Electrophysiology of Human Gametes: A Systematic Review

Darbandi Sara,Darbandi Mahsa,Khorram Khorshid Hamid Reza,Sengupta Pallav 대한남성과학회 2022 The World Journal of Men's Health Vol.40 No.3

Purpose: Oocytes and spermatozoa are electrogenic cells with the ability to respond to electrical stimuli and modulate their electrical properties accordingly. Determination of the ionic events during the gamete maturation helps to design suitable culture media for gametes in assisted reproductive technology (ART). The present systematic review focuses on the electrophysiology of human gametes during different stages of maturation and also during fertilization. Materials and Methods: The reports published in the English language between January 2000 and July 2021 were extracted from various electronic scientific databases following the PRISMA checklist using specific MeSH keywords. Results: Subsequent to the screening process with defined inclusion and exclusion criteria, 60 articles have been included in this review. Among them, 11 articles were directly related to the electrophysiology of human oocytes and 49 physiology department to the electrophysiology of human spermatozoa. Conclusions: Gametes generate electrical currents by ionic exchange, particularly Na+, K+, Cl-, H+, Zn2+, Cu2+, Se2+, Mg2+, HCO3 -, and Ca2+ through specific ion channels in different stages of gamete maturation. The ionic concentrations, pH, and other physicochemical variables are modulated during the gametogenesis, maturation, activation, and the fertilization process following gamete function and metabolism. The electrical properties of human gametes change during different stages of maturation. Although it is demonstrated that the electrical properties are significant regulators of cell signaling and are fundamental to gamete maturation and fertilization, their exact roles in these processes are still poorly understood. Further research is required to unveil the intricate electrophysiological processes of human gamete maturation.

Improved Schedulability Analysis of Real-Time Sporadic Tasks with EDF Preemptive Scheduling

Darbandi, Armaghan,Kim, Myung-Kyun The Korea Institute of Information and Commucation 2012 Journal of information and communication convergen Vol.10 No.4

This paper proposes an analysis method to check the schedulability of a set of sporadic tasks under earliest deadline first (EDF) scheduler. The sporadic task model consists of subtasks with precedence constraints, arbitrary arrival times and deadlines. In order to determine the schedulability, we present an approach to find exact worst case response time (WCRT) of subtatsks. With the technique presented in this paper, we exploit the precedence relations between subtasks in an accurate way while taking advantage of the deadline of different subtasks. Another nice feature of our approach is that it avoids calculation time overhead by exploiting the concept of deadline busy period. Experimental results show that this consideration leads to a significant improvement compared with existing work.

Mobility Overhead in IEEE 802.15.4e Low Latency Deterministic Networks

Darbandi, A.,Kim, M. K. Science and Engineering Research Support Society 2018 International Journal of Control and Automation Vol.11 No.5

Smart Message Schedule Configuration for Static Segment of Flexray

Armaghan Darbandi,Myung Kyun Kim 한국산학기술학회 2015 SmartCR Vol.5 No.4

FlexRay is designed to support highly sophisticated interaction among electronic component units in modern automobiles. This protocol supports high data rates, up to 10 Mbit/s, and is a hybrid protocol which divides the time into two segments; static segment and dynamic segment. In static segment the time-triggered messages and in dynamic segment event-triggered messages are scheduled. This paper addresses message scheduling subject to precedence constraints in static segment of FlexRay. Our objective is to obtain optimum and sub-optimum scheduling solutions with respect to minimizing the number of used slots, and subject to the FlexRay specifications. We formulate the optimization problem using Integer Linear Programming, and we present a greedy heuristic which helps to reduce the search space of our optimization and achieves sub-optimal solutions more quickly. Our experiments on a prototypical application from a major automotive OEM demonstrate the efficiency of our proposed approaches.

An evolutionary yield function based on Barlat 2000 yield function for the superconducting niobium sheet

Payam Darbandi,Farhang Pourboghrat 한국소성가공학회 2011 기타자료 Vol.2011 No.8

Superconducting radio frequency (SRF) niobium cavities are widely used in high-energy physics to accelerate particle beams in particle accelerators. The performance of SRF cavities is affected by the microstructure and purity of the niobium sheet, surface quality, geometry, etc. Following optimum strain paths in the forming of these cavities can significantly control these parameters. To select these strain paths, however, information about the mechanical behavior, microstructure, and formability of the niobium sheet is required. In this study the Barlat 2000 yield function has been used as a yield function for high purity niobium. Results from this study showed that, due to intrinsic behavior, it is necessary to evolve the anisotropic coefficients of Barlat’s yield function in order to properly model the plastic behavior of the niobium sheet. The accuracy of the newly developed evolutionary yield function was verified by applying it to the modeling of the hydrostatic bulging of the niobium sheet. Also, in a separate attempt crystal plasticity finite element method was use to model the behavior of the polycrystalline niobium sheet with a particular initial texture.

Path Collision-aware Real-time Link Scheduling for TSCH Wireless Networks

( A. Darbandi ),( Myung Kyun Kim ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.9

As low-power and low-rate WSNs are being widely used for industrial applications, the scheduling of such applications becomes a critical issue to guarantee meeting the stringent requirements of determinism and tight latencies. This paper studies the link scheduling problem for real-time industrial applications in time-slotted channel hopping (TSCH) networks. We propose a heuristic algorithm for centralized link scheduling referred to as path-collision aware least laxity first (PC-LLF) algorithm, which dynamically prioritizes the packets based on the laxity time to the end-to-end deadlines and the amount of collisions that messages might deal with along their designated paths to the destination device. We propose schedulability analysis of real-time applications scheduled under our prioritization approach over TSCH networks, based on the literature on real-time schedulability analysis of multiprocessors and distributed systems. We show that our methodology provides an improved schedulability condition with respect to the existing approaches. Performance evaluation studies quantify to quantify the performance of our proposed approach under a variety of scenarios.

SCHEDULE CONSTRUCTION UNDER PRECEDENCE CONSTRAINTS IN FLEXRAY IN-VEHICLE NETWORKS

Armaghan Darbandi,윤석훈,김명균 한국자동차공학회 2017 International journal of automotive technology Vol.18 No.4

As embedded time-triggered applications have widely replaced mechanical systems in modern automobiles, holistic scheduling of tasks and messages of such applications on in-vehicle networks has become a critical issue. For offering QoS (Quality of Service) guarantees, the holistic schedule must satisfy numerous constraints such as protocol specifications, delay constraints and precedence constraints between tasks schedules and messages transmissions. Existing approaches to this problem search through a vast design space of all possible joint task and message schedules. This leads to a high complexity and limits the scalability of such approaches for scheduling the large scale systems. To cope with this problem, we propose an approach that divides the holistic scheduling problem to two sub-problems: the sub-problem of message scheduling and the sub-problem of task scheduling, while precedence relations and end-to-end information passing between task instances and messages are preserved and the end-to-end deadlines are guaranteed. This helps to reduce the workload on the problem solvers and improves efficiency and scalability. In the first sub-problem, our approach optimizes scheduling the set of messages and allocates time windows for scheduling each task with respect to precedence constraints, end-to-end deadlines and FlexRay protocol specifications. The length of each time window helps to preserve the respective tasks schedulability and to provide flexibility for both task and message scheduling. The objective is defined with respect to extensibility issues. In the second sub-problem, our approach optimizes schedule of the set of tasks with respect to their allocated time windows and timing constraints. The objective is defined with respect to latency issues. We optimize the solution to each sub-problem using Mixed Integer Linear Programming optimization framework. Performance evaluations show that, compared with existing holistic scheduling approaches, our approach is more scalable and obtains better solutions in a reasonable amount of time.

Scheduling of Time Triggered Messages in Static Segment of FlexRay

Armaghan Darbandi,Sungoh Kwon,Myung Kyun Kim 보안공학연구지원센터 2014 International Journal of Software Engineering and Vol.8 No.6

SCALABLE HOLISTIC SCHEDULING OF SAFETY-CRITICAL SYSTEMS ON IN-VEHICLE TDMA NETWORKS

Armaghan Darbandi,Myung Kyun Kim 한국자동차공학회 2019 International journal of automotive technology Vol.20 No.5

Recently, the authors have proposed a scalable holistic scheduling approach for time-triggered applications on FlexRay, under end-to-end deadline and data dependency constraints. This approach divides the problem to two sub-problems that can be solved separately. The first sub-problem optimally schedules the set of messages to minimize number of used slots, and with respect to information exchanges between tasks and messages, end-to-end deadlines and FlexRay protocol constraints. The second sub-problem optimally schedules the set of tasks to minimize tasks response times, with respect to the solution returned by the first sub-problem. In this paper, our goal is to increase the scalability of our solution to each subproblem. We propose a greedy heuristic approach for the first sub-problem that can find feasible solutions at a low runtime cost. In addition, to resolve assignment conflicts, we apply rescheduling the conflicted application with offset modification and priority promotion procedures. Furthermore, we show that the task scheduling in the second sub-problem can be divided into K independent child sub-problems, where K is the number of ECUs. Our experiments show high scalability and efficiency of our approaches comparing with our optimization-based approaches in the previous work.

A Web-Based Global Educational Model for Training in Semen Analysis during the COVID-19 Pandemic

Agarwal Ashok,Finelli Renata,Durairajanayagam Damayanthi,Leisegang Kristian,Sharma Rakesh,Gupta Sajal,Singh Neha,Belo Andrea,Darbandi Mahsa,Madani Sarah,Covarrubias Simryn,Darbandi Sara,Sadeghi Raha,P 대한남성과학회 2021 The World Journal of Men's Health Vol.39 No.4

Purpose: In response to the COVID-19 pandemic, the American Center for Reproductive Medicine (ACRM) transitioned its annual training in assisted reproductive technology (ART) from a hands-on, laboratory-based training course to a fully online training endorsed by the American College of Embryology. Here we describe our experience and assess the quality of an online training format based on participant outcomes for the first three modules of a planned series of online ART training. Materials and Methods: These modules included manual semen analysis, sperm morphology and ancillary semen tests (testing for leukocytospermia, sperm vitality, and anti-sperm antibody screening). The virtual format consisted of lecture presentations featuring laboratory protocols with corresponding video demonstrations of routine techniques and best practices. Practical scenarios, troubleshooting, and clinical interpretation of laboratory results were also discussed. At the end of each module, an optional multiple choice question test was held as a prerequisite to obtain certification on the topics presented. Course quality was assessed using participant responses collected via online surveys. Results: The digital delivery methods used were found to have largely or completely met the participants’ expectations for all questions (>85%). The majority (>87%) of the participants either strongly agreed or agreed that the course content was well-structured with appropriate depth, and that their overall expectations of the course had been met. Conclusions: This training format appears to be a realistic teaching option to freely share highly specialized expertise and technical knowledge with participants from anywhere in the world with varying levels of competency or experience.