64 research outputs found
Experimental Study of Noise-induced Phase Synchronization in Vertical-cavity Lasers
We report the experimental evidence of noise-induced phase synchronization in
a vertical cavity laser. The polarized laser emission is entrained with the
input periodic pump modulation when an optimal amount of white, gaussian noise
is applied. We characterize the phenomenon, evaluating the average frequency of
the output signal and the diffusion coefficient of the phase difference
variable. Their values are roughly independent on different waveforms of
periodic input, provided that a simple condition for the amplitudes is
satisfied. The experimental results are compared with numerical simulations of
a Langevin model
Contextual Structured Reporting in Radiology:Implementation and Long-Term Evaluation in Improving the Communication of Critical Findings
Structured reporting contributes to the completeness of radiology reports and improves quality. Both the content and the structure are essential for successful implementation of structured reporting. Contextual structured reporting is tailored to a specific scenario and can contain information retrieved from the context. Critical findings detected by imaging need urgent communication to the referring physician. According to guidelines, the occurrence of this communication should be documented in the radiology reports and should contain when, to whom and how was communicated. In free-text reporting, one or more of these required items might be omitted. We developed a contextual structured reporting template to ensure complete documentation of the communication of critical findings. The WHEN and HOW items were included automatically, and the insertion of the WHO-item was facilitated by the template. A pre- and post-implementation study demonstrated a substantial improvement in guideline adherence. The template usage improved in the long-term post-implementation study compared with the short-term results. The two most often occurring categories of critical findings are "infection / inflammation" and "oncology", corresponding to the a large part of urgency level 2 (to be reported within 6 h) and level 3 (to be reported within 6 days), respectively. We conclude that contextual structured reporting is feasible for required elements in radiology reporting and for automated insertion of context-dependent data. Contextual structured reporting improves guideline adherence for communication of critical findings
Drift and Diffusion in Periodically Driven Renewal Processes
We consider the drift and diffusion properties of periodically driven renewal
processes. These processes are defined by a periodically time dependent waiting
time distribution, which governs the interval between subsequent events. We
show that the growth of the cumulants of the number of events is asymptotically
periodic and develop a theory which relates these periodic growth coefficients
to the waiting time distribution defining the periodic renewal process. The
first two coefficients, which are the mean frequency and effective diffusion
coefficient of the number of events are considered in greater detail. They may
be used to quantify stochastic synchronization.Comment: 29 pages, 6 figures, submitted to Journal of Statistical Physic
Safety of Levetiracetam in paediatrics: a systematic review
Objective
To identify adverse events (AEs) associated with Levetiracetam (LEV) in children.
Methods
Databases EMBASE (1974-February 2015) and Medline (1946-February 2015) were searched for articles in which paediatric patients (≤18 years) received LEV treatment for epilepsy. All studies with reports on safety were included. Studies involving adults, mixed age population (i.e. children and adults) in which the paediatric subpopulation was not sufficiently described, were excluded. A meta-analysis of the RCTs was carried out and association between the commonly reported AEs or treatment discontinuation and the type of regimen (polytherapy or monotherapy) was determined using Chi2 analysis.
Results
Sixty seven articles involving 3,174 paediatric patients were identified. A total of 1,913 AEs were reported across studies. The most common AEs were behavioural problems and somnolence, which accounted for 10.9% and 8.4% of all AEs in prospective studies. 21 prospective studies involving 1120 children stated the number of children experiencing AEs. 47% of these children experienced AEs. Significantly more children experienced AEs with polytherapy (64%) than monotherapy (22%) (p<0.001). Levetiracetam was discontinued in 4.5% of all children on polytherapy and 0.9% on monotherapy (p<0.001), the majority were due to behavioural problems.
Conclusion
Behavioural problems and somnolence were the most prevalent adverse events to LEV and the most common causes of treatment discontinuation. Children on polytherapy have a greater risk of adverse events than those receiving monotherapy
Identificação de aspectos ambientais relacionados à produção de embalagens de perfumaria: contribuição para projetos sustentáveis
Italian guidelines for primary headaches: 2012 revised version
The first edition of the Italian diagnostic and therapeutic guidelines for primary headaches in adults was published in J Headache Pain 2(Suppl. 1):105–190 (2001). Ten years later, the guideline committee of the Italian Society for the Study of Headaches (SISC) decided it was time to update therapeutic guidelines. A literature search was carried out on Medline database, and all articles on primary headache treatments in English, German, French and Italian published from February 2001 to December 2011 were taken into account. Only randomized controlled trials (RCT) and meta-analyses were analysed for each drug. If RCT were lacking, open studies and case series were also examined. According to the previous edition, four levels of recommendation were defined on the basis of levels of evidence, scientific strength of evidence and clinical effectiveness. Recommendations for symptomatic and prophylactic treatment of migraine and cluster headache were therefore revised with respect to previous 2001 guidelines and a section was dedicated to non-pharmacological treatment. This article reports a summary of the revised version published in extenso in an Italian version
Estratégias de gestão ambiental e seus fatores determinantes: uma análise institucional
<i>GRIN2A</i>-related disorders:genotype and functional consequence predict phenotype
Alterations of the N-methyl-d-aspartate receptor (NMDAR) subunit GluN2A, encoded by GRIN2A, have been associated with a spectrum of neurodevelopmental disorders with prominent speech-related features, and epilepsy. We performed a comprehensive assessment of phenotypes with a standardized questionnaire in 92 previously unreported individuals with GRIN2A-related disorders. Applying the criteria of the American College of Medical Genetics and Genomics to all published variants yielded 156 additional cases with pathogenic or likely pathogenic variants in GRIN2A, resulting in a total of 248 individuals. The phenotypic spectrum ranged from normal or near-normal development with mild epilepsy and speech delay/apraxia to severe developmental and epileptic encephalopathy, often within the epilepsy-aphasia spectrum. We found that pathogenic missense variants in transmembrane and linker domains (misTMD+Linker) were associated with severe developmental phenotypes, whereas missense variants within amino terminal or ligand-binding domains (misATD+LBD) and null variants led to less severe developmental phenotypes, which we confirmed in a discovery (P = 10-6) as well as validation cohort (P = 0.0003). Other phenotypes such as MRI abnormalities and epilepsy types were also significantly different between the two groups. Notably, this was paralleled by electrophysiology data, where misTMD+Linker predominantly led to NMDAR gain-of-function, while misATD+LBD exclusively caused NMDAR loss-of-function. With respect to null variants, we show that Grin2a+/- cortical rat neurons also had reduced NMDAR function and there was no evidence of previously postulated compensatory overexpression of GluN2B. We demonstrate that null variants and misATD+LBD of GRIN2A do not only share the same clinical spectrum (i.e. milder phenotypes), but also result in similar electrophysiological consequences (loss-of-function) opposing those of misTMD+Linker (severe phenotypes; predominantly gain-of-function). This new pathomechanistic model may ultimately help in predicting phenotype severity as well as eligibility for potential precision medicine approaches in GRIN2A-related disorders
Greener workplace: understanding senior management's adoption decisions through the Theory of Planned Behaviour
Human Resources (HR) policies and practices have changed due to global environmental instability. These policies and practices are key factors for successful environmental management. Using the Theory of Planned Behaviour, this article aims to understand the critical factors which influence senior management’s decision to adopt ‘green’ HR practices. Data were collected from 210 organisations in Australia using two separate surveys. Survey one, which was addressed directly to HR managers and directors, contained questions relating to HR policies (the dependent variables), while survey two, which was addressed directly to CEOs and senior managers, contained questions about environmental-related attitudes, subjective norms and perceived control (the independent variables). Results indicated that senior management’s environmental-related attitudes, subjective norms from stakeholders and perceived green resource readiness influenced their decision to adopt green HR initiatives. However, attitudes and green resource readiness in particular had greater impacts than subjective norms. Limitations, implications and future research are also outlined
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