134 resultados para joint invariant


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Periprosthetic joint infection (PJI) after THA is a major complication with an incidence of 1-3%. We report our experiences with a technique using a custom-made articulating spacer (CUMARS) at the first of two-stage treatment for PJI. This technique uses widely available all-polyethylene acetabular components and the Exeter Universal stem, fixed using antibiotic loaded acrylic cement. Seventy-six hips were treated for PJI using this technique. Performed as the first of a two-stage procedure, good functional results were commonly seen, leading to postponing second stage indefinitely with retention of the CUMARS prosthesis in 34 patients. The CUMARS technique presents an alternative to conventional spacers, using readily available components that are well tolerated, allowing weight bearing and mobility, and achieving comparable eradication rates.

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Introduction Calculating segmental torso masses in Adolescent Idiopathic Scoliosis (AIS) patients allows the gravitational loading on the scoliotic spine during relaxed standing to be estimated. Methods Low dose CT data was used to calculate vertebral level-by-level torso masses and spinal joint torques for 20 female AIS patients (mean age 15.0 ± 2.7 years, mean Cobb angle 53 ± 7.1°). ImageJ software (v1.45 NIH USA) was used to threshold the T1 to L5 CT images and calculate the segmental torso volume and mass for each vertebral level. Masses for the head, neck and arms were taken from published data. Intervertebral joint torques in the coronal and sagittal planes at each vertebral level were found from the position of the centroid of the segment masses relative to the joint centres (assumed to be at the centre of the intervertebral disc. The joint torque at each level was found by summing torque contributions for all segments above that joint. Results Segmental torso mass increased from 0.6kg at T1 to 1.5kg at L5. The coronal plane joint torques due to gravity were 5-7Nm at the apex of the curve; sagittal torques were 3-5.4Nm. Conclusion CT scans were in the supine position and curve magnitudes are known to be smaller than those in standing. Hence, this study has shown that gravity produces joint torques potentially of higher than 7Nm in the coronal plane and 5Nm in the sagittal plane during relaxed standing in scoliosis patients. The magnitude of these torques may help to explain the mechanics of AIS progression and the mechanics of bracing. This new data on torso segmental mass in AIS patients will assist biomechanical models of scoliosis.

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INTRODUCTION Calculating segmental (vertebral level-by-level) torso masses in Adolescent Idiopathic Scoliosis (AIS) patients allows the gravitational loading on the scoliotic spine during relaxed standing to be estimated. METHODS Existing low dose CT scans were used to calculate vertebral level-by-level torso masses and joint moments occurring in the spine for a group of female AIS patients with right-sided thoracic curves. Image processing software, ImageJ (v1.45 NIH USA) was used to reconstruct the torso segments and subsequently measure the torso volume and mass corresponding to each vertebral level. Body segment masses for the head, neck and arms were taken from published anthropometric data. Intervertebral joint moments at each vertebral level were found by summing each of the torso segment masses above the required joint and multiplying it by the perpendicular distance to the centre of the disc. RESULTS AND DISCUSSION Twenty patients were included in this study with a mean age of 15.0±2.7 years and a mean Cobb angle 52±5.9°. The mean total trunk mass, as a percentage of total body mass, was 27.8 (SD 0.5) %. Mean segmental torso mass increased inferiorly from 0.6kg at T1 to 1.5kg at L5. The coronal plane joint moments during relaxed standing were typically 5-7Nm at the apex of the curve (Figure 1), with the highest apex joint of 7Nm. CT scans were performed in the supine position and curve magnitudes are known to be 7-10° smaller than those measured in standing [1]. Therefore joint moments produced by gravity will be greater than those calculated here. CONCLUSIONS Coronal plane joint moments as high as 7Nm can occur during relaxed standing in scoliosis patients, which may help to explain the mechanics of AIS progression. The body mass distributions calculated in this study can be used to estimate joint moments derived using other imaging modalities such as MRI and subsequently determine if a relationship exists between joint moments and progressive vertebral deformity.

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In this paper we propose the hybrid use of illuminant invariant and RGB images to perform image classification of urban scenes despite challenging variation in lighting conditions. Coping with lighting change (and the shadows thereby invoked) is a non-negotiable requirement for long term autonomy using vision. One aspect of this is the ability to reliably classify scene components in the presence of marked and often sudden changes in lighting. This is the focus of this paper. Posed with the task of classifying all parts in a scene from a full colour image, we propose that lighting invariant transforms can reduce the variability of the scene, resulting in a more reliable classification. We leverage the ideas of “data transfer” for classification, beginning with full colour images for obtaining candidate scene-level matches using global image descriptors. This is commonly followed by superpixellevel matching with local features. However, we show that if the RGB images are subjected to an illuminant invariant transform before computing the superpixel-level features, classification is significantly more robust to scene illumination effects. The approach is evaluated using three datasets. The first being our own dataset and the second being the KITTI dataset using manually generated ground truth for quantitative analysis. We qualitatively evaluate the method on a third custom dataset over a 750m trajectory.

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Vision-based place recognition involves recognising familiar places despite changes in environmental conditions or camera viewpoint (pose). Existing training-free methods exhibit excellent invariance to either of these challenges, but not both simultaneously. In this paper, we present a technique for condition-invariant place recognition across large lateral platform pose variance for vehicles or robots travelling along routes. Our approach combines sideways facing cameras with a new multi-scale image comparison technique that generates synthetic views for input into the condition-invariant Sequence Matching Across Route Traversals (SMART) algorithm. We evaluate the system’s performance on multi-lane roads in two different environments across day-night cycles. In the extreme case of day-night place recognition across the entire width of a four-lane-plus-median-strip highway, we demonstrate performance of up to 44% recall at 100% precision, where current state-of-the-art fails.

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This paper presents an online, unsupervised training algorithm enabling vision-based place recognition across a wide range of changing environmental conditions such as those caused by weather, seasons, and day-night cycles. The technique applies principal component analysis to distinguish between aspects of a location’s appearance that are condition-dependent and those that are condition-invariant. Removing the dimensions associated with environmental conditions produces condition-invariant images that can be used by appearance-based place recognition methods. This approach has a unique benefit – it requires training images from only one type of environmental condition, unlike existing data-driven methods that require training images with labelled frame correspondences from two or more environmental conditions. The method is applied to two benchmark variable condition datasets. Performance is equivalent or superior to the current state of the art despite the lesser training requirements, and is demonstrated to generalise to previously unseen locations.

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The influence of constructivism and the ongoing drive for convergence, both of career theories and between theory and practice, have been key drivers in the career development literature for two decades (Patton, International Handbook of Career Guidance, 2008). Both contextual action theory and systems theory are derived from the root metaphor of contextualism, which has been proffered as a worldview to assist scientists and practitioners in organizing day-to-day experiential data. This chapter identifies the theoretical contributions of the Systems Theory Framework (STF) (Patton and McMahon, Career development and systems theory: A new development, 1999, Career psychology in South Africa, 2006) and Contextual Action Theory (Young and Valach, The future of career, 2000, Journal of Vocational Behavior 64:499–514, 2004; Young et al., Career choice and development, 1996, Career choice and development, 2002), each of which has advanced thinking in theory integration and in the integration between theory and practice in the career development and counseling field. Young et al. (Career development in childhood and adolescence, 2007) noted the connections between the Patton and McMahon systems theory approach and the contextual action theory approach and these connections will be highlighted in terms of the application of these theoretical developments to practice in career counseling, with a particular focus on the commonalities between the two approaches and what counselors can learn from each of them. In particular, this chapter will discuss common conceptual understandings and practice dimensions.

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Joint moments and joint powers are widely used to determine the effects of rehabilitation programs and prosthetic components (e.g., alignments). A complementary analysis of the 3D angle between joint moment and joint angular velocity has been proposed to assess whether the joints are predominantly driven or stabilized.

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Study Design: Comparative analysis Background: Calculations of lower limbs kinetics are limited by floor-mounted force-plates. Objectives: Comparison of hip joint moments, power and mechanical work on the prosthetic limb of a transfemoral amputee calculated by inverse dynamics using either the ground reactions (force-plates) or knee reactions (transducer). Methods: Kinematics, ground reactions and knee reactions were collected using a motion analysis system, two force-plates and a multi-axial transducer mounted below the socket, respectively. Results: The inverse dynamics using ground reactions under-estimated the peaks of hip energy generation and absorption occurring at 63 % and 76 % of the gait cycle (GC) by 28 % and 54 %, respectively. This method over-estimated a phase of negative work at the hip (from 37 %GC to 56 %GC) by 24%. It under-estimated the phases of positive (from 57 %GC to 72 %GC) and negative (from 73 %GC to 98 %GC) work at the hip by 11 % and 58%, respectively. Conclusions: A transducer mounted within the prosthesis has the capacity to provide more realistic kinetics of the prosthetic limb because it enables assessment of multiple consecutive steps and a wide range of activities without issues of foot placement on force-plates. CLINICAL RELEVANCE The hip is the only joint that an amputee controls directly to set in motion the prosthesis. Hip joint kinetics are associated with joint degeneration, low back pain, risks of fall, etc. Therefore, realistic assessment of hip kinetics over multiple gait cycles and a wide range of activities is essential.

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Background: Preventing risk factor exposure is vital to reduce the high burden from lung cancer. The leading risk factor for developing lung cancer is tobacco smoking. In Australia, despite apparent success in reducing smoking prevalence, there is limited information on small area patterns and small area temporal trends. We sought to estimate spatio-temporal patterns for lung cancer risk factors using routinely collected population-based cancer data. Methods: The analysis used a Bayesian shared component spatio-temporal model, with male and female lung cancer included separately. The shared component reflected exposure to lung cancer risk factors, and was modelled over 477 statistical local areas (SLAs) and 15 years in Queensland, Australia. Analyses were also run adjusting for area-level socioeconomic disadvantage, Indigenous population composition, or remoteness. Results: Strong spatial patterns were observed in the underlying risk factor exposure for both males (median Relative Risk (RR) across SLAs compared to the Queensland average ranged from 0.48-2.00) and females (median RR range across SLAs 0.53-1.80), with high exposure observed in many remote areas. Strong temporal trends were also observed. Males showed a decrease in the underlying risk across time, while females showed an increase followed by a decrease in the final two years. These patterns were largely consistent across each SLA. The high underlying risk estimates observed among disadvantaged, remote and indigenous areas decreased after adjustment, particularly among females. Conclusion: The modelled underlying exposure appeared to reflect previous smoking prevalence, with a lag period of around 30 years, consistent with the time taken to develop lung cancer. The consistent temporal trends in lung cancer risk factors across small areas support the hypothesis that past interventions have been equally effective across the state. However, this also means that spatial inequalities have remained unaddressed, highlighting the potential for future interventions, particularly among remote areas.

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Joint ventures are formed and dissolved regularly in the mining industry. What impact do such changes have on the viability of mineral exploration projects? The Australian Centre for Entrepreneurship Research (ACE) has taken 9 years' worth of data (2002-2011) on 1,025 joint ventures in the Australasian mining industry and studied trends in fomentation, dissolution, and reconfiguration and how they impact project outcomes. This research is generously sponsored by the Queensland Exploration Council (QEC) and the Australian Research Council (ARC).

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In this paper we introduce a novel domain-invariant covariance normalization (DICN) technique to relocate both in-domain and out-domain i-vectors into a third dataset-invariant space, providing an improvement for out-domain PLDA speaker verification with a very small number of unlabelled in-domain adaptation i-vectors. By capturing the dataset variance from a global mean using both development out-domain i-vectors and limited unlabelled in-domain i-vectors, we could obtain domain- invariant representations of PLDA training data. The DICN- compensated out-domain PLDA system is shown to perform as well as in-domain PLDA training with as few as 500 unlabelled in-domain i-vectors for NIST-2010 SRE and 2000 unlabelled in-domain i-vectors for NIST-2008 SRE, and considerable relative improvement over both out-domain and in-domain PLDA development if more are available.

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Purpose To test the effectiveness of static and dynamic orthoses using them as an exclusive treatment for proximal interphalangeal (PIP) joint flexion contracture compared with other hand therapy conservative treatments described in the literature. Methods 60 patients who used orthoses were compared with a control group that received other hand therapy treatments. Clinical assessments were measured before the experiment and 3 months after and included active PIP joint extension and function. Results A significant improvement in the extension active range of motion at the PIP joint in the second measurement was found in both groups, but it was significantly greater in the experimental group. Improvement in function (Disabilities of the Arm, Shoulder, and Hand score) between the first and second assessment was similar in the control and experimental groups. Conclusions Using night progressive static and daily dynamic orthoses as an exclusive treatment during the proliferative phase led to significant improvements in the PIP joint active extension, but the improvement did not correlate with increased function as perceived by the patient.

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“If Hollywood could order intellectual property laws for Christmas, what would they look like? This is pretty close.” David Fewer “While European and American IP maximalists have pushed for TRIPS-Plus provisions in FTAs and bilateral agreements, they are now pushing for TRIPS-Plus-Plus protections in these various forums.” Susan Sell “ACTA is a threat to the future of a free and open Internet.” Alexander Furnas “Implementing the agreement could open a Pandora's box of potential human rights violations.” Amnesty International. “I will not take part in this masquerade.” Kader Arif, Rapporteur for the Anti-Counterfeiting Trade Agreement 2011 in the European Parliament Executive Summary As an independent scholar and expert in intellectual property, I am of the view that the Australian Parliament should reject the adoption of the Anti-Counterfeiting Trade Agreement 2011. I would take issue with the Department of Foreign Affairs and Trade’s rather partisan account of the negotiations, the consultations, and the outcomes associated with the Anti-Counterfeiting Trade Agreement 2011. In my view, the negotiations were secretive and biased; the local consultations were sometimes farcical because of the lack of information about the draft texts of the agreement; and the final text of the Anti-Counterfeiting Trade Agreement 2011 is not in the best interests of Australia, particularly given that it is a net importer of copyright works and trade mark goods and services. I would also express grave reservations about the quality of the rather pitiful National Interest Analysis – and the lack of any regulatory impact statement – associated with the Anti-Counterfeiting Trade Agreement 2011. The assertion that the Anti-Counterfeiting Trade Agreement 2011 does not require legislative measures is questionable – especially given the United States Trade Representative has called the agreement ‘the highest-standard plurilateral agreement ever achieved concerning the enforcement of intellectual property rights.’ It is worthwhile reiterating that there has been much criticism of the secretive and partisan nature of the negotiations surrounding the Anti-Counterfeiting Trade Agreement 2011. Sean Flynn summarizes these concerns: "The negotiation process for ACTA has been a case study in establishing the conditions for effective industry capture of a lawmaking process. Instead of using the relatively transparent and inclusive multilateral processes, ACTA was launched through a closed and secretive “‘club approach’ in which like-minded jurisdictions define enforcement ‘membership’ rules and then invite other countries to join, presumably via other trade agreements.” The most influential developing countries, including Brazil, India, China and Russia, were excluded. Likewise, a series of manoeuvres ensured that public knowledge about the specifics of the agreement and opportunities for input into the process were severely limited. Negotiations were held with mere hours notice to the public as to when and where they would be convened, often in countries half away around the world from where public interest groups are housed. Once there, all negotiation processes were closed to the public. Draft texts were not released before or after most negotiating rounds, and meetings with stakeholders took place only behind closed doors and off the record. A public release of draft text, in April 2010, was followed by no public or on-the-record meetings with negotiators." Moreover, it is disturbing that the Anti-Counterfeiting Trade Agreement 2011 has been driven by ideology and faith, rather than by any evidence-based policy making Professor Duncan Matthews has raised significant questions about the quality of empirical evidence used to support the proposal of Anti-Counterfeiting Trade Agreement 2011: ‘There are concerns that statements about levels of counterfeiting and piracy are based either on customs seizures, with the actual quantities of infringing goods in free circulation in any particular market largely unknown, or on estimated losses derived from industry surveys.’ It is particularly disturbing that, in spite of past criticism, the Department of Foreign Affairs and Trade has supported the Anti-Counterfeiting Trade Agreement 2011, without engaging the Productivity Commission or the Treasury to do a proper economic analysis of the proposed treaty. Kader Arif, Rapporteur for the Anti-Counterfeiting Trade Agreement 2011 in the European Parliament, quit his position, and said of the process: "I want to denounce in the strongest possible manner the entire process that led to the signature of this agreement: no inclusion of civil society organisations, a lack of transparency from the start of the negotiations, repeated postponing of the signature of the text without an explanation being ever given, exclusion of the EU Parliament's demands that were expressed on several occasions in our assembly. As rapporteur of this text, I have faced never-before-seen manoeuvres from the right wing of this Parliament to impose a rushed calendar before public opinion could be alerted, thus depriving the Parliament of its right to expression and of the tools at its disposal to convey citizens' legitimate demands.” Everyone knows the ACTA agreement is problematic, whether it is its impact on civil liberties, the way it makes Internet access providers liable, its consequences on generic drugs manufacturing, or how little protection it gives to our geographical indications. This agreement might have major consequences on citizens' lives, and still, everything is being done to prevent the European Parliament from having its say in this matter. That is why today, as I release this report for which I was in charge, I want to send a strong signal and alert the public opinion about this unacceptable situation. I will not take part in this masquerade." There have been parallel concerns about the process and substance of the Anti-Counterfeiting Trade Agreement 2011 in the context of Australia. I have a number of concerns about the substance of the Anti-Counterfeiting Trade Agreement 2011. First, I am concerned that the Anti-Counterfeiting Trade Agreement 2011 fails to provide appropriate safeguards in respect of human rights, consumer protection, competition, and privacy laws. It is recommended that the new Joint Parliamentary Committee on Human Rights investigate this treaty. Second, I argue that there is a lack of balance to the copyright measures in the Anti-Counterfeiting Trade Agreement 2011 – the definition of piracy is overbroad; the suite of civil remedies, criminal offences, and border measures is excessive; and there is a lack of suitable protection for copyright exceptions, limitations, and remedies. Third, I discuss trade mark law, intermediary liability, and counterfeiting. I express my concerns, in this context, that the Anti-Counterfeiting Trade Agreement 2011 could have an adverse impact upon consumer interests, competition policy, and innovation in the digital economy. I also note, with concern, the lobbying by tobacco industries for the Anti-Counterfeiting Trade Agreement 2011 – and the lack of any recognition in the treaty for the capacity of countries to take measures of tobacco control under the World Health Organization Framework Convention on Tobacco Control. Fourth, I note that the Anti-Counterfeiting Trade Agreement 2011 provides no positive obligations to promote access to essential medicines. It is particularly lamentable that Australia and the United States of America have failed to implement the Doha Declaration on the TRIPS Agreement and Public Health 2001 and the WTO General Council Decision 2003. Fifth, I express concerns about the border measures in the Anti-Counterfeiting Trade Agreement 2011. Such measures lack balance – and unduly favour the interests of intellectual property owners over consumers, importers, and exporters. Moreover, such measures will be costly, as they involve shifting the burden of intellectual property enforcement to customs and border authorities. Interdicting, seizing, and destroying goods may also raise significant trade issues. Finally, I express concern that the Anti-Counterfeiting Trade Agreement 2011 undermines the role of existing international organisations, such as the United Nations, the World Intellectual Property Organization and the World Trade Organization, and subverts international initiatives such as the WIPO Development Agenda 2007. I also question the raison d'être, independence, transparency, and accountability of the proposed new ‘ACTA Committee’. In this context, I am concerned by the shift in the position of the Labor Party in its approach to international treaty-making in relation to intellectual property. The Australian Parliament adopted the Australia-United States Free Trade Agreement 2004, which included a large Chapter on intellectual property. The treaty was a ‘TRIPs-Plus’ agreement, because the obligations were much more extensive and prescriptive than those required under the multilateral framework established by the TRIPS Agreement 1994. During the debate over the Australia-United States Free Trade Agreement 2004, the Labor Party expressed the view that it would seek to mitigate the effects of the TRIPS-Plus Agreement, when at such time it gained power. Far from seeking to ameliorate the effects of the Australia-United States Free Trade Agreement 2004, the Labor Government would seek to lock Australia into a TRIPS-Double Plus Agreement – the Anti-Counterfeiting Trade Agreement 2011. There has not been a clear political explanation for this change in approach to international intellectual property. For both reasons of process and substance, I conclude that the Australian Parliament and the Australian Government should reject the Anti-Counterfeiting Trade Agreement 2011. The Australian Government would do better to endorse the Washington Declaration on Intellectual Property and the Public Interest 2011, and implement its outstanding obligations in respect of access to knowledge, access to essential medicines, and the WIPO Development Agenda 2007. The case study of the Anti-Counterfeiting Trade Agreement 2011 highlights the need for further reforms to the process by which Australia engages in international treaty-making.