The catfish resources

widely distributed in the tropical Indo-Pacific and they constitute a regular, sometimes dominant, component of the demersal fish landhigs along the Indian Coast. Species of the genus Tachysurus contribute nearly 99% of the catfish catch, particularly T. thalassinus. T. tenuispinis, T. serratus and T. dussumieri. Osteogeneiosus militaris also forms a fishery along the northwest coast

Long-lived Giant Number Fluctuations in a Swarming Granular Nematic

Coherently moving flocks of birds, beasts or bacteria are examples of living matter with spontaneous orientational order. How do these systems differ from thermal equilibrium systems with such liquid-crystalline order? Working with a fluidized monolayer of macroscopic rods in the nematic liquid crystalline phase, we find giant number fluctuations consistent with a standard deviation growing linearly with the mean, in contrast to any situation where the Central Limit Theorem applies. These fluctuations are long-lived, decaying only as a logarithmic function of time. This shows that flocking, coherent motion and large-scale inhomogeneity can appear in a system in which particles do not communicate except by contact.Comment: This is the author's version of the work. It is posted here by permission of the AAAS. The definitive version is to appear in SCIENC

केंद्रीय समुद्री मात्स्यिकी अनुसंधान संस्थान मुख्यालय कोचीन

केंद्रीय समुद्री मात्स्यिकी अनुसंधान संस्थान मुख्यालय कोची

Applicability of a Representation for the Martin's Real-Part Formula in Model-Independent Analyses

Using a novel representation for the Martin's real-part formula without the full scaling property, an almost model-independent description of the proton-proton differential cross section data at high energies (19.4 GeV - 62.5 GeV) is obtained. In the impact parameter and eikonal frameworks, the extracted inelastic overlap function presents a peripheral effect (tail) above 2 fm and the extracted opacity function is characterized by a zero (change of sign) in the momentum transfer space, confirming results from previous model-independent analyses. Analytical parametrization for these empirical results are introduced and discussed. The importance of investigations on the inverse problems in high-energy elastic hadron scattering is stressed and the relevance of the proposed representation is commented. A short critical review on the use of Martin's formula is also presented.Comment: Two comments and one reference added at the end of Subsec. 3.3; 23 pages, 9 figures; to be published in Int. J. Mod. Phys.

Study on the induced maturation of the Indian pearl oyster Pinctada fucata (Gould) at Tuticorin, Tamil Nadu, India

In the induced maturation experiments of the pearl oyster Pinctada fucata (Gould), 7.5 ± 3.54%, 6.67% and 15 ± 7.07% fully mature pearl oysters were obtained on day 43, 42 and 36 in oysters fed with mixed algae (T-1), mixed algae and raw corn flour (T-2), mixed algae and raw rice flour (T-3), respectively under laboratory conditions. Among the treatments, it was observed that the (T-3) mixed algae with raw rice flour gave the best results with pearl oysters maturing 62.5 ± 7.08% under laboratory conditions on day 29 itself. Whereas, 35 % ± 7.07 % of fully mature pearl oysters were obtained on the 15th day and 36th day from the farm and laboratory, respectively and none in the non fed. Of the matured animals, 43.33% of stage III animals fed on mixed algae changed to stage IV within 19 days, while gonad of 40 ± 14.14% of pearl oysters without feeding changed to stage IV within 26 days under laboratory conditions. Maturity of 53.12 ± 11.97% pearl oysters did not change when maintained in the farm conditions within 24 days

A quantitative evaluation of metallic conduction in conjugated polymers

As the periodicity in crystalline materials creates the optimal condition for electronic delocalization, one might expect that in partially crystalline conjugated polymers delocalization is impeded by intergrain transport. However, for the best conducting polymers this presumption fails. Delocalization is obstructed by interchain rather than intergrain charge transfer and we propose a model of weakly coupled disordered chains to describe the physics near the metal-insulator transition. Our quantitative calculations match the outcome of recent broad-band optical experiments and provide a consistent explanation of metallic conduction in polymers.Comment: 4 pages incl. 3 figure

Results on nucleon life-time from the Kolar gold field experiment

The KGF nucleon decay experiment has been in operation since October 1980 with a 140 ton calorimetric detector at a depth of 2.3 Km underground. The detector comprises 34 layers of proportional counters arranged in an orthogonal geometry with 12 mm thick iron plates in between successive layers. The proportional counters are made up of square (10 x 10 square centimeters) iron plates of wall thickness 2.3 mm. Each of the 1600 counters is instrumented to provide data on ionization, DE/dx and arrival time. The visible energy of a particle is determined to an accuracy of approximately 20% from the ionization and range of its track. The end point ionization of a stopping track provides the direction of motion as well as the nature of the particle (mu/pi,k,p). Decay of mu is recorded with an overall efficiency of only 20% in view of the thickness of 13 g/square centimeters between successive layers

Data acquisition system for phase-2 KGF proton decay experiment

Phase-2 of KGF proton decay experiment using 4000 proportional counters will start operating from middle of 1985. The detection systems, in addition to measuring the time information to an accuracy of 200 n see, also records ionization in the hit counters. It also monitors different characteristics of the counters like pulse height spectrum, pulse width spectrum and counting rate. The acquisition system is discussed