Augmented Reality and Context Awareness for Mobile Learning Systems

Learning is one of the most interactive processes that humans practice. The level of interaction between the instructor and his or her audience has the greatest effect on the output of the learning process. Recent years have witnessed the introduction of e-learning (electronic learning), which was then followed by m-learning (mobile learning). While researchers have studied e-learning and m-learning to devise a framework that can be followed to provide the best possible output of the learning process, m-learning is still being studied in the shadow of e-learning. Such an approach might be valid to a limited extent, since both aims to provide educational material over electronic channels. However, m-learning has more space for user interaction because of the nature of the devices and their capabilities. The objective of this work is to devise a framework that utilises augmented reality and context awareness in m-learning systems to increase their level of interaction and, hence, their usability. The proposed framework was implemented and deployed over an iPhone device. The implementation focused on a specific course. Its material represented the use of augmented reality and the flow of the material utilised context awareness. Furthermore, a software prototype application for smart phones, to assess usability issues of m-learning applications, was designed and implemented. This prototype application was developed using the Java language and the Android software development kit, so that the recommended guidelines of the proposed framework were maintained. A questionnaire survey was conducted at the University, with approximately twenty-four undergraduate computer science students. Twenty-four identical smart phones were used to evaluate the developed prototype, in terms of ease of use, ease of navigating the application content, user satisfaction, attractiveness and learnability. Several validation tests were conducted on the proposed augmented reality m-learning verses m-learning. Generally, the respondents rated m-learning with augmented reality as superior to m-learning alone

Rutile-TiO2 based materials for lithium ion batteries

Although widely used, the most promising Li-based energy storage systems still suffer from a lack of suitable electrodes. There is therefore a need to seek new materials to satisfy the increasing demands for energy storage worldwide. TiO2 is a very promising anode material for lithium rechargeable batteries. It has a low insertion voltage of Li and high theoretical specific capacity. However, Li insertion into bulk rutile is negligible at room temperature due to the dense close packing of the rutile structure; also it suffers from a poor electronic conductivity. The electrochemical performance of pure rutile reveals that only 0.11 mol of Li can be inserted into rutile structure with a specific capacity of 26 mAh/ g. The main objective of this thesis has been to seek ways to improve the performance and charge storage capacity of rutile by compositional modification Improvement of the electronic conductivity of rutile by quenching oxygen-deficient samples and its influence on electrochemical performance have been studied and compared with that of fully oxidized rutile. An improvement in charge-discharge capacity was achieved; 0.21 Li per mol of TiO2 corresponding to 49 mAh/ g in the first cycle, but for subsequent cycles, both became similar which indicates that increasing the electronic conductivity by quenching did not give a long term improvement and suggests that lattice dimensions rather than electronic conductivity may be the reason for the poor perfomance of rutile anode. Substitution of Ti4+ with metal ions of either similar or different valence to increase the lattice dimensions and/or to increase the electronic conductivity is an option to improve the electrochemical performance of rutile TiO2. In this study, the effect of doping with large Sn4+ and co-doping with Cu-M (M= Nb, Ta) on the electrical and electrochemical performance is presented. The objective was first, to increase the unit cell dimensions of rutile by doping. This is based on the hypothesis that insertion of Li into TiO2 rutile would be easier with an expanded unit cell. Solid solutions have been prepared via solid state reaction where Ti4+ is partially replaced by either Sn4+ or a combination of divalent (Cu2+) and pentavalent ions (Nb5+, Ta5+). Single-phase solid solutions of the doped systems have been characterised by XRD and indexed on a tetragonal rutile structure; lattice parameter refinement confirms the expansion in the unit cell dimensions. Lithium test cells were fabricated using the rutile solid soultions as anodes. The first discharge step reveals that up to one mole of Li ion can intercalate into codoped Cu-Nb or Cu-Ta at room temperature with a discharge capacity up to 78 mAh/g while a specific capacity of 154 mAh/ g was delivered by Sn-doped rutile. These examples of lattice expanded doped rutile show a much higher electroactivity towards Li insertion than undoped rutile with excellent retention of capacity during cycling. Ex-situ XRD indicates excellent structural stability during cycling with no evidence of major changes in the rutile crystal structure. However, a major drawback in their electrochemical behaviour was a significant loss of capacity on cycling. The variation in the electrical properties of doped systems with the nature and composition of metal electrode and atmosphere was studied for Cu-Nb and Cu-Ta co-doped rutile. The formation of a potential barrier, due to the presence of residual phase at the grain boundary, was indicated by impedance spectroscopy (IS) in codoped system, the data showing a Schottky-like nature. The SnxTi1-xO2 system exhibits resistive behaviour, with high activation energy for all compositions. The effect of rutile TiO2 as starting material on the electrochemical performance of Li4Ti5O12 (LTO) was examined and compared with that of anatase TiO2. High purity LTO was obtained using rutile starting material but the specific capacity was slightly higher for LTO prepared using anatase than rutile

The Teaching Practices Level among the Secondary School Physics Teachers for the Second Grade in Light of the Scientific Inquiry Characteristics in Riyadh City

The study aims to uncover the teaching practice level among secondary school physics teachers for the second grade in Riyadh. The study used a descriptive survey to attain its goal. The study item was a notecard, and the sample included 61 female public school Physics teachers. The results revealed a lack of physics teachers' teaching practices in second-grade secondary school for scientific inquiry characteristics such as scientificoriented questions, formulating explanations from evidence, linking descriptions to scientific knowledge, and communicating and justifying explanations. Moreover, there were no statistically significant variations in physics teachers' teaching techniques based on years of experience, except for behaviors relating descriptions to scientific knowledge, favoring professors with 15 years or more of experience. Except for teaching practices linked to "communication and justification of explanations," there were statistically significant variations between physics teachers' teaching practices for variable training courses in scientific inquiry. As a result of these findings, the researcher proposes providing training and professional development programs for female instructors in scientific investigations and revising teacher preparation programs for male and female teachers

The effects of cultural aspects and leadership practices on the healthcare organizations' performance: the case of Saudi Arabia

This article aims to investigate the effects of cultural factors and leadership practices towards organisational performance development in healthcare organizations. A case study of one of Saudi Arabia’s key healthcare providers was used. This study investigated the leadership practices, organizational culture, and performance improvement in the case study of healthcare organisations using qualitative interpretive paradigm to explore, explain and describe “the current state” based on the perceptions and opinion of individuals. Constructive-interpretivism philosophical approach is used for this study, employing a qualitative strategy. The study is specifically sought to determine the factors that promote and inhibit leadership performance improvement culture. Results suggest the heavy influences of organisational culture and other factors in the case study sector such as religious and national cultures, on the leadership performance. Research participants indicate that positive and negative behaviours of leaders and executives in top management affect the performance of employees and shape the organisational culture. The implications of these findings are highlighted, as well as the need to further explore how cultural factors and leadership practicescan affect the level of productivity in this vital sector

Acceptor and Donor Dopants in Potassium Sodium Niobate Based Ceramics

B-site doping in potassium sodium niobate (KNN) with Mn2+ (Mn′′′Nb) and Ti4+ (Ti′Nb) dopants were soluble but prevented KNN from achieving a high relative density, while Sn4+ (Sn′Nb) was not soluble in the structure as evidenced by second phase peaks in X-ray diffraction (XRD) traces. However, SnO2 was an effective sintering aid in KNN-50/50. A-site doping with Sr2+ (Sr⋅(Na,K)) up to 1 mol% initially improved dielectric properties but higher sintering temperatures were required for compositions with >1 mol% Sr. Samples with 5% and 7% of Sr-doping completely shifted the transition of TO–T to below RT and broadened the TC peaks as the relaxor. All Ti-doped and Sr-doped compositions showed an increase in conductivity, manifested as high values of dielectric loss (tanδ). More than 1% of acceptor and donor dopants showed the ionic-type conduction mechanism, while 1% displayed the electronic mechanism as attributed from the strongly frequency-dependent tanδ. In conclusion, these samples have the potential to open up new applications in the field of electroceramics

Structure and electrochemical activity of nickel aluminium fluoride nanosheets during urea electro-oxidation in an alkaline solution

An electrocatalyst of potassium nickel aluminium hexafluoride (KNiAlF6) nanosheets has been prepared using solid-phase synthesis at 900 °C. X-ray diffraction, scanning electron microscopy, and conductivity studies confirmed the formation of KNiAlF6 nanosheets having a cubic defect pyrochlore structure with an average thickness of 60–70 nm and conductivity of 1.297 × 103 S m−1. The electrochemical catalytic activity of the KNiAlF6 nanosheets was investigated for urea oxidation in alkaline solution. The results show that the KNiAlF6 nanosheets exhibit a mass activity of ∼395 mA cm−2 mg−1 at 1.65 V vs. HRE, a reaction activation energy of 4.02 kJ mol−1, Tafel slope of 22 mV dec−1 and an oxidation onset potential of ∼1.35 V vs. HRE which is a significant enhancement for urea oxidation when compared with both bulk Ni(OH)2 and nickel hydroxide-based catalysts published in the literature. Chronoamperometry and impedance analysis of the KNiAlF6 nanosheets reveal lower charge transfer resistance and long-term stability during the prolonged urea electro-oxidation process, particularly at 60 °C. After an extended urea electrolysis process, the structure and morphology of the KNiAlF6 nanosheets were significantly changed due to partial transformation to Ni(OH)2 but the electrochemical activity was sustained. The enhanced electrochemical surface area and the replacement of nickel in the lattice by aluminium make KNiAlF6 nanosheets highly active electrocatalysts for urea oxidation in alkaline solution

Factors associated with poor outcomes among hospitalized patients with COVID-19: Experience from a MERS-CoV referral hospital

BACKGROUND: Coronavirus disease 2019 (COVID-19) has resulted in millions of deaths, including more than 6000 deaths in the Kingdom of Saudi Arabia (KSA). Identifying key predictors of intensive care unit (ICU) admission and mortality among infected cases would help in identifying individuals at risk to optimize their care. We aimed to determine factors of poor outcomes in hospitalized patients with COVID-19 in a large academic hospital in Riyadh, KSA that serves as a Middle East Respiratory Syndrome coronavirus (MERS-CoV) referral center. METHODS: This is a single-center retrospective cohort study of hospitalized patients between March 15 and August 31, 2020. The study was conducted at King Saud University Medical City (KSUMC). COVID-19 infection was confirmed using real-time reverse transcriptase polymerase chain reaction (RT-PCR) for SARS-COV-2. Demographic data, clinical characteristics, laboratory, radiological features, and length of hospital stay were obtained. Poor outcomes were, admission to ICU, need for invasive mechanical ventilation (IMV), and in-hospital all-cause mortality. RESULTS: Out of 16,947 individuals tested in KSUMC, 3480 (20.5%) tested positive for SARS-CoV-2 and of those 743 patients (21%) were hospitalized. There were 62% males, 77% were younger than 65 years. Of all cases, 204 patients (28%) required ICU admission, 104 (14%) required IMV, and 117 (16%) died in hospital. In bivariate analysis, multiple factors were associated with mortality among COVID-19 patients. Further multivariate analysis revealed the following factors were associated with mortality: respiratory rate more than 24/min and systolic blood pressure 37 units/L in the first 48 h of presentation, while a RT-PCR cycle threshold (Ct) value ≤24 was a predictor for IMV. CONCLUSION: Variable factors were identified as predictors of different outcomes among COVID-19 patients. The only predictor of IMV was a low initial Ct values of SARS-CoV-2 PCR. The presence of tachypnea, hypotension, lymphopenia, and elevated AST in the first 48h of presentation were independently associated with mortality. This study provides possible independent predictors of mortality and invasive mechanical ventilation. The data may be helpful in the early identification of high-risk COVID-19 patients in areas endemic with MERS-CoV

What is the right sequencing approach? Solo VS extended family analysis in consanguineous populations.

Testing strategies is crucial for genetics clinics and testing laboratories. In this study, we tried to compare the hit rate between solo and trio and trio plus testing and between trio and sibship testing. Finally, we studied the impact of extended family analysis, mainly in complex and unsolved cases. Three cohorts were used for this analysis: one cohort to assess the hit rate between solo, trio and trio plus testing, another cohort to examine the impact of the testing strategy of sibship genome vs trio-based analysis, and a third cohort to test the impact of an extended family analysis of up to eight family members to lower the number of candidate variants. The hit rates in solo, trio and trio plus testing were 39, 40, and 41%, respectively. The total number of candidate variants in the sibship testing strategy was 117 variants compared to 59 variants in the trio-based analysis. We noticed that the average number of coding candidate variants in trio-based analysis was 1192 variants and 26,454 noncoding variants, and this number was lowered by 50-75% after adding additional family members, with up to two coding and 66 noncoding homozygous variants only, in families with eight family members. There was no difference in the hit rate between solo and extended family members. Trio-based analysis was a better approach than sibship testing, even in a consanguineous population. Finally, each additional family member helped to narrow down the number of variants by 50-75%. Our findings could help clinicians, researchers and testing laboratories select the most cost-effective and appropriate sequencing approach for their patients. Furthermore, using extended family analysis is a very useful tool for complex cases with novel genes

SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues

Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types

A first update on mapping the human genetic architecture of COVID-19

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