|
Archives |
Volume 6, Issue No 3, September 2019 <<Previous Volume II Next Volume>>
Issues in Volume 6 Cover Page and Table of Contents Full Articles
A Preliminary Assessment on Avian Community in the Urban Forest of Universiti Malaysia Sabah
Wing-Shen Lim; Andy Russel Mojiol. 2019. Transactions on Science and Technology, 6(3), 292 - 297 Abstract Preliminary assessment was conducted on avian community that presented at the urban forest of Universiti Malaysia Sabah in present study. Four line transects were established at four randomly-selected locations that surrounded the Forestry Complex in UMS. Point-count survey was employed in sampling avian individuals, and then ancillary data was collected through visual assessment, at each sampling post established along respective transects. A total of 201 avian individuals belonged to 46 species and 23 families were sighted and identified in present study, and then 5 threatened species were encountered at arboretum (Transect 1), stairway (Transect 2) and natural-regenerated forest (Transect 4) habitats. Urban forest habitat of UMS was determined with rich resident avian diversity, especially at the stairway habitat. UMS serves as a shelter to wide range of resident avian species, as well as to several migratory and threatened avian species. Due to small sampling area and short sampling time employed in present study, there is a need to conduct similar study on the entire campus of UMS, to provide a holistic understanding on the relationship between avian community and habitat condition at urban forest ecosystem of UMS, as well as for other urban forests in Kota Kinabalu, Sabah. View article
Cryopreservation Effect on the Expression of DNA Methylation Genes in Wharton’s Jelly-Derived Mesenchymal Stem Cells
Mellinda Jenuit; Vun Vun Hiew; Haselamirrah Mohd Akhir; Peik Lin Teoh. 2019. Transactions on Science and Technology, 6(3), 298 - 303 Abstract Mesenchymal stem cells (MSCs) derived from Wharton’s jelly (WJ) has become an alternative source to obtain MSCs for clinical application. This is due to less ethical concerns and invasive procedures compared to embryonic and bone marrow stem cells. To ensure plentiful supply, cryopreservation is commonly used to preserve the cell viability. However, this technique may affect the characteristics and epigenetic regulation of these cells. In this study, we investigate how cryopreservation affects genes associated with stemness, differentiation and epigenetic control. Firstly, the cell morphology and proliferation were examined under light microscope and trypan blue exclusion, respectively. Then, gene expression study was performed using RT-PCR. WJMSCs were cultured at passage 6 and 9 and cryopreserved for 2 week and 6 months. Our results showed no much change on their fibroblast-like morphology and proliferation capacity. In contrast, genes modulated the characteristics of MSCs such as NANOG, RUNX2, OCN and DNA methylation were altered after cryopreservation. In addition to other previous studies, this study has shed light on potential implications of cryopreservation on the epigenetic regulation of WJMSCs. View article
Parametric Studies of Polymethacrylate-based Monolith Fabrication
Aldrin Felix Simbas; Clarence M. Ongkudon. 2019. Transactions on Science and Technology, 6(3), 304 - 309 Abstract Polymethacrylate monoliths (PM) have interconnected pores that allow physical form of filtration whereby particles that are smaller than the pore size can flow through while particles that are larger than the pore size are unable to pass through. The size of the pores determines the effectiveness of PM in filtering certain particles. Larger pore size means more void spaces within the structure of a monolith which affects its mechanical strength. Besides that, pore size also affects the flow rate and energy required to push a liquid sample through for filtration. Therefore, information regarding parameters that affect the pore size formation of a fully polymerized PM is important not only for the targeted particle size, but also for the structural strength and operating energy requirement of the intended filters. Among the parameters investigated were thickness of monolith, percentage of porogen, percentage of initiator and polymerization temperature. Higher polymerization temperature yield PM with smaller pore size. The increase of percentage initiator and porogen used were observed to increase the pore size of the PM formed. Finally, the pore size of PM becomes bigger as the monolith becomes thicker (observed from 1 mm to 5 mm thickness) View article
Production Polystyrene Micro-Emulsion as Template for Monolith Synthesis
Nurfaezah Ibadat; Clarence M Ongkudon; Mailin Misson. 2019. Transactions on Science and Technology, 6(3), 310 - 315 Abstract Monolith have received much attention as high-performance chromatographic matrices due to its convective mass transfer and interconnected porous structure. Biodegradable polymers, free radicals and cross-linkers are among the templates used to form pore structure. However, poor heat dissipation and uneven pore size distribution across monolith remain as a key challenge in monolith fabrication. Therefore, this study aims to synthesize and characterize polystyrene micro-emulsion as template for monolith. The operating conditions for the synthesis of the polymeric micro-emulsion, that includes polymer concentration (14 - 35 wt %), surfactant concentration (1 - 9 wt %), temperature (30 - 70oC) and stirring rate (500 - 1000 rpm), were designed using Response Surface Methodology (RSM). The characterizations of resulting particles were observed using Scanning Electron Microscopy (SEM) and Inverted Microscope. The sizes of the particles were determined within range of 5.9 - 11.7 µm. Out of the 30 tested samples with different operating conditions, observation under the inverted microscope indicated homogenous particles of polystyrene microemulsion while some forming aggregations. Sample that was synthesized using 21 wt% polymer, 3 wt% surfactant, stirring rate at 875 rpm and heated at 40 oC resulted homogenous particles with particle diameter ranging from 7.92 µm to 8.80 µm. Good particle homogeneity was also obtained at a higher polymer concentration (35 wt %) using similar surfactant concentration and operating temperature at slower stirring rate (625 rpm). Samples aggregation were observed when using 35 wt % polymer, 7 wt % surfactant heated at 50oC at 750 rpm as well as sample under parameter of 25 wt% polymer wt % surfactant for 60oC stirring at 875 rpm. The findings of the study provide useful insights on the feasibility of polymeric micro-emulsion particles as a directing template for monolith fabrication with structured pores. View article
Morphological Behavior of Densified Low-Density Plantation Wood Species: A Preliminary Study
Yu Feng Tan; Kang Chiang Liew. 2019. Transactions on Science and Technology, 6(3), 316 - 321 Abstract This work presents the morphological effect of densification technique employed on underutilized low-density plantation wood species, Batai (Falcataria moluccana) with an average density of 360 kg/m3 on air-dried weight. Timbers were cut into laminas, air-dried and conditioned. Laminas were pre-treated using pressurized steamer at 130oC, 175 kPa for 10 minutes to soften the wood structure. Densification process happens when the laminas were hot pressed immediately at 170oC, 2 MPa, for 45 minutes. The targeted thicknesses of densified laminas were controlled with 5 mm, 10 mm, and 15 mm metal stoppers. The laminas were left to cool in the hot press machine until the temperature of the lamina reached below 100oC to reduce springback effect before conditioning. Undensified laminas were used as control. Light microscopy was used to observe the morphological structure for both densified and undensified laminas. The microscopic result showed that the vessels of cell structures can be collapsed easily. The volume of the void spaces had decreased compared to undensified lamina which contributed to the improvement in the density of the lamina. However, as the densified lamina were left to condition until 7 days, the vessels started to swell up. View article
Concentration of Cd, Cr, Cu, Pb and Zn in Water During Southwest Monsoon in Salut-Mengkabong Lagoon, Tuaran, Sabah
Peirong Han; Carolyn Payus; Leong Wan Vun. 2019. Transactions on Science and Technology, 6(3), 322 - 327 Abstract Concentrations of selected heavy metals (Cd, Cr, Cu, Pb and Zn) in water were determined adjacent to aquaculture sites located in Salut-Mengkabong Lagoon, Tuaran, Sabah. Samples collected from six stations were analyzed by Inductively Coupled Plasma – Optical Emission Spectrometer (ICP-OES). The average concentrations of Cr, Cu Pb and Zn in lagoon water were 3.43 × 10-3, 4.37 × 10-3, 2.55 × 10-2, 1.51 × 10-1mg/L respectively and concentration for Cd was below detection limit. Referring to Malaysia Marine Water Quality Criteria and Standard (MMWQS), concentrations of Cd and Cr were in acceptable range whereas Cu, Pb and Zn were slightly higher than the standard. This study offers result of five heavy metals’ concentrations during south-west monsoon which is important reference for aquaculture activities and lagoon water quality management. View article |