3,036 research outputs found
Sedation for Gastrointestinal Endoscopic Procedures in the Elderly: Getting Safer but Still Not Nearly Safe Enough
Previously published UK reports showed that excessively large doses of benzodiazepines and opiates were being commonly used to sedate elderly patients for gastrointestinal (GI) endoscopy. This unsafe practice has lead to avoidable morbidity and mortality. We have taken the opportunity provided by recent reports to examine whether GI endoscopy sedation practice in the elderly has improved in the light of this evidence and the publication of guidelines in which specific recommendations on sedation dosage are given
Nonsingular, big-bounce cosmology from spinor-torsion coupling
The Einstein-Cartan-Sciama-Kibble theory of gravity removes the constraint of
general relativity that the affine connection be symmetric by regarding its
antisymmetric part, the torsion tensor, as a dynamical variable. The minimal
coupling between the torsion tensor and Dirac spinors generates a spin-spin
interaction which is significant in fermionic matter at extremely high
densities. We show that such an interaction averts the unphysical big-bang
singularity, replacing it with a cusp-like bounce at a finite minimum scale
factor, before which the Universe was contracting. This scenario also explains
why the present Universe at largest scales appears spatially flat, homogeneous
and isotropic.Comment: 7 pages; published versio
Evaluation of the ADOS Revised Algorithm: The Applicability in 558 Dutch Children and Adolescents
The revised ADOS algorithms, proposed by Gotham et al. (J Autism Dev Disord 37:613–627, 2007), were investigated in an independent sample of 558 Dutch children (modules 1, 2 and 3). The revised algorithms lead to better balanced sensitivity and specificity for modules 2 and 3, without losing efficiency of the classification. Including the restricted repetitive behaviour domain in the algorithm contributes to a clinical ASD classification in modules 2 and 3. For module 1, the results indicate less improvement, probably due to the low-functioning population. In most groups, the advantages of the revised algorithms are achieved without losing the strength of the original algorithm
Diffuse-interface model for rapid phase transformations in nonequilibrium systems
A thermodynamic approach to rapid phase transformations within a diffuse
interface in a binary system is developed. Assuming an extended set of
independent thermodynamic variables formed by the union of the classic set of
slow variables and the space of fast variables, we introduce finiteness of the
heat and solute diffusive propagation at the finite speed of the interface
advancing. To describe the transformation within the diffuse interface, we use
the phase-field model which allows us to follow the steep but smooth change of
phases within the width of diffuse interface. The governing equations of the
phase-field model are derived for the hyperbolic model, model with memory, and
for a model of nonlinear evolution of transformation within the
diffuse-interface. The consistency of the model is proved by the condition of
positive entropy production and by the outcomes of the fluctuation-dissipation
theorem. A comparison with the existing sharp-interface and diffuse-interface
versions of the model is given.Comment: 15 pages, regular article submitted to Physical Review
Optimal Self-Organization
We present computational and analytical results indicating that systems of
driven entities with repulsive interactions tend to reach an optimal state
associated with minimal interaction and minimal dissipation. Using concepts
from non-equilibrium thermodynamics and game theoretical ideas, we generalize
this finding to an even wider class of self-organizing systems which have the
ability to reach a state of maximal overall ``success''. This principle is
expected to be relevant for driven systems in physics like sheared granular
media, but it is also applicable to biological, social, and economic systems,
for which only a limited number of quantitative principles are available yet.Comment: This is the detailled revised version of a preprint on
``Self-Organised Optimality'' (cond-mat/9903319). For related work see
http://www.theo2.physik.uni-stuttgart.de/helbing.html and
http://angel.elte.hu/~vicsek
The Impact of Mixing Modes on Reliability in Longitudinal Studies
Mixed-mode designs are increasingly important in surveys, and large longitudinal studies are progressively moving to or considering such a design. In this context, our knowledge regarding the impact of mixing modes on data quality indicators in longitudinal studies is sparse. This study tries to ameliorate this situation by taking advantage of a quasi-experimental design in a longitudinal survey. Using models that estimate reliability for repeated measures, quasi-simplex models, 33 variables are analyzed by comparing a single-mode CAPI design to a sequential CATI-CAPI design. Results show no differences in reliabilities and stabilities across mixed modes either in the wave when the switch was made or in the subsequent waves. Implications and limitations are discussed. </jats:p
What are we measuring? Convergence of leadership with interpersonal and non-interpersonal personality.
Since leadership styles have been most commonly defined in terms of interpersonal influence, one would assume that they have their main projections on the interpersonal circumplex. In this study, the relations between leadership styles from the Multifactor Leadership Questionnaire and Leader Behaviour Description Questionnaire and both interpersonal and HEXACO personality scales are investigated. As expected, charismatic leadership and leader's consideration have strong projections on the interpersonal circumplex, with main projections on the warm-agreeable octant. Transactional leadership, passive leadership, and task-oriented leadership have considerably weaker or no projections on the circumplex. Leader's consideration is most strongly related to interpersonal personality while both transactional and passive leadership are most strongly related to non-interpersonal personality. It is concluded that especially charismatic leadership and leader's consideration are captured almost fully by the HEXACO personality inventory. Copyright © 2008 SAGE Publications
Improving cluster recovery with feature rescaling factors
The data preprocessing stage is crucial in clustering. Features may describe entities using different scales. To rectify this, one usually applies feature normalisation aiming at rescaling features so that none of them overpowers the others in the objective function of the selected clustering algorithm. In this paper, we argue that the rescaling procedure should not treat all features identically. Instead, it should favour the features that are more meaningful for clustering. With this in mind, we introduce a feature rescaling method that takes into account the within-cluster degree of relevance of each feature. Our comprehensive simulation study, carried out on real and synthetic data, with and without noise features, clearly demonstrates that clustering methods that use the proposed data normalization strategy clearly outperform those that use traditional data normalization
- …