The fundamental pattern of chewing induced by the network of neurons called central pattern generator has been reported
to be modified by the information arising from the various oro-facial sensory receptors including muscle spindles of jaw
closing muscles. The cell bodies of primary afferent neurons from these muscle spindles lie in mesencephalic trigeminal
nucleus (MTN) in the brainstem. The aim of the study was to understand whether muscle spindles from jaw-closing
muscles play any role in hard food chewing. Single neuronal discharge of muscle spindle afferents was recorded from the
MTN simultaneous with jaw-movement and electromyograpic (EMG) activities of the left masseter (jaw-closing) muscle
during chewing soft and hard foods (apple and pellet) in awake rabbits. Ten consecutive chewing cycles were taken for
analysis. Discharge of nineteen muscle spindles from seven rabbits was successfully recorded. Muscle-spindle discharge
was significantly higher during the closing phase of jaw-movement for the hard food chewing than for the soft food. The
jaw-closing muscle EMG activity was significantly higher during hard food chewing compared to soft food. The spindle
discharge was higher when the masseter muscle activity was greater for chewing hard food. Significant positive (r=0.822,
p=<0.001) correlation was found between the difference of muscle activity between apple and pellet and the difference
of spindle discharge between apple and pellet. Above findings suggest that the increase of spindle discharge during
hard food chewing may play a role for facilitating jaw-closing muscle activities and thereby provides servo-assistance
to jaw-closing muscles to compensate the hardness of food.
The objective of this study was to determine the nutrient composition of selected commercial biscuits in Malaysia. A total
of six brands from each type of biscuit (chocolate chip, corn, cracker with sugar, vegetable flavoured cracker, cream
filled, oatmeal, shortbread and fully coated chocolate wafer) and five brands of wholemeal crackers were sampled
from local supermarkets in the Klang Valley. The total energy content in commercial biscuits was ranging from 453.30
to 499.25 kcal/100 g. Carbohydrate was the major macronutrient in commercial biscuits ranging from 56.86 to 66.07
g/100 g. The highest protein content was found in the wholemeal crackers (9.92 g/100 g) and the lowest protein content
was found in the cream filled biscuits (5.65 g/100 g). Fat content lay in the range of 16.89 to 25.75 g/100 g. The major
minerals detected in biscuits were sodium, followed by calcium and magnesium. The vitamin content in A and E of the
biscuits examined was almost comparable. Small quantities of trans fatty acids were detected in all biscuits in the range
of 0.02 to 0.68 g/100 g. These findings indicate that Malaysian commercial biscuits are a good source of carbohydrate
(34.12-39.64 g per serving), calcium (26.09-384.67 g per serving), magnesium (10.42-37.24 g per serving) and contain
low proportion of trans fatty acids (0.01-0.41 g per serving).
The present study evaluates the petroleum source rock generation potential of the Neogene Bhuban shales from Bangladesh.
Organic geochemical and organic petrological methods were used for analyzing 11 drill core samples from 4 gas fields
in the basin. Source rock potential, maceral composition, organic matter abundance, biomarker distribution, thermal
maturity, hydrocarbon generation and depositional environment were evaluated. Kerogen in the studied shale samples
is classified mainly as Type III with lesser amounts of Type II. Vitrinite is the dominant maceral group observed in the
analyzed Bhuban samples followed by liptinite and inertinite. Vitrinite reflectance, Tmax and biomarker parameters
indicate the thermal maturity ranges from just pre-oil window to mid-oil window. Based on its total organic carbon
(TOC), extractable organic matter (EOM) and hydrogen index (HI), the analyzed Bhuban shales are ranked as mainly poor
to fair source rocks but with good gas generation potential. The dominant terrestrial environment prevailed during the
deposition of the studied Bhuban shales while the condition was sub-oxic as indicated by cross-plots of pristane versus
phytane and sterane versus pristane/phytane ratios.
MeSH terms: Bangladesh; Carbon; Diterpenes; Environment; Hydrocarbons; Hydrogen; Petroleum; Terpenes; Biomarkers; Oil and Gas Fields
A new type of cyclone design configuration called MR-deDuster, which contains multi cyclone, has been developed.
A theoretical study had been carried out to evaluate and predict the performance of a MR-deDuster. In this paper, a
comparative study was done to investigate the performance of MR-deDuster with other conventional cyclones in terms
of collection efficiency and pressure drop. The performance of MR-deDuster was measured by its collection efficiency
based on the particle size distribution of activated carbon. It was found that MR-deDuster is able to collect as high as
94% of PM10 which is high comparing with many other conventional cyclones. In addition, the pressure drop of the unit
is relatively low compared to the other cyclones which highlight the ability of the unit to capture the fine particle at low
pressure drop.
The deposition of anticoagulant residues in the eggs of barn owls, Tyto alba by assessing eggshell thickness were
investigated in oil palm plantations. Three study plots were set aside; one plot each baited with chlorophacinone and
bromadiolone, respectively and the third was left unbaited. Four baiting campaigns were conducted on the rodenticide
designated plots, coinciding with the breeding seasons of T. alba. High performance liquid chromatography (HPLC)
showed that 29.73% (n=37) and 5.35% (n=56) of addled eggs collected from rodenticide treated plots contained
bromadiolone and chlorophacinone, respectively, with mean concentration of residues from 0.009 to 0.031 µg/g wet
weight. None of the addled eggs (n=28) collected from the unbaited plot contained bromadiolone or chlorophacinone
residues. The detection of rodenticide residues in both albumen and yolk indicated high risk of secondary poisoning to
both compounds. However, low levels of residues detected have no effects on shape of egg, eggshell mass or thickness.
A study on water quality and aquatic insects has been conducted at the Lower Kinabatangan River Catchment, Sabah,
Malaysia. The quality of water surface and aquatic insects’ composition were studied in streams near to oil palm plantation
(OP), secondary forest (SF) and oxbow lake (OB). The study also aims to identify the seasonal variation in the aquatic
insects’ composition during the weak La Niña event. A total of 135 water samples and 1678 aquatic insect individuals
(four orders and 14 families) were collected during fieldwork campaign that spanned over the inter-monsoonal period,
wet and dry seasons between October 2004 and June 2005. OP has the highest abundance of aquatic insects particularly
during the dry season. Biological indices showed that all stations were in moderate water category. The water quality
index (WQI) was calculated and indicated that the quality of the river categorised into Class II. Discriminant analysis
(DA) was employed to classify the independent variables into mutually-exclusive groups. Suspended sediment (SS) and
chemical oxygen demand (COD) were high during the wet season. Suspended sediment was high in oxbow lake and could
be a strong reason behind low abundance of aquatic insects. Precipitation anomalies were found to affect seasonal
variations of water quality and aquatic insects at the Lower Kinabatangan River.
The effects of dietary protein level on the growth performance and ammonia excretion of the leopard coral grouper,
Plectropomus leopardus were investigated for eight weeks. Fish were fed diets with 40, 45, 50, 55 and 60% crude protein
levels in separate recirculating systems. Fish fed with the 50% crude protein containing diet showed the best ingestion
rate, which was significantly higher than that found in the other groups. As the dietary protein level increased, the
specific growth rate increased significantly and it reached the highest level at 50% crude protein containing diet. Based
on the results of all measured parameters 50% protein containing diet was the best among all test diets. The regression
equation for dietary protein level versus ammonia excretion indicated that the optimal dietary protein level with the
least ammonia excretion was 53.14%. More research is still needed to elucidate the effects of 53.14% crude protein
containing diet on the specific growth rate, feed conversion ratio, protein efficiency ratio and ingestion rate of leopard
coral grouper before recommending this level. Until then, 50% protein containing diet can be recommended for leopard
coral grouper culture in the recirculation system.
Bee species diversity and pollen sources of Apidae (Hymenoptera) in Thung Salaeng Luang National Park, lower northern
Thailand, were studied from 2011 to 2012. The forest types encountered were deciduous dipterocarp, deciduous with
bamboo, seasonal evergreen and dipterocarp - pine forests. Sweep nets and honey bait traps were used to collect bee
samples. The beta diversity of native bees was high with 22 recorded insect species from 12 genera and pollen grains
collected by native bees were 62 plant species from 28 families. The plant family Fabaceae (Leguminosae) contained the
greatest number of species (9 species). The main pollen source of native bees was Hopea odorata Roxb. (Dipterocarpaceae)
which was collected by 19 bee species. The result from biodiversity indices i.e. species diversity (H’), species evenness
(J’), similarity habitat (Ss
) and species richness (D) indicated that this area has relatively high species diversity. In
addition, the dwarf honey bees, Apis florea Fabricius, 1787, are the main pollinator at the study site with the highest
number of pollinated plant species (46 species). Thus, this bee could be used as a biological indicator for future studies.
The main objective of the present study was to provide a comprehensive LCI of medium scale composting of food waste
and yard waste at institutional level, based on substance flow analysis (SFA). A secondary objective was to present the
composition and assess the quality of the final compost product from composting of typical Asian organic waste (food
waste and yard waste). The experiments were designed to represent a batch situation in an institutional medium size
composting scenario with input material of food waste mixed with grass clippings and dried leaves. Two composting
runs were carried out with the intention to showcase the heterogeneity of organic waste and study the effect of windrow
size on the performance of the process. The input and output material were sampled and characterized in order to
quantify the substance balance of the process. SFA was performed by means of the mass balance model STAN 2.5 to
compute unknown parameters (gaseous emissions). SFAs have been performed for C, N, K, P, Cd, Cr, Cu, Ni and Pb. The
composting windrows were fed with 212.4 and 393 kg, respectively. VS content reduction is greater in composting pile
with larger size (Run 2). The loss of C during composting was recorded in the range of 0.146-0.166 kg/kg ww. The C
losses via leachate were insignificant (0.02% of the total input C). The total N loss during the process was 0.005-0.012
kg/kg ww. The leachate generation was measured as 0.012-0.013 kg/kg ww. The flows of selected heavy metals were
assessed. Heavy metals were of minor significance due to low concentrations in the inputs (food waste and yard waste).
Heavy metals were found to be released to the atmosphere. However, majority of heavy metals remain in the finished
compost. The C/N reduction during the process was in the range of 10-23%. In general, the compost composition was
considered to be within the ranges previously reported in literature and thus ready for application in gardening. The LCI
presented in the present study can be used as a starting point for making environmental assessments of medium-scale
co-composting of food waste and yard waste in tropical environment. No major environmental problems were identified
from the process, except for the emissions of GHGs.
A dietary study was conducted to assess the use of mushroom stalk (MM), Pleurotus sajor caju, an agriculture waste and
soy bean meal (SBM) as partial and complete replacement of fishmeal (FM) in tilapia fingerling diets. The study was
conducted for 56 days. The diets were processed into sinking pellets. The experimental diets were formulated to replace
fish meal protein at 0, 33, 67 and 100% (diet 4, 3, 2 and 1). In this experiment, Nile tilapia fingerlings weighing about
1.00 g were fed each of four isonitrogenous diet. They were randomly distributed into 12 plastic tanks with each tank
stocking 20 fish. The experiment was conducted in three replicates for each treatment. All the diets were well accepted
by the fish. No physical abnormalities were observed in all treatments. Good growth performance was shown in 33%
replacement (diet 3) of FM diet. However, diet 1 (100% replacement) gave the highest increment in crude protein level
and the best result of feed conversion ratio (FCR) and protein efficiency ratio (PER). Furthermore, the 100% replacement
of FM (diet 1) was the best with a production cost of RM2.61/kg.
Heavy metal pollution leads to human health problems and represents a constant threat to the environment. Pollutant
clean-up using conventional methods are often hampered by high cost and ineffective pollutant removal. Phytoremediation
technique is a preferable alternative due to its minimal side effects to the environment in addition to reasonable treatment
cost. In this study, we investigated the potential of Centella asiatica and Orthosiphon stamineus as phytoremediation
agents. Both species were grown in contaminated soil obtained from industrial land. Plant growth response and their
ability to accumulate and translocate zinc, copper and lead were assessed. From this study, root growth of C. asiatica
was compromised when grown in contaminated soil. Copper was highly accumulated in C. asiatica roots while the
leaves were more concentrated with zinc and lead. Conversely, all three tested metals were highly detected in the roots
of O. stamineus, although the root elongation was not adversely affected. Low amount of metals in the stems of both
species permits longer stem length. Correlation study showed that the accumulation of zinc, copper and lead in plant
tissues varies depending on plant species and the type of metals. Based on the bioaccumulation, translocation and
enrichment factor, our study showed that C. asiatica was tolerant towards zinc, copper and lead; hence suitable for
phytoextraction. By contrast, O. stamineus acted as a moderate accumulator of the tested metal elements.
In Malaysia, nests of Aerodramus fuciphagus (white-nest swiftlet) and Aerodramus maximus (black-nest swiftlet) are
harvested for commercial purposes, as one of the most valuable animal products. The taxonomy of a species is crucial,
as delineating species boundaries is fundamental to discover life’s diversity. However, swiftlet taxonomy has been
controversial, due to numerous undefined parameters. Although there are these limitations, morphological taxonomy
cannot be the unique approach for species identification and it is a valuable component in taxonomy studies. We have
undertaken a morphological approach to analyse community relationships among species of swiftlets. In this study, we
selected three different swiftlet species to generate two sets of comparisons: Within species and among different habitats.
This study found that A. fuciphagus from man-made habitats is generally larger in size compared to the natural habitat and
A. maximus is larger compared with A. fuciphagus. We postulate the difference in body size is due to dietary behaviour
and genetic variations of the swiftlets.
A phytosociological study on the flora and vegetation community of Palaquium gutta (Hook.f.) Baill. was carried out in
Compartment 13 of Ayer Hitam Forest Reserve, Selangor. The main objectives of this study were to identify, characterize
and classify the P. gutta community which is naturally distributed in Ayer Hitam Forest Reserve. A total of 10 plots (30×30
m in size) were constructed according to the line transect method. The vegetation sampling and data analysis were done
according to the Braun-Blanquet approach. The results showed that there were 59 species belonging to 54 genera and 34
families in the form of herbs, shrubs, understorey trees and also canopy tree layers. The most common species in the study
area were P. gutta and Endospermum diadenum (Miq.) Airy Shaw. The phytosociological study identified a community
of Palaquium gutta-Endospermum. diadenum along with two sub-communities known as Dracaena sp. sub-community
and Streblus elongatus sub-community. The results also showed that most of the species belong to the Euphorbiaceae.
This indicates that the forest is a secondary forest.
A study was conducted to determine the effects of a plant growth regulator (paclobutrazol, PBZ) and commercial
fertilizer (Krista-K Plus) as a source of potassium nitrate (KNO3
) on the growth of Xanthostemon chrysantus. It was
also attempted to investigate the anatomical changes in the leaf and stem after the treatment. Nine treatments, i.e.
control (no PBZ and Krista-K Plus application), 0 PBZ gL-1 + 100 g Krista-K Plus, 0 PBZ gL-1 + 200 g Krista-K Plus,
0.125 PBZ gL-1 + 0 g Krista-K Plus, 0.125 PBZ gL-1 + 100 g Krista-K Plus, 0.125 PBZ gL-1 + 200 g Krista-K Plus, 0.25
PBZ gL-1 + 0 g Krista-K Plus, 0.25 PBZ gL-1 + 100 g Krista-K Plus and 0.25 PBZ gL-1 + 200 g Krista-K Plus, were
tested. PBZ was soil drenched at the commencement of the study while Krista-K Plus was applied at three-month
intervals. Plant growth performances such as tree height, diameter at breast height, canopy diameter and leaf area
were recorded monthly throughout the study period. Stem and leaf samples were collected before the application
of treatments and after six months of treatments for anatomical observation by using electron microscope. Plant
height, diameter at breast height, crown diameter and leaf area were significantly reduced with the application of
PBZ. Palisade parenchyma thickness was increased by 33.83% with 0.25 PBZ gL-1 + 200 g Krista-K Plus, while only
2.44% increment recorded in the control tree. Xylem thickness in the stem was reduced by 21.81% after treated with
the highest dosage of PBZ, while the control tree only had 1.78% increment. Spongy parenchyma thickness in the leaf
was unaffected. However, palisade parenchyma was found the thickest after combined treatment with 0.25 PBZ gL-1
+ 200 g Krista-K Plus. Micrograph images of the cross-section of leaf lamina and stem showed that the cells were
tightly arranged in response to the application of PBZ.
In this paper, an improved trigonometrically fitted zero-dissipative explicit two-step hybrid method with fifth algebraic
order is derived. The method is applied to several problems where by the solutions are oscillatory in nature. Numerical
results obtained are compared with existing methods in the scientific literature. The comparison shows that the new
method is more effective and efficient than the existing methods of the same order.
MeSH terms: Algorithms; Paper; Two-Hybrid System Techniques
The basis of the nonlinear least square fitting is to fit the nonlinear rotation curve model with the observed rotation curve
of the Orion dwarf galaxy. It has been the most powerful tool to study the distribution of dark matter in galaxies where it
is used to obtain the proper mass model of a galaxy. In this paper, we present the rotation curve fit of Orion dwarf galaxy,
corrected for asymmetric drift by using the gradient method of nonlinear least square. Our results showed an excellent
agreement between the mass models of cored halo profile with the observed rotation curve. Thus, we can estimate the
value of disk mass, MD; the core radius, r0
and core density, ro
of the galaxy with 1-s of uncertainty. We finally indicated
the dark matter halo distribution as cored dark matter halo with density, 3.9 × 106
MŸ
kpc-3.
This paper presents various imputation methods for air quality data specifically in Malaysia. The main objective was to
select the best method of imputation and to compare whether there was any difference in the methods used between stations
in Peninsular Malaysia. Missing data for various cases are randomly simulated with 5, 10, 15, 20, 25 and 30% missing.
Six methods used in this paper were mean and median substitution, expectation-maximization (EM) method, singular
value decomposition (SVD), K-nearest neighbour (KNN) method and sequential K-nearest neighbour (SKNN) method. The
performance of the imputations is compared using the performance indicator: The correlation coefficient (R), the index
of agreement (d) and the mean absolute error (MAE). Based on the result obtained, it can be concluded that EM, KNN
and SKNN are the three best methods. The same result are obtained for all the eight monitoring station used in this study.
MeSH terms: Data Accuracy; Air Pollution; Malaysia; Probability; Cluster Analysis
This study utilized the incorporation of nanoparticle filler into an epoxy system to study the effect of different nanosized
montmorillonite (MMT) fillers on the thermal stability and mechanical properties of epoxy. The sample was prepared
using diglycidyl ether of bisphenol A (DGEBA) with different surface treatments of montmorillonite filler by mechanical
stirring. The results of thermal stability and mechanical properties of epoxy/clay system obtained from thermal gravimetric
analyzer (TGA), universal testing machine (UTM) and scanning electron microscopy (SEM) were discussed. With the same
amount of filler introduced into the system, different thermal stability of epoxy composite can be observed. Bentonite,
which contained other contaminant components, can downgrade the enhanced properties of the filler.
In this research, the surface hydrophobicity of a mesoporous molecular sieve synthesized from rice husk silica, called
RH-MCM41 was improved via silylation techniqueto enhance the adsorption efficiency of non-polar volatile organic
compound. The effect of chlorosilane leaving on was analyzed with three silanes containing different numbers of chloride
leaving group; trimethylchlorosilane (TMCS), dimethyldichlorosilane (DMDCS) and methyltrichlorosilane (MTCS). The
unmodified RH-MCM-41 was soaked in 100 mL of 5% v/v of silane reagent at 30ºC for 24 h. The results showed that the
silane loading on the RH-MCM-41 was in the order of increasing number of leaving groups as MTCS > DMDCS > TMCS. The
crystallinity results studied by X-ray diffractometry indicated that the silylation did not affect the hexagonal pattern of
RH-MCM-41. However, the porosity of the silylated RH-MCM-41 was significantly decreased after silylation, especially by
MTCS, due to pore blocking. After silylation, the adsorption performance of gaseous BTEX (benzene, toluene, ethylbenzene
and xylene) on the silylated RH-MCM-41 was determined by gas chromatography equipped with flame ionization detector
(GC-FID). From the results of humidity effect on adsorbability, the BTEX adsorption capacity of the unsilylated RH-MCM-41
was dropped a half, conversely the BTEX adsorption capacity of all silylated RH-MCM-41 was decreased in range of 20-
30% when the relative humidity increased from 25 to 99%. This was indicated that the influence of humidity on the BTEX
adsorption was relieved after silylation. In additions, the maximum BTEX adsorption capacity belonged to RH-MCM-41
silylated by TMCS which was recommended for the enhancement of non-polar volatile organic compounds adsorption.
Palm oil mill effluent (POME) treatment has developed in the last decade. Due to the characteristic and volume of POME,
it needed a complete treatment to reduce the pollutant content. Three pre-treatments method, ultrafiltration, adsorption
and decantation were applied prior to nanofiltration (NF) membrane. The polyethersulphone membrane, montmorillonite
as the adsorbent and modern decanter was investigated in this research. Two types of NF membrane, named NF-1 and
NF-ASP30 were used after pre-treatment. The removal of four important parameters were determined i.e. COD, TSS, colour
and turbidity. The results showed that the adsorption and UF is better than decantation pre-treatment. The ultrafiltration
and adsorption can reduce POME content more than 80% for all parameter while decantation varied between 40 and 80%.
The combination of ultrafiltration and adsorption with both of NF membrane can removed almost all the parameter. But
the decantation can only remove the turbidity but not for the rest of the parameters. Besides the POME content, the flux
decline for both of NF membrane was also investigated. The flux of NF-1 membrane was higher than NF-ASP30 membrane
but NF-ASP was more relative stable for the flux decline. Overall, NF-1 has better performance in flux decline.