Transmission Failure Research Articles

BDNF/TrkB Signaling Increases Autophagy Flux in Cervical Spinal Cord

Autophagy is a homeostatic process for the elimination of damaged, unnecessary proteins or organelles within cells. Our overarching hypothesis is that autophagy contributes to neuromuscular dysfunction, specifically increased NMTF seen with aging. Understanding the mechanisms regulating autophagy flux is essential to discovering therapeutic agents which may mitigate the effects of neuromuscular dysfunction across conditions including old age. In recent studies, we found that in 18 month old mice autophagy in the cervical spinal cord is accelerated and neuromuscular transmission failure (NMTF) in diaphragm muscle‐phrenic nerve preparations is increased. Neurotrophin activity, specifically brain‐derived neurotrophic factor (BDNF) signaling through its high affinity receptor tropomyosin‐related kinase receptor subtype B (TrkB) decreases NMTF. Thus, we predict BDNF/TrkB signaling suppresses autophagy in phrenic motor neurons located in the cervical spinal cord. We hypothesize that inhibiting TrkB kinase activity accelerates autophagy in phrenic motor neurons. TrkBF616A mice at 18 months of age were randomized to receive 1 week treatment with vehicle (n=4) or 1NMPP1 (TrkB kinase inhibitor; n=6). Additionally, 18 month old wild type C57BL/6 mice (n=2) were studied. Whole cervical spinal cord (CSC) was harvested for measurements of autophagy marker protein expression analyzed by Western blotting. Data for the vehicle‐treated TrkBF616A and wild type mice was combined given lack of differences for any measurement. p62, a marker associated with the initiation of autophagy, was significantly decreased in the 1NMPP1‐treated group compared to vehicle‐treated or wild type mice. LC3, a protein marking the autophagosome membrane elongation phase, was not significantly changed across groups indicating that LC3‐tagged autophagosomes proceed to lysosomal degradation and do not accumulate. These results support our hypothesis that inhibiting BDNF/TrkB signaling accelerates autophagy flux in the CSC and reveal trophic effects of BDNF/TrkB signaling in the neuromuscular system. Accelerated autophagy may underlie age‐related neuromuscular dysfunction in a BDNF/TrkB signaling dependent manner.Support or Funding InformationSupport: NIH R01 AG057052

Age‐Related Loss of Phrenic Motor Neurons: Reduced Myogenic Influence?

There is an age‐associated loss of phrenic motor neurons (PhMNs) and withdrawal of pre‐synaptic terminals at neuromuscular junctions (NMJs) in 24‐month old Fischer 344 (F344) rats. Previously, we showed that age‐related PhMN loss is concomitant with neuromuscular transmission failure and diaphragm muscle (DIAm) sarcopenia (an age‐related atrophy of muscle fibers and a decrease in specific force). It is unknown if pre‐synaptic terminal withdrawal precedes PhMN loss, which would implicate a reduction in a trophic influence emanating from muscle fibers (myogenic). We hypothesized that age‐related PhMN loss results from pre‐synaptic terminal withdrawal and reduced myogenic influence, which occurs predominantly at type IIx and/or IIb DIAm fibers (innervated by larger PhMNs). F344 rats were obtained from the National Institutes of Aging. Experimental ages were chosen to represent 100% and 50% survival at 6 months and 24 months‐old, respectively. PhMNs were first retrogradely labeled by intrapleural injection of cholera toxin‐subunit B (CTB), which is dependent on binding to pre‐synaptic terminal gangliosides. Thus, with pre‐synaptic terminal withdrawal, PhMNs would not be labeled. Subsequently (3 days after CTB), PhMNs were retrogradely labeled by sectioning the phrenic nerve and dipping the proximal end into a Rhodamine dextran (Rho) solution – this labeling is not dependent on pre‐synaptic terminals. CTB and Rho labeled PhMNs were visualized by confocal microscopy. Only optical slices containing the nucleus of Rho‐ and/or CTB‐labeled PhMNs were counted. We analyzed the differences in labeling of PhMNs by CTB and Rho in both age groups. In labeled PhMNs, short and long axis measurements were used to determine somal surface areas by assuming a prolate spheroid shape. In 6‐month old rats, there was no significant difference in the number of PhMNs labeled by CTB or Rho. In 24‐month old rats, the total number of labeled PhMNs was reduced compared to the 6‐month old rats, which primarily affected larger PhMNs. Furthermore, at 24‐months, fewer PhMNs were labeled with CTB compared to Rho and those labeled with Rho had larger somal surface areas. These results support our hypothesis that the age‐related loss of larger PhMNs results from pre‐synaptic terminal withdrawal and reduced myogenic influence.Support or Funding InformationSupport: NIH R01‐AG044615American Physiological Society

저전력 IoT 네트워크에서 불안정한 노드를 회피하는 적응적인 ADP-RPL

A recent challenge is that IoT devices tend to be configured in an LLN environment. LLN has thousands of nodes with limited processing power, memory, and energy, and these nodes are typically connected by lossy links. The RPL for LLN is designed for use in resource-constrained devices in industry, homes, and cities. The primary purpose of the RPL is to provide IPv6 connectivity for many battery-powered embedded devices using low-power radios. The RPL is expected to be very active in smart factories in Industry 4.0. However, smart factories are an environment with high interference and mobility. Although RPL is designed for LLN, energy consumption may increase due to frequent parent changes in unstable networks. Adaptive RPL (ADP-RPL) calculates the degradation of link quality as the rank value increases and the parent"s change time and then reflects it in the rank value sent to neighboring nodes. In order to prevent frequent parent changes, we used a threshold that is proportional to the rank of neighboring nodes. In this paper, we evaluated the performance of ADP-RPL using a Cooja simulator. As a result, ADP-RPL shows better performance with more nodes. In order to evaluate performance in the actual environment, a test was performed in an environment in which GET and POST messages were transmitted using the CoAP protocol. RE-Mote device was used to evaluate the indoor space where interference occurred. In the real environment, the rate of ADP-RPL transmission failure and the number of parent changes were reduced compared to RPL.

A protection routing with secure mechanism in Möbius cubes

The protection routing uses the multi-paths technique for integrating route discovery and route maintenance mechanisms in a network, and thus it can tolerate the failure of one component (including a node or a link). Tapolcai (2013) proposed a method showing that a network possessing two completely independent spanning trees (CISTs for short) suffices to configure a protection routing. However, it is well-known that the problem of determining whether there exist two CISTs in a graph (or network) is NP-complete. In this paper, we extend Tapolcai’s method such that the protection routing is configured by a combination of multiple CISTs. The first application of such an extension is that it can be used to deal with the problem of security in transmission, which we call the secure-protection routing scheme (SPR-scheme for short). Thus, a network transmission using the SPR-scheme ensures that no node other than the destination can receive the complete message. Moreover, we show that if a message M is transmitted in a network G using the SPR-scheme configured by a combination of n CISTs, then each intermediate node of G can receive a maximum of 2∕n ratio of M. From a similar idea of the extension, another application is the so-called multiple-protection routing scheme (MPR-scheme for short) which can be used to increase the capability of fault-tolerance. For assessing the performance of routing using MPR-scheme, we first propose a construction of three CISTs in the two types of Möbius cubes, which are hypercube-variant networks and are superior to hypercubes due to having a smaller diameter. For the n-dimensional Möbius cube, the diameters of CISTs we constructed are at most 14 when n=6 and at most 2n+1 when n⩾7. So, we configure the desired protection routing in the Möbius cubes via the three CISTs. Then, we provide simulation results to experimentally evaluate the performance of the newly proposed MPR-scheme in the n-dimensional Möbius cubes for 6⩽n⩽10. As an important point, our results show that the adoption of routing using MPR-scheme will result in a significant slowdown in the transmission failure rate.

Adoption of Exhaust Air Dust Testing in SPF Rodent Facilities.

Reliable detection of unwanted microbial agents is essential for meaningful health monitoring in laboratory animal facilities. Most rodents at our institution are housed in IVC rack systems to minimize aerogenic transmission of infectious agents between cages. The most commonly used rodent health monitoring systems expose live sentinel rodents to soiled bedding collected from other rodent cages on IVC racks and subsequently test these soiled-bedding sentinels for evidence of infection with excluded agents. However, infectious agents might go undetected when using this health surveillance method, due to inefficient organism shedding or transmission failure. In 2016, our institution switched the health monitoring methodology for the majority of our SPF rodent colonies to real-time PCR testing of environmental samples collected from the exhaust plenums of IVC racks. Here we describe our rationale for this conversion, describe some interesting health monitoring cases that arose soon after the conversion, and discuss a potential problem with the conversion-residual nucleic acids. We compared cost and implementation effort associated with 2 sampling methods, sticky swabs and in-line collection media. We also compared the ability of these 2 sampling methods to detect 2 prevalent microbes in our facilities, Helicobacter and murine norovirus. Our institution-wide switch to health monitoring by real-time PCR assay of exhaust air dust samples thus far has provided a sensitive, simple, and reliable approach for maintenance of SPF conditions in laboratory rodents and has dramatically reduced the use of live sentinel animals.

RECENT WORK ON EPISTEMIC ENTITLEMENT

AbstractTyler Burge and Crispin Wright distinguish between justification and entitlement. For both entitlement is the new notion. For Burge, entitlement is warrant without reasons. Burge’s account of reasons is explained. For Wright, entitlement is a non-evidential right to claim knowledge of authenticity-conditions. Wright’s account is motivated by warrant transmission failure. Burge and Wright mean different things by entitlement; they do not share a common project. Burge’s use connects to mainstream epistemological inquiry into knowledge and warrant. Wright’s use connects to mainstream epistemology inquiry into skepticism and warrant transmission. Recent work from and about both is discussed. Among other results, it is shown that Burge’s distinction is not a version of the internalism vs. externalism distinction. For Burge, both justifications and entitlements are externalist.

Altered anoctamin-1 and tyrosine phosphorylation in congenital ureteropelvic junction obstruction

PurposeUreteropelvic junction (UPJ) obstruction is the most common cause of congenital hydronephrosis in children. The pathophysiology of UPJ obstruction and the exact mechanism of pelviureteral peristalsis are poorly understood. Anoctamin-1 (ANO1), a Ca2+-activated chloride channel, has been shown to play a key role in muscle wall contractions in the gastrointestinal tract. We designed this study to investigate the hypothesis that ANO1 is expressed in smooth muscle cells (SMCs) of the human UPJ and that tyrosine phosphorylation is altered in UPJ obstruction. Materials and methodsFresh frozen specimens of UPJ obstruction (n = 28) and control specimens from patients who underwent Wilms' tumor nephrectomy (n = 20) were prepared. Western blot (WB) was performed to evaluate levels of ANO1 protein expression and changes in tyrosine phosphorylation. In addition analysis of ANO1 and phalloidin using confocal-immunofluoresence-double staining and 3D reconstruction were carried out. ResultsOur WB results revealed increased tyrosine phosphorylation in UPJ obstruction samples compared to controls, and decreased ANO1 expression in UPJ obstruction. Confocal microscopy showed that ANO1 immunoreactivity was decreased in SMCs of UPJ obstruction compared to controls. ConclusionsWe provide evidence, for the first time, of the presence of ANO1 expression in the human UPJ. We speculate that altered tyrosine phosphorylation, observed in UPJ obstruction, may lead to a failure of transmission of peristaltic waves in UPJ obstruction by inhibiting Ca2+-activated chloride channels in SMCs.

Adaptive TCP Transmission Adjustment for UAV Network Infrastructure

A UAV network composed of multiple UAVs allows a wide operating radius and various tasks to be performed. However, a UAV network mostly suffers from high probability of transmission failure due to interference or mobility. Also, nodes connected to the network often experience connection loss and segment loss caused by frequent node mobility and routing update. Since congestion is not the only cause of data loss in UAV networks, the TCP congestion control should not be run if there is a possibility of transient link instability unless a reduction in transmission speed is required. For this reason, we propose an algorithm to improve the transmission performance of UAV network through TCP with Slow-Start threshold (Ssthresh) value adjusted. The adjustment algorithm is called Adaptive Ssthresh Reviser for flying Ad hoc Network (ASRAN) that quickly restores unnecessary decrease of transmission speed in UAV network.

Fiber optic deployment challenges and their management in a developing country: A tutorial and case study in Ghana

AbstractThe telecommunication industry in Ghana has undergone various stages of transformation. The industry has experienced exponential growth over the last decades. Sustaining this growth hinges on efficient infrastructural deployment and management. Fiber optics technology has become the primary network infrastructure and a communication medium, which provides higher bandwidth capacity high speed for current and emerging technologies. As the demand for new technology and services increases, fiber optics technology brings the promise of a flexible, scalability, full‐service network platform with potentially unlimited capacity. Although mobile network operators have invested significantly and strategically in fiber optic infrastructure, there has been an increase in the number of network outages caused by frequent failures in fiber optics networks such as fiber cable cuts. Fiber cable cuts have become the single most significant cause of transmission failure or disruption to telecommunication services in Ghana with an enormous impact on the subscriber's experience. This research seeks to investigate the challenges in fiber cable deployment in Ghana, with emphasis on the technical, regulatory, managerial challenges and recommend the appropriate solutions. The challenges of frequent fiber cuts can be attributed to external factors such as dig‐ups during road construction. Lack of regulatory guidelines and policies on fiber deployment and management poses a major threat to the fiber management in Ghana.

Optimized Cluster-Based Dynamic Energy-Aware Routing Protocol for Wireless Sensor Networks in Agriculture Precision

Wireless sensor networks (WSNs) are becoming one of the demanding platforms, where sensor nodes are sensing and monitoring the physical or environmental conditions and transmit the data to the base station via multihop routing. Agriculture sector also adopted these networks to promote innovations for environmental friendly farming methods, lower the management cost, and achieve scientific cultivation. Due to limited capabilities, the sensor nodes have suffered with energy issues and complex routing processes and lead to data transmission failure and delay in the sensor-based agriculture fields. Due to these limitations, the sensor nodes near the base station are always relaying on it and cause extra burden on base station or going into useless state. To address these issues, this study proposes a Gateway Clustering Energy-Efficient Centroid- (GCEEC-) based routing protocol where cluster head is selected from the centroid position and gateway nodes are selected from each cluster. Gateway node reduces the data load from cluster head nodes and forwards the data towards the base station. Simulation has performed to evaluate the proposed protocol with state-of-the-art protocols. The experimental results indicated the better performance of proposed protocol and provide more feasible WSN-based monitoring for temperature, humidity, and illumination in agriculture sector.

Inhibition of TrkB kinase activity impairs transdiaphragmatic pressure generation.

Signaling via the tropomyosin-related kinase receptor subtype B (TrkB) regulates neuromuscular transmission, and inhibition of TrkB kinase activity by 1NMPP1 in TrkBF616A mice worsens neuromuscular transmission failure (NMTF). We hypothesized that acute inhibition of TrkB kinase activity will impair the ability of the diaphragm muscle to produce maximal transdiaphragmatic pressure (Pdi) without impacting the ability to generate forces associated with ventilation, consistent with the greater susceptibility to NMTF in motor units responsible for higher-force nonventilatory behaviors. Adult male and female TrkBF616A mice were injected with 1NMPP1 (n = 8) or vehicle (DMSO; n = 8) 1 h before Pdi measurements during eupneic breathing, hypoxia/hypercapnia (10% O2/5% CO2), tracheal occlusion, spontaneous deep breaths ("sighs") and during maximal activation elicited by bilateral phrenic nerve stimulation. In the vehicle-treated group, Pdi increased from ~10 cmH2O during eupnea and hypoxia/hypercapnia, to ~35 cmH2O during sighs and tracheal occlusion, and to ~65 cm H2O during maximal stimulation. There was no effect of acute 1NMPP1 treatment on Pdi generated during most behaviors, except during maximal stimulation (~30% reduction; P < 0.05). This reduction in maximal Pdi is generally similar to the worsening of NMTF previously reported with TrkB kinase inhibition in rodents. Accordingly, impaired TrkB signaling limits the range of motor behaviors accomplished by the diaphragm muscle and may contribute to neuromuscular dysfunction, primarily by impacting fatigable, higher force-generating motor units.NEW & NOTEWORTHY TrkB signaling plays an important role in maintaining neuromuscular function in the diaphragm muscle and may be necessary to accomplish the various motor behaviors ranging from ventilation to expulsive, behaviors requiring near-maximal forces. This study shows that inhibition of TrkB kinase activity impairs maximal pressure generation by the diaphragm muscle, but the ability to generate the lower pressures required for ventilatory behaviors is not impacted.

Risk Minimization Against Transmission Failures of Federated Learning in Mobile Edge Networks

A variety of modern AI products essentially require raw user data for training diverse machine learning models. With the increasing concern on data privacy, federated learning, a decentralized learning framework, enables privacy-preserving training of models by iteratively aggregating model updates from participants, instead of aggregating raw data. Since all the participants, i.e., mobile devices, need to transfer their local model updates concurrently and iteratively over mobile edge networks, the network is easily overloaded, leading to a high risk of transmission failures. Although previous works on transmission protocols have already tried their best to avoid transmission collisions, the number of iterative concurrent transmissions should be fundamentally decreased. Inspired by the fact that raw data are often generated unevenly among devices, those devices with a small proportion of data could be properly excluded since they have little effect on the convergence of models. To further guarantee the accuracy of models, we propose to properly select a subset of devices as participants to ensure the given proportion of involved data. Correspondingly, we propose to minimize the risk against the transmission failures during model updates. Afterwards, we design a randomized algorithm ($ran$ RFL) to choose suitable participants by using a series of delicately calculated probabilities, and prove that the result is concentrated on its optimum with high probability. Extensive simulations show that through delicate participant selection, $ran$ RFL decreases the maximal error rate of model updates by up to 38.3% compared with the state-of-the-art schemas.

Design and Analysis of a Water Quality Monitoring Data Service Platform

Water is one of the basic resources for human survival. Water pollution monitoring and protection have been becoming a major problem for many countries all over the world. Most traditional water quality monitoring systems, however, generally focus only on water quality data collection, ignoring data analysis and data mining. In addition, some dirty data and data loss may occur due to power failures or transmission failures, further affecting data analysis and its application. In order to meet these needs, by using Internet of things, cloud computing, and big data technologies, we designed and implemented a water quality monitoring data intelligent service platform in C# and PHP language. The platform includes monitoring point addition, monitoring point map labeling, monitoring data uploading, monitoring data processing, early warning of exceeding the standard of monitoring indicators, and other functions modules. Using this platform, we can realize the automatic collection of water quality monitoring data, data cleaning, data analysis, intelligent early warning and early warning information push, and other functions. For better security and convenience, we deployed the system in the Tencent Cloud and tested it. The testing results showed that the data analysis platform could run well and will provide decision support for water resource protection.

Using Imperfect Transmission in MEC Offloading to Improve Service Reliability of Time-Critical Computer Vision Applications

The emerging time-critical Internet-of-Things (IoT) use cases, e.g., augmented reality (AR), virtual reality (VR), autonomous vehicle etc., on the one hand, involve computation intensive computer vision (CV) components in the services, on the other hand, the computation task should be completed within the stringent latency constraint, otherwise, the service reliability will deteriorate. The state-of-the-art work has shown that it is promising to tackle this challenge by offloading the computation tasks to the edge servers (ESs) using mobile edge computing (MEC). However, offloading tasks from local IoT devices to remote ESs could cause communication errors, thereby resulting in transmission failure even service timeout. The existing work mainly requires perfect transmission during task offloading at physical layer or transport layer. In fact, CV algorithms for, e.g., image classification and recognition, are able to tolerate certain level distortion of the input image to maintain the required inference accuracy. In this paper, we focus on the service reliability at application layer and study how feasible it is to improve the service reliability of the time-critical CV services in MEC system by allowing imperfect transmission. The service reliability is modeled by the transmission failure probability, service timeout probability and inference accuracy. The optimization goal is to maximize the service reliability, subject to the latency constraint. Due to the non-convexity, we solve this problem by the semi-definite relaxation based algorithm for a multi-user scenario. We evaluate the algorithm considering the practical scenarios, i.e., object detection with SSD and YOLOv2. The proposed algorithm achieves the performance closed to the exhaustive method but at a much lower complexity.

A Practical Weather Detection Method Built in the Surveillance System Currently Used to Monitor the Large-Scale Freeway in China

Road weather conditions are closed-related to the transportation safety and traffic capacity. With the development of road surveillance systems, weather conditions could be recognized from video. However, it is hard to be detected by machine. To address it, a deeply supervised convolution neural network (DS-CNN) is designed and trained on a self-established dataset. The traffic image dataset includes five groups labeled with “sunny”, “overcast”, “rainy”, “snowy” and “foggy”. Each group has manually labeled and selected more than 2500 images. The DS-CNN, can achieve the precision rate of 0.9681 and the recall rate of 0.9681. This practical weather detection method has been built in the surveillance system covers five freeways. The experimental result used in practice shows much worse detection results at first with disturbance of difference scenarios, worn camera, transmission failure and so on. With further improvement of DS-CNN, we found that it was much more effective than hand-crafted features in this task, and a deeper neural architecture could derive more powerful features. Moreover, the results show that dense weather information has more details in a small scale. In order to fast report the regional weather detection result, a designed visualization method is also proposed in spatiotemporal dimension to fuse with currently-used system. The high accuracy and fast detection speed with friendly visualization would lead to more precise traffic management and prompt the road weather traffic control to more intelligence levels.

The Effect of Human Chorionic Gonadotropin on the In vitro Development of Immature to Mature Human Oocytes: A Randomized Controlled Study.

Context:In controlled ovarian hyperstimulation cycles, 15% of oocytes have been proven to be immature. Key factors include failure in signal transmission from the cumulus cell to the oocyte, insufficient level of luteinizing hormone, and internal conditions of the oocyte itself.Aims:The aim of the present study was to investigate the effect of human chorionic gonadotropin (hCG) on the in vitro maturity of partially cumulus-denuded immature oocytes collected after controlled ovarian stimulation for in vitro fertilization (IVF).Settings and Design:This was a prospective, randomized controlled design at the department of obstetrics and gynaecology, university hospital.Subjects and Methods:Infertile women underwent gonadotropin-releasing hormone antagonist stimulated protocol for IVF with final maturation triggered by hCG, partially cumulus-denuded immature human oocytes were allocated to two groups: the first was treated with fertilization medium and the second was treated with fertilization medium and hCG. They were cultured for 24 h. Outcomes measured were the oocyte maturation rates to metaphase II (MII) and glucose-6-phosphate dehydrogenase (G6PD) activity of in vitro maturation (IVM) mature oocytes which represent the oocyte quality.Statistical Analysis Used:The Mann–Whitney U-test and One-way ANOVA were used to compare continuous variables, and Chi-square was used for categorical data.Results:In all, 250 immature stimulated oocytes were allocated (125 per group). The maturation rate was higher in the hCG supplement group (48% vs. 39.2%) without significance. The positive brilliant cresyl blue results among the MII oocytes developed from the metaphase I (MI) were significantly higher in the hCG group (P = 0.001).Conclusions:Rescue IVM in fertilization culture medium plus hCG was slightly better than that in the only fertilization culture. MII oocytes developed from MI in hCG supplemented medium had a higher quality based on the measured G6PD activity.

Transaction processing monitors on real-time databases

The development of distributed database systems has given rise to the transfer of data from one connected terminal to another. During the transmission of the data among various connected terminals, data can be corrupted, infrastructures can fail, hardware can malfunction and network can disconnect; all of these can cause failure in data transmission. This research focuses on Transaction Processing Monitor (TPM) on a real-time database and the standard middleware applications it provides for use in different e-commerce systems from large enterprises to medium and small businesses available on the internet to monitor the transfer of data between multiple terminals. The researchers reviewed many articles that provided detailed information on TPM because of the significant growth and popularity that it has gained. The paper also reviewed various concepts of Transaction Processing Monitors on real-time databases, different areas of TPM functionalities and transactional properties as well as the architectures of Transaction Processing Monitors. This paper also recommended high-end benchmark platform for Transaction Processing Monitor which is very vital to meet the high performance needs of online transactions and to determine their operational status either for success or failure.

Reinforcement Learning Based Anti-Jamming Schedule in Cyber-Physical Systems

In this paper, the security issue of cyber-physical systems is investigated, where the observation data is transmitted from a sensor to an estimator through wireless channels disturbed by an attacker. The failure of this data transmission occurs, when the sensor accesses the channel that happens to be attacked by the jammer. Since the system performance measured by the estimation error depends on whether the data transmission is a success, the problem of selecting the channel to alleviate the attack effect is studied. Moreover, the state of each channel is time-variant due to various factors, such as path loss and shadowing. Motivated by energy conservation, the problem of selecting the channel with the best state is also considered. With the help of cognitive radio technique, the sensor has the ability of selecting a sequence of channels dynamically. Based on this, the problem of selecting the channel is resolved by means of reinforcement learning to jointly avoid the attack and enjoy the channel with the best state. A corresponding algorithm is presented to obtain the sequence of channels for the sensor, and its effectiveness is proved analytically. Numerical simulations further verify the derived results.

Landslide susceptibility mapping for transmission lines: dynamic monitoring, analysis and alerts for extreme natural events

In Brazil and other countries, most electric-sector enterprises do not present a systematic space–time evaluation of their structures to identify environmental vulnerabilities. Thus, this study aims to analyze the susceptibility of mass movements in transmission lines, in the Serra da Mantiqueira region (Brazil), subject to the effects of tropical rains to operationalize a dynamic platform of analysis and alertness in the most critical areas. For this study, static and dynamic data were collected in the region from public and private sources. Next, multiple criteria were defined through the analytic hierarchy process (AHP). Using geographic information systems (GIS) and map algebra, it was possible to determine a susceptibility map in five classes. Subsequently, based on the identified areas and dynamic meteorological and hydrological data, a real-time platform was operationalized for monitoring, analysis, and alerts to environmental risks. Consequently, a geographic database with a regional coverage (14,000 km2) was generated, involving seven criteria: slope, distance of transmission lines, drainage density, soil use, soil type, fracture and failure density, and precipitation. The susceptibility classes found in the study region were very low (1.5%), low (12%), average (34.9%), high (45.3%), and very high (6.2%). It was also possible to identify different mass movements in areas close to the transmission lines, as well as other risk elements such as dwellings, roads, reservoir borders, and telecommunications towers. The operationalized monitoring platform allowed the establishment of dynamic analyses on the occurrence of extreme natural events, by sending notifications and an online map of the affected areas. Thus, this platform developed in this study can become an instrument of evaluation, monitoring, and management for the public management and regulatory agencies of the electric sector.

Experimental Study on the Uniaxial Compression Failure and Ultrasonic Transmission of Brittle Shale Considering the Bedding Effect

The rock failure process, especially the crack propagation process in rock, can essentially reveal many mechanical problems in the rock. The bedding structure of shale is one of the main influencing factors of rock failure. This study performed an ultrasonic dynamic transmission test on Longmaxi Formation shale specimens with different bedding angles under uniaxial compression and comprehensively analyzed the mechanical and ultrasonic evolution characteristics. The deformation and failure of the shale samples indicated obvious brittle characteristics, and the final failure mode was dominated by shear cracks along the bedding planes and tensile-compressive cracks along the maximum principal stress direction. The difference index of the bedding calculated by the ultrasonic response speed showed that with increasing deformation and failure, the influence of the bedding structure on the failure decreased. In the process of uniaxial compression, the ultrasonic transmission velocity changed periodically. Relying on the obvious jumping points of the ultrasonic velocity curve, we could initially judge the possible key points of the changes in the pores and cracks during the rock failure process. A new method to calculate the rock brittleness index based on the characteristic response velocity of ultrasonic waves was proposed. Compared with the classical method, this method revealed a good applicability. This study can further clarify the relationship between the acoustic characteristics of ultrasonic transmission and rock deformation and failure, and can lay a certain theoretical foundation for the subsequent study of ultrasonic transmission and rock structure, along with its mechanical, physical and chemical properties.