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Frontiers in Robotics and AI 2024Soft robots exhibit complex nonlinear dynamics with large degrees of freedom, making their modelling and control challenging. Typically, reduced-order models in time or...
Soft robots exhibit complex nonlinear dynamics with large degrees of freedom, making their modelling and control challenging. Typically, reduced-order models in time or space are used in addressing these challenges, but the resulting simplification limits soft robot control accuracy and restricts their range of motion. In this work, we introduce an end-to-end learning-based approach for fully dynamic modelling of any general robotic system that does not rely on predefined structures, learning dynamic models of the robot directly in the visual space. The generated models possess identical dimensionality to the observation space, resulting in models whose complexity is determined by the sensory system without explicitly decomposing the problem. To validate the effectiveness of our proposed method, we apply it to a fully soft robotic manipulator, and we demonstrate its applicability in controller development through an open-loop optimization-based controller. We achieve a wide range of dynamic control tasks including shape control, trajectory tracking and obstacle avoidance using a model derived from just 90 min of real-world data. Our work thus far provides the most comprehensive strategy for controlling a general soft robotic system, without constraints on the shape, properties, or dimensionality of the system.
PubMed: 38899065
DOI: 10.3389/frobt.2024.1403733 -
BioRxiv : the Preprint Server For... Jun 2024Many psychiatric disorders involve excessive avoidant or defensive behavior, such as avoidance in anxiety and trauma disorders or defensive rituals in...
OBJECTIVE
Many psychiatric disorders involve excessive avoidant or defensive behavior, such as avoidance in anxiety and trauma disorders or defensive rituals in obsessive-compulsive disorders. Developing algorithms to predict these behaviors from local field potentials (LFPs) could serve as foundational technology for closed-loop control of such disorders. A significant challenge is identifying the LFP features that encode these defensive behaviors.
APPROACH
We analyzed LFP signals from the infralimbic cortex and basolateral amygdala of rats undergoing tone-shock conditioning and extinction, standard for investigating defensive behaviors. We utilized a comprehensive set of neuro-markers across spectral, temporal, and connectivity domains, employing SHapley Additive exPlanations for feature importance evaluation within Light Gradient-Boosting Machine models. Our goal was to decode three commonly studied avoidance/defensive behaviors: freezing, bar-press suppression, and motion (accelerometry), examining the impact of different features on decoding performance.
MAIN RESULTS
Band power and band power ratio between channels emerged as optimal features across sessions. High-gamma (80-150 Hz) power, power ratios, and inter-regional correlations were more informative than other bands that are more classically linked to defensive behaviors. Focusing on highly informative features enhanced performance. Across 4 recording sessions with 16 subjects, we achieved an average coefficient of determination of 0.5357 and 0.3476, and Pearson correlation coefficients of 0.7579 and 0.6092 for accelerometry jerk and bar press rate, respectively. Utilizing only the most informative features revealed differential encoding between accelerometry and bar press rate, with the former primarily through local spectral power and the latter via inter-regional connectivity. Our methodology demonstrated remarkably low time complexity, requiring <110 ms for training and <1 ms for inference.
SIGNIFICANCE
Our results demonstrate the feasibility of accurately decoding defensive behaviors with minimal latency, using LFP features from neural circuits strongly linked to these behaviors. This methodology holds promise for real-time decoding to identify physiological targets in closed-loop psychiatric neuromodulation.
PubMed: 38895388
DOI: 10.1101/2024.06.06.597165 -
BioRxiv : the Preprint Server For... Jun 2024Social phobia is highly detrimental for social behavior, mental health, and productivity. Despite much previous research, the behavioral and neurobiological mechanisms...
Social phobia is highly detrimental for social behavior, mental health, and productivity. Despite much previous research, the behavioral and neurobiological mechanisms associated with the development of social phobia remain elusive. To investigate these issues, the present study implemented a mouse model of social threat conditioning in which mice received electric shock punishment upon interactions with unfamiliar conspecifics. This resulted in immediate reductions in social behavior and robust increases in defensive mechanisms such as avoidance, freezing, darting, and ambivalent stretched posture. Furthermore, social deficits lasted for prolonged periods and were independent of contextual settings, sex variables, or particular identity of the social stimuli. Shedding new light into the neurobiological factors contributing to this phenomenon, we found that optogenetic silencing of the prelimbic (PL), but not the infralimbic (IL), subregion of the medial prefrontal cortex (mPFC) during training led to subsequent forgetting and development of lasting social phobia. Similarly, pharmacological inhibition of NMDARs in PL also impaired the development of social phobia. These findings are consistent with the notion that social-related trauma is a prominent risk factor for the development of social phobia, and that this phenomenon engages learning-related mechanisms within the prelimbic prefrontal cortex to promote prolonged representations of social threat.
PubMed: 38895224
DOI: 10.1101/2024.06.04.597446 -
Sensors (Basel, Switzerland) Jun 2024Path planning creates the shortest path from the source to the destination based on sensory information obtained from the environment. Within path planning, obstacle... (Review)
Review
Path planning creates the shortest path from the source to the destination based on sensory information obtained from the environment. Within path planning, obstacle avoidance is a crucial task in robotics, as the autonomous operation of robots needs to reach their destination without collisions. Obstacle avoidance algorithms play a key role in robotics and autonomous vehicles. These algorithms enable robots to navigate their environment efficiently, minimizing the risk of collisions and safely avoiding obstacles. This article provides an overview of key obstacle avoidance algorithms, including classic techniques such as the Bug algorithm and Dijkstra's algorithm, and newer developments like genetic algorithms and approaches based on neural networks. It analyzes in detail the advantages, limitations, and application areas of these algorithms and highlights current research directions in obstacle avoidance robotics. This article aims to provide comprehensive insight into the current state and prospects of obstacle avoidance algorithms in robotics applications. It also mentions the use of predictive methods and deep learning strategies.
PubMed: 38894362
DOI: 10.3390/s24113573 -
International Journal of Molecular... May 2024In this study, we examined the potential antidepressant-like effects of Chinese quince fruit extract ( fruit extract, CSFE) in an in vivo model induced by repeated...
In this study, we examined the potential antidepressant-like effects of Chinese quince fruit extract ( fruit extract, CSFE) in an in vivo model induced by repeated injection of corticosterone (CORT)-induced depression. HPLC analysis determined that chlorogenic acid (CGA), neo-chlorogenic acid (neo-CGA), and rutin (RT) compounds were major constituents in CSFE. Male ICR mice (5 weeks old) were orally administered various doses (30, 100, and 300 mg/kg) of CSFE and selegiline (10 mg/kg), a monoamine oxidase B (MAO-B) inhibitor, as a positive control following daily intraperitoneal injections of CORT (40 mg/kg) for 21 days. In our results, mice treated with CSFE exhibited significant improvements in depressive-like behaviors induced by CORT. This was evidenced by reduced immobility times in the tail suspension test and forced swim test, as well as increased step-through latency times in the passive avoidance test. Indeed, mice treated with CSFE also exhibited a significant decrease in anxiety-like behaviors as measured by the elevated plus maze test. Moreover, molecular docking analysis indicated that CGA and neo-CGA from CSFE had stronger binding to the active site of MAO-B. Our results indicate that CSFE has potential antidepressant effects in a mouse model of repeated injections of CORT-induced depression.
Topics: Animals; Molecular Docking Simulation; Antidepressive Agents; Male; Mice; Fruit; Plant Extracts; Mice, Inbred ICR; Depression; Rosaceae; Behavior, Animal; Monoamine Oxidase; Disease Models, Animal; Corticosterone; Monoamine Oxidase Inhibitors; Chlorogenic Acid; East Asian People
PubMed: 38892026
DOI: 10.3390/ijms25115838 -
Animals : An Open Access Journal From... May 2024A commercial roadkill Virtual Fence (VF) mitigation device (iPTE Traffic Solutions) was used in a field trial to test its effectiveness, for which previously published...
A commercial roadkill Virtual Fence (VF) mitigation device (iPTE Traffic Solutions) was used in a field trial to test its effectiveness, for which previously published results have been inconsistent, along a 4.9 km segment of road on Bruny Island, Tasmania. A total of 585 days of monitoring roadkill by species was conducted, with six sections that were alternatively switched on or off according to the Crossover and Multiple Before-After-Control-Impact (MBACI) experimental designs that divided monitoring into "off-on" then "on-off" periods. Aggregate counts, for each period by section combination, from daily counts of Tasmanian pademelons () were modelled, with a total count of 222. The statistical analysis used the MBACI design to estimate the VF effect using a log-odds ratio parameter (LORP) while accounting for local spatio-temporal effects. Both versions of the analysis, either averaged over the three spatial replicates (paired sections) or two temporal replicates (blocks), showed no statistically significant effect of the VF, judged as an LORP estimate not sufficiently below zero. Corresponding percentage reduction estimates of 9% and 16% were derived from the LORP. The corresponding statistical power required to detect a nominal significant reduction of 50% in rate was 0.5 and 0.6, respectively. This study confirms the results from a similar previous field trial in southern Tasmania that this VF is likely to lead to, if anything, only a minor reduction in roadkill.
PubMed: 38891688
DOI: 10.3390/ani14111641 -
Cells Jun 2024Precise control of neuronal activity is crucial for the proper functioning of neurons. How lipid homeostasis contributes to neuronal activity and how much of it is...
Precise control of neuronal activity is crucial for the proper functioning of neurons. How lipid homeostasis contributes to neuronal activity and how much of it is regulated by cells autonomously is unclear. In this study, we discovered that absence of the lipid regulator , a functional ortholog of the peroxisome proliferator-activated receptor (PPAR) in , resulted in defective pathogen avoidance behavior against (PA14). Functional NHR-49 was required in the neurons, and more specifically, in a set of oxygen-sensing body cavity neurons, URX, AQR, and PQR. We found that lowering the neuronal activity of the body cavity neurons improved avoidance in mutants. Calcium imaging in URX neurons showed that mutants displayed longer-lasting calcium transients in response to an O upshift, suggesting that excess neuronal activity leads to avoidance defects. Cell-specific rescue of NHR-49 in the body cavity neurons was sufficient to improve pathogen avoidance, as well as URX neuron calcium kinetics. Supplementation with oleic acid also improved avoidance behavior and URX calcium kinetics, suggesting that the defective calcium response in the neuron is due to lipid dysfunction. These findings highlight the role of cell-autonomous lipid regulation in neuronal physiology and immune behavior.
Topics: Animals; Caenorhabditis elegans; Lipid Metabolism; Caenorhabditis elegans Proteins; Neurons; Pseudomonas aeruginosa; Calcium; Mutation; Avoidance Learning; Receptors, Cytoplasmic and Nuclear
PubMed: 38891110
DOI: 10.3390/cells13110978 -
Npj Mental Health Research Jun 2024Anxiety, a condition characterized by intense fear and persistent worry, affects millions each year and, when severe, is distressing and functionally impairing. Numerous...
Anxiety, a condition characterized by intense fear and persistent worry, affects millions each year and, when severe, is distressing and functionally impairing. Numerous machine learning frameworks have been developed and tested to predict features of anxiety and anxiety traits. This study extended these approaches by using a small set of interpretable judgment variables (n = 15) and contextual variables (demographics, perceived loneliness, COVID-19 history) to (1) understand the relationships between these variables and (2) develop a framework to predict anxiety levels [derived from the State Trait Anxiety Inventory (STAI)]. This set of 15 judgment variables, including loss aversion and risk aversion, models biases in reward/aversion judgments extracted from an unsupervised, short (2-3 min) picture rating task (using the International Affective Picture System) that can be completed on a smartphone. The study cohort consisted of 3476 de-identified adult participants from across the United States who were recruited using an email survey database. Using a balanced Random Forest approach with these judgment and contextual variables, STAI-derived anxiety levels were predicted with up to 81% accuracy and 0.71 AUC ROC. Normalized Gini scores showed that the most important predictors (age, loneliness, household income, employment status) contributed a total of 29-31% of the cumulative relative importance and up to 61% was contributed by judgment variables. Mediation/moderation statistics revealed that the interactions between judgment and contextual variables appears to be important for accurately predicting anxiety levels. Median shifts in judgment variables described a behavioral profile for individuals with higher anxiety levels that was characterized by less resilience, more avoidance, and more indifference behavior. This study supports the hypothesis that distinct constellations of 15 interpretable judgment variables, along with contextual variables, could yield an efficient and highly scalable system for mental health assessment. These results contribute to our understanding of underlying psychological processes that are necessary to characterize what causes variance in anxiety conditions and its behaviors, which can impact treatment development and efficacy.
PubMed: 38890545
DOI: 10.1038/s44184-024-00074-x -
CNS Neuroscience & Therapeutics Jun 2024Alzheimer's disease (AD) is a devastating dementia characterized by extracellular amyloid-β (Aβ) protein aggregates and intracellular tau protein deposition....
AIMS
Alzheimer's disease (AD) is a devastating dementia characterized by extracellular amyloid-β (Aβ) protein aggregates and intracellular tau protein deposition. Clinically available drugs mainly target acetylcholinesterase (AChE) and indirectly sustain cholinergic neuronal tonus. Butyrylcholinesterase (BChE) also controls acetylcholine (ACh) turnover and is involved in the formation of Aß aggregates and senile plaques. UW-MD-95 is a novel carbamate-based compound acting as a potent pseudo-irreversible BChE inhibitor, with high selectivity versus AChE, and showing promising protective potentials in AD.
METHODS
We characterized the neuroprotective activity of UW-MD-95 in mice treated intracerebroventricularly with oligomerized Aβ peptide using behavioral, biochemical, and immunohistochemical approaches.
RESULTS
When injected acutely 30 min before the behavioral tests (spontaneous alternation in the Y-maze, object recognition, or passive avoidance), UW-MD-95 (0.3-3 mg/kg) showed anti-amnesic effects in Aβ-treated mice. When injected once a day over 7 days, it prevented Aβ-induced memory deficits. This effect was lost in BChE knockout mice. Moreover, the compound prevented Aβ-induced oxidative stress (assessed by lipid peroxidation or cytochrome c release), neuroinflammation (IL-6 and TNFα levels or GFAP and IBA1 immunoreactivity) in the hippocampus and cortex, and apoptosis (Bax level). Moreover, UW-MD-95 significantly reduced the increase in soluble Aβ level in the hippocampus induced by Aβ.
CONCLUSION
UW-MD-95 appeared as a potent neuroprotective compound in the Aβ model of AD, with potentially an impact on Aβ accumulation that could suggest a novel mechanism of neuroprotection.
Topics: Animals; Neuroprotective Agents; Alzheimer Disease; Amyloid beta-Peptides; Mice; Peptide Fragments; Disease Models, Animal; Male; Cholinesterase Inhibitors; Butyrylcholinesterase; Mice, Inbred C57BL; Maze Learning; Dose-Response Relationship, Drug; Oxidative Stress
PubMed: 38887858
DOI: 10.1111/cns.14814 -
Microbiome Jun 2024Despite serious health and social consequences, effective intervention strategies for habitual alcohol binge drinking are lacking. The development of novel therapeutic...
BACKGROUND
Despite serious health and social consequences, effective intervention strategies for habitual alcohol binge drinking are lacking. The development of novel therapeutic and preventative approaches is highly desirable. Accumulating evidence in the past several years has established associations between the gut microbiome and microbial metabolites with drinking behavior, but druggable targets and their underlying mechanism of action are understudied.
RESULTS
Here, using a drink-in-the-dark mouse model, we identified a microbiome metabolite-based novel treatment (sodium valerate) that can reduce excessive alcohol drinking. Sodium valerate is a sodium salt of valeric acid short-chain fatty acid with a similar structure as γ-aminobutyric acid (GABA). Ten days of oral sodium valerate supplementation attenuates excessive alcohol drinking by 40%, reduces blood ethanol concentration by 53%, and improves anxiety-like or approach-avoidance behavior in male mice, without affecting overall food and water intake. Mechanistically, sodium valerate supplementation increases GABA levels across stool, blood, and amygdala. It also significantly increases H4 acetylation in the amygdala of mice. Transcriptomics analysis of the amygdala revealed that sodium valerate supplementation led to changes in gene expression associated with functional pathways including potassium voltage-gated channels, inflammation, glutamate degradation, L-DOPA degradation, and psychological behaviors. 16S microbiome profiling showed that sodium valerate supplementation shifts the gut microbiome composition and decreases microbiome-derived neuroactive compounds through GABA degradation in the gut microbiome.
CONCLUSION
Our findings suggest that sodium valerate holds promise as an innovative therapeutic avenue for the reduction of habitual binge drinking, potentially through multifaceted mechanisms. Video Abstract.
Topics: Animals; Male; Mice; Gastrointestinal Microbiome; gamma-Aminobutyric Acid; Fatty Acids, Volatile; Alcohol Drinking; Amygdala; Ethanol; Mice, Inbred C57BL; Disease Models, Animal; Binge Drinking; Pentanoic Acids
PubMed: 38886761
DOI: 10.1186/s40168-024-01829-6