587 research outputs found
Toxicity induced by Solanapyrone A in Chickpea shoots and its metabolism through Glutathione/Glutathione-S-Transferase system
Solanapyrone A and C were isolated from a Pakistani isolate of Ascochyta rabiei, Pk-1. Two experiments were conducted to investigate the phytotoxic effects of the most potent toxin, solanapyrone A on chickpea cultivars and its subsequent detoxification through glutathion/glutathion-s-transferase(GST) system. When the shoots of cultivars were fed solanapyrone A, symptoms mimicking to Ascochyta blight appeared and extent of manifestation of symptoms varied with the cultivar. In the first experiment, the effect of three different plant ages of 2 cultivars with different levels of resistance to toxin was determined in terms of GST activity unit. GST activity in Balkasar-2000 (a resistant cultivar) increased 1.92 times, 1.72 and 1.65 times in two-week-old seedling, eight-week-old and adult plants (all treated) respectively as compared to their respective controls. In the highly susceptible cultivar, AUG-424, a slight increase (1.14 times) over control was noticed in GST activity at all the three ages. In the second experiment, where shoots of three cultivars were tested against 2 doses of the toxin, an increase in GST activity in Noor-91 (a moderately susceptible cultivar) and AUG-424 was significantly less than resistant cultivar, Balkasar-2000 showing direct relationship between resistance and activity of the enzyme. It may be concluded that it is a reason for difference in response of cultivars to the disease
A partial Lagrangian approach to mathematical models of epidemiology.
This paper analyzes the first integrals and exact solutions of mathematical models of epidemiology via the partial Lagrangian approach by replacing the three first-order nonlinear ordinary differential equations by an equivalent system containing one second order equation and a first-order equation. The partial Lagrangian approach is then utilized for the second-order ODE to construct the first integrals of the underlying system.We investigate the SIR and HIV models.We obtain two first integrals for the SIR model with and without demographic growth. For the HIV model without demography, five first integrals are established and two first integrals are deduced for the HIV model with demography. Then we utilize the derived first integrals to construct exact solutions
to the models under investigation. The dynamic properties of these models are studied too. Numerical solutions are derived for SIR models by finite difference method and are compared with exact solutions
Isolation of phytohormones producing plant growth promoting rhizobacteria from weeds growing in Khewra salt range, Pakistan and their implication in providing salt tolerance to Glycine max L.
Present investigation was made to isolate and characterize plant growth promoting rhizobacteria (Rkh1 - Rkh4) from rhizosphere of four weeds: Chrysopogon aucheri, Lactuca dissecta, Solanum surratenseand Sonchus arvensis thriving under high salinity (EC: 2.3 dS/m) of Khewra salt range and the results were compared with strain Rak isolated from rhizosphere (EC: 0.2 dS/m) of Solanum surratense grown in arid area of district Attock. The tolerance of all the strains was checked against the salt present in culture media in the form of rhizospheric soil filtrate of weeds collected from Khewra salt range. The nutrient contents of rhizospheric soil of weeds were measured. All the strains were capable to producephytohormones indole-3-acetic acid (IAA), gibberellic acid (GA3), trans-zeatin riboside (t-zr) and abscisic acid (ABA) in the culture media. Inoculation of strains on soybean seedlings treated with or without 20 dS/m NaCl resulted in better growth and higher proline contents than control plants. Thestrains isolated from weeds of Khewra salt range particularly Rkh3 appears more promising for potential biofertilizers in saline fields
Assessment of antibacterial activity of three plants used in Pakistan to cure respiratory diseases
The in vitro antimicrobial activity of Justicia adhatoda, Glycyrrhiza glabra and Hyssopus officinalis extracts were studied against selected bacteria by using agar well diffusion assay. Methanol, ethanol, chloroform, diethyl-ether and aqueous extracts were tested in crude form for antibacterial activity against Bacillus subtillus, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium and Staphylococcus aureus. Maximum antibacterial activity was exhibited by all the three plant extracts. The results obtained with P. aeruginosa were particularly interesting since it was not inhibited by the antibiotic used but the tested plant extracts effectively inhibited the growth of P. aeruginosa. Themethanolic extract of J. adhatoda was effective against S. typhimurium. All the plants extract in water were effective against spore forming of B. subtillus while S. aureus and E. coli were not effectively inhibited by extracts of tested plants. The results of analysis of variance have shown significant differences between the species, treatments and interaction between the species and treatments. However, the differences were non-significant between the treatments for G. glabra. The results indicatethat J. adhatoda, G. glabra and H. officinalis present a noteworthy potential of antibacterial activities
Particulate pollution in urban residential built environments during winter and summer seasons in Lahore, Pakistan
Indoor air pollution in urban residential areas of developing countries is of growing public health concern. The seasonal variation in mass concentration of PM1, PM2.5 and PM10was investigated in a residential built environment in Lahore, Pakistan by two DustTrak aerosol monitor (model 8520, TSI Inc.) during the winter and summer season. The measurements were carried out in the kitchen and living room simultaneously.The 24-hr meanconcentrationsfor PM1, PM2.5 and PM10in the kitchen and living room during the winter season were 157μg/m3 (±54), 733 μg/m3(±243), 409 μg/m3(±177) and 135μg/m3 (±39), 240 μg/m3 (±87), 300 μg/m3 (±115), respectively.During the summer the 24-hr mass concentration, for the same size fraction, in the kitchen and living room fell to 37μg/m3 (±4), 74μg/m3 (±11), 100 μg/m3 (±22) and31μg/m3 (±4), 71 μg/m3 (±19), 190 μg/m3 (±21), respectively. Apart from a higher concentration in winter than summer, a vast variation in 24hr and hourly mean concentration was also observed in the latter than in the former.Moreover background concentrations (hourly minimum) were also higher in winter than summer. These clearly highlight the impact of ventilation on indoor particulate matter as the sampling spaces (kitchen and living room) were more ventilated in summer than winter. The higher concentrationof the coarse size fraction in the living room than in the kitchen during summer time also shows the contribution from outdoor sources. These findings highlightthe impact of location, use and management of a residential built environment on exposure to indoor air pollutants
Effect of Gas Flowrate on Nucleation Mechanism of MWCNTs for a Compound Catalyst
Activation of the catalyst particles during a CVD process can be anticipated from the carbon feeding rate. In this study, Fe2O3/Al2O3 catalyst was synthesized with uniformly dispersed iron over alumina support for onward production of multiwalled carbon nanotubes (MWCNTs) in a fluidized bed chemical CVD reactor. The effect of the ethylene flowrate on catalytic activity of the compound catalyst and morphology of the as-grown MWCNTs was also investigated in this study. The dispersed active phases of the catalyst and optimized gas flowrate helped in improving the tube morphology and prevented the aggregation of the as-grown MWCNTs. The flowrates, below 100 sccm, did not provide sufficient reactants to interact with the catalyst for production of defect-free CNT structures. Above 100 sccm, concentration of the carbon precursor did not show notable influence on decomposition rate of the gas molecules. The most promising results on growth and structural properties of MWCNTs were gained at ethylene flowrate of 100 sccm. At this flowrate, the ratio of G and D intensity peaks (IG/ID) was deliberated about 1.40, which indicates the growth of graphitic structures of MWCNTs
EFFECT OF INDUCED MUTATION FOR VARIETAL IMPROVEMENT IN SOME LOCAL GRAPEVINE CULTIVARS
ABSTRACT Grape is important crop with high nutritional value, however there is a great need for improving the quality of the crop. Cultures were maintained in vitro on MS medium supplemented with 2.5 mg/L BAP+ TDZ 3.0 mg/ L. The effect of different doses of gamma irradiation as well as chemical mutagenesis by Sodium azide was studied. It was noted that doses up to 5 Gy helped to increase plant height from irradiated nodes. At 5 Gy, there was an increase of 4.7, 5 and 4.5 cm in plant height in Desi, Sundar Khani and Chinese varieties of grapes respectively. On further increase in concentration from 6 to 10 Gy, there was a gradual decrease in plant height. Sodium azide was selected to induce mutations in the nodal explants. Nodal explants of the varieties were subjected to different sodium azide concentrations ranging from 0.1 to 0.5%. It was noted that the height of plantlet decreased with an increase in concentration of sodium azide In explants treated with 0.2% sodium azide the plant height was 4 cm which increased to 4.2cm when the explants were treated with 0.3% sodium azide. Further increase in concentration not only caused decreases in length but also led to complete necrosis. In the present study, DNA analysis by RAPD markers was used to analyze mutagenesis. The RAPD analyses indicated that the plantlets subjected to gamma radiation had a great genetic diversity as compared to the control
Evaluation of Antioxidant and Antimicrobial Potential of Two Endangered Plant Species Atropa belladonna and Matricaria chamomilla
Background: Plants are the natural source of antioxidants as well as antimicrobial compounds that has great potentials in pharmaceuticalindustry. In the present study, two medicinal plants Atropa belladonna and Matricaria chamomilla were collected from Northern areas ofPakistan.Materials and Methods: The extracts of the collected plants were obtained by microwave assisted extraction (MAE) with changing parameters, power level and time; methanol and ethanol were solvents used during extraction. The extracts of plants were tested against different bacterialstrains.Results: It was observed that ethanolic extracts of Atropa belladonna has more significant antimicrobial activity against S.aureus than E.coli. Inparallel, methanolic extract of Matricaria chamomilla showed greater significant antibacterial activity against S.aureus when compared withE.coli. In comparison, ethanolic extracts of Matricaria chamomilla has shown more significant results against S. aureus than E.coli (p.0.05).Both plants had no antibacterial activity against S.typhi. The free radical scavenging activity observed by DPPH assay, indicate that both plantshave antioxidant activity at all levels of concentrations in solvent tested during the present work. However, methanolic extracts had greaterantioxidant activity when compared with ethanolic extracts.Conclusion: Present study is thus helpful in highlighting present potentials for antioxidant and antimicrobial properties in the selected plants.Key words: Antimicrobial, antioxidant, Atropa belladonna, Matricaria chamomill
Monetary Policy and Financial Asset Prices: Empirical Evidence From Pakistan
Monetary transmission mechanism assumed to be significantly influenced by the effect of policy decisions on financial markets. However, various previous studies have come up with different outcomes. The purpose of this study is to examine the impact of monetary policy on different asset classes (shares and bonds) in Pakistan. This study using stock price and bond yield as dependent variable and discount rate, money supply, inflation, and exchange rate are independent variables. Data of all variables have collected from 2010 to 2016, and Vector Autoregressive (VAR) technique has applied. The empirical results indicate that there is an impact of monetary policy components on both stock and bond market as an increase in policy rate causes decline in stocks prices and bonds yields. The findings of this study will help the potential investors in making long-term (in general) and short-term (in particular) investment strategies concerning monetary policy.DOI: 10.15408/sjie.v7i2.709
Seed storage protein polymorphism in ten elite rice (Oryza sativa L.) genotypes of Sindh
Seed protein profiling is the most promising tool in determining the molecular polymorphism and genetic homology. Seed storage proteins help in cultivar identification by avoiding the external environmental influences. Electrophoretically detectable proteins in rice grains possess the potential of characterizing the germplasms by their taxonomic and evolutionary aspects. This study was aimed at exploiting the genetic variations among ten elite rice genotypes of Sindh through electrophoretical separation of grain proteins by sodium dodecyl sulphate polyacryamide gel electrophoresis (SDSPAGE). In conclusion, the investigation revealed negligible polymorphism, with reference to the total seed protein profiles, among the rice genotypes of Sindh, Pakistan used in this study. Hence, it is highly important to include a significant number of rice genotypes to explore their existing genotypic diversity for future rice breeding programs. The SDS-PAGE in combination with 2-D electrophoresis is further suggested for documenting contrasting variations of isoforms of protein peptides.Key words: Seed storage proteins, polymorphism, Oryza sativa, Sindh, SDS-PAG
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