432 research outputs found

    Acceptance of VR Shopping: Examining the Role of Technological Characteristics and Consumer Fashion Involvement

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    The present study examined the effect of vividness and interactivity, the two technological characteristics of VR, and fashion involvement, a consumer characteristic, on consumer’s intent to use VR stores under the framework of the Technology Acceptance Model (TAM). The subjects of the present study were asked to experience a commercially available fashion-brand VR store through a computer monitor and their responses were measured. The results revealed the effects of the technological characteristics of the VR store on consumer beliefs. The higher the perceived vividness of the VR store, the greater the perception that it is easy to use and playful. A higher level of perceived interactivity meant a higher degree of perceived usefulness, ease of use, and playfulness. The results also showed that consumer fashion involvement had a significant impact on perceived playfulness but not on perceived usefulness and ease of use. In addition, a higher degree of perceived ease of use translated into a higher level of perceived usefulness. Regarding the effect of consumer beliefs on usage intention, the more the VR store was perceived as being useful and the greater the playfulness derived from the experience, the higher the consumer intention to adopt the shopping platform. However, the perceived ease of use had a significantly negative impact on consumer usage intention. This shows that, even if VR stores are perceived as easy to use, a lack of perceived benefits, such as usefulness or playfulness, will negate their positive impact on consumer usage intention

    Effects of the energy spread of secondary electrons in a dc-biased single-surface multipactor

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    The effects of the energy spread of secondary electrons are theoretically investigated for a dc-biased single-surface multipactor. In our previous publication [S. G. Jeon et al., Phys. Plasmas 16, 073101 (2009)], we obtained the conditions for the phase lock of an electron bunch, assuming zero velocity spread of the secondary electrons. In this work, we extended our previous theory to derive a quadratic map, by which the stability and bifurcation of the electron bunch can be systematically investigated. For the study of the energy spread of the secondary electrons, a randomized term was added to this map. The modified map then showed significant smearing-out of the bifurcated branches. The theoretical results were verified by particle-in-cell simulations, which showed good agreement in wide parameter ranges for both cases of monoenergetic and energy-spread secondary electrons.open4

    Electron bunching from a dc-biased, single-surface multipactor with realistically broad energy spectrum and emission angle of secondary electrons

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    We studied the influences of wide energy spectrum and emission angle of secondary electrons on electron bunching from a dc-biased single surface multipactor. In our previous study of the same system, an ideally narrow energy spread of secondary electrons without emission angle was used in the analysis of the electron trajectory [M. S. Hur, J.-I. Kim, G.-J. Kim, and S.-G. Jeon, Phys. Plasmas 18, 033103 (2011) and S.-G. Jeon, J.-I. Kim, S.-T. Han, S.-S. Jung, and J. U. Kim, Phys. Plasmas 16, 073101 (2009)]. In this paper, we investigated the cases with realistic energy spectrum, which is featured by a wide energy spread and significant emission angle. To theoretically approach the matter of emission angle, we employed a concept of effective longitudinal velocity distribution. The theoretical results are verified by particle-in-cell (PIC) simulations. We also studied the electron bunching from a copper by PIC simulations, where we observed stable electron bunches with bunch width of approximately 80 mu m.open3

    Effects of Aroma Massage on Home Blood Pressure, Ambulatory Blood Pressure, and Sleep Quality in Middle-Aged Women with Hypertension

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    The purpose of this study was to evaluate the effects of aroma massage applied to middle-aged women with hypertension. The research study had a nonequivalent control group, nonsynchronized design to investigate the effect on home blood pressure (BP), ambulatory BP, and sleep. The hypertensive patients were allocated into the aroma massage group (n=28), the placebo group (n=28), and the no-treatment control group (n=27). To evaluate the effects of aroma massage, the experimental group received a massage with essential oils prescribed by an aromatherapist once a week and body cream once a day. The placebo group received a massage using artificial fragrance oil once a week and body cream once a day. BP, pulse rate, sleep conditions, and 24-hour ambulatory BP were monitored before and after the experiment. There was a significant difference in home systolic blood pressure (SBP) (F=6.71, P=0.002) between groups after intervention. There was also a significant difference in SBP (F=13.34, P=0.001) and diastolic blood pressure (DBP) (F=8.46, P=0.005) in the laboratory between aroma massage and placebo groups. In sleep quality, there was a significant difference between groups (F=6.75, P=0.002). In conclusion, aroma massage may help improve patient quality of life and maintain health as a nursing intervention in daily life

    Shock ion acceleration by an ultrashort circularly polarized laser pulse via relativistic transparency in an exploded target

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    We investigated ion acceleration by an electrostatic shock in an exploded target irradiated by an ultrashort, circularly polarized laser pulse by means of one- and three-dimensional particle-in-cell simulations. We discovered that the laser field penetrating via relativistic transparency (RT) rapidly heated the upstream electron plasma to enable the formation of a high-speed electrostatic shock. Owing to the RT-based rapid heating and the fast compression of the initial density spike by a circularly polarized pulse, a new regime of the shock ion acceleration driven by an ultrashort (20-40 fs), moderately intense (1-1.4 PW) laser pulse is envisaged. This regime enables more efficient shock ion acceleration under a limited total pulse energy than a linearly polarized pulse with crystal laser systems of lambda similar to 1 mu mopen

    Tide-related changes in mRNA abundance of aromatases and estrogen receptors in the ovary and brain of the threespot wrasse Halichoeres trimaculatus

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    Author Posting. © The Author(s), 2018. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Ocean Science Journal 53 (2018): 239-249, doi:10.1007/s12601-018-0016-0.The threespot wrasse (Halichoeres trimaculatus; Family Labridae) is a common coral reef species of the Indo-Pacific Ocean. Given that this species spawns daily at high tide (HT), we hypothesized that endocrine changes in relation to gonadal development are synchronized with the tidal cycle. To test this, we examined the transcript abundance of two cytochrome P450 aromatases (cyp19a and cyp19b) and two estrogen receptors (er and er) in the ovary and brain of this species in response to tidal change. When fish were collected around four tidal points [low tide (LT), flood tide (FT), high tide (HT), and ebb tide (ET)], gonadosomatic index and oocyte diameter increased around HT and FT, respectively. Ovulatory follicles were observed in ovaries around HT. Real-time quantitative polymerase-chain reaction revealed that mRNA abundance of cyp19a and er, but not er, in the ovary increased around ET and HT, respectively. On the other hand, mRNA levels of cyp19b in the forebrain were significantly higher around FT. Increases of er and er mRNA abundance around FT were observed in all areas of the brain and the midbrain, respectively. The changes in mRNA abundance of key genes involved in reproduction at specific tidal cycles, along with the development of the vitellogenic oocytes in the ovary, support our hypothesis that synchronization of endocrine changes to the tidal periodicity plays a role in the gonadal development of this species. We hypothesize that conversion of testosterone to E2 in the brain may be associated with the spawning behavior given that the wrasse exhibits group spawning with a territory-holding male around HT.This study was supported partially by the 21st Century COE program “The Comprehensive Analyses on Biodiversity in Coral Reef and Island Ecosystems in Asian and Pacific Regions” from the Ministry of Education, Culture, Sports, Science and Technology, Japan, JSPS KAKENHI Grant number 16H05796, and the Natural Sciences and Engineering Research Council (NSERC, Canada) Discovery Grant program

    Effect of pectoralis major myofascial release massage for breastfeeding mothers on breast pain, engorgement, and newborns’ breast milk intake and sleeping patterns in Korea: a randomized controlled trial

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    Purpose Supportive interventions to improve breastfeeding practice are needed in nursing. This study investigated the effects of pectoralis major myofascial release massage (MRM) on breast pain and engorgement among breastfeeding mothers and on breast milk intake and sleep patterns among newborns. Methods Breastfeeding mothers who had delivered between 37 and 43 weeks and had 7- to 14-day-old newborns were recruited from a postpartum care center in Gunpo, Korea. Participants were randomized to the MRM or control group. The outcome variables were breast pain and breast engorgement among breastfeeding mothers and breast milk intake and sleep time among newborns. The experimental treatment involved applying MRM to separate the pectoralis major muscle and the underlying breast tissue in the chest. After delivery, the first MRM session (MRM I) was provided by a breast specialist nurse, and the second (MRM II) was administered 48 hours after MRM I. Results Following MRM, breast pain (MRM I: t=−5.38, p<.001; MRM II: t=−10.05, p<.001), breast engorgement (MRM I: right, t=−1.68, p=.100; left, t=−2.13, p=.037 and MRM II: right, t=−4.50, p<.001; left, t=−3.74, p<.001), and newborn breast milk intake (MRM I: t=3.10, p=.003; MRM II: t=3.09, p=.003) differed significantly between the groups. Conclusion MRM effectively reduced breast engorgement and breast pain in breastfeeding mothers, reducing the need for formula supplementation, and increasing newborns’ breast milk intake. Therefore, MRM can be utilized as an effective nursing intervention to alleviate discomfort during breastfeeding and to improve the rate of breastfeeding practice (clinical trial number: KCT0002436)
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