4,312 research outputs found

    Switching Costs and Loyalty: Understanding How Trust Moderates Online Consumers’ Ties to Merchants

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    Information technology has transformed how travelers interact with travel service providers. Due to fierce competition in the online air travel industry, e-ticketing services have focused attention on fostering customer loyalty. This is an important strategy because, in general, initial transactions with new customers are less profitable than transactions with existing customers. Drawing on research on customer loyalty, switching costs, and trust, this study develops, and proposes an empirical test, for a model incorporating trust as a moderator of the relationship between switching costs and online customer loyalty. We propose that in the presence of high customer trust, e-businesses should have less need to rely on switching costs as a driver of customer loyalty. If supported, this proposition will extend understanding of customer loyalty, switching costs, and trust in e-commerce environments and provide practical, theory-driven, guidelines to e-businesses seeking to develop customer loyalty programs

    Discovery of a Classic FR-II Broad Absorption Line Quasar from the FIRST Survey

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    We have discovered a remarkable quasar, FIRST J101614.3+520916, whose optical spectrum shows unambiguous broad absorption features while its double-lobed radio morphology and luminosity clearly indicate a classic Fanaroff-Riley Type II radio source. Its radio luminosity places it at the extreme of the recently established class of radio-loud broad absorption line quasars (Becker et al. 1997, 2000; Brotherton et al. 1998). Because of its hybrid nature, we speculate that FIRST J101614.3+520916 is a typical FR-II quasar which has been rejuvenated as a broad absorption line (BAL) quasar with a Compact Steep Spectrum core. The direction of the jet axis of FIRST J101614.3+520916 can be estimated from its radio structure and optical brightness, indicating that we are viewing the system at a viewing angle of > 40 degrees. The position angles of the radio jet and optical polarization are not well-aligned, differing by 20 to 30 degrees. When combined with the evidence presented by Becker et al. (2000) for a sample of 29 BAL quasars showing that at least some BAL quasars are viewed along the jet axis, the implication is that no preferred viewing orientation is necessary to observe BAL systems in a quasar's spectrum. This, and the probable young nature of compact steep spectrum sources, leads naturally to the alternate hypothesis that BALs are an early stage in the lives of quasars.Comment: 14 pages, 6 postscript figures; accepted for publication in the Astrophysical Journa

    Cold hardiness and overwintering strategies of hatchlings in an assemblage of northern turtles.

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    Field and laboratory studies were conducted during 1989-1994 to investigate the overwintering strategies of hatching turtles representing four families native to western Nebraska. Whereas hatchling snapping turtles (Chelydra serpentina) and spiny soft-shelled turtles (Apalone spinifera) overwinter in aquatic habitats, yellow mud turtles (Kinosternon flavescens) and ornate box turtles (Terrapene ornata) burrow below the natal nest and hibernate in sandy soil. Painted turtles (Chrysemys picta) overwinter within their shallow natal nests, but this species, and T. ornata, tolerate extensive tissue freezing. Overwintering behaviors of these species are consistent with indices of physiological cold hardiness and patterns of geographic distribution. Frost commonly penetrated and persisted below 10 cm, the soil depth as which hatchling C. picta routinely hibernate. Field and laboratory data suggested that hatchling C. picta survive either by remaining super-cooled (unfrozen) or by tolerating tissue freezing, the strategy employed depending on prevailing physiological and microenvironmental conditions. Whereas relatively lower temperatures can be survived in the supercooled state, supercooling capacity may be limited via the inoculation of body fluids by environmental ice. Alternatively, wheras freeze tolerence fortuitously is promoted by ice inoculation, this strategy may be viable only at relatively high subzero temperatures. A cold-hardiness stragefy based on both survival mechanisms may promote winter survival in hatchling C. picta by conferring protection under dynamic physiological and microenvironmental conditions. Physiological cold hardiness and behavior are integrated determinants of the northern distributions of temperature region turtles

    Serum 25-Hydroxyvitamin D and Intact Parathyroid Hormone Influence Muscle Outcomes in Children and Adolescents

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    Increases in 25-hydroxyvitamin D concentrations are shown to improve strength in adults; however, data in pediatric populations are scant and equivocal. In this ancillary study of a larger-scale, multi-sited, double-blind, randomized, placebo-controlled vitamin D intervention in US children and adolescents, we examined the associations between changes in vitamin D metabolites and changes in muscle mass, strength, and composition after 12 weeks of vitamin D3 supplementation. Healthy male and female, black and white children and adolescents between the ages of 9 and 13 years from two US states (Georgia 34°N and Indiana 40°N) were enrolled in the study and randomly assigned to receive an oral vitamin D3 dose of 0, 400, 1000, 2000, or 4000 IU/d for 12 weeks between the winter months of 2009 to 2011 (N = 324). Analyses of covariance, partial correlations, and regression analyses of baseline and 12-week changes (post-baseline) in vitamin D metabolites (serum 25(OH)D, 1,25(OH)2 D, intact parathyroid hormone [iPTH]), and outcomes of muscle mass, strength, and composition (total body fat-free soft tissue [FFST], handgrip strength, forearm and calf muscle cross-sectional area [MCSA], muscle density, and intermuscular adipose tissue [IMAT]) were assessed. Serum 25(OH)D and 1,25(OH)2 D, but not iPTH, increased over time, as did fat mass, FFST, forearm and calf MCSA, forearm IMAT, and handgrip strength (p < 0.05). Vitamin D metabolites were not associated with muscle strength at baseline nor after the 12-week intervention. Changes in serum 25(OH)D correlated with decreases in forearm IMAT, whereas changes in serum iPTH predicted increases in forearm and calf MCSA and IMAT (p < 0.05). Overall, increases in 25(OH)D did not influence muscle mass or strength in vitamin D-sufficient children and adolescents; however, the role of iPTH on muscle composition in this population is unknown and warrants further investigation

    Atomic Hydrogen and Star Formation in the Bridge/Ring Interacting Galaxy Pair NGC 7714/7715 (Arp 284)

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    We present high spatial resolution 21 cm HI maps of the interacting galaxy pair NGC 7714/7715. We detect a massive (2 x 10**9 M(sun)) HI bridge connecting the galaxies that is parallel to but offset from the stellar bridge. A chain of HII regions traces the gaseous bridge, with H-alpha peaks near but not on the HI maxima. An HI tidal tail is also detected to the east of the smaller galaxy NGC 7715, similarly offset from a stellar tail. The strong partial stellar ring on the eastern side of NGC 7714 has no HI counterpart, but on the opposite side of NGC 7714 there is a 10**9 M(sun) HI loop 11 kpc in radius. Within the NGC 7714 disk, clumpy HI gas is observed associated with star formation regions. Redshifted HI absorption is detected towards the starburst nucleus. We compare the observed morphology and gas kinematics with gas dynamical models in which a low-mass companion has an off-center prograde collision with the outer disk of a larger galaxy. These simulations suggest that the bridge in NGC 7714/7715 is a hybrid between bridges seen in systems like M51 and the purely gaseous `splash' bridges found in ring galaxies like the Cartwheel. The offset between the stars and gas in the bridge may be due to dissipative cloud-cloud collisions occuring during the impact of the two gaseous disks.Comment: 31 pages, Latex, 11 figures, to be published in the July 10, 1997 issue of the Astrophysical Journa

    A Resolved Ring of Debris Dust around the Solar Analog HD 107146

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    We present resolved images of the dust continuum emission from the debris disk around the young (80-200 Myr) solar-type star HD 107146 with CARMA at λ = 1.3 mm and the CSO at λ = 350 Ό. Both images show that the dust emission extends over an approximately 10" diameter region. The high-resolution (3") CARMA image further reveals that the dust is distributed in a partial ring with significant decrease in a flux inward of 97 AU. Two prominent emission peaks appear within the ring separated by ~140° in the position angle. The morphology of the dust emission is suggestive of dust captured into a mean motion resonance, which would imply the presence of a planet at an orbital radius of ~45-75 AU

    Periodontal Status and Quality of Life: Impact of Fear of Pain and Dental Fear

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    Background. Oral health-related quality of life (OHRQoL) is impacted by periodontal disease and orofacial pain. There is a limited research examining the impact of avoidance of care or physiological arousal related to the fear of pain response on periodontal-related OHRQoL. Methods. Data are from the Center for Oral Health Research in Appalachia family-based study focusing on 1,339 adults. Measures included a modified Periodontal Screening and Recording Index across sextants of dentition, dental fear survey, Fear of Pain Questionnaire-9, and Oral Health Impact Profile-14. Structural equation modeling was used to estimate the effects of periodontal disease screening indicators on OHRQoL including the mediating role of dental fear while accounting for fear of pain. Results. A significant total effect was found for the mandibular anterior sextant, components of dental anxiety/fear, and indicators of OHRQoL (pain and discomfort, , ; psychosocial impact, , ). The maxillary anterior region was significantly associated with pain discomfort (, ) and functionality (, ). Conclusions. Findings provide a granular perspective of periodontal disease indicators and OHRQoL. Dental avoidance/anticipatory fear and physiological arousal mediate OHRQoL in individuals who have indicators of periodontal disease in sextants that may be visible and susceptible to higher pain and psychosocial impact
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