5,110 research outputs found
The role of Supplier Relationship Management in reducing Greenhouse Gas emissions from food supply chains:Supplier engagement in the UK supermarket sector
How Insurers Competed in the Affordable Care Act's First Year
Prior to the Affordable Care Act (ACA), most states' individual health insurance markets were dominated by one or two insurance carriers that had little incentive to compete by providing efficient services. Instead, they competed mainly by screening and selecting people based on their risk of incurring high medical costs. One of the ACA's goals is to encourage carriers to participate in the health insurance marketplaces and to shift the focus from competing based on risk selection to processes that increase consumer value, like improving efficiency of services and quality of care. Focusing on six states—Arkansas, California, Connecticut, Maryland, Montana, and Texas—this brief looks at how carriers are competing in the new marketplaces, namely through cost-sharing and composition of provider networks
Converting Land from Poplar Tree Bioenergy Planting to Cropland: An Example
Many landowners ask about the process and costs for returning land to crop production after trees are cut for biomass. A field on the Squaw Creek bottom, Story County, Iowa was planted to hybrid poplar trees in spring 2000. The trees were planted in rows with a 10-ft spacing. The trees were cut in spring 2010. The resulting field was four acres, and this is the account of the first corn crop in 2011 on the area
Second generation Robo-AO instruments and systems
The prototype Robo-AO system at the Palomar Observatory 1.5-m telescope is
the world's first fully automated laser adaptive optics instrument. Scientific
operations commenced in June 2012 and more than 12,000 observations have since
been performed at the ~0.12" visible-light diffraction limit. Two new infrared
cameras providing high-speed tip-tilt sensing and a 2' field-of-view will be
integrated in 2014. In addition to a Robo-AO clone for the 2-m IGO and the
natural guide star variant KAPAO at the 1-m Table Mountain telescope, a second
generation of facility-class Robo-AO systems are in development for the 2.2-m
University of Hawai'i and 3-m IRTF telescopes which will provide higher Strehl
ratios, sharper imaging, ~0.07", and correction to {\lambda} = 400 nm.Comment: 11 pages, 4 figures, 3 table
Similarity Metrics for Closed Loop Dynamic Systems
To what extent and in what ways can two closed-loop dynamic systems be said to be "similar?" This question arises in a wide range of dynamic systems modeling and control system design applications. For example, bounds on error models are fundamental to the controller optimization with modern control design methods. Metrics such as the structured singular value are direct measures of the degree to which properties such as stability or performance are maintained in the presence of specified uncertainties or variations in the plant model. Similarly, controls-related areas such as system identification, model reduction, and experimental model validation employ measures of similarity between multiple realizations of a dynamic system. Each area has its tools and approaches, with each tool more or less suited for one application or the other. Similarity in the context of closed-loop model validation via flight test is subtly different from error measures in the typical controls oriented application. Whereas similarity in a robust control context relates to plant variation and the attendant affect on stability and performance, in this context similarity metrics are sought that assess the relevance of a dynamic system test for the purpose of validating the stability and performance of a "similar" dynamic system. Similarity in the context of system identification is much more relevant than are robust control analogies in that errors between one dynamic system (the test article) and another (the nominal "design" model) are sought for the purpose of bounding the validity of a model for control design and analysis. Yet system identification typically involves open-loop plant models which are independent of the control system (with the exception of limited developments in closed-loop system identification which is nonetheless focused on obtaining open-loop plant models from closed-loop data). Moreover the objectives of system identification are not the same as a flight test and hence system identification error metrics are not directly relevant. In applications such as launch vehicles where the open loop plant is unstable it is similarity of the closed-loop system dynamics of a flight test that are relevant
Conservation of long-range synteny and microsynteny between the genomes of two distantly related nematodes
BACKGROUND: Comparisons between the genomes of the closely related nematodes Caenorhabditis elegans and Caenorhabditis briggsae reveal high rates of rearrangement, with a bias towards within-chromosome events. To assess whether this pattern is true of nematodes in general, we have used genome sequence to compare two nematode species that last shared a common ancestor approximately 300 million years ago: the model C. elegans and the filarial parasite Brugia malayi. RESULTS: An 83 kb region flanking the gene for Bm-mif-1 (macrophage migration inhibitory factor, a B. malayi homolog of a human cytokine) was sequenced. When compared to the complete genome of C. elegans, evidence for conservation of long-range synteny and microsynteny was found. Potential C. elegans orthologs for II of the 12 protein-coding genes predicted in the B. malayi sequence were identified. Ten of these orthologs were located on chromosome I, with eight clustered in a 2.3 Mb region. While several, relatively local, intrachromosomal rearrangements have occurred, the order, composition, and configuration of two gene clusters, each containing three genes, was conserved. Comparison of B. malayi BAC-end genome survey sequence to C. elegans also revealed a bias towards intrachromosome rearrangements. CONCLUSIONS: We suggest that intrachromosomal rearrangement is a major force driving chromosomal organization in nematodes, but is constrained by the interdigitation of functional elements of neighboring genes
A Survey of Chromospheric Activity in the Solar-Type Stars in the Open Cluster M67
We present the results of a spectroscopic survey of the Ca II H & K core
strengths in a sample of 60 solar-type stars that are members of the solar-age
and solar-metallicity open cluster M67. We adopt the HK index, defined as the
summed H+K core strengths in 0.1 nm bandpasses centered on the H and K lines,
respectively, as a measure of the chromospheric activity that is present. We
compare the distribution of mean HK index values for the M67 solar-type stars
with the variation of this index as measured for the Sun during the
contemporary solar cycle. We find that the stellar distribution in our HK index
is broader than that for the solar cycle. Approximately 17% of the M67 sun-like
stars exhibit average HK indices that are less than solar minimum. About 7%-12%
are characterized by relatively high activity in excess of solar maximum values
while 72%-80% of the solar analogs exhibit Ca II H+K strengths within the range
of the modern solar cycle. The ranges given reflect uncertainties in the most
representative value of the maximum in the HK index to adopt for the solar
cycle variations observed during the period A.D. 1976--2004. Thus, ~ 20% - 30%
of our homogeneous sample of sun-like stars have mean chromospheric H+K
strengths that are outside the range of the contemporary solar cycle. Any
cycle-like variability that is present in the M67 solar-type stars appears to
be characterized by periods greater than ~ 6 years. Finally, we estimate a mean
chromospheric age for M67 in the range of 3.8--4.3 Gyr.Comment: Accepted in The Astrophysical Journa
Real‑world challenge for clinicians treating advanced gastroesophageal adenocarcinoma (Review)
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