Annual Report 2000 - 2001

Autonomous Institutions

Agharkar Research Institute, Pune

Research at the Agharkar Research Institute focuses on the area of Life Sciences and is carried out under three areas, viz. Animal Sciences, Microbial Sciences and Plant Sciences. Presented below is the area wise report:

Animal sciences Biometry & Nutrition

Analysis of the longitudinal database on adolescent growth of rural children revealed that (i) sitting height of an individual is likely to be influenced by intra-uterine genetic factors while leg height is governed by postnatal environmental influence. (ii) delayed adolescent growth coupled with early age at marriage increased the risk of pregnancy wastage in rural girls. Shorter the period between onset of menarche and first conception larger was the risk.

Studies on Maternal Nutrition and Birth Outcome revealed that: (i) Maternal intake of ALNA rich foods was associated with birth size in rural undernourished mothers suggesting that when diets are inadequate in macronutrients, foods rich in micronutrients such as GLV, can play an important role in improving fetal growth. (ii) Strenuous activities of rural women were observed to have adverse effect on birth weight. This suggests that reducing maternal activity specifically at late gestation could be a modifiable factor for improving fetal growth. In urban affluent mothers among macronutrients maternal fat intakes in early gestation influenced birth size while among the micronutrients, the foods rich in antioxidants showed relation with birth size among urban mothers.

Experiments were carried out on Wistar rats to examine the effect of nutritional rehabilitation and dehabilitation on growth of rats and on their biochemical profile in adult life. It was observed that maternal nutrition during lactation is more critical than during gestation for growth of pups. There is sex dependent and permanent change in organ weight of rats due to protein restriction during critical periods of development particularly on kidney and pancreas.

Energy costs other than resting were measured for 4 additional activities - walking, walking with load (5kg), bending & sweeping and cycling on ergometer. Prediction equation for RMR was revised and compared with other reported studies. The equation based on body weight as an independent factor was comparable with that reported for populations in other countries while the equation based on fat free mass (FFM) for Indian was significantly different than the reported ones. This indicates the importance of body composition in prediction of RMR.

Comparison of daily Vs weekly supplementation of iron folic acid showed similar improvement in Hb in non-pregnant as well as pregnant women. Efficacy of weekly supplementation was similar to that in daily, with respect to weight gain during pregnancy, when the supplementation was initiated from pre-conception stage. This finding indicates importance of pre-conception stage as also of weekly supplementation adequacy.

While studying the growth during early infancy and risks for adult diseases it was observed that individuals who were undernourished in early life but have higher body weight as adults had higher systolic B.P. than those who were undernourished in early life and remained thin as adults. The analysis indicated that the imbalance of growth in early life is risk factor for hypertension in adult life.

Statistical models are being developed to investigate linkages of micronutrient status and health. Several socioeconomic, environmental, dietary and biochemical factors were examined for their influence on erythrocyte membrane zinc status in adults using multiple logistic regression analyses. A significant correlation was observed between intakes of fruit, GLV and milk products with zinc status. Cereal and pulse intakes, environmental conditions, and family size were observed to be good predictors of Zn deficiency. Logistic regression analyses of micronutrient deficiencies in early anemic humans indicated stronger interactions of copper and zinc with iron than any of the vitamins.

Chemistry

In the project on Pheromones and Semiochemicals repellent formulations for honeybees based on thioethers were identified and patented. These are useful for preventing honeybee visits in areas sprayed with pesticides. The major constituent of Nosnov gland pheromone of Apis mellifera maintained in India was found to be nerol and a minor constituent, neral was found from bees from cooler areas.

Geology & Palaeontology

The foraminiferal studies of the clays of Gulf of Kachchh showed the dominance of forms belonging to Milioliina and Rotaliina. The diversity is low and foraminiferal tests are thin and fragile. This may be due to lack of adequate precipitation of CaCO3 to be used for thickening of the shell. Such conditions may arise where there is absence of normal salinity due to fresh water influx. The magnetic studies revealed the presence of magnetite in the profile and s-ratio indicated relative increase of magnetic mineral flux approximately 1.5 meter below the surface.

Palynological evidences favour dense vegetation, heavy precipitation and high moisture conditions in and around Dhamapur during Holocene. The absence of such conditions at present may be attributed to ecological shifts, tectonic adjustment at local level and anthropogenic influence.

While making a factual assessment of the view that the Marwar Supergroup is Neoproterozoic-Eocambrian in age, it was realized that the evidences cited in support of a Cambrian age for a part of the Marwar Supergroup are not unequivocal. Field investigations and palaeontological studies undertaken for the purpose revealed the presence of Planolites in the Bap Formation. It was also found that trace fossil reported as 'Chordophyceous remains' by earlier workers from the Jodhpur Sandstone is in fact a product of weathering.

Palaeontological studies pertaining to the Kurnool Group and the Cuddappah Supergroup revealed that the so-called trace fossils from the Gulcheru Quartzite, in reality are pseudofossils. The ichnogenus Planolites from sediments in vicinity of Nagarjuna Sagar was identified as P. beverleyensis. Remains of Procaryotic algae as carbonaceous filaments were found to occur in the Koilkuntla Limestone. One of the forms is tentatively identified as Grypania spiralis.

Zoology

In studies on genotoxicity assessment, the mouse bone marrow micronucleus assay to detect potential clastogens and aneugens in mice was studied using fluorescent in situ hybridization (FISH) of centromeric satellite DNA probe. Initial observations indicated that VBS and MMC can serve as positive controls in assessment of potential aneugens and clastogens of plant origin.

In developmental biology, the role of FGF in early development of the nervous system was studied by blocking endogenous FGF function. Preliminary results show that about 50% embryos treated with anti-FGF antibody developed abnormally. Neural tissue was severely affected in all such embryos. The abnormalities included inhibition of closure of neural tube along the entire axis and hole in the forebrain. Amongst these embryos, 37% also showed misplaced somites. These studies confirm the role of FGF in early chick development.

Microbial Sciences

The research activities in the areas of Microbial Sciences are spread over three major thrust areas viz. metal-microbe interactions and their applications, microbial treatment of industrial wastes and fermentation of industrially important compounds. The highlights are:

Nanometer-scale semiconductor quantum crystallites are important in modern electronics and computer technology. We have successfully synthesized cadmium sulfide and other metal-sulfide nanocrystallites by adopting a microbiological route. UV absorbance, Fluorescence, X-ray diffraction and Transmission Electron Microscopy studies showed that the nanocrystallites thus synthesized were size reproducible and had sharp particle size distribution. The purified CdS nanocrystallites were used to fabricate a heterojunction with poly (p-phenylenevinylene (PPV). The result is superior to the diodes fabricated similarly using chemically synthesized cadmium sulfide nanocrystallites.

Monocrotophos and Dimethoate are among the widely used but hazardous organophosphorus pesticides. Hence their biodegradation was studied. Monocrotophos was found to be completely degraded to carbon dioxide by Bacillus, Arthrobacter and Pseudomonas species with methylamine and acetic acid as the intermediate metabolites. Biodegradation of Dimethoate was found to be plasmid associated in Pseudomonas aeruginosa.

The lipase of anaerobic bacterium Selenomonas lipolytica was found to contain two forms namely Lipase I & Lipase II. Lipase I had a mole wt. of 240 kda and exhibited maximum enzymic activity at pH 6.0 and temperature 45oC. N terminal sequence of first ten amino acids was found to be different from that of known Lipases. Lipase II on the other hand was found to be a low mole wt. protein (29 kda).

The acid tolerant strain belonging to genus Methanobrevibacter was studied further for its 16S rRNA sequence. On the basis of this sequence and acid-tolerance characteristics the strain was identified as a novel species and named as Methanobrevibacter acididurans (Type strain ATM).

A fibrin specific fibrinolytic enzyme (EC.NO.3.4.21.23) was purified from the spent broth of a thermophilic Streptomyces sp. The process for production of this enzyme was patented as Actinokinase. This prokaryotic enzyme resembles urokinase, an eukaryotic protein.

Methanogens produced tryptophan when indole and serine were supplemented in the medium of an immobilized cell system. The isolated tryptophan was about 99% pure. By the similar process phenylalanine was also obtained by supplementing phenylpyruvate and glutamate.
In studies on 'metabolic flux in methane producing bacteria, the rate of glycogen synthesis, methanogenesis and ATP formation were found to be related to each other. Methanogenesis was completely inhibited by 2-bromoethane sulfonate (BES) affecting ATP formation also.

Disposal of waste plastics has become a very serious problem. Hence attempts were made to initiate microbial degradation of polyethylene based plastics. Microbial consortium comprising of Bacillus and Pseudomonas sp. has been obtained by enrichment technique from soil. The culture is found to grow on polyethylene (PE) film and polybag (carrybag) pieces. In case of polybags there was visible damage in the surface of the film.

Plant Sciences

Botany

Germplasm collection of wild plant resources and medico-botanical studies are the major thrust areas of Botany group.

Under the collection and conservation project on germplasm of Carissa, Azadirachtra, Aloe, Asparagus and Bruhat Panchmula group of species, multiplication through various means has been attempted.

Leaves of Neem tree (Azadirachta indica A.Juss) have been investigated for comparative antiinflammatory action between normal bitter type and its variant non-bitter types.The medicinally promising genus Asparagus is being studied for chemical analysis and agronomic trials.

Thirteen species of endemic/rare trees were located at 14 different spots in South Konkan regions and their germplasm was procured for nursery evaluation.Work on seed bank collection and standardization of cultivation techniques for commercially important medicinal plants like Boerhavia, Eclipta, Rubia, etc. is initiated in collaboration with Ayurveda Research Institute.

Under Medico-botany thrust area the methanol extract of defatted Jatropha curcus roots were evaluated for local, systemic acute and sub-acute models in animals with positive results. The same extract was fractionated to locate active antidiarrhoeal fraction in albino mice.

Crude extract of Sterculia foetida leaves was purified by column chromatography. A white crystalline triterpenoid and another crystalline compound was obtained by column chromatography. Study of chemical reactions and spectral analysis of the derivatives is in progress. Spectroscopic studies of Curcuma amada rhizome extract showed presence of chemical compounds with hydroxyl, ester. carbonyl and olefin functionalities. The extract showed significant dose-dependent anti-inflammatory activity in acute and chronic administration in Albino rats.

A new project on comparative pharmacognostical studies in some important bark drugs is initiated. In this project six bark drugs are selected for pharmacognostic evaluation due to seasonal variations. Of this, Madhuca , Mimusops and Nyctanthus are studied with macroscopical characters and physical constants.

The finding of a mangrove fern of family Polypodiaceae from the Nawargaon intertrappean beds of Wardha district, Maharashtra, is significant as it forms the oldest record of its kind which has geological and palaeobiogeographical implications. The present permineralized remains of a mangrove fern from the Late Cretaceous Intertrappean beds of India also opened up new vistas as there was a possibility of an ancient sea way, Tethyian influence across Central India prior to the initiation of volcanic eruptions.

Genetics and Plant Breeding

The research in this area is concentrated on genetic improvement of soybean, wheat and grapes.

Soybean varieties MACS-693 and MACS-694 developed at ARI Centre ranked first and second in Southern Zone. MACS-693 ranked second in North Eastern Zone also. Six varieties from this centre are included in All India co-ordinated trials across the zones. The centre has supplied 729.20 quintals breeder seed and 11.50 quintals nucleus seed to different seed multiplying agencies in Maharashtra and Madhya Pradesh. In Frontline Demonstrtions, MACS-450 recorded the highest yield of 3582 kg/ha which was the highest in the country.

A Durum wheat variety MACS-3125 developed at this centre ranked first in Peninsular Zone and has surpassed the yields of bread wheat. Likewise, MACS-3208 has performed well in Central Zone. About 225.6 quintals breeder seed was supplied to multiplying agencies. In Frontline demonstrations, MACS-2694 gave highest yield of 61.5 qtls/ha and the average yield of improved technology was 16.4% higher than the control variety HD-2189.

Eleven genotypes/species of wild relatives of grapes were collected. Out of these, 3 species were found to be tolerant to drought. 282 F1 hybrid seedlings were raised. 31 hybrids were evaluated for their fruit quality and four were found to be promising. Likewise, 102 hybrid seedlings were evaluated for powdery mildew resistance and 68 found to be resistant.

Agricultural Biotechnology: Genetic relationships in cultivated grapes, Vitis vinifera and other Vitis species were analyzed by Random Amplified Polymorphic DNA analyses. A total of 44 genotypes analyzed formed 3 distinct clusters. Wild species and rootstocks were distinctly different from cultivated grapes and formed a separate group. Within cultivated grapes vinifera and labrusca types formed two distinct groups.

Mycology & Plant Pathology

The lichen unit at ARI has been recognised as a collaborating centre of AICOPTAX for the research on lichens of Western Ghats of India under Ministry of Environment & Forestry, Govt. of India.

Lichen species Bulbothrix setschwanensis has been successfully cultured in vitro, producing lichen metabolites atranorin and salazinic acids. The effect of various culture conditions on the growth of Bulbothrix setschwanensis in vitro with special reference to the production of salazinic acid and on bioactivities like inhibition of tyrosinase and superoxide dismutase (SOD) like activites have been studied.

Over 300 lichen specimens have been collected from the western ghats in Maharashtra.

In the Identification Service For Plant Pathogens/Other Fungi, several interesting fungi, new taxa, new diseases, some entomogenous fungi and fungi isolated from specialized habitats were identified. The newly started fungal culture collection houses about 50 cultures of a variety of fungi belonging mainly to ascos and deuteros. 190 specimens were added to Ajrekar Mycological Herbarium which included 25 type specimens.

Three edible mushroom species namely, P. cystidiosus, P. ëous and P. eryngii were grown on media containing the trace elements Zn, Mn and Cu, Se in different concentrations, ranging from 10 to 100 ppm and 0.1 to 0.5 ppm respectively. The growth was enhanced in comparison to the control by addition of some of these elements. The laccase reaction of the filterate of these cultures indicated that the production of laccase by the three strains was higher, in presence of Cu ++. P.eryngii and P. cystidiosus produced higher amounts of laccase than Pleurotus ëous.

Birbal Sahni Institute of Palaeobotany, Lucknow

The Institute has been carrying out researches on various aspects of Palaeobotany and allied subjects under following Thrust Areas:

• Antiquity of Life
  
• Gondwana Supercontinent: Regional geology, floristics, terrane accretion, plate tectonics and configuration
  
• Biopetrology of Indian coals in relation to coal bed methane
  
• Floristics of petroliferous basins, and
  
• Quaternary vegetation, climate and monsoon.

Significant contributions and discoveries

• First record of metazoan fossils like vertical burrows/ichnofossils and medusoid remains from Neoproterozoic Panium Quartzite of Kurnool Basin indicates the appearance of animal life in Indian shield area.
• Discovery of Early Permian plant remains and Late Asselian palynomorphs from Karakoram Terrane provides crucial clue regarding the palaeogeographic reconstruction of the Karakoram-Himalayan block in the Permian. The Karakoram Terrane was close to the Salt Range. The micro-continents accreted with Indian Plate during Cimmerian orogenic cycle. Permian plant fossils from Arunachal Pradesh indicate presence of Glossopteris floral elements comparable with the flora of Barakar Formation of peninsular India. Among the Gondwana group of plants, dichotomous development pattern in Glossopterid has been analysed on the basis of morphological features of leaves and fructifications.
• Palynological study of intra-cratonic Gondwana sequences indicate palynofloral transition from Late Triassic to Early Jurassic sequences particularly in Rajmahal Basin. Neocomian palynofossil investigations demonstrate continuity of Upper Jurassic-Early Cretaceous sequences in Indian Craton. Petrological investigations of Permian Barakar coals from Kanhan area of Satpura Gondwana Basin indicate coals within the threshold of methane generation.
• Plant bearing Tertiary sediments of Warkala Formation, Kerala coast and Mahuadanr, Bihar have been found to contain insect remains in resin lumps. The productive resins are suitable for the study of fossil DNA. A collaborative study has been initiated with Centre for Cellular and Molecular Biology, Hyderabad.
• On the basis of fossil angiospermic remains from Tertiary sediments of Arunachal Pradesh existence of tropical evergreen to littoral and swampy forests conditions were deduced. The flora also shows the migration of some plants from Malaysia. Prevalence of evergreen semi-evergreen forest under warm humid climate is interpreted around Bilaspur in the Himalayan foot-hills on the basis of leaf impressions recovered from Siwalik sediments. Moist conditions with plenty of rainfall have been interpreted on the basis of fossil woods of Intertrappean sediments of Kachchh. Further discovery of mango fossil leaf in Meghalaya confirms the earliest record of mango in North East Himalayan region of India during Palaeocene (55 Ma).
• Selective association and distribution of microfossils from Eocene rocks of Morni Hills (H.P.) indicate fluctuating environment of deposition due to sea level changes. Palynology of Siwalik sediments of Nadah area (Haryana) suggests presence of wet grassland with open and mixed flora during Pinjor sedimentation. Botryococcus, an oil forming green algae have been recovered from Eocene rocks of Jammu and Kashmir. The study is helpful in understanding the source rock evaluation which might help in the discovery of oil fields in the foot-hills of Himalayas.
• Pollen analysis of sedimentary profile from Punlota Lake, Nagaur District (Rajasthan) has revealed successive climatic phases 9200-8050 yrs B.P. arid, 8050-3810 yrs. B.P. warm moist, around 3810-1325 yrs B.P. decrease in warm and moist conditions, and lastly comparatively drier or more or less similar conditions as in preceding phase. Silty clay sediments from the lake bed, Priyadarshini, Eastern Antarctica have been processed. A low hydrolysing periglacial depositional environment is deduced. Pollen analysis identifies three pollen zones based on the fluctuations in the retrieved palynomorph which apparently manifest palaeoclimatic oscillations during Holocene.
• The evidence of carbonised botanical remains from archaeological site at Mesolithic Damdama in Pratapgarh District (U.P.) indicates the shift from the hunter-gatherer economy of Stone age people to the sedentary life style of early Neolithic agriculturalists in the Ganga Valley. The tree ring chronology prepared from samples of Abies pindrow growing around Dokriani Bamak Glacier extending back to 1614 A.D. exhibits periods of low and high growth which might be linked with glacial fluctuation of this region. The chronology of palynologically analysed peat samples from Phulera, Kumaon (U.P.) works out to 15900±150 yrs B.P. (C-14 age). The sample from Priyadarshini Lake, Antarctica is dated as 7190±300 yrs B.P.
• During the year 61 research papers and 54 abstracts were published and 57 papers were accepted for publication. Thirty-five research papers were presented in International and National Conferences. In International Conferences 2 scientists were deputed while 28 scientists attended the Conferences organised in the country.

Forensic Palynology

• In order to carry out researches on forensic palynology a core group of scientists of Quaternary palynologist is formed to undertake the study in collaboration with the organisations dealing with forensic sciences in New Zealand and USA. This is the emerging new application of palaeobotanical researches in forensic science and useful for Police Department.

Integrated Long Term Programme

- A project entitled "Floral and climatic evolution based on Geologic and Biotic events during Precambrian and Phanerozoic Time" has been initiated under ILTP of co-operation in Science and Technology between BSIP (India) and Russian Academy of Sciences (Russia). BSIP has been chosen as the nodal agency under the umbrella of Earth and Planetary Sciences on palaeoclimatic researches.

Publications

The Palaeobotanist volumes 49 (1 & 2) have been published, the latter consisting of research papers on North-East, India. Newsletter 2000 and bilingual Annual Report 1999-2000 were published, highlighting Institute's research and other activities. A Monograph entitled "An introduction to Gymnosperms, Cycas and Cycadales" of Prof. D. D. Pant, Allahabad is being processed for publication.

Consultancy services

The Institute has rendered consultancy services to the personnel from various organisations in radiocarbon dating, electron microscopy, palynology and identification of fossil remains.

Web Site and Internet access:

The Institute web site (www.bsip-india.org) has been launched on November 14, 1999. The Institute has registered a domain "bsip.res.in" on the Internet. Internet access to scientists has been provided at 60 nodes throughout the institute.

Bose Institute, Calcutta

Through the 83 years of glorious existence since its foundation by Acharya Jagadis Chandra Bose in 1917, Bose Institute has emerged as a potential, scientifically active multidisciplinary research Institute in India. Research and training in various fields of physical and biological sciences are undertaken in ten Departments and Sections viz., Physics, Chemistry, Botany, Microbiology, Biochemistry, Biophysics, Animal Physiology, Plant Molecular and Cellular Genetics, Immunotechnology and Environmental Sciences. Through years of its existence the prestigious Institute has proved itself to be pioneer in the frontiers of modern Physical and Life Sciences. Its work and achievements have attracted attention of Scientists from our country and abroad. Many of our faculties are Bhatnagar awardees, Fellows of National Academies and recipients of National and International awards, and have intra-, inter- institutional and International research collaborations.

Bose Institute is conducting research in the following main areas (Institute Projects) :

• Improvement of Plant Productivity, Nitrogen Fixation and Photosynthesis using modern Biotechnology and Plant Breeding.
  
• Chemical and biological studies of Plant and Marine organisms.
  
• Studies on structure, function and dynamics of biomolecules.
  
• Studies on ecology, environmental pollution and related problems.
  
• Studies on microbes and parasites for industrial and medical applications.
  
• Problems in condensed matter, intermediate energy physics and related interdisciplinary areas.

Major Achievements:

Considerable progress has been achieved in the areas of neutron dosimetry, quantum disentanglement, teleportation, propagation of strangelets through the terrestrial atmosphere, cosmological dark matter and quantum antiferromagnets, among other areas. Enrichment of medically important EPA and DHA has been made from Sting Ray Oil. Hepatoprotective role of the herb Desmotrichum filmbriatum has been demonstrated for the first time. A novel reagent has been developed for the N-formylation of (hetero) arylamines. A beneficial role of MIM in Cat II TB patients has be indicated. ABRE-based promoter has been constructed and to overexpress Samdecarboxylase, the cDNA has been ligated into Ti-based plasmid. To inhibit ethylene biosynthesis in fruit, transgenic tomato plants have been generated. A number of in vitro grown plantlets of Teak, Kalmegh and Ambroma augusta were transferred to The Department of Science & Technology, Govt. of West Bengal. SoxA, SoxB and SoxC genes in sulfur oxidizing operon in Thiobacillus have been identified by PCR based genome walking technique. The effect of the side chain on the backbone conformation, structural features of the cis peptide bonds and the microenvironment around different protein residues have been elucidated. The structure of the Calotropin DII and Acetanilide - Cox interaction complex are fully characterised. A few medically important potential substrate - receptor, drug-receptor, protein-protein interaction at structural level has been characterized by computer modelling and deposited in Protein Data Bank. Carbofuran, a pesticide, showed mobilization of cholesterol molecules from fish hepatic cytosol to plasma membrane with inhibition of membrane Ca2+ - ATPase activity. The cytosolic inositol synthase(s) from Oryza and Porteresia have been completely sequenced. A full length cDNA for cytosolic FruP2ase from Porteresia has been sequenced and submitted to Gene Bank (Accession number Af 218845). Bioaccumulation of aflatoxin from liver of farm animals in the consuming individual is possible and continuous accumulation of the toxin may be determined. Protein A (PA), the cell wall protein of Sta[ju;pcpccis aireis, has been found to initiate pro-proliferative signals to the immunocytes and pro-apoptotic signals to the tumor cells of the same host. Two peptides, 16 and 20 mer as derived from PA by protease digestions, have been found to mimic many of these functions of the mother protein.

Patents filed/Technology Transfer :

• Superheated Drop Detector Technology developed in the Department of Physics, B.I. has been transferred to Defence Research Laboratory, Jodhpur and also to Indira Gandhi Centre for Atomic Research.
  
• Technology developed in the Department of Chemistry for the production of EPA (patented), a potent medicine for atheroschlerosis and thrombosis (cardiovascular diseases) has now been transferred to P.G. Hospital, Calcutta.
  
• A simple process for the preparation of iodoquinol, an antiamoebic compound has been developed in the Department of Chemistry and patented and is awaiting for transfer to industry.
  
• Technology of using a bioimmunomodulator for reducing morbidity and mortality of poultry chicken developed in the Department of Chemistry and patented, is awaiting for transfer.
  
• Technology developed for clonal propagation of economically important plants, mass culture of spirulina developed in the Department of Botany is awaiting for transfer.
  
• Management of Tapping Pannel Dryness Syndrome in Rubber Derived in the Department of Botany has been transferred to Ruber Research Institute and Rubber Board of India.
  
• Biotechnical and Ecophysiological components of seed Vigour for Direct Seeding Cultivation in rice developed in the Department of Botany has been transferred to Directorate of Rice Research, ICAR.
  
• Technologies viz. Protein Purification, Measurement of Photochemical Reaction, Cell Culture and Regeneration of Plants, Recombinant DNA work to study Gene Cloning etc. developed in the Department of Botany awaiting transfer.
  
• PCR-based techniques for rapid identification of Vibrio cholerae and mycobacteria developed in the Department of Microbiology awaiting transfer.
  
• Technologies viz. Expression of heterologous proteins, Improvement of Plant Productivity, Studies of microbes and parasites for industrial and medical applications, Molecular characterisation of Thalassaemia in local population developed in the Department of Biochemistry awaiting transfer.
  
• Technologies on better production of fish (triploid catfish, H. Fossils and rapid ovarian development in freshwater prawn, M. rosenbergii developed in the Animal Physiology Section awaiting field transfer.
  
• Technology for better production of silk developed in the Animal Physiology Section awaiting transfer.
  
• Technologies developed in the PMCG Section viz. Genetically modified homogeneous diosgenin yielding Costas speciosus, Batch-culture pyrethrin production for commercial purpose, Alien gene transfer techniques in chickpea, mungbean and mustard, Micropropagation protocols for industrially important poplar genotypes awaiting transfer.
  
• ELISA kit for detection of Aflatoxin, Techniques for identification and separation of IgG antibody molecule developed in the Immunotechnology Section awaiting transfer.
  
• An water filter to decontaminate arsenic has been developed in the Environmental Science Section.
  
• Technology developed in the Department of Botany for isolation of acrylamide from plant sources awaiting transfer.
  
• Technology developed in the Department of Botany on Generation and demonstration of tissue culture-based raised planting materials - teak and medicinal plants Endrographio pAnicclata transferred to Department of Science & Technology, Govt. of West .Bengal.
  
• Technology developed in the Department. of Botany for Downstream processing in tissue culture awaiting transfer.
  
• Technology developed in PMCG Section patented in USA on Plastid transformation of arabidopsis thaliana transferred to Rutgars Univ., USA where the collaborative research undertaken.
  
• Technology for Removal of Sulphur from coal by Microbial process transferred to Burn Standard Co., the funding agency.

Indian Association for the Cultivation of Science, Calcutta

The Indian Association for the Cultivation of Science (IACS), established in 1876, has been continuing its efforts for excellence in scientific research. The various scientific activities and achievements during the year are summarized below :

Materials Science

Research work was carried out in the following disciplines during this period : transport properties of magnetic/metallic multilayers and intermetallic compounds, Colossal magnetoresistance and low temperature properties of polyaniline blends. Electronic structure calculation for strongly correlated systems, Synthesis of binary and ternary semiconductors for fabrication of thin film solar cells. Nanostructured materials in thin film form, hard coating materials : Diamond and nitride (c-BN and AIN) films, Transparent and doped conducting oxide film using sol-gel technique, Rapid thermal processing (RTP) for the fabrication of large area solar cells; Metal-conducting Polymer Schottky Contact, X-ray crystal structure determination of some nucleosides, natural products and organic crystals, Studies on morphology, growth and characterization of non-linear optical materials, Characterization of lattice defects from x-ray powder profile analysis of metals, alloys, thin films, composites and industrial materials; Evidence of single electron capture into excited states in N2++-N2 collisions in ion beam scattering experiment. Angular distribution of photofragments in intense field multiphoton dissociation. New technique of population inversion by chirped lasers.

Solid State Physics

Recently single crystal epr studies on bi-metallic copper-bis-ethylene diamine manganese tetrachloride have been made elucidating new information about the nature of exchange coupling in this low D-magnetic compound. High field Zeeman study on the CdCsCl-type single crystals also showed interesting results. To find the conditions of geometric frustration at low temperature in ferro and antiferromagnetic RE-pyrochlorates, importance of single ion magnetic anisotropy and its relative strength w.r.t dipolar and exchange interactions have been shown. Structural change in the glass-network structure in Bi2O3-P2O5 glass has been detected by acoustic method. A density modification technique has been developed to improve the E-map obtained from the direct method for a known protein complex. A new scaling formalism for the conductivity spectra of ionic glasses indicating a relation of relaxation dynamics with glass structure has been developed. Light -emitting devices (LEDs) have been fabricated fabricated based on Langmuir-Blodgett films of a porphyrin derivative and decacyclene. LEDs have also been fabricated based on layer-by-layer self assembled films. A high pulsed magnetic field arrangement has been developed to study colossal magnetoresistive materials. Relaxor type ferroelectric transition have been observed, for the first time, in multicomponent glassy materials ambedded with nanocrysalline ferroelectric BaTiO3 particles/clusters. It has been established that in the Bi based Bi-Sr-Ca-Cu-Mn-O etc. glasses becomes superconductor with nanocrystalline (<20nm) grains/or clusters. It is not possible to prepare single phase high Tc superconductors with grain size >20nm. Many multicomponent transition metal oxide glasses are also found to contain nanocrystalline clusters of different sizes and there is a critical size of the nano-clusters above which thermal, electrical and other properties show nonlinear variations indicating a glass to glass type phase transition. This work is being done in collaboration with Prof. H Sakata of Tokai University, Japan. Effect of magnetic polarons on the electrical transport mechanism in colossal magnetoresistive materials like Ca-Pb-Mn-Cr-O oxides has been observed from the temperature and magnetic field dependent Seebeck coefficient data. Dielectric relaxation behaviour in some ferroelectric liquid crystals (for example, SC-1013) have been studied using the new facility developed in the department mostly funded by AvH Foundation Germany. This work is being done in collaboration with Prof. W Haase, Technical University, Darmstadt, Germany, and Prof. E Okabe (Schisso petrochemicals Corporation, Japan).

Spectroscopy

Preliminary calculation of angular correlation in doubly excited states have been made for ground and low lying excited states of two electron systems. Allowed and forbidden transition properties of closed and open shell atoms and highly stripped isoelectronic ions have been studied using time dependent perturbation theory. Excited states and spectroscopic parameters by HDHF Method Spectroscopy of foreign atoms under liquid He environment, spectroscopy of highly stripped exotic ions and those of photo-biological systems by quantum mechanical approach have been initiated. Ab-initio study on above threshold multiphoton dissociation and non-dissociative autoionisation in hydrogen reproduced observed photoelectron energy spectrum, Photodissociation dynamics of LiH molecule by using Fourier Grid method, Lasing without population inversion in small molecules in presence of coherent light and squeezed light are being investigated. Measurements on the charge transfer processes in doubly charged nitrogen molecular ion using Transitional Energy Spectroscopy have been initiated. Laser Raman spectroscopic studies on crystalline state photodimerisation reaction, Surface enhanced Raman scatering using LB technique, a systematic investigation of Raman profiles of some double molecules have been carried out and further extension of the programmes are contemplated. Studies of spontaneous polarisation and Response time of a new electro-optical material based on Ferroelectric liquid crystal dispersed in a polymer matrix, which is suitable for large area displays has been made. Electro-optic and dielectric spectroscopy in the SmC* and SmCa* phases of a liquid crystal material are in progress in a frequency range from 10Hz - 13MHz. Studies on photophysical/ photoconductive and photoinduced electron transfer reactions within several electron donor and acceptor systems, synthesis of several biochromphores, mimic to photosynthesis devices, studies on photoluminescence quenching in a regular polythiopene in pristine and annealed films using Ti:Sapphire laser and streak camera with CCD have been successfully carried out. Twisted molecular charge transfer has been identified in S-N,N-dimethylaminocinnamaldehyde from theoretical and experimental stand point which seems to compete with hydrogen bonding interaction in protic solvent. Encapsulation of this molecule by a- and b- cyclodextrin brings forth new interesting complexes. Dark and Photo-conduction properties of some organometallic compound have been carried out with special emphasis on checking the temperature dependent fluctuations in the factor (g). Investigations on the non-linear behaviour of some organometallic compounds in the vapour-adsorbed state, both by electrical and spectroscopic methods are in progress.

Theoretical Physics

In atomic and molecular physics positron-hydrogen scattering of ortho positronium off helium target, ionisation of atoms by various means and ionisation and excitation in the presence of a laser have been studied. In positron-hydrogen scattering, the effect of target inelastic channels is found to be significant. The total cross section for the ortho-positronium scattering is in good agreement with measurements carried out at University College London. In particle Physics, the decay of heavy hadrons within and beyond the standard model has been carried out with particular emphasis on the decay of the rare B and D mesons. Neutrino induced muon production and gamma ray induced interactions have been the theme of astroparticle physics research. Work done in the area of biophysics and environmental science centres round the statistical analysis of the coding and non coding parts of DNA. Heavy metal pollution and its effect of marine life has been studied. Research in statistical physics nonlinear dynamics etc. has led to the analytical observation that the plane Conetle flow that is known to be stable at all Reynold's number can because unstable if there is a small imperfection in the plate geometry.

Energy Research Unit

The process of setting up of a prototype plant for the production of large area multijunction a-Si solar modules has been started under a project funded by Department of Science and Technology and Ministry of Noncon-ventional Energy Sources. Transparent conducting Zinc Oxide films have been developed by r.f. magnetron sputtering. Using a layer of ZnO as back Reflector in double junction solar cells (area~1cm2), 11.7% increase in efficiency has been achieved. The integrated electrical-optical modelling programme set up in this laboratory, has been used to analyse the junction of two component subcells in tandem solar cells. The role of substrate temperature on the phase transition between amorphous and nanocrystalline/ microcrystalline silicon films have been studied using x-ray diffraction, Raman scattering, SEM, TEM and conductivity measurements. The intrinsic mc-silicon layer with low light induced degradation has been developed for the active layer of solar cells. Work on solid phase crystallisation of a-Si films have been started. A new project has started jointly with a French group to develop a new variety of Si:H alloy which has been termed "polymorphous silicon". Preliminary studies have shown that the material has lower degradation compared to standard a-Si:H. Under a DST sponsored project studies on glow discharge plasma has been made by optically emission spectroscopy and Laugmuir probe. Under a project funded by Aeronautical Development Agency(DRDO) process for depositing Radar opaque optically transparent coating on polycarbonate substrate has been developed.

MLS Processor's Unit

Newer types of nanocomposites have been designed and synthesized. Composites of nickel-zinc ferrite and nanosized iron particles show interesting magnetic properties - it now seems possible to make materials with desired magnetization and coercivity in a wide range. Nanocrystalline oxides when grown within a suitable gel matrix exhibit unusual electrical conductivity which has been ascribed to an interfacial amorphous phase. Metallic nanowires have been grown within a polymeric film as well as nanopores of a silica gel.

Biological Chemistry

Oligosaccharides related to the antigen from Shigella dysenteriae types 3,4 and 9, S. boydii type 5 and D-parosamine have been synthesised as a part of our work towards the development of carbohydrate based antibacterial vaccines. Lectin-carbohydrate interaction plays a major role in infection process as demonstrated by enhanced infection to jute seedling by phytopathogen. Macrophomina phaseolina in presence of its extra cellular agglutinin as well as jute cell wall carbohydrates. Influence of different plant growth hormones on the mycelial growth and lectin production has shown acid gibberellic acid to be the most potent among many others, viz. Kinetin and indole acetic acid. Secondary structures of somatic and excretory-secretory antigen of Ascaris lumbricoides helminth have been determined by circular dichroism study. Among IgE-reactive antigenic proteins in Rohu, Hilsa and Pomfret fishes, the same present in Hilsa has been found to cause high degree of food allergy in patients allergic to fish studied among population in greater Calcutta. Swollen chitosan beads and gels prepared from shrimp shells have been found to be very efficient in removing metal ions from effluent. The beads and gels after treatment can be reused for number of times. Isolation of lactose from whey using chitosan gel as demineralising agent is being studied. It has been found to remove metal ions from whey without increasing its volume. With the objective to understand the differentiation process, a new project was initiated. Differentiated plant tissues (carrot, Solanum nigrum and Dalbergia sissoo) have been transformed to undifferentiated callus. An alpha-turn mimetic, g-turn induced hairpins and 5-membered NH….N hydrogen bonded rings (a novel motif) have been successfully designed in model pseudopeptides and peptides using nonprotein amino acids with aims to mimic protein structural elements and to create novel motifs that are not found in nature.

Inorganic Chemistry

The activity of the Department centres around : synthesis of metal bound azo anion radicals, oxorhenium(V) complexes and their reactivity toward diphosphines, new organometalalics through insertion of alkynes/ isonitriles in M-C bonds, polyol chelation in oxovanadium species, metal-promoted regioselective aromatic ring amination processes at coordinated diaza ligands, redox and spectral properties of di- and poly-metallic complexes involving RuII-CuII, OsII-CuII etc., new Tri- and tetra-aza macrocycles, photoluminescent copper(I) complexes, reactivity of Pd(II) chelates with vitamin-B6 molecules, electron transfer pathways in bridged manganese(III,IV) systems, low temperature magnetic interactions in one-dimensional bridged copper(II) polymers, water-soluble polymeric dioxovanadium(V) compounds with extended helical structures, binuclear molybdenum(VI) complexes with multidentate N,O donors, reversible oxygen binding in high-spin cobalt(II)-pentacoordinated species.

Organic Chemistry

The continuing research efforts have unfolded novel methods of carbon-carbon bond formations mediated by photocycloaddition reaction, metal mediated selective bond formations, transition metal induced radical reactions, Lewis acid catalysed and microwave assisted processes. These have been successfully applied for the total synthesis of some bioactive monoterpenes and sesquiterpenes and related compounds containing unusual carbo- and heterocyclic structures. A number of nitrogen and sulfur heterocyclic systems have been synthesised employing transition metal induced cyclisations and these will be of use for studying structure-activity relationships. A total of 15 papers have been published in reputed journals.

Physical Chemistry

Recording and analysis of single vibronic level luminescence and Hole-burning spectra of organic molecules, observation and analysis of ultrafast solvation dynamics in lipids and sol-gels, correlating features of excited state intramolecular proton transfer (ESITP) with the nature of the potential energy surfaces on which the transfer takes place and the use of ESIPT as a probe for polymer-surfactant interaction highlight the experimental research activities of the department. In theory, remarkable results obtained by us include prediction of core effects on the ionization potentials of heavy atoms by relativistic coupled cluster based linear response theory, demonstration of environment induced dynamical chaos and tracing the origin of the symmetry that exists between the growth and decay of fluctuations in thermalised quantum systems.

Polymer Science

During the year under review researches in the following areas were carried out : conducting polymer colloids, controlled/living radical polymerization, polymer blends, polymer crystallization, polymer gelation, elastomer blends and polymer-surfactant interactions. Conducting polymer colloids provide a valuable method of processing the intractable conducting polymers. We have investigated mechanisms of the formation of polyniline (a conducting polymer) colloids so that better colloids can be prepared and utilized. Controlled/Living radical polymerization has emerged as a very important means of producing various polymers with controlled chain length, well defined end groups and polymer molecules of nearly uniform chain lengths. Such materials are greatly sought after in fabricating advanced materials. We have explored the applicability of the method for water soluble polymers such as polyacrylamide. Crystallization behaviour of polymers has been studied for polymer blend systems comprising of poly(ethylene terephthalate)(PET), an important commodity polymer, and poly(vinylidene fluoride) (PVF2), a piezoelectric polymer. The study suggests that these two polymers are miscible in the melt. In another study which involves blending the crystalline piezoelectric polymer PVF2 with an amorphous polymer, poly(methyl acrylate), gels were found to be formed and these gels were proved to contain solvents which are complexed with the polymers. Furthermore, detailed investigations are in progress for characterizing some conducting polymer gels e.g. polyaniline sulphonic acid gels and poly(3-hexylthiophene) gels. Systematic studies were carried out on the covulcanization of blends of rubbers which vary greatly in polarity and unsaturation. Some of these blends may exhibit improved properties and therefore may find commercial utilization. Polymer surractant mixtures have great application potentials. A fundamental understanding of these systems is also of great theoretical interest. In this vein a detailed study on the solution properties of some cationic detergents in presence of the water soluble polymer hydroxypropylcellulose was pursued. Investigations w ere also carried out on the solution properties of micellar solutions of mixtures of ionic and nonionic surfractants which may yield surfactant systems with novel properties.

Indian Institute of Astrophysics, Bangalore

The major activity of the Institute during the above period was directed towards the preparations for the installation of the Optical/Infrared Telescope of 2-meter aperture at the Indian Astronomical Observatory (IAO) at Hanle in Ladakh, at an altitude of 15000 feet above mean sea level, the highest astronomical site in the world. This telescope being capable of remote operation, the Satellite Communication and Control Station had to be established at the Centre for Research and Education in Science & Technology (CREST) campus of the Institute at Hosakote near Bangalore. The dedicated team of scientists and engineers of the Indian Institute of Astrophysics working in close cooperation with various agencies of the Government and institutions in the private sector accomplished these challenging and multifaceted tasks with speed, economy and efficiency.

The following facilities were established at Hanle to be in readiness to install the telescope that was expected to arrive there in the summer of 2000:

• Solar Power Plants, 2 Nos., each of 30 KW peak power with adequate storage for operating the telescope for 3-nights without additional input.
  
• Liquid nitrogen plant, for cooling the CCD cameras.
  
• Satellite based communication links (2 Nos.) to the remote control and operation station at Hosakote, one 2 Mbps duplex and one 64 kbps duplex.
  
• Dome of 10.5m diameter and 16m high with innovative design (by IIA), capable of automatic operation.
  
• Cmputational facilities for a variety of purposes such as, control of power, the focal plane instruments, the dome, communication system etc..
  
• Facilities for scientists, engineers and technicians to stay.
  
• Facilities for archiving the data.
  
• Power and communication cables interconnecting the various units.
  
• The road from the valley to Mt. Saraswati.

The CREST on the land donated by the Government of Karnataka in Hosakote, was equipped to complement the infrastructure at Hanle. The control and operation centre at Hosakote was equipped with communication equipments; computers and office space for round the clock activities. Suitable facilities are also created for archiving the astronomical data.

The Vainu Bappu Observatory (VBO) at Kavalur also made important observations during the year and new facilities were commissioned at the Observatory. The Liquid Nitrogen Plant installed on the Observatory grounds provides more than 5 liters of LN2 per hour and all the requirement of the coolant for the CCD-cameras. A new medium-resolution spectrograph commissioned to work with the Vainu Bappu Telescope is functioning satisfactorily.

The readiness of the facilities at VBO may be seen from the recent multi-band observations from VBO of the after-glow of the gamma ray burst GRB000301c, which was detected by the All-Sky Monitor on board the Rossi X-ray Timing Explorer on 2000 March 1, 4108 UT (universal time) and also by Ulysses and NEAR. The coordinates of the event, R. A. =16h 20m 21s.5 and declination = +29024'56".37 within an error box of 50" x 50", was communicated internationally to all observers, and within three hours of the receipt of the electronic-mail, the multi-band photometric observations were commenced at VBO, and these provided important anchor points for delineating the light- curve of the after-glow of the gamma ray burst.

More details of the scientific research and development activities during the year are given below.

Scientific Research

Sun And The Solar System

Solar Physics

The Kodaikanal Solar Observatory operated by the Institute has a large database consisting of daily full disk white light solar images over a period of several decades (1906 - 1987). The long-term programme of analysing these images is continuing. Recently, Institute's scientists in collaboration with scientists from some other institutions in the world have succeeded in measuring the positions and areas of all sunspots (numbering 332620) to an accuracy of about 0.5 arc see from 18,900 images covering the 82 year period. Two important measurable quantities have been extracted from this data set, namely, (i) the solar rotation rates at different solar latitudes and the variation of the rotation rate with the solar cycle, and (ii) the tilt angles of spot groups (i.e., the angle between the line joining the centroids of the Leading and the Following spots in the group and the local parallel of latitude). From the measurements of the rotation rates of the spots two important results have been established, namely (a) bigger spots generally rotate slower than the smaller spots and (b) the residual rotation rate (in degree per day) of all spots shows that the rotation during the years of solar minimum is faster than that during the solar maximum years. These results as well as those of the tilt angle measurements of the spot groups have important implications for the dynamics of the solar interior, in particular, for the structure and dynamics of the solar magnetic field, which are being studied in details.

A Stokes Polarimeter was developed and successfully installed at the Kodaikanal Tower Telescope to study the vector magnetic field of sunspots. A sunspot KKL 21263 (NOAA 8516) was observed with this instrument and the associated magnetic field parameters were successfully determined. This instrument is expected to provide many valuable data pertaining to solar magnetic fields in the years to come.

A continuing puzzle in solar physics is the unknown mechanism by which the Sun is able to maintain a very hot atmosphere (called "chromosphere") above its surface without losing the heat through conduction to the surface. The main sites in the chromosphere where the heat is thought to he generated are the so-called "bright points". There are generally two opposing schools of thought regarding the nature of these bright points, one claiming association of these bright points with magnetic phenomena and the other modelling them as purely of hydrodynamic origin. In this context, recent work by Institute's scientists have provided strong support to the magnetic association hypothesis by firmly establishing the association of the bright points in the interior Of the Calcium 11 K line network in the solar chromosphere with the underlying sub are see magnetic elements at the photospheric level.

In another piece of work on solar chromosphere, by analysing data provided by the SOHO, Institute's scientists have found evidence for the existence of the so--called "meso-scale granulation" in the solar upper chromosphere, of roughly the same size as observed earlier in the photosphere and lower chromosphere. These meso-granulations, which are convective cells arising from the solar convection zone and having horizontal sizes in the "medium" range of few thousand kilometers, are found mostly in the photosphere and are generally not seen to extend to the chromosphere. Thus, this new result, if confirmed by future detailed studies, has important implications for the energetics of solar convection process.

There has also been important theoretical work done in the Institute on the problem of solar chromospheric beating with the aim of identifying the precise mechanism by which energy is transported from the photosphere to the chromosphere through the magnetic flux tubes. In this direction work has been done to study the excitation of oscillations in the magnetic network of the Sun through the foot point motion of photospheric magnetic flux tubes located in the intergranular lanes. Result of this study shows that in order to transport enough energy on a sufficiently steady time scale to account for chromospheric beating, one need to include the effect of turbulent convective flows on flux tubes in intergranular lanes.

The problem of explaining the heating of the solar corona and maintaining it at a temperature of - a million degrees constitutes one of the most enigmatic of all the major unsolved problems in solar physics. Institute's scientists have used the coronal spectroscopic data from the ground-based Norikura Solar Observatory of National Astronomical Observatory of Japan and the space-based SOHO images to throw light on this problem. From the power spectral analysis of the time-series of line intensity, line width and Doppler velocity data obtained from the time sequences of the coronal emission line spectra in Fe X 63740 A and Fe XIV 53030 A, strong evidence for coronal oscillations with periodicities in the range of a few minutes to a few tens of minutes has been established. In particular, a 3-minute periodicity is consistently seen in both green and red line spectra reported earlier by scientists elsewhere using independent data. These results lend strong support to the hypothesis that magnetohydrodynamic (MHD) waves of short periods (- minutes) are responsible for the energy transport to and heating of the corona.

In another piece of work, Institute's scientists have discovered interesting correlationship between the magnetic activity in some persistent active regions of the Sun and the enhancement of the 53030 A coronal green line emission, a result that might have important bearing on the role of magnetic fields in the coronal heating problem.

Study of the Sun in radio wavelengths is continuing in the Institute using the Gauribidanur radio telescope operated by the Institute. Radio emission associated with transient Extreme Ultraviolet (EUV) jets from polar regions of the Sun was identified for the first time with the Gauribidanur radio heliograph. This instrument has also provided important data on the coronal mass ejection events of April 13, 1997 and September 12, 1998.

Solar Terrestrial Physics

The Solar Terrestrial Physics (STP) group of the institute participated in the Equatorial Spread F (ESF) campaign held during April 1999 under the Indian Solar-Terrestrial Energy Program (I- STEP). Regular data acquisition in the monitoring mode continued with the experimental facilities (IPS42 digital ionosonde, HF Doppler Radar and Magnetometer) at Kodaikanal Observatory.

A comprehensive study of the ionospheric storm of November 4, 1993 in the Indian equatorial region was undertaken in the Institute because of, the absence hitherto of an assessment of the response of equatorial upper atmosphere to this magnetic storm. The study, based on data from the ionosonde and magnetometer networks in the country, brought to light several new facets of the storm-time behavior of the equatorial ionosphere, indicating, in particular, a significant electrodynamic coupling between high- and low latitude ionosphere.

Work is continuing in the Institute on the inter-relationships between solar wind, magnetosphere and ionosphere. The global manifestation of the waveform of the geomagnetic storm sudden commencement (SC) of November 18, 1993 has been evaluated using high time resolution data of several magnetometer networks coupled with HF Doppler Radar measurements at Kodaikanal. The work revealed that the dip equatorial appearance of the preliminary reverse impulse (PRI) of the SC deviated quite significantly from the pattern established by previous statistical studies as well as the one predicted by currently available theoretical models of SC.

Institute's scientists are also involved in detailed study of the effects of Meteor Showers on the ionosphere. In particular, the effect of Leonid meteor showers during the years 1996 through 1998, on the characteristics of sporadic-E layers at equatorial latitudes has been studied using data of rapid ionospheric soundings at several stations in the country. The results showed an increase in the occurrence of Es layers at altitudes in the range 100-140 km throughout the equatorial region at the times of peak shower activity. The finding underscores the need for further studies to ascertain the origin of the observed changes in Es behavior, in particular the relative roles of deposition of metallic ions due to shower activity and the physical mechanisms that cause ion-convergence and lead to Es layers.

Solar System Objects

Following the earlier observations of the Comet Hale-Bopp at the Vainu Bappu Observatory (VBO), Institute's scientists are currently involved in determining the physical nature of the cometary grains in this comet. The porosity and organic fraction of the grains have been determined by comparing the computed variation of polarization of the light scattered by an ensemble of grains of various different assumed porosity and organic fraction with observational data. In addition, by modelling the spectro-polarimetric observations of the Comet Hale-Bopp done earlier at VBO, new information on the grain composition, namely, the proportion of glassy versus crystalline silicates has been obtained.

Stars And Stellar Systems

Stars

The study of stars of various types - their composition, structure and evolution - constitutes a subject of intense research activity in the Institute.

Important new insights have been obtained on the nature of the so-called R Coronae Borealis (RCB) stars. These stars are photometrically distinct from other stars by their decline at unpredictable times by one to several magnitudes, as a cloud of carbon soot obscures the stellar photosphere for weeks to months. Spectroscopically, the distinctive signature of an RCB is weak Balmer lines which indicate an atmosphere deficient in hydrogen. What are the evolutionary paths by which some stars with their normal hydrogen-rich atmospheres are converted to RCBS with helium-rich atmospheres? And what are the physical processes that trigger and control the development of the unpredictable photometric decline of these stars? These are two of the fundamental questions about RCB stars that researchers are currently trying to answer.

A set of high-resolution optical spectra of R CrB star acquired before, during and after its 1995-96 decline has been analyzed by Institute's scientists in collaboration with scientists from several other Institutions in the world in order to attempt to answer the second of the above questions. This novel data set provides new information on the decline of the star. This includes the discovery that the onset of the decline is marked by distortions of absorption lines of high-excitation lines, and quickly followed by emission in these and in low-excitation lines. This 'photospheric trigger' implies that dust causing the decline is formed close to the star. An outcome of the above analysis is that R CrB might have a compact companion surrounded by an accretion disk. This suggestion has been submitted as a proposal to the Hubble Space Telescope (HST) for high resolution UV spectroscopy in collaboration with scientists from several other Institutions in the world. The proposal has been accepted and 13 orbits have been allocated for this study.

Among other works on RCB stars, the surface abundance analysis of 18 R CrB stars has been completed. In an interesting piece of work, the presence of cool gas (T ~ 1100 K) in the atmosphere of the R CrB star V854 Cen during a deep minimum has been detected by the analysis of C2 molecular lines. This is an important observation which indicates that dust nucleation occurs in the atmospheres of these hot stars (Teff ~ 7000 K) after passage of a shock wave.

In the context of stellar evolution, work on the atmospheric abundances and physical properties of intermediate temperature He stars is being pursued in the Institute using high resolution spec troscopy and model atmospheres exclusively developed for this programme.

Another area of stellar astronomy in which significant new results have been obtained by Institute's scientists is the so-called post-AGB (post-asymptotic giant branch) phase of stellar evolution. During this phase in the advanced stage of evolution of typically low-mass stars, substantial mass loss occurs from the outer envelop of the star. The ejected mass, which forms a shell around the hot central star, is ionized by the radiation from the hot central star and is visible as a planetary nebula. The central star, subsequently cools, contracts and ends up as a white dwarf.

One of Institute's scientists in collaboration with a team of international scientists has studied the rapid evolution of a newly horn planetary nebula - the so--called Stingray Nebula - by analyzing the images of this nebula obtained with the Hubble Space Telescope. This study has provided new insights on the early structure and evolution of planetary nebulae.

Interstellar Medium

Work is being done on the so-called Young Stellar Objects (YS0s). Stars are born in the cores of interstellar molecular clouds. In their early pre-main-sequence phase, these "stars" or YS0s are still surrounded by their parent cloud envelop and often have circumstellar disks that drive bipolax jets and outflows and also cause polarization of star light by scattering. Institute's scientists are studying YS0s in several star forming regions by emission-line imaging, spectroscopy and polarimetry, and have so fax observed about 25 of these objects. This study is likely to yield important insight into the process of star formation.

Gamma Ray Bursts

Sustained efforts over the past few years fructified this year when Institute's scientists were able to make early observations of the afterglow of the Gamma Ray Burst (GRB) GRBOO0301c. Multi-band observations of the Optical Transient (OT) associated with GRBOO0301c was carried out between 2-4 March 2000 using the 2.34-m Vainu Bappu Telescope (VBT) at Kayalur. When combined with other reported data, the initial decline in the R-band magnitude with log (t - to), the time since the burst, is fit with a slope a1 = -0.70 + 0.07 which steepens after about 6.0 days to a slope of a2 = -2.44 + 0.29. It is found that this change in slope does not occur smoothly, rather there is an indication of a possible bimodal distribution. The available measurements of the evolution of (B-R) color do not show any discernible evolution in the first 12 days. These observations have important implications for the GRB models which are currently under investigation.

Theoretical Asrophysics

Radiative Transfer

Radiative transfer continues to be one of the major areas of research activity in Theoretical Astrophysics in the Institute.

Using detailed radiative transfer calculations, the Institute's scientists had shown in the previous year that the observed linear polarization in the molecular lines of C2, MgH, ete in the spectrum of the quiet sun is caused by coherent scattering processes in the solar atmosphere as in the case of atomic lines. Extending that work further, the parameters such as the oscillator strengths, the inelastic collision rates, and depolarizing elastic collision rates for a number of observed molecular transition lines in the solar atmosphere have now been obtained, which have important implications for the states of various molecules in the solar atmosphere.

Radiative transfer calculations were used to understand the nature of the recently discovered brown dwarf Gliese 229B. In particular, the formation of methane line at 2.3 micron in Brown Dwarf Gliese 229B was studied. By fitting the synthetic continuum, spectra with the observed spectra at a wide range of wavelengths, the physical properties of the object such as the elective temperature and surface gravity were determined.

Magnethydrodynamics (MHD)

A remarkable fact about the large-scale magnetic fleid in the Sun is that it is mostly concentrated in isolated magnetic flux tubes at the visible surface and also in the form of coronal loops where the field strengths are of order 1500 Gauss. Why flux tubes rather than uniformly distributed magnetic field? Institute's scientists are engaged in attempts to answer this question by studying the relaxation of a compressible plasma to equilibrium configuration with flow. Three classes of equilibrium solutions corresponding to energy extrema satisfying the constraints of conservation of mass, energy, angular momentum, cross helicity and relative magnetic helicity, have been found. One of these solutions with increasing radial density profile has been identified to be relevant for solar flux tubes. Further studies exploring the stability of these solutions are in progress.

Plasma physics and accretion process

A kinetic theory of the Jeans instability of a dusty plasma has been developed. The effect of grain charge fluctuations due to the attachment of electrons and ions to the grain surface has been considered. It is demonstrated that the grain charge fluctuations alter the growth rate of the gravitational collapse of the dusty plasma.

It is shown that a certain class of flare models for variability from accretion disk coronae are subject to beam-plasma instabilities. These instabilities can prevent significant direct acceleration and greatly reduce the variable X-ray emission argued to arise via inverse Compton scattering involving relativistic electrons in beams and soft photons from the disk.

The process of formation of quasar black holes from magnetized accretion of a collapsed disk has been studied. It is shown that, in a self-similar accretion flow model, for typical halo parameters, about IOSMD accretes (thus forming a black hole) via small magnetic stresses (or alternatively by self-gravity induced instability) in ~ 108 years. A model of self-gravitating evolution of a compact magnetized disk has also been studied. The formalism can be applied to other contexts like formation of protostellar disks as well, and has important implications for dwarf galaxy formation and a residual large scale seed magnetic field.

Galactic Dynamics

It is known that more than 90% of the material content of the Universe is in the form of some unknown, invisible matter. The nature and distribution of this so-called "dark matter" in the Universe is one of the major unsolved problems of contemporary cosmology. This dark matter, widely believed to he constituted of some unknown weakly interacting particles of small mass, is a major component of the total masses of individual galaxies, including that of our own Galaxy, the Milky Way, as well as the masses of clusters of galaxies. Institute's scientists are engaged in trying to decipher the phase space distribution of these dark matter particles in our Galaxy from various observational data. An efficient Poisson Equation solver for axisymmetric mass distributions has been developed for this purpose using the method of spherical harmonics expansion of the gravitational potential of dark matter in the Galaxy. This code has been used to self-consistently solve the phase space distribution of the dark matter coupled to the visible matter in the Galaxy. The results show that in order to explain the Galactic rotation curve data and the dynamics of the dwarf spheroidals in the outskirts of the Galaxy, the velocity dispersion of the dark matter particles in the solar neighbourhood has to be >~ 570 km s-1, a value significantly larger than the usually assumed value of ~ 270 km s-1. This result is important in the context of interpretation of the data from various experiments that are currently underway at various laboratories in the world to directly detect the dark matter particles in cryogenic detectors, and implies important constraints on the nature of the dark matter particles.

Important new results have also been obtained in the study of galaxy dynamics by means of numerical N-body simulations. These include a study of the tidal effects on a satellite galaxy caused by a centrally concentrated massive perturber, an investigation of oscillations of galaxies, a study of the process of violent relaxation in elliptical galaxies, and several other related issues.

Atomic Astrophysics

Atomic Astrophysic