3,416 research outputs found
A Note on Symplectic, Multisymplectic Scheme in Finite Element Method
We find that with uniform mesh, the numerical schemes derived from finite
element method can keep a preserved symplectic structure in one-dimensional
case and a preserved multisymplectic structure in two-dimentional case in
certain discrete version respectively. These results are in fact the intrinsic
reason that the numerical experiments indicate that such finite element
algorithms are accurate in practice.Comment: 7 pages, 3 figure
Can sub-GeV dark matter coherently scatter on the electrons in the Atom?
A novel detection of sub-GeV dark matter is proposed in the paper. The
electron cloud is boosted by the dark matter and emits an electron when it is
dragged back by the heavy nucleus, namely the coherent scattering of the
electron cloud of the atom. The survey in the X-ray diffraction shows that the
atomic form factors are much more complicate than the naive consideration. The
results of the relativistic Hartree-Fock(RHF) method give non-trivial shapes of
the atoms. The detailed calculation of the recoil of the electron cloud, the
kinetics, the fiducial cross section and the corresponding calculation of
detection rate are given analytically. The numerical results show that the
limits of the RHF form factors are much stringent than the recoil of a single
electron, almost 4 orders stronger, and also gives tight limitations comparing
to the Migdal effect below about several hundred MeV. The physical picture and
the corresponding results are promising and need further explorations.Comment: 14 pages, 8 figures, accepted by Communications in Theoretical
Physic
Differential expression of CCN family members CYR611, CTGF and NOV in gastric cancer and their association with disease progression
CCN is an acronym for cysteine-rich protein 61 (CYR61), connective tissue growth factor (CTGF) and nephroblastoma overexpressed (NOV). Aberrations of certain CCN members including CYR61, CTGF, Wnt1-inducible signalling pathway protein (WISP)-1 and -3 have been reported in gastric cancer. The present study aimed to examine the clinical relevance of NOV along with CYR61 and CTGF in gastric cancer by analysing their transcript levels. CYR61, CTGF and NOV transcript expression in 324 gastric cancer samples with paired adjacent normal gastric tissues were determined using real-time quantitative PCR and the results were statistically analysed against patient clinicopathological data using SPSS software. NOV mRNA levels in gastric cancer tissues were significantly elevated when compared with levels in their paired adjacent non-cancerous tissues. Local advanced tumours with invasive expansion (T3 and T4) expressed higher levels of NOV (p=0.013) compared with the less invasive tumours (T1 and T2). CYR61 transcript levels were also significantly increased in gastric cancers compared with levels in the adjacent non cancerous tissues. Kaplan-Meier survival curves revealed that patients with CYR61-low transcript levels had longer overall survival (OS) (p=0.018) and disease-free survival (DFS) (p=0.015). NOV overexpression promoted the in vitro proliferation of AGS cells while the knockdown resulted in a reduced proliferation of HGC27 cells. A similar effect was observed for the invasion of these two gastric cancer cell lines. NOV expression was increased in gastric cancer which was associated with local invasion and distant metastases. Taken together, the expression of NOV and CYR61 was increased in gastric cancer. The elevated expression of CYR61 was associated with poorer survival. NOV promoted proliferation and invasion of gastric cancer cells. Further investigations may highlight their predictive and therapeutic potential in gastric cancer.Cancer Research Wales; Chinese Medical Research Scholarship of Cardiff UniversitySCI(E)[email protected]; [email protected]
Bayesian Uncertainty Quantification for Functional Response
This chapter addresses the stochastic modeling of functional response, which is a major concern in engineering implementation. We first introduce a general framework and several conventional models for functional data, including the functional linear model, penalized regression splines, and the spatial temporal model. However, in engineering practice, a naive mathematical modeling of functional response may fail due to the lack of expressing the underlying physical mechanism. We propose a series of quasiphysical models to handle the functional response. A motivating example of metamaterial design is thoroughly discussed to demonstrate the idea of quasiphysical models. In real applications, various uncertainties have to be taken into account, such as that of the permittivity or permeability of the substrate of the metamaterial. For the propagation of uncertainty, simulationābased methods are discussed. A Bayesian framework is presented to deal with the model calibration in the case of functional response. Experimental results illustrate the efficiency of the proposed method
5 GHz TMRT observations of 71 pulsars
We present integrated pulse profiles at 5~GHz for 71 pulsars, including eight
millisecond pulsars (MSPs), obtained using the Shanghai Tian Ma Radio Telescope
(TMRT). Mean flux densities and pulse widths are measured. For 19 normal
pulsars and one MSP, these are the first detections at 5~GHz and for a further
19, including five MPSs, the profiles have a better signal-to-noise ratio than
previous observations. Mean flux density spectra between 400~MHz and 9~GHz are
presented for 27 pulsars and correlations of power-law spectral index are found
with characteristic age, radio pseudo-luminosity and spin-down luminosity. Mode
changing was detected in five pulsars. The separation between the main pulse
and interpulse is shown to be frequency independent for six pulsars but a
frequency dependence of the relative intensity of the main pulse and interpulse
is found. The frequency dependence of component separations is investigated for
20 pulsars and three groups are found: in seven cases the separation between
the outmost leading and trailing components decreases with frequency, roughly
in agreement with radius-to-frequency mapping; in eleven cases the separation
is nearly constant; in the remain two cases the separation between the outmost
components increases with frequency. We obtain the correlations of pulse widths
with pulsar period and estimate the core widths of 23 multi-component profiles
and conal widths of 17 multi-component profiles at 5.0~GHz using Gaussian
fitting and discuss the width-period relationship at 5~GHz compared with the
results at at 1.0~GHz and 8.6~GHz.Comment: 46 pages, 14 figures, 8 Tables, accepted by Ap
Clinical features and surgical effect of vireoretinal diseases with contralateral blindness
AIM: To investigate the clinical characteristics and surgical results of vireoretinal diseases in 68 patients with contralateral blindness(solitary eye). <p>METHODS: A total of 68 patients(68 eyes)with contralateral blindness were enrolled in this retrospective consecutive study. The clinical characteristics, surgical procedures and temponade materials chosen, preoperative and postoperative visual acuity, complications and prognosis were analyzed. The follow-up ranged from 4 months to 5 years, with an average of(11.30Ā±9.57)months. At the last follow-up, the surgical effects were evaluated.<p>RESULTS:After operation, visual acuity increased significantly. The number of eyes with vision of 0.05 or better increased from 22 eyes(32.4%)preoperative to 60 eyes(88.2%)postoperative, and that of 0.3 or better from 3 eyes(4.4%)to 37 eyes(54.4%). The best-corrected visual acuity before and after surgery also differed significantly(<i>t</i>=8.986, <i>P<</i>0.01). <p>CONCLUSION: With vitreoretinal surgery, visual impairment or loss due to vitreoretinal diseases can be avoided in most patients with contralateral blindness
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