The aim of this study was to establish an effective protocol for callus induction from the seed explants of Solanum dubium and to investigate the callus extract ability in milk clotting activity. The effects of growth regulator, basal media strength and sucrose were studied using different concentrations (0.5, 1.0, 1.5, and 2.0 mg/L) of indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), naphthalene acetic acid (NAA) and 2,4-dichlorophenoxy-acetic acid (2,4-D) alone or in combination with 0.5 mg/L of 6-benzylamino purine (BAP). For milk clotting activity, about 50 or 100 μL extracts of seed callus was mixed with 2 mL 50% milk held at 55°C for 5 and 10 min until milk clotting occurred. The results showed that NAA alone or in combination with BAP gave a higher callusing percentage (80 to100%) compared to the other plant growth regulators at the same concentrations. When an auxin was supplied in combination with BAP, a significant increase in callusing percentage or degree of callusing was observed. The time required for callus to be developed was shortened and the quality of the induced callus improved. An increase in callus growth in low sucrose (10 g/L) concentration was found be comparable (88%) to high sucrose concentration (30 g/L; 60%). Crude extracts obtained from S. dubium callus were shown to exhibit milk clotting activity.
In this study, the pyrG gene which encodes for orotidine 5-monophosphate decarboxylase (OMP decarboxylase) of Aspergillus oryzae strain S1 was cloned and analysed. This 1.8kb A. oryzae pyrG encompasses the 5’-regulatory flanking region (465 bp), open reading frame (899 bp) and 3’-regulatory region (475 bp). The pyrG contained one intron at position 623-687 bp based on the AUGUSTUS and FGENESH (SoftBerry) analysis corresponding to the intron present in the pyrG of A. oryzae (Accession Number: Y13811). In silico analysis showed that the enzyme encoded by the A. oryzae S1 pyrG gene has a theoretical molecular weight of 30.28 kDa and theoretical pI value of 5.92. This enzyme is hydrophilic, located in a region outside of the transmembrane and it functions in the cytoplasm. Five motives such as N-glycosylation site, protein kinase C (PKC) phosphorylation site, casein kinase II (CK-2) phosphorylation site, N-myristolation site and orotidine 5-monophoshate decarboxylase active site have been identified in the pyrG amino acid sequence. The three dimensional structure of this enzyme generated via protein homology modeling using the bioinformatic software, Swiss Model, shows that OMP decarboxylase is a protein with an α/ß barrel structure possessing 8 ß-strands surrounded by 9 α-helices. The amino acid residues involved in the active site have been identified and it is located on one of the ß-strands. The pyrG DNA sequence will be used for the complementation of a pyrG auxotroph mutant of A. oryzae.
Yeasts with GRAS (Generally Regarded as Safe) status are commonly used as hosts for heterologous protein production. Yeasts are suitable expression hosts as they have been extensively characterised genetically. The objective of this project was to isolate yeasts from Malaysian food sources and subsequently to develop these as alternative hosts for heterologous protein production. Yeasts were isolated from Malaysian traditional fermented food namely ‘tapai’, ‘tuak’ and ‘ragi’. A total of 23 isolates were obtained and subjected to molecular identification by amplification and sequencing of the universally conserved ribosomal internal transcribed spacer (ITS), 26S rDNA and 18S rDNA sequences. We identified three species of yeasts, Saccharomyces cerevisiae, Hanseniaspora guilliermondii and Pichia anomala, which have a long tradition of usage in food production and have no adverse effects on humans. To test the feasibility of the yeasts as heterologous expression hosts, we have constructed an integrative vector, p1926Zeo containing the yeast 26S rDNA and Zeocin® resistance cassette. The p1926Zeo vector was linearised and transformed into both P. anomala and H. guilliermondii isolates via electroporation. Both hosts were successfully transformed at a relatively high efficiency. The transformants obtained had a growth profile similar to the respective wild type, indicating that integration of the plasmids into the host chromosome did not affect growth. These transformants were stable as they exhibited resistance to Zeocin even after 20 generations. Thus, both P. anomala and H. guilliermondii isolates exhibited the potential to be further developed as alternative heterologous protein expression hosts.
Hypercholesterolemia is the main risk factor of atherosclerosis which is directly related to coronary heart disease. Velvet bean (Mucuna pruriens L.) is predicted to have potential anticholesterolemia since a previous study showed that this plant had high antioxidant activity. The purpose of this research was to determine the anticholesterol activity of crude extract and ethyl acetate fraction of velvet bean compared to simvastatin and vitamin E in decreasing the plasma level of total cholesterol, LDL and triglyceride and increasing the HDL level on hypercholesterolemic rats. Thirty male Wistar rats were divided into ten groups. Group I was fed with standard diet as negative control group and all the other groups were fed with high-fat diet and were given fructose solution. High-fat diet and fructose solution increased the level of total cholesterol, LDL-cholesterol and triglyceride and decreased the level of HDL-cholesterol significantly compared to the negative control group. The treatment groups were given 3 various doses of crude extract (50, 100, 200 mg/kgBW) and ethyl acetate fraction (15, 30, 60 mg/kgBW) of velvet bean, simvastatin 2.7 mg/kgBW and vitamin E 60 mg/kgBW daily for ten days. The data were analyzed by one way Analysis of Variance (ANOVA) and Duncan’s Post Hoc Test. The best results were shown by 15 mg/kgBW of ethyl acetate fraction in decreasing total cholesterol and 60 mg/kgBW of ethyl-acetate fraction for the LDL-cholesterol, 200 mg/kgBW of crude extract in increasing HDL-cholesterol and 50 and 200 mg/kgBW of crude extract and 60 mg of ethyl acetate fraction in lowering the triglyceride.
Diamondback moth (DBM), Plutella xylostella and beet armyworm (BAW), Spodoptera exigua are major insect pests of crucifer crops found worldwide. Since these pests are highly resistant to many chemical insecticides, using biological control agent(s) or biopesticides might be a good choice to overcome this problem. Nosema bombycis is a microsporidial pathogen with the potential to control insect pests. This study was aimed at producing N. bombycis spores in vivo and to test their efficacies against DBM and BAW in laboratory conditions. Production of this pathogen was carried out by feeding both DBM and BAW larval instars with artificial diet inoculated with viable spores of N. bombycis. Spore concentrations in the larvae were determined and accumulated. If a concentration of 1.56×108 spores/mL was obtained, the production was continued. For laboratory efficacy tests, artificial diets with different spore concentrations namely 1×104, 1×105 and 1×106 spores/μL were fed to different larval instar. Mortality rates were analysed using the Two-way ANOVA test. For both DBM and BAW, third instar showed the highest mean mortality rates and the mortality in each instars were significantly different (P<0.05). The concentration 1×106 spores/μL caused the highest mean mortality rates and each concentration resulted in significantly different mortality (P<0.05). However, there was no interaction between both factors, where a combination of spore concentrations and instars did not show any significant differences (P>0.05). These results indicated that third instar larvae for both species and 1×106 spores/μL treatments demonstrated the highest efficacy rates.
Anochetus maryatiae, a new species of Formicidae from the subfamily Ponerinae, tribe Ponerini from Ulu Gombak is described and illustrated. This ant genus was last studied in Malaysia by Brown in 1978. Observations were made on morphometric characters which included parameter measurements of total length, head length, head width, mandible length, scape length, antenna length, maximum eye length, oculomandibular distance, funicular length segment 1 to 4, pronotum width, propodeum height, petiole length, petiole height, dorsal petiole width, cephalix index and mandibular index. It was followed by a brief diagnosis, description of morphological structure, microsculpture, pilosity and discussion. Although it has resemblance with Anochetus tua, it could be easily distinguished from other species in having reticulate pronotum. This is the only species from Malaysia with such microsculpture on the pronotum. In addition to that, A. maryatie varies with A. tua in having smaller total length, less than 7.5 mm and lighter colour.
MeSH terms: Animals; Ants; Body Weights and Measures; Color; Head; Humans; Malaysia; Mandible; Population Groups
Hydrocarbon is a light-non aqueous phase liquid or known as LNAPL. It poses environmental hazard if accidentally spilled out into the soil and water systems as a result of its insoluble nature in water. LNAPL component infiltrates into soil through pore spaces and afloat at the top of groundwater level. Some of this hydrocarbon would trap and clog within the voids, difficult to remove and costly to clean. The occurence of hydrocarbon in the soil definitely degraded the behaviour of soils in terms of engineering properties. This study aimed to investigate the engineering properties of oil-contaminated soil for two different residual soils originally developed from in-situ weathering of granitic and metasedimentary rocks. The physical characterisations of the soil were determined including particle size distribution, specific gravity test and x-ray diffraction (XRD). The engineering parameters for the contaminated and uncontaminated soils were Atterberg limits, compaction and soil shear strength (UU tests). The amounts of hydrocarbon added to soil were varied at 0%, 4%, 8%, 12% and 16% of dried weigth of soil samples. The results from the particle size distribution analysis showed that residual soil from granitic rock comprises of 38% sand, 33% silt and 4% clay while metasedimentary soil consists of 4% sand, 43% silt dan 29% clay. The mean values of specific gravity for the granitic and metasedimentary soils were 2.56 and 2.61, respectively. The types of minerals present in granitic soil sample were quartz, kaolinite and gibbsite while metasedimentary soil consists of quartz and kaolinite. The Atterberg limits value decreased as a result of increasing amount of added hydrocarbon into the soil. A similar behaviouir was observed with the values of maximum dry density and optimum water content with increasing hydrocarbon content. The overall unconsolidated undrained shear strength, Cu showed a decreasing trend with the increase in hydrocarbon content.
This research develops a new non-standard scheme based on the Adomian decomposition method (ADM) to solve nonlinear equations. The ADM was adopted to solve the nonlinear differential equation resulting from the discretization of the differential equation. The new scheme does not need to linearize or non-locally linearize the nonlinear term of the differential equation. Two examples are given to demonstrate the efficiency of this scheme.
MeSH terms: Numerical Analysis, Computer-Assisted; Research
Kelikatan minyak enjin bergred tunggal mengalami perubahan apabila berlakunya perubahan pada suhu dan tekanan. Namun begitu, secara realiti kelikatan minyak enjin juga mengalami perubahan terhadap usia guna. Oleh itu, kajian ini memperkenalkan satu hubungan kelikatan minyak enjin terhadap perubahan suhu serta usia guna. Hubungan ini berasaskan kepada persamaan matematik empirik yang melibatkan teori pelincir Newtonan dan bukan Newtonan. Hubungan yang baru ini dikenali sebagai model kelikatan matematik (ηmath). Dalam model ini, kelikatan minyak enjin dipengaruh oleh dua faktor iaitu faktor suhu (ks) dan faktor masa (km). Nilai kedua-dua faktor ini bergantung kepada formula bahan tambah minyak enjin tersebut. Analisis reologi meter likat telah digunakan untuk mendapatkan nilai kedua-dua faktor ini. Hasil kajian menunjukkan kelikatan minyak enjin mengalami penurunan apabila usia guna meningkat. Ini dibuktikan melalui model kelikatan matematik (ηmath) dan juga analisis reologi meter likat.
In recent years, there has been considerable interest in simple sequence repeats (SSRs) particularly as molecular markers with applications in many different fields. We have carried out an effort to identify and analyse SSRs in the genome of the Asian seabass, Lates calcarifer by random sequencing. Genomic DNA was isolated from the muscle tissue of L. calcarifer, sheared by nebulisation and ligated into plasmid vector. Recombinant clones were selected randomly from the genomic libraries constructed. Subsequently, plasmid DNA was extracted and subjected to one-pass sequencing. A total of 4175 random sequences, also known as genome survey sequences (GSSs), with a total length of 1.7 Mb was generated. Screening of the whole L. calcarifer GSS data set allowed for the identification of a total of 151 perfect (100% similarity) SSRs. These SSR consensus patterns spread over a wide range of size (1 to 226 bp). The most frequent consensus pattern is dinucleotide, which represents 60% of all SSRs identified. The dinucleotides (AC)n, (AT)n and (AG)n were also found to occur frequently in the L. calcarifer genome. Sequence comparison between L. calcarifer and other fish species showed variation in repeat content, indicating the different ways in which repeats may evolve in the genome of these species. Data generated from this random sequencing of the L. calcarifer genome should serve as a valuable resource for further studies of this organism.
Ficus deltoidea is one of the common medicinal plants used in Malaysia. This epiphytic plant, from the Moraceae family has been claimed to have antidiabetic property. However, scientific evidence to confirm its efficacy is still lacking. The present study was undertaken to evaluate the effect of ethanolic extract of F. deltoidea on glucose level in normal rats at different prandial state. The results showed that, all doses of ethanolic extract of F. deltoidea reduced fasting blood glucose particularly after 6 h of administration. Interestingly, the extract did not produce severe hypoglycemia as shown by its comparable effect with metformin. Likewise, postprandial hyperglycemia was also significantly reduced particularly after 4 and 6 h of administration. Furthermore, extract was used at a dose of 1000 mg/kg b.w., reduced postprandial hyperglycemia similar to metformin. This suggests that postprandial antihyperglycemic mechanism of this extract is mediated through enhancement of glucose uptake into muscle cells and reduction of hepatic gluconeogenesis. Glucose tolerance activity was also significantly improved in the presence of ethanolic extract of F. deltoidea. From this study, it is suggested that ethanolic extract of F. deltoidea reduced postprandial hyperglycemia and improves glucose tolerance activity in normal rats.
Kajian ini telah dijalankan untuk menentukan kesan suplimentasi tokotrienol (TT) dan tokoferol (TF) ke atas status oksidatif dan aktiviti enzim antioksidan pada hepar tikus dalam keadaan stres. Sebanyak 24 ekor tikus Sprague-Dawley jantan telah dibahagikan secara rawak kepada empat kumpulan. Dua kumpulan kawalan, kumpulan stres (CS) dan kumpulan tanpa stres (C) serta dua kumpulan rawatan yang diberikan tokotrienol (TTS) atau tokoferol (TFS) secara oral paksaan pada dos 60 mg/kg berat badan selama 28 hari dan didedahkan kepada stres. Setelah tamat tempoh rawatan, tikus-tikus daripada kumpulan CS, TTS dan TFS telah didedahkan kepada stres restain selama dua jam sehari untuk empat hari berturut-turut. Kemudian, darah tikus diambil untuk menentukan aktiviti enzim antioksidan iaitu superoksid dismutas (SOD) dan glutation peroksidase (GPx) manakala hepar diambil untuk menentukan kandungan malondialdehid (MDA) dan tahap glutation. Hasil kajian mendapati kandungan MDA meningkat dan glutation menurun secara signifikan pada tisu hepar pada kumpulan CS setelah diaruh stres, berbanding kumpulan tanpa stres. Walau bagaimanapun, tikus yang diberi suplimentasi tokotrienol dan tokoferol menunjukkan penurunan signifikan kandungan MDA dan peningkatan glutation berbanding kumpulan kawalan. Keputusan kajian ini mencadangkan bahawa tokotrienol dan tokoferol mampu menghalang tekanan oksidatif pada hepar akibat stres. Hasil daripada kajian ini juga menunjukkan peningkatan yang signifikan dalam aktiviti GPx plasma tikus pada kumpulan CS. Kumpulan tikus yang disuplimentasikan dengan tokotrienol menunjukkan penurunan yang signifikan dalam aktiviti GPx berbanding kumpulan CS. Sebagai kesimpulan, tokotrienol dan tokoferol berkesan dalam mengurangkan status oksidatif pada hepar tikus dan ini dapat diperhatikan dengan peningkatan glutation hepar dan penurunan aktiviti GPx plasma tikus yang teraruh stres.
Papanicolaou test is a diagnostic test for uterine cervical cancer screening and routinely examined. It has limitations. A better technique is needed to identify true cervical malignancy process. Molecular cancer marker detection may have high the sensitivity and specificity in detecting cancer. Survivin, a marker candidate, is upregulated in many malignancy processes. Ninety women have joined in this cross sectional study by consecutive sampling. Survivin expression was examined by indirect immunoperoxidase method. It was predominantly found in metaplastic cells. Correlation between survivin expression and Papanicolaou test results was calculated by Fischer’s-exact test. Using Papanicolaou test result as an indicator for the presence of uterine cervical abnormalities, the performance indicators were calculated. Fischer’s-exact test showed that survivin expression was not significantly useful as cervical cancer molecular marker. Survivin expression of the uterine cervical exfoliative cells cannot be used as a diagnostic test for uterine cervical malignancy process.
The end stage renal disease (ESRD) patients requires hemodialysis to survive. Efficacy of the treatment is determined by evaluation of minimal dialysis dose (Kt/V) which is 1.2. A cross sectional study was conducted among patients that undergo hemodialysis in a dialysis centre in Kuala Lumpur, Malaysia. The objectives of the study were to determine the association between dialysis dose and demographic factors and assessed the association between biochemical blood parameter and the demographic factors. The biochemical blood parameters were serum albumin, creatinine, cholesterol and hemoglobin. Result showed that all Indians and 54% of Chinese patients achieved the required dialysis dose. However only 29% of Malay patients attained the effective dialysis dose. More women patients accomplished the dialysis dose of at least 1.2 compared to men patients with odd ratio of 11.24. All the biochemical blood parameters were independent of the demographic factors. However, the cholesterol level was associated significantly with gender (p<0.05). In conclusion, the study found the biochemical blood parameter and dialysis dose were not influenced by the demographic factors.
Grammatophyllum seeds are minute and lack endosperm. As with their other orchids counterpart, the seeds are dependent on mycorrhizal fungi for seed germination in nature. The ability to uptake nutrients from substrate is assisted by preferable fungal symbionts. Seeds of Grammatophyllum speciosum Blume. were used to determine the specificity of its fungus relationship using fungi isolated from roots of G. speciosum, G. stapeliiflorum and G. scriptum. A total of 31 different species of fungus was isolated and inoculated onto G. speciosum seed on Oat Meal Agar (OMA). The result obtained from the test demonstrated that seed germination rates were best when co-cultured with Fusarium sp. number 3 isolated from G. speciosum. An increment in 63.3% was measured when compared to the seed’s original size. The seed can also germinate when inoculated with fungus isolated from different species, implying that G. speciosum is a generalist in its association with fungal symbionts.
1-(5-Mercapto-1,3,4-oxadiazol-2-yl)-2-(pyridine-2-ylamino)ethanone (3), has been synthesized from 2-(pyridine-2-ylamino)acetohydrazide (2). A yellow colored compound (2) was reacted with carbon disulfide and potassium hydroxide in absolute ethanol to obtain the 1-(5-mercapto-1,3,4-oxadiazol-2-yl)-2-(pyridine-2-ylamino)ethanone. Structures of the synthesized compounds were supported by means of IR, NMR, MS spectroscopic and elemental analysis. The synthesized compounds were evaluated for their antimicrobial activity and were expressed as the corresponding minimum inhibitory concentration (MIC). A brown colored compound (3) with 90% yield has been successfully synthesized. This compound was found to have significant antimicrobial activity with MIC value ranging from 30.2 - 43.2 μg cm-3. The findings of the present study indicate that cyclization of hydrazide acid group of 2-(pyridine-2-ylamino)acetohydrazide (2) into 1,3,4-oxadiazole nucleus resulted in increased antimicrobial activity.
Microfungi isolated from Malay traditional vegetables such as Centella asiatica, Cosmos caudatus, Oenanthe javanica, Persicaria odorata and Psophocarpus tetragonolobus are well diverse. A total of 40 isolates of the fungi were identified and classified into four genera such as Aspergillus, Fusarium, Penicillium and Trichoderma. Five species of Fusarium were morphologically identified as F. oxysporum, F. semitectum, F. proliferatum, F. solani and F. konzum. Three species of Aspergillus were identified as A. niger, A. fumigatus and A. flavus. The highest number of microfungi was isolated from Cosmos caudatus (12 isolates), followed by Persicaria odorata (9 isolates), Oenanthe javanica (8 isolates), Centella asiatica (6 isolates) and Psophocarpus tetragonolobus (5 isolates). Four isolates of Fusarium species were able to produce moniliformin (MON) and five isolates were able to produce fumonisin B1 (FB1). This is the first report on diversity of microfungi associated with some Malay traditional vegetables.
A geotechnical study needs to be carried out to determine the engineering parameters of the rock mass at the project site in executing construction projects such as tunnels, dams, highways and buildings. Design and safety factor of the construction are highly dependent on soil and rock engineering parameters which are usually determined by in-situ test such as Standard Penetration Test (SPT) and seismic tests. The SPT test which normally involves drilling and laboratory works always incur high operating cost, while seismic tests on the other hand are fast, cheap, non-destructive and an easy to operate method for rock mass characterization. The spectral analysis of surface waves (SASW) method is an in situ and non-destructive measurement that is rapid and cost effective. The aims of this study were to determine Rock Quality Designation (RQD) value, excavation classification analysis as well as site characterization by using the SASW method. WinSASW 3.1.3 was used for inversion processing of the SASW data to produce shear wave velocity (Vs) versus depth profiles. The profiles were then analyzed and correlated with rock mass engineering geological parameters such as RQD and site characterization as well as excavation classification of rock mass. Twenty (20) SASW tests were conducted on the granitic rock mass and four (4) SASW tests were conducted on a cut hill slope of metasedimentary rocks. RQD values were computed based on shear wave velocities and ultrasonic velocities of intact (fresh) rock. The differences between RQD obtained from SASW method and those from discontinuity survey were found to be less than 10%. Excavation classification for granitic rock mass at JKR Quarry was empirically determined using both SASW and ultrasonic velocities as well as RQD value of the rock mass. Site characterization for metasedimentary rocks mass at Bukit Tampoi was determined based on shear wave velocities from SASW method.
Time series analysis and forecasting has become a major tool in many applications in air pollution and environmental management fields. Among the most effective approaches for analyzing time series data is the model introduced by Box and Jenkins, ARIMA (Autoregressive Integrated Moving Average). In this study we used Box-Jenkins methodology to build ARIMA model for monthly ozone data taken from an Automatic Air Quality Monitoring System in Kemaman station for the period from 1996 to 2007 with a total of 144 readings. Parametric seasonally adjusted ARIMA (0,1,1) (1,1,2)12 model was successfully applied to predict the long-term trend of ozone concentration. The detection of a steady statistical significant upward trend for ozone concentration in Kemaman is quite alarming. This is likely due to sources of ozone precursors related to industrial activities from nearby areas and the increase in road traffic volume.
MeSH terms: Air Pollution; Forecasting; Industry; Ozone; Moclobemide
Predictor-corrector two point block methods are developed for solving first order ordinary differential equations (ODEs) using variable step size. The method will estimate the solutions of initial value problems (IVPs) at two points simultaneously. The existence multistep method involves the computations of the divided differences and integration coefficients when using the variable step size or variable step size and order. The block method developed will be presented as in the form of Adams Bashforth - Moulton type and the coefficients will be stored in the code. The efficiency of the predictor-corrector block method is compared to the standard variable step and order non block multistep method in terms of total number of steps, maximum error, total function calls and execution times.