801 research outputs found
Sailing the Archipelago in a Boat of Rhymes Pantun in the Malay World
The extremely popular poetic form from Insular Southeast Asia, the pantun, travelled from its unknown source throughout the Malay Archipelago, first in Malay, then in the languages of Southeast Asia. In the ports and states where they were received, local colour, other idiosyncrasies, references, and linguistic characteristics have been added, and in fact, special forms with special names developed. This basic form is known, composed, and loved in at least 40 dialects of Malay, and 35 non-Malay languages, in the Peninsula and many of the islands of Malaysia and Indonesia. It spread through trade routes, ports, and also via diasporas and colonial economic projects which caused numerous peoples to move, who in turn brought the pantun along with them. It is now the most dynamic single literary form and has the longest history
Hybrid features-based prediction for novel phish websites
Phishers frequently craft novel deceptions on their websites and circumvent existing anti-phishing techniques for insecure intrusions, users’ digital identity theft, and then illegal profits. This raises the needs to incorporate new features for detecting novel phish websites and optimizing the existing anti-phishing techniques. In this light, 58 new hybrid features were proposed in this paper and their prediction susceptibilities were evaluated by using feature co-occurrence criterion and a baseline machine learning algorithm. Empirical test and analysis showed the significant outcomes of the proposed features on detection performance. As a result, the most influential features are identified, and new insights are offered for further detection improvement
Students' Interest and Usefulness of Fieldwork Approaches to History
It is very exciting that history in the Integrated Cmriculum forSecondary School (ICSS) has been included as one of the core subjects inthe lower and upper secondary levels of Malaysian schools. These subjectsare officially included in the time table of the ordinary, religious, science,vocational and technical schools in the country. One of the most importantand effective methods introduced in the teaching and learning of historyis a fieldwork approaches, particularly a site visit. Since history is acompulsory subject, it is necessary to study and analyse the ICSS historycurriculum to see i f it really could achieve the objectives of the syllabus,successfully imparting knowledge and develop interest among studentsin the subject. The study involved about eight hundred students of selectedsecondary schools in the states of Perak and Terengganu. Instr\imentsused were questionnaire and interview which were conducted with theselected respondents. The analysis of the study were presented inpercentage by using six Likert scale responses. The study shows that historyfieldwork contain many usefulness such as to develop, spark/ stimulate,motivate, investigate, prove, gain social experience, social sldUs, buildteacher-student relation, teaching-learning method, and fulfil NationalCurriculum. Moreover, the effective used of history fieldwork can enhancestudent interest in developing the country towards the advancement of'first class mind' of human capital of Malaysian. It is hoped that the findingwill enlighten teachers and students in the learning of history in the ICSStowards achieving the stipulated aspiration, especially 1-Malaysia
Chemical constituents and acetylcholinesterase inhibitory activity of Beilschmiedia insignis Gamble
ABSTRACT. Secondary metabolites from natural products are potential sources of acetylcholinesterase inhibitors, which are key enzymes in the treatment of many neurodegenerative diseases. Inspired by the reported activities of alkaloids herein we report the chemical investigation on the chemical constituents from Beilschmiedia insignis and their acetylcholinesterase inhibitory activity. Isolation of the stem bark of B. insignis led to the isolation and identification of five aporphine alkaloids, namely isocorydine (1), norisocorydine (2), (+)-laurotetanine (3), (+)-N-methyllaurotetanine (4), and (+)-boldine (5), together with β-sitosterol (6), β-sitostenone (7), lupeol (8), and lupenone (9). The chemical structures of these compounds were obtained by analysis of their spectroscopic data, as well as the comparison with that of reported data. Acetylcholinesterase inhibitory activity revealed that all isolated alkaloids were found to inhibit AChE with percentage inhibition values ranged from 44.9 to 74.5%. This is the first report on phytochemicals from B. insignis.
KEY WORDS: Lauraceae, Beilschmiedia insignis, Alkaloid, Acetylcholinesterase, Alzheimer
Bull. Chem. Soc. Ethiop. 2021, 35(3), 685-691.
DOI: https://dx.doi.org/10.4314/bcse.v35i3.1
Cross match-CHMM fusion for speaker adaptation of voice biometric
The most significant factor affecting automatic voice biometric performance is the variation in the signal characteristics, due to speaker-based variability, conversation-based variability and technology variability. These variations give great challenge in accurately modeling and verifying a speaker. To solve this variability effects, the cross match (CM) technique is proposed to provide a speaker model that can adapt to variability over periods of time. Using limited amount of enrollment utterances, a client barcode is generated and can be updated by cross matching the client barcode with new data. Furthermore, CM adds the dimension of multimodality at the fusion-level when the similarity score from CM can be fused with the score from the default speaker modeling. The scores need to be normalized before the fusion takes place. By fusing the CM with continuous Hidden Markov Model (CHMM), the new adapted model gave significant improvement in identification and verification task, where the equal error rate (EER) decreased from 6.51% to 1.23% in speaker identification and from 5.87% to 1.04% in speaker verification. EER also decreased over time (across five sessions) when the CM is applied. The best combination of normalization and fusion technique methods is piecewise-linear method and weighted sum
Chemical constituents and acetylcholinesterase inhibitory activity of Piper abbreviatum Opiz
Plants of the genus Piper have long been used as medicinal herbs. The chemistry of Piper species has been widely investigated and phytochemical investigations conducted in all parts of the world have led to the isolation of a number of physiologically active compounds. Thus, this study was carried out to investigate the phytochemicals from Piper abbreviatum and their acetylcholinesterase inhibitory activity, which has not been previously investigated. Fractionation and purification of the aerial parts of P. abbreviatum led to the isolation and identification of five methoxylated flavonoids, namely 5,7-dimethoxyflavone, 4ʹ,5,7-trimethoxyflavone, 3',4',5,7-tetramethoxyflavone, 5-hydroxy-7-methoxyflavone, 5-hydroxy-4ʹ,7-dimethoxyflavone, together with lupeol, lupenone, β-sitosterol, and β-sitostenone. The structures of these compounds were obtained by analysis of their spectroscopic data, as well as the comparison with that of reported data. Acetylcholinesterase inhibitory activity revealed that all isolated flavones were found to inhibit AChE with percentage inhibition values ranged from 24.2 to 58.2%. This is the first report on the isolation of methoxylated flavonoid from P. abbreviatum. The high variants of flavonoid compounds from this species may be used as chemotaxonomic markers for this Piper species.
KEY WORDS: Piperaceae, Piper, Piper abbreviatum, Flavonoid, Acetylcholinesterase
Bull. Chem. Soc. Ethiop. 2020, 34(3), 625-632.
DOI: https://dx.doi.org/10.4314/bcse.v34i3.1
Comparison of Double Unit Tunnel Form Building before and after Repair and Retrofit under in-Plane Cyclic Loading
This paper present the experimental work on the seismic performance of double unit tunnel form building (TFB) subjected to in-plane lateral cyclic loading. A one third scale of 3-storey double unit of TFB is tested at ±0.01%, ±0.1%, ±0.25%, ±0.5%, ±0.75% and ±1.0% drifts until the structure achieves its strength degradation. After that, the TFB is repaired and retrofitted using additional shear wall, steel angle and CFRP sheet. A similar testing approach is applied to the specimen after repair and retrofit. The crack patterns, lateral strength, stiffness, ductility and equivalent viscous damping (EVD) were analyzed and compared before and after repair and retrofit. The result indicates that the lateral strength increases by 22 in pushing direction and 27% in pulling direction. Moreover, the stiffness and ductility obtained before and after retrofit increase tremendously by 87.87% and 39.66%, respectively. Meanwhile, the energy absorption measured by equivalent viscous damping obtained after retrofit increase by 12.34% in pulling direction. It can be concluded that the proposed retrofit method is capable to increase the lateral strength capacity, stiffness and energy absorption of double unit TFB
Chemical constituents and lipoxygenase inhibitory activity of Piper stylosum Miq.
ABSTRACT. Chemical constituents and lipoxygenase inhibitory activity of the aerial part of Piper stylosum have been studied. Fractionation and purification of the extracts afforded five lignans, identified as yangambin (1), sesamin (2), syringaresinol (3), pinoresinol (4), and medioresinol (5), together with other constituents; 4-allyl resorcinol, β-sitosterol, β-sitostenone, taraxerol, vanilin, and vanilic acid. The structures of these compounds were established by analysis of their spectral data, as compared to that of reported compounds. The lipoxygenase inhibitory activity of the extracts and isolated lignans were also evaluated. KEY WORDS: Piperaceae, Piper, Piper stylosum, Lignan, Lipoxygenase Bull. Chem. Soc. Ethiop. 2019, 33(3), 587-592. DOI: https://dx.doi.org/10.4314/bcse.v33i3.1
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