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Vitamin D Status in Saudi Patients with Type 1 Diabetes Mellitus

Open Journal of Endocrine and Metabolic Diseases 2013年第2期3卷 137-143页

作者： Khalid Salim Aljabri S. A. Bokhari K. A. alqurashi Department of Endocrinology King Fahad Armed Forces Hospital Jeddah KSA

Aims/Introduction: There are studies in different countries regarding the prevalence of vitamin D deficiency in non diabetic population. Few studies were done in adults with type 1 diabetes mellitus. This study was conducted to determine Vitamin D Status among Saudi patients with type 1 diabetes and to correlate the associated environmental risk factors. Materials and Methods: A cross-sectional single centre study was conducted in 221 Saudi patients with type 1 diabetes mellitus. These patients were recruited through the Diabetes Centre at King Fahad Armed Forces Hospital between January 2008 and June 2009. 25-hydroxy-vitamin D, Parathyroid hormone, calcium, phosphate and alkaline phosphatase were measured. Results: There were 221 patients with type 1 diabetes mellitus, 92 males (42%) and 129 females (58%). The mean age was 21.3 ± 7.2 and the mean diabetes duration was 7.5 ± 5.7. The frequency of 25-hydroxyvitamin D 50 nmol/l and <25 nmol/l were 97% and 60% respectively. The frequency of 25-hydroxyvitamin D 25 nmol/l was significantly more frequent in female. 67% were either only exposed face or totally covered. Duration of sun exposure in 64% was less than 30 minutes per day. The area of skin exposed and duration of sunlight exposure associated significantly with Vitamin D levels (p 0.0001 and p 0.0001 respectively). Age was associated with more vitamin D < 25 nmol/l (the odds ratio (95% confidence interval);4.8 (4.6,14.5), p = 0.005;5.3 (1.8,15.5), p = 0.003;3.9 (1.5,10.5), p = 0.007 for age groups 12 - 15, 16 - 19 and 20 - 24 years old consequently. Male gender and exposing face, arms and legs to sun were associated with vitamin D ≥ 25 nmol/l;the odds ratio (95% confidence interval);0.27 (0.11,0.6), p = 0.001;0.26 (0.09,0.75), p = 0.01 consequently. Conclusions:

关键词： Type 1 Diabetes Mellitus Vitamin D Deficiency Frequency

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Stochastic modelling and estimation of inertial sensors

Stochastic modelling and estimation of inertial sensors

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第五届中国卫星导航学术年会

作者： Youlong Wu Jinling Wang Xiaoming Wang Muwaffaq alqurashi School of Mechanical Engineering Nanjing University of Science and Technology School of Civil and Environmental Engineering University of New South Wales

The Global Navigation Satellite System（GNSS） and Inertial Navigation System（INS） are two main navigation systems with complementary *** some GNSS challenged environments,due to signal jamming or blockage,INS becomes stand-alone navigation *** is a dead reckoning based system,and its performance will gradually degrade with *** performance degradation is mainly caused by the deterministic errors and stochastic errors according to their ***,precise modelling inertial sensors are the first and the most important step for the inertial navigation *** errors are due to manufacturing and mounting defects and can be calibrated out from the raw *** the other hand,stochastic errors are the random errors which cannot be removed from the measurements and should be modelled as ***,the better identification of the stochastic errors is critical for *** work on analysing and modelling inertial sensors is based on the computing the Allan variance of inertial sensors output and using least squares fitting or reading results from the Allan variance log-log plot *** paper presents a methodology for estimating the stochastic errors using segmented weighted ***,individual noise is simulated and the noise spectraldensity can be obtained through the least square to validate each noise ***,thesimulation studies with the combination of different noise types are carried out to compare withthe traditional *** proposed algorithm demonstrates remarkable improvement,especially in estimate the long-term errors compared with the traditional *** testresults also confirm the effectiveness of the new method.

关键词： Allan variance·stochastic modelling·inertial sensors

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Study of the Security Enhancements in Various E-Mail Systems

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Journal of Information Security 2015年第1期6卷 1-11页

作者： Afnan S. Babrahem Eman T. Alharbi Aisha M. Alshiky Saja S. alqurashi Jayaprakash Kar Department of Information Technology Faculty of Computing and Information Technology King Abdulaziz University Jeddah KSA Department of Information Systems Information Security Research Group Faculty of Computing and Information Technology King Abdulaziz University Jeddah KSA

E-mail security becomes critical issue to research community in the field of information security. Several solutions and standards have been fashioned according to the recent security requirements in order to enhance the e-mail security. Some of the existing enhancements focus on keeping the exchange of data via e-mail in confident and integral way. While the others focus on authenticating the sender and prove that he will not repudiate from his message. This paper will survey various e-mail security solutions. We introduce different models and techniques used to solve and enhance the security of e-mail systems and evaluate each one from the view point of security.

关键词： E-Mail Security Enhancement Malware Attacks Authentication Integrity

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