1,615 research outputs found
How learners’ interactions sustain engagement: a MOOC case study
In 2015, 35 million learners participated online in 4,200 MOOCs organised by over 500 universities. Learning designers orchestrate MOOC content to engage learners at scale and retain interest by carefully mixing videos, lectures, readings, quizzes, and discussions. Universally, far fewer people actually participate in MOOCs than originally sign up with a steady attrition as courses progress. Studies have correlated social engagement to completion rates. The FutureLearn MOOC platform specifically provides opportunities to share opinions and to reflect by posting comments, replying, or following discussion threads. This paper investigates learners’ social behaviours in MOOCs and the impact of engagement on course completion. A preliminary study suggested that dropout rates will be lower when learners engage in repeated and frequent social interactions. We subsequently reviewed the literature of prediction models and applied social network analysis techniques to characterise participants’ online interactions examining implications for participant achievements. We analysed discussions in an eight week FutureLearn MOOC, with 9855 enrolled learners. Findings indicate that if learners starts following someone, the probability of their finishing the course is increased; if learners also interact with those they follow, they are highly likely to complete, both important factors to add to the prediction of completion model
Comparison of the effect of calcium on the bioavailability of iron from Spirulina platensis and ferrous sulphate in vivo
Changes in blood parameters of endurance horses in 30-km training.
Eight endurance horses registered for competition in different categories of Sultan Cup Endurance Ride, in November 2009 were selected for an evaluation of the soundness of the horses and an examination of the changes of blood parameters in training prior to the competition. Three blood samples were taken from each horse: pre-ride, immediate post ride and 24 hours post-ride. All horses were trained at 30 km and departed at the same time and tested on the same track. Blood samples were evaluated for both
haematology and biochemistry components: red blood cell (RBC), packed cell volume (PCV), white blood cell (WBC), segmented neutrophil, lymphocyte counts, electrolytes
concentration, total protein (TP), aspartate aminotransferase (AST), creatine kinase (CK)
and lactate. One horse was diagnosed with exertional rhabdomyolysis post-training and was removed from statistical analysis. In this study, the significant changes in most blood parameters indicated that the 30-km endurance training induced some physiological responses in horses with minimal stress and loss of water and electrolytes as reflected in the changes of blood parameters. Although elevation in serum muscle enzymes and lactate was significant, it was believed to be a normal physiological response of horses towards training without noticeable muscle injuries and/or metabolic acidosis
Complete Chloroplast Genome Sequence of Omani Lime (Citrus aurantiifolia) and Comparative Analysis within the Rosids
The genus Citrus contains many economically important fruits that are grown worldwide for their high nutritional and medicinal value. Due to frequent hybridizations among species and cultivars, the exact number of natural species and the taxonomic relationships within this genus are unclear. To compare the differences between the Citrus chloroplast genomes and to develop useful genetic markers, we used a reference-assisted approach to assemble the complete chloroplast genome of Omani lime (C. aurantiifolia). The complete C. aurantiifolia chloroplast genome is 159,893 bp in length; the organization and gene content are similar to most of the rosids lineages characterized to date. Through comparison with the sweet orange (C. sinensis) chloroplast genome, we identified three intergenic regions and 94 simple sequence repeats (SSRs) that are potentially informative markers with resolution for interspecific relationships. These markers can be utilized to better understand the origin of cultivated Citrus. A comparison among 72 species belonging to 10 families of representative rosids lineages also provides new insights into their chloroplast genome evolution
The effect of different doses of calcium supplementation on iron availability from Spirulina platensis by an in Vitro digestion/Caco-2 cell culture model
The effect of ultrasound pretreatment on some selected physicochemical properties of black cumin (Nigella Sativa)
Background
In the present study, the effects of ultrasound pretreatment parameters including irradiation time and power on the quantity of the extracted phenolic compounds quantity as well as on some selected physicochemical properties of the extracted oils including oil extraction efficiency, acidity and peroxide values, color, and refractive index of the extracted oil of black cumin seeds with the use of cold press have been studied.
Methods
For each parameter, three different levels (30, 60, and 90 W) for the ultrasound power and (30, 45, and 60 min) and for the ultrasound irradiation time were studied. Each experiment was performed in three replications.
Results
The achieved results revealed that, with enhancements in the applied ultrasound power, the oil extraction efficiency, acidity value, total phenolic content, peroxide value, and color parameters increased significantly (P 0.05).
Conclusions
In summary, it could be mentioned that the application of ultrasound pretreatment in the oil extraction might improve the oil extraction efficiency, the extracted oil’s quality, and the extracted phenolic compounds content.info:eu-repo/semantics/publishedVersio
Unmet needs of patients with chronic obstructive pulmonary disease (COPD): A qualitative study on patients and doctors
Background: Chronic Obstructive Pulmonary Disease (COPD) is a chronic disease with repeated exacerbations resulting in gradual debilitation. The quality of life has been shown to be poor in patients with COPD despite efforts to improve self-management. However, the evidence on the benefit of self-management in COPD is conflicting. Whether this could be due to other unmet needs of patients have not been investigated. Therefore, we aimed to explore unmet needs of patients from both patients and doctors managing COPD.
Methods: We conducted a qualitative study with doctors and patients in Malaysia. We used convenience sampling to recruit patients until data saturation. Eighteen patients and eighteen doctors consented and were interviewed using a semi-structured interview guide. The interviews were audio-recorded, transcribed verbatim and checked by the interviewers. Data were analysed using a thematic approach.
Results: The themes were similar for both the patients and doctors. Three main themes emerged: knowledge and awareness of COPD, psychosocial and physical impact of COPD and the utility of self-management. Knowledge about COPD was generally poor. Patients were not familiar with the term chronic obstructive pulmonary disease or COPD. The word ‘asthma’ was used synonymously with COPD by both patients and doctors. Most patients experienced difficulties in their psychosocial and physical functions such as breathlessness, fear and helplessness. Most patients were not confident in self-managing their illness and prefer a more passive role with doctors directing their care.
Conclusions: In conclusion, our study showed that knowledge of COPD is generally poor. There was mislabelling of COPD as asthma by both patients and physicians. This could have resulted in the lack of understanding of treatment options, outcomes, and prognosis of COPD. The misconception that cough due to COPD was contagious, and breathlessness that resulted from COPD, had important physical and psychosocial impact, and could lead to social isolation. Most patients and physicians did not favour self-management approaches, suggesting innovations based on self-management may be of limited benefit
Using Historical Return Data in the Black-Litterman Model for Optimal Portfolio Decision
In this paper, the Black-Litterman model which is the improved mean-variance optimization model, is discussed. Basically, the views given by the investors were incorporated into this model so that their views on risk and return, and risk tolerance could be quantified. For doing so, the market rates of return for the assets were calculated from the geometric mean. Moreover, the views of the investors were expressed in the matrix form. Then, the covariance matrix and the diagonal covariance matrix of the assets return were calculated. Accordingly, the mean rate of the asset return was computed. On this basis, the Black-Litterman optimization model was constructed. This model formulation was done by taking a set of possible rates of return for the assets. Particularly, the corresponding optimal portfolios of the assets with lower risk and higher expected return were further determined. For illustration, the historical return data for S&P 500, 3-month Treasury bill, and 10-year Treasury bond from 1928 to 2016 were employed to demonstrate the formulation of the ideal investment portfolio model. As a result, the efficient frontier of the portfolio is shown and the discussion is made. In conclusion, the Black-Litterman model could provide the optimal investment decision practically
Using Historical Return Data in the Black-Litterman Model for Optimal Portfolio Decision
In this paper, the Black-Litterman model which is the improved mean-variance optimization model, is discussed. Basically, the views given by the investors were incorporated into this model so that their views on risk and return, and risk tolerance could be quantified. For doing so, the market rates of return for the assets were calculated from the geometric mean. Moreover, the views of the investors were expressed in the matrix form. Then, the covariance matrix and the diagonal covariance matrix of the assets return were calculated. Accordingly, the mean rate of the asset return was computed. On this basis, the Black-Litterman optimization model was constructed. This model formulation was done by taking a set of possible rates of return for the assets. Particularly, the corresponding optimal portfolios of the assets with lower risk and higher expected return were further determined. For illustration, the historical return data for S&P 500, 3-month Treasury bill, and 10-year Treasury bond from 1928 to 2016 were employed to demonstrate the formulation of the ideal investment portfolio model. As a result, the efficient frontier of the portfolio is shown and the discussion is made. In conclusion, the Black-Litterman model could provide the optimal investment decision practically
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