169 research outputs found
What do cyclists need to see to avoid single-bicycle crashes?
The number of single-bicycle crash victims is substantial in countries with high levels of cycling. To study the role of visual characteristics of the infrastructure, such as pavement markings, in single-bicycle crashes, a study in two steps was conducted. In Study 1, a questionnaire study was conducted among bicycle crash victims (n = 734). Logistic regression was used to study the relationship between the crashes and age, light condition, alcohol use, gaze direction and familiarity with the crash scene. In Study 2, the image degrading and edge detection method (IDED-method) was used to investigate the visual characteristics of 21 of the crash scenes. The results of the studies indicate that crashes, in which the cyclist collided with a bollard or road narrowing or rode off the road, were related to the visual characteristics of bicycle facilities. Edge markings, especially in curves of bicycle tracks, and improved conspicuity of bollards are recommended. Statement of Relevance: Elevated single-bicycle crash numbers are common in countries with high levels of cycling. No research has been conducted on what cyclists need to see to avoid this type of crash. The IDED-method to investigate crash scenes is new and proves to be a powerful tool to quantify 'visual accessibility'. © 2011 Taylor & Francis
One single dose of etomidate negatively influences adrenocortical performance for at least 24 h in children with meningococcal sepsis
Objective: To investigate the effect of one single bolus of etomidate used for intubation on adrenal function in children with meningococcal sepsis. Design: Retrospective study conducted between 1997 and 2004. Setting: University-affiliated paediatric intensive care unit (PICU). Patients and participants: Sixty children admitted to the PICU with meningococcal sepsis, not treated with steroids. Interventions: Adrenal hormone concentrations were determined as soon as possible after PICU admission, and after 12 h and 24 h. To assess disease severity, PRISM score and selected laboratory parameters were determined. Measurements and main results: On admission, before blood was drawn, 23 children had been intubated with etomidate, 8 without etomidate and 29 were not intubated. Children who were intubated had significantly higher disease severity parameters than those not intubated, whereas none of these parameters significantly differed between children intubated with or without etomidate. Children who received etomidate had significantly lower cortisol, higher ACTH and higher 11-deoxycortisol levels than those who did not receive etomidate. Arterial glucose levels were significantly lower in children who were intubated with etomidate than in non-intubated children. When children were intubated with etomidate, cortisol levels were 3.2 times lower for comparable 11-deoxycortisol levels. Eight children died, seven of whom had received etomidate. Within 24 h cortisol/ACTH and cortisol/11-deoxycortisol ratios increased significantly in children who received etomidate, but not in children who did not, resulting in comparable cortisol/ACTH ratios with sti
Blind Inversion of Wiener Systems
A system in which a linear dynamic part is followed by a non
linear memoryless distortion a Wiener system is blindly inverted
This
kind of systems can be modelised as a postnonlinear mixture and using
some results about these mixtures an e cient algorithm is proposed
Results in a hard situation are presented and illustrate the e ciency of
this algorith
Separable time-causal and time-recursive spatio-temporal receptive fields
We present an improved model and theory for time-causal and time-recursive
spatio-temporal receptive fields, obtained by a combination of Gaussian
receptive fields over the spatial domain and first-order integrators or
equivalently truncated exponential filters coupled in cascade over the temporal
domain. Compared to previous spatio-temporal scale-space formulations in terms
of non-enhancement of local extrema or scale invariance, these receptive fields
are based on different scale-space axiomatics over time by ensuring
non-creation of new local extrema or zero-crossings with increasing temporal
scale. Specifically, extensions are presented about parameterizing the
intermediate temporal scale levels, analysing the resulting temporal dynamics
and transferring the theory to a discrete implementation in terms of recursive
filters over time.Comment: 12 pages, 2 figures, 2 tables. arXiv admin note: substantial text
overlap with arXiv:1404.203
Acute Stress Response in Critically Ill Children
The understanding of the endocrine changes in critically ill children is important, as it
provides insights in the pathophysiology of the acute stress in children and its
differences compared with adults. Furthermore, it delineates prognostic factors for
survival and supports the rational use of present and future pharmaceutical
interventions. Much more than in critically ill adults, the acute phase of critical illness
comes into prominence in critically ill children, as they show a very rapid and fierce
course of disease, followed by a quick recovery if they survive. This chapter presents
a comprehensive summary of the results of various studies undertaken to evaluate
endocrine changes seen during the acute stress response in critically ill children
suffering from sepsis or septic shock with purpura (Chapters 2 to 6) or undergoing
open-heart surgery (Chapter 7). These studies evaluated three
hypothalamic-pituitary-end-organ axes:
I. Hypothalamic-pituitary-adrenal axis (Chapter 2 and Chapter 3)
II. Hypothalamic-pituitary-thyroid axis (Chapter 4 and Chapter 5)
III. Growth hormone / insulin-like growth factor axis (Chapter 6 and Chapter 7)
Chapter 1 provides a general overview of these hormonal axes and the current
knowledge on the changes during the acute phase of critical illness in children and
adults
Can Passive Cough Monitoring Predict COPD Exacerbations?
Purpose: Validation of an alert mechanism for COPD exacerbations based on coughing detected by a stationary unobtrusive nighttime monitor. Methods: This prospective double-blind longitudinal study of cough monitoring included 40 chronic obstructive pulmonary disease (COPD) patients. Participants underwent cough monitoring and completed a daily questionnaire for 12 weeks. If no exacerbation occurred within that period patients were asked to continue being monitored for a further 12 weeks. The automated system identified deteriorating trends in cough based on a personalized cough classifier and the alerts were compared with patient reported exacerbation onsets. Results: Thirty-eight patients [median age 72 (range 57–84)], median FEV-1% predicted 43% (range 20–106%) completed the study and had 41 exacerbations over a total of 3981 days. For 32 patients, the cough monitor data allowed classifier personalization, trend analysis, and alert generation. Based on the trend data, it is estimated that ∼30% of exacerbations are not associated with an increase in cough. The alert mechanism flagged 59% of the exacerbations. For the cases with alerts preceding the onset, the associated lead time was 4 days or more. Conclusion: Though based on a single variable only, the cough-based alert system captured more than half of the exacerbations in a passive, free-living scenario. No adherence issues were reported, and patients confirmed the unobtrusive and hassle-free nature of the approach
One single dose of etomidate negatively influences adrenocortical performance for at least 24 h in children with meningococcal sepsis
Objective: To investigate the effect of one single bolus of etomidate used for intubation on adrenal function in children with meningococcal sepsis. Design: Retrospective study conducted between 1997 and 2004. Setting: University-affiliated paediatric intensive care unit (PICU). Patients and participants: Sixty children admitted to the PICU with meningococcal sepsis, not treated with steroids. Interventions: Adrenal hormone concentrations were determined as soon as possible after PICU admission, and after 12h and 24h. To assess disease severity, PRISM score and selected laboratory parameters were determined. Measurements and main results: On admission, before blood was drawn, 23 children had been intubated with etomidate, 8 without etomidate and 29 were not intubated. Children who were intubated had significantly higher disease severity parameters than those not intubated, whereas none of these parameters significantly differed between children intubated with or without etomidate. Children who received etomidate had significantly lower cortisol, higher ACTH and higher 11-deoxycortisol levels than those who did not receive etomidate. Arterial glucose levels were significantly lower in children who were intubated with etomidate than in non-intubated children. When children were intubated with etomidate, cortisol levels were 3.2 times lower for comparable 11-deoxycortisol levels. Eight children died, seven of whom had received etomidate. Within 24h cortisol/ACTH and cortisol/11-deoxycortisol ratios increased significantly in children who received etomidate, but not in children who did not, resulting in comparable cortisol/ACTH ratios with still significantly lowered cortisol/11-deoxycortisol ratios 24h after admission. Conclusions: Our data imply that even one single bolus of etomidate negatively influences adrenal function for at least 24h. It might therefore increase risk of death
Adjustment of Insulin Pump Settings in Type 1 Diabetes Management: Advisor Pro Device Compared to Physicians’ Recommendations
Aims: To compare insulin dose adjustments made by physicians to those made by an artificial intelligence-based decision support system, the Advisor Pro, in people with type 1 diabetes (T1D) using an insulin pump and self-monitoring blood glucose (SMBG). Methods: This was a multinational, non-interventional study surveying 17 physicians from 11 countries. Each physician was asked to provide insulin dose adjustments for the settings of the pump including basal rate, carbohydrate-to-insulin ratios (CRs), and correction factors (CFs) for 15 data sets of pumps and SMBG of people with T1D (mean age 18.4 ± 4.8 years; eight females; mean glycated hemoglobin 8.2% ± 1.4% [66 ± 11mmol/mol]). The recommendations were compared among the physicians and between the physicians and the Advisor Pro. The study endpoint was the percentage of comparison points for which there was an agreement on the direction of insulin dose adjustments. Results: The percentage (mean ± SD) of agreement among the physicians on the direction of insulin pump dose adjustments was 51.8% ± 9.2%, 54.2% ± 6.4%, and 49.8% ± 11.6% for the basal, CR, and CF, respectively. The automated recommendations of the Advisor Pro on the direction of insulin dose adjustments were comparable)49.5% ± 6.4%, 55.3% ± 8.7%, and 47.6% ± 14.4% for the basal rate, CR, and CF, respectively(and noninferior to those provided by physicians. The mean absolute difference in magnitude of change between physicians was 17.1% ± 13.1%, 14.6% ± 8.4%, and 23.9% ± 18.6% for the basal, CR, and CF, respectively, and comparable to the Advisor Pro 11.7% ± 9.7%, 10.1% ± 4.5%, and 25.5% ± 19.5%, respectively, significant for basal and CR. Conclusions: Considerable differences in the recommendations for changes in insulin dosing were observed among physicians. Since automated recommendations by the Advisor Pro were similar to those given by physicians, it could be considered a useful tool to manage T1D
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