Showing papers by "Aligarh Muslim University published in 1994"

DNA breakage by tannic acid and Cu(II): sequence specificity of the reaction and involvement of active oxygen species

Abstract: Tannic acid has numerous chemical, food and pharmacological applications. In the presence of Cu(II) and molecular oxygen it was found to cause breakage of calf thymus DNA and supercoiled plasmid DNA. Treatment of λ phage DNA with tannic acid protected cleavage with restriction endonucleases DraI and EcoRI∗ but not with SmaI and HaeIII. The results indicate that under the conditions used tannic acid preferably binds to AT base pairs. Restriction analysis of open circular form II plasmid DNA generated by tannic acid-Cu(II) treatment further showed that the strand breakage is caused at specific sites or sequences. In this reaction Cu(I) was shown to be an essential intermediate by using the Cu(I) sequestering reagents neocuproine and bathocuproine. By using job plots, we established that in the absence of DNA, six Cu(II) ions can be reduced by one tannic acid molecule. The involvement of active oxygen species in the reaction was established by the inhibition of DNA breakage by superoxide dismutase, thiourea, mannitol, formate and catalase.

Population status of nonhuman primates in Asia, with emphasis on rhesus macaques in India.

Abstract: Over 50 species of nonhuman primates live in 20 nations in Asia, interacting ecologically with over 3 billion people. The population status of different species of primates ranges from rare and endangered to abundant and relatively secure. The distribution, numbers, and trends of most species are not known, even for those such as Macaca fascicularis which are extensively used in biomedical research. Field surveys of rhesus populations since 1959 showed a serious 90% decline in population numbers in northern India throughout the 1960s and 1970s, followed by a partial recovery throughout the 1980s. Factors probably responsible for this recovery include a ban on trapping for export, increased agricultural production and economic development, increased conservation efforts, and perhaps a renewal of respect and tolerance for wildlife by the people of India. The history of rhesus populations in India can provide guidelines for conservation and management programs for other species. © 1994 Wiley-Liss, Inc.

Inactivation and repair of bacteriophage lambda by furfural.

Abstract: Furfural is a dietary mutagen and is present in various frequently consumed food products. In earlier work we have shown that it induces single strand breaks in duplex DNA which occur preferentially in AT base pairs. Experiments on the conservation of EcoRI cleavage site in mutant plasmids further established that repair of furfural damaged plasmid DNA occurs on propagation in the host cells. In this paper it is shown that the strand scissions induced by furfural in DNA account for its biological activity as assayed by inactivation of bacteriophage lambda. Using various repair defective mutants of E. coli we have shown that DNA repair predominantly involves the polA pathway.

Six-coordinate dinuclear hexaazamacrocyclic complexes of nickel(II), copper(II) and zinc(II) with tetraamide group ligands

Abstract: A series of 20–24 membered macrocyclic dinuclear transition metal complexes [M2L1X4]-[M2L4X4] (M = NiII, CuII or ZnII; X = Cl or NO3) have been synthesized by template condensation of diethylenetriamine with dicarboxylic acids. The bonding and stereochemistry of the complexes have been characterized by i.r.,1H-n.m.r., e.p.r. and electronic spectral studies, magnetic susceptibility and conductivity measurements. The Ni and Zn complexes exhibit octahedral geometry around the metal ion, whereas the Cu complexes possess a distorted octahedral geometry. Each metal ion is coordinated by two amide nitrogens and two secondary nitrogens of the diethylenetriamine moiety; the fifth and sixth coordination sites are occupied by the anions.

A revision of the Indian species of gonatocerus nees hymenoptera:chalcidoidea:mymaridae

Abstract: The Indian species of Gonatocerus Nees are revised. Thirty-nine valid species are recognized from India, including eleven species described as new in this paper. The Indian species are referred to three already known species-groups (ater-, sulphuripes-, litoralis-gioxips), and a new species-group (asulcifrons-group) proposed here for two Indian species. Separate keys to the species-groups and to species of three groups are given. The present study led to the proposal of 13 specific synonymies. Also five species are recorded from India for the first time, one species (kodaianus) described in Ooctonus Haliday is transferred to Gonatocerus as a new combination, and one species, G. longicrus Kieffer, is regarded as insertae sedis.

Kinetics of the interaction of ninhydrin with a [Cr(histidine)(H2O)3]2+ complex

Abstract: The composition of the N-diketohydrindylidene histidinato chromium(III) complex formed by interaction of ninhydrin with the [Cr(histidine)(H2O)3]2+ complex has been determined using Job's method of continuous variations. The reaction is slow and the kinetic studies were carried out under varying conditions of pH, temperature and [ninhydrin]. The observed pseudo-first order rate constant under these conditions follow the rate equation: $${1 \mathord{\left/ {\vphantom {1 k}} \right. \kern- ulldelimiterspace} k}_{obs} = {1 \mathord{\left/ {\vphantom {1 {\left\{ {K_t k_3 [N]} \right\} + {1 \mathord{\left/ {\vphantom {1 {k_3 }}} \right. \kern- ulldelimiterspace} {k_3 }}}}} \right. \kern- ulldelimiterspace} {\left\{ {K_t k_3 [N]} \right\} + {1 \mathord{\left/ {\vphantom {1 {k_3 }}} \right. \kern- ulldelimiterspace} {k_3 }}}}$$ The reaction has the features of a template mechanism which proceeds through coordination of ninhydrin to the [Cr(histidine)]2+ complex. The reaction is expected to involve the combination of two ligands (ninhydrin and histidine) attached to the same CrIII (CLAM reaction). The CrIII ion provides a better opportunity for the reaction of ninhydrin and histidine by assembling their reactive groups together. On the basis of the observed data the probable mechanism has been proposed.

2‐Hydrazino‐6‐methyl‐benzothiazole as an Effective Inhibitor for the Corrosion of Mild Steel in Acidic Solutions.

Abstract: Weight loss measurements and potentiostatic polarization studies show that 2-hydrazino-6-methyl-benzothiazole (HMBT) acts as an effective inhibitor for the corrosion of mild steel in 1 N HCl and 1 N H 2 SO 4 . It behaved predominantly as cathodic inhibitor in HCl and mixed inhibitor in H 2 SO 4 . Hydrogen permeation studies also show that HMBT acts as an effective cathodic inhibitor by decreasing hydrogen permeation current through mild steel surface. The adsorption of HMBT on mild steel from 1 N HCl and 1 N H 2 SO 4 is found to obey Langmuir's adsorption isotherm.

Single and interactive effects of root-knot nematode and coal-smoke on okra

Abstract: SUMMARY Effects of coal-smoke pollutants and the root-knot nematode Meloidogyne incognita race 1, singly and jointly, were investigated on okra, Abelmoschus esculentus in 1988 and 1989. Plants in clay pots were placed at two sites (Kl and K2), 1 and 2 km away from the stack of a coal-fired thermal power plant, and also at the Department of Botany, AMU (control site). The mean concentrations of SO2, NO2 and suspended particulate matter (SPM) were 141, 76 and 309 ag m-3 at K1, and 184, 93 and 205 atg m-3 at K2, but the concentrations of the pollutants at the control site were very low. Okra plants at the K2 site showed browning of the leaves, whereas injury was mild at K1. The intensity of the browning and the impact of nematode disease was appreciably higher in the infected plants at the polluted sites in both the years. The plants grown at the two sites exhibited suppressions in plant growth, yield and photosynthetic pigments, particularly at K2. M. incognita at the control site also caused significant reductions, but joint effects of the nematode and coal-smoke were synergistic. Nematode reproduction was enhanced at K1, but was unaffected at K2. Egg laying was reduced by 13 and 27 % at K1 and K2, respectively. The response of stomata and trichomes to air pollutants was negative and positive at the two sites, respectively, and stomatal opening was directly correlated with the percent suppressions in dry matter production, yield etc.

Free radical-induced fragmentation of proteins by quercetin

Abstract: The flavonoid, quercetin, is known to bind to DNA and, in the presence of Cu(II) and other ions, causes fragmentation of the molecule We examined whether quercetin might bind to protein and cause similar fragmentation By using UV spectroscopic and fluorescence quenching experiments we show that quercetin binds to bovine serum albumin and that the complex does, in the presence of Cu(II), lead to fragmentation of the protein The binding involves binding to tryptophan residues in the albumin The reaction is not detected in certain other tryptophan-containing proteins We discuss the possible implications for protein damage by this and other radical-generating reagents

Geochemistry of Early Proterozoic Mafic and Ultramafic Rocks of Jharol Group, Rajasthan, Northwestern India

Abstract: The deep water Jharol sediments of Aravalli Supergroup host sporadic bodies of mafic-ultramafic. rocks. Field evidence suggests that at least some of these rocks are extrusive in nature. Low to medium grade metamorphism and intense deformation has obliterated the original mineralogy and texture of these rocks. The ultramafic rocks are relatively more altered (serpentinized) with highly disturbed geochemical composition which cannot be used for petrogenetic interpretations. On the other hand, the mafic rocks are relatively less altered with some relict plagioclase feldpars. Geochemically, these mafic volcanics are Mgand Fe- rich tholeiites. These tholeiites have nearly flat to slightly enriched REE patterns (about 30 to 40x % chondrite La and 20 to 25x % Chondrite Yb), with (LalYb)N ratio ranging between 1.29 and 1.54 and (GdIYb)N ratio ranging between 0.97 and 1.07. All samples show slight to strong positive Eu anomaly. Immobile incompatible-element geochemical patterns and other binary plots suggest that these tholeiites have enriched chemistry and that grobably they have been derived from enriched source(s) and resemble closely with within plate and initial rift tholeiites. Trace elements, including REE based petrogenetic modelling indicate that (a) the source had about 3x% chondoritic REE abundances with nearly flat to slightly depleted pattern and (b) that these rocks were generated by about 8 to 12% partial melting of the modelled source followed by some olivine and clinopyroxene fractionation. Field as well as trace element characteristics indicate rift related (lithospheric extension) generation of these basalts with some influence of asthenosphere (deep mantle) on the lithospheric source(s) as indicated by positive Nb and Sr anomalies.

DNA breakage by tannic acid and Cu(II): generation of active oxygen species and biological activity of the reaction

Abstract: Tannic acid was shown to reduce oxygen to superoxide anioon. In the presence of Cu(II), the hydroxyl radical and hydrogen peroxide were formed. Strand scission reaction was shown to account for the biological activity of tannic acid as assayed by bacteriophage inactivation. The inactivating activity occurs through the Fenton pathway for free radical production and subsequent DNA cleavage by these radicals.

Estimation of climatic transition in Riyadh (Saudi Arabia) in global warming perspectives

Abstract: The present exercise is a study to enquire into the recent climatic transition, if any in Riyadh, Saudi Arabia. Conventional climatic indicators such as rainfall distribution, temperature regime, relative humidity, sunshine duration, wind velocity and evaporation characteristics were examined over a period of twenty six years of available meteorological data. The analyses showed a remarkable mutual resemblance and unidirectional trend in all the temperature parameters like absolute monthly maximum, absolute monthly minimum, mean monthly maximum, mean monthly minimum and mean monthly temperatures and the mean monthly maximum and mean monthly minimum relative humidities. Similarly, the trends in sunshine duration, wind velocity and pan evaporation were also supportingly in accordance to the general trends of climatic transition. The analysis based on a smaller period climatic data shows a good deal of agreement with the trends of studies on global warming projections made by simulated models on the basis of CO2 concentration changes in the atmosphere.

Medicinal Plantlore of Aligarh, India

Abstract: The folk healing uses of 25 plants common to rural areas of Aligarh are described. The botanical and local names of the plants are provided, as are particulars of prescriptions for therapeutic use, mode of administration, precautions and side effects, if any. The plants are used for treating arthritis, bronchial and pulmonary problems, diabetes, fevers, fractures and injuries, hydrophobia, jaundice, piles, pain, skin infections, tooth and tonsil problems, and urinary, gastric and intestinal diseases.

S =1 and S =2 EPR signals in modified CuO and BaCuO 2

Abstract: EPR spectra of (i) CuO annealed in air at different temperatures up to 900 \ifmmode^\circ\else\textdegree\fi{}C and (ii) CuO reacted with BaO in the ratio 3:2 at different temperatures up to 900 \ifmmode^\circ\else\textdegree\fi{}C were studied. In (i), evidence for the formation of monomers, dimers, and tetramers of copper ions was found. In (ii), in addition to those spectra obtained in (i), aggregates of four copper ions coupled through cyclic exchange with resultant electronic spin S=2 and affected by the immediate barium neighbors were obtained. It is found that these copper aggregates giving the EPR signals are magnetically isolated from the main CuO cluster.

Optimum feeding rate, and energy and protein maintenance requirements of young Clarias batrachus (L.), a cultivable catfish species

Abstract: . Protein and energy maintenance and optimum feed requirements are reported in the catfish, Clarias batrachus (L.), fed a purified diet (40% CP; 1487·1kJ/100g) at 0 to 8% (BW/day) ration levels. Linear (r = 0·985) increase was observed in daily average growth increment up to a ration level of 4% (BW/day), corresponding to 6·03g protein/(kg0·8BW/day) and 224·26 kJ energy/(kg0·8 BW/day). Maintenance requirements, obtained by regressing daily average growth increment to zero, were 0·942 g/(kg0·8 BW/day) for protein and 36·02 kJ/(kg0·8BW/day) for energy. Net gains in muscle protein and energy also depicted linear increase (r = 0·975) with feeding levels up to 6·03g protein/(kg0·8 BW/day) and 224·26kJ energy/(kg0·8 BW/day). On fitting the above data to regression equations, giving the amount of dietary protein and energy required to maintain a constant amount of body protein and energy, values of 1·005g/(kg0·8 BW/day) and 42·11 kJ/(kg0·8BW/day) were obtained for protein and energy respectively. The optimum feeding rate for this species, as evident from specific growth rate and conversion efficiencies, appears to be 3% (BW/day) at 30 ± 2°C. Moisture and lipid contents in muscle were found to be significantly (P < 0·05) affected by the ration levels.

Binuclear Transition Metal Complexes of Schiff Base Macrocycles Containing the Furanyl Moiety

Abstract: Binucleating macrocycles L comprised of two molecules of 2,5-diformylfuran and two molecules of 1,3-diaminopropane have been synthesized as cobalt(II), nickel(II) and copper(II) complexes by template reactions. On the basis of various spectroscopic studies the 20-membered macrocyclic complexes can be described as having six-coordinate octahedral structures where L is bonding through the nitrogens of 1,3-diaminopropane and the oxygens of the furanyl moiety. The elemental analyses and molecular ion peak from the mass spectra confirm their proposed 2:1 metal ligand stoichiometry. The overall geometries have been proposed on the basis of elemental analysis, i.r., 1H nmr, mass, reflectance spectra and magnetic susceptibility measurements. Referee I: R. K. Steinhaus Referee II: L. O. Spreer

Optimal design of accelerated life test plans under periodic inspection and type I censoring: The case of Rayleigh failure law

Abstract: Statistically optimal accelerated life test plans are determined for the case of Rayleigh failure distribution under the assumptions of periodic inspection and Type I censoring and two stress levels. For optimal plans the proportion of test units allocated to the low stress level and equally spaced inspection times are determined such that the asymptotic variance of the maximum likelihood estimator of p-th quantile at the use condition is minimized. Procedures for selecting a sample size are also discussed.