Naresuan University Journal
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Dual transcriptional-translational cascade permits cellular level tuneable expression control.
No full textThe ability to induce gene expression in a small molecule dependent manner has led to many applications in target discovery, functional elucidation and bio-production. To date these applications have relied on a limited set of protein-based control mechanisms operating at the level of transcription initiation. The discovery, design and reengineering of riboswitches offer an alternative means by which to control gene expression. Here we report the development and characterization of a novel tunable recombinant expression system, termed RiboTite, which operates at both the transcriptional and translational level. Using standard inducible promoters and orthogonal riboswitches, a multi-layered modular genetic control circuit was developed to control the expression of both bacteriophage T7 RNA polymerase and recombinant gene(s) of interest. The system was benchmarked against a number of commonly used E. coli expression systems, and shows tight basal control, precise analogue tunability of gene expression at the cellular level, dose-dependent regulation of protein production rates over extended growth periods and enhanced cell viability. This novel system expands the number of E. coli expression systems for use in recombinant protein production and represents a major performance enhancement over and above the most widely used expression systems
Meat, the metabolites: an integrated metabolite profiling and lipidomics approach for the detection of the adulteration of beef with pork
No full textAdulteration of high quality food products with sub-standard and cheaper grades is a world-wide problem taxing the global economy. Currently, many traditional tests suffer from poor specificity, highly complex outputs and a lack of high-throughput processing. Metabolomics has been successfully used as an accurate discriminatory technique in a number of applications including microbiology, cancer research and environmental studies and certain types of food fraud. In this study, we have developed metabolomics as a technique to assess the adulteration of meat as an improvement on current methods. Different grades of beef mince and pork mince, purchased from a national retail outlet were combined in a number of percentage ratios and analysed using GC-MS and UHPLC-MS. These techniques were chosen because GC-MS enables investigations of metabolites involved in primary metabolism whilst UHPLC-MS using reversed phase chromatography provides information on lipophilic species. With the application of chemometrics and statistical analyses, a panel of differential metabolites were found for identification of each of the two meat types. Additionally, correlation was observed between metabolite content and percentage of fat declared on meat products' labelling.</p
The Handbook of Post Crisis Financial Modelling
No full textFollowing the 2008 financial crisis many questioned the academic community’s role in predicting the events that had unfolded, impacting heavily on the public’s perception of the role of finance in society. Prior to the crisis, very little research existed to model events as extreme as those which occurred during the crisis. There is now greater interest in extreme event modeling than at any other time in history and, in addition, many facets of mainstream finance have evolved since the crisis. This unique handbook brings together original research from leading practitioners and academics in the fields of banking, finance and financial history to explore key issues affecting financial modeling since the 2008 financial crisis. It offers theoretical, empirical, policy and practical insights into many of the key themes involved in the calibration of essential economic and financial variables that are used to model crises. The book begins by offering a historical context to the events, before moving on to discuss the role of central banks, governments, policy-making, the costs of bail-outs and the ‘too-big-to-fail’ controversy. The authors offer an analysis on the link between efficiency and bank safety, the role of ‘minimal assumptions’ in modeling and the private information price of risk (PIPR). They conclude by addressing the use of specific models and possible approaches to macroeconomic modeling for the future.</p
Magnetic characterisation of microstructural feature distribution in P9 and T22 steels by major and minor BH loop measurements
No full textThis paper investigates the magnetic properties and parameters measured from major/minor loops and used to characterise different microstructural feature distributions in P9 and T22 steel in different heat treatment or service conditions. The present study introduces a non-destructive way of selecting microstructural features of interest and/or excluding those of little relevance by examination of minor loop measurements at a selected range of applied fields and discusses the fundamental mechanism in terms of domain processes. There is remarkable consistency in magnetic behaviours and properties such as initial/incremental permeability values between the measurements by different techniques. This behaviour has been ascribed to the similar underlying domain processes and hence similar selected microstructural features that are affecting the domain processes. © 2015 The Authors
Influence of past breast feeding on pattern and severity of presentation of juvenile idiopathic arthritis
No full textRandomized controlled trial of stereotactic 11-G vacuum-assisted core biopsy for the diagnosis and management of mammographic microcalcification
No full textObjective:To compare the accuracy of 11-G vacuum-assisted biopsy (VAB) with 14-G core needle biopsy (CNB) to diagnose mammographic microcalcification (MM) and effect on surgical outcomes.Methods: Following ethical approval, VAB and CNB (control) were compared in a randomized prospective study for first-line diagnosis of MM and subsequent surgical outcomes in two breast-screening units. Participants gave written informed consent. Exclusions included comorbidity precluding surgery, prior ipsilateral breast cancer and lesions >40 mm requiring mastectomy as first surgical procedure. The final pathological diagnosis was compared with the initial biopsy result. Quality-of-life (QOL) questionnaires were administered at baseline, 2, 6 and 12 months. 110 participants were required to show a 25% improvement in diagnosis with VAB compared with CNB (90% power).Results: Eligibility was assessed for 787 cases; 129 females recalled from the National Health Service breast screening programme were randomized. Diagnostic accuracy of VAB was 86% and that of CNB was 84%. Using VAB, 2/14 (14.3%) cases upgraded from ductal carcinoma in situ to invasion at surgery and 3/19 (15.8%) using CNB. Following VAB 7/16 (44%) cases required repeat surgery vs 7/24 (29%) after CNB. Both groups recorded significant worsening of functional QOL measures and increased breast pain at follow-up.Conclusion: VAB and CNB were equally accurate at diagnosing MM, and no significant differences in surgical outcomes were observed.Advances in Knowledge: The first randomized controlled study of VAB for diagnosis of microcalcification using digital mammography showed no difference in diagnostic accuracy of VAB and CNB, or in the proportion of participants needing repeat non-operative biopsy or second therapeutic operation to treat malignancy
Effects of Aluminium on Rat Brain Mitochondria Bioenergetics: an In vitro and In vivo Study
No full textNumerous studies have highlighted the potential of aluminium as an aetiological factor for some neurodegenerative disorders, particularly Alzheimer’s disease and Parkinson’s disease. Our previous studies have shown that aluminium can cause oxidative stress, reduce the activity of some antioxidant enzymes, and enhance the dopaminergic neurodegeneration induced by 6-hydroxydopamine in an experimental model of Parkinson’s disease in rats. We now report a study on the effects caused by aluminium on mitochondrial bioenergetics following aluminium addition and after its chronic administration to rats. To develop our study, we used a high-resolution respirometry to test the mitochondrial respiratory capacities under the conditions of coupling, uncoupling, and non-coupling. Our study showed alterations in leakiness, a reduction in the maximum capacity of complex II-linked respiratory pathway, a decline in the respiration efficiency, and a decrease in the activities of complexes III and V in both models studied. The observed effects also included both an alteration in mitochondrial transmembrane potential and a decrease in oxidative phosphorylation capacity when relatively high concentrations of aluminium were added to the isolated mitochondria. These findings contribute to explain both the ability of aluminium to generate oxidative stress and its suggested potential to act as an etiological factor by promoting the progression of neurodegenerative disorders such as Parkinson’s disease
Entropy Balancing: A maximum-entropy reweighting scheme to adjust for convergence error’
No full textThis paper presents a newly available technique to adjust for bias in non-probabilistically selected samples. To date, applications of this innovative technique—termed entropy balancing—have been restricted to evaluation settings, where the goal is to reduce model dependence prior to the estimation of treatment effects. In a novel application, we demonstrate the technique’s utility in cases where the goal is to correct for sample bias originating in coverage error. The appeal of entropy balancing in this latter setting lies in its capacity to optimise the twin goals of improved balance in covariate distribution and maximum retention of information. Entropy balancing combines the opportunity to incorporate a large set of moment conditions in the calculation of weights, with the ability to directly implement exact balance. The technique thus builds upon the theoretical appeal of the more widely known and applied propensity score adjustment method, while addressing that method’s practical limitations. We demonstrate the utility of the entropy balancing technique empirically, through an example using the Young Lives Project survey data for rural Andhra Pradesh, South India. We conclude by summarising the potential of this procedure to contribute to robust survey-based research more widely
Investigation of Dealloying of S phase (Al2CuMg) in AA2024- T3 Aluminium Alloy by High Resolution 2D and 3D Electron Imaging
No full textLeader-Member Exchange (LMX) and Performance: A Meta-Analytic Review
No full textThis paper reports a meta-analysis that examines the relationship between leader–member exchange (LMX) relationship quality and a multidimensional model of work performance (task, citizenship, and counterproductive performance). The results show a positive relationship between LMX and task performance (146 samples, ρ = .30) as well as citizenship performance (97 samples, ρ = .34), and negatively with counterproductive performance (19 samples, ρ = ‒.24). Of note, there was a positive relationship between LMX and objective task performance (20 samples, ρ = .24). Trust, motivation, empowerment, and job satisfaction mediated the relationship between LMX and task and citizenship performance with trust in the leader having the largest effect. There was no difference due to LMX measurement instrument (e.g., LMX7, LMX-MDM). Overall, the relationship between LMX and performance was weaker when (a) measures were obtained from a different source or method and (b) LMX was measured by the follower than the leader (with common source- and method-biased effects stronger for leader-rated LMX quality). Finally, there was evidence for LMX leading to task performance but not for reverse or reciprocal directions of effects