New specimens of the basal ornithischian dinosaur Lesothosaurus diagnosticus Galton, 1978 from the Early Jurassic of South Africa

We describe new specimens of the basal ornithischian dinosaur Lesothosaurus diagnosticus Galton, 1978 collected from a bonebed in the Fouriesburg district of the Free State, South Africa. The material was collected from the upper Elliot Formation (Early Jurassic) and represents the remains of at least three individuals. These individuals are larger in body size than those already known in museum collections and offer additional information on cranial ontogeny in the taxon. Moreover, they are similar in size to the sympatric taxon Stormbergia dangershoeki. The discovery of three individuals at this locality might imply group-living behaviour in this early ornithischian.Palaeontologia africana 2016. ©2016 Paul M. Barrett, Richard J. Butler, Adam M. Yates, Matthew G. Baron&Jonah N. Choiniere. This is an open-access article published under the Creative Commons Attribution 4.0 Unported License (CC BY4.0). To view a copy of the license, please visit http://creativecommons.org/licenses/by/4.0/. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This item is permanently archived at: http://wiredspace.wits.ac.za/handle/10539/19886. The attached file is the published version of the article

Playing the Goblin Post Office game improves movement control of the core: a case study

Movement function of the core (trunk and pelvis) can be improved in cerebral palsy, potentially leading to benefits which transfer to activities of daily living. A single child with CP diplegia played our custom made game which runs on the CAREN system. Three playing postures gradually introduced more and more joints in the legs to be controlled. Vicon cameras tracked trunk and pelvic rotations which drove a dragon towards envelope targets. Forward speed of the game was adjusted by an adaptive algorithm leading to a maximum settled speed for the various conditions. Results showed that core control improved after the six week training period. The trunk was better controlled than the pelvis, sideways rotations were better controlled than fore-aft rotations of body segments, and single plane rotations were more efficient than cross-plane rotations of the core. The quantifiable improvements suggest a good potential for our technique to improve core control which is a prerequisite for good movement control of the legs and arms

The effects of virtual reality game training on trunk to pelvis coupling in a child with cerebral palsy

Background: Good control of trunk and pelvic movements is necessary for well controlled leg movements required to perform activities of daily living. The nature of movement coupling between the trunk and pelvis varies and depends on the type of activity. Children with cerebral palsy often have reduced ability to modulate coupling between the trunk and pelvis but movement patterns of the pelvis can be improved by training. The aim of this study was to examine how pelvis to trunk coupling changed while playing a computer game driven by pelvic rotations

Near-stasis in the long-term diversification of Mesozoic tetrapods

How did evolution generate the extraordinary diversity of vertebrates on land? Zero species are known prior to ~380 million years ago, and more than 30,000 are present today. An expansionist model suggests this was achieved by large and unbounded increases, leading to substantially greater diversity in the present than at any time in the geological past. This model contrasts starkly with empirical support for constrained diversification in marine animals, suggesting different macroevolutionary processes on land and in the sea. We quantify patterns of vertebrate standing diversity on land during the Mesozoic–early Paleogene interval, applying sample-standardization to a global fossil dataset containing 27,260 occurrences of 4,898 non-marine tetrapod species. Our results show a highly stable pattern of Mesozoic tetrapod diversity at regional and local levels, underpinned by a weakly positive, but near-zero, long-term net diversification rate over 190 million years. Species diversity of non-flying terrestrial tetrapods less than doubled over this interval, despite the origins of exceptionally diverse extant groups within mammals, squamates, amphibians, and dinosaurs. Therefore, although speciose groups of modern tetrapods have Mesozoic origins, rates of Mesozoic diversification inferred from the fossil record are slow compared to those inferred from molecular phylogenies. If high speciation rates did occur in the Mesozoic, then they seem to have been balanced by extinctions among older clades. An apparent 4-fold expansion of species richness after the Cretaceous/Paleogene (K/Pg) boundary deserves further examination in light of potential taxonomic biases, but is consistent with the hypothesis that global environmental disturbances such as mass extinction events can rapidly adjust limits to diversity by restructuring ecosystems, and suggests that the gradualistic evolutionary diversification of tetrapods was punctuated by brief but dramatic episodes of radiation.27 page(s

Climate constrains the evolutionary history and biodiversity of crocodylians

The fossil record of crocodylians and their relatives (pseudosuchians) reveals a rich evolutionary history, prompting questions about causes of long-term decline to their present-day low biodiversity. We analyse climatic drivers of subsampled pseudosuchian biodiversity over their 250 million year history, using a comprehensive new data set. Biodiversity and environmental changes correlate strongly, with long-term decline of terrestrial taxa driven by decreasing temperatures in northern temperate regions, and biodiversity decreases at lower latitudes matching patterns of increasing aridification. However, there is no relationship between temperature and biodiversity for marine pseudosuchians, with sea-level change and post-extinction opportunism demonstrated to be more important drivers. A ‘modern-type' latitudinal biodiversity gradient might have existed throughout pseudosuchian history, and range expansion towards the poles occurred during warm intervals. Although their fossil record suggests that current global warming might promote long-term increases in crocodylian biodiversity and geographic range, the 'balancing forces' of anthropogenic environmental degradation complicate future predictions

Effect of soccer footwear on landing mechanics

Lower-extremity injury is common in soccer. A number of studies have begun to assess why specific lower-extremity injuries occur. However, currently few studies have examined how footwear affects lower-extremity mechanics. In order to address this question, 14 male (age: 22.1±3.9 years, height: 1.77±0.06m, and mass: 73.3±11.5kg) and 14 female (age: 22.8±3.1 years, height: 1.68±0.07m and mass: 64.4±9.2kg) competitive soccer players underwent a motion analysis assessment while performing a jump heading task. Each subject performed the task in three different footwear conditions (running shoe, bladed cleat, and turf shoe). Two-way analyses of variance were used to examine statistical differences in landing mechanics between the footwear conditions while controlling for gender differences. These comparisons were made during two different parts (prior to and following) of a soccer-specific jump heading task. A statistically significant interaction for the peak dorsiflexion angle (P=0.02) and peak knee flexion angle (P=0.05) was observed. Male soccer players exhibited a degree increase in dorsiflexion in the bladed cleat while female soccer players exhibited a three-degree reduction in peak knee flexion in the bladed cleat condition. Other main effects for gender and footwear were also observed. The results suggest that landing mechanics differ based upon gender, footwear, and the type of landing. Therefore, training interventions aimed at reducing lower-extremity injury should consider utilizing sport-specific footwear when assessing movement patterns. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd

Changes in landing mechanics in patients following anterior cruciate ligament reconstruction when wearing an extension constraint knee brace.

BACKGROUND: Anterior cruciate ligament (ACL) reconstruction is associated with a high incidence of second tears (graft tears and contralateral ACL tears). These secondary tears have been attributed to asymmetrical lower extremity mechanics. Knee bracing is one potential intervention that can be used during rehabilitation that has the potential to normalize lower extremity asymmetry; however, little is known about the effect of bracing on movement asymmetry in patients following ACL reconstruction. HYPOTHESIS: Wearing a knee brace would increase knee joint flexion and joint symmetry. It was also expected that the joint mechanics would become more symmetrical in the braced condition. OBJECTIVE: To examine how knee bracing affects knee joint function and symmetry over the course of rehabilitation in patients 6 months following ACL reconstruction. STUDY DESIGN: Controlled laboratory study. LEVEL OF EVIDENCE: Level 3. METHODS: Twenty-three adolescent patients rehabilitating from ACL reconstruction surgery were recruited for the study. The subjects all underwent a motion analysis assessment during a stop-jump activity with and without a functional knee brace on the surgical side that resisted extension for 6 months following the ACL reconstruction surgery. Statistical analysis utilized a 2 × 2 (limb × brace) analysis of variance with a significant alpha level of 0.05. RESULTS: Subjects had increased knee flexion on the surgical side when they were braced. The brace condition increased knee flexion velocity, decreased the initial knee flexion angle, and increased the ground reaction force and knee extension moment on both limbs. Side-to-side asymmetry was present across conditions for the vertical ground reaction force and knee extension moment. CONCLUSION: Wearing a knee brace appears to increase lower extremity compliance and promotes normalized loading on the surgical side. CLINICAL RELEVANCE: Knee extension constraint bracing in postoperative ACL patients may improve symmetry of lower extremity mechanics, which is potentially beneficial in progressing rehabilitation and reducing the incidence of second ACL tears

Quality of life can be good after slide tracheoplasty for long-segment tracheal stenosis

OBJECTIVES: The objectives of this study were to measure 'health-related quality of life' (HRQoL) in children following slide tracheoplasty for long-segment tracheal stenosis (LSTS) and to explore the relationship of comorbidities and parental mental health with HRQoL outcomes. METHODS: A cross-sectional study was undertaken with children who had undergone slide tracheoplasty. Participants included parents and children (age 5-15 years) recruited over a 13-month period, who were asked to complete validated measures of HRQoL, development and behaviour. Scores were compared to published norms. RESULTS: Forty-two children (male 69%; n = 29) were included; mean age was 5.3 (standard deviation 3.5) years and mean follow-up was 45 (range 4-179) months. Mean total HRQoL scores for children with repaired LSTS did not differ from those of healthy norms other than for children aged 13-23 months, but 10 children (24%) had scores >2 SD below the mean for healthy children. HRQoL was poorer in children with non-cardiac congenital comorbidities than in those with isolated LSTS (mean scores 60.34 ± 17.19 and 85.52 ± 12.19, respectively, P = 0.01). There was good agreement between children's and parents' scores, although children rated their HRQoL as better than their parents did. Anxious parents rated their children's HRQoL as significantly worse than non-anxious parents (P<0.001). CONCLUSIONS: Older children with isolated LSTS can have excellent HRQoL after surgery. Younger children, at an earlier time point postoperatively, and those with non-cardiac congenital comorbidities have poorer HRQoL. Further longitudinal evaluation is required to identify psycho-social (including parental) predictors of outcome which may inform, or be amenable to, intervention