Longer Latency Research Articles

Closed-Loop Optogenetic Perturbation of Macaque Oculomotor Cerebellum: Evidence for an Internal Saccade Model.

Internal models are essential for the production of accurate movements. The accuracy of saccadic eye movements is thought to be mediated by an internal model of oculomotor mechanics encoded in the cerebellum. The cerebellum may also be part of a feedback loop that predicts the displacement of the eyes and compares it to the desired displacement in real time to ensure that saccades land on target. To investigate the role of the cerebellum in these two aspects of saccade production, we delivered saccade-triggered light pulses to channelrhodopsin-2-expressing Purkinje cells in the oculomotor vermis (OMV) of two male macaque monkeys. Light pulses delivered during the acceleration phase of ipsiversive saccades slowed the deceleration phase. The long latency of these effects and their scaling with light pulse duration are consistent with an integration of neural signals at or downstream of the stimulation site. In contrast, light pulses delivered during contraversive saccades reduced saccade velocity at short latency and were followed by a compensatory reacceleration which caused gaze to land on or near the target. We conclude that the contribution of the OMV to saccade production depends on saccade direction; the ipsilateral OMV is part of a forward model that predicts eye displacement, whereas the contralateral OMV is part of an inverse model that creates the force required to move the eyes with optimal peak velocity for the intended displacement.

Study of the peripheral and central auditory pathways in patients with mucopolysaccharidosis

ObjectiveTo investigate the peripheral and central auditory pathways in mucopolysaccharidosis (MPS) individuals. MethodThe research sample comprised 15 individuals (one female and 14 males), aged 8 to 46 years. The following procedures were used: medical history survey, otoscopy, speech and pure-tone threshold audiometry, acoustic immittance measures, and central auditory pathway assessment with brainstem auditory evoked potentials (BAEP) and long-latency auditory evoked potentials (LLAEP). ResultsThe pure-tone audiometry identified hearing loss in 13 individuals, and more than 90 % of the hearing loss was sensorineural. The degree of hearing loss was between mild to moderately severe with descendent configuration. Type A tympanogram predominated, and acoustic reflexes were present according to the types and degrees of hearing loss. Among the individuals with abnormal BAEP, longer wave III and V absolute latencies were the main findings. In addition, the unilateral absence of wave I was observed in two cases. In the LLAEP, longer latencies were observed in 14 individuals, and the most impaired components were the P1 and P3 in children and adolescents and the P2, N2 and P3 in adult individuals. ConclusionThe peripheral auditory pathway assessment revealed a predominantly sensorineural hearing loss, affecting mainly high frequencies, and in the central pathway was observed abnormal brainstem and cortical auditory processing in individuals with MPS.

Synchrony in auditory 40-Hz gamma oscillations increases in older age and correlates with hearing abilities and cortical GABA levels

Abstract Synchronized 40-Hz gamma oscillations in specific sensory and higher-order thalamocortical networks provide a neural mechanism for feature binding. Aging-related changes in gamma oscillations may cause deficits in auditory feature binding, contributing to impaired speech-in-noise perception. Gamma synchrony is controlled through inhibitory mechanisms mediated by the neurotransmitter γ-aminobutyric acid (GABA), which has been shown to decline in aging. This study investigated aging-related changes in gamma oscillations and how they relate to auditory function and cortical GABA levels. Magnetoencephalograms of 40-Hz auditory steady-state responses (ASSRs) were recorded in young and older adults by presenting amplitude-modulated tones in quiet and mixed with concurrent multi-talker babble noise. Responses in the quiet condition had longer latencies and more prominent amplitudes, indicating the 40-Hz ASSRs in noise were dominated by a sensory component and in quiet by a component involved in higher-order processing. The ASSR amplitudes increased in older adults under both stimulus conditions. However, larger ASSR amplitudes were associated with more severe hearing and speech-in-noise loss only in the noise condition. This suggests the aging-related increase in synchrony of sensory gamma oscillations has a detrimental effect on auditory processing. It may cause increased interference between competing sounds in the central auditory system, making it difficult for the aging auditory system to separate speech features from noise and bind them into a distinct perceptual object. Also in older adults, larger amplitudes of the 40-Hz ASSRs in the quiet condition were associated with higher left auditory cortex GABA concentrations measured with magnetic resonance spectroscopy, supporting GABA’s role in internally generated gamma synchrony in aging.

Preceding Benign Paroxysmal Positional Vertigo as a Trigger for Persistent Postural-Perceptual Dizziness: Which Clinical Predictors?

Persistent postural-perceptual dizziness (PPPD) is a syndrome described as secondary, when it is the consequence of an organic disorder (s-PPPD), or primary, when no somatic triggers can be identified. We evaluated a group of patients diagnosed as s-PPPD, with Benign Positional Paroxysmal Vertigo (BPPV) as the main somatic trigger, with the aim of identifying the predictive clinical elements of evolution towards PPPD. Retrospective case review. Tertiary referral center. We evaluated 126 patients diagnosed with PPPD; 54 patients were classified as p-PPPD (43%) and 72 as s-PPPD (57%). Of these, 51 patients had BPPV as a somatic trigger of PPPD, and in this group, we evaluated the prevalence of some clinical features (age, sex, latency between the onset of BPPV and the final diagnosis, recurrence of BPPV and the presence of migraine headache) for comparison with a group of patients who suffered from BPPV without an evolution towards PPPD (control group). In the group with PPPD secondary to BPPV, we found a significantly higher mean age and a longer latency between the onset of BPPV and the final diagnosis compared to the control group. No difference between the two groups was found regarding sex, recurrence rate and the presence of migraine headache. The parameters most involved as potential precipitants of PPPD after BPPV were the age of the patients and a long latency between the onset of BPPV and the final diagnosis; the mean age of the subjects who developed PPPD following BPPV was significantly higher. These findings lead us to emphasize the importance of the early identification and treatment of BPPV, especially in older patients.

Subcortical Auditory Processing and Speech Perception in Noise Among Individuals With and Without Extended High-Frequency Hearing Loss.

The significance of extended high-frequency (EHF) hearing (> 8 kHz) is not well understood so far. In this study, we aimed to understand the relationship between EHF hearing loss (EHFHL) and speech perception in noise (SPIN) and the associated physiological signatures using the speech-evoked frequency-following response (sFFR). Sixteen young adults with EHFHL and 16 age- and sex-matched individuals with normal hearing participated in the study. SPIN performance in right speech-right noise, left speech-left noise, and binaural listening conditions was evaluated using the Turkish Matrix Test. Additionally, subcortical auditory processing was assessed by recording sFFRs elicited by 40-ms /da/ stimuli. Individuals with EHFHL demonstrated poorer SPIN performances in all listening conditions (p < .01). Longer latencies were observed in the V (onset) and O (offset) peaks in these individuals (p ≤ .01). However, only the V/A peak amplitude was found to be significantly reduced in individuals with EHFHL (p < .01). Our findings highlight the importance of EHF hearing and suggest that EHF hearing should be considered among the key elements in SPIN. Individuals with EHFHL show a tendency toward weaker subcortical auditory processing, which likely contributes to their poorer SPIN performance. Thus, routine assessment of EHF hearing should be implemented in clinical settings, alongside the evaluation of standard audiometric frequencies (0.25-8 kHz).

Ambulation for latency during expectant management of preterm prelabor rupture of membranes: a randomized controlled trial (AMBLE)

BackgroundIndividuals hospitalized with preterm prelabor rupture of the membranes (PPROM) are often advised to limit their activity or adhere to bedrest. Some evidence suggests that greater activity is associated with longer latency and improved outcomes, but no high-quality evidence from a randomized-controlled trial exists. ObjectiveTo evaluate whether encouragement to ambulate at least 2,000 steps daily impacts latency among individuals with PPROM compared with usual care. Study DesignMultisite unblinded, two-arm randomized trial of individuals at 23 0/7 to 35 0/7 weeks gestation undergoing inpatient expectant management of PPROM with planned delivery at least 7 days away. Each participant wore a Fitbit InspireTM that tracked steps. The intervention arm was encouraged (verbal and Fitbit-based reminders) to reach a goal of 2,000 steps per day. The usual care arm was allowed ad lib activity with no step goal or reminders. The primary outcome was latency (days) from randomization to delivery. Secondary analyses included composite neonatal and maternal clinical outcomes and maternal mental health survey results. Statistical analyses were intent-to-treat under a Bayesian framework using neutral priors (a priori assumed 50:50 likelihood of longer latency in either arm). 100 participants were required to have 80% power to demonstrate a 4-day difference in latency with 75% certainty (Bayesian probability). ResultsAmong 163 eligible individuals, 100 (61%) were randomized, and after loss to follow-up, 95 were analyzed. Gestational age at randomization was 29 3/7 weeks (interquartile range [IQR] 26 2/7, 31 5/7) in the intervention arm and 27 4/7 weeks (IQR 25 4/7, 29 6/7) in the usual care arm. Median step counts were 1,690/day in the intervention arm (IQR 1,031-2,641) and 1,338/day in the usual care arm (IQR 784-1,913). Median days of latency were 9 days in the intervention arm (IQR 4-17) and 6 days in the usual care arm (IQR 2-14). The primary analysis indicated a 65% posterior probability that the intervention increased latency versus usual care (posterior relative risk [RR] 1.09; 95% credible interval [CrI], 0.70-1.71). The RR for composite neonatal adverse outcome was 0.55 (95% CrI 0.32-0.82) with 99% posterior probability of intervention benefit and for composite maternal adverse outcome was 0.94 (95% CrI 0.72-1.20), with 70% posterior probability of intervention benefit. There was a 94% posterior probability of the intervention arm having a greater decrease in maternal stress score from baseline to before delivery compared with the usual care arm (mean arm difference 3.24 points [95% CrI -7.23-0.79]). Adjustment for gestational age at randomization had minimal impact on secondary outcome results. ConclusionsIndividuals with PPROM randomized to encouragement to ambulate had a longer latency to delivery and improved neonatal and mental health outcomes with similar maternal clinical outcomes compared to usual care.

Vestibular evoked myogenic potentials and videonystagmography findings in type 2 diabetes mellitus patients with and without polyneuropathy

BackgroundVestibular impairment is a common pathology in patients with type 2 diabetes mellitus (DM) due to ischemia of the vestibular end organs and lysis of the myelin of the vestibular nerve. We aimed to evaluate function of the vestibular end organs and vestibular nerve in patients with type 2 DM with polyneuropathy and compare results to those of the patients without polyneuropathy.MethodThe participants consisted of three groups: thirty patients with type 2 diabetes mellitus without polyneuropathy (DM), thirty patients with type 2 diabetes mellitus with polyneuropathy (DPN), and thirty healthy non-diabetic individuals as the control group. Clinical examination, videonystagmography, cervical vestibular evoked myogenic potential(cVEMP), ocular vestibular evoked myogenic potential (oVEMP), Gans Sensory Organization Performance (SOP) test, and nerve conduction study were all performed on all groups.ResultsP1 and N1 cVEMP latencies and n1 and p1 oVEMP latencies were statistically significantly delayed in both the DM and DPN groups than the control. Also, amplitudes of P1-N1 and n1-p1 were statistically significantly lower in the DM and DPN groups than the control group. DPN patients had longer latencies and lower amplitude of the cVEMP and oVEMP response compared to diabetes patients without neuropathy. There was a statistically significant prevalence of BPPV in the DPN group compared to the control and DM groups. DPN included the following: 4 (13.3%) had vestibular pattern, 12 had polyneuropathic pattern, and 5 (16.7%) had vestibular and polyneuropathic pattern as regards the Gans Sensory Organization Performance (SOP) test.ConclusionVEMP is considered a promising objective tool in the assessment of the vestibular end organ disorders in patients with type 2 DM with and without polyneuropathy. Diabetics with prominent diabetic polyneuropathy showed higher vestibular impairment than diabetics without DPN, which may increase the risk of falling.

Fault-Seg-LNet: A method for seismic fault identification based on lightweight and dynamic scalable network

Improving the precision and efficiency of fault interpretation is of great significance for assisting in the search for oil-gas reservoir. At present, seismic image segmentation places more emphasis on the pursuit of model precision, while ignoring severe memory consumption and longer latency. Therefore, this paper proposes the seismic fault identification method based on lightweight and dynamic scalable network to assist in fault interpretation for actual geophysical prospecting work. Specifically, the fault identification model Fault-Seg-LNet based on multi-paths learning framework is proposed to connect convolutional streams in parallel from high-resolution to low-resolution, which can explicitly maintain high-resolution feature representation instead of restoring resolution from low-scale feature mapping. The multi-paths with multi-scales interaction (MPMSI) module is proposed to achieve repeated multi-scales feature interaction, which can strengthen the expression ability of the network in capturing fine-grained feature and global feature. The dynamic scalable paradigm is proposed to dynamically adjust the input resolution, network width and depth, which can achieve superior model segmentation precision while maintaining low complexity and high efficiency. Experimental results on synthetic dataset and field dataset show that the seismic fault identification method based on lightweight and dynamic scalable network can achieve the tradeoff between model precision and efficiency, and can locate and segment fault with different scales on seismic images.

Auditory central pathways in children and adolescents with multiple sclerosis.

Multiple sclerosis (MS) is an inflammatory demyelinating disease. Auditory evoked potential studies have demonstrated conduction and neural processing deficits in adults with MS, but little is known about the electrophysiological responses in children and adolescents. to evaluate the central auditory pathway with brainstem auditory evoked potentials (BAEP) and long-latency auditory evoked potentials (LLAEP) in children and adolescents with MS. The study comprised 17 individuals with MS, of both sexes, aged 9 to 18 years, and 17 healthy volunteers, matched for age and sex. All individuals had normal hearing and no middle ear impairments. They were assessed with click-BAEP and LLAEP through oddball paradigm and tone-burst stimuli. Abnormal responses were observed in 60% of electrophysiologic assessments of individuals with MS. In BAEP, 58.82% of MS patients had abnormal responses, with longer wave V latency and therefore longer III-V and I-V interpeak latencies than healthy volunteers. In LLAEP, 52.94% of MS patients had abnormal responses. Although statistical differences were found only in P2-N2 amplitude, MS patients had longer latencies and smaller amplitudes than healthy volunteers in all components. Children and adolescents with MS had abnormal BAEP responses, with delayed neural conduction between the cochlear nucleus and the lateral lemniscus. Also, abnormal LLAEP results suggest a decrease in neural processing speed and auditory sensory discrimination response.

Exposure to petroleum-derived and biopolymer microplastics affect fast start escape performance and aerobic metabolism in a marine fish

Evidence suggests that petroleum-derived polymers can impact marine organisms however, little is understood about whether biopolymers affect the behaviour and physiology of marine teleost fish. The aim of this research was to examine the potential effects of microplastics from a petroleum-derived polymer, (polyethylene, PE), and a biopolymer, (edible food coating EFC) on the escape performance, routine swimming, and aerobic metabolism of Forsterygion capito (the mottled triplefin). PE exposure negatively affected fish through longer latencies (∼25 % slower to respond), slower maximum speeds and higher responsiveness in escape performance compared to control fish. Furthermore, fish exposed to PE displayed slower mean speeds and reduced the distance travelled by ∼25 %. After an exhaustive challenge, PE-exposed fish showed higher excess post-exercise oxygen consumption during recovery, compared to control fish. By contrast, EFC exposure only negatively affected maximum speed during an escape. Directionality and mean speed in escape performance, metabolic rate and recovery time were unaffected by biopolymer exposure. With the ever-increasing number of microplastics in the ocean, a shift to biodegradable polymers may be beneficial to marine organisms due to the smaller effect found when compared to petroleum-derived polymers in this study. As a central tool for conservation, this study represents a significant advance to predict the impact of microplastics on wild fish populations.

Sleep disorders after COVID-19 in Czech population: Post-lockdown national online survey

ObjectiveThis study aimed to determine the frequency, type, and correlates of a broad spectrum of sleep disorders in adults with COVID-19 up to 32 months after infection. MethodsWe conducted a national online survey (Jun 2021–Dec 2022), gathering information on COVID-19 diagnosis, acute disease course, and the subsequent development of sleep disorders from 1507 respondents (mean age 44.5 ± 13.1 years, 64.1% women). Results81.3% (1223) reported at least one sleep difficulty that either worsened or first appeared with COVID-19. Females reported a higher number of symptoms (2.03 ± 1.44 versus 1.72 ± 1.43 in men, p < 0.0001). Most common were insomnia symptoms (59.4%), followed by night sweats (38.4%), hypersomnolence (33.3%), vivid dreams or nightmares (26.4%), restless leg syndrome (RLS) (22.8%), and sleep-related breathing disorders (11.1%). All symptoms were associated with a more severe acute disease. A mild decreasing trend in the persistence of sleep symptoms with a longer latency since infection was observed, with 66.7% reporting at least half of their symptoms present at 3–5 months after acute infection, compared to 64.9% at 6–8 months, and 62.4% at 9–11 months (p = 0.0427). However, among those after 12 or more months, over half of the symptoms persisted in 69.5%. The frequency of vivid dreams and nightmares increased in association with COVID-19 in 32.9% (p < 0.001). 9.4% (141) reported new-onset or increased parasomnic manifestations after the infection. ConclusionsOur research shows that sleep disturbances are a common and persistent manifestation of COVID-19 that affects a large proportion of the population and deserves careful monitoring.

Impairment of oculomotor functions in patients with early to advanced amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) can result into an incomplete locked in state (iLIS), in which communication depends on eye tracking computer devices. Oculomotor function impairments in ALS have been reported, but there is little research, particularly with respect to patients in iLIS. In the present study, we compared reflexive and executive oculomotor function by means of an eye tracking test battery between three groups: advanced ALS patients in iLIS (n = 22), patients in early to middle ALS stages (n = 44) and healthy subjects (n = 32). Patients with ALS showed significant deteriorations in oculomotor functions, with stronger impairments in iLIS. More specifically, ALS patients produced visually guided prosaccades with longer latencies and more frequent hypometria compared to healthy subjects. Longest latencies were obtained in iLIS patients, with a stronger prolongation for vertical than for horizontal prosaccades. ALS patients made more antisaccade errors and generated antisaccades with longer latencies. Smooth pursuit was also impaired in ALS. In the earlier ALS stages, bulbar onset patients presented stronger antisaccade and smooth pursuit deficits than spinal onset patients. Our findings reveal a relevant deterioration of important oculomotor functions in ALS, which increases in iLIS. It includes impairments of reflexive eye movements to loss of executive inhibitory control, indicating a progressing pathological involvement of prefrontal, midbrain and brainstem areas. The assessment of oculomotor functions may therefore provide clinically relevant bio- and progression marker, particularly in advanced ALS.

Spontaneous and Visual Stimulation Evoked Firing Sequences Are Distinct Under Desflurane Anesthesia.

Recurring spike sequences are thought to underlie cortical computations and may be essential for information processing in the conscious state. How anesthesia at graded levels may influence spontaneous and stimulus-related spike sequences in visual cortex has not been fully elucidated. We recorded extracellular single-unit activity in the rat primary visual cortex in vivo during wakefulness and three levels of anesthesia produced by desflurane. The latencies of spike sequences within 0-200ms from the onset of spontaneous UP states and visual flash-evoked responses were compared. During wakefulness, spike latency patterns linked to the local field potential theta cycle were similar to stimulus-evoked patterns. Under desflurane anesthesia, spontaneous UP state sequences differed from flash-evoked sequences due to the recruitment of low-firing excitatory neurons to the UP state. Flash-evoked spike sequences showed higher reliability and longer latency when stimuli were applied during DOWN states compared to UP states. At deeper levels, desflurane altered both UP state and flash-evoked spike sequences by selectively suppressing inhibitory neuron firing. The results reveal desflurane-induced complex changes in cortical firing sequences that may influence visual information processing.

Isolated Sixth Nerve Palsy and COVID-19: A Recurrent Case in a 7-Month-Old Child and Analysis of Reported Cases.

With the SARS-CoV-2 pandemic (COVID-19), data on central and peripheral nervous system involvement, including those causing cranial nerve 6 (CN6) palsy, have been limited to case reports. To extract clinically relevant features of COVID-19-related CN6 palsy, we report on a recurrent pediatric case and analysis of reported cases associated with infection or immunization. A PubMed search revealed 18 cases of isolated CN6 palsy in addition to the index case (n = 19). Clinical characteristics, workup, and temporal associations between systemic symptoms onset or vaccination, symptoms onset, and resolution were compiled and analyzed. The median age of CN6 onset was 43 years (interquartile range [IQR]: 28-52). Sixteen cases (84.2%) were associated with COVID-19 illness and 3 (15.8%) were associated with COVID-19 vaccination. Four cases (23.5%) had positive neuroimaging findings. The median latency from first COVID-19 symptoms or vaccination to onset of CN6 palsy was 6 days (IQR: 2.3-16), and the median time from onset to resolution was 30 days (IQR: 14-60). Latency to onset of CN6 palsy was significantly and directly associated with time to resolution (R 2 = 0.401, P = 0.010). Patients who had a positive SARS-CoV-2 antibody test had significantly longer days from symptoms to onset (6.0 vs 24.5, P = 0.030), and patients with a positive SARS-CoV-2 polymerase chain reaction test had a significantly shorter time to resolution (17.50 vs 90, P = 0.042). Isolated CN6 palsy from COVID-19 is rare, can occur in infants as young as 7 months, and can be recurrent. Longer latency from systemic symptoms onset portends greater recovery times, and this relationship may reflect multiple mechanisms by which COVID-19 (and/or an immune response thereto) causes cranial neuropathies with direct clinical relevance.

Genetic Ablation of Dentate Hilar Somatostatin-Positive GABAergic Interneurons is Sufficient to Induce Cognitive Impairment.

Aging is often associated with a decline in cognitive function. A reduction in the number of somatostatin-positive (SOM+) interneurons in the dentate gyrus (DG) has been described in cognitively impaired but not in unimpaired aged rodents. However, it remains unclear whether the reduction in SOM + interneurons in the DG hilus is causal for age-related cognitive dysfunction. We hypothesized that hilar SOM+ interneurons play an essential role in maintaining cognitive function and that a reduction in the number of hilar SOM + interneurons might be sufficient to induce cognitive dysfunction. Hilar SOM+ interneurons were ablated by expressing a diphtheria toxin transgene specifically in these interneurons, which resulted in a reduction in the number of SOM+ /GAD-67+ neurons and dendritic spine density in the DG. C-fos and Iba-1 immunostainings were increased in DG and CA3, but not CA1, and BDNF protein expression in the hippocampus was decreased. Behavioral testing showed a reduced recognition index in the novel object recognition test, decreased alternations in the Y maze test, and longer latencies and path lengths in the learning and reversal learning phases of the Morris water maze. Our results show that partial genetic ablation of SOM+ hilar interneurons is sufficient to increase activity in DG and CA3, as has been described to occur with aging and to induce an impairment of learning and memory functions. Thus, partial ablation of hilar SOM + interneurons may be a significant contributing factor to age-related cognitive dysfunction. These mice may also be useful as a cellularly defined model of hippocampal aging.

Mechanism of Robo1 in the pentylenetetrazol-kindled epilepsy mouse model.

The neural network hypothesis is one of the important pathogenesis of drug-resistant epilepsy. Axons guide molecules through synaptic remodeling and brain tissue remodeling, which may result in the formation of abnormal neural networks. Therefore, axon guidance plays a crucial role in disease progression. However, although Robo1 is one of the important components of axon guidance, the role of Robo1 in epilepsy remains unclear. In this study, we aimed to explore the mechanism of Robo1 in epilepsy. Male adult C57BL/6 mice were intraperitoneally injected with pentylenetetrazol to establish an epilepsy model. Lentivirus (LV) was given via intracranial injection 2 weeks before pentylenetetrazol injection. Different expressions of Robo1 between the control group, LV-mediated Robo1 short hairpin RNA group, empty vector control LV group, and normal saline group were analyzed using Western blot, immunofluorescence staining, Golgi staining, and video monitoring. Robo1 was increased in the hippocampus in the pentylenetetrazol-induced epilepsy mouse model; lentiviral Robo1 knockdown prolonged the latency of seizure and reduced the seizure grade in mice and resulted in a decrease in dendritic spine density, while the number of mature dendritic spines was maintained. We speculate that Robo1 has been implicated in the development and progression of epilepsy through its effects on dendritic spine morphology and density. Epileptic mice with Robo1 knockdown virus intervention had lower seizure grade and longer latency. Follow-up findings suggest that Robo1 may modulate seizures by affecting dendritic spine density and morphology. Downregulation of Robo1 may negatively regulate epileptogenesis by decreasing the density of dendritic spines and maintaining a greater number of mature dendritic spines.

SPIDEN: deep Spiking Neural Networks for efficient image denoising.

In recent years, Deep Convolutional Neural Networks (DCNNs) have outreached the performance of classical algorithms for image restoration tasks. However, most of these methods are not suited for computational efficiency. In this work, we investigate Spiking Neural Networks (SNNs) for the specific and uncovered case of image denoising, with the goal of reaching the performance of conventional DCNN while reducing the computational cost. This task is challenging for two reasons. First, as denoising is a regression task, the network has to predict a continuous value (i.e., the noise amplitude) for each pixel of the image, with high precision. Moreover, state of the art results have been obtained with deep networks that are notably difficult to train in the spiking domain. To overcome these issues, we propose a formal analysis of the information conversion processing carried out by the Integrate and Fire (IF) spiking neurons and we formalize the trade-off between conversion error and activation sparsity in SNNs. We then propose, for the first time, an image denoising solution based on SNNs. The SNN networks are trained directly in the spike domain using surrogate gradient learning and backpropagation through time. Experimental results show that the proposed SNN provides a level of performance close to the state of the art with CNN based solutions. Specifically, our SNN achieves 30.18 dB of signal-to-noise ratio on the Set12 dataset, which is only 0.25 dB below the performance of the equivalent DCNN. Moreover we show that this performance can be achieved with low latency, i.e., using few timesteps, and with a significant level of sparsity. Finally, we analyze the energy consumption for different network latencies and network sizes. We show that the energy consumption of SNNs increases with longer latencies, making them more energy efficient compared to CNNs only for very small inference latencies. However, we also show that by increasing the network size, SNNs can provide competitive denoising performance while reducing the energy consumption by 20%.

Why is it difficult for children and adults to follow a person's eye gaze in polynomial social relationships with compound audio-visual stimuli: An eye-tracking study.

Acquiring triadic social interactions could facilitate language and communication skills in early infancy. However, studies have rarely investigated polynomial relationships, defined as relationships among the self, two or more people, and objects. During the development from a child to an adult, the responsiveness to a preferred stimulus modality changes from visual to auditory dominance. Nevertheless, how people observe compound visual stimuli in polynomial social relationships and why it is difficult to ignore auditory cues remain unclear. Moreover, there is a need to identify differences between children's and adults' observing latencies in the time to the first fixation when detecting a stimulus. This study examined whether participants (24 adults and 19 children) demonstrated similar gaze patterns under triadic and polyadic conditions. The participants observed a target visual stimulus looked at by a face stimulus while we presented spoken names, either congruent or incongruent with the target visual stimulus. The results indicated that when the number of people in social relationships increased, children and adults decreased fixations on the target face and the stimulus and showed a shorter mean fixation duration on the face. Moreover, children had longer latencies and more fixation errors for the target stimulus, which might reflect children's difficulties in communicating with others. We expect that understanding children's communication transition from triadic to polynomial social relationships with audio-visual stimulus congruencies would facilitate understanding language development and social communication patterns.

Insights from the judgment bias paradigm: Social group and tank size does not affect mental state in female guppies.

Optimal holding conditions are key to animal welfare. How stressful husbandry is perceived by the animal can be determined via assessment of an animal's mental state - where it is positioned on the continuum between optimistic and pessimistic state - and can be measured using the judgment bias paradigm. In this test, individuals are trained to distinguish a rewarded from an unrewarded cue before being presented an ambiguous, intermediate cue. The response time to the ambiguous cue is then indicative of mental state. A shorter latency suggests a more positive (optimistic) mental state, a longer latency a more negative (pessimistic) mental state. Here, we used the judgment bias paradigm to assess the impact of standard laboratory housing conditions on the mental states of female guppies (Poecilia reticulata). As it is debated which holding conditions confer optimal welfare, we tested the impact of husbandry on mental state by keeping animals for three weeks in small or large social groups in either small or large tanks. We found that the different standard housing conditions we used did not lead to differences in mental state. As an unexpected side result, we found that female guppies seem lateral. Our findings of comparable mental state across housing conditions suggest that guppies either perceive the tested conditions as equally stressful or alternatively, that guppies are relatively resilient to the combination of group and tank sizes tested in this study. We conclude that the judgment bias paradigm can be a useful tool to assess fish welfare. This article is protected by copyright. All rights reserved.

Risk Factors for Adverse Maternal Outcomes among Patients with Severe Preeclampsia Before 34 Weeks.

This study aimed to characterize rates of maternal morbidity associated with early (<34 wk) preeclampsia with severe features and to determine factors associated with developing these morbidities. Retrospective cohort study of patients with early preeclampsia with severe features at a single institution from 2013 to 2019. Inclusion criteria were admission between 23 and 34 weeks and diagnosis of preeclampsia with severe features. Maternal morbidity defined as death, sepsis, intensive care unit (ICU) admission, acute renal insufficiency (acute kidney injury [AKI]), postpartum (PP) dilation and curettage, PP hysterectomy, venous thromboembolism (VTE), PP hemorrhage (PPH), PP wound infection, PP endometritis, pelvic abscess, PP pneumonia, readmission, and/or need for blood transfusion. Death, ICU admission, VTE, AKI, PP hysterectomy, sepsis, and/or transfusion of >2 units were considered severe maternal morbidity (SMM). Simple statistics used to compare characteristics among patients experiencing any morbidity and those not. Poisson regression used to assess relative risks. Of 260 patients included, 77 (29.6%) experienced maternal morbidity and 16 (6.2%) experienced severe morbidity. PPH (n = 46, 17.7%) was the most common morbidity, although 15 (5.8%) patients were readmitted, 16 (6.2%) needed a blood transfusion, and 14 (5.4%) had AKI. Patients who experienced maternal morbidity were more likely to be advanced maternal age, have preexisting diabetes, have multiples, and deliver nonvaginally (all ps < 0.05). Diagnosis of preeclampsia < 28 weeks or longer latency from diagnosis to delivery were not associated with increased maternal morbidity. In regression models, the relative risk of maternal morbidity remained significant for twins (adjusted odds ration [aOR]: 2.57; 95% confidence interval [CI]: 1.67, 3.96) and preexisting diabetes (aOR: 1.64; 95% CI: 1.04, 2.58), whereas attempted vaginal delivery was protective (aOR: 0.53; 95% CI: 0.30, 0.92). In this cohort, more than 1 in 4 patients diagnosed with early preeclampsia with severe features experienced maternal morbidity, whereas 1 in 16 patients experienced SMM. Twins and pregestational diabetes were associated with higher risk of morbidity, whereas attempted vaginal delivery was protective. These data may be helpful in promoting risk reduction and counseling patients diagnosed with early preeclampsia with severe features. · One in four patients diagnosed with preeclampsia w/ severe features experienced maternal morbidity.. · One in 16 patients with preeclampsia w/ severe features experienced severe maternal morbidity.. · Factors most associated with morbidity/severe morbidity were twins and pregestational diabetes.. · Patients who attempted vaginal delivery appeared to have a lower rate of morbidity..