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Nonlinear Themoacoustic In/Stability of a Rijke Tube with a Distributed Heat Source. 7th European Combustion Meeting. Budapest, Hungary,
No full textThe clash of expectancies: Does the P300 amplitude reflect both passive and active expectations?
No full textWe investigated the clash of different types of expectations by studying event-related potentials and behavioural correlates of passive and active expectations. In the three tasks we used, target stimuli could either confirm or disconfirm both expectations, or confirm one while disconfirming the other. Depending on the task, expected events were related to either increased or decreased P300 amplitude. This was contingent on whether the expected item was probable given the context, or whether it was a target match. This suggests that the effect of expectancy on the P300 amplitude can be direct or indirect. In the case of a direct effect, the evidence suggests that most likely only unconscious, automatic estimation of stimulus probability is reflected in the size of P300 amplitude. However, active, conscious expectancies can influence the P300 activity via indirect routes, by influencing stimulus significance, by leading to the closure of perceptual epoch, or by changing the level of difficulty of processing. Such indirect effect of expectancy can have an opposite direction to the effect of automatically formed expectancies-that is, expected stimuli could be related to larger P300 amplitudes
Predictors of sleep quality and successful weaning from mechanical ventilation among patients in respiratory care centers
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High mitochondrial mass identifies a sub-population of stem-like cancer cells that are chemo-resistant.
No full textChemo-resistance is a clinical barrier to more effective anti-cancer therapy. In this context, cancer stem-like cells (CSCs) are thought to be chemo-resistant, resulting in tumor recurrence and distant metastasis. Our hypothesis is that chemo-resistance in CSCs is driven, in part, by enhanced mitochondrial function. Here, we used breast cell lines and metastatic breast cancer patient samples to begin to dissect the role of mitochondrial metabolism in conferring the CSC phenotype. More specifically, we employed fluorescent staining with MitoTracker (MT) to metabolically fractionate these cell lines into mito-high and mito-low sub-populations, by flow-cytometry. Interestingly, cells with high mitochondrial mass (mito-high) were specifically enriched in a number of known CSC markers, such as aldehyde dehydrogenase (ALDH) activity, and they were ESA+/CD24-/low and formed mammospheres with higher efficiency. Large cell size is another independent characteristic of the stem cell phenotype; here, we observed a >2-fold increase in mitochondrial mass in large cells (>12-μm), relative to the smaller cell population (4-8-μm). Moreover, the mito-high cell population showed a 2.4-fold enrichment in tumor-initiating cell activity, based on limiting dilution assays in murine xenografts. Importantly, primary human breast CSCs isolated from patients with metastatic breast cancer or a patient derived xenograft (PDX) also showed the co-enrichment of ALDH activity and mitochondrial mass. Most significantly, our investigations demonstrated that mito-high cells were resistant to paclitaxel, resulting in little or no DNA damage, as measured using the comet assay. In summary, increased mitochondrial mass in a sub-population of breast cancer cells confers a stem-like phenotype and chemo-resistance. As such, our current findings have important clinical implications for over-coming drug resistance, by therapeutically targeting the mito-high CSC population
The Use of Fuzzy Logic to Reduce uncertainty in Risk Management for Oil and Gas industry: Analysis of Texas City Oil Refinery Plant Explosion
No full textHistorically, risk matrices are used as bases of decision for improving safety, reliability and availability of oil and gas assets. Quantitative Risk Assessment (QRA) is used to determine the position of a component, unit, or process in the risk and criticality matrix. The red line introduce with authorities, which divides the risk matrix into two regions. The desirable section refers to the region where the production of consequence and likelihood reflect the criticality as very low or low. The undesirable region refers to the situation where the criticality reports as Medium or high Crossing the line towards undesirable region was the only concern of managers. All the efforts of experts, engineers and operators focused to bring the whole asset just below the red line. In other words the acceptable region defined as being just a step behind the red line. In fact such attitudes represent the view of looking at the problem as black and white rather than considering some uncertainties that might involve in risk assessment methods
National record linkage study of mortality for a large cohort of opioid users ascertained by drug treatment or criminal justice sources in England, 2005-2009.
No full textBACKGROUND: Globally, opioid drug use is an important cause of premature mortality. In many countries, opioid using populations are ageing. The current study investigates mortality in a large cohort of opioid users; with a focus on testing whether excess mortality changes with age.METHODS: 198,247 opioid users in England were identified from drug treatment and criminal justice sources (April, 2005 to March, 2009) and linked to mortality records. Mortality rates and standardised mortality ratios (SMRs) were calculated by age-group and gender.RESULTS: There were 3974 deaths from all causes (SMR 5.7, 95\% Confidence Interval: 5.5 to 5.9). Drug-related poisonings (1715) accounted for 43\% of deaths. Relative to gender-and-age-appropriate expectation, mortality was elevated for a range of major causes including: infectious, respiratory, circulatory, liver disease, suicide, and homicide. Drug-related poisoning mortality risk continued to increase beyond 45 years and there were age-related increases in SMRs for specific causes of death (infectious, cancer, liver cirrhosis, and homicide). A gender by age-group interaction revealed that whilst men have a greater drug-related poisoning mortality risk than women at younger ages, the difference narrows with increasing age.CONCLUSION: Opioid users' excess mortality persists into old age and for some causes is exacerbated. This study highlights the importance of managing the complex health needs of older opioid users
Two-dimensional X-ray CT image based meso-scale fracture modelling of concrete
No full textTwo-dimensional meso-scale finite element models with realistic aggregates, cement paste and voids of concrete are developed using microscale X-ray Computed Tomography images. Cohesive elements with traction-separation laws are pre-embedded within cement paste and aggregate-cement interfaces to simulate complex nonlinear fracture. Tension tests using a large number of images were simulated with statistical analysis. The very different load-carrying capacities and crack patterns demonstrate the effects of random distribution of phases. It is found that the tensile strength decreases as the void fraction increases, and the relative strength of cement paste and interfaces dominates the microcracking behaviour, which in turn affects macrocracking and load-carrying capacity. (C) 2014 The Authors. Published by Elsevier Ltd
