Constructing minimal telescopers for rational functions in three discrete variables

We present a new algorithm for constructing minimal telescopers for rational functions in three discrete variables. This is the first discrete reduction-based algorithm that goes beyond the bivariate case. The termination of the algorithm is guaranteed by a known existence criterion of telescopers. Our approach has the important feature that it avoids the potentially costly computation of certificates. Computational experiments are also provided so as to illustrate the efficiency of our approach

Photoplethysmographic imaging and analysis of pulsatile pressure wave in palmar artery at 10 wavelengths

CC BY: © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 International License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.Significance As a noncontact method, imaging photoplethysmography (iPPG) may provide a powerful tool to measure pulsatile pressure wave (PPW) in superficial arteries and extract biomarkers for monitoring of artery wall stiffness. Aim We intend to develop a approach for extraction of the very weak cardiac component from iPPG data by identifying locations of strong PPW signals with optimized illumination wavelength and determining pulse wave velocity (PWV). Approach Monochromatic in vivo iPPG datasets have been acquired from left hands to investigate various algorithms for retrieval of PPW signals, distribution maps and waveforms, and their dependence on arterial location and wavelength. Results A robust algorithm of pixelated independent component analysis (pICA) has been developed and combined with spatiotemporal filtering to retrieve PPW signals. Spatial distributions of PPW signals have been mapped in 10 wavelength bands from 445 to 940 nm and waveforms were analyzed at multiple locations near the palmar artery tree. At the wavelength of 850 nm selected for timing analysis, we determined PWV values from 12 healthy volunteers in a range of 0.5 to 5.8 m/s across the hand region from wrist to midpalm and fingertip.ECU Open Access Publishing Support Fun

Clinical study of intraocular pressure and retinal thickness affected by residual triamcinolone acetonide after vitrectomy

AIM: To study the effect of residual triamcinolone acetonide(TA)to intraocular pressure(IOP)and retinal thickness in patients after vitrectomy. METHODS: Retrospective study. The medical data of 83 patients(83 eyes)after vitrectomy in our hospital from October 2016 to October 2017 were analyzed retrospectively. The 83 patients were treated with TA as vitreous dyeing. Vitreous cavity was not filled with silicone oil or gas. Totally 32 eyes were observed that triamcinolone acetonide was residual in vitreous cavity, 51 eyes were not observed the residual, and after 1wk and 3mo, intraocular pressure and macular center concave thickness(CMT)of two groups was compared. RESULTS: There was no statistical difference in preoperative average intraocular pressure between two groups(t=0.56, P>0.05). After 1wk, IOP of no residual group was 15.48±3.8mmhg, IOP of residual Group was 20.09±6.14mmhg. IOP of residual group were higher than IOP of no residual group, the difference was statistically significant(t=3.81,Pt=4.54, Pt=3.75,Pt=0.21, P>0.05). CONCLUSION: The residual triamcinolone acetonide as a dyeing agent during vitrectomy may raise the risk of postoperative intraocular pressure in short term, and after 3mo without any significant effect on the thickness of macular center