7,997 research outputs found

    Gamma-ray Novae: Rare or Nearby?

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    Classical Novae were revealed as a surprise source of gamma-rays in Fermi LAT observations. During the first 8 years since the LAT was launched, 6 novae in total have been detected to > 5 sigma in gamma-rays, in contrast to the 69 discovered optically in the same period. We attempt to resolve this discrepancy by assuming all novae are gamma-ray emitters, and assigning peak one-day fluxes based on a flat distribution of the known emitters to a simulated population. To determine optical parameters, the spatial distribution and magnitudes of bulge and disc novae in M31 are scaled to the Milky Way, which we approximate as a disc with a 20 kpc radius and elliptical bulge with semi major axis 3 kpc and axis ratios 2:1 in the xy plane. We approximate Galactic reddening using a double exponential disc with vertical and radial scale heights of r_d = 5 kpc and z_d = 0.2 kpc, and demonstrate that even such a rudimentary model can easily reproduce the observed fraction of gamma-ray novae, implying that these apparently rare sources are in fact nearby and not intrinsically rare. We conclude that classical novae with m_R < 12 and within ~8 kpc are likely to be discovered in gamma-rays using the Fermi LAT.Comment: Accepted by MNRAS, 10 pages, 7 figure

    Mobile App Monetization – Expectations and Attitudes Formed by Users in Response to Advertising and Pay To Download Monetization Models

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    Professional project report submitted in partial fulfillment of the requirements for the degree of Masters of Arts in Journalism from the School of Journalism, University of Missouri--Columbia.This research attempts to discover the attitudes and expectations formed by different methods of mobile app monetization in users who have paid to download apps or encountered any method of monetization in their use of apps. The goal is to help lead app developers and marketers to proper conclusions about how to monetize mobile apps in ways that are unobtrusive to users. The research is completed via focus group and online survey. Upon examination, it is clear users prefer a single method of monetization -- pay to download OR advertising based, for example -- rather than a hybrid approach commonly seen in traditional media. Men may be more likely to download apps on a more frequent basis, also paying for upgrades more frequently. Users seek out brands they recognize and rely on friends and other users to provide them information about apps they should download.Includes bibliographic references

    Partnering with healthcare: The experiences of consumer representatives

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    The importance of consumer advocacy in person-centred healthcare service planning and delivery is growing. In Australia, the role of the Consumer Representative (known internationally as Patient and Family Advisors ) is to advocate for patients and their families\u27 needs to improve service planning, healthcare design, and service evaluation. As the role of consumer representatives evolves and matures within the healthcare setting, it is crucial to comprehend their experiences and identify key insights to support and enhance their role within healthcare organizations. To achieve this, a focus group of four Consumer Representatives was conducted and their views were compiled into a single commentary. Our findings suggest that Consumers Representatives are driven by a desire to assist others, but they may feel dissatisfied if their role is perceived as tokenistic or lacks meaningful engagement. Consumer Representatives suggested various ways to improve consumer participation, including role clarification, meeting facilitation, and the development of supportive consumer networks. Experience Framework This article is associated with the Patient, Family & Community Engagement lens of The Beryl Institute Experience Framework (https://www.theberylinstitute.org/ExperienceFramework). Access other PXJ articles related to this lens. Access other resources related to this lens

    Slow Axonal Transport of Neurofilament Protein in Cultured Neurons

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    We have investigated the axonal transport of neurofilament protein in cultured neurons by constricting single axons with fine glass fibers. We observed a rapid accumulation of anterogradely and retrogradely transported membranous organelles on both sides of the constrictions and a more gradual accumulation of neurofilament protein proximal to the constrictions. Neurofilament protein accumulation was dependent on the presence of metabolic substrates and was blocked by iodoacetate, which is an inhibitor of glycolysis. These data indicate that neurofilament protein moves anterogradely in these axons by a mechanism that is directly or indirectly dependent on nucleoside triphosphates. The average transport rate was estimated to be at least 130 μm/h (3.1 mm/d), and ∼90% of the accumulated neurofilament protein remained in the axon after detergent extraction, suggesting that it was present in a polymerized form. Electron microscopy demonstrated that there were an abnormally large number of neurofilament polymers proximal to the constrictions. These data suggest that the neurofilament proteins were transported either as assembled polymers or in a nonpolymeric form that assembled locally at the site of accumulation. This study represents the first demonstration of the axonal transport of neurofilament protein in cultured neurons

    OB Associations

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    Since the previous (1990) edition of this meeting enormous progress in the field of OB associations has been made. Data from X-ray satellites have greatly advanced the study of the low-mass stellar content of associations, while astrometric data from the Hipparcos satellite allow for a characterization of the higher-mass content of associations with unprecedented accuracy. We review recent work on the OB associations located within 1.5 kpc from the Sun, discuss the Hipparcos results at length, and point out directions for future research.Comment: To appear in The Physics of Star Formation and Early Stellar Evolution II, eds C.J. Lada & N. Kylafis (Kluwer Academic), 30 pages, 9 EPS-figures, LaTeX using crckapb.sty, epsfig.sty, amssymb.st

    Wild Bill Donovan: The Last Hero

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    Law and Finance Matter: Lessons from Externally Imposed Courts

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    This paper provides novel evidence on the real and financial market effects of legal institutions. Our analysis exploits persistent and externally imposed differences in court enforcement that arose when the U.S. Congress assigned state courts to adjudicate contracts on a subset of Native American reservations. Using area-specific data on small business lending, we find that reservations assigned to state courts, which enforce contracts more predictably than tribal courts, have stronger credit markets. Moreover, the law-driven component of credit market development is associated with significantly higher per capita income, with stronger effects in sectors that depend more on external financing

    Courting Economic Development

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    We show that court enforcement uncertainty hinders economic development using sharp variation in judiciaries across Native American reservations in the United States. Congressional legislation passed in 1953 assigned state courts the authority to resolve civil disputes on a subset of reservations, while tribal courts retained authority on unaffected reservations. Although affected and unaffected reservations had similar economic conditions when the law passed, reservations under state courts experienced significantly greater long-run growth. When we examine the distribution of incomes across reservations, the average difference in development is due to the lower incomes of the most impoverished reservations with tribal courts. We show that the relative under-development of reservations with tribal courts is driven by reservations with the most uncertainty in court enforcement
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