381 research outputs found
Intraocular lens with integrated means of fixation
An intraocular lens has an optic body with at least a posterior surface defining a roughness portion disposed close to the periphery of the optic body wherein the roughness portion further defines an attachment configuration specified by parameters falling within certain specific ranges determined statistically using a profilometer. The parameters measure on the order of micrometers. The attachment configuration holds the lens in place without the use of spiral shaped fibrous arms
The Importance of Noise Colour in Simulations of Evolutionary Systems.
Simulations of evolutionary dynamics often employ white noise as a model of stochastic environmental variation. Whilst white noise has the advantages of being simply generated and analytically tractable, empirical analyses demonstrate that most real environmental time series have power spectral densities consistent with pink or red noise, in which lower frequencies contribute proportionally greater amplitudes than higher frequencies. Simulated white noise environments may therefore fail to capture key components of real environmental time series, leading to erroneous results. To explore the effects of different noise colours on evolving populations, a simple evolutionary model of the interaction between life-history and the specialism-generalism axis was developed. Simulations were conducted using a range of noise colours as the environments to which agents adapted. Results demonstrate complex interactions between noise colour, reproductive rate, and the degree of evolved generalism; importantly, contradictory conclusions arise from simulations using white as opposed to red noise, suggesting that noise colour plays a fundamental role in generating adaptive responses. These results are discussed in the context of previous research on evolutionary responses to fluctuating environments, and it is suggested that Artificial Life as a field should embrace a wider spectrum of coloured noise models to ensure that results are truly representative of environmental and evolutionary dynamics
Microtomography developments on the ANATOMIX beamline at Synchrotron SOLEIL
The new ANATOMIX beamline at Synchrotron SOLEIL is dedicated to hard X-ray
full-field tomography techniques. Operating in a range of photon energies from
approximately 5 to 50 keV, it offers both parallel-beam projection
microtomography and nanotomography using a zone-plate transmission X-ray
microscope and thus covers a range of spatial resolution from 20 nm to 20
m, expressed in terms of useful pixel size. Here we describe the
microtomography instrumentation and its performance.Comment: Paper submitted for publication in the Proceedings of the 15th
International Conference on X-Ray Microscopy (XRM 2020), 19--24 July 2020,
Taipei, Taiwan, edited by D.-H. Wei and C.-M. Cheng and H.-W. Shiu and T.-H.
Chuang, AIP Conf. Pro
Vaccine-associated enhanced disease : case definition and guidelines for data collection, analysis, and presentation of immunization safety data
This is a Brighton Collaboration Case Definition of the term & ldquo;Vaccine Associated Enhanced Disease & rdquo; to be utilized in the evaluation of adverse events following immunization. The Case Definition was developed by a group of experts convened by the Coalition for Epidemic Preparedness Innovations (CEPI) in the context of active development of vaccines for SARS-CoV-2 vaccines and other emerging pathogens. The case definition format of the Brighton Collaboration was followed to develop a consensus definition and defined levels of certainty, after an exhaustive review of the literature and expert consultation. The document underwent peer review by the Brighton Collaboration Network and by selected Expert Reviewers prior to submission.
(c) 2021 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
LUNEX5 : A FEL PROJECT TOWARDS THE FIFTH GENERATION IN FRANCE
ISBN978-3-95450-117-5 - http://accelconf.web.cern.ch/AccelConf/FEL2011/papers/tupa09.pdfInternational audienc
Saying Hello World with Epsilon - A Solution to the 2011 Instructive Case
Epsilon is an extensible platform of integrated and task-specific languages
for model management. With solutions to the 2011 TTC Hello World case, this
paper demonstrates some of the key features of the Epsilon Object Language (an
extension and reworking of OCL), which is at the core of Epsilon. In addition,
the paper introduces several of the task-specific languages provided by Epsilon
including the Epsilon Generation Language (for model-to-text transformation),
the Epsilon Validation Language (for model validation) and Epsilon Flock (for
model migration).Comment: In Proceedings TTC 2011, arXiv:1111.440
Causal hierarchy within the thalamo-cortical network in spike and wave discharges
Background: Generalised spike wave (GSW) discharges are the electroencephalographic (EEG) hallmark of absence seizures, clinically characterised by a transitory interruption of ongoing activities and impaired consciousness, occurring during states of reduced awareness. Several theories have been proposed to explain the pathophysiology of GSW discharges and the role of thalamus and cortex as generators. In this work we extend the existing theories by hypothesizing a role for the precuneus, a brain region neglected in previous works on GSW generation but already known to be linked to consciousness and awareness. We analysed fMRI data using dynamic causal modelling (DCM) to investigate the effective connectivity between precuneus, thalamus and prefrontal cortex in patients with GSW discharges. Methodology and Principal Findings: We analysed fMRI data from seven patients affected by Idiopathic Generalized Epilepsy (IGE) with frequent GSW discharges and significant GSW-correlated haemodynamic signal changes in the thalamus, the prefrontal cortex and the precuneus. Using DCM we assessed their effective connectivity, i.e. which region drives another region. Three dynamic causal models were constructed: GSW was modelled as autonomous input to the thalamus (model A), ventromedial prefrontal cortex (model B), and precuneus (model C). Bayesian model comparison revealed Model C (GSW as autonomous input to precuneus), to be the best in 5 patients while model A prevailed in two cases. At the group level model C dominated and at the population-level the p value of model C was ∼1. Conclusion: Our results provide strong evidence that activity in the precuneus gates GSW discharges in the thalamo-(fronto) cortical network. This study is the first demonstration of a causal link between haemodynamic changes in the precuneus - an index of awareness - and the occurrence of pathological discharges in epilepsy. © 2009 Vaudano et al
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