19672 research outputs found
Sort by
Design and control of a wearable lower-body exoskeleton for squatting and walking assistance in manual handling works
No full textSeveral manual-handling works (e.g. load-lifting, carrying, carpet-laying, etc.) involve repetitive lower limb movements (RLLM) such as squatting, kneeling, or walking which are notable risk factors for work-related musculoskeletal disorders of the lower-limb and lumbar spine. Wearable exoskeletons can augment workers’ strength and minimize muscular activation in RLLM, thus enhancing efficiency and improving workers health. In this paper, we present the design and control of a wearable lower-body exoskeleton to assist RLLM. The design of the exoskeleton is anthropomorphic with six-degrees of freedom (6-DoF) on each leg: 1-active and 1-passive DoF on the hip-joint, 1-active and 1-passive DoF on the knee-joint, and 2-passive DoFs on the ankle-joint. The active DoFs are actuated by bi-directional brushless DC motors to permit sagittal movements. The exoskeleton controller is designed hierarchical with a low-level linear quadratic gaussian (LQG) torque controller, a middle-level user-input torque estimator based on dual extended Kalman filter (EKF), and a novel high-level supervisory algorithm for movement detection and synchronization of the exoskeleton with the user. Initial evaluation of the prototype is conducted on five healthy participants recruited to perform repetitive load-lifting and carrying manual-handling tasks. Electromyogram sensors are placed at the participants’ right Vastus Intermedius and right Gastrocnemius to extract muscle activity signals. Results show that the exoskeleton could provide torque assistance by amplifying participants’ input joint torques and could minimize muscular activation in the two muscles by more than 36% respectively in all movement tasks. © 201
Assessment of Potential Anticancer Activity of Brown Seaweed Compounds Using Zebrafish Phenotypic Assay
No full textDespite the extensive work on anticancer drug discovery, the number of potent lead compounds that enter the preclinical and clinical trials thus far is still low due to the poor selectivity and understanding in pharmacodynamics. In view of the homology between zebrafish embryogenesis and carcinogenesis in human, zebrafish embryos can be used in the screening platform to elucidate the molecular targets of potential anticancer compounds. In the present study, the possible targets modulating the potential anticancer effects of selected brown seaweed-derived compounds (ie alginate, fucoidan, phloroglucinol, fucosterol, and fucoxanthin) were examined. Teratogenic effects induced by the compounds were observed after 72 hours post-fertilization. Fucoidan, phloroglucinol, and fucosterol were observed to significantly reduce the pigmentation of the zebrafish in a dose-dependent manner at low concentrations (fucoidan, <60 µg/mL; phloroglucinol, <10 µg/mL; fucosterol, <3 µg/mL). On the other hand, embryos treated with fucoxanthin at 200 µg/mL and 300 µg/mL exhibited either phenotypes of curved trunk or bent tail. Further validation work using dual antiplatelet therapy (DAPT) and dorsomorphin as positive controls suggest that fucoxanthin might target the Notch and bone morphogenetic protein (BMP) pathways, respectively. Findings from this exploratory study henceforth have demonstrated the utility of zebrafish embryo to accelerate the discovery of potential compounds for targeted anticancer therapy. © The Author(s) 201
Issues limiting the evaluation of post implemented enterprise architecture
No full textEvaluation in enterprise architecture (EA) project is crucial to provide comprehensive information of the developed EA artefacts. It may assist in accurate evaluation of implemented Information Systems (ISs) in order to realize the achievement of EA’s goals and support EA decision makers. This research aims to identify and elaborate the existing issues of EA evaluation models. One of the crucial identified issues is to understand, capture and represent core aspects of EA artefacts. Most existing evaluation models do not provide structured approach which cover comprehensive aspect of EA implementation and some do not provide good practices to be applied. Hence, this research intends to cover the gap by exploring critical issues in EA implementation evaluation and elaborating main shortcomings of the reviewed EA models and methods through a systematic literature review. Copyright © 2019 Institute of Advanced Engineering and Science. All rights reserved
Enhancing streamflow forecasting using the augmenting ensemble procedure coupled machine learning models: case study of Aswan High Dam
No full textThe potential of the most recent pre-processing tool, namely, complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN), is examined for providing AI models (artificial neural network, ANN; M5-model tree, M5-MT; and multivariate adaptive regression spline, MARS) with more informative input–output data and, thence, evaluate their forecasting accuracy. A 130-year inflow dataset for Aswan High Dam, Egypt, is considered for training, validating and testing the proposed models to forecast the reservoir inflow up to six months ahead. The results show that, after the pre-processing analysis, there is a significant enhancement in the forecasting accuracy. The MARS model combined with CEEMDAN gave superior performance compared to the other models–CEEMDAN-ANN and CEEMDAN-M5-MT–with an increase in accuracy of, respectively, about 13–25% and 6–20% in terms of the root mean square error. © 2019, © 2019 IAHS
Sleep disturbance among Malaysian patients with end-stage renal disease with pruritus
No full textBackground: Chronic kidney disease-associated pruritus (CKD-aP) is a well-recognized, frequent and compromising complication among patients on hemodialysis. Despite advancement in basic medical sciences, CKD-aP is still a major complication and a challenge for both physicians and patients to manage. The aim of this study was to estimate the prevalence of CKD-aP among hemodialysis patients in Malaysia, to determine the impact of CKD-aP on sleep quality and any factors associated with CKD-aP. Method: A multi-centered, cross-sectional study design was conducted from February 2017 to September 2017 at a tertiary hospital and its affiliated dialysis centers, in Kuala Lumpur, Malaysia. Included were patients > 18 years of age who were undergoing hemodialysis and could understand Malay. Participants were asked to fill the Malay 5D-itch scale and the Malay Pittsburgh sleep quality index (PSQI) upon recruitment. Results: A total of 334/334 patients were recruited (response rate = 100%). The majority were male (59.6%) and Chinese (61.7%). A total of 61.3% had pruritus, of which most patients (63.4%) reported that their pruritus was mild. More than half (54.1%) reported that they slept > 6 h, and 93.2% experienced no sleep disturbances during the night. However; the overall PSQI median score [IQR] was 6.0 [5.0-9.0]. No significant association was found between demographic and clinical characteristics of patients with the severity of pruritus. Patients with moderate to severe pruritus were found to be 5.47 times more likely to experience poor sleep quality as compared to patients with mild or no pruritus. Conclusion: In Malaysia, the prevalence of CKD-aP was 61.3%, of which the majority reported that their pruritus was mild. Patients with moderate to severe pruritus were found to be 5.47 times more likely to experience poor sleep quality as compared to patients with mild or no pruritus. © 2019 The Author(s)
STEM education in schools: Teachers’ readiness to change
No full textChange is an important aspect for the implementation of STEM education in school. For teachers to implement STEM, they should have readiness to change and to have no resistance to change. However, teachers are still teaching for examination purposes regardless of the efforts from the Ministry urging them to change. Thus, the aim of this study was to investigate 20 science teachers and 18 pre-service teachers’ readiness to change and resistance to change with regards to STEM implementation. The participants were involved in the STEMBuild Training of Trainers (TOT) Program. The program consisted of three phases, which were: conception of STEM, knowledge building, and practical implementation. The content of the program was in-line with the Malaysian primary school curriculum. This was a pre-experimental design study because it involved only one group. Change beliefs scale and resistance to change scale were administered after the program. For the change beliefs scale the teachers had the highest mean score for Personal Valence and lowest mean score for Self-efficacy. Even though these two subscales of change beliefs showed opposite direction of belief towards change, the participants mean scores of the overall change beliefs was high which indicated a positive inclination towards the change. In terms of resistance to change scale, the teachers were generally supporters of the change. The findings revealed that the participants were ready to carry out the STEM activities in school, they adhered to the belief for this change and their resistance to change was minimal. © School of Engineering, Taylor’s University
Effect of hybridization on properties of hemp-carbon fibre-reinforced hybrid polymer composites using experimental and finite element analysis
No full textPurpose: In the recent years, the industries show interest in natural and synthetic fibre-reinforced hybrid composites due to weight reduction and environmental reasons. The purpose of this experimental study is to investigate the properties of the hybrid composites fabricated by using carbon, untreated and alkaline-treated hemp fibres. Design/methodology/approach: The composites were tested for strengths under tensile, flexural, impact and shear loadings, and the water absorption characteristics were also observed. The finite element analysis (FEA) was carried out to analyse the elastic behaviour of the composites and predict the strength by using ANSYS 15.0. Findings: From the experimental results, it is observed that the hybrid composites can withstand the maximum tensile strength of 61.4 MPa, flexural strength of 122.4 MPa, impact strength of 4.2 J/mm 2 and shear strength of 25.5 MPa. From the FEA results, it is found that the maximum stress during tensile, flexural and impact loading is 47.5, 2.1 and 1.03 MPa, respectively. Originality/value: The results of the untreated and alkaline-treated hemp-carbon fibre composites were compared and found that the alkaline-treated composites perform better in terms of mechanical properties. Then, the ANSYS-predicted values were compared with the experimental results, and it was found that there is a high correlation occurs between the untreated and alkali-treated hemp-carbon fibre composites. The internal structure of the broken surfaces of the composite samples was analysed using a scanning electron microscopy (SEM) analysis. © 2019, Emerald Publishing Limited
Transfer of the waterfall source isolate Pectobacterium carotovorum M022 to Pectobacterium fontis sp. nov., a deep-branching species within the genus Pectobacterium
No full textPectobacterium carotovorum M022 T has been isolated from a waterfall source in Selangor district (Malaysia). Using genomic and phenotypic tests, we re-examined the taxonomical position of this strain. Based on 14 concatenated housekeeping genes (fusA, rpoD, rpoS, acnA, purA, gyrB, recA, mdh, mtlD, groEL, secY, glyA, gapA and rplB), multi-locus sequence analysis revealed that strain M022 T falls into a novel clade separated from the other Pectobacterium species. The in silico DNA-DNA hybridization and average nucleotide identity values were lower than the 70 and 95% threshold values, respectively. In addition, by combining genomic and phenotypic tests, strain M022 T may be distinguished from the other Pectobacterium isolates by its incapacity to grow on D(+)-xylose, L-rhamnose, cellobiose and lactose. Strain M022 T (=CFBP 8629T=LMG 30744 T ) is proposed as the type strain of the Pectobacterium fontis sp. nov. © 2019 IUMS
Knowledge and practice of colorectal cancer screening in an urban setting: cross-sectional survey of primary care physicians in government clinics in Malaysia
No full textINTRODUCTION Colorectal cancer (CRC) was the third most commonly diagnosed cancer worldwide in 2008 (1.23 million cases, 9.7%). CRC screening was shown to be effective in reducing 70% of CRC mortality. However, the screening rate for CRC remains poor. METHODS A cross-sectional survey was conducted among primary care physicians (PCPs) in public primary care clinics in Kuala Lumpur, Malaysia. A 30-item self-administered questionnaire was used to assess the knowledge and practice of CRC screening. RESULTS The response rate was 86.4% (n = 197/228). Less than half (39.1%) of the respondents answered correctly for all risk stratification scenarios. Mean knowledge score on CRC screening modalities was 48.7% ± 17.7%. The knowledge score was positively associated with having postgraduate educational qualification and usage of screening guidelines. Overall, 69.9% of PCPs reported that they practised screening. However, of these, only 25.9% of PCPs screened over 50% of all eligible patients. PCPs who agreed that screening was cost-effective (odds ratio [OR] 3.34, 95% confidence interval [CI] 1.69-6.59) and those who agreed that they had adequate resources in their locality (OR 1.92, 95% CI 1.01-3.68) were more likely to practise screening. Knowledge score was not associated with the practice of screening (p = 0.185). CONCLUSION Knowledge and practice of CRC screening was inadequate among PCPs. Knowledge of screening did not translate into its practice. PCPs' perceptions about cost-effectiveness of screening and adequate resources were important determinants of the practice of screening. © 2019 Singapore Medical Association. All rights reserved
An inconsistent phase selection assessment for harmonic peaks elimination in operational modal testing
No full textAn improvement on modal analysis technique is always exacerbated by the limitation on both operational modal analysis (OMA) and experimental modal analysis (EMA). In a recent year, a novel method was introduced named impact-synchronous modal analysis (ISMA) which represents a magnificent achievement in this field. The efficiency of this method as a viable option for EMA and OMA is proven in previous research. However, a quick and straightforward real-time ISMA method is desired as the current procedure is labour-intensive and time-consuming due to the lack of control on the impact timing with respect to phase angle of the disturbances. Thus, the aim of this paper is to identify the significance of phase difference information between acceleration response and cyclic load component in eliminating the disturbances through impact-synchronous time averaging. The paper presented a phase selection assessment, and the results showed that a few averages, (i.e. four averages) are sufficient to filter out the disturbances by 72–80% of dominant periodic response due to cyclic load and over 50% reduction for second harmonic, when the phase angles with respect to the impact are inconsistent for each impact applied. A better modal identification result is obtained through a straightforward way of eliminating the periodic response. Thus, the estimated frequency response function is strongly enhanced and good correlation is observed between modal extraction data and benchmark EMA result. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature