Showing papers by "University of Madras published in 1980"
TL;DR: Using the crystal data on 21 proteins, a new scale of hydrophobic indices for the residues is set up, which provides valuable information with regard to hydrophilic domains, nucleation sites, surface domains, loop sites and the spatial positions of residues in protein molecules.
172 citations
TL;DR: In this article, it is shown that the standard prescription in conventional quantum theory for the joint probabilities of compatible observables is sufficient to characterize, more or less completely, the appropriate generalized collapse postulate which associates with each observable a unique "finitely additive expectation valued measure".
Abstract: In order to provide a mathematical framework for discussing the statistical correlations between the outcomes, when an arbitrary sequence of observables are measured, it is necessary to generalize the conventional von Neumann-Luders collapse postulate to observables with a continuous spectrum. It is shown that the standard prescription in conventional quantum theory for the joint probabilities of compatible observables is sufficient to characterize, more or less completely, the appropriate “generalized collapse postulate” which associates with each observable a unique “finitely additive expectation valued measure”. An interesting feature of the collapse associated with observables with continuous spectra, which again follows from the basic principles of conventional quantum theory, is that it must be formulated in terms of the so-called non-normal conditional expectations, which implies that the joint probabilities associated with successive observations of such observables are not in general σ-additive. The implications of this non-σ-additivity on the determination of expectation values, correlation functions etc., are also investigated. It is demonstrated that the basic prescriptions introduced in this paper constitute a natural completion of the framework of conventional quantum theory for discussing the statistics of an arbitrary sequence of observations.
48 citations
TL;DR: I1 .
Abstract: I1 . Haemocytes in haemolymph coagulation . . . . . . . (a) Cystocytes . . . . . . . . . . . (i) Light microscopic features . . . . . . . (ii) Ultrastructure . . . . . . . . . (iii) Histochemistry . . . . . . . . . (iv) Terminology . . . . . . . . . (b) Granular haemocytes . . . . . . . . . (i) Light microscopic features . . . . . . . (iii) Histochemistry . . . . . . . . . (2) Cystocytes in coagulation . . . . . . . . .
41 citations
TL;DR: The nucleicacid-directed protein synthesis is shown to be a natural consequence of a particular way of favourable interaction between nucleic acids and amino acids, and the model provides the missing link between the chemical evolution of small organic molecules and biological evolution through the process of mutations in nucleicacids and nucleic acid-directedprotein synthesis.
Abstract: The physical basis for the natural evolution of a primitive decoding system is presented using the concepts of molecular interactions. Oligoribonucleotides of five residues havingU at the 5′-end, a purine at the 3′-end and any combination of three bases in the middle is taken as a primitive tRNA (PIT). From conformational considerations PIT is expected to haveU-turn conformation wherein, N3−H3 of baseU hydrogen-bonds with phosphate, three residues ahead leaving triplet bases called primitive anticodons (PAC) into a helical conformation, and this creates a cleft betweenU and PAC. An amino acid can be comfortably nestled into the cleft with the amide hydrogens and carboxyl oxygen hydrogen-bonded to the last purine and the first uridine, while the side-chain can interact with the cleft side of PAC. The other side of PAC is free to base-pair with triplet codons on a longer RNA. Also two PACs can ‘recognize’ consecutive triplet codons, and this leads to a dynamic interaction in which the amino and carboxyl ends are brought into proximity, making the formation of peptide bond feasible. The cleft formed by different anticodon triplets, broadly speaking, shows preferences for the corresponding amino acids of the presently known codon assignment. Thus the nucleicacid-directed protein synthesis, which is a unique feature of all ‘living’ organisms is shown to be a natural consequence of a particular way of favourable interaction between nucleic acids and amino acids, and our model provides the missing link between the chemical evolution of small organic molecules and biological evolution through the process of mutations in nucleicacids and nucleicacid-directed protein synthesis.
39 citations
TL;DR: Tannins in aquatic environment cause harmful effects to aquatic life and a few microorganisms degrade tannins and the factors influencing degradation are discussed.
Abstract: Tannins in aquatic environment cause harmful effects to aquatic life. They are inhibitory to microbial growth, respiration and metabolism. A few microorganisms degrade tannins and the factors influencing degradation are discussed. The need for coordinated approach is emphasized.
33 citations
26 citations
25 citations
TL;DR: In this article, the lone-pair orbital interactions arising in a phosphodiester were incorporated into semi-empirical conformational energy calculations using a unifold "torsional potential" around the virtual bond linking the ester oxygen atoms.
Abstract: The lone-pair orbital interactions arising in a phosphodiester are incorporated into semiempirical conformational energy calculations using a unifold "torsional potential" around the virtual bond linking the ester oxygen atoms. The results explain the observed experimental data better than other methods.
24 citations
TL;DR: In this paper, the carbinol 8 was found to rearrange to the bicyclo (2, 2,2) octane derivative 10 in the presence of base; the rearrangement involved a transannular reaction in a ten membered ring resulting from an Oxy-Cope system.
24 citations
TL;DR: In this article, the authors measured the defect density and activation energy of an annealed polycrystalline polysilicon film of thickness 270-1670 A. The defect density F 0 (E ) max varies considerably from 21.4 to 5.25 μΩ cm eV -1 in the thickness range of 270 -1670
22 citations
TL;DR: In this paper, the dielectric properties of thermally evaporated TbF 3 thin film capacitors (Al/TbF3 /Al) of various thicknesses were studied in the frequency range 0.5-30 kHz at various temperatures (300-443 K).
TL;DR: Information theory is applied on 19 protein crystals to predict the spatial/zonal preference of residues in carp myogen using the knowledge of amino acid sequence and the implication of packing densities in different spatial zones is discussed.
TL;DR: In this article, the authors considered the SU2 × U1 theory in the absence of strings, using the formalism introduced by Nambu, and found a different space dependent Higgs vacuum with interesting properties under space inversion.
TL;DR: Using crystal data for a set of proteins and hydrophobic indices for amino acids, a criterion is drawn to identify nucleation sites in globular proteins and the properties of these sites are described in terms of certain relevant parameters.
TL;DR: Intra-individual factor as a function of time of day is also responsible for individual variability in the haemolymph protein concentration of the crab.
Abstract: The suitability of micro-Kjeldahl, biuret and Folin-Ciocalteu methods of protein determination in analysing the haemolymph protein concentration of Scylla serrata was assessed. It was found that biuret method is simple, reliable and the results are consistent.Intra-individual factor as a function of time of day is also responsible for individual variability in the haemolymph protein concentration of the crab.
TL;DR: In this paper, the kinetics of bromination of several aromatic compounds (anilides, anisoles, and phenols) were investigated in 80% aqueous acetic acid (v/v) in the temperature range 20-50°C using N-bromosuccinimide (NBS) as the reagent.
Abstract: The kinetics of bromination of several aromatic compounds (anilides, anisoles, and phenols) was investigated in 80% aqueous acetic acid (v/v) in the temperature range 20–50°C using N-bromosuccinimide (NBS) as the reagent. The reaction was found to be first order in the aromatic substrate (ArH), and zero order in NBS, the overall order being 1. Stoichiometry of the reaction was 1:1. An increase in solvent polarity increased the reaction rate, and chloride ions were found to be specific catalysts for the reaction. Arrhenius activation energy remained almost constant for all the substrates. A probable mechanism explaining all these observed facts was proposed. The mechanism involved an attack by Br+ or more probably by a solvated Br+ ion on the aromatic substrate.
TL;DR: The temporal sequence observed in the deposition of various deutoplasmic bodies, the occurrence of carotenoids linked to yolk, and the chemical nature of the follicle cells suggest an autoheterosynthesis of yolk in this species.
Abstract: Histochemical studies on maturing ovaries of C. clibanarius reveal that the yolk is deposited in 3 different forms: yolk spheres containing lipoproteins, smaller globules of a glycolipoproteinaceous nature, and granules containing only neutral and phospholipids. The temporal sequence observed in the deposition of various deutoplasmic bodies, the occurrence of carotenoids linked to yolk, and the chemical nature of the follicle cells suggest an autoheterosynthesis of yolk in this species.
TL;DR: In this article, metal-containing polyurethanes were synthesized from manganese and lead salts of mono(hydroxyethyl)phthalate by condensing them with hexamethylene diisocyanate and toluene diiscyanate in dimethylformamide as solvent.
TL;DR: In this article, it was shown that 4-methyl-8-acetyl-5,6,7,8-tetrahydro-1-naphthol 4 behaves similarly to the epimeric acetate 3c.
TL;DR: In this paper, the polymerization kinetics of methacrylamide (M) initiated by S2O ion in the presence and absence of the metal ions Ag+ and Cu2+ has been studied.
Abstract: The polymerization kinetics of methacrylamide (M) initiated by S2O ion in the presence and absence of the metal ions Ag+ and Cu2+ has been studied. The rate laws have been established and are compared with those of acrylamide. The results indicate that steric hindrance from the α-methyl group affects the initiation reaction. Cu2+ ions are found to reduce the rate of polymerization.
TL;DR: In this paper, a row of closely packed equispaced etch pits are observed on etching (010) basal cleavages of gypsum with analar grade nitric acid and 0·1 N potassium hydroxide solution.
Abstract: A row of closely packed equispaced etch pits are observed on etching (010) basal cleavages of gypsum with analar grade nitric acid and 0·1 N potassium hydroxide solution. It is established that these rows of pits are true to the whole bulk of the crystal, by successive etching and etching of match pairs, thin flakes as well as using different etchants. These rows of pits reveal low angle grain boundaries consisting of equispaced edge dislocations in the crystal. Irregular arrays of etch pits observed exactly correspond to its match face. Studying these rows on higher resolution, it is observed that they may reveal tilt or twist boundaries consisting of both edge and screw dislocations, probably created due to the impingement of the mis-oriented guest crystal causing stresses to the growing crystal. The implications are discussed.
TL;DR: Electrophoretic studies on the phenol oxidase of Paraplerurus sauridae indicated that the enzyme exists in multiple forms, and the possible mechanism of activation of the enzyme is suggested.
TL;DR: Helical parameter analysis has been carried out to examine various possible forms of Z-type poly(dinucleotide) helices and shows that the latter forms are characterised by conformational changes either in the 5′-side C4′–C5′ bond or 3′-sugar pucker in the dinucleotide repeat.
TL;DR: Molecular modelling studies reveal that only the anti or high anti-glycosyl conformations of ribavirin can mimic the inosine base, and it is suggested that experiments on the configurational isomers of Ribavirin, viz., aravirin and cycloaravirin would conclusively establish the conformational specificity and biological function of ribvirin and analogues.
TL;DR: In this paper, the electrical properties of thin film capacitors of SmF 3 were studied in the frequency range 0.5-30 kHz at various temperatures (300-376 K).
TL;DR: In this article, the second order rate constant of the Fe2+ reduction of trans-azido-pyridinebis(dimethylglyoximato)cobalt(III) and transazidoamminebis (dimethyl glyoximaton) cobalt (III) in aqueous perchlorate medium at I = 1.0 mol dm−3 ionic strength have been studied.
TL;DR: The lack of significant time-of-day variation in copper concentration and the occurrence of variation in total protein concentration and copper-protein ratio, indicate fluctuations in copper-free proteins, which may either be periodically sequestered or released by the tissues during different hours of the day.
Abstract: InScylla serrata, haemolymph copper is bound to protein and it can be more reliably determined by the 2,2′ biquinoline method than by other spectrophotometric methods. Ionic or free copper is absent from the haemolymph. The lack of significant time-of-day variation in copper concentration and the occurrence of variation in total protein concentration and copper-protein ratio, indicate fluctuations in copper-free proteins, which may either be periodically sequestered or released by the tissues during different hours of the day.
01 Mar 1980
TL;DR: It is concluded from cytology of the hybrids that small structural differences exist between the chromosomes of the parents and the potential ability of theParents to produce new recombinations inF2 is discussed.
Abstract: Cytomorphological characters ofSolanum indicum L. andS. melongena L., and of their hybrids (F
1) were studied. The hybrids were fertile with mostly normal meiosis. It is concluded from cytology of the hybrids that small structural differences exist between the chromosomes of the parents. The potential ability of the parents to produce new recombinations inF
2 is discussed. The conflicting observations of different workers on these species crosses are likely due to occurrence of variability in genetic architecture ofS. indicum andS. melongena. The plants ofF
2 progeny were tested againstFusarium oxysporum,Phomopsis vexans andLeucinodes orbonalis. The plants found to be resistant were used in the study and from the subsequent studies a large population ofF
4 generation was raised with desirable agricultural features.