Tank depressurisation

This paper analyses the activation of two mechanical depressurisation devices, the transformer protector (TP), a leading example of a fast tank depressurisation technique (FTDT) and the pressure relief valve (PRV) during an internal arc on a transformer installed at the JSC RusHydro Boguchanskaya Hydro Power Plant, located in Krasnoyarsk Krai, Russia. The incident occurred on a 400 MVA three phase transformer on the 3rd May, 2013. Using all the available data, including SCADA records, dissolved gas analysis and voltage/current measurements, computational simulations were performed to study the dynamic pressure evolution and static pressure build up inside the tank. Simulation results on tank protections were analysed in the context of general arcing events. This incident demonstrates that the frst dynamic pressure peak due to the arc quickly activates the FTDT, while the PRV activates with static pressure only

Pareto Optimal Strategies for Event Triggered Estimation

Although resource-limited networked autonomous systems must be able to efficiently and effectively accomplish tasks, better conservation of resources often results in worse task performance. We specifically address the problem of finding strategies for managing measurement communication costs between agents. A well understood technique for trading off communication costs with estimation accuracy is event triggering (ET), where measurements are only communicated when useful, e.g., when Kalman filter innovations exceed some threshold. In the absence of measurements, agents can use implicit information to achieve results almost as well as when explicit data is always communicated. However, there are no methods for setting this threshold with formal guarantees on task performance. We fill this gap by developing a novel belief space discretization technique to abstract a continuous space dynamics model for ET estimation to a discrete Markov decision process, which scalably accommodates threshold-sensitive ET estimator error covariances. We then apply an existing probabilistic trade-off analysis tool to find the set of all optimal trade-offs between resource consumption and task performance. From this set, an ET threshold selection strategy is extracted. Simulated results show our approach identifies non-trivial trade-offs between performance and energy savings, with only modest computational effort.Comment: 8 pages, accepted to IEEE Conference on Decision and Control 202

Endocannabinoid receptor blockade increases hepatocyte growth factor and reduces insulin levels in obese women with polycystic ovary syndrome

There is evidence from animal and in-vitro studies that activation of the endocannabinoid system (EC) through cannabinoid receptor 1 (CB-1) is associated with liver injury, inflammation and hepatocellular carcinoma.1 Data suggests endogenous cannabinoids (EC) are related to fatty liver metabolism with a role in non-alcoholic fatty liver disease (NAFLD) through modulating lipid metabolism that may be ameliorated by CB1 receptor antagonism with rimonabant.2 This is of particular importance as NAFLD is the most common cause of chronic liver disease with liver dysfunction leading liver cirrhosis. The diagnosis of NAFLD can only be confirmed by a liver biopsy, as liver enzymes such as alanine aminotransferase (ALT) used, as a serum marker may not be elevated

A retrospective analysis of longitudinal changes in bone mineral content in cystic fibrosis

Background: We aimed to describe the longitudinal changes in bone mineral content and influencing factors, in children with cystic fibrosis (CF). Methods: One hundred children (50 females) had dual X-ray absorptiometry (DXA) performed. Of these, 48 and 24 children had two to three scans, respectively over 10 years of follow-up. DXA data were expressed as lumbar spine bone mineral content standard deviation score (LSBMCSDS) adjusted for age, gender, ethnicity and bone area. Markers of disease, anthropometry and bone biochemistry were collected retrospectively. Results: Baseline LSBMCSDS was >0.5 SDS in 13% children, between −0.5; 0.5 SDS, in 50% and ≤−0.5 in the remainder. Seventy-eight percent of the children who had baseline LSBMCSDS >−0.5, and 35% of the children with poor baseline (LSBMCSDS<−0.5), showed decreasing values in subsequent assessments. However, mean LS BMC SDS did not show a significant decline in subsequent assessments (−0.51; −0.64; −0.56; p=0.178). Lower forced expiratory volume in 1 s percent (FEV1%) low body mass index standard deviation scores (BMI SDS) and vitamin D were associated with reduction in BMC. Conclusions: Bone mineral content as assessed by DXA is sub-optimal and decreases with time in most children with CF and this study has highlighted parameters that can be addressed to improve bone health

Bioprinted autologous human skin equivalents for in vitro testing of therapeutic antibodies

In recent years, advances in tissue engineering have brought forward the accessibility of human skin equivalents for in vitro applications; however, the availability of human-based engineered tissue models suitable for high-throughput screening of biologics remains limited. Here, we report a method of manufacturing fully autologous (with both fibroblasts and keratinocytes from the same donor) human skin equivalents for determining preclinical therapeutic antibody adverse immune reactions in vitro. Using a combination of precise solenoid microvalve-based bioprinting and 96-well scale Alvetex inserts, autologous skin cells were bioprinted and cultured to develop a scalable approach to manufacturing skin equivalents. We demonstrated that fibroblasts and keratinocytes can be bioprinted with a high degree of precision while maintaining viability post printing. Histological staining showed that the bioprinted 96-well based skin equivalents were comparable to human skin. The fully autologous human skin equivalents were co-cultured in vitro with autologous peripheral blood monocytes with and without muromonab-CD3 (OKT3) and natalizumab (Tysabri), biologics which are known to cause and inhibit adverse immune reactions (type IV hypersensitivity), respectively. Analysis of supernatants from skin-equivalent monocyte co-cultures revealed significant proinflammatory cytokine responses (such as interferon gamma) in co-cultures treated with OKT3 when compared to Tysabri and negative controls. Consequently, this study provides proof of concept that through a combination of bioprinting and Alvetex scaffold-based culture systems, scalable human skin equivalents can be manufactured for high-throughput identification of adverse immune reactions during preclinical stages of the drug development process

Making L2 learners' reasoning skills visible : the potential of Computer Supported Collaborative Learning Environments

AbstractThis paper explores the use of Computer Supported Collaborative Learning Environments (CSCLE) as multimodal spaces for promoting critical thinking for English as Second Language Learning (L2) education from multiple perspectives (Technology, Thinking Skills and Interaction). The exploration focuses on the use of a multitouch tabletop, and an accompanying application called Digital Mysteries, as affordances in CSCLE’s for making reasoning skill-based thinking visible for L2 learning in Higher Education.Despite the worldwide promotion of teaching thinking in L2 education, it is not always easy for teachers to identify the types of thinking skills being targeted in L2 pedagogical tasks. To the authors’ knowledge, little empirical interactional evidence is available to demonstrate critical thinking in L2 learner talk during group work. This paper examines interactions among three groups of Chinese English Language learners at a higher education institution in a CSCLE. Video data were collected of students’ thinking-in-action whilst engaging in multimodal interactions in the environment. Results show that new technologies can provide innovative and empirically driven ways in which L2 learners’ thinking is externalised and how critical reasoning can be tracked, promoted, evaluated and self-regulated. The findings suggest that collaborations in a CSCLE can support the completion of tasks embedding high levels of cognitive complexity by L2 learners with effective use of limited cognitive resources. This leads to a number of recommendations about integrating the teaching of critical thinking skills into the L2 classroom using CSCLE technologies

Assessment of sigma metrics results of serum glucose and lipid profile tested by automated chemistry analyzer in medical city hospitals in Iraq

Background: A major target of quality assurance is the minimization of error rates in order to enhance patient safety, six sigma or sigma metrics were used to assess the analytical quality of automated clinical chemistry, six sigma metrics is used in combination with total allowable error, method imprecision and bias. The goal is to attain the highest possible sigma scale within the acceptable limits of total allowable error. For assessment of sigma metrics results of serum glucose and lipid profile and verification of reference values for these analytes tested by automated chemistry analyzer in Medical City hospitals.Methods: In the present study, internal quality control (EQA) and external quality assessment (EQA) data were analyzed for the period from May to July 2017 using chemistry autoanalyzer (Siemens Dimension RxL Max) at the Teaching Laboratories of the Medical City. Mean, standard deviation, coefficient of variation, bias, total error and sigma metrics were calculated for glucose, cholesterol, triglycerides and HDL.Results: Excellent sigma values (≥6) were elicited for triglycerides (10.9), Satisfactory sigma values (≥3) were elicited for cholesterol (3.4) and HDL (3.4), while glucose performed poorly (2.3) on the sigma scale.Conclusions: Sigma metrics helps to assess analytical methodologies and augment laboratory performance. It acts as a guide for planning quality control strategy. It can be a self-assessment tool regarding the functioning of clinical laboratory. Triglycerides was the best performer when it was gauzed on the sigma scale, with a sigma metrics value of 10.9 and glucose had the least sigma metrics value of 2.5 so there is need for improvement and the method should be controlled with greater attention to ensure quality.