Screening of Locally Isolated Actinomycetes and Endophytic Fungi for Production of Bioactive Compounds

Isolation of actinomycetes were done using Humic acid B-vitamins Agar (HVA) while endophytic fungi were from Potato Dextrose Agar (PDA). Isolated strains were then subjected to enzymatic and also antimicrobial testing. Positive strains for antimicrobial testing were then subjected to carbon source utilization testing and viewed under microscope to determine their spores morphology. From the enzymatic test conducted for actinomycetes, 110 isolates showed positive result for cellulase activity, 107 for xylanase activity and 22 for mannanase activity. Fifteen isolates of endophytic fungi have the ability to degrade cellulose, 28 of the isolates were able to degrade xylan and 12 isolates have the potential to degrade mannan. Thirteen isolates of actinomycetes showed positive result towards the 5 strains of pathogenic microorganisms with the highest on Yersinia enterocolitica. While test done using endophytic fungi showed only 1 isolate with antimicrobial property toward Xanthomonas campestris. Biolog test was done to determine the metabolite diversity of each actinomycetes. Twelve of the 13 isolates of actinomycetes were identified to be from the genus of Streptomyces by observing their spore arrangement and 1 of the isolate could not be identified. Biolog test could not be done on the endophytes fungi strain 13 because this strain does not produce spores.Through microscopic imaging the identity of the endophytes fungi isolate also could not be determined. Actinomycetes isolate number 200 was further identified by targeting its 16S rRNA gene. By using this technique Actinomycetes isolate number 200 was confirmed to be from the genus Streptomyces

Conceptual changes in scientific argumentation through guided group settings

The main goal of scientific argumentation is to foster students’ understanding of scientific concepts (von Aufschnaiters et al., 2008; Nussbaum, 2011; Sadler, 2004; Zohar and Nemet, 2002) and to eliminate alternative frameworks (Cross et al., 2008). The involvement of students in argumentative activities also enhances their scientific reasoning skills (Osborne et al., 2004). In order to induce conceptual changes through collaboration, instructional intervention are usually conducted following the socio-cognitive conflict design (Amigues, 1988). This design is based on the idea whereby the pairing of students with different initial conceptions will lead to their cognitive conflict. As a result, they will then seek for equilibrium to accommodate their naive concepts as scientific concepts. According to Kendeou and Broek (2007), when students’ existing concepts are activated and integrated with a scientific explanation, this will lead to an imbalance. The identification of this imbalance will trigger deeper information processing that causes conceptual changes. Mason (1996) stressed that conceptual change is likely to occur when students are asked to clarify, explain, and defend their own ideas

Preliminary screening of endophytic fungi isolated from medicinal plants in MARDI Sessang, Sarawak for their bioactivity

A total of 100 isolates of endophytic fungi were isolated from 19 species of medicinal plants collected at MARDI Station Sessang, Sarawak. A total of 55% of the endophytic fungi were isolated from the leaves while 45% from the branches. Screening of isolates for enzymatic secretion found that 15, 28 and 12 isolates were able to hydrolyze cellulose, xylan and mannan respectively. All 100 isolates were also tested for their antimicrobial activity towards selected phytopathogenic and human pathogenic microbes. The test indicated that only one isolate showed positive result when tested against Xanthomonas campestris. The results indicate that the endophytic fungi isolated from medicinal plant at MARDI Research Station Sessang, Sarawak may have the potential to be further exploited for its bioactivity

Adaptive Automation: Using secondary task measurement to determine function allocation

The present study investigated the behaviour of secondary task performance in Adaptive Automation to determine whether it could be used as a sensitive index of operator’s mental workload to trigger changes in support system. The majority of this study is to verify the method that is been used in performance-based automation is appropriate for which it used secondary task measurement as an indicator to initiate changes in LOA to assist human operator in the right time with right amount. This investigation did not start a new experiment but used experiment data that was done by previous researchers. Previous experiment used simulation software called Automated Cabin Air Management System (AutoCAMS) which simulates a life support system in the operational context of spaceflight. During the simulation, participants were required to ensure system stabilization and repair all 10 faults when occurred. Meanwhile, participants also need to respond quickly to 2 secondary tasks. With the experiment data, two simple analyses were made which are identifying the pattern of secondary task performance around the occurrence of fault and determine the effectiveness of using detector in secondary task measurement to detect fault events. These analyses were based on secondary task performance should worsen whenever fault event occurred due to additional workload. However, the result from the analysis did not appear to be inclined with expectation that the patterns were random and the detector could not accurately detect fault event but some false alarm. It was concluded that secondary task performance could not correctly indicating operator’s mental workload that could be used to trigger initiation in support system. Based on the result, secondary task is very sensitive that could be easily disturbed by any variation within the system. One of the factors that was discussed is the interference issue caused by additional tasks that share the same input, output, and time which resulted in performance impairment. Meanwhile, human operator self-defined his own method to manage all the tasks concurrently such as anticipation that resulted in no change can be observed in secondary task measurement. To decrease the effect of disturbance on secondary task measurement, some refinement on the simulation and analysis were suggested. Those refinements include redesign secondary task, use other method of analysis, and other approaches of measuring operator’s mental workload. Unfortunately, limited time assigned to this study caused further investigation could not be made

Penghujahan saintifik pelajar melalui pembinaan hujah bertulis dalam pengajaran dan pembelajaran berintegrasikan penghujahan

Penghujahan saintifik merupakan matlamat utama pendidikan sains masa kini dan diberi penekanan utama memandangkan kebolehannya dalam memupuk pembinaan pengetahuan saintifik pelajar. Kajian ini bertujuan mengkaji penguasaan dan skema penghujahan saintifik pelajar dalam pembinaan hujah saintifik selepas tamat sesi pengajaran berintegrasikan penghujahan berdasarkan kerangka Berland dan McNeil. Seramai 176 pelajar tingkatan empat aliran sains dari lima buah sekolah menengah terlibat dalam kajian ini. Data kajian dikumpul dengan menggunakan instrumen Ujian Penghujahan Saintifik Terbuka (UPSB) dan Temubual Separa Berstruktur Pelajar (TSBP). Data daripada hujah bertulis pelajar dianalisis dengan menggunakan sistem perisian SPSS Version 19.0 serta teknik analisis kandungan bagi menghuraikan secara mendalam penguasaan dan skema penghujahan pelajar. Dapatan kajian menunjukkan terdapat perbezaan signifikan antara hujah saintifik dengan hujah tidak saintifik yang dibina oleh pelajar. Pelajar aliran sains berupaya membentuk hujah saintifik dengan konsep sains yang tepat. Walaubagaimana pun, kebanyakan hujah saintifik yang dibentuk adalah hujah mudah pada aras makroskopik. Ini menunjukkan pelajar mempunyai pengetahuan terhadap fenomena yang dikaji tetapi tidak berupaya memberikan hubungan antara ketiga-tiga aras perwakilan iaitu makroskopik, sub mikroskoipk dan persimbolan bagi konsep yang terlibat. Sementara itu, skema penghujahan saintifik yang kerap dijumpai dalam kalangan pelajar adalah skema mudah yang terdiri daripada elemen dakwaan, bukti dan alasan ringkas pada aras makroskopik serta kekurangan elemen penyangkal berkaitan hujah alternatif. Justeru, guru sains seharusnya merancang pengajaran supaya berpusatkan pelajar serta menekankan aktiviti-aktiviti yang berteraskan penghujahan saintifik. Pendedahan dan pengalaman kemahiran penghujahan saintifik yang diperolehi dapat meningkatkan penguasaan penghujahan saintifik pelajar sekaligus meningkatkan pemahaman pengetahuan kandungan sains pelajar

Isolation and screening of actinomycetes from Malaysian soil for their enzymatic and antimicrobial activities

Actinomycetes, a slow growing gram positive bacteria, are known as an organism that is useful in the search for bioactive compounds. In this study, 212 isolates of actinomycetes were isolated from soil samples collected in the area of Serdang, Bangi, Petaling Jaya and Putrajaya. From the total of 212 isolates, 91 showed the ability to degrade cellulose; 16 for mannan and 90 for xylan. The 212 isolates were then subjected to anti-microbial testing, where they were tested for their ability to produce anti-microbial activity against selected phytopathogens. From the test, only two strains of isolates (strain 161 and 176) showed positive result towards Xanthomonas campestris. These two isolates were then identified using research microscope

Erratum to: Comparative Studies of the Growth and Characterization of Germanium Epitaxial Film on Silicon (001) with 0° and 6° Offcut

In the original article we presented results that show that the strain in germanium (Ge) epitaxial films grown directly on a silicon (Si) (001) with 6° offcut has a tensile strain of 0.6%. This strain value is much higher than the typical tensile strain value of 0.2% reported for Ge/Si. This discrepancy is due unintentional omission of the Si offcut angle and azimuth angle (φ) of the sample during high-resolution x-ray diffraction (HRXRD) measurement, and it has unfortunately resulted in a misleading result

New Existence Results for Fixed Point Problem and Minimization Problem in Compact Metric Spaces

We first present some new existence theorems for fixed point problem and minimization problem in compact metric spaces without assuming that mappings possess convexity property. Some applications of our results to new fixed point theorems for nonself mappings in the setting of strictly convex normed linear spaces and usual metric spaces are also given