347 research outputs found
Evolutionary analysis of sustainable tourism
This paper aims to explore an effective green incentive mechanism for government to develop traditional tourism into green tourism by establishing a dynamic evolutionary game model among governments, tourism enterprises, and tourists. We first discuss the evolutionary stable strategy (ESS) regarding green innovation and its corresponding conditions for each stakeholder, and then analyze the ESS between tourism enterprises and tourists, with and without consideration of government green supervision. The optimal green incentive condition for driving all stakeholders to conduct green behavior is identified. More importantly, we advise the government to first implement green incentive mechanism in the areas where the tourism market scale is relatively small. Additionally, we utilize numerical examples to illustrate the findings and provide some managerial insights
Interplay between spin wave and magnetic vortex
In this paper, the interplay between spin wave and magnetic vortex is
studied. We find three types of magnon scatterings: skew scattering, symmetric
side deflection and back reflection, which associate with respectively magnetic
topology, energy density distribution and linear momentum transfer torque
within vortex. The vortex core exhibits two translational modes: the intrinsic
circular mode and a coercive elliptical mode, which can be excited based on
permanent and periodic magnon spin-transfer torque effects of spin wave.
Lastly, we propose a vortex-based spin wave valve in which via inhomogeneity
modulation we access arbitrary control of the phase shift.Comment: 33 pages, 23 figures, 1 tabl
Study of Three Rotating Radio Transients with FAST
Rotating radio transients (RRATs) are peculiar astronomical objects whose
emission mechanism remains under investigation. In this paper, we present
observations of three RRATs, J1538+2345, J1854+0306 and J1913+1330, observed
with the Five-hundred-meter Aperture Spherical radio Telescope (FAST).
Specifically, we analyze the mean pulse profiles and temporal flux density
evolutions of the RRATs. Owing to the high sensitivity of FAST, the derived
burst rates of the three RRATs are higher than those in previous reports. RRAT
J1854+0306 exhibited a time-dynamic mean pulse profile, whereas RRAT J1913+1330
showed distinct radiation and nulling segments on its pulse intensity trains.
The mean pulse profile variation with frequency is also studied for RRAT
J1538+2345 and RRAT J1913+1330, and the profiles at different frequencies could
be well fitted with a cone-core model and a conal-beam model, respectively.Comment: Sci. China-Phys. Mech. Astron. 62, 959503 (2019
Comparison of bypass surgery and drug-eluting stenting in diabetic patients with left main and/or multivessel disease: A systematic review and meta-analysis of randomized and nonrandomized studies
Background: With advances in theinterventional field, the choice between coronary artery bypass grafting (CABG) and percutaneous coronary intervention with drug-eluting stents (PCI-DES) for the diabetic subset with left main (LM) and/or multivessel disease (MVD) remains consistently controversial.
Methods and results: We conducted a systematic review of randomized controlled trials (RCTs) and observational controlled trials (OCTs) comparing the two strategies for the diabetic subset with LM and/or MVD. PubMed, EMBASE, CENTRAL databases, Google Scholar and SinoMed were systematically searched for eligible studies without language and publicaÂtion restrictions. We identified 19 trials (4 randomized and 15 nonrandomized), enrolling 5,805 patients in OCTs and 3,060 patients in RCTs, respectively. PCI-DES was associated with higher mortality compared with CABG (11.7% DES vs. 9.1% CABG, RR 1.23, 95% CI 1.00–1.53, p = 0.06). Patients after PCI-DES had higher prevalence of myocardial infarction (MI) when compared with CABG (8.5% DES vs. 4.6% CABG, RR 1.68, 95% CI 1.20–2.37, p = 0.003). PCI-DES patients were at substantially lower risk of stroke (2.0% DES vs. 3.9% CABG, RR 0.51, 95% CI 0.39–0.67, p < 0.00001), but at several-fold higher risk of repeat revascularization (19.0% DES vs. 6.3% CABG, RR 2.95, 95% CI 2.46–3.55, p < 0.00001). The OCT patients risked a lower mortality as compared to the RCT patients (9.6% OCTs vs. 11.9% RCTs, RR 0.81, 95% CI 0.71–0.92, p = 0.001).
Conclusions: CABG for patients with diabetes mellitus and LM and/or MVD had advanÂtages over PCI-DES in all-cause death, nonfatal MI, and repeat revascularization, but the substantial disadvantage in nonfatal stroke. The high-selected patients (RCTs) risked a higher mortality than the real-world patients (OCTs)
A Pooling Strategy for Detecting Carbapenem Resistance Genes by the Xpert Carba-R Test in Rectal Swab Specimens
Rapid and accurate detection of carriers of carbapenemase-producing organisms (CPO) in hospitalized patients is critical for infection control and prevention. This study aimed to evaluate a pooling strategy for the detection of carbapenem resistance genes (CRG) in multiple specimens using the Xpert Carba-R test. Two rectal swabs each were collected from 415 unique patients. One swab was tested by Carba-R on the five specimen-pooled strategy. The other swab was tested individually by culture followed by DNA sequence analysis for CRG as the reference. At the first 5:1 pooling testing, 22 of 83 pools were positive, which yielded 34 positives from individual specimens when positive pools were subsequently retested. All individual specimens in the 61 negative pools were retested as negative by Carba-R. Among the 34 Carba-R-positive samples, 30 and four were positive and negative, respectively, by culture and sequencing. The remaining 381 Carba-R-negative specimens were also negative by culture and sequencing. Overall sensitivity, specificity, positive predictive value, and negative predictive value of the 5:1 pooled screening were 100.0% (95% confidence interval [CI] = 85.9% to 100%), 99.0% (95% CI = 97.2% to 99.7%), 88.2% (95% CI = 71.6% to 96.2%), and 100.0% (95% CI = 98.8% to 100%), respectively. Using the 5:1 pooling strategy, our study completed CRG screening in 414 patients with 193 reagents with significant cost savings. The 5:1 pooling strategy using the Carba-R test showed a potential method for screening CRG from rectal swabs with good sensitivity and decreased cost
A visual tool for building logical data models of websites
Information sources over the WWW contain a large amount of data organized according to different interests and values. Thus, it is important that facilities are there to enable users to extract information of interest in a simple and effective manner. To do this, We propose the Wiccap Data Model, an XML data model that maps Web information sources into commonly perceived logical models, so that information can be extracted automatically according to users' interests. To accelerate the creation of data models, we have implemented a visual tool, called the Mapping Wizard, to facilitate and automate the process of producing Wiccap Data Models. Using the tool, the time required to construct a logical data model for a given website is significantly reduced
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