8,383 research outputs found
Inverse scattering results for manifolds hyperbolic near infinity
We study the inverse resonance problem for conformally compact manifolds
which are hyperbolic outside a compact set. Our results include compactness of
isoresonant metrics in dimension two and of isophasal negatively curved metrics
in dimension three. In dimensions four or higher we prove topological
finiteness theorems under the negative curvature assumption.Comment: 25 pages. v3: Minor corrections, references adde
ERS Farm Typology for a Diverse Agricultural Sector
The Economic Research Service (ERS) developed a farm typology which categorizes farms into more homogeneous groups than do classifications based on sales volume alone, producing a more effective policy development tool. The typology is used to describe U.S. farms.Farm Management,
Glial Cell Extracellular Matrix in Alzheimer’s Disease
Many studies have yielded conflicting results regarding the toxicity of AB, the peptide which is the principal component of senile plaques in brains of patients with Alzheimer\u27s disease. Using in vitro and in vivo models, we have studied the role of glial cells and extracellular matrix molecules m mediating the effects of AB. Glial cells respond to AB substrate by accumulating and depositing chondroitin sulfate proteoglycans (CSPGs) which are inhibitory to neurite outgrowth. CSPGs are present around the senile plaque core, an area with both dystrophic neurites and a general decrease in normal neurites. We suggest that CSPG may contribute to the pathology by leading to regenerative failure of neurites surrounding senile plaques
Direct Evidence for the Source of Reported Magnetic Behavior in "CoTe"
In order to unambiguously identify the source of magnetism reported in recent
studies of the Co-Te system, two sets of high-quality, epitaxial CoTe films
(thickness 300 nm) were prepared by pulse laser deposition (PLD).
X-ray diffraction (XRD) shows that all of the films are epitaxial along the
[001] direction and have the hexagonal NiAs structure. There is no indication
of any second phase metallic Co peaks (either or ) in the XRD
patterns. The two sets of CoTe films were grown on various substrates with
PLD targets having Co:Te in the atomic ratio of 50:50 and 35:65. From the
measured lattice parameters for the former and
for the latter, the compositions CoTe (63.1% Te) and CoTe
(63.8% Te), respectively, are assigned to the principal phase. Although XRD
shows no trace of metallic Co second phase, the magnetic measurements do show a
ferromagnetic contribution for both sets of films with the saturation
magnetization values for the CoTe films being approximately four times
the values for the CoTe films. Co spin-echo nuclear magnetic
resonance (NMR) clearly shows the existence of metallic Co inclusions in the
films. The source of weak ferromagnetism reported in several recent studies is
due to the presence of metallic Co, since the stoichiometric composition "CoTe"
does not exist.Comment: 19 pages, 7 figure
INCORPORATING GOVERNMENT PROGRAM PROVISIONS INTO A MEAN-VARIANCE FRAMEWORK
E-V studies traditionally have relied on historical data to calculate returns and variance. Historical data may not fully reflect current conditions, particularly when decisions involve government-supported crops. This paper presents a method for calculating mean and variance using subjectively-estimated data. The method is developed for both government-supported and non-program crops. Comparisons to alternative methods suggest the approach provides reasonable accuracy.Agricultural and Food Policy,
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Obituary for Prof. Paul Dubin
On May 23rd, 2018, Paul Dubin, Research Professor of Chemistry at the University of Massachusetts Amherst, passed away at the age of 77. Dubin was born in 1941 in New York City to Carolyn and George Dubin. He graduated from the Bronx High School of Science, City College of New York, in 1962, and received his PhD at Rutgers University in New Jersey in 1970 under the supervision of Ulrich P. Strauss. He went on to postdoctoral studies with Frank E. Karasz at the University of Massachusetts Amherst and David A. Brant at the University of California, Irvine from 1970–1972. Dubin worked as a research scientist at Dynapol, Memorex Corp., and Clairol Research Laboratories before joining the faculty in the Department of Chemistry at Indiana University–Purdue University Indianapolis, where he remained for most of his professional life. In 2005 Dubin returned to the University of Massachusetts Amherst as a part-time Research Professor
Chondroitin Sulfate Proteoglycans Are Associated with the Lesions of Alzheimer\u27s Disease
Chondroitin sulfate proteoglycans (CSPG) are extracellular matrix proteins inhibitory to neurite outgrowth in vitro and correlated with decreased neurite outgrowth after CNS injury. Previously, heparan sulfate proteoglycan and dermatan sulfate proteoglycan have been shown to be associated with senile plaques (SPs) and neurofibrillary tangles (NFTs) but CSPG was not. In an immunocytochemical study, three monoclonal antibodies to different sulfation states of the chondroitin glycosaminoglycan were used to localize CSPG in cases of Alzheimer\u27s disease. Chondroitin 4-sulfate was found in both SPs and NFTs. An antibody to unsulfated chondroitin strongly immunostained intracellular NFTs and the dystrophic neurites of SPs. Chondroitin 6-sulfate was found in NFTs and the area around SPs. These results suggest that CSPG, in addition or as an alternative to B-amyloid protein, could be responsible for the regression of neurites around senile plaques in Alzheimer\u27s disease
Impact of public release of performance data on the behaviour of healthcare consumers and providers.
BACKGROUND: It is becoming increasingly common to publish information about the quality and performance of healthcare organisations and individual professionals. However, we do not know how this information is used, or the extent to which such reporting leads to quality improvement by changing the behaviour of healthcare consumers, providers, and purchasers.
OBJECTIVES: To estimate the effects of public release of performance data, from any source, on changing the healthcare utilisation behaviour of healthcare consumers, providers (professionals and organisations), and purchasers of care. In addition, we sought to estimate the effects on healthcare provider performance, patient outcomes, and staff morale.
SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, and two trials registers on 26 June 2017. We checked reference lists of all included studies to identify additional studies.
SELECTION CRITERIA: We searched for randomised or non-randomised trials, interrupted time series, and controlled before-after studies of the effects of publicly releasing data regarding any aspect of the performance of healthcare organisations or professionals. Each study had to report at least one main outcome related to selecting or changing care.
DATA COLLECTION AND ANALYSIS: Two review authors independently screened studies for eligibility and extracted data. For each study, we extracted data about the target groups (healthcare consumers, healthcare providers, and healthcare purchasers), performance data, main outcomes (choice of healthcare provider, and improvement by means of changes in care), and other outcomes (awareness, attitude, knowledge of performance data, and costs). Given the substantial degree of clinical and methodological heterogeneity between the studies, we presented the findings for each policy in a structured format, but did not undertake a meta-analysis.
MAIN RESULTS: We included 12 studies that analysed data from more than 7570 providers (e.g. professionals and organisations), and a further 3,333,386 clinical encounters (e.g. patient referrals, prescriptions). We included four cluster-randomised trials, one cluster-non-randomised trial, six interrupted time series studies, and one controlled before-after study. Eight studies were undertaken in the USA, and one each in Canada, Korea, China, and The Netherlands. Four studies examined the effect of public release of performance data on consumer healthcare choices, and four on improving quality.There was low-certainty evidence that public release of performance data may make little or no difference to long-term healthcare utilisation by healthcare consumers (3 studies; 18,294 insurance plan beneficiaries), or providers (4 studies; 3,000,000 births, and 67 healthcare providers), or to provider performance (1 study; 82 providers). However, there was also low-certainty evidence to suggest that public release of performance data may slightly improve some patient outcomes (5 studies, 315,092 hospitalisations, and 7502 providers). There was low-certainty evidence from a single study to suggest that public release of performance data may have differential effects on disadvantaged populations. There was no evidence about effects on healthcare utilisation decisions by purchasers, or adverse effects.
AUTHORS\u27 CONCLUSIONS: The existing evidence base is inadequate to directly inform policy and practice. Further studies should consider whether public release of performance data can improve patient outcomes, as well as healthcare processes
Science-based restoration monitoring of coastal habitats, Volume Two: Tools for monitoring coastal habitats
Healthy coastal habitats are not only important ecologically; they also support healthy coastal communities and improve the quality of people’s lives. Despite their many benefits and values, coastal habitats have been systematically modified, degraded, and destroyed throughout the United States and its protectorates beginning with European colonization in the 1600’s (Dahl 1990). As a result, many coastal habitats around the United States are in desperate need of restoration. The monitoring of restoration projects, the focus of this document, is necessary to ensure that restoration efforts are successful, to further the science, and to increase the efficiency of future restoration efforts
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