Sleep Deprivation and Depression : A bi-directional association

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Design of Robust Digital Pole Placer for Car Active Suspension with Input Constraint

This chapter deals with the problem of state feedback control for an active quarter-car suspension system with control input constraint. The dynamics of the suspension system is first formed in terms of the control objectives: ride comfort, suspension deflection, and maximum actuator control force. The control task is formulated as robustly placing the closed poles in a desired region against different passenger load. Since digital computers are widely used in the vehicle industry, a new saturated controller design method is presented for regional pole-placement of uncertain discrete time systems. The constraint of control input saturation is considered in the design phase. The desired dynamic performance for uncertain discrete-time systems is represented by the settling time and damping ratio. A sufficient condition is derived to place the poles in a desired region. The design is formulated in terms of linear matrix inequality optimization. The effectiveness of the proposed design is illustrated by applying it to a quarter?car active suspension system. Different road tests for the proposed controller are carried out: step and bump disturbances. The proposed design achieves the desired oscillation damping due to road disturbances in addition to passenger comfort. The results are compared with the passive suspension system

Gender Difference in Relationship of Apnoea/Hypopnoea Index with Body Mass Index and Age in the Omani Population

Objectives: Obstructive sleep apnoea/hypopnoea syndrome (OSAHS) is a disorder characterised by repetitive upper airway collapse during sleep in association with daytime sleepiness. It has an estimated prevalence of 2% and 4% among middle-aged women and men respectively. The aim of the study was to look at the association of body mass index (BMI), age and gender and prevalence of OSAHS in the Omani population. Methods:Polysomnography reports and hospital medical records of all patients who took part in the Sleep Study at the Sleep Laboratory of the Clinical Physiology Department, Sultan Qaboos University Hospital, between January 1995 and December 2006, were retrospectively reviewed. Data from both sources was gathered and analysed. Results: A total of 1,042 sleep studies were conducted with 608 valid studies for analysis. The study showed that the apnoea/hypopnoea index (AHI) >15 was more prevalent in men compared to women (47.9% versus 33.5%, P = 0.001). There was significant correlation of AHI with BMI (P <0.0001) among men compared to women (P = 0.1); however, age was significantly correlated with AHI among women (P <0.0001), but not with men (P = 0.1). Conclusion: The results indicate that there is a gender difference in the prevalence of OSAHS and obesity is a major risk factor for OSAHS among Omani men whereas age is found to be a risk factor for OSAHS among women.

Daytime Sleepiness Among Young Adult Omani Car Drivers

Objectives: Sleepiness and fatigue play significant roles in exacerbating the occurrence of car crashes. However, there is a dearth of studies examining the prevalence of sleepiness while driving among Omanis. This study aimed to determine the proportion of young Omani adults who confess to daytime sleepiness while driving and to investigate associations between gender, daytime sleepiness and risk of obstructive sleep apnoea syndrome (OSAS). Methods: This cross-sectional study took place at the Sultan Qaboos University Hospital, Muscat, Oman, between May and July 2014 and included 600 young adult Omani non-commercial drivers. The Berlin Questionnaire and Epworth Sleepiness Scale (ESS) were distributed among the participants, along with additional questions about their sleeping habits. Associations between daytime sleepiness while driving and nocturnal sleep duration, risk of OSAS and gender were determined. Results: A total of 492 private vehicle drivers took part in the study (response rate: 82%), of which 50.4% were male. Overall, 124 Omanis (25.2%) reported experiencing daytime sleepiness while driving at least once per month. There was a significant association between nocturnal sleep duration of 10 on the ESS, indicating a greater propensity for daytime sleepiness (P = 0.006). However, male drivers were significantly more likely to report sleepiness while driving (P = 0.001). Conclusion: Sleepiness while driving was common among young male drivers in Oman and might be due to nocturnal sleep deprivation. Further studies are needed so that preventative measures can be developed. Keywords: Motor Vehicles; Traffic Accidents; Sleep; Fatigue; Obstructive Sleep Apnea Syndrome; Oman

Genetic Improvement in Dromedary Camels: Challenges and Opportunities

International audienc

Effects of an Adenotonsillectomy on the Cognitive and Behavioural Function of Children Who Snore: A naturalistic observational study

Objectives: This study aimed to evaluate cognitive and behavioural changes among 9–14-year-old Omani children with obstructive sleep apnoea (OSA) after an adenotonsillectomy (AT). Methods: This naturalistic observational study was conducted at the Sultan Qaboos University Hospital, Muscat, Oman, between January 2012 and December 2014. Omani children with adenotonsillar hypertrophy (ATH) underwent overnight polysomnography and those with confirmed OSA were scheduled for an AT. Cognitive and behavioural evaluations were performed using standardised instruments at baseline prior to the procedure and three months afterwards. Results: A total of 37 children were included in the study, of which 24 (65%) were male and 13 (35%) were female. The mean age of the males was 11.4 ± 1.9 years, while that of the females was 11.1 ± 1.5 years. Following the AT, there was a significant reduction of 56% in mean apnoea-hypopnoea index (AHI) score (2.36 ± 4.88 versus 5.37 ± 7.17; P <0.01). There was also a significant positive reduction in OSA indices, including oxygen desaturation index (78%), number of desaturations (68%) and number of obstructive apnoea incidents (74%; P <0.01 each). Significant improvements were noted in neurocognitive function, including attention/concentration (42%), verbal fluency (92%), learning/recall (38%), executive function (52%) and general intellectual ability (33%; P <0.01 each). There was a significant decrease of 21% in both mean inattention and hyperactivity scores (P <0.01 each). Conclusion: These results demonstrate the effectiveness of an AT in improving cognitive function and attention deficit hyperactivity disorder-like symptoms among children with ATH-caused OSA. Such changes can be observed as early as three months after the procedure. Keywords: Adenoidectomy; Obstructive Sleep Apnea; Cognitive Function; Behavior; Attention Deficit Hyperactivity Disorders; Children; Oman

Harmonics Temporal Profile in High-Voltage Networks: Case Study

This chapter presents a case study about harmonics measurements in high-voltage networks. Measurements were conducted at two locations in the main interconnected system (MIS) of Oman. Voltage and current THDs were recorded for a period of 1 week. The power quality analyzer was set to record required data for a period of 1 week, and the observation period for each recorded value is 10 minutes. At the first location, the grid station (132/33) is feeding industrial as well as other customers. The second grid station (220/132/33 kV) is dedicated to large industrial customers including arc furnaces and rolling mills. The power quality analyzer was installed at the 132 kV side of power transformers at both locations. Recorded data are analyzed, and temporal harmonics profiles are studied. A clear temporal variation of harmonics similar to that of aggregate load and local voltage profiles was observed at the grid station feeding mixed residential and industrial loads. However, this correlation between system load and harmonics profile diminishes at the grid station dedicated for heavy industrial loads

Advances in diamond nanofabrication for ultrasensitive devices

This paper reviews some of the major recent advances in single-crystal diamond nanofabrication and its impact in nano- and micro-mechanical, nanophotonics and optomechanical components. These constituents of integrated devices incorporating specific dopants in the material provide the capacity to enhance the sensitivity in detecting mass and forces as well as magnetic field down to quantum mechanical limits and will lead pioneering innovations in ultrasensitive sensing and precision measurements in the realm of the medical sciences, quantum sciences and related technologies