150 research outputs found
The Comparative Correlative Construction in Modern Standard Arabic
Much discussion of the comparative correlative construction exemplified by The more I read, the more I understand has been concerned with how much cross?linguistic variation there is in this area. Culicover and Jackendoff (1999) suggest that there is considerable variation, but Den Dikken (2005) suggests with data from a variety of languages that the variation is quite limited. Modern Standard Arabic has a comparative correlative construction which is quite different from Engish and the other languages that Den Dikken considers, suggesting that there is more variation in this domain than he assumes. However, it is not difficult to provide an analysis of the construction and other related constructions within the HPSG framework
Open-Circuit Voltage in Inverted Polycarbazole:Fullerene Bulk Heterojunction Solar Cells
The correlation between cathode work function and open-circuit voltages (Voc) in inverted polycarbazole:fullerene (PCDTBT:PC70BM) bulk-heterojunction solar cells has been investigated by postannealing of indium tin oxide (ITO) electrodes. The ITO function is seen to change from 4.2 to 4.5 eV without the need to insert additional interfacial layers with annealing temperature up to 400 °C. The best device performance was obtained at room temperature with the ITO work function of 4.2 eV with a Voc of 0.89 eV, a Jsc of 8.06 mA·cm-2, a fill factor (FF) of 64.70%, and a power conversion efficiency of 4.62%. Together with previously published results, we are able to extract two regimes of Voc dependence on the cathode work function: first, a linear relationship when the cathode work function exceeds the lowest unoccupied molecular orbital (LUMO) of PCBM and, second, a constant Voc regime when the ITO work function reduces below the LUMO level. These results provide general guidelines for the cathode contact design in inverted polymer solar cells
Investigation into the genetic variation of Toll-Like Receptor 9 in cattle using both Sanger and next-generation sequencing from FTA-Cards
The susceptibility or resistance to infectious diseases depends on the host immune response. The genetic variation of immune-relevant genes such as Toll-Like Receptor (TLR) genes is associated with susceptibility or resistance to the pathogen. In this thesis, the genetic variation of Toll-like receptor 9 (TLR9) was investigated; this gene is known to have a function in parasite recognition. In a previous study from the Hide lab, 80 bovine blood samples were collected from bulls in Ahoada, Nigeria and the samples were stored on Whatman FTA cards. In this study bovine genomic DNA was extracted from the FTA cards using three different approaches: 5% Chelex resin, the REPLI-g Mini (Qiagen) and the DNeasy Blood & Tissue Kit (Qiagen). The most efficient method for DNA extraction was via the DNeasy Blood & Tissue (Qiagen) kit and this allowed a PCR protocol to be developed for amplification of a fragment of the bovine TLR9 gene. Subsequently, Sanger sequencing and Next Generation Sequencing (NGS) approaches validated the existence of genetic variation across a 554 bp region of exon 2 (f1TLR9) of the bovine TLR9 gene. Moreover, our data revealed that there is no significant correlation between Trypanosoma infection and the existence of genetic variations of f1TLR9 in Bos. indicus cattle from Nigeria; the interrater reliability between NGS and Sanger sequencing was intermediate. In conclusion, high- quality bovine DNA was extracted from FTA cards to allow PCR amplification and detection of genetic variation within exon 2 of the TLR9 gene by two independent sequencing approaches. These results provide a methodology for facilitating future studies into the existence of genetic variation in other TLR and immune-relevant genes and whether, or not, these correlate with disease susceptibility, or resistance, in both humans and animals
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Compliance with tobacco control policy and visibility of cigarette retailers around educational facilities in Riyadh, Saudi Arabia
Background: In Saudi Arabia, cardiovascular diseases are among the top causes of death and disability, and smoking is one of the leading risk factors, particularly among males. Objective: Our study aims to evaluate the compliance with the anti-smoking law among cigarette retailers and examine the visibility of cigarette retailers around educational facilities in Riyadh city, Saudi Arabia. Methods: We conducted a mapping survey and geospatial analysis of cigarette retailers around educational facilities from February to March 2020 (before the COVID-19 restriction) in Al-Olaya municipality in Riyadh city as a pilot study. We found 249 retailers, of which 152 sold cigarettes. Data analyses in ArcMap 10.6 compared the visibility within 250 and 500 meters from educational facilities. Results: We found many retailers were not compliant with the tobacco control regulation: 57.1% of minimarkets sell cigarettes, 15.8% of cigarette retailers display the products openly, and 12.5% of cigarette retailers sold cigarettes by the stick. Moreover, 71% of the total cigarette retailers were within 500 m from schools, and 62% of all schools had at least one cigarette retailer within 500 m buffer (5-min walking or 2–3-min driving distance). Conclusion: There is non-compliance with the anti-smoking law among cigarette retailers and high visibility of cigarette retailers around educational facilities in Saudi Arabia. Monitoring is needed for the effective implementation of tobacco control policies
Thermally stable solution processed vanadium oxide as a hole extraction layer in organic solar cells
Low-temperature solution-processable vanadium oxide (V2Ox) thin films have been employed as hole extraction layers (HELs) in polymer bulk heterojunction solar cells. V2Ox films were fabricated in air by spin-coating vanadium(V) oxytriisopropoxide (s-V2Ox) at room temperature without the need for further thermal annealing. The deposited vanadium(V) oxytriisopropoxide film undergoes hydrolysis in air, converting to V2Ox with optical and electronic properties comparable to vacuum-deposited V2O5. When s-V2Ox thin films were annealed in air at temperatures of 100 °C and 200 °C, OPV devices showed similar results with good thermal stability and better light transparency. Annealing at 300 °C and 400 °C resulted in a power conversion efficiency (PCE) of 5% with a decrement approximately 15% lower than that of unannealed films; this is due to the relative decrease in the shunt resistance (Rsh) and an increase in the series resistance (Rs) related to changes in the oxidation state of vanadium
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Consumption of a flavonoid-rich acai meal is associated with acute improvements in vascular function and a reduction in total oxidative status in healthy overweight men
Background: Acai (Euterpe oleracea) is a polyphenol-rich fruit marketed as beneficial for health. Experimental data showing improvements in health markers arising from acai consumption in humans is limited.
Objective: The objective of the present study was to investigate the effect of acai consumption on acute changes in vascular function and on other disease risk markers, including postprandial plasma insulin, glucose, and oxidative stress.
Design: Twenty-three healthy male volunteers, aged 30–65 y and with a body mass index (in kg/m2) of 25–30, completed a randomized,controlled, high-fat challenge, double-blind, crossover, acute dietary intervention trial. The volunteers consumed either an acai-based smoothie (AS) or a macronutrient-matched control smoothie (PS) together with a high-fat breakfast meal challenge. The primary endpoint was the assessment of endothelial function in the brachial artery by flow-mediated dilatation (FMD).
Results: The acute consumption of an AS containing 694 mg total phenolics improved vascular function, with postprandial increases in FMD from baseline of 1.4% at 2 h compared with 0.4% after consumption of the PS (P = 0.001) and increases at 6 h of 0.8% for the AS compared with 20.3% for the PS (P , 0.001). There was also a significantly lower incremental area under the curve (iAUC)for total peroxide oxidative status after acai consumption relative to the control. No significant changes were observed in blood pressure,heart rate, or postprandial glucose response. However, the first postprandial insulin peak (after breakfast) and the iAUC for insulin were elevated for the AS relative to the PS.
Conclusions: In this acute study in overweight men, acai consumption was associated with improvements in vascular function, which may lower the risk of a cardiovascular event. Future intervention studies, perhaps with a chronic design, in wider populations and with other biomarkers of disease risk are needed to fully elucidate the benefits of acai to health
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Density of Fast Food Outlets around Educational Facilities in Riyadh, Saudi Arabia: Geospatial Analysis
Background: Childhood obesity remains a public health issue globally. The latest estimate from the World Health Organization showed that over 340 million children and adolescents aged 5–19 were overweight or obese in 2016. Objective: Our study aimed to assess the density of fast food outlets around educational facilities in Riyadh, Saudi Arabia.
Methods: We employed geospatial and quantitative analyses using data on fast food outlets (from surveys conducted between November 2019 and May 2020) and educational facilities in Riyadh city. Data analyses conducted using ArcMap 10.6 and Stata 15 compared the density within 500 m and 500–1000 m from the facilities.
Results: We found a high density of fast food outlets around educational facilities. Nearly 80% of fast food were within twelve-minute walking or five-minute driving distances from schools, and nearly 70% of all educational facilities had at least one fast food outlet within the buffer. We also found the densities were high within both the areas closer and the areas farther away from educational facilities. In addition, the density was significantly higher around private schools compared to government schools, and the density around girls-only schools and both-gender schools was higher than that around boys-only schools.
Conclusion: There is a high density of fast food outlets around educational facilities in Saudi Arabia. Effective policies are needed to help reduce potential exposure to fast food among young people in Saudi Arabia and other countries with similar settings
Nanosecond pulsed laser texturing of optical diffusers
High-quality optical glass diffusers have applications in aerospace, displays, imaging systems, medical devices, and optical sensors. The development of rapid and accurate fabrication techniques is highly desirable for their production. Here, a micropatterning method for the fast fabrication of optical diffusers by means of nanosecond pulsed laser ablation is demonstrated (λ=1064 nm, power=7.02, 9.36 and 11.7 W and scanning speed=200 and 800 mm s-1). The experiments were carried out by point-to-point texturing of a glass surface in spiral shape. The laser machining parameters, the number of pulses and their power had significant effect on surface features. The optical characteristics of the diffusers were characterized at different scattering angles. The features of the microscale structures influenced average roughness from 0.8 μm to 1.97 μm. The glass diffusers scattered light at angles up to 20° and their transmission efficiency were measured up to ∼97% across the visible spectrum. The produced optical devices diffuse light less but do so with less scattering and energy losses as compared to opal diffusing glass. The presented fabrication method can be applied to any other transparent material to create optical diffusers. It is anticipated that the optical diffusers presented in this work will have applications in the production of LED spotlights and imaging devices
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