On some elastic instabilities in biaxial nematics

Within the framework of the continuum elastic theory of biaxial nematic liquid crystals, we have addressed ourselves to the structure, stability and energetics of some singular and non-singular topological defects, and certain director configurations. We find that certain non-singular hybrid disclinations could be energetically favourable relative to certain half-strength disclinations. The interaction between singular hybrids depends strongly on the biaxial elastic anisotropy. We suggest possible defect structures that can exist in spherical droplets of biaxial nematics. Further we find structural instabilities, in confined geometries, arising due to the inherent biaxiality of the system

Shrimp farming by private enterprise- A case study

In view of the encouraging results shown by the research organisations of India and other countries in prawn culture on scientific methods, a commercial research and development project on prawn culture was established by the TATA Oil Mills Co. Ltd., at Pulicat. Experiments were conducted in aarthern ponds of size ranging from 0.4 to 1.25 ha- Stocking rates ranging from 6.5 to 15 prawns/mz were attempted and production to the tune of 0.5 to 1.0 tonne/ha/crop was achieved. Survival rate over 80% could be maintained in all the crops. An artificial feed formulated with shrimp meal, trash fish and vitamin mineral mix along with other usual ingredients, with a protein content of 40%, proved to be better than the other conventional feed. Effect of design of a pond, aging of pond, stocking density, stocking size and various hydrobioiogical parameters viz. salinity, dissolved oxygen and pH were also studied. The intensive stocking rate, the successful feed formula and the effective water managements adopted were the important reasons for the successful production of shrimps in this farm. The cost of production of 1 kg of shrimps considering the variable cost, varied from Ks 20.00 to 34.00 and thus a net revenue of Rg. 8000.00 to 20,000.00/ha/crop was achieved

Mean first passage times for bond formation for a Brownian particle in linear shear flow above a wall

Motivated by cell adhesion in hydrodynamic flow, here we study bond formation between a spherical Brownian particle in linear shear flow carrying receptors for ligands covering the boundary wall. We derive the appropriate Langevin equation which includes multiplicative noise due to position-dependent mobility functions resulting from the Stokes equation. We present a numerical scheme which allows to simulate it with high accuracy for all model parameters, including shear rate and three parameters describing receptor geometry (distance, size and height of the receptor patches). In the case of homogeneous coating, the mean first passage time problem can be solved exactly. In the case of position-resolved receptor-ligand binding, we identify different scaling regimes and discuss their biological relevance.Comment: final version after minor revision

Serum vitamin D decreases during chemotherapy: an Australian prospective cohort study

Background and Objectives: Vitamin D plays an important role in bone and muscle function, and cell prolifera-tion. The impact of chemotherapy and associated behavioural changes such as fatigue and sun avoidance on vit-amin D (25(OH) D) is unknown. This study aims to evaluate variations in serum vitamin D during chemotherapy and the predictive value of latitude, season and pre-existing vitamin D deficiency. Methods and Study Design: A 12-week prospective cohort study was conducted in chemotherapy-naïve patients in two Australian locations with different sun exposure. Vitamin D deficiency was defined as ≤ 25 nmol/L and insufficiency 26-50 nmol/L 25(OH) D. Demographics, chemotherapy regimen, nutritional status, sun exposure, geographic location, and sea-son were collected at baseline, 6 and 12 weeks after commencing chemotherapy. Results: Eighty-five patients (μ55.3±13.4 years of age; 49% female) were recruited, 96% Caucasian. Fifty-four patients were treated with cura-tive intent (mostly for breast [n=29] or colorectal [n=12] cancers). At baseline, 10 patients were vitamin D defi-cient and 33 were insufficient. Mean serum 25(OH) D (nmol/L) was higher at latitude -27.5o (Brisbane) than lati-tude -34.9o (Adelaide) (μ61.9±22.1 vs μ42.2±19.2, p < 0.001) and varied according to season (spring: μ46.9±20.3, summer: μ50.8±18.2, autumn: μ76.4±25.2, winter: μ36.5±15.7, p < 0.001). Serum 25(OH) D decreased with chemotherapy (baseline: μ49.2±22.3, 6-weeks: μ40.9±19.0, 12-weeks: μ45.9±19.7, p=0.05), with a significant and more rapid decline in winter and autumn (p=0.03). Conclusions: Chemotherapy is associated with a decrease in serum vitamin D, particularly during winter and autumn. Investigations into the underlying mechanism and as-sociated potential outcomes with this decrease requires further investigation

5th International Symposium on Cage Aquaculture in Asia Book of Abstracts

The 5th International Symposium on Cage Aquaculture in Asia (CAA5) is being organised by the Asian Fisheries Society and the ICAR-Central Marine Fisheries Research Institute (CMFRI), in association with the Asian Fisheries Society Indian Branch, from the 25th to 28th of November 2015 at Kochi, India. The event will cover an array of topics related to cage culture under the broad headings of Marine Production Systems, Inland Production Systems, Breeding and Seed Production, Nutrition and Feed, Health and Environment Management and Economics, Livelihood and Policies

5th International Symposium on Cage Aquaculture in Asia Programme Guide

The 5th International Symposium on Cage Aquaculture in Asia (CAA5) is being organised by the Asian Fisheries Society and the ICAR-Central Marine Fisheries Research Institute (CMFRI), in association with the Asian Fisheries Society Indian Branch, from the 25th to 28th of November 2015 at Kochi, India. The event will cover an array of topics related to cage culture under the broad headings of Marine Production Systems, Inland Production Systems, Breeding and Seed Production, Nutrition and Feed, Health and Environment Management and Economics, Livelihood and Policies

Training Manual ICAR Short course on Application of advanced molecular methods in marine fishery resource management, conservation and sustainable mariculture

Molecular Biology and Biotechnology has undergone incredible progress in this decade mainly due to the rapid advancements in DNA sequencing technologies. Marine biology and fishery science also reaped the fruits of these modern inventions improving our understanding regarding complex adaptations in aquatic organisms. Fish Genetics have evolved into genomics incorporating knowledge about neutral and non-neutral markers. A project called Genome 10k was started by the international community of scientists for sequencing the genome of 10000 vertebrates. Whole genomes of many marine organisms are now available which provided insights into the evolution of many important traits. Transcriptome sequencing provides insights into expressed genes and metagenome sequencing provides information regarding the microbes present in environment. All these technologies are rapid and cost effective. Over years, these technologies provided exciting opportunities for understanding ecology and evolution. Genomic information can also be sustainably utilized to enhance productivity of mariculture activities by selective breeding, genetic improvement and manipulation of economically important traits. ICAR-Central Marine Fisheries Research Institute has contributed significantly to marine biotechnology research in the country and played a pivotal role in development of marine fisheries sector. The short course on “Application of advanced molecular methods in marine fisheries resource management, conservation and sustainable mariculture” conducted in ICAR-CMFRI from 24th October, 2018 to 2nd November, 2018 is specially designed to provide exposure to various applications of molecular tools in fisheries resource management, conservation of biodiversity and mariculture. I hope this compendium of lectures and protocols will be extremely useful for the participants to effectively utilize the knowledge in their own area of research. Simultaneously, on behalf of ICAR-CMFRI, I warmly welcome all the participants from various institutions and wish them all success in their future endeavors. I am sure that this training will result in new knowledge, collaborations and friendships

A potential new resource of prawn from the Karnataka coast

Along the Karnataka coast, Mangalore, Maipe and Karwar are centres from where prawns are caught in fairly good quantities throughout the year. It is estimated that around 4 to 5 thousand tonnes of prawns are landed in this state annually and the important species contributing to the fishery are Metapenaeus dobsoni, M. affinis, M. monoceros, Parapenaeopsis stylifera, Penaeus indicus, P. merguiensis and P. monodon belonging to the penaeid group

First Report on Infection of Argulus quadristriatus (Arthropoda: Crustacea: Branchiura) on Marine Fish Cobia in Brood Stock Pond Culture [2019]

A total of 30 specimens of fish cobia Rachycentron canadum (Total Length = 45–120 cm, Weight = 3.0–25 kg) were stocked at the density of 1 kg/m³ in the polythene lined earthen pond. After 3 months of stocking, fish cobia was found with infection of ectoparasites. Then fishes were sampled at fortnight interval to find the percentage distribution of ectoparasites in different parts of the body for a year and also any pathological symptoms. Identification of the parasite was made through light and electron microscopies. The parasite was identified as Argulus quadristriatus Devaraj and Ameer Hamsa, 1977 (Crustacea: Branchiura: Argulidae) commonly called as fish lice. The maximum distribution of pathogenic argulid was observed on the head and operculum of cobia and was found high in summer months from April to June. Pathological symptoms were observed on cobia as erratic swimming, rubbing against substrate in the pond and lesions of epithelial tissues on the infected regions. It must be due to continuous rupturing and feeding of argulids on the skin of cobia using its powerful antennae. Scanning electron micrographs revealed some important morphological features of A. quadristriatus. This is a first report of A. quadristriatus infection on cobia reared in a land-based pond ecosystem

Breeding and larval rearing of three species of damselfishes (family: Pomacentridae)

The annual world ornamental fish trade is to the tune of around 4.5 billion dollars (1995) with a growth rate of about 8%. Nearly 50% of the revenue from the trade is contributed by marine ornamental fishes. With the spread of scientific knowledge on marine aquarium management and development of an array of aquarium gadgets, there is an Increased demand for tropical marine aquarium fishes in recent years and this opens up the possibility of developing a lucrative marine ornamental fish trade the worldover