394 research outputs found

    The digital surgeon\u27s warning: Do disclaimers have a place in beauty and fashion advertising?

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    The purpose of this study is to investigate the effects of disclaimers of photogenic manipulation, models’ body types, and the interaction between the two through the theoretical lenses of social comparison theory and priming effects. In an online experiment, this study employs a 3 (no disclaimer, presence of digital enhancement disclaimer, absence of digital enhancement disclaimer) by 2 (thin model body type and average model body type) factorial analysis to tease apart the effects of disclaimers on consumers (social comparison, self-esteem, and wishful identification) and the organizations that are compelled or choose to employ them (brand attitudes and perceptions of credibility, perceived organizational morality, purchasing intention, and loyalty). The results of this study highlight the implications and considerations for advertisements in the beauty and fashion industries as well as any company that uses digital manipulation on physically attractive models in their advertisements

    Catalysts for Portable, Solid State Hydrogen Genration Systems

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    Hydrogen and air powered proton exchange membrane fuel cells are a potential alternative to batteries. In portable power systems, the design requirements often focus on cost efficiency, energy density, storability, as well as safety. Ammonia borane (AB), a chemical hydride containing 19.6 wt. % hydrogen, has a high hydrogen capacity and is a stable and non-toxic candidate for storing hydrogen in portable systems. Throughout this work, Department of Energy guidelines for low power portable hydrogen power systems were used as a baseline and comparison with commercially available systems. In order to make this comparison, the system parameters of a system using AB hydrolysis were estimated by developing capacity and cost correlations from the commercial systems and applying them to this work. Supporting experiments were designed to evaluate a system that would use a premixed solid storage bed of AB and a catalyst. This configuration would only require a user input of water in order to initiate the hydrogen production. Using ammonia borane hydrolysis, the hydrogen yield is ∌9 wt. %, when all reactants are considered. In addition to the simplicity of initiating the reaction, hydrolysis of AB has the advantage of suppressing the production of some toxic borazines that are present when AB is thermally decomposed. However, ammonia gas will be formed and this problem must be addressed, as ammonia is damaging to PEM fuel cells. The catalyst focused on throughout this work was Amberlyst - 15; an ion exchange resin with an acid capacity of 4.7 eq/kg and ammonia adsorbent. At less than 0.30/g,thisisacosteffectivealternativetopreciousmetalcatalysts.Thetestingwiththiscatalystwascomparedtoatraditionalcatalystinliterature,200.30/g, this is a cost effective alternative to precious metal catalysts. The testing with this catalyst was compared to a traditional catalyst in literature, 20% platinum in carbon, costing more than 40/g. The Amberlyst catalyst was found to reduce the formation of ammonia in the gas products from ∌3.71 wt. % with the Pt/C catalyst to90 % to \u3c 30 % over a 70 day aging study. This results implies the need for a systems scale solution, such as mechanical separation, or a material scale solution, such as coating the Amberlyst or AB in a water soluble coating. It was found that ammonia borane catalyzed hydrolysis, using Amberlyst - 15 as a catalyst, has potential to be a cost effective, energy dense, and safe option for generating hydrogen for a portable fuel cell system

    AUTOMATIC POST-ADOPTIVE INFORMATION TECHNOLOGY USE: THE ROLE OF INNOVATIVENESS GOAL

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    The business value of information technology (IT) is realized through the continuous use of IT subsequent to users’ adoption. Understanding post-adoptive IT usage is useful in realizing potential IT business value. Most previous research on post-adoptive IT usage, however, dismisses the unintentional and unconscious aspects of usage behavior. This paper advances understanding of the unintentional, unconscious, and thereby automatic usage of IT features during the post-adoptive stage. Drawing from Social Psychology literature, we argue human behaviors can be triggered by environmental cues and directed by the person’s mental goals, thereby operating without a person’s consciousness and intentional will. On this basis, we theorize the role of a user’s innovativeness goal, as the desired state of an act to innovate, in directing the user’s unintentional, unconscious, and automatic post-adoptive IT feature usage behavior. To test the hypothesized mechanisms, a human experiment employing a priming technique, is described

    Optimization under uncertainty and risk: Quadratic and copositive approaches

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    Robust optimization and stochastic optimization are the two main paradigms for dealing with the uncertainty inherent in almost all real-world optimization problems. The core principle of robust optimization is the introduction of parameterized families of constraints. Sometimes, these complicated semi-infinite constraints can be reduced to finitely many convex constraints, so that the resulting optimization problem can be solved using standard procedures. Hence flexibility of robust optimization is limited by certain convexity requirements on various objects. However, a recent strain of literature has sought to expand applicability of robust optimization by lifting variables to a properly chosen matrix space. Doing so allows to handle situations where convexity requirements are not met immediately, but rather intermediately. In the domain of (possibly nonconvex) quadratic optimization, the principles of copositive optimization act as a bridge leading to recovery of the desired convex structures. Copositive optimization has established itself as a powerful paradigm for tackling a wide range of quadratically constrained quadratic optimization problems, reformulating them into linear convex-conic optimization problems involving only linear constraints and objective, plus constraints forcing membership to some matrix cones, which can be thought of as generalizations of the positive-semidefinite matrix cone. These reformulations enable application of powerful optimization techniques, most notably convex duality, to problems which, in their original form, are highly nonconvex. In this text we want to offer readers an introduction and tutorial on these principles of copositive optimization, and to provide a review and outlook of the literature that applies these to optimization problems involving uncertainty

    Accuracy Analysis of the Measurement of Centre of Gravity and Moment of Inertia with a Swing

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    Floating devices under wave and current loads are typically designed based on numerical methods followed by a validation with experimental investigations. This allows an independent check due to the comparison of two different modelling approaches based on different assumptions. At an early stage of the project, numerical simulations are based on theoretical (ideal) values of the centre of gravity (CG) and moment of inertia (MI). The building process of a scaled model results very often in a requested simplification of certain parts, which can influence the CG and also the MI of the scaled model. Knowing those discrepancies allows us to improve the comparability of both approaches but the measurement of those values is connected with either a higher uncertainty or a high level of effort. A significant improvement of such measurements can be reached by the deployment of a specific experimental set-up. This paper presents the classification of the newly designed swing with a high accuracy inertial inclinometer, which was verified by the marker-based motion capturing system. The achieved experiences are useful for the future use of the set-up as well as similar investigations. The comparison with the theoretical values for the swing as well as an example model showed very good agreements and a high accuracy of few millimetres for the CG and an error smaller 1% for MI

    Analyse des Einflusses von unterschiedlichen Narkoseverfahren auf die intraoperative HĂ€modynamik und den Katecholaminbedarf bei Lebertransplantation

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    Zielsetzung Sowohl Narkosen mit Narkosegasen, als auch total intravenöse AnĂ€sthesie sind gĂ€ngige und etablierte Verfahren in der AnĂ€sthesie. Im Gegensatz zu Aspekten wie Awareness und postoperative Aufwachzeiten, ist die intraoperative HĂ€modynamik und der intraoperative Katecholaminbedarf bisher wenig untersucht worden. Unser Ziel war es zu zeigen, dass das Narkoseverfahren einen Einfluss auf die intraoperative HĂ€modynamik und den intraoperativen Katecholaminbedarf haben kann. Methodik: In Rahmen einer retrospektiven Untersuchung wurden die digital erfassten Narkoseprotokolle, sowie die Patientenakten und Kurven der Intensivstation von 261 Patienten, bei denen im Zeitraum von Juni 2006 bis Dezember 2011 eine Lebertransplantation durchgefĂŒhrt wurde, ausgewertet. Die Narkose wurde entweder als total-intravenöse AnĂ€sthesie (TIVA) oder balancierte AnĂ€sthesie (BA) mit Sevofluran durchgefĂŒhrt. Hierbei wurden der prĂ€operative Status, der perioperative Verlauf (einschließlich der erweiterten hĂ€modynamischen Parameter (systolischer Blutdruck (RRsyst), arterieller Mitteldruck MAP), Zentralvenöser Druck (ZVD), Herzindex (CI), Schlagvolumenvarianz (SVV) und pulmonalarterieller Druck (PAP) und aller gegebenen Medikamente), sowie der postoperative Status erfasst und ausgewertet. Die Kreislaufparameter und Medikamentendosierungen wurden zu den Zeitpunkten 60 (= 60minPrĂ€) und 15 (= 15minPrĂ€) Minuten vor und 15 (= 15minPost) und 60 Minuten (= 60minPost) nach Reperfusion erfasst, ebenso wie die minimalen, maximalen und durchschnittlichen Werte bzw. Dosierungen. Ergebnis Es wurden 262 Patienten eingeschlossen, die entweder mit TIVA (n = 85) oder BA (n = 177) narkotisiert wurden. Die Patientendemographie unterschied sich nicht zwischen den beiden untersuchten Gruppen. Die TIVA-Gruppe wies an allen untersuchten Zeitpunkten, ebenso wie im Durchschnitt (p = <0,0001) signifikant höhere MAP-Werte auf (p = <0,0001 60minPrĂ€ & 60minPost, p = 0,024 15minPrĂ€, p = 0,012 15minPost). Gleichzeitig waren der Noradrenalin-Bedarf an allen untersuchten Zeitpunkten (p = <0,0001 alle 4 Zeitpunkte) signifikant niedriger, genau wie der Adrenalin- (p = <0,0001 bzw. p = 0,038 15 bzw. 60minPost) und Vasopressin-Bedarf (p = 0,003 bzw. p = <0,0001 60minPost) an beiden Zeitpunkten nach der Reperfusion. Das GesamtĂŒberleben in den ersten 36 Monaten war in der TIVA-Gruppe höher, die Intensivaufenthaltsdauer (TIVA 11,9 ±13,2 vs. BA 12,2 ±15,1) und die postoperative Beatmungsdauer (77,3 h (TIVA) vs. 104,8 h (BA)) kĂŒrzer. Die Unterschiede waren hierbei statistisch nicht signifikant. Schlussfolgerung Die Ergebnisse legen nahe, dass eine Propofol-basierte TIVA mit einer stabileren HĂ€modynamik bei niedrigerem Katecholaminbedarf im gesamten perioperativen Verlauf von Lebertransplantationen einhergeht. Um valide Aussagen ĂŒber das Outcome treffen zu können, erscheint die DurchfĂŒhrung einer randomisierten, kontrollierten Studie sinnvoll

    Did Bacillus megaterium pick up plasmid virulence genes?

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    Includes bibliographical references.Plasmids are known to carry genes that allow bacteria to survive in different environments. Virulence genes that cause bacteria to be pathogenic are also found on plasmids. Bacillus megaterium is a non-pathogenic, spore-forming bacteria that is found in soil, but recently a strain of B. megaterium was reported to cause a mild case of diarrhea in an infant. This appears to be the first case of infection caused by B. megaterium (CHI). Bacillus cereus is a related species and a known gastroenteric pathogen. Research has shown that the pathogenicity in some strains of B. cereus is caused by either an operon containing four genes, hblA/B/C/D, or by a single gene, bceT. The pathogenic strain of B. megaterium, (CHI), was tested by PCR and hybridization, to see if it picked up either of these two factors that cause pathogenicity in B. cereus by plasmid exchange. PCR products were obtained in CHI for the genes hblA and bceT using specific primers suggesting that such genes are present in the B. megaterium (CHI) strain. However, a hybridization experiment using bceT product as a probe for CHI failed to show a signal.B.S. (Bachelor of Science
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