216 research outputs found
Flexible VWAP Executions in Electronic Trading
For the execution of large equity orders, institutional investors often use the Volume Weighted Average Price (VWAP) as a benchmark to measure execution quality. To achieve this, they have the possibility to either cross their orders in a nonintermediated electronic system or to submit a VWAP agency order to a broker that executes the orders manually. Though more expensive in explicit costs, agency VWAP is still more attractive to investors than VWAP crossings, in particular due to higher flexibility. This work proposes a new electronic crossing model addressing and solving the flexibility restrictions present in today’s VWAP crossing
特別支援教育専攻学生を対象とした障害理解のための教材開発(2)―糖尿病・血友病等の「自己注射」場面を中心にした教材―
特別支援教育専攻学生の指導では、対象とする障害児・者が活用する機器・道具を提示し、その使用法の解説がなされてきた。これは感覚・情報系障害領域では指導上意義がある。また肢体不自由・運動障害系では、車イスや生活補助具、障害体験グッズなどが障害理解教材として活用されてきた。しかし病弱教育領域では、子どもの困難理解につながる「病気体験」は、健常学生にはできない。そこで教員は、病院見学、療養生活の映像資料等を活用し、病気の影響や困難をイメージさせる方法をとることが多い。本研究では糖尿病および血友病を例にとり、病気による「困難」を体験・体感させる教材について検討した。糖尿病・血友病の自己注射モデルを提示し、その作製・改善とそれを使用した授業経過を分析対象とした。学生による試作及び改良モデルは、自己注射実施時の困難・不安・躊躇を「体感」させることを目的としているが、作製過程そのものが、学生による困難・不安・躊躇といった自己注射実施を必要とする疾患のもつ障害特性の理解を促進することが推察された
Emergency medical service provider decision-making in out of hospital cardiac arrest: An exploratory study
© 2017 The Author(s). Background: There are approximately 60,000 out-of-hospital cardiac arrests (OHCA) in the United Kingdom (UK) each year. Within the UK there are well-established clinical practice guidelines that define when resuscitation should be commenced in OHCA, and when resuscitation should cease. Background literature indicates that decision-making in the commencement and cessation of resuscitation efforts in OHCA is complex, and not comprehensively understood. No relevant research from the UK has been published to date and this research study seeks to explore the influences on UK Emergency Medical Service (EMS) provider decision-making when commencing and ceasing resuscitation attempts in OHCA. The aim of this research to explore the influences on UK Emergency Medical Services provider decision-making when commencing and ceasing resuscitation attempts in OHCA. Methods: Four focus groups were convened with 16 clinically active EMS providers. Four case vignettes were discussed to explore decision-making within the focus groups. Thematic analysis was used to analyse transcripts. Results: This research found that there are three stages in the decision-making process when EMS providers consider whether to commence or cease resuscitation attempts in OHCA. These stages are: the call; arrival on scene; the protocol. Influential factors present at each of the three stages can lead to different decisions and variability in practice. These influences are: factual information available to the EMS provider; structural factors such as protocol, guidance and research; cultural beliefs and values; interpersonal factors; risk factors; personal values and beliefs. Conclusions: An improved understanding of the circumstantial, individual and interpersonal factors that mediate the decision-making process in clinical practice could inform the development of more effective clinical guidelines, education and clinical decision support in OHCA. These changes have the potential to lead to greater consistency. and EMS provider confidence, with the potential for improved patient outcome from OHCA
Using statistical and artificial neural networks to predict the permeability of loosely packed granular materials
Well-known analytical equations for predicting permeability are generally reported to overestimate this important property of porous media. In this work, more robust models developed from statistical (multivariable regression) and Artificial Neural Network (ANN) methods utilised additional particle characteristics [‘fines ratio’ (x50/x10) and particle shape] that are not found in traditional analytical equations. Using data from experiments and literature, model performance analyses with average absolute error (AAE) showed error of ~40% for the analytical models (Kozeny–Carman and Happel–Brenner). This error reduces to 9% with ANN model. This work establishes superiority of the new models, using experiments and mathematical techniques
Genes Associated with 2-Methylisoborneol Biosynthesis in Cyanobacteria: Isolation, Characterization, and Expression in Response to Light
The volatile microbial metabolite 2-methylisoborneol (2-MIB) is a root cause of taste and odor issues in freshwater. Although current evidence suggests that 2-MIB is not toxic, this compound degrades water quality and presents problems for water treatment. To address these issues, cyanobacteria and actinomycetes, the major producers of 2-MIB, have been investigated extensively. In this study, two 2-MIB producing strains, coded as Pseudanabaena sp. and Planktothricoids raciborskii, were used in order to elucidate the genetic background, light regulation, and biochemical mechanisms of 2-MIB biosynthesis in cyanobacteria. Genome walking and PCR methods revealed that two adjacent genes, SAM-dependent methyltransferanse gene and monoterpene cyclase gene, are responsible for GPP methylation and subsequent cyclization to 2-MIB in cyanobacteria. These two genes are located in between two homologous cyclic nucleotide-binding protein genes that may be members of the Crp-Fnr regulator family. Together, this sequence of genes forms a putative operon. The synthesis of 2-MIB is similar in cyanobacteria and actinomycetes. Comparison of the gene arrangement and functional sites between cyanobacteria and other organisms revealed that gene recombination and gene transfer probably occurred during the evolution of 2-MIB-associated genes. All the microorganisms examined have a common origin of 2-MIB biosynthesis capacity, but cyanobacteria represent a unique evolutionary lineage. Gene expression analysis suggested that light is a crucial, but not the only, active regulatory factor for the transcription of 2-MIB synthesis genes. This light-regulated process is immediate and transient. This study is the first to identify the genetic background and evolution of 2-MIB biosynthesis in cyanobacteria, thus enhancing current knowledge on 2-MIB contamination of freshwater
Soil mobility of surface applied polyaromatic hydrocarbons in response to simulated rainfall
Polyaromatic hydrocarbons (PAHs) are emitted from a variety of sources and can accumulate on and within surface soil layers. To investigate the level of potential risk posed by surface contaminated soils, vertical soil column experiments were conducted to assess the mobility, when leached with simulated rainwater, of six selected PAHs (naphthalene, phenanthrene, fluoranthene, pyrene, benzo(e)pyrene and benzo(ghi)perylene) with contrasting hydrophobic characteristics and molecular weights/sizes. The only PAH found in the leachate within the experimental period of 26 days was naphthalene. The lack of migration of the other applied PAHs were consistent with their low mobilities within the soil columns which generally parallelled their log Koc values. Thus only 2.3% of fluoranthene, 1.8% of pyrene, 0.2% of benzo(e)pyrene and 0.4% of benzo(ghi)perylene were translocated below the surface layer. The PAH distributions in the soil columns followed decreasing power relationships with 90% reductions in the starting levels being shown to occur within a maximum average depth of 0.94 cm compared to an average starting depth of 0.5 cm. A simple predictive model identifies the extensive time periods, in excess of 10 years, required to mobilise 50% of the benzo(e)pyrene and benzo(ghi)perylene from the surface soil layer. Although this reduces to between 2 and 7 years for fluoranthene and pyrene, it is concluded that the possibility of surface applied PAHs reaching and contaminating a groundwater aquifer is unlikely
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