10,718 research outputs found

    A novel extended potential field controller for use on aerial robots

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    © 2016 IEEE. Unmanned Aerial Vehicles (UAV), commonly known as drones, have many potential uses in real world applications. Drones require advanced planning and navigation algorithms to enable them to safely move through and interact with the world around them. This paper presents an extended potential field controller (ePFC) which enables an aerial robot, or drone, to safely track a dynamic target location while simultaneously avoiding any obstacles in its path. The ePFC outperforms a traditional potential field controller (PFC) with smoother tracking paths and shorter settling times. The proposed ePFC's stability is evaluated by Lyapunov approach, and its performance is simulated in a Matlab environment. Finally, the controller is implemented on an experimental platform in a laboratory environment which demonstrates the effectiveness of the controller

    Demographic and contextual infl uences in injury risk among adolescents in a low-income country setting: Results from a school-based survey in Tanzania

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    Objective: This study investigated the social, demographic and contextual factors associated with injury among adolescents in a low-income urban sub-Saharan African setting.Methods: Data on 2 176 adolescents aged 11–16 years were divided into three groups: Those that reported not being injured, those that had been injured once, and those that had been injured multiple times within a 12-month recall period. We conducted bivariate analyses to screen for associations with several social, demographic and contextual factors. Then a multinomial logistic regression was performed to examine associations while adjusting for covariates.Results: Within the recall period, 22.14% of participants reported one serious injury and 10.96% reported multiple injuries. Compared with non-injured participants, those injured two or more times were mainly male (relative risk ratio (RRR) = 1.71 [1.27–2.31]), younger (RRR = 0.77 [0.68–0.86]), depressed (RRR = 1.98 [1.43–2.74]) and had high rates of truancy (RRR = 2.56; CI = 1.71–3.84). A travel time of more than 30 minutes to and from school was also associated with increased rates of injury (RRR = 1.61; CI = 1.13–2.29).Conclusions: Injuries are an important source of morbidity among school-attending adolescents in Dar es Salaam. The findings support more research into the contextual factors that predispose adolescents to excessive injury in the region. School settings have the potential to provide safety education in the region.Keywords: injury, sub-Saharan Africa, urban setting, school healt

    A comparative study of the effects of aerobic and resisted exercises on selected cardiopulmonary parameters in patients with asthma

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    Asthma is a multi-factorial disease associated with genetic, allergic, environmental, infectious, emotional, and nutritional issues. Globally, asthma affects about 300 million people and about 250,000 people die from it every year. These deaths are related to lack of proper treatment. Treatment involves controlling trigger factors, drug therapy, and other non-pharmacological methods. Although a few studies have evaluated the effects of exercises on asthma control, there is the need for well-designed outcome studies that will differentiate efficacious exercise management for asthma from those that hold little therapeutic value. This study compared the effects of aerobic and resisted exercises on selected cardiopulmonary parameters in patients with asthma.Forty-five patients with asthma were recruited from the Respiratory Unit, Department of Medicine, Lagos University Teaching Hospital (LUTH), Lagos and were randomly assigned to 3 different groups. Group A underwent aerobic exercise and counselling sessions; Group B, resisted exercise and counselling sessions; and Group C had counselling sessions only. Groups A and B had exercise intervention that lasted 10-15 minutes, twice weekly for 6 weeks. Cardiopulmonary parameters were assessed at baseline and at the end of 6 weeks.Only Group B showed significant improvements in all the cardiovascular variables (SBP: p=0.01, DBP: p=0.03, HR: p=0.02 and RPP: p=0.01). There were also significant improvements in most of the pulmonary 1 1 variables of Group A (RR: p=0.01, FEV : p=0.01, FVC: p=0.01 and FEV %: p=0.02), however, there was none in Groups B and C. Comparison of the mean changes in selected variables between the two therapeutic exercise 1 groups showed significant differences in SBP (p=0.01), DBP (p=0.04), RPP (p=0.02), RR (p=0.01), FEV 1 (p=0.01), FVC (p=0.05), FEV % (p=0.01) and IC (p=0.05).Aerobic exercise was more effective in improving pulmonary parameters while resisted exercise was more effective in improving cardiovascular parameters in patients with asthma.Keywords: aerobic exercise, asthma, cardiopulmonary, resisted exercis

    A Home Exercise Programme Is No More Beneficial than Advice and Education for People with Neurogenic Claudication: Results from a Randomised Controlled Trial

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    Objective: To compare the effectiveness of a physiotherapy programme with a control treatment of advice and education in patients with neurogenic claudication symptoms. Design: Pragmatic randomised controlled clinical trial. Setting: Primary care-based musculoskeletal service. Patients: Adults aged 50 or over with neurogenic claudication symptoms causing limitation of walking. Interventions: Condition-specific home exercises combined with advice and education, or advice and education alone. Main outcome measures: The primary outcome was the difference in improvement of symptom severity scores on the Swiss Spinal Stenosis Scale at eight weeks. Secondary outcomes included measures of physical function, pain and general well-being at eight weeks and 12 months. Results: There was no significant difference between groups in the Swiss Spinal Stenosis symptom severity scale at eight weeks (t = 0.47, p = 0.643): mean change (SD) control group -0.18 (0.47), treatment group -0.10 (0.66), difference (95% CI) 0.08 (-0.19, 0.35); baseline-adjusted difference 0.06 (-0.19, 0.31)]. An unplanned subgroup analysis suggested that for patients with the top 25% of baseline symptom severity scores, the physiotherapy exercise programme resulted in an improvement in the primary outcome, and modest but consistently better secondary outcomes at both time-points compared to the control group. The effectiveness in different subgroups requires further direct evaluation. Conclusions: In the treatment of patients with neurogenic claudication symptoms, a physiotherapist-prescribed home exercise programme is no more effective than advice and education

    Mothers’ perception and management of abdominal colic in infants in Enugu, Nigeria

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    Background: Abdominal colic is common in infants but generally harmless. The exact aetiology is unknown but it has been associated with vicious cycle of crying and swallowing of air by the infant. The excessive crying associated with it can result in a lot of distress for family members creating unnecessary panics. We sought to find the perception and management of abdominal colic by mothers in Enugu.Objective: Objective of this study is to determine the perception and ‘home management’ of abdominal colic in infants by mothers in Enugu, south-east Nigeria and the factors associated with them.Materials and Methods: A cross-sectional survey involving 177 mothers that presented with their infants at the pediatric outpatient clinic of the University of Nigeria Teaching Hospital, Ituku Ozalla, Enugu between June and November 2011. A pretested questionnaire was used after obtaining their consent.Results: A total of one hundred and seventy-seven mothers participated in this study. They were aged 20 to 60 years with mean age of 34 ± 7.3 years. Most of them (99.4%) believed that babies can have abdominal colic. While 41.3% attributed no problems to colic, the rest believed that it causes loose/greenish stools (12.4%), fever (16.4%) and vomiting (9.6%) etc. Most of the mothers (87.7%) do apply medications for colic which range from paracetamol (33.1%), Gbomoro (16.2%), teething powder (15.4%), salt water (13.2%), Buscopan (7.7%) and gripe water (4.6%).Conclusions: Mothers attribute symptoms of childhood illnesses to abdominal colic. This may have led to unnecessary and sometimes harmful management. There is need for health education of mothers and potential mothers.Key words: Abdominal colics, enugu, infant

    THERMORESPONSIVE, REDOX-POLYMERIZED CELLULOSIC HYDROGELS UNDERGO IN SITU GELATION AND RESTORE INTERVERTEBRAL DISC BIOMECHANICS POST DISCECTOMY

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    Back and neck pain are commonly associated with intervertebral disc (IVD) degeneration. Structural augmentation of diseased nucleus pulposus (NP) tissue with biomaterials could restore degeneration-related IVD height loss and degraded biomechanical behaviors; however, effective NP replacement biomaterials are not commercially available. This study developed a novel, crosslinked, dual-polymer network (DPN) hydrogel comprised of methacrylated carboxymethylcellulose (CMC) and methylcellulose (MC), and used in vitro, in situ and in vivo testing to assess its efficacy as an injectable, in situ gelling, biocompatible material that matches native NP properties and restores IVD biomechanical behaviors. Thermogelling MC was required to enable consistent and timely gelation of CMC in situ within whole IVDs. The CMC-MC hydrogel was tuned to match compressive and swelling NP tissue properties. When injected into whole IVDs after discectomy injury, CMC-MC restored IVD height and compressive biomechanical behaviors, including range of motion and neutral zone stiffness, to intact levels. Subcutaneous implantation of the hydrogels in rats further demonstrated good biocompatibility of CMC-MC with a relatively thin fibrous capsule, similar to comparable biomaterials. In conclusion, CMC-MC is an injectable, tunable and biocompatible hydrogel with strong potential to be used as an NP replacement biomaterial since it can gel in situ, match NP properties, and restore IVD height and biomechanical function. Future investigations will evaluate herniation risk under severe loading conditions and assess long-term in vivo performance

    Improving 3D ultrasound prostate localisation in radiotherapy through increased automation of interfraction matching.

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    Background and purpose Daily image guidance is standard care for prostate radiotherapy. Innovations which improve the accuracy and efficiency of ultrasound guidance are needed, particularly with respect to reducing interobserver variation. This study explores automation tools for this purpose, demonstrated on the Elekta Clarity Autoscan®. The study was conducted as part of the Clarity-Pro trial (NCT02388308). Materials and methods Ultrasound scan volumes were collected from 32 patients. Prostate matches were performed using two proposed workflows and the results compared with Clarity's proprietary software. Gold standard matches derived from manually localised landmarks provided a reference. The two workflows incorporated a custom 3D image registration algorithm, which was benchmarked against a third-party application (Elastix). Results Significant reductions in match errors were reported from both workflows compared to standard protocol. Median (IQR) absolute errors in the left-right, anteroposterior and craniocaudal axes were lowest for the Manually Initiated workflow: 0.7(1.0) mm, 0.7(0.9) mm, 0.6(0.9) mm compared to 1.0(1.7) mm, 0.9(1.4) mm, 0.9(1.2) mm for Clarity. Median interobserver variation was ≪0.01 mm in all axes for both workflows compared to 2.2 mm, 1.7 mm, 1.5 mm for Clarity in left-right, anteroposterior and craniocaudal axes. Mean matching times was also reduced to 43 s from 152 s for Clarity. Inexperienced users of the proposed workflows attained better match precision than experienced users on Clarity. Conclusion Automated image registration with effective input and verification steps should increase the efficacy of interfraction ultrasound guidance compared to the current commercially available tools

    The role of ECL2 in CGRP receptor activation: a combined modelling and experimental approach

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    The calcitonin gene-related peptide (CGRP) receptor is a complex of a calcitonin receptor-like receptor (CLR), which is a family B G-protein-coupled receptor (GPCR) and receptor activity modifying protein 1. The role of the second extracellular loop (ECL2) of CLR in binding CGRP and coupling to Gs was investigated using a combination of mutagenesis and modelling. An alanine scan of residues 271–294 of CLR showed that the ability of CGRP to produce cAMP was impaired by point mutations at 13 residues; most of these also impaired the response to adrenomedullin (AM). These data were used to select probable ECL2-modelled conformations that are involved in agonist binding, allowing the identification of the likely contacts between the peptide and receptor. The implications of the most likely structures for receptor activation are discussed.</jats:p

    Orbital bleeding in rats while under diethylether anaesthesia does not influence telemetrically determined heart rate, body temperature, locomotor and eating activity when compared with anaesthesia alone

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    The question addressed was whether orbital bleeding in rats, while under diethylether anaesthesia, affects their locomotor activity, body core temperature, heart rate rhythm and eating pattern. Roman High Avoidance (RHA) and Roman Low Avoidance (RLA) rats were used to enhance generalization of the results. Orbital bleeding when the rats were under diethylether anaesthesia was compared with diethylether anaesthesia alone. To take into account any effects of handling, the rats were also subjected to sham anaesthesia. The RHA rats urinated more during anaesthesia, needed more time to recover from the anaesthesia and showed a greater endocrine stress response to diethylether anaesthesia when compared with the RLA rats. During anaesthesia, the RHA rats showed a greater fall of body temperature and bradycardia than did the RLA rats. Diethylether anaesthesia reduced locomotor activity in the RHA rats, but had no effect in the RLA rats. In neither RHA nor RLA rats did anaesthesia plus orbital puncture, versus anaesthesia alone, influence body temperature, heart rate rhythm, locomotor and eating activity. The lack of effect of orbital puncture occurred both in the short term (within 2 h) and long term (within 48 hours) and thus this study indicates that orbital puncture had, at least with respect to variables measured in the present study, no effect superimposed on that of diethylether anaesthesia
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