EFFECT OF PERMEABLE VESSEL CLOSURE AND GELLING AGENT ON REDUCTION OF HYPERHYDRICITY IN IN VITRO CULTURE OF CARNATION

Hyperhydricity, an abnormal morphological appearance and physiological&lt;br /&gt;function, is an important problem in carnation tissue culture. The problem causes premature flowering, high occurrence of abnormal shoots, difficulty in transferring hyperhydric plantlets to soil, and low survival rate of plantlets. High relative humidity and the water potential are considered as the key factors involved in the abnormality. Furthermore, permeable culture vessel and gelling agent were assured to be high potential treatment to eliminate it. Objective of this research was to reduce  hyperhydricity in regenerants of carnation using different permeable vessel closures and gelling agents and to assess the multiplication and  acclimatization abilities of recovered shoots. Experiment was arranged in randomized complete block design with four replications. First factor was different types of closure, i.e. cotton wool, plastic wrap, parafilm and aluminium foil, while second one was gelling agents, i.e. bacto agar, phytagel, swallow agar, and Type 900 agar. The recovered shoots were then multiplied, rooted, and acclimatized. The results showed that hyperhydricity was successfully reduced by applying permeable closure (cotton wool and plastic wrap) in combination with Type 900 agar. The combination of plastic wrap and Type 900 agar was the most appropriate treatment in reducing hyperhydricity and producing good quality shoots. The treatment reduced the problem down to 23% of total condition of hyperhydricity (100%) and increased leaf chlorophyll content from 0.0883 to 0.1288 mg mg-1. The plastic wrap was easily applied and cheaper material compared to cotton wool. The recovered shoots were able to produce 1-3 healthy axillary shoots and easily rooted on half-strength MS. The recovered plantlets were simply acclimatized with survival rate up to 100% on kossas peat + soil (1:1, v/v) and flowered 4-5 months after acclimatization with decreasing in number and size of flower.</jats:p

EFFECT OF PERMEABLE VESSEL CLOSURE AND GELLING AGENT ON REDUCTION OF HYPERHYDRICITY IN IN VITRO CULTURE OF CARNATION

Hyperhydricity, an abnormal morphological appearance and physiologicalfunction, is an important problem in carnation tissue culture. The problem causes premature flowering, high occurrence of abnormal shoots, difficulty in transferring hyperhydric plantlets to soil, and low survival rate of plantlets. High relative humidity and the water potential are considered as the key factors involved in the abnormality. Furthermore, permeable culture vessel and gelling agent were assured to be high potential treatment to eliminate it. Objective of this research was to reduce  hyperhydricity in regenerants of carnation using different permeable vessel closures and gelling agents and to assess the multiplication and  acclimatization abilities of recovered shoots. Experiment was arranged in randomized complete block design with four replications. First factor was different types of closure, i.e. cotton wool, plastic wrap, parafilm and aluminium foil, while second one was gelling agents, i.e. bacto agar, phytagel, swallow agar, and Type 900 agar. The recovered shoots were then multiplied, rooted, and acclimatized. The results showed that hyperhydricity was successfully reduced by applying permeable closure (cotton wool and plastic wrap) in combination with Type 900 agar. The combination of plastic wrap and Type 900 agar was the most appropriate treatment in reducing hyperhydricity and producing good quality shoots. The treatment reduced the problem down to 23% of total condition of hyperhydricity (100%) and increased leaf chlorophyll content from 0.0883 to 0.1288 mg mg-1. The plastic wrap was easily applied and cheaper material compared to cotton wool. The recovered shoots were able to produce 1-3 healthy axillary shoots and easily rooted on half-strength MS. The recovered plantlets were simply acclimatized with survival rate up to 100% on kossas peat + soil (1:1, v/v) and flowered 4-5 months after acclimatization with decreasing in number and size of flower

Comparison of Xpert GBS v. culture for rapid detection of group B streptococcus in pregnant women: Sensitivity, specificity and predictive values

Background. Group B streptococcus (GBS) is a leading cause of invasive disease, particularly in newborns. Seventy-five percent of neonates will be colonised by mothers carrying the organism. Confirmation of maternal colonisation with GBS is essential for prompt treatment and prevention of neonatal sepsis. The current gold standard of culture for isolation of GBS has a disadvantage of long turnaround time (24 - 72 hours). Rapid assays are required to determine maternal carriage of GBS.Objectives. To determine the usefulness of the Xpert GBS technology v. culture methods to detect GBS carriage in pregnant women.Methods. This was a prospective observational study of 284 pregnant women between 26 and 37 weeks’ gestation. Two vaginorectal swabs were collected from each participant. One swab was processed using the gold-standard culture method, while the second swab was processed using the Xpert GBS assay. The performance of the Xpert GBS assay was then compared with that of the culture method.Results. Two swabs were processed from each of 284 pregnant women between 26 and 37 weeks’ gestation. Culture detected 70 GBS isolates from a total of 279 specimens (25.1%), whereas the Xpert GBS detected 66 positive specimens (23.7%). The Xpert GBS assay had a sensitivity of 87% and specificity of 98%, with a positive predictive value of 92% and a negative predictive value of 96%.Conclusions. The Xpert GBS assay is a rapid and sensitive tool for prenatal detection of GBS. The assay should ideally be available in every labour ward, where women can be screened for GBS on arrival

Physicochemical and sensory properties of traditional baked cake (kuih bakar) with coconut milk and soy milk

Coconut milk is widely used in Malaysia as one of the essential ingredients in preparing traditional baked cake or ‘kuih bakar’. Increased demand for coconut milk affects its availability and cost. Thus, it is important to study a possible alternative ingredient to ensure the continuity of this traditional dessert. This project aimed to determine the physicochemical and sensory properties of ‘kuih bakar’ produced with coconut milk and soy milk. In the present study, ‘kuih bakar’ was prepared with fresh coconut milk (FCM) (positive control), fresh soy milk (FSM), commercial coconut milk (CCM), commercial soy milk (CSM), and without milk (negative control). Proximate analysis showed that substitution of coconut milk with soy milk reduced the fat and increased the protein content of ‘kuih bakar’ significantly (p 0.05) on the colour properties and water activity of the sample. There were significant differences (p < 0.05) in scores during sensory evaluation between the samples but the ‘kuih bakar’ produced with FSM showed no significant difference (p < 0.05) as compared to FCM and CCM. This study demonstrated that physicochemical and sensory attributes of traditional ‘kuih bakar’ can be maintained by using FSM as a substitution of the traditional coconut milk used in producing ‘kuih bakar’

Tight-binding parameters for charge transfer along DNA

We systematically examine all the tight-binding parameters pertinent to charge transfer along DNA. The $\pi$ molecular structure of the four DNA bases (adenine, thymine, cytosine, and guanine) is investigated by using the linear combination of atomic orbitals method with a recently introduced parametrization. The HOMO and LUMO wavefunctions and energies of DNA bases are discussed and then used for calculating the corresponding wavefunctions of the two B-DNA base-pairs (adenine-thymine and guanine-cytosine). The obtained HOMO and LUMO energies of the bases are in good agreement with available experimental values. Our results are then used for estimating the complete set of charge transfer parameters between neighboring bases and also between successive base-pairs, considering all possible combinations between them, for both electrons and holes. The calculated microscopic quantities can be used in mesoscopic theoretical models of electron or hole transfer along the DNA double helix, as they provide the necessary parameters for a tight-binding phenomenological description based on the $\pi$ molecular overlap. We find that usually the hopping parameters for holes are higher in magnitude compared to the ones for electrons, which probably indicates that hole transport along DNA is more favorable than electron transport. Our findings are also compared with existing calculations from first principles.Comment: 15 pages, 3 figures, 7 table

Suitable priming for rice yield improvement

Low yield of rice has made reaching self-sufficiency level in Malaysia elusive. So, Malaysia has become a target of rice exporting countries within and outside Asia. To solve this problem, a pre-sowing seed treatment was used as a physiological intervention to alleviate the impeding problems of achieving better growth and yield of Malaysian rice variety MR219. A glass house experiment, which involved the use of solutions of osmotic salts and plant hormones, was used for this investigation. Data on germination percentages, height, number of tillers and productive tillers, tiller efficiency and yield were taken. In both osmopriming and hormonal priming treatments, the highest number of tillers and productive tillers were from pre-germination. The tallest plants from osmopriming were from 150mM treatment, while 50 ppm GA3 had the tallest in hormonal priming. The highest tiller efficiency for osmopriming was from 150mM and and 200mM sodium chloride, while in hormonal priming it was 200 ppm salicylic acid. For yield per panicle in osmopriming, it was 50mM and 100mM magnesium chloride that had the highest, while in hormonal priming it was 200 ppm methyl jasmonate. Finally, the highest grain yield per hill was produced by 200 ppm methyl jasmonate in hormonal priming, while 50Mm magnesium chloride had the highest yield in osmotic priming. So, it is concluded that the use of 200 ppm methyl jasmonate and 50Mm magnesium chloride could be used as potential hormonal priming and osmopriming, respectively, for yield improvement of MR219 rice in Malaysia

Natural organic matter (NOM) fouling characteristics during water treatment with a submerged ultrafiltration membrane reactor: a case study / A. W. Zularisam, A.F. Ismail and M.R. Salim

Natural organic mailer (NOM) has been claimed as the major membrane foulant in drinking water treatment processes. However, the primary fraction of NOM which is believed to cause membrane fouling and significant influence of rejection mechanisms are still unclear and not yet well-established. The main objective of this study is to evaluate the effect of fractionated NOM and their fouling potentials on the submerged ultrafiltration membrane reactor performance. The membrane fouling characteristics of NOM based on hydraulic resistances (Rcp Rg R R) rejection of UV 254nm. DOC, and flux decline were assessed using 68 kDa MWCO hydrophobic polysulfone (PS) and 50 kDa MWCO hydrophilic cellulose acetate (CA) membranes. Both PS and CA membranes were spun by a simple forced convective dry/wet spinning technique. The Sungai Pontian Kecil river water was taken as a sample and was subjected to non-ionic macro-porous ion exchange resins (DAX-8 and XAD-4). The sample was fractionated into three specific classes which were hydrophilic, transphilic and hydrophilic compounds. Results showed that the low aromatic hydrophilic fraction content of NOM attributed to the worst flux decline despite lesser solute rejection than hydrophobic component. In addition, the PS membrane was surprisingly found to exhibit higher NOM rejection especially for the component with higher SUVA (UV254nm/DOC) despite smaller nominal MWCO posed by the hydrophilic CA membrane. Charge interaction between hydrophobic component and membrane surface plays more important role than steric exclusion mechanism. NOM rejection mechanisms were found to be a function of both membrane type and water characteristics

Fully-developed laminar flow in trapezoidal ducts with rounded corners : a numerical solution and case study

Purpose This paper aims to numerically solve fully developed laminar flow in trapezoidal ducts with rounded corners which result following forming processes. Design/methodology/approach A two-dimensional model for a trapezoidal duct with rounded corners is developed and conservation of momentum equation is solved. The flow is assumed to be steady, fully developed, laminar, isothermal and incompressible. The key flow characteristics including the Poiseuille number and the incremental pressure drop have been computed and tabulated for a wide range of: sidewall angle (θ); the ratio of the height of the duct to its smaller base (α); and the ratio of the fillet radius of the duct to its smaller base (β). Findings The results show that Poiseuille number decreases, and all the other dimensionless numbers increase with increasing the radii of the fillets of the duct; these effects were found to amplify with decreasing duct heights or increasing sidewall angles. The maximum axial velocity was shown to increase with increasing the radii of the fillets of the duct. For normally used ducts in hydrogen fuel cells, the impact of rounded corners cannot be overlooked for very low channel heights or very high sidewall angles. Practical implications The data generated in this study are highly valuable for engineers interested in estimating pressure drops in rounded trapezoidal ducts; these ducts have been increasingly used in hydrogen fuel cells where flow channels are stamped on thin metallic sheets. Originality/value Fully developed laminar flow in trapezoidal ducts with four rounded corners has been solved for the first time, allowing for more accurate estimation of pressure drop