The effect of high voltage, high frequency pulsed electric field on slain ovine cortical bone

High power, high frequency pulsed electric fields known as pulsed power (PP) has been applied recently in biology and medicine. However, little attention has been paid to investigate the application of pulse power in musculoskeletal system and its possible effect on functional behavior and biomechanical properties of bone tissue. This paper presents the first research investigating whether or not PP can be applied safely on bone tissue as a stimuli and what will be the possible effect of these signals on the characteristics of cortical bone by comparing the mechanical properties of this type of bone pre and post expose to PP and in comparison with the control samples. A positive buck‑boost converter was applied to generate adjustable high voltage, high frequency pulses (up to 500 V and 10 kHz). The functional behavior of bone in response to pulse power excitation was elucidated by applying compressive loading until failure. The stiffness, failure stress (strength) and the total fracture energy (bone toughness) were determined as a measure of the main bone characteristics. Furthermore, an ultrasonic technique was applied to determine and comprise bone elasticity before and after pulse power stimulation. The elastic property of cortical bone samples appeared to remain unchanged following exposure to pulse power excitation for all three orthogonal directions obtained from ultrasonic technique and similarly from the compression test. Nevertheless, the compressive strength and toughness of bone samples were increased when they were exposed to 66 h of high power pulsed electromagnetic field compared to the control samples. As the toughness and the strength of the cortical bone tissue are directly associated with the quality and integrity of the collagen matrix whereas its stiffness is primarily related to bone mineral content these overall results may address that although, the pulse power stimulation can influence the arrangement or the quality of the collagen network causing the bone strength and toughness augmentation, it apparently did not affect the mineral phase of the cortical bone material. The results also confirmed that the indirect application of high power pulsed electric field at 500 V and 10 kHz through capacitive coupling method was safe and did not destroy the bone tissue construction.

Metabolic dysfunction and laminitis

Objective: This review focuses on laminitis that develops as a result of metabolic dysfunction and aims to provide a concise assessment of the current state of knowledge on this form of the disease. Outline: The most prevalent form of laminitis is associated with metabolic or endocrinopathic diseases, such as Equine Metabolic Syndrome and pituitary pars intermedia dysfunction, and the feeding of high-energy diets, particularly those rich in non-structural carbohydrates. Insulin dysregulation is the key hormonal imbalance implicated in causing this form of laminitis and hyperinsulinaemia is an important risk factor for the disease. Hyperinsulinaemia can occur in association with insulin resistance, obesity, regionalised adiposity, dysregulated cortisol metabolism and may also be related to other factors, such as breed and genetic predisposition. Recognition of hyperinsulinaemia is best achieved by using a dynamic oral glucose test that can be performed relatively easily under field conditions. Insulin produces a unique pathological lesion in the lamellae and the features of this lesion have informed investigations on the pathogenesis of the disease. Research into the mechanism of disease is continuing so that more targeted therapies than are currently available can be developed. However, dietary restriction and exercise remain effective management strategies for metabolic disease. Conclusions: Although the pathogenic mechanism/s of metabolic and endocrinopathic forms of laminitis remain the subject of intense research, ample data on risk factors for the disease are available. Efforts focussed on preventing the disease should aim to identify metabolic disease and reduce obesity and insulin resistance in at-risk individuals.

Light of Extinction

Light of Extinction presents a diverse series of views into the complex antics of a semi-autonomous gaggle of robotic actants. Audiences initially enter into the 'backend' of the experience to be rudely confronted with the raw, messy operations of a horde of object-manipulating robotic forms. Seen through viewing apertures these ‘things’ deny any opportunity to grasp their imagined order. Audiences then flow on into the 'front end' of the work where now, seen through another aperture, the very same forms seemingly coordinate a stunning deep-field choreography, floating lusciously within inky landscapes of media, noise and embodied sound. As one series of conceptions slip into extinction, so others flow on in. The idea of the 'extinction of human experience' expresses a projected fear for that which will disappear when biodiverse worlds have descended into an era of permanent darkness. ‘Light Of Extinction' re-positions this anthropomorphic lament in order to suggest a more rounded acknowledgement of what might still remain - suggesting the previously unacknowledged power and place of autonomous, synthetic creation. Momentary disbelief gives way to a relieving celebration of the imagined birth of ‘things’ – without need for staples such as conventional light or the harmonious lullabies of long-extinguished sounds.

Computational aspects of probabilistic assessment of UAS robust autonomy

As the level of autonomy in Unmanned Aircraft Systems (UAS) increases, there is an imperative need for developing methods to assess robust autonomy. This paper focuses on the computations that lead to a set of measures of robust autonomy. These measures are the probabilities that selected performance indices related to the mission requirements and airframe capabilities remain within regions of acceptable performance.

Lumbar epidural steroids are not cost effective in sciatica

Background Lumbar Epidural Steroids Injections (ESI’s) have previously been shown to provide some degree of pain relief in sciatica. Number Needed To Treat (NNT) to achieve 50% pain relief has been estimated at 7 from the results of randomised controlled trials. Pain relief is temporary. They remain one of the most commonly provided procedures in the UK. It is unknown whether this pain relief represents good value for money. Methods 228 patients were randomised into a multi-centre Double Blind Randomised Controlled Trial. Subjects received up to 3 ESI’s or intra-spinous saline depending on response and fall off with the first injection. All other treatments were permitted. All received a review of analgesia, education and physical therapy. Quality of life was assessed using the SF36 at 6 points and compared using independent sample t-tests. Follow up was up to 1 yr. Missing data was imputed using last observation carried forward (LOCF). QALY’s (Quality of Life Years) were derived from preference based heath values (summary health utility score). SF-6D health state classification was derived from SF-36 raw score data. Standard gambles (SG) were calculated using Model 10. SG scores were calculated on trial results. LOCF was not used for this. Instead average SG were derived for a subset of patients with observations for all visits up to week 12. Incremental QALY’s were derived as the difference in the area between the SG curve for the active group and placebo group. Results SF36 domains showed a significant improvement in pain at week 3 but this was not sustained (mean 54 Active vs 61 Placebo P<0.05). Other domains did not show any significant gains compared with placebo. For derivation of SG the number in the sample in each period differed. In week 12, average SG scores for active and placebo converged. In other words, the health gain for the active group as measured by SG was achieved by the placebo group by week 12. The incremental QALY gained for a patient under the trial protocol compared with the standard care package was 0.0059350. This is equivalent to an additional 2.2 days of full health. The cost per QALY gained to the provider from a patient management strategy administering one epidural as suggested by results was £25 745.68. This result was derived assuming that the gain in QALY data calculated for patients under the trial protocol would approximate that under a patient management strategy based on the trial results (one ESI). This is above the threshold suggested by some as a cost effective treatment. Conclusions The transient benefit in pain relief afforded by ESI’s does not appear to be cost-effective. Further work is needed to develop more cost-effective conservative treatments for sciatica.

The younger audience : children and broadcasting in New Zealand

The role and influence of media in the The lives of children are ongoing sources of public, political and academic debates. These debates move back and forth along a care-control continuum (Cohen, 1997), and reflect a commitment both to educate children and to regulate their media experiences. Rapid advancements in computer technologies have vastly expanded the range of media experiences available to children. The development of Internet information and the rapid expansion of channels as a result of digital television have created increasingly accessible and diverse sources of media for children. These media are instantaneous and, in some circumstances, constantly available. As a result, a substantial body of international research has emerged that examines the influence of media consumption on children. How much time do children spend interacting with media? What sorts of media do they access? Are media harmful or beneficial to children? If so, in which contexts? Do media influence children’s personal development? And what role should governments, broadcasters and independent producers play in the regulation of the media? These questions remain central to contemporary debates about children and the media. This paper examines current patterns of television and radio consumption by New Zealand children in the context of household and peer environments. It explores parental attitudes towards and responsibilities for the protection of children in relation to broadcast media. The paper also aims to provide children with a voice by exploring their views about media content, and how they feel about the controls and regulations currently placed on their media consumption. Children do not constitute a unitary social category. They comprise a disparate group with diverse cultures and styles that must be examined from within. Rather than treating and studying children as inferior and underdeveloped beings, it is important to identify children as individual social actors (Smith, Taylor & Gollop, 2000). Children are often viewed as passive, invisible and irrational. However, a growing body of scholarship recognises that children are a heterogeneous group with valid and meaningful life experiences that must be accessed and analysed within specific cultural contexts (Burman, 1994; Atwool, 2000). In order to understand the media consumption habits of children and to explore issues of regulatory responsibility, it was essential to access children and their families. To this end, and within a New Zealand context, this paper enters relatively uncharted waters. To date, there are no other comprehensive New Zealand-based research projects that specifically identify the attitudes and behaviours of children in relation to broadcast media, and broadcasting standards.

Mammographic density-a review on the current understanding of its association with breast cancer

There has been considerable recent interest in the genetic, biological and epidemiological basis of mammographic density (MD), and the search for causative links between MD and breast cancer (BC) risk. This report will critically review the current literature on MD and summarize the current evidence for its association with BC. Keywords 'mammographic dens*', 'dense mammary tissue' or 'percent dens*' were used to search the existing literature in English on PubMed and Medline. All reports were critically analyzed. The data were assigned to one of the following aspects of MD: general association with BC, its relationship with the breast hormonal milieu, the cellular basis of MD, the generic variations of MD, and its significance in the clinical setting. MD adjusted for age, and BMI is associated with increased risk of BC diagnosis, advanced tumour stage at diagnosis and increased risk of both local recurrence and second primary cancers. The MD measures that predict BC risk have high heritability, and to date several genetic markers associated with BC risk have been found to also be associated with these MD risk predictors. Change in MD could be a predictor of the extent of chemoprevention with tamoxifen. Although the biological and genetic pathways that determine and perhaps modulate MD remain largely unresolved, significant inroads are being made into the understanding of MD, which may lead to benefits in clinical screening, assessment and treatment strategies. This review provides a timely update on the current understanding of MD's association with BC risk.

Accelerometer data reduction : a comparison of four reduction algorithms on select outcome variables

Purpose Accelerometers are recognized as a valid and objective tool to assess free-living physical activity. Despite the widespread use of accelerometers, there is no standardized way to process and summarize data from them, which limits our ability to compare results across studies. This paper a) reviews decision rules researchers have used in the past, b) compares the impact of using different decision rules on a common data set, and c) identifies issues to consider for accelerometer data reduction. Methods The methods sections of studies published in 2003 and 2004 were reviewed to determine what decision rules previous researchers have used to identify wearing period, minimal wear requirement for a valid day, spurious data, number of days used to calculate the outcome variables, and extract bouts of moderate to vigorous physical activity (MVPA). For this study, four data reduction algorithms that employ different decision rules were used to analyze the same data set. Results The review showed that among studies that reported their decision rules, much variability was observed. Overall, the analyses suggested that using different algorithms impacted several important outcome variables. The most stringent algorithm yielded significantly lower wearing time, the lowest activity counts per minute and counts per day, and fewer minutes of MVPA per day. An exploratory sensitivity analysis revealed that the most stringent inclusion criterion had an impact on sample size and wearing time, which in turn affected many outcome variables. Conclusions These findings suggest that the decision rules employed to process accelerometer data have a significant impact on important outcome variables. Until guidelines are developed, it will remain difficult to compare findings across studies

Effect of vertical misalignment of adjacent sleepers on the increase in dynamic loads around rail joints

In spite of the extensive usage of continuous welded rails, a number of rail joints still exist in the track. Although a number of them exist as part of turnouts in the yards where the speed is not of concern, the Insultated Rail Joints (IRJs) that exist in ballasted tracks remain a source of significant impact loading. A portion of the dynamic load generated at the rail joints due to wheel passage is transmitted to the support system which leads to permanent settlements of the ballast layer with subsequent vertical misalignment of the sleepers around the rail joints. The vertical misalignment of the adjacent sleepers forms a source of high frequency dynamic load raisers causing significant maintenance work including localised grinding of railhead around the joint, re-alignment of the sleepers and/or ballast tamping or track component renewals/repairs. These localised maintenance activities often require manual inspections and disruptions to the train traffic loading to significant costs to the rail industry. Whilst a number of studies have modelled the effect of joints as dips, none have specifically attended to the effect of vertical misalignment of the sleepers on the dynamic response of rail joints. This paper presents a coupled finite element track model and rigid body track-vehicle interaction model through which the effects of vertical of sleepers on the increase in dynamic loads around the IRJ are studied. The finite element track model is employed to determine the generated dip from elastic deformations as well as the vertical displacement of sleepers around the joint. These data (dip and vertical misalignments) are then imported into the rigid body vehicle-track interaction model to calculate the dynamic loads.

Design-led innovation : Overcoming challenges to designing competitiveness to succeed in high cost environments

This chapter focuses on demonstrating the role of Design-Led Innovation (DLI) as an enabler for the success of Small to Medium Enterprises (SMEs) within high growth environments. This chapter is targeted toward businesses that may have been exposed to the concept of design previously at a product level and now seek to better understand its value through implementation at a strategic level offering. The decision to engage in the DLI process is made by firms who want to remain competitive as they struggle to compete in high cost environments, such as the state of the Australian economy at present. The results presented in this chapter outline the challenges in the adoption of the DLI process and the implications it can have. An understanding of the value of DLI in practice—as an enabler of business transformation in Australia—is of benefit to government and the broader design community.

Trait and behavioural motor control is associated with resistance to overconsumption

While overall obesity rates are rising, a minority of individuals appear to resist overconsumption and remain lean in spite of an ‘obesogenic’ environment. Studying the factors hypothesised to underpin behaviours associated with resistance to overconsumption may inform weight management strategies in an adverse environment. Trait (BIS-11) and behavioural (response inhibition, GoStop) self control were assessed in the laboratory. Snack food consumption was measured covertly via a sham taste test. Lack of motor control was positively correlated (r = .32, p <. 05) and successful response inhibition was negatively correlated (r = −.35, p <. 05) with snack food intake. Low motor control was also associated with further food intake when satiated (r = .39, p < .01). These relationships were independent of self-reported palatability and perceived reward value of the food. Motor control may be an important factor implicated in ‘mindless’ eating in an environment abundant in palatable, energy-dense snack foods.

Hormonal carcinogenesis in breast cancer : cellular and molecular studies of malignant progression

We have established and characterized a series of variant cell lines in which to identify the critical factors associated with E2-induced malignant progression, and the acquisition to tamoxifen resistance in human breast cancer. Sublines of the hormone-dependent MCF-7 cell line (MCF7/MIII and MCF7/LCC1) form stable, invasive, estrogen independent tumors in the mammary fat pads of ovariectomized athymic nude mice. These cells retain expression of both estrogen (ER) and progesterone receptors (PGR), but retain sensitivity to each of the major structural classes of antiestrogens. The tamoxifen-resistant MCF7/LCC2 cells retain sensitivity to the inhibitory effects of the steroidal antiestrogen ICI 182780. By comparing the parental hormone-dependent and variant hormone-independent cells, we have demonstrated an altered expression of some estrogen regulated genes (PGR, pS2, cathepsin D) in the hormone-independent variants. Other genes remain normally estrogen regulated (ER, laminin receptor, EGF-receptor). These data strongly implicate the altered regulation of a specific subset or network of estrogen regulated genes in the malignant progression of human breast cancer. Some of the primary response genes in this network may exhibit dose-response and induction kinetics similar to pS2, which is constitutively upregulated in the MCF7/MIII, MCF7/LCC1 and MCF7/LCC2 cells.

An approach for extending Building Information Models (BIM) to specifications

The Construction industry accounts for a tenth of global GDP. Still, challenges such as slow adoption of new work processes, islands of information, and legal disputes, remain frequent, industry-wide occurrences despite various attempts to address them. In response, IT-based approaches have been adopted to explore collaborative ways of executing construction projects. Building Information Modelling (BIM) is an exemplar of integrative technologies whose 3D-visualisation capabilities have fostered collaboration especially between clients and design teams. Yet, the ways in which specification documents are created and used in capturing clients' expectations based on industry standards have remained largely unchanged since the 18th century. As a result, specification-related errors are still common place in an industry where vast amounts of information are consumed as well as produced in the course project implementation in the built environment. By implication, processes such as cost planning which depend on specification-related information remain largely inaccurate even with the use of BIM-based technologies. This paper briefly distinguishes between non-BIM-based and BIM-based specifications and reports on-going efforts geared towards the latter. We review exemplars aimed at extending Building Information Models to specification information embedded within the objects in a product library and explore a viable way of reasoning about a semi-automated process of specification using our product library.

Autonomy in technology design

Issues of autonomy impact motivation, the user experience and even psychological wellbeing, yet many questions surrounding design for autonomy remain unanswered. This workshop will explore theory, issues and design strategies related to autonomy drawing on theoretical frameworks available in psychology and looking at autonomy from multiple levels. These include user autonomy within the context of software environments, technologies that increase autonomy in daily life, and how technologies might foster autonomy as a component of psychological development.

The biology of breast tumor progression : acquisition of hormone independence and resistance to cytotoxic drugs

Many breast tumors appear to follow a predictable clinical pattern, being initially responsive to endocrine therapy and to cytotoxic chemotherapy but ultimately exhibiting a phenotype resistant to both modalities. Using the MCF-7 human breast cancer cell line as an example of an 'early' phenotype (estrogen and progesterone receptor positive, steroid responsive, low metastatic potential), we have isolated and characterized a series of hormone-independent but hormone-responsive variants (MIII and MCF7/LCC1). However, these variants remain responsive to both antiestrogens and cytotoxic drugs (methotrexate and colchicine). MIII and MCF7/LCCl cells appear to mimic some of the critical aspects of the early progression to a more aggressive phenotype. An examination of the phenotype of these cells suggests that some hormone-independent breast cancer cells are derived from hormone-dependent parental cells. The development of a hormone-independent phenotype can arise independently of acquisition of a cytotoxic drug resistant phenotype.