650 research outputs found

    Evaluating Tourism Market Regulation from Tourists’ Perspective: Scale Development and Validation

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    Despite the increasing attention given to tourism regulation in recent years, great ambiguity surrounds this concept and no valid and reliable instrument exists to measure tourism market regulation (TMR). This study uses multi-step mixed methods to develop a measurement scale of TMR from the perspective of tourists. In the first step, interviews and focus groups are undertaken to formulate a clear definition of TMR and its attributes. In the second step, a scale development procedure is adopted to analyze two rounds of data for dimension exploration via EFA and confirmation via CFA. Through these analyses, five dimensions are generated: regulatory oversight, truth in advertising, tourism contract compliance, fulfilling tourism contracts, and travel feedback processing. The reliable and valid results contribute to refining TMR in the context of China. They also provide a useful tool for tourists and destination marketing organizations to measure and govern TMR in other regions/countries

    Slit2/Robo4 Signaling Modulates HIV-1 gp120-Induced Lymphatic Hyperpermeability

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    Dissemination of HIV in the host involves transit of the virus and virus-infected cells across the lymphatic endothelium. HIV may alter lymphatic endothelial permeability to foster dissemination, but the mechanism is largely unexplored. Using a primary human lymphatic endothelial cell model, we found that HIV-1 envelope protein gp120 induced lymphatic hyperpermeability by disturbing the normal function of Robo4, a novel regulator of endothelial permeability. HIV-1 gp120 induced fibronectin expression and integrin α5β1 phosphorylation, which led to the complexing of these three proteins, and their subsequent interaction with Robo4 through its fibronectin type III repeats. Moreover, pretreatment with an active N-terminus fragment of Slit2, a Robo4 agonist, protected lymphatic endothelial cells from HIV-1 gp120-induced hyperpermeability by inhibiting c-Src kinase activation. Our results indicate that targeting Slit2/Robo4 signaling may protect the integrity of the lymphatic barrier and limit the dissemination of HIV in the host

    Slit2N and Robo4 regulate lymphangiogenesis through the VEGF-C/VEGFR-3 pathway

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    Background: Signaling through vascular endothelial growth factor C (VEGF–C) and VEGF receptor 3 (VEGFR-3) plays a central role in lymphangiogenesis and the metastasis of several cancers via the lymphatics. Recently, the Slit2/Robo4 pathway has been recognized as a modulator of vascular permeability and integrity. Signaling via the Robo receptor inhibits VEGF-mediated effects; however, its effects on lymphatic endothelial cell function have not been well characterized. Results: We found that pretreatment with Slit2N, an active fragment of Slit2, inhibited VEGF-C-mediated lung-derived lymphatic endothelial cell (L-LEC) proliferation, migration, and in vitro tube formation. Slit2N induced the internalization of VEGFR-3, which blocked its activation, and inhibited the activation of the PI3K/Akt pathway by VEGF-C in L-LECs. Moreover, we found that inhibition of VEGF-C-induced effects by Slit2N was Robo4-dependent. Conclusion: These results indicate that Slit2N/Robo4 modulates several key cellular functions, which contribute to lymphangiogenesis, and identify this ligand-receptor pair as a potential therapeutic target to inhibit lymphatic metastasis of VEGF-C-overexpressing cancers and manage lymphatic dysfunctions characterized by VEGF-C/VEGFR-3 activation

    Electronic specific heat and low energy quasiparticle excitations in superconducting state of La2−xSrxCuO4La_{2-x}Sr_xCuO_4 single crystals

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    Low temperature specific heat has been measured and extensively analyzed on a series of La2−xSrxCuO4La_{2-x}Sr_xCuO_4 single crystals from underdoped to overdoped regime. From these data the quasiparticle density of states (DOS) in the mixed state is derived and compared to the predicted scaling law Cvol/TH=f(T/H)C_{vol}/T\sqrt{H}=f(T/\sqrt{H}) of d-wave superconductivity. It is found that the scaling law can be nicely followed by the optimally doped sample (x=0.15) in quite wide region of (T/H≤8K/TT/\sqrt{H} \leq 8 K /\sqrt{T}). However, the region for this scaling becomes smaller and smaller towards more underdoped region: a clear trend can be seen for samples from x=0.15 to 0.069. Therefore, generally speaking, the scaling quality becomes worse on the underdoped samples in terms of scalable region of T/HT/\sqrt{H}. This feature in the underdoped region is explained as due to the low energy excitations from a second order (for example, anti-ferromagnetic correlation, d-density wave, spin density wave or charge density wave order) that may co-exist or compete with superconductivity. Surprisingly, deviations from the d-wave scaling law have also been found for the overdoped sample (x=0.22). While the scaling law is reconciled for the overdoped sample when the core size effect is taken into account. An important discovery of present work is that the zero-temperature data follow the Volovik's relation Δγ(T=0)=AH\Delta \gamma(T=0)=A\sqrt{H} quite well for all samples investigated here although the applicability of the d-wave scaling law to the data at finite temperatures varies with doped hole concentration. Finally we present the doping dependence of some parameters, such as, the residual linear term γ0\gamma_0, the α\alpha value, etc. ...Comment: 15 pages, 24 figure

    TAp63 Is a Master Transcriptional Regulator of Lipid and Glucose Metabolism

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    SummaryTAp63 prevents premature aging, suggesting a link to genes that regulate longevity. Further characterization of TAp63−/− mice revealed that these mice develop obesity, insulin resistance, and glucose intolerance similar to those seen in mice lacking two key metabolic regulators, Silent information regulator T1 (Sirt1) and AMPK. While the roles of Sirt1 and AMPK in metabolism have been well studied, their upstream regulators are not well understood. We found that TAp63 is important in regulating energy metabolism by accumulating in response to metabolic stress and transcriptionally activating Sirt1, AMPKα2, and LKB1, resulting in increased fatty acid synthesis and decreased fatty acid oxidation. Moreover, we found that TAp63 lowers blood glucose levels in response to metformin. Restoration of Sirt1, AMPKα2, and LKB1 in TAp63−/− mice rescued some of the metabolic defects of the TAp63−/− mice. Our study defines a role for TAp63 in metabolism and weight control

    Tourist Intercultural Competence: A Multidimensional Measurement and its Impact on Tourist Active Participation and Memorable Cultural Experiences

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    Cultural tourism has received increasing attention. Tourists’ intercultural competence represents the abilities to appropriately and efficiently interact with people across different cultures, helping tourists attain developing positive cultural exchange experiences. By adopting both qualitative and quantitative approaches, a multi-dimensional measurement of tourists’ intercultural competence was developed and validated in this study. Four factors of tourists’ intercultural competence were identified: intercultural responsibility, understanding, appreciation, and action. Furthermore, this study examined the association between tourists’ intercultural competence and memorable cultural experience and determined the mediating effects of tourists’ active participation. This study contributes to the cultural tourism literature by proposing a measurement of tourists’ intercultural competences and by establishing a framework illustrating how cultural tourists interact with different cultures, thus attaining memorable cultural experiences. Managerial implications for destination marketing and tourist management are discussed herein

    Achieving Senior Tourists’ Active Aging Through Value Co–creation: A Customer-Dominant Logic Perspective

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    Senior tourists have their own travel behaviors and preferences and require specific resources from the tourism industry and the broader society. This study adopts customer-dominant logic to understand how participating in tourism activities can support seniors to co-create active aging value. Interviews were conducted with 31 senior tourists and 16 tourism and hospitality service providers. Six value themes were identified from the interviews, namely, enjoyment, connectedness, mental vitality, independence, sense of belonging, and selfesteem. The six values were categorized into functional, social, and spiritual dimensions. A value co-creation nexus was developed with continuum- and development-oriented active aging as the two extremes. This nexus highlighted the differentiated efforts exerted by cocreators to create value and identified the value co-creation routines of stakeholders, their corresponding values, and their facilitators. Value co-creation activities were introduced into active aging with tourism as the context. The findings of this study can support the management of tourism services, promote inclusiveness in society, and aid in government policy making

    Experimental evidence on the Altshuler-Aronov-Spivak interference of the topological surface states in the exfoliated Bi2Te3 nanoflakes

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    Here we demonstrate the Altshuler-Aronov-Spivak (AAS) interference of the topological surface states on the exfoliated Bi2Te3 microflakes by a flux period of h/2e in their magnetoresistance oscillations and its weak field character. Both the osillations with the period of h/e and h/2e are observed. The h/2e-period AAS oscillation gradually dominates with increasing the sample widths and the temperatures. This reveals the transition of the Dirac Fermions' transport to the diffusive regime.Comment: version 3;Applied Physics Letters in pres
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