Marginal reversible jump Markov chain Monte Carlo with application to motor unit number estimation

Motor unit number estimation (MUNE) is a method which aims to provide a quantitative indicator of progression of diseases that lead to loss of motor units, such as motor neurone disease. However the development of a reliable, repeatable and fast real-time MUNE method has proved elusive hitherto. Ridall et al. (2007) implement a reversible jump Markov chain Monte Carlo (RJMCMC) algorithm to produce a posterior distribution for the number of motor units using a Bayesian hierarchical model that takes into account biological information about motor unit activation. However we find that the approach can be unreliable for some datasets since it can suffer from poor cross-dimensional mixing. Here we focus on improved inference by marginalising over latent variables to create the likelihood. In particular we explore how this can improve the RJMCMC mixing and investigate alternative approaches that utilise the likelihood (e.g. DIC (Spiegelhalter et al., 2002)). For this model the marginalisation is over latent variables which, for a larger number of motor units, is an intractable summation over all combinations of a set of latent binary variables whose joint sample space increases exponentially with the number of motor units. We provide a tractable and accurate approximation for this quantity and also investigate simulation approaches incorporated into RJMCMC using results of Andrieu and Roberts (2009).

Factor analysis of the Self Report Version of the Strengths and Difficulties Questionnaire in a sample of children with intellectual disability

The rate of emotional and behavioral disturbance in children with intellectual disability (ID) is up to four times higher than that of their typically developing peers. It is important to identify these difficulties in children with ID as early as possible to prevent the chronic co-morbidity of ID and psychopathology. Children with ID have traditionally been assessed via proxy reporting, but appropriate and psychometrically rigorous instruments are needed so that children can report on their own emotions and behaviors. In this study, the factor structure of the self-report version of the Strengths and Difficulties Questionnaire (SDQ) was examined in a population of 128 children with ID (mean age = 12 years). Exploratory and Confirmatory Factor Analysis showed a three factor model (comprising Positive Relationships, Negative Behavior and Emotional Competence) to be a better measure than the original five factor SDQ model in this population.

A general model for MAC generation using direct injection

This paper presents a model for generating a MAC tag by injecting the input message directly into the internal state of a nonlinear filter generator. This model generalises a similar model for unkeyed hash functions proposed by Nakano et al. We develop a matrix representation for the accumulation phase of our model and use it to analyse the security of the model against man-in-the-middle forgery attacks based on collisions in the final register contents. The results of this analysis show that some conclusions of Nakano et al regarding the security of their model are incorrect. We also use our results to comment on several recent MAC proposals which can be considered as instances of our model and specify choices of options within the model which should prevent the type of forgery discussed here. In particular, suitable initialisation of the register and active use of a secure nonlinear filter will prevent an attacker from finding a collision in the final register contents which could result in a forged MAC.

Development and review of vignettes representing older people with cognitive impairment

This paper describes a process undertaken to develop and review five clinical vignettes to be used in geriatric nursing educational research. The purpose of this process was to provide valid depictions of delirium and its subtypes and distinguish delirium from dementia. Five vignettes depicting hospital bedside interactions between nursing staff, family, and an older patient who displayed signs of one of the following conditions: delirium (hyper and hypo-active types respectively), dementia, or delirium (both types) superimposed on dementia were constructed. Vignette accuracy and reliability was established using a multistage process that culminated in formal review by a group of ten international nursing and medical delirium experts. The final five vignettes accurately depicted the given scenario as agreed by the experts and were at an appropriate level of simplicity and clarity. Given the increased interest in vignettes for both nursing research and educational purposes, the described method of vignette development and review has the ability to assist other vignette developers in creating reliable representations of their desired clinical scenarios.

Chlamydia pneumoniae : modern insights into an ancient pathogen

Chlamydia pneumoniae is an enigmatic human and animal pathogen. Originally discovered in association with acute human respiratory disease, it is now associated with a remarkably wide range of chronic diseases as well as having a cosmopolitan distribution within the animal kingdom. Molecular typing studies suggest that animal strains are ancestral to human strains and that C. pneumoniae crossed from animals to humans as the result of at least one relatively recent zoonotic event. Whole genome analyses appear to support this concept – the human strains are highly conserved whereas the single animal strain that has been fully sequenced has a larger genome with several notable differences. When compared to the other, better known chlamydial species that is implicated in human infection, Chlamydia trachomatis, C. pneumoniae demonstrates pertinent differences in its cell biology, development, and genome structure. Here, we examine the characteristic facets of C. pneumoniae biology, offering insights into the diversity and evolution of this silent and ancient pathogen.

Assignment of lease between lessees as joint tenants-is lessor’s consent required?

The decision of Lockrey v Historic Houses Trust of New South Wales [2012] NSWSC 654 raises an interesting issue about the necessity of seeking the consent of the lessor where there is an assignment of a lease between joint tenants who already hold the lease when one joint tenant sells the business operated on the leased premises to the other joint tenant. A secondary issue raised by the proceedings concerns whether the lessor’s consent was unreasonably withheld under the processes under Retail Leases Act 1994 (NSW) (“the Act”) upon the grounds of lack of provision of information as to the remaining lessee’s financial standing.

Book review : Olivier Corten, The Law Against War

Olivier Corten’s The Law Against War is a comprehensive, meticulously-researched study of contemporary international law governing the use of armed force in international relations. As a translated and updated version of a 2008 book published in French, it offers valuable insights into the positivist methodology that underpins much of the European scholarship of international law. Corten undertakes a rigorous analysis of state practice from 1945 onwards, with a view to clarifying the current meaning and scope of international law’s prohibition on the use of force. His central argument is that the majority of states remain attached to a strict interpretation of this rule. For Corten, state practice indicates that the doctrines of anticipatory self-defence, pre-emptive force and humanitarian intervention have no basis in contemporary international law. His overall position accords with a traditional, restrictive view of the circumstances in which states are permitted to use force...

Privacy-aware workflow management

Information security policies play an important role in achieving information security. Confidentiality, Integrity, and Availability are classic information security goals attained by enforcing appropriate security policies. Workflow Management Systems (WfMSs) also benefit from inclusion of these policies to maintain the security of business-critical data. However, in typical WfMSs these policies are designed to enforce the organisation’s security requirements but do not consider those of other stakeholders. Privacy is an important security requirement that concerns the subject of data held by an organisation. WfMSs often process sensitive data about individuals and institutions who demand that their data is properly protected, but WfMSs fail to recognise and enforce privacy policies. In this paper, we illustrate existing WfMS privacy weaknesses and introduce WfMS extensions required to enforce data privacy. We have implemented these extensions in the YAWL system and present a case scenario to demonstrate how it can enforce a subject’s privacy policy.

Tech-Savvy Youth and Participatory Research in “iScapes”

This chapter provides a theoretically and empirically grounded discussion of participatory research methodologies with respect to investigating the dynamic and evolving phenomenon of young people constructing identities and social relations in “iScapes”. We coin the term iScapes to refer to the online/offline interconnectedness of spaces in the fabric of everyday life. Specifically, we offer a critical analysis of the participatory research methods we used in our own research project to understand the ways in which high school students use new media and information communication technologies (ICTs) to construct identities, form social relations, and engage in creative practices as part of their everyday lives. The chapter concludes with reflexive deliberations on our approach to participatory research that may benefit other researchers who share a similar interest in youth and new media.

Mentoring pre-service teachers on school students’ differentiated learning

This Australian study explores the mentoring of pre-service teachers in selecting and implementing teaching strategies to meet students‟ learning needs. Two case studies involving 28 mentor teachers in a professional development program and a mentor-mentee partnership during a four week practicum provided data about mentoring teaching strategies for differentiated learning. Findings showed that contexts for learning about differentiation occurred at the pre action, in-action, and post-action stages. Central to each stage were pedagogical knowledge practices such as planning, preparation, classroom management, assessment, and problem solving (reflection-in-action to present solutions to problems) as key to in-action strategising and the mentoring processes. Mentoring pre-service teachers on how to devise teaching strategies for differentiated learning needs to be researched with a wider range of mentors and pre-service teachers, including those at different stages of development.

Fast scanning electron microscope (FSEM)

High magnification and large depth of field with a temporal resolution of less than 100 microseconds are possible using the present invention which combines a linear electron beam produced by a tungsten filament from an SX-40A Scanning Electron Microscope (SEM), a magnetic deflection coil with lower inductance resulting from reducing the number of turns of the saddle-coil wires, while increasing the diameter of the wires, a fast scintillator, photomultiplier tube, photomultiplier tube base, and signal amplifiers and a high speed data acquisition system which allows for a scan rate of 381 frames per second and 256.times.128 pixel density in the SEM image at a data acquisition rate of 25 MHz. The data acquisition and scan position are fully coordinated. A digitizer and a digital waveform generator which generates the sweep signals to the scan coils run off the same clock to acquire the signal in real-time.

Preparation of porous nanofibers from electrospun polyacrylonitrile/calcium carbonate composite nanofibers using porogen leaching technique

Production of nanofibrous polyacrylonitrile/calcium carbonate (PAN/CaCO3) nanocomposite web was carried out through solution electrospinning process. Pore generating nanoparticles were leached from the PAN matrices in hydrochloric acid bath with the purpose of producing an ultimate nanoporous structure. The possible interaction between CaCO3 nanoparticles and PAN functional groups was investigated. Atomic absorption method was used to measure the amount of extracted CaCO3 nanoparticles. Morphological observation showed nanofibers of 270–720 nm in diameter containing nanopores of 50–130 nm. Monitoring the governing parameters statistically, it was found that the amount of extraction (ε) of CaCO3was increased when the web surface area (a) was broadened according to a simple scaling law (ε = 3.18 a0.4). The leaching process was maximized in the presence of 5% v/v of acid in the extraction bath and 5 wt % of CaCO3 in the polymer solution. Collateral effects of the extraction time and temperature showed exponential growth within a favorable extremum at 50°C for 72 h. Concentration of dimethylformamide as the solvent had no significant impact on the extraction level.

Birds : indicators of environmental repair in oil affected coastlines

Bird coastal communities were studied along Bribie Island and Moreton Island, two islands within Moreton Bay, Brisbane, Queensland, Australia, using the point counts method. A total of 128 five-hundred metre radius area surveys and 81 beach drive surveys were conducted and observations made over four seasons. Bird species were identified, counted and recorded. The data was compared between the two islands and, between sites on each island as oil-spill affected sites to non-oil spill affected sites. Species such as waders, shorebirds, terns/gulls and raptors were identified as species at most risk from an oil spill and the data was selected to look mainly at these species. The data indicated that sites affected by the oil spill contained 50% less oil-affected species than sites not affected by the oil spill. Bribie Island held on average 5 species per site in the oil affected sites compared to 12 species in non-oil affected sites. This same trend was observed on Moreton Island which held 6 species compared to 14 species. Bird data will continue to be counted over several years to determine whether the observed data is a true reflection of the affects of an oil spill on the habitat of shorebirds.