791 research outputs found
Quality of teaching in higher education:Reviewing teaching behaviour through classroom observations
This study examines the extent to which lecturers demonstrate effective teaching behaviour. The results of 203 observations reveal substantial differences in detected teaching behaviour. Lecturers mostly demonstrated teaching behaviour in the domains classroom climate, efficient organisation, and instruction. Teaching behaviour relating to the domains activating teaching and teaching learning strategies was observed less frequently, with almost no evidence of behaviour associated with the domain differentiation. The quality of teaching in small classes was slightly higher than that in large classes. These findings can help tailor professional learning activities to lecturers’ professional development needs
Kenyan doctoral students’ success: Roles of motivation and self-efficacy
Doctor of philosophy (PhD) degree holders are highly regarded in Kenya, especially in academia, and the Kenyan economy needs them to undertake administrative, research and innovation roles in both academia and industry. However, attaining this qualification is arduous, and Kenyan PhD programmes are characterized by low enrolment numbers, long degree completion times and low graduation rates. In other countries, PhD students’ success has been linked to motivation and self-efficacy. This cross-sectional study explores the extents to which motivation and self-efficacy relate to PhD student success in Kenya and to which this relationship differs across background and program characteristics. Using multiple linear regression, the authors analyse data from an online questionnaire administered to 628 PhD students enrolled between 2010 and 2018. The findings indicate that extrinsic motivation does not predict PhD students’ pace. Intrinsic motivation positively predicts students’ pace in the Medical Sciences program cluster and for those aged 51 years or older. Self-efficacy negatively predicts students’ pace in the Medical Sciences program cluster
How is a professional development programme related to the development of university teachers’ self-efficacy beliefs and teaching conceptions?
This study explores how the impact of a five ECTS professional development programme for university teachers affects their self-efficacy beliefs and teaching conceptions using a mixed methods approach. For the quantitative part of the study, participants completed pre-post surveys. From these surveys, we find that the programme led to an overall significant increase in reported self-efficacy beliefs. A sub-sample of ten participants participated in the qualitative part, which consists of four phases: three reflective assignments and an interview. Individual teachers demonstrate a dominant teaching conception in each phase and in almost half of the sub-sample it developed over time, moving from a teacher-centered to a more student-centered conception. When examining the development of self-efficacy and teaching conceptions collectively, three development groups are identified. Noteworthy is that teacher development is credited to the programme as a whole and not to a specific aspect
Influences of deep learning, need for cognition and preparation time on open- and closed-book test performance
Objectives The ability to master discipline-specific knowledge is one of the competencies medical students must acquire. In this context, 'mastering' means being able to recall and apply knowledge. A way to assess this competency is to use both open- and closed-book tests. Student performance on both tests can be influenced by the way the student processes information. Deep information processing is expected to influence performance positively. The personal preferences of students in relation to how they process information in general (i.e. their level of need for cognition) may also be of importance. In this study, we examined the inter-relatedness of deep learning, need for cognition and preparation time, and scores on open- and closed-book tests. Methods This study was conducted at the University Medical Centre Groningen. Participants were Year 2 students (n = 423). They were asked to complete a questionnaire on deep information processing, a scale for need for cognition on a questionnaire on intellectualism and, additionally, to write down the time they spent on test preparation. We related these measures to the students' scores on two tests, both consisting of open- and closed-book components and used structural equation modelling to analyse the data. Results Both questionnaires were completed by 239 students (57%). The results showed that need for cognition positively influenced both open- and closed-book test scores (beta-coefficients 0.05 and 0.11, respectively). Furthermore, study outcomes measured by open-book tests predicted closed-book test results better than the other way around (beta-coefficients 0.72 and 0.11, respectively). Conclusions Students with a high need for cognition performed better on open- as well as closed-book tests. Deep learning did not influence their performance. Adding open-book tests to the regularly used closed-book tests seems to improve the recall of knowledge that has to be known by heart. Need for cognition may provide a valuable addition to existing theories on learning
Influence of open- and closed-book tests on medical students' learning approaches
CONTEXT Two learning approaches are consistently distinguished in the literature: deep and surface learning. The deep learning approach is considered preferable. Open-book tests are expected to stimulate deep learning and to offer a possible way of handling the substantial growth in medical knowledge. In this study we test the hypothesis that open-book tests stimulate deep learning more than closed-book tests. METHODS Medical students in Years 2 (n = 423) and 3 (n = 306) participated in this study. They evaluated their preparation for open- and closed-book tests using the test for Deep Information Processing (DIP). This questionnaire consists of 24 items divided into three subscales: Critical Reading; Broaden One's Context, and Structuring. A paired t-test was used to analyse the data. RESULTS Both cohorts scored significantly higher when preparing for closed-book tests for the overall DIP score and on the Broaden One's Context and Structuring scales. Year 3 students also scored significantly higher on the Critical Reading scale when preparing for closed-book tests. Gender differences were found: women used deeper learning approaches than men. CONCLUSIONS Our hypothesis was not supported. In fact, the opposite was found: closed-book tests stimulated a deep learning approach more than open-book tests. Three possible explanations are: deep learning is particularly necessary for remembering and recalling knowledge; students feel more confident when preparing for closed-book tests, and students are more motivated to study for closed-book tests. The debate on the concept of deep learning in higher education should probably be renewed
A Unified Approach for the Total Synthesis of cyclo-Archaeol, iso-Caldarchaeol, Caldarchaeol, and Mycoketide
Ir-catalyzed asymmetric alkene hydrogenation is presented as the strategy par excellence to prepare saturated isoprenoids and mycoketides. This highly stereoselective synthesis approach is combined with an established 13 C-NMR method to determine the enantioselectivity of each methyl-branched stereocenter. It is shown that this analysis is fit for purpose and the combination allows the synthesis of the title compounds with a significant increase in efficiency
Critical Exponents of the Superconducting Phase Transition
We study the critical exponents of the superconducting phase transition in
the context of renormalization group theory starting from a dual formulation of
the Ginzburg-Landau theory. The dual formulation describes a loop gas of
Abrikosov flux tubes which proliferate when the critical temperature is
approached from below. In contrast to the Ginzburg-Landau theory, it has a
spontaneously broken global symmetry and possesses an infrared stable fixed
point. The exponents coincide with those of a superfluid with reversed
temperature axis.Comment: Postscript file. For related work see www adress
http://www.physik.fu-berlin.de/kleiner_re.html in our homepage
http://www.physik.fu-berlin.de/kleinert.htm
A promiscuous archaeal cardiolipin synthase enables construction of diverse natural and unnatural phospholipids
Cardiolipins (CL) are a class of lipids involved in the structural organization of membranes, enzyme functioning, and osmoregulation. Biosynthesis of CLs has been studied in eukaryotes and bacteria, but has been barely explored in archaea. Unlike the common fatty acyl chain-based ester phospholipids, archaeal membranes are made up of the structurally different isoprenoid-based ether phospholipids, possibly involving a different cardiolipin biosynthesis mechanism. Here, we identified a phospholipase D motif-containing cardiolipin synthase (MhCls) from the methanogen Methanospirillum hungatei. The enzyme was overexpressed in Escherichia coli, purified, and its activity was characterized by LC-MS analysis of substrates/products. MhCls utilizes two archaetidylglycerol (AG) molecules in a transesterification reaction to synthesize glycerol-di-archaetidyl-cardiolipin (Gro-DACL) and glycerol. The enzyme is non-selective to the stereochemistry of the glycerol-backbone and the nature of the lipid tail, as it also accepts phosphatidylglycerol (PG) to generate glycerol-di-phosphatidyl-cardiolipin (Gro-DPCL). Remarkably, in the presence of AG and PG, MhCls formed glycerol-archaetidyl-phosphatidyl-cardiolipin (Gro-APCL), an archaeal-bacterial hybrid cardiolipin species that so far has not been observed in nature. Due to the reversibility of the transesterification, in the presence of glycerol, Gro-DPCL can be converted back into two PG molecules. In the presence of other compounds that contain primary hydroxyl groups (e.g., alcohols, water, sugars), various natural and unique unnatural phospholipid species could be synthesized, including multiple di-phosphatidyl-cardiolipin species. Moreover, MhCls can utilize a glycolipid in the presence of phosphatidylglycerol to form a glycosyl-mono-phosphatidyl-cardiolipin species, emphasizing the promiscuity of this cardiolipin synthase, that could be of interest for bio-catalytic purposes
A versatile method to separate complex lipid mixtures using 1-butanol as eluent in a reverse-phase UHPLC-ESI-MS system
Simple, robust and versatile LC-MS based methods add to the rapid assessment of the lipidome of biological cells. Here we present a versatile RP-UHPLC-MS method using 1-butanol as the eluent, specifically designed to separate different highly hydrophobic lipids. This method is capable of separating different lipid classes of glycerophospholipid standards, in addition to phospholipids of the same class with a different acyl chain composition. The versatility of this method was demonstrated through analysis of lipid extracts of the bacterium Escherichia coli and the archaeon Sulfolobus acidocaldarius. In contrast to 2-propanol-based methods, the 1-butanol-based mobile phase is capable of eluting highly hydrophobic analytes such as cardiolipins, tetraether lipids and mycolic acids during the gradient instead of the isocratic purge phase, resulting in an enhanced separation of cardiolipins and extending the analytical range for RPLC
[F-18]Atorvastatin Pharmacokinetics and Biodistribution in Healthy Female and Male Rats
Statins are 3-hydroxy-3-methylglutaryl- coenzyme A reductase inhibitors that are widely used to prevent cardiovascular diseases. However, a series of pleiotropic mechanisms have been associated with statins, particularly with atorvastatin. Therefore, the assessment of [F-18]atorvastatin kinetics with positron emission tomography (PET) may elucidate the mechanism of action of statins and the impact of sexual dimorphism, which is one of the most debated interindividual variations influencing the therapeutic efficacy. [F-18]Atorvastatin was synthesized via a previously optimized F-18-deoxyfluorination strategy, used for preclinical PET studies in female and male Wistar rats (n = 7 for both groups), and for subsequent ex vivo biodistribution assessment. PET data were fitted to several pharmacokinetic models, which allowed for estimating relevant kinetic parameters. Both PET imaging and biodistribution studies showed negligible uptake of [F-18]atorvastatin in all tissues compared with the primary target organ (liver), excretory pathways (kidneys and small intestine), and stomach. Uptake of [F-18]atorvastatin was 38 +/- 3% higher in the female liver than in the male liver. The irreversible 2-tissue compartment model showed the best fit to describe [F-18]atorvastatin kinetics in the liver. A strong correlation (R-2 > 0.93) between quantitative Ki (the radiotracer's unidirectional net rate of influx between compartments) and semi-quantitative liver's SUV (standard uptake value), measured between 40 to 90 min, showed potential to use the latter parameter, which circumvents the need for blood sampling as a surrogate of Ki for monitoring [F-18]atorvastatin uptake. Preclinical assays showed faster uptake and clearance for female rats compared to males, seemingly related to a higher efficiency for exchanges between the arterial input and the hepatic tissue. Due to the slow [F-18]atorvastatin kinetics, equilibrium between the liver and plasma concentration was not reached during the time frame studied, making it difficult to obtain sufficient and accurate kinetic information to quantitatively characterize the radiotracer pharmacokinetics over time. Nevertheless, the reported results suggest that the SUV can potentially be used as a simplified measure, provided all scans are performed at the same time point. Preclinical PET-studies with [F-18]atorvastatin showed faster uptake and clearance in female compared to male rats, apparently related to higher efficiency for exchange between arterial blood and hepatic tissue.</p
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