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.
Forecasting of groundwater level variations is a significantly needed in groundwater resource management. Precise water level prediction assists in practical and optimal usage of water resources. The main objective of using an artificial neural network (ANN) was to investigate the feasibility of feed-forward, Elman and Cascade forward neural networks with different algorithms to estimate groundwater levels in the Langat Basin from 2007 to 2013. In order to examine the accuracy of monthly water level forecasts, effectiveness of the steepness coefficient in the sigmoid function of a developed ANN model was evaluated in this research. The performance of the models was evaluated using the mean squared error (MSE) and the correlation coefficient (R). The results indicated that the ANN technique was well suited for forecasting groundwater levels. All models developed had shown acceptable results. Based on the observation, the feed-forward neural network model optimized with the Levenberg-Marquardt algorithms showed the most beneficial results with the minimum MSE value of (0.048) and maximum R value of (0.839), obtained for simulation of groundwater levels. The present research conclusively showed the capability of ANNs to provide excellent estimation accuracy and valuable sensitivity analyses.
In this study, the effect of hydrolysis on electrospinnability of chitosan/PVA blend solution has been investigated. Since crude chitosan (Mw=8.96105 g/mole, DD=40%) could not be dissolved even in concentrated acetic acid, it was hydrolyzed with 33.5 wt. % of NaOH at 90°C for 24 and 42 h. Hydrolyzed chitosan with two different time duration was analyzed using Fourier transform infrared (FTIR). Morphology of the product nanofiber was investigated by field emission scanning electron microscope (FESEM.). FTIR results showed that the hydrolysis did not destroy the molecular backbone of chitosan but increased the degree of deacetylation from 40 to 84% and 92% for 24 and 42 h hydrolysis time, respectively. FESEM image analysis was carried out and histogram was drawn to study on the distribution of fiber diameter. It showed that though the composition of chitosan/PVA remained the same, but mean fiber diameter, standard deviation and required applied voltage for electrospinning was smaller for the solution containing maximum time hydrolyzed chitosan. It indicated that longer hydrolysis time resulted in finer nanofiber which mostly attributed to lower required voltage for electrospinning. Threshold composition for defect free fiber is 50:50 and 60:40 of chitosan/PVA for 24 and 42 h hydrolysis, respectively. It meant that 42 h hydrolysis ensured the presence of more chitosan in the chitosan/PVA polymer blend because of smaller presence of amino group in chitosan molecule.
The sewage irrigation area in Tianjin reached 6 billion m2 in 2003 which accounts for 22% of the irrigated areas. Polycyclic aromatic hydrocarbons (PAHs) contamination caused by sewage irrigation on agricultural land has attracted considerable attention because of their toxic and hazardous risks to human beings. In order to evaluate the health risk of PAHs to farmers in four age groups, a multimedia/multipathway exposure model was applied. The results showed that the chronic daily intake (CDI) of children, adolescents, adults and the aged to the 16 PAH compounds exposure were 2.83, 2.34, 1.44, 1.05 μg·kg-1·d-1, respectively. The non-cancer risk of life long exposure in sewage irrigation was 2.75×10-3 and the cancer risk was 2.49×10-5. From the long-term safety point of view, the health risks caused by PAHs were at a relatively high level. Hence, we suggest that crops of sewage irrigated areas and their distribution channels should be re-concerned by the government in the future city planning.
Ariid catfishes, belong to family Ariidae is considered as one of the taxonomically problematic groups, which is still under review by fish taxonomist globally. Species level identification of some ariids often resulted in species misidentification because of their complex characters and very similar morphological characters within genera. A vigilant and detail observation is very important during the species level identification of ariid species. In these contexts, this study was carried out in order to determine the morphological variations of one of the ariid genera, Plicofollis, which have been giving misleading taxonomic information in the south-east Asian countries. A Truss network technique was used throughout the study period. The study was conducted based on 20 truss measurements using 22 to 23 specimens per species, namely P. argyropleuron, P. nella and P. tenuispinis found in Peninsular Malaysian waters. Morphological variations were determined using a multivariate technique of discriminant function analysis (DFA). The results obtained in this study showed that discriminant analysis using truss network measurements has produced very clear separations of all the species in Plicofollis group. Several important morphological characters have been identified, which represent body depth and caudal regions of the fish. The documentary evidences of these variables could be considered as the constructive functional features, which could enable us to assess more accurately to distinguish the species within this complex Ariidae family.
The origin of formation water salinity variation in Chang 9 stratum, Jiyuan oilfield, Ordos basin is studied here. 91 formation water samples show that water salinity is characterized by a wide range and a complex plane distribution. In order to find out the main cause of such distribution complexity and reveal the relationship between formation water and evolution of reservoir traps, core data, chemical analysis result of formation water and log data are analyzed from perspectives of diagenesis and tectonism. And then, their characteristics are presented as the followings. In high salinity area, tuffaceous mudstone interlayer is found growing. Besides, the condition of Na++K+ is opposite to that of Ca2+, for its rate of concentration increase slows down with total salinity accumulating. In low salinity area, while, with fracture and faults developing, some formation water of CaCl2 type turns into MgCl2, NaHCO3 or Na2SO4 type. The cause is thus proposed to be composed of two aspects. One covers tuff alteration and later diagenesis for the high salinity. To be specific, montmorillonite, developed from tuff alteration, absorbs cation selectively and then ions migrate, during which more Na++K+ get lost, while more Ca2+ reserved. Afterwards, those reserved Ca2+ get released with montmorillonite transforming to illite, which results in a loss of Na++K+ and accumulation of Ca2+. Lots of ions are released into formation water during that process and later diagenetic process, which leads to the high water salinity. The other aspect is the development of faults and fractures, through which, the upper low salinity formation water gets connected. And that is the main cause of low salinity. At last, geological significance is discussed from two angles. Firstly, tuff alteration and later diagenesis are pivotal to reservoir reconstruction; and secondly, faults and fractures play an important role in oil transportation and storage.
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.
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.
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.
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
populations
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
= 0.001;
p = 0.997). The information provided in this study will help initiating sustainable management and conservation of the
threatened M. vittatus in the region.
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 allelochemical 2,4-di-tert-butylphenol (2,4-DTBP) is one of the natural compounds present in medicinal plants.
This compound has been reported to possess herbicidal properties. However, its effect on weed growth parameters is
unknown for it to be utilized in weed management. Hence, the herbicidal potential of the allelochemical 2,4-DTBP on the
root and leaf tissues of the grassy weed, Leptochloa chinensis (L.) Nees and the broadleaf weed, Hedyotis verticillata
(L.) Lam was investigated. After 2,4-DTBP treatment, both bioassay species had abnormal and much shorter root hairs
compared to those of untreated plants. The roots of H. verticillata were severely damaged with the root nodes turned
brown. The phytotoxic effect of 2,4-DTBP on L. chinensis and H. verticillata became apparent at seven days and 14 days
after treatment with symptoms of lamina wilting and necrosis, respectively. These results demonstrated that 2,4-DTBP
could be used as a natural herbicide for the control of L. chinensis and H. verticillata.
In this paper, a minibioreactor platform made of low cost polymers is presented. The minibioreactor prototype was designed
as an alternative solution for carrying out microbial fermentation experiments in laboratory. The minibioreactor prototype
has a working volume of 1.5 mL and was fabricated from poly(methylmethacrylate) (PMMA) and poly(dimethylsiloxane)
(PDMS) polymers. Cell density was measured online whilst agitation rates and the temperature of the reactor content
can be tightly controlled to desired set-point values. As proof-of-concept, various S. cerevisae fermentation experiments
were conducted. In every experiment, the minibioreactor operated stably for the entire length of operation which was
nearly 40 h with very minimal volume loss i.e. about 2.8 µL·h-1 at 37ºC. The minibioreactor has the maximum oxygen
transfer rate (OTR) of 16.6 mmol·L-1·h-1 under the agitation rate of 300 rpm. Under these conditions, cell specific growth
rate as high as 0.291 h-1 was obtained. The experimental data in the minibioreactor operation was also reproducible
using shake flask where similar growth profiles were attained under a similar growth conditions.
The concern on the widespread use of surfactants is increasing worldwide as they can be potential toxicants by polluting
the environment, with the damage formed depending on their exposure and persistence in the ecosystem. This paper
was intended to evaluate the biodegradability of palm-based surfactant, MES, in order to establish their environmental
friendliness. The respirometric method was used to monitor the biodegradation of various homologues of MES over 28
days as described in the OECD 301F Manometric respirometry test method. The results showed all the MES homologues
tested were readily biodegradable with percentage of biodegradation achieved for C12, C14 and C16 MES was 73%
within 6 days, 66% within 8 days and 63% within 16 days, respectively, while linear alkylbenzene sulphonates (LAS)
sample 60% biodegraded within 8 days. From the results, it can be concluded that the longer the carbon chain length, the
lower is the biodegradability of MES as the microorganisms took longer time to degrade a longer chain surfactant. Other
than that, the presence of aromatic structure in LAS may also extend the biodegradation process. The use of palm-based
surfactant, i.e. MES, is more environmental friendly and can be used as an alternative to petroleum-based surfactant to
reduce adverse environmental effects of surfactant on ecosystem.