141 research outputs found

    Evolution and Mutation in the EU’s DNA

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    Activation calculations for the target of a spallation ultra-cold neutron source at PSI

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    A spallation ultra-cold neutron source—UCN source—is scheduled to start operation at PSI in 2006 using up to 2 mA 590 MeV protons from the ring cyclotron. It will be operated in a pulsed mode with an average current of 20 ÎŒA. For safe maintenance, during operation as well as handling, transport and storage of the UCN target assembly after its lifespan, detailed knowledge about the activation induced by the impinging protons and secondary radiation fields is required. The Monte Carlo transport code MCNPX was coupled with the European Activation System—EASY—to calculate the residual nuclide production in the UCN target assembly. The nuclide inventory is finally used to design the shielded exchange flask that is needed to safely remove and transport the UCN target assembly after its lifespan to a hotcell for dismantlin

    Context-Aware Marketing Attribution Based on Survival Analysis

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    Companies increasingly invest in digital marketing channels to promote their products and services. While the expenditures for each marketing channel are known, the contribution of marketing channels to a successful conversion, and therefore the value they generate, is unknown, but highly relevant for strategic decision-making. In this paper, we develop a novel, context-aware additive hazard marketing attribution (CAHMA) model based on survival analysis to address this problem. In addition to channel-specific, time-decaying effects of marketing on the users’ conversion rate, we control for the effects of contextual features, such as the device or country from which users interact with marketing channels. Based on a prototypical implementation, we demonstrate the model’s applicability and evaluate it on real-world data from the industry. We find that CAHMA outperforms other models in terms of accuracy while offering unique interpretability of the results and hence, providing deep insights for practitioners into the effects of marketing

    Deal or no deal? : assessing the daily deal shopper

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    We build upon previous work done in online shopping segmentation but follow a customer-revealed approach by using an explorative cluster analysis on a sample of 11,848 daily deal shoppers located in Switzerland. We identify six segments into which the daily deal shoppers can be categorized: recreational shoppers, mobile shoppers, traditionalists, bargain hunters, socializers, and convenience seekers. These clusters are distinctively different in terms of shopping motives, online behavior, and demographics

    Bargain Hunting on Black Friday - Making Great Deals and Bragging About Them

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    Online customer reviews (OCRs) are helpful when they provide an unbiased view on a product. Large-scale shopping events (e.g., Black Friday) generate large volumes of OCRs. We hypothesize that OCRs from such events are biased due to price discounts and smart shopper feelings. To test our hypotheses, we use OCR data of a large US electronics retailer that emerge from Black Friday purchases and regular purchases. We find that numerical ratings from Black Friday purchases are considerably higher. This effect is also observable in an increase of the average numerical rating through Black Friday purchases. We further observe that textual OCR content from Black Friday purchases focuses more on the purchase conditions (e.g., price discounts) at the expense of other, potentially more helpful content. We further provide managerial implications on how retailers may counteract the negative consequences of such biased OCRs on the quality of their OCR systems

    Tell Me Why (I Want It That Way) – Effects of Explanations and Online Customer Reviews on Trust in Recommender Systems

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    Review-based recommender systems (RS) have shown great potential in helping users manage information overload and find suitable items. However, a lack of trust still impedes the widespread acceptance of RS. To increase users’ trust, research proposes various methods to generate justifications or explanations. Furthermore, online customer reviews (OCRs) are found to be a trustworthy and reliable source of information. However, it is still unclear how justifications compare to explanations in their influence on users’ trust and whether basing them on OCRs additionally adds trust. Hence, we conduct an online experiment with 531 participants and find that explanations exceed justifications in increasing users’ trust, while basing them on OCRs directly increases users’ intentions to use the system and adopt recommendations without increasing trust in the RS themselves. Unifying different research streams from review-based RS and Explainable Artificial Intelligence, we provide an overarching, holistic view on the conception of justifications and explanations

    Dynamic Pricing on Two-Sided Platforms: Consequences on Customers’ Fairness Perceptions and Purchase Intentions

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    Technological advancements simplify the application of dynamic pricing, i.e., the flexible and rapid adjustment of prices to changes in demand. Consequently, companies increasingly use dynamic pricing in their business models, although research reports negative consequences on customer fairness perceptions. This holds not only for one-sided businesses, but also for popular two-sided platforms. However, these platforms differ from one-sided businesses in that the total prices paid by customers consist of product prices and platform fees – and both price components can be dynamically adjusted. In an online experiment, we examine customers’ fairness perceptions and purchase intentions when product price and platform fee change dynamically. We find that dynamic price increases reduce fairness perceptions and purchase intentions, while the cause of the price increases is irrelevant to customers. These results indicate an imbalance in the risks and benefits of dynamic pricing between the pricing strategies of the platform and the provider

    Author Correction: Cooperation of Striatin 3 and MAP4K4 promotes growth and tissue invasion

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    MAP4K4 is associated with increased motility and reduced proliferation in tumor cells, but the regulation of this dichotomous functionality remained elusive. We find that MAP4K4 interacts with striatin 3 and 4 (STRN3/4) and that STRN3 and MAP4K4 exert opposing functions in Hippo signaling and clonal growth. However, depletion of either STRN3 or MAP4K4 in medulloblastoma cells reduces invasion, and loss of both proteins abrogates tumor cell growth in the cerebellar tissue. Mechanistically, STRN3 couples MAP4K4 to the protein phosphatase 2A, which inactivates growth repressing activities of MAP4K4. In parallel, STRN3 enables growth factor-induced PKCΞ activation and direct phosphorylation of VASPS157 by MAP4K4, which both are necessary for efficient cell invasion. VASPS157 directed activity of MAP4K4 and STRN3 requires the CNH domain of MAP4K4, which mediates its interaction with striatins. Thus, STRN3 is a master regulator of MAP4K4 function, and disruption of its cooperation with MAP4K4 reactivates Hippo signaling and represses tissue invasion in medulloblastoma

    Cooperation of Striatin 3 and MAP4K4 promotes growth and tissue invasion

    Full text link
    MAP4K4 is associated with increased motility and reduced proliferation in tumor cells, but the regulation of this dichotomous functionality remained elusive. We find that MAP4K4 interacts with striatin 3 and 4 (STRN3/4) and that STRN3 and MAP4K4 exert opposing functions in Hippo signaling and clonal growth. However, depletion of either STRN3 or MAP4K4 in medulloblastoma cells reduces invasion, and loss of both proteins abrogates tumor cell growth in the cerebellar tissue. Mechanistically, STRN3 couples MAP4K4 to the protein phosphatase 2A, which inactivates growth repressing activities of MAP4K4. In parallel, STRN3 enables growth factor-induced PKCΞ activation and direct phosphorylation of VASPS157 by MAP4K4, which both are necessary for efficient cell invasion. VASPS157 directed activity of MAP4K4 and STRN3 requires the CNH domain of MAP4K4, which mediates its interaction with striatins. Thus, STRN3 is a master regulator of MAP4K4 function, and disruption of its cooperation with MAP4K4 reactivates Hippo signaling and represses tissue invasion in medulloblastoma

    USING GASEOUS EMISSIONS OF A PROTON ACCELERATOR FACILITY AS TRACER FOR SMALL-SCALE ATMOSPHERIC DISPERSION

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    The gaseous effluents of the proton accelerator facility located in the Western part of the Paul Scherrer Institute, Aargau, Switzerland, contain a mixture of positron emitters (50 % 15O, 20 % 13N and 30 % 11C). For the experimental verification of a future upgrade of the dispersion model in the complex topography of the Aare valley, a measuring campaign using three continuous gamma-spectrometric measuring stations was launched in 2011. The concept of a modified man-made-gross-count (MMGC) ratio yields a clear signal associated with the positron emitters while minimising the influence of radon progeny rain-out events. A dependence of the measured MMGC ratios on the emitted activity and wind direction could be demonstrated using frequency distributions of the modified MMGC ratio measured in 2012 and 2013. A significant fraction of high MMGC-ratio values was found associated with dispersion directions (based on measurements of the wind direction in 70 m above ground) not towards or even against the direction between stack and measuring statio
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