13,833 research outputs found
Academic performance & student engagement in level 1 physics undergraduates
At the beginning of academic year 2007-08, staff in the Department of Physics
& Astronomy at the University of Glasgow started to implement a number of
substantial changes to the administration of the level 1 physics undergraduate
class. The main aims were to improve the academic performance and progression
statistics. With this in mind, a comprehensive system of learning support was
introduced, the main remit being the provision of an improved personal contact
and academic monitoring and support strategy for all students at level 1. The
effects of low engagement with compulsory continuous assessment components had
already been observed to have a significant effect for students sitting in the
middle of the grade curve. Analysis of data from the 2007-08 class showed that
even some nominally high-achieving students achieved lowered grades due to the
effects of low engagement. Nonetheless, academic and other support measures put
in place during 2007-08 played a part in raising the passrate for the level 1
physics class by approximately 8% as well as raising the progression rate by
approximately 10%.Comment: 12 pages, 3 figure
Evaluation of gene importance in microarray data based upon probability of selection
BACKGROUND: Microarray devices permit a genome-scale evaluation of gene function. This technology has catalyzed biomedical research and development in recent years. As many important diseases can be traced down to the gene level, a long-standing research problem is to identify specific gene expression patterns linking to metabolic characteristics that contribute to disease development and progression. The microarray approach offers an expedited solution to this problem. However, it has posed a challenging issue to recognize disease-related genes expression patterns embedded in the microarray data. In selecting a small set of biologically significant genes for classifier design, the nature of high data dimensionality inherent in this problem creates substantial amount of uncertainty. RESULTS: Here we present a model for probability analysis of selected genes in order to determine their importance. Our contribution is that we show how to derive the P value of each selected gene in multiple gene selection trials based on different combinations of data samples and how to conduct a reliability analysis accordingly. The importance of a gene is indicated by its associated P value in that a smaller value implies higher information content from information theory. On the microarray data concerning the subtype classification of small round blue cell tumors, we demonstrate that the method is capable of finding the smallest set of genes (19 genes) with optimal classification performance, compared with results reported in the literature. CONCLUSION: In classifier design based on microarray data, the probability value derived from gene selection based on multiple combinations of data samples enables an effective mechanism for reducing the tendency of fitting local data particularities
Correlating the Energetics and Atomic Motions of the Metal-Insulator Transition of M1 Vanadium Dioxide
Materials that undergo reversible metal-insulator transitions are obvious
candidates for new generations of devices. For such potential to be realised,
the underlying microscopic mechanisms of such transitions must be fully
determined. In this work we probe the correlation between the energy landscape
and electronic structure of the metal-insulator transition of vanadium dioxide
and the atomic motions occurring using first principles calculations and high
resolution X-ray diffraction. Calculations find an energy barrier between the
high and low temperature phases corresponding to contraction followed by
expansion of the distances between vanadium atoms on neighbouring sub-lattices.
X-ray diffraction reveals anisotropic strain broadening in the low temperature
structure's crystal planes, however only for those with spacings affected by
this compression/expansion. GW calculations reveal that traversing this barrier
destabilises the bonding/anti-bonding splitting of the low temperature phase.
This precise atomic description of the origin of the energy barrier separating
the two structures will facilitate more precise control over the transition
characteristics for new applications and devices.Comment: 11 Pages, 8 Figure
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