291 research outputs found
The role of unit evaluation, learning and culture dimensions related to student cognitive style in hypermedia learning
Recent developments in learning technologies such as hypermedia are\ud
becoming widespread and offer significant contributions to improving the delivery\ud
of learning and teaching materials. A key factor in the development of hypermedia\ud
learning systems is cognitive style (CS) as it relates to usersâ information\ud
processing habits, representing individual usersâ typical modes of perceiving,\ud
thinking, remembering and problem solving.\ud
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A total of 97 students from Australian (45) and Malaysian (52) universities\ud
participated in a survey. Five types of predictor variables were investigated with\ud
the CS: (i) three learning dimensions; (ii) five culture dimensions; (iii) evaluation\ud
of units; (iv) demographics of students; and (v) country in which students studied.\ud
Both multiple regression models and tree-based regression were used to analyse\ud
the direct effect of the five types of predictor variables, and the interactions within\ud
each type of predictor variable. When comparing both models, tree-based\ud
regression outperformed the generalized linear model in this study. The research\ud
findings indicate that unit evaluation is the primary variable to determine studentsâ\ud
CS. A secondary variable is learning dimension and, among the three dimensions,\ud
only nonlinear learning and learner control dimensions have an effect on studentsâ\ud
CS. The last variable is culture and, among the five culture dimensions, only\ud
power distance, long term orientation, and individualism have effects on studentsâ\ud
CS. Neither demographics nor country have an effect on studentsâ CS.\ud
These overall findings suggest that traditional unit evaluation, studentsâ\ud
preference for learning dimensions (such as linear vs non-linear), level of learner\ud
control and culture orientation must be taken into consideration in order to enrich\ud
studentsâ quality of education. This enrichment includes motivating students to\ud
acquire subject matter through individualized instruction when designing,\ud
developing and delivering educational resources
Protrusive Push versus Enveloping Embrace: Computational Model of Phagocytosis Predicts Key Regulatory Role of Cytoskeletal Membrane Anchors
Encounters between human neutrophils and zymosan elicit an initially protrusive cell response that is distinct from the thin lamella embracing antibody-coated targets. Recent experiments have led us to hypothesize that this behavior has its mechanistic roots in the modulation of interactions between membrane and cytoskeleton. To test and refine this hypothesis, we confront our experimental results with predictions of a computer model of leukocyte mechanical behavior, and establish the minimum set of mechanistic variations of this computational framework that reproduces the differences between zymosan and antibody phagocytosis. We confirm that the structural linkages between the cytoskeleton and the membrane patch adherent to a target form the âswitchboardâ that controls the target specificity of a neutrophil's mechanical response. These linkages are presumably actin-binding protein complexes associating with the cytoplasmic domains of cell-surface receptors that are engaged in adhesion to zymosan and Fc-domains
Absorption Cross Sections of NH_3, NH_2D, NHD_2, and ND_3 in the Spectral Range 140-220 nm and Implications for Planetary Isotopic Fractionation
Cross sections for photoabsorption of NH_3, NH_2D, NHD_2, and ND_3 in the spectral region 140-220 nm were determined at ~298 K using synchrotron radiation. Absorption spectra of NH_2D and NHD_2 were deduced from spectra of mixtures of NH_3 and ND_3, of which the equilibrium concentrations for all four isotopologues obey statistical distributions. Cross sections of NH_2D, NHD_2, and ND_3 are new. Oscillator strengths, an integration of absorption cross sections over the spectral lines, for both A â X and B â X systems of NH_3 agree satisfactorily with previous reports; values for NH_2D, NHD_2, and ND_3 agree with quantum chemical predictions. The photolysis of NH_3 provides a major source of reactive hydrogen in the lower stratosphere and upper troposphere of giant planets such as Jupiter. Incorporating the measured photoabsorption cross sections of NH_3 and NH_2D into the Caltech/JPL photochemical diffusive model for the atmosphere of Jupiter, we find that the photolysis efficiency of NH_2D is lower than that of NH_3 by as much as 30%. The D/H ratio in NH_2D/NH_3 for tracing the microphysics in the troposphere of Jupiter is also discussed
Absorption cross sections of HCl and DCl at 135-232 nanometers: implications for photodissociation on Venus
Cross sections for photoabsorption of HCl and DCl are determined in the spectral region of 135-232 nm using radiation from a synchrotron light source. At wavelengths near the onset of absorption (λ > 200 nm), cross sections of HCl are approximately 5-10 times larger than those of DCl. These data are used to calculate rates of photodissociation of HCl and DCl in the Venusian atmosphere. For the entire wavelength region measured, the rate of photodissociation of DCl is only 16% that of HCl. The difference in rates of photodissociation contributes to the exceptionally large [D]/[H] ratio of the Venusian atmosphere
Enhancement of deuterated ethane on Jupiter
We report laboratory measurements of cross sections of CH_3D and C_2H_5D in the extreme ultraviolet. The results are incorporated in a photochemical model for the deuterated hydrocarbons up to C_2 in the upper atmosphere of Jupiter, taking into account the fast reactions for exchanging H and D atoms between H_2 and CH_4, H + HD â D + H_2, CH_3 + D â CH_2D + H. Since there is no reliable kinetics measurement for the reaction, CH_2D + H â CH_3 + D, we use Yung et al.'s estimate for its rate constant. The strong temperature dependence for this reaction leads to large isotopic fractionation for CH_3D and C_2H_5D in the upper atmosphere of Jupiter, where their production rates depend on the abundance of deuterated methyl radical. The model predicts that the D/H ratio in deuterated ethane is about 15 times that of the bulk atmosphere. A confirmation of this result would provide a sensitive test of the photochemistry of hydrocarbons in the atmosphere of Jupiter
Feminism and a View of Conservative Gender Roles among Young Working Women in Malaysia
People are often influenced by norms and ideologies, including the concepts of feminism and conservative gender roles. With perceptions evolving constantly, we intend to investigate the subject of feminism and the view of young working women in Malaysia with regards to conservative gender roles. Studies on the subject have been scarce or minimal so far, hence understanding the general populationâs perception will allow us to better measure public awareness on the topic of our research. The demographic of participants in this study specifically encompasses working women, between the ages of eighteen and forty years old. The participants were recruited through virtual mediums, namely WhatsApp, Facebook and Instagram. They were then asked to participate in a semi-structured interview to aid in the collection of detailed data which was then analysed through the process of transcription and coding for recurring themes. The study suggests that young working women in Malaysia are more in tune with feminism than originally anticipated due to digital platforms. Among the inequalities faced in the workforce, the most cited are equal and fair pay. Family upbringing, tradition and culture were often cited as shaping the general evolution of gender roles. Research can be done on feminism, gender roles and their implications on the LGBT community as a whole
Isotopic Fractionation of Nitrogen in Ammonia in the Troposphere of Jupiter
Laboratory measurements of the photoabsorption cross section of ^(15)NH_3 at wavelengths between 140 and 220 nm are presented for the first time. Incorporating the measured photoabsorption cross sections of ^(15)NH_3 and ^(14)NH_3 into a one-dimensional photochemical diffusive model, we find that at 400 mbar, the photolytic efficiency of ^(15)NH_3 is about 38% greater than that of ^(14)NH_3. In addition, it is known that ammonia can condense in the region between 200 and 700 mbar, and the condensation tends to deplete the abundance ratio of ^(15)NH_3 and ^(14)NH_3. By matching the observed ratio of ^(15)NH_3 and ^(14)NH_3 at 400 mbar, the combined effect of photolysis and microphysics produces the ratio of (2.42 ± 0.34) à 10^(-3) in the deep atmosphere, in excellent agreement with the Galileo spacecraft measurements. The usefulness of the isotopic composition of ammonia as a tracer of chemical and dynamical processes in the troposphere of Jupiter is discussed
Genetic insight into the putative causal proteins and druggable targets of osteoporosis: a large-scale proteome-wide mendelian randomization study
Background: Osteoporosis is a major causative factor of the global burden of disease and disability, characterized by low bone mineral density (BMD) and high risks of fracture. We aimed to identify putative causal proteins and druggable targets of osteoporosis.Methods: This study utilized the largest GWAS summary statistics on plasma proteins and estimated heel BMD (eBMD) to identify causal proteins of osteoporosis by mendelian randomization (MR) analysis. Different GWAS datasets were used to validate the results. Multiple sensitivity analyses were conducted to evaluate the robustness of primary MR findings. We have also performed an enrichment analysis for the identified causal proteins and evaluated their druggability.Results: After Bonferroni correction, 67 proteins were identified to be causally associated with estimated BMD (eBMD) (p < 4 Ă 10â5). We further replicated 38 of the 67 proteins to be associated with total body BMD, lumbar spine BMD, femoral neck BMD as well as fractures, such as RSPO3, IDUA, SMOC2, and LRP4. The findings were supported by sensitivity analyses. Enrichment analysis identified multiple Gene Ontology items, including collagen-containing extracellular matrix (GO:0062023, p = 1.6 Ă 10â10), collagen binding (GO:0005518, p = 8.6 Ă 10â5), and extracellular matrix structural constituent (GO:0005201, p = 2.7 Ă 10â5).Conclusion: The study identified novel putative causal proteins for osteoporosis which may serve as potential early screening biomarkers and druggable targets. Furthermore, the role of plasma proteins involved in collagen binding and extracellular matrix in the development of osteoporosis was highlighted. Further studies are warranted to validate our findings and investigate the underlying mechanism
Early exclusion of major adverse cardiac events in emergency department chest pain patients: A prospective observational study
Background
The current evaluation of patients with chest pain presenting to an emergency department (ED) with suspected acute coronary syndrome (ACS) is a lengthy process involving serial measurements of troponin.
Objective
We aimed to validate the diagnostic accuracy of a Thrombolysis in Myocardial Infarction (TIMI) score with single high-sensitive cardiac troponin T (hs-cTnT) for early rule out of 30-day major adverse cardiac events (MACE), and to compare the TIMI score with combinations of heart-type fatty acid binding protein (H-FABP) and a modified HEART (history, electrocardiogram, age, risk factors, troponin) score.
Methods
We recruited 602 consecutive adult patients with chest pain and suspected ACS in the ED. Each patient had TIMI and HEART scores, and a point-of-care H-FABP test.
Results
MACE occurred in 42 (7.0%) patients within 30 days. A low risk for 30-day MACE was identified by a modified TIMI score of 0 in 65 (11%) patients, and by a HEART score †2 in 96 (16%) patients. No MACE occurred in these groups, giving both scores a sensitivity of 100% (95% confidence interval [CI] 91.6â100%), and specificity of 11.6% (95% CI 9.2â14.5%) and 17.1% (95% CI 14.2â20.5%), respectively. Use of combined TIMI and HEART scores improved the specificity further to 22.0% (95% CI 18.7â25.6%) without lowering sensitivity. Early H-FABP measurement > 7 ÎŒg/L had a sensitivity of 41.5% (95% CI 27.8â56.6%) and a specificity of 91.1% (95% CI 88.4â93.2%) for predicting 30-day MACE.
Conclusions
A modified TIMI score of 0 or a HEART score of †2, incorporating a single hs-cTnT level, will identify patients with low risk of 30-day MACE for early discharge within 2 h of ED arrival
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