7,162 research outputs found
Impact of published clinical outcomes data: case study in NHS hospital trusts
Objective To examine the impact of the publication of clinical outcomes data on NHS Trusts in Scotland to inform the development of similar schemes elsewhere. Design Case studies including semistructured interviews and a review of background statistics. Setting Eight Scottish NHS acute trusts. Participants 48 trust staff comprising chief executives, medical directors, stroke consultants, breast cancer consultants, nurse managers, and junior doctors. Main outcome measures Staff views on the benefits and drawbacks of clinical outcome indicators provided by the clinical resource and audit group (CRAG) and perceptions of the impact of these data on clinical practice and continuous improvement of quality. Results The CRAG indicators had a low profile in the trusts and were rarely cited as informing internal quality improvement or used externally to identify best practice. The indicators were mainly used to support applications for further funding and service development. The poor effect was attributable to a lack of professional belief in the indicators, arising from perceived problems around quality of data and time lag between collection and presentation of data; limited dissemination; weak incentives to take action; a predilection for process rather than outcome indicators; and a belief that informal information is often more useful than quantitative data in the assessment of clinical performance. Conclusions Those responsible for developing clinical indicator programmes should develop robust datasets. They should also encourage a working environment and incentives such that these data are used to improve continuously
Criticality and the practice-based MA: An argument drawn from teaching on the Masters in Teaching and Learning (MTL)
This paper considers the notion of 'criticality' in relation to the Masters in Teaching and Learning (MTL), the Teacher Development Agency (TDA)-funded masters programme for school teachers in England. After the two current cohorts complete the MTL in 2013 - one a cohort of Newly Qualified Teachers (NQTs) and one of more senior Teaching and Learning Responsibility holders (TLRs) - government funding will not be provided for any subsequent recruitment to the course. In light of this, debates around the MTL may be viewed as redundant, but we do need to acknowledge that there will be a cohort of students who hold a Masters in Teaching and Learning and for whom it is a valid qualification. Beyond this, discussion of what a masters course in education might consist of is still a relevant and urgent matter. Our argument in this paper draws upon our experience of working on the MTL but is, we submit, applicable more generally to the 'practice-based' masters courses that have proliferated in recent years. Our focus is upon criticality as an essential component of 'masterliness'. We consider briefly ways in which critique might be construed and practised before going on to argue that a certain idea of critique, which draws upon historical conceptions of education's role in serving the social good, is essential to educational practice and to claims to mastery in education. We conclude by drawing attention to difficulties that may be presented to teacherresearchers on master's courses that offer themselves as school-based programmes of professional development
Estimating Effects and Making Predictions from Genome-Wide Marker Data
In genome-wide association studies (GWAS), hundreds of thousands of genetic
markers (SNPs) are tested for association with a trait or phenotype. Reported
effects tend to be larger in magnitude than the true effects of these markers,
the so-called ``winner's curse.'' We argue that the classical definition of
unbiasedness is not useful in this context and propose to use a different
definition of unbiasedness that is a property of the estimator we advocate. We
suggest an integrated approach to the estimation of the SNP effects and to the
prediction of trait values, treating SNP effects as random instead of fixed
effects. Statistical methods traditionally used in the prediction of trait
values in the genetics of livestock, which predates the availability of SNP
data, can be applied to analysis of GWAS, giving better estimates of the SNP
effects and predictions of phenotypic and genetic values in individuals.Comment: Published in at http://dx.doi.org/10.1214/09-STS306 the Statistical
Science (http://www.imstat.org/sts/) by the Institute of Mathematical
Statistics (http://www.imstat.org
Saccharomyces cerevisiae: a nomadic yeast with no niche?
Different species are usually thought to have specific adaptations, which allow them to occupy different ecological niches. But recent neutral ecology theory suggests that species diversity can simply be the result of random sampling, due to finite population sizes and limited dispersal. Neutral models predict that species are not necessarily adapted to specific niches, but are functionally equivalent across a range of habitats. Here we evaluate the ecology of S. cerevisiae, one of the most important microbial species in human history. The artificial collection, concentration, and fermentation of large volumes of fruit for alcohol production produces an environment in which S. cerevisiae thrives, and therefore it is assumed that fruit is the ecological niche that S. cerevisiae inhabits and has adapted to. We find very little direct evidence that S. cerevisiae is adapted to fruit, or indeed to any other specific niche. We propose instead a neutral nomad model for S. cerevisiae, which we believe should be used as the starting hypothesis in attempting to unravel the ecology of this important microbe
Superprotonic phase transition of CsHSO4: A molecular dynamics simulation study
The superprotonic phase transition (phase II --> phase I; 414 K) of cesium hydrogen sulfate, CsHSO4, was simulated using molecular dynamics with the "first principles" MSXX force field (FF). The structure, binding energy, and vibrational frequencies of the CsHSO4 monomer, the binding energy of the (H2SO4)2 dimer, and the torsion barrier of the HSO4- ion were determined from quantum mechanical calculations, and the parameters of the Dreiding FF for Cs, S, O, and H adjusted to reproduce these quantities. Each hydrogen atom was treated as bonded exclusively to a single oxygen atom (proton donor), but allowed to form hydrogen bonds to various second nearest oxygen atoms (proton acceptors). Fixed temperature-pressure (NPT) dynamics were employed to study the structure as a function of temperature from 298 to 723 K. In addition, the influence of several force field parameters, including the hydrogen torsional barrier height, hydrogen bond strength, and oxygen charge distribution, on the structural behavior of CsHSO4 was probed. Although the FF does not allow proton migration (i.e., proton jumps) between oxygen atoms, a clear phase transition occurred as demonstrated by a discrete change of unit cell symmetry (monoclinic to tetragonal), cell volume, and molar enthalpy. The dynamics of the HSO4- group reorientational motion also changed dramatically at the transition. The observation of a transition to the expected tetragonal phase using a FF in which protons cannot migrate indicates that proton diffusion does not drive the transition to the superprotonic phase. Rather, high conductivity is a consequence of the rapid reorientations that occur in the high temperature phase. Furthermore, because no input from the superprotonic phase was employed in these simulations, it may be possible to employ MD to hypothesize superprotonic materials
Isolation and characterization of Caenorhabditis elegans DNA sequences homologous to the v-abl oncogene.
Journal ArticleDNA sequences homologous to the v-abl oncogene were isolated from a Caenorhabditis elegans genomic library by their ability to hybridize with a v-src probe. The DNA sequence of 2465 nucleotides of one clone was determined. This region corresponds to the 5' protein kinase domain of v-abl plus approximately equal to 375 base pairs toward the 3' end. Four potential introns were identified. The homology between the deduced amino acid sequence of the C. elegans clone and that of the 1.2-kilobase-pair protein kinase region of v-abl is 62%. The tyrosine residue corresponding to the tyrosine that is phosphorylated in the v-src protein is conserved in the C. elegans sequence. When 95 amino acids around this tyrosine were compared with the corresponding sequences of Drosophila c-abl, v-abl, and v-src, the identities were 83%, 79%, and 56%, respectively. Hybridization of the cloned DNA with C. elegans poly(A)+ RNA revealed a major transcript of 4.4 kilobases
Dependence of kink oscillation damping on the amplitude
Context. Kink oscillations of coronal loop are one of the most ntensively studied oscillatory phenomena in the solar corona. In the large-amplitude rapidly damped regime these oscillations are observed to have a low quality-factor, with only a few cycles of oscillation detected before they are damped. The specific mechanism responsible for the rapid damping is commonly accepted to be associated with the linear coupling between collective kink oscillations and localised torsional oscillations, the phenomenon of resonant absorption of the kink mode. However, the role of finite amplitude effects is still not clear.
Aims. We investigated the empirical dependence of the kink oscillation damping time and its quality factor, defined as the ratio of the
damping time to the oscillation period, on the oscillation amplitude.
Methods. We analysed decaying kink oscillation events detected previously with TRACE, SDO/AIA and and STEREO/EUVI in the EUV 171Å band.
Results. We found that the ratio of the kink oscillation damping time to the oscillation period systematically decreases with the oscillation amplitude. The quality factor dependence on the oscillation isplacement amplitude has been approximated by the powerlaw dependence with the exponent of −1/2, however we stress that this is a “by eye”estimate, and a more rigorous estimation of the scaling law requires more accurate measurements and increased statistics. We conclude that damping of kink oscillations of coronal loops depends on the oscillation amplitude, indicating the possible role of nonlinear mechanisms for damping
Scalar and tensorial topological matter coupled to (2+1)-dimensional gravity:A.Classical theory and global charges
We consider the coupling of scalar topological matter to (2+1)-dimensional
gravity. The matter fields consist of a 0-form scalar field and a 2-form tensor
field. We carry out a canonical analysis of the classical theory, investigating
its sectors and solutions. We show that the model admits both BTZ-like
black-hole solutions and homogeneous/inhomogeneous FRW cosmological
solutions.We also investigate the global charges associated with the model and
show that the algebra of charges is the extension of the Kac-Moody algebra for
the field-rigid gauge charges, and the Virasoro algebrafor the diffeomorphism
charges. Finally, we show that the model can be written as a generalized
Chern-Simons theory, opening the perspective for its formulation as a
generalized higher gauge theory.Comment: 40 page
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