292 research outputs found

    Taking Stock of the Digital Revolution: A Critical Analysis and Agenda for Digital, Social Media, and Mobile Marketing Research

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    Marketing has been revolutionized due to the rise of digital media and new forms of electronic communication. In response, academic researchers have attempted to explain consumer- and firm-related phenomena related to digital, social media, and mobile marketing (DSMM). This paper presents a critical historical analysis of, and forward-looking agenda for, this work. First, we assess marketing’s contribution to understanding DSMM since 2000. Extant research falls under three eras, and a fourth era currently underway. Era 1 focused on digital tools and platforms as consumer and marketer decision aids. Era 2 studied online communications channels (e.g., online forums) as word of mouth marketing “laboratories,” capturing the potential of DSMM for social information transmission. Era 3 embraced the notion of “connected consumers” by considering various antecedents and consequences of socially interconnected consumers in marketplaces. Era 4, currently starting, considers mobile marketing and brings psychological and social theories to bear on emergent DSMM issues. Second, we critique the DSMM literature and advance a series of recommendations for future research. While we find much to applaud, we argue that several problems limit the relevance of this research moving forward and suggest ways to alleviate these concerns moving forward

    The photomultiplier tube calibration system of the MicroBooNE experiment

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    We report on the design and construction of a LED-based fiber calibration system for large liquid argon time projection detectors. This system was developed to calibrate the optical systems of the MicroBooNE experiment. As well as detailing the materials and installation procedure, we provide technical drawings and specifications so that the system may be easily replicated in future LArTPC detectors.National Science Foundation (U.S.) (Grant PHY-1205175

    Characterization of metal ion-induced [3H]inositol hexakisphosphate binding to rat cerebellar membranes

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    The binding of [3H]inositol hexakisphosphate ([3H] InsP6) to rat cerebellar membranes has been characterized with the objective of establishing the role, if any, of a membrane protein receptor. In the presence of EDTA, we have previously identified an InsP6-binding site with a capacity of approximately 20 pmol/mg protein (Hawkins, P. T., Reynolds, D. J. M., Poyner, D. R., and Hanley, M. R. (1990) Biochem. Biophys. Res. Commun. 167, 819-827). However, in the presence of 1 mM Mg2+, the capacity of [3H]InsP6 binding to membranes was increased approximately 9-fold. This enhancing effect of Mg2+ was reversed by addition of 10 microM of several cation chelators, suggesting that the increased binding required trace quantities of other metal cations. This is supported by experiments where it was possible to saturate binding by addition of excess membranes, despite not significantly depleting radioligand, pointing to removal of some other factor. Removal of endogenous cations from the binding assay by pretreatment with chelex resin also prevents the Mg(2+)-induced potentiation. Consideration of the specificity of the chelators able to abolish this potentiation suggested involvement of Fe3+ or Al3+. Both these ions (but not several others) were able to increase [3H]InsP6 binding to chelex-pretreated membranes at concentrations of 1 microM. It is possible to demonstrate synergy between Fe3+ and Mg2+ under these conditions. We propose that [3H]InsP6 may interact with membranes through non-protein recognition possibly via phospholipids, in a manner dependent upon trace metals. The implications of this for InsP6 biology are considered

    Experimental and theoretical determination of electronic properties in L

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    HS 2325+8205 - an ideal laboratory for accretion disk physics

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    We identify HS 2325+8205 as an eclipsing, frequently outbursting dwarf nova with an orbital period of 279.841731(5) min. Spectroscopic observations are used to derive the radial velocity curve of the secondary star from absorption features and also from the H-alpha emission lines, originating from the accretion disc, yielding K_secondary = K_abs = 237 +- 28 km/s and K_emn = 145 +- 9 km/s respectively. The distance to the system is calculated to be 400 (+200, -140) pc. A photometric monitoring campaign reveals an outburst recurrence time of 12-14 d, The combination of magnitude range (17-14 mag), high declination, eclipsing nature and frequency of outbursts makes HS 2325+8205 the ideal system for "real-time" studies of the accretion disc evolution and behavior in dwarf nova outbursts.Comment: 20 pages, 7 figures. Accepted for Publications of the Astronomical Society of the Pacifi

    GPCR-styrene maleic acid lipid particles (GPCR-SMALPs):their nature and potential

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    G-protein-coupled receptors (GPCRs) form the largest class of membrane proteins and are an important target for therapeutic drugs. These receptors are highly dynamic proteins sampling a range of conformational states in order to fulfil their complex signalling roles. In order to fully understand GPCR signalling mechanisms it is necessary to extract the receptor protein out of the plasma membrane. Historically this has universally required detergents which inadvertently strip away the annulus of lipid in close association with the receptor and disrupt lateral pressure exerted by the bilayer. Detergent-solubilized GPCRs are very unstable which presents a serious hurdle to characterization by biophysical methods. A range of strategies have been developed to ameliorate the detrimental effect of removing the receptor from the membrane including amphipols and reconstitution into nanodics stabilized by membrane scaffolding proteins (MSPs) but they all require exposure to detergent. Poly(styrene-co-maleic acid) (SMA) incorporates into membranes and spontaneously forms nanoscale poly(styrene-co-maleic acid) lipid particles (SMALPs), effectively acting like a 'molecular pastry cutter' to 'solubilize' GPCRs in the complete absence of detergent at any stage and with preservation of the native annular lipid throughout the process. GPCR-SMALPs have similar pharmacological properties to membrane-bound receptor, exhibit enhanced stability compared with detergent-solubilized receptors and being non-proteinaceous in nature, are fully compatible with downstream biophysical analysis of the encapsulated GPCR

    A 3-D PYRAMID/PRISM APPROACH TO VIEW KNOWLEDGE REQUIREMENTS FOR THE BATCH MEANS METHOD WHEN TAUGHT IN A LANGUAGE-FOCUSED, UNDERGRADUATE SIMULATION COURSE

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    We develop a 3-D knowledge pyramid/prism model to structure the relationships of (i) lower-level learning, (ii) ‘optional ’ knowledge bases, (iii) concurrent knowledge, and (ii) new knowledge; so one may view the learning needs of a higher-level learning objective. Our paradigm stems from Bloom’s taxonomy of learning, but has the advantage of supporting ‘just-in-time ’ and ‘learn-by-doing’ delivery, teaching and learning styles. We illustrate the paradigm through the BMMKP (the 3-D knowledge pyramid/prism model of the highest-level, batch-means-method learning objective for our language-focused, undergraduate course). The BMMKP reveals how highly dependent and fully integrated this learning is to calculus, probability, statistics, and queuing theory—regardless of the simulation modeling language chosen to teach in the course. The BMMKP is then used to develop a set of lower-level learning objectives for the undergraduate course. The 3-D pyramid/prism approach should lend itself well as a communication tool for visualizing other simulation learning objectives.
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