499 research outputs found

    Michael Dorman to Newsday, 28 September 1962

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    Dorman relates an interview with John Faulkner, emphasizes the town\u27s connection to William Faulkner, and discusses varied opinions on the ongoing situation.https://egrove.olemiss.edu/west_union_med/1056/thumbnail.jp

    Mass Loss In M67 Giants: Evidence From Isochrone Fitting

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    We present a study of the stellar content of the open cluster M67. We have computed new evolutionary sequences of stellar models with solar abundance that cover all phases of evolution from the Zero-Age Main Sequence to the bright end of the Asymptotic Giant Branch (AGB). We examine the fit between the calculated and the observed red giant branch (RGB) in particular, and discuss factors that most influence its quality. The distinct color gap between the RGB and the clump giants is compared with the temperature gap between the He-burning tracks and the computed 5 Gyr isochrone. This purely differential approach strongly indicates that the clump giants have M \lta 0.70\msun\ , implying an amount of mass loss (0.6\approx 0.6 \msun) well in excess of that found in globular cluster stars. Observational constraints on mass loss processes favor the interpretation that mass loss in cool low-mass giant stars increases with metallicity.Comment: 21pp., plain TeX astro-ph/yymmnn

    How does socio-economic and demographic dissimilarity determine physical and virtual segregation?

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    It is established that socio-economic and demographic dissimilarities between populations are determinants of spatial segregation. However, the understanding of how such dissimilarities translate into actual segregation is limited. We propose a novel network-analysis approach to comprehensively study the determinants of communicative and mobility-related spatial segregation, using geo-tagged Twitter data. We constructed weighted spatial networks representing tie strength between geographical areas, then modeled tie formation as a function of socio-economic and demographic dissimilarity between areas. Physical and virtual tie formation were affected by income, age, and race differences, although these effects were smaller by an order of magnitude than the geographical distance effect. Tie formation was more frequent when destination area had higher median income and lower median age. We hypothesize that physical tie formation is more costly than a virtual one resulting in stronger segregation in the physical world. Economic and cultural motives may result in stronger segregation of relatively rich and young populations from their surroundings. Our methodology can help identify types of states that lead to spatial segregation and thus guide planning decisions for reducing its adverse effects

    Possible High-Redshift, Low-Luminosity AGN Activity in the Hubble Deep Field

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    In the Hubble Deep Field (HDF), twelve candidate sources of high-redshift (z > 3.5) AGN activity have been identified. The color selection criteria were established by passing spectra of selected quasars and Seyfert galaxies (appropriately redshifted and modified for "Lyman forest" absorption), as well as stars, observed normal and starburst galaxies, and galaxy models for various redshifts through the filters used for the HDF observations. The actual identification of AGN candidates also involved convolving a Laplacian-of-Gaussian filter with the HDF images, thereby removing relatively flat galactic backgrounds and leaving only the point-like components in the centers. Along with positions and colors, estimated redshifts and absolute magnitudes are reported, with the candidates falling toward the faint end of the AGN luminosity function. One candidate has been previously observed spectroscopically, with a measured redshift of 4.02. The number of sources reported here is consistent with a simple extrapolation of the observed quasar luminosity function to magnitude 30 in B_Johnson. Implications for ionization of the intergalactic medium and for gravitational lensing are discussed.Comment: 10 pages LaTex plus 2 separate files (Table 1 which is a two-page landscape LaTex file; and Figure 6 which is a large (0.7 MB) non-encapsulated postscript file). Accepted for publication in the Astronomical Journa

    Derived Parameters for NGC 6791 from High-Metallicity Isochrones

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    We have computed 8, 10, and 12 Gyr isochrones and physically consistent models of zero-age red horizontal branch stars for stellar masses between 0.55 and 1.3~\msun, all at [Fe/H] =+0.15=+0.15. Comparison to the NGC 6791 BVI photometry of Ka{\l}u\.zny & Udalski (1992) and Montgomery, Janes & Phelps (1994) yields an age of 10.0±0.510.0\pm0.5 Gyr at an apparent distance modulus 13.49 < \dmv < 13.70. The color offsets required to fit the isochrones, combined with the spectroscopic results of Friel & Janes, imply that the foreground reddening to NGC 6791 lies in the range 0.24 > \ebv >0.19 with +0.27<+0.27 < [Fe/H] <+0.44<+0.44. The zero-age horizontal branch models suggest that the red horizontal branch stars of NGC 6791 have masses \lesssim 0.7\msun. The masses are similar to those found for M67 red clump stars by Tripicco, Dorman & Bell (1993) and for globular cluster red horizontal branch stars, despite higher and lower masses (respectively) in those cases. This suggests the presence of a mechanism that tends to reduce stellar envelopes on the zero-age horizontal branch {\it to} a given mass rather than {\it by} a given amount.Comment: 23 pages, postscript fil

    Peculiar Multimodality on the Horizontal Branch of the Globular Cluster NGC 2808

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    We present distributions of colors of stars along the horizontal branch of the globular cluster NGC 2808, from Hubble Space Telescope WFPC2 imaging in B, V, and an ultraviolet filter (F218W). This cluster's HB is already known to be strongly bimodal, with approximately equal-sized HB populations widely separated in the color-magnitude diagram. Our images reveal a long blue tail with two gaps, for a total of four nearly distinct HB groups. These gaps are very narrow, corresponding to envelope-mass differences of only \sim 0.01 Msun. This remarkable multimodality may be a signature of mass-loss processes, subtle composition variations, or dynamical effects; we briefly summarize the possibilities. The existence of narrow gaps between distinct clumps on the HB presents a challenge for models that attempt to explain HB bimodality or other peculiar HB structures.Comment: LaTeX, including compressed figures. To appear in ApJL. Larger (851k) PostScript version, including high-quality figures, available from http://astro.berkeley.edu/~csosin/pub

    Budget impact of adding ivabradine to standard of care in patients with chronic systolic heart failure in the United States

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    BACKGROUND: Heart failure (HF) costs 21billionannuallyindirecthealthcarecosts,80OBJECTIVE:ToestimatethebudgetimpactofivabradinefromaU.S.commercialpayerperspective.METHODS:Abudgetimpactmodelestimatedthepermemberpermonth(PMPM)impactofintroducingivabradinetoexistingformulariesbycomparingareferencescenario(SoC)andanewdrugscenario(ivabradine+SoC)inhypothetical1millionmembercommercialandMedicareAdvantageplans.Inbothscenarios,U.S.claimsdatawereusedforthereferencecumulativeannualratesofhospitalizations(HF,nonHFcardiovascular[CV],andnonCV),andhospitalizationrateswereadjustedusingSHIFTdata.ThemodelcontrolledformortalityriskusingSHIFTandU.S.lifetabledata,andhospitalizationcostswereobtainedfromU.S.claimsdata:HFrelated=21 billion annually in direct health care costs, 80% of which is directly attributable to hospitalizations. The SHIFT clinical study demonstrated that ivabradine plus standard of care (SoC) reduced HF-related and all-cause hospitalizations compared with SoC alone. OBJECTIVE: To estimate the budget impact of ivabradine from a U.S. commercial payer perspective. METHODS: A budget impact model estimated the per-member-per month (PMPM) impact of introducing ivabradine to existing formularies by comparing a reference scenario (SoC) and a new drug scenario (ivabradine + SoC) in hypothetical 1 million-member commercial and Medicare Advantage plans. In both scenarios, U.S. claims data were used for the reference cumulative annual rates of hospitalizations (HF, non-HF cardiovascular [CV], and non-CV), and hospitalization rates were adjusted using SHIFT data. The model controlled for mortality risk using SHIFT and U.S. life table data, and hospitalization costs were obtained from U.S. claims data: HF-related = 37,507; non-HF CV = 28,951;andnonCV=28,951; and non-CV = 17,904. The annualized wholesale acquisition cost of ivabradine was 4,500,withbaselineuseforthisnewdrugat2RESULTS:BasedontheapprovedU.S.indication,approximately2,000commerciallyinsuredpatientsfroma1millionmembercommercialplanwereeligibletoreceiveivabradine.IvabradineresultedinaPMPMcostsavingsof4,500, with baseline use for this new drug at 2%, increasing 2% per year. RESULTS: Based on the approved U.S. indication, approximately 2,000 commercially insured patients from a 1 million-member commercial plan were eligible to receive ivabradine. Ivabradine resulted in a PMPM cost savings of 0.01 and 0.04inyears1and3ofthecoremodel,respectively.Afterincludingtheacquisitionpriceforivabradine,themodelshowedadecreaseintotalcostsinthecommercial(0.04 in years 1 and 3 of the core model, respectively. After including the acquisition price for ivabradine, the model showed a decrease in total costs in the commercial (991,256 and 474,499,respectively)andMedicarepopulations(474,499, respectively) and Medicare populations (13,849,262 and 4,280,291,respectively)inyear1.Thisdecreasewasdrivenbyivabradinesreductioninhospitalizationrates.Forthecoremodel,theestimatedpharmacyonlyPMPMinyear1was4,280,291, respectively) in year 1. This decrease was driven by ivabradine’s reduction in hospitalization rates. For the core model, the estimated pharmacy-only PMPM in year 1 was 0.01 for the commercial population and $0.24 for the Medicare Advantage population. CONCLUSIONS: Adding ivabradine to SoC led to lower average annual treatment costs. The negative PMPM budget impact indicates that ivabradine is an affordable option for U.S. payers

    Update on a Pharmacokinetic-Centric Alternative Tier II Program for MMT—Part I: Program Implementation and Lessons Learned

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    Concerns have been raised regarding environmental manganese exposure since high exposures have been associated with neurological disorders. The USA Environmental Protection Agency most recent human health risk assessment of inhaled manganese conducted in 1993 identified specific areas of uncertainty regarding manganese pharmacokinetics. This led to the development of a test rule under the USA Clean Air Act that required the generation of pharmacokinetic information on the inorganic manganese combustion products of the organometallic fuel additive methylcyclopentadienyl manganese tricarbonyl (MMT). The Alternative Tier 2 testing program for MMT, described in this paper, has yielded substantial pharmacokinetic data and has enabled the generation of physiologically based pharmacokinetic (PBPK) models for manganese. These models are capable of predicting tissue manganese concentrations across a variety of dose routes, levels, and durations while accounting for factors such as age, gender, and reproductive status, enabling the consideration of tissue dosimetry in future risk assessments

    A sensitive soil biological indicator to changes in land-use in regions with Mediterranean climate

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    The demand for reliable indicators to quantify soil health has increased recently. We propose and test the use of soil microbial functional diversity as an indicator of multifunctional performance in agriculturally important areas. Agricultural fields in the Mediterranean and semiarid regions of Israel were selected as test sites and measured in Spring and Autumn seasons. Measurements included microbial parameters, basic soil abiotic properties and biological responses to agricultural management relative to measures of a natural ecosystem. Using a canonical correlation analysis we found that soil moisture was the most important basic soil property with different responses in Spring and Autumn. In Spring, it had a strongly negative relation with microbial biomass (MB), community level physiological profiling (CLPP) and the Shannon-Weaver index H', while in Autumn it had a strong relation with CLPP. We further show a significant interaction between CLPP and climate for land-use type "orchards". CLPP measured in the autumn season was thus identified as a useful and rapid biological soil health indicator, recommended for application in semiarid and Mediterranean agricultural regions. Apart from obtaining a better understanding of CLPP as the soil indicator, the study concludes that CLPP is well suited to differentiate between soils in different climates, seasons and land use types. The study shows a promising direction for further research on characterizing soil health under a larger variety of conditions.</p
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