160 research outputs found

    Gamification and Marketing Management: A Literature Review and Future Agenda

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    Given the motivational effect of game elements and mechanisms on user experience in various non-game contexts, gamification has widely been used as an effective marketing technique to enhance the performance of business practices. In the past decade, a variety of studies have explored and investigated the value that gamification can provide in consumer-facing marketing activities. However, there is still a dearth of granular understanding of how gamification in marketing has been studied in the current literature. This paper follows the PRISMA literature review process and systematically reviews 93 papers consisting of 111 empirical studies on gamification and marketing management. The synthesized findings provide a holistic picture of the adopted research methods, different investigated gamification affordances and advergames, various gamified industries, and marketing performance indicators regarding products, services, and brands. Five agenda points, mainly relating to methodology and themes, are further suggested.Peer reviewe

    GASZ promotes germ cell derivation from embryonic stem cells

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    AbstractPrimordial germ cells (PGCs) are the first germ-line population that forms from the proximal epiblast of the developing embryo. Despite their biological importance, the regulatory networks whereby PGCs arise, migrate, and differentiate into gametes during embryonic development remains elusive, largely due to the limited number of germ cells in the early embryo. To elucidate the molecular mechanisms that govern early germ cell development, we utilized an in vitro differentiation model of embryonic stem cells (ESCs) and screened a series of candidate genes with specific expression in the adult reproductive organs. We discovered that gain of function of Gasz, a gene previously reported to participate in meiosis of postnatal spermatocytes, led to the most robust upregulation of PGC formation from both human and murine ESCs. In contrast, Gasz deficiency resulted in pronounced reduction of germ cells during ESC differentiation and decreased expression of MVH and DAZL in genital ridges during early embryonic development. Further analyses demonstrated that GASZ interacted with DAZL, a key germ cell regulator, to synergistically promote germ cell derivation from ESCs. Thus, our data reveal a potential role of GASZ during embryonic germ cell development and provide a powerful in vitro system for dissecting the molecular pathways in early germ cell formation during embryogenesis

    Abundance ratios of OH/CO and HCO+/CO as probes of the cosmic ray ionization rate in diffuse clouds

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    The cosmic-ray ionization rate (CRIR, ζ2\zeta_2) is one of the key parameters controlling the formation and destruction of various molecules in molecular clouds. However, the current most commonly used CRIR tracers, such as H3+_3^+, OH+^+, and H2_2O+^+, are hard to detect and require the presence of background massive stars for absorption measurements. In this work, we propose an alternative method to infer the CRIR in diffuse clouds using the abundance ratios of OH/CO and HCO+^+/CO. We have analyzed the response of chemical abundances of CO, OH, and HCO+^+ on various environmental parameters of the interstellar medium in diffuse clouds and found that their abundances are proportional to ζ2\zeta_2. Our analytic expressions give an excellent calculation of the abundance of OH for ζ2\zeta_2 ≤\leq10−15^{-15} s−1^{-1}, which are potentially useful for modelling chemistry in hydrodynamical simulations. The abundances of OH and HCO+^+ were found to monotonically decrease with increasing density, while the CO abundance shows the opposite trend. With high-sensitivity absorption transitions of both CO (1--0) and (2--1) lines from ALMA, we have derived the H2_2 number densities (nH2n_{\rm H_2}) toward 4 line-of-sights (LOSs); assuming a kinetic temperature of Tk=50 KT_{\rm k}=50\,{\rm K}, we find a range of (0.14±\pm0.03--1.2±\pm0.1)×\times102^2 cm−3^{-3}}. By comparing the observed and modelled HCO+^+/CO ratios, we find that ζ2\zeta_2 in our diffuse gas sample is in the { range of 1.0−1.0+14.81.0_{-1.0}^{+14.8} ×\times10−16−2.5−2.4+1.4^{-16}- 2.5_{-2.4}^{+1.4} ×\times10−15^{-15} s−1^{-1}. This is ∼\sim2 times higher than the average value measured at higher extinction, supporting an attenuation of CRs as suggested by theoretical models.Comment: 22 pages, 9 figures, accepted by Ap

    Haemodynamic mechanism of formation and distribution of coronary atherosclerosis: A lesion-specific model

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    © IMechE 2020. Coronary arterial disease, as the most devastated cardiovascular disease, is caused by the atherosclerosis in the coronary arteries, which blocks the blood flow to the heart, resulting in the deficient supply of oxygen and nutrition to the heart, and eventually leading to heart failure. To date, haemodynamic mechanisms for atherosclerosis development are not fully understood although it is believed that the haemodynamic disturbance at the region of the arterial bifurcation, particular, bifurcation angle, plays an important role in the atherosclerosis development. In this study, two types of computational fluid dynamics models, lesion-specific and idealized models, combined with the computer tomography imaging techniques, are used to explore the mechanism of formation and distribution of the atherosclerosis around the bifurcation of left coronary artery and its association with the bifurcation angle. The lesion-specific model is used to characterize the effect of personalized features on the haemodynamic performance, while the idealized model is focusing on the effect of single factor, bifurcation angle, on the haemodynamic performance. The simulated results from both types of the models, combined with the clinical observation, revealed that the three key areas around the bifurcations are prone to formation of the atherosclerosis. Unlike the idealized models, lesion-specific modelling results did not show the significant correlation between the wall shear stress and bifurcation angle, although the mean value of the wall shear stress in smaller bifurcation angles (less than 90°) is higher than that with larger bifurcation angles (greater than 90°). In conclusion, lesion-specific computational fluid dynamics modelling is an efficient and convenient way to predict the haemodynamic performance around the bifurcation region, allowing the comprehensive information for the clinicians to predict the atherosclerosis development. The idealized models, which only focus on single parameter, may not provide the sufficient and reliable information for the clinical application. A novel multi-parameters modelling technique, therefore, is suggested to be developed in future, allowing the effects of many parameters on the haemodynamic performance to be evaluated

    Dependence of Chemical Abundance on the Cosmic Ray Ionization Rate in IC 348

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    Ions (e.g., H3+_3^+, H2_2O+^+) have been used extensively to quantify the cosmic-ray ionization rate (CRIR) in diffuse sightlines. However, measurements of CRIR in low-to-intermediate density gas environments are rare, especially when background stars are absent. In this work, we combine molecular line observations of CO, OH, CH, and HCO+^+ in the star-forming cloud IC~348, and chemical models to constrain the value of CRIR and study the response of the chemical abundances distribution. The cloud boundary is found to have an AVA_{\rm V} of approximately 4 mag. From the interior to the exterior of the cloud, the observed 13^{13}CO line intensities drop by an order of magnitude. The calculated average abundance of 12^{12}CO (assuming 12^{12}C/13^{13}C = 65) is (1.2±\pm0.9) ×\times10−4^{-4}, which increases by a factor of 6 from the interior to the outside regions. The average abundance of CH (3.3±\pm0.7 ×\times 10−8^{-8}) is in good agreement with previous findings in diffuse and translucent clouds (AVA_{\rm V} << 5 mag). However, we did not find a decline in CH abundance in regions of high extinction (AV≃A_{\rm V}\simeq8 mag) as previously reported in Taurus. By comparing the observed molecular abundances and chemical models, we find a decreasing trend of CRIR as AVA_{\rm V} increases. The inferred CRIR of ζcr\zeta_{cr} = (4.7±\pm1.5) ×\times 10−16^{-16} s−1^{-1} at low AVA_{\rm V} is consistent with H3+^+_3 measurements toward two nearby massive stars.Comment: 21 pages, 11 figures. Submitted to Ap

    Hot deformation behavior and processing maps of an as-cast Al-5Mg-3Zn-1Cu (wt%) alloy

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    One of the key issues limiting the application of Al-Mg-Zn-Cu alloys in the automotive industry is forming at a low cost. Isothermal uniaxial compression was accomplished in the range of 300–450 °C, 0.001–10 s−1 to study the hot deformation behavior of an as-cast Al-5.07Mg-3.01Zn-1.11Cu-0.01Ti alloy. Its rheological behavior presented characteristics of work-hardening followed by dynamic softening and its flow stress was accurately described by the proposed strain-compensated Arrhenius-type constitutive model. Three-dimensional processing maps were established. The instability was mainly concentrated in regions with high strain rates or low temperatures, with cracking being the main instability. A workable domain was determined as 385–450 °C, 0.001–0.26 s−1, in which dynamic recovery (DRV) and dynamic recrystallization (DRX) occurred. As the temperature rose, the dominant dynamic softening mechanism shifted from DRV to DRX. The DRX mechanisms transformed from continuous dynamic recrystallization (CDRX), discontinuous dynamic recrystallization (DDRX), and particle-stimulated nucleation (PSN) at 350 °C, 0.1 s−1 to CDRX and DDRX at 450 °C, 0.01 s−1, and eventually to DDRX at 450 °C, 0.001 s−1. The eutectic T-Mg32(AlZnCu)49 phase facilitated DRX nucleation and did not trigger instability in the workable domain. This work demonstrates that the workability of as-cast Al-Mg-Zn-Cu alloys with low Zn/Mg ratios is sufficient for hot forming
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