Salmonella typhimurium MMP13 harboring pMMP99, a recombinant plasmid derived by cloning a ghost cassette into
T-vector, were employed for production of ghost cells. Growth of MMP13 (pMMP99) showed an initial increase after a
shift in temperature from 28 to 42°C, and then decreased gradually with ghost formation being complete within 3 h.
Ghost yield of MMP13 (pMMP99) were 99.99% less than 104 CFU/mL. MMP13 (pMMP101-1) showed a ghost yield similar
to MMP13 (pMMP99). Immune responses of BALB/c mice against ghost cells originated from MMP13 (pMMP101-1) were
assessed by measuring total IgG, IgG1, IgG2a, and secretory IgA levels in each sample. Levels of total IgG, IgG1 and
IgG2a and vaginal IgA, increased abruptly after 4 weeks post vaccination, whereas the fecal IgA level did not induce
significant change. Splenocyte proliferation was observed at the cellular level owing to stimulation of ghost cells. Ghost
vaccination protected 25-59% of mice against wild-type S. typhimurium more than those of controls.
Little is known about the diversity and roles of microbial communities in the South China Sea, especially the eastern
region. This study aimed to expand our knowledge on the diversity of these communities in Malaysian waters, as well as
their potential involvement in the breakdown or osmoregulation of dimethylsulphoniopropionate (DMSP). Water samples
were collected during local cruises (Kuching, Kota Kinabalu, and Semporna) from the SHIVA expedition and the diversity
of bacterial communities were analysed through the isolation and identification of 176 strains of cultured bacteria. The
bacteria were further screened for the existence of two key genes (dmdA, dddP) which were involved in competing,
enzymatically-mediated DMSP degradation pathways. The composition of bacterial communities in the three areas varied
and changes were mirrored in physico-chemical parameters. Riverine input was highest in Kuching, which was mirrored
by dominance of potentially pathogenic Vibrio sp., whereas the Kota Kinabalu community was more indicative of an
open ocean environment. Isolates obtained from Kota Kinabalu and Semporna showed that the communities in these
areas have potential roles in bioremediation, nitrogen fixing and sulphate reduction. Bacteria isolated from Kuching
displayed the highest abundance (44%) of both DMSP-degrading genes, while the bacterial community in Kota Kinabalu
had the highest percentage (28%) of dmdA gene occurrence and the dddP gene responsible for DMS production was
most abundant (33%) within the community in Semporna. To the best of our knowledge, this is the first study looking at
the diversity of culturable bacteria in coastal waters of East Malaysia and also their potential roles in the DMS(P) cycle.
Antibiotic resistant bacterial population is a great threat for human as well as for other domestic animals. Unscientific
use of antibiotics in clinical sectors create a selective pressure on bacteria that make bacteria resistant to a wide range
of drugs. The current finding demonstrated the isolation and characterization of multi antibiotics resistant bacterial
species from oil contaminated soil and its lateral gene transfer efficiency at different temperature. Among six bacterial
isolates, the strain OD1 showed highest antibiotic resistant capacity was selected for further studies. Morphological,
biochemical and 16S rDNA sequence analysis confirmed the bacterial strains as Alcaligenes faecalis strain OD1. It was
recorded that antibiotics resistant gene transfer was highly dependent on temperature and showed maximum transfer
efficiency at 25°C (9.6 ×10-6).
The threatened indigenous small fish, Mystus vittatus (Bloch 1794) is a commercially important fish of Bangladesh.
The present study describes the fecundity and its relationships with some of the morphometrics and condition factors
(Fulton’s, KF; Relative weight, WR) of M. vittatus. A total of 50 matured female M. vittatus were collected using the cast
net from the Padma River during May-July, 2012. Total fecundity (FT
) of each female was calculated as the number
of oocytes found in each ovary, whereas relative fecundity (FR) was the number of oocytes per gram of fish weight.
The total length (TL) ranged from 8.21 to 12.36 cm (10.60±1.08 cm) and the body weight (BW) varied between 6.0 and
21.65 g (14.08±4.15 g). The FT
ranged from 3256 to 22549 with a mean value of 13064.50±4920 while the FR ranged
from 472 to 1648 oocytes per gram of female, with a mean of 929±245. Significant and strong relationships were found
between FT vs. TL (r
2 = 0.63; p<0.001), FT vs. BW (r2 = 0.61; p<0.001), FT vs. OW (r
2 = 0.89; p<0.001) and FT vs. GSI (rs =
0.67; p<0.001), but insignificant relationships were recorded for FT vs. KF (rs = 0.11; p = 0.452), FT vs.WR (rs
p = 0.997). The information provided in this study will help initiating sustainable management and conservation of the
threatened M. vittatus in the region.
Cobia Rachycentron canadum, is one of the emerging aquaculture species but is usually a non-target resource in fisheries
industry and within Malaysia, their landings are among the highest worldwide. Identification of stocks with unique
morphological characters is important for effective management and sustainable utilization. Morphometric variations
among three different cobia populations from Kedah, Terengganu and Johor were studied. All the morphometric
characteristics varied among the three populations as all the elements of the first Eigen vector were positive. Discriminant
analysis suggested that head depth (HD) and maximum body depth, (MaxD) were the most varied among the populations.
Cobia populations from Kedah and Johor were in a single cluster in the dendrogram with a 63.69% similarity while
Terengganu was in another cluster with a similarity of 8.01% from Kedah and Johor. The differences in the observed
morphometry may be resulted from different trophic activities and/or habitat productiveness explored by each of the
A total of 9 species of Indigofera have been identified on the Islands of Java and Madura. Only one species has been
utilized by batik makers and weavers as a natural dye, while the other 8 species are of unknown potential as natural
dyes. This study seeks to demonstrate the correlation between morphological characteristics and the level and quality of
indicant compound, in order to assist batik producers and weavers in determining the species that can be used as dyestuff.
The potential blue colour dyestuff yield of Indigofera was determined by leaf immersion, followed by quantitative and
qualitative examination of the indicant present. Morphological characteristics were then analysed to identify those that
correlated with the presence of indicant. The indicant differences were analysed using SPSS; the relationship between the
characteristics was analyzed by Pearson correlation and logistic regression. Four species, namely I. tinctoria, I. arrecta, I.
suffruticosa and I. longiracemosa contained indigo. The colour produced by indigo dye obtained from these four species
of Indigofera had a ‘4–5’ value of colour change and colour staining in tests involving washing, sweat, bright light and
heat stress. This value meets the ‘good quality’ standard of the Indonesian National Standards (SNI). I. suffruticosa has
the highest indicant content at 1.4 g/kg, followed by I. tinctoria, I. arrecta, and I. longiracemosa with 0.414, 0.13, and
0.038 g/kg, respectively. The colour of upper and lower dried foliages were correlated to potential indigo dye producers.
he deficiency of oxygen in water during submergence is one of the frequently perceived environmental factors that limits
or hampers production of the rice cultivation. Rice plants comprise of elongated submerged tissues that help to bear with
the rise of water level in natural location. This characteristic helps the plant to deal with flooding stress. The mechanism
on flooding tolerance and adaptation mostly includes the physiological changes, one of which is the shortened growth
of elongation towards keeping the carbohydrates and energy for production of the antioxidant regulations in rice plants.
Furthermore, molecular studies and gene cloning might help suggest a better understanding of means and adaptations
built-up by rice plants in order to stay alive and to remain active during flooding stress, might help to focus on some
novel approaches to the up gradation as well as improvement on the natural cultivation of rice plants.
Marudu Bay, north coast of Sabah is characterized with mesotrophic water body and typical environmental parameters
throughout the year. The current study was undertaken to evaluate the effect of environmental parameters and nutrients
in mesotrophic water on the occurrence and distribution of potentially harmful phytoplankton species. The samplings
were conducted over a period of thirteen months, covering southwest monsoon (SWM), inter-monsoon (IM), and northeast
monsoon (NEM), at ten stations throughout the bay. Physical parameters (temperature, salinity, pH, dissolved oxygen,
current speed and secchi depth), biological parameters (cell densities of phytoplankton) and chemical parameters
(phosphate, nitrate, silicate and ammonia) were examined. The results indicated at least eight potentially harmful
phytoplankton species (Dinophysis caudata, D. miles, Ceratium furca, C. fursus, Prorocentrum micans, P. sigmoides, P.
triestinum and Pseudo-nitzschia sp.) were detected in north coast of Sabah. However, the potentially harmful phytoplankton
species contributed only about 1.3% of the total phytoplankton community. Under nutrient deprivation conditions, the
potentially harmful phytoplankton species distribution was mainly influenced by the ability to utilize other nitrogen
sources, cell mobility and toleration to low nutrients environments.
The study to determine the concentrations of dissolved heavy metals in the Sungai Semenyih and to use the environmetric
methods to evaluate the influence of different pollution sources on heavy metals concentrations was carried out. Cluster
analysis (CA) classified 8 sampling stations into two clusters based on the similarity of sampling stations characteristics,
cluster 1 included stations 1, 2, 3 and 4 (low pollution area), whereas cluster 2 comprised of stations 5, 6, 7 and 8
(high pollution area). Principal component analysis (PCA) of the two datasets yield two factors for low pollution area
and three factors for the high pollution area at Eigenvalues >1, representing 92.544% and 100% of the total variance
in each heavy metals data sets and allowed to gather selected heavy metals based on the anthropogenic and lithologic
sources of contamination.
Effects of radiation on free convection about a heated horizontal circular cylinder in the presence of heat generation is investigated numerically. The cylinder is fixed and immersed in a stationary fluid, in which the temperature is uniformly heated about the temperature of the surrounding fluid. The governing equations are transformed into dimensionless non-linear partial differential equations and solved by employing a finite difference method. An implicit finite difference scheme of Crank Nicolson method is used to analyze the results. This study determined the effects of radiation parameter, heat generation parameter, and the Prandtl number, on the temperature and velocity profiles. The results of the local heat transfer and skin-friction coefficient in the presence of radiation for some selected values of and are shown graphically.
MeSH terms: Body Temperature Regulation; Clothing; Hot Temperature; Temperature; Friction; Convection
A new numerical method was proposed in this paper to address the nonlinear quadratic optimal control problems, with state and control inequality constraints. This method used the quasilinearization technique and Haar wavelet operational matrix to convert the nonlinear optimal control problem into a sequence of quadratic programming problems. The inequality constraints for trajectory variables were transformed into quadratic programming constraints using the Haar wavelet collocation method. The proposed method was applied to optimize the control of the multi-item inventory model with linear demand rates. By enhancing the resolution of the Haar wavelet, we can improve the accuracy of the states, controls and cost. Simulation results were also compared with other researchers' work.
In this paper, the problem of free convection boundary layer flow on a horizontal circular cylinder in a nanofluid with viscous dissipation and constant wall temperature is investigated. The transformed boundary layer equations are solved numerically using finite difference scheme namely the Keller-box method. Numerical solutions were obtained for the reduced skin friction coefficient, Nusselt number and Sherwood number as well as the velocity and temperature profiles.The features of the flow and heat transfer characteristics for various values of the Brownian motion parameter, thermophoresis parameter, Lewis number and Eckert number were analyzed and discussed.
This study focuses on the potential of electric arc furnace (EAF) steel slag and copper mine tailings as asphalt paving materials with respect to issues of volumetric properties and leaching. In this study, four different asphalt mixes were investigated; each contained EAF steel slag and copper mine tailings of various proportions. Apart from the microstructure analysis of the materials, a toxicity characteristics leaching procedure (TCLP) test was conducted on both the mixes and the aggregates. All the mixes were evaluated by the following parameters: Voids in the mineral aggregates (VMA), voids in total mix (VTM), voids filled with asphalt (VFA), Marshall stability and flow and specific gravity. F-test ANNOVA was used to evaluate the degree of significance of the mixes with each of the evaluated standards. It was observed that the mixes containing either EAF steel slag or copper mine tailings or both gave better results than the control mix. In terms of the TCLP test, none of the detected hazardous elements exceeded the standard limits, which indicates the possibility of using them as construction materials.
MeSH terms: Construction Materials; Copper; Hydrocarbons; Minerals; Specific Gravity; Steel; Toxicity Tests
Cellulose was extracted from kenaf core pulp (KCP) by a series of bleaching processes (D) and alkali treatment (E) in the sequence of (DEED) and pretreated with acid hydrolysis in room temperature for 6 hours. The pretreated and non-treated cellulose were dissolved in lithium hydroxide/urea (LiOH/urea) and subsequently used to produce cellulose membrane cross linked with various percentages of glyoxal from 2.5 to 20%. The effects of acid hydrolysis pretreatment on solubility, crystallinity and morphology were investigated. The acid hydrolysis pretreatment leads to higher solubility of the cellulose solution. The formation of cellulose II and crystallinity index of the cellulose membrane were examined by X-ray diffraction (XRD). Cellulose membrane without acid hydrolysis pretreatment cross linked with higher percentage of glyoxal has higher tensile strength compared with the treated cellulose.
The aimed of this study was to evaluate the resistance of sesenduk (Endospermum diadenum) wood, treated using admixture
of low molecular weight phenol formaldehyde (LmwPF) resin and nanoclay, against white rot fungus (Pycnoporus
sanguineus) and subterranean termites (Coptotermes curvignathus Holmgren). Seven sample groups including untreated
sesenduk wood and treated sesenduk wood using 10, 15 and 20% LmwPF resin and the admixture of the 1.5% nanoclay
with every level of resin concentrations. Air-dried samples were impregnated using vacuum-pressure process. After
impregnation, the treated samples were heated in an oven at 150°
C for 30 min. Five test blocks from each treatment
group were tested separately against P. sanguineus and C. curvignathus in accordance with AWPA E10-12 and AWPA E1-13
standards, respectively. The results showed that both treatments had significant effects on the percentage weight loss and
decay rate of the samples. The weight loss due to termite attack was found reduce with the increasing PF concentration.
Generally, the addition of 1.5% nanoclay in PF resin slightly increased the resistance against both deteriorating agents
compared to the wood treated using PF alone. It was found that the PF resin can be used as an effective method to improve
the durability of sesenduk wood.
Glufosinate ammonium or ammonium salt (ammonium-(2RS)-2-amino-4- (methylphosphinato) butyric acid; C5H15N2O4P) is a commonly used polar herbicide in Malaysia and present in a variety of environmental waters at the sub-ppb level. Thus, glufosinate ammonium is analyzed in soil and water using high-performance liquid chromatography (HPLC), which is a complex yet the most powerful analysis tool. HPLC is tremendously sensitive and highly automated and HPLC instrumentation and machinery have improved over the years. However, typical problems are still encountered. HPLC users and advanced learners require help in identifying, separating and correcting typical problems. All HPLC systems consist of similar basic components. Although it is a modular system, trouble can occur in each component and change the overall performance. Resolving these problems may be expensive. This review describes the different aspects of HPLC, particularly troubleshooting, common problems and easy guidelines for maintenance.
Gynura procumbens which is locally known as 'Sambung nyawa' in Malay and 'Feng Wei Jian' in Chinese, belongs to the botanical family of Compositae. In this study, antioxidant property of G. procumbens extracts was evaluated using DPPH radical scavenging, metal chelating and β-carotene bleaching assays. To the best of our knowledge, this is the first report that evaluated the cytotoxicity of G. procumbens extracts on human colon cancer cells (HT-29, HCT 116, HCT-15, SW480, Caco-2) and human normal colon cells (CCD-18Co). The results showed that ethyl acetate extract contained the highest total phenolic content (172.68 mg of GAEs/g of extract) compared to methanol, hexane and water extracts. Methanol extract possessed better overall antioxidant activities while ethyl acetate extract demonstrated better cytotoxic activity. At 24 h treatment, ethyl acetate extract demonstrated selective cytotoxicity against HT-29 and HCT 116 cells with IC50 values of 35.7 and 42.6 μg/mL, respectively. In addition, methanol extract showed negligible level of toxicity when administered orally. All the results indicated that G. procumbens may provide benefits in prevention and treatment of cancer.
The effects of nitrogen (N) fertilization at different growth stages were investigated on durum wheat (Triticum durum L.) grain yield and yield components (with irrigated bed planting) in Diyarbakir, Turkey. N was applied at a rate of 140 kg ha–1 and distributed to one, two and three applications at various combinations with five different growth stages (i.e. sowing, seedling growth, early tillering, stem elongation and booting). This study included 13 treatments, including the control (zero nitrogen). The N application timings (NAT) of the 50% sowing + 50% early tillering and 66% sowing + 33% early tillering treatments were most suitable for durum wheat. The results showed that NAT had significant effect on flowering time, SPAD readings of the early milky ripe stage, plant density, thousand kernel weights, grain filling duration, grain filling rate, grain N content, grain yield, harvest index and grain N yield. In summary, the highest values of parameters studied were obtained from the 50% sowing + 50% first tillering and 66% sowing + 33% early tillering treatments. N fertilization application rate and time of durum wheat genotypes should consist of applying 50-60% of the total N fertilizer at sowing and 40–50% at the early tillering stage under irrigated conditions and with bed planting.
As a natural anti-oxidant source, Tualang honey, produced by wild bees nesting on the Tualang tree (Koompassia excelsa) is expected to have positive influence on health, including memory. This study investigated the effect of Tualang honey on the cell count of memory formation related hippocampal pyramidal neuron and on spatial memory performance (SMP) of rats using the radial arm maze (RAM). Sprague Dawley male rats (n=24), 7-8 weeks old were divided into two groups; experimental group group force-fed 1 mL/100 g body weight with 70% honey (HG); and the control group with 0.9% saline (CG) for 12 weeks. Nissl staining technique (with cresyl violet) was employed for neurohistological analysis of the hippocampal tissue. Six randomly selected rats from each group were used for the neuronal soma counting of pyramidal cell layer CA1, CA3a and CA3c regions. Two-way ANOVA analysis showed positively significant differences between treatment and control groups for SMP comparison of working memory and reference memory components, as well as the number of pyramidal neurons. Hence, this positive effects of Tualang honey, as demonstrated behaviorally and neurohistologically, supported report that Tualang honey could improve memory and deter hippocampal morphological impairments; possibly due to its high anti-oxidant properties.
MeSH terms: Analysis of Variance; Animals; Bees; Body Weight; Carisoprodol; Cell Count; Honey; Male; Memory, Short-Term; Staining and Labeling; Trees; Oxidants; Rats, Sprague-Dawley; Pyramidal Cells; Control Groups; Benzoxazines; Rats; CA1 Region, Hippocampal; Spatial Memory
Nicotine has been identified as one of the causal factor for oxidative stress, hypertension and hyperlipidemia. Roselle has been widely studied for its potential as an antioxidant, antihyperlipidemic and antihypertensive. However, no studies have been done to investigate if roselle could diminish the oxidative stress caused by nicotine which could further lead to cardiac damages. Thus, this study was aimed to investigate the effect of roselle extract (HSE) on blood pressure, serum lipid profile, oxidative stress marker levels and histological changes to the heart in nicotine-treated rats. A total of 21 Sprague-Dawley rats were randomly divided into 3 groups (n=7 per group): Control group received normal saline (0.5 mL/day, i.p); nicotine group received 0.6 mg/kg/BW nicotine (i.p); and treated group received 100 mg/kg/b.w HSE through oral force feeding followed with 0.6 mg/kg/b.w nicotine (i.p) for 21 consecutive days. The results showed that HSE significantly (p>0.05) reduced the heart rate but no effect to the blood pressure. For lipid profile study, HSE increased the high-density lipoprotein concentration significantly (p<0.05) in rats given with nicotine, without any significant changes in total cholesterol, triglyceride and low-density lipoprotein (LDL) concentration. Besides, HSE treatment was also found to reverse malondialdehyde (MDA) level, superoxide dimustase (SOD) enzyme activity and protein concentration significantly (p<0.05) in nicotine-treated rats. In summary, these results indicated that HSE is an effective antioxidant against oxidative damage in heart caused by nicotine, but not as antihyperlipidemic and antihypertensive agent in this rat model.