Simultaneous Bayesian recognition of locomotion and gait phases with wearable sensors

Recognition of movement is a crucial process to assist humans in activities of daily living, such as walking. In this work, a high-level method for the simultaneous recognition of locomotion and gait phases using wearable sensors is presented. A Bayesian formulation is employed to iteratively accumulate evidence to reduce uncertainty, and to improve the recognition accuracy. This process uses a sequential analysis method to autonomously make decisions, whenever the recognition system perceives that there is enough evidence accumulated. We use data from three wearable sensors, attached to the thigh, shank, and foot of healthy humans. Level-ground walking, ramp ascent and descent activities are used for data collection and recognition. In addition, an approach for segmentation of the gait cycle for recognition of stance and swing phases is presented. Validation results show that the simultaneous Bayesian recognition method is capable to recognize walking activities and gait phases with mean accuracies of 99.87% and 99.20%. This process requires a mean of 25 and 13 sensor samples to make a decision for locomotion mode and gait phases, respectively. The recognition process is analyzed using different levels of confidence to show that our method is highly accurate, fast, and adaptable to specific requirements of accuracy and speed. Overall, the simultaneous Bayesian recognition method demonstrates its benefits for recognition using wearable sensors, which can be employed to provide reliable assistance to humans in their walking activities

Probabilistic locomotion mode recognition with wearable sensors

Recognition of locomotion mode is a crucial process for control of wearable soft robotic devices to assist humans in walking activities. We present a probabilistic Bayesian approach with a sequential analysis method for recognition of locomotion and phases of the gait cycle. Our approach uses recursive accumulation of evidence, as biological systems do, to reduce uncertainty present in the sensor measurements, and thus improving recognition accuracy. Data were collected from a wearable sensor, attached to the shank of healthy human participants, from three locomotion modes; level-ground walking, ramp ascent and ramp descent. We validated our probabilistic approach with recognition of locomotion in steady-state and gait phases in transitional states. Furthermore, we evaluated the effect, in recognition accuracy, of the accumulation of evidence controlled by increasing belief thresholds. High accuracy results achieved by our approach, demonstrate its potential for robust control of lower limb wearable soft robotic devices to provide natural and safe walking assistance to humans

Prediction of gait events in walking activities with a Bayesian perception system

In this paper, a robust probabilistic formulation for prediction of gait events from human walking activities using wearable sensors is presented. This approach combines the output from a Bayesian perception system with observations from actions and decisions made over time. The perception system makes decisions about the current gait events, while observations from decisions and actions allow to predict the most probable gait event during walking activities. Furthermore, our proposed method is capable to evaluate the accuracy of its predictions, which permits to obtain a better performance and trade-off between accuracy and speed. In our work, we use data from wearable inertial measurement sensors attached to the thigh, shank and foot of human participants. The proposed perception system is validated with multiple experiments for recognition and prediction of gait events using angular velocity data from three walking activities; level-ground, ramp ascent and ramp descent. The results show that our method is fast, accurate and capable to evaluate and adapt its own performance. Overall, our Bayesian perception system demonstrates to be a suitable high-level method for the development of reliable and intelligent assistive and rehabilitation robots

Vegetation zonation along the geological and geomorphological gradient at Eastern slope of Sulaiman range, Pakistan

The vegetation of gypsiferous strata of Sulaiman range (30°33/ N to 30°41/30// north latitude and 70°32/ E to 70°41/30// east longitude, annual rainfall more than 100 mm) was analyzed using ordination (DECORANA) and classificatory cluster analysis techniques. Four plant associations were recognized in the study area. The application of the classification to the ordination allowed an interpretation of vegetation distribution in terms of topography and redistribution of rainwater, the nature of soil, bed rock and geological strata. The pattern of plant communities along the first ordination axis suggested that beside the landscape, substrate plays an important role in determining the boundaries between the plant communities. The assessment of the floristic suggested that there were three classes of plants: first there are plants of alluvial sandy plains (psymophytes), secondly; those of permanent water courses (hydrophytes) and thirdly, there are plants that grow on rocky hard strata (xerophytes/lithophytes). The observed pattern in available soil calcium seems related to long term redistribution of water that occurs during rainfall events because soil calcium, magnesium and moisture content have similar distributions along the transect. High calcium content for rocky strata was due to its parent geological gypsiferous formation. Although the boundaries across the landscape were associated with down slope movement of water, soil particles and cations, it was difficult to assess the relative importance of these factors in comparison with landscape level. The vegetation patterns revealed are discussed in relation to environmental factors and problems of plant assemblage in vegetation of the area.Key words: Vegetation analysis, plant communities, Sulaiman range, Pakistan

Detection of somaclonal variation by random amplified polymorphic DNA analysis during micropropagation of Phalaenopsis bellina (Rchb.f.) Christenson

Phalaenopsis bellina (Rchb.f.) Christenson orchid species are known for their beautiful flower shape, graceful inflorescence and fragrance. Protocorm-like bodies (PLBs) of P. bellina were induced from leaf segments. The PLBs were then subjected to proliferation using ½ strength Murashige and Skoog (MS) media with two subcultures at three months intervals. Twelve decamer random amplified polymorphic DNA (RAPD) primers were used to study somaclonal variation among the mother plant, the initially induced PLBs and proliferated PLBs after 3 and 6 months in culture. Eight out of twelve primers produced 172 bands with 18 polymorphic bands in all the treatments. The amplified products varied between 125 to 8000 bp. Among the primers used, P 16 produced the highest number of bands (29), while primer OPU 10 produced the lowest number (15). The range of similarity coefficient was from 0.83 to 1.0 among the different sub-cultures and mother plant (MP). It was found that minimal or no changes occurred between the MP and the PLBs produced after 3 months of induction. The induced PLBs were then subcultured for six months for proliferation and this resulted in about 17% dissimilarity with MP. It is reported that micropropagation of P. bellina can be carried out successfully using ½ strength MS media for 6 months but further proliferation may result in somaclonal variation which might change the prolific characteristic of this orchids.Key word: Moth orchid, somaclonal variation, random amplified polymorphic DNA, protocorm-like bodies

A model identification approach to quantify impact of whole-body vertical vibrations on limb compliant dynamics and walking stability

Extensive research is ongoing in the field of orthoses/exoskeleton design for efficient lower limbs assistance. However, despite wearable devices reported to improve lower limb mobility, their structural impacts on whole-body vertical dynamics have not been investigated. This study introduced a model identification approach and frequency domain analysis to quantify the impacts of orthosis-generated vibrations on limb stability and contractile dynamics. Experiments were recorded in the motion capture lab using 11 unimpaired subjects by wearing an adjustable ankle–foot orthosis (AFO). The lower limb musculoskeletal structure was identified as spring-mass (SM) and spring-mass-damper (SMD) based compliant models using the whole-body centre-of-mass acceleration data. Furthermore, Nyquist and Bode methods were implemented to quantify stabilities resulting from vertical impacts. Our results illustrated a significant decrease (p < 0.05) in lower limb contractile properties by wearing AFO compared with a normal walk. Also, stability margins quantified by wearing AFO illustrated a significant variance in terms of gain-margins (p < 0.05) for both loading and unloading phases whereas phase-margins decreased (p < 0.05) only for the respective unloading phases. The methods introduced here provide evidence that wearable orthoses significantly affect lower limb vertical dynamics and should be considered when evaluating orthosis/prosthesis/exoskeleton effectiveness

Neurodegeneration and Epilepsy in a Zebrafish Model of CLN3 Disease (Batten Disease)

The neuronal ceroid lipofuscinoses are a group of lysosomal storage disorders that comprise the most common, genetically heterogeneous, fatal neurodegenerative disorders of children. They are characterised by childhood onset, visual failure, epileptic seizures, psychomotor retardation and dementia. CLN3 disease, also known as Batten disease, is caused by autosomal recessive mutations in the CLN3 gene, 80–85% of which are a ~1 kb deletion. Currently no treatments exist, and after much suffering, the disease inevitably results in premature death. The aim of this study was to generate a zebrafish model of CLN3 disease using antisense morpholino injection, and characterise the pathological and functional consequences of Cln3 deficiency, thereby providing a tool for future drug discovery. The model was shown to faithfully recapitulate the pathological signs of CLN3 disease, including reduced survival, neuronal loss, retinopathy, axonopathy, loss of motor function, lysosomal storage of subunit c of mitochondrial ATP synthase, and epileptic seizures, albeit with an earlier onset and faster progression than the human disease. Our study provides proof of principle that the advantages of the zebrafish over other model systems can be utilised to further our understanding of the pathogenesis of CLN3 disease and accelerate drug discovery

Increased myofibroblasts in the small airways, and relationship to remodelling and functional changes in smokers and COPD patients: potential role of epithelial-mesenchymal transition

Introduction: Previous reports have shown epithelial–mesenchymal transition (EMT) as an active processthat contributes to small airway fibrotic pathology. Myofibroblasts are highly active pro-fibrotic cells thatsecrete excessive and altered extracellular matrix (ECM). Here we relate small airway myofibroblastpresence with airway remodelling, physiology and EMT activity in smokers and COPD patients.Methods: Lung resections from nonsmoker controls, normal lung function smokers and COPD currentand ex-smokers were stained with anti-human α-smooth muscle actin (SMA), collagen 1 and fibronectin.αSMA+ cells were computed in reticular basement membrane (Rbm), lamina propria and adventitia andpresented per mm of Rbm and mm2 of lamina propria. Collagen-1 and fibronectin are presented as apercentage change from normal. All analyses including airway thickness were measured using Image-proplus 7.0.Results: We found an increase in subepithelial lamina propria (especially) and adventitia thickness in allpathological groups compared to nonsmoker controls. Increases in αSMA+ myofibroblasts were observedin subepithelial Rbm, lamina propria and adventitia in both the smoker and COPD groups compared tononsmoker controls. Furthermore, the increase in the myofibroblast population in the lamina propria wasstrongly associated with decrease in lung function, lamina propria thickening, increase in ECM proteindeposition, and finally EMT activity in epithelial cells.Conclusions: This is the first systematic characterisation of small airway myofibroblasts in COPD based ontheir localisation, with statistically significant correlations between them and other pan-airway structural,lung function and ECM protein changes. Finally, we suggest that EMT may be involved in such changes

Halal dating: changing relationship attitudes and experiences among young British Muslims

Young Muslims in the UK are making space to gain greater control over their personal lives through the diction of ‘halal’ and ‘haram’ when reflecting on and negotiating personal relationships. This article explores the significance of ‘halal dating’ within the lived experiences and sexual relationships of young British Muslims. It draws upon 56 in-depth interviews conducted with young (16–30 years) British Muslims of Pakistani heritage. This research shows that, contrary to popular stereotype and widespread expectations, many young British Muslims do date, or have dated. By entertaining the idea that certain forms of dating may be halal, these young Muslims are finding and claiming agency to make relationship choices of their own