93 research outputs found
Attitudes of Kuwaiti Youth Towards Commercial Advertisements: a Field Study on the Students of Kuwait University
This study was based on the analytical survey method. The study was applied to a sample of 1149 Kuwaiti young males who were randomly selected. The study concluded:Social media was the most popular by 86.5%; and 47.8% of respondents showed interest in advertisements. The Internet ranked first in following up advertisements by 84.4%, followed by mobile phones which ranked second by 77.5%;The motive of recognition of what is new was ranked first by 60.9%, and the impact of advertisement came high by 42%. As for the behavioral effects, the item of retention and repetition of advertisement (music lyrics) ranked first by 44.2%. Keywords: Advertising- Youth - Kuwait - Purchasing - Social medi
Crystallization, mechanical, rheological and degradation behavior of polytrimethylene terephthalate, polybutylene terephthalate and polycarbonate blend.
Blends of polycarbonate (PC), polytrimethylene terephthalate (PTT) and poly butylene terephthalate (PBT) are an important class of commercial blends with numerous applications providing good chemical resistance and impact resistance even at low temperatures. Polycarbonate/polyester blends are known to react during thermal processing causing the formation of copolymers to have new mechanical and thermal properties. The aim of this project was to study the crystallization, mechanical, rheological and degradation behavior of blends of PC, PTT and PBT and explain these behaviors in terms of transesterification and other plausible mechanisms. PC, PTT and PBT (50:25:25 wt/wt ratio) were melt-blended in a single screw extruder and the extruded blends were pelletized. Non isothermal crystallization kinetics of the blend and neat polymers were investigated using a Perkin Elmer diamond DSC instrument having a fast response time. This thermoplastic blend was able to crystallize rapidly from the melt. Non isothermal crystallization kinetic parameters were analyzed using different numerical methods. Those parameters of the blend fell between those of PTT and PBT. The cause of this behavior could be due to the nature of PC as an amorphous polymer. Rheological properties of the blends were also studied at different temperatures. Rheological measurements were conducted to study the storage modulus, loss modulus, and viscosity values vis a vis the neat materials. Changes in complex viscosity (η*) and shear viscosity (η) were attributed to transesterification. The study presented in this work showed two fundamental issues that have never been addressed in the literature: one is the synthesis of a novel tricomponent system and other is how transesterification during polymer processing might affect the degradation and rheological properties of the tricomponent blend. Effect of blending on mechanical properties was carried out using tensile tests revealing a higher yield strength and elastic modulus of the blend. The morphology of the blend and neat polymers was studied using Scanning electron microscope (SEM), showing immiscibility of the blend components. X ray analysis was carried out to determine the crystalline nature of the blend vis a vis neat polymers. Existence of PTT and PBT peaks proved the immiscible nature of the system. Polymer blends can undergo, during processing, degradation because of the presence of both temperature and mechanical stresses. Compared to neat polymers, degradation of polymer blends shows distinct features because of the interaction between the different chemical species. These interactions can give rise to degradation or to the formation of copolymers which act as stabilizing agents. The non isothermal degradation kinetics of the blend and neat polymers were studied using dynamic thermogravimetry. The thermal stability of the polymers in air was studied and compared to that in nitrogen. The kinetic parameters were analyzed using different numerical methods. Polymers normally transesterify, above their melting points and interchange reactions commonly occur between polyester moieties or among polyester and polycarbonate entities. The transesterification occurring in the blend was analyzed with the help of Fourier Transform Infra- Red (FTIR) using spectral features based on changes of infra red bands
MRI characterisation of the lumbar spine in lower trunk rotation
Statistical data indicates that the percentage of prevalence of spine-related pain is considered to be high, and even up to 84%. The spinal manipulation technique, which is based on applying external forces to the shoulder and pelvis to twist the human spine can decrease lower back pain. Better understanding of the biomechanical behaviour of the normal lumbar spine during each rotational position of the lower trunk will provide valuable translational information to guide better physiotherapy in the future. It will also provide normal variant data that will help healthcare professionals and specialist in artificial spine implants to understand certain aspects of spinal pain. Therefore, this study proposes an MRI study of the lumbar spine during different lower-trunk rotational positions to investigate their effect on the normal spine structures with consideration of the shoulder and pelvis girdles’ motion.
To control the angle of the lower-trunk rotation, an MRI holder and an adaptive goniometer have been developed to position the subject and obtain accurate pelvis angle of rotation during the scan. Before starting the MRI scan, the position of the subject on the MRI holder was checked by calculating specific parameters. Standard supine and four lower-trunk rotational positions with unrestricted left and right shoulder movements were performed. T2 Sagittal, T2 coronal and T2 Axial 3D acquisition cuts were performed for the lumbar spine with a 1.5-T MRI scanner. The MR images were collected from volunteers and analysed using Image J software depending on the determination of particular anatomical landmarks and image processing techniques.
The results show that there is a significant difference between the position of the right and left scapula during lower trunk rotation, while there is no significant relation between the angle of rotation of L5 and the rotational angle of the posterior superior iliac spines relative to the horizontal plane in three tested sections of the sacroiliac joints. In addition, there is no significant difference in the angle of rotation of the examined sections of the sacroiliac joints during different rotational positions of the lower trunk. The effect of different lower trunk rotational positions on the angle of rotation of the lower lumbar segment and spinal canal depth was measured and it was found that the second rotational lower trunk rotational position caused the highest relative motion of the lower lumbar vertebra, while the first lower trunk rotational position caused the highest rotational torque between L5 and L3. In addition, the mean
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difference in the spinal canal depth increased significantly following the degree of the applied lower trunk rotational position. Lower trunk rotation caused morphologic changes in the intervertebral discs and intervertebral foramens at L3-L4, L4-L5, and L5-S1 levels. However, the significant change in the area, width and height of the intervertebral foramen and disc depended on the rotational positions of the lower trunk. A strong anatomical relationship was indicated between the posterior height of the intervertebral disc at both sides and the foraminal height. Finally, the degree of the lateral bending was the greatest at the L4-L5 level. The mean differences between the left and right superior articular processes according to their orientation angle and gapping distance at the L3-L4 level were higher than those of the other tested levels, while the L5 level recorded the lowest values. However, the mean differences did not achieve significant effects.
These results may provide baseline information to enable the development of artificial implants of the right and left lumbar facet joints according to changes in lower trunk rotational positions. They can also help to explain the treatment benefits of manipulation therapy in spinal conditions
Tuberous Sclerosis Complex with Renal Stones and Distal Renal Tubular Acidosis: Case Report and Literature Review
Distal renal tubular acidosis (RTA) is a common cause of renal stones and nephrocalcinosis in children. Distal RTA can be either acquired or congenital because of a genetic defect. Tuberous sclerosis complex is an autosomal dominant inherited neurocutaneous syndrome with variable renal involvement. We describe a case of a six-year-old boy with tuberous sclerosis complex who developed distal RTA and renal stones
بناء برنامج تعليمي قائم على تطبيقات الذكاء الاصطناعي وقياس فاعليته في تنمية المفاهيم الجغرافية الحديثة لدى الطلاب الموهوبين بالمرحلة الثانوية في المملكة العربية السعودية
هدفت الدراسة الحالية إلى بناء برنامج تعليمي مقترح قائم على تطبيقات الذكاء الاصطناعي، وقياس فاعليته في تنمية المفاهيم الجغرافية الحديثة لدى الطلاب الموهوبين بالمرحلة الثانوية في المملكة العربية السعودية. ولتحقيق ذلك، اختيرت عينة عشوائية متيسرة بلغت (37) طالبًا من مجتمع الدراسة، وقد وقع الاختيار على إحدى المدارس الثانوية – نظام المقررات – في مدينة الطائف عشوائيًا، وعلى خمسة طلاب من مجموعة الدراسة لإجراء دراسة الحالة، بعد الحصول على موافقتهم للمشاركة. واتبعت الدراسة منهجية التثليث، التي تضمنت ثلاث مناهج بحثية، وهي: المنهج الوصفي الوثائقي لبناء البرنامج التعليمي المقترح، والمنهج شبه التجريبي– ذو تصميم المجموعة الواحدة لقياس فاعلية البرنامج التعليمي المقترح، ومنهج دراسة الحالة لإثراء الدراسة بالبيانات النوعية التي تدعم تفسير النتائج الكمية. وجمعت بيانات الدراسة الكمية باستخدام اختبار التحصيل المعرفي للمفاهيم الجغرافية الحديثة، أيضًا استخدمت لجمع البيانات النوعية أسئلة المقابلة شبه المقننة. وحُللت البيانات الكمية بالأساليب الإحصائية الوصفية والاستدلالية المناسبة باستخدام برنامج (SPSS)، ورُتبت البيانات النوعية وصُنفت لدراسة الحالة، وعُرضت نتائجها بالطريقة المستندة إلى الطريقة المجذرة لتحليل البيانات النوعية. وكشفت نتائج الدراسة في جانبها الكمي عن وجود فروق ذات دلالة إحصائية عند مستوى الدلالة (0.01 ≥ α)، بين متوسطي درجات مجموعة الدراسة في التطبيقين القبلي والبعدي للمتغير المعتمد في اختبار التحصيل المعرفي للمفاهيم الجغرافية الحديثة، لصالح التطبيق البعدي. كشفت النتائج أيضًا عن تأثير كبير(مرتفع) للبرنامج التعليمي المقترح؛ فقد بلغ معامل التأثير (7.28)، ووصلت نسبة معامل بلاك للكسب المعدل للمتغير المعتمد إلى (1.27)، مما يدل على فاعلية عالية للمتغير المعتمد على البرنامج التعليمي. كما أكدت النتائج النوعية على الدور الرائد للبرنامج التعليمي في تزويد الطلاب الموهوبين بالمفاهيم الجغرافية الحديثة؛ لارتباطها بواقعهم الحالي. وبناءً على نتائج الدراسة؛ قُدمت مجموعة من التوصيات والمقترحات ذات الصلة
Women’s empowerment and its effect on community development in Oman: predictive model and indicators for best practices
ABSTRACT
This study investigates the level of women’s empowerment in Omani society from the point of view of female university students from three public universities with respect to educational opportunity, equality in employment and their social status in the community. The study proposes a model for how to empower women based on the perceptions of university females and the factors that must be considered for improving the status of women in Oman. The model also provides indicators for social
and community practices using confirmatory factor analysis and Path Analysis to determine pertinent factors and their effects on women’s development. The results showed a strong direct effect of women’s empowerment in Oman on community development. Despite the latest developments in Oman, as long as cultural rigidity remains, tradition upholds a conservative viewpoint of women, and families adhere to their uncompromised principles, women will remain subordinated by these factors according to the viewpoint of participants. This study concludes with recommendations for further research, including enrolment of females in all areas of specialisation creating more job opportunities for women, encouraging women’s leadership, and
additional education of women’s rights and needs
Medicago orbicularis Has Antioxidant, Antihemolytic, and Anti-cancerous Activities and Augments Cisplatin-Induced Cytotoxicity in A549 Lung Cancer Cells
Cancer is the second leading cause of death, worldwide. Lung cancer is the leading cause of cancer-related mortality. Plant-based therapeutics and herbal medicine have played a vital role in the development of several anti-cancerous agents, and has been used to reduce the severe side effects of chemotherapy as well. Since the anti-lung cancer properties of the plant Medicago. orbicularis are not explored yet, we identified its phytochemical composition and investigated the anti-oxidant, anti-hemolytic, and anti-cancerous properties of extracts of this plant in A549 human lung adenocarcinoma cells. Results show that all parts of M. orbicularis (stems, leaves, and fruits) exhibit remarkable anti-oxidant and hemolytic activities. In addition, all extracts showed a dose-dependent anti-cancerous cytotoxic activity against A549 cells; with fruit extracts being the most potent. This cytotoxic effect could be related, at least partly, to the induction of apoptosis, where M. orbicularis fruit extracts activated Caspase-3 and PARPP-1, and reduced the ratio of anti-apoptotic BCL-2/ pro-apoptotic BAX, thereby promoting cellular death. Furthermore, the use of M. orbicularis, in combination with a conventional chemotherapeutic agent, cisplatin, was assessed. Indeed, combination of cisplatin and M. orbicularis fruit extracts was more cytotoxic and induced more aggregation of A549 cells than either treatment alone. GC-MS analysis and total polyphenol and flavonoid content determination indicated that M. orbicularis is rich in compounds that have anti-cancerous effects. M. orbicularis may be a potential source of anti-cancerous agents to manage progression of lung cancer and its resistance to therapy.This work was supported by the a grant from the Lebanese University to SN and student grants
number QUST-1-BRC-2022-315; QUST-1-BRC-2022-316, QUST-1-BRC-2023-836; and QUST-1-BRC-2023-846 to
AS. Publication fees APC were covered by Qatar National Library (QNL)
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