Developments in GRworkbench

The software tool GRworkbench is an ongoing project in visual, numerical General Relativity at The Australian National University. Recently, GRworkbench has been significantly extended to facilitate numerical experimentation in analytically-defined space-times. The numerical differential geometric engine has been rewritten using functional programming techniques, enabling objects which are normally defined as functions in the formalism of differential geometry and General Relativity to be directly represented as function variables in the C++ code of GRworkbench. The new functional differential geometric engine allows for more accurate and efficient visualisation of objects in space-times and makes new, efficient computational techniques available. Motivated by the desire to investigate a recent scientific claim using GRworkbench, new tools for numerical experimentation have been implemented, allowing for the simulation of complex physical situations.Comment: 14 pages. To appear A. Moylan, S.M. Scott and A.C. Searle, Developments in GRworkbench. Proceedings of the Tenth Marcel Grossmann Meeting on General Relativity, editors M. Novello, S. Perez-Bergliaffa and R. Ruffini. Singapore: World Scientific 200

The ACIGA Data Analysis programme

The Data Analysis programme of the Australian Consortium for Interferometric Gravitational Astronomy (ACIGA) was set up in 1998 by the first author to complement the then existing ACIGA programmes working on suspension systems, lasers and optics, and detector configurations. The ACIGA Data Analysis programme continues to contribute significantly in the field; we present an overview of our activities.Comment: 10 pages, 0 figures, accepted, Classical and Quantum Gravity, (Proceedings of the 5th Edoardo Amaldi Conference on Gravitational Waves, Tirrenia, Pisa, Italy, 6-11 July 2003

Pericentromeric organization at the fusion point of mouse Robertsonian translocation chromosomes

In mammals, Robertsonian (Rb) translocation (the joining of two telo/acrocentric chromosomes at their centromere to form a metacentric) is the most effective process in chromosomal evolution leading to speciation; its occurrence also affects human health (through the induction of trisomies) and the fertility of farm animals. To understand the mechanism of Rb translocation, we used the house mouse as a model system and studied the organization of pericentromeric satellite DNAs (satDNA) of telocentrics and Rb chromosomes, both minor and major satDNA. The chromosome-orientation fluorescence in situ hybridization (CO-FISH) technique was used to analyze the major satDNA. To detect the very small amount of minor satDNA, a procedure was developed that combines CO-FISH with primed in situ labeling and conventional FISH and is five times more sensitive than the CO-FISH procedure alone. It was found that both the major and the minor satDNA tandem repeats are oriented head-to-tail in telocentric and Rb chromosomes, and their polarity is always the same relative to the centromere. We suggest that all tandemly repetitive satDNAs in a species probably are locked into such a symmetry constraint as a universal consequence of chromosomal evolution. Rb translocation breakpoints were found localized within the minor satDNA of telocentrics, and these sequences contributed symmetrically to the formation of the centromeric region of the Rb chromosomes. These results are important for an understanding of the geometry of Rb translocations and suggest the study of DNA orientation as a new tool for investigating these rearrangements

Robust Bayesian detection of unmodelled bursts

A Bayesian treatment of the problem of detecting an unmodelled gravitational wave burst with a global network of gravitational wave observatories reveals that several previously proposed statistics have implicit biases that render them sub-optimal for realistic signal populations.Comment: 9 pages, 1 figure, submitted to CQG Amaldi proceedings special issu

Reply to Taheripour, Delgado and Tyner (2020)

The present letter is aimed at providing a step-by-step comment on the criticisms raised by Taheripour, Delgado and Tyner, authors of the Response to Santeramo and Searle (2019). The paper by Santeramo and Searle (2019) analyses the responsiveness of the US soy and palm oil markets to price changes. The authors find positive cross-price elasticities of palm oil import with respect to soy oil price, and vice versa. Hereafter we will refer to the paper by Taheripour, Delgado and Tyner as TDT (2020) and to the paper by Santeramo and Searle as SS (2019)

A comparison of efficient permutation tests for unbalanced ANOVA in two by two designs--and their behavior under heteroscedasticity

We compare different permutation tests and some parametric counterparts that are applicable to unbalanced designs in two by two designs. First the different approaches are shortly summarized. Then we investigate the behavior of the tests in a simulation study. A special focus is on the behavior of the tests under heteroscedastic variances.Comment: 20 pages, 9 figures, Working Paper of the Department of Management And Enigineering of the University of Padov