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Van Der Walt S.,Stellenbosch University | Schonberger J.L.,University of North Carolina at Chapel Hill | Nunez-Iglesias J.,Victorian Life science Computation Initiative | Boulogne F.,Princeton University | And 4 more authors.
PeerJ | Year: 2014

Scikit-image is an image processing library that implements algorithms and utilities for use in research, education and industry applications. It is released under the liberal Modified BSD open source license, provides a well-documented API in the Python programming language, and is developed by an active, international team of collaborators. In this paper we highlight the advantages of open source to achieve the goals of the scikit-image library, and we showcase several real-world image processing applications that use scikit-image. More information can be found on the project homepage, http://scikit-image.org. © 2014 Van derWalt et al.

Roberts J.A.,National Enterovirus Reference Laboratory | Roberts J.A.,RMIT University | Kuiper M.J.,Victorian Life science Computation Initiative | Thorley B.R.,National Enterovirus Reference Laboratory | And 3 more authors.
Journal of Molecular Graphics and Modelling | Year: 2012

The wild type 1 poliovirus capsid was first described in atomic detail in 1985 using X-ray crystallography. Numerous poliovirus capsid structures have been produced since, but none resolved the spatial positioning and conformation of a predicted N-terminal α-helix of the capsid protein VP1, which is considered critical to virus replication. We studied the helical structure under varying conditions using in silico reconstruction and atomistic molecular dynamics (MD) simulation methods based on the available poliovirus capsid atom coordinate data. MD simulations were performed on the detached N-terminal VP1 helix, the biologically active pentamer form of the pre-virion structure, reconstructed empty virus capsids and a full virion containing the poliovirus RNA genome in the form of a supercoiled structure. The N-terminal α-helix structure proved to be stable and amphipathic under all conditions studied. We propose that a combination of spatial disorder and proximity to the genomic RNA made this particular structure difficult to resolve by X-ray crystallography. Given the similarity of our in silico model of poliovirus compared to X-ray crystallography data, we consider computational methods to be a useful complement to the study of picornaviruses and other viruses that exhibit icosahedral symmetry. © 2012 Elsevier Inc.

Nguyen-Dumont T.,University of Melbourne | Hammet F.,University of Melbourne | Mahmoodi M.,University of Melbourne | Tsimiklis H.,University of Melbourne | And 15 more authors.
Breast Cancer Research and Treatment | Year: 2015

Loss-of-function mutations in PALB2 are associated with an increased risk of breast cancer, with recent data showing that female breast cancer risks for PALB2 mutation carriers are comparable in magnitude to those for BRCA2 mutation carriers. This study applied targeted massively parallel sequencing to characterize the mutation spectrum of PALB2 in probands attending breast cancer genetics clinics in the USA. The coding regions and proximal intron–exon junctions of PALB2 were screened in probands not known to carry a mutation in BRCA1 or BCRA2 from 1,250 families enrolled through familial cancer clinics by the Breast Cancer Family Registry. Mutation screening was performed using Hi-Plex, an amplicon-based targeted massively parallel sequencing platform. Screening of PALB2 was successful in 1,240/1,250 probands and identified nine women with protein-truncating mutations (three nonsense mutations and five frameshift mutations). Four of the 33 missense variants were predicted to be deleterious to protein function by in silico analysis using two different programs. Analysis of tumors from carriers of truncating mutations revealed that the majority were high histological grade, invasive ductal carcinomas. Young onset was apparent in most families, with 19 breast cancers under 50 years of age, including eight under the age of 40 years. Our data demonstrate the utility of Hi-Plex in the context of high-throughput testing for rare genetic mutations and provide additional timely information about the nature and prevalence of PALB2 mutations, to enhance risk assessment and risk management of women at high risk of cancer attending clinical genetic services. © 2015, Springer Science+Business Media New York.

Park D.J.,University of Melbourne | Lesueur F.,International Agency for Research on Cancer | Nguyen-Dumont T.,University of Melbourne | Pertesi M.,International Agency for Research on Cancer | And 25 more authors.
American Journal of Human Genetics | Year: 2012

An exome-sequencing study of families with multiple breast-cancer-affected individuals identified two families with XRCC2 mutations, one with a protein-truncating mutation and one with a probably deleterious missense mutation. We performed a population-based case-control mutation-screening study that identified six probably pathogenic coding variants in 1,308 cases with early-onset breast cancer and no variants in 1,120 controls (the severity grading was p < 0.02). We also performed additional mutation screening in 689 multiple-case families. We identified ten breast-cancer-affected families with protein-truncating or probably deleterious rare missense variants in XRCC2. Our identification of XRCC2 as a breast cancer susceptibility gene thus increases the proportion of breast cancers that are associated with homologous recombination-DNA-repair dysfunction and Fanconi anemia and could therefore benefit from specific targeted treatments such as PARP (poly ADP ribose polymerase) inhibitors. This study demonstrates the power of massively parallel sequencing for discovering susceptibility genes for common, complex diseases. © 2012 The American Society of Human Genetics.

PubMed | University of Chicago, QIMR Berghofer Medical Research Institute, University of South Australia, The Royal Womens Hospital and 13 more.
Type: Journal Article | Journal: Nature | Year: 2015

Patients with high-grade serous ovarian cancer (HGSC) have experienced little improvement in overall survival, and standard treatment has not advanced beyond platinum-based combination chemotherapy, during the past 30 years. To understand the drivers of clinical phenotypes better, here we use whole-genome sequencing of tumour and germline DNA samples from 92 patients with primary refractory, resistant, sensitive and matched acquired resistant disease. We show that gene breakage commonly inactivates the tumour suppressors RB1, NF1, RAD51B and PTEN in HGSC, and contributes to acquired chemotherapy resistance. CCNE1 amplification was common in primary resistant and refractory disease. We observed several molecular events associated with acquired resistance, including multiple independent reversions of germline BRCA1 or BRCA2 mutations in individual patients, loss of BRCA1 promoter methylation, an alteration in molecular subtype, and recurrent promoter fusion associated with overexpression of the drug efflux pump MDR1.

Pope B.J.,Victorian Life Science Computation Initiative | Fitch B.G.,IBM | Pitman M.C.,IBM | Rice J.J.,IBM | And 2 more authors.
IEEE Transactions on Biomedical Engineering | Year: 2011

Future multiscale and multiphysics models that support research into human disease, translational medical science, and treatment can utilize the power of high-performance computing (HPC) systems. We anticipate that computationally efficient multiscale models will require the use of sophisticated hybrid programming models, mixing distributed message-passing processes [e.g., the message-passing interface (MPI)] with multithreading (e.g., OpenMP, Pthreads). The objective of this study is to compare the performance of such hybrid programming models when applied to the simulation of a realistic physiological multiscale model of the heart. Our results show that the hybrid models perform favorably when compared to an implementation using only the MPI and, furthermore, that OpenMP in combination with the MPI provides a satisfactory compromise between performance and code complexity. Having the ability to use threads within MPI processes enables the sophisticated use of all processor cores for both computation and communication phases. Considering that HPC systems in 2012 will have two orders of magnitude more cores than what was used in this study, we believe that faster than real-time multiscale cardiac simulations can be achieved on these systems. © 2011 IEEE.

Pope B.J.,Victorian Life science Computation Initiative | Pope B.J.,University of Melbourne | Nguyen-Dumont T.,University of Melbourne | Hammet F.,University of Melbourne | Park D.J.,University of Melbourne
Source Code for Biology and Medicine | Year: 2014

Background: We recently described Hi-Plex, a highly multiplexed PCR-based target-enrichment system for massively parallel sequencing (MPS), which allows the uniform definition of library size so that subsequent paired-end sequencing can achieve complete overlap of read pairs. Variant calling from Hi-Plex-derived datasets can thus rely on the identification of variants appearing in both reads of read-pairs, permitting stringent filtering of sequencing chemistry-induced errors. These principles underly ROVER software (derived from Read Overlap PCR-MPS variant caller), which we have recently used to report the screening for genetic mutations in the breast cancer predisposition gene PALB2. Here, we describe the algorithms underlying ROVER and its usage.Results: ROVER enables users to quickly and accurately identify genetic variants from PCR-targeted, overlapping paired-end MPS datasets. The open-source availability of the software and threshold tailorability enables broad access for a range of PCR-MPS users.Methods: ROVER is implemented in Python and runs on all popular POSIX-like operating systems (Linux, OS X). The software accepts a tab-delimited text file listing the coordinates of the target-specific primers used for targeted enrichment based on a specified genome-build. It also accepts aligned sequence files resulting from mapping to the same genome-build. ROVER identifies the amplicon a given read-pair represents and removes the primer sequences by using the mapping co-ordinates and primer co-ordinates. It considers overlapping read-pairs with respect to primer-intervening sequence. Only when a variant is observed in both reads of a read-pair does the signal contribute to a tally of read-pairs containing or not containing the variant. A user-defined threshold informs the minimum number of, and proportion of, read-pairs a variant must be observed in for a 'call' to be made. ROVER also reports the depth of coverage across amplicons to facilitate the identification of any regions that may require further screening.Conclusions: ROVER can facilitate rapid and accurate genetic variant calling for a broad range of PCR-MPS users. © 2014 Pope et al.; licensee BioMed Central Ltd.

Pope B.J.,Victorian Life Science Computation Initiative
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference | Year: 2011

Future multiscale and multiphysics models must use the power of high performance computing (HPC) systems to enable research into human disease, translational medical science, and treatment. Previously we showed that computationally efficient multiscale models will require the use of sophisticated hybrid programming models, mixing distributed message passing processes (e.g. the message passing interface (MPI)) with multithreading (e.g. OpenMP, POSIX pthreads). The objective of this work is to compare the performance of such hybrid programming models when applied to the simulation of a lightweight multiscale cardiac model. Our results show that the hybrid models do not perform favourably when compared to an implementation using only MPI which is in contrast to our results using complex physiological models. Thus, with regards to lightweight multiscale cardiac models, the user may not need to increase programming complexity by using a hybrid programming approach. However, considering that model complexity will increase as well as the HPC system size in both node count and number of cores per node, it is still foreseeable that we will achieve faster than real time multiscale cardiac simulations on these systems using hybrid programming models.

Nguyen-Dumont T.,University of Melbourne | Pope B.J.,Victorian Life science Computation Initiative | Pope B.J.,University of Melbourne | Hammet F.,University of Melbourne | And 4 more authors.
Analytical Biochemistry | Year: 2013

Although per-base sequencing costs have decreased during recent years, library preparation for targeted massively parallel sequencing remains constrained by high reagent cost, limited design flexibility, and protocol complexity. To address these limitations, we previously developed Hi-Plex, a polymerase chain reaction (PCR) massively parallel sequencing strategy for screening panels of genomic target regions. Here, we demonstrate that Hi-Plex applied with hybrid adapters can generate a library suitable for sequencing with both the Ion Torrent and the TruSeq chemistries and that adjusting primer concentrations improves coverage uniformity. These results expand Hi-Plex capabilities as an accurate, affordable, flexible, and rapid approach for various genetic screening applications. © 2013 Elsevier Inc. All rights reserved.

PubMed | Victorian Life science Computation Initiative, University of Melbourne, Cancer Epidemiology Center and Our Ladys Childrens Hospital
Type: | Journal: Familial cancer | Year: 2017

An apparently balanced t(2;3)(q37.3;q13.2) translocation that appears to segregate with renal cell carcinoma (RCC) has indicated potential areas to search for the elusive genetic basis of clear cell RCC. We applied Hi-Plex targeted sequencing to analyse germline DNA from 479 individuals affected with clear cell RCC for this breakpoint translocation and genetic variants in neighbouring genes on chromosome 2, ACKR3 and COPS8. While only synonymous variants were found in COPS8, one of the missense variants in ACKR3:c.892C>T, observed in 4/479 individuals screened (0.8%), was predicted likely to damage ACKR3 function. Identification of causal genes for RCC has potential clinical utility, where risk assessment and risk management can offer better outcomes, with surveillance for at-risk relatives and nephron sparing surgery through earlier intervention.

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