Abstract:A dichloromethane extract of the stem bark of Cryptocarya nigra showed strong in vitro inhibition of Plasmodium falciparum growth, with an IC 50 value of 2.82 μg/mL. The phytochemical study of this extract has led to the isolation and characterization of four known alkaloids: (+)-N-methylisococlaurine (1), atherosperminine (2), 2-hydroxyathersperminine (3), and noratherosperminine (4). Structural elucidation of all alkaloids was accomplished by means of high field 1D-and 2D-NMR, IR, UV and LCMS spectral data. The isolated extract constituents (+)-N-methylisococlaurine (1), atherosperminine (2) and 2-hydroxy-atherosperminine (3) showed strong antiplasmodial activity, with IC 50 values of 5.40, 5.80 and 0.75 μM, respectively. In addition, (+)-N-methylisocolaurine (1) and atherosperminine (2) showed high antioxidant activity in a DPPH assay with IC 50 values of 29.56 ug/mL and 54.53 ug/mL respectively. Compounds 1 and 2 also both showed high antioxidant activity in the FRAP assay, with percentages of 78.54 and 70.66 respectively and in the metal chelating assay, with IC 50 values of 50.08 ug/mL and 42.87 ug/mL, respectively.
The insecticidal activities of extracts from 22 Malaysian medicinal plant extracts from 8 botanical families were tested against rice weevil: Sitophilus oryzae (L.) and lesser grain borer: Rhyzopertha dominica (F.). The extracts were obtained using hexane, methanol, and dichloromethane to extract potential biopesticides from dried leaves. The toxicity levels were examined periodically based on antifeedant activity and contact toxicity assays using treated grain assay. Hexane extracts of Alpinia conchigera, Alpinia scabra, Curcuma mangga, Curcuma purpurascens, Goniothalamus tapisoides, Piper sarmentosum, and methanol extracts of Curcuma aeruginosa, C. mangga, and Mitragyna speciosa were the most potent extracts against S. oryzae and R. dominica with lethal concentration (LC50) values of ≤ 0.42 mg/mL and ≤ 0.49 mg/mL, respectively. The contact toxicity test results showed that methanol extracts of C. aeruginosa and C. mangga, dichloromethane extracts of Cryptocarya nigra, and hexane extracts of C. mangga, and C. purpurascens resulted in 100% mortality of both pests within 28 days exposure of 5 mg/cm2 concentration.
This paper investigates students’ academic achievements through e-learning approaches based on students’ preference. E-learning approaches can be considered as asynchronous, synchronous and blended learning. Asynchronous learning happens when there is no set time for it to occur. Allows students to learn whenever and wherever they want, at their own pace. Web conferencing and chatting are used to deliver organised and time-bound activities characterise synchronous e-learning. Due to the Movement Control Order (MCO), which went into effect on March 18, 2020, lecturers at the Preparatory Centre for Science and Technology, Universiti Malaysia Sabah (PPST, UMS) could teach either synchronous or asynchronous classes. The independent sample t-test will be used, and the outcomes reveal statistically significant difference in the mean of both online learning strategies. Therefore, from the results we can conclude that students that prefer asynchronous learning approach improves the academic performance of students. However, higher end-of-course grades in asynchronous courses do not necessarily indicate that the asynchronous mode of instruction was more effective. This is because based on students’ preference for both methods that asked in questionnaires. The results also can be affected by various factors such as blended learning that is implemented for learning.
The jotter book concept is not a novel method in scientific research. This practice is common not only among undergraduate students but also among postgraduate students, scientists, and researchers who use it to understand theories, concepts, and newly learned experimental procedures since it is important and significant pre-laboratory (pre-lab) preparation before an experiment is conducted. However, using a jotter book as one component of alternative pre-laboratory (pre-lab) assessment in assessing student achievement at pre-University level is something that has never been done before. In this paper, we proposed the rationale in implementation of the jotter book as one of the alternative assessments for the Chemistry course (SK0011-Practical Chemistry I and SK0021-Practical Chemistry II) for the foundation of science students in the Preparatory Centre for Science and Technology (PPST), Universiti Malaysia Sabah. Sample of 353 students from the intake session 2020/2021 are involved in this study. The improvement in the student grade from semester 1 to semester 2 will be discuss in this paper as the preliminary study.
Since its accreditation by MQA in 2018, the UMS Foundation in Science Program, through PPST has continuously produced high quality standards for students furthering their studies in UMS. Clinging to its accredited program means that quality assurance of foundation’s teaching and learning will be maintained and monitored. Herein, this study reports the feedback given by the foundation program’s alumni whose continue in undergraduate study of UMS Engineering. The objective is to investigate the students’ perception on knowledge and skills they obtained throughout the foundation year in relation to their courses study. A questionnaire with open ended question was constructed through a google form and designed in accordance with the MQA program review and monitoring guideline with 4 Likert scale (1- strongly disagree, 2- disagree, 3-agree and 4-strongly agree). Among 35 student’s replies, almost everyone answered high percentage of number 3 and 4, indicating an agreement towards knowledge and skills aspects. 100% student agree that the foundation program give them new knowledge and strengthen the basic theories in their engineering courses. Meanwhile, 94% believed that the foundation courses strengthen the personal skills, contribute to the achievement in engineering course and assist them to apply the skills obtained in foundation for lifelong learning. In open-ended questions, two themes of answers: (i) strength; (ii) hopes and expectations were organized, which highly in line with the students’ feedback in the Likert scale scores. This is in accordance with the student agreement that Foundation in Science Programme of UMS does provide basic knowledge and skills that relevant to the Engineering course in UMS. Further suggestions received and changes to the programme in the new academic year will be continuously monitored and reviewed for academic quality assurance.
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