Namoi : Talking fish - making connections with the rivers of the Murray-Darling Basin

The Namoi River winds its way through 42 000 square kilometres of blacksoil plain in the north east of New South Wales. Fed by the rivers of the western slopes of the Great Dividing Range, it contributes about one quarter of the Darling River’s flow. The river, its floodplain, wetlands, swamps and waterholes, are the traditional lands of the Gamilaraay* people. The Namoi is a very different river to the one the Gamilaraay people once knew and fished...

An audit of first-aid treatment of pediatric burns patients and their clinical outcome

This study describes the first aid used and clinical outcomes of all patients who presented to the Royal Children's Hospital, Brisbane, Australia in 2005 with an acute burn injury. A retrospective audit was performed with the charts of 459 patients and information concerning burn injury, first-aid treatment, and clinical outcomes was collected. First aid was used on 86.1% of patients, with 8.7% receiving no first aid and unknown treatment in 5.2% of cases. A majority of patients had cold water as first aid (80.2%), however, only 12.1% applied the cold water for the recommended 20 minutes or longer. Recommended first aid (cold water for >or=20 minutes) was associated with significantly reduced reepithelialization time for children with contact injuries (P=.011). Superficial depth burns were significantly more likely to be associated with the use of recommended first aid (P=.03). Suboptimal treatment was more common for children younger than 3.5 years (P<.001) and for children with friction burns. This report is one of the few publications to relate first-aid treatment to clinical outcomes. Some positive clinical outcomes were associated with recommended first-aid use; however, wound outcomes were more strongly associated with burn depth and mechanism of injury. There is also a need for more public awareness of recommended first-aid treatment.

A methodological approach to reporting corrected small field relative outputs

Purpose The goal of this work was to set out a methodology for measuring and reporting small field relative output and to assess the application of published correction factors across a population of linear accelerators. Methods and materials Measurements were made at 6 MV on five Varian iX accelerators using two PTW T60017 unshielded diodes. Relative output readings and profile measurements were made for nominal square field sizes of side 0.5 to 1.0 cm. The actual in-plane (A) and cross-plane (B) field widths were taken to be the FWHM at the 50% isodose level. An effective field size, defined as FSeff=A·B, was calculated and is presented as a field size metric. FSeffFSeff was used to linearly interpolate between published Monte Carlo (MC) calculated kQclin,Qmsrfclin,fmsr values to correct for the diode over-response in small fields. Results The relative output data reported as a function of the nominal field size were different across the accelerator population by up to nearly 10%. However, using the effective field size for reporting showed that the actual output ratios were consistent across the accelerator population to within the experimental uncertainty of ±1.0%. Correcting the measured relative output using kQclin,Qmsrfclin,fmsr at both the nominal and effective field sizes produce output factors that were not identical but differ by much less than the reported experimental and/or MC statistical uncertainties. Conclusions In general, the proposed methodology removes much of the ambiguity in reporting and interpreting small field dosimetric quantities and facilitates a clear dosimetric comparison across a population of linacs

A practical and theoretical definition of very small field size for radiotherapy output factor measurements

Purpose This work introduces the concept of very small field size. Output factor (OPF) measurements at these field sizes require extremely careful experimental methodology including the measurement of dosimetric field size at the same time as each OPF measurement. Two quantifiable scientific definitions of the threshold of very small field size are presented. Methods A practical definition was established by quantifying the effect that a 1 mm error in field size or detector position had on OPFs, and setting acceptable uncertainties on OPF at 1%. Alternatively, for a theoretical definition of very small field size, the OPFs were separated into additional factors to investigate the specific effects of lateral electronic disequilibrium, photon scatter in the phantom and source occlusion. The dominant effect was established and formed the basis of a theoretical definition of very small fields. Each factor was obtained using Monte Carlo simulations of a Varian iX linear accelerator for various square field sizes of side length from 4 mm to 100 mm, using a nominal photon energy of 6 MV. Results According to the practical definition established in this project, field sizes < 15 mm were considered to be very small for 6 MV beams for maximal field size uncertainties of 1 mm. If the acceptable uncertainty in the OPF was increased from 1.0 % to 2.0 %, or field size uncertainties are 0.5 mm, field sizes < 12 mm were considered to be very small. Lateral electronic disequilibrium in the phantom was the dominant cause of change in OPF at very small field sizes. Thus the theoretical definition of very small field size coincided to the field size at which lateral electronic disequilibrium clearly caused a greater change in OPF than any other effects. This was found to occur at field sizes < 12 mm. Source occlusion also caused a large change in OPF for field sizes < 8 mm. Based on the results of this study, field sizes < 12 mm were considered to be theoretically very small for 6 MV beams. Conclusions Extremely careful experimental methodology including the measurement of dosimetric field size at the same time as output factor measurement for each field size setting and also very precise detector alignment is required at field sizes at least < 12 mm and more conservatively < 15 mm for 6 MV beams. These recommendations should be applied in addition to all the usual considerations for small field dosimetry, including careful detector selection.

Distribution harmonic state estimation based on a modified PSO considering parameters uncertainty

This paper presents a new algorithm based on a Modified Particle Swarm Optimization (MPSO) to estimate the harmonic state variables in a distribution networks. The proposed algorithm performs the estimation for both amplitude and phase of each injection harmonic currents by minimizing the error between the measured values from Phasor Measurement Units (PMUs) and the values computed from the estimated parameters during the estimation process. The proposed algorithm can take into account the uncertainty of the harmonic pseudo measurement and the tolerance in the line impedances of the network as well as the uncertainty of the Distributed Generators (DGs) such as Wind Turbines (WTs). The main features of the proposed MPSO algorithm are usage of a primary and secondary PSO loop and applying the mutation function. The simulation results on 34-bus IEEE radial and a 70-bus realistic radial test networks are presented. The results demonstrate that the speed and the accuracy of the proposed Distribution Harmonic State Estimation (DHSE) algorithm are very excellent compared to the algorithms such as Weight Least Square (WLS), Genetic Algorithm (GA), original PSO, and Honey Bees Mating Optimization (HBMO).

A novel algorithm based on honey bee mating optimization for distribution harmonic state estimation including distributed generators

This paper presents a new algorithm based on honey-bee mating optimization (HBMO) to estimate harmonic state variables in distribution networks including distributed generators (DGs). The proposed algorithm performs estimation for both amplitude and phase of each harmonics by minimizing the error between the measured values from phasor measurement units (PMUs) and the values computed from the estimated parameters during the estimation process. Simulation results on two distribution test system are presented to demonstrate that the speed and accuracy of proposed distribution harmonic state estimation (DHSE) algorithm is extremely effective and efficient in comparison with the conventional algorithms such as weight least square (WLS), genetic algorithm (GA) and tabu search (TS).

Distribution harmonic state estimation based on a hybrid PSO and SA algorithm considering parameters uncertainty

This paper presents a new algorithm based on a Hybrid Particle Swarm Optimization (PSO) and Simulated Annealing (SA) called PSO-SA to estimate harmonic state variables in distribution networks. The proposed algorithm performs estimation for both amplitude and phase of each harmonic currents injection by minimizing the error between the measured values from Phasor Measurement Units (PMUs) and the values computed from the estimated parameters during the estimation process. The proposed algorithm can take into account the uncertainty of the harmonic pseudo measurement and the tolerance in the line impedances of the network as well as uncertainty of the Distributed Generators (DGs) such as Wind Turbines (WT). The main feature of proposed PSO-SA algorithm is to reach quickly around the global optimum by PSO with enabling a mutation function and then to find that optimum by SA searching algorithm. Simulation results on IEEE 34 bus radial and a realistic 70-bus radial test networks are presented to demonstrate the speed and accuracy of proposed Distribution Harmonic State Estimation (DHSE) algorithm is extremely effective and efficient in comparison with the conventional algorithms such as Weight Least Square (WLS), Genetic Algorithm (GA), original PSO and Honey Bees Mating Optimization (HBMO) algorithm.

Predicting the likelihood of QA failure using treatment plan accuracy metrics

This study used automated data processing techniques to calculate a set of novel treatment plan accuracy metrics, and investigate their usefulness as predictors of quality assurance (QA) success and failure. 151 beams from 23 prostate and cranial IMRT treatment plans were used in this study. These plans had been evaluated before treatment using measurements with a diode array system. The TADA software suite was adapted to allow automatic batch calculation of several proposed plan accuracy metrics, including mean field area, small-aperture, off-axis and closed-leaf factors. All of these results were compared the gamma pass rates from the QA measurements and correlations were investigated. The mean field area factor provided a threshold field size (5 cm2, equivalent to a 2.2 x 2.2 cm2 square field), below which all beams failed the QA tests. The small aperture score provided a useful predictor of plan failure, when averaged over all beams, despite being weakly correlated with gamma pass rates for individual beams. By contrast, the closed leaf and off-axis factors provided information about the geometric arrangement of the beam segments but were not useful for distinguishing between plans that passed and failed QA. This study has provided some simple tests for plan accuracy, which may help minimise time spent on QA assessments of treatments that are unlikely to pass.

Where are all the female participants in sports and exercise medicine research?

The aim of this study is to estimate the ratio of male and female participants in Sports and Exercise Medicine research. Original research articles published in three major Sports and Exercise Medicine journals (Medicine and Science in Sport and Exercise, British Journal of Sports Medicine and American Journal of Sports Medicine) over a three year period were examined. Each article was screened to determine the following: total number of participants, the number of female participants and the number of male participants. The percentage of females and males per article in each of the journals was also calculated. Cross tabulations and Chi square analysis were used to compare the gender representation of participants within each of the journals. Data were extracted from 1, 382 articles involving a total of 6, 076, 705 participants. 2, 366, 998 (39%) participants were female and 3, 709, 707 (61%) male. The average percentage of female participants per article across the journals ranged from 35-37%. Females were significantly under-represented across all of the journals (X2 =23566, df=2, p<0.00001). There were no significant differences between the three journals. In conclusion, Sports and Exercise Medicine practitioners should be cognisant of sexual dimorphism and gender disparity in the current literature.

Known and chosen key differential distinguishers for block ciphers

In this paper we investigate the differential properties of block ciphers in hash function modes of operation. First we show the impact of differential trails for block ciphers on collision attacks for various hash function constructions based on block ciphers. Further, we prove the lower bound for finding a pair that follows some truncated differential in case of a random permutation. Then we present open-key differential distinguishers for some well known round-reduced block ciphers.

Questions of Science [third edition]

Table of Contents Timeline of Thinkers Timeline of Thoughts Evolution of Science Chapter 1. Introduction Chapter 2. Humans: the measure of all things Chapter 3. Men with beards: long beards Chapter 4. I doubt it Chapter 5. With good reason Chapter 6. Here be dragons Chapter 7. Stirrings of science Chapter 8. Degrees of separation Chapter 9. The Greek legacy Chapter 10. A scientific focus Chapter 11. Questions of science Chapter 12. Creatures of habit Chapter 13. A scientific method Chapter 14. Outside the square Chapter 15. Probably Chapter 16. Human, all too human Chapter 17. Cultures of science Chapter 18. 21st Century Science Chapter 19. Science in question Chapter 20. How do we know? Chapter 21. Sources

Privacy enhancements for hardware-based security modules

The increasing growth in the use of Hardware Security Modules (HSMs) towards identification and authentication of a security endpoint have raised numerous privacy and security concerns. HSMs have the ability to tie a system or an object, along with its users to the physical world. However, this enables tracking of the user and/or an object associated with the HSM. Current systems do not adequately address the privacy needs and as such are susceptible to various attacks. In this work, we analyse various security and privacy concerns that arise when deploying such hardware security modules and propose a system that allow users to create pseudonyms from a trusted master public-secret key pair. The proposed system is based on the intractability of factoring and finding square roots of a quadratic residue modulo a composite number, where the composite number is a product of two large primes. Along with the standard notion of protecting privacy of an user, the proposed system offers colligation between seemingly independent pseudonyms. This new property when combined with HSMs that store the master secret key is extremely beneficial to a user, as it offers a convenient way to generate a large number of pseudonyms using relatively small storage requirements.

Living City 2013 Workshop

Living City 2013 Workshop, as part of a school term’s design-based curriculum connected to the KGSC/QUT Design Excellence Program and run from 11 February – 1 May, 2013, was essentially a three-day place-based urban design immersion workshop program for 25 Year 11 Visual Art and Design Students and 2 Teachers from Kelvin Grove State College (KGSC) held at both Queensland University of Technology (QUT) Gardens Point Campus and The Edge, State Library of Queensland. Mentored by 4 design professionals, 2 tertiary design academics, 2 public artists, and 12 QUT tertiary design students, the workshop explored youth-inspired public space design solutions for the active Brisbane City Council redevelopment site of Queens Wharf Road precinct. As well as the face-to-face workshops, for Living City 2013, an interactive web environment was introduced to enable students to connect with each other and program mentors throughout the course of the program. The workshop, framed within notions of ecological, economic, social and cultural sustainability, aimed to raise awareness of the layered complexity and perspectives involved in the design of shared city spaces and to encourage young people to voice their own concerns as future citizens about the shape and direction of their city. The program commenced with an introductory student briefing by stakeholders and mentors at KGSC on 11 February, an introduction to site appraisal and site visit held at QUT and Queens Wharf Road on 20 February, and a follow up site analysis session on 6 March. Day 1 Workshop on April 17 at the Edge, State Library of Queensland, as part of the Design Minds partnership (http://designminds.org.au/kelvin-grove-state-college-excellence-in-art-design/), focused on mentoring team development of a concept design for a range of selected sites. Two workshops on April 22 and 23 at QUT, to develop these designs and presentation schemes, followed this. The workshop program culminated in a visual presentation of concept design ideas and discussion with a public audience in the Ideas Gallery on The Deck, King George Square during the Brisbane City Council City Centre Master Plan Ideas Fiesta on 1 May, 2013, as referenced in the Ideas Fiesta Wrap-up Report (http://www.brisbane.qld.gov.au/planning-building/planning-guidelines-tools/city-centre-master-plan/city-centre-master-plan-ideas-fiesta). Students were introduced to design methodology, team thinking strategies, the scope of design practices and professions, presentation skills and post-secondary pathways, while participating teachers acquired content and design learning strategies transferable in many other contexts. The program was fully documented on the Living City website (http://www.livingcity.net.au/LC2013x/index.html) and has been recognised by the Brisbane City Council Youth Strategy 2014-2019 as a best practice model for making Brisbane a well-designed, subtropical city.

Certified pseudonyms colligated with master secret key

A pseudonym provides anonymity by protecting the identity of a legitimate user. A user with a pseudonym can interact with an unknown entity and be confident that his/her identity is secret even if the other entity is dishonest. In this work, we present a system that allows users to create pseudonyms from a trusted master public-secret key pair. The proposed system is based on the intractability of factoring and finding square roots of a quadratic residue modulo a composite number, where the composite number is a product of two large primes. Our proposal is different from previously published pseudonym systems, as in addition to standard notion of protecting privacy of an user, our system offers colligation between seemingly independent pseudonyms. This new property when combined with a trusted platform that stores a master secret key is extremely beneficial to an user as it offers a convenient way to generate a large number of pseudonyms using relatively small storage.

A simple method for EPID-based in vivo dosimetry for radiotherapy treatments of head-and-neck cancers

This study used a homogeneous water-equivalent model of an electronic portal imaging device (EPID), contoured as a structure in a radiotherapy treatment plan, to produce reference dose images for comparison with in vivo EPID dosimetry images. Head and neck treatments were chosen as the focus of this study, due to the heterogeneous anatomies involved and the consequent difficulty of rapidly obtaining reliable reference dose images by other means. A phantom approximating the size and heterogeneity of a typical neck, with a maximum radiological thickness of 8.5 cm, was constructed for use in this study. This phantom was CT scanned and a simple treatment including five square test fields and one off-axis IMRT field was planned. In order to allow the treatment planning system to calculate dose in a model EPID positioned a distance downstream from the phantom to achieve a source-to-detector distance (SDD) of 150 cm, the CT images were padded with air and the phantom’s “body” contour was extended to encompass the EPID contour. Comparison of dose images obtained from treatment planning calculations and experimental irradiations showed good agreement, with more than 90% of points in all fields passing a gamma evaluation, at γ (3%, 3mm )Similar agreement was achieved when the phantom was over-written with air in the treatment plan and removed from the experimental beam, suggesting that water EPID model at 150 cm SDD is capable of providing accurate reference images for comparison with clinical IMRT treatment images, for patient anatomies with radiological thicknesses ranging from 0 up to approximately 9 cm. This methodology therefore has the potential to be used for in vivo dosimetry during treatments to tissues in the neck as well as the oral and nasal cavities, in the head-and-neck region.