Rattans are one of the most unique and economically important plants for most tropical countries. There is however, a lack of interest in the specific study of the rattan spines. In this paper, we tested a new hypothesis concerning the functional role of rattan spines. We proposed that rattan spines also serve as a visual deterrent against herbivores or seed predators. In our proposed method we used an Imaging software, ImageJ, to measure the spine area of four species of rattan (Calamus insignis, Myrialepis schortechinii, Plectocomiopsis geminiflorus and Calamus caesius) from two different orientations (root to shoot and vice versa). Our results showed that rattan spines were very heterogeneous and highly variable between different species. One common trait that the rattan spines share is that spine area measurements of shoot to root (ShR) are larger than root to shoot (RH) orientation. We propose that the downwards spine angle might be specifically designed to discourage climbing leaf and seed predators.
Ethanolamine kinase (EK) is the first enzyme in the Kennedy pathway for the biosynthesis of phosphatidylethanolamine. Although EK has been reported to be involved in phospholipid biosynthesis, carcinogenesis, cell growth, muscle development and sex determination during embryonic development, little is known about its transcriptional regulation by endogenous or exogenous signals. Human EK exists as EK1, EK2α and EK2β isoforms, encoded by two separate genes, named ek1 and ek2. Compared to ek1 gene, ek2 is expressed at a higher level in liver and EK2 isoforms also accept choline as substrate besides ethanolamine, which could contribute to liver carcinogenesis. The main aim of this study was to analyze and characterize the human ek2 promoter in cultured mammalian cells. Human ek2 (2011 bp) promoter was cloned into reporter vector, pGL4.10 [luc2] and the promoter activities were studied in human liver carcinoma (HepG2 cells). Sequence analyses showed that ek2 promoter contains numerous putative transcription factor binding sites including AP4 and it is devoid of a recognizable consensus TATA box but it contains a high number of guanine (G) and cytosine (C) nucleotides. PCR mutagenesis of three nucleotides at E-box motif of AP4 transcription binding site located between -293 and -276 of ek2 promoter was successfully performed to show that AP4 transcription factor binding site acts as a repressive element in the regulation of ek2 expression. AP4 upregulation has been implicated in bad prognosis of carcinoma, therefore the regulatory role of AP4 binding site reported in this study could be a link between ek2 and carcinogenesis. Although further studies need to be carried out to understand and to determine the repression mechanism of AP4 in ek2 promoter, the characterization and analysis of ek promoter performed in this study provide important understanding of its basal transcriptional regulation which would allow us to control ek expression levels in pathologic conditions that involve this gene.
The Cox proportional hazards model is most widely used in survival analysis for modeling censored survival data. In
this model, the effect of the covariates is assumed to act multiplicatively on the baseline hazard rate and the ratio of the
hazards is constant over survival time. This is an important assumption and sometimes may not hold in some survival
studies. The Cox model can lead to biased results when the proportionality assumption is not satisfied. In such a situation,
the additive hazards regression models have been an alternative to proportional hazards models. The Aalen model
allows for time-varying covariate effects. In some situations, some covariate effects may be constant but the others may
not. In such cases, the Cox-Aalen model is a better alternative since it allows to combine both kinds of covariates in
the same model. In this study the Cox proportional hazards model, Aalen’s additive hazards model and the Cox-Aalen
model have been considered. These models have been applied to kidney transplant data and the differences in estimates
of the unknown parameters obtained by the Aalen’s model, the Cox model and the Cox-Aalen model are investigated.
We used the density functional theory to calculate the vibrational frequencies of clusters of atoms. We obtained the bond distances and angles for which the energy of the Schrödinger equation is minimum. We found the bond distance between two Se atoms to be 232.1 pm when double zeta wave function was used. The frequency of oscillations was calculated to be 325.3 cm-1 but the intensity was zero because Se2 molecules were present in a very small number. When polarised double zeta wave function (DZP) was used, the bond length of Se2 was found to be 223.1 pm and the frequency is 367.4 cm-1. Similarly for other clusters of selenium, we calculated the frequencies and compared with the experimental data. The experimental Raman spectra give 250 cm-1 for a selenium glass. By comparing the experimental frequencies with those calculated we found that linear Se3 was present in the glass. This indicates the possibility of linear growth in the glass.
Forest degradation and deforestation are some of the major global concerns as it can reduce forest carbon storage and sequestration capacity. Forest rehabilitation on degraded forest areas has the potential to improve carbon stock, hence mitigate greenhouse gases emission. However, the carbon storage and sequestration potential in a rehabilitated tropical forest remains unclear due to the lack of information. This paper reports an initiative to estimate biomass-carbon partitioning, storage and sequestration in a rehabilitated forest. The study site was at the UPM-Mitsubishi Corporation Forest Rehabilitation Project, UPM Bintulu Sarawak Campus, Bintulu, Sarawak. A plot of 20 × 20 m2 was established each in site 1991 (Plot 1991), 1999 (Plot 1999) and 2008 (Plot 2008). An adjacent natural regenerating secondary forest plot (Plot NF) was also established for comparison purposes. The results showed that the contribution of tree component biomass/carbon to total biomass/carbon was in the order of main stem > branch > leaf. As most of the trees were concentrated in diameter size class ≤ 10 cm for younger rehabilitated forests, the total above ground biomass/carbon was from this class. These observations suggest that the forests are in the early successional stage. The total above ground biomass obtained for the rehabilitated forest ranged from 4.3 to 4,192.3 kg compared to natural regenerating secondary forest of 3,942.3 kg while total above ground carbon ranged from 1.9 to 1,927.9 kg and 1,820.4 kg, respectively. The mean total above ground biomass accumulated ranged from 1.3 × 10-2 to 20.5 kg/0.04 ha and mean total carbon storage ranged from 5.9 × 10-3 to 9.4 kg/0.04 ha. The total CO2 sequestrated in rehabilitated forest ranged from 6.9 to 7,069.1 kg CO2/0.04 ha. After 19 years, the rehabilitated forest had total above ground biomass and carbon storage comparable to the natural regeneration secondary forest. The rehabilitated forest activities have the potential to increase carbon stock through tree planting. Therefore, forest rehabilitation has shown the potential role as a carbon sink that helps to reduce emissions of greenhouse gases and mitigate climate change.
This study evaluated four different doses of Strobilanthes crispa juice (700, 2100, 3500 and 4900 mg kg-1 of body weight) administered orally to normal female and male Sprague dawley rats on possible changes in various physical, behaviour, morphology and biochemical parameter. The rats were treated with a single dose of juice and observed for 14 days. No significant toxicity was observed with respect to clinical parameters and organ morphology. In addition, no significant changes were observed in the level of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase,
creatinine and albumin. The S. crispa juice was found to be safe at the maximum dose used in this study (4900 mg kg-1 of body weight).
The importance of intercomparison programme for radiation therapy dose delivery at radiotherapy centres (RC) has widely been reported. We at Nuclear Malaysia Agency (NM) intend to develop a national level intercomparison programme in terms of absorbed dose to water Dw. We started with one RC which has voluntered to participate in the programme in the dose delivery of 6 MV x-ray beam. Two types of comparison were made to get the accuracy. Type I is based on the measured value of the Dw at reference depth, Dw(zref)mea : RC results was compared with NM, in which NM results was taken as a standard. Type II is based on calculated value the Dw(zref), Dw(zref)cal : both NM and RC results were compared with Dw(zref)cal, in which Dw(zref)cal was taken as a standard. Two on-site measurements were made at this centre to check for results consistency and to get the average accuracy. Results obtained were consistent for the two measurements and the average values in the accuracy are within the acceptable accuracy limit of ± 3%, namely Type I: 1.10 ± 0.58 % for the RC, and Type II: 0.99 ± 0.60 % and −0.11 ± 0.26% respectively for the RC and NM.
Mathematically, the human alimentary tract organs were simplified in the model structure as separate compartments with
pathways of transfer that are kinetically homogenous and equally distributed. The development of gastro-compartment
model follows the first order kinetics of differential equations to describe cadmium absorption, distribution and elimination
in the human digestive system. With the aid of in vitro DIN assay, an artificial gastric and gastrointestinal fluid were
prepared using water leach purification (WLP) residue as a sample that contained toxic metals cadmium. The Simulation,
Analysis and Modelling II (SAAM II) V2.1 software is employed to design models easily, simulate experiments quickly and
analyze data accurately. Based on the experimental inputs and fractional transfer rates parameter incorporated to the
gastro-compartment model, the concentration of cadmium against time profile curves were plotted as the model output.
The curve presented concentration of cadmium in both gastric and gastrointestinal fluid where initially absorption phase
(first hour) occurred followed by the distribution phase (second to third hours) and elimination process (third to fifth
hours). The concentration of cadmium obtained from the simulated model structures was in good agreement with the
fitted model predicted measurements as statistical t-test conducted showed the values were not significantly different.
Therefore, modeling approach with SAAM II software gave realistic and better estimation of cadmium dissolution into
the human gastrointestinal tract.
A conditional expectation operator plays an important role in geometry of Banach spaces. However, the main issue
is with regards to the existence of a conditional expectation operator that permits other objects to be considered
such as martingales and martingale convergence theorems. Thus, the purpose of this study is to provide an abstract
characterization of a conditional expectation operator on a space of measurable sections.
Acanthamoeba spp. merupakan ameba hidup bebas yang tersebar luas di persekitaran. Ameba ini menyebabkan penyakit
keratitis terutamanya kepada individu yang memakai kanta sentuh terkontaminasi atau mempunyai sejarah trauma
pada mata. Tujuh puluh empat sampel kikisan kornea pesakit keratitis daripada 4 buah hospital di sekitar Lembah
Kelang telah dikultur untuk menemukan Acanthamoeba spp. Keputusan kajian mendapati Acanthamoeba spp. berjaya
dipencilkan daripada 14.87% sampel kikisan kornea pesakit keratitis. Berdasarkan kajian ini, kesemua pesakit keratitis
Acanthamoeba adalah merupakan pemakai kanta sentuh yang majoritinya (90.9%) terdiri daripada kaum wanita. Kanta
sentuh lembut terlibat dalam 90.9% kes manakala jenis kanta separa keras cuma satu kes 9.1%. Kesemua 11 pencilan
Acanthamoeba yang dipencilkan adalah daripada kumpulan polyphagids yang biasanya patogenik kepada manusia dan
menyebabkan jangkitan ini. Kegagalan pengguna kanta sentuh mengamalkan tahap kebersihan kanta sentuh yang baik
merupakan faktor risiko yang penting dalam kejadian keratitis Acanthamoeba di Malaysia.
Bioaccumulation of lead and Copper in Avicennia marina and Rhizophora apiculata was studied. Samples of leaves, barks and roots were collected from Balok mangrove forest, Pahang. Pb and Cu accumulation was higher in Avicennia marina root tissue compared to bark and leaf but lower than surrounding sediment level. The average concentration of Pb in A. marina leaf, bark, root and sediment was observed to be 5.39 ppm, 3.63 ppm, 18.21 ppm and 23.13 ppm, and average Cu concentration was 4.13 ppm, 4.27 ppm, 4.81 ppm and 12.33 ppm, respectively. R. apiculata also showed higher concentration of Pb and Cu in root tissue compared to bark and leaf tissues but lower than surrounding sediment. The average concentration of Pb in R. apiculata leaf, bark, root and sediment was observed to be 4.30 ppm, 2.97 ppm, 22.45 ppm and 31.23 ppm, respectively. The average Cu concentration was 2.93 ppm, 4.71 ppm, 4.81 ppm and 15.52 ppm, respectively. Results of concentration factors (CF) showed that the accumulation of Pb and Cu was higher in A. marina than in R. apiculata.
The aim of this study was to determine the accumulation of settling particles in coral reefs of Peninsular Malaysia. Settling particles were collected from the coral reefs of Port Dickson, Pulau Langkawi, Pulau Tioman, Pulau Redang and Pulau Tinggi from 2005 to 2008. The average total settling particles in Pulau Langkawi and Port Dickson was 49.8 mg/cm2/day, while for Pulau Tioman, Pulau Redang, and Pulau Tinggi was 3.5 mg/cm2/day. The results showed that accumulations rate in west coast were higher than east coast of Peninsular Malaysia. However, Pulau Tioman in the east coast received high accumulations rate of settling particles in certain times of the year due to sediment resuspension at shallow reefs caused by high energy seasonal yearly wave and monsoon.
In this work, a new optical screening method for acrylamide was developed. Bacterial Bacillus sp. strain ZK 34 was used to
hydrolyse acrylamide to the corresponding acid and ammonia. Nessler’s reagent was used to detect the produced ammonia
and the yellow complex formed was treated as signal. Bacterial pellet was immobilised in the alginate membrane. The
optimum composition of alginate used is 2%. The mass ratio of alginate:bacterial of 1:0.5 gave the optimum respond.
Optimum concentration for NaOH and Nessler’s reagent were 0.075 M and 2.5 mM, respectively. The yellow complex
of mercury (II) amido-iodine formed was directly proportional to the concentrations of acrylamide up to 50.00 ppm
with the limit of detection of 1.30 ppm. This sensor shows a good reproducibility which the relatives standard deviation
(RSD) values from 3.17-6.15%. Therefore, the detection of acrylamide based on the amidase hydrolysis is suitable for
screening this carcinogen compound.
The activities of key C4 photosynthetic enzymes including phosphoenolpyruvate carboxylase (PEPcase), NADP-malic
enzyme (NADP-ME), malate dehydrogenase (MDH) and pyruvate phosphate dikinase (PPDK) were assayed in flag leaves
at three major growth stages (heading, anthesis and grain filling) among 59 winter wheat genotypes grown in field
conditions. All C4 enzymes expressed in the flag leaves and their activation showed a wide range of variation in relation
to different growth stages in all the genotypes. PEPcase, NADP-ME and MDH displayed the highest mean activities of
1.018, 0.758 and 0.731 µmol. min–1.mg–1 protein at heading stage, respectively; while PPDK showed the highest mean
activity (0.888 µmol. min–1.mg–1 protein) at grain filling stage. The activities of PEPcase and PPDK were higher at
heading stage, decreased at anthesis and again increased at grain filling stage, while NADP-ME and MDH exhibited a
decreasing trend at the three stages. The results of the current study could be valuable and useful for wheat researchers
in improving photosynthetic capacity of wheat.
The activity of two liquid mixed radionuclide sources in NPL'S standard glass ampoules were determined by gamma-ray spectrometry measurement using a standard point source placed at 38.5 cm axially above the detector. A radio nuclide 137Cs was chosen, Results obtained were within 3% agreement with the calculated value. The same degree of deviation was obtained when the NPL standard source of equal geometry, chemical composition and density was used.
Keaktifan dua sumber radionuklid campuran cecair yang terkandung dalam bekas kaca piawai NPL ditentukan dengan kaedah pengukuran spektrometri sinar-gama menggunakan satu sumber titik piawai diletakkan pada 38.5 em di atas pengesan, Satu sumber radionuklid 137Cs dipilih. Keputusan yang diperoleh bersetuju dalam lingkungan 3% dengan nilai yang dikira. Darjah simpangan yang sama diperoleh apabila sumber piawai NPL yang sama dari segi geometri, komposisi kimia dan ketumpatan digunakan,
The activity concentration of 210Po from six different samples consisting of raw charcoal, surface sediment, rainwater (suspended solids (SSrw) and dissolved phase (Drw) and estuarine water (suspended solids (SSew) and dissolved phase (Dew)), were analyzed. The activity concentration of
210Po in solid samples was between 7.63 ± 0.67 and 744.28 ± 21.12 Bqkg-1 and in dissolved samples varied between 0.34 ± 0.03 and 86.33 ± 6.51 mBqL-1. On average, 210Po activity in SSrw sample was the highest, at nearly three times its original form (charcoal). SSew and surface sediment samples were
similarly distributed between 15th March and 1st August samplings, but were relatively lower than charcoal and SSrw samples. The natural meteorological variability also enhanced 210Po distribution and dispersion to a few kilometers from the coal-fired power plant.
Masalah pencemaran sumber air tawar dan kesan ketoksikan logam telah mendapat perhatian di serata negara. Dua
spesies organisma air tawar daripada filum moluska Filopaludina sumatrensis dan Corbicula fluminea didedahkan
kepada tiga logam terpilih iaitu arsenik (As) kromium (Cr) dan selenium (Se) pada kepekatan berbeza selama 96 jam di
dalam makmal terkawal. Kadar kematian dinilai serta kepekatan kematian median (LC50) dan masa kematian median
(LT50) dihitung. Nilai LC50 dan LT50 didapati menurun dengan pertambahan masa dan kepekatan pendedahan bagi
kedua-dua spesies dan kesemua logam. Keputusan daripada kajian ini memperlihatkan ketoksikan logam As, Cr dan Se
semakin meningkat dengan peningkatan kepekatan dan masa pendedahan logam kepada F. sumatrensis dan C. fluminea.
Nilai LC50 96 jam As, Cr dan Se bagi F. sumatrensis adalah 4.22, 3.78 dan 45.92 mg/L dan 11.84, 2.23 dan 35.63 mg/L
masing-masing bagi C. fluminea. Keputusan menunjukkan Cr adalah logam paling toksik terhadap F. sumatrensis dan
C. fluminea. Trend ketoksikan logam bagi kedua-dua moluska ini adalah sama iaitu Cr > As > Se.
Cosmos caudatus or ‘ulam raja’ is a local plant with antioxidant properties and has the potential to treat free radicals-associated diseases. However, its toxic effects need to be elucidated. Acute toxicity study was carried out in male rats. Rats aged 3 months, weighing 150-200 g were divided into 4 groups, i.e. rats being fed on distilled water (control), Cosmos caudatus extract dose 50 mg/kg (CC50), Cosmos caudatus 500 mg/kg (CC500) and Cosmos caudatus 2000 mg/kg (CC2000), respectively. A single treatment was given to the respective groups and the animals were sacrificed after 7 days. Biochemical parameters before and after treatment were measured. Liver enzymes, i.e. alkaline phosphatase (ALP) and alanine transaminase (ALT), were found to be increased post treatment in CC500 and CC2000 groups. Creatinine levels were lower in CC500 and CC2000 groups post treatment compared with control group while albumin levels were lower in CC2000 group than all the other groups. In conclusion, Cosmos caudatus may cause acute hepatotoxicity at high doses.
Bacterial adhesion to host cells is the most important probiotic character. However, the adhesion of probiotic should not
affect the viability of the host cells. In this study, Lactobacillus plantarum strain L8, Lactobacillus plantarum strain L20
and Lactobacillus pentosus strain S1 were tested for their cytotoxic effects through MTT assay and their ability to adhere
and colonize on HT-29 and CCD-18Co intestinal cells as detected microscopically using light microscopy and Scanning
Electron Microscopy (SEM). No cytotoxicity effects were observed on both intestinal cells following 24 h treatment with
all Lactobacillus strains. Additionally, all strains demonstrated strong adhesive activity where more than 100 bacteria
adhered to both intestinal cells although differences in the adhesion scores observed among different strains. The adhesion
as observed via SEM showed an autoagreggative pattern and adhered as clusters on the surface of both intestinal cells.
In conclusion, all three Lactobacillus strains are non-cytotoxic to both cells with strong adhesion ability on intestinal
cells and this study also proved that Malaysian fermented fish are good source of probiotic bacteria.
The adsorption of CO at polycrystalline copper surface was investigated spectroscopically. It was found that CO adsorbed as a linear adsorbed CO, Cu-COL and was a dominant species on copper surface at low CO concentration. A Cu-COL was electrochemically converted to a bridge bonded CO, Cu-COB at a high CO concentration condition. Increasing the CO surface coverage, qCO will increase the formation of adsorbed bridge bonded CO. A nitrogen gas purging treatment was used to examine the stability of an adsorbed CO through the evacuation process. The result showed that Cu-COB remained intact while Cu-COL was completely removed from the copper surface. It suggests that Cu-COL may involve in a weak bonding to a copper surface such as in a physisorbed interaction, while Cu-COB consists much stronger bonding such as a chemisorbed interaction. The N2 purging treatment also gave an additional prove that Cu-COB was partly converted to Cu(I)-CO at anodic potential regions.