237 research outputs found

    Opium And Insurgency: Development And Decay In Southern Afghanistan

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    Gamification of e-Learning: an investigation into the influence of gamification on student motivation.

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    Master of Commerce in Information Systems & Technology. University of KwaZulu-Natal, Durban, 2017.Traditional teacher-centred learning is being confronted by an increasing awareness of the value of student-centred learning. E-learning, despite its limitations, is often presented as a solution to learning challenges prevalent in teacher-centred learning since it affords students greater control of the learning process. Combined with this, academics are increasingly competing for students’ attention and struggle to motivate students. However, students, when confronted with the array of games and social media platforms available, willingly dedicate several hours glued to their screens socialising, engaging and gaming. Such willingness to engage these so-called distractions whilst displaying reluctance to engage their academic work may be attributed to a lack of motivation. This is even more prevalent in the domain of e-learning. Adopting an embedded mixed methods case study design, this study explored the influence of gamification of e-learning on motivation. Herein, expectations and factors influencing experiences of gamification of e-learning were explored. Furthermore, through Self-Determination Theory (SDT) & Intrinsic Motivation Inventory (IMI) as theoretical lenses, this study explored how gamification of e-learning influences motivation. Gamification is conceptualised as an objective-driven user-centred technique which integrates game mechanics, dynamics and game aesthetics into real-world contexts to motivate behaviour. Gartner envisages that by 2020, gamification will be deeply integrated into the prevalent higher education structures. Whilst many applications of gamification aim towards enhancing classroom-based learning, the exploration of gamification of e-learning in higher education, particularly in a developing country, remains an emerging domain of research. This research found that participants experienced gamification and various game elements differently, based on their BrainHex gamer profiles. In terms of SDT, whilst progression through the gamified course was guided and consistent, with all participants progressing as a single group, they experienced a sense of autonomy. Participants also experienced a greater sense of competence and relatedness in engaging with the gamified course. In the context of IMI, participants’ experiences suggest that gamification was valuable, increased curiosity and was effective for learning. However, they reported experiencing tension and a high degree of effort required by the gamified course. Students expected transparency in terms of scoring and raised queries where required. They generally preferred visual cues whilst engaging with the gamified course, expected almost real-time feedback in terms of scoring and resolution of queries, but had varying views on which game elements motivated them. Essentially, it was found that gamification positively influenced participants’ motivation. However, it must be noted that whilst gamification motivated students, some experienced demotivation. Contributing factors include not understanding the game from the outset, being demotivated by not earning frequent rewards and losing progress in the game due to external factors

    Measurements of the normal size of spleen and spleen to left kidney ratio among sudanese children up to five years age using ultrasonography

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    Background: Knowledge of the normal range of spleen size in the population being examined is very important because there are many different pathological conditions that may alter in spleen size. Also, gender, height, weight and BMI of individual, affect the splenic length and could result in incorrect interpretation of splenic measurements, spleen to left kidney ratio is one of recent parameter mention in literature aid in diagnosis of splenomegaly in children.Methods: The study was a cross-sectional study conducted in Khartoum state at Al-Buluk and Gaafar Ibnauf Paediatric Tertiary Hospital during the period from March 2018 to August 2018. A total of 101 children (males and females) with aged ranged 1 month to 5 years included in study. A transabdominal scan was performed, and measurement of spleen and left kidney taken after an ethical verbal consent from their parents, then data analyzed by SPSS, Mean±SD. Deviation for study variables calculated then correlation between patients factors and ultrasound measurements done.Results: The study found that the mean measurements of the normal size of the spleen and spleen to left kidney ratio for children up to five years of age, Splenic length was 7.24±1.12 cm, width was 3.83±0.81 cm , thickness 2.91±0.55 cm and spleen to left kidney ratio was 1.04±0.0.70 ranged (0.86-1.23). The male have larger spleen than female with no statistically significant differences in spleen sizes between the sexes. There was a strong significant correlation between age, weight, height  spleen and left kidney length (p<0.01)respectively and a moderate association with BMI (p<0.05).Conclusions: Spleen and left kidneys was growing rapidly and similarly in infant up to one year of life 1 mm\1 mm for each month and then decreasing growth rate of kidney in relate to spleen for 1 mm growth of spleen kidney grow 0.8 mm in up to five years of age. There was strong significant positive correlation between spleen and left kidney measurement with age, height, weight of individual. The spleen to left kidney ratio for children up to five years ranged (0.86-1.23) with mean 1.04, so if the ratio less or more than this ranged it should be considered in clinical context for diagnosis of splenomegaly or shrunken spleen in children up to five years of age

    Evolution of Escherichia coli to 42 °C and Subsequent Genetic Engineering Reveals Adaptive Mechanisms and Novel Mutations.

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    Adaptive laboratory evolution (ALE) has emerged as a valuable method by which to investigate microbial adaptation to a desired environment. Here, we performed ALE to 42 °C of ten parallel populations of Escherichia coli K-12 MG1655 grown in glucose minimal media. Tightly controlled experimental conditions allowed selection based on exponential-phase growth rate, yielding strains that uniformly converged toward a similar phenotype along distinct genetic paths. Adapted strains possessed as few as 6 and as many as 55 mutations, and of the 144 genes that mutated in total, 14 arose independently across two or more strains. This mutational recurrence pointed to the key genetic targets underlying the evolved fitness increase. Genome engineering was used to introduce the novel ALE-acquired alleles in random combinations into the ancestral strain, and competition between these engineered strains reaffirmed the impact of the key mutations on the growth rate at 42 °C. Interestingly, most of the identified key gene targets differed significantly from those found in similar temperature adaptation studies, highlighting the sensitivity of genetic evolution to experimental conditions and ancestral genotype. Additionally, transcriptomic analysis of the ancestral and evolved strains revealed a general trend for restoration of the global expression state back toward preheat stressed levels. This restorative effect was previously documented following evolution to metabolic perturbations, and thus may represent a general feature of ALE experiments. The widespread evolved expression shifts were enabled by a comparatively scant number of regulatory mutations, providing a net fitness benefit but causing suboptimal expression levels for certain genes, such as those governing flagellar formation, which then became targets for additional ameliorating mutations. Overall, the results of this study provide insight into the adaptation process and yield lessons important for the future implementation of ALE as a tool for scientific research and engineering

    Soft X-ray spectro-ptychography on boron nitride nanotubes, carbon nanotubes and permalloy nanorods

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    Spectro-ptychography offers improved spatial resolution and additional phase spectral information relative to that provided by scanning transmission X-ray microscopes (STXM). However, carrying out ptychography at the lower range of soft X-ray energies (e.g., below 200 eV to 600 eV) on samples with weakly scattering signals can be challenging. We present soft X-ray ptychography results at energies as low as 180 eV and illustrate the capabilities with results from permalloy nanorods (Fe 2p), carbon nanotubes (C 1s), and boron nitride bamboo nanostructures (B 1s, N1s). We describe optimization of low energy X-ray spectro-ptychography and discuss important challenges associated with measurement approaches, reconstruction algorithms, and their effects on the reconstructed images. A method for evaluating the increase in radiation dose when using overlapping sampling is presented.Comment: 32 pages, 7 figure

    Transendothelial migration of human umbilical mesenchymal stem cells across uterine endothelial monolayers: junctional dynamics and putative mechanisms

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    Introduction: During pregnancy, fetal stem cells can transfer to the maternal circulation and participate in tissue repair. How they transmigrate across maternal endothelial barriers and whether they can subsequently influence maternal endothelial integrity is not known. Methods: Mesenchymal stem cells (WJ-MSC) were isolated from Wharton's jelly and their interactions with human uterine microvascular endothelial cell (HUtMEC) monolayers, junctional occupancy and expression/phosphorylation of vascular endothelial (VE)- cadherin and vascular endothelial growth factor (VEGF-A) secretion was studied over 48h by real time, confocal microscopy, immunoblotting and ELISA. Results: WJ-MSC displayed exploratory behaviour with interrogation of paracellular openings and spreading into the resultant increased gaps followed by closing of the endothelium over the WJ-MSC. 62% of added cells crossed within 22h to sub-endothelial niches. There was a concomitant loss of junctional VE-cadherin in HUtMEC followed by a full return and increased VE-cadherin expression after 22h. During early hours, VE-cadherin showed a transient phosphorylation at Tyrosine (Tyr)-685 when VEGF-A secretion were high. From 16 to 22h, there was increased de-phosphorylation of Tyr-731. Anti-VEGF-A blocked Tyr-685 phosphorylation but not the decrease in P-Tyr731; this partially inhibited WJ-MSC transmigration. Discussion: Fetal WJ-MSC can traverse uterine endothelial monolayers by mediating a non-destructive paracellular pathway. They can promote junctional stability of uterine endothelium from the sub-endothelial niche. Mechanistically, WJ-MSC induces VEGF-dependent phosphorylation events linked with paracellular permeability and VEGF-independent de-phosphorylation events associated with leukocyte extravasation. Our data also allows consideration of a possible role of fetal MSC in mature functioning of the uterine vasculature needed for optimal utero-placental perfusion

    Foetal magnetic resonance imaging : a necessity or adjunct? A modality comparison of in-utero ultrasound and ultrafast foetal magnetic resonance imaging

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    BACKGROUND: Congenital anomalies occur in approximately 2% of newborns, resulting in severe medical, physical and social disabilities. Managing clinicians, therefore, require more confidence in their diagnosis and prognostic accuracy before appropriately counselling the parents regarding termination of pregnancy. OBJECTIVE: The aim of this study was to investigate the role of magnetic resonance imaging (MRI) following the diagnosis of foetal anomalies at a foetomaternal unit of a tertiary South African institution. METHODS: Eighty-eight pregnant women in their late second/third trimester who underwent both an ultrasound (US) at the foetomaternal unit and foetal MRI at the Radiology Department from 01 July 2013 to 30 September 2019 were included in this clinical study conducted at Steve Biko Academic Hospital. RESULTS: Despite the high degree of concurrence (73.9%) between both modalities regarding the main diagnoses, MRI provided additional information in 45.5% of patients and changed the diagnosis in 25% of the patients. It further demonstrated superiority in providing diagnostic information in 97% of cases where the US alone was inadequate to counsel parents regarding the termination of pregnancy, and it completely changed the clinical management in 42% of cases. CONCLUSION: It is clearly evident from this study that foetal MRI is a necessity when termination of pregnancy is being considered following an US conducted by the foetomaternal unit. This allows for a complete foetal assessment and gives the managing clinician sufficient diagnostic confidence to prognosticate the future quality of life of the child.https://sajr.org.zaRadiologyStatistic

    Origine sociale et comportement politique

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    Les conséquences politiques de la mobilité sociale intergénérationnelle sur les comportements et les attitudes politiques des individus ont fait l'objet, depuis une vingtaine d'années, d'une série de recherches en particulier aux Etats-Unis et en Angleterre. A la suite de ces travaux une conclusion majeure semble s'imposer : les « mobiles sociaux » adopteraient un comportement politique intermédiaire entre leur groupe d'origine et leur groupe d'arrivée. Dans cette recherche, qui se fonde sur l'analyse d'un échantillon représentatif de cadres moyens et supérieurs, l'origine sociale paraît effectivement déterminer pour partie les comportements et attitudes politiques des individus appartenant aux couches moyennes salariées. Toutefois, une étude plus précise de ce mécanisme montre que l'effet de l'origine sociale sur le comportement et les attitudes politiques n'est pas seulement fonction de la distance entre la position sociale du père et celle du fils mais se diversifie également selon la nature et les conditions du trajet social effectué par l'individu.The political consequences of intergenerational social mobility on individuals' political attitudes and behavior have been studied in a series of inquiries over the past twenty years, especially in the United States and England. As a result of this work, it seems that one major conclusion may be drawn: the "socially mobile" seem to adopt a political behavior which is intermediate to that of the group from which they started out and that into which they are arriving. In this study based on a representative sample of middle — and upper — level executives, social origin indeed seems to be in part a determining factor in the political behavior and attitudes of individuals belonging to the middle range of the wage scale. However, a closer study of this mechanism shows that the effect of social origin upon political behavior and attitudes is not only a function of the distance between the father's and the son's social positions, but also differs according to the nature and conditions of the individual's social ascension
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