The shoot tip explants of the tillered onion line Z-018 were used as experimental materials. The effects of colchicine
and pendimethalin on the induction of polyploid tillered onion were studied in vitro with different concentrations and
treatment time. Treatment with 250 μmol/L colchicine for 4 days caused a variant rate of 42.22% and a mortality rate
of 36.67%, whereas treatment with 30 μmol/L pendimethalin for 6 days caused a variant rate of 41.11% and a mortality
rate of 24.44%. Subsequent cytological identification showed that tetraploid plants were successfully induced by both
mutagens. Compared with the diploid plants, the tetraploid plants exhibited slower growth, thicker leaves, stems and
roots, larger stomatal apparatus and increased number of chloroplasts. In addition, the obtained tetraploid plants have
thicker tubular leaves, decreased number of tillers, larger bulbs and increased yield of the products. This provides the
basis for future research on tillered onion germplasm resources.
Drought is one of the commonly occurring environmental stresses, limiting crop production in many countries. Selection
of cultivar is the most effective and economical means for alleviating the adverse effects of drought stress on crops. The
present study aimed to investigate the growth, some physiological processes, yield and quality of some newly-developed
wheat cultivars (AARI-2011, AAS-2011, Faisalabad-2008, Millat-2011 and Punjab-2011) under field drought stress
conditions. The cultivars were sown in a field under normal irrigation and drought-induced conditions. Maximum net
photosynthetic rate was recorded in cv. AAS-2011 at growth stage of 67 days after wheat emergence under normal irrigation
and cv. Faisalabad-2008 at 67 days after wheat emergence under drought condition. Leaf stomatal conductance and
transpiration rate were maximum in cv. Faisalabad-2008 under drought conditions. The adverse effects of drought stress
were observed more on cv. Millat-2011 than Faisalabad-2008, with respect to net photosynthetic rate and transpiration.
Drought exerted a significant adverse effect on leaf stomatal conductance at 74 days after wheat emergence which was
recorded as 230 mmol m-2 s-1. Among the cultivars, AAS-2011 recorded maximum yield traits and grain yield under normal
irrigation condition and Faisalabad-2008 under drought condition. Cultivar Millat-2011 was the most susceptible to
drought and Faisalabad-2008 the most resistant to drought. Faisalabad-2008 maintained the quality at the most under
drought stress conditions. It is concluded that Fasialabad-2008 should be grown under field drought conditions to achieve
maximal yield and quality of wheat.
Flavonoid is an industrially-important compound due to its high pharmaceutical and cosmeceutical values. However,
conventional methods in extracting and synthesizing flavonoids are costly, laborious and not sustainable due to small
amount of natural flavonoids, large amounts of chemicals and space used. Biotechnological production of flavonoids
represents a viable and sustainable route especially through the use of metabolic engineering strategies in microbial
production hosts. In this review, we will highlight recent strategies for the improving the production of flavonoids
using synthetic biology approaches in particular the innovative strategies of genetically-encoded biosensors for in
vivo metabolite analysis and high-throughput screening methods using fluorescence-activated cell sorting (FACS).
Implementation of transcription factor based-biosensor for microbial flavonoid production and integration of systems
and synthetic biology approaches for natural product development will also be discussed.
The unsteady blood flow in the stenosed porous artery subjected to a magnetic field was studied analytically. Oscillating
pressure gradient and periodic body acceleration were imposed on the flow field. The effects of the magnetic field and
the permeability of the stenosed artery on the blood velocity were studied. The results showed that the magnetic field
affected the flow field significantly which can be beneficial for some practical problems.
Sesquiterpenes are a three-isoprene unit compounds which belong to terpenoid family of secondary metabolites. These
volatile compounds are one of the major constituents of essential oils in plants and plays major roles in plant signaling
of defense mechanism. The effects of methyl jasmonate (MeJA) concentrations (100 and 200 μM) on the production
of sesquiterpene compounds after incubation period for 1, 3, and 6 days were investigated in Persicaria minor cell
suspension culture. Headspace Solid-Phase Microextraction (HS-SPME) method was used to absorb volatile compounds
from suspension cells and liquid medium. They were then analyzed through Gas Chromatography-Mass Spectrometry
(GC-MS) to identify sesquiterpene compounds. Among the 15 sesquiterpene compounds identified, α- muurolene was found
in significantly higher concentration in all MeJA treated cultures. The results showed that α-muurolene was detected in
the suspension cells at the highest peak area of 14.17% at 100 μM MeJA treated cultures with 3-day incubation. Analysis
of liquid medium of the treatments identified secretion of α-muurolene into the culture medium, with total peak area of
0.72%. These results showed that sesquiterpene production in MeJA induced P. minor suspension culture depended on
the MeJA concentration and also culture incubation period.
In this paper, Taguchi experimental design technique was applied for optimization of chromium (Cr)/silver (Ag)/indium
tin oxide (ITO) SPR sensor for operation in near infrared region. Four factors were considered which include wavelength,
thickness of Cr, thickness of Ag, and thickness of ITO. Finite-difference-time-domain (FDTD) method was used in numerical
analysis for minimum reflectance (Rmin) and full-width-at-half-maximum (FWHM) performance parameters. The results
obtained from the Taguchi method shows that the optimized parameter for Rmin was 785 nm of wavelength, Cr (1 nm),
Ag (40 nm) and ITO (20 nm), whereas the optimized parameter for FWHM was 785 of wavelength, Cr (0 nm), Ag (40 nm)
and ITO (0 nm). In short, the optimum parameters for achieving the desired performance of sensor were successfully
predicted using Taguchi optimization method.
STK15 is a serine/threonine kinase that regulates chromosomal segregation during mitosis. Single nucleotide polymorphisms (SNPs) in this gene, Phe31Ile (rs2273535) and Val57Ile (rs1047972), are inconsistently associated with gastrointestinal cancer (GIC) across different populations. However, this association is unclear in Malaysian population. Therefore, this study investigated the association of STK15 Phe31Ile and Val57Ile polymorphisms to GIC risk in Malaysia. Genomic DNA was extracted from 185 GIC patients and 1110 healthy controls and was subjected to polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. SNPs were further confirmed using sequencing. We found that the 31Phe allele and 31Phe/Phe genotype in the Phe31Ile SNP significantly increased GIC risk in Malaysian population, particularly in gastric cancer (p<0.017). The combined analysis for both SNPs also increased the risk of GIC in this study. Etiological factors such as age, gender and ethnicity were not associated with GIC in the population. This is the first study to report the association of STK15 Phe31Ile and Val57Ile SNPs with an increased risk of GIC in Malaysians; the 31Phe allele is exclusively associated with the risk of gastric cancer. In addition, GIC incidences among Malaysians have significantly shifted to a younger age (<50 years).
Cardiovascular disease (CVD) is a major cause of morbidity and mortality in chronic kidney disease (CKD) patients. This study aimed to determine the roles of CVD biomarkers in CKD patients. This was a case-control study which recruited consecutive patients with stage 2-4 CKD patients with and without CVD. Serum levels of highly-sensitive C reactive protein (hs-CRP), cystatin C (CysC), asymmetrical dimetylarginine (ADMA) and symmetrical dimethylarginine (SDMA) were measured. Sixty two stage 2-4 CKD patients with a mean age of 60.3 ± 10.4 years were recruited. Twenty three (37.1%) of them had CVD. Those CKD patients with CVD were older (64.1±8.0 vs 58.1± 1.1, p<0.05) and had significantly higher systolic blood pressure (139.4 ± 16.2 vs 129.4 ± 14.8 mmHg, p<0.05). Diabetic patients had 8 times (95% CI 1.25-51.77, p< 0.05) higher risk to develop CVD. CKD patients with CVD had a higher serum creatinine (185.0 ± 54.1 vs 154.1 ± 54.4 μmol/L, p<0.05), a lower estimated glomerular filtration rate (33.7 ± 12.2 vs 42.2 ± 14.5 mL/min/1.73m2 p<0.05) and a lower triglyceride levels (1.3 (1.1-1.7) vs 1.8 (1.4-2.3) mmol/L, p<0.05), compared to those without CVD. Fasting blood sugar was 7.1 ± 2.7 mmol/L in CVD group and 6.3 ± 1.6 mmol/L in non CVD group (p>0.05). There were no differences in their mean serum levels of hs-CRP, CysC, ADMA and SDMA. Risk factors including age, diabetes mellitus, hypertension and renal functions were still the most important CVD risk factors in CKD patients.
Thermally driven electrochemical cells (thermocells) are able to convert thermal gradient applied across redox electrolyte
into electricity. The performance of the thermocells heavily depends on the magnitude and integrity of the applied thermal
gradient. Herein, we study the iodide/triiodide (I–/I3
–) based 1-Ethyl-3-methyl-imidazolium Ethylsulfate ([EMIM][EtSO4])
solutions in a thermocell. In order to comprehend the role of fluidity of the electrolyte, we prepared set of solutions by
diluting [EMIM][EtSO4] with 0.002, 0.004, and 0.010 mol of Acetonitrile (ACN). We realized a significant improvement
in ionic conductivity (σ) and electrochemical Seebeck (Se) of diluted electrolytes as compared to base [EMIM][EtSO4]
owing to the solvent organization. However, the infra-red thermography indicated faster heat flow in ACN-diluted-[EMIM]
[EtSO4] as compared to the base [EMIM][EtSO4]. Therefore, the maximum power density of base [EMIM][EtSO4] (i.e.
118.5 µW.m-2) is 3 times higher than the ACN-diluted-[EMIM][EtSO4] (i.e. 36.1 µW.m-2) because of the lower thermal
conductivity. Hence this paper illustrates the compromise between the fast mass/flow transfer due to fluidity (of diluted
samples) and the low thermal conductivity (of the pure [EMIM][EtSO4]).
Menstrual irregularity and disordered eating were previously identified as risk factors for low bone mineral density
(BMD) in female athletes. Therefore, an investigation for more potential factors that could be associated with low BMD
among Malaysian female athletes is required. The aim of this study was to assess the association of BMD with energy
availability, body weight, body fat, estrogen level and bone loading status in female athletes and to what extent those
factors predict BMD. Energy intake and expenditure, body weight, Bone Physical Activity Questionnaire (BPAQ) score
and estrogen level were determined from 85 female athletes aged 18-30 years in this cross-sectional study. Bone mineral
density was measured by using an ultrasound bone densitometry device at the calcaneus bone. The female athletes’ body
weight and fat percentage were 56±9 kg and 27±6%, respectively and they were all eumenorrheic. Fifty three percent
of them had low BMD (z- score < 0). Their mean energy intake (1291±33 kcal/day) was lower than energy expenditure
(1807±34 kcal/day) which resulted in a low energy availability (29±1 kcal/day/kg FFM). BMD was positively associated
with BPAQ score (r=0.4, p=0.000) and body weight (r=0.3, p=0.005) but negatively associated with energy expenditure
(r=-0.4, p=0.000). There was no association of BMD with energy intake, energy availability, body fat percentage and
estrogen level. In conclusion, BMD was associated with energy expenditure, body weight and BPAQ score among female
athletes. Regression analysis showed that energy expenditure and BPAQ score were the main factors to predict BMD.
The vector autoregressive (VAR) approach is useful in many situations involving model development for multivariables
time series. VAR model was utilised in this study and applied in modelling and forecasting four meteorological variables.
The variables are n rainfall data, humidity, wind speed and temperature. However, the model failed to address the
heteroscedasticity problem found in the variables, as such, multivariate GARCH, namely, dynamic conditional correlation
(DCC) was incorporated in the VAR model to confiscate the problem of heteroscedasticity. The results showed that the use
of the VAR coupled with the recognition of time-varying variances DCC produced good forecasts over long forecasting
horizons as compared with VAR model alone.
To control the corrosion rate, the Magnesium (Mg) was coated with poly (l-lactic acid) (PLLA) using electrospinning
technique. The effectiveness of the PLLA coating on the high purity Magnesium (HP Mg) and alloy AZ91 were tested in
Hank’s solution immersion test. The corrosion behaviour of Mg coated PLLA was studied through hydrogen evolution,
weight loss and scanning electron microscope (SEM) before, during and after samples were immersed. The solution
was maintained at pH 7 by bubbling CO2
gas. The results showed that surface treatment on Mg by coating with PLLA
had reduced the rate of corrosion during the immersion test. The PLLA coating was also characterized and the coating
adhesion was evaluated.
Sungai Selangor is very important from the viewpoint of water supply and multipurpose water use in Malaysia. The
water quality of this river is degrading due to point and non-point sources of pollution. This study, focus on the water
quality assessment and simulation the effect of the pollution sources from urbanization to the Sungai Selangor basin.
Water quality Index (WQI) is used to define the status of river water quality and the QUAL2K was used as a simulation
model. Water quality parameters DO, BOD and NH3
-N have been chosen for modeling. In addition, five different model
scenarios were simulated to observe the impacts of pollution sources on the Sungai Selangor water quality. WQI results
showed that most of the stations in this river basin recorded water inferior to Class III. The water quality model presented
different scenarios for changes of Sungai Selangor water quality. Simulation results for different scenarios showed
that reduced levels of BOD and NH3
-N at 51.10% and 66.18%, respectively, can be obtained if Scenario-5 is employed.
The river water quality issue in the Rawang sub- basin within the study area is considered crucial to create significant
improvement within the sub basin and in the downstream area of Sungai Selangor basin.
In this work, we investigate the effects of Ni doping on the thermoelectric (TE) properties of Yb0.25Co4Sb12 sample. Yb0.25Co4-xNixSb12 (0 ≤ x ≤ 0.5) samples were prepared by mechanical alloying and subsequently consolidated by spark plasma sintering. The morphology of consolidated samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDS). The thermoelectric properties of bulk samples were measured from room temperature to 800 K. The XRD analysis confirmed that, the successful formation of the Co4Sb12 skutterudite phase and Ni is substituted into Co site of the skutterudite crystal lattice. Moreover, the electrical resistivity decreased to 14.6 μΩm at 785 K for Yb0.25Co3.5Ni0.5Sb12 sample, due to increase of the electron concentration by Ni-addition. The absolute Seebeck coefficient reached the highest value of 223 μV/K at 592 K for Yb0.25Co3.7Ni0.3Sb12 sample, thus yielding a maximum value of power factor of 2.41 × 10-3 W/mK2 at 592 K. The highest dimensionless thermoelectric figure of merit value ZT of 0.49 at 692 K has been achieved for the Yb0.25Co3.7Ni0.3Sb12 sample, compared to ZT=0.06 for the Yb0.25Co4Sb12 sample at same temperature. This work indicates a strategy to improve the thermoelectric performance by Ni substitution of Co sites in the Yb0.25Co4Sb12 skutterudite through simultaneous improvement of its electrical conductivity, Seebeck coefficient and reduction of its thermal conductivity.
The application of La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) as a potential cathode working on a BaCe0.54Zr0.36Y0.1O2.95 (BCZY)
electrolyte for proton conducting solid oxide fuel cell was investigated. LSCF nanoceramic powders were synthesized by
an activated carbon-assisted sol-gel process using metal nitrate-based chemicals. The LSCF powder was transformed to a
slurry and spin-coated onto both surfaces of BCZY pellet to form a symmetrical cell with the configuration of LSCF|BCZY|LSCF.
The symmetrical cell was subsequently sintered at 950°C for 2 h to allow a good contact formation between electrode/
electrolyte layers. The phase structural verification of the calcined powders was investigated by X-Ray diffractometer
(XRD). Field-emission scanning electron microscopy (FESEM) was employed to examine the morphology of the sintered
cell. The electrochemical behaviour of the symmetrical cell was studied by an electrochemical impedance spectroscopy.
The formation of a single perovskite LSCF phase with a crystallite size of 20 nm was obtained at 700°C as corroborated
by XRD analysis. The FESEM images showed a good contact between LSCF cathode and BCZY electrolyte at electrode/
electrolyte interfacial layer. The ASR obtained for LSCF symmetrical cell measured at 700°C with and without Pt current
collector is 0.87 and 31.25 Ωcm2, respectively.
Biodiesel, one of the renewable energy sources has gained attention for decades as the alternative fuel due to its remarkable properties. However, there are several drawbacks from the industrial production of biodiesel such as the spike in the production cost, environmental issues related to the usage of homogeneous catalyst and profitability in long term. One of the solutions to eliminate the problem is by utilizing low cost starting material such as palm fatty acid distillate (PFAD). PFAD is a byproduct from the refining of crude palm oil and abundantly available. Esterification of PFAD to biodiesel will be much easier with the presence of heterogeneous acid catalyst. Most of acid catalyst preparation involves series of heating process using conventional method. In this study, microwave was utilized in catalyst preparation, significantly reducing the reaction time from conventional heating method. The catalyst produced was characterized using X-Ray Diffraction (XRD), Brunauer Emmet and Teller (BET), Scanning Electron Microscopy (SEM), Temperature-Programmed Desorption - Ammonia (TPD-NH3) and Fourier Transform Infrared (FTIR) while percentage yield and conversion of the PFAD were analysed by gas chromatography - flame ionization detector (GC-FID) and acid-base titration, respectively. It has been demonstrated that the percentage yield of biodiesel from the PFAD by employing sulfonated glucose acid catalyst (SGAC) reached 98.23% under the following conditions: molar ratio of methanol to PFAD of 10:1, catalyst loading of 2.5% and reaction temperature of 70oC. The microwave-assisted SGAC showed its potential to replace the SGAC produced via conventional heating method.
The objective of this study was to assess the effectiveness of the 5A’s smoking cessation intervention (5A’s) to that of brief advice (BA) conducted by dentists. A single-blinded randomized controlled trial was designed to compare the effectiveness of the interventions. Six Dental Public Health specialists were recruited, randomized and trained to participate in this trial. Two hundred and fifty patients were required on both arms. The main outcome measures were biochemically validated self-reported abstinence and behaviour change at 6-months follow-up. The odd of quitters in 5A’s intervention was 3.81 (95% CI: 1.87-7.76; p= 0.00) times higher compared to BA. After controlling other factors, the odds ratio for the 5A’s was 1.90 (95% CI: 0.652-5.547; p=0.24) higher compared to BA. The 5A’s was found to be more effective in initiating positive behaviour change compared to BA. However, after controlling other factors, there was no difference in the effectiveness although the odds ratio was slightly higher in 5A’s.
The aim of this study was to investigate how various diets influence testis maturation stages in mud crab (Scylla olivacea)
broodstock. Morphological and histological assessments were performed in triplicate (10 male crabs each). Daily,
subject crabs were fed a squid (Loligo sp.) and a fish (Decapterus sp.) diet at 5-10% of body weight. Diets were analyzed
following methods from the Association of Analytical Communities (AOAC). In comparison to control (wild) crabs, the
two diets generally did not cause significant differences (p>0.05) in body weight, carapace width and gonadosomatic
index (GSI), except in the GSI of squid-fed crabs (p<0.05). At the end of the experiment, crabs that reached Stage 3 testis
maturation included were 6 fish-fed individuals and 23 squid-fed individuals. Additionally, differences in crude protein
and fat levels across diets influenced the nature of male gonadal development. In conclusion, a squid diet was sufficient
to induce Stage 3 testis maturation in Scylla olivacea within 60 days of culture. Our results prove the usefulness in
developing appropriate feeding regimes for male Scylla olivacea broodstock.
Thrips (Thysanoptera) are common pests on legume plants, yet little is known about their ecology or diversity in Peninsular
Malaysia. In legumes, thrips are typically found in flowers, where their feeding activity causes malformations that
eventually lead to crop damage. In this study, we examined the diversity of thrips species, particularly Megalurothrips
usitatus, in three selected legume farms around Peninsular Malaysia (Janda Baik, Pahang; Bestari Jaya, Selangor; and
Jelebu, Negeri Sembilan). Each month from April 2013 to May 2014, depending on growing season, legume flowers were
inspected for thrips in five random plots from each farm. Sampling was performed six times in Bestari Jaya and Jelebu
and twelve times in Janda Baik. The most abundant thrips species on legumes was M. usitatus (89.97%) followed by
Thrips parvispinus (9.77%), T. hawaiiensis (0.13%) and Ceratothripoides brunneus (0.12%). The abundance of M. usitatus
was not different between long bean, French bean and winged bean which equally distributed among different arbitrary
strata on legume plants. Temperature and light intensity were found to be positively correlated with the abundance of
M. usitatus, but relative humidity showed a negative relationship. M. usitatus was found in large numbers during hot
and dry months, but in lower numbers during raining season. This study suggested that wet season may help to regulate
the populations of M. usitatus on legume plants.
Nocturnal birds in the tropics remain little studied primarily due to the logistical difficulties of surveying these birds at
night. While call playback has been widely employed in the temperate regions, its practicality has not been adequately
demonstrated on tropical owl species. This study aimed to test the feasibility of estimating the density of the Sunda scopsowl
(Otus lempiji) in a lowland forest in Peninsular Malaysia based on call playback and distance sampling. From a
total of 58 detections of the owl species from October 2012 to May 2013, 72.41% (42 detections) were made when the
birds were breeding. The densities of the owl were estimated at 1.6 individuals and 2.6 individuals per 10 ha based on
spontaneous and provoked calls (i.e. before and after call playback), respectively. Broadcasting of the calls significantly
increased the numbers of detections (χ2
= 16.038, p<0.001) during both breeding and non-breeding seasons of the birds.
The combination of call playback and distance sampling improved the detectability as well as precision of the owl’s
density estimation and can be potentially applied on other little known owl species in Southeast Asia.