NEURONAL ADAPTATIONS IN THE NUCLEUS ACCUMBENS CORE UNDER ACUTE AND CHRONIC EXPOSURE TO CANNABINOIDS

Thesis (Ph.D.) - Indiana University, Neuroscience, 2015Cannabis, known as marijuana, is the most commonly used illicit drug in the United States, but we have limited knowledge about its effects on the brain, particularly the reward circuitry. Cannabinoids, the psychoactive ingredient of cannabis, activate cannabinoid receptors in the mesolimbic area, resulting in increased dopamine transmission in the nucleus accumbens (NAc). This effect is believed to enhance goal-directed behavioral responses, including the motivation to obtain natural and drug rewards, but NAc signaling under cannabinoid exposure remain largely unknown. To address this gap, this dissertation work examines two main signaling changes in the NAc core: neuronal activities and dopamine dynamics. Since cannabis derivatives are usually used for a prolonged time, ongoing changes in the NAc core were investigated in response to acute and repeated exposure of cannabinoids. Therefore, in Experiment 1, NAc neuronal signaling was obtained on initial and repeated exposure (seven daily injections) of a cannabinoid receptor agonist, CP55,940 (0.2 mg/kg or 0.4 mg/kg) in male Sprague-Dawley rats using an in vivo electrophysiology technique. The overall effect of CP55,940 on CB1/2 receptor activation acutely inhibited NAc neuron activity and reduced correlated neuronal activity/burst firing, and these effects lasted for the seven days of injections. This result suggests that cannabinoids reduce neuronal signaling and disrupt functional communication in the NAc core for a prolonged period. However, cannabinoid increased the theta power of local field potentials after acute CP55,940 injection but repeated treatment failed to maintain this effect. In Experiment 2, the electrically evoked dopamine overflow was collected using fast scan cyclic voltammetry (FSCV). Using kinetic analysis, dopamine release and reuptake were assessed immediately following one or seven daily injections of CP55,940 (0.2 mg/kg, i.p.) or a vehicle. A single injection of CP55,940 increased the stimulation-evoked dopamine concentration without altering dopamine reuptake. However, repeated CP55,940 exposure led to a similar level of dopamine concentration as the chronic vehicle treatment. The sustained neuronal signaling but altered dopamine dynamics in the NAc core after repeated cannabinoid exposure suggest separate mechanisms in the development of tolerance. As the present results indicate, altered signaling of the NAc core could provide evidence of changes in motivational states that, in turn, may play a role in changing reward-related behaviors

An Analysis of the Appropriate Number of Workers in Elderly Care Hospital by Pathfinder in Korea

: This study estimated the appropriate number of employees that are able to evacuate all occupants during the day time and nighttime through an evacuation simulation. During the daytime, 200 patients and 44 workers evacuated after 416 se This result showed that the number of workers was greater than the standard number of daytime worker placements because this record was faster than the Korean Fire Department’s average arrival time of 430 seconds. Therefore, the appropriate number of workers during the daytime for all occupants to escape within the Korean Fire Department’s average arrival time of 430 seconds is 30 persons, 25 persons for the standard evacuation time of 480 seconds, and 20 persons for the average time of flashover of 540 seconds. During the nighttime, a total of 205 people, including 200 patients and 5 workers, needed 1,475 seconds to evacuate. As this time exceeds the average time of flashover, it was shown that the number of workers was fewer than the standard number of nighttime worker placements. Therefore, the appropriate number of workers at nighttime is 35 persons for 430 seconds, 30 persons for 480 seconds, and 25 persons for 540 second

Analysis of the Impact of Decreasing the Width of Direct Stairs in Apartments on RSET for All Occupants in Korea

This study analyzed the RSETs for 11-story or less apartments where the building-related laws were not retroactively applied, with consideration of the decrease of direct stairs width due to obstacles piled up on the direct stairs. The RSET was shown to be 631.8 seconds when the width of the direct stairs was 1,260mm. The evacuation time exceeded 5 minutes even when there were no obstacles due to the delayed evacuation start time. The risk increased when the width of the direct stairs was decreased to 960mm, 760mm, and 560mm because of obstacles, and the RSETs were 768.8 seconds, 803.3 seconds, and 834.4 seconds respectively. There are various ways to eliminate the occurrence of obstacles on direct stairs which increase RSET : First, it is necessary to remove the exception that permits the placement of obstacles on the stairs. Second, penalties for the placement of obstacles on the direct stairs should be enforced as written. Third, the fire safety managers need the authority to act on behalf of the fire officials. Lastly, it is necessary to encourage residents to report instances of obstacle accumulation. Henceforth, more research is needed on the spread speed of smoke and toxic gases depending on whether fire doors are installed through fire simulation

Comprehensive Korean Medicine Treatment for Benign Essential Blepharospasm in a Patient Responding Poorly to Botulinum Toxin Treatment

Peer reviewe

Effects of Sound on Postural Stability during Quiet Standing

Loss of postural stability can increase the likelihood of slips and falls in workplaces. The present study intended to extend understanding of the effects of frequency and pressure level of sound on postural stability during standing. Eleven male subjects participated. Standing on a force platform, the subjects' center of pressures were measured under different combinations of pressure level and frequency of the sound. Variables such as the position variability of COP and the length of postural sway path in anterior-posterior (AP) and medio-lateral (ML) direction were evaluated. Subjective ratings of perceived disturbance at each experimental condition were also obtained using a 7-point rating scale. Results showed that the length of sway path and the position variability of COP increased as the frequency of sound increased in posterior-anterior axis. The effect of sound pressure level, however, was not significant on both the postural sway length and the position variability of COP. These results suggested substantial disturbance of standing balance system among subjects exposed to high frequency noise. The results implied that physical workers should be alerted that their abilities of postural balance could be degraded significantly as disturbance caused by a sound existed

Selective deep convolutional neural network for low cost distorted image classification

Neural networks trained using images with a certain type of distortion should be better at classifying test images with the same type of distortion than generally-trained neural networks, given other factors being equal. Based on this observation, an ensemble of convolutional neural networks (CNNs) trained with different types and degrees of distortions is used. However, instead of simply classifying test images of unknown distortion types with the entire ensemble of CNNs, an extra tiny CNN is specifically trained to distinguish between the different types and degrees of distortions. Then, only the dedicated CNN for that specific type and degree of distortion, as determined by the tiny CNN, is activated and used to classify a possibly distorted test image. This proposed architecture, referred to as a \textit{selective deep convolutional neural network (DCNN)}, is implemented and found to result in high accuracy with low hardware costs. Detailed simulations with realistic image distortion scenarios using three popular datasets show that memory, MAC operations, and energy savings of up to 93.68%, 93.61%, and 91.92%, respectively, can be achieved with almost no reduction in image classification accuracy. The proposed selective DCNN scores up to 2.18x higher than the state-of-the-art DCNN model when evaluated using NetScore, a comprehensive metric that considers both CNN performance and hardware cost. In addition, it is shown that even higher hardware cost reduction can be achieved when selective DCNN is combined with previously proposed model compression techniques. Finally, experiments conducted with extended types and degrees of image distortion show that selective DCNN is highly scalable.11Ysciescopu

H2 pressure swing adsorption for IGCC power plant and techno-economic analysis of integrating PSA to IGCC with carbon capture

Carbon capture and sequestration technologies emerge as the effectual remediation processes to reduce CO2 emissions from coal power plants. Integrated gasification combined cycle (IGCC) is a representative technology for utilizing coal as feedstock and is consequently playing a more important role to cover the global energy demand. The IGCC produces H2-rich mixture at high pressures (30-35 bar) after capturing CO2. It is reported that the high purity H2 recovered from the IGCC process can be economically supplied to a hydrogen turbine or fuel cell. And a PSA process is a strong candidate to produce high purity H2 from the IGCC effluent gas. However, due to higher operating pressure than the present H2 PSA processes, reducing the operating costs and efficiency has emerged as one of the key issues. Please click Additional Files below to see the full abstract

Learning Transferable Adversarial Robust Representations via Multi-view Consistency

Despite the success on few-shot learning problems, most meta-learned models only focus on achieving good performance on clean examples and thus easily break down when given adversarially perturbed samples. While some recent works have shown that a combination of adversarial learning and meta-learning could enhance the robustness of a meta-learner against adversarial attacks, they fail to achieve generalizable adversarial robustness to unseen domains and tasks, which is the ultimate goal of meta-learning. To address this challenge, we propose a novel meta-adversarial multi-view representation learning framework with dual encoders. Specifically, we introduce the discrepancy across the two differently augmented samples of the same data instance by first updating the encoder parameters with them and further imposing a novel label-free adversarial attack to maximize their discrepancy. Then, we maximize the consistency across the views to learn transferable robust representations across domains and tasks. Through experimental validation on multiple benchmarks, we demonstrate the effectiveness of our framework on few-shot learning tasks from unseen domains, achieving over 10\% robust accuracy improvements against previous adversarial meta-learning baselines.Comment: *Equal contribution (Author ordering determined by coin flip). NeurIPS SafetyML workshop 2022, Under revie

Effects of Lowering Dialysate Calcium Concentrations on Arterial Stiffness in Patients Undergoing Hemodialysis

BACKGROUND/AIMS: We assessed changes in hemodynamic and arterial stiffness parameters following reductions of dialysate calcium concentrations in patients undergoing hemodialysis. METHODS: In this prospective study, 20 patients on maintenance hemodialysis (10 females, 10 males) with dialysate calcium concentrations of 1.75 mmol/L were enrolled. At the start of the study, the dialysate calcium level was lowered to 1.50 mmol/L. Serial changes in biochemical, hemodynamic, and arterial stiffness parameters, including pulse wave velocity (PWV) and augmentation index (AIx), were assessed every 2 months for 6 months. We also examined changes in the calcification-inhibitory protein, serum fetuin-A. RESULTS: During the 6-month study period, serum total calcium and ionized calcium decreased consistently (9.5 ± 1.0 to 9.0 ± 0.7, p = 0.002 vs. 1.3 ± 0.1 to 1.1 ± 0.1, p = 0.035). Although no apparent changes in blood pressure were observed, heart-femoral PWW (hf-PWV) and AIx showed significant improvement (p = 0.012, 0.043, respectively). Repeated-measures ANOVA indicated a significant effect of lowering dialysate calcium on hf-PWV (F = 4.58, p = 0.004) and AIx (F = 2.55, p = 0.049). Accompanying the change in serum calcium, serum fetuin-A levels significantly increased (95.8 ± 45.8 pmol/mL at baseline to 124.9 ± 82.2 pmol/mL at 6 months, p = 0.043). CONCLUSIONS: Lowering dialysate calcium concentration significantly improved arterial stiffness parameters, which may have been associated with upregulation of serum fetuin-A.ope