Malaysian Journal of Science 2021-10-31T00:00:00+08:00 Editor-in-Chief / Journal Manager Open Journal Systems <p style="text-align: justify;">Malaysian Journal of Science (MJS), launched in 1972, is the official peer-reviewed open access journal of the&nbsp;<a href="">Faculty of Science, University of Malaya</a>.&nbsp;Effective from&nbsp;year 2020 onwards, the frequency of regular issues publication is&nbsp;three&nbsp;times a&nbsp;year; on&nbsp;every February, June and October. MJS is indexed in Scopus, EMBASE, Compendex, GEOBASE, EMBiology, Elsevier BIOBASE, FLUIDEX ,World Textiles, CAB Abstracts, Chemical Abstracts Service Database and ASEAN Citation Index (ACI).</p> <p style="text-align: justify;">MJS is a reputable journal with a growing number of audience, which focuses on current developments in all disciplines of science. The journal publishes original articles, review articles, short communications and case reports that are of importance to the scientific community.&nbsp;</p> <p style="text-align: justify;"><strong>eISSN&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;: 2600-8688<br></strong><strong><strong>Print ISSN&nbsp; &nbsp;: 1394-3065<br></strong></strong><strong><strong>Publisher&nbsp; &nbsp; : Faculty of Science, University of Malaya</strong></strong>&nbsp;</p> ISOLATION, CHARACTERIZATION AND ANTIBACTERIAL SREENING OF ANTIBIOTICS PRODUCED FROM STREPTOMYCES ISOLATED FROM DUMPSITE SOILS IN ILORIN, NORTH CENTRAL NIGERIA 2020-09-10T16:50:51+08:00 Risikat Nike Ahmed Mercy Oluwaseyi Bamigboye Kamoldeen Abiodun Ajijolakewu Sheriffdeen Olakunle Idris Nimat Toyosi Ajide Bamigboye <p><strong>Abstract </strong></p> <p>Antibiotics are one of the most exploited metabolites produced by soil actinomycetes. This study isolated fifteen actinomycetes (A1 – A15) from dumpsite soils within Ilorin metropolis &amp; screened them for antibacterial activity. Isolates were identified with morphology &amp; biochemical characteristics.Their &nbsp;activity against clinical bacteria (<em>Escherichia coli</em>, <em>Pseudomonas aeruginosa</em>, <em>Klebsiella pneumoniae</em> &amp; <em>Staphylococcus aureus</em>) was determined. Their bioactive metabolites after fermentation was assayed for &nbsp;by agar well diffusion &amp; compared with reference antibiotics. Molecular analysis of two most active isolates was done. The most active metabolite was subjected to GCMS. All isolates were identified as <em>Streptomyces,</em> 7 isolates exhibited activity against 3 test bacteria with highest (10.5mm±0.35) by <em>Streptomyces</em><em> griseoplanus </em>while <em>S. aureus</em> demonstrated total resistance to all isolates. Secondary activity revealed 7 of the metabolites as effective against the bacteria &nbsp;with highest activity (28.5±1.04mm) by <em>S.</em> <em>sparsogenes</em> showing similar activity with Cefuroxime (28.01±0.01mm). The two most active isolates&nbsp; were <em>Streptomyces</em><em> griseoplanus </em>strain NR725RL-ISP 5009 &amp; <em>Streptomyces sparsogenes</em> strain NBRC 1308616S &amp; RNA nucleotide similarity revealed close phylogenic relationship. GC-MS revealed10 compounds in <em>S.</em> <em>sparsogenes</em> strain NBRC 1308616S metabolite. <em>Streptomyces</em> from dumpsite soils within &nbsp;Ilorin produced bioactive compounds against &nbsp;clinical test bacteria and thus could be &nbsp;potential sources of antibiotics.</p> <p>&nbsp;</p> 2021-10-31T00:00:00+08:00 Copyright (c) 2021 Malaysian Journal of Science ELUCIDATING THE GONADAL DEVELOPMENT AND SEX DIFFERENTIATION OF THE RICE PADDY EEL, Monopterus albus (Zuiew, 1993), BASED ON GONADAL HISTOMORPHOLOGY AND STEROID HORMONE LEVELS 2021-06-23T13:05:44+08:00 Dulce Marie Pili Nisperos Gliceria B. Ramos <p>The establishment and survival of the population of species in their breeding ground can be attributed to the species’ reproductive characteristic and capacity. The<em> Monopterus albus species</em> is an introduced fish in the Philippines. It is a protogynous hermaphrodite which has a natural ability for sex reversal. This study describes the histomorphology of the different stages of gonadal maturation and determines the concentration levels of the steroid hormones 17ß-estradiol (E2) and testosterone (T) in the blood plasma. These aim to a further understanding on the gonadal development and sex differentiation of the rice paddy eel as a hermaphroditic fish. Fish samples were collected randomly from farm ponds located in three provinces within the island of Luzon, Philippines. The sexual identity of the fish was categorized based on the presence or absence of ovarian and testicular tissues. Histological analysis of the gonad showed that immature, maturing-matured female gonad exhibited ovarian tissues of varying stages. The intersex gonad showed the existence of both ovarian and testicular tissues. Enzyme-linked immunosorbent assay (ELISA) was used to determine the concentration levels of gonadal steroid hormones. Differences in the concentration levels of the two hormones were evident across all the stages of gonad maturation. The functional role of these hormones in vitellogenesis and spermatogenesis leads to the development of this sex-changing gonads. This reproductive characteristic contributes to our understanding of the reproductive success of hermaphroditic fish.</p> 2021-10-31T00:00:00+08:00 Copyright (c) 2021 Malaysian Journal of Science MODIFIED TEA LEAVES RESIDUAL FOR NICOTINE ADSORPTION 2020-10-02T10:52:57+08:00 Y. Walid AlBizreh rasha Almostafa Malak ALJoubbeh <p>The boiled tea leaves residual was modified with oleum of weight 1:1 to prepare an adsorbent that is capable to adsorb nicotine on its surface. The surface properties of the sample were studied by using the FT-IR spectroscopy after each treatment resulting obvious peaks that indicate the modification of the sample with oleum and the adsorption of nicotine on its surface. The concentration of nicotine in the prepared solutions was measured by the use of spectral analysis. The change of nicotine΄s adsorption was studied with the change of time. An increase in the adsorbed amount was noticed until the equilibrium was reached after 24hours. In addition, an increase of the adsorbed amount of nicotine with the increase of its initial concentration was observed at the room temperature. The experimental data corresponded with adsorption models of Langmuir, Freundlish and Temkin, besides, a mechanism of the adsorption of nicotine was suggested to occur with the participation of the two nitrogen atoms.</p> 2021-10-31T00:00:00+08:00 Copyright (c) 2021 Malaysian Journal of Science THE CHARACTERISTICS OF SAGO FROND SAP FROM TWO SELECTED GROWTH STAGES; ANGKAT PUNGGUNG AND UPONG MUDA PALMS 2021-05-21T09:51:46+08:00 Nurazureen Matnin Dayang Salwani Awang Adeni Muhammad Norhelmi Ahmad Nurashikin Suhaili <p>Sago frond is produced in abundance upon harvesting of the sago palms for starch extraction, hence need to be utilized and developed into beneficial products. In this study, the sap which contains sugars and starch is obtained by roller crushing the skinned frond for use as fermentation medium. Fronds from different growth stages (namely <em>Angkat punggung</em> and <em>Upong muda</em>) and different positions within the rosette (inner and outer circle) of the sago palm were studied. Based on the results, the outer circle frond of <em>Upong muda</em> palm gave the highest volume of sap at 290mL/kg which equivalent to 1600 mL/frond. On top of that, sago frond sap has an acidic pH, with glucose as major sugar component and contained various kinds of minerals like calcium, potassium and manganese. All fronds from different growth stages contain glucose between 28-68 g/L and xylose 21-29 g/L, respectively. After 21 days of storage, it can be concluded that the amount of reducing sugars and starch in all samples obtained from different growth stages remained almost unchanged from the original. Subsequently after this study, both fresh and stored sago frond sap can be used as a fermentation substrate without any modification.</p> 2021-10-31T00:00:00+08:00 Copyright (c) 2021 Malaysian Journal of Science STOCHASTIC MODELING AND SENSITIVITY ANALYSIS OF AN INTEGRATED HARDWARE-SOFTWARE SYSTEM SUBJECT TO DIFFERENT WEATHER CONDITIONS 2020-06-22T15:33:17+08:00 Monika Saini Ashish Kumar <p>The current study covenants with stochastic investigation of an integrated hardware-software system considering hardware failure, software up-gradation upon failure, precautionary maintenance (PM) after a pre-determined process time, maximum repair time of hardware and different weather conditions. All time dependent indiscriminate variables are arbitrarily dispersed. Some important reliability measures like MTSF, availability and revenue of the system are obtained by using well established techniques semi-Markov process. Regenerative point technique has also been taken into consideration during model development. Sensitivity analysis of these measures is also performed. Finally, empirical analysis is done to demonstrate the results for a specific case. To climax the significance of the study, graphs of MTSF, availability, profit and sensitivity are also depicted.</p> 2021-10-31T00:00:00+08:00 Copyright (c) 2021 Malaysian Journal of Science AN EFFICIENT HYBRID DERIVATIVE-FREE PROJECTION ALGORITHM FOR CONSTRAINT NONLINEAR EQUATIONS 2021-04-08T17:12:58+08:00 Kanikar Muangchoo <p>In this paper, by combining the Solodov and Svaiter projection technique with the conjugate gradient method for unconstrained optimization proposed by Mohamed et al. (2020), we develop a derivative-free conjugate gradient method to solve nonlinear equations with convex constraints. The proposed method involves a spectral parameter which satisfies the sufficient descent condition. The global convergence is proved under the assumption that the underlying mapping is Lipschitz continuous and satisfies a weaker monotonicity condition. Numerical experiment shows that the proposed method is efficient.</p> 2021-10-31T00:00:00+08:00 Copyright (c) 2021 Malaysian Journal of Science FUZZY LIMITS OF FUZZY FUNCTIONS 2021-06-21T23:41:34+08:00 Abdulhameed Qahtan Abbood Altai <p>In this paper, we study the theory of fuzzy limit of fuzzy function depending on the Altai’s principle and using the representation theorem (resolution principle) to run the fuzzy arithmetic.</p> 2021-10-31T00:00:00+08:00 Copyright (c) 2021 Malaysian Journal of Science AN UPDATE CHECKLIST OF VULNERABLE FRESHWATER FISH RASBORA BALIENSIS (HUBBS & BRITTAN 1954) (CYPRINIFORMES: CYPRINIDAE) IN INDONESIA 2021-04-30T15:03:36+08:00 Veryl Hasan Dian Samitra <p><em>Rasbora baliensis</em> (Hubbs &amp; Brattan, 1954) is a vulnerable freshwater fish from Indonesia which was described in East Java, Bali Island, and West Lesser Sunda Islands. Specimens of <em>R. baliensis</em> were collected from several new Rivers in Java and East Lesser Sunda Islands and shows the current distribution range of this species.</p> 2021-10-31T00:00:00+08:00 Copyright (c) 2021 Malaysian Journal of Science