Investigations on the cation induced liquid crystalline phases of high molecular weight DNA

Liquid Crystalline DNA is emerging as an active area of research, due to its potential applications in diverse fields, ranging from nanoelectronics to therapeutics. Since, counter ion neutralization is an essential requirement for the expression of LC DNA, and the present level of understanding on the LC phase behavior of high molecular weight DNA is inadequate, a thorough investigation is required to understand the nature and stability of these phases under the influence of various cationic species. The present study is, therefore mainly focused on a comparative investigation of the effect of metal ions of varying charge, size, hydration and binding modes on the LC phase behavior of high molecular weight DNA. The main objectives of the works are investigations on the induction and stabilization of LC phases of high molecular weight DNA by alkali metal ions, investigations on the induction and stabilization of LC phases of high molecular weight DNA by alkaline earth metal ions, effects of multivalent, transition and heavy metal ions on the LC phase behavior of high molecular weight DNA and investigations on spermine induced LC behavior of high molecular weight DNA in the presence of alkali and alkaline earth metal ions. The critical DNA concentration (CD) required for the expression of LC phases, phase transitions and their stability varied considerably when the binding site of the metal ions changed from phosphate groups to the nitrogenous bases of DNA, with Li+ giving the highest stability. Multiple LC phases with different textures, sometimes diffused and unstable or otherwise mainly distinct and clear, were observed on mixing metal ions with DNA solutions, which in turn depended on the charge, size, hydration factor, binding modes, concentration of the metal ions and time. Molecular modeling studies on binding of selected metal ions to DNA supported the experimental findings

Studies on the Deep - Water Crab Charybdis (Goniohellenus ) Smithii Macleay From the Seas Around India

The present study deals with a general introduction which outlines the objective of the study providing an exhaustive review of works on crabs with particular reference to deep-sea forms. In the first section, Taxonomy and Geographical disribution of the crab are dealt with. The species is described in detail based on several male and female specimens obtained from the pelagic and bottom collections, and its identity in Indian waters is established. It is also distinguished from a closely allied species so far not reported from Indian waters. The second section comprises the biology of the species and it is dealt with under four subheading, namely Habit and Habitats, Reproduction, Food and feeding and Proximate composition. The different habitats occupied by juveniles, subadults and adults of the species have been described and discussed in the light of available information on differential distribution of other related species. The reproductive biology is described in various details touching on gross anatomy and histology of the reproductive systems, spermatogenesis, oogenesis, size at maturity, ovarian maturation process, fecundity, egg carriage and breeding. The food and feeding habits of the species have been studied with reference to the different life stages such as juveniles, subadults and adults during the different phases of life based on stomach content analysis. The percentage of meat recovery and protein, carbohydrate and lipid content of meat have been described in the section dealing with proximate composition. In section three the distribution and abundance of the crab for the entire Indian EEZ and some contiguous ares have been described and illustrated in detail separately for pelagic and benthic realms. The size frequency disrtibution, sex ratios, length weight relationship and relative abundance of breeding population in the experimental catches have been dealt with in detail and discussed.

Studies on Methylene Blue Sensitized Poly(Vinyl Alcohol): Effect of Molecular Weight of the Polymer and Crosslinking Agents on its Holographic Properties

Dept.of Polymer Science and Rubber Technology,Cochin University of Science and Technology

Probiotic effect of Bacillus NL110 and Vibrio NE17 on the survival, growth performance and immune response of Macrobrachium rosenbergii (de Man)

Eight hundred and eighty-¢ve strains of bacterial isolates fromvarious samples associatedwith the natural habitat ofMacrobrachiumrosenbergii were screened for their probiotic potential. Two putative probionts namely Bacillus NL110 and Vibrio NE17 isolated from the larvae and egg samples, respectively, were selected for experimental studies and were introduced to the juveniles of M. rosenbergii (0.080 0.001g) through di¡erent modes such as through feed, water and both. The probiotic potential of the above bacteria in terms of improvements inwater quality, growth, survival, speci¢c growth rate (SGR), feed conversion ratio and immune parameters was evaluated. The treatment groups showed a signi¢cant improvement in SGR and weight gain (Po0.001). Survival among di¡erent treatment groups was better than that in the control group. There were also signi¢cant improvements in the water quality parameters such as the concentration of nitrate and ammonia in the treatment groups (Po0.05). Improvements in immune parameters such as the total haemocyte count (Po0.05), phenoloxidase activity and respiratory burst were also signi¢cant (Po0.001). It is concluded that screening of the natural micro£ora of cultured ¢sh and shell¢sh for putative probionts might yield probiotic strains of bacteria that could be utilized for an environment-friendly and organic mode of aquaculture.

Probiotic effect of Bacillus NL110 and Vibrio NE17 on the survival, growth performance and immune response of Macrobrachium rosenbergii (de Man)

Eight hundred and eighty-¢ve strains of bacterial isolates fromvarious samples associatedwith the natural habitat ofMacrobrachiumrosenbergii were screened for their probiotic potential. Two putative probionts namely Bacillus NL110 and Vibrio NE17 isolated from the larvae and egg samples, respectively, were selected for experimental studies and were introduced to the juveniles of M. rosenbergii (0.080 0.001g) through di¡erent modes such as through feed, water and both. The probiotic potential of the above bacteria in terms of improvements inwater quality, growth, survival, speci¢c growth rate (SGR), feed conversion ratio and immune parameters was evaluated. The treatment groups showed a signi¢cant improvement in SGR and weight gain (Po0.001). Survival among di¡erent treatment groups was better than that in the control group. There were also signi¢cant improvements in the water quality parameters such as the concentration of nitrate and ammonia in the treatment groups (Po0.05). Improvements in immune parameters such as the total haemocyte count (Po0.05), phenoloxidase activity and respiratory burst were also signi¢cant (Po0.001). It is concluded that screening of the natural micro£ora of cultured ¢sh and shell¢sh for putative probionts might yield probiotic strains of bacteria that could be utilized for an environment-friendly and organic mode of aquaculture

Prevalence and antimicrobial resistance of Salmonella enteritidis and other salmonellas in the eggs and egg-storing trays from retails markets of Coimbatore, South India

A study was conducted to determine the incidence of Salmonella enterica serovar Enteritidis and other Salmonella serovars on eggshell, egg contents and on egg-storing trays. A total of 492 eggs and 82 egg-storing trays were examined over a period of 1 year from different retail outlets of a residential area of Coimbatore city, South India. Salmonella contamination was recorded in 38 of 492 (7.7%) eggs out of which 29 was in eggshell (5.9%) and 9 in egg contents (1.8%). Around 7.5% of the egg-storing trays were also found to be contaminated with Salmonella. Serotyping of the Salmonella strains showed that 89.7% of the strains from eggshell, 100% of the strains from egg contents and 71.4% of the strains from egg-storing trays were Salmonella Enteritidis. Other serovarvars encountered were S. Cerro, S. Molade and S. Mbandaka from eggshell and S. Cerro from egg-storing trays. Seasonal variations in the prevalence pattern were identified with, a higher prevalence during monsoon months followed by post-monsoon and premonsoon. Further examination of the Salmonella strains was carried out by testing their antimicrobial sensitivity against 10 commonly used antimicrobials. Results revealed high prevalence of multiple antimicrobial resistance among these strains suggesting possible prior selection by use of antimicrobials in egg production

Prevalence and antimicrobial resistance of Salmonella enteritidis and other salmonellas in the eggs and egg-storing trays from retails markets of Coimbatore, South India

A study was conducted to determine the incidence of Salmonella enterica serovar Enteritidis and other Salmonella serovars on eggshell, egg contents and on egg-storing trays. A total of 492 eggs and 82 egg-storing trays were examined over a period of 1 year from different retail outlets of a residential area of Coimbatore city, South India. Salmonella contamination was recorded in 38 of 492 (7.7%) eggs out of which 29 was in eggshell (5.9%) and 9 in egg contents (1.8%). Around 7.5% of the egg-storing trays were also found to be contaminated with Salmonella. Serotyping of the Salmonella strains showed that 89.7% of the strains from eggshell, 100% of the strains from egg contents and 71.4% of the strains from egg-storing trays were Salmonella Enteritidis. Other serovarvars encountered were S. Cerro, S. Molade and S. Mbandaka from eggshell and S. Cerro from egg-storing trays. Seasonal variations in the prevalence pattern were identified with, a higher prevalence during monsoon months followed by post-monsoon and premonsoon. Further examination of the Salmonella strains was carried out by testing their antimicrobial sensitivity against 10 commonly used antimicrobials. Results revealed high prevalence of multiple antimicrobial resistance among these strains suggesting possible prior selection by use of antimicrobials in egg production

Length-weight relationship, relative condition factor (Kn) and morphometry of Arius subrostratus (Valenciennes, 1840) from a coastal wetland in Kerala

The length – weight relationship and relative condition factor of the shovel nose catfish, Arius subrostratus (Valenciennes, 1840) from Champakkara backwater were studied by examination of 392 specimens collected during June to September 2008. These fishes ranged from 6 to 29 cm in total length and 5.6 to 218 g in weight. The relation between the total length and weight of Arius subrostratus is described as Log W = -1.530+2.6224 log L for males, Log W = - 2.131 + 3.0914 log L for females and Log W = - 1.742 + 2.8067 log L for sexes combined. The mean relative condition factor (Kn) values ranged from 0.75 to 1.07 for males, 0.944 to 1.407 for females and 0.96 to 1.196 for combined sexes. The length-weight relationship and relative condition factor showed that the well-being of A. subrostratus is good. The morphometric measurements of various body parts and meristic counts were recorded. The morphometric measurements were found to be non-linear and there is no significant difference observed between the two sexes. From the present investigation, the fin formula can be written as D: I, 7; P: I, 12; A: 17 – 20; C: 26 – 32. There is no change in meristic counts with the increase in body length.

Studies on Selected Myctophid Fishes in Arabian Sea with respect to their Status in Deep Sea Trawl Bycatch, Length-Weight Relationship, Reproductive Biology and Population Dynamics

Available information on abundance of myctophids and their utilisation indicate that there is excellent scope for development of myctophid fisheries in Indian Ocean. Most of the conventional fish stocks have reached a state of full exploitation or over-exploitation. Hence there is need to locate new and conventional fishery resources in order to fill in the supply-demand gap, in the face of increasing demand for fish. Information on length-weight relationship, age and growth, spawning season, fecundity and age at maturity and information on bycatch discards are required for sustainable utilization of myctophid resource in the Indian Ocean