This indoor study was aimed to analyze the production of fatty acids with their growth profile from few marine algae under the genus Chaetoceros isolated from coastal water of Pahang, Malaysia. The algae were established into culture using standard marine media (f/2 media) and the variation of fatty acid for each species was determined using GCMS. Statistical analysis of one-way ANOVA was performed to evaluate the significant and homogeneity data on the growth of each alga and total fatty acid percentage obtained. The results showed that four taxa were successfully cultivated and identified as Chaetoceros baculites, Chaetoceros anastomosans, Chaetoceros affinis var. willei and Chaetoceros affinis var. affinis. Out of four Chaetoceros, C. baculites showed the highest growth rate (0.75 cell.day-1) and division’s value (1.08) while C. anastomosans showed the highest doubling time value (8.66). Statistical analysis showed that all species have significantly different growth rate (p<0.05). Myristic acid was the main component for fatty acid storage for C. baculites, C. anastomosans and C. affinis var. willei whereas palmitic acid for C. affinis var. affinis. All species contained about 35 to 75% of total percentage fatty acids throughout the growth day. Based on total percentage, both affinis varieties had high fatty acid percentage compared with the other two species with the total percentage of more than 70%. As a conclusion, all four taxa are suitable to be used in lipid industry in Malaysia with C. affinis var. affinis is the best candidate for bio-fuel industry and C. anastomosans for pharmaceutical industry.
Acinetobacter baumanii is an opportunistic bacterium that causes widespread nosocomial infections and tends to be multi-resistant to most of antibiotics. Tigecycline is a well-known antibiotic that possesses a wide-range of activities and is very active in vitro towards a variety of resistant pathogens, including A. baumanii. The aim of this study was to evaluate the effects of the imipenem and tigecycline combination against carbapenem-resistant A. baumanii (CRAB). The minimal inhibitory concentration (MIC) was determined using the E-test method. The microbroth checkerboard technique was employed to determine the effects of the imipenem and tigecycline interaction by obtaining the fractional inhibitory concentration (FIC) index value. A time kill (TK) study was performed to identify any synergistic effects when both imipenem and tigecycline were used against CRAB strains. The result demonstrated that all A. baumanni strains exhibited imipenem MIC values of 32 µg/mL. The combination of imipenem and tigecycline demonstrated an additive effect (FIC > 0.5-4) against all of the strains and synergistic activity (decrement of > 2 log10 CFU/mL) towards AC 34/07 and AC 32/06 strains. The use of imipenem in combination with tigecycline resulted in a more efficient activity and an increased capability to control CRAB infections. This effect showed potential combination and may be of importance in the development or modification of antimicrobial agents for the treatment of CRAB infections.
Water scarcity is a global concern, as the demand for water is increasing tremendously and poor management of water resources will accelerates dramatically the depletion of available water. The precise prediction of evapotranspiration (ET), that consumes almost 100% of the supplied irrigation water, is one of the goals that should be adopted in order to avoid more squandering of water especially in arid and semiarid regions. The capabilities of feedforward backpropagation neural networks (FFBP) in predicting reference evapotranspiration (ET0) are evaluated in this paper in comparison with the empirical FAO Penman-Monteith (P-M) equation, later a model of FFBP+Genetic Algorithm (GA) is implemented for the same evaluation purpose. The study location is the main station in Iraq, namely Baghdad Station. Records of weather variables from the related meteorological station, including monthly mean records of maximum air temperature (Tmax), minimum air temperature (Tmin), sunshine hours (Rn), relative humidity (Rh) and wind speed (U2), from the related meteorological station are used in the prediction of ET0 values. The performance of both simulation models were evaluated using statistical coefficients such as the root of mean squared error (RMSE), mean absolute error (MAE) and coefficient of determination (R2). The results of both models are promising, however the hybrid model shows higher efficiency in predicting ET0 and could be recommended for modeling of ET0 in arid and semiarid regions.
In estimation problems in renewal function, when the distribution is not known, nonparametric estimators of renewal function are used. Frees (1986a, Warranty analysis and renewal function estimation, Naval Res. Logist. Quart, 33, 361-372) proposed the nonparametric estimator of renewal function for large values of t. Frees’s estimator is easy to apply in practice. It is a preferred estimator for large values of t. However, its statistical properties still have not been investigated in detailed. For this reason, in this study, we investigate asymptotic properties of this estimator such as consistency, asymptotic unbiasedness and asymptotic normality. Also Monte Carlo simulation study is given to assess the performance of this estimator according to value of renewal function. Simulation results indicate that in the large values of t, Frees estimator is sufficiently close to the renewal function for the Gamma distribution with various parameters.
The study monitored the characteristics of the leachate collected from ten different landfills and presented the experimental work for the treatment of leachate by immobilized Trametes menziesii. Variation in biological oxygen demand (BOD), chemical oxygen demand (COD) and ammoniacal nitrogen (NH3-N) showed that the age of the leachate has a significant effect on its characteristics and composition. The BOD5/COD ratio tends to decrease as the age of leachate increases, varying from 0.71 for a relatively 'fresh' leachate to 0.62 for an older (more stabilized) one. Variations in the characteristics of the leachate suggested that these leachates are difficult to treat. The principal pollutants in the leachate samples were organic and ammonia loads. Treatment of leachate using immobilized Trametes menziesii achieved 89.14 and 2.11% removals for leachate BOD5 and COD, respectively. These findings suggested that using immobilized Trametes menziesii can remove promising percentage of BOD and COD leachate.
Recently, there is strong interest on the subject of outlier problem in circular data. In this paper, we focus on detecting outliers in a circular regression model proposed by Down and Mardia. The basic properties of the model are available including the exact form of covariance matrix of the parameters. Hence, we intend to identify outliers in the model by looking at the effect of the outliers on the covariance matrix. The method resembles closely the COVRATIO statistic for the case of linear regression problem. The corresponding critical values and the performance of the outlier detection procedure are studied via simulations. For illustration, we apply the procedure on the wind data set.
MeSH terms: Research; Trenbolone Acetate; Wind; Linear Models
Disposal of dye wastewater into water streams without treatment endangers human and marine lives. This work focused on the second largest class of textile dyes after azo dyes due to its high resistivity to biodegradation and high toxicity. The photocatalytic degradation of Reactive Blue 4 (RB4), an anthraquinone dye, has been investigated using pure anatase nano titanium (IV) oxide (TiO2). The dye molecules were fully degraded and the addition of hydrogen peroxide (H2O2) enhanced the photodegradation efficiency. It is found that the degradation as the hydroxyl radicals in the bulk solution is sufficient for complete mineralisation. The disappearance of the dye follows pseudo-first-order kinetics. The effect of pH, amount of photocatalyst, UV-light intensity, light source and concentration of hydrogen peroxide was ascertained.
Pure phase Bi1.6Y0.4-xNdxO3 solid solution with x = 0.00, 0.10 and 0.20 was successfully synthesised via conventional solid state method at 850°C in 21 h. The materials were refined and fully indexed with space group Fm-3m and lattice parameters, a ranging from 5.5124(1) Å to 5.5289(4) Å. Variation of the lattice parameters of these materials were found in an almost linear correlation with increasing Nd2 O3 dopant concentration. Thermal analysis of Bi1.6Y0.4-xNdx O3 solid solution showed no thermal event that associated with any phase transition or weight loss within the studied temperature range of 35 to 900°C. The electrical properties of the samples were investigated by ac impedance analyser, HP4192 at temperature ranging from 25 to 800°C over frequency of 5 Hz to 13 MHz. Bi1.6Y0.3Nd0.1O3 exhibited the highest oxide ion conductivity among the synthesised samples in Bi1.6Y0.4-xNdxO3 solid solution.
An interpenetrating polymer network (IPN), N-isopropylacrylamide/O-nitrochitosan (NONK) was developed in the presence of ammonium persulfate using solution polymerization technique. O-nitrochitosan (ONK) was synthesized from chitosan, before it was further reacted with N-isopropylacrylamide. A new vibration of the C-N bond formed between the NH from ONK and the CH2 from NIPAAm was detected at the peak 1154 and 1171 cm-1 using attenuated total reflection Fouriertransform infrared (ATR-FTIR) spectroscopy. In the polymerization, the primary amine became a secondary amine and the peaks of the amide I (C=O peak) and amide II (N–H) were broadened. The structure of ONK was confirmed using nuclear magnetic resonance (NMR). At 10°C, the result from swelling test was found that IPN poly(NONK82) had the highest swelling percentage, 1171%, compared to poly (NIPAAm) at 467%. Micrograph from scanning electron microscopy (SEM) indicated the pore size of IPN NONK increased with an increasing ratio of ONK.
The bulking treatment with phenolic resin is well known as a treatment to improve the properties of low density wood but high amount of formaldehyde emission will be released during and after treatment. A study was conducted to determine the performance of phenolic resin treated sesenduk (Endospermum diadenum) wood post treated with ammonium carbonate and urea. Wood strips were treated separately with 30% low molecular weight phenol formaldehyde resin (LmwPF) resin and mixture of LmwPF with urea (30% based on solid PF) using empty-cell process. Two products were produced from the treatment, i.e. impreg and compreg. After conditioning, the surfaces of the samples were applied with ammonium carbonate solution at 10, 20 and 30 g/m2 . The samples were then stacked and stored at 60°C for 48 h. Properties such as formaldehyde emission, strength and dimensional stability were evaluated. The results showed that the post treatment with ammonium carbonate has successfully reduced the formaldehyde emission from the sesenduk wood. The degree of reduction was depended on the amount of ammonium carbonate applied on the samples. The results also showed that the sesenduk wood treated with mixture of PF and urea had lower formaldehyde emission. Post treatment with ammonium carbonate did not significantly affect the physical and mechanical properties of the sesenduk wood.
Six parents (P1, P2, P3, P4, P5 and P6) half diallel population of Jatropha curcas were evaluated to determine the combining ability, genetic components of variance and heterosis for yield contributing traits. Diallel analysis showed that both additive and dominance gene action was responsible for the genetic regulation of all the traits under study. The cross combination P1 × P3 showed the highest positive specific combining ability for seed yield per plant. Combining ability results were also in close agreement with the findings of estimate of genetic components of variance. The seeds per fruit (89%) and 100-seed weight (93%) showed maximum narrow sense heritability. Seed yield per plant showed high mid parent (254.13%) and better parent (202.36%) heterosis in the cross combinations of P2 × P5 and P1 × P3, respectively.The parents of P1, P2, P3 and P5 were found to be superior for seed yield components when used in cross. Considering seed production for each plant, the hybrids P1 × P2, P1 × P3, P2 × P5 and P4 × P6 could be selected for the development of hybrid varieties.
A mathematical model based on Michaelis-Menten kinetics was proposed and used to simulate the sago starch hydrolysis and the remaining sago starch concentration. The simulation model was tested with comparison to the real experimental results. The glucoamylase enzyme (E.C. 3.2.1.3) from Aspergillus niger was employed in the present study to hydrolyze the substrate i.e. sago starch into reducing sugars. The experiment was performed in a 2 L stirred tank reactor. The quantitative effects such as temperature, substrate concentration, enzyme amount, pH and agitation speed were set to optimal value at 61°C, 1.0 gL–1, 0.2 Uml–1 , pH4.5 and 100 rpm, respectively. The computer software, Polymath® 6.0 was employed in this research. The numerical method based on Runge-Kutta Fehlberg 45 was used to solve the system of non-linear ordinary differential equations (ODEs) of sago starch hydrolysis. The model prediction was well agreed with experimental results where the high values of regression coefficient, R2 = 0.9643 was obtained.
The beryllium (Be) concentrations were determined in the shells, opercula and soft tissues of the Nerita lineata and in the surface sediments collected from nine geographical sites of Peninsular Malaysian mangrove area in April 2011. The ranges of Be concentrations (µg/kg dry weight) were: <1.00- 4.00 for shells, <1.00-2.00 for opercula and 3.00-41.00 for soft tissues of N. lineata. For sediments, Be ranges were found between 1200 and 3810 µg/kg dry weight. The distribution of Be was found to be: sediment> soft tissues > shells ≥ opercula. The insignificant (p>0.05) relationships of Be between snails and sediments and low bioaccumulation factor (ratio of soft tissues to sediment) (<1.00), could be attributed to the fact that Be contamination being not serious in the Peninsular Malaysian mangrove area. The snail N. lineata as a good biomonitor of Be needs further investigations. Lastly, Peninsular Malaysia mangrove was not contaminated by Be based on the present findings.
Dissolved and suspended particulate metals (Al, Fe, Cd, Cu, Zn, Pb) in Setiu River basin, Terengganu which is situated at coastal area of southern South China Sea were investigated. The water samples were collected from nine stations from June 2007 to January 2008, in conjunction with the Southwest monsoon and Northeast monsoon. The average concentrations of dissolved Al, Fe, Cd, Cu, Zn and Pb were (µg L-1): 50±60, (2.0±3.4) ×102 , 2.5±2.6, 3.0±1.4, 7.5±5.1 and 6.0±5.0, respectively. Meanwhile, the concentrations of suspended particulate metals were (µg g-1): (13±10)%, (10±13)%, 15±13, 65±94, (3.5±2.5) ×102 and (1.2±1.5) ×102 , respectively. Seasonal variations of dissolved and suspended particulate metals were observed. The results were compared with selected Malaysian national rivers, world averageand established guidelines. In addition, the enrichment of suspended particulate metals and the partitioning of metals between dissolved and suspended particulate phases were discussed.
This study was conducted to study the morphological features of species under the genus Chaetoceros isolated from the coastal waters of Pahang, Malaysia. The species were isolated, cultivated and viewed under light microscope (LM) and scanning electron microscope (SEM). Four taxa were successfully isolated and cultivated in pure culture, namely Chaetoceros affinis var. affinis, Chaetoceros affinis var. willei, Chaetoceros anastomosans and Chaetoceros baculites. Both varieties of C. affinis were considered as distinct taxa where both strains can be distinguished based on morphological characteristics. C. affinis var. affinis has a thick cell wall compared with C. affinis var. willei. C. anastomosans has special features including a silica bar on the intersection of setae and the production of mucous. The length of the aperture opening is a new record from this study. The new record obtained for C. baculites includes the size of the aperture, the terminal setae, spinal arrangement, the thinness of the cell wall and the location of the species in tropical waters. Detailed data on each species will be added to the taxonomic information for future studies.
Three short sediment cores (12-32 cm) from South China Sea off Southern Terengganu were collected during May (postNortheast monsoon) and September (pre-Northeast monsoon) 2007. The concentration of total organic carbon (TOC) obtained ranged from 0.41-2.23 and 0.38-2.31% during post and pre-monsoon, respectively. TOC concentration was found to decrease with depth and distance from the coast and river mouth. In particular, station with close proximity to the coast exhibits most pronounced variation of TOC with depth. Besides spatial variation, it is noted that the seasonal variations also considerably affect the distribution and concentrations of TOC, where both near and offshore sampling stations showed significant variations in TOC content during May and September sampling. These findings suggest the importance of terrestrial organic carbon flux, physical mixing and seasonal variations in regulating the concentration and distribution of the organic carbon in the study area.
The Sandakan Formation of the Segama Group is exposed across the Sandakan Peninsular in eastern Sabah. This Upper Miocene part of the Segama Group unconformably overlies the Garinono Formation and is conformably overlain by the Bongaya Formation. This formation was investigated with detailed logging of outcrops and microfossils analysis in order to map the depositional facies and sedimentary environment. This study showed the presence of seven lithofacies: Thick amalgamated sandstone; thin, lenticular interbedded HCS sandstones and mudstone; laminated mudstone with Rhizophora; trough cross-bedded sandstone; laminated mudstone; strip mudstone with thin sandstone and siltstone; and interbedded HCS sandstone and mudstone. Based on the presence of Rhizophora, Brownlowia, Florchuetia sp., Polypodium, Stenochleana palustris, Ascidian spicule low angle cross bedding, very fine grained sandstone, thin alternations of very fine sandstone, silt and clay layers showing cyclicity (muddy rhythemites), rocks in the Sandakan Formation are interpreted as mangal estuary and open marine facies. Three facies associations could be deduced from the seven lithofacies: Gradual coarsening upwards shoreface; abrupt change facies and prograding estuary facies association.
The purpose of this paper was to provide a practical guide assisting field workers in identification and interpretation of frequently occurring bioerosional textures created in limestone by intertidal organisms along the coasts of Langkawi Islands, Malaysia. The discussion follows the textural succession from the supratidal down to the lower intertidal zone. Traces left by lichens, boring sponges, molluscs (littorinid snails, the chiton Acanthopleura, the bivalve Lithophaga) and the echinoid Echinometra are illustrated. Products of bioconstructing organisms, specifically oysters and barnacle are also described. Ecological tolerance of each group is given.
Eurycoma longifolia is one of the well-known herbal plants in Southeast Asian region due to its remarkable properties, especially the root part that can be used as aphrodisiac, anti-cancer, anti-malaria and anti-ulcer agent. Uncontrolled harvesting of this plant has reduced its population. Thus, an efficient protocol involving the induction of direct somatic embryogenesis from cotyledon culture of E. longifolia has been developed. 15% explants forming embryos were achieved on Modified Murashige and Skoog’s (MMS) medium supplemented with 0.1 mg/L zeatin plus 0.2 mg/L indole-3-butyric acid (IBA). However, the addition of 0.12 mg/L thidiazuron (TDZ) has increased the percentage up to 22.0%. The maturation phase occurred in the same medium, thus decreased the frequency of subculture and the genetic instability of the embryos. Secondary somatic embryogenesis growth of 20%, which was the highest percentage of growth, was achieved from the primary embryos that were cultured in the MMS medium with the treatment of 2.0 mg/L IBA plus 0.075 mg/L TDZ. The results indicated that the direct somatic embryogenesis obtained can be further used to develop a protocol for plantlet regeneration of E. longifolia.
Passing over the ocean surface, typhoon absorbs heat from the sea water as it needs the heat as its ‘fuel’. The process is via evaporation of water. Subsequently, the sea surface temperature (SST) in that area will significantly decrease. Due to strong typhoon wind water is evaporated from the surface layer of the ocean, the amount of water mass in that area is lost, but the same amount of salt will remain, causing sea surface salinity (SSS) to increase. Strong winds induced by typhoons will also cause turbulence in the water, causing entrainment, where cold deeper water is brought up to the surface layer of the ocean, which will consequently increase its SSS and change the isothermal layer and mixed layer depth (MLD). Here, isothermal layer means the ocean layer where temperature is almost constant and MLD is the depth where salinity is almost constant. This paper focuses on the effect of typhoons on SST, SSS, isothermal layer and MLD by taking 15 typhoons in the Northwest Pacific throughout 2009 typhoon season (typhoons Lupit and Ketsana are used as examples in results) into consideration. Temperature and salinity data from selected Array of Regional Geostrophic Oceanography (ARGO) floats close to the individual typhoon’s track are used in this study. The results showed that SST decreased up to 2.97°C; SSS increased up to 0.44 pss and majority of the typhoons showed deepening of isothermal layer (between 39.8 m and 4.6 m) and MLD (between 69.6 and 4.6 m) after the passage of typhoons. Passing of each individual typhoon also removed significant amount of heat energy from the affected area. The highest amount of heat of 841 MJ m-2 to the lowest of 30 MJ m-2 was calculated during the study period. For comparison purpose, an equivalent amount of electrical energy in kWh is also calculated using the amount of heat removed by the typhoons.