ABSTRACT
We discuss integrable discretizations of 3-dimensional cyclic systems, that is, orthogonal coordinate systems with one family of circular coordinate lines. In particular, the underlying circle congruences are investigated in detail and characterized by the existence of a certain flat connection. Within the developed framework, discrete cyclic systems with a family of discrete flat fronts in hyperbolic space and discrete cyclic systems, where all coordinate surfaces are discrete Dupin cyclides, are investigated.
ABSTRACT
The contour of an arbitrary figure can be represented as a group of circles of curvature in contact with it, with each curvature circle represented by its center OC and radius r. We propose a series of cell models for detecting this circle, which is composed of a lateral geniculate nucleus (LGN) cell, nondirectionally selective (NDS) simple cell, and curvature-circle detection cell (CDC). The LGN and NDS simple cells were previously modeled. The CDC has been modeled as follows. Each tangent in contact with this circle is detected by an NDS simple cell that performs the Hough transformation of LGN cell responses, and then this tangent is transformed to a three-dimensional (3D) normal line in a CDC column. This transformation has been named a 3D normal-line transform. Performing this transformation for all tangents causes a CDC at the intersection of these normal lines to fire most intensively, and thus the OC and r of the circle is detected as the coordinates of this intersection. Therefore, the CDC has been modeled as this 3D normal-line transform. Based on this CDC, we model two types of constancy CDC: a position-invariant CDC and a curvature-invariant CDC. These three types of CDC reflect the response to various stimuli in actual area V4 cells. In order to validate these CDC types neurophysiologically, we propose an experimental method using microelectrodes. Cell models previously reported correspond to this hierarchy: the S1, S2, and C2 cells correspond to the NDS simple cell, CDC, and position-invariant CDC, respectively.
ABSTRACT
Objective To evaluate the safety and effect of one-way barbs line (absorbable sutures v - locTM180) in primary suturing of laparoscopic choledocholithotomy. Methods From July 2014 to June 2015, clinical data of 86 cases performed primary suturing in laparoscopic choledocholithotomy by the same performer were retrospectively analyzed. The patients were divided into three groups, One-way barbs line continuous full-thickness suture group (A group), ordinary absorption line continuous full-thickness suture group (B group) and ordinary absorption line discontinuous full-thickness suture group (C group). The bile duct suture needed time, intraoperative blood loss, postoperative eating time, postoperative hospital stay and postoperative bile fistula were compared. Results All the 86 cases underwent successful operation without T tube, and none of them received alternative open operation. Compared with group B and C, time needed for bile duct suturing in A group have statistical significance. There was no significant difference in the intraoperative blood loss, postoperative eating time, postoperative hospital stay between the three groups (P > 0.05). The incidence of postoperative bile fistula in A group were none. The incidence of postoperative bile fistula in B group was 1 case, the incidence of postoperative bile fistula in C group was 2 cases.Conclusions The method of one-way barbs line continuous full-thickness suture were simple and secure in primary suturing of laparoscopic choledocholithotomy.
