The effect of repeated loading and freeze-thaw cycling on immature bovine thoracic motion segment stiffness

There is growing interest in the biomechanics of ‘fusionless’ implant constructs used for deformity correction in the thoracic spine, however, there are questions over the comparability of in vitro biomechanical studies from different research groups due to the various methods used for specimen preparation, testing and data collection. The aim of this study was to identify the effect of two key factors on the stiffness of immature bovine thoracic spine motion segments: (i) repeated cyclic loading and (ii) multiple freeze-thaw cycles, to aid in the planning and interpretation of in vitro studies. Two groups of thoracic spine motion segments from 6-8 week old calves were tested in flexion/extension, right/left lateral bending, and right/left axial rotation under moment control. Group (A) were tested with continuous repeated cyclic loading for 500 cycles with data recorded at cycles 3, 5, 10, 25, 50, 100, 200, 300, 400 and 500. Group (B) were tested after each of five freeze-thaw sequences, with data collected from the 10th load cycle in each sequence. Group A: Flexion/extension stiffness reduced significantly over the 500 load cycles (-22%; P=0.001), but there was no significant change between the 5th and 200th load cycles. Lateral bending stiffness decreased significantly (-18%; P=0.009) over the 500 load cycles, but there was no significant change in axial rotation stiffness (P=0.137). Group B: There was no significant difference between mean stiffness over the five freeze-thaw sequences in flexion/extension (P=0.813) and a near significant reduction in mean stiffness in axial rotation (-6%; P=0.07). However, there was a statistically significant increase in stiffness in lateral bending (+30%; P=0.007). Comparison of in vitro testing results for immature thoracic bovine spine segments between studies can be performed with up to 200 load cycles without significant changes in stiffness. However, when testing protocols require greater than 200 cycles, or when repeated freeze-thaw cycles are involved, it is important to account for the effect of cumulative load and freeze-thaw cycles on spine segment stiffness.

Left vs right in black and white : a review

LIKE much of the work that David Williamson is known for, Let the Sunshine concentrates on tensions between characters who operate mainly as mouthpieces for opposing ideologies. Left-wing documentary-maker Toby and his wife Ros have moved to Noosa to escape the rat race in Sydney and some bad press surrounding one of Toby's projects. Trying to make social connections in town, Ros has reconnected with high school classmate Natasha, now the cosmetically-enhanced wife of wealthy right-wing property developer Ron. The posturing and conflict between Toby and Ron come to a head when the women invite their grown children -- struggling songwriter Rick and stressed corporate lawyer Emma -- to dinner to celebrate Toby's birthday, and the results of this encounter drive the rest of the plot. The scenario of Let the Sunshine is contrived, the characters are stereotyped, and their conflicts are little more than an old clash of ideologies cast loosely across the mainstream news media's characterisation of the sides in debates about development, climate change and the economic crisis.

Evaluation of coronary angiographic projections to balance the clinical yield with the radiation risk

Objective: Radiation safety principles dictate that imaging procedures should minimise the radiation risks involved, without compromising diagnostic performance. This study aims to define a core set of views that maximises clinical information yield for minimum radiation risk. Angiographers would supplement these views as clinically indicated. Methods: An algorithm was developed to combine published data detailing the quality of information derived for the major coronary artery segments through the use of a common set of views in angiography with data relating to the dose–area product and scatter radiation associated with these views. Results: The optimum view set for the left coronary system comprised four views: left anterior oblique (LAO) with cranial (Cr) tilt, shallow right anterior oblique (AP-RAO) with caudal (Ca) tilt, RAO with Ca tilt and AP-RAO with Cr tilt. For the right coronary system three views were identified: LAO with Cr tilt, RAO and AP-RAO with Cr tilt. An alternative left coronary view set including a left lateral achieved minimally superior efficiency (,5%), but with an ,8% higher radiation dose to the patient and 40% higher cardiologist dose. Conclusion: This algorithm identifies a core set of angiographic views that optimises the information yield and minimises radiation risk. This basic data set would be supplemented by additional clinically determined views selected by the angiographer for each case. The decision to use additional views for diagnostic angiography and interventions would be assisted by referencing a table of relative radiation doses for the views being considered.

Detection of right-to-left Atrial communication using agitated saline contrast imaging : experience with 1162 patients and recommendations for echocardiography

Background: Right-to-left shunting via a patent foramen ovale (PFO) has a recognized association with embolic events in younger patients. The use of agitated saline contrast imaging (ASCi) for detecting atrial shunting is well documented, however optimal technique is not well described. The purpose of this study is to assess the efficacy and safety of ASCi via TTE for assessment of right-to-left atrial communication in a large cohort of patients. Method: A retrospective review was undertaken of 1162 consecutive transthoracic (TTE) ASCi studies, of which 195 had also undergone clinically indicated transesophageal (TEE) echo. ASCi shunt results were compared with color flow imaging (CFI) and the role of provocative maneuvers (PM) assessed. Results: 403 TTE studies (35%) had paradoxical shunting seen during ASCi. Of these, 48% were positive with PM only. There was strong agreement between TTE ASCi and reported TEE findings (99% sensitivity, 85% specificity), with six false positive and two false negative results. In hindsight, the latter were likely due to suboptimal right atrial opacification, and the former due to transpulmonary shunting. TTE CFI was found to be insensitive (22%) for the detection of a PFO compared with TTE ASCi. Conclusions: TTE ASCi is minimally invasive and highly accurate for the detection of right-to-left atrial communication when PM are used. TTE CFI was found to be insensitive for PFO screening. It is recommended that TTE ASCi should be considered the initial diagnostic tool for the detection of PFO in clinical practice. A dedicated protocol should be followed to ensure adequate agitated saline contrast delivery and performance of provocative maneuvers.

Do left and right asymmetries of hemispheric preference interact with attention to predict local and global performance in applied tasks?

Many cognitive neuroscience studies show that the ability to attend to and identify global or local information is lateralised between the two hemispheres in the human brain; the left hemisphere is biased towards the local level, whereas the right hemisphere is biased towards the global level. Results of two studies show attention-focused people with a right ear preference (biased towards the left hemisphere) are better at local tasks, whereas people with a left ear preference (biased towards the right hemisphere) are better at more global tasks. In a third study we determined if right hemisphere-biased followers who attend to global stimuli are likely to have a stronger relationship between attention and globally based supervisor ratings of performance. Results provide evidence in support of this hypothesis. Our research supports our model and suggests that the interaction between attention and lateral preference is an important and novel predictor of work-related outcomes.

Disentangling the cognitive components supporting Austin Maze performance in left versus right temporal lobe epilepsy

Neuropsychological tests requiring patients to find a path through a maze can be used to assess visuospatial memory performance in temporal lobe pathology, particularly in the hippocampus. Alternatively, they have been used as a task sensitive to executive function in patients with frontal lobe damage. We measured performance on the Austin Maze in patients with unilateral left and right temporal lobe epilepsy (TLE), with and without hippocampal sclerosis, compared to healthy controls. Performance was correlated with a number of other neuropsychological tests to identify the cognitive components that may be associated with poor Austin Maze performance. Patients with right TLE were significantly impaired on the Austin Maze task relative to patients with left TLE and controls, and error scores correlated with their performance on the Block Design task. The performance of patients with left TLE was also impaired relative to controls; however, errors correlated with performance on tests of executive function and delayed recall. The presence of hippocampal sclerosis did not have an impact on maze performance. A discriminant function analysis indicated that the Austin Maze alone correctly classified 73.5% of patients as having right TLE. In summary, impaired performance on the Austin Maze task is more suggestive of right than left TLE; however, impaired performance on this visuospatial task does not necessarily involve the hippocampus. The relationship of the Austin Maze task with other neuropsychological tests suggests that differential cognitive components may underlie performance decrements in right versus left TLE.

Submission: Towards a Stronger and More Efficient IP Rights System : Getting the Balance Right

1. In March 2009, the Australian Government, through IP Australia its administrator of Intellectual Property Rights (IPR) acquired by registration or grant, issued two consultation papers for comment by interested stakeholders. 2. The Consultation Papers have invited written submissions directed towards the object of the paper, namely encouraging discussion on certain proposed changes and their impact on business and innovation. 3. I understand the invitation to make written submissions is predominantly in the areas raised by the Consultation Papers and the questions posed. However, I have made a brief reference to several other areas of concern with the current Australian patent law, which in my opinion inhibit innovation and therefore come under the wider agenda of the government to work toward a stronger and more efficient IP rights system. 4. In this regard, the Consultation Papers indicate that if the IPR are less likely to be invalidated and more likely to be enforced, this confidence will reflect in a greater investment in research leading to innovation. 5. This submission relates to the Balance Paper.

Left versus right hemisphere differences in brain connectivity: 4-Tesla HARDI tractography in 569 twins

Diffusion imaging can map anatomical connectivity in the living brain, offering new insights into fundamental questions such as how the left and right brain hemispheres differ. Anatomical brain asymmetries are related to speech and language abilities, but less is known about left/right hemisphere differences in brain wiring. To assess this, we scanned 457 young adults (age 23.4±2.0 SD years) and 112 adolescents (age 12-16) with 4-Tesla 105-gradient high-angular resolution diffusion imaging. We extracted fiber tracts throughout the brain with a Hough transform method. A 70×70 connectivity matrix was created, for each subject, based on the proportion of fibers intersecting 70 cortical regions. We identified significant differences in the proportions of fibers intersecting left and right hemisphere cortical regions. The degree of asymmetry in the connectivity matrices varied with age, as did the asymmetry in network topology measures such as the small-world effect.

The Aboriginal voice and the left-leaning 'Australia' (Baz Luhrmann, 2008)

Arguing that Baz Luhrmann's "Australia" (2008) is a big-budget, non-independent film espousing a left-leaning political ideology in its non-racist representations of Aborigines on film, this paper suggests the addition of a 'fourth formation' to the 1984 Moore and Muecke model is warranted. According to their theorising, racist "first formation" films promote policies of assimilation whereas "second formation" films avoid overt political statements in favour of more acceptable multicultural liberalism. Moore and Muecke's seemingly ultimate "third formation films", however, blatantly foreground the director's leftist political dogma in a necessarily low budget, independent production. "Australia", on the other hand, is an advance on the third formation because its feminised Aboriginal voice is safely backed by a colossal production budget and indicates a transformation in public perceptions of Aboriginal issues. Furthermore, this paper argues that the use of low-cost post-production techniques such as voice-over narration by racially appropriate individuals and the use of diegetic song in Australia work to ensure the positive reception of the left-leaning message regarding the Stolen Generations. With these devices Luhrmann effectively counters the claims of right-wing denialists such as Andrew Bolt and Keith Windschuttle.

Friedman Economic Policies, Social Exclusion and Crime: Toward a Gendered Left Realist Subcultural Theory.

Left realists contend that people lacking legitimate means of solving the problem of relative deprivation may come into contact with other frustrated disenfranchised people and form subcultures, which in turn, encourage criminal behaviors. Absent from this theory is an attempt to address how, today, subcultural development in North America and elsewhere is heavily shaped simultaneously by the recent destructive consequences of right-wing Friedman or Chicago School economic policies and marginalized men's attempts to live up to the principles of hegemonic masculinity. The purpose of this paper, then, is to offer a new left realist theory that emphasizes the contribution of these two key determinants.

The right to choose an assisted death : time for legislation?

The legal framework that operates at the end of life in Australia needs to be reformed. • Voluntary euthanasia and assisted suicide are currently unlawful. • Both activities nevertheless occur not infrequently in Australia, in part because palliative care cannot relieve physical and psychological pain and suffering in all cases. • In this respect, the law is deficient. The law is also unfair because it doesn’t treat people equally. Some people can be helped to die on their own terms as a result of their knowledge and/or connections while some are able to hasten their death by the refusal of life-sustaining treatment. But others do not have access to the means for their life to end. • A very substantial majority of Australians have repeatedly expressed in public opinion polls their desire for law reform on these matters. Many are concerned at what they see is happening to their loved ones as they reach the end of their lives, and want the confidence that when their time comes they will be able to exercise choice in relation to assisted dying. • The most consistent reason advanced not to change the law is the need to protect the vulnerable. There is a concern that if the law allows voluntary euthanasia and assisted suicide for some people, it will be expanded and abused, including pressures being placed on highly dependent people and those with disabilities to agree to euthanasia. • But there is now a large body of experience in a number of international jurisdictions following the legalisation of voluntary euthanasia and/or assisted suicide. This shows that appropriate safeguards can be implemented to protect vulnerable people and prevent the abuse that opponents of assisted dying have feared. It reveals that assisted dying meets a real need among a small minority of people at the end of their lives. It also provides reassurance to people with terminal and incurable disease that they will not be left to suffer the indignities and discomfort of a nasty death. • Australia is an increasingly secular society. Strong opposition to assisted death by religious groups that is based on their belief in divine sanctity of all human life is not a justification for denying choice for those who do not share that belief. • It is now time for Australian legislators to respond to this concern and this experience by legislating to enhance the quality of death for those Australians who seek assisted dying.

Evaluation of inflow cannulation site for implantation of right-sided rotary ventricular assist device

Right heart dysfunction is one of the most serious complications following implantation of a left ventricular assist device (LVAD), often leading to the requirement for short or long term right ventricular support (RVAD). The inflow cannulation site induces major haemodynamic changes and so there is a need to optimize the site used depending on the patient's condition. Therefore, this study evaluated and compared the haemodynamic influence of right atrial (RAC) and right ventricular (RVC) inflow cannulation sites. An in-vitro, variable heart failure, mock circulation loop was used to compare RAC and RVC in mild and severe biventricular heart failure (BHF) conditions. In the severe BHF condition, higher ventricular ejection fraction (RAC: 13.6%, RVC: 32.7%) and thus improved heart chamber and RVAD washout was observed with RVC, which suggested this strategy might be preferable for long term support (ie. bridge to transplant or destination therapy) to reduce the risk of thrombus formation. In the mild BHF condition, higher pulmonary valve flow (RAC: 3.33 L/min, RVC: 1.97 L/min) and lower right ventricular stroke work (RAC: 0.10 W, RVC: 0.13 W) and volumes were recorded with RAC. These results indicate an improved potential for myocardial recovery, thus RAC should be chosen in this condition. This in-vitro study suggests that RVAD inflow cannulation site should be chosen on a patient-specific basis with a view to the support strategy to promote myocardial recovery or reduce the risk of long-term complications.

Getting the right words right

Oscar Wilde once complained that having spent an entire morning putting a comma into one of his poems, he spent the afternoon removing it. Peter Selgin calls this revisionitis: the inability of a writer to part with their work, the compulsion to go on fiddling and picking until there is nothing left to fret about. There can be real danger, Selgin warns, in fussing with things. The question then of how much to revise or how little to rewrite is one without certain answer and writers themselves hold differing views...

Parameterization and reliability of single-leg balance test assessed with inertial sensors in stroke survivors: a cross-sectional study

Background and purpose There are no published studies on the parameterisation and reliability of the single-leg stance (SLS) test with inertial sensors in stroke patients. Purpose: to analyse the reliability (intra-observer/inter-observer) and sensitivity of inertial sensors used for the SLS test in stroke patients. Secondary objective: to compare the records of the two inertial sensors (trunk and lumbar) to detect any significant differences in the kinematic data obtained in the SLS test. Methods Design: cross-sectional study. While performing the SLS test, two inertial sensors were placed at lumbar (L5-S1) and trunk regions (T7–T8). Setting: Laboratory of Biomechanics (Health Science Faculty - University of Málaga). Participants: Four chronic stroke survivors (over 65 yrs old). Measurement: displacement and velocity, Rotation (X-axis), Flexion/Extension (Y-axis), Inclination (Z-axis); Resultant displacement and velocity (V): RV=(Vx2+Vy2+Vz2)−−−−−−−−−−−−−−−−−√ Along with SLS kinematic variables, descriptive analyses, differences between sensors locations and intra-observer and inter-observer reliability were also calculated. Results Differences between the sensors were significant only for left inclination velocity (p = 0.036) and extension displacement in the non-affected leg with eyes open (p = 0.038). Intra-observer reliability of the trunk sensor ranged from 0.889-0.921 for the displacement and 0.849-0.892 for velocity. Intra-observer reliability of the lumbar sensor was between 0.896-0.949 for the displacement and 0.873-0.894 for velocity. Inter-observer reliability of the trunk sensor was between 0.878-0.917 for the displacement and 0.847-0.884 for velocity. Inter-observer reliability of the lumbar sensor ranged from 0.870-0.940 for the displacement and 0.863-0.884 for velocity. Conclusion There were no significant differences between the kinematic records made by an inertial sensor during the development of the SLS testing between two inertial sensors placed in the lumbar and thoracic regions. In addition, inertial sensors. Have the potential to be reliable, valid and sensitive instruments for kinematic measurements during SLS testing but further research is needed.

Reclaiming fair use: How to put balance back in copyright

This lively book, Reclaiming Fair Use: How to Put Balance Back in Copyright, is designed to liberate people from the "Mind Forg'd Manacles" of copyright law. The authors - film and media scholar Patricia Aufderheide and professor of law and stalwart defender of the public interest Peter Jaszi - hope to help readers "understand how to think about and use copyright, and especially your right to use copyrighted material without permission or payment when you make a work - whether a blog entry, a song, a mashup, a poem, a documentary, a magazine article, a lesson plan, a scholarly archive, a slide show, a technical manual, a scrapbook, a collage, or a brochure"...