School of Mathematics and Statistics - Research Publications

Assessment of serum symmetric dimethylarginine and creatinine concentrations in hyperthyroid cats before and after a fixed dose of orally administered radioiodine

2020-07-07T19:19:59Z

Yu, L; Lacorcia, L; Finch, S; Johnstone, T 2020 Assessment of serum symmetric dimethylarginine and creatinine concentrations in hyperthyroid cats before and after a fixed dose of orally administered radioiodine Background: Serum symmetric dimethylarginine (SDMA) is a sensitive renal biomarker for detecting early chronic kidney disease (CKD) in nonhyperthyroid cats, but knowledge regarding its performance in hyperthyroid cats remains limited. Objectives: To determine the relationship between serum SDMA, creatinine and total thyroxine (TT4) concentrations in hyperthyroid cats before (T0) and 3 months after (T1) receiving a PO fixed dose of radioiodine. Animals: Eighty client‐owned hyperthyroid cats. Methods: Prospective cohort study. Serum TT4, and SDMA, creatinine concentrations, and urine specific gravity were measured at T0 and T1. Nonparametric tests were used to determine the relationship among SDMA, and creatinine and TT4 concentrations. Agreement between SDMA and creatinine regarding CKD staging at both time points was assessed using Goodman and Kruskal's gamma statistic. Results: Mean serum SDMA concentration increased after treatment of hyperthyroidism. However, 21 of 75 cats experienced a decrease in SDMA between T0 and T1, whereas creatinine decreased in only 2 cats. A moderate correlation between SDMA and creatinine was seen at T1 (r = 0.53; P < .001) but not at T0 (r = 0.13; P = .25). Where assessable at T1, poor agreement was observed between SDMA and creatinine and CKD stage (Goodman and Kruskal's gamma 0.20; P = .29). Conclusions and clinical importance: Discordant outcomes between SDMA and creatinine after radioiodine treatment in cats with hyperthyroidism suggest extrarenal factors may interfere with the reliability of SDMA to adequately reflect renal function. As a result, SDMA should not be interpreted in isolation in hyperthyroid cats treated with radioiodine. Journal Article

A few clarifications on MIRIBEL

2020-07-07T14:01:13Z

Faria, M; Bjornmalm, M; Crampin, EJ; Caruso, F 2020-01-01 A few clarifications on MIRIBEL We are inspired by the responses1,2,3,4 to our recently proposed ‘reporting standards’ for bio–nano research (Minimum Information Reporting in Bio–Nano Experimental Literature — MIRIBEL)5. However, we wish to clarify several points made in MIRIBEL and discuss a few concerns raised by the community, with a view toward encouraging uptake of the MIRIBEL standard and improving future research. Journal Article

The mean-square dichotomy spectrum and a bifurcation to a mean-square attractor

2020-07-05T08:24:52Z

Doan, TS; Rasmussen, M; Kloeden, PE 2015-05-01 The mean-square dichotomy spectrum and a bifurcation to a mean-square attractor The dichotomy spectrum is introduced for linear mean-square random dynamical systems, and it is shown that for finite-dimensional mean-field stochastic differential equations, the dichotomy spectrum consists of finitely many compact intervals. It is then demonstrated that a change in the sign of the dichotomy spectrum is associated with a bifurcation from a trivial to a non-trivial mean-square random attractor. Journal Article

Learning arithmetic blocks: a concrete model for teaching decimals

2020-04-04T18:11:55Z

Archer, Shona; Condon, Caroline; STACEY, KAYE; STEINLE, VICKI; McCarthy, Heather; Helme, Sue; Sullivan, Gerard; Tromp, Calvin 2006 Learning arithmetic blocks: a concrete model for teaching decimals This booklet is an introduction to using the LAB model with your students. It outlines a number of activities using LAB to assist students in gaining an understanding of the decimal number system. Copyright confirmation in progress. Any queries to UMER-enquiries@unimelb.edu.au Book

Lesson ideas and activities for teaching decimals

2020-04-04T18:11:46Z

Condon, Caroline; Archer, Shona; STACEY, KAYE; STEINLE, VICKI; Scott, Nick; Helme, Sue; Sullivan, Gerard; Tromp, Calvin 2006 Lesson ideas and activities for teaching decimals The Department of Science and Mathematics Education has produced this booklet to assist teachers with students learning to work confidently with decimal numbers. It contains many classroom activities that will motivate and engage students making the teaching and learning of decimals both enjoyable and effective. Copyright confirmation in progress. Any queries to UMER-enquires@unimelb.edu.au; Further information regarding the book is available at http://staff.edfac.unimelb.edu.au/~kayecs/projects/decprojlink.htm Book

Frobenius circulant graphs of valency four

2020-04-04T11:04:32Z

Thomson, Alison; ZHOU, SANMING 2008 Frobenius circulant graphs of valency four A first kind Frobenius graph is a Cayley graph Cay.K; S/ on the Frobenius kernel of a Frobenius group K o H such that S D aH for some a 2 K with haH i D K, where H is of even order or a is an involution. It is known that such graphs admit ‘perfect’ routing and gossiping schemes. A circulant graph is a Cayley graph on a cyclic group of order at least three. Since circulant graphs are widely used as models for interconnection networks, it is thus highly desirable to characterize those which are Frobenius of the first kind. In this paper we first give such a characterization for connected 4-valent circulant graphs, and then describe optimal routing and gossiping schemes for those which are first kind Frobenius graphs. Examples of such graphs include the 4-valent circulant graph with a given diameter and maximum possible order. © 2008 Australian Mathematical Society. Online edition of the journal is available at http://journals.cambridge.org/JAZ Journal Article

Queueing analysis of network traffic: methodology and visualization tools

2020-04-04T03:39:17Z

ROLLS, D.; MICHAILIDIS, G.; HERNANDEZ-CAMPOS, F. 2005 Queueing analysis of network traffic: methodology and visualization tools Journal Article

The density of the time to ruin for a Sparre Andersen process with Erlang arrivals and exponential claims

2020-04-03T23:36:01Z

DICKSON, D.; HUGHES, B.; ZHANG, L. 2005 The density of the time to ruin for a Sparre Andersen process with Erlang arrivals and exponential claims Journal Article

Positive and real-positive solutions to the equation axa* = c in C*-algebras

2020-04-03T22:39:41Z

CVETKOVI-ILIC, D.; DAJIC, A.; KOLIHA, J. 2007 Positive and real-positive solutions to the equation axa* = c in C*-algebras Journal Article

Finite symmetric graphs with 2-arc transitive quotients II

2020-04-03T22:38:21Z

LU, Z.; ZHOU, S. 2007 Finite symmetric graphs with 2-arc transitive quotients II Journal Article

Specht modules and semisimplicity criteria for Brauer and Birman-Murakami-Wenzl algebras

2020-04-03T22:37:17Z

ENYANG, J. 2007 Specht modules and semisimplicity criteria for Brauer and Birman-Murakami-Wenzl algebras Journal Article

Some infinite soluble groups, their modules, and the arithmeticity of associated automorphism groups

2020-04-03T22:36:47Z

BROOKES, C.; GROVES, J. 2005 Some infinite soluble groups, their modules, and the arithmeticity of associated automorphism groups Journal Article

An application of classical invariant theory to identifiability in nonparametric mixtures

2020-04-03T22:36:39Z

ELMORE, R.; HALL, P.; NEEMAN, A. 2005 An application of classical invariant theory to identifiability in nonparametric mixtures Journal Article

Spectral curves and the mass of hyperbolic monopoles

2020-04-03T22:35:05Z

NORBURY, P.; ROMAO, N. 2007 Spectral curves and the mass of hyperbolic monopoles Journal Article

Angle structures and normal surfaces

2020-04-03T18:20:55Z

LUO, F.; TILLMANN, S. 2008 Angle structures and normal surfaces C1 - Refereed Journal Article Journal Article

Alcove walks, Hecke algebras, spherical functions, crystals and column strict tableaux

2020-04-03T18:19:55Z

RAM, A. 2006 Alcove walks, Hecke algebras, spherical functions, crystals and column strict tableaux C1 - Refereed Journal Article Journal Article

String topology prospectra and Hochschild cohomology

2020-04-03T18:19:03Z

GRUHER, K.; WESTERLAND, C. 2008 String topology prospectra and Hochschild cohomology C1 - Refereed Journal Article Journal Article

Finite symmetric graphs with two-arc transitive quotients

2020-04-03T18:17:52Z

IRANMANESH, M. A.; PRAEGER, C. E.; ZHOU, S. 2005 Finite symmetric graphs with two-arc transitive quotients C1 - Refereed Journal Article Journal Article

An oscillation theorem for groups of isometries

2020-04-03T18:16:19Z

HJORTH, G. 2008 An oscillation theorem for groups of isometries C1 - Refereed Journal Article Journal Article

Minimal spheres of arbitrarily high morse index

2020-04-03T18:15:41Z

HASS, J.; NORBURY, P. T.; RUBINSTEIN, J. H. 2003 Minimal spheres of arbitrarily high morse index C1 - Refereed Journal Article Journal Article

Integrable lattice realisations of conformal twisted boundary conditions

2020-04-03T11:48:10Z

CHUI, CHEUK HO OTTO; MERCAT, CHRISTIAN; ORRICK, WILLIAM PENDLETON; PEARCE, PAUL ANTHONY 2001 Integrable lattice realisations of conformal twisted boundary conditions C1 - Journal Articles Refereed Journal Article

Self-Avoiding Random Walk with Multiple Site Weightings and Restrictions

2020-04-03T11:46:40Z

KRAWCZYK, JAROSLAW; PRELLBERG, THOMAS; OWCZAREK, ALEKSANDER; RECHNITZER, ANDREW 2006 Self-Avoiding Random Walk with Multiple Site Weightings and Restrictions C1 - Journal Articles Refereed Journal Article

A parallel algorithm for the enumeration of self-avoiding polygons on the square lattice

2020-04-03T11:43:44Z

JENSEN, IWAN 2003 A parallel algorithm for the enumeration of self-avoiding polygons on the square lattice C1 - Journal Articles Refereed Journal Article

Interpretations of some parameter dependent generalizations of classical matrix ensembles

2020-04-03T11:37:47Z

FORRESTER, PETER JOHN; RAINS, ERIC 2005 Interpretations of some parameter dependent generalizations of classical matrix ensembles C1 - Journal Articles Refereed Journal Article

Semantics-Based Composition of Integrated Cardiomyocyte Models Motivated by Real-World Use Cases

2020-07-05T08:24:52Z

Neal, ML; Carlson, BE; Thompson, CT; James, RC; Kim, KG; Tran, K; Crampin, EJ; Cook, DL; Gennari, JH 2015-12-30 Semantics-Based Composition of Integrated Cardiomyocyte Models Motivated by Real-World Use Cases Semantics-based model composition is an approach for generating complex biosimulation models from existing components that relies on capturing the biological meaning of model elements in a machine-readable fashion. This approach allows the user to work at the biological rather than computational level of abstraction and helps minimize the amount of manual effort required for model composition. To support this compositional approach, we have developed the SemGen software, and here report on SemGen's semantics-based merging capabilities using real-world modeling use cases. We successfully reproduced a large, manually-encoded, multi-model merge: the "Pandit-Hinch-Niederer" (PHN) cardiomyocyte excitation-contraction model, previously developed using CellML. We describe our approach for annotating the three component models used in the PHN composition and for merging them at the biological level of abstraction within SemGen. We demonstrate that we were able to reproduce the original PHN model results in a semi-automated, semantics-based fashion and also rapidly generate a second, novel cardiomyocyte model composed using an alternative, independently-developed tension generation component. We discuss the time-saving features of our compositional approach in the context of these merging exercises, the limitations we encountered, and potential solutions for enhancing the approach. Journal Article

Representation theory of sl(2 vertical bar 1)

2020-07-05T08:24:52Z

Gotz, G; Quella, T; Schomerus, V 2007-06-15 Representation theory of sl(2 vertical bar 1) Journal Article

Using Genetic Distance to Infer the Accuracy of Genomic Prediction

2020-07-05T08:24:52Z

Scutari, M; Mackay, I; Balding, D 2016-09-01 Using Genetic Distance to Infer the Accuracy of Genomic Prediction The prediction of phenotypic traits using high-density genomic data has many applications such as the selection of plants and animals of commercial interest; and it is expected to play an increasing role in medical diagnostics. Statistical models used for this task are usually tested using cross-validation, which implicitly assumes that new individuals (whose phenotypes we would like to predict) originate from the same population the genomic prediction model is trained on. In this paper we propose an approach based on clustering and resampling to investigate the effect of increasing genetic distance between training and target populations when predicting quantitative traits. This is important for plant and animal genetics, where genomic selection programs rely on the precision of predictions in future rounds of breeding. Therefore, estimating how quickly predictive accuracy decays is important in deciding which training population to use and how often the model has to be recalibrated. We find that the correlation between true and predicted values decays approximately linearly with respect to either FST or mean kinship between the training and the target populations. We illustrate this relationship using simulations and a collection of data sets from mice, wheat and human genetics. Journal Article

Why weight? Modelling sample and observational level variability improves power in RNA-seq analyses

2020-07-05T08:24:52Z

Liu, R; Holik, AZ; Su, S; Jansz, N; Chen, K; Leong, HS; Blewitt, ME; Asselin-Labat, M-L; Smyth, GK; Ritchie, ME 2015-09-03 Why weight? Modelling sample and observational level variability improves power in RNA-seq analyses Variations in sample quality are frequently encountered in small RNA-sequencing experiments, and pose a major challenge in a differential expression analysis. Removal of high variation samples reduces noise, but at a cost of reducing power, thus limiting our ability to detect biologically meaningful changes. Similarly, retaining these samples in the analysis may not reveal any statistically significant changes due to the higher noise level. A compromise is to use all available data, but to down-weight the observations from more variable samples. We describe a statistical approach that facilitates this by modelling heterogeneity at both the sample and observational levels as part of the differential expression analysis. At the sample level this is achieved by fitting a log-linear variance model that includes common sample-specific or group-specific parameters that are shared between genes. The estimated sample variance factors are then converted to weights and combined with observational level weights obtained from the mean-variance relationship of the log-counts-per-million using 'voom'. A comprehensive analysis involving both simulations and experimental RNA-sequencing data demonstrates that this strategy leads to a universally more powerful analysis and fewer false discoveries when compared to conventional approaches. This methodology has wide application and is implemented in the open-source 'limma' package. Journal Article

Boundary regularized integral equation formulation of the Helmholtz equation in acoustics

2020-07-05T08:24:52Z

Sun, Q; Klaseboer, E; Khoo, B-C; Chan, DYC 2015-01-01 Boundary regularized integral equation formulation of the Helmholtz equation in acoustics A boundary integral formulation for the solution of the Helmholtz equation is developed in which all traditional singular behaviour in the boundary integrals is removed analytically. The numerical precision of this approach is illustrated with calculation of the pressure field owing to radiating bodies in acoustic wave problems. This method facilitates the use of higher order surface elements to represent boundaries, resulting in a significant reduction in the problem size with improved precision. Problems with extreme geometric aspect ratios can also be handled without diminished precision. When combined with the CHIEF method, uniqueness of the solution of the exterior acoustic problem is assured without the need to solve hypersingular integrals. Journal Article

Asymmetrically gauged WZNW models

2020-07-05T08:24:52Z

Quella, T; Schomerus, V 2003-01-01 Asymmetrically gauged WZNW models Journal Article