7,572 research outputs found

    Chiral Anomaly Effects and the BaBar Measurements of the γγπ0\gamma\gamma^{*}\to \pi^{0} Transition Form Factor

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    The recent BaBar measurements of the γγπ0\gamma\gamma^{*}\to \pi^{0} transition form factor show spectacular deviation from perturbative QCD prediction for large space-like Q2Q^{2} up to 34GeV234\,\rm GeV^{2}. When plotted against Q2Q^{2}, Q2F(Q2)Q^{2}F(Q^{2}) shows steady increase with Q2Q^{2} in contrast with the flat Q2Q^{2} behavior predicted by perturbative QCD, and at 34GeV234\,\rm GeV^{2} is more than 50% larger than the QCD prediction. Stimulated by the BaBar measurements, we revisit our previous paper on the cancellation of anomaly effects in high energy processes Z0π0γZ^{0}\to \pi^{0}\gamma, e+eπ0γe^{+}e^{-}\to \pi^{0}\gamma and apply our results to the γγπ0\gamma^{*}\gamma\to \pi^{0} transition form factor measured in the e+ee+eπ0e^{+}e^{-}\to e^{+}e^{-}\pi^{0} process with one highly virtual photon. We find that, the transition form factor F(Q2)F(Q^{2}) behaves as (m2Q2)×(ln(Q2/m2))2(\frac{m^{2}}{Q^{2}})\times (\ln(Q^{2}/m^{2}))^{2} and produces a striking agreement with the BaBar data for Q2F(Q2)Q^{2}F(Q^{2}) with m=132MeVm=132\,\rm MeV which also reproduces very well the CLEO data at lower Q2Q^{2}.Comment: v4, LaTeX, 8 pages, one figure, minor changes(references), to appear in Int. J. Mod. Phys.

    The Distribution of Dengue Virus Serotype in Quang Nam Province (Vietnam) during the Outbreak in 2018

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    Objectives: Quang Nam province in the Centre of Vietnam has faced an outbreak of dengue hemorrhagic fever (DHF) in 2018. Although DHF is a recurrent disease in this area, no epidemiological and microbiological reports on dengue virus serotypes have been conducted mainly due to lack of facilities for such a kind of advanced surveillance. The aim of this study was to detect different dengue virus serotypes in patients’ blood samples. Design and Methods: Suspected cases living in Quang Nam province (Vietnam) and presenting clinical and hematological signs of dengue hemorrhagic fever were included in the study. The screening was performed, and the results were compared by using two methodologies: RT real-time PCR (RT-rPCR) and the Dengue NS1 rapid test. Results: From December 2018 to February 2019, looking both at RT-rPCR [+] and NS1 [+] methodologies, a total of 488 patients were screened and 336 were positive for dengue virus detection (74 children and 262 adults); 273 of these patients (81.3%) underwent viral serotype identification as follows: 12.82% (35/273) D1 serotype, 17.95% (49/273) D2, 0.37% (1/273) D3, 68.50 (187/283) D4, and 0.37% (1/273) D2+D4 serotypes. The RT-rPCR outcomes showed higher sensitivity during the first three days of infection compared to NS1 (92.3% vs. 89.7%). The NS1 increased sensitivity after the first 3 days whilst the RT-rPCR decreased. Conclusions: Advanced surveillance with dengue virus serotypes identification, if performed routinely, may help to predict and prevent further DHF epidemics based on the exposure of the different serotypes during different periods that lead to the intensification of disease severity as a consequence of antibody-dependent enhancement (ADE)

    Non-minimal Einstein-Yang-Mills-Higgs theory: Associated, color and color-acoustic metrics for the Wu-Yang monopole model

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    We discuss a non-minimal Einstein-Yang-Mills-Higgs model with uniaxial anisotropy in the group space associated with the Higgs field. We apply this theory to the problem of propagation of color and color-acoustic waves in the gravitational background related to the non-minimal regular Wu-Yang monopole.Comment: 14 pages, no figure

    A Biomimetic steering robot for Minimally invasive surgery application

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    International audienceMinimally Invasive Surgery represents the future of many types of medical inter- ventions such as keyhole neurosurgey or transluminal endoscopic surgery. These procedures involve insertion of surgical instruments such as needles and endoscopes into human body through small incision/ body cavity for biopsy and drug delivery. However, nearly all surgical instruments for these procedures are inserted manually and there is a long learning curve for surgeons to use them properly. Many research efforts have been made to design active instruments (endoscope, needles) to improve this procedure during last decades. New robot mechanisms have been designed and used to improve the dexterity of current endoscope. Usually these robots are flexible and can pass the constrained space for fine manipulations. In recent years, a con- tinuum robotic mechanism has been investigated and designed for medical surgery. Those robots are characterized by the fact that their mechanical components do not have rigid links and discrete joints in contrast with traditional robot manipula- tors. The design of these robots is inspired by movements of natural animals such as tongues, elephant trunks and tentacles. The unusual compliance and redundant degrees of freedom of these robots provide strong potential to achieve delicate tasks successfully even in cluttered and unstructured environments. This chapter will present a complete application of a continuum robot for Mini- mally Invasive Surgery of colonoscopy. This system is composed of a micro-robotic tip, a set of position sensors and a real-time control system for guiding the explo- ration of colon. Details will be described on the modeling of the used pneumatic actuators, the design of the mechanical component, the kinematic model analysis and the control strategy for automatically guiding the progression of the device inside the human colon. Experimental results will be presented to check the perfor- mances of the whole system within a transparent tube

    Origin of Drastic Change of Fermi Surface and Transport Anomalies in CeRhIn5 under Pressure

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    The mechanism of drastic change of Fermi surfaces as well as transport anomalies near P=Pc=2.35 GPa in CeRhIn5 is explained theoretically. The key mechanism is pointed out to be the interplay of magnetic order and Ce-valence fluctuations. We show that the antiferromagnetic state with "small" Fermi surfaces changes to the paramagnetic state with "large" Fermi surfaces with huge enhancement of effective mass of electrons with keeping finite c-f hybridization. This explains the drastic change of the de Haas-van Alphen signals. Furthermore, it is also consistent with the emergence of T-linear resistivity simultaneous with the residual resistivity peak at P=Pc in CeRhIn5.Comment: 5 pages, 3 figures, submitted to Journal of Physical Society of Japa

    Implicit and explicit solvent models for the simulation of a single polymer chain in solution: Lattice Boltzmann vs Brownian dynamics

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    We present a comparative study of two computer simulation methods to obtain static and dynamic properties of dilute polymer solutions. The first approach is a recently established hybrid algorithm based upon dissipative coupling between Molecular Dynamics and lattice Boltzmann (LB), while the second is standard Brownian Dynamics (BD) with fluctuating hydrodynamic interactions. Applying these methods to the same physical system (a single polymer chain in a good solvent in thermal equilibrium) allows us to draw a detailed and quantitative comparison in terms of both accuracy and efficiency. It is found that the static conformations of the LB model are distorted when the box length L is too small compared to the chain size. Furthermore, some dynamic properties of the LB model are subject to an L1L^{-1} finite size effect, while the BD model directly reproduces the asymptotic LL \to \infty behavior. Apart from these finite size effects, it is also found that in order to obtain the correct dynamic properties for the LB simulations, it is crucial to properly thermalize all the kinetic modes. Only in this case, the results are in excellent agreement with each other, as expected. Moreover, Brownian Dynamics is found to be much more efficient than lattice Boltzmann as long as the degree of polymerization is not excessively large.Comment: 11 figures, submitted to J. Chem. Phy

    Role of Light Vector Mesons in the Heavy Particle Chiral Lagrangian

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    We give the general framework for adding "light" vector particles to the heavy hadron effective chiral Lagrangian. This has strong motivations both from the phenomenological and aesthetic standpoints. An application to the already observed D \rightarrow \overbar{K^*} weak transition amplitude is discussed.Comment: 19 pages, LaTeX documen

    A randomized controlled trial of a pharmacist-led intervention to enhance knowledge of Vietnamese patients with type 2 diabetes mellitus

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    OBJECTIVES: We aimed to assess whether a pharmacist-led intervention enhances knowledge, medication adherence and glycemic control in patients with type 2 diabetes mellitus (T2DM). METHODS: We conducted a single-blinded randomized controlled trial in Vietnam. Individuals with T2DM were recruited from a general hospital and randomly allocated to intervention and routine care. The intervention group received routine care plus counselling intervention by a pharmacist, including providing drug information and answering individual patients' queries relating to T2DM and medications, which had not been done in routine care. We assessed the outcomes: knowledge score as measured by the Diabetes Knowledge Questionnaire, self-reported adherence and fasting blood glucose (FBG) at the 1-month follow-up. KEY FINDINGS: A total of 165 patients (83 intervention, 82 control) completed the study; their mean age was 63.33 years, and 49.1% were males. The baseline characteristics of the patients were similar between the groups. At 1-month follow-up, the pharmacist's intervention resulted in an improvement in all three outcomes: knowledge score [B = 5.527; 95% confidence intervals (CI): 3.982 to 7.072; P < 0.001], adherence [odds ratio (OR) = 9.813; 95% CI: 2.456 to 39.205; P = 0.001] and attainment of target FBG (OR = 1.979; 95% CI: 1.029 to 3.806; P = 0.041). CONCLUSIONS: The pharmacist-led intervention enhanced disease knowledge, medication adherence and glycemic control in patients with T2DM. This study provides evidence of the benefits of pharmacist counselling in addition to routine care for T2DM outpatients in a Vietnam population

    Multivariate morphometric analysis of Apis cerana of southern mainland Asia

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    Multivariate morphometric analyses were performed on a series of worker honeybees, Apis cerana, representing 557 colonies from all of southern mainland Asia extending from Afghanistan to Vietnam south of the Himalayas. Scores from the principal components analysis revealed five statistically separable but not entirely distinct morphoclusters of bees: (1) the Hindu Kush, Kashmir, N. Myanmar, N. Vietnam and S. China; (2) Himachal Pradesh region of N. India; (3) N. India, Nepal; (4) central and S. Myanmar and Vietnam, Cambodia, Thailand, S. China and peninsular Malaysia; (5) central and S. India. The major morphoclusters are distributed coherently with the different climatic zones of the region. While populations are definable, nomenclatural adjustments remain for the future
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