Internet addiction, fatigue, and sleep problems among adolescent students: a large-scale study

Aim: The aim of the present study was to examine the association between Internet Addiction (IA), fatigue, and sleep problems among university students. Methods: A total of 3,000 Turkish students aged 18 to 25 years were approached and 2,350 students (78.3%) participated in this cross-sectional study from April 2017 to September 2017 in public and private universities in Istanbul. Data were collected via a structured questionnaire including socio-demographic details, lifestyle and dietary habits, Internet Addiction Test (IAT), Fatigue Scale, and Epworth Sleepiness Scale [ESS]. Descriptive statistics, multivariate and factorial analyses were performed. Results: The overall prevalence of IA among the studied population was 17.7%. There were significant differences between gender, family income, father’s occupation, school performance, frequency and duration of watching television, physical activity, internet use duration, and sleep duration (all p<0.001). Significant differences were also found between participants with IA and those without IA in having headaches, blurred vision, double vision, hurting eyes, hearing problems, and eating fast food frequently (all p<0.001). Using multivariate regression analysis, the duration of internet use, physical and mental symptoms, headache, hurting eyes, tired eyes, hearing problems and ESS scores were significantly associated with (and primary predictors of) IA. Conclusion: The present study demonstrated that IA was associated with poor dietary habits, sleep problems, and fatigue symptoms

Safety of vaginal birth after cesarean delivery

Objective: To compare the outcomes of labor induction in women with a history of 1 cesarean section (CS) who undergo trial of labor. Methods: A prospective observational study of 702 pregnant women who had 1 previous CS was conducted at Women's Hospital, Hamad Medical Corporation, Doha, Qatar, between April 2003 and April 2004. Those with no history of vaginal delivery were assigned to one group and those with a history of vaginal delivery were assigned to another group, and the latter group was then divided into 2 subgroups according to the results of trial of labor. Results: Of these 702 women with a history of 1 CS, 62.4% also had a history of vaginal delivery. After trial of labor, vaginal delivery occurred more often among women with no history of vaginal delivery (64.8%). Moreover, trial of labor resulted in a vaginal delivery more often in women who were delivered only once and by CS (87.7%) than in women who also had a history of vaginal delivery (79.2%). Conclusion: These findings indicate that women who have had a CS should strongly consider natural delivery for subsequent pregnancies. (c) 2005 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved

Association between blood levels of lead, blood pressure and risk of diabetes and heart disease in workers

Background: Previous studies have supported the association between high levels of blood lead levels (BLL) and elevated blood pressure. In addition, significant correlations between BLL and a variety of risk factors for blood pressure and diabetes mellitus have been well-established. Objective: To examine the relationship between BLL, blood pressure and diabetes as well as other selected social and biochemical factors, among workers in the United Arab Emirates (UAE). Methods: This comparative study included 110 industrial workers (exposed to lead in the workplace) and 110 non-industrial workers (not exposed), all were recruited in the city of Al-Ain, Abu-Dhabi Emirate, UAE and the groups were evenly matched for age, gender and nationality. Results: The industrial workers had a significantly higher mean of BLL (median 81 and geometric mean (GM) 62 mug/dl) than did non-industrial workers (median 11 and GM 13 mug/dl). In the present study, the lead-exposed group also had significantly higher blood lead levels, body-mass index (BMI), systolic and diastolic blood pressures., fasting blood glucose and plasma levels of total cholesterol, lactate dehydrogenase and uric acid than did the non-exposed group. Furthermore a significant correlation between BLL and systolic blood pressure was observed. Conclusion: The study supports the hypothesis of a positive association between lead exposure, high blood pressure and risk of diabetes and heart disease

Bio-Inspired Passive Drag Reduction Techniques: A Review

It was believed that fluid flow and the laminar to turbulent transition delay were more easily controlled on smooth surfaces until the discovery of the grooved shark skin surface that changed the whole idea of how smooth the surface should be to have high flow in submerged surfaces. Riblets have gained renewed interest in academic fields of study and in industry due to several advantages in manipulating the turbulence boundary layer. Drag reduction using small, longitudinally grooved surface provides up to 10 % lower energy consumption in several applications. This review provides an overview of the mechanism of drag reduction with riblets, the different geometries and types, and the latest developments in drag reduction riblet technology

Wall pressure signatures of turbulent flow over longitudinal

Five triangular riblets longitudinal in the streamwise direction have been studied experimentally. The riblets have pick to pick spaced (s) equal to 1000 μm and with groove height to space ratio (h/s) 0.4, 0.6, 0.8 and 1. The tests were conducted in a full turbulence water channel on a flat plate for Reynolds numbers 13000 to 53000 based on channel hydraulic diameter. Pressure drop was measured using pressure transmitter gauge with pressure tap points of 12.7 mm in diameter were provided at the bottom of the channel. The main purpose of the present study is to investigate the response of turbulent flow to longitudinal grooves of triangular shaped riblets and compare the effect of the turbulence structure over smoothed and grooved surfaces with pressure drop measurements. 10.20 was the maximum drag reduction appear at h/s equal to (1)

Wall pressure signatures of turbulent flow over longitudinal

Five triangular riblets longitudinal in the streamwise direction have been studied experimentally. The riblets have pick to pick spaced (s) equal to 1000 μm and with groove height to space ratio (h/s) 0.4, 0.6, 0.8 and 1. The tests were conducted in a full turbulence water channel on a flat plate for Reynolds numbers 13000 to 53000 based on channel hydraulic diameter. Pressure drop was measured using pressure transmitter gauge with pressure tap points of 12.7 mm in diameter were provided at the bottom of the channel. The main purpose of the present study is to investigate the response of turbulent flow to longitudinal grooves of triangular shaped riblets and compare the effect of the turbulence structure over smoothed and grooved surfaces with pressure drop measurements. 10.20 was the maximum drag reduction appear at h/s equal to (1)