Lag time and parameter mismatches in synchronization of unidirectionally coupled chaotic external cavity semiconductor lasers

We report an analysis of synchronization between two unidirectionally coupled chaotic external cavity master/slave semiconductor lasers with two characteristic delay times, where the delay time in the coupling is different from the delay time in the coupled systems themselves. We demonstrate for the first time that parameter mismatches in photon decay rates for the master and slave lasers can explain the experimental observation that the lag time is equal to the coupling delay time.Comment: LaTex, 5 pages, submitted to PRE(R

Assessment of oceanic tuna and allied fish resources of the Indian exclusive economic zone based on exploratory surveys

The present paper overview the results of survey on marine resources of the Indian EEZ including tuna and eillied fish species, their distribution, catch rates, seasonality, assessment of stocks etc. supplemented by the chartered vessels' data. The paper also presents the trends in the tuna fishing and future survey programme of the Fishery Survey of India

Cost-effective valorization of cassava fibrous waste into enantiomerically pure D-lactic acid: Process engineering and kinetic modeling approach

Cassava fibrous waste (CFW) valorization on the synthesis of D (-) lactic acid (DLA) holds enormous importance, particularly in the production of thermostable and biodegradable polymers. In this study, microbial kinetic modelling was carried out to investigate the dynamics of cassava fibrous waste enzyme hydrolysate (CFWEH) utilization towards DLA production. Designed biomass approach was attempted to evaluate the natural DLA producing organisms, capable of metabolizing CFWEH into optically pure DLA. Sporolactobacillus inulinus (NBRC 13595) was found to be the elite strain, resulting the yield of 99.43 % optically pure DLA using CFWEH-supplemented medium. Yeast extract (2 gL −1) was observed to be potential nitrogen source over other complex nitrogen sources for kinetic modelling investigation. Kinetic parameters predicted from the proposed model for DLA production showed maximum specific growth rate, - 0.36 (h−1); growth-associated product coefficient ( gg −1) and specific productivity ( gg −1h−1) respectively. Experimental data of biomass growth, substrate consumption and DLA production with initial sugar concentrations ranging from 20–180 gL −1 was found to be synchronized well with the simulated dynamic profiles. Kinetic investigation reported in this study is a novice attempt enumerating the valorization potential of CFW for the synthesis of value-added products including DLA at commercial scale in near future

Spatiotemporal communication with synchronized optical chaos

We propose a model system that allows communication of spatiotemporal information using an optical chaotic carrier waveform. The system is based on broad-area nonlinear optical ring cavities, which exhibit spatiotemporal chaos in a wide parameter range. Message recovery is possible through chaotic synchronization between transmitter and receiver. Numerical simulations demonstrate the feasibility of the proposed scheme, and the benefit of the parallelism of information transfer with optical wavefronts.Comment: 4 pages, 5 figure

Multilocational testing of pigeonpea for broad-based resistance to sterility mosaic in India

During 1978-83, 88 pigeon pea lines resistant to sterility mosaic (SM) from different research centres in India were tested at 10 locations (Badnapur, Bangalore, Dholi, Pantnagar, Faizabad, Kanpur, Ludhiana, Patancheru, Vamban and Varanasi) to identify lines with stable and broad-based resistance. The multilocation evaluation was carried out through the joint Indian Council of Agricultural Research and the ICRISAT Uniform Trial for Pigeon Pea Sterility Mosaic Resistance. SM resistant genotypes were identified at each of the 10 locations. Lines ICP 7867, ICP 10976 and ICP 10977 were resistant or tolerant at all 10 locations. These lines are now being used by breeders at ICRISAT as well as in the Indian national programme for developing SM resistant and high yielding cultivars

Physics and Applications of Laser Diode Chaos

An overview of chaos in laser diodes is provided which surveys experimental achievements in the area and explains the theory behind the phenomenon. The fundamental physics underpinning this behaviour and also the opportunities for harnessing laser diode chaos for potential applications are discussed. The availability and ease of operation of laser diodes, in a wide range of configurations, make them a convenient test-bed for exploring basic aspects of nonlinear and chaotic dynamics. It also makes them attractive for practical tasks, such as chaos-based secure communications and random number generation. Avenues for future research and development of chaotic laser diodes are also identified.Comment: Published in Nature Photonic

Validation of Landsat Thematic Mapper-derived phytoplankton pigments through synchronous surface measurements: area off Calicut to Azhikal in the Arabian Sea

This paper deals with an estimation of phytoplankton pigments from Landsat Thematic Mapper (Tivi) data after removal of atmospheric effect. The pigments derived from Landsat TIV1 data of October, 1986 and March, 1987 have been compared with corresponding surface values measured during ship cruise programmes synchronous to satellite overpass. In-water algorithm for Landsat TM bands was developed from the sea data collected off Quilon to Malpe In the Arabian sea at different periods of the year. A uniform bias towards underestimation of pigments has been observed in the case of October data and an appropriate modification In the pigment algorithm for Landsat TM has bnen suggested

Of cattle, sand flies and men : a systematic review of risk factor analyses for South Asian visceral leishmaniasis and implications for elimination

Background: Studies performed over the past decade have identified fairly consistent epidemiological patterns of risk factors for visceral leishmaniasis (VL) in the Indian subcontinent. Methods and Principal Findings: To inform the current regional VL elimination effort and identify key gaps in knowledge, we performed a systematic review of the literature, with a special emphasis on data regarding the role of cattle because primary risk factor studies have yielded apparently contradictory results. Because humans form the sole infection reservoir, clustering of kala-azar cases is a prominent epidemiological feature, both at the household level and on a larger scale. Subclinical infection also tends to show clustering around kala-azar cases. Within villages, areas become saturated over a period of several years; kala-azar incidence then decreases while neighboring areas see increases. More recently, post kalaazar dermal leishmaniasis (PKDL) cases have followed kala-azar peaks. Mud walls, palpable dampness in houses, and peridomestic vegetation may increase infection risk through enhanced density and prolonged survival of the sand fly vector. Bed net use, sleeping on a cot and indoor residual spraying are generally associated with decreased risk. Poor micronutrient status increases the risk of progression to kala-azar. The presence of cattle is associated with increased risk in some studies and decreased risk in others, reflecting the complexity of the effect of bovines on sand fly abundance, aggregation, feeding behavior and leishmanial infection rates. Poverty is an overarching theme, interacting with individual risk factors on multiple levels. Conclusions: Carefully designed demonstration projects, taking into account the complex web of interconnected risk factors, are needed to provide direct proof of principle for elimination and to identify the most effective maintenance activities to prevent a rapid resurgence when interventions are scaled back. More effective, short-course treatment regimens for PKDL are urgently needed to enable the elimination initiative to succeed