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Daisy A.,Tamil Nadu Agricultural University | Kamaraj S.,TamilNadu Agricultural University
Journal of Microbial and Biochemical Technology | Year: 2011

With the aim of improving knowledge about the stability and reliability of anaerobic night soil treatment systems, several researchers have studied the effects of different digester design and operational performance of such digester. In general, anaerobic digesters are affected by changes in external factors, but the severity of the effect is dependent upon the type, magnitude, duration and frequency of the imposed changes. Special attention is paid to the advantages of anaerobic digestion in limiting the emission of greenhouse gases This review summarises the causes, generation rate of night soil, composition of slurry, pathogen and its harmful effects and effects of operation in different digester on anaerobic night soil treatment systems. However, there still remain some unclear technical and scientific aspects that are necessary for the improvement of the stability and reliability of anaerobic processes. An overview of research achievements and future developments is given. © 2011 Daisy A, et al. Source

Shanmugam S.,TamilNadu Agricultural University | Kjaer K.H.,University of Aarhus | Ottosen C.-O.,University of Aarhus | Rosenqvist E.,Copenhagen University | And 2 more authors.
Journal of Agronomy and Crop Science | Year: 2013

This study analysed the alleviating effect of elevated CO2 on stress-induced decreases in photosynthesis and changes in carbohydrate metabolism in two wheat cultivars (Triticum aestivum L.) of different origin. The plants were grown in ambient (400 μl l-1) and elevated (800 μl l-1) CO2 with a day/night temperature of 15/10 °C. At the growth stages of tillering, booting and anthesis, the plants were subjected to heat stress of 40 °C for three continuous days. Photosynthetic parameters, maximum quantum efficiency of photosystem II (PSII) photochemistry (Fv/Fm) and contents of pigments and carbohydrates in leaves were analysed before and during the stress treatments as well as after 1 day of recovery. Heat stress reduced PN and Fv/Fm in both wheat cultivars, but plants grown in elevated CO2 maintained higher PN and Fv/Fm in comparison with plants grown in ambient CO2. Heat stress reduced leaf chlorophyll contents and increased leaf sucrose contents in both cultivars grown at ambient and elevated CO2. The content of hexoses in the leaves increased mainly in the tolerant cultivar in response to the combination of elevated CO2 and heat stress. The results show that heat stress tolerance in wheat is related to cultivar origin, the phenological stage of the plants and can be alleviated by elevated CO2. This confirms the complex interrelation between environmental factors and genotypic traits that influence crop performance under various climatic stresses. © 2013 Blackwell Verlag GmbH. Source

Swamy G.J.,Kongu Engineering College | Sangamithra A.,Kongu Engineering College | Chandrasekar V.,TamilNadu Agricultural University
Dyes and Pigments | Year: 2014

The aim of the study was to investigate the influence of independent process variables like extraction temperature, time and mass of beetroot on the aqueous extraction of betalain from beetroot. The optimum conditions for the aqueous extraction of betalamic acid, betaxanthin and betacyanin from beetroot were performed using a three-factor and three-level Box-Behnken design under response surface methodology. The pigments were extracted from beetroot at temperature (40-70 °C), time (30-90 min) and mass of beetroot (0.5-1.5 g) using water as solvent. The data obtained from the experiments were analyzed by Pareto analysis of variance. Further, the data was fitted to a second-order polynomial equation using multiple regression analysis. The optimal conditions based on both individual and combinations of all responses (extraction temperature - 60°C, time - 84 min and mass - 1.5 g) were found out. At this optimum condition, the total betalamic acid, betaxanthin and betacyanin content were found to be 9.9 mg/100 g, 16.3 mg/100 g and 30.9 mg/100 g with desirability value of 0.999. The experimental values closely agreed with the corresponding predicted values. © 2014 Elsevier Ltd. All rights reserved. Source

Manimaran P.,Directorate of Rice Research | Ramkumar G.,Directorate of Rice Research | Sakthivel K.,TamilNadu Agricultural University | Sundaram R.M.,Directorate of Rice Research | And 2 more authors.
Biotechnology Advances | Year: 2011

Genetically modified crops are one of the prudent options for enhancing the production and productivity of crop plants by safeguarding from the losses due to biotic and abiotic stresses. Agrobacterium-mediated and biolistic transformation methods are used to develop transgenic crop plants in which selectable marker genes (SMG) are generally deployed to identify 'true' transformants. The commonly used SMG obtained from prokaryotic sources when employed in transgenic plants pose risks due to their lethal nature during selection process. In the recent past, some non-lethal SMGs have been identified and used for selection of transformants with increased precision and high selection efficiency. Considering the concerns related to bio-safety of the environment, it is desirable to remove the SMG in order to maximize the commercial success through wide adoption and public acceptance of genetically modified (GM) food crops. In this review, we examine the availability, and the suitability of wide range of non-lethal selection markers and elimination of SMG methods to develop marker-free transgenics for achieving global food security. As the strategies for marker-free plants are still in proof-of-concept stage, adaptation of new genomics tools for identification of novel non-lethal marker systems and its application for developing marker-free transgenics would further strengthen the crop improvement program. © 2011 Elsevier Inc. Source

Ramasamy S.,Madurai Kamaraj University | Velmurugan G.,Madurai Kamaraj University | Rajan K.S.,Madurai Kamaraj University | Ramprasath T.,University of Alberta | Kalpana K.,TamilNadu Agricultural University
PLoS ONE | Year: 2015

Physiological cardiac hypertrophy is an adaptive mechanism, induced during chronic exercise. As it is reversible and not associated with cardiomyocyte death, it is considered as a natural tactic to prevent cardiac dysfunction and failure. Though, different studies revealed the importance of microRNAs (miRNAs) in pathological hypertrophy, their role during physiological hypertrophy is largely unexplored. Hence, this study is aimed at revealing the global expression profile of miRNAs during physiological cardiac hypertrophy. Chronic swimming protocol continuously for eight weeks resulted in induction of physiological hypertrophy in rats and histopathology revealed the absence of tissue damage, apoptosis or fibrosis. Subsequently, the total RNA was isolated and small RNA sequencing was executed. Analysis of small RNA reads revealed the differential expression of a large set of miRNAs during physiological hypertrophy. The expression profile of the significantly differentially expressed miRNAs was validated by qPCR. In silico prediction of target genes by miRanda, miRdB and TargetScan and subsequent qPCR analysis unraveled that miRNAs including miR-99b, miR-100, miR-19b, miR-10, miR-208a, miR-133, miR-191a, miR-22, miR-30e and miR-181a are targeting the genes that primarily regulate cell proliferation and cell death. Gene ontology and pathway mapping showed that the differentially expressed miRNAs and their target genes were mapped to apoptosis and cell death pathways principally via PI3K/Akt/mTOR and MAPK signaling. In summary, our data indicates that regulation of these miRNAs with apoptosis regulating potential can be one of the major key factors in determining pathological or physiological hypertrophy by controlling fibrosis, apoptosis and cell death mechanisms. © 2015 Ramasamy et al. Source

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