The objective of this study was to determine the antioxidant activity of Rhodomyrtus tomentosa fruit extract and its effect on triacylglycerides (TG), total cholesterol (TC), low density lipoprotein (LDL), high density lipoprotein (HDL) and lipid peroxidation in induced-cholesterol New Zealand White Rabbits. In DPPH assay, at concentration of 200 ug/mL methanol extract give 62.13% inhibition of DPPH free radicals with IC50 of 107 μg/mL. Similarly, in FRAP assay the methanol extract at concentration of 500 ug/mL showed the highest absorbance (0.16) for antioxidant activity. Whereas, in metal chelating assay the methanol extract at concentration of 100 mg/mL exhibited 36% inhibition of metal chelating ions. The antioxidant activities were due to the presence of phenolics compounds of quinic acid, gallic acid and caffeic acid, which were identified with Q-TQF MS. Total phenolic and total flavonoid content was the highest in water extract at 66.515 mg of GAE/g and 1.828 mg of QE/g, respectively. The water extract of R. tomentosa was non-toxic at LC50 = 616.083 μg/mL. The white New Zealand rabbits group A was fed by oral gavages with normal diet; Group B cholesterol 1% diet; group C cholesterol 1% diet with fruit extract 50 mg/kg and Group D cholesterol 1% diet with simvastatin standard drug 5 mg/kg. The rabbits in group C has a significantly reduced (p<0.05) total cholesterol (TC), low density lipoprotein (LDL) and significantly increased (p<0.05) high density lipoprotein (HDL) and triacylglycerides (TG) as compared with group B. The lipid peroxidation was reduced significantly (p<0.05) as indicated by the low TBARs-MDA level in group C. Thus, these results showed that the R. tomentosa fruit extracts was able to reduce cholesterol level and increased HDL level which can prevent the formation of atherosclerosis in New Zealand white rabbits.
Water deficit and environmental pollution owing to excessive nitrogen use have caused considerable attention. In a field experiment, a combination of three water levels (20, 40 and 60 cm) and nitrogen fertilizer rates (0, 85 and 170 kg ha-1) was applied. The main objectives of this study were to optimize water and nitrogen application and exploit their interactive effects on the growth characteristics, yield and water and nitrogen use efficiency of spinach. The results showed that water and nitrogen significantly influenced average plant height and leaf area. Total aboveground biomass (TB) was affected by nitrogen fertilizer and TB decreased in water deficit. Adding nitrogen fertilizer amount resulted in higher leaf chlorophyll content and chlorophyll content obtained the maximum value in N2 treatment, but chlorophyll content was not affected by water deficit. Spinach yield was higher at N1 compared with N0 and N2 at all water levels. Abundant water supply resulted in the highest spinach yield, but yield reduced at lower water level (W3). The correlation analysis between spinach yield and leaf number was relatively weak (R2=0.58). On the contrast, the correlation analysis between spinach yield and leaf weight showed a correlationship (R2=0.91), indicating that leaf weight was the primary reason for yield increase in all treatments. Nitrogen fertilization significantly decreased NUE in all the treatments. WUE of spinach increased with adding nitrogen application in most conditions.
A study on the chironomids (Diptera:Chironomidae) diversity at pristine ecosystem was carried out at upstream of Sungai Langat, Selangor. The study determines chironomids distribution and composition at 7 streams and river within the upstream site of Langat Catchment. Chironomid was sampled using Surber net and water quality was measured based on Malaysia WQI. The result indicated that Chironomidae was represented by three subfamilies namely Chironominae, Orthocladiinae and Tanypodinae, which comprises of 2502 individuals. Chironominae was the most dominant subfamily (1619 individuals) followed by Orthocladinae (629 individuals) and Tanypodinae (254 individuals). Polypedilum (subfamily: Chironominae) is the most dominant genus found followed by Rheocricotopus (subfamily: Orthocladiinae), Microtendipes and Cryptochironomus. Polypedilum was abundant in all stations except Sg. Langat 3 which was dominated by Rheocricotopus. Sungai Langat 3 has the highest number of individual (1113) which is (44.5%) from total chironomid individual and followed by Sg. Lolo with 468 individuals that were dominated by Polypedilum.
MeSH terms: Animals; Chironomidae; Larva; Malaysia; Ecosystem; Rivers; Water Quality
Population biology including population structure, reproduction, length-weight relationship and condition factor of a commercially important clupeid freshwater fish, Gudusia chapra was studied in the Old Brahmaputra River, Bangladesh during January-December 2009. In the present study, a total of 2032 specimens (1091 male; 941 female) were collected. The overall sex ratio showed significant difference from the expected value 1:1 (male: female = 1:0.86, χ2 = 11.07, p<0.001). Length-frequency distribution showed a size predominance of females over males, where mean female size consistently exceeded that of males throughout the year. Female size at first sexual maturity was estimated as 8.3 cm in standard length (SL). Monthly gonadosomatic index (GSI) was higher during March-September with a peak in April, indicating this was the main spawning season. The allometric coefficient b of the length-weight relationship (LWR) indicated negative allometric growth in males and females, but the analysis of covariance (ANCOVA) showed significant differences in slope and intercept between the sexes (p<0.001). Fulton’s condition factor by months and SLs varied in both sexes and was attributed to variations in GSI with maturity.
Three forest types were recognized at Chini watershed namely inland, seasonal flood and riverine forests. The soil physico-chemical characteristics from the three forest types were investigated to determine the soil properties variation within a landscape scale. Thirty sampling stations were established, represented by fourteen inland, nine stations in seasonal flood forest and seven in riverine forest. In each station, three soil samples were taken at 0-15 cm depth by using an auger. The study showed 71% of the soil in the inland forest was found to be dominated by clay, 44% of the soil in the seasonal flood forest by clay loam and 42% of the soil in the riverine forest was dominated by silty clay. The pH of all three types of forest studied was acidic and insignificantly different. Organic matter content in the study sites was moderate. The mean of electric conductivity (EC) and cation exchange capacity (CEC) values in the studied soils were low. Based on ANOVA, there were significant differences of the available P and K, K+, Ca2+ and Mg2+ cations and electrical conductivity amongst the three forest types (p<0.05). Cluster analysis showed that the variations of the soil physico-chemical characteristics between the three forest types were low thus indicating that the soil physico-chemical investigated in this study were not the only main contributing factors in floristic variation of the three forest types in Chini watershed.
MeSH terms: Aluminum Silicates; Analysis of Variance; Cations; Electric Conductivity; Nerve Tissue Proteins; Seasons; Soil; RNA-Binding Proteins; Floods; Forests
A unit root test based on the modified least squares (MLS) estimator for first-order autoregressive process is proposed and compared with unit root tests based on the ordinary least squares (OLS), the weighted symmetric (WS) and the modified weighted symmetric (MWS) estimators. The percentiles of the null distributions of the unit root test are also reported. The empirical probabilities of type I error and powers of the unit root tests were estimated via Monte Carlo simulation. The simulation results showed that all unit root tests can control the probability of type I error for all situations. The empirical power of the test is higher than the other unit root tests, and Apart from that, the and tests also provide the highest empirical power. As an illustration, the monthly series of U.S. nominal interest rates on three-month treasury bills is analyzed.
MeSH terms: Animals; Beak; Monte Carlo Method; Probability; Tooth Root; Models, Statistical; Least-Squares Analysis
Linear time series models are not able to capture the behaviour of many financial time series, as in the cases of exchange rates and stock market data. Some phenomena, such as volatility and structural breaks in time series data, cannot be modelled implicitly using linear time series models. Therefore, nonlinear time series models are typically designed to accommodate for such nonlinear features. In the present study, a nonlinearity test and a structural change test are used to detect the nonlinearity and the break date in three ASEAN currencies, namely the Indonesian Rupiah (IDR), the Malaysian Ringgit (MYR) and the Thai Baht (THB). The study finds that the null hypothesis of linearity is rejected and evidence of structural breaks exist in the exchange rates series. Therefore, the decision to use the self-exciting threshold autoregressive (SETAR) model in the present study is justified. The results showed that the SETAR model, as a regime switching model, can explain abrupt changes in a time series. To evaluate the prediction performance of SETAR model, an Autoregressive Integrated Moving Average (ARIMA) model used as a benchmark. In order to increase the accuracy of prediction, both models are combined with an exponential generalised autoregressive conditional heteroscedasticity (EGARCH) model. The prediction results showed that the construct model of SETAR-EGARCH performs better than that of the ARIMA model and the combined ARIMA and EGARCH model. The results indicated that nonlinear models give better fitting than linear models.
Missing values have always been a problem in analysis. Most exclude the missing values from the analyses which may lead to biased parameter estimates. Some imputations methods are considered in this paper in which simulation study is conducted to compare three methods of imputation namely mean substitution, hot deck and expectation maximization (EM) imputation. The EM imputation is found to be superior especially when the percentage of missing values is high as it constantly gives low RMSE as compared with other two methods. The EM imputation method is then applied to the PM10 concentrations data set for the southwest and northeast monsoons in Petaling Jaya and Seberang Perai, Malaysia which has missing values. Four types of distributions, namely the Weibull, lognormal, gamma and Gumbel distribution are considered to describe the PM10 concentrations. The Weibull distribution gives the best fit for the southwest monsoon data for Petaling Jaya. The lognormal distribution outperformed the others in describing the southwest monsoon in Seberang Perai. Meanwhile, for the northeast monsoon in both locations, gamma distribution is the best distribution to describe the data.
This article concerns with a mixed convection peristaltic flow of an electrically conducting fluid in an inclined asymmetric channel. Analysis has been carried out in the presence of Joule heating. The fluid viscosity and thermal conductivity are assumed to vary as a linear function of temperature. A nonlinear coupled governing system is computed. Numerical results were presented for the velocity, pressure gradient, temperature and streamlines. Heat transfer rate at the wall is computed and analyzed. Graphs reflecting the contributions of embedded parameters were discussed.
Single phase LiTa1-xNbxO3 solid solution with 0.00 ≤ x ≤ 1.00 was successfully synthesised via conventional solid-state method at 950°C for 24 h. These materials were refined and fully indexed with hexagonal crystal system, space group of R3c; lattice parameters, a ranging from 5.1410(6) Ǻ to 5.1471(3) Ǻ and c ranging from 13.7467(1) Ǻ to 13.8341(1) Ǻ; with α = β = 90° and γ = 120°. Variation of the lattice parameters in these materials was found to be negligibly small throughout the subsolidus solution. No thermal event was detected within the studied temperature range of 50 to 1000°C. The electrical properties of samples were characterised by AC impedance analyser, HP4192A at temperature ranging from room temperature to 850°C over a frequency range of 5 Hz to 13 MHz. LiTa1-xNbxO3 materials exhibited bulk response with associated capacitances in the order of 10-12 F cm-1 and the temperature-dependent conductivities were found to increase with increasing temperatures. The results showed that LiTa1-xNbxO3 samples were of typical ferroelectrics.
Fukushima Daiichi nuclear disaster led to radioactive contamination crisis was resulted from a series of system failures, nuclear meltdown and radioactive material releases, following the 9.0 magnitude of earthquake and tsunami on March 11, 2011. The objectives of this study were; to investigate the movement of radionuclides based on oceanography and morphology of Pacific Ocean and Southeast Asia (Malaysia); to estimate the time for radionuclides to reach Malaysia and to calculate the amount of total absorbed dose rate for selected marine biotas namely benthic fish and pelagic fish. ERICA code system was used because it has the ERICA integrated approach to assess the radiation risk of biota. The estimations of radionuclide discharge from Fukushima Daiichi nuclear disaster were based on Cs-137 (half-life of 30.17 years), I-131 (half-life of 0.02 years). The parameters such as discharge rate of radionuclides (Bq/s), water depth (m), the distance between the target coast of Malaysia and radionuclide release point (m), the distance between the receptor and radionuclide release (m) and the velocity of the water/ocean currents (m/s) were studied. The results showed that the minimum estimated arrival time of radionuclides to reach Malaysia is located in Sandakan, Sabah, which is approximated at 4.82 years (Dec 2015) with an average of 5.039±0.310 years after the accident. Meanwhile, maximum estimated arrival time of radionuclides to Malacca is 5.87 years (Jan 2017) with an average of 5.527±0.480 years. The lowest estimated total absorbed dose rate by benthic fish is 0.0583 μGy/h with an average of (6.33±0.71) × 10-2 μGy/h in Malacca whereas the highest estimated total absorbed dose rate by benthic fish is 0.0751 μGy/h with an average of (7.11±0.57) × 10-2 μGy/h in Sandakan, Sabah. Pelagic fish in Malacca shows the lowest estimated total absorbed dose rate of 0.00149 μGy/h with an average of (1.62±0.18) × 10-3 μGy/h whereas Sandakan, Sabah showed the highest estimated total absorbed dose rate of 0.00193 μGy/h with an average of (1.83±0.15) × 10-3 μGy/h. The total absorbed dose rate and risk quotient of ERICA code system show that for all reference organisms, the probability of exceeding the selected screening dose rate of 400 μGy/h by aquatic biota is below the probability selected. Therefore, no measurable population of chronic exposure effects would occur at this stage. Nonetheless, a normal experimental analysis of fish samples should be performed in order to monitor the radiation effects to marine ecosystem.
Ancient remains are considered very valuable artefacts, as they allow for the study of ancient cultures, phylogeny, evolution and the reconstruction of demographic history. To obtain all the information contained within remains, the investigation of such samples requires the expertise and various techniques from multiple fields of study. The present review focuses on the molecular biology and radiographic approaches used to identify ancient samples. Studies of ancient remains face various limitations; for example, the quality and quantity of the ancient samples can affect the difficulty of the investigations. Due to these limitations, new sophisticated techniques are being introduced to replace the earlier conventional techniques. A search was conducted using PubMed, Scopus, Science Direct and Science Finder to provide a new and timely review on the molecular mitochondrial DNA and radiographic analysis for human archaeology identification. The present review has determined that molecular biological approaches are very accurate and useful for the use in the ancestral determination of incomplete specimens, whereas observations of the dental pulp chamber are suitable for age at death estimations in both adults and children. However, these techniques are expensive and require expert personnel. Therefore, conventional approaches remain the favourite methods of most institutions, especially in Asia.
Biological activities of crude methanolic extracts from leaves, barks, twigs and roots of Enicosanthellum pulchrum were investigated in four bioassays. The antioxidant, 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging assay showed that bark and twig extracts showed high inhibitory activity with 60 and 56% inhibition at 1 mg/mL and IC50 values of 0.43 ± 0.04 and 0.64 ± 0.05 mg/mL, respectively. The bark and root extracts showed greater reducing power (FRAP) than several standard drugs used in the bioassay. Methanolic extracts of leaves, twigs and roots displayed strong cytotoxicity to breast cancer cell line (MCF-7), myelomonocytic leukaemia cell line (WEHI-3) and ovarian cancer cell line (CAOV-3); the IC50 of the leaf extract were 7.8 ± 0.85 μg/mL (MCF-7) and 9.0 ± 0.13 μg/mL (WEHI-3), while those for the twig and root extracts were 13.9 ± 0.35 and 7.3 ± 0.98 μg/mL (CAOV-3), respectively. In the antimicrobial assays, the extracts were tested against ten bacterial strains and two fungal strains. Bark and twig extracts displayed high inhibitory activity to Bacillus subtilis with 13.3 ± 0.57 and 12.0 ± 0.01 mm inhibition, respectively. In addition, the twig extract displayed better minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) compared with the bark extract (MIC 0.5 and 1.0 mg/mL, MBC 1.0 and 2.0 mg/mL, respectively). For antifungal activity, all extracts showed inhibition on Candida albicans but not on Aspergillus niger. The obtained results suggested that this plant may possibly contain bioactive compounds in the active extracts.
Recently the interest of public and stakeholders were focus on the environmental status of Kuching Wetland National Park (KWNP) due to the increase of urbanization processes and anthropogenic activities. A field sampling which covered 10 stations was conducted at the outer and inner boundary of KWNP in August 2011 during high tide. Physico-chemical water parameters were recorded. Triplicate of near bottom water samples were collected using 2.5 L Van don water sampler (Wildco®) for further analyses of nutrient, chlorophyll a (chl a), biological oxygen demand (BOD) and total suspended solids (TSS). The aimed of the study were to assess the water quality of KWNP and to determine the distribution pattern of physico-chemical components and its relationship to the phytoplankton chlorophyll a concentrations in water between the outer and inner part of KWNP. One-way analyses of similarity indicated that all the study sites were significantly different between stations (p-value < 0.05) and boundaries (p-value < 0.05). Water temperature, pH, ammonium nitrogen (NH4–N) and inorganic phosphorous (Inorg–P) were known affecting the abundance of phytoplankton communities. The concentrations of nitrate nitrogen (NO3–N) at the outer and inner boundaries of KWNP were over-ranged as compared to Malaysia marine standards.
The present study investigated the efficiency of aerobic granular sludge (AGS) technology in treating effluent from soy sauce industry which is categorized as a high strength wastewater. The combination of anaerobic and aerobic granulation technology in SBR system was used in this study which was efficiently treated COD from the soy sauce wastewater where 87% of removal was achieved. Ammonia and colour was removed at a maximum of 87 and 76%, respectively, in the SBR system. Matured, dense and compact granules with 2.5 mm in diameters were developed with a good settling velocity (45 m/h) and 28 mL/gSS of sludge volume index (SVI). Hence, AGS technology was proven as an excellent treatment for soy sauce wastewater for being discharge into the environment, as the effluent was treated in one biological reactor with high hydraulic and organic loadings besides less production of sludge. In this study, the capabilities of AGS technology in treating relatively higher concentration of organic impurities present in the soy sauce wastewater were demonstrated.
Infiltration caused by rainfall will lead to the changes of moisture content and soil pore water pressure or matric suction of the soil. These changes indicate the behavior of the soil especially during wetting and drying process. This paper presents the experimental test result of rain water infiltration into soil column for two samples of soils. The main objectives were to study the effect of rainfall intensity and duration of soil infiltration process for the forest soil and to compare its result to the gravelly sand. Infiltration experimental in this study involved three main components; water supply system, soil column and instrumentations, including percolation collection system. This study uses two types of tensiometers; 5 and 10 cm long. The results of TDR and tensiometers which were used to obtained moisture content and matric suction, respectively, shows that the system was successfully developed. For the forest soil, the result showed that moisture content of the top section is higher compared with the other sections. On the other hand, for gravelly sand, the moisture content in middle section is higher compared with the top and bottom section of the soil. Meanwhile, matric suction for both soils dropped during rainfall and gradually increases towards drying process. Other than that the comparison of soil matric suction between 5 and 10 cm tensiometers shows significant results for gravelly sand compared to forest soil.
Phaleria macrocarpa seeds are rapidly killed with desiccation to moisture content (MC) below 20%. Desiccation tolerance of their embryonic axes was studied for storage and germplasm conservation purposes. Embryonic axes were extracted aseptically from fresh seeds obtained from fully ripe fruits in a horizontal laminar air flow cabinet. They were then desiccated under aseptic condition for periods ranging from 0-8 h. For each desiccation treatment, embryonic axes were drawn randomly for the determination of MC according to ISTA, electrolyte leakage and proliferation on Murashige and Skoog (MS) media supplemented with 1 mg/l 6-benzylaminopurine (BAP) and 1 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D). The results obtained from this study indicated that the embryonic axes could tolerate dehydration down to 13.6% with desiccation for 8 h while retaining relatively high viability of 76.7%. This was supported by only gradual increment of electrolyte leakage with the desiccated embryonic axes. All non-desiccated embryonic axes with MC of 52.5% were capable to grow into normal plantlets in vitro but dehydration to MC of 36.0% and further down to 13.6% generally resulted in callus formation with up to 16.7% of the embryonic axes while at least 60.0% of the other embryonic axes were still capable to proliferate as normal plantlets in vitro.
Reducing emissions from deforestation and forest degradation-plus (REDD+) is considered as an important mitigation strategy against global warming. However, the implementation of REDD+ can adversely affect local people who have been practicing shifting cultivation for generations. We analyzed Landsat-5 Thematic Mapper images of 1990 and 2009 to quantifying deforestation and forest degradation at Lubuk Antu District, a typical rural area of Sarawak, Malaysia. The results showed significant loss of intact forest at 0.9% per year, which was substantially higher than the rate of Sarawak. There were increases of oil palm and rubber areas but degraded forest, the second largest land cover type, had increased considerably. The local people were mostly shifting cultivators, who indicated readiness of accepting the REDD+ mechanism if they were given compensation. We estimated the monthly willingness to accept (WTA) at RM462, which can be considered as the opportunity cost of foregoing their existing shifting cultivation. The monthly WTA was well correlated with their monthly household expenses. Instead of cash payment, rubber cultivation scheme was the most preferred form of compensation.
MeSH terms: Conservation of Natural Resources; Malaysia; Rubber; Thiourea; Global Warming; Forests
Kajian ini tertumpu kepada penentuan taburan terbaik untuk memodelkan siri data maksimum tahunan (MT) dan siri maksimum hujan dalam tempoh ribut yang melebihi 48 jam (MR). Data hujan setiap jam dari tahun 1970 hingga 2008 dari 4 stesen hujan di Semenanjung Malaysia telah digunakan dalam kajian ini. Kedua jenis data maksimum ini mempunyai kegunaan yang sangat baik bagi mengesan banjir di kawasan bandar terutama yang disebabkan oleh kegagalan sistem perparitan dalam menampung hujan lebat semasa tempoh ribut yang panjang, manakala kajian yang boleh meramalkan ketahanan empangan dalam masa 50 atau 100 tahun kehadapan sangat bergantung kepada penentuan taburan hujan maksimum tahunan. Pelbagai taburan yang sering digunakan bagi kajian pemodelan ekstrim digunakan untuk mendapatkan taburan yang terbaik bagi menerangkan taburan kedua jenis data hujan maksimum tersebut. Dua ujian kebagusan model telah digunakan iaitu kaedah bergraf dan kaedah PRKD. Hasil menunjukkan bahawa taburan Pearson Jenis 3 adalah yang terbaik untuk menerangkan taburan hujan maksimum tahunan pada kesemua stesen hujan yang digunakan pada kajian ini. Taburan Pareto dan Gama adalah taburan yang terbaik bagi menerangkan taburan hujan maksimum yang berlaku pada tempoh ribut yang panjang. Hasil kajian penentuan taburan terbaik bagi hujan maksimum tahunan di atas juga telah berjaya dalam meramalkan hujan maksimum yang akan berlaku untuk masa 50 dan 100 tahun yang akan datang.
The objective of this study was to identify the exogenous variables of risk and investment management efficiency by using a two-stage data envelopment analysis (DEA) method. The first stage involves obtaining the efficiency scores of risk and investment management via DEA that requires only the traditional inputs and outputs. In the second stage, the Tobit regression analysis is conducted in which the efficiency score obtained from the first stage is treated as a dependent variable, while the exogenous factors are considered to be independent variables. The exogenous factors consist of operating systems, organizational form, consumer preference and size. The results showed that the mutual company as well as the takaful system demonstrate better risk management performance than their stock and conventional system counterparts. In addition, size is also a significant indicator for risk management efficiency in which the larger insurer/takaful operator exhibits better risk management performance than the smaller one. However, consumer preference is found to be insignificantly correlated with the efficiency of risk management. In contrast, with risk management, organizational form, operating system and size are not indicators of the investment management efficiency, but consumer preference is significantly and positively associated with investment management efficiency.