7,846 research outputs found
Admissibility of a wide cluster solution in "anisotropic" higher-order traffic flow models
We analytically investigate a wide cluster solution and show that it is not admitted in some of the traffic flow models in the literature. For those traffic flow models that admit the wide cluster solution, the relationship between two important control parameters and the critical densities that divide an equilibrium solution into stable and unstable regions is thoroughly discussed in detail. We find that such wide clusters exist with a free traffic density in an unstable region, and with one or three critical densities. These results are different from the cases in the well-known higher-order traffic flow models of Payne and Whitham [H. J. Payne, "Models of freeway traffic and control," in Mathematical Models of Public Systems, A. G. Bekey, ed., Simulation Council Proc. Ser. 1, La Jolla, CA, 1971, pp. 51-61], [G. B. Whitham, Linear and Nonlinear Waves, John Wiley and Sons, New York, 1974], Kühne [R. D. Kühne, "Macroscopic freeway model for dense traffic-stop-start waves and incident detection," in Proceedings of the 9th International Symposium on Transportation and Traffic Theory, J. Volmuller and R. Hamerslag, eds., VNU Science Press, Utrecht, 1984, pp. 21-42], and Kerner and Konhäuser [B. S. Kerner and P. Konhäuser, Phys. Rev. E (3), 50 (1994), pp. 54-83]. © 2007 Society for Industrial and Applied Mathematics.published_or_final_versio
CAD/CAM techniques for the conservative and efficient management of tooth wear
The prevalence of tooth wear has increased significantly in recent decades. Whilst many treatment approaches are available, there is no consensus on the best materials or techniques. Advances in digital workflows have the potential to reduce the biological cost of treatment, improve treatment outcomes and reduce costs. This article describes modern CAD/CAM techniques which preserve tooth tissue and improve efficiency
Gamification in e-learning: The mitigation role in technostress
The digital world demands graduates who are accustomed to deal with technology. Blended learning is one of the strategies by combining online media with face-to-face classes. It cannot be denied that students who interact with technology experience stress and tension. This condition have an impact on the learning process so that a way out is needed to bring it down. Gamification is a gaming technique that is applied to non-game applications to increase pleasure when interacting with these applications. This feature has been implemented in business applications, social media, e-commerce, and e-learning. However, the impact of playfulness in mitigating technostress has not been studied. This research examined the role of feedback mechanism and presentation mechanism in giving pleasure in LMS. Furthermore, this playfulness is expected to reduce the stress experienced by users. The research was conducted using a quasi-experimental method by giving participants time to follow the course with the gamification feature. The results showed that the gamification mechanism is able to provide pleasure which in turn will reduce the user's stress level. Based on the user-perceived of playfulness, gamification can reduce stress levels so it will reduce user resistance and increase the effectiveness of technology implementation
Effect of Coenzyme Q10 on early wound healing after recession coverage surgery with the modified coronally advanced tunnel technique and a connective tissue graft: A 6-month, triple-blinded, randomized, placebo-controlled pilot trial.
OBJECTIVES
Coenzyme Q10 (CoQ10) or ubiquinone is one of a cell's most important electron carriers during oxidative phosphorylation and many other cellular processes. As a strong anti-oxidant with further anti-inflammatory effects CoQ10 is of potential therapeutical value. The aim of this randomized controlled clinical trial was to investigate the effect of topical CoQ10 on early wound healing after recession coverage surgery using the modified coronally advanced tunnel (MCAT) and palatal connective tissue graft (CTG).
MATERIALS AND METHODS
Thirty patients with buccal gingival recessions were evaluated after being randomly allocated to: 1) MCAT and CTG with topical application of a coenzyme Q10 spray for 21 days or 2) MCAT and CTG with placebo spray. Wound healing was evaluated by the early wound healing index (EHI). Patient-reported pain was analyzed by a 100-mm visual analogue scale (VAS) at day 2, 7, 14 and 21 post-surgically. Mean recession coverage, gain of keratinized tissue and esthetic outcomes were assessed at 6 months.
RESULTS
EHI and pain scores showed no significant differences. Time to recovery defined as VAS<10 mm was shorter in the test group. Mean root coverage after 6 months was 84.62 ± 26.57% and 72.19 ± 26.30% for test and placebo, p=0.052. Complete root coverage was obtained in 9 (60%) test and in 2 (13.3%) placebo patients. Increase in keratinized tissue width and esthetical outcomes were similar for both groups.
CONCLUSION
CoQ10 had no significant effect on early wound healing and on mean root coverage after 6 months.
CLINICAL RELEVANCE
Early wound healing: in young healthy patients with no inflammatory oral conditions topical CoQ10 does not improve early healing
Entropy on Spin Factors
Recently it has been demonstrated that the Shannon entropy or the von Neuman
entropy are the only entropy functions that generate a local Bregman
divergences as long as the state space has rank 3 or higher. In this paper we
will study the properties of Bregman divergences for convex bodies of rank 2.
The two most important convex bodies of rank 2 can be identified with the bit
and the qubit. We demonstrate that if a convex body of rank 2 has a Bregman
divergence that satisfies sufficiency then the convex body is spectral and if
the Bregman divergence is monotone then the convex body has the shape of a
ball. A ball can be represented as the state space of a spin factor, which is
the most simple type of Jordan algebra. We also study the existence of recovery
maps for Bregman divergences on spin factors. In general the convex bodies of
rank 2 appear as faces of state spaces of higher rank. Therefore our results
give strong restrictions on which convex bodies could be the state space of a
physical system with a well-behaved entropy function.Comment: 30 pages, 6 figure
CITRUS TRISTEZA VIRUS RESISTANCE GENE LOCUS: SMALL RNA PROFILE AND PRELIMINARY EPIGENETIC STUDIES
Small interfering RNAs (siRNAs), play a vital role in epigenetics of plant virus-host plant interactions. It has been extensively studied at both the transcriptional and post-transcriptional levels. In plants, siRNAs initiate and manage gene silencing by directing DNA methylation and/or histone methylation. In Arabidopsis, the ~24 nt siRNAs directs DNA methylation (RNA-directed DNA methylation, RdDM) and chromatin remodeling at their target loci. Recent advances in highthroughput sequencing techniques has enabled thorough exploration of small RNAs populations and allow rapid analysis of massive datasets to assemble complete full-length genome sequence for different plant species. This large database of sequence information also allows identification of genome regions specifically matched by siRNAs that likely differ among tolerant, resistant or
susceptible hosts and advance epigenetic studies on diseased plants.
Resistance to Citrus tristeza virus (CTV), the most severe virus affecting Citrus spp.,
associated with a single dominant gene locus Ctv occurring in Poncirus trifoliata while all Citrus spp. are considered susceptible. This locus contains 22 putative genes, but their regulation and mechanism for resistance remains unknown.
In our study, CTV was graft-inoculated on Carrizo citrange (Poncirus trifoliata x C. sinensis
(I think) ) and C. aurantium (sour orange) seedlings, and the population of siRNA characterized by high-throughput sequencing using an ILLUMINA platform. The Ctv-derived siRNA (~2% of the total short reads) were dominated in both hosts by the 24-nt. However, CTV infection caused an increase in accumulation of 24-nt siRNA sequences homologous to the Ctv gene in Carrizo but it decreased in sour orange. Distribution of the 24nt along the Ctv gene locus (282Kb) had a clearly different distribution between the two host. The predominant hot spot of siRNA in Carrizo mapped in the putative gene Ctv-20, whereas in sour orange it associated to the intergenic region between the putative genes Ctv-11 and Ctv-12, where a Copia-like retrotransposon C is located. This distribution profile was conserved for each species between CTV-infected and uninfected plants but, as previously mentioned, the frequency of the 24nt siRNAs was altered by the presence of the virus.
We supposed that the different profile of 24nt between the two host in the locus ctv is due to
RdDM mechanisms. To demonstrate the methylation status of the resistance locus we performed a
bisulfite treatment of DNA. in which unmethylated cytosine was converted to uracile, while
methylated cytosine did not react. A methylcytosines mapping was carried out on Ctv-11 and Ctv-12 sequences. By specific software were found 5 different CpG islands in the Copia-likeretrotransposon sequence and 42 primer pair were designed. The PCR analyses have been carried out using MSP and BSP primers followed by combined bisulfite restriction analysis (COBRA)
Algorithms for Colourful Simplicial Depth and Medians in the Plane
The colourful simplicial depth of a point x in the plane relative to a
configuration of n points in k colour classes is exactly the number of closed
simplices (triangles) with vertices from 3 different colour classes that
contain x in their convex hull. We consider the problems of efficiently
computing the colourful simplicial depth of a point x, and of finding a point,
called a median, that maximizes colourful simplicial depth.
For computing the colourful simplicial depth of x, our algorithm runs in time
O(n log(n) + k n) in general, and O(kn) if the points are sorted around x. For
finding the colourful median, we get a time of O(n^4). For comparison, the
running times of the best known algorithm for the monochrome version of these
problems are O(n log(n)) in general, improving to O(n) if the points are sorted
around x for monochrome depth, and O(n^4) for finding a monochrome median.Comment: 17 pages, 8 figure
Decision-Making for Maritime Networks: Evaluating Corporate and Social Profitability of an Integrated Short Sea Shipping Network in the Upper Tyrrhenian Sea
This study applies cost benefit analysis (CBA) approaches to evaluate corporate and social profitability of a coordinated management proposal for a Short Sea Shipping (SSS) network in the upper Tyrrhenian area. The profitability of the maritime network is assessed first for the shipping companies operating therein and then for society as a whole. Corporate profitability analysis reveals a supply system currently over-sized compared to actual demand. The reasons for this must be found in the corporate competition strategies that traditionally characterize the free maritime transport market in the area. Social profitability analysis proves the potential positive impact of services rescheduling and coordination in terms of time savings and emission reduction in port areas and demonstrates the benefits new integrated management policies could yield for achieving higher efficiency and sustainability in SSS Tyrrhenian networks
Current profiles and AC losses of a superconducting strip with elliptic cross-section in perpendicular magnetic field
The case of a hard type II superconductor in the form of strip with elliptic
cross-section when placed in transverse magnetic field is studied. We approach
the problem in two steps, both based on the critical-state model. First we
calculate numerically the penetrated current profiles that ensure complete
shielding in the interior, without assuming an a priori form for the profiles.
In the second step we introduce an analytical approximation that asumes that
the current profiles are ellipses. Expressions linking the sample magnetization
to the applied field are derived covering the whole range of applied fields.
The theoretical predictions are tested by the comparison with experimental data
for the imaginary part of AC susceptibility.Comment: 12 pages; 3 figure
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