1,934 research outputs found

    Extremely Luminous Water Vapor Emission from a Type 2 Quasar at Redshift z = 0.66

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    A search for water masers in 47 Sloan Digital Sky Survey Type 2 quasars using the Green Bank Telescope has yielded a detection at a redshift of z = 0.660. This maser is more than an order of magnitude higher in redshift than any previously known and, with a total isotropic luminosity of 23,000 L_sun, also the most powerful. The presence and detectability of water masers in quasars at z ~ 0.3-0.8 may provide a better understanding of quasar molecular tori and disks, as well as fundamental quasar and galaxy properties such as black hole masses. Water masers at cosmologically interesting distances may also eventually provide, via direct distance determinations, a new cosmological observable for testing the reality and properties of dark energy, currently inferred primarily through Type 1a supernova measurements.Comment: 8 pages including 1 figure; accepted for publication in ApJ Letter

    Demand for Mental Health Services: An Episode of Treatment Approach

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    This paper analyzes the demand for mental health services using data aggregated to the level of episode of treatment or the bundle of mental health services received during a period of continuous contact with the health care system. We estimate a multinomial logit model and provide estimates of the price elasticity of demand for episodes of mental health care by treatment category (inpatient, outpatient, outpatient with prescription drugs) and the price elasticity of demand for outpatient visits within an episode of care.Demand for health care services; price elasticity of demand; episodes of treatment

    Feral swine \u3ci\u3eSus scrofa\u3c/i\u3e: a new threat to the remaining breeding wetlands of the Vulnerable reticulated flatwoods salamander \u3ci\u3eAmbystoma bishopi\u3c/i\u3e

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    Feral swine Sus scrofa have been implicated as a major threat to sensitive habitats and ecosystems as well as threatened wildlife. Nevertheless, direct and indirect impacts on threatened species (especially small, fossorial species) are not well documented. The decline of the U.S. federally endangered reticulated flatwoods salamander Ambystoma bishopi, categorized as Vulnerable on the IUCN Red List, has been rapid and there are few remaining breeding locations for this species. The flatwoods salamander depends on complex herbaceous vegetation in all life stages, including eggs, larvae and adults. Historically sets of hog tracks have been observed only occasionally in the vicinity of monitored reticulated flatwoods salamander breeding wetlands, and damage to the wetlands had never been recorded. However, during the autumn–winter breeding season of 2013-2014 we observed a large increase in hog sign, including extensive rooting damage, in known flatwoods salamander breeding wetlands. Our objective was to assess the amount of hog sign and damage in these wetlands and to take corrective management actions to curb additional impacts. Of 28 wetlands surveyed for hog sign, presence was recorded at 68%, and damage at 54%. Of the 11 sites known to be occupied by flatwoods salamanders in 2013-2014, 64% had presence, and 55% had damage. We found that regular monitoring of disturbance in wetland habitats was a valuable tool to determine when intervention was needed and to assess the effectiveness of intervention. Habitat damage caused by feral hogs poses a potentially serious threat to the salamanders, which needs to be mitigated using methods to control and exclude hogs from this sensitive habitat

    Demand for Mental Health Services: An Episode of Treatment Approach

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    This paper analyzes the demand for mental health services using data aggregated to the level of episode of treatment or the bundle of mental health services received during a period of continuous contact with the health care system. We estimate a multinomial logit model and provide estimates of the price elasticity of demand for episodes of mental health care by treatment category (inpatient, outpatient, outpatient with prescription drugs) and the price elasticity of demand for outpatient visits within an episode of care

    Self-interaction chromatography as a tool for optimizing conditions for membrane protein crystallization

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    The second virial coefficient, or B value, is a measurement of how well a protein interacts with itself in solution. These interactions can lead to protein crystallization or precipitation, depending on their strength, with a narrow range of B values (the `crystallization slot') being known to promote crystallization. A convenient method of determining the B value is by self-interaction chromatography. This paper describes how the light-harvesting complex 1-reaction centre core complex from Allochromatium vinosum yielded single straight-edged crystals after iterative cycles of self-interaction chromatography and crystallization. This process allowed the rapid screening of small molecules and detergents as crystallization additives. Here, a description is given of how self-interaction chromatography has been utilized to improve the crystallization conditions of a membrane protein

    Predicting Dementia With Routine Care EMR Data

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    Our aim is to develop a machine learning (ML) model that can predict dementia in a general patient population from multiple health care institutions one year and three years prior to the onset of the disease without any additional monitoring or screening. The purpose of the model is to automate the cost-effective, non-invasive, digital pre-screening of patients at risk for dementia. Towards this purpose, routine care data, which is widely available through Electronic Medical Record (EMR) systems is used as a data source. These data embody a rich knowledge and make related medical applications easy to deploy at scale in a cost-effective manner. Specifically, the model is trained by using structured and unstructured data from three EMR data sets: diagnosis, prescriptions, and medical notes. Each of these three data sets is used to construct an individual model along with a combined model which is derived by using all three data sets. Human-interpretable data processing and ML techniques are selected in order to facilitate adoption of the proposed model by health care providers from multiple institutions. The results show that the combined model is generalizable across multiple institutions and is able to predict dementia within one year of its onset with an accuracy of nearly 80% despite the fact that it was trained using routine care data. Moreover, the analysis of the models identified important predictors for dementia. Some of these predictors (e.g., age and hypertensive disorders) are already confirmed by the literature while others, especially the ones derived from the unstructured medical notes, require further clinical analysis

    Homogeneous nucleation of a non-critical phase near a continuous phase transition

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    Homogeneous nucleation of a new phase near a second, continuous, transition, is considered. The continuous transition is in the metastable region associated with the first-order phase transition, one of whose coexisting phases is nucleating. Mean-field calculations show that as the continuous transition is approached, the size of the nucleus varies as the response function of the order parameter of the continuous transition. This response function diverges at the continuous transition, as does the temperature derivative of the free energy barrier to nucleation. This rapid drop of the barrier as the continuous transition is approached means that the continuous transition acts to reduce the barrier to nucleation at the first-order transition. This may be useful in the crystallisation of globular proteins.Comment: 6 pages, 1 figur

    The effect of the thioether-bridged, stabilized angiotensin-(1-7) analogue cyclic Ang-(1-7) on cardiac remodeling and endothelial function in rats with myocardial infarction

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    Modulation of renin-angiotensin system (RAS) by angiotensin-(17) (Ang-(17)) is an attractive approach to combat the detrimental consequences of myocardial infarction (MI). However Ang-(17) has limited clinical potential due to its unfavorable pharmacokinetic profile. We investigated effects of a stabilized, thioether-bridged analogue of Ang-(17) called cyclic Ang-(17) in rat model of myocardial infarction. Rats underwent coronary ligation or sham surgery. Two weeks thereafter infusion with 0.24 or 2.4 ÎĽg/kg/h cAng-(17) or saline was started for 8 weeks. Thereafter, cardiac morphometric and hemodynamic variables as wells as aortic endothelial function were measured. The average infarct size was 13.8 and was not changed by cAng-(17) treatment. MI increased heart weight and myocyte size, which was restored by cAng-(17) to sham levels. In addition, cAng-(17) lowered left ventricular end-diastolic pressure and improved endothelial function. The results suggest that cAng-(17) is a promising new agent in treatment of myocardial infarction and warrant further research.</p

    The effect of the thioether-bridged, stabilized angiotensin-(1-7) analogue cyclic Ang-(1-7) on cardiac remodeling and endothelial function in rats with myocardial infarction

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    Modulation of renin-angiotensin system (RAS) by angiotensin-(17) (Ang-(17)) is an attractive approach to combat the detrimental consequences of myocardial infarction (MI). However Ang-(17) has limited clinical potential due to its unfavorable pharmacokinetic profile. We investigated effects of a stabilized, thioether-bridged analogue of Ang-(17) called cyclic Ang-(17) in rat model of myocardial infarction. Rats underwent coronary ligation or sham surgery. Two weeks thereafter infusion with 0.24 or 2.4 ÎĽg/kg/h cAng-(17) or saline was started for 8 weeks. Thereafter, cardiac morphometric and hemodynamic variables as wells as aortic endothelial function were measured. The average infarct size was 13.8 and was not changed by cAng-(17) treatment. MI increased heart weight and myocyte size, which was restored by cAng-(17) to sham levels. In addition, cAng-(17) lowered left ventricular end-diastolic pressure and improved endothelial function. The results suggest that cAng-(17) is a promising new agent in treatment of myocardial infarction and warrant further research.</p
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