Multi-user bidirectional communication using isochronal synchronisation of array of chaotic directly modulated semiconductor lasers

Isochronal synchronisation between the elements of an array of three mutually coupled directly modulated semiconductor lasers is utilized for the purpose of simultaneous bidirectional secure communication. Chaotic synchronisation is achieved by adding the coupling signal to the self feedback signal provided to each element of the array. A symmetric coupling is effective in inducing synchronisation between the elements of the array. This coupling scheme provides a direct link between every pair of elements thus making the method suitable for simultaneous bidirectional communication between them. Both analog and digital messages are successfully encrypted and decrypted simultaneously by each element of the array.

Studies on fungal flora with special reference to Yeasts in the Cochin backwaters

Man's concern with environmental deterioration is one of the major reasons for the increased interest in marine and estuarine microbes. Microbes form an important link in the biogeochemical cycling and their cyclinq activites often determine to a large measure the potential productivity of an ecosystem In the recycling of the nutrients in the estuary, bacteria and fungi therefore play a particularly significant role.The allochthonous plant materials contain biopolymers such as cellulose, lignin, humus etc., that are difficult to degrade into simpler substances. The fungi have the ability to degrade _substances, thereby making them available for cycling within the system. The present study is devoted to find the composition and the activity of myco populations of Cochin backwater. For convenience the thesis is divided into eight chapters. The opening chapter briefly reviews the literature and projects the importance of work and the main objectives. Second chapter discusses the materials and methods. In the third chapter the systematic and taxonomy of estuarine yeasts are examined in detail since this information is scarcely available for our waters. The general ecological aspects of the yeasts and filamentous fungi in the area of study are examined in the fourth chapter using appropriate statistical techniques. A special reference to the fungi in a small mangrove ecosystem is attempted in the fifth chapter. The biochemical studies are discussed in the sixth chapter and the penultimate chapter provides an overall discussion. In the last chapter the summary of the work is presented.

SHGs and Cooperatives in the Fishing Sector: An Inclusive Development Option for the Fisher folk of Kerala

The Kerala model of development mostly bypassed the fishing community, as the fishers form the main miserable groups with respect to many of the socio-economic and quality of life indicators. Modernization drive in the fishing sector paradoxically turns to marginalization drives as far as the traditional fishers in Kerala are concerned. Subsequent management and resource recuperation drives too seemed to be detrimental to the local fishing community. Though SHGs and cooperatives had helped in overcoming many of the maladies in most of the sectors in Kerala in terms of livelihood and employment in the 1980s, the fishing sector by that time had been moving ahead with mechanization and export euphoria and hence it bypassed the fishing sector. Though it has not helped the fishing sector in the initial stages, but because of necessity, it soon has become a vibrant livelihood and employment force in the coastal economy of Kerala. Initial success made it to link this with the governmental cooperative set up and soon SHGs and Cooperatives become reinforcing forces for the inclusive development of the real fishers.The fisheries sector in Kerala has undergone drastic changes with the advent of globalised economy. The traditional fisher folk are one of the most marginalized communities in the state and are left out of the overall development process mainly due to the marginalization of this community both in the sea and in the market due to modernization and mechanization of the sector. Mechanization opened up the sector a great deal as it began to attract people belonging to non-fishing community as moneylenders, boat owners, employers and middle men which often resulted in conflicts between traditional and mechanized fishermen. These factors, together with resource depletion resulted in the backwardness experienced by the traditional fishermen compared to other communities who were reaping the benefits of the overall development scenario.The studies detailing the activities and achievements of fisher folks via Self Help Groups (SHGs) and the cooperative movement in coastal Kerala are scant. The SHGs through cooperatives have been effective in livelihood security, poverty alleviation and inclusive development of the fisher folk (Rajasenan and Rajeev, 2012). The SHGs have a greater role to play as estimated fall in demand for marine products in international markets, which may result in reduction of employment opportunities in fish processing, peeling, etc. Also, technological advancement has made them unskilled to work in this sector making them outliers in the overall development process resulting in poor quality of physical and social infrastructure. Hence, it is all the more important to derive a strategy and best practice methods for the effective functioning of these SHGs so that the