A new species of Argulus (Brachiura) from a marine fish Psammoperca waigiensis (Cuvier)

A specimen of ArguluJ taken from the body surface of the marine perch Psammo- perca waigiensis (Cuvier) caught from the Palk Bay near Mandapam has been found to be a new species, and its description is given here. Species and subspecies of the genus Argulus Milller so far recorded from India are A. indieus Weber, A. gigan- teus Ramakrishna, A. bengalen.ri.r Ramakrishna, A. siameni-is Wilson, A. siamensis penin.rulari.r Ramakrishna and A. puthenvelien.ri.r Ramakrishna (see Ramakrishna, 1951, 1962 ) . The postembryonic development of A. puthenvelien.ri.r has been dealt with by Thomas (1961). Thomas & Devaraj (in press) have described two new species, namely A. fluviatili.r and A. cauveriensis collected from the river Cauvery

Bifurcation Diagram for Compartmentalized Granular Gases

The bifurcation diagram for a vibro-fluidized granular gas in N connected compartments is constructed and discussed. At vigorous driving, the uniform distribution (in which the gas is equi-partitioned over the compartments) is stable. But when the driving intensity is decreased this uniform distribution becomes unstable and gives way to a clustered state. For the simplest case, N=2, this transition takes place via a pitchfork bifurcation but for all N>2 the transition involves saddle-node bifurcations. The associated hysteresis becomes more and more pronounced for growing N. In the bifurcation diagram, apart from the uniform and the one-peaked distributions, also a number of multi-peaked solutions occur. These are transient states. Their physical relevance is discussed in the context of a stability analysis.Comment: Phys. Rev. E, in press. Figure quality has been reduced in order to decrease file-siz

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

Sudden Collapse of a Granular Cluster

Single clusters in a vibro-fluidized granular gas in N connected compartments become unstable at strong shaking. They are experimentally shown to collapse very abruptly. The observed cluster lifetime (as a function of the driving intensity) is analytically calculated within a flux model, making use of the self-similarity of the process. After collapse, the cluster diffuses out into the uniform distribution in a self-similar way, with an anomalous diffusion exponent 1/3.Comment: 4 pages, 4 figures. Figure quality has been reduced in order to decrease file-siz

Production pattern in the marine fisheries of Kerala

Fisheries play a crucial role in the Kerala economy. Although the coastline is only about one tenth of the coastline of India, landings in Kerala constitute more than 30 pet of the country's total marine fish production. This sector provides the main source of income for about 147900 active fishermen and for almost an equal number engaged in the activities of processing and marketing. Earnings from export of marine production from Kerala have during the past two decades increased considerably. The marine fisheries sector is therefore one of the major concerns of the economic planners in the state of Kerala and the object of A various development programmes

HCV IRES manipulates the ribosome to promote the switch from translation initiation to elongation.

The internal ribosome entry site (IRES) of the hepatitis C virus (HCV) drives noncanonical initiation of protein synthesis necessary for viral replication. Functional studies of the HCV IRES have focused on 80S ribosome formation but have not explored its role after the 80S ribosome is poised at the start codon. Here, we report that mutations of an IRES domain that docks in the 40S subunit's decoding groove cause only a local perturbation in IRES structure and result in conformational changes in the IRES-rabbit 40S subunit complex. Functionally, the mutations decrease IRES activity by inhibiting the first ribosomal translocation event, and modeling results suggest that this effect occurs through an interaction with a single ribosomal protein. The ability of the HCV IRES to manipulate the ribosome provides insight into how the ribosome's structure and function can be altered by bound RNAs, including those derived from cellular invaders

Automated computation of one-loop integrals in massless theories

We consider one-loop tensor and scalar integrals, which occur in a massless quantum field theory and we report on the implementation into a numerical program of an algorithm for the automated computation of these one-loop integrals. The number of external legs of the loop integrals is not restricted. All calculations are done within dimensional regularization.Comment: 28 pages, version to be publishe