Browsing by Issue Date, starting with "1989"

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Gene frequencies in natural and laboratory populations of Drosophila nasuta
(1989) ARUN KUMAR; J.P. GUPTA
Gene arrangement frequencies of different chromosome types of three inversions, HL‐2, IH‐35 and IIT‐2 are reported in some natural and laboratory populations of Drosophila nasuta. In general, the frequencies of inversion heterozygotes for these inversions are in excess of what is expected under Hardy‐Weinberg equilibrium in both natural and laboratory populations. This suggests that these inversion heterozygotes are hetero‐tic to the species as far as viability is concerned. Similar to what occurs in the cosmopolitan species, chromosomes with standard gene sequences are more frequent than inverted gene sequences in this species. The scarcity of inversion homozygotes is due to reduced viability of their carriers, which probably have lethal or sublethal combinations of alleles in the inverted sections of their chromosomes. Further, the inversion frequencies in laboratory populations follow the frequencies in natural populations. Copyright © 1989, Wiley Blackwell. All rights reserved
Calcite fabrics in the hinge zones of experimentally folded single layers of marble and limestone
(1989) V.K Gairola
The preferred orientations of poles to (0006) and (1014) planes in calcite have been studied in the inner and outer arcs of experimentally produced single-layer buckle folds in Carrara marble and Solnhofen limestone. The textures produced in the medium-grained marble differ from that of the fine-grained limestone. Further, the pole figures from the inner fold arcs are characterized by a general orthorhombic symmetry and a strong preferred orientation of the crystallographic fabric elements, whereas that from the outer fold arcs generally exhibits a triclinic symmetry and a weak preferred orientation. The difference in the pole figures in medium-grained marble and fine-grained limestone is attributed to the mechanism of internal deformation in calcite. The orthorhombic symmetry of the pole figures from the inner fold arc suggests a coaxial strain history in this zone, whereas the triclinic symmetry of the fabric diagrams from the outer fold arcs is attributed to a non-coaxial strain history. © 1989.
Role of inula racemosa and saussurea lappa in management of angina pectoris
(Informa Healthcare, 1989) S. Dwivedi; P.N. Somani; K.N. Udupa
The effect of crude root powder of Inula racemosa and Saussurea lappa was assessed in angina pectoris patients. I. racemosa (n==30) was found to possess significant antianginal property. In addition it also lowered the diastolic blood pressure, plasma cortisol and catecholamines. S. lappa (n==30) reduced the frequency of angina but did not produce any other change. Of the two, I. racemosa appears to be a better antianginal drug. © 1989 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.
Effect of cisplatin, lipopolysaccharide, muramyl dipeptide and recombinant interferon-gamma on murine macrophages in vitro. II. Production of H2O2, O2̄ and interleukin-1
(1989) A. Sodhi; B. Geetha
Murine macrophage monolayers treated with cisplatin, lipopolysaccharide (LPS), muramyl dipeptide (MDP) or recombinant interferon-γ (rIFNγ) for 2-48 h showed significant increases in the release of H2O2, O2̄ and interleukin-1 (IL-1) as compared to unrelated macrophages. The treatment of macrophages with different combinations of the above agents did not induce synergistic or additive effects on the production of H2O2, O2̄ and IL-1. The priming of macrophages with rIFN-γ had a significant effect in the additional increased production of H2Ō, O2- and IL-1 when subsequently treated with cisplatin, LPS or MDP.
A theory of freezing for molecular liquids
(1989) Udai P. Singh; Udayan Mohanty; Yashwant Singh
A synthesis of density functional-variational theory with statistical mechanical perturbation theory of liquids and spherical harmonics expansion is proposed to investigate the nature of freezing transitions in molecular systems. The theory is applied to hard core fluid models consisting of hard ellipsoids and hard dumbbells. For a small anisotropy of molecules the fluid freezes to an orientationally disordered lattice phase (plastic phase). For a large enough anisotropy an orientational freezing (nematic phase) occurs in the fluid of hard ellipsoids. These results are in qualitative agreement with computer simulations. At the isotropic-plastic transition we find that values of the first peak of the liquid structure factor vary with anisotropies for both hard dumbbells and hard ellipsoidal molecules. A criterion for orientational freezing is found. © 1989.
Measurement of heavy ion range in a complex medium using a solid state nuclear track detector
(1989) R.K. Jain; S.K. Bose; K.K. Dwivedi
A simple method has been described for measuring the range and energy loss of a heavy ion (239U) in a complex medium (Hostaphan, approximately 168 mu m) with the help of CR-39 solid-state nuclear track detectors. The authors present results obtained from measurements of range, energy loss of 16.34 MeV/u 239U ions in Hostaphan, and other related track parameters such as the bulk etch rate, the track etch rate, the sensitivity of the track detector VT/VG, the critical angle sin-1 (VG/VT) etc. The experimental range is compared with the corresponding theoretical value. The critical energy loss rate (dE/dX)c has been found to be 5 MeV mg-1 cm-2 for this detector material. © 1989 IOP Publishing Ltd.
View from beneath: Pathology in focus cysticercosis of the tongue
(1989) R.K. Jain; O.P. Gupta; N.C. Aryya
[No abstract available]
Chemistry of organic eutectics and 1:1 addition compound: p-phenylenediamine-catechol system
(1989) U.S. Rai; K.D. Mandal
The phase diagram of the p-phenylenediamine-catechol system, determined by the thaw-melt method, shows the formation of a 1:1 molecular compound and two eutectics. The linear velocities of crystallization of the pure components, the eutectics and the addition compound, determined by measuring the rate of movement of the growth front in a capillary, suggest that crystallization data obey the Hillig-Turnbull equation v = u(ΔT)n. where u and n are constants and ΔT is the undercooling. Experimental values of the heats of fusion and the entropy of fusion and calculated excess thermodynamic functions were considered and the results were explained on the basis of cluster formation in the eutectic melt. X-ray diffraction data of the pure components, the eutectics and the addition com- pound infer that these eutectics are not simply a mechanical mixture of the two components; preferential ordering of atomic planes occurs during their formation. The IR studies carried out on this system suggest intermolecular hydrogen bonding between the two components which form the molecular compound. © 1989.
Crystal and molecular structure of tetrachloro tetraaquo‐(1,8,10,17‐tetraazacyclooctadecane‐9,10‐dithione) dicopper (II)
(1989) Lallan Mishra; A.K. Pandey
Tetradentate bioactive macrocyclic thiourea 1,8,10,17‐tetraazacyclooctadecane‐9,18‐dithione(L) has been complexed with copper chloride dihydrate yielding bluish green coloured paramagnetic complex of orthorhombic geometry. The composition and tentative environment around Cu(II) is assigned on the basis of elemental analysis, IR, ESR spectra, X‐ray diffraction and magnetic studies. Copyright © 1989 WILEY‐VCH Verlag GmbH & Co. KGaA
Effect of latent iron deficiency on metal levels of rat brain regions
(Humana Press, 1989) Arti Shukla; K.N. Agarwal; Girja S. Shukla
Seven different metals (iron, copper, zinc, calcium, managanese, lead, and cadmium) were studied in eight different brain regions (cerebral cortex, cerebellum, corpus striatum, hypothalamus, hippocampus, midbrain, medulla oblongata, and pons) of weaned rats (21-d-old) maintained on an iron-deficient (18-20 mg iron/kg) diet for 8 wk. Iron was found to decrease in all the brain regions, except medulla oblongata and pons, in comparison to their respective levels in control rats, receiving an iron-sufficient (390 mg iron/kg) diet. Brain regions showed different susceptibility toward iron deficiency-induced alterations in the levels of various metals, such as zinc, was found to increase in hippocampus (19%, p<0.05) and midbrain (16%, p<0.05), copper in cerebral cortex (18%, p<0.05) and corpus striatum (16%, p<0.05), calcium in corpus striatum (22%, p<0.01) and hypothalamus (17%, p<0.02), and manganese in hypothalamus (18%, p<0.05) only. Toxic metals lead and cadmium also increased in cerebellum (19%, p<0.05) and hippocampus (17%, p<0.05) regions, respectively. Apart from these changes, liver (64%, p<0.001) and brain (19%, p<0.01) nonheme iron contents were found to decrease significantly, but body, liver, and brain weights, packed cell volume, and hemoglobin content remained unaltered in these experimental rats. Rehabilitation of iron-deficient rats with an iron-sufficient diet for 2 wk recovered the values of zinc in both the hippocampus and midbrain regions and calcium in the hypothalamus region only. Liver nonheme iron improved significantly; however, no remarkable effect was noticed in brain nonheme iron following rehabilitation. It may be concluded that latent iron deficiency produced alterations in various metal levels in different brain regions, and corpus striatum was found to be the most vulnerable region for such changes. It is also evident that brain regions were resistant for any recovery in their altered metallic levels in response to rehabilitation for 2 wk. © 1989 Humana Press, Inc.
Effects of mammalian pituitary gonadotropins on the seasonally quiescent ovary of the Indian wall lizard, Hemidactylus flaviviridis
(1989) U. RAI; S. HAIDER
Adult Indian wall lizards, Hemidactylus flaviviridis (Rüppell) with seasonally quiescent ovaries were treated either with ovine FSH or LH. Quantitative as well as histochemical observations revealed that only FSH could stimulate the ovarian growth and steroidogenesis whereas LH had no effect either on ovarian growth or on ovarian steroidogenesis. Copyright © 1989, Wiley Blackwell. All rights reserved
Withaperuvin H, a withanolide of Physalis peruviana roots
(1989) Yoshiteru Oshima; Hiroshi Hikino; Mahendra Sahai; Anil B. Ray
Withaperuvin H, a novel hexacyclic withanolide containing an unusual sulphide linkage, has been isolated from the roots of Physalis peruviana and its structure determined as (1) on the basis of chemical and spectral evidence.
Structure and transformation behavior of a rapidly solidified Al6.4wt.%Hf alloy
(1989) S.K. Pandey; C. Suryanarayana
An Al6.4wt.%Hf alloy was rapidly solidified from the liquid state using the melt-spinning technique. Transmission electron microscopy and diffraction techniques have been extensively employed to characterize the metastable and stable phases produced in the as-quenched condition and those obtained on subsequent thermal annealing. In the as-quenched state, the alloy showed the presence of only a supersaturated solid solution. On annealing the foils, the formation of a metastable cubic ordered phase Al3Hf was observed. This discontinuous precipitate transformed to the equilibrium phases on annealing at temperatures higher than 773 K. © 1989.
Developments in austenitic steels containing manganese
(1989) P. Rama Rao; V.V. Kutumbarao
Two broad categories of austenitic steels are considered in this review: (a) alloys based on the Fe-Mn-C system, typified by austenitic wear resistant (Hadfield) steels and (b) alloys based on the Fe-Mn-Cr system, typified by austenitic corrosion resistant steels. Advances made in recent years in understanding and improving the relevant properties and manufacturing methods of these steels are critically appraised. The development of austenitic manganese bearing high technology steels for fusion reactor and other non-magnetic applications, as well as those that can be used in cryogenic structures, is also considered. © 1989 Maney Publishing.
Lipid histochemistry of the epidermis of Natrix piscator during its sloughing cycle
(1989) J.P.N. SINGH; A.K. MlTTAL
The lipid histochemistry of the scale and hinge epidermis of the chequered water snake, Natrix piscator, throughout the sloughing cycle, has been described. The presence of comparatively high concentrations of phospholipids in the mesos layer and a‐layer, in comparison to neutral lipids, has been associated with a permeability barrier to transcutaneous water flux. Free fatty acids, present in almost all epidermal layers and in eosinophilic granular cells, may protect the epidermis from bacterial and fungal attacks. Cholesterol, in addition to phospholipids, in various keratinized layers, is assumed to be derived from membranous structures of epidermal cells and is regarded as a stabilizer of the phospholipids in membranes. Copyright © 1989, Wiley Blackwell. All rights reserved
Serum immunoglobulins and complement componnt C3 in Bancroftian filariasis
(1989) G. Nath; T.M. Mohapatra; P.C. Sen
[No abstract available]
Electrophoretic studies on male haemolymph in two groups of Heteroptera: Chemical characterization of plasma proteins
(1989) P.R. Yadav; Dinesh Kumar
SDS-PAGE on male haemolymph plasma from the three bugs, Lethocerus indicus, Ranatra filiformis and Antilochus coqueberti representing the two groups of Heteroptera, was carried out in order to determine the chemical nature of the prosthetic groups attached to the haemolymph proteins by using several chemical tests. These chemical characterizations indicate that the haemolymph contains a complex of glycoproteins, lipoproteins and ribonucleoproteins of varying electrophoretic patterns in the two groups. Most of the plasma proteins show glycosylation, and some of them further show attachment with the lipid and RNA molecules. © 1989.
A semi-wet route to the synthesis of YBa2Cu3O7-y ceramics
(1989) Dhananjai Pandey; V.S. Tiwari; A.K. Singh
Advantages of a semi-wet route to the synthesis of YBa2Cu3O7-y employing coprecipitation of yttrium and barium as precursor carbonates are presented. It is shown that the precursor carbonate is an intimate mixture of fine barium carbonate and amorphous yttrium carbonate particles. YBa2Cu3O7-y powders prepared under identical conditions by the conventional dry route and the present semi-wet route are analysed for compositional inhomogeneities and coherently scattering domain size (D), using principles of X-ray line profile analysis. It is shown that unlike the powders prepared by the conventional method, which contain compositional inhomogeneities and possess domains of about 2200 AA, powders obtained under identical conditions by the semi-wet route are free from compositional inhomogeneities and possess larger domain size (around 4000 AA). Since the actual particle size in both the cases is several μ m, the loss of coherency in each particle is attributed to the presence of twin interfaces. Better compositional homogeneity and lower density of twin interfaces in specimens prepared by the semi-wet route are believed to be responsible for the improved superconducting behaviour of ceramics prepared by the present method. © 1989 IOP Publishing Ltd.
Synthesis and spectral studies of lanthanide metal complexes of acetone (n-benzoyl)glycyl hydrazone
(1989) T.R. Rao; Genda Singh
Acetone (N-benzoyl)glycyl hydrazone (BzAGH) has been found to react with trivalent lanthanide metal ions to form complexes of the type [Ln(BiAGH)CI(H20)3]cl2where Ln = La(III), Fr(III) Nd(III), Sm(III), Eu(Ill), Gd(III), Tb(Ill) andDy(III). The complexes have been characterized by elemental analyses, molar conductance, magnetic, electronic, IR, 11H NMR and 13C NMR spectral techniques. Molar conductance studies in 0.001 M MeOH solutions indicate a 2:1 electrolytic behaviour of all the complexes. The nephelauxetic ratio, the bonding parameter, the Sinha1s parameter and the covalency angular overlap parameter have been calculated from the electronic spectra of the Pr(III), Nd(III) and Sm(III) complexes. The IR and 1H NMR spectral studies reveal that BzAGH acts as a neutral bidentate chelating ligand in the complexes. © 1989, Taylor & Francis Group, LLC. All rights reserved.
Further comments on J-shaped stress-strain curves and the crack resistance of biological materials
(1989) Yiu-Wing Mai; Anthony G. Atkins
The assertion by Kendall and Fuller (1987) that biological materials with J-shaped stress-strain curves are not necessarily more difficult to tear than Hookean solids, as suggested by Gordon (1978) is re-examined. While it is true that under certain conditions cracking is easier in materials with J-shaped stress-strain curves, the authors show that these conditions are not at all representative of biological materials. Gordon’s hypothesis remains true, therefore, that biological materials are difficult to break because of their lack of shear stiffness. © 1989 IOP Publishing Ltd.