3,333 research outputs found
Evaluation of the usefulness of a computerâbased learning program to support student learning in pharmacology
This study aims to evaluate the effectiveness of a computerâbased teaching program in supporting and enhancing traditional teaching methods. The program covers the pharmacology of inflammation and has been evaluated with a group of secondâyear medical students at a UK university. The study assessed subjectâspecific knowledge using a preâ and postâtest and surveyed, by questionnaire, studentsâ perceptions of the usefulness of the program to support learning before and after use. The use of computers for learning amongst this cohort of students was widespread. The results demonstrated an increase in students â knowledge of the pharmacology of inflammation, coupled with a positive attitude towards the CBL program they had used and the advantages that this mode of study may provide in enabling students to manage their own learning. However, students did not feel that the program could substitute for traditional teaching (lectures)
Spectral density and metal-insulator phase transition in Mott insulators within RDMFT
We present a method for calculating the spectrum of periodic solids within
reduced density matrix functional theory. This method is validated by a
detailed comparison of the angular momentum projected spectral density with
that of well established many-body techniques, in all cases finding an
excellent agreement. The physics behind the pressure induced insulator-metal
phase transition in MnO is investigated. The driving mechanism of this
transition is identified as increased crystal field splitting with pressure,
resulting in a charge redistribution between the Mn and symmetry
projected states.Comment: arXiv admin note: text overlap with arXiv:0912.111
The generalized gradient approximation kernel in time-dependent density functional theory
A complete understanding of a material requires both knowledge of the excited
states as well as of the ground state. In particular, the low energy
excitations are of utmost importance while studying the electronic, magnetic,
dynamical, and thermodynamical properties of the material. Time-Dependent
Density Functional Theory (TDDFT), within the linear regime, is a successful
\textit{ab-initio} method to access the electronic charge and spin excitations.
However, it requires an approximation to the exchange-correlation (XC) kernel
which encapsulates the effect of electron-electron interactions in the
many-body system. In this work we derive and implement the spin-polarized XC
kernel for semi-local approximations such as the adiabatic Generalized Gradient
Approximation (AGGA). This kernel has a quadratic dependence on the wavevector,
{\bf q}, of the perturbation, however the impact of this on the electron energy
loss spectra (EELS) is small. Although the GGA functional is good in predicting
structural properties, it generality overestimates the exchange spin-splitting.
This leads to higher magnon energies, as compared to both ALDA and experiment.
In addition, interaction with the Stoner spin-flip continuum is enhanced by
AGGA, which strongly suppresses the intensity of spin-waves.Comment: 11 pages, 7 figure
A comparison of bilateral muscular imbalance ratio calculations using functional tests.
Bilateral muscular imbalance can increase the risk of injury and negatively impact sporting performance. Bilateral muscular imbalances are typically calculated as ((side 1-side 2)/reference value) x 100, to provide a percentage value of the difference between limbs. Using different numerator (right-left or strong-weak) or reference values (left, right, strong, weak, average of the two) could mask or inflate the true difference value. The present study aimed to compare the bilateral muscular imbalance ratio calculations, using the absolute difference between limbs as the numerator and the five different options as reference values. Twenty three males (21.6±1.9 years, 1.80±0.06 m, 80.5±13.8 kg) and eleven females (20.8± 1.5 years, 1.62±0.03 m, 68.0±6.5 kg) performed the one-legged 6m timed test and the onelegged triple hop distance test. The five possible combinations were compared with a 2 (gender) x 2 (functional test) x 5 (calculation method) ANOVA for each test. Significant differences (P<0.05) were found between gender when the right leg was used as the reference value (males:6.1%, females:9.1%), and within calculation methods for males (range:5.9%-6.5%) and females (range:8.4%-9.4%), with low effect sizes (range: 0.07-0.26). The present findings demonstrate that using a different reference value for calculating bilateral muscular imbalances does not result in a practically significant difference. These findings can be used to inform a more standardised calculation method which will afford conditioning coaches a more correct evaluation and monitoring of training and rehabilitation programmes
Reduced Density Matrix Functional for Many-Electron Systems
Reduced density matrix functional theory for the case of solids is presented
and a new exchange correlation functional based on a fractional power of the
density matrix is introduced. We show that compared to other functionals, this
produces more accurate results for both finite systems. Moreover, it captures
the correct band gap behavior for conventional semiconductors as well as
strongly correlated Mott insulators, where a gap is obtained in absence of any
magnetic ordering.Comment: 4 figs and 1 tabl
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