Prevalence of bone attrition on knee radiographs and MRI in a community-based cohort

OBJECTIVES: Bone attrition probably constitutes remodeling of the bone, resulting in flattening or depression of the articular surfaces. Defining bone attrition is challenging because it is an accentuation of the normal curvature of the tibial plateaus. We aimed to define bone attrition on magnetic resonance imaging (MRI) of the knee using information from both radiographs and MRIs, and to assess whether bone attrition is common prior to end stage disease osteoarthritis (OA) in the tibio-femoral joint. METHODS: All knees of participants in the community-based sample of the Framingham OA Study were evaluated for bone attrition in radiographs and MRIs. Radiographs were scored based on templates designed to outline the normal contours of the tibio-femoral joint. MRIs were analyzed using the semi-quantitative Whole-Organ Magnetic Resonance Imaging Scoring (WORMS) method. The prevalence of bone attrition was calculated using two different thresholds for MRI scores. RESULTS: Inter-observer agreement for identification of bone attrition was substantial for the radiographs (kappa=0.71, 95% CI 0.67-0.81) and moderate for MRI (kappa=0.56, 95% CI 0.40-0.72). Of 964 knees, 5.7% of the radiographs showed bone attrition. Of these, 91% of MRIs were also read as showing bone attrition. We selected a conservative threshold for bone attrition on MRI scoring (> or = 2 on a 0-3 scale) based on agreement with attrition on the radiograph or when bone attrition on MRI co-occurred with cartilage loss on OA. Using this threshold for bone attrition on MRI, bone attrition was common in knees with OA. For example, in knees with mild OA but no joint space narrowing, 13 of 88 MRIs (14.8%) showed bone attrition. CONCLUSIONS: Using MRI we found that many knees with mild OA without joint narrowing on radiographs had bone attrition, even using conservative definitions. The validity of our definition of bone attrition should be evaluated in further studies. Bone attrition may occur in milder OA and at earlier stages of disease than previously thought.

Two dimensional Lattice Boltzmann simulation of fluid flow through an idealized micro-structure of disordered media

This technical report discusses the application of Lattice Boltzmann Method (LBM) in the fluid flow simulation through porous filter-wall of disordered media. The diesel particulate filter (DPF) is an example of disordered media. DPF is developed as a cutting edge technology to reduce harmful particulate matter in the engine exhaust. Porous filter-wall of DPF traps these soot particles in the after-treatment of the exhaust gas. To examine the phenomena inside the DPF, researchers are looking forward to use the Lattice Boltzmann Method as a promising alternative simulation tool. The lattice Boltzmann method is comparatively a newer numerical scheme and can be used to simulate fluid flow for single-component single-phase, single-component multi-phase. It is also an excellent method for modelling flow through disordered media. The current work focuses on a single-phase fluid flow simulation inside the porous micro-structure using LBM. Firstly, the theory concerning the development of LBM is discussed. LBM evolution is always related to Lattice gas Cellular Automata (LGCA), but it is also shown that this method is a special discretized form of the continuous Boltzmann equation. Since all the simulations are conducted in two-dimensions, the equations developed are in reference with D2Q9 (two-dimensional 9-velocity) model. The artificially created porous micro-structure is used in this study. The flow simulations are conducted by considering air and CO2 gas as fluids. The numerical model used in this study is explained with a flowchart and the coding steps. The numerical code is constructed in MATLAB. Different types of boundary conditions and their importance is discussed separately. Also the equations specific to boundary conditions are derived. The pressure and velocity contours over the porous domain are studied and recorded. The results are compared with the published work. The permeability values obtained in this study can be fitted to the relation proposed by Nabovati [8], and the results are in excellent agreement within porosity range of 0.4 to 0.8.

Variations of the FEAST Eigenvalue Algorithm

FEAST is a recently developed eigenvalue algorithm which computes selected interior eigenvalues of real symmetric matrices. It uses contour integral resolvent based projections. A weakness is that the existing algorithm relies on accurate reasoned estimates of the number of eigenvalues within the contour. Examining the singular values of the projections on moderately-sized, randomly-generated test problems motivates orthogonalization-based improvements to the algorithm. The singular value distributions provide experimentally robust estimates of the number of eigenvalues within the contour. The algorithm is modified to handle both Hermitian and general complex matrices. The original algorithm (based on circular contours and Gauss-Legendre quadrature) is extended to contours and quadrature schemes that are recursively subdividable. A general complex recursive algorithm is implemented on rectangular and diamond contours. The accuracy of different quadrature schemes for various contours is investigated.

EC Electronic Communications and Competition Law

Telecommunications have developed at an incredible speed over the last couple of decades. The decreasing size of our phones and the increasing number of ways in which we can communicate are barely the only result of this (r)evolutionary development. The latter has indeed multiple implications. The change of paradigm for telecommunications regulation, epitomised by the processes of liberalisation and reregulation, was not sufficient to answer all regulatory questions pertinent to communications. Today, after the transition from monopoly to competition, we are faced perhaps with an even harder regulatory puzzle, since we must figure out how to regulate a sector that is as dynamic and as unpredictable as electronic communications have proven to be, and as vital and fundamental to the economy and to society at large. The present book addresses the regulatory puzzle of contemporary electronic communications and suggests the outlines of a coherent model for their regulation. The search for such a model involves essentially deliberations on the question "Can competition law do it all?", since generic competition rules are largely seen as the appropriate regulatory tool for the communications domain. The latter perception has been the gist of the 2002 reform of the European Community (EC) telecommunications regime, which envisages a withdrawal of sectoral regulation, as communications markets become effectively competitive and ultimately bestows the regulation of the sector upon competition law only. The book argues that the question of whether competition law is the appropriate tool needs to be examined not in the conventional contexts of sector specific rules versus competition rules or deregulation versus regulation but in a broader governance context. Consequently, the reader is provided with an insight into the workings and specific characteristics of the communications sector as network-bound, converging, dynamic and endowed with a special societal role and function. A thorough evaluation of the regulatory objectives in the communications environment contributes further to the comprehensive picture of the communications industry. Upon this carefully prepared basis, the book analyses the communications regulatory toolkit. It explores the interplay between sectoral communications regulation, competition rules (in particular Article 82 of the EC Treaty) and the rules of the World Trade Organization (WTO) relevant to telecommunications services. The in-depth analysis of multilevel construct of EC communications law is up-to-date and takes into account important recent developments in the EC competition law in practice, in particular in the field of refusal to supply and tying, of the reform of the EC electronic communications framework and new decisions of the WTO dispute settlement body, such as notably the Mexico-Telecommunications Services Panel Report. Upon these building elements, an assessment of the regulatory potential of the EC competition rules is made. The conclusions drawn are beyond the scope of the current situation of EC electronic communications and the applicable law and explore the possible contours of an optimal regulatory framework for modern communications. The book is of particular interest to communications and antitrust law experts, as well as policy makers, government agencies, consultancies and think-tanks active in the field. Experts on other network industries (such as electricity or postal communications) can also profit from the substantial experience gathered in the communications sector as the most advanced one in terms of liberalisation and reregulation.

A system for 3-D reconstruction of a patient-specific surface model from calibrated X-ray images

This paper presents a system for 3-D reconstruction of a patient-specific surface model from calibrated X-ray images. Our system requires two X-ray images of a patient with one acquired from the anterior-posterior direction and the other from the axial direction. A custom-designed cage is utilized in our system to calibrate both images. Starting from bone contours that are interactively identified from the X-ray images, our system constructs a patient-specific surface model of the proximal femur based on a statistical model based 2D/3D reconstruction algorithm. In this paper, we present the design and validation of the system with 25 bones. An average reconstruction error of 0.95 mm was observed.

Early implant placement with simultaneous guided bone regeneration following single-tooth extraction in the esthetic zone: 12-month results of a prospective study with 20 consecutive patients

BACKGROUND: Early implant placement is one of the treatment options in postextraction sites in the anterior maxilla. Implant placement is performed after a soft tissue healing period of 4 to 8 weeks. Implant placement is combined with a simultaneous guided bone regeneration (GBR) procedure to rebuild esthetic facial hard and soft tissue contours. METHODS: In this prospective case-series study, 20 consecutive patients treated with an implant-borne single crown were prospectively followed for 12 months. Clinical, radiologic, and esthetic parameters were recorded to assess treatment outcomes. RESULTS: At the 12-month examination, all 20 implants were successfully integrated, demonstrating ankylotic stability and healthy peri-implant soft tissues as documented by standard parameters. The esthetic outcomes assessed by a pink esthetic score (PES) and a white esthetic score (WES) demonstrated pleasing results overall. The WES values were slightly superior to the PES values. The periapical radiographs showed minimal crestal bone loss around the used bone level implants, with mean bone loss of 0.18 mm at 12 months. Only one implant showed >0.5 mm bone loss, combined with minor mucosal recession of 0.5 to 1.0 mm. CONCLUSIONS: This prospective case series study evaluating the concept of early implant placement demonstrated successful tissue integration for all 20 implants. The short-term follow-up of 12 months revealed pleasing esthetic outcomes overall, as assessed by objective parameters. The risk for mucosal recession was low; only one patient showed minor recession of the facial mucosa. These encouraging results need to be confirmed with 3- and 5-year follow-up examinations.

Tracking of industrial objects by using CAD models

In this paper we present a model-based approach for real-time camera pose estimation in industrial scenarios. The line model which is used for tracking is generated by rendering a polygonal model and extracting contours out of the rendered scene. By un-projecting a point on the contour with the depth value stored in the z-buffer, the 3D coordinates of the contour can be calculated. For establishing 2D/3D correspondences the 3D control points on the contour are projected into the image and a perpendicular search for gradient maxima for every point on the contour is performed. Multiple hypotheses of 2D image points corresponding to a 3D control point make the pose estimation robust against ambiguous edges in the image.

Orphanhood, Poverty and the Care Dilemma: Review of Global Policy Trends

The care and protection of children experiencing orphanhood presents a major child-care policy challenge. This paper draws on a review of the literature to document divergent conceptualizations of orphanhood, how the hurdles for the care of orphans reflect wider issues of poverty and inequality, as well as the ways in which different care interventions (familial, institutional, community-based and rights-based) might be appropriated for children in need. It is argued that the map of contemporary orphanhood overlaps with the contours of global poverty, inequality, age-based deprivations and marginalization. An example of a ‘globalised’ model of orphan care, namely SOS Children’s Villages, is presented and its implications for policy are examined. The paper highlights the significance of fighting poverty and enhancing the care-giving capabilities of extended families in the care and protection of children from a rights-based perspective. It suggests that external interventions should primarily address the structural causes of poverty and marginality, rather than amplifying inequalities through the selective support of orphans in economically vulnerable communities.

Use of EORTC Target Definition Guidelines for Dose-Intensified Salvage Radiation Therapy for Recurrent Prostate Cancer: Results of the Quality Assurance Program of the Randomized Trial SAKK 09/10

PURPOSE Different international target volume delineation guidelines exist and different treatment techniques are available for salvage radiation therapy (RT) for recurrent prostate cancer, but less is known regarding their respective applicability in clinical practice. METHODS AND MATERIALS A randomized phase III trial testing 64 Gy vs 70 Gy salvage RT was accompanied by an intense quality assurance program including a site-specific and study-specific questionnaire and a dummy run (DR). Target volume delineation was performed according to the European Organisation for the Research and Treatment of Cancer guidelines, and a DR-based treatment plan was established for 70 Gy. Major and minor protocol deviations were noted, interobserver agreement of delineated target contours was assessed, and dose-volume histogram (DVH) parameters of different treatment techniques were compared. RESULTS Thirty European centers participated, 43% of which were using 3-dimensional conformal RT (3D-CRT), with the remaining centers using intensity modulated RT (IMRT) or volumetric modulated arc technique (VMAT). The first submitted version of the DR contained major deviations in 21 of 30 (70%) centers, mostly caused by inappropriately defined or lack of prostate bed (PB). All but 5 centers completed the DR successfully with their second submitted version. The interobserver agreement of the PB was moderate and was improved by the DR review, as indicated by an increased κ value (0.59 vs 0.55), mean sensitivity (0.64 vs 0.58), volume of total agreement (3.9 vs 3.3 cm(3)), and decrease in the union volume (79.3 vs 84.2 cm(3)). Rectal and bladder wall DVH parameters of IMRT and VMAT vs 3D-CRT plans were not significantly different. CONCLUSIONS The interobserver agreement of PB delineation was moderate but was improved by the DR. Major deviations could be identified for the majority of centers. The DR has improved the acquaintance of the participating centers with the trial protocol.

Apatani phonology and lexicon, with a special focus on tone

Despite being one of the most extensively researched of Eastern Himalayan languages, the basic morphological and phonological-prosodic properties of Apatani (Tibeto-Burman > Tani > Western) have not yet been adequately described. This article attempts such a description, focusing especially on interactions between segmental-syllabic phonology and tone in Apatani. We highlight three features in particular – vowel length, nasality and a glottal stop – which contribute to contrastively-weighted syllables in Apatani, which are consistently under-represented in previous descriptions of Apatani, and in absence of which tone in Apatani cannot be effectively analysed. We conclude that Apatani has two “underlying”, lexically-specified tone categories H and L, whose interaction with word structure and syllable weight produce a maximum of three “surface” pitch contours – level, falling and rising – on disyllabic phonological words. Two appendices provide a set of diagnostic procedures for the discovery and description of Apatani tone categories, as well as an Apatani lexicon of approximately one thousand entries.

Fully Automatic Segmentation of AP Pelvis X-rays via Random Forest Regression and Hierarchical Sparse Shape Composition

Knowledge of landmarks and contours in anteroposterior (AP) pelvis X-rays is invaluable for computer aided diagnosis, hip surgery planning and image-guided interventions. This paper presents a fully automatic and robust approach for landmarking and segmentation of both pelvis and femur in a conventional AP X-ray. Our approach is based on random forest regression and hierarchical sparse shape composition. Experiments conducted on 436 clinical AP pelvis x-rays show that our approach achieves an average point-to-curve error around 1.3 mm for femur and 2.2 mm for pelvis, both with success rates around 98%. Compared to existing methods, our approach exhibits better performance in both the robustness and the accuracy.

EC Electronic Communications and Competition Law

Telecommunications have developed at an incredible speed over the last couple of decades. The decreasing size of our phones and the increasing number of ways in which we can communicate are barely the only result of this (r)evolutionary development. The latter has indeed multiple implications. The change of paradigm for telecommunications regulation, epitomised by the processes of liberalisation and reregulation, was not sufficient to answer all regulatory questions pertinent to communications. Today, after the transition from monopoly to competition, we are faced perhaps with an even harder regulatory puzzle, since we must figure out how to regulate a sector that is as dynamic and as unpredictable as electronic communications have proven to be, and as vital and fundamental to the economy and to society at large. The present book addresses the regulatory puzzle of contemporary electronic communications and suggests the outlines of a coherent model for their regulation. The search for such a model involves essentially deliberations on the question "Can competition law do it all?", since generic competition rules are largely seen as the appropriate regulatory tool for the communications domain. The latter perception has been the gist of the 2002 reform of the European Community (EC) telecommunications regime, which envisages a withdrawal of sectoral regulation, as communications markets become effectively competitive and ultimately bestows the regulation of the sector upon competition law only. The book argues that the question of whether competition law is the appropriate tool needs to be examined not in the conventional contexts of sector specific rules versus competition rules or deregulation versus regulation but in a broader governance context. Consequently, the reader is provided with an insight into the workings and specific characteristics of the communications sector as network-bound, converging, dynamic and endowed with a special societal role and function. A thorough evaluation of the regulatory objectives in the communications environment contributes further to the comprehensive picture of the communications industry. Upon this carefully prepared basis, the book analyses the communications regulatory toolkit. It explores the interplay between sectoral communications regulation, competition rules (in particular Article 82 of the EC Treaty) and the rules of the World Trade Organization (WTO) relevant to telecommunications services. The in-depth analysis of multilevel construct of EC communications law is up-to-date and takes into account important recent developments in the EC competition law in practice, in particular in the field of refusal to supply and tying, of the reform of the EC electronic communications framework and new decisions of the WTO dispute settlement body, such as notably the Mexico-Telecommunications Services Panel Report. Upon these building elements, an assessment of the regulatory potential of the EC competition rules is made. The conclusions drawn are beyond the scope of the current situation of EC electronic communications and the applicable law and explore the possible contours of an optimal regulatory framework for modern communications. The book is of particular interest to communications and antitrust law experts, as well as policy makers, government agencies, consultancies and think-tanks active in the field. Experts on other network industries (such as electricity or postal communications) can also profit from the substantial experience gathered in the communications sector as the most advanced one in terms of liberalisation and reregulation.

Governance of Digital Game Environments and Cultural Diversity : Transdisciplinary Enquiries

Digital game environments are of increasing economic, social and cultural value. As their influence on diverse facets of life grows, states have felt compelled to intervene and secure some public interests. Yet, the contours of a comprehensive governance model are far from recognisable and governments are grappling with the complexity and fluidity of online games and virtual worlds as private spaces and as experimentation fields for creativity and innovation. This book contributes to a more comprehensive and fine-grained understanding of digital game environments, which is a precondition for addressing any of the pressing governance questions posed. Particular attention is given to the concept and policy objective of cultural diversity, which also offers a unique entry point into the discussion of the appropriate legal regulation of digital games. Governance of Digital Game Environments and Cultural Diversity will be of interest to researchers of media law, internet law and governance, cultural studies, anthropology and sociology. As the book addresses a highly topical theme, it will attract the attention of policymakers at national, regional and international levels and will also serve as a great resource tool for scholars in new media and, in particular, digital games and virtual worlds.

Spatial Patterns in Mass Balance of the Siple Coast and Amundsen Sea Sectors, West Antarctica

Local rates of change in ice-sheet thickness were calculated at IS sites in West Antarctica using the submergence velocity technique. This method entails a comparison of the vertical velocity of the ice sheet, measured using repeat global positioning system surveys of markers, and local long-term rates of snow accumulation obtained using firn-core stratigraphy. Any significant difference between these two quantities represents a thickness change with time. Measurements were conducted at sites located similar to 100-200 km apart along US ITASE traverse routes, and at several isolated locations. All but one of the sites are distributed in the Siple Coast and the Amundsen Sea basin along contours of constant elevation, along flowlines, across ice divides and close to regions of enhanced flow. Calculated rates of thickness change are different from site to site. Most of the large rates of change in ice thickness (similar to 10 cm a(-1) or larger) are observed in or close to regions of rapid flow, and are probably related to ice-dynamics effects. Near-steady-state conditions are calculated mostly at sites in the slow-moving ice-sheet interior and near the main West Antarctic ice divide. These results are consistent with regional estimates of ice-sheet change derived from remote-sensing measurements at similar locations in West Antarctica.

Electronic Communications as a Distinct and Unique Object of Regulation

The present paper is an abridged version of the first chapter to the book EC Electronic Communications and Competition Law (London: Cameron May, 2007). It is intended to pinpoint the contours of the communications sector as an object of regulation - an exercise that is essential to any thoughts on appropriate regulatory design. The communications sector is defined through its salient features of being (i) network-bound; (ii) dynamic; (iii) converging; (iv) sensitive to regulation and society’s reactions; and as one (v) with special societal role and as (vi) part of the new economy.