2,740 research outputs found
Hospital Community Benefits After the ACA: The Emerging Federal Framework
Outlines the federal framework on requirements for hospitals to provide community benefit activities in exchange for tax-exempt status under the 2010 healthcare reform, including community health needs assessments; state policy options; and challenges
RISK ANALYSIS OF ADOPTING ZERO RUNOFF SUBIRRIGATION SYSTEMS IN GREENHOUSE OPERATIONS: A MONTE CARLO SIMULATION APPROACH
Zero runoff subirrigation (ZRS) technology can effectively manage fertilizer input while improving greenhouse production efficiency. However, high capital investment costs and inadequate technical information to growers are impediments for adoption. A Monte Carlo simulation was used to compare the profitability and risks of alternative ZRS system investments for greenhouse operations in the northeastern and north central United States. Results showed that the Dutch movable tray system and the flood floor system were most profitable and least risky for small potted plant and bedding crop flat production, respectively. The trough bench system was least favorable because its profitability was low and highly volatile.Risk and Uncertainty,
Artesunate reduces but does not prevent posttreatment transmission of Plasmodium falciparum to Anopheles gambiae.
Combination therapy that includes artemisinin derivatives cures most falciparum malaria infections. Lowering transmission by reducing gametocyte infectivity would be an additional benefit. To examine the effect of such therapy on transmission, Gambian children with Plasmodium falciparum malaria were treated with standard regimens of chloroquine or pyrimethamine-sulfadoxine alone or in combination with 1 or 3 doses of artesunate. The infectivity to mosquitoes of gametocytes in peripheral blood was determined 4 or 7 days after treatment. Infection of mosquitoes was observed in all treatment groups and was positively associated with gametocyte density. The probability of transmission was lowest in those who received pyrimethamine-sulfadoxine and 3 doses of artesunate, and it was 8-fold higher in the group that received pyrimethamine-sulfadoxine alone. Artesunate reduced posttreatment infectivity dramatically but did not abolish it completely. The study raises questions about any policy to use pyrimethamine-sulfadoxine alone as the first-line treatment for malaria
Multi-wavelength observations and modelling of a canonical solar flare
This paper investigates the temporal evolution of temperature, emission
measure, energy loss and velocity in a C-class solar flare from both an
observational and theoretical perspective. The properties of the flare were
derived by following the systematic cooling of the plasma through the response
functions of a number of instruments -- RHESSI (>5 MK), GOES-12 (5-30 MK),
TRACE 171 A (1 MK) and SOHO/CDS (~0.03-8 MK). These measurements were studied
in combination with simulations from the 0-D EBTEL model. At the flare on-set,
upflows of ~90 km s-1 and low level emission were observed in Fe XIX,
consistent with pre-flare heating and gentle chromospheric evaporation. During
the impulsive phase, upflows of ~80 km s-1 in Fe XIX and simultaneous downflows
of 20 km s-1 in He I and O V were observed, indicating explosive chromospheric
evaporation. The plasma was subsequently found to reach a peak temperature of
~13 MK in approximately 10 minutes. Using EBTEL, conduction was found to be the
dominant loss mechanism during the initial ~300s of the decay phase. It was
also found to be responsible for driving gentle chromospheric evaporation
during this period. As the temperature fell below ~8 MK, and for the next
~4,000s, radiative losses were determined to dominate over conductive losses.
The radiative loss phase was accompanied by significant downflows of <40 km s-1
in O V. This is the first extensive study of the evolution of a canonical solar
flare using both spectroscopic and broad-band instruments in conjunction with a
hydrodynamic model. While our results are in broad agreement with the standard
flare model, the simulations suggest that both conductive and non-thermal beam
heating play important roles in heating the flare plasma during the impulsive
phase of at least this event.Comment: 10 pages, 7 figures, 2 tables. Accepted for publication in A&
Semantic patterns for sentiment analysis of Twitter
Most existing approaches to Twitter sentiment analysis assume that sentiment is explicitly expressed through affective words. Nevertheless, sentiment is often implicitly expressed via latent semantic relations, patterns and dependencies among words in tweets. In this paper, we propose a novel approach that automatically captures patterns of words of similar contextual semantics and sentiment in tweets. Unlike previous work on sentiment pattern extraction, our proposed approach does not rely on external and fixed sets of syntactical templates/patterns, nor requires deep analyses of the syntactic structure of sentences in tweets. We evaluate our approach with tweet- and entity-level sentiment analysis tasks by using the extracted semantic patterns as classification features in both tasks. We use 9 Twitter datasets in our evaluation and compare the performance of our patterns against 6 state-of-the-art baselines. Results show that our patterns consistently outperform all other baselines on all datasets by 2.19% at the tweet-level and 7.5% at the entity-level in average F-measure
Deciphering the Microbiome: Integrating Theory, New Technologies, and Inclusive Science
The diversity and functional significance of microbiomes have become increasingly clear through the extensive sampling of Earth\u27s many habitats and the rapid adoption of new sequencing technologies. However, much remains unknown about what makes a “healthy” microbiome, how to restore a disrupted microbiome, and how microbiomes assemble. In December 2019, we convened a workshop that focused on how to identify potential “rules of life” that govern microbiome structure and function. This collection of mSystems Perspective pieces reflects many of the main challenges and opportunities in the field identified by both in-person and virtual workshop participants. By borrowing conceptual and theoretical approaches from other fields, including economics and philosophy, these pieces suggest new ways to dissect microbiome patterns and processes. The application of conceptual advances, including trait-based theory and community coalescence, is providing new insights on how to predict and manage microbiome diversity and function. Technological and analytical advances, including deep transfer learning, metabolic models, and advances in analytical chemistry, are helping us sift through complex systems to pinpoint mechanisms of microbiome assembly and dynamics. Integration of all of these advancements (theory, concepts, technology) across biological and spatial scales is providing dramatically improved temporal and spatial resolution of microbiome dynamics. This integrative microbiome research is happening in a new moment in science where academic institutions, scientific societies, and funding agencies must act collaboratively to support and train a diverse and inclusive community of microbiome scientists
Investigating Self-Directed Learning Dimensions: Adapting the Bouchard Framework
Self-Directed Learning (SDL) is gaining interest, as online learning is increasingly learner-centered. FutureLearn courses provide an array of online interactions and content deliveries, which have allowed the authors to investigate a diversity of SDL elements. This preliminary research examines the SDL taking place in three FutureLearn courses, and categorises those learner actions into meaningful elements and dimensions for the learners. The SDL framework by Bouchard [1] is used to interpret the self-reported findings coming from active learners. The research uses a grounded theory approach to look for learner experiences related to four dimensions (algorithmic, conative, semiotic, and economic) of the Bouchard [1] framework, and to discover new dimensions. Various research instruments are used: online surveys, learning logs, and one-on-one interviews, all collected pre-, during, or post-course. The initial adaptation of Bouchard’s framework offers insights into SDL, its meaning, and value as perceived by the learners
Fe XI emission lines in a high resolution extreme ultraviolet spectrum obtained by SERTS
New calculations of radiative rates and electron impact excitation cross
sections for Fe XI are used to derive emission line intensity ratios involving
3s^23p^4 - 3s^23p^33d transitions in the 180-223 A wavelength range. These
ratios are subsequently compared with observations of a solar active region,
obtained during the 1995 flight Solar EUV Research Telescope and Spectrograph
(SERTS). The version of SERTS flown in 1995 incorporated a multilayer grating
that enhanced the instrumental sensitivity for features in the 170 - 225 A
wavelength range, observed in second-order between 340 and 450 A. This
enhancement led to the detection of many emission lines not seen on previous
SERTS flights, which were measured with the highest spectral resolution (0.03
A) ever achieved for spatially resolved active region spectra in this
wavelength range. However, even at this high spectral resolution, several of
the Fe XI lines are found to be blended, although the sources of the blends are
identified in the majority of cases. The most useful Fe XI electron density
diagnostic line intensity ratio is I(184.80 A)/I(188.21 A). This ratio involves
lines close in wavelength and free from blends, and which varies by a factor of
11.7 between N_e = 10^9 and 10^11 cm^-3, yet shows little temperature
sensitivity. An unknown line in the SERTS spectrum at 189.00 A is found to be
due to Fe XI, the first time (to our knowledge) this feature has been
identified in the solar spectrum. Similarly, there are new identifications of
the Fe XI 192.88, 198.56 and 202.42 A features, although the latter two are
blended with S VIII/Fe XII and Fe XIII, respectively.Comment: 21 pages, 9 gigures, accepted for publication in the Astrophysical
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