, resulting in nearly an order of magnitude decrease in K sub p at 1200 C. Further improvements were achieved by adding about 1 wt percent Si to the quaternary alloy. The k sub p value of 0.012 mg squared/cm (sup 4)/hr for Nb-40Al-8Cr-1Y-1Si at 1200 C was identical to the best NiAl + Zr alloys. These NbAl3 alloys also exhibited excellent cyclic oxidation resistance for 100 hr at 1200 C, being nearly equivalent to NiAl + Zr
Fluorescent visualization of a spreading surfactant
The spreading of surfactants on thin films is an industrially and medically
important phenomenon, but the dynamics are highly nonlinear and visualization
of the surfactant dynamics has been a long-standing experimental challenge. We
perform the first quantitative, spatiotemporally-resolved measurements of the
spreading of an insoluble surfactant on a thin fluid layer. During the
spreading process, we directly observe both the radial height profile of the
spreading droplet and the spatial distribution of the fluorescently-tagged
surfactant. We find that the leading edge of spreading circular layer of
surfactant forms a Marangoni ridge in the underlying fluid, with a trough
trailing the ridge as expected. However, several novel features are observed
using the fluorescence technique, including a peak in the surfactant
concentration which trails the leading edge, and a flat, monolayer-scale
spreading film which differs from concentration profiles predicted by current
models. Both the Marangoni ridge and surfactant leading edge can be described
to spread as . We find spreading exponents, and for the ridge peak and
surfactant leading edge, respectively, which are in good agreement with
theoretical predictions of . In addition, we observe that the
surfactant leading edge initially leads the peak of the Marangoni ridge, with
the peak later catching up to the leading edge
The First Data Release of the KODIAQ Survey
We present and make publicly available the first data release (DR1) of the
Keck Observatory Database of Ionized Absorption toward Quasars (KODIAQ) survey.
The KODIAQ survey is aimed at studying galactic and circumgalactic gas in
absorption at high-redshift, with a focus on highly-ionized gas traced by OVI,
using the HIRES spectrograph on the Keck-I telescope. KODIAQ DR1 consists of a
fully-reduced sample of 170 quasars at 0.29 < z_em < 5.29 observed with HIRES
at high resolution (36,000 <= R <= 103,000) between 2004 and 2012. DR1 contains
247 spectra available in continuum normalized form, representing a sum total
exposure time of ~1.6 megaseconds. These co-added spectra arise from a total of
567 individual exposures of quasars taken from the Keck Observatory Archive
(KOA) in raw form and uniformly processed using a HIRES data reduction package
made available through the XIDL distribution. DR1 is publicly available to the
community, housed as a higher level science product at the KOA. We will provide
future data releases that make further QSOs, including those with pre-2004
observations taken with the previous-generation HIRES detectors.Comment: 14 pages, 9 figures, Submitted to AJ. All data products available at
the Keck Observatory Archive beginning May 15, 2015. URL:
https://koa.ipac.caltech.edu/applications/KODIA
funcX: A Federated Function Serving Fabric for Science
Exploding data volumes and velocities, new computational methods and
platforms, and ubiquitous connectivity demand new approaches to computation in
the sciences. These new approaches must enable computation to be mobile, so
that, for example, it can occur near data, be triggered by events (e.g.,
arrival of new data), be offloaded to specialized accelerators, or run remotely
where resources are available. They also require new design approaches in which
monolithic applications can be decomposed into smaller components, that may in
turn be executed separately and on the most suitable resources. To address
these needs we present funcX---a distributed function as a service (FaaS)
platform that enables flexible, scalable, and high performance remote function
execution. funcX's endpoint software can transform existing clouds, clusters,
and supercomputers into function serving systems, while funcX's cloud-hosted
service provides transparent, secure, and reliable function execution across a
federated ecosystem of endpoints. We motivate the need for funcX with several
scientific case studies, present our prototype design and implementation, show
optimizations that deliver throughput in excess of 1 million functions per
second, and demonstrate, via experiments on two supercomputers, that funcX can
scale to more than more than 130000 concurrent workers.Comment: Accepted to ACM Symposium on High-Performance Parallel and
Distributed Computing (HPDC 2020). arXiv admin note: substantial text overlap
with arXiv:1908.0490
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