302 research outputs found
A Short Review on the Development of Salt Tolerant Cultivars in Rice
Rice is staple food for half of the world. With a population of almost 9.6 billion by the year 2050, there is a dire need of developing techniques to improve the crop plants, not only in terms of better yield but also to withstand harsh environmental conditions and stresses like drought, temperature, flood and salinity. Salinity is second to drought stress and hence it is very important to develop crops tolerant to salinity stress. This review discusses the mechanisms of salt tolerance and the recent developments in understanding the complex tolerance phenomena. One way to address the salinity issue is to develop tolerant rice varieties using conventional and modern breeding techniques for which screening the rice germplasm for the varieties with desired traits is critical. Conventional methods to develop tolerant rice varieties are discussed along with modern biotechnology techniques are also discussed. Quantitative Trait Loci (QTL) and Marker Assisted Selection (MAS) are promising techniques. In addition to these modern techniques, some recent developments in the fields of transgenic plants, haploid breeding and Somaclonal variations have also been discussed. The limited knowledge about molecular and genetic mechanisms to tolerate abiotic stresses, however is a barrier to efficiently develop tolerant cultivars. A combination of conventional and modern biotechnology techniques could possibly open up the new ways
Paper Session II-C - Satellite Remote Sensing for Environment and Resource Managment
In the recent years there have been valuable achievements in data pre-processing r image processing and interpretation and other related techniques. These developments in the field of satellite remote sensing have resulted in much more useful studies of environment and resource management. We present a review of some of such studies with emphasis on different land use /landcover features in some urban areas of Pakistan. These studies were made using SPOT multispectral and panchromatic data. Our analysis will be found useful for updating information of different urban features. In the end we present our future programs regarding the resource management and environment using earth resource satellites like LANDSAT and SPOT
Morphological Characterization of Malaysian Wild Banana Musa Acuminata
Fourteen populations of Musa acuminata ranging from populations in the lowlands of northern (ssp. siamea) to central Malaysian region (ssp. malaccensis) and highland banana (ssp. truncata) were characterized based on chromosome number and 46 morphological characters. A large amount of variation was observed within the populations. However, only highland bananas appeared morphologically distinct. Lowland populations both from northern and central Malaysia were found to be overlapping and no distinguishing pattern was observed. The morphological characters found variable within these populations were related to developmental changes and mutations. The results obtained in this study were not revolutionary. However, the survey of a large number of characters treated with multivariate techniques further sharpened the existing groupings of the Musa acuminata subspecies
Characterization of Malaysian Wild Bananas Based on Anthocyanins
The male buds of 16 Musa species (Musaceae) populations were investigated by HPLC for the occurrence of anthocyanins. The investigation was based on the presence of 6 anthocyanins. The 16 Musa samples could be classified into three distinct species i.e. Musa acuminata, Musa violascens and Musa balbisiana. Musa acuminata could be divided into two subspecies : malaccensis (lowland) and tmncata (highland) according to their constituents and content of major anthocyanins. No variation was observed in the composition of the anthocyanins of Kedah type ssp. siamea and Selangor types ssp. malaccensis. The classification of M. acuminata into two subspecies based on anthocyanin data further supported the current taxonomic grouping of the species
Investigation of the cardiac depressant effect of Caralluma tuberculate N.E.Br on isolated rabbit heart
Purpose: To investigate the histopathological and cardiac depressant effect of the aqueous methanol extract of Caralluma tuberculata N.E. Br (AMECT) (family: Asclepiadaceae)’ and to determine if there is a scientific basis for its cardiovascular diseases-related folkloric use.
Methods: The effect of AMECT in different concentrations ranging from 0.00001 to 1.0 mg/mL were evaluated in isolated perfused rabbit heart to assess their effect on the force of contraction and heart rate using Langendorff’s apparatus. Atropine and adrenaline were used to identify the underlying mechanism of response produced by AMECT. The extract was studied for its possible mechanism in the absence and presence of atropine and adrenaline. In addition, sub-chronic toxicity and histopathological study of heart tissues in rats were assessed by administering 500 mg/kg of extract.
Results: At all concentrations, AMECT produced significant (p < 0.001) negative ionotropic and negative chronotropic effects. The most significant effect was observed at 0.001 mg/mL and higher concentrations hence 0.001 mg/mL was selected for further studies. Pre-incubation with atropine did not significantly inhibit the effects of AMECT. However, AMECT significantly (p < 0.01) blocked the cardiac stimulant effect of adrenaline. In the histopathological studies, AMECT did not produce any significant cellular changes or signs of toxicity in the sub-chronic toxicity study.
Conclusion: The cardiac-depressant responses of AMECT may involve the β-adrenergic receptors in the myocardium of isolated rabbit heart thus confirming the rationale for its use in ethnomedicine for cardiac diseases
Iron-modified biochar improves plant physiology, soil nutritional status and mitigates Pb and Cd-hazard in wheat (Triticum aestivum L.)
Environmental quality and food safety is threatened by contamination of lead (Pb) and cadmium (Cd) heavy metals in agricultural soils. Therefore, it is necessary to develop effective techniques for remediation of such soils. In this study, we prepared iron-modified biochar (Fe-BC) which combines the unique characteristics of pristine biochar (BC) and iron. The current study investigated the effect of pristine and iron modified biochar (Fe-BC) on the nutritional values of soil and on the reduction of Pb and Cd toxicity in wheat plants (Triticum aestivum L.). The findings of present study exhibited that 2% Fe-BC treatments significantly increased the dry weights of roots, shoots, husk and grains by 148.2, 53.2, 64.2 and 148%, respectively compared to control plants. The 2% Fe-BC treatment also enhanced photosynthesis rate, transpiration rate, stomatal conductance, intercellular CO2, chlorophyll a and b contents, by 43.2, 88.4, 24.9, 32.5, 21.4, and 26.7%, respectively. Moreover, 2% Fe-BC treatment suppressed the oxidative stress in wheat plants by increasing superoxide dismutase (SOD) and catalase (CAT) by 62.4 and 69.2%, respectively. The results showed that 2% Fe-BC treatment significantly lowered Cd levels in wheat roots, shoots, husk, and grains by 23.7, 44.5, 33.2, and 76.3%. Whereas, Pb concentrations in wheat roots, shoots, husk, and grains decreased by 46.4, 49.4, 53.6, and 68.3%, respectively. Post-harvest soil analysis showed that soil treatment with 2% Fe-BC increased soil urease, CAT and acid phosphatase enzyme activities by 48.4, 74.4 and 117.3%, respectively. Similarly, 2% Fe-BC treatment significantly improved nutrients availability in the soil as the available N, P, K, and Fe contents increased by 22, 25, 7.3, and 13.3%, respectively. Fe-BC is a viable solution for the remediation of hazardous Cd and Pb contaminated soils, and improvement of soil fertility status
Disposition Kinetics and Optimal Dosage of Ciprofloxacin in Healthy Domestic Ruminant Species
The purpose of this experimental study was to determine the disposition kinetics and optimal dosages of ciprofloxacin in healthy domestic ruminant species including adult female buffalo, cow, sheep and goat. The drug was given as a single intramuscular dose of 5 mg/kg. The plasma concentrations of the drug were determined with HPLC and pharmacokinetic variables were determined. The biological half-life (t1/2 β was longer in cows (3.25 ± 0.46 h) followed by intermediate values in buffaloes (3.05 ± 0.20 h) and sheep (2.93 ± 0.45 h) and shorter in goats (2.62 ± 0.39 h). The volume of distribution (Vd) in buffaloes was 1.09 ± 0.06 l/kg, cows 1.24 ± 0.16 l/kg, sheep 2.89 ± 0.30 l/kg and goats 3.76 ± 0.92 l/kg. Total body clearance (ClB) expressed in l/h/kg was minimum in buffaloes 0.25 ± 0.02 followed by values in cows 0.31 ± 0.02 and sheep 0.75 ± 0.04 and maximum in goats 1.09 ± 0.11. An optimal dosage regimen for 12-h interval consisted of 5.17, 5.62, 6.54 and 6.10 mg/kg body weight as priming and 4.84, 5.37, 6.26 and 5.91 mg/kg body weight as maintenance intramuscular dose in buffalo, cow, sheep and goat, respectively. The manufacturers of ciprofloxacin have claimed 5 mg/kg dose to be repeated after 24 h. However, the investigated dosage regimen may be repeated after 12 h to maintain MIC at the end of the dosage interval. Therefore, it is imperative that an optimal dosage regimen be based on the disposition kinetics data determined in the species and environment in which a drug is to be employed clinically
Synergistic effects of activated carbon and nano-zerovalent copper on the performance of hydroxyapatite-alginate beads for the removal of As\u3csup\u3e3+\u3c/sup\u3e from aqueous solution
© 2019 Elsevier Ltd In this study, activated carbon (AC) and nano-zerovalent copper (nZVCu) functionalized hydroxyapatite (HA) and alginate beads were synthesized and used for the removal of As3+ from aqueous solution. The characterization by X-ray diffraction, scanning electron microscopy, X-ray energy dispersive spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, high resolution transmission electron microscopy, BET surface area analysis, thermogravimetric analysis, and Fourier transform infrared spectroscopy revealed successful formation of the AC/nZVCu/HA-alginate, nZVCu/HA-alginate, AC/HA-alginate, and HA-alginate beads. The scanning electron microscopy and surface analysis revealed the prepared beads to be highly mesoporous which led to the maximum adsorption of As3+, i.e., 13.97, 29.33, 30.96, and 39.06 mg/g by HA-alginate, AC/HA-alginate, nZVCu/HA-alginate, and AC/nZVCu/HA-alginate beads, respectively. The thermogravimteric analysis showed the nZVCu/HA-alginate beads to be highly stable while the AC composite beads as the least stable to heat treatment. The HA-alginate beads achieved 39% removal of As3+, however, removal efficiency was promoted to 95% by coupling AC and nZVCu with HA-alginate beads at a reaction time of 120 min. The removal of As3+ by the prepared AC & nZVCu coupled HA-alginate beads was promoted with increasing [As3+]0 and [AC/nZVCu/HA-alginate]0. The pH of aqueous solution significantly influenced the removal of As3+ by AC/nZVCu/HA-alginate beads and maximum removal was achieved at pH 5.8. Freundlich adsorption isotherm and pseudo-second-order kinetic models were found to best fit the removal of As3+ by the synthesized beads. The high performance of AC/nZVCu/HA-alginate beads in the removal of As3+ even after seven cyclic treatment as well as least leaching of Cu ions into aqueous solution suggest enhanced reusability and stability of HA-alginate beads by coupling with AC and nZVCu. The results suggest that the synthesized beads have good potential for the removal of As3+ from aqueous solutions
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