81 research outputs found

    Economic reform and political risk in the GCC: implications for U.S. government and business

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    The following is a transcript of the eighty-fifth in a series of Capitol Hill conferences convened by the Middle East Policy Council. The meeting was held at the Russell Senate Office Building in Washington, DC, on July 12, 2016, with Richard J. Schmierer, chairman of the board of directors of the Middle East Policy Council, moderating, and Thomas R. Mattair, Council executive director, serving as discussant. The video can be accessed at www.mepc.org

    Multimodal assessment of the effect of chewing gum on nicotine withdrawal

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    The present study was designed to evaluate the usefulness of chewing gum to reduce nicotine withdrawal, craving, and salivary cortisol concentrations during temporary nicotine deprivation. A total of 20 male smokers were studied under conditions when gum was and was not accessible during a 4-hour deprivation period. All subjects smoked an initial cigarette shortly after arrival for the two experimental sessions and were informed that they would be unable to smoke for the remainder of each session. The sessions consisted of each subject watching a movie, then waiting in the lab for two consecutive 30-min intervals. Self-reported nicotine withdrawal and craving were assessed four times and salivary cortisol five times during each experimental session. Results from this study indicate that chewing gum helps with self-reported withdrawal but not craving when a smoker is prevented from smoking. This study also provides preliminary data on the use of salivary cortisol as a physiological marker that may map these self-reports of nicotine withdrawal and craving

    Chitosan and its structural modifications for small interfering RNA delivery

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    The use of RNA interference mechanism and small interfering RNA (siRNA) in cancer gene therapy is a very promising approach. However, the success of gene silencing is underpinned by the efficient delivery of intact siRNA into the targeted cell. Nowadays, chitosan is one of the most widely studied non-viral vectors for siRNA delivery, since it is a biodegradable, biocompatible and positively charged polymer able to bind to the negatively charged siRNA forming nanoparticles (NPs) that will act as siRNA delivery system. However, chitosan shows several limitations such as low transfection efficiency and low solubility at physiological pH. Therefore, a variety of chemical and non-chemical structural modifications of chitosan were investigated in the attempt to develop a chitosan derivative showing the features of an ideal siRNA carrier. In this review, the most recently proposed chemical modifications of chitosan are outlined. The type of modification, chemical structure, physicochemical properties, siRNA binding affinity and complexation efficiency of the modified chitosan are discussed. Moreover, the resulting NPs characteristics, cellular uptake, serum stability, cytotoxicity and gene transfection efficiency in vitro and/or in vivo are described and compared to the unmodified chitosan. Finally, a critical analysis of a selection of modifications is included, highlighting the most promising ones for this purpose in the future

    Physical and chemical properties of seawater during 2013–2015 in the 400 m water column in the northern Gulf of Aqaba, Red Sea

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    This research investigated physical (temperature, salinity, and density) and chemical (dissolved oxygen, ammonium, nitrate, nitrite, phosphate, and silicate) properties of offshore seawater in the Red Sea northern Gulf of Aqaba; Jordanian Site were measured during 2013–2015 to assess the temporal and seasonal variation of the upper 400 m of the water column. The study also investigated seasonal variations, assessing the relationships of temperature with physical and chemical parameters. The average value of temperature for all data was 23.03 ± 1.58 °C. Temperature followed an expected seasonal cycle during 2013–2015, with well-mixed conditions in the upper 400 m of the water column during spring (Feb–Apr) and stratification during summer (Jul–Aug). There were no significant differences among years for temperature, but highly significant differences among months and depths. The average value of salinity (psu) for all data was 40.60 ± 0.10 with significant positive or negative differences among years, months, and depths. In general, dissolved oxygen, ammonium, nitrate, nitrite, and phosphate data showed positive or negative significant differences among months and depths with no significant annual variations. Silicate only showed significant differences among depths. Correlation tests between temperature and other parameters in the upper 25 m of the water column revealed significant inverse-relationships between temperature and all other parameters (other than salinity) that were attributed to the dominant thermal controls on seawater density, to the thermodynamic controls on oxygen solubility and to seasonal increases in light irradiance that allowed nutrient consumption by primary producers. In the intermediate water column (100–150 m), similar correlations were found as in the 0–25 m data, except for silicate. In the deeper waters (300–400 m), only salinity, density, and phosphate showed significant correlations with temperature, and indicated that the seasonal effects of primary production at depth were minimal. In general, the values of all parameters during the years 2013–2015 in the upper 400 m were comparable with previous studies (e.g., 1998–2003). In conclusion, this research manifested the strong correlation of temperature with some chemical parameters and presumed seasonal controls on primary production. Given the general lack of interannual variation, water quality in the northern Gulf of Aqaba appears relatively stable

    Cardiovascular Disease Diagnosis from DXA Scan and Retinal Images Using Deep Learning

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    Cardiovascular diseases (CVD) are the leading cause of death worldwide. People affected by CVDs may go undiagnosed until the occurrence of a serious heart failure event such as stroke, heart attack, and myocardial infraction. In Qatar, there is a lack of studies focusing on CVD diagnosis based on non-invasive methods such as retinal image or dual-energy X-ray absorptiometry (DXA). In this study, we aimed at diagnosing CVD using a novel approach integrating information from retinal images and DXA data. We considered an adult Qatari cohort of 500 participants from Qatar Biobank (QBB) with an equal number of participants from the CVD and the control groups. We designed a case-control study with a novel multi-modal (combining data from multiple modalities—DXA and retinal images)—to propose a deep learning (DL)-based technique to distinguish the CVD group from the control group. Uni-modal models based on retinal images and DXA data achieved 75.6% and 77.4% accuracy, respectively. The multi-modal model showed an improved accuracy of 78.3% in classifying CVD group and the control group. We used gradient class activation map (GradCAM) to highlight the areas of interest in the retinal images that influenced the decisions of the proposed DL model most. It was observed that the model focused mostly on the centre of the retinal images where signs of CVD such as hemorrhages were present. This indicates that our model can identify and make use of certain prognosis markers for hypertension and ischemic heart disease. From DXA data, we found higher values for bone mineral density, fat content, muscle mass and bone area across majority of the body parts in CVD group compared to the control group indicating better bone health in the Qatari CVD cohort. This seminal method based on DXA scans and retinal images demonstrate major potentials for the early detection of CVD in a fast and relatively non-invasive manner

    ABO, Lewis blood group systems and secretory status with H.pylori infection in yemeni dyspeptic patients: a cross- sectional study

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    Abstract Background The ABO and Lewis blood group antigens are potential factors in susceptibility to H. pylori infection. This research aimed to examine the prevalence of Helicobater pylori (H.pylori) infection and its association with ABO, Lewis blood group systems, and secretory status in Yemeni symptomatic patients. Methods In a cross-sectional study, 103 patients referred for endoscopy due to dyspepsia were included. H pylori infection was assessed using stool antigen and serum antibody rapid tests. ABO and Lewis blood group systems were examined using hemagglutination assay. Saliva samples were investigated for identification of the secretory phenotype using hemagglutination inhibition test. Results The prevalence of H. pylori infection was (80.6%), with a higher rate of infection in females than males. The ABO blood groups were found to be significantly different between males and females (p = 0.047). The O blood group was prevalent among H. pylori patients, especially secretors. There was a significant association between ABO blood groups and H. pylori infection (p = 0.001). The Le (a + b+) phenotype was the most common, followed by Le (a + b-), Le (a-b+), and Le (a-b-). Lewis blood group systems and secretory status of symptomatic patients were not associated with H. pylori infection. The results showed that serum Ab test for H. pylori achieved poor sensitivity (68%), specificity of 55%; positive predictive value (PPV) 86%, negative predictive value (NPV) 29% and accuracy 65.1%. Conclusion The prevalence of H. pylori infection was high in Yemeni patients. This infection was linked to the O and Le (a + b+) secretor phenotype. The H. pylori stool Ag test is the most reliable noninvasive diagnostic method for detecting H. pylori infection

    Wound Complications in Preoperatively Irradiated Soft-Tissue Sarcomas of the Extremities

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    PURPOSE: To determine whether the involvement of plastic surgery and the use of vascularized tissue flaps reduces the frequency of major wound complications after radiation therapy for soft-tissue sarcomas (STS) of the extremities. METHODS AND MATERIALS: This retrospective study evaluated patients with STS of the extremities who underwent radiation therapy before surgery. Major complications were defined as secondary operations with anesthesia, seroma/hematoma aspirations, readmission for wound complications, or persistent deep packing. RESULTS: Between 1996 and 2010, 73 patients with extremity STS were preoperatively irradiated. Major wound complications occurred in 32% and secondary operations in 16% of patients. Plastic surgery closed 63% of the wounds, and vascularized tissue flaps were used in 22% of closures. When plastic surgery performed closure the frequency of secondary operations trended lower (11% vs 26%; P =.093), but the frequency of major wound complications was not different (28% vs 38%; P =.43). The use of a vascularized tissue flap seemed to have no effect on the frequency of complications. The occurrence of a major wound complication did not affect disease recurrence or survival. For all patients, 3-year local control was 94%, and overall survival was 72%. CONCLUSIONS: The rates of wound complications and secondary operations in this study were very similar to previously published results. We were not able to demonstrate a significant relationship between the involvement of plastic surgery and the rate of wound complications, although there was a trend toward reduced secondary operations when plastic surgery was involved in the initial operation. Wound complications were manageable and did not compromise outcomes
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