Prospective five-year subsidence analysis of a cementless fully hydroxyapatite-coated femoral hip arthroplasty component

Early subsidence >1.5 mm is considered to be a predictive factor for later aseptic loosening of the femoral component following total hip arthroplasty (THA). The aim of this study was to assess five-year subsidence rates of the cementless hydroxyapatite-coated twinSys stem (Mathys Ltd., Bettlach, Switzerland).This prospective single-surgeon series examined consecutive patients receiving a twinSys stem at Maria Middelares Hospital, Belgium. Patients aged >85 years or unable to come to follow-up were excluded. Subsidence was assessed using Ein Bild Roentgen Analyse--Femoral Component Analysis (EBRA-FCA). Additional clinical and radiographic assessments were performed. Follow-ups were prospectively scheduled at two, five, 12, 24, and 60 months.In total, 218 THA (211 patients) were included. At five years, mean subsidence was 0.66 mm (95% CI: 0.43-0.90). Of the 211 patients, 95.2% had an excellent or good Harris Hip Score. There were few radiological changes. Kaplan-Meier analysis indicated five-year stem survival to be 98.4% (95% CI: 97.6-100%).Subsidence levels of the twinSys femoral stem throughout the five years of follow-up were substantially lower than the 1.5 mm level predictive of aseptic loosening. This was reflected in the high five-year survival rate

Links between social information processing in middle childhood and involvement in bullying. [IF 0.95]

The aim of this study was to investigate the way in which bullies, victims, bully/victims, and those not involved process social information. A peer nomination measure of bullying and victimization was administered twice over an interval of one year. The sample consisted of 236 (126 girls and 110 boys) children at the beginning of the study (TI) and 242 children one year later (T2) (mean age: 8 years). To test how children responded when provoked, both spontaneously and after prompting, we used provocation scenarios, and to test their attributional interpretations we used ambiguous scenarios. The results showed that children not involved in bullying responded in an assertive way to provocation more often than bullies and victims, but not more than bully/victims. In general, aggressive answers diminished after prompting and irrelevant answers increased. Appealing for the help of an adult or a peer was the strategy most often chosen. When the intent of the perpetrator was ambiguous, bully/ victims attributed more blame, were angrier, and would retaliate more than those not involved. Partly similar results were obtained when stably involved children were compared with those unstably involved. Suggestions for intervention are presented. © 2003 Wiley-Liss, Inc

Peer victimization in Dutch school classes of four- to five-year-olds: Contributing factors at the school level

This research was designed to examine how factors within young children's environment (e.g., school factors, neighborhood) contribute to explaining peer victimization. The sample comprised 2,003 children (between 4 and 5 years of age) from 98 classrooms in 23 elementary schools in the Netherlands. Teachers were asked to complete a questionnaire on exposure to victimization for each child. Multilevel analyses revealed that gender and social climate of the school were directly related to victimization. Furthermore, results indicated that peer victimization in boys was less prevalent when they attended smaller schools. In low-SES neighborhoods victimization scores were significantly lower when schools had implemented clear antibullying policies. Finally, variation among school classes appeared to be strongly associated with victimization, even more so than variation among schools. These findings support broadening the focus beyond the individual child at risk. © 2009 by The University of Chicago. All rights reserved

On the validity of nonlinear Alfvén resonance in space plasmas

Aims. In the approximation of linear dissipative magnetohydrodynamics (MHD), it can be shown that driven MHD waves in magnetic plasmas with high Reynolds number exhibit a near resonant behaviour if the frequency of the wave becomes equal to the local Alfvén (or slow) frequency of a magnetic surface. This behaviour is confined to a thin region, known as the dissipative layer, which embraces the resonant magnetic surface. Although driven MHD waves have small dimensionless amplitude far away from the resonant surface, this near-resonant behaviour in the dissipative layer may cause a breakdown of linear theory. Our aim is to study the nonlinear effects in Alfvén dissipative layer Methods. In the present paper, the method of simplified matched asymptotic expansions developed for nonlinear slow resonant waves is used to describe nonlinear effects inside the Alfvén dissipative layer. Results. The nonlinear corrections to resonant waves in the Alfvén dissipative layer are derived, and it is proved that at the Alfvén resonance (with isotropic/anisotropic dissipation) wave dynamics can be described by the linear theory with great accuracy

Impaired Postural Control Reduces Sit-to-Stand-to-Sit Performance in Individuals with Chronic Obstructive Pulmonary Disease

Abstract Background: Functional activities, such as the sit-to-stand-to-sit (STSTS) task, are often impaired in individuals with chronic obstructive pulmonary disease (COPD). The STSTS task places a high demand on the postural control system, which has been shown to be impaired in individuals with COPD. It remains unknown whether postural control deficits contribute to the decreased STSTS performance in individuals with COPD. Methods: Center of pressure displacement was determined in 18 individuals with COPD and 18 age/gender-matched controls during five consecutive STSTS movements with vision occluded. The total duration, as well as the duration of each sit, sit-to-stand, stand and stand-to-sit phase was recorded. Results: Individuals with COPD needed significantly more time to perform five consecutive STSTS movements compared to healthy controls (1966 vs. 1364 seconds, respectively; p = 0.001). The COPD group exhibited a significantly longer stand phase (p = 0.028) and stand-to-sit phase (p = 0.001) compared to the control group. In contrast, the duration of the sit phase (p = 0.766) and sit-to-stand phase (p = 0.999) was not different between groups. Conclusions: Compared to healthy individuals, individuals with COPD needed significantly more time to complete those phases of the STSTS task that require the greatest postural control. These findings support the proposition that suboptimal postural control is an important contributor to the decreased STSTS performance in individuals with COPD

Analysis of MERCATOR data Part I: variable B stars

We re-classified 31 variable B stars which were observed more than 50 times in the Geneva photometric system with the P7 photometer attached to the MERCATOR telescope (La Palma) during its first 3 years of scientific observations. HD89688 is a possible beta Cephei/slowly pulsating B star hybrid and the main mode of the COROT target HD180642 shows non-linear effects. The Maia candidates are re-classified as either ellipsoidal variables or spotted stars. Although the mode identification is still ongoing, all the well-identified modes so far have a degree l = 0, 1 or 2.Comment: 4 pages, 3 figures. To appear in: Proceedings of JENAM 2005 'Distant worlds', Communications in Asteroseismolog

Caractérisation d'une insertion CG dans le gène du collagène VII chez un patient atteint d'épidermolyse bulleuse dystrophique récessive de Hallopeau-Siemens

L'épidermolyse bulleuse dystrophique récessive généralisée mutilante de Hallopeau-Siemens (EBDR-HS) est une génodermatose grave, caractérisée par une fragilité cutanéo-muqueuse extrême associée à une forte diminution, voire une absence des fibres d'ancrage essentiellement constituées de collagène VIL Une liaison génétique a été établie entre le gène du collagène VII et le phénotype de l'EBDR-HS. Au cours de ce travail, on a caractérisé, à l'aide des techniques de DGGE et de séquençage d'ADN, une insertion d'un doublet CG chez un patient atteint d'EBDRHS. Cette insertion conduit à un décalage du cadre de lecture et à la création d'un codon stop précoce prédisant la synthèse de collagène VII dépourvu de 76 % de la protéine totale. Ces résultats suggèrent fortement que cette mutation, identifiée dans le gène du collagène VII est responsable des anomalies des fibres d'ancrage chez le patient étudié. De plus ils sont très utiles au conseil génétique et au diagnostic prénatal

Shift of paradigm needed towards improving human-elephant coexistence in monoculture landscapes in Sabah

This article outlines the contemporary situation of the Bornean elephant Elephas maximus borneensis in Sabah (Malaysian Borneo), and focuses on the existing challenges that need to be addressed to enable people and elephants to coexist, particularly in man‐made landscapes dominated by oil‐palm plantations. Bornean elephants are confined mostly to Sabah, to the north‐east 5% of the Borneo Island. Sabah started to expand its commercial plantation sector in the early 1980s and is the largest producer of palm oil in Malaysia, contributing c. 10% of global output for this commodity. The rapid pace of plantation expansion has resulted in the loss of the majority of lowland areas that are also needed by large mammal species to sustain breeding populations. Elephants are extreme lowland/floodplain specialists, and they still attempt to use their former and preferred habitat, which is now mostly dominated by oil‐palm plantations. At the time of writing, the land‐use planning system favoured by the government insufficiently incorporates the ecological and management needs for elephants across the entire landscape. This article also highlights the need for better collaboration and coordination between stakeholders to address the increasing rate of human–elephant conflicts in Sabah