Effect of bake-hardening treatment on the mechanical properties of high strength bainitic steel produced by thermomechanical processing

The influence of pre-straining and bake-hardening on the mechanical properties of thermomechanically processed 0.2C-1.5Si-1.5Mn-0.2Mo-0.004Nb (wt%) steel was analysed using tensile test, transmission electron microscopy (TEM) and atom probe tomography (APT). This steel after processing had high strength (~1200MPa) and good ductility (~20%) due to the formation of fully bainitic microstructure with nano-layers of bainitic ferrite and retained austenite. The bake hardening (BH) of pre-strained (PS) samples increased the yield strength of steel up to 690MPa and showed the bake-hardening response of 220MPa due to the operation of several strengthening mechanisms such as transformation induced plasticity during pre-straining and pinning the dislocations by carbon during bake-hardening treatment. The carbon content of the bainitic ferrite and retained austenite before and after bake-hardening treatment, the solute distribution between these phases and the local composition of fine Fe-C clusters and particles formed during bake-hardening treatment was calculated using APT. The bainitic ferrite and retained austenite microstructural characteristics such as thickness of the layers and their dislocation density before and after bake-hardening treatment were studied using TEM.

Focused ion-beam (FIB) fabrication of micro-sized pillars for microcompression test

Pillars were fabricated by focused-ion beam (FIB) in a dual beam scanning electron microscope (SEM, FEI Quanta 3D). A multi-step milling procedure was adopted to prepare the pillars using Ga+ ion beam operated at 30 kV. The beam current was reduced from 5 nA for coarse milling down to 50 pA for fine milling, to minimize the surface damage induced by the Ga+ ion beam. The pillars were imaged at 52° tilt angle by SEM prior to the microcompression tests.

Content validity of visual analog scales to assess symptom severity of acute angioedema attacks in adults with hereditary angioedema : an interview study

Background: Hereditary angioedema (HAE) is a rare, debilitating, potentially life-threatening condition characterized by recurrent acute attacks of edema of the skin, face/upper airway, and gastrointestinal and urogenital tracts. During a laryngeal attack, people with HAE may be at risk of suffocation, while other attacks are often associated with intense pain, disfigurement, disability, and/or vomiting. The intensity of some symptoms is known only to the person experiencing them. Thus, interview studies are needed to explore such experience and patient-reported outcome measures (PROMs) are required for systematic assessment of symptoms in the clinical setting and in clinical trials of treatments for acute HAE attacks.

Objective: The aim of this interview study was to assess the content validity and suitability of four visual analog scale (VAS) instruments for use in clinical studies. The VAS instruments were designed to assess symptoms at abdominal, oro-facial-pharyngeal-laryngeal, peripheral, and urogenital attack locations. This is the first known study to report qualitative data about the patient's experience of the rare disorder, HAE.

Methods: Semi-structured exploratory and cognitive debriefing interviews were conducted with 27 adults with a confirmed clinical/laboratory diagnosis of HAE (baseline plasma level of functional plasma protein C1 esterase inhibitor [C1INH] <50% of normal without evidence for acquired angioedema). There were 17 participants from the US and 10 from Italy, with mean age 42.5 (SD 14.5) years, range 18–72 years, mean HAE duration 21.3 (SD 14.1) years, range 1–45 years, 67% female, and 44% VAS-naïve. Experience of acute angioedema attacks was first explored, noting spontaneous mentions by participants of HAE symptomatology. Cognitive debriefing of the VAS instruments was undertaken to assess the suitability, comprehensibility, and relevance of the VAS items. Asymptomatic participants completed the VAS instruments relevant to their angioedema experience, reporting as if they were experiencing an acute angioedema attack at the time. Interviews were conducted in the clinic setting in the US and Italy over an 8-month period.

Results: Participants mentioned spontaneously almost all aspects of acute angioedema attacks covered by the four VAS instruments, thus providing strong support for inclusion of nearly all VAS items, with no important symptoms missing. Predominant symptoms found to be associated with acute angioedema attacks were edema and pain, and there was evidence of varying degrees of disruption to everyday activities supporting the inclusion of an overall severity item reflecting the disabling effects of HAE symptoms. VAS item wording was understood by participants.

Conclusion: This interview study explored and reported the patient experience of HAE attacks. It demonstrated the content validity of the four anatomical location HAE VAS instruments and their suitability for use in clinical trials of recombinant human C1INH (rhC1INH) treatment for ascertaining trial participants' assessments of the severity of acute angioedema symptoms.

Wireless instantaneous neurotransmitter concentration system-based amperometric detection of dopamine, adenosine, and glutamate for intraoperative neurochemical monitoring - laboratory investigation

Object  In a companion study, the authors describe the development of a new instrument named the Wireless Instantaneous Neurotransmitter Concentration System (WINCS), which couples digital telemetry with fast-scan cyclic voltammetry (FSCV) to measure extracellular concentrations of dopamine. In the present study, the authors describe the extended capability of the WINCS to use fixed potential amperometry (FPA) to measure extracellular concentrations of dopamine, as well as glutamate and adenosine. Compared with other electrochemical techniques such as FSCV or high-speed chronoamperometry, FPA offers superior temporal resolution and, in combination with enzyme-linked biosensors, the potential to monitor nonelectroactive analytes in real time.

Methods  The WINCS design incorporated a transimpedance amplifier with associated analog circuitry for FPA; a microprocessor; a Bluetooth transceiver; and a single, battery-powered, multilayer, printed circuit board. The WINCS was tested with 3 distinct recording electrodes: 1) a carbon-fiber microelectrode (CFM) to measure dopamine; 2) a glutamate oxidase enzyme–linked electrode to measure glutamate; and 3) a multiple enzyme–linked electrode (adenosine deaminase, nucleoside phosphorylase, and xanthine oxidase) to measure adenosine. Proof-of-principle analyses included noise assessments and in vitro and in vivo measurements that were compared with similar analyses by using a commercial hardwired electrochemical system (EA161 Picostat, eDAQ; Pty Ltd). In urethane-anesthetized rats, dopamine release was monitored in the striatum following deep brain stimulation (DBS) of ascending dopaminergic fibers in the medial forebrain bundle (MFB). In separate rat experiments, DBS-evoked adenosine release was monitored in the ventrolateral thalamus. To test the WINCS in an operating room setting resembling human neurosurgery, cortical glutamate release in response to motor cortex stimulation (MCS) was monitored using a large-mammal animal model, the pig.

Results   The WINCS, which is designed in compliance with FDA-recognized consensus standards for medical electrical device safety, successfully measured dopamine, glutamate, and adenosine, both in vitro and in vivo. The WINCS detected striatal dopamine release at the implanted CFM during DBS of the MFB. The DBS-evoked adenosine release in the rat thalamus and MCS-evoked glutamate release in the pig cortex were also successfully measured. Overall, in vitro and in vivo testing demonstrated signals comparable to a commercial hardwired electrochemical system for FPA.

Conclusions  By incorporating FPA, the chemical repertoire of WINCS-measurable neurotransmitters is expanded to include glutamate and other nonelectroactive species for which the evolving field of enzyme-linked biosensors exists. Because many neurotransmitters are not electrochemically active, FPA in combination with enzyme-linked microelectrodes represents a powerful intraoperative tool for rapid and selective neurochemical sampling in important anatomical targets during functional neurosurgery.

eLearning content authentication using bipartite matching

Content authenticity and correctness is one of the important challenges in eLearning as there can be many solutions for one specific problem in the cyber space. Therefore, we feel the necessity of mapping problem to solutions using graph partition and weighted bipartite matching. This paper presents a novel architecture and methodology for a personal eLearning system called PELS that is developed by us. We also present an efficient algorithm to partition question-answer (QA) space and explore best possible solution to a particular problem. Our approach can be efficiently applied to social eLearning space where there is one-to-many and many-to-many relationship with a level of bonding. The main advantage of our approach is that we use QA ranking by adjusted edge weights provided by subject matter experts (SME) or expert database. Finally, we use statistical methods called confidence interval and hypothesis test on the data to check the reliability and dependability of the quality of results.

Second-year pre-service teachers’ responses to proportional reasoning test items

A recent international study of pre-service teachers identified that proportional reasoning was problematic for pre-service teachers. Proportional reasoning is an important topic in the middle years of schooling and therefore it is critical that teachers understand this topic and can rely on their Mathematical Content Knowledge (MCK) when teaching. The focus of this paper is second-year Australian primary pre-service teachers’ MCK of real number items related to ratio, rate, proportion and proportional reasoning. This paper reports on strengths and weakness of pre-service teachers’ MCK when responding to test items; including a method suitable for analysing responses to five items and ranked by three levels of difficulty. The results revealed insights into their correct methods of solutions and common incorrect responses, identifying difficulty, where multiplication and division were required. The method of coding test items by difficulty ranking may assist with developing an appropriate learning trajectory, which will assist pre-service teachers develop their MCK of this and other difficult topics.

Simplified or erroneous? It’s a fine line

Novice learners need to have simplified explanations because they are unable to understand fuller, more-involved explanations. However, there is a dangerously thin line between simplified explanations and over-simplified erroneous explanations, which lead to later misunderstandings and misconceptions. It is harder to unlearn misunderstandings and misconceptions, than to learn something new ab initio.

It is virtually impossible for any teacher to know everything that students will need for future study and careers, as each subject will lead to a myriad of pathways. For example, in my undergraduate 1st year class, students will go into numerous majors across more than 16 degree programs ranging from arts to zoology and from engineering to food-and-nutrition. 

Descriptive analysis of landings during international netball competition: enhancing ecological validity of laboratory testing environments

Non-contact landings have been identified as a common activity associated with injury in netball. Investigating injury risk factors during landing via laboratory-based analysis warrants the performance of sportspecific landing tasks with the inclusion of “game- like” factors to enhance ecological validity of testing protocols. Understanding how players perform landing tasks in a competitive environment is, therefore, essential.

The purpose of this study was to perform a descriptive analysis of in-game landings performed by netball players, with regard to the landing techniques used and game events surrounding these landings; with the intent of providing information to enhance the ecological validity of laboratory-based testing environments. Landings were categorised according to landing technique and game events surrounding the landing.

The initial laboratory diagnosis of equine influenza in Australia in 2007

Until August 2007, Australia had not recorded an outbreak of equine influenza; indeed, significant quarantine precautions exist to safeguard against such an event. This article outlines the lead up to virus confirmation and the procedures to first test, then contain it.

Endurance training in obese humans improves glucose tolerance and mitochondrial fatty acid oxidation and alters muscle lipid content

Muscle fatty acid (FA) metabolism is impaired in obesity and insulin resistance, reflected by reduced rates of FA oxidation and accumulation of lipids. It has been suggested that interventions that increase FA oxidation may enhance insulin action by reducing these lipid pools. Here, we examined the effect of endurance training on rates of mitochondrial FA oxidation, the activity of carnitine palmitoyltransferase I (CPT I), and the lipid content in muscle of obese individuals and related these to measures of glucose tolerance. Nine obese subjects completed 8 wk of moderate-intensity endurance training, and muscle biopsies were obtained before and after training. Training significantly improved glucose tolerance, with a reduction in the area under the curve for glucose (P< 0.05) and insulin (P = 0.01) during an oral glucose tolerance test. CPT I activity increased 250% (P = 0.001) with training and became less sensitive to inhibition by malonyl-CoA. This was associated with an increase in mitochondrial FA oxidation (+120%, P < 0.001). Training had no effect on muscle triacylglycerol content; however, there was a trend for training to reduce both the total diacylglcyerol (DAG) content (−15%, P = 0.06) and the saturated DAG-FA species (−27%, P = 0.06). Training reduced both total ceramide content (−42%, P = 0.01) and the saturated ceramide species (−32%, P < 0.05). These findings suggest that the improved capacity for mitochondrial FA uptake and oxidation leads not only to a reduction in muscle lipid content but also a to change in the saturation status of lipids, which may, at least in part, provide a mechanism for the enhanced insulin action observed with endurance training in obese individuals.

Overexpression of sphingosine kinase 1 in liver reduces triglyceride content in mice fed a low but not high-fat diet

 Hepatic insulin resistance is a major risk factor for the development of type 2 diabetes and is associated with the accumulation of lipids, including diacylglycerol (DAG), triacylglycerols (TAG) and ceramide. There is evidence that enzymes involved in ceramide or sphingolipid metabolism may have a role in regulating concentrations of glycerolipids such as DAG and TAG. Here we have investigated the role of sphingosine kinase (SphK) in regulating hepatic lipid levels. We show that mice on a high-fat high-sucrose diet (HFHS) displayed glucose intolerance, elevated liver TAG and DAG, and a reduction in total hepatic SphK activity. Reduced SphK activity correlated with downregulation of SphK1, but not SphK2 expression, and was not associated with altered ceramide levels. The role of SphK1 was further investigated by overexpressing this isoform in the liver of mice in vivo. On a low-fat diet (LFD) mice overexpressing liver SphK1, displayed reduced hepatic TAG synthesis and total TAG levels, but with no change to DAG or ceramide. These mice also exhibited no change in gluconeogenesis, glycogenolysis or glucose tolerance. Similarly, overexpression of SphK1 had no effect on the pattern of endogenous glucose production determined during a glucose tolerance test. Under HFHS conditions, normalization of liver SphK activity to levels observed in LFD controls did not alter hepatic TAG concentrations. Furthermore, DAG, ceramide and glucose tolerance were also unaffected. In conclusion, our data suggest that SphK1 plays an important role in regulating TAG metabolism under LFD conditions.

A new computerized adaptive test advancing the measurement of health-related quality of life (HRQoL) in children: the Kids-CAT

Purpose: Assessing health-related quality of life (HRQoL) via Computerized Adaptive Tests (CAT) provides greater measurement precision coupled with a lower test burden compared to conventional tests. Currently, there are no European pediatric HRQoL CATs available. This manuscript aims at describing the development of a HRQoL CAT for children and adolescents: the Kids-CAT, which was developed based on the established KIDSCREEN-27 HRQoL domain structure. Methods: The Kids-CAT was developed combining classical test theory and item response theory methods and using large archival data of European KIDSCREEN norm studies (n = 10,577–19,580). Methods were applied in line with the US PROMIS project. Item bank development included the investigation of unidimensionality, local independence, exploration of Differential Item Functioning (DIF), evaluation of Item Response Curves (IRCs), estimation and norming of item parameters as well as first CAT simulations. Results: The Kids-CAT was successfully built covering five item banks (with 26–46 items each) to measure physical well-being, psychological well-being, parent relations, social support and peers, and school well-being. The Kids-CAT item banks proved excellent psychometric properties: high content validity, unidimensionality, local independence, low DIF, and model conform IRCs. In CAT simulations, seven items were needed to achieve a measurement precision between.8 and.9 (reliability). It has a child-friendly design, is easy accessible online and gives immediate feedback reports of scores. Conclusions: The Kids-CAT has the potential to advance pediatric HRQoL measurement by making it less burdensome and enhancing the patient–doctor communication.

Erratum to: A new computerized adaptive test advancing the measurement of health-related quality of life (HRQoL) in children: the Kids-CAT

Abstract
Purpose
Assessing health-related quality of life (HRQoL) via Computerized Adaptive Tests (CAT) provides greater measurement precision coupled with a lower test burden compared to conventional tests. Currently, there are no European pediatric HRQoL CATs available. This manuscript aims at describing the development of a HRQoL CAT for children and adolescents: the Kids-CAT, which was developed based on the established KIDSCREEN-27 HRQoL domain structure.
Methods
The Kids-CAT was developed combining classical test theory and item response theory methods and using large archival data of European KIDSCREEN norm studies (n=10,577–19,580). Methods were applied in line with the US PROMIS project. Item bank development included the investigation of unidimensionality, local independence, exploration of Differential Item Functioning (DIF), evaluation of Item Response Curves (IRCs), estimation and norming of item parameters as well as first CAT simulations.
Results
The Kids-CAT was successfully built covering five item banks (with 26–46 items each) to measure physical well-being, psychological well-being, parent relations, social support and peers, and school well-being. The Kids-CAT item banks proved excellent psychometric properties: high content validity, unidimensionality, local independence, low DIF, and model conform IRCs. In CAT simulations, seven items were needed to achieve a measurement precision between .8 and .9 (reliability). It has a child-friendly design, is easy accessible online and gives immediate feedback reports of scores.
Conclusions
The Kids-CAT has the potential to advance pediatric HRQoL measurement by making it less burdensome and enhancing the patient–doctor communication.

The current status of greenhouse gas reporting by Chinese companies: a test of legitimacy theory

Purpose – The purpose of this paper is to investigate the factors driving greenhouse gas reporting by Chinese companies.
Design/methodology/approach – Content analysis of annual reports and corporate social responsibility (CSR) reports for the year 2010 of the top 100 A-share companies listed on Shanghai Stock Exchange was conducted to investigate the extent of greenhouse gas reporting. Multiple regression analysis was performed to determine the factors driving these companies’ greenhouse gas reporting.
Findings – It was found that most Chinese companies reported neutral and good news. The results also indicate larger companies operating in an industry which has higher level of carbon dioxide emissions tend to have higher levels of greenhouse gas disclosures, consistent with the expectation of legitimacy theory. However, profitability and overseas listing were not significantly related to greenhouse gas reporting. This is consistent with the findings of previous literature. Finally, contrary to expectations, state-owned companies report less greenhouse gas information than private companies.
Originality/value – The paper contributes towards theory development by testing legitimacy theory in the context of greenhouse gas reporting by Chinese companies and contributes to existing literature on greenhouse gas reporting by focussing on the large emerging economy of China. The practical contribution of the paper rests in the area of accounting practice. The results outline the dearth in greenhouse gas reporting by Chinese companies, suggesting there needs to be future development of accounting standards in this area.