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Authors: Munaf Fathi Badr, Ekhlas Hameed Karam and Noor Mohammaed Mjeed

Abstract

The objective of this paper is to present a proposed control model for the electromechanical damper mass spring system including the backstepping technique in comparison with the conventional proportional–derivative–integral (PID) controller unit to realize the best performance of the control systems. The suggested approach demanded the construction in laboratory arrangement of damper mass spring system which linked with electrical position sensor, and the theoretical work involved the derivation of the required mathematical equations in order to formulate the simulation models in Matlab software package. The obtained results show that the backstepping control technique provides the better performance associated with stable control system especially with increasing the value of selected mechanical load.

Open access

Abstract

In the recently published researches in the object localization field, 3D object localization takes the largest part of this research due to its importance in our daily life. 3D object localization has many applications such as collision avoidance, robotic guiding and vision and object surfaces topography modeling. This research study represents a novel localization algorithm and system design using a low-resolution 2D ultrasonic sensor array for 3D real-time object localization. A novel localization algorithm is developed and applied to the acquired data using the three sensors having the minimum calculated distances at each acquired sample, the algorithm was tested on objects at different locations in 3D space and validated with acceptable level of precision and accuracy. Polytope Faces Pursuit (PFP) algorithm was used for finding an approximate sparse solution to the object location from the measured three minimum distances. The proposed system successfully localizes the object at different positions with an error average of ±1.4 mm, ±1.8 mm, and ±3.7 mm in x-direction, y-direction, and z-direction, respectively, which are considered as low error rates.

Open access

Abstract

Background and Aims

The past-year prevalence of problematic pornography use (PPU) was 1–6% in adult populations. As a result of treatment obstacles and barriers, such as unaffordable treatments, only a minority of problematic pornography users may seek treatment. Having a free, online, self-help program may overcome treatment barriers and may help those individuals who cannot receive traditional or offline treatment for PPU. Although the effectiveness of such online programs reducing substance use and problematic gambling have been reported, no prior study has examined the efficacy of an online self-help intervention aiming to reduce PPU.

Methods

This two-armed randomized controlled trial (RCT) will examine the effectiveness of an online self-help program (Hands-off) to reduce PPU, while also considering psychopathological comorbidities. The six-week intervention condition includes six core modules developed to reduce PPU based on motivational interviewing, cognitive behavioral therapy, mindfulness, and wise social-psychological intervention techniques. The target sample size is 242 participants. Self-report questionnaires will be administered at baseline, right after the end of the intervention, at one-month, and three-month follow-ups after the end of the intervention. The primary outcome will be the level of PPU. Secondary outcomes will include pornography use frequency, pornography craving, pornography use-avoidance self-efficacy, sex mindset, sexual satisfaction, negative and positive emotions, and life satisfaction. Data will be analyzed on an intention-to-treat basis using linear mixed models.

Results

Results will be reported at conferences and published in a scientific peer-reviewed journal. The participants will be sent a lay-person-friendly summary of the results via e-mail.

Open access

Abstract

Background and aims

Individuals with addictive disorders are usually characterized by impaired executive control, persistent craving and excessive reward-seeking. However, it is unclear whether there is a deviation in the connection pattern among the neural systems implicated in these problem behaviors.

Methods

One hundred thirty-six online gaming players were recruited in the current study (68 Internet gaming disorder (IGD) subjects and 68 recreational game users (RGUs) who served as controls matched on age, sex, years of education, and years of gaming). Dynamic interactions among the reward system (striatum), control system (prefrontal cortex), and the interoceptive awareness system (insula) were calculated and compared when subjects were facing gaming cues.

Results

The results revealed that RGUs showed a significant positive correlation in the putamen-middle frontal gyrus (MFG)-insula neural pathway when facing gaming cues, which was missing in the IGD subjects. Additionally, dynamic causal modeling (DCM) analysis revealed that the MFG region was more inhibited by the putamen in the IGD subjects relative to the RGUs.

Conclusions

These findings suggest that the inhibitory neuromodulation of the putamen to the prefrontal cortex in IGD individuals undermines the balance among the tripartite systems. Our findings provide novel neurobiological evidence for understanding the internal connection bias of the addicted individual’s neural system and how the addictive disorder impairs executive control; consequently, the pathway from the striatum to the prefrontal cortex may serve as a potential biomarker to predict the risk of developing an addiction.

Open access

Abstract

Background and aims

Few studies have tested the underlying mechanisms in the association between workaholism and depression. This study aims to investigate the potential mediation effects of work-life balance stress and chronic fatigue and depression among Chinese male workers in Hong Kong.

Methods

A population-based study among male workers in Hong Kong (n =  1,352) was conducted. The self-reported scales of assessing workaholism, work-life balance stress, chronic fatigue and depressive symptoms were included in the questionnaire. Path analysis was conducted to test the proposed mediation model.

Results

Workaholism was directly and indirectly associated with depression through work-life balance stress and chronic fatigue, respectively. The association between work-life balance stress and chronic fatigue was statistically significant in the correlation analysis but not in the path analysis. As high as 30.5% of the participants were classified as having probable chronic fatigue, while 8.4% of the participants were classified as having probable depression.

Discussion

Workaholism is a stressor that may induce negative consequences on well-being and health among male workers in Hong Kong. Interventions to help workers with time and stress management and fatigue reduction may be beneficial for their mental health. Theoretical and practical implications are discussed.

Open access

Abstract

Background and aims

The working memory (WM) ability of internet addicts and the topology underlying the WM processing in internet addiction (IA) are poorly understood. In this study, we employed a graph theoretical framework to characterize the topological properties of the IA brain network in the source cortical space during WM task.

Methods

A sample of 24 subjects with IA and 23 matched healthy controls (HCs) performed visual 2-back task. Exact Low Resolution Electromagnetic Tomography was adopted to project the pre-processed EEG signals into source space. Subsequently, Lagged phase synchronization was calculated between all pairs of Brodmann areas, the graph theoretical approaches were then employed to estimate the brain topological properties of all participants during the WM task.

Results

We found better WM behavioral performance in IA subjects compared with the HCs. Moreover, compared to the HC group, more integrated and hierarchical brain network was revealed in the IA subjects in alpha band. And altered regional centrality was mainly resided in frontal and limbic lobes. In addition, significant relationships between the IA severity and the significant altered graph indices were found.

Conclusions

In conclusion, these findings provide evidence to support the notion that altered topological configuration may underline changed WM function observed in IA.

Open access

Abstract

Background and aims

The working memory (WM) ability of internet addicts and the topology underlying the WM processing in internet addiction (IA) are poorly understood. In this study, we employed a graph theoretical framework to characterize the topological properties of the IA brain network in the source cortical space during WM task.

Methods

A sample of 24 subjects with IA and 23 matched healthy controls (HCs) performed visual 2-back task. Exact Low Resolution Electromagnetic Tomography was adopted to project the pre-processed EEG signals into source space. Subsequently, Lagged phase synchronization was calculated between all pairs of Brodmann areas, the graph theoretical approaches were then employed to estimate the brain topological properties of all participants during the WM task.

Results

We found better WM behavioral performance in IA subjects compared with the HCs. Moreover, compared to the HC group, more integrated and hierarchical brain network was revealed in the IA subjects in alpha band. And altered regional centrality was mainly resided in frontal and limbic lobes. In addition, significant relationships between the IA severity and the significant altered graph indices were found.

Conclusions

In conclusion, these findings provide evidence to support the notion that altered topological configuration may underline changed WM function observed in IA.

Open access

Abstract

Objective

It has been shown that high-intensity interval training (HIIT) leads to skeletal muscle hypertrophy; however, its mechanisms of cellular and molecular regulation are still unclear. The purpose of this study was to investigate the effect of HIIT on muscle hypertrophy and major signal transduction pathways.

Design

12 male rats were randomly divided into two groups: control and HIIT. The exercise group performed 30-min HIIT in each session (5 × 4-min intervals running at 85–95% VO2max separated by 2-min active rest at 55–60% VO2max), 3 days/week for 8 weeks. Muscle fiber cross-sectional area (CSA) and the expression of signal transduction pathway proteins were determined in the gastrocnemius muscle.

Results

In the HIIT group, the expression of IGF-I, IGF-IR Akt, p-Akt, AMPKα, p-AMPKα and follistatin increased significantly, whereas a significant decrease was observed in the expression of FoxO1, p-FoxO1, myostatin, ActRIIB, Smad2/3 and p-Smad2/3 (P < 0.05). However, there were no significant differences between the HIIT and control groups in the expression of mTOR, p-mTOR, P70S6K, and p-P70S6K (P > 0.05). In addition, CSA and gastrocnemius muscle weight increased significantly in the HIIT group (P < 0.05).

Conclusions

HIIT induced muscle hypertrophy by improving IGF-I/Akt/FoxO and myostatin/Smad signal transduction pathways.

Restricted access
Authors: Bach Xuan Tran, Giang Hai Ha, Giang Thu Vu, Chi Linh Hoang, Son Hoang Nguyen, Cuong Tat Nguyen, Carl. A. Latkin, Wilson WS Tam, Cyrus S. H. Ho and Roger C. M. Ho

Abstract

Background and aims

Excessive use of electronic devices has become a major global problem. However, little is known about the development and current landscape of research concerning this field. This study aimed at exploring the overall publication trend and topics of research on the overuse of electronic devices and the Internet from 1971 to 2017.

Methods

We systematically searched the Web of Science (WoS) and Scopus databases for published articles on the excessive use of electronic devices and the Internet. Data regarding the publication volume, international collaborations, and geographical locations were analyzed by bibliometrics analysis. Latent Dirichlet Allocation (LDA) was undertaken to categorize publications into different research topics.

Results

A total of 2,276 papers from the WOS and 600 papers from the Scopus were included. We found a dramatic increase in the number of scientific papers towards addiction to electronic devices and the Internet. The United State led in all publication parameters including the total number of papers and total citations. China, Korea and Taiwan were among the most prolific countries/regions. Smartphone addiction was the main concern, and the relationship between the overuse of electronic devices and the Internet and mental health issues have been highlighted. On the other hand, our study found a limited appearance of discussion on effective treatment and intervention.

Discussion and Conclusion

The findings of this study call for more national and international cooperation in evaluating and intervening addiction to electronic devices and the Internet to gather more knowledge about this phenomenon and evaluate the effectiveness of treatment.

Open access
Authors: Bach Xuan Tran, Giang Hai Ha, Giang Thu Vu, Chi Linh Hoang, Son Hoang Nguyen, Cuong Tat Nguyen, Carl. A. Latkin, Wilson WS Tam, Cyrus S. H. Ho and Roger C. M. Ho

Abstract

Background and aims

Excessive use of electronic devices has become a major global problem. However, little is known about the development and current landscape of research concerning this field. This study aimed at exploring the overall publication trend and topics of research on the overuse of electronic devices and the Internet from 1971 to 2017.

Methods

We systematically searched the Web of Science (WoS) and Scopus databases for published articles on the excessive use of electronic devices and the Internet. Data regarding the publication volume, international collaborations, and geographical locations were analyzed by bibliometrics analysis. Latent Dirichlet Allocation (LDA) was undertaken to categorize publications into different research topics.

Results

A total of 2,276 papers from the WOS and 600 papers from the Scopus were included. We found a dramatic increase in the number of scientific papers towards addiction to electronic devices and the Internet. The United State led in all publication parameters including the total number of papers and total citations. China, Korea and Taiwan were among the most prolific countries/regions. Smartphone addiction was the main concern, and the relationship between the overuse of electronic devices and the Internet and mental health issues have been highlighted. On the other hand, our study found a limited appearance of discussion on effective treatment and intervention.

Discussion and Conclusion

The findings of this study call for more national and international cooperation in evaluating and intervening addiction to electronic devices and the Internet to gather more knowledge about this phenomenon and evaluate the effectiveness of treatment.

Open access