2,006 research outputs found

    Consumer evaluations of extension fit and its impact upon brand personality

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    While the use of extension strategies have been discussed to a great extent, there is a lack of empirical evidence into the affect extensions have upon core brand personality. The primary objective of this research is to address the apparent gap in the literature by empirically investigating the impact that extensions have on core brand personality. This study also seeks to examine the impact of extension fit upon consumer evaluations extensions. After reviewing the literature, a conceptual framework linking to a set of hypotheses was developed, highlighting the impact of fit upon consumer evaluations of (a) brand personality and (b) the extension. A before-after (with control) experimental design was chosen to test the research hypotheses. This type of design was selected due to the high level of control it possessed. Mail questionnaires were produced on the basis of the literature review (Chapter 2) and conceptual framework (Chapter 3). The research instrument was pretested and then presented to a sample of executive MBA students. A response of 102 matched cases was achieved. Previously established scales were used in order to collect the data (e.g. Aaker's 1997 scale was utilised to measure brand personality). Recognised measure development procedures were then employed in order to verify the reliability and validity of the measures. Finally, the hypotheses were tested via t- tests, ANCOVA and multiple regression analyses. The main findings suggest that whilst fit does significantly affect extension evaluations, it has little impact on brand personality. Specifically, there is no difference in brand personality evaluations due to good and poor levels of fit. However, higher levels of fit are associated with more favourable extension evaluations

    Scaling in a continuous time model for biological aging

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    In this paper we consider a generalization to the asexual version of the Penna model for biological aging, where we take a continuous time limit. The genotype associated to each individual is an interval of real numbers over which Dirac δ\delta--functions are defined, representing genetically programmed diseases to be switched on at defined ages of the individual life. We discuss two different continuous limits for the evolution equation and two different mutation protocols, to be implemented during reproduction. Exact stationary solutions are obtained and scaling properties are discussed.Comment: 10 pages, 6 figure

    Do Alterations in the Rate of Gastric Emptying after Injection Sclerotherapy for Oesophageal Varices Play any Role in the Development of Portal Hypertensive Gastropathy?

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    Bleeding from portal hypertensive gastropathy (PHG) has been estimated to account for upto 30% of all upper gastrointestinal haemorrhage in patients with cirrhosis and portal hypertension. Although portal hypertension seems to be an essential prerequisite, the precise mechanisms responsible for the development of PHG are unknown. The aim of this study was to examine the role of injection sclerotherapy of oesophageal varices in the development of PHG. Gastric emptying was studied using a radionuclide test meal with the emptying characteristics of a slow liquid in 57 patients with cirrhosis and/or portal hypertension (median age 53 yrs), of whom 34 had received injection sclerotherapy for their oesophageal varices and 20 normal healthy volunteers (median age 42 yrs). As vagal damage is associated with more rapid emptying of liquids, despite hold up of solids, this technique might be expected to demonstrate such damage if gastric emptying was accelerated. The results indicated that there was no difference in the rate of gastric emptying between normal healthy volunteers and portal hypertensive patients. However, patients who had received injection sclerotherapy emptied their stomachs faster than those who had not (p<0.05). Furthermore, the speed of gastric emptying correlated directly with the number of injections (r=0.41; p=0.02) and the volume of sclerosant injected (r=0.39; p=0.03). These observations suggest that injection sclerotherapy for oesophageal varices results in disturbances of gastric emptying that may contribute to the pathogenesis of portal hypertensive gastropathy

    Taking Development Seriously: Critique of the 2008 \u3ci\u3eJME\u3c/i\u3e Special Issue on Moral Functioning

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    This essay comments on articles that composed a Journal of Moral Education Special Issue (September, 2008, 37[3]). The issue was intended to honor the 50th anniversary of Lawrence Kohlberg’s doctoral dissertation and his subsequent impact on the field of moral development and education. The articles were characterized by the issue editor (Don Collins Reed) as providing a “look forward” from Kohlberg’s work toward a more comprehensive or integrated model of moral functioning. Prominent were culturally pluralist and biologically based themes, such as cultural learning; expert skill; culturally shaped and neurobiologically based predispositions or intuitions; and moral self-relevance or centrality. Inadequately represented, however, was Kohlberg’s (and Piaget’s) key concept of development as the construction of a deeper or more adequate understanding not reducible to particular socialization practices or cultural contexts. Also neglected were related cognitive-developmental themes, along with supportive evidence. Robert Coles’s account of a sudden rescue is used as a heuristic to depict Piaget’s/Kohlberg’s approach to the development of moral functioning. We conclude that, insofar as the Special Issue does not take development seriously, it moves us not forward but, instead, back to the problems of moral relativism and moral paralysis that Kohlberg sought to redress from the start of his work more than 50 years ago

    Epithelial senescence in idiopathic pulmonary fibrosis is propagated by small extracellular vesicles

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    BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease that affects 3 million people worldwide. Senescence and small extracellular vesicles (sEVs) have been implicated in the pathogenesis of IPF, although how sEVs promote disease remains unclear. Here, we profile sEVs from bronchial epithelial cells and determine small RNA (smRNA) content. METHODS: Conditioned media was collected and sEVs were isolated from normal human bronchial epithelial cells (NHBEs) and IPF-diseased human bronchial epithelial cells (DHBEs). RESULTS: Increased sEV release from DHBEs compared to NHBEs (n = 4; p < 0.05) was detected by nanoparticle tracking analysis. NHBEs co-cultured with DHBE-derived sEVs for 72 h expressed higher levels of SA-β-Gal and γH2AX protein, p16 and p21 RNA and increased secretion of IL6 and IL8 proteins (all n = 6-8; p < 0.05). sEVs were also co-cultured with healthy air-liquid interface (ALI) cultures and similar results were observed, with increases in p21 and p16 gene expression and IL6 and IL8 (basal and apical) secretion (n = 6; p < 0.05). Transepithelial electrical resistance (TEER) measurements, a reflection of epithelial barrier integrity, were decreased upon the addition of DHBE-derived sEVs (n = 6; p < 0.05). smRNA-sequencing identified nineteen significantly differentially expressed miRNA in DHBE-derived sEVs compared to NHBE-derived sEVs, with candidate miRNAs validated by qPCR (all n = 5; p < 0.05). Four of these miRNAs were upregulated in NHBEs co-cultured with DHBE-derived sEVs and three in healthy ALI cultures co-cultured with DHBE-derived sEVs (n = 3-4; p < 0.05). CONCLUSIONS: This data demonstrates that DHBE-derived sEVs transfer senescence to neighbouring healthy cells, promoting the disease state in IPF

    Observations of Persistent Leonid Meteor Trails. 1. Advection of the Diamond Ring

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    From a single image of a persistent trail left by a -1.5 magnitude Leonid meteor on November 17, 1998, the relative winds between 92.5 and 98 km altitude are derived, where the altitudes are determined by a sodium lidar. These are converted to true winds 82 sec after the appearance of the meteor by fixing the winds at 98 km to match the results of following the trail with the lidar for twelve minutes. The image and winds reveal a fine example of the effects of a gravity wave having a vertical wavelenth of 5.50 ± 0.02 km, a horizontal wavelength of 2650 ± 60 kin, an intrinsic period of 19.5 ± 0.4 hours, and an observed period of 8.6 ± 0.1 hours. Effects of the gravity wave are still present in the wind field 70 rain later

    Single molecule binding of a ligand to a G-protein-coupled receptor in real time using fluorescence correlation spectroscopy, rendered possible by nano-encapsulation in styrene maleic acid lipid particles

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    The fundamental importance of membrane proteins in cellular processes has driven a marked increase in the use of membrane mimetic approaches for studying and exploiting these proteins. Nano-encapsulation strategies which preserve the native lipid bilayer environment are particularly attractive. Consequently, the use of poly(styrene co-maleic acid) (SMA) has been widely adopted to solubilise proteins directly from cell membranes by spontaneously forming "SMA Lipid Particles" (SMALPs). G-protein-coupled receptors (GPCRs) are ubiquitous "chemical switches", are central to cell signalling throughout the evolutionary tree, form the largest family of membrane proteins in humans and are a major drug discovery target. GPCR-SMALPs that retain binding capability would be a versatile platform for a wide range of down-stream applications. Here, using the adenosine A2A receptor (A2AR) as an archetypical GPCR, we show for the first time the utility of fluorescence correlation spectroscopy (FCS) to characterise the binding capability of GPCRs following nano-encapsulation. Unbound fluorescent ligand CA200645 exhibited a monophasic autocorrelation curve (dwell time, τD = 68 ± 2 μs; diffusion coefficient, D = 287 ± 15 μm2 s-1). In the presence of A2AR-SMALP, bound ligand was also evident (τD = 625 ± 23 μs; D = 30 ± 4 μm2 s-1). Using a non-receptor control (ZipA-SMALP) plus competition binding confirmed that this slower component represented binding to the encapsulated A2AR. Consequently, the combination of GPCR-SMALP and FCS is an effective platform for the quantitative real-time characterisation of nano-encapsulated receptors, with single molecule sensitivity, that will have widespread utility for future exploitation of GPCR-SMALPs in general
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