Feeder Line Research Articles

Dynamic Characteristic Analysis of Multi-Virtual Synchronous Generator Systems Considering Line Impedance in Multi-Node Microgrid

With the increasing integration of distributed energy resources into modern power systems, virtual synchronous generators (VSGs) have been a promising approach to imitate the inertial response of synchronous generators, thereby enhancing microgrid stability in a dynamic state. When many VSGs are integrated into microgrids, the dynamic characteristics of the system become increasingly complex. Current studies typically assume that different VSGs are connected to a common coupling point, focusing on analyzing the interaction characteristics, which may overlook the widely distributed line impedances in microgrids with distance between different facilities. This may lead to incomplete understanding of the interaction dynamics when VSGs are distributed over long feeder lines. Therefore, this paper proposes and investigates a multi-node, multi-VSG model incorporating line impedances among different nodes, establishing transfer function models for multi-node load disturbances and the frequency responses of individual VSGs. The study explores the dynamic response characteristics of VSGs under varying parameter influences and proposes principles for designing VSG port impedance and inertia parameters to optimize system dynamic frequency characteristics. The findings, validated through simulations in PSCAD v46, provide insights for enhancing the flexibility and reliability of grids incorporating VSGs.

Transportation connectivity development strategy in the Wakatobi islands, Indonesia

This study aims to analyze connectivity or accessibility between regions in Wakatobi islands, both within and between islands, to understand the available transportation network. Based on an understanding of the dynamics of connectivity, it is expected to provide a solid foundation for the development of more efficient and sustainable transportation infrastructure in the future. A combination of qualitative and quantitative approaches is used to explore data more comprehensively and accurately. The two primary airports and several ports are still insufficient in enhancing connectivity for both the residents and tourists within the archipelago. Improving road, sea, and air transportation networks is a necessity and expectation to improve connectivity between regions. An analysis of accessibility potential provides an overview of transportation costs and expensive and long travel fares. There are several needs that need to be met in the form of the revitalization of local ports, the development of the concept of Air Buses between crossing ports, optimizing routes between airports, and the implementation of Bus/BRT (Bus Rapid Transit) on each island with feeder lines. Furthermore, the development of connectivity in Wakatobi must consider various alternative modes of transportation, increasing service frequencies, and developing supporting infrastructure. This conclusion is the basis for the preparation of a holistic and sustainable connectivity development plan in the Wakatobi archipelago.

Feeder–Line Concept Development For Public Transportation Network In Urban Area Based On O-D Matrix And Performance Evaluation

The management of the public transport network system is very important because it affects the future of the city and supports the activities of the community in travelling and movement. This research aims to develop a feeder-line concept on the public transport network based on O-D Matrix and Operational Performance Evaluation. The research method used is the operational performance standard indicator approach based on the Directorate General of Land Transportation SK 687/AJ.206/DRJD/2002 and the O-D Matrix method in determining new route recommendations. This research uses secondary data as well as primary surveys to assess operational performance. The results show that the level of operational performance of public transport in the research area there are still several routes below the standard with a total of routes operating from D1 to D8 of which 75% of the routes are in good condition and the other 25% of the routes have substandard assessment results with a total value of ?18. Thus, it is recommended that rerouting to be carried out on routes whose operational performance is still below standard, namely routes D7, and D8 based on the characteristics of the feeder-line concept to BRT Corridor 2.

Increased activity reduces the prevalence of woody breast in Ross 708 and Ranger Gold broilers

Woody or wooden breast (WB) is characterized by hardening and paleness of the Pectoralis major muscle and can affect up to 85% of broilers. We hypothesized that increased locomotor activity would lead to a lower prevalence of WB and increased tibia bone quality, with a greater effect on a faster growing than a slower growing broiler strain. Ross 708 (N = 188) and Ranger Gold (N = 213) broilers were raised in 3.05×3.05 m2 pens in groups of 23 to 24 and 26 to 27, respectively. Target ages for the Ross 708 and Ranger Gold birds were 42 and 56 d. There were 8 pens per strain: 4 assigned to an exercise treatment and 4 unexercised controls. An exercise regimen was applied for 10 min every hour for 6 h during each weekday with the goal of increasing frequency of standing and walking. A perch was placed between the feeder and drinker line in the exercise treatment pens to further promote broiler activity. WB severity was determined by palpation for all birds at the target age. Tibial bone mineral content (BMC) and bone mineral density (BMD) were measured using a dual-energy x-ray absorptiometry. The Fisher's Exact Test was used to determine treatment effects on the prevalence and severity of WB. Both prevalence (Ross 708: 77.5 vs. 90.5% control, P = 0.013; Ranger Gold: 57.9 vs. 76.4% control, P = 0.005) and severity (Ross 708: 12.9 vs. 24.2% control, P = 0.02; Ranger Gold: 4.7 vs. 0.02% control, P = 0.01) were reduced by treatment. The effects of strain, treatment and their interaction on tibial BMC and BMD were analyzed using linear mixed models. Only strain affected BMC (P = 0.003) and BMD (P = 0.03), with Ross 708 broilers having higher BMC (control: 3.246 g ± 0.061; treatment: 3.251 g ± 0.058) and BMD (control: 0.177 g/cm2 ± 0.002; treatment: 0.174 g/cm2 ± 0.002) values compared to Ranger Gold's BMC (control: 2.966 g ± 0.067; treatment: 2.987 g ± 0.064) and BMD (control: 0.168 g/cm2 ± 0.002; treatment: 0.168 g/cm2 ± 0.002) values. However, per unit of final body weight, Ranger Gold birds had a significantly higher BMC (P = 0.006) and BMD (P = 0.01) than Ross 708 broilers. Promoting broiler activity can reduce the prevalence and severity of WB prevalence in fast and slow growing broilers.

Distribution network line loss analysis method based on improved clustering algorithm and isolated forest algorithm

The long-term loss of distribution network in the process of distribution network development is caused by the backward management mode of distribution network. The traditional analysis and calculation methods of distribution network loss can not adapt to the current development environment of distribution network. To improve the accuracy of filling missing values in power load data, particle swarm optimization algorithm is proposed to optimize the clustering center of the clustering algorithm. Furthermore, the original isolated forest anomaly recognition algorithm can be used to detect outliers in the load data, and the coefficient of variation of the load data is used to improve the recognition accuracy of the algorithm. Finally, this paper introduces a breadth-first-based method for calculating line loss in the context of big data. An example is provided using the distribution network system of Yuxi City in Yunnan Province, and a simulation experiment is carried out. And the findings revealed that the error of the enhanced fuzzy C-mean clustering algorithm was on average − 6.35, with a standard deviation of 4.015 in the situation of partially missing data. The area under the characteristic curve of the improved isolated forest algorithm subjects in the case of the abnormal sample fuzzy situation was 0.8586, with the smallest decrease, based on the coefficient of variation, and through the refinement of the analysis, it was discovered that the feeder line loss rate is 7.62%. It is confirmed that the suggested technique can carry out distribution network line loss analysis fast and accurately and can serve as a guide for managing distribution network line loss.

Feeder bus service design under spatially heterogeneous demand

In rapidly sprawling urban areas and booming intercity express rail networks, efficiently designed feeder bus systems are more essential than ever to transport passengers to and from trunk-line rail terminals. When the feeder service region is sufficiently large, the spatial heterogeneity in demand distribution must be considered. This paper develops continuum approximation models for optimizing a heterogeneous fixed-route feeder network in a rectangular service region next to a rail terminal. Our work enhances previous studies by: (i) optimizing heterogeneous stop spacings along with line spacings and headways; (ii) accounting for passenger boarding and alighting numbers on bus dwell times and patron transfer delays at the rail terminal; and (iii) examining the advantages of asymmetric coordination between trunk and feeder schedules in both service directions. To tackle the increased modeling complexity, we introduce a semi-analytical method that combines analytically derived properties of the optimal solution with an iterative search algorithm. Local transit agencies can readily utilize this approach to design a real fixed-route feeder system.This paper reveals many findings and insights not previously reported. For instance, integrating the heterogeneous stop spacing optimization further reduces the system cost (by 4% under specific operating conditions). The cost savings increase with demand heterogeneity but decrease with the demand rate and service region size. Choosing the layout of feeder lines where buses pick up and drop off passengers along the service region’s shorter side also significantly lowers the system cost (by 6% when the service region’s aspect ratio is 1 to 2). Furthermore, coordinating trunk and feeder schedules in both service directions yields an additional cost saving of up to 20%.

Low-voltage Compensation of Distribution Networks Based on A Hybrid UPQC with Single and Three-phase Converters

Abstract For remote distribution networks, low voltage is prevalent, which seriously affects the normal use of electricity. Aiming at solving the voltage sag/dip problems in 10.5 kV distribution networks, a hybrid UPQC with a shunt single-phase rectifier and a series three-phase inverter is proposed in this paper. The shunt single-phase rectifier is connected to the feeder lines with the highest and lowest voltage phases to supply enough energy to the series inverter, and the three-phase inverter compensates the voltage deviation by injecting active power through a series transformer, such that the voltage sag/dip problems can be mitigated. The control strategies of the two converters are designed in detail in this paper. Compared with the traditional UPQC with two three-phase converters, the proposed method has the advantage of simpler control methods and lower cost. Finally, the proposed method is verified through MATLAB/Simulink model.

A new adaptive droop control strategy for improved power sharing accuracy and voltage restoration in a DC microgrid

In a DC Microgrid, accurate power sharing and voltage restoration are two primary control goals to guarantee power quality and reliable operation. Inaccurate power sharing is a significant concern due to discrepancies in feeder line resistance, faulty equipment, lack of monitoring and control, and nonlinear load. Moreover, inaccurate power sharing may lead to overloading of converters and cause a cascade of failures throughout the entire system. This study proposes a new adaptive droop control strategy to address these challenges. To enhance accurate power sharing, error current sharing is formulated by considering bus current and total rated current. This is regulated by the adaptive controller to adjust droop resistance. Additionally, the impact of droop voltage because of feeder line resistance is considered in the proposed strategy. The primary control loop regulates the output voltage of converter utilizing the proposed observer-based optimum sliding mode control (OOSMC). The controller gain of the OOSMC is optimized using a gradient-based method to enhance transient and steady state response of the converter output. In the secondary loop, the twin-delayed deep deterministic policy gradient (TD3) for voltage restoration is employed with a new reward function to optimally tune the proportional-integral (PI) controller. Finally, the superiority of the proposed strategy is evaluated through rigorous testing scenarios, including the use of constant power load (CPL) and sudden failure in the converters. Moreover, the proposed strategy is validated by simulations and laboratory-based experiments. The results show that the OOSMC outperforms GA and PSO while the TD3 has better performance than traditional PI. Furthermore, when the equivalent power-rated converters are implemented in the system, the proposed strategy can transfer identical power sharing of 4 W to the load and provide accurate current sharing of 0.167 A compared to conventional droop control while the DC bus voltage is maintained at the 24 V reference value. In the case of different power-rated converters, the proposed strategy can achieve power sharing accuracy. The first, second and third converters supply 2 W, 4 W, and 6 W, respectively, to the load and provide accurate current sharing. Meanwhile the DC bus voltage can be kept at the reference voltage of 24 V. In the scenario of various kinds of disturbances, the proposed strategy can achieve accurate power and current sharing when the system is tested under load and input voltage variations. Meanwhile the DC bus voltage always returns to the voltage reference. Moreover, the proposed strategy can share power and current accurately when the converter occurs a sudden failure.

Mitigation of Ethiopian industry sector power quality problems using ultra-capacitor based dynamic voltage restorer

Nowadays, power quality issues; specifically, voltage sag, swell, harmonics, and interruptions have become significant challenges for customers in Ethiopia. These problems can lead to equipment damage, production losses, reduced trust, and increased unsold energy for utility providers. To address these issues, the implementation of Flexible Alternating Current Transmission Systems (FACTS) and Custom Power Devices (CPD) is crucial. In this study, we focus on Desta Garment PLC, an Ethiopian garment industry. Due to faults in a nearby substation, the factory's feeder line frequently experiences voltage sag, swell, and interruptions. As a result, the factory faces partial shutdowns and occasional hours-long interruptions. To mitigate these voltage quality problems, we propose the use of an Ultra Capacitor-based Dynamic Voltage Restorer (DVR). The DVR has been carefully selected and implemented with advanced control strategy which is adaptive fuzzy proportional integral controller. We collected one year of data from the factory and conducted simulations using MATLAB, comparing scenarios with and without the DVR. The simulation results demonstrate that the proposed mitigation technique significantly enhances voltage sag and swell conditions. Importantly, the performance aligns with both IEEE 1250–1995 and IEEE 519–1992 standards. This study highlights the effectiveness of the Ultra Capacitor-based DVR in improving power quality and ensuring stable operations for Desta Garment PLC. By addressing voltage fluctuations, the factory can maintain productivity and minimize disruptions.

Printed Dual Band Antenna with Parasite Elements for LTE and 5G Applications

A printed antenna for long-term evolution (LTE) band (1.71–1.755 GHz) and 5G band (3.3–3.8 GHz) has been investigated in this article. A balanced feeder line is employed to feed the radiating element at the 5G band of operation, which becomes a radiator at the LTE band. The measured reflection coefficient (S11≤−10 dB) bandwidth is 6% (LTE band: 1.67–1.776 GHz) and 30.76% (5G band: 2.875–3.92 GHz). This antenna radiates with a gain of 3.25 dBi at the LTE band in the broadside and 6.5dBi at the 5G band in the end-fire direction. An open-ended tuning stub is used to tune out the reactance of the radiating element to enhance its radiation and act as a reflector to enhance the directivity in the 5G band. The printed parasite strip forces the beam towards the axial direction (end-fire) and enhances the gain in the 5G band. Both bands form an orthogonal radiation pattern. This antenna can also be utilized for WiMAX (3.5 GHz) band applications.

Key technologies and applications of cloud-edge collaborative integrated low and medium voltage distributed photovoltaic coordination control

The large-scale distributed photovoltaic access leads to overvoltage, equipment overload, and difficulty in on-site consumption, which causes power to be sent back to the high voltage level, posing hidden dangers to the safe operation of the distribution network. This article proposes optimizing the medium-voltage distribution network at the cloud side with the goal of maximum consumption and operating cost, forming a rolling strategy adjustment based on load forecasting within the day. At the edge side, the distributed photovoltaic control in the low-voltage distribution network within the jurisdiction is adjusted based on the daily adjustment strategy issued by the cloud side, completing the optimization and regulation of distributed photovoltaics on a distribution substation unit basis to achieve the control and integration of distributed power sources and consumption, coordination between operation and side, and coordinated control in the integrated medium and low-voltage zoning, achieving autonomous distribution substations and feeder lines. Field applications have proven that this solution solves problems such as line and transformer overload, and voltage quality caused by distributed photovoltaic power generation.

Preclinical evaluation and first-in-dog clinical trials of PBMC-expanded natural killer cells for adoptive immunotherapy in dogs with cancer

BackgroundNatural killer (NK) cells are cytotoxic cells capable of recognizing heterogeneous cancer targets without prior sensitization, making them promising prospects for use in cellular immunotherapy. Companion dogs develop spontaneous cancers...

Application of a Centroid Frequency-Based Back Propagation Neural Network Fault Location Method for a Distribution Network Considering Renewable Energy Assessment

The distribution network is a crucial component of the power system as it directly connects to users and serves the purpose of distributing power and balancing the load. With the integration of new energy sources through distributed generation (DG), the distribution network has undergone a transformation from a single power radial network into a complex multi-source network. Consequently, traditional fault location methods have proven inadequate in this new network structure. Therefore, the focus of this paper is to investigate fault location techniques specifically tailored for DG integration into distribution networks. This paper analyzes how fault conditions impact the characteristics of single-phase grounding faults and extracts spectral feature quantities to describe differences in zero-sequence currents under various fault distances. This paper also proposes a fault location method based on centroid frequency and a BPNN (back propagation neural network). The method uses centroid frequency to describe the features of zero-sequence currents; to simulate the mapping relationship between fault conditions and spectral features, BPNN is employed. The mapping relationship differs for different lines and distribution networks. When a line faults, the spectral features are calculated, along with the transition resistance and fault closing angle. The corresponding mapping relationship is then called upon to complete distance measurements. This location method can be applied to various types of distribution lines and fault conditions with high accuracy. Even with insufficient training samples, sample expansion can ensure accuracy in fault distance measurement. We built a distribution network consisting of four feeders with different types and lengths of each line on Simulink and verified the effectiveness of the proposed method by setting different fault conditions. The results suggest that the method has a clear advantage over other frequency domain-based approaches, especially for hybrid lines and feeder lines with branches in distribution networks. Additionally, the method achieves a measurement accuracy within a range of 100 m.

ROBUST OPTIMIZATION MODEL OF CONTAINER LINER ROUTES IN FEEDER LINE NETWORK

The universal application of the hub-and-spoke maritime network makes feeder line network key to restricting the quality and efficiency of maritime transportation. However, container liner routes in feeder line network are susceptible to the changes in shipment demand and international fuel prices. Therefore, based on the hub-and-spoke maritime network, this paper constructs a robust optimization model of container liner routes in feeder line network. Under the capacity and time constraints, routes optimization and ship equipment under uncertain environment are analysed. An improved tabu search algorithm was designed based on the characteristics of the model. The example analysis proves that the model can still ensure the robustness of routes under uncertain environment, which is more applicable than the deterministic model.

Abstract 5233: Engineered NK-like NKG2C+ CD8 T cells mediate superior anti-tumor efficacy over conventional CD8 T cells and NK cells

Abstract We have recently characterized a unique CD8 T cell subset that expresses NKG2C, as well as multiple other natural killer cell markers. These NKG2C+ CD8 T cells demonstrate NK-like effector functions against various tumor targets, can be efficiently expanded and engineered using GMP-compatible techniques, and most importantly, display beneficial qualities unique to T and NK cells while minimizing the therapeutic deficits of each. NKG2C+ CD8 cells can be easily expanded using a genetically modified K562 feeder line and can be efficiently engineered via retroviral transduction. We genetically engineered NKG2C+ CD8 T cells to express an anti-CD19-28-z CAR construct to target B cell malignancies and compared effector functions of the CAR-engineered NKG2C+ CD8 T cells against CAR+NKG2C- (conventional) CD8 T cells and CAR+ NK cells in vitro and in vivo. We examined expansion, engineering efficiency, tumor control, and extent of cytokine release syndrome (CRS). We also engineered NKG2C+ CD8 T cells with a transgenic NY-ESO-1 TCR to target melanoma and compared the functional responses and efficacy of TCR-engineered NKG2C+ CD8 T cells against TCR-engineered conventional CD8 T cells. CAR+NKG2C+ CD8 T cells demonstrated superior in vitro effector function when compared to CAR+ conventional CD8 T cells and CAR+NK cells and did not upregulate characteristic T cell exhaustion markers, such as PD-1, TIM-3, and LAG-3. These CAR+NKG2C+ CD8 T cells demonstrated superior control of a CD19+ NALM6 tumor model in NRG mice, which was further enhanced with administration of IL-15. CAR+NKG2C+ CD8 T cells with IL-15 demonstrate dramatic and enhanced persistence, as well as superior cytotoxicity and activation in vivo when compared to CAR+ conventional CD8 T cells and CAR+ NK cells. Using a SCID-beige CRS mouse model, we observed reduced CRS in mice treated with CAR+ NKG2C+ CD8 T cells than in mice treated with CAR+ conventional CD8 T cells, with lower levels of proinflammatory cytokines and minimal expansion of murine myeloid subsets. Similarly, TCR-engineered NKG2C+ CD8 T cells demonstrated enhanced tumor control and in vivo persistence in an A375 melanoma-bearing NRG mouse model compared to TCR-engineered conventional CD8 T cells. We have successfully demonstrated that CAR- or TCR-engineered NKG2C+ CD8 T cells have superior anti-tumor efficacy, in vitro and in vivo, to conventional CD8 T cell and NK cell counterparts due to their innate tumor killing and greater in vivo persistence. These cells mediate less CRS and provide a safer alternative to traditional engineered T cell therapeutics. Ultimately, our NKG2C+ CD8 T cells represent a unique platform for engineered T cell therapies to target both solid tumors and hematologic malignancies, that is easily expanded ex vivo, does not require CD4 T cells for in vivo persistence, and is resistant to exhaustion. Citation Format: Kyle Lupo, M. Kazim Panjwani, Anthony Daniyan, Christopher Klebanoff, Katharine Hsu. Engineered NK-like NKG2C+ CD8 T cells mediate superior anti-tumor efficacy over conventional CD8 T cells and NK cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5233.

Сучасний стан ринку морських контейнерних перевезень

The aim of this article is to study the dynamics of development of both the global and national market of container transportation. One of the ways to increase the efficiency of transportation is the rational organization of the work of ships, taking into account the needs and requirements of the market, both of service consumers and of the carriers themselves. The increase in demand for container transportation of goods and the rapid growth of the container capacity of container ships led to a change in approaches to the organization of their work. Thus, the number of ports of call on main lines has begun to decrease. In addition, the movement patterns on them have become almost asymmetrical. Individual lines began to serve at their own container terminals in ports of call, or at terminals that have an agreement to serve only their vessels. Vessels with smaller container capacities were pushed onto feeder lines calling at hub ports located at the intersection of main services and regional ports. In addition, there are changes in the structure of cargo flows, the organization of lines, ports of call and cooperation between transportation participants, the division of the global transportation market into segments served by certain operators, changes in the role of hub ports in delivery schemes depending on the corresponding ports of call on the lines and container capacity vessels serving them. These changes occur under the influence of not only the construction of mega-sized ships, pandemics, piracy, military operations and affect not only the economy of a certain country, but also the global economy as a whole, political, social, geographical and transport, ecological and other spheres of human activity. Research of various factors on the changes taking place in the container transportation market will allow predicting and, possibly, leveling the consequences of their influence in the future. Prospects for further research in this direction are the identification of the main reference points at which significant changes in container transportation took place, the identification of factors that had an impact and the modeling of both individual situations and their interaction as a whole.

Utilisation of electric vehicles and battery energy storage systems for the enhancement of PV hosting capacity in a distribution network

To foster decarbonisation of the transportation sector, there is a growing widespread global adoption of electric vehicles (EVs) as a clean, environmentally friendly alternative to fossil-fuel-dependent internal combustion engine vehicles (ICEV). This has required the electrical power system to distribute power to EV charging stations. In addition, battery energy storage systems (BESSs) have also been deployed to improve network resilience. Both EVs and BESSs on distribution networks (DNs) may be charged using photovoltaic (PV) resources. Subsequently, huge numbers of PV plants have been installed globally over the past decade. With excessive PV penetration into the distribution network (DN), the consequences are risks of operational constraint violations such as over-voltages, feeder line congestion, protection maloperation and high harmonics. This requires limiting the amount of installed PV to alleviate these risks. The maximum amount of PV which can be integrated into the DN without violating these network operational limits is the PV hosting capacity (PVHC). This paper proposes models for quantifying the impacts of EVs and BESSs on the PV hosting capacity of DNs using the stochastic particle swarm and gradient descent algorithm (PSO-GD). The simulation results of case studies have shown that the proposed method is accurate, fast, and efficient.

The Line-Haul Feeder Vehicle Routing Problem: A Classification and Review

Today, goods transportation is considered to be one of the most important activities of national economics. Logistics and supply chain play an important role in the industry and services, considering the needs of the people, while there is an increase in the population. In addition, the role of logistics in urban areas, especially in restaurants, grocery stores, etc., is clearly visible. Besides, the final price of the goods is the most important factor that is always considered in service and in production. Due to this important factor, transportation has been found to be one of the most significant and influential factors in determining the price of goods. For these reasons, the newest variant of the vehicle routing problem, called the line feeder vehicle routing problem (LFVRP), is considered in this paper, in which various types of vehicles (large and small vehicles) are used for providing services to customers. In this particular type of delivery issue, these vehicles must start from the warehouse, meet customers, and finally return to the depot. In fact, the issue of LFVRP is related to the fast customer service in urban areas because in this case, all that are considered to be of priority are to minimize transportation costs and overall distribution time for fast customer service, especially in urban areas. Due to the many applications of this problem in the real world, a general review of this problem is conducted, and the versions of this problem are described along with the algorithms for its solution in the paper.

Abstract 24 Development of an In Vitro B-Cell Differentiation Model for the Characterization of the Origin and Causation of ETV6::RUNX1+ Preleukemic Cells

Abstract Introduction Pregnant women are exposed to various carcinogenic substances that can subsequently affect their progeny. Recurrent preleukemic chromosomal translocations characteristic for childhood acute lymphoblastic leukemia (ALL) frequently emerge before birth in utero. The most common translocation t (12;21) occurs in 25% of B-cell precursor ALL and results in the formation of the chimeric oncogenic transcription factor ETV6::RUNX1. Objectives We aim to analyze factors promoting the generation of preleukemic ETV6::RUNX1 translocations, investigate the biological origin of these preleukemic cells, and develop an in vitro model of early B-cell differentiation to analyze the mechanisms underlying the persistence of ETV6::RUNX1+ preleukemic cells and leukemia evolution in children. Methods Genomic inverse PCR for exploration of ligated breakpoints (GIPFEL) (Schafer et. al., 2018) was applied to identify ETV6::RUNX1+ cord blood units (CBU). Screening results were validated by Sanger sequencing and quantified by real-time PCR (ipsogen ETV6-RUNX1 Kit, Qiagen). ETV6::RUNX1+ CBUs were thawed, sorted for CD34+ and CD19+ cells, and analyzed by qPCR. CD34+ were differentiated towards B-cell lineage on MSC feeder lines according to a modified protocol (Ichii et. al., 2008). Results We screened a cohort of 1405 cord bloods collected in 2004 and discovered that 103 (7.3%) carried the ETV6::RUNX1 fusion gene. The preleukemic translocation was detected in CD34+ stem and early B progenitor cells. For the establishment of an in vitro B-cell differentiation model, bone marrow (BM-MSCs) and CB (USSCs, CB-MSCs) stromal feeder cells were compared and the effect of different media (SCGM, DMEM/5 % FCS, MSCBM/10 % FCS) in the presence of stem cell factor (SCF), Flt-3, IL3, +/- IL7 was assessed. BM-MSCs demonstrated the highest ability to support B-lymphopoieses towards CD19+ cell differentiation in MSCBM media (~30%), primarily due to the release of IL-7 by the feeder layer. Currently, factors that may promote generation of preleukemic translocations in utero e.g. nitrosamines contained in food products, are being tested in this model. Discussion We identified the HSC/early B progenitor state as the origin of ETV6::RUNX1 translocations in CB. The establishment of an in vitro B-cell differentiation system will allow to test the impact of environmental carcinogens on the generation of ETV6::RUNX1+ pre-leukemic cells and their leukemic evolution.

On design of power sharing for VSC‐based islanded AC microgrids: An adaptive MIMO controller equipped with a predictor

AbstractIn an AC microgrid, the active/reactive power is usually shared among its distributed generators (DGs) based on the frequency‐active power () droop and the voltage‐reactive power () droop. By increasing the resistant/inductance ratio () of feeder lines; however, adverse effects of interactions between these two control loops are intensified. In this paper, an adaptive multi‐input multi‐output (MIMO) current control structure is proposed to tackle this problem in AC microgrids with arbitrary numbers of DGs in the primary control level. A deep analysis based on the relative gain array (RGA) matrix and the diagonal dominance concept is provided to systematically design MIMO controllers. The proposed technique is based on the Lyapunov's stability theory, and the asymptotic stability of the whole microgrid is guaranteed. For each DG, the suggested design procedure is started by defining a model reference in which the desired control objectives, including the settling time and the steady‐state error, are considered. Then, a feedback‐feedforward controller is established where its gains are adaptively tuned by some rules derived from a Lyapunov function. Moreover, a predictor is used to estimate the adverse effects of other DGs which are taken into account as external disturbances during the design process of the adaptive controller. By considering some realistic scenarios through time‐domain simulations in MATLAB/SIMULINK, it is shown that the proposed strategy can be successfully used to solve the power sharing problem in AC microgrids.