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Full-Text Articles in Physical Sciences and Mathematics

Enhanced Molecular Chaperone Activity Of The Small Heat-Shock Protein Alphab-Cystallin Following Covalent Immobilization Onto A Solid-Phase Support, V Bellotti, Heath Ecroyd, J Carver, H J Griesser, B Thierry, J G Shapter, S S Griesser, S Giorgetti, M R Nussio, J A Gerrard, J Garvey Dec 2012

Enhanced Molecular Chaperone Activity Of The Small Heat-Shock Protein Alphab-Cystallin Following Covalent Immobilization Onto A Solid-Phase Support, V Bellotti, Heath Ecroyd, J Carver, H J Griesser, B Thierry, J G Shapter, S S Griesser, S Giorgetti, M R Nussio, J A Gerrard, J Garvey

Heath Ecroyd

The well-characterized small heat-shock protein, alphaB-crystallin, acts as a molecular chaperone by interacting with unfolding proteins to prevent their aggregation and precipitation. Structural perturbation (e.g., partial unfolding) enhances the in vitro chaperone activity of alphaB-crystallin. Proteins often undergo structural perturbations at the surface of a synthetic material, which may alter their biological activity. This study investigated the activity of alphaB-crystallin when covalently bound to a support surface; alphaB-crystallin was immobilized onto a range of solid material surfaces, and its characteristics and chaperone activity were assessed. Immobilization was achieved via a plasma-deposited thin polymeric interlayer containing aldehyde surface groups and reductive …


Small Town Water Governance In Developing Countries: The Uncertainty Curse, Magnus Moglia, Pascal Perez, Stewart Burn Nov 2012

Small Town Water Governance In Developing Countries: The Uncertainty Curse, Magnus Moglia, Pascal Perez, Stewart Burn

Professor Pascal Perez

lack of consideration of local circumstances and process requirements, and in particular inadequate involvement of affected stakeholders as well as inadequate cross-sectorial coordination. This is not surprising given poor organizational memory combined with decisions being made under time pressure and strict deadlines combined with little adaptive capacity. Additionally, information about the importance of process requirements and engagement is qualitative and as such is unfortunately often given secondary importance. To address this, we suggest a Risk assessment component as part of the project design phase based on Bayesian Networks (BNs) utilizing expert and local knowledge. This not only improves organizational memory …


Dynamic Modelling Of Hydroelectric Turbine-Generator Unit Connected To A Hvdc System For Small Signal Stability Analysis, Yin Chin Choo, Ashish Agalgaonkar, Kashem Muttaqi, Sarath Perera, Michael Negnevitsky Nov 2012

Dynamic Modelling Of Hydroelectric Turbine-Generator Unit Connected To A Hvdc System For Small Signal Stability Analysis, Yin Chin Choo, Ashish Agalgaonkar, Kashem Muttaqi, Sarath Perera, Michael Negnevitsky

Associate Professor Kashem Muttaqi

This paper presents the linearised small-signal dynamic modelling of hydroelectric turbine-generator (TG) unit with CIGRE first high-voltage direct current (HVDC) benchmark system in the synchronously rotating D-Q reference frame for small-signal stability analysis. The interaction behaviour between the hydroelectric unit and the dynamics and control of HVDC system is investigated utilising eigen-analysis,participation factor analysis and by conducting sensitivity studies. The computation of eigenvalues and eigenvectors for small signal stability analysis provides an invaluable insight onto the power system dynamic behaviour by characterising the damping and frequency of the system oscillatory modes. Theconsequences of different operating conditions, such as active and …


Comparison Of Small-Scale And Large-Scale Mixing Characteristics: Correlations Between Small-Scale And Large-Scale Mixing And Extensional Characteristics Of Wheat Flour Dough, Helen Allen, Simon Diffey, Allen H, Zena Pumpa, Simon Nath, Jennifer Morell, Gulay Cullis, Alison Smith Nov 2012

Comparison Of Small-Scale And Large-Scale Mixing Characteristics: Correlations Between Small-Scale And Large-Scale Mixing And Extensional Characteristics Of Wheat Flour Dough, Helen Allen, Simon Diffey, Allen H, Zena Pumpa, Simon Nath, Jennifer Morell, Gulay Cullis, Alison Smith

Professor Brian Cullis

measurements provide valuable information about dough strength and stability (STAB) traits. These measurements are important in milling and baking operations, and for varietal selection in wheat breeding programmes. There are several techniques with different sample sizes used for measuring these traits so there is interest in examining the agreement between methods in terms of genotypic (varietal) rankings. This issue has been investigated by using two different mixing methods, a small-scale Mixograph (2 g) and large-scale Farinograph (50 g) using data from a doubled haploid population (190 lines) from a Chara (excellent dough strength)×WW2449 (poor dough strength) cross. The cross was …


Small Area Estimation Under Spatial Nonstationarity, Hukum Chandra, Nicola Salvati, Ra Chambers, Nikos Tzavidis Nov 2012

Small Area Estimation Under Spatial Nonstationarity, Hukum Chandra, Nicola Salvati, Ra Chambers, Nikos Tzavidis

Dr Raymond Chambers

"A geographical weighted empirical best linear unbiased predictor (GWEBLUP) for a small area average is proposed, and an estimator of its conditional mean squared error is developed. The popular empirical best linear unbiased predictor under the linear mixed model is obtained as a special case of the GWEBLUP. Empirical results using both model-based and design-based simulations, with the latter based on two real data sets, show that the GWEBLUP predictor can lead to efficiency gains when spatial nonstationarity is present in the data. A practical gain from using the GWEBLUP is in small area estimation for out of sample areas. …


M-Quantile Models For Small Area Estimation, Raymond Chambers, Nikos Tzavidis Nov 2012

M-Quantile Models For Small Area Estimation, Raymond Chambers, Nikos Tzavidis

Dr Raymond Chambers

No abstract provided.


Small Area Estimation Of Proportions In Business Surveys, Hukum Chandra, Ray Chambers, Nicola Salvati Nov 2012

Small Area Estimation Of Proportions In Business Surveys, Hukum Chandra, Ray Chambers, Nicola Salvati

Dr Raymond Chambers

Binary data are often of interest in business surveys, particularly when the aim is to characterize grouping in the businesses making up the survey population. When small area estimates are required for such binary data, use of standard estimation methods based on linear mixed models (LMMs) becomes problematic.We explore two model-based techniques of small area estimation for small area proportions, the empirical best predictor (EBP) under a generalized linear mixed model and the model-based direct estimator (MBDE) under a population-level LMM. Our empirical results show that both the MBDE and the EBP perform well. The EBP is a computationally intensive …


Model-Based Direct Estimation Of Small-Area Distributions, Nicola Salvati, Hukum Chandra, Ray Chambers Nov 2012

Model-Based Direct Estimation Of Small-Area Distributions, Nicola Salvati, Hukum Chandra, Ray Chambers

Dr Raymond Chambers

"Much of the small-area estimation literature focuses on population totals and means. However, users of survey data are often interested in the finite-population distribution of a survey variable and in the measures (e.g. medians, quartiles, percentiles) that characterize the shape of this distribution at the small-area level. In this paper we propose a model-based direct estimator (MBDE, Chandra and Chambers) of the small-area distribution function. The MBDE is defined as a weighted sum of sample data from the area of interest, with weights derived from the calibrated spline-based estimate of the finite-population distribution function introduced by Harms and Duchesne, under …


Small Area Estimation Using A Nonparametric Model-Based Direct Estimator, Raymond Chambers, Nicola Salvati, M. Giovanna Ranalli, Hukum Chandra Nov 2012

Small Area Estimation Using A Nonparametric Model-Based Direct Estimator, Raymond Chambers, Nicola Salvati, M. Giovanna Ranalli, Hukum Chandra

Dr Raymond Chambers

Nonparametric regression is widely used as a method of characterizing a non-linearrelationship between a variable of interest and a set of covariates. Practical application ofnonparametric regression methods in the field of small area estimation is fairly recent,and has so far focussed on the use of empirical best linear unbiased prediction under amodel that combines a penalized spline (p-spline) fit and random area effects. The conceptof model-based direct estimation is used to develop an alternative nonparametric approachto estimation of a small area mean. The suggested estimator is a weighted average of thesample values from the area, with weights derived from a …


Chemical Cross-Linking Of The Chloroplast Localized Small Heat-Shock Protein, Hsp21, And The Model Substrate Citrate Synthase, Emma Ahrman, W Lambert, Andrew Aquilina, C V Robinson, Cs Emanuelsson Oct 2012

Chemical Cross-Linking Of The Chloroplast Localized Small Heat-Shock Protein, Hsp21, And The Model Substrate Citrate Synthase, Emma Ahrman, W Lambert, Andrew Aquilina, C V Robinson, Cs Emanuelsson

J. A. Aquilina

The molecular mechanism whereby the small heat-shock protein (sHsp) chaperones interact with and prevent aggregation of other proteins is not fully understood. We have characterized the sHsp-substrate protein interaction at normal and increased temperatures utilizing a model substrate protein, citrate synthase (CS), widely used in chaperone assays, and a dodecameric plant sHsp, Hsp21, by chemical cross-linking with 3,3'-Dithiobis[sulfosuccinimidylpropionate] (DTSSP) and mass spectrometric peptide mapping. In the absence of CS, the cross-linker captured Hsp21 in dodecameric form, even at increased temperature (47 degrees C). In the presence of equimolar amounts of CS, no Hsp21 dodecamer was captured, indicating a substrate-induced Hsp21 …