Semi-Global Exponential Stability of Augmented Primal-Dual Gradient Dynamics for Constrained Convex Optimization

Primal-dual gradient dynamics that find saddle points of a Lagrangian have been widely employed for handling constrained optimization problems. Building on existing methods, we extend the augmented primal-dual gradient dynamics (Aug-PDGD) to incorporate general convex and nonlinear inequality constraints, and we establish its semi-global exponential stability when the objective function is strongly convex. We also provide an example of a strongly convex quadratic program of which the Aug-PDGD fails to achieve global exponential stability. Numerical simulation also suggests that the exponential convergence rate could depend on the initial distance to the KKT point

Cross-Layer Handover Scheme for Multimedia Communications in Next GenerationWireless Networks

ROC NSC [97-2221-230 E-018-020-MY3, 98-2218-E-151-004-MY3]In order to achieve seamless handover for real-time applications in the IP Multimedia Subsystem (IMS) of next generation network, a multiprotocol combined handover mechanism is proposed in this paper. We combine SIP (Session Initiation Protocol), FMIP (Fast Mobile IPv6 Protocol), and MIH (Media Independent Handover) protocols by cross-layer design and optimize those protocols' signaling flows to improve the performance of vertical handover. Theoretical analysis and simulation results illustrate that our proposed mechanism performs better than the original SIP and MIH combined handover mechanism in terms of service interruption time and packet loss

Skin sympathetic nerve activity in patients with obstructive sleep apnea

Background: Obstructive sleep apnea (OSA) is associated with increased cardiac arrhythmia and sudden cardiac death. We recently developed a new method (neuECG) to noninvasively measure electrocardiogram and skin sympathetic nerve activity (SKNA). Objective: The purpose of this study was to test the hypothesis that SKNA measured during sleep study is higher in patients with OSA than in those without OSA. Methods: We prospectively recorded neuECG and polysomnography in 26 patients undergoing a sleep study. Sleep stages were scored into rapid eye movement (REM), and non-REM sleep stages 1 (N1), 2 (N2), and 3 (N3). Average voltage of skin sympathetic nerve activity (aSKNA) and SKNA burst area were calculated for quantification. Apnea/hypopnea index (AHI) >5 per hour was used to diagnose OSA. Results: There was a positive correlation (r = 0.549; P = .018) between SKNA burst area and the arousal index in OSA but not in the control group. aSKNA during sleep was 0.61 ± 0.09 μV in OSA patients (n = 18) and 0.53 ± 0.04 μV in control patients (n = 8; P = .025). Burst area was 3.26 (1.90-4.47) μV·s/min in OSA patients and 1.31 (0.67-1.94) μV·s/min in control (P = .047). More apparent differences were found during N2, when the burst area in OSA (3.06 [1.46-5.52] μV·s/min) was much higher than that of the control (0.89 [0.79-1.65] μV·s/min; P = .03). Conclusion: OSA patients have higher SKNA activity than control patients, with the most pronounced differences observed during N2. Arousal at the end of apnea episodes is associated with large SKNA bursts. Overlaps of aSKNA and SKNA burst area between groups suggest that not all OSA patients have increased sympathetic tone

Multi-resolution cell orientation congruence descriptors for epithelium segmentation in endometrial histology images

It has been recently shown that recurrent miscarriage can be caused by abnormally high ratio of number of uterine natural killer (UNK) cells to the number of stromal cells in human female uterus lining. Due to high workload, the counting of UNK and stromal cells needs to be automated using computer algorithms. However, stromal cells are very similar in appearance to epithelial cells which must be excluded in the counting process. To exclude the epithelial cells from the counting process it is necessary to identify epithelial regions. There are two types of epithelial layers that can be encountered in the endometrium: luminal epithelium and glandular epithelium. To the best of our knowledge, there is no existing method that addresses the segmentation of both types of epithelium simultaneously in endometrial histology images. In this paper, we propose a multi-resolution Cell Orientation Congruence (COCo) descriptor which exploits the fact that neighbouring epithelial cells exhibit similarity in terms of their orientations. Our experimental results show that the proposed descriptors yield accurate results in simultaneously segmenting both luminal and glandular epithelium

Small dataset for hot cracking susceptibility of Al alloys and Ni alloys using dynamic X-ray radiography (DXR) technique

Hot cracking as the major concern in the manufacturing process of metal alloys is detrimental to part performance and can lead to catastrophic failure. However, current research in this field is restricted to the scarcity of the relevant hot cracking susceptibility data. Here, using the DXR technique provided at 32-ID-B beamline of Advanced Photon Source (APS) at Argonne National Laboratory, we characterized the hot cracking formation in Laser Powder Bed Fusion (L-PBF) process for ten commercial alloys (Al7075, Al6061, Al2024, Al5052, Haynes 230, Haynes 160, Haynes X, Haynes 120, Haynes 214, and Haynes 718). The extracted DXR images captured the post-solidification hot cracking distribution and allow the quantification of the hot cracking susceptibility of those alloys. We further exploited this in our recent effort on hot cracking susceptibility prediction [1] and established a hot cracking susceptibility dataset posted on Mendeley Data for the purpose of facilitating the relevant research in this field

Adipocyte-Derived Extracellular Vesicles: Small Vesicles with Big Impact

While increasing numbers of studies have established that adipose tissue plays a vital role in balancing energy intake and energy expenditure as both an energy and an endocrine organ, the detailed functions of adipose tissue remain unclear. Adipose tissues are complex, with multiple resident cell populations that communicate to diverse cells and organs via local and systemic metabolic, thermal, and inflammatory signaling. In normal physiology, adipose tissue-derived extracellular vesicles mediate the regulation of energy storage/consumption in adipose tissue, liver, and muscle. In a pathological sense, fat-derived extracellular vesicles can promote the progression of obesity, endocrine diseases, cancer, and reproductive system disorders. In this review, we demonstrate that adipocyte-derived extracellular vesicles function not only in physiological balance but also in the pathological process. We aim to illustrate the impact of adipocyte-derived extracellular vesicles and their value in understanding both homeostasis and disorders

A clinical analysis of vitrectomy for severe vitreoretinopathy in patients with chronic renal

Abstract Background The recent advancement in the management of chronic renal failure (CRF) has significantly increased the longevity of the patients, which increase the incidence of severe vitreoretinopathy. The vitrectomy is highly risky in this particular group of patients due to their systemic comorbidity. The timing surgical intervention is usually delayed because of the systemic conditions. This study is to evaluate the safety and effectiveness of 25-guage vitrectomy for severe vitreoretinopathy in the CRF patients. Methods In this retrospective study, 16 eyes of 16 CRF patients with severe vitreoretinopathy were undergone 25-guage vitrectomy in the department of Ophthalmology of the Second Hospital of Tianjin Medical University from February 2015 to April 2017. The visual outcome, complications and perioperative medical management were documented and analyzed. Results The best-corrected visual acuity(BCVA)of fourteen eyes were lower than 20/200 preoperatively. Surgery duration ranged from 28 to 72 min, with a mean of 48.4 ± 13.6 min. During the surgery, 12 eyes were diagnosed with DR, while two them were complicated with tractional retinal detachment and one with branch retinal vein occlusion. Three eyes were diagnosed with branch retinal vein occlusion, and one eye was diagnosed with hypertensive retinopathy. Postoperative BCVA of six eyes ≥20/40, seven eyes ≥20/200, and three eyes < 20/200. BCVA of eight eyes improved more than three lines, three eyes improved two lines, and four eyes improved one line. BCVA decreased from hand movement to light perception in one patient who developed neovascular glaucoma two weeks after surgery. Conclusion In chronic renal failure patients with severe vitreoretinopathy, the well-planned minimally invasive vitrectomy is effective and safe. Additionally, careful management of the perioperative systemic conditions is important to improve the visual acuity and quality of life as well