Microsatellite DYS385 is a highly polymorphic marker in the Y chromosome. It has been used for investigating population genetic structure and personal identification in various ethnic groups of the world. This research aimed to analyze the microsatellite DYS385 polymorphism among 9 Tai and 11 Mon-Khmer speaking populations of northern Thailand. Fiftysix different haplotypes were found in 453 samples from 20 populations. Haplotype diversities and discrimination powers of populations belonging to the Tai linguistic family was higher than those of the Mon-Khmer group. Genetic affinities based on DYS385 variation do not conform to linguistic classification but a fraction of genetic divergence patterns can be explained by geographic distances.
In this study, we investigated the effects of 2,4-Dichlorophenoxy acetic acid (2,4-D) treatment on selected physiological parameters and fruit quality of wax apple fruits under field conditions. Foliar spray of 2,4-D at 0, 5, 10 and 20 mg L-1 concentrations were used from bud stage to the 3rd week of fruit development. Physiological parameters determined included net photosynthesis, stomatal conductivity, chlorophyll content and chlorophyll fluorescence. Net photosynthetic rate and photosynthetic efficiency via chlorophyll fluorescence significantly (p≤0.05) increased with 5 and 10 mg L-1 2, 4-D treatments. Furthermore, 5 mg L-1 2,4-D reduced bud and fruit drop, increased fruit weight and dry matter content in leaves. An improved fruit set, enhanced fruit growth, faster color development and advanced maturity were also recorded in treated plants. In addition, fruit yield increased by 39 and 48% with 5 and 10 mg L-1 2,4-D treatments, respectively. Fruit K+ content, total sugar, protein content and chalcone synthase (CHS) activities increased with 2,4-D treatments. Increased leaf soluble protein and elevated sucrose phosphate synthase (SPS) activity were also observed in 5 mg L-1 treated plants. Positive correlation between photosynthesis rate and SPS activity of leaves (R2=0.98) and between CHS activity and color development of fruits (R2=0.98) were recorded in 5 mg L-1 treatments. The results also suggested that 5 and 10 mg L-1 2,4-D treatments are promising for enhancing plant productivity and fruit quality in wax apple trees under field conditions.
Dengue fever is a vector-borne viral disease which is now endemic in more than 100 countries affecting more than 2.5 billion people worldwide. In recent years, dengue fever has become a major threat to public health in Pakistan. In this paper, we derived an explicit formula for reproduction number R0 (the most important epidemiological parameter) and then used real data of dengue fever cases of different hospitals of Lahore (Pakistan) on R0. Conditions for local stability of equilibrium points are discussed. In the end, simulations are carried out for different situations.
MeSH terms: Dengue; Environment; Hospitals; Pakistan; Public Health
We consider the problem of outlier detection in bivariate exponential data fitted using the generalized linear model via Bayesian approach. We follow closely the work outlined by Unnikrishnan (2010) and present every step of the detection procedure in details. Due to the complexity of the resulting joint posterior distribution, we obtain the information on the posterior distribution from samples generated by Markov Chain Monte Carlo sampling, in particular, using either the Gibbs sampler or the Metropolis-Hastings algorithm. We use local breast cancer patients’ data to illustrate the implementation of the method.
A number of relative permeability models were present in the literature, which were used to generate relative permeability data for the fluids, present in the porous medium. Some models were more significant to reservoir geology and displacement system (imbibitions and drainage system), while developing the correlations. Similarly, the same is kept in mind while performing reservoir studies. Therefore, in this study different models based on displacement system and formation geology have been compared, while including the effect of fluid saturation distribution/end point saturation in a reservoir. The generated relative permeability data by using these models have been further used to predict the reservoir performance for gas and water-displacement systems. The results based on this study showed that at lower saturations of displacing fluid (gas and/or water), the generated reservoir performance curves based on relative permeability data generated by using Corey and Wylie and Gardner models, gives higher degree of deviation on comparative basis. The behavior of these error or deviation curves for displacing phase is opposite in case of gas and water-oil displacement systems. While in case of displaced phase (oil), generally analogous behavior can be observed for both systems in terms of deviation/ error profiles trends. These reservoir performance curve(s) are of utmost significance in developing reservoir in an appropriate manner and a slight variation in relative permeability data can have a significant impact at macroscopic level.
MeSH terms: Body Fluids; Geology; Models, Theoretical; Permeability; Water; Porosity
Miocene larger benthic foraminifera have been discovered from a limestone unit of the Kalumpang Formation. The limestone is exposed at the Teck Guan Quarry, Tawau, southeast Sabah. The Kalumpang Formation consists predominantly of interbedded mudstone and sandstone (graywacke), conglomerate, limestone, marl, chert and volcanic rocks. Five limestone samples have been collected and processed for petrographic analysis and identification of larger benthic foraminifera. The limestone is classified as packstone and mudstone. A total of seventeen species of larger benthic foraminifera have been identified. The foraminifera are divided into two assemblages namely Assemblage I and Assemblage II. Assemblage I is characterized by the presence of Lepidocyclina (Nephrolepidina) parva, Operculina sp. and Lepidocyclina (Eulepidina) formosa. This assemblage is an indicative of Aquitanian to Burdigalian in age (Early Miocene). Assembalge II comprises of Lepidocyclina (Nephrolepidina) sumatrensis, Lepidocyclina (Nephrolepidina) angulosa, Lepidocyclina (Nephrolepidina) ferreroi Lepidocyclina sp., Miogypsina sp., Katacycloclypeus annulatus, Katacyloclypeus martini, Cycloclypeus carpenteri, Cycloclypeus indopacificus, Cycloclypeus sp., Flosculinella bontangensis, Operculina complanata, Amphistegina bowdenensis and Amphistegina sp. This assemblage is an indicative of Langhian to Serravallian age (Middle Miocene). The foraminiferal assemblages suggest that the depositional environment was a warm tropical shallow-marine at the fore-reef shelf zone.
The determination of variance of surface air temperature is very essential since it has a direct impact on vegetation, environment and human livelihood. Forecast of surface air temperature is difficult because of the complex physical phenomenon and the random-like behavior of atmospheric system which influences the temperature event on the earth surface. In this study, forecast models based on artificial neural network (ANN) and genetic programming (GP) approaches were proposed to predict lead seven days minimum and maximum surface air temperature using the weather parameters observed at the station Chennai, India. The outcome of this study stated that models formulated using ANN approach are more accurate than genetic programming for all seven days with the highest coefficient of determination (R2), least mean absolute error (MAE), root mean square error (RMSE) and mean absolute percentage error (MAPE) on deployment with independent test dataset. ANN models give statistically acceptable mean absolute error of 0.59oC for lead day one in minimum temperature forecast and 0.86oC variance for lead day one in maximum temperature forecast. The study also clarified that the level of accuracy of the proposed prediction models were found to be better for smaller lead days when compared with higher lead days with both approaches.
Hydraulic fracturing becomes more difficult when confronted with a formation of high fracturing pressure. In such formations, acidizing before the main fracturing treatment provide a method to reduce fracture pressure. The aim of this paper was to investigate the evolution of fracture pressure in a wellbore with acidizing. Five experiments were conducted to study the mechanisms of acid damage on reservoir minerals and cementing materials properties. Consequently, a mathematical model to predict fracture pressure with acidizing has been established and verified by field data. The analysis results showed that it is possible to reduce fracture pressure with decreased rock strength and fracture critical stress intensity factor by means of acid damage. Acid damage destroys the crystal structure of mineral particles, breaks the crystalline layers in cementing materials, increases rock porosity and reduces the rock strength. In addition, as the acid concentration, formation temperature and acid treatment time increased, it was useful to reduce fracture pressure in the wellbore. Using the proposed model, we were able to select the optimal acid damage construction parameters to reduce fracture pressure.
AISYAH ABU BAKARRed palm weevil (RPW), Rhynchophorus ferrugineus has been reported as a serious pest of coconut, sago palm and date palm in many parts of the world. In Malaysia, RPW is a lethal pest of coconut in Terengganu and sago palm in Sarawak. However, very limited information about the reproductive performance of RPW is available, specifically in Malaysia. In the present study, the reproductive performance of RPW reared on sago palm (Metroxylon sagu) were studied using nine pairs of virgin RPW under laboratory conditions. The number of eggs laid and eggs viability were recorded daily until females could not produce eggs. The total number of eggs laid were 3081 and the average number of eggs deposited by a female was 342.3+0.97 eggs (ranged from 270 to 396). The percentage of hatchability was 52.4% and out of the total 1614 hatched eggs, only 118 individuals (7.3%) were survived until late instar. However, no significant differences in fecundity, hatchability and total survived larvae in different RPW pairs were observed. Females longevity was found to be strongly influenced by the number of eggs laid; the higher number of eggs laid, the shorter is the life span of the female. This study is important to understand the biological aspects of RPW, as a first step to develop effective control strategy of the pest.
The aim of this paper was to identify the determinants that influence vehicle theft by applying a negative binomial regression model. The identification of these determinants is very important to policy-makers, car-makers and car owners, as they can be used to establish practical steps for preventing or at least limiting vehicle thefts. In addition, this paper also proposed a crime mapping application that allows us to identify the most risky areas for vehicle theft. The results from this study can be utilized by local authorities as well as management of internal resource planning of insurance companies in planning effective strategies to reduce vehicle theft. Indirectly, this paper has built ingenuity by combining information obtained from the database of Jabatan Perangkaan Malaysia and insurance companies to pioneer the development of location map of vehicle theft in Malaysia.
The series samples of xTeO2-(70-x)B2O3-30MgO with 0≤x≤30 mol% have been prepared via the solid-state reaction method. The composition sample of 30TeO2-40B2O3-30MgO were chosen as a doped sample in the composition of 100-y(30TeO2-40B2O3-30MgO)-yEu3+ with 0.2≤y≤2 mol% and were heated at 750oC. The XRD results showed that the major phase was Mg(Te2O5) while MgO(B2O3)2, MgTe6O13, Mg2 (B2O5) and MgB4O7 was observed as a minor phase. The small phase of EuB2O4 and Eu2 Te4 O11 were detected by XRD when the composition of 30TeO2-40B2O3-30MgO were doped with 1.5% of Eu3+. The EDX analysis of 30TeO2-40B2O3-30MgO doped with 1.5% Eu3+ sample was confirmed the presence of boron (B), magnesium (Mg), tellurium (Te), oxygen (O) and europium (Eu) elements. From the FESEM images, the surface morphology of doped 1.5% Eu3+ samples was agglomerated compared with the undoped sample. The average diameter of the grain size is in the range of 50-100 µm. The emission spectra of the Eu3+-doped 30TeO2-40B2O3-30MgO ceramic consists of intense and sharp lines ranging from 550-725 nm. The luminescence spectra showed that the emission intensity of 30TeO2-40B2O3-30MgO doped with Eu3+ was enhanced with the increase of Eu3+ ion from 0.2 to 1.5 mol%, which resulted in enhancement of the red emission of the samples. The longest decay time for 30TeO2-40B2O3-30MgO doped with 1.5 mol % Eu3+ was 0.892 ms.
Polyhydroxyalkanoates (PHAs) has been investigated for more than eighty years. Ever since then, the scientists are kept on synthesizing and developing new polymers and application to suit human interests nowadays. The resourcefulness of PHAs has made them a good candidates for the study of their potential in a variety of areas from biomedical/medical fields to food, packaging, textile and household material. In medical field (specifically in tissue engineering application), producing a biocompatible 3-D scaffold with adaptable physical properties are essential. However, to the best of our knowledge, scaffolds from PHB and PHBV with thickness greater than 1 mm have not been produced yet. In this work, PHB and PHBV porous 3-D scaffolds with an improved thickness greater than 4 mm was fabricated using conventional method of solvent-casting particulate-leaching (SCPL). A preliminary assessment on the improved thickness 3-D scaffolds was carried out to examine its pore interconnectivity by using non-invasive color staining method. The vertical cross sections image of the stained scaffolds was analyzed by image analyzer software. This technique was considered simple, fast and cost effective method prior to the usage of super accurate analytical instruments (micro-computed tomography). The results showed that over 80% of the pores have been interconnected with the adjacent pores. Moreover, there was a good correlation between the predicted pore interconnectivity and porosity. These results indicated how well a simple technique can do by giving an overview of the internal morphology of a porous 3-D structure material.
MeSH terms: Drug Packaging; Humans; Software; Solvents; Staining and Labeling; Textiles; Porosity; Tissue Engineering; Intracellular Signaling Peptides and Proteins; Polyhydroxyalkanoates; X-Ray Microtomography
Multilocus sequence typing (MLST) has been used to characterise methicillin-resistant Staphylococcus aureus (MRSA) isolates into sequence types (STs) and together with SCCmec typing, form the clonal nomenclature for MRSA. MLST was conducted as per the standard protocol on ten out of 236 isolates collected previously from January to December 2009 representing four different SCCmec types. Relationship analysis was performed with eBURST via the MLST website. Four unlinked ‘singleton’ STs were detected: ST30, ST239, ST772 and ST1178. Together with SCCmec typing, five MRSA clones were identified: ST30-IV, ST239-II, ST239-III, ST772-V and ST1178-IV. Clones ST239-III and ST30-IV are already established in Malaysian hospitals and in the local community, respectively. ST772-V is an emerging clone reported previously to have a propensity to displace pre-existing predominant clones. A clone involving the predominant ST in Malaysia (ST239) with SCCmec type II is the first of its kind to be identified. MRSA clones in our centre are very diverse and clone surveillance with large sample sizes should be undertaken as collaborative efforts between local institutions to maximise detection coverage.
Eye movement is one of the most important mechanisms that function to collect the information from the environment to stimulate the motor action and thus enable a person to perform daily activities. The purpose of this study was to investigate whether eye movement parameters when performing activities of daily living (ADL) is affected by learning effect when the ADL were repeated. Thirteen school children aged between 15 and 19 years old (mean 16.31±1.89 years) participated in this study. They undergone two evaluations, baseline and follow up, separated by at least 10 weeks. The evaluation included assessment of visual acuity at near and distance using Lighthouse reduced ETDRS chart and Early Treatment Diabetic Retinopathy (ETDRS) chart, respectively; eye movement parameters (task duration, saccade latency and number of saccades) while performing ADL (identifying colours, coins and food) were recorded using Positive Science Portable LLC eye tracker. The mean value for the visual acuity at distance and near for baseline and follow up were logMAR -0.05±0.05 and logMAR -0.05±0.05, respectively. The results showed that comparison of eye movement parameters for performance of ADL at baseline and follow up were not statistically significant. Therefore, the findings of this study suggested that learning effect is not a factor that will influence change in eye movement parameters when performing ADL. These findings implied some benefit in using eye movement parameters for example to evaluate performance of ADL when given intervention in persons with nystagmus.
The study aimed to determine the influence of sample preparation and extraction parameters on the antibacterial activity of inflorescences from banana (Musa balbisiaba cv. Saba). Banana inflorescences were extracted using various solvent extractions and tested for antibacterial activity using agar-well diffusion assay against gram-positive bacteria (Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes and Brochothrix thermosphacta) and gram-negative bacteria (Salmonella typhimurium, Salmonella enteritidis, Escherichia coli O157:H7, Enterobacter sakazakii, Yersinia enterocolitica and Vibrio parahaemolyticus) The effects of geographical origin, drying methods and extraction parameters (sample-to-solvent ratio, extraction time and temperature as well as methanol to solvent ratio) on antibacterial activity of the banana by-product were carried out. Among all the extracts evaluated, methanolic extract from the buds showed significant higher inhibitory against all gram positive bacteria ranging from 12.56-13.54 mm. Interestingly, no significant different (p>0.05) was observed on the effect of geographical origin as well as extraction methods on the antibacterial capacity. Meanwhile, the extracts produced from 50°C oven dried sample seem to have comparable antibacterial activity with the freeze dried samples. Extraction parameters (sample-to-solvent ratio, extraction time and temperature as well as methanol to solvent ratio) were found responsible in determining the efficacy of the antibacterial. In conclusion, methanolic extracts from banana inflorescence buds could be a new source of natural antibacterial and further bioassay guided fractionation should be carried out to determine the bioactive compounds and their biological activities.
Studies have shown that some characters, such as morphological, biochemical and behavioural characteristics were shared among con-specifics of closely related frog species. It is hypothesized that closely related frogs would have similar vocal apparatus structure to produce similar call characteristics, in order to be recognized by con-specifics. The vocal apparatus structures of the frogs from Ranidae were, thus, investigated and calls were recorded from various locations in Sarawak, Borneo. The vocal apparatus was sliced and stained using haematoxylin and eosin staining method. The prepared slides were scanned using Dotslide System Olympus BX51. Captured images were further measured using Microscope Olympus BX51. The results showed that the vocal apparatus structure of ranids in Sarawak differed in length between pulvinar vocale and posterior margin (pvpm) or known as vocal cord stricter. This character was deemed to be the most significant character to discriminate the Sarawak ranids. It is suggested that histological analysis is also a good method for study of phenotypic variation of frog species, as shown by the vocal apparatus structure of the anurans. This study provides an alternative method to differentiate taxonomic identity among frog species.
The objectives of this study were to determine the effect of different cryoprotectants and sperm densities for longterm storage of orange mud crab, Scylla olivacea spermatozoa. Spermatozoa were obtained by homogenizing the spermatophores using a glass homogenizer in an ice-bath followed by centrifugation at 4°C. Spermatozoa were then suspended in calcium-free saline (Ca-F saline) containing 5% of the following cryoprotectants: Glycerol, dimethyl sulfoxide (DMSO) and methanol. Sperm which vibrated and rotated were counted as live during sperm viability assessment. Samples of spermatozoa were cooled to -196°C by two-step freezing, first to -80°C and then by plunging into liquid nitrogen (LN). Spermatozoa were gradually cooled at 1°C/min. Thawing was carried out in a 30°C water bath for 2 min. This yielded live sperm after storage in LN for 30 days. The best sperm viability was obtained from a density of 108 cells per mL in DMSO. There was no significant difference (p>0.05) among cryoprotectants toward sperm viability. However, sperm viability was significantly affected (p>0.05) by cell densities. In conclusion, DMSO gave the best protection to sperm cells of S. olivacea, but the effectiveness of DMSO as a cryoprotectant is influenced by sperm density.
The seeds of 6 × 6 half diallel progenies of Jatropha curcas were used to evaluate the effects of genotypes (parents and their hybrids) on germination traits of jatropha at Universiti Kebangsaan Malaysia. Germination traits were varied significantly (p<0.01) among the seeds of hybrids and their parents. The germination was started at four days after planting and prolonged until 15 days. Seed germination varied from 58.06 to 92.76% among the parents and 53.43 to 98.96% among the hybrids. The highest germination was observed in the hybrid P2 × P4 and none of the hybrid or parent showed complete (100%) germination. The maximum GI (germination index) and SVI (seedling vigour index) were found in the hybrids P1 × P5 and P1 × P2 and the lowest in P2 × P4 and P3 × P6, respectively. For most germination parameters parents behaved poorly than that of the hybrids.
Eight seaweed species in Teluk Kemang and three seagrass species in Teluk Pelanduk, Port Dickson, respectively, were screened for antibacterial activities. The antibacterial activities were screened using disc diffusion test, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against six aquacultural pathogens strains Aeromonas hydrophila ATCC35654, Vibrio harveyi BB120, Vibrio harveyi ATCC14126, Vibrio alginolyticus ATCC17749, Vibrio parahaemolyticus ATCC17803 and Vibrio anguillarum ATCC43313. The results showed that among all the pathogens, seaweed Padina minor and seagrass Thalassia hemprichii had the strongest antibacterial activity against Vibrio harveyi BB120 and Vibrio harveyi ATCC14126, respectively. The lowest values for minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were obtained from Padina minor against V. harveyi BB120 and Thalassia hemprichii against V. harveyi ATCC14126, respectively. The findings suggested that seaweed and seagrass in Port Dickson coastal water have the potential to prevent bacterial diseases particularly in aquaculture.
Palm-based DHSA is a new chemical developed in MPOB that has three reactive sites that would enable the preparation of many useful derivatives. New chemicals introduced into the market have to be registered and information on their environmental performance such as biodegradability has to be supplied as required under various national and international laws. Biodegradability screening tests, such as the OECD 301 series, are basic tools for assessment of the environmental fate of chemicals in aquatic environments. A substance is considered readily biodegradable when its biodegradability reaches the pass levels of 60% carbon dioxide (CO2)/theoretical carbon dioxide (ThCO2) evolution, 60% biochemical oxygen demand (BOD)/theoretical oxygen demand (ThOD) or 70% dissolved organic carbon (DOC) removal within 28 days. Palm-based DHSA was found to be readily biodegradable where its biodegradability reached 65% within 28 days test period determined via the OECD 301C Modified MITI (I) test method, which passed the 60% level of BOD/ThOD requirement as stipulated in the OECD Guidelines for testing of chemicals. This result is indicative of DHSA’s rapid degradation in aquatic environments. Hence, DHSA is not expected to accumulate in the food chains and will not pose problems in the aquatic environments although it is poorly soluble in water.