Tolerant Networks Research Articles

Donor-specific Immune Senescence as a Candidate Biomarker of Operational Tolerance Following Liver Transplantation in Adults: Results of a Prospective, Multicenter Cohort Study

Immunosuppression can be withdrawn from selected liver transplant recipients, although robust clinical predictors of tolerance remain elusive. The Immune Tolerance Network ITN056ST study (OPTIMAL) assessed clinical outcomes and mechanistic correlates of phased immunosuppression withdrawal (ISW) in non-autoimmune, non-viral adult liver transplant recipients. Enrolled subjects were ≥3 years post-transplant with minimal/absent inflammation or fibrosis on a screening liver biopsy. The primary endpoint was operational tolerance at 52 weeks following complete ISW. Of 61 subjects who initiated ISW, 34 failed during ISW and 10 restarted immunosuppression due to clinically manifest acute rejection. Of the 17 subjects remaining off immunosuppression at 1 year, 10 were ultimately deemed tolerant by biopsy. There were no cases of chronic rejection or graft loss. The majority of subjects (78.6%), including those who experienced rejection, ended the study on same or less calcineurin inhibitor than at baseline. 28.3% developed de novo DSA during ISW, which persisted in 11.3%. A minority (16.4%) of histologically and clinically stable long-term adult liver transplant recipients can successfully discontinue and remain off immunosuppression. Increased frequency of donor-specific T cell senescence, C4d deposition and higher density of immune synapses on the screening liver biopsy emerged as potential candidate biomarkers for operational tolerance. NCT02533180.

Survey on securing wireless networks through a blockchain-based framework

In the contemporary era, blockchain technology has brought about a significant transformation in the realm of digital currency through innovations like Bitcoin. A blockchain serves as a decentralized ledger, ensuring an immutable record of transactions across a network. Recent observations indicate the pivotal role of blockchain technology not only in the financial sector but also in networking. This study considers blockchain as the essential link in establishing a genuinely decentralized, trustless, and secure environment for network nodes. The objective is to provide a systematic and comprehensive overview of futuristic endeavours in this domain. The exploration begins with an examination of the fundamental operational concepts of blockchains and how these systems achieve decentralization, security, and suitability. The focus then shifts towards addressing open research challenges within blockchain technologies, particularly in securing diverse communication networks such as Distributed Computing, Vehicular Ad-hoc Networks, Opportunistic Networks, and Delay Tolerant Networks. Simulation results underscore the superior security performance of blockchain, especially under conditions of attack.

New Trust Based Smart Data Forwarding Mechanism in Vehicular Delay Tolerant Network

Vehicular Delay Tolerant Network (VDTN) is the growing field with a considerable possibility to handle future wireless application’s requirements. Using vehicles for the data communication purpose can be contemplated as a substitute for the wired and wireless systems. This paper proposes a trust-based data forwarding mechanism for Vehicular Delay Tolerant Network (VDTN). Data forwarding in VDTN requires every vehicular or stationary node to participate in data forwarding. But some time malicious nodes show non-cooperative behaviour in data forwarding. Therefore, malicious nodes must be identified specifically to accelerate the data forwarding. A threshold based social skeleton membership process along with new trust-based data forwarding mechanism is proposed in this paper. We reveal that the social skeleton members perform better in data forwarding in terms of data delivery ratio, data delay and data overhead. Simulation results demonstrate that the trust-based data forwarding improves the data delivery ratio with trust-based data forwarding approach. After simulation a comparative analysis of two different scenarios is presented with epidemic routing, prophet routing and spray and wait routing.

FloatingBlue: A Delay Tolerant Networks-Enabled Internet of Things Architecture for Remote Areas Combining Data Mules and Low Power Communications.

Monitoring vast and remote areas like forests using Wireless Sensor Networks (WSNs) presents significant challenges, such as limited energy resources and signal attenuation over long distances due to natural obstacles. Traditional solutions often require extensive infrastructure, which is impractical in such environments. To address these limitations, we introduce the "FloatingBlue" architecture. This architecture, known for its superior energy efficiency, combines Bluetooth Low Energy (BLE) technology with Delay Tolerant Networks (DTN) and data mules. It leverages BLE's low power consumption for energy-efficient sensor broadcasts while utilizing DTN-enabled data mules to collect data from dispersed sensors without constant network connectivity. Deployed in a remote agricultural area in the Amazon region, "FloatingBlue" demonstrated significant improvements in energy efficiency and communication range, with a high Packet Delivery Ratio (PDR). The developed BLE beacon sensor achieved state-of-the-art energy consumption levels, using only 2.25 µJ in sleep mode and 11.8 µJ in transmission mode. Our results highlight "FloatingBlue" as a robust, low-power solution for remote monitoring in challenging environments, offering an energy-efficient and scalable alternative to traditional WSN approaches.

Revisiting the role of light signaling in plant responses to salt stress

Abstract As one of the grave environmental hazards, soil salinization seriously limits crop productivity, growth and development. When plants are exposed to salt stress, they suffer a sequence of damage mainly caused by osmotic stress, ion toxicity and subsequently oxidative stress. As sessile organisms, plants have developed many physiological and biochemical strategies to mitigate the impact of salt stress. These strategies include altering root development direction, shortening the life cycle, accelerating dormancy, closing stomata to reduce transpiration and decreasing biomass. Apart from being a prime energy source, light is an environmental signal, which profoundly influences plant growth and development and also participates in plants’ response to salt stress. This review summarizes the regulatory network of salt tolerance by light signals in plants, which is vital to further understanding plants’ adaptation to high salinity. In addition, the review highlights potential future uses of genetic engineering and light supplement technology by light-emitting diode (LED) to improve crop growth in saline-alkali environments in order to make full use of the vast saline land.

Transcriptomic and Physiological Studies Unveil that Brassinolide Maintains the Balance of Maize's Multiple Metabolisms under Low-Temperature Stress.

Low-temperature (LT) is one of the major abiotic stresses that restrict the growth and development of maize seedlings. Brassinolides (BRs) have been shown to enhance LT tolerance in several plant species; the physiological and molecular mechanisms by which BRs enhance maize tolerance are still unclear. Here, we characterized changes in the physiology and transcriptome of N192 and Ji853 seedlings at the three-leaf stage with or without 2 μM 2,4-epibrassinolide (EBR) application at 25 and 15 °C environments via high-performance liquid chromatography and RNA-Sequencing. Physiological analyses revealed that EBR increased the antioxidant enzyme activities, enhanced the cell membrane stability, decreased the malondialdehyde formation, and inhibited the reactive oxygen species (ROS) accumulation in maize seedlings under 15 °C stress; meanwhile, EBR also maintained hormone balance by increasing indole-3-acetic acid and gibberellin 3 contents and decreasing the abscisic acid level under stress. Transcriptome analysis revealed 332 differentially expressed genes (DEGs) enriched in ROS homeostasis, plant hormone signal transduction, and the mitogen-activated protein kinase (MAPK) cascade. These DEGs exhibited synergistic and antagonistic interactions, forming a complex LT tolerance network in maize. Additionally, weighted gene co-expression network analysis (WGCNA) revealed that 109 hub genes involved in LT stress regulation pathways were discovered from the four modules with the highest correlation with target traits. In conclusion, our findings provide new insights into the molecular mechanisms of exogenous BRs in enhancing LT tolerance of maize at the seedling stage, thus opening up possibilities for a breeding program of maize tolerance to LT stress.

Evolving Concepts in Pathophysiology, Screening, and Prevention of Type 1 Diabetes: Report of Diabetes Mellitus Interagency Coordinating Committee Workshop.

The approval of teplizumab to delay the onset of type 1 diabetes is an important inflection point in the decades-long pursuit to treat the cause of the disease rather than its symptoms. The National Institute of Diabetes and Digestive and Kidney Diseases convened a workshop of the Diabetes Mellitus Interagency Coordinating Committee titled "Evolving Concepts in Pathophysiology, Screening, and Prevention of Type 1 Diabetes" to review this accomplishment and identify future goals. Speakers representing Type 1 Diabetes TrialNet (TrialNet) and the Immune Tolerance Network emphasized that the ability to robustly identify individuals destined to develop type 1 diabetes was essential for clinical trials. The presenter from the U.S. Food and Drug Administration described how regulatory approval relied on data from the single clinical trial of TrialNet with testing of teplizumab for delay of clinical diagnosis, along with confirmatory evidence from studies in patients after diagnosis. The workshop reviewed the etiology of type 1 diabetes as a disease involving multiple immune pathways, highlighting the current understanding of prognostic markers and proposing potential strategies to improve the therapeutic response of disease-modifying therapies based on the mechanism of action. While celebrating these achievements funded by the congressionally appropriated Special Diabetes Program, panelists from professional organizations, nonprofit advocacy/funding groups, and industry also identified significant hurdles in translating this research into clinical care.

Generalized [formula omitted]-sparse algorithms for constructing fault tolerant RBF networks

In the construction process of radial basis function (RBF) networks, two common crucial issues arise: the selection of RBF centers and the effective utilization of the given source without encountering the overfitting problem. Another important issue is the fault tolerant capability. That is, when noise or faults exist in a trained network, it is crucial that the network’s performance does not undergo significant deterioration or decrease. However, without employing a fault tolerant procedure, a trained RBF network may exhibit significantly poor performance. Unfortunately, most existing algorithms are unable to simultaneously address all of the aforementioned issues. This paper proposes fault tolerant training algorithms that can simultaneously select RBF nodes and train RBF output weights. Additionally, our algorithms can directly control the number of RBF nodes in an explicit manner, eliminating the need for a time-consuming procedure to tune the regularization parameter and achieve the target RBF network size. Based on simulation results, our algorithms demonstrate improved test set performance when more RBF nodes are used, effectively utilizing the given source without encountering the overfitting problem. This paper first defines a fault tolerant objective function, which includes a term to suppress the effects of weight faults and weight noise. This term also prevents the issue of overfitting, resulting in better test set performance when more RBF nodes are utilized. With the defined objective function, the training process is designed to solve a generalized M-sparse problem by incorporating an ℓ0-norm constraint. The ℓ0-norm constraint allows us to directly and explicitly control the number of RBF nodes. To address the generalized M-sparse problem, we introduce the noise-resistant iterative hard thresholding (NR-IHT) algorithm. The convergence properties of the NR-IHT algorithm are subsequently discussed theoretically. To further enhance performance, we incorporate the momentum concept into the NR-IHT algorithm, referring to the modified version as “NR-IHT-Mom”. Simulation results show that both the NR-IHT algorithm and the NR-IHT-Mom algorithm outperform several state-of-the-art comparison algorithms.

A blockchain transaction mechanism in the delay tolerant network

Current blockchain systems have high requirements on network connection and data transmission rate, for example, nodes have to receive the latest blocks in time to update the blockchain, nodes have to immediately broadcast the generated block to other nodes for consensus, which restricts the blockchain to run only on real-time connection networks, but the existence of delay tolerant networks poses a great challenge to the deployment of blockchain systems. To address this challenge, a novel blockchain transaction mechanism is proposed. First, the block structure is modified by adding a flag, and on this basis, the definition of the extrachain is proposed. Secondly, based on the blockchain transaction process, transaction verification and consensus algorithms on the extrachain are presented. Thirdly, both the extrachain selection algorithm and appending algorithm are proposed, so that the extrachain can be appended to the blockchain fairly and safely. Finally, an extrachain transmission scheme is presented to broadcast the blocks generated in the delayed network to the normal network. Theoretical analysis and simulation experiments further illustrate the efficiency of the proposed mechanism.

Natural plant disease suppressiveness in soils extends to insect pest control

BackgroundSince the 1980s, soils in a 22-km2 area near Lake Neuchâtel in Switzerland have been recognized for their innate ability to suppress the black root rot plant disease caused by the fungal pathogen Thielaviopsis basicola. However, the efficacy of natural disease suppressive soils against insect pests has not been studied.ResultsWe demonstrate that natural soil suppressiveness also protects plants from the leaf-feeding pest insect Oulema melanopus. Plants grown in the most suppressive soil have a reduced stress response to Oulema feeding, reflected by dampened levels of herbivore defense-related phytohormones and benzoxazinoids. Enhanced salicylate levels in insect-free plants indicate defense-priming operating in this soil. The rhizosphere microbiome of suppressive soils contained a higher proportion of plant-beneficial bacteria, coinciding with their microbiome networks being highly tolerant to the destabilizing impact of insect exposure observed in the rhizosphere of plants grown in the conducive soils. We suggest that presence of plant-beneficial bacteria in the suppressive soils along with priming, conferred plant resistance to the insect pest, manifesting also in the onset of insect microbiome dysbiosis by the displacement of the insect endosymbionts.ConclusionsOur results show that an intricate soil–plant-insect feedback, relying on a stress tolerant microbiome network with the presence of plant-beneficial bacteria and plant priming, extends natural soil suppressiveness from soilborne diseases to insect pests.4oEYADM9UCsv5obDEsLZQ_Video

Investigating stronger tolerant network against cascading failures in focusing on changing degree distributions.

Many real-world networks with Scale-Free structure are significantly vulnerable against both intentional attacks and catastrophic cascading failures. On the other hand, it has been shown that networks with narrower degree distributions have strong robustness of connectivity by enhancing loops. This paper numerically reveals that such networks are also tolerant against cascading failures. Our findings will be useful in designing stronger tolerant network infrastructures.

Delay and Disruption Tolerant Networking for Terrestrial and TCP/IP Applications: A Systematic Literature Review

Delay and Disruption Tolerant Networking (DTN) is a network architecture created basically to overcome non-continuing connectivity. There has been a great deal of research on this topic, from space communication to terrestrial applications. Since there are still many places on earth where there is no means of communication, the focus of this work is on the latest. A systematic literature review (SLR) was performed to know the main issues and advances related to the implementation of DTN for terrestrial and TCP/IP applications, especially in places where telecommunication infrastructure is lacking. The result is a classification of papers based on key aspects, such as architecture, performance, routing, and applications. A matrix of all the papers about these aspects is included to help researchers find the missing piece and concrete terrestrial solutions. The matrix uses three colors, green, yellow, and red according to the focus, either high, medium, or low, so that it is easy to identify specific papers.

Prototipe Aplikasi Komunikasi Menggunakan Jaringan Delay Tolerant Network Pada Perangkat Seluler Android

In the current global context, the exchange of information through Internet networks has become increasingly vital, necessitating the effectiveness of communication technology. This is particularly true in areas with weak or unstable signal coverage such as intermittent areas. To address challenges such as frequent connection drops in these areas, Delay Tolerant Networking (DTN) architecture is offered as an alternative solution to overcome these problems. The conducted research aims to design and test a data communication application prototype using DTN architecture implemented on the Android operating system. The approach taken involves using the Analysis, Design, Development, Implementation, and Evaluation (ADDIE) method. In detail, the application is implemented on the Android operating system and integrates various routing protocols such as Epidemic, Spray and Wait, MaxProp, and ProphetV2 to optimize data transmission and reception under varying network conditions. Data collection techniques include measuring latency and data transfer speed in predetermined testing scenarios, while data analysis techniques involve evaluating the measurement results to determine the effectiveness of the routing protocols used. Evaluation is conducted and the results showing an average latency between 800-1400ms and speeds of 100-400kbps, depending on the distance and varying network conditions. This study validates the effectiveness of DTN in maintaining consistent communication in challenging network environments. The impact of this research on the advancement of informatics is to pave the way for further development and adaptation of DTN technology in various mobile applications and data networks.

Reliable community card system for detecting and isolating selfish vehicles in smart and connected communities‐based VDTN's

AbstractSmart and connected communities (SCC) is a new area of the Internet of Things with the potential to improve people's lives. The goal of developing SCC for a community is to encourage people to focus on the present, consider the future, and reflect on the past. In SCC, nodes (vehicles) can use their mobility to collect data from interconnected devices and send it to a variety of delay‐tolerant applications. Vehicular delay tolerant networks are an ideal fit for such services. However, the problem is that the devices and nodes (vehicles), having limited resources, may become unwilling to cooperate due to their selfish behavior. This article presents a reliable community card system (RCCS) with two main parts: a reliable community and community‐based card tracking system (CBCTS). The reliable community contains all trustworthy vehicles with a certain level of community reputation determined by their honesty level. In CBCTS, every vehicle needs a community card to participate in the network and the neighboring vehicles act as monitoring vehicle. The evaluation results show that the proposed RCCS is quite effective, with detection time and packet delivery. Similarly, it causes minimal overhead and energy consumption compared to all other existing techniques.

Clustered DTN routing based on sensing node relationship strength

AbstractDelay tolerant networks (DTNs) is a network evolved from mobile networks. Differing from the traditional network, which has a stable end‐to‐end transmission path, DTNs are sparse and intermittently connected mobile ad hoc network, which are widely used in harsh environments, such as battlefields, seabed, space communication networks, and so on. In DTNs, intermittent connectivity, partitioned network, long delays and node mobility characteristics make the network fail to communicate frequently, therefore, how to successfully forward the message is of extreme importance. Up to now, almost all the traditional models in DTNs use the store‐carry‐forward method. This paper proposes a novel clustered DTN routing model based on sensing node relationship strength. The routing mechanism takes advantage of the number of other nodes encountered by the nodes in the process of movement and the changes in the number of nodes to calculate the strength of the relationship between nodes, and clusters DTN routing according to the strength of the relationship between nodes. Moreover, the relationship between nodes in a cluster and other clusters is used to transmit messages between clusters, and messages are transmitted within clusters according to the strength of the relationship between nodes. Simulation results show that the routing mechanism not only increases the success rate of message transmission, but also reduces the transmission delay of messages and improves network performance.

Design and operation of a load-tolerant ICRH system in Experimental Advanced Superconducting Tokamak

Ion Cyclotron Resonance Heating (ICRH) has been a dependable tool for sturdy plasma heating with high RF power of several megawatts. However, a sudden increase in the reflected power during ICRH heating experiments is a problem that should be solved for future fusion experimental devices. To solve this issue, a load tolerant matching network has been designed for the ICRH system in EAST. The matching network includes a 3-stub tuner impedance matching system with conjugate-T structure, 30 Ω to 50 Ω transmission line and center grounded antenna strap. By maintaining a low reflection ratio in the network for a wide range of resistance, this matching network can allow sturdy high-power operations without fast impedance matching in EAST. In our matching network, the two arms of a conjugate-T are designed to have a λ/2 length difference which could mitigate current imbalance and antenna poloidal phasing outside of the control problem. The T-point corresponds to the maximum point of the standing wave voltage, which could greatly improve the input impedance of the antenna.

Characterization of putative calcium-dependent protein kinase-1 (TaCPK-1) gene: hubs in signalling and tolerance network of wheat under terminal heat.

The online version contains supplementary material available at 10.1007/s13205-024-03989-6.

Overexpression of the Panax ginseng CyP gene enhances abiotic and biotic stress tolerance in transgenic Arabidopsis

To explore the response of the cyclophilin (CyP) gene to abiotic and biotic stress, transgenic Arabidopsis was exposed to salt stress and inoculated with Phytophthora cactorum. The CyP gene enhanced salt tolerance by increasing proline content and slowing chlorophyll decline compared to wild-type plants. Under P. cactorum infection, the CyP protein interacted with spores and restricted spore germination to enhance resistance to P. cactorum. Thus, the CyP protein positively regulates gene expression in the abiotic and biotic stress tolerance networks. The CyP gene may be valuable for ginseng breeding programs aiming to develop new cultivars with enhanced stress tolerance.

Laser communications relay demonstration: experiments with delay tolerant networking

Laser communications relay demonstration: experiments with delay tolerant networking

Immunosuppression withdrawal in living-donor renal transplant recipients following induction with antithymocyte globulin and rituximab: Results of a prospective clinical trial

Durable tolerance in kidney transplant recipients remains an important but elusive goal. We hypothesized that adding B cell depletion to T cell depletion would generate an immune milieu postreconstitution dominated by immature transitional B cells, favoring tolerance. The Immune Tolerance Network ITN039ST Research Study of ATG and Rituximab in Renal Transplantation was a prospective multicenter pilot study of live donor kidney transplant recipients who received induction with rabbit antithymocyte globulin and rituximab and initiated immunosuppression (IS) withdrawal (ISW) at 26 weeks. The primary endpoint was freedom from rejection at 52 weeks post-ISW. Six of the 10 subjects successfully completed ISW. Of these 6 subjects, 4 restarted immunosuppressive medications due to acute rejection or recurrent disease, 1 remains IS-free for over 9 years, and 1 was lost to follow-up after being IS-free for 42 weeks. There were no cases of patient or graft loss. CD19+ B cell frequencies returned to predepletion levels by 26 weeks posttransplant; immunoglobulin D+CD27--naïve B cells predominated. In contrast, memory cells dominated the repopulation of the T cell compartment. A regimen of combined B and T cell depletion did not generate the tolerogenic B cell profile observed in preclinical studies and did not lead to durable tolerance in the majority of kidney transplant recipients.