78 research outputs found

    Effect of Web Channel Richness and Web Information Richness On Satisfaction and Learning: A Study of Simple and Complex Products

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    The present paper addresses the following question: What are the effects of web channel richness and web information richness on learning about a product and browsing satisfaction? Based on the extant literature in communications and in marketing, we argue that the effects of web channel richness and web information richness will depend on the complexity of products sold. Two hundred and seven professionals, managers, and students browsed 22 web pages selling either complex or simple products. The results indicate that when individuals browsed for complex products satisfaction depended on both informational richness and channel richness. Satisfaction was highest when the two type of richness were high and satisfaction was lowest when both types were low. Learning, on the other hand depended on the informational richness of a web page. Contrary to the expectations, web page richness was also important for learning and satisfaction when browsing for simple products. Satisfaction depended on both web information and web channel richness, whereas learning was higher when the informational richness of a web page was high. This paper contributes to the literature by developing concepts that can serve as the theoretical foundations for studying web site richness. It helps in understanding the relative impacts of the richness of the information presented on a web site and of the richness of the communication tools used. As such, it can help managers and IS professionals to better understand how to effectively design web sites

    Capacity Planning with Financial and Operational Hedging in Low‐Cost Countries

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    The authors of this paper outline a capacity planning problem in which a risk-averse firm reserves capacities with potential suppliers that are located in multiple low-cost countries. While demand is uncertain, the firm also faces multi-country foreign currency exposures. This study develops a mean-variance model that maximizes the firm’s optimal utility and derives optimal utility and optimal decisions in capacity and financial hedging size. The authors show that when demand and exchange rate risks are perfectly correlated, a risk- averse firm, by using financial hedging, will achieve the same optimal utility as a risk-neutral firm. In this paper as well, a special case is examined regarding two suppliers in China and Vietnam. The results show that if a single supplier is contracted, financial hedging most benefits the highly risk-averse firm when the demand and exchange rate are highly negatively related. When only one hedge is used, financial hedging dominates operational hedging only when the firm is very risk averse and the correlation between the two exchange rates have become positive. With both theoretical and numerical results, this paper concludes that the two hedges are strategic tools and interact each other to maximize the optimal utility

    A Test Case Generation Method for Workflow Systems Based on I/O_WF_Net

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    At present, the testing of the workflow system is mainly based on manual testing, and the functions of only some tools are relatively simple. The design of test cases mainly depends on the experience of testers, which makes the lack of test coverage. In this paper, a test case generation method based on the I/O_WF_Net model is proposed. A test case generation algorithm that satisfies the process branch coverage criterion is designed, which solves the problem of automatic test case generation for workflow systems. The algorithm divides the model according to "split-merge pairs" to generate a decomposition tree of the model, and then traverses the tree to generate test cases. A workflow system modelling and test case generation tool are designed and implemented, and an actual workflow system is used as the experimental object to verify the effectiveness of the method

    Topological Shape Optimization Design of the Whole Bead of 265/35R18 Steel-Belted Radial Tire

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    The tire bead, as the most important load-bearing component at the bead area, is closely related to the durability of the tire, but its structure is developing slowly. For this reason, the topological whole bead design was proposed, although it performs well, many defects existed due to the design based on traditional experience. Therefore, this paper studies the topology shape optimization algorithm, delves into the main criterion based on von Mises and the interlaminar shear stress, and provides guidance for the structurally optimal design of the 265/35R18 radial tire whole bead. The finite element simulation results show that the von Mises of the inner end of the chafer and the end of the carcass cord are reduced by 14.48% and 24.12%, respectively. The interlaminar shear stress decreased by 28.96% and 49.51%, respectively. The von Mises of chafer and carcass cord decreased by 13.17% to 40.36% and 7.71% to 20.51%, respectively. The optimization design is of great significance to further improve the safety performance of tires

    Case report: Prenatal diagnosis of rare chromosome mosaicism: discordant results between chorionic villi and amniotic fluid samples

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    Objective: We described a unique case of near-negative chromosome mosaicism in chorionic villi but complete monosomy X in amniotic fluid.Methods: Chorionic villus sampling and amniocentesis were performed separately in the first and second trimesters. Chromosomal microarray (CMA) and rapid aneuploidy detection (QF-PCR and FISH) were performed on placental villi and uncultured amniotic fluid. After pregnancy termination, the placenta, umbilical cord, and fetal muscle tissues were sampled for FISH detection.Results: The CMA revealed a lower signal from chromosome X in chorionic villi, with a copy number of 1.85, implying the presence of mosaic monosomy X. However, the QF-PCR and FISH results were nearly normal. In uncultured amniotic fluid, CMA and rapid aneuploidy detection indicated complete monosomy X. Across different sampling points on the aborted fetus, the FISH results varied from normal, to mosaic, and then complete monosomy X.Conclusion: This case presents a rare and complex situation where sampling from uncultured chorionic villi indicated low-level chromosome mosaicism, while sampling from amniotic fluid revealed complete monosomy X. Although some of these discordant outcomes may be due to methodological limitations, we conclude that prenatal consultation should be combined with fetal ultrasound phenotype and genetic testing for a comprehensive evaluation of fetal genetic abnormalities

    Identification of Interacting Proteins of Transcription Factor DpAP2 Related to Carotenoid Biosynthesis From Marine Microalga Dunaliella parva

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    Carotenoids are widely distributed and structurally diverse, which have significant roles in the photosynthesis of plants. As a precursor of vitamin A, carotenoids are also antioxidants that reduce various chronic diseases, which are beneficial for human health. Currently, the existing studies concerned the biological roles of APETALA2 (AP2)/ethylene-responsive factor (ERF) genes originated from higher plants. The AP2 superfamily of the transcriptional regulator was identified in higher plants, which was related to growth, development, carotenoid metabolism, and responses to various stresses. However, the regulatory mechanisms of the AP2-modulating carotenoid metabolism have not been reported in microalgae, which remain to be elucidated. Dunaliella parva AP2 (i.e., DpAP2), an important transcription factor, promotes carotenoid accumulation by binding to the promoter of target gene. Here, we identified an important AP2/ERF transcription factor, DpAP2, which could promote carotenoid accumulation by binding to the promoter of target gene. To demonstrate the function of DpAP2, the interacting proteins were identified by the yeast two-hybrid system. The results showed that DpAP2 could interact with three proteins with different activities (DNA-binding transcription factor activity, protein kinase activity, and alpha-D-phosphohexomutase activity); these proteins may be associated with multiple biological processes. This paper laid a good foundation for a deep understanding of the regulatory mechanisms of DpAP2 and genetic engineering breeding in D. parva

    Case report: Optical genome mapping revealed double rearrangements in a male undergoing preimplantation genetic testing

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    Chromosome rearrangement is one of the main causes of abortion. In individuals with double chromosomal rearrangements, the abortion rate and the risk of producing abnormal chromosomal embryos are increased. In our study, preimplantation genetic testing for structural rearrangement (PGT-SR) was performed for a couple because of recurrent abortion and the karyotype of the male was 45, XY der (14; 15)(q10; q10). The PGT-SR result of the embryo in this in vitro fertilization (IVF) cycle showed microduplication and microdeletion at the terminals of chromosomes 3 and 11, respectively. Therefore, we speculated whether the couple might have a cryptic reciprocal translocation which was not detected by karyotyping. Then, optical genome mapping (OGM) was performed for this couple, and cryptic balanced chromosomal rearrangements were detected in the male. The OGM data were consistent with our hypothesis according to previous PGT results. Subsequently, this result was verified by fluorescence in situ hybridization (FISH) in metaphase. In conclusion, the male’s karyotype was 45, XY, t(3; 11)(q28; p15.4), der(14; 15)(q10; q10). Compared with traditional karyotyping, chromosomal microarray, CNV-seq and FISH, OGM has significant advantages in detecting cryptic and balanced chromosomal rearrangements

    Rhombohedral stacking-faults in exfoliated highly oriented pyrolytic graphite

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    The recent observation of possible granular superconductivity in highly oriented pyrolytic graphite (HOPG) has attracted significant research interest. Here we report a novel investigation on the structural-properties of exfoliated-HOPG. We investigated two types of exfoliation methods, involving either a full (method-1) or partial (method-2) contact between adhesive tape and the main HOPG. Structural characterization was obtained by employing X-ray diffraction (XRD), Raman spectroscopy and electron microscopy (SEM). In particular, Raman point and mapping spectroscopy revealed significant structural-transitions from ABA (Bernal) to ABC (rhombohedral) stacking (stacking-faults), in those samples obtained with the method-2. Interestingly, strained regions exhibiting structural-deformations with a ridge-like morphology were reproducibly identified. The acquired Raman-spectra revealed a local enhancement of the D and D’ bands-intensity together with contributions arising from Electronic Raman Scattering (ERS) across the band-gap of rhombohedral-graphite, at middle (∼1870 cm−1) and high (∼ 2680 cm−1) frequency. HRTEM of the samples produced with the method-2 allowed also for the identification of local-coexistence of ripplocation-like defects with moiré superlattices, an indicator of non-uniform c-axis configuration

    Efficacy of early prone or lateral positioning in patients with severe COVID-19: a single-center prospective cohort

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    Abstract Background Position intervention has been shown to improve oxygenation, but its role in non-invasively ventilated patients with severe COVID-19 has not been assessed. The objective of this study was to investigate the efficacy of early position intervention on non-invasively ventilated patients with severe COVID-19. Methods This was a single-center, prospective observational study in consecutive patients with severe COVID-19 managed in a provisional ICU at Renmin Hospital of Wuhan University from 31 January to 15 February 2020. Patients with chest CT showing exudation or consolidation in bilateral peripheral and posterior parts of the lungs were included. Early position intervention (prone or lateral) was commenced for &amp;gt; 4 hours daily for 10 days in these patients, while others received standard care. Results The baseline parameters were comparable between the position intervention group (n = 17) and the standard care group (n = 35). Position intervention was well-tolerated and increased cumulative adjusted mean difference of SpO2/FiO2 (409, 95% CI 86 to 733) and ROX index (26, 95% CI 9 to 43) with decreased Borg scale (−9, 95% CI −15 to −3) during the first 7 days. It also facilitated absorption of lung lesions and reduced the proportion of patients with high National Early Warning Score 2 (≥ 7) on days 7 and 14, with a trend toward faster clinical improvement. Virus shedding and length of hospital stay were comparable between the two groups. Conclusions This study provides the first evidence for improved oxygenation and lung lesion absorption using early position intervention in non-invasively ventilated patients with severe COVID-19, and warrants further randomized trials. </jats:sec
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