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Enhanced coproduction of astaxanthin and lipids by the green microalga Chromochloris zofingiensis: Selected phytohormones as positive stimulators
No full textPhytohormones comprise a variety of trace bioactive compounds that can stimulate cell growth and promote metabolic shifts. In the present work, a two-stage screening strategy was innovatively established to identify positive phytohormones for enhancement of astaxanthin and lipid coproduction in microplate-based cultures of mixotrophic Chromochloris zofingiensis. The results showed that auxins were the most efficient stimulators for astaxanthin accumulation. The maximum content of 13.1 mg/g and yield of 89.9 mg/L were obtained using indole propionic acid (10 mg/L) and indoleacetic acid (7.8 mg/L), representing the highest levels of astaxanthin in this microalga reported to date. Total lipids with the highest content (64.5% DW) and productivity (445.7 mg/L/d) were coproduced with astaxanthin using indoleacetic acid. Statistical analysis revealed close relations between phytohormones and astaxanthin and lipid biosynthesis. This study provides a novel original strategy for improving astaxanthin and lipid coproduction in C. zofingiensis using the selected phytohormones as positive stimulators. © 2019 Elsevier Lt
Toleransi antara Agama: Analisis terhadap Jaminan Keamanan Umar ke atas Islamicjerusalem
No full textAsia Tenggara telah dihiasi dengan masyarakat berbilang kaum, pelbagai budaya dan pelbagai agama. Oleh itu, adalah jelas bahawa Asia Tenggara ini terdiri daripada negara-negara dengan pelbagai penganut agama. Malangnya, di sesetengah negara, agama telah 'digunakan' sebagai penghalang untuk mendapatkan keamanan dan kestabilan. Berhubung dengan ini, keadilan adalah aspek yang sangat penting untuk keamanan dan kestabilan. Sementara itu, adalah tidak kurang pentingnya toleransi agama juga dapat menjadi pemangkin untuk mencapai keamanan itu. Sebagai antara majoriti negara Islam, Malaysia dan Indonesia telah memainkan peranan mereka dalam toleransi agama dan harus terus melakukannya dalam usaha mewujudkan kehidupan yang aman damai di rantau ini. Oleh itu, kertas kerja ini bertujuan untuk meneroka toleransi agama pada masa pembebasan Islam pertama terhadap Islamicjerusalem pada zaman Umar al Khattab untuk melihatnya sebagai model dalam zaman kini. Kajian ini bersifat kualitatif dan menggunakan kaedah kajian sejarah dalam menangani data. Implikasi kajian menunjukkan bahawa Muslim dan bukan Islam harus memberikan lebih perhatian terhadap toleransi agama agar dapat meneruskan kedamaian dan kestabilan di dunia moden ini
“The Malay Garden” is “The Malaysian Garden (MGC)”: The Reality and Challenges of Establishing a National Identity
No full textThe Malaysian Garden Concept (MGC) is an initiative by the National Landscape Department (NLD) to develop a garden concept that will one day achieve its fame, as the garden concepts are well known today. A comparative study was to determine the level of MGC criteria applies to public parks built by the NLD. The selected case studies were from a public park built after the MGC guidelines established in 2009 (n = 6). 5 MGC experts were interviewed in this study to confirm the issues raised. For the record, planning to create these guidelines took a long time and involved various parties associated with the profession of Landscape Architect. The methodology of the study using observation and interview techniques (selected through criterion sampling method). From the research conducted, researchers have found that the level of compliance with the MGC guidelines is worrisome, and possibly no effort to uphold this concept by the responsible party. There are 3 criteria that hard to be implemented by most of these public parks are Architectural structure & local elements; Culture & Heritage; and High Intrinsic Value. This research has shown that it is not easy to apply a "heritage & culture" principles in landscape design, especially to a multiracial and multicultural country like Malaysia. © 2020, Hampstead Psychological Associates. All rights reserved
Modelling and performance analysis of parabolic trough solar concentrator for different heat transfer fluids under Malaysian condition
No full textWith the increasing energy demand, depleting fossil fuel, and commitment to the Paris climate agreement, Malaysia should tap into this natural resource and harness its solar energy potential. In this research, a location in Malaysia was chosen based on its yearly direct normal irradiance (DNI) and an optimization strategy for a potential parabolic trough power plant. Besides that, an energetic and exergetic comparison and analysis between 6 HTFs (Pressurized water, Therminol VP-1, Syltherm 800, Solar salt, Hitec XL) on real-world climatic condition (based on Malaysian climatic condition) with varying inlet temperature level (300K–900K), ambient temperature and wind speed was done by using 1-D mathematical model that was coded in MATLAB®. Bayan Lepas received the highest yearly DNI and Sodium liquid outperformed other HTFs at varying DNI and inlet temperature level except at 300K with an advantage ranging between 0.036% and 0.99% in thermal efficiency and 0.438%–0.85% in exergetic efficiency to other HTFs. Sodium liquid at the temperature level of 700K also showed the strongest exergetic gained for any potential implementation of PTSC power plant in Malaysia. For climatic impact on the performance of HTFs, Energetic performance increase with ambient temperature while exergetic performance showed otherwise for all HTFs. Wind speed increment has a negligible impact on PTSC performance for all HTFs with sodium liquid's performance being the most resistant to any wind increment. © 201
Post-stroke depression in rehabilitation
No full textDepression is a frequent companion of stroke. It is associated with a degree of functional impairment that might adversely affect rehabilitation. A study was carried out to determine the rate of self-reported depression at admission and after six months, and the associated factors, in patients with stroke who were referred for rehabilitation. A multiple binary logistic regression was used to determine the associated factors at six months. Depression was recorded in 45% of patients at admission and in 39% at six months after the stroke. Patients who were employed, those who were depressed at admission, those who did not return to work and those who did not return to driving six months after stroke, were significantly associated with depression. © 2020, Faculty of Medicine, University of Malaya. All rights reserved
Predictive factors of prostate cancer diagnosis with PSA 4.0–10.0 ng/ml in a multi-ethnic Asian population, Malaysia
No full textObjectives: To identify the associated factors determining prostate cancer detection using transrectal ultrasound (TRUS)-guided prostate biopsy, within a multi-ethnic Malaysian population with prostate specific antigen (PSA) between 4.0 and 10.0 ng/ml. Methods: Study subjects included men with initial PSA between 4.0 and 10.0 ng/ml that have undergone 12-core TRUS-guided prostate biopsy between 2009 and 2016. The prostate cancer detection rate was calculated, while potential factors associated with detection were investigated via univariable and multivariable analysis. Results: A total of 617 men from a multi-ethnic background encompassing Chinese (63.5%), Malay (23.1%) and Indian (13.3%) were studied. The overall cancer detection rate was 14.3% (88/617), which included cancers detected at biopsy 1 (first biopsy), biopsy 2 (second biopsy with previous negative biopsy) and biopsy ≥ 3 (third or more biopsies with prior negative biopsies). Indian men displayed higher detection rate (23.2%) and increased risk of prostate cancer development (OR 1.85, 95% CI 1.03–3.32, p < 0.05), compared to their Malay (9.8%) and Chinese (14.0%) counterparts. Multivariable analysis revealed that ethnicity and PSA density (PSAD) are independent factors associated with overall prostate cancer detection rate. A unit increase of PSAD reflected an increase in PSA after controlling for prostate volume. Conclusion: Prostate cancer detection in Malaysia is comparatively lower. Our study suggests that ethnicity and PSA density should be considered when recommending first or repeat TRUS-guided prostate biopsy for prostate cancer detection in a multi-ethnic Malaysian population. © 201
Effects of shorter phase-resolved partial discharge duration on PD classification accuracy
No full textPartial discharge (PD) pattern recognition is useful to diagnose insulation condition. PD measurement data is commonly represented in phase-resolved partial discharge (PRPD) format. PRPD is useful as it provides a visible pattern for different PD source and various features can be extracted for PD pattern recognition. Shorter PRPD duration will enable more training data but the information in each data is less and vice versa. This works aims to investigate the effects of using very short duration PRPD data on the accuracy of PD pattern recognition. The results conclude that machine learning models such as Artificial Neural Network (ANN) and Support Vector Machine (SVM) are robust enough such that reduction of PRPD duration from 15-seconds to 1-second causes less than 5 % drop in the classification accuracy. However, this is only true for noise free condition. When the same PD data is overlapped with random noise, the classification accuracy suffers a significant reduction up to 19%. Therefore, longer PRPD duration is recommended to withstand the effects of noise contamination. © 2020, Institute of Advanced Engineering and Science. All rights reserved
Usability Elements in Digital Textbook Development: A Systematic Review
No full textThe growth of digital technology triggers a new wave to the development of new media alternative including digital textbook. A variety of digital textbook formats and the content is easily transportable cross media can lead to complexity of user expectations. Considering usability elements is one of the critical successful factors to ensure the digital textbook meets the user expectation. Despite, overwhelming research and standards pertaining usability, there is still a lack of efforts to systematically review the concept of usability elements in the digital textbook development context. The research seeks at addressing this gap by evaluating the current literature on the notion of usability components regarded in digital textbook development. A systematic analysis of the Scopus and Web of Science databases acknowledged 17 related studies from 213 journal articles, guided by the evaluation method of the PRISMA Statement (Preferred Reporting Items for Systematic Reviews and Meta-Analysis). Further review of these articles resulted 17 usability factors have been identified. These usability factors further produced a total of 49 usability properties. The review provides a better understanding of usability factors and criteria that need to be considered in the development of digital textbook and shows that usability elements is crucial for improving the digital textbook quality. In addition, this research provides a basis for the future research in usability elements of digital textbook. © 2019, Springer Science+Business Media, LLC, part of Springer Nature
A 1-V 4-mW Differential-Folded Mixer with Common-Gate Transconductor Using Multiple Feedback Achieving 18.4-dB Conversion Gain, +12.5-dBm IIP3, and 8.5-dB NF
No full textThis article reports a novel differential-folded mixer with multiple-feedback techniques for performance enhancement. Specifically, we introduce the capacitor cross-coupled (CCC) common-gate (CG) transconductance stage to improve the noise figure (NF) at low power by boosting the effective transconductance, while enhancing the linearity via suppressing the second-order harmonic distortion. Typically, the created loop gain of the CCC can raise the third-order intermodulation (IM3) distortion, penalizing the input-referred third-order intercept point (IIP3). Here, we propose a positive and a second capacitive feedback into the CCC CG transconductor, not only to suppress the IM3 distortion current but also adds in design flexibility to the input transistors. Furthermore, the positive feedback also improves the input impedance matching, conversion gain, and NF through a flexible design criterion. Prototyped in a 0.13- μm process, the proposed mixer operating at 900 MHz dissipates 4 mW at 1 V. The measured double sideband (DSB) NF is 8.5 dB, the conversion gain ( GC ) is 18.4 dB and the IIP3 is +12.5 dBm. © 1993-2012 IEEE