229 research outputs found

    Supporting sit-to-stand rehabilitation using smartphone sensors and arduino haptic feedback modules

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    The aim of this project is to design and build a system to aid patients in their rehabilitation after suffering a stroke. A stroke is one of the most serious conditions that an individual can suffer from, and the rehabilitation is often a long and difficult process. For many with movement effects, the sit-to-stand exercise is an important step in rehabilitation. The focus of this ongoing project is to create a system to assist sit-to-stand rehabilitation through the use of haptic feedback on balance. In this poster we present our initial prototype using standard smartphone accelerometers linked wirelessly to Arduino based vibration feedback modules mounted on the patients' legs. Initial feedback on the prototype is promising

    Platinum group element signatures in the North Atlantic Igneous Province: Implications for mantle controls on metal budgets during continental breakup

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    The North Atlantic Igneous Province (NAIP) is a large igneous province (LIP) that includes a series of lava suites erupted from the earliest manifestations of the (proto)-Icelandic plume, through continental and ultimately oceanic rifting. The lavas of one of these sub-provinces, the British Palaeogene Igneous Province (BPIP), were some of the first lavas to be erupted in the NAIP and overlie a thick crustal basement and sedimentary succession with abundant S-rich mudrocks. We present the first platinum-group element (PGE) and Au analyses of BPIP flood basalts from the main lava fields of the Isle of Mull and Morvern and the Isle of Skye, in addition to a suite of shallow crustal dolerite volcanic plugs on Mull, and other minor lavas suites. BPIP lavas display both Ssaturated and S-undersaturated trends which, coupled with elevated PGE abundances (> MORB), suggest that the BPIP is one of the most prospective areas of the NAIP to host Ni-Cu-PGE-(Au) mineralisation in conduit systems. Platinum-group element, Au and chalcophile element abundances in lavas from West and East Greenland, and Iceland, are directly comparable to BPIP lavas, but the relative abundances of Pt and Pd vary systematically between lavas suites of different ages. The oldest lavas (BPIP and West Greenland) have a broadly chondritic Pt/Pd ratio (~ 1.9). Lavas from East Greenland have a lower Pt/Pd ratio (~ 0.8) and the youngest lavas from Iceland have the lowest Pt/Pd ratio of the NAIP (~ 0.4). Hence, Pt/Pd ratio of otherwise equivalent flood basalt lavas varies temporally across the NAIP and appears to be coincident with the changing geodynamic environment of the (proto)-Icelandic plume through time. We assess the possible causes for such systematic Pt/Pd variation in light of mantle plume and lithospheric controls, and suggest that this reflects a change in the availability of lithospheric mantle Pt-rich sulphides for entrainment in ascending plume magmas. Hence the precious metal systematics and potential prospectivity of a LIP may be affected by contamination of plume-derived magmas by subcontinental lithospheric mantle at the margins of cratons that has been enriched by Palaeoproterzoic orogenesis

    Is treadmill walking with virtual reality an acceptable and plausible training modality for stroke survivors?

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    Introduction and Objectives: For many stroke survivors recovering independent walking is an important objective, however, although most survivors recover some walking ability it is often insufficient to meet the challenges of community walking[1]. Treadmill walking, through forced use of the paretic side, has some evidence as an intervention but lacks transfer to community walking[2]. With the rationale of providing a more realistic, variable walking experience, the addition of virtual reality (VR) to treadmills is a recent, promising, development. This aim of this study, therefore, was to investigate the credibility and acceptability of treadmill training with VR among stroke survivors. Methods: This was a feasibility study testing the validity of treadmill training with and without VR through comparison with overground walking. User acceptability was assessed through independent interviews. Six ambulant stroke survivors (aged 56.5Ā±10.6years, 116Ā±93.3months post stroke) were recruited from local stroke clubs. They attended an introductory session for baseline measurements (over ground gait biomechanics, functional mobility and cognition) and familiarisation with the treadmill VR system (MOTEKMedical, Netherlands) including wearing a harness. They then participated in two training sessions, one week apart, each session included treadmill walking without VR (TW) and treadmill walking with VR (TWVR) e.g. road and forest paths visualisations. The final session included a second measurement of gait biomechanics which provided the data for statistical comparison. Each individual was independently interviewed before and after their participation. Results: In general minor, non-significant, differences were observed for TM, TMVR and overground walking. There was, however, a consistent, and statistically significant (p= 0.032) finding of greater hip flexion for TWVR, see table for details. Universally, participants found the experience acceptable and enjoyable, although ā€œchallengingā€. Conclusion: This feasibility study found treadmill walking (with and without VR) to be similar enough to overground walking to justify it as a training modality for chronic stroke survivors who had already attained some independence in walking. One possible difference, greater hip flexion during treadmill walking, may be a product of harness wearing, and/or relate to the setup of the visualisations. Participants found the experience of treadmill walking acceptable. Although they preferred walking with the visualisations there were few biomechanical differences to simple treadmill walking. Further exploration of individual variability, however, should be undertaken as this may be a factor in ranslating gains from treadmill training to community walking. In conclusion, similarities between overground and treadmill walking (with and without VR) support its use as a training modality in stroke rehabilitation. No great advantage was evident from the use of visualisation other than participantā€™s preference, however these findings require further testing

    A mantle plume origin for the Palaeoproterozoic Circum-Superior Large Igneous Province

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    The Circum-Superior Large Igneous Province (LIP) consists predominantly of ultramafic-mafic lavas and sills with minor felsic components, distributed as various segments along the margins of the Superior Province craton. Ultramafic-mafic dykes and carbonatite complexes of the LIP also intrude the more central parts of the craton. Most of this magmatism occurred āˆ¼1880 Ma. Previously a wide range of models have been proposed for the different segments of the CSLIP with the upper mantle as the source of magmatism. New major and trace element and Nd-Hf isotopic data reveal that the segments of the CSLIP can be treated as a single entity formed in a single tectonomagmatic environment. In contrast to most previous studies that have proposed a variety of geodynamic settings, the CSLIP is interpreted to have formed from a single mantle plume. Such an origin is consistent with the high MgO and Ni contents of the magmatic rocks, trace element signatures that similar to oceanic-plateaus and ocean island basalts and ĪµNd-ĪµHf isotopic signatures which are each more negative than those of the estimated depleted upper mantle at āˆ¼1880 Ma. Further support for a mantle plume origin comes from calculated high degrees of partial melting, mantle potential temperatures significantly greater than estimated ambient Proterozoic mantle and the presence of a radiating dyke swarm. The location of most of the magmatic rocks along the Superior Province margins probably represents the deflection of plume material by the thick cratonic keel towards regions of thinner lithosphere at the craton margins. The primary magmas, generated by melting of the heterogeneous plume head, fractionated in magma chambers within the crust, and assimilated varying amounts of crustal material in the process

    A re-appraisal of the petrogenesis and tectonic setting of the Ordovician Fishguard Volcanic Group, SW Wales

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    The Fishguard Volcanic Group represents an excellently preserved example of a volcanic sequence linked to the closure of the Iapetus Ocean. This study re-examines the petrogenesis and proposed tectonic setting for the Llanvirn (467ā€“458 Ma) Fishguard Volcanic Group, South Wales, UK. New major and trace element geochemical data and petrographic observations are used to reevaluate the magma chamber processes, mantle melting and source region. The new data reveal that the Fishguard Volcanic Group represents a closely related series of basalts, basaltic andesites, dacites and rhyolites originating from a spinel lherzolite source which had been modified by subduction components. The rocks of the Fishguard Volcanic Group are co-genetic and the felsic members are related to the more primitive basalts mainly by low-pressure fractional crystallization. The geochemistry of the lavas was significantly influenced by subduction processes associated with a coeval arc, while significant amounts of assimilation of continental crust along with fractional crystallization appear to have contributed to the compositions of the most evolved lavas. The Fishguard Volcanic Group was erupted into a back-arc basin where extensive rifting but no true seafloor spreading had occurred

    Supra-subduction zone tectonic setting of the Muslim Bagh Ophiolite, northwestern Pakistan: Insights from geochemistry and petrology

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    The geology of the Muslim Bagh area comprises the Indian passive continental margin and suture zone, which is overlain by the Muslim Bagh Ophiolite, Bagh Complex and a Flysch Zone of marineā€“fluvial successions. The Muslim Bagh Ophiolite has a nearly-complete ophiolite stratigraphy. The mantle sequence of foliated peridotite is mainly harzburgite with minor dunite and contains podiform chromite deposits that grade upwards into transition zone dunite. The mantle rocks (harzburgite/dunite) resulted from large degrees of partial melting of lherzolite and have also been affected by meltā€“peridotite reaction. The Muslim Bagh crustal section has a cyclic succession of ultramaficā€“mafic cumulate with dunite at the base, that grades into wehrlite/pyroxenite with gabbros (olivine gabbro, norite and hornblende gabbro) at the top. The sheeted dykes are immature in nature and are rooted in crustal gabbros. The dykes are mainly metamorphosed dolerites, with minor intrusions of plagiogranites. The configuration of the crustal section indicates that the crustal rocks were formed over variable time periods, in pulses, by a low magma supply rate. The whole rock geochemistry of the gabbros, sheeted dykes and the mafic dyke swarm suggests that they formed in a supra-subduction zone tectonic setting in Neo-Tethys during the Late Cretaceous. The dykes of the mafic swarm crosscut both the ophiolite and the metamorphic sole rocks and have a less-marked subduction signature than the other mafic rocks. These dykes were possibly emplaced off-axis and can be interpreted to have been generated in the spinel peridotite stability zone i.e., < 50ā€“60 km, and to have risen through a slab window. The Bagh Complex is an assemblage of Triassicā€“Cretaceous igneous and sedimentary rocks, containing tholeiitic, N-MORB-like basalts and alkali basalts with OIB-type signatures. Nbā€“Ta depletion in both basalt types suggests possible contamination from continental fragments incorporated into the opening Tethyan oceanic basin during break-up of Gondwana. The lithologies and ages of the Bagh Complex imply that these rocks formed in an area extending from the continental margin over the Neo-Tethyan ocean floor. The Bagh Complex was then juxtaposed with the Muslim Bagh Ophiolite in the final stage of tectonic emplacement

    Petrology and geochemistry of mafic dykes from the Muslim Bagh Ophiolite (Pakistan): implications for petrogenesis and emplacement

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    Two different types of mafic dykes are found in the Muslim Bagh Ophiolite: 1) a sheeted dyke complex and 2) a mafic dyke swarm. Relative to the host plutonic section, the sheeted dykes are poorly developed, implying that they formed in an oceanic setting with a low and intermittent supply of magma, probably because of cyclic accumulation of crystals at the base of the magma chamber. Both the sheeted dykes and the dyke swarms have been metamorphosed to greenschist/amphibolite facies conditions. With the exception of the upper level gabbros and sheeted dykes, the dyke swarms crosscut almost the whole ophiolite suite as well as the metamorphic sole rocks, but are truncated structurally at the contact with the underlying mƩlange and sediments. Hence, the injection of the dyke swarms postdates the formation of both the main Muslim Bagh Ophiolite and the metamorphic sole rocks, but predates the accretion of the mƩlange and the final emplacement of the ophiolite onto the Indian plate margin. Both the sheeted dykes and dyke swarms are tholeiitic and have a geochemical signature of either island arc tholeiites (IAT) or are transitional between mid-oceanic ridge basalts and IAT. Oceanic rocks with such characteristics, especially their enrichment in large-ion lithophile elements, are generally thought to have formed by processes involving a subduction zone component in the source region by fluids released from the subducting slab. The Muslim Bagh Ophiolite sheeted dykes originated in the late Cretaceous, in a supra-subduction zone tectonic setting related to the subduction of a narrow branch of the Neo-Tethys Ocean, followed by a subduction rollback due to splitting of the nascent arc in the Tethys Ocean. This intra-oceanic subduction led to the formation of a metamorphic sole, followed by the off-axis intrusion of mafic dykes into the ophiolite through a slab window. The Muslim Bagh Ophiolite was accreted to the Bagh Complex and finally obducted onto the Indian Platform

    Pervasive mantle plume head heterogeneity: Evidence from the late Cretaceous Caribbean-Colombian oceanic plateau

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    In SW Colombia picritic pillow lavas and tuffs, as well as breccias composed of picritic clasts, occur interspersed with basalts of the Central Cordillera and represent accreted portions of the āˆ¼90 Ma Colombian/Caribbean oceanic plateau (CCOP). We present new geochemical data for these picrites and high-MgO basalts from SW Colombia, along with new data from Deep Sea Drilling Project Leg 15 drill sites. The 40Ar/39Ar ages for the CCOP in the Central Colombian Cordillera range from 87 to 93 Ma. Both SW Colombia picrites and Leg 15 basalts are compositionally diverse and range from reasonably enriched ((La/Nd)n > 1 and (ĪµNd)i +8.0). Nb/Y and Zr/Y systematics suggest that the depleted component is not depleted MORB mantle, but is an intrinsic part of the plume. The bulk of the CCOP compositions can be explained by mixing between this depleted mantle and a HIMU component. However, radiogenic isotope systematics indicate the presence of an EM2 (or possibly EM1) component within the plume. Mantle melt modeling suggests that the enriched magma types are the product of deeper, small degree melting of a pervasively heterogeneous plume comprising a refractory matrix with enriched streaks/blobs, whereas shallower, more extensive melting, results in the formation of relatively depleted magmas

    Erratum to:Effects of a physical activity and nutrition program in retirement villages: a cluster randomised controlled trial

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    Abstract Background This cluster randomised controlled trial aimed to determine if a 6-Ā month home-based intervention could improve the physical activity and dietary behaviours of adults aged 60 to 80Ā years living in retirement villages located in Perth, Western Australia. Methods Participants (nĀ =Ā 363) from 38 retirement villages were recruited into the trial and allocated to the intervention (nĀ =Ā 197: 17 sites) or control (nĀ =Ā 166: 21 sites) group and were blinded. Previously validated instruments-Fat and Fibre Barometer and International Physical Activity Questionnaire, along with anthropometric measures (weight, height, waist and hip circumferences) and blood pressure were collected at baseline and 6Ā ļ»æ-month time period. Comparisons between intervention and control groups were undertaken pre- and post- intervention using univariate chi-square and t-tests. Multi-level mixed regression analyses were then conducted to ascertain the effects of the intervention on changes in the outcome variables over time and between groups. Results A total of 139 (70.5%) intervention and 141 (84.9%) control group participants completed the program and post-test assessments. The intervention group demonstrated significant increases in time (80Ā min more per week on average) devoted to moderate-intensity physical activity, engagement in strength exercises (from 23.7% to 48.2%), frequency of fruit consumed as well as fat avoidance and fibre intake scores, in addition to a 0.5Ā kg mean reduction in weight post program, whereas no apparent changes were observed in the control group. Mixed regression results further confirmed statistically significant improvements in weight loss (pĀ <Ā 0.05), engagement in strength exercises (pĀ <Ā 0.001) and fruit intake (pĀ =Ā 0.012) by the intervention participants at post-test relative to their controls. Conclusions Retirement offers a time to reassess lifestyle, and adopt positive health enhancing physical activity and dietary behaviours. This intervention was successful in improving weight, engagement in strength exercises, increasing levels of moderate-intensity physical activity and consumption of fruit among retirement village residents. Further investigation is needed on how to better engage retirement village managers in such programs. Trial registration Australia and New Zealand Clinical Trial Registry (ACTRN12612001168842) registered November 2, 2012
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