Transmission Failure Research Articles

Gap Filling and consistency analysis in monthly rainfall series: case study in southeastern Mato Grosso

The analysis of precipitation time series is crucial for understanding climate patterns and managing water resources. However, data gaps caused by missing information, technical issues, and data transmission failures compromise the accuracy of climate analyses and forecasts. This study aims to address these gaps and assess the consistency of monthly rainfall series in southeastern Mato Grosso, using the regional weighting method and the double-mass analysis. Data from five rainfall stations were selected: Vale Rico (01654005), Alto Araguaia (01753000), Fazenda Taquari (01853000), Alto Garças (01653004), and Itiquira (01754000), covering the period from 1984 to 2019, were extracted from the Hidroweb platform of the National Water and Sanitation Agency (ANA). The regional weighting method was effective in filling gaps. Consistency checks using the double-mass method revealed a linear trend in data, indicating no inconsistencies in the filled data. Notably, the Fazenda Taquari station (01853000), with had the mostgaps filled, showed a pronounced linear trend, demonstrating the effectiveness of the methodology. The findings suggest that the regional weighting method is suitable approach for gap filling in rainfall series, thereby enhancing the quality of data for hydrological studies in the region.

Collision Warning of Connected Autonomous Vehicles Based on Vehicular Networking

The early collision warning is an effective way to reduce traffic accidents for Connected Autonomous Vehicles (CAV), so it is of significance for studying the collision warning system based on vehicular networking. As two crucial indicators of collision warning, warning reliability and warning lead time have great impacts on vehicle collision rates. This paper proposes a collision warning approach for CAV based on vehicular networking and aims to lower vehicle collision rates by enhancing warning reliability and accuracy of warning lead time. The approach exploits various metrics to enhance warning reliability, reducing the number of relays involved in issuing warnings to avoid data transmission failure caused by traffic congestion. Moreover, the accuracy of warning lead time is enhanced by exploiting the information-centric mechanism to perform warning fusion. Finally, the CAV-based collision warning system is evaluated to justify its superiority.

Perceptual constancy for an odor is acquired through changes in primary sensory neurons.

The ability to consistently recognize an object despite variable sensory input is termed perceptual constancy. This ability is not innate; rather, it develops with experience early in life. We show that, when mice are naïve to an odor object, perceptual constancy is absent across increasing concentrations. The perceptual change coincides with a rapid reduction in activity from a single olfactory receptor channel that is most sensitive to the odor. This drop in activity is not a property of circuit interactions within the olfactory bulb; instead, it is due to a sensitivity mismatch of olfactory receptor neurons within the nose. We show that, after forming an association of this odor with food, the sensitivity of the receptor channel is matched to the odor object, preventing transmission failure and promoting perceptual stability. These data show that plasticity of the primary sensory organ enables learning of perceptual constancy.

Wear Simulations of Involute Harmonic Gear Under Mixed Lubrication Condition

ABSTRACTHarmonic gears are widely used in precise space technology, robotic, medical equipment and other fields, while the magnitude of surface topography changes due to wear is usually comparable to or larger than the original surface roughness and elastic deformation, leading to severe transmission failures. This paper reports a numerical approach to simulate the lubrication status considering wear evolution based on mixed elastohydrodynamic lubrication (EHL) and Archard models, in which the Reynolds equation is solved with finite difference method and surface deformation is calculated by the discrete convolution‐fast Fourier transform (DC‐FFT) algorithm. The interfacial pressure and film thickness distributions are validated by comparison with available results from literature. The harmonic gear lubrication and wear performances are calculated, including effects of machined surface, velocity, load, wear time and material properties, and the results suggest that avoiding long‐term and high‐torque working with a large wear coefficient can effectively prevent surface wear failure, which is beneficial for increasing the harmonic gears' lifespan.

Dissociation of mitochondrial and ribosomal biogenesis during thallium administration in rat kidney.

Thallium (Tl) is a heavy metal with toxicity comparative to other heavy metals such as As, Cd, and Hg. Nevertheless, fewer studies have been reported concerning the molecular mechanism of Tl toxicity as compared to other heavy metals. To obtain insight into Tl toxicity in the kidney, rats were intraperitoneally administered Tl2SO4 (30 mg/kg), and the kidneys were removed 2 or 5 days later to examine the effects of Tl. Transcriptome analysis using DNA microarray of the rat kidney 2 and 5 days after Tl administration showed that cytoplasmic ribosomal proteins are the most upregulated category; many of the genes involved in ribosome biosynthesis were upregulated by Tl administration. This upregulation was associated with the activation of eukaryotic transcription initiation factor 2α (eIF2α), implying that increased ribosome biogenesis was linked to the subsequent activation of protein translation. In contrast, decreased mitochondrial biogenesis was revealed via proteomic analysis. Although we found an increase in Myc, a positive regulator of both ribosomal and mitochondrial biogenesis, decreased levels of NRF1 and TFAM, positive regulators of mitochondrial biogenesis whose gene expression is directory activated by Myc, were paradoxically observed. Taken together, differing responses of ribosomes and mitochondria to Tl toxicity were observed. Failure of transmission of the Myc signal to NRF1/TFAM might be involved in the observed disruption of coordinated responses in mitochondria and ribosomes during Tl administration in rat kidney.

An aperiodically intermittent control for finite-time and fixed-time synchronization of stochastic FCNN with switching parameters

The main objective of this paper is to design an aperiodically intermittent control to ensure the finite and fixed time synchronization of fuzzy cellular neural networks (FCNNs) involving switching parameters with threshold properties, time-dependent discrete, continuous-type delays, and stochastic disturbances during transmission. Cellular neural networks (CNNs), with their grid-like structure, excel in image-processing tasks. Incorporating the fuzziness in the CNNs may handle the uncertainties and incomplete information in an effective manner. Furthermore, this paper introduces the concept of user-controlled FCNNs, which retain the dynamic properties of conventional FCNNs while incorporating significant factors that could potentially degrade the performance of the considered model. Due to randomness, FCNNs are framed as a set of stochastic differential equations with memristors. Generally, a memristor functions as a non-volatile memory device, reserving past data and utilizing it in the event of transmission failure. Further, the synchronization process is an effective approach that helps to ensure the dynamical behaviors of two different models; hence, the paper formulates the synchronization problem for the FCNN model with control (response) and without control input (drive). In terms of control design, this paper also considers the aperiodically intermittent control (APIC) scheme that can drive the user-controlled FCNN solution trajectories onto conventional FCNN solution trajectories within a prescribed time. Additionally, the APIC scheme incorporates an adaptive mechanism that effectively manages switching behaviors and uncertainties. Furthermore, this study proposes a theoretical framework in the form of sufficient stability conditions that helps to ensure the synchronization of the drive-response model via the global asymptotical stability of the stochastic error model derived from the drive-response model under the APIC scheme in the mean square. The proposed stochastic FCNN model is numerically simulated, and the corresponding outcomes are graphically illustrated.

Leakage prediction approach and influencing factor analysis from seal test

PurposeLeakage serves as a core indicator of sealing performance degradation, particularly under high-speed and heavy-duty operational where increased leakage is common. Within heavy-duty vehicle transmissions, the leakage can lead to excessive pressure loss and eventual transmission failure. This study aims to introduce a predictive method for assessing sealing ring leakage in vehicle transmissions based on operating conditions.Design/methodology/approachSeal test was carried out using a specialized seal test rig. Various data points were collected during this test, including leakage, friction torque, oil temperature, oil pressure and rotating speed. The collected data underwent noise separation and reconstruction using the complete ensemble empirical mode decomposition with adaptive noise method. Subsequently, a leakage prediction model is developed using the random forest regression with parameter optimization. A quantitative evaluation for influencing factors in leakage prediction process is investigated.FindingsThe results achieve a mean accuracy index exceeding 95%, demonstrating close alignment between predicted and actual leakage values. Feature contribution results highlight that the trends of the oil temperature, friction torque and oil pressure significantly affect the leakage prediction, with the oil temperature trend exerting the most substantial influence.Originality/valueThis work sheds light on the interplay between operating conditions and sealing performance degradation, offering valuable insights for understanding and addressing sealing issues effectively.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2024-0271/

Persistence of Helicobacter Pylori Coccoid Forms in Different Environments

Objective: The present study aims to determine the possibility of H. pylori coccoid forms to survive in our surrounding environments, thus exhibiting public health hazard. Method: Helicobacter pylori strain Makkah 7 accession number HQ622108, was inoculated in samples of soil, well, tap, swimming pool, and sewage water; in which, an average initial inoculum of 107 CFU/ml was inoculated. The experiment was conducted, outdoor where ambient temperature varied between 39-55°C in Jeddah city, Saudi Arabia. The survival rate of H. pylori strain was quantitatively and qualitatively studied for five months. Results: Viable counts were undetectable after 24 hours, while total count varied between 107 to 106, and declined to 103 bacterial cell/ml five months later. Interestingly, microscopic examination revealed few non-motile rods and motile coccoid forms. All samples were removed and placed at 4°C for one month. Following, total count, morphology, and motility were examined, showing motile coccoid forms. Electron microscopic and, molecular studies were carried out, confirming that the species is H. pylori, which was detected by using 16S rRNA primer for H. pylori with a product size of 163 bp. The ability of H. pylori strain to persist and survive, by being motile in the coccoid form, for five months under such hostile environment, strongly indicates that the coccoid form plays a vital role in the transmission, recrudescence, and therapeutic failure. It is indeed a hazardous and a crucial infectious phase of this bacterium. Conclusion: Detecting coccoid forms in water and soil, accompanied by their eradication, must be seriously considered and applied. Consequently, hindering and preventing different diseases caused by H. pylori.

Synaptic and extrasynaptic distribution of NMDA receptors in the cortex of Alzheimer's disease patients.

Synaptic and extrasynaptic distribution of N-methyl-D-aspartate receptors (NMDARs) has not been addressed in the brain from Alzheimer´s disease (AD) subjects, despite theircontribution to neurodegeneration. We have developed a protocol to isolate synaptic and extrasynaptic membranes from controls and AD frontal cortex. We characterized the distribution of the NMDAR subunits GluN2B, GluN2A, GluN1, and GluN3A, as well aspost-translational modifications, such as phosphorylation and glycosylation. Lower levels of synaptic GluN2B and GluN2A were found in AD fractions, while extrasynaptic GluN2B and GluN1 levels were significantly higher; GluN3A distribution remained unaffected in AD. We also identified different glycoforms of GluN2B and GluN2A in extrasynaptic membranes. Synaptic Tyr1472 GluN2B phosphorylation was significantly lower in AD fractions. Reduction of synaptic NMDAR subunits, particularly for GluN2B, is likely to contribute to synaptic transmission failure in AD. Additionally, the increment of extrasynaptic NMDAR subunits could favor the activation of excitotoxicity in AD. New protocol to isolate synaptic and extrasynaptic membranes from the human cortex. Low GluN2B and GluN2A levels in Alzheimer´s disease (AD) synaptic membranes. High GluN2B and GluN1 levels in AD extrasynaptic membranes. Specific glycoforms of extrasynaptic GluN2B and GluN2A. Low phosphorylation at Tyr1472 in synaptic GluN2B in AD.

Temporal host–symbiont dynamics in community contexts: Impacts of host fitness and vertical transmission efficiency on symbiosis prevalence

Abstract Symbiotic associations play a role in plant ecology and evolution, but the outcome of the interaction depends on the life‐history traits of the partners and the environmental context. Although symbiosis with vertically transmitted microorganisms should result in mutualism, it is not clear how the transmission process aligns with the outcome of the context‐dependent symbiosis. For 3 years, we sampled individuals of an annual plant species that forms symbiosis with a vertically transmitted fungal endophyte, in paired stands of two contrasting vegetation communities (humid mesophytic meadows [HMM]: productive/low stress, and humid prairies [HP]: less productive/high stress). We estimated the prevalence of symbiosis at the population level, and the fitness of the plant, the symbiotic status and vertical transmission efficiency at the individual level. Over 3 years, the prevalence of symbiosis was ≈100% in HMM and ≈75% in HP. Plant fitness was very low and high in years with precipitation below and above the yearly mean, respectively. The higher fitness of endophyte‐symbiotic plants was evident in the HMM and high precipitation years. Vertical transmission of endophytes was higher in HMM (≈96%) compared to HP (≈93%) and was not related to plant fitness. Despite transmission inefficiencies in HP, changes in prevalence within the growing season (from seeds to the final plant stand) suggest a fitness advantage for symbiotic plants. Vertical transmission is expected to promote mutualism as it aligns partners' fitness. Although symbiotic plants showed higher fitness and the probability of transmission failures was higher among low‐fitness plants, the variation in transmission efficiency between plants and vegetation communities was not related to the fitness of the individual host. Our study provides evidence that context‐dependent vertical transmission efficiency and endophyte‐mediated fitness advantages interact complexly to determine the prevalence of symbiosis in populations that occur in contrasting vegetation communities. Read the free Plain Language Summary for this article on the Journal blog.

Ways to Organize and Identify Steganographic Channels in IP Networks

The article is devoted to an overview of network steganography methods that can be used to build hidden message transmission channels in IP networks, as well as methods aimed at identifying such hidden channels. The article gives the concept of a stegocontainer, and provides classification of network steganography methods. The article discusses the following methods of organizing hidden channels: the method of changing the contents of network packet headers, the Transcoding Steganography (TranSteg) method, the delay modulation method, the Lost Audio Packet Steganography (LACK) method, the Retransmission Steganography (RSTEG) method. In the review of the method of changing the contents of network packet headers, the principle of implementing changes in values in some service fields of IP (Internet Protocol) and TCP (Transmission Control Protocol) packet headers, which do not lead to data transmission failure, are considered. In the overview of the TranSteg method, the principle of transcoding the contents of network packets delivering real-time traffic is considered in order to free up space in the packet, which will be used to transmit hidden information. In the review of the delay modulation method, the principles of hidden message encoding are considered, which is carried out by changing the delay value of sending packets in the network. In the review of the LACK method, the mechanism of deliberate retention of RTP packets with an embedded steganographic message is considered. In the review of the RSTEG method, the principle of TCP segment exchange is considered, which provides the possibility of transmitting a steganogram. A number of parameters are given by which it is possible to conclude that there is a hidden channel in the network. The applicability of statistical methods and the methods with a classifier for detecting hidden channels in IP networks is considered. The expediency of implementing statistical methods and methods with a classifier in integration with systems for capturing and analyzing network traffic is indicated.

A WHO remit to improve global standards for medical products of human origin.

In recent decades, considerable advances have been made in assuring the safety of blood transfusion and organ transplantation. However, with the increasing movement of medical products of human origin across international boundaries, there is a need to enhance global norms and governance. These products, which include blood, organs, tissues, cells, human milk and faecal microbiota, are today crucial for health care but they also pose unique risks due to their human origin, such as disease transmission and graft failure. Moreover, the demand for medical products of human origin often exceeds supply, leading to dependence on international supply chains, and emerging technologies like cell and gene therapy present further challenges because of their unproven efficacy and long-term risks. Current regulatory mechanisms, especially in low- and middle-income countries, are insufficient. The World Health Organization (WHO) has both the mandate and experience to lead the development of international quality and safety standards, consistent product nomenclature, and robust traceability and biovigilance systems. An international, multistakeholder approach is critical for addressing the complexities of how medical products of human origin are used globally and for ensuring their safety. This approach will require promoting uniform product descriptions, enhancing digital communication systems and leveraging existing resources to support countries in establishing regulations for these products. As illustrated by World Health Assembly resolution WHA77.4 on transplantation in 2024, WHO's ongoing efforts to ensure the safe, efficient and ethical use of medical products of human origin worldwide provide the opportunity to galvanize international cooperation on establishing norms.

Bidirectional dysregulation of synaptic glutamate signaling after transient metabolic failure.

Ischemia leads to a severe dysregulation of glutamate homeostasis and excitotoxic cell damage in the brain. Shorter episodes of energy depletion, for instance during peri-infarct depolarizations, can also acutely perturb glutamate signaling. It is less clear if such episodes of metabolic failure also have persistent effects on glutamate signaling and how the relevant mechanisms such as glutamate release and uptake are differentially affected. We modeled acute and transient metabolic failure by using a chemical ischemia protocol and analyzed its effect on glutamatergic synaptic transmission and extracellular glutamate signals by electrophysiology and multiphoton imaging, respectively, in the mouse hippocampus. Our experiments uncover a duration-dependent bidirectional dysregulation of glutamate signaling. Whereas short chemical ischemia induces a lasting potentiation of presynaptic glutamate release and synaptic transmission, longer episodes result in a persistent postsynaptic failure of synaptic transmission. We also observed unexpected differences in the vulnerability of the investigated cellular mechanisms. Axonal action potential firing and glutamate uptake were surprisingly resilient compared to postsynaptic cells, which overall were most vulnerable to acute and transient metabolic stress. We conclude that short perturbations of energy supply lead to a lasting potentiation of synaptic glutamate release, which may increase glutamate excitotoxicity well beyond the metabolic incident.

Inducible deletion of endothelial cell Efnb2 delays capillary regeneration and attenuates myofibre reinnervation following myotoxin injury in mice.

Acute injury of skeletal muscle disrupts myofibres, microvessels and motor innervation. Myofibre regeneration is well characterized, however its relationship with the regeneration of microvessels and motor nerves is undefined. Endothelial cell (EC) ephrin-B2 (Efnb2) is required for angiogenesis during embryonic development and promotes neurovascular regeneration in the adult. We hypothesized that, following acute injury to skeletal muscle, loss of EC Efnb2 would impair microvascular regeneration and the recovery of neuromuscular junction (NMJ) integrity. Mice (aged 3-6months) were bred for EC-specific conditional knockout (CKO) of Efnb2 following tamoxifen injection with non-injected CKO mice as controls (CON). The gluteus maximus, tibialis anterior or extensor digitorum longus muscle was then injured with local injection of BaCl2. Intravascular staining with wheat germ agglutinin revealed diminished capillary area in the gluteus maximus of CKO vs. CON at 5days post-injury (dpi); both recovered to uninjured (0dpi) level by 10dpi. At 0dpi, tibialis anterior isometric force of CKO was less than CON. At 10dpi, isometric force was reduced by half in both groups. During intermittent contractions (75Hz, 330mss-1, 120s), isometric force fell during indirect (sciatic nerve) stimulation whereas force was maintained during direct (electrical field) stimulation of myofibres. Neuromuscular transmission failure correlated with perturbed presynaptic (terminal Schwann cells) and postsynaptic (nicotinic acetylcholine receptors) NMJ morphology in CKO. Resident satellite cell number on extensor digitorum longus myofibres did not differ between groups. Following acute injury of skeletal muscle, loss of Efnb2 in ECs delays capillary regeneration and attenuates recovery of NMJ structure and function. KEY POINTS: The relationship between microvascular regeneration and motor nerve regeneration following skeletal muscle injury is undefined. Expression of Efnb2 in endothelial cells (ECs) is essential to vascular development and promotes neurovascular regeneration in the adult. To test the hypothesis that EfnB2 in ECs is required for microvascular regeneration and myofibre reinnervation, we induced conditional knockout of Efnb2 in ECs of mice. Acute injury was then induced by BaCl2 injection into gluteus maximus, tibialis anterior or extensor digitorum longus (EDL) muscle. Capillary regeneration was reduced at 5days post-injury (dpi) in gluteus maximus of conditional knockout vs. controls; at 10dpi, neither differed from uninjured. Nerve stimulation revealed neuromuscular transmission failure in tibialis anterior with perturbed neuromuscular junction structure. Resident satellite cell number on EDL myofibres did not differ between groups. Conditional knockout of EC Efnb2 delays capillary regeneration and attenuates recovery of neuromuscular junction structure and function.

Congenital myasthenic syndrome secondary to pathogenic variants in the SLC5A7 gene: report of two cases

BackgroundCongenital Myasthenic Syndromes (CMS) are rare genetic diseases, which share as a common denominator muscle fatigability due to failure of neuromuscular transmission. A distinctive clinical feature of presynaptic CMS variants caused by defects of the synthesis of acetylcholine is the association with life-threatening episodes of apnea. One of these variants is caused by mutations in the SLC5A7 gene, which encodes the sodium-dependent HC-3 high-affinity choline transporter 1 (CHT1). To our knowledge there are no published cases of this CMS type in Latin America.Case presentationWe present two cases of CHT1-CMS. Both patients were males presenting with repeated episodes of apnea, hypotonia, weakness, ptosis, mild ophthalmoparesis, and bulbar deficit. The first case also presented one isolated seizure, while the second case showed global developmental delay. Both cases, exhibited incomplete improvement with treatment with pyridostigmine.ConclusionsThis report emphasizes the broad incidence of CMS with episodic apnea caused by mutations in the SLC5A7 gene and the frequent association of this condition with serious manifestations of central nervous system involvement.

Підвищення ефективності забезпечення працездатності транспортних засобів

Accidental failures, leading to unplanned repairs, significantly increase the cost of their elimination compared to planned measures. A significant part of such failures are not sudden in nature. Gradual failure is preceded by a gradual change in some parameters. The impact of gradual failures on the efficient operation of road freight transport is increasing. Despite the fact that the failure of the engine, clutch or automatic transmission is not dangerous to the life and health of people, their impact on the economic condition of the enterprise is significant. There is a trend of decreasing the size of the rolling stock fleet for most of the country's motor transport enterprises. Therefore, the importance of keeping each car in working condition increases. To increase the accuracy of the prevention of gradual and sudden-gradual failures, a forecasting method based on the diagnosis of trucks with a specialized diagnostic car scanner TEXA Navigator MULTIHUB is proposed. The selection of diagnostic parameters was carried out in accordance with the requirements for compliance with the accuracy, efficiency, and informativeness of the diagnostic parameters. The research was carried out on MAN TG-X, MAN TGA, VOLVO FH 12, DAF 105 XF, and DAF 106 cars. A sequential cylinder shutdown test was conducted to determine the compression and efficiency of all cylinders. A gradual change in the operating parameter is determined based on the obtained decrease in revolutions. In the next test, the correction of the injectors for the amount of fuel injected into the cylinders is checked. The reference value is taken as 0. The correction tolerance for increasing or decreasing the fuel supply time should be within +1 or –1. Based on the received data, the nozzle is determined, in the correction gradually increases, which signals a problem with the nozzle's operation. For the clutch, a test of the position of the start of switching on and off was carried out. By reducing the percentage of idling, you can determine the gradual engagement of the clutch. All the conducted tests make it possible to graphically display a change in a parameter or property and, using extrapolation, to predict the moment of failure. All cars carry out freight transportation in international traffic. Control parameters and data extrapolation made it possible to predict engine, clutch, and automatic transmission failures. Selected diagnostic parameters can be used to predict and prevent failures.

Informing parents of newborns with sickle cell trait detected at neonatal screening: A northern France experience.

Neonatal screening for sickle cell disease (SCD) in France, targeted since 1995, indirectly detects newborns with sickle cell trait (SCT). Information about carrier status must be communicated to families in accordance with the 2006 National Consultative Ethics Committee recommendations; however, no national protocol for this exists. In the departments of Nord and Pas-de-Calais, the Regional Neonatal Screening Center transmits this information through a general practitioner (GP). This study aimed to assess the success rate of local practices in transmitting SCT information to parents. The secondary objectives included explaining transmission failures, evaluating post-information couple screening rates, and conducting a nationwide evaluation of SCT information dissemination. In this retrospective, multicenter study, family doctors were surveyed regarding newborns screened for SCT between January 1 and December 31, 2020, in the Nord and Pas-de-Calais departments. Among the 260 screened newborns, 197 were eligible for analysis. Results showed that 31.2% of newborns with SCT had their GP definitively sharing information with their parents. Based on this information, subsequent parental screening accounted for 13.6% of cases. The reasons cited by the GP for failing to convey information included elusive families (52.5%), unfamiliarity or refusal of the role (35%), limited SCD knowledge (25%), and ethical considerations (12.5%). This study highlights the difficulty and heterogeneity in transmitting carrier status information to parents of newborns with SCT. Our findings could serve as a foundation for the development of new methods for information transmission, given the generalization of neonatal screening for SCD by the French National Authority for Health.

Using ranging for collision-immune IEEE 802.11 rate selection with statistical learning

Appropriate data rate selection at the physical layer is crucial for Wi-Fi network performance: too high rates lead to loss of data frames, while too low rates cause increased latency and inefficient channel use. Most existing methods adopt a probing approach and empirically assess the transmission success probability for each available rate. However, a transmission failure can also be caused by frame collisions. Thus, each collision leads to an unnecessary decrease in the data rate. We avoid this issue by resorting to the fine timing measurement (FTM) procedure, part of IEEE 802.11, which allows stations to perform ranging, i.e., measure their spatial distance to the AP. Since distance is not affected by sporadic distortions such as internal and external channel interference, we use this knowledge for data rate selection. Specifically, we propose FTMRate, which applies statistical learning (a form of machine learning) to estimate the distance based on measurements, predicts channel quality from the distance, and selects data rates based on channel quality. We define three distinct estimation approaches: exponential smoothing, Kalman filter, and particle filter. Then, with a thorough performance evaluation using simulations and an experimental validation with real-world devices, we show that our approach has several positive features: it is resilient to collisions, provides near-instantaneous convergence, is compatible with commercial-off-the-shelf devices, and supports pedestrian mobility. Thanks to these features, FTMRate outperforms existing solutions in a variety of line-of-sight scenarios, providing close to optimal results. Additionally, we introduce Hybrid FTMRate, which can intelligently fall back to a probing-based approach to cover non-line-of-sight cases. Finally, we discuss the applicability of the method and its usefulness in various scenarios.

Bidirectional dysregulation of synaptic glutamate signaling after transient metabolic failure.

Ischemia leads to a severe dysregulation of glutamate homeostasis and excitotoxic cell damage in the brain. Shorter episodes of energy depletion, for instance during peri-infarct depolarizations, can also acutely perturb glutamate signaling. It is less clear if such episodes of metabolic failure also have persistent effects on glutamate signaling and how the relevant mechanisms such as glutamate release and uptake are differentially affected. We modelled acute and transient metabolic failure by using a chemical ischemia protocol and analyzed its effect on glutamatergic synaptic transmission and extracellular glutamate signals by electrophysiology and multiphoton imaging, respectively, in the hippocampus. Our experiments uncover a duration-dependent bidirectional dysregulation of glutamate signaling. Whereas short chemical ischemia induces a lasting potentiation of presynaptic glutamate release and synaptic transmission, longer episodes result in a persistent postsynaptic failure of synaptic transmission. We also observed unexpected differences in the vulnerability of the investigated cellular mechanisms. Axonal action potential firing and glutamate uptake were unexpectedly resilient compared to postsynaptic cells, which overall were most vulnerable to acute and transient metabolic stress. We conclude that even short perturbations of energy supply lead to a lasting potentiation of synaptic glutamate release, which may increase glutamate excitotoxicity well beyond the metabolic incident.

Usability and feasibility of the open-source GeRI platform for remote assessments in older adults with prostate cancer.

e13664 Background: The Geriatric Remote Initiative (GeRI) is an open-source tool to collect patient-generated health data for older adults with cancer. It comprises a WiFi-enabled Raspberry Pi tablet, a Bangle.js 2 wrist accelerometer, and Mi Body Composition Scale 2 for data collection. Following the initial phase where feedback from older cancer survivors and caregivers refined a demonstration GeRI platform, this study deployed a live version of GeRI in advanced prostate cancer patients to evaluate its feasibility and usability. Methods: In this single-arm pilot feasibility and usability study, we evaluated GeRI among ten advanced prostate cancer patients aged ≥65 years undergoing androgen deprivation (ADT) across varied frailty risk categories. Participants interacted with GeRI for ≥12 weeks. Data collection comprised demographics, clinical information, and vulnerability assessment (Cancer and Aging Research Group [CARG] score) from in-clinic surveys. Biometric (wearable/scale) and electronic patient-reported outcomes data from the tablet were securely transmitted to the institution’s HIPAA-compliant cloud. Usability was evaluated using the System Usability Scale (SUS), aiming for an average score of 68 or higher. Feasibility was achieved if ≥6 participants completed at least 50% of all prompted interactions with the system components (surveys, wearable, and weight/bioimpedance) throughout a 12-week study period. Results: Ten men with metastatic hormone-sensitive prostate cancer [median age: 73 years; 40% minority; median of 3 months of ADT exposure (IQR: 2-4.5); 80% had intensified ADT with 60% getting concurrent prostate-directed radiation] engaged with GeRI for a median of 104 days (IQR: 93-131). 40% were vulnerable with a CARG>5. System usability, evaluated by SUS, yielded a mean score of 84 (SD: 12.5). All participants met the feasibility criterion. Deficiencies in obtaining complete 48-hour accelerometry data from 7 participants were noted with only 1 being due to persistent non-wear of the wearable and the remainder due to transmission failure. Conclusions: The GeRI platform exhibited exceptional usability and met all feasibility benchmarks in a geriatric oncology setting, highlighting its potential despite technical hurdles in accelerometry data collection. Further deployment of GeRI is underway [or planned] through an expanded program focusing on other cancer types, including head and neck, and more robust biometric data collection.