scholarly journals Deciphering Elapsed Time and Predicting Action Timing from Neuronal Population Signals

2011 ◽  
Vol 5 ◽  
Author(s):  
Shigeru Shinomoto ◽  
Takahiro Omi ◽  
Akihisa Mita ◽  
Hajime Mushiake ◽  
Keisetsu Shima ◽  
...  
Keyword(s):  
Neuronal Population ◽  
Elapsed Time ◽  
Action Timing

The relevance of proprioception in action timing studied in a case of deafferentation

2001 ◽  
Author(s):  
Prisca Stenneken ◽  
Gisa Aschersleben ◽  
Jonathan Cole ◽  
Wolfgang Prinz
Keyword(s):  
Action Timing

Phosphene perceptions and safety of chronic visual cortex stimulation in a blind subject

2020 ◽  
Vol 132 (6) ◽  
pp. 2000-2007 ◽  
Author(s):  
Soroush Niketeghad ◽  
Abirami Muralidharan ◽  
Uday Patel ◽  
Jessy D. Dorn ◽  
Laura Bonelli ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Adverse Events ◽  
Clinical Intervention ◽  
Occipital Cortex ◽  
Neuronal Population ◽  
Serious Adverse Events ◽  
Stimulation Parameters ◽  
The Right ◽  
Visual Cortical ◽  
Stimulation Of

Stimulation of primary visual cortices has the potential to restore some degree of vision to blind individuals. Developing safe and reliable visual cortical prostheses requires assessment of the long-term stability, feasibility, and safety of generating stimulation-evoked perceptions.A NeuroPace responsive neurostimulation system was implanted in a blind individual with an 8-year history of bare light perception, and stimulation-evoked phosphenes were evaluated over 19 months (41 test sessions). Electrical stimulation was delivered via two four-contact subdural electrode strips implanted over the right medial occipital cortex. Current and charge thresholds for eliciting visual perception (phosphenes) were measured, as were the shape, size, location, and intensity of the phosphenes. Adverse events were also assessed.Stimulation of all contacts resulted in phosphene perception. Phosphenes appeared completely or partially in the left hemifield. Stimulation of the electrodes below the calcarine sulcus elicited phosphenes in the superior hemifield and vice versa. Changing the stimulation parameters of frequency, pulse width, and burst duration affected current thresholds for eliciting phosphenes, and increasing the amplitude or frequency of stimulation resulted in brighter perceptions. While stimulation thresholds decreased between an average of 5% and 12% after 19 months, spatial mapping of phosphenes remained consistent over time. Although no serious adverse events were observed, the subject experienced mild headaches and dizziness in three instances, symptoms that did not persist for more than a few hours and for which no clinical intervention was required.Using an off-the-shelf neurostimulator, the authors were able to reliably generate phosphenes in different areas of the visual field over 19 months with no serious adverse events, providing preliminary proof of feasibility and safety to proceed with visual epicortical prosthetic clinical trials. Moreover, they systematically explored the relationship between stimulation parameters and phosphene thresholds and discovered the direct relation of perception thresholds based on primary visual cortex (V1) neuronal population excitation thresholds.

Abdominal decompression illness following repetitive diving: a case report and review of the literature

2019 ◽  
pp. 211-215
Author(s):  
Peter Beale ◽  
Levi Kitchen ◽  
W.R. Graf ◽  
M.E. Fenton ◽  
Keyword(s):  
Case Report ◽  
The Body ◽  
Decompression Illness ◽  
Review Of The Literature ◽  
Hyperbaric Chamber ◽  
Foreign National ◽  
Biochemical Effects ◽  
Elapsed Time ◽  
Nitrogen Bubbles ◽  
Abdominal Decompression

The complete pathophysiology of decompression illness is not yet fully understood. What is known is that the longer a diver breathes pressurized air at depth, the more likely nitrogen bubbles are to form once the diver returns to surface [1]. These bubbles have varying mechanical, embolic and biochemical effects on the body. The symptoms produced can be as mild as joint pain or as significant as severe neurologic dysfunction, cardiopulmonary collapse or death. Once clinically diagnosed, decompression illness must be treated rapidly with recompression therapy in a hyperbaric chamber. This case report involves a middle-aged male foreign national who completed three dives, all of which incurred significant bottom time (defined as: “the total elapsed time from the time the diver leaves the surface to the time he/she leaves the bottom)” [2]. The patient began to develop severe abdominal and back pain within 15 minutes of surfacing from his final dive. This case is unique, as his presentation was very concerning for other medical catastrophes that had to be quickly ruled out, prior to establishing the diagnosis of severe decompression illness. After emergency department resuscitation, labs and imaging were obtained; abdominal decompression illness was confirmed by CT, revealing a significant abdominal venous gas burden.

scholarly journals A deep convolutional visual encoding model of neuronal responses in the LGN

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Eslam Mounier ◽  
Bassem Abdullah ◽  
Hani Mahdi ◽  
Seif Eldawlatly
Keyword(s):  
Firing Rate ◽  
Visual Information ◽  
Visual Stimulation ◽  
Neuronal Population ◽  
Neuronal Firing ◽  
Electrode Arrays ◽  
Deep Convolutional Neural Networks ◽  
Firing Rates ◽  
Spatiotemporal Representation

AbstractThe Lateral Geniculate Nucleus (LGN) represents one of the major processing sites along the visual pathway. Despite its crucial role in processing visual information and its utility as one target for recently developed visual prostheses, it is much less studied compared to the retina and the visual cortex. In this paper, we introduce a deep learning encoder to predict LGN neuronal firing in response to different visual stimulation patterns. The encoder comprises a deep Convolutional Neural Network (CNN) that incorporates visual stimulus spatiotemporal representation in addition to LGN neuronal firing history to predict the response of LGN neurons. Extracellular activity was recorded in vivo using multi-electrode arrays from single units in the LGN in 12 anesthetized rats with a total neuronal population of 150 units. Neural activity was recorded in response to single-pixel, checkerboard and geometrical shapes visual stimulation patterns. Extracted firing rates and the corresponding stimulation patterns were used to train the model. The performance of the model was assessed using different testing data sets and different firing rate windows. An overall mean correlation coefficient between the actual and the predicted firing rates of 0.57 and 0.7 was achieved for the 10 ms and the 50 ms firing rate windows, respectively. Results demonstrate that the model is robust to variability in the spatiotemporal properties of the recorded neurons outperforming other examined models including the state-of-the-art Generalized Linear Model (GLM). The results indicate the potential of deep convolutional neural networks as viable models of LGN firing.

scholarly journals Tcf4 Is Involved in Subset Specification of Mesodiencephalic Dopaminergic Neurons

Biomedicines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 317
Author(s):  
Simone Mesman ◽  
Iris Wever ◽  
Marten P. Smidt
Keyword(s):  
Neuronal Differentiation ◽  
Dopaminergic Neurons ◽  
Neuronal Development ◽  
Neuronal Population ◽  
Minor Role ◽  
Initial Increase ◽  
E Box ◽  
A Minor ◽  
Bhlh Factor

During development, mesodiencephalic dopaminergic (mdDA) neurons form into different molecular subsets. Knowledge of which factors contribute to the specification of these subsets is currently insufficient. In this study, we examined the role of Tcf4, a member of the E-box protein family, in mdDA neuronal development and subset specification. We show that Tcf4 is expressed throughout development, but is no longer detected in adult midbrain. Deletion of Tcf4 results in an initial increase in TH-expressing neurons at E11.5, but this normalizes at later embryonic stages. However, the caudal subset marker Nxph3 and rostral subset marker Ahd2 are affected at E14.5, indicating that Tcf4 is involved in correct differentiation of mdDA neuronal subsets. At P0, expression of these markers partially recovers, whereas expression of Th transcript and TH protein appears to be affected in lateral parts of the mdDA neuronal population. The initial increase in TH-expressing cells and delay in subset specification could be due to the increase in expression of the bHLH factor Ascl1, known for its role in mdDA neuronal differentiation, upon loss of Tcf4. Taken together, our data identified a minor role for Tcf4 in mdDA neuronal development and subset specification.

#81: Care Process Measures and Outcomes of Percutaneous Pulmonary Valve Implantation-associated Infective Endocarditis

2021 ◽  
Vol 10 (Supplement_1) ◽  
pp. S9-S9
Author(s):  
B Rubbab ◽  
C Talluto ◽  
A Nuibe ◽  
R Levorson
Keyword(s):  
Infective Endocarditis ◽  
Tetralogy Of Fallot ◽  
Median Duration ◽  
Pulmonary Valve ◽  
Coagulase Negative Staphylococcus ◽  
Elapsed Time ◽  
Percutaneous Pulmonary Valve Implantation ◽  
Valve Implantation ◽  
Percutaneous Pulmonary Valve ◽  
Pulmonary Valve Implantation

Abstract Background Percutaneous pulmonary valve implantation (PPVI) is being increasingly used as a minimally invasive corrective procedure for right ventricular outflow tract (RVOT) dysfunction. Ten-year survival following PPVI is estimated at over 90% due to the durability of the various bioprosthetic valves. However, infective endocarditis (IE) remains a potential complication of such valves with significant morbidity and mortality. We evaluated the presenting symptoms, clinical features, pathogens, and outcomes of patients with IE following PPVI to identify opportunities to improve early diagnosis and management. Methods A convenience sample of patients at a large Pediatric Cardiology practice in Northern Virginia was queried for PPVI and IE from January 1, 2016, to June 30, 2019. Manual chart review was done to extract clinical points of interest and descriptive analyses were performed. Patients were classified as having IE per modified Duke’s criteria. Results We identified 14 patients who underwent PPVI. Five of these patients (36%) developed IE. All IE patients had underlying Tetralogy of Fallot and none had previous episodes of IE. 60% of patients with IE were male with a median age of 26 years old (IQR 20–30). Four IE patients had a Melody valve and 1 had a SAPIEN valve. The median elapsed time between PPVI and IE diagnosis was 128 days (IQR 32–391) with a median duration of illness prior to the diagnosis of IE of 6 days (IQR 5–9). All IE patients had to present fever. 40% of IE patients had to present chest pain and 20% had presenting musculoskeletal pain. All IE patients had an elevated initial C-reactive protein (CRP) with a median value of 13.1 mg/dL (IQR 12.5–15.2). The median initial white blood cell count was 9.3 × 103/μL (IQR 8.1–10.3). The median duration of bacteremia was 1 day (IQR 1–2). A pathogen was recovered in all five IE patients with different organisms amongst the patients: coagulase-negative Staphylococcus species were recovered in patients who developed IE within 60 days from PPVI (Staphylococcus lugdunensis and Staphylococcus epidermidis) whereas coagulase-negative Staphylococcus species and oral commensal organisms were found in IE patients beyond 60 days from PPVI (Staphylococcus sanguinis, Gamella haemolysans, and Neisseria elongata). The initial echocardiogram did not show vegetations in any of the patients and 40% went on to have sternotomy with valve replacement. There were no deaths. Conclusions With an increase in PPVI, clinicians should have a high index of suspicion for IE in patients with underlying Tetralogy of Fallot who present with fever and elevated CRP, regardless of elapsed time from PPVI or valve type. Empiric antimicrobial therapy for suspected IE following PPVI should remain broad with other possible pathogens beyond coagulase-negative Staphylococcus species.

scholarly journals Wildfires Vegetation Recovery through Satellite Remote Sensing and Functional Data Analysis

Mathematics ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1305
Author(s):  
Feliu Serra-Burriel ◽  
Pedro Delicado ◽  
Fernando M. Cucchietti
Keyword(s):  
Remote Sensing ◽  
Data Analysis ◽  
Functional Data Analysis ◽  
Functional Data ◽  
Vegetation Index ◽  
Vegetation Recovery ◽  
Functional Responses ◽  
Elapsed Time ◽  
Synthetic Controls ◽  
Available Information

In recent years, wildfires have caused havoc across the world, which are especially aggravated in certain regions due to climate change. Remote sensing has become a powerful tool for monitoring fires, as well as for measuring their effects on vegetation over the following years. We aim to explain the dynamics of wildfires’ effects on a vegetation index (previously estimated by causal inference through synthetic controls) from pre-wildfire available information (mainly proceeding from satellites). For this purpose, we use regression models from Functional Data Analysis, where wildfire effects are considered functional responses, depending on elapsed time after each wildfire, while pre-wildfire information acts as scalar covariates. Our main findings show that vegetation recovery after wildfires is a slow process, affected by many pre-wildfire conditions, among which the richness and diversity of vegetation is one of the best predictors for the recovery.

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