Pelagic sharks by-catch in the tuna longline fishery of the Indian EEZ

Several species of pelagic and oceanic sharks are caught by the tuna longliners of FSI while surveying the oceanic tuna resources in the Indian EEZ. Though the sharks are not targeted species in tuna longlining, they constitute a major share of the catches. The sharks hooked could be, therefore, treated as by- catches or incidental catches of the tuna longline fisher

Experimental Characterisation of Moreno Cross Slot Couplers for Blass Matrix Design

This paper presents the experimental characterisation of Moreno cross-slot coupler which is the basic building block of multiple beam forming network (Blass matrix). The lack of exact theory of such coupler requires extensive experimental evaluation. A novel test jig has been designed, fabricated and tested for this purpose. The experimental results for different scattering parameters are presented

Cure kinetics and thermodynamics of polyurethane network formation based on castor oil based polyester polyol and 4,4’-diphenyl methane diisocyanate

336-342In this work, isothermal curing kinetics of a non-catalysed and non-blown reaction between castor oil based polyester polyol and polymeric 4, 4’-diphenyl methane diisocyanate (MDI) has been investigated using Differential Scanning calorimeter (DSC) and viscosity build up studies. Several phenomenological models like Ozawa, Kissinger and Kissinger- Akahira-Sunose (KAS) isoconversional methods has been adopted to study polymerisation kinetics through DSC. DSC cure kinetics is studied at different heating rates (5°C/min, 10°C/min, 15°C/min and 20°C/min). Viscosity build up studies are also done for evaluating the kinetic parameters. These studies have been conducted for an isocyanate index [NCO equivalents/OH equivalents] of 1:1 and 1:2. Dynamic viscosity is measured as a function of time and rate constant and activation energy of the curing system is evaluated. Activation energy obtained for 1:1 index through Ozawa and Kissinger methods is found to be in the range of 70kJ/mol and for 1:2 index it is found to be in the range of 50kJ/mol. Thermodynamic parameters like Gibb’s free energy (Activation Free Energy), activation enthalpy and activation entropy of the polymerisation kinetics is calculated using Wynne-Jones-Eyring-Evans Theory

Designing new thermoreversible gels by molecular tailoring of hydrophilic-hydrophobic interactions

We have shown that the lattice fluid hydrogen bond (LFHB) model can successfully quantify the first-order volume transition in hydrogels. The model predicts that a critical balance of hydrophilic and hydrophobic interactions is required for a gel to exhibit a discontinuous volume transition. In this work we will report the swelling behavior of a new thermoreversible copolymer hydrogel, which has been synthesized from two monomers, whose homopolymers do not show any volume transition in water in the observable range of temperatures. The discontinuous volume transition phenomenon in the copolymer gel was observed only at a critical balance of hydrophilic-hydrophobic interactions. The discontinuous nature of the volume transition is lost with a subtle change in the hydrophilic-hydrophobic balance. The copolymer gel was synthesized from 2-acrylamido 2-methyl propane sulfonic acid (AMPS), which is a hydrophilic monomer, and N-tertiary butylacrylamide (N-t-BAm), which is a hydrophobic monomer. The hydrophilic-hydrophobic balance in the gel was altered by either changing the composition of the co-monomers or by substituting the N-t-BAm with another hydrophobic monomer, N-isopropylacrylamide (NIPAm)

Diurnal variations in the vertical distribution and abundance of zooplankton in the continental shelf waters off Cochin during April 1991

The present study is based on zooplankton samples collected by vertical hauls from 0-30, 30-60 and 60-90 m depths from a 100 m depth station in the continental shelf (09° 44' N, 75° 42*8) off Cochin for two days at three hourly interval. The mean displacement volume of zooplankton biomass at these depth zones were 6.24, 6.70 and 6.07 ml/100 m water while their numerical counts were 14490,13355 and 11290 no/100 m respectively. The overall mean volume (ml) and number per 100 m in the endre water column (0-90 m) were 6.34 and 13045 respectively and were distributed as 5.89 ml and 11715 no/100 m^ in the daytime and 6.79 ml and 14376 no/100 m^ during night hours respectively. The biomass was dominated by copepods (75.6%), decapod larvae (12.2%), chaetognaths (6.5%) and appendicularians (2.4%) in April. In general, copepods, decapod larvae and appendicularians showed increasing trend in number from the bottom (60-90 m) to the surface layer (0-30 m); chaetognaths, medusae, pteropods, heteropods, salps and doliolids were distributed more in the middle zone (30-60 m); while ostracods and planktonic polychaetes were more in the bottom zone (60-90 m). Distribution of amphipods and ostracods indicated significant diurnal vertical migration. The phenomenon of mid- night sinking was noticed in the case of copepods, chaetognaths, appendicularians, medusae, siphonophores, salps and doliolids

Quantitative abundance of amphipods around Andaman-Nicobar Islands

The present study deals with the quantitative distribution and abundance of amphipods of the Andaman Sea in time and space, based on the zooplankton samples collected during the cruises 46- 73 of FORV Sagar Sampada during 1988-1990. Mean number of amphipods (no/1000 m ) reached the maximum of 1763 in January and the minimum of 315 in July. The seasonal density was maximum during the northeast monsoon and minimum for the southwest monsoon and their mean numbers were estimated as 812 and 463/1000 m respectively. In general, they were abundant in the region where the station depths ranged between 50 and 100 m with the mean estimated as 800/1000 m of water. Analysis of day and night samples did not show any remarkable variation. The distribution and abundance of amphipods in relation to time and space are discussed in the paper

Genital ambiguity: a cytogenetic evaluation of gender

Background: Genital ambiguity is a complex genetic disorder of sexual differentiation into male or female. The purpose of the present study is to correlate the sex of rearing with the genetic sex and to find out the prevalence of chromosomal anomalies in patients with ambiguous genitalia. The findings can help in proper diagnosis, genetic counselling, and the reassignment of sex, if necessary.  Methods: In this cross-sectional study, 22 patients from north Kerala, ranging in age from 17 days to 17 years, were included. All cases were subjected to the following: a detailed history, physical examination, evaluation of clinical data, and cytogenetic analysis. Based on the standard protocol, peripheral blood lymphocyte culture was done. Chromosomal analysis was carried out with the help of an automated karyotyping system after G-banding of chromosomes.Results: Out of the 22 patients with ambiguous genitalia, 12 patients were genetic females with karyotype 46, XX, and nine patients were genetic males with 46, XY karyotype. One was a rare variant of Klinefelter syndrome with karyotype 49, XXXXY. The most common diagnosis was congenital adrenal hyperplasia, followed by partial androgen insensitivity syndrome. Discrepancies between genetic sex and sex of rearing were noted in 27% of the cases.Conclusions: This study unfolds the variable etiology of ambiguous genitalia and emphasizes the importance of karyotyping in diagnosis, proper assignment of the sex, and appropriate management of patients with genital ambiguity.

Some observations on the possibilities of culture of the Indian sand whiting Sillago sihama (Forskal) in brackish waters

Indian sand whiting, Sillago sihama (Forskal) forms a dominant species in the estuarine fish catches during the south-west monsoon when they are in great demand and fetch a high price as sea fishing remains suspended due to rough weather conditions. The paper deals with preliminary observations on certain aspects of the biology of the fish related to its culture. The ability of the species to withstand very wide raoges of salinity makes it suitable for culture io both brackish and fresh waters

A STUDY ON THE DISTRIBUTION AND ABUNDANCE OF NORMAL FLORA ON THE HUMAN SKIN AND ITS RELATIONSHIP TO THE USE AND NON-USE OF COSMETICS

The long term use of cosmetics modifies the microbial ecology on the skin surface. The present study quantitatively assayed the microbial flora on female respondents (age group of 18-20 yrs) using and not using cosmetics, plus those who use coconut oil alone on the skin surface. The results showed that the higher number of microbial flora is observed on skin surface of respondents using coconut oil (90.4 x 102 cfu/ 5 cm2 skinarea). The microbial count of respondents using and not using cosmetics were 34.4 x102 and 45.6 x102 cfu, respectively, per 5 cm2 area of skin surface. Cosmetics (C1 to C6) were assayed for antibacterial activity where C1, C2, C3, C4 and C6 were resistant to the three species of test bacteria namely Staphylococcus aureus, Coagulase negative Staphylococcus and E. coli. The sample C5 exhibited a low level of antibacterial activity against E. coli with a diameter of zone of growth inhibition of 9 mm. An assay carried out for a period of six months to compare the modifying effect of cosmetics on skin microflora of a respondent whose left hand was applied with a body lotion (C7) and her right hand not applied with any topical applicants. There was reduction in the number of microflora on the left hand with an average count of 13.3 x 102 cfu/ 5 cm2 area on the skin surface, than on the right hand with an average count of 22.6 x 102 cfu/ 5 cm2 area on the skin surface