68 research outputs found

    Quantifying the Effect of Mobile Channel Visits on Firm Revenue

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    The explosive penetration of mobile devices is one of the most prominent trends in e-business. Although the importance of mobile channel has prompted growing literature, little is known about the revenue implications of customer visit toward mobile channel. This study examines (1) the differential effect of mobile visits in affecting firm revenue (i.e. mobile vs. desktop visits), and (2) which type of mobile visits are more effective (i.e., direct vs. search engine and referral traffic; visits for high vs. low involvement products). We collect an unique objective daily data from a leading online travel agency in China. With a vector autoregressive (VAR) method, we find that, compared with desktop channel, mobile channel visits have shorter carryover effect, but larger short-term effect on firm revenues. Further, mobile channel has larger short-term effect on firm revenues for search engine traffic and lower involvement products. Our findings provide important theoretical contributions and notable implications for mobile commerce strategy

    (Main Section: Ecological Planning)

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    Appropriate microclimate design for urban parks is important, as it impacts on thermal comfort and thereby influences the utilization of outdoor spaces by the public. Modifying the vegetation arrangement can improve the microclimate, especially under hot season conditions. However, it is difficult to measure microclimatic variations in the individual components within a park. Therefore, we combined in-situ measurements and a three-dimensional microclimate model ENVI-met, to examine variations in the microclimate of an urban neighborhood park in Seoul, Korea. Different vegetation arrangements were investigated with respect to their effects on microclimate and thermal comfort on a typical summer day. The study showed that: 1) the simulated results of ENVI-met were similar to the observed data, with an index of agreement of 0.69–0.88; 2) green spaces with multi-layered and dense canopy cover provided the most comfortable conditions. However, the cooling efficiency of vegetation may decrease when the plantation is too dense; and 3) the main factor affecting thermal comfort in the hot season was mean radiant temperature. The findings of this study provide useful information to guide planning of vegetation arrangements in future urban park designs

    Cardiac CT perfusion imaging of pericoronary adipose tissue (PCAT) highlights potential confounds in coronary CTA

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    Features of pericoronary adipose tissue (PCAT) assessed from coronary computed tomography angiography (CCTA) are associated with inflammation and cardiovascular risk. As PCAT is vascularly connected with coronary vasculature, the presence of iodine is a potential confounding factor on PCAT HU and textures that has not been adequately investigated. Use dynamic cardiac CT perfusion (CCTP) to inform contrast determinants of PCAT assessment. From CCTP, we analyzed HU dynamics of territory-specific PCAT, myocardium, and other adipose depots in patients with coronary artery disease. HU, blood flow, and radiomics were assessed over time. Changes from peak aorta time, Pa, chosen to model the time of CCTA, were obtained. HU in PCAT increased more than in other adipose depots. The estimated blood flow in PCAT was ~23% of that in the contiguous myocardium. Comparing PCAT distal and proximal to a significant stenosis, we found less enhancement and longer time-to-peak distally. Two-second offsets [before, after] Pa resulted in [ 4-HU, 3-HU] differences in PCAT. Due to changes in HU, the apparent PCAT volume reduced ~15% from the first scan (P1) to Pa using a conventional fat window. Comparing radiomic features over time, 78% of features changed >10% relative to P1. CCTP elucidates blood flow in PCAT and enables analysis of PCAT features over time. PCAT assessments (HU, apparent volume, and radiomics) are sensitive to acquisition timing and the presence of obstructive stenosis, which may confound the interpretation of PCAT in CCTA images. Data normalization may be in order.Comment: 13 pages, 8 figure

    Protection Evaluation of a Five-Gene-Deleted African Swine Fever Virus Vaccine Candidate Against Homologous Challenge

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    African swine fever virus (ASFV) represents a serious threat to the global swine industry, and there are no safe or commercially available vaccines. Previous studies have demonstrated that inactivated vaccines do not provide sufficient protection against ASFV and that attenuated vaccines are effective, but raise safety concerns. Here, we first constructed a deletion mutant in which EP153R and EP402R gene clusters were knocked out. Based on the deletion mutant, a further deletion from the MGF_360-12L, MGF_360-13L to MGF_360-14L genes was obtained. The five-genes knockout virus was designated as ASFV-ΔECM3. To investigate the efficacy and safety of the ASFV-ΔECM3 virus as a vaccine candidate, the evaluation of the virus was subsequently carried out in pigs. The results showed that the ASFV-ΔECM3 virus could induce homologous protection against the parental isolate, and no significant clinical signs or viremia were observed. These results show that the contiguous deletion mutant, ASFV-ΔECM3 encompassing the EP153R/EP402R and MGF_360-12L/13L/14L genes, could be a potential live-attenuated vaccine candidate for the prevention of ASFV infection

    A common Shox2–Nkx2-5 antagonistic mechanism primes the pacemaker cell fate in the pulmonary vein myocardium and sinoatrial node

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    In humans, atrial fibrillation is often triggered by ectopic pacemaking activity in the myocardium sleeves of the pulmonary vein (PV) and systemic venous return. The genetic programs that abnormally reinforce pacemaker properties at these sites and how this relates to normal sinoatrial node (SAN) development remain uncharacterized. It was noted previously that Nkx2-5, which is expressed in the PV myocardium and reinforces a chamber-like myocardial identity in the PV, is lacking in the SAN. Here we present evidence that in mice Shox2 antagonizes the transcriptional output of Nkx2-5 in the PV myocardium and in a functional Nkx2-5(+) domain within the SAN to determine cell fate. Shox2 deletion in the Nkx2-5(+) domain of the SAN caused sick sinus syndrome, associated with the loss of the pacemaker program. Explanted Shox2(+) cells from the embryonic PV myocardium exhibited pacemaker characteristics including node-like electrophysiological properties and the capability to pace surrounding Shox2(−) cells. Shox2 deletion led to Hcn4 ablation in the developing PV myocardium. Nkx2-5 hypomorphism rescued the requirement for Shox2 for the expression of genes essential for SAN development in Shox2 mutants. Similarly, the pacemaker-like phenotype induced in the PV myocardium in Nkx2-5 hypomorphs reverted back to a working myocardial phenotype when Shox2 was simultaneously deleted. A similar mechanism is also adopted in differentiated embryoid bodies. We found that Shox2 interacts with Nkx2-5 directly, and discovered a substantial genome-wide co-occupancy of Shox2, Nkx2-5 and Tbx5, further supporting a pivotal role for Shox2 in the core myogenic program orchestrating venous pole and pacemaker development

    The 5th International Conference on Biomedical Engineering and Biotechnology (ICBEB 2016)

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    Empirical view of interactions between reselling and agency selling in platform-based retailing

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    Platform-based retailing markets, such as Amazon, operate in a hybrid mode, which contains both reselling and agency selling. Prior studies have only used theoretical models to discuss how to choose between reselling and agency selling. However, empirical interactions between these two selling modes have not been well studied. We analyze the relationship between reselling and agency selling, the moderating effect of spillovers and the popularity of agency selling by using panel vector auto-regression model. Notably, reselling and agency selling are mutually promotive as a 1 percent increase in sales in reselling (agency selling) upsurges sales in agency selling (reselling) by .052 (.047) percent. We show that different types of spillovers exert different impacts on the main effect. In addition, we find that the popularity of agency selling strengthens the positive relationship between reselling and agency selling. Our results provide important theoretical contributions and managerial implications

    Genetic Regulation of Sinoatrial Node Development and Pacemaker Program in the Venous Pole

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    The definitive sinoatrial node (SAN), the primary pacemaker of the mammalian heart, develops from part of pro-pacemaking embryonic venous pole that expresses both Hcn4 and the transcriptional factor Shox2. It is noted that ectopic pacemaking activities originated from the myocardial sleeves of the pulmonary vein and systemic venous return, both derived from the Shox2+ pro-pacemaking cells in the venous pole, cause atrial fibrillation. However, the developmental link between the pacemaker properties in the embryonic venous pole cells and the SAN remains largely uncharacterized. Furthermore, the genetic program for the development of heterogeneous populations of the SAN is also under-appreciated. Here, we review the literature for a better understanding of the heterogeneous development of the SAN in relation to that of the sinus venosus myocardium and pulmonary vein myocardium. We also attempt to revisit genetic models pertinent to the development of pacemaker activities in the perspective of a Shox2-Nkx2-5 epistatic antagonism. Finally, we describe recent efforts in deciphering the regulatory networks for pacemaker development by genome-wide approaches

    Long-wavelength chromophores with thermally activated delayed fluorescence based on fluorescein derivatives

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    Long-wavelength chromophores are developed based on fluorescein derivatives by introducing a strong acceptor 2-(3-cyano-4,5,5-trimethylfuran-2(5H)-ylidene) malononitrile (TFM). By changing the number of TFM, we obtained two chromophores, which are named DTFM-DCF and STFM-DCF, respectively. Due to the large, rigid pi-conjugated structure and strong electron-withdrawing capability of TFM, the maximum emission wavelengths of these molecules span from 681 to 755 nm in dichloromethane. Meanwhile, these two chromophores, which exhibit the property of thermally activated delayed fluorescence, have long-lived luminescence with 9.02 mu s for STFM-DCF and 0.43 mu s for DTFM-DCF in deaerated dichloromethane at room temperature. (C) 2018 Society of Photo-Optical Instrumentation Engineers (SPIE

    Are Ecosystem Services Provided by Street Trees at Parcel Level Worthy of Attention? A Case Study of a Campus in Zhenjiang, China

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    Street trees in urban areas have positive impacts on the environment, such as climate regulation, air purification, and runoff mitigation. However, the ecosystem services (ES) provided by street trees at the parcel level remain a notable gap in the existing literature. This study quantified the ES benefits provided by street trees at Jiangsu University in Zhenjiang, China, which could represent the parcel level. A widely applied model, i-Tree Eco, was used to evaluate the ES, including carbon storage, carbon sequestration, pollutant removal, rainwater runoff reduction, and their economic value. We also analyzed how these are affected by the structure of tree species. The results revealed that the 10 most abundant species accounted for 84.3% of the total number of trees, with an unstable structure of species composition. A reasonable age proportion was important since a lower proportion of young trees may make future benefit outputs unstable. The annual economic value provided by ES was USD 205,253.20, with an average of USD 79.90 per tree. Platanus orientalis had the highest single plant benefit, indicating that the management pattern of street trees could be adapted in different environments to maximize benefits. Thus, street trees at the parcel level should receive more attention with strategic planning and management in order to maximize the ES and their economic value
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