Greater Latency Research Articles

Effect of SARS-CoV-2 Infection on Incident Diabetes by Viral Variant: Findings From the National COVID Cohort Collaborative (N3C).

The coronavirus 2019 (COVID-19) pandemic has evolved over time by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant, disease severity, treatment, and prevention. There is evidence of an elevated risk of incident diabetes after COVID-19; our objective was to evaluate whether this association is consistent across time and with contemporary viral variants. We conducted a retrospective cohort study using National COVID Cohort Collaborative (N3C) data to evaluate incident diabetes risk among COVID-positive adults compared with COVID-negative patients or control patients with acute respiratory illness (ARI). Cohorts were weighted on demographics, data site, and Charlson comorbidity index score. The primary outcome was the cumulative incidence ratio (CIR) of incident diabetes for each viral variant era. Risk of incident diabetes 1 year after COVID-19 was increased for patients with any viral variant compared with COVID-negative control patients (ancestral CIR 1.16 [95% CI 1.12-1.21]; Alpha CIR 1.14 [95% CI 1.11-1.17]; Delta CIR 1.17 [95% CI 1.13-1.21]; Omicron CIR 1.13 [95% CI 1.10-1.17]) and control patients with ARI (ancestral CIR 1.17 [95% CI 1.11-1.22]; Alpha CIR 1.14 [95% CI 1.09-1.19]; Delta CIR 1.18 [95% CI 1.11-1.26]; Omicron CIR 1.20 [95% CI 1.13-1.27]). There was latency in the timing of incident diabetes risk with the Omicron variant; in contrast with other variants, the risk presented after 180 days. Incident diabetes risk after COVID-19 was similar across different SARS-CoV-2 variants. However, there was greater latency in diabetes onset in the Omicron variant era.

In-sensor reservoir computing based on optoelectronic synaptic devices

Artificial neural networks built with optoelectronic synaptic devices have been proven to process visual information effectively. However, it takes great latency time and energy consumption, especially facing dynamic visual information, due to the separated optical sensor, memory, and process unit. Reservoir computing (RC) based on optoelectronic synaptic devices provides an in-sensor RC for processing temporal information efficiently. It achieves efficient computation by sensing and processing optical signals directly with optoelectronic synaptic devices. Optoelectronic synaptic devices shine in visual information processing, whose application in visual sensing and processing will provide a viable hardware solution for in-sensor computing. Therefore, the application of optoelectronic synaptic devices in reservoir computing has prompted increasing attention. Herein, for promoting the application of physical reservoir computing (PRC) with optoelectrical synapses in machine vision, synaptic plasticity will be introduced first in this work and then illustrate the basic functions of optoelectronic synapses as well as their application in reservoir computing further, and provide a perspective on PRC with optoelectronic synapses in the final.

6LoWPAN MAC layer parameters optimization using evolutionary algorithm based ANN topology in wireless body area networks

Since the IPv6 Wireless Personal Area Network (6LoWPAN) can be utilized for information dissemination, this network gains significant attention in recent years. Proxy mobile IPv6 (PMIPv6) is standard for mobility control based on network at entire IP wireless applications. But, group-based body area networks cannot respond effectively. A new improved group flexibility system decrease the number of control messages contain router requests as well as advertising messages when compared to the group-based PMIPv6 protocol, in order to minimize delay and signaling costs. The IEEE 802.15.4 standard for low-power personal area networks (6LoWPAN) complies through IPv6-compliant MAC and physical layers. If the default parameters, excessive collisions, packet loss, and great latency occur arbitrarily in high traffic by default MAC parameters while using a great number of 6LoWPAN nodes. The implemented Whale optimization algorithm is based on artificial neural network optimization, genetic algorithm or particle swarm optimization to choose and authenticate MAC parameters. This manuscript proposes a novel intelligent method for choosing optimally configured MAC 6LoWPAN layer set parameters. Results of simulations based on the metrics such as Average delay time (ADT), Average signaling cost, Delivery ratio, Energy consumption, Latency, Network Life time (Nlt), Packet Overhead (PO), Packet loss. The performance of the proposed method provides 19.08%, 25.87%, 31.98%, 26.98%, 31.98%, 26.98% and 23.89% lower Latency, 12.67%, 25.98%, 31.98%, 26.98%, 27.98%, 31.97% and 27.85% lower Packet Overhead and 19.78%, 27.96%, 37.98%, 18.09%, 28.97%, 27.98% and 56.04% higher Delivery ratio compared with the existing methods such as 6LoWPAN-NUM-OHCA-FFA, 6LoWPAN-GTCCF-PSO, 6LoWPAN- DODAG-ACO, 6LoWPAN- MAC-GA-PSO, 6LoWPAN-NCG-DTC-NGIPSA and 6LoWPAN-TDMA-GTS-SHJA algorithms respectively.

Blockchain enabled data security in vehicular networks

Recently, researchers have applied blockchain technology in vehicular networks to take benefit of its security features, such as confidentiality, authenticity, immutability, integrity, and non-repudiation. The resource-intensive nature of the blockchain consensus algorithm makes it a challenge to integrate it with vehicular networks due to the time-sensitive message dissemination requirements. Moreover, most of the researchers have used the Proof-of-Work consensus algorithm, or its variant to add a block to a blockchain, which is a highly resource-intensive process with greater latency. In this paper, we propose a consensus algorithm for vehicular networks named as Vehicular network Based Consensus Algorithm (VBCA) to ensure data security across the network using blockchain that maintains a secured pool of confirmed messages exchanged in the network. The proposed scheme, based on a consortium blockchain, reduces average transaction latency, and increases the number of confirmed transactions in a decentralized manner, without compromising the integrity and security of data. The simulation results show improved performance in terms of confirmed transactions, transaction latency, number of blocks, and block creation time.

Real-Time Scheduling on Hierarchical Heterogeneous Fog Networks

Cloud computing is widely used to support offloaded data processing for applications. However, latency constrained data processing has requirements that may not always be suitable for cloud-based processing. Fog computing brings processing closer to data generation sources, by reducing propagation and data transfer delays. It is a viable alternative for processing tasks with real-time requirements. We propose a scheduling algorithm RTH2S (Real Time Heterogeneous Hierarchical Scheduling) for a set of real-time tasks on a heterogeneous integrated fog-cloud architecture. We consider a hierarchical model for fog nodes, with nodes at higher tiers having greater computational capacity than nodes at lower tiers, though with greater latency from data generation sources. Tasks with various profiles have been considered. For regular profile jobs, we use least laxity first (LLF) to find the preferred fog node for scheduling. For tagged profiles, based on tag values, the jobs are split in order to finish execution before the deadline, or the LLF heuristic is used. Using HPC2N workload traces across 3.5 years of activity, the real-time performance of RTH2S versus comparable algorithms is demonstrated. Our proposed approach is validated using both simulation (to demonstrate scale up) as well as a lab-based testbed.

Size Preference of Live Fish Prey in the Pellet-Consuming Pikeperch

The production of pikeperch in a recirculation aquaculture system (RAS) is of growing importance. However, the use of combined technologies may also be justified, especially in countries with larger pond areas. However, this requires the most effective adaptation of pellet-consuming individuals to pond conditions. Foraging training, a form of environmental enrichment to compensate for the poor environment in hatchery rearing, can play a major role in this. The aim of our study was to investigate the prey size preference already observed in wild pikeperch, during prey capture by intensively reared naive individuals. We investigated predation success, latency, number of attempts during the process, and size distribution, in a total of 152 foraging trials of 38 pikeperch fingerlings (mean TL = 90.65 mm) at three different prey sizes (predator–prey length ratio (PPR): 0.11, 0.22, 0.33). Although predation on medium–large prey was more successful overall, it was achieved in more attempts and with greater latency. Small prey was captured with the fewest attempts. These results suggest that when calculating prey size in the foraging training of pikeperch, it is recommended to use a 0.11–0.22 PPR less than the optimal PPR described for wild individuals.

Metformin mitigates amyloid β1-40-induced cognitive decline via attenuation of oxidative/nitrosative stress and neuroinflammation.

Metformin is an antidiabetic medicine widely used for management of type 2 diabetes with neuroprotective effects and promising potential to attenuate cognitive impairment. The efficacy of metformin in attenuation of Alzheimer's disease (AD) pathology has not been well-documented. Thus, this study was designed to assess protective effect of metformin against Aβ1-40-instigared cognitive impairment. After intra-CA1 microinjection of aggregated Aβ1-40, rats received oral metformin (50 and/or 200mg/kg/day) for two weeks. Cognition function was analyzed in various behavioral tasks besides measurement of hippocampal oxidative stress, apoptosis, and inflammation along with H&E staining and 3-nitrotyrosine (3-NT) immunohistochemistry. Obtained data showed significant improvement of discrimination score in novel object recognition test, higher alternation score in Y maze, greater latency in passive avoidance task, and lower working and reference memory errors in radial arm maze in metformin-treated Aβ-injured group. Moreover, metformin treatment attenuated hippocampal levels of nitrite, MDA, protein carbonyl, ROS, TNFα, GFAP, DNA fragmentation intensity, caspase 3 activity, AChE activity, and increased SOD activity and level of IL-10 as an anti-inflammatory factor. In addition, metformin treatment was associated with lower CA1 neuronal loss and it also decreased intensity of 3-NT immunoreactivity as an indicator of nitrosative stress. Taken together, obtained findings showed neuroprotective and anti-dementia property of metformin in male rats and this may have potential benefit in attenuation of cognitive decline and related complications in patients with neurodegenerative disorders such as AD besides diabetes mellitus.

Single-component flame-retardant and smoke-suppressive epoxy resins enabled by an aluminum/phosphorus/imidazole-containing complex

To simplify the manufacture and address the intrinsic flammability of epoxy resin (EP) products, the single-component, fire-safe EP systems are increasingly in demand. However, current design strategy is difficult to achieve the simultaneous improvement in storage stability, flame retardancy and smoke suppression. Herein, a phosphorus/imidazole-containing, aluminum-based complex (ADIM) was synthesized, and applied as a latent curing agent for EP. The shelf life of EP/ADIM system reached 30 days, and its gel time at 150 °C was only 42 min, indicative of great thermal latency and fast curing rate. EP/ADIM thermoset showed superior flame retardancy, as confirmed by a limiting oxygen index (LOI) of 35.0% and a UL-94 V-0 classification. In addition, the total smoke production and maximum smoke density of EP/ADIM thermoset were 38.7% and 22.3% lower than those of EP thermoset cured by imidazole (EP/IM), demonstrating obviously-enhanced smoke suppression. ADIM inhibited the heat release and smoke generation of the EP matrix via radical capturing and catalytic charring. Moreover, EP/ADIM thermoset exhibited comparable thermal resistance and mechanical properties to EP/IM thermoset. Hence, this work offers an integrated design strategy for creating high-performance, fire-safe, single-component EP with well-preserved mechanical and thermal properties.

In‐Sensor Reservoir Computing Based on Optoelectronic Synapse

Conventional machine vision systems suffer from great data latency and energy consumption in cognitive tasks due to the separated vision sensors, memory units, and processors. In‐sensor computing based on optoelectronic synapses allows efficient computation by directly sensing and processing optical signals. Herein, an optoelectronic synapse based on Au/ZnO:N/IGZO/TiN structure is proposed. It shows uniform optical SET and electrical RESET behaviors, with various light‐tunable plasticity. Furthermore, a 4‐bit reservoir is experimentally implemented on the device, which is ideal to construct in‐sensor reservoir computing (RC) system. By converting spatiotemporal optical signals to higher dimensional feature space, in‐sensor RC has a great advantage in processing sequential visual information. Simulation results demonstrate that the in‐sensor RC system based on the proposed synapse achieves a considerable recognition accuracy (90.45%) for the MNIST dataset with very limited 36‐30‐10 perceptron network, and a 97.14% accuracy for human action classification from sequential vision data based on the Weizmann dataset. This work proves the low training cost and great efficiency for processing spatiotemporal and sequential optical signals, which may pave a new way for future machine vision applications.

Level Scaling and Pulse Regulating to Mitigate the Impact of the Cycle-to-Cycle Variation in Memristor-Based Edge AI System

As a novel nonvolatile device, the memristor has already delivered many of its promises including low computation complexity and high energy efficiency for the edge artificial intelligence (AI) system in Internet of Things (IoT) applications. However, the intrinsic variability of switching behavior of memristors has been a major obstacle to their implementation. In this study, first, with the Al/TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /TiO <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{2-{x}}$ </tex-math></inline-formula> /Al stack structure, memristive crossbar chips are fabricated and tested, and then, we present a model that experimentally demonstrates and quantifies the natural stochasticity of cycle-to-cycle variations. Finally, we propose level scaling and pulse regulating methods to mitigate the adverse impact of cycle-to-cycle variations. The relationship of the level of conductance and cycle-to-cycle variation is studied, and the experiment results show an optimal number of the levels to mitigate the impact of cycle-to-cycle variations in the system. Additionally, the system compresses the number of pulses when the conductance is updated by the pulse stimulus to reduce cycle-to-cycle variations, resulting in the great energy and latency reduction. This work paves the way for the adoption of memristors for more efficient applications for the era of the edge computing in IoT.

Laterality of motor symptom onset and facial expressivity in Parkinson disease using face digitization

ABSTRACT The onset of motor symptoms in Parkinson disease (PD) is typically unilateral. Previous work has suggested that laterality of motor symptoms may also influence non-motor symptoms including cognition and emotion perception. In line with hemispheric differences in emotion processing, we tested whether left side/right brain motor onset was associated with worse expression of facial affect when compared to right side/left brain motor onset. We evaluated movement changes associated with facial affect in 30 patients with idiopathic PD (15 left-sided motor onset, 15 right-sided motor onset) and 20 healthy controls. Participants were videotaped while posing three facial expressions: fear, anger, and happiness. Expressions were digitized and analyzed using software that extracted three variables: two measures of dynamic movement change (total entropy and entropy percent change) and a measure of time to initiate facial expression (latency). The groups did not differ in overall amount of movement change or percentchange. However, left-sided onset PD patients were significantly slower in initiating anger and happiness facial expressions than were right-sided onset PD patients and controls. Our results indicated PD patients with left-sided symptom onset had greater latency in initiating two of three facial expressions, which may reflect laterality effects in intentional behaviour.

Hearing brain evaluated using near-infrared spectroscopy in congenital toxoplasmosis

Congenital toxoplasmosis (CT) is a known cause of hearing loss directly caused by Toxoplasma gondii. Hearing loss might result from sensory, neural, or sensorineural lesions. Early treated infants rarely develop hearing loss, but retinochoroidal lesions, intracranial calcifications and hydrocephalus are common. In this study, we aimed to evaluate the brain evoked hemodynamic responses of CT and healthy infants during four auditory stimuli: mother infant directed speech, researcher infant directed speech, mother reading and researcher recorded. Children underwent Transitionally Evoked Otoacoustic Emission Auditory Testing and Automated Brainstem Auditory Response tests with normal auditory results, but with a tendency for greater latencies in the CT group compared to the control group. We assessed brain hemodynamics with functional near-infrared spectroscopy (fNIRS) measurements from 61 infants, and we present fNIRS results as frequency maps of activation and deactivation for each stimulus. By evaluating infants in the three first months of life, we observed an individual heterogeneous brain activation pattern in response to all auditory stimuli for both groups. Each channel was activated or deactivated in less than 30% of children for all stimuli. There is a need of prospective studies to evaluate if the neurologic or auditory changes course with compromise of children outcomes.

A cooperative resource allocation model for IoT applications in mobile edge computing

With the advancement in the development of the Internet of Things (IoT) technology, as well as the industrial IoT, various applications and services are benefiting from this emerging technology such as smart healthcare systems, virtual realities applications, connected and autonomous vehicles, to name a few. However, IoT devices are known for being limited computation capacities which is crucial to the device’s availability time. Traditional approaches used to offload the applications to the cloud to ease the burden on the end user’s devices, however, greater latency and network traffic issues still persist. Mobile Edge Computing (MEC) technology has emerged to address these issues and enhance the survivability of cloud infrastructure. While a lot of attempts have been made to manage an efficient process of applications offload, many of which either focus on the allocation of computational or communication protocols without considering a cooperative solution. In addition, a single-user scenario was considered. Therefore, we study multi-user IoT applications offloading for a MEC system, which cooperatively considers to allocate both the resources of computation and communication. The proposed system focuses on minimizing the weighted overhead of local IoT devices, and minimize the offload measured by the delay and energy consumption. The mathematical formulation is a typical mixed integer nonlinear programming (MINP), and this is an NP-hard problem. We obtain the solution to the objective function by splitting the objective problem into three sub-problems. Extensive set of evaluations have been performed so as to get the evaluation of the proposed model. The collected results indicate that offloading decisions, energy consumption, latency, and the impact of the number of IoT devices have shown superior improvement over traditional models.

Contrasting mechanisms for hidden hearing loss: Synaptopathy vs myelin defects.

Hidden hearing loss (HHL) is an auditory neuropathy characterized by normal hearing thresholds but reduced amplitudes of the sound-evoked auditory nerve compound action potential (CAP). In animal models, HHL can be caused by moderate noise exposure or aging, which induces loss of inner hair cell (IHC) synapses. In contrast, recent evidence has shown that transient loss of cochlear Schwann cells also causes permanent auditory deficits in mice with similarities to HHL. Histological analysis of the cochlea after auditory nerve remyelination showed a permanent disruption of the myelination patterns at the heminode of type I spiral ganglion neuron (SGN) peripheral terminals, suggesting that this defect could be contributing to HHL. To shed light on the mechanisms of different HHL scenarios observed in animals and to test their impact on type I SGN activity, we constructed a reduced biophysical model for a population of SGN peripheral axons whose activity is driven by a well-accepted model of cochlear sound processing. We found that the amplitudes of simulated sound-evoked SGN CAPs are lower and have greater latencies when heminodes are disorganized, i.e. they occur at different distances from the hair cell rather than at the same distance as in the normal cochlea. These results confirm that disruption of heminode positions causes desynchronization of SGN spikes leading to a loss of temporal resolution and reduction of the sound-evoked SGN CAP. Another mechanism resulting in HHL is loss of IHC synapses, i.e., synaptopathy. For comparison, we simulated synaptopathy by removing high threshold IHC-SGN synapses and found that the amplitude of simulated sound-evoked SGN CAPs decreases while latencies remain unchanged, as has been observed in noise exposed animals. Thus, model results illuminate diverse disruptions caused by synaptopathy and demyelination on neural activity in auditory processing that contribute to HHL as observed in animal models and that can contribute to perceptual deficits induced by nerve damage in humans.

La memoria espacial, y los niveles de BDNF en el hipocampo, disminuyen en ratas adolescentes deprimidas farmacológicamente con reserpina

Los cuadros depresivos en humanos cursan con significativas alteraciones en la memoria espacial. Este trabajo estudió esta función en un modelo animal de depresión. Ratas Wistar (n=28), machos y hembras, fueron administradas con reserpina (0.0 o 1.0 mg/kg/cada 2 días por cuatro días). Luego del tratamiento se evaluó la función motora a través de la prueba de la barra y la respuesta de ansiedad a través de un laberinto elevado en cruz. Posteriormente, los animales fueron entrenados durante una semana (en sesiones diarias de 5 minutos) en un laberinto de múltiples T que indaga la memoria espacial. Luego se repitió la evaluación en el laberinto elevado en cruz y los animales fueron sacrificados para disecar el hipocampo y medir los niveles de BDNF a través de western blot. En la prueba de la barra los animales tratados con reserpina tuvieron una respuesta motora con igual agarre, pero menor movilidad, que los controles. En ambas tomas del laberinto elevado en cruz los animales tratados con reserpina pasaron significativamente menos tiempo en los brazos abiertos y exhibieron una latencia más elevada para entrar por primera vez en los brazos cerrados. Los animales tratados con reserpina tardaron significativamente más tiempo en resolver el laberinto de múltiples T que los controles, y cometieron más errores, efecto que estuvo asociado a niveles menores de BDNF en el hipocampo. Estos resultados sugieren que la reserpina indujo una depresión experimental, sin compromiso motor, que estuvo asociada a déficits en la adqui-sición de información espacial.

Cell-permeable lanthanide-platinum(IV) anti-cancer prodrugs.

Platinum compounds are a vital part of our anti-cancer arsenal, and determining the location and speciation of platinum compounds is crucial. We have synthesised a lanthanide complex bearing a salicylic group (Ln = Gd, Eu) which demonstrates excellent cellular accumulation and minimal cytotoxicity. Derivatisation enabled access to bimetallic lanthanide–platinum(ii) and lanthanide–platinum(iv) complexes. Luminescence from the europium–platinum(iv) system was quenched, and reduction to platinum(ii) with ascorbic acid resulted in a “switch-on” luminescence enhancement. We used diffusion-based 1H NMR spectroscopic methods to quantify cellular accumulation. The gadolinium–platinum(ii) and gadolinium–platinum(iv) complexes demonstrated appreciable cytotoxicity. A longer delay following incubation before cytotoxicity was observed for the gadolinium–platinum(iv) compared to the gadolinium–platinum(ii) complex. Functionalisation with octanoate ligands resulted in enhanced cellular accumulation and an even greater latency in cytotoxicity.

TMOD-23. A NOVEL BRAF V600E LOW-GRADE GLIOMA MOUSE MODEL HIGHLIGHTS EXOMIC AND TUMOR IMMUNE ALTERATIONS AND DIFFERING THERAPEUTIC RESPONSES IN LOW- AND HIGH-GRADE GLIOMAS

Abstract Pediatric low-grade glioma (pLGG), the most common brain cancer in children, is difficult to treat especially at recurrence. The BRAF V600E mutation is the second most common mutation in pLGG, and in a high-risk group for progression is associated with deletion of the tumor suppressor CDKN2A. A better understanding of the factors contributing to progression, in particular the role of the immune infiltrate is needed, but studies have been hindered by the lack of low-grade glioma mouse models. We utilized transgenic mice with a cre-activatable (CA) allele of BRAF V600E to generate endogenous models for low-grade gliomas. We found that BRAF V600E expression cooperates with hemizygous CDKN2A deletion to induce low-grade gliomas, with tumors forming at a greater latency than by homozygous deletion. Cell line derivatives from low-grade lesions continue to grow slower upon orthotopic injection than those we previously derived from high-grade tumors. Murine LGG can progress to higher grade tumors within the mouse lifespan and we observe exomic changes and alterations in the tumor immune infiltrate associated with progression, the details of which will be discussed at the meeting. High-grade cells’ phenotypic changes within in vivo passage are accompanied by exomic changes. The high-grade glioma immune infiltrate is altered by dual MAPK pathway inhibition with dabrafenib and trametinib. Adding dual immune checkpoint inhibition by anti-PD-L1 and anti-CTLA-4 antibodies significantly extends survival of dabrafenib-trametinib dual treatment. Human BRAF V600E mutant tumors reportedly have a higher tumor immune infiltrate than that of BRAF wildtype gliomas, consistent with our murine RESULTS: Here we present a novel model for BRAF V600E mutant gliomas in mice that has a frequent rate of progression, similar to human BRAF V600E mutant gliomas, and an active immune infiltrate in high grade tumors which makes them susceptible to the immunostimulatory effects of dual checkpoint inhibition.

MirroredK‐AryN‐Tree and its efficiency of fault tolerance

SummaryFat‐tree is one of the most commonly used topologies in the interconnection networks of modern supercomputers and datacenters. In a traditional fat‐tree,k‐aryn‐tree for instance, the degree of root switches is less than that of other switches. Fat‐tree is a folded version of a Clos network. A Clos network uses the same degree switches in all stages. However, fat‐tree or Clos network has a high switch cost and great packet latency. This paper introduces a MirroredK‐AryN‐Tree (MiKANT) network and presents switch fault‐tolerant routing algorithms for it. Compared withk‐aryn‐trees and Clos networks, MiKANT connects more compute nodes with fewer switches and links so that it can be implemented at a lower hardware cost, it uses switches that have the same number of ports to keep the regularity, and it shortens the average distance to reduce the packet latency for achieving higher communication performance. We give three simple deadlock‐free switch fault‐tolerant routing algorithms for MiKANT and evaluate their performance. The simulation results show that the proposed algorithms achieve much higher performance than the shortest path routing algorithm. Although MiKANT uses fewer switches and links than fat‐tree, the simulation result shows that it has an almost the same successful routing ratio as the fat‐tree for the switch fault tolerance.

Object recognition is enabled by an experience-dependent appraisal of visual features in the brain’s value system

This paper addresses perceptual synthesis by comparing responses evoked by visual stimuli before and after they are recognized, depending on prior exposure. Using magnetoencephalography, we analyzed distributed patterns of neuronal activity – evoked by Mooney figures – before and after they were recognized as meaningful objects. Recognition induced changes were first seen at 100–120 ​ms, for both faces and tools. These early effects – in right inferior and middle occipital regions – were characterized by an increase in power in the absence of any changes in spatial patterns of activity. Within a later 210–230 ​ms window, a quite different type of recognition effect appeared. Regions of the brain’s value system (insula, entorhinal cortex and cingulate of the right hemisphere for faces and right orbitofrontal cortex for tools) evinced a reorganization of their neuronal activity without an overall power increase in the region. Finally, we found that during the perception of disambiguated face stimuli, a face-specific response in the right fusiform gyrus emerged at 240–290 ​ms, with a much greater latency than the well-known N170m component, and, crucially, followed the recognition effect in the value system regions. These results can clarify one of the most intriguing issues of perceptual synthesis, namely, how a limited set of high-level predictions, which is required to reduce the uncertainty when resolving the ill-posed inverse problem of perception, can be available before category-specific processing in visual cortex. We suggest that a subset of local spatial features serves as partial cues for a fast re-activation of object-specific appraisal by the value system. The ensuing top-down feedback from value system to visual cortex, in particular, the fusiform gyrus enables high levels of processing to form category-specific predictions. This descending influence of the value system was more prominent for faces than for tools, the fact that reflects different dependence of these categories on value-related information.

Robotic telestenting performance in transcontinental and regional pre-clinical models.

This study was conducted to evaluate the association of geographic distance with robotic telestenting performance by comparing performance measures in transcontinental and regional pre-clinical models of telestenting. Robotic telestenting, in which percutaneous coronary intervention (PCI) is performed on a remotely located patient, might improve PCI access, but has not been attempted over vast distances likely required to reach many underserved regions. Telestenting performance was compared in regional (Boston to New York [206 miles]) and transcontinental (Boston to San Francisco [3,085 miles]) ex vivo models of telestenting, wherein a physician in Boston attempted robotic PCI on endovascular simulators in New York and San Francisco, respectively. PCI was attempted over both wired and fifth generation (5G)-wireless networks. Outcome measures included procedural success, procedural time, and perceived latency. Procedural success was achieved in 20 consecutive target lesions in the regional model and in 16 consecutive target lesions in the transcontinental model. The transcontinental model had a greater latency than the regional model over both wired (121.5 ± 2.4 ms vs. 67.8 ± 0.9 ms; p < .001) and 5G-wireless networks (162.5 ± 1.1 ms vs. 86.6 ± 0.6 ms; p < .001), but perceived latencies were graded "imperceptible" in all cases in both models. Transcontinental and regional models did not have significantly different procedural times over wired (4.1 ± 1.9 min vs. 9.0 ± 7.1 min; p = .051) or 5G-wireless (3.0 ± 0.6 vs. 6.3 ± 1.2; p = .36) networks. Transcontinental robotic manipulation of coronary devices is now possible and was not associated with adverse performance compared to robotic telestenting conducted regionally.