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Ashesh Nandy 《PloS one》2009,4(8)
DNA sequences seen in the normal character-based representation appear to have a formidable mixing of the four nucleotides without any apparent order. Nucleotide frequencies and distributions in the sequences have been studied extensively, since the simple rule given by Chargaff almost a century ago that equates the total number of purines to the pyrimidines in a duplex DNA sequence. While it is difficult to trace any relationship between the bases from studies in the character representation of a DNA sequence, graphical representations may provide a clue. These novel representations of DNA sequences have been useful in providing an overview of base distribution and composition of the sequences and providing insights into many hidden structures. We report here our observation based on a graphical representation that the intra-purine and intra-pyrimidine differences in sequences of conserved genes generally follow a quadratic distribution relationship and show that this may have arisen from mutations in the sequences over evolutionary time scales. From this hitherto undescribed relationship for the gene sequences considered in this report we hypothesize that such relationships may be characteristic of these sequences and therefore could become a barrier to large scale sequence alterations that override such characteristics, perhaps through some monitoring process inbuilt in the DNA sequences. Such relationship also raises the possibility of intron sequences playing an important role in maintaining the characteristics and could be indicative of possible intron-late phenomena. 相似文献
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Leander A. H. Petersen Christian Lieven Subir K. Nandy John Villadsen Sten B. Jørgensen Ib Christensen Krist V. Gernaey 《Biotechnology and bioengineering》2019,116(11):2884-2895
The methanotrophic bacterium Methylococcus capsulatus is capable of assimilating methane and oxygen into protein-rich biomass, however, the diverse metabolism of the microorganism also allows for several undesired cometabolic side-reactions to occur. In this study, the ammonia cometabolism in Methylococcus capsulatus is investigated using pulse experiments. Surprisingly Methylococcus capsulatus oxidizes ammonia to nitrate through a yet unknown mechanism and fixes molecular nitrogen even at a high dissolved oxygen tension. The observed phenomena can be modeled using 14 ordinary differential equations and 18 kinetic parameters, of which 6 were revealed by Morris screening to be identifiable from the experimental data. Monte Carlo simulations showed that the model was robust and accurate even with uncertainty in the parameter values as confirmed by statistical error analysis. 相似文献
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Photosynthesis and antioxidative enzyme activities in five Indian mangroves with respect to their adaptability 总被引:1,自引:0,他引:1
Five typical mangroves were taken (Bruguiera gymnorrhiza, Excoecaria agallocha, Heritiera fomes, Phoenix paludosa and Xylocarpus granatum) both from Sundarbans (in situ) and grown in a mesophytic environment (ex situ, in the Institute’s premises) for 12–15 years.
A comparative account of PAR utilization for maximum photosynthesis, stomatal conductance and production of two antioxidant
enzymes (peroxidase and Superoxide dismutase) were done between the in situ and ex situ habitats. The present work revealed
that the average net photosynthesis was slightly higher in mangroves from non-saline habitats than that of the native ones.
At the same time, stomatal conductances were remarkably reduced under salinity-stressed habitats when compared with those
of the mesophytic counterparts, by 25–52%. Salinity imposed increase of antioxidant enzymes was observed. Both the investigated
antioxidant enzymes showed considerable increase in saline-grown individuals and proved their efficient scavenging ability
to evolve reactive oxygen species (ROS), but these increases were relatively lower in Heritiera and Xylocarpus even though the net photosynthesis was higher. This might be related to their lower adaptability under increased salinity
stress than those of the other three species investigated. 相似文献
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Novotnik Breda Nandy Arpita Venkatesan Senthil Velan Radović Jagoš R. Fuente Juan De la Nejadi Siavash Silva Renzo C. Kouris Angela Thangadurai Venkataraman Bryant Steven Karan Kunal Shor Roman Strous Marc Larter Stephen R. 《Reviews in Environmental Science and Biotechnology》2020,19(1):217-240
Reviews in Environmental Science and Bio/Technology - The world’s energy system is still dominated by fossil fuels. While there is a rapid reduction in the cost of renewable energy and the... 相似文献
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Bandyopadhyay Arindam Garai Saraswati Banerjee Prajna Paramita Bhattacharya Shelley Chattopadhyay Ansuman 《Molecular biology reports》2021,48(3):2497-2505
Molecular Biology Reports - Globally, breast cancer is a serious concern that exhibits a persistent rise in its incidence and related mortality even after significant advancement in the field of... 相似文献
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Mayukh Das Tushar Suvra Bhowmick Ranjan K. Nandy Gopinath B. Nair & Banwarilal L. Sarkar 《FEMS microbiology ecology》2009,67(3):502-510
Cholera is a public health threat in all developing countries. Kolkata, a city in eastern India, is an endemic zone for cholera. During the course of a comprehensive investigation on the distribution of phages of Vibrio cholerae O1 and O139 in freshwater bodies in Kolkata, we were able to isolate the phages of V. cholerae O1 and O139. Vibrio cholerae O1 phages were found at all the sites and exhibited a distinct seasonal cycle, with a primary peak (13.6–17.2 PFU mL−1 ) during monsoon (June to August) in both 2006 and 2007. Vibrio cholerae O139 phages were present in the environment and were predominant during monsoon in the year 2006, except for late winter and early summer from February to April. In contrast, in the year 2007, the O139 phages could be isolated only during July to December, with the highest counts of 12.0 PFU mL−1 determined in August. The multiplex PCR results showed that 90 samples were positive for wbe of V. cholerae O1, 32 samples for O139 ( wbf ) and 18 samples for both. This study shows that surveillance of vibriophages indicates the presence of V. cholerae O1 and O139 in water bodies in and around Kolkata and could therefore serve as a powerful biomonitoring agent. 相似文献