Showing papers by "Aligarh Muslim University published in 2002"

Heavy Metal Toxicity: Effect on Plant Growth and Metal Uptake by Wheat, and on Free Living Azotobacter

Abstract: A pot study was conducted to investigate the toxiceffects of certain heavy metals on the plant growth and grainyield of wheat (Triticum aestivum L.). The resultsrevealed that heavy metals brought about significant reductionsin both parameters, Cd being the most toxic metal followed by Cu,Ni, Zn, Pb and Cr. Moreover, the presence of Cd in the soilresulted in the maximum inhibition (84.9%) in the number of freeliving Azotobacter chroococcum cells over the control. Thephytotoxicity was apparently due to the susceptibility of thefree living Azotobacter chroococcum cells to the toxicdoses of heavy metals.Protein content decreased from 19.0–71.4% in metal exposedplants at metal concentrations equivalent to those found inpolluted soil. Metal uptake by grains was directly related tothe applied heavy metal with greater concentrations of metalsfound in cases where metals were added separately rather than incombinations. The toxic effects on the plant growth, nitrogencontent in plant parts, and protein content in grains, exerted bytwo metals in combination were not additive, but rather only assevere as for the most toxic metal alone.

Clastogenicity of pentachlorophenol, 2,4-D and butachlor evaluated by Allium root tip test.

Abstract: The meristematic mitotic cells of Allium cepa is an efficient cytogenetic material for chromosome aberration assay on environmental pollutants. For assessing genotoxicity of pentachlorophenol (PCP), 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-chloro-2,6-diethyl-N-(butoxymethyl) acetanilide (butachlor), 50% effective concentration (EC(50)), c-mitosis, stickiness, chromosome breaks and mitotic index (MI) were used as endpoints of genotoxicity. EC(50) values for PCP and butachlor are 0.73 and 5.13 ppm, respectively. 2,4-D evidently induced morphological changes at higher concentrations. Some changes like crochet hooks, c-tumours and broken roots were unique to 2,4-D at 5-20 ppm. No such abnormalities were found in PCP and butachlor treated groups, however, root deteriorated and degenerated at higher concentrations (<3 ppm) in PCP. MI in 2,4-D showed a low average of 14.32% followed by PCP (19.53%), while in butachlor it was recorded 71.6%, which is near to the control value. All chemicals induced chromosome aberrations at statistically significant level. The highest chromosome aberration frequency (11.90%) was recorded in PCP at 3 ppm. Large number of c-mitotic anaphases indicated that butachlor acts as potent spindle inhibitor, whereas, breaks, bridges, stickiness and laggards were most frequently found in PCP showing that it is a potent clastogen.

Induction of micronuclei and erythrocyte alterations in the catfish Clarias batrachus by 2,4-dichlorophenoxyacetic acid and butachlor.

Abstract: The micronucleus test (MNT) in fish erythrocytes has increasingly been used to detect the genotoxic effects of environmental mutagens and its frequency is considered to reflect the genotoxic damage to cells, mainly the chromosomes. Besides, morphologically altered erythrocyte is taken as an index of cytotoxicity. Both parameters were used in the present study by two herbicides, 2,4-dichlorophenoxyacetic acid (2,4-D, in 25, 50 and 75 ppm concentrations) and 2-chloro-2,6-diethyl- N -(butoxymethyl) acetanilide (butachlor, in 1, 2 and 2.5 ppm concentrations) for genotoxic and cytotoxic endpoints. The study was carried out by an in vivo method on peripheral erythrocytes of catfish Clarias batrachus using multiple sampling times (48, 72 and 96 h). Cytogenetic preparations were made by haematoxylin-eosin staining technique. Pycnotic and granular micronuclei (MN) were consistently observed irrespective of chemical tested. A wide range of altered cells was also observed. Echinocytes accompanied by altered nuclei and vacuoles were prominent feature of 2,4-D, whereas, anisochromasia and anisocytosis of erythrocytes were characteristic of butachlor. Increase in MN as well as altered cells frequencies were significant. A positive dose-response relationship in all exposures and sampling times was observed. Herbicides used were found to be genotoxic as well as cytotoxic in this fish. The suitability of the adopted parameters for the screening of the aquatic genotoxicants is discussed.

On Commutativity of Rings With Derivations

Abstract: Let R be a ring and d : R → R a derivation of R. In the present paper we investigate commutativity of R satisfying any one of the properties (i)d([x,y]) = [x,y], (ii)d(x o y) = xoy, (iii)d(x) o d(y) = 0, or (iv)d(x) o d(y) = x o y, for all x, y in some apropriate subset of R.

Salt-induced cloud point in anionic surfactant solutions: Role of the headgroup and additives

Abstract: Anionic surfactants are not known to show a clouding phenomenon in aqueous solutions. On the other hand, this is a general feature for nonionic surfactants. Here the effect of addition of tetra-n-butylammonium bromide (Bu4NBr) on the clouding phenomenon in sodium dodecylbenzenesulfonate (SDBS) has been studied by measuring cloud points (CP) for each combination. Similar type of studies were also performed with poly(ethylene glycol) t-octylphenyl ether (TX-100). The CP varies in an opposite manner for the two classes of surfactants, which is explained in terms of charge variation in each type of micelles by the addition of Bu4NBr. A relationship between [SDBS] vs [Bu4NBr] has been worked out for getting the CP − phenomenon in SDBS solutions: nearly one Bu4NBr molecule is needed for each two SDBS monomers for getting the CP in the system. With 10-mM SDBS, the addition of Bu4NBr shows an interesting phase behavior, where a stable colloidal phase with bluish − white appearance (preclouded) appears preceded b...

Characterization of a partially folded intermediate of stem bromelain at low pH

Abstract: Equilibrium studies on the acid included denaturation of stem bromelain (EC 3.4.22.32) were performed by CD spectroscopy, fluorescence emission spectroscopy and binding of the hydrophobic dye, 1-anilino 8-naphthalene sulfonic acid (ANS). At pH 2.0, stem bromelain lacks a well defined tertiary structure as seen by fluorescence and near-UV CD spectra. Far-UV CD spectra show retention of some native like secondary structure at pH 2.0. The mean residue ellipticities at 208 nm plotted against pH showed a transition around pH 4.5 with loss of secondary structure leading to the formation of an acid-unfolded state. With further decrease in pH, this unfolded state regains most of its secondary structure. At pH 2.0, stem bromelain exists as a partially folded intermediate containing about 42.2% of the native state secondary structure Enhanced binding of ANS was observed in this state compared to the native folded state at neutral pH or completely unfolded state in the presence of 6 m GdnHCl indicating the exposure of hydrophobic regions on the protein molecule. Acrylamide quenching of the intrinsic tryptophan residues in the protein molecule showed that at pH 2.0 the protein is in an unfolded conformation with more tryptophan residues exposed to the solvent as compared to the native conformation at neutral pH. Interestingly, stem bromelain at pH 0.8 exhibits some characteristics of a molten globule, such as an enhanced ability to bind the fluorescent probe as well as considerable retention of secondary structure. All the above data taken together suggest the existence of a partially folded intermediate state under low pH conditions.

The system of generalized vector equilibrium problems with applications

Abstract: In this paper, we introduce the system of generalized vector equilibrium problems which includes as special cases the system of generalized implicit vector variational inequality problems, the system of generalized vector variational and variational-like inequality problems and the system of vector equilibrium problems. By using a maximal element theorem, we establish existence results for a solution of these systems. As an application, we derive existence results for a solution of a more general Nash equilibrium problem for vector-valued functions.

Aromatic Triazoles as Corrosion Inhibitors for Mild Steel in Acidic Environments

Abstract: 3-hydroxyphenyl-4-phenyl-5-mercapto-1,2,4,triazole (HPMT); 3-aminophenyl-4-phenyl-5-mercapto-1,2,4,triazole (APMT); 3,4-diphenyl-5-mercapto-1,2,4-triazole (DPMT); and 3-cinnamyl-4-phenyl-5-mercapto-1,2,4,triazole (CPMT) were synthesized in the laboratory, and their influence on the inhibition of corrosion of mild steel in 1 N hydrochloric acid (HCl) and 1 N sulfuric acid (H2SO4) was investigated by weight loss and potentiodynamic polarization techniques. The inhibition efficiency of these compounds was found to vary with concentration, temperature, and immersion time. Good inhibition efficiency was evidenced in both acid solutions. The adsorption of these compounds on the steel surface for both acids was found to obey Temkin's adsorption isotherm. The potentiodynamic polarization data showed that the compounds studied were filming (adsorption) inhibitors.

Semiconductor-mediated photocatalyzed degradation of two selected pesticide derivatives, terbacil and 2,4,5-tribromoimidazole, in aqueous suspension

Abstract: The photocatalyzed degradation of two selected pesticide derivatives, namely 3-tert-butyl-5-chloro-6-methyluracil (terbacil 1) and 2,4,5-tribromoimidazole (TBI, 2) has been investigated in aqueous suspensions of titanium dioxide (TiO2) under a variety of conditions employing a pH-stat technique. The degradation was studied by monitoring the change in substrate concentration of the model compound employing HPLC analysis and the decrease in total organic carbon (TOC) content, respectively, as a function of irradiation time. The degradation kinetics were studied under different conditions such as reaction pH, substrate and photocatalyst concentration, type of TiO2 photocatalyst and the presence of alternative additives such as H2O2, KBrO3 and (NH4)2S2O8 besides molecular oxygen. The degradation rates and the photonic efficiencies were found to be strongly influenced by the above parameters. Toxicity tests for the irradiated samples of the pesticide derivatives measuring the luminescence of bacteria Vibrio fischeri after 30 min of incubation were also performed. The degradation products were analyzed by GC/MS technique and probable pathways for the formation of the products are proposed.

Influence of cohesion on scour around bridge piers

Abstract: Experimental results on temporal variation of scour around circular bridge piers founded in cohesionless and cohesive sediments under steady clear water flows are reported. The difference between scour patterns in cohesionless and cohesive sediments is brought out. Considering the horse shoe vortex to be the prime agent causing scour, a procedure is developed for computing the temporal variation of scour depth in cohesive sediments. Empirical relationships have also been obtained for maximum scour depth around bridge piers in cohesive sediments.

Characterization of solutions for vector equilibrium problems

Abstract: In this paper, we characterize the solutions of vector equilibrium problems as well as dual vector equilibrium problems. We establish also vector optimization problem formulations of set-valued maps for vector equilibrium problems and dual vector equilibrium problems, which include vector variational inequality problems and vector complementarity problems. The set-valued maps involved in our formulations depend on the data of the vector equilibrium problems, but not on their solution sets. We prove also that the solution sets of our vector optimization problems of set-valued maps contain or coincide with the solution sets of the vector equilibrium problems.

In vitro fungitoxicity of the essential oil of Syzygium aromaticum

Abstract: The in vitro antifungal activity of clove oil was studied against four test fungi namely Alternaria alternata, Fusarium chlamydosporum, Helminthosporum oryzae and Rhizoctonia bataticola by the agar well diffusion method. These test fungi were found to be highly sensitive to clove oil at a concentration of 100 μl/well. The inhibition zone diameter was found to be in the range of 55–65 mm. The toxicity of clove oil on the germination and growth of A. alternata was further examined in liquid medium. Concentration- and time-dependent toxicity was recorded from 0.05 to 20% (v/v) concentration. The minimum fungistatic concentration was found to be 0.05%. Above this concentration, lysis of conidia and inhibition of mycelial growth were detected. Microscopic analysis showed 20–40% lysis of conidia after 72 h of incubation at 5% concentration. However at higher clove oil concentration (10%), up to 20% of conidia were lysed within 24 h of incubation. Similar concentration- and time-dependent toxicity was observed at different concentrations and time intervals. The findings indicated that clove oil possesses fungicidal activity against phytopathogenic fungi. Further study is required to determine whether it could have value in the management of plant infectious diseases.

Influence of Dietary Phytic Acid on the Growth, Conversion Efficiency, and Carcass Composition of Mrigal Cirrhinus mrigala (Hamilton) Fry

Abstract: .— The effects of phytic acid on growth, protein efficiency, feed conversion, and carcass composition of mrigal Cirrhinus mrigala fry (2.5–3.5 cm) reared indoors at 18–22 C in 70-L flow-through (1-1.5 L/min) circular tanks were examined. Fish were fed isonitrogenous (40% crude protein) and isocaloric (4.32 kcal/g) purified test diets in the form of moist cake containing different levels (0.5, 1.0, 1.5, 2.0 and 2.5%) of phytic acid (dodecasodiurn salt) at a rate of 4% body weight twice daily (0800 and 1600 h). The highest weight gain (94.87%). specific growth rate (133%). protein efficiency ratio (2.02), and best feed conversion ratio (1.21) were observed in fish fed the control diet containing no phytic acid. Live weight gain and specific growth rate were significantly reduced by dietary phytic acid inclusion above 1%. Dietary inclusion of phytic acid markedly influenced the carcass composition of the fish. Whole body crude protein and fat content declined significantly (P < 0.05) in fish fed diets containing phytic acid, while percentage of moisture and ash in these fish was significantly (P≤ 0.05) higher than fish in control diets.

Inhibition of mild steel corrosion in the presence of fatty acid triazoles

Abstract: The influence of some fatty acid triazoles namely, 4-Phenyl-5-undecyl-4H- [1,2,4] triazole-3-thiol (PUTT), 5-Heptadec-8-enyl-4-phenyl-4H- [1,2,4] triazole-3-thiol (HPTT), and 5-Dec-9-enyl-4-phenyl-4H- [1,2,4] triazole-3-thiol (DPTT) on the corrosion of mild steel in 1 M hydrochloric acid (HCl) and 0.5 M sulfuric acid (H2SO4) was studied by weight loss and potentiodynamic polarization methods. The values of activation energy and free energy of adsorption of all the triazoles were calculated to investigate the mechanism of corrosion inhibition. The potentiodynamic polarization studies were carried out at room temperature, according to which all the compounds were mixed type inhibitors and inhibit the corrosion of mild steel by blocking the active sites of the metal. The adsorption of all the triazoles on mild steel surface in both the acid solutions was found to obey the Langmuir adsorption isotherm. All the compounds showed good inhibition efficiency in both acids. The inhibition efficiency of the compounds was found to vary with their nature and concentration, solution temperature and immersion time. Electrochemical impedance spectroscopy was also used to investigate the mechanism of the corrosion inhibition.

Effects of gibberellic acid spray on nitrogen yield efficiency of mustard grown with different nitrogen levels

Abstract: Mustard is cultivated throughout the world for oil in its seeds. Itrequires high nitrogen input for improved productivity but the nitrogen appliedto the soil is not fully utilised by the crops due to various constraints. Theobjective of the reported research was to determine if foliar- appliedgibberellic acid (GA3) could enhance crop growth and increasenitrogen-use efficiency. A field experiment was conducted during 1997–98in which GA3 (10−5 M) was applied tofoliage at 40d after sowing (pre-flowering) to mustard grown with 0, 40(sub-optimal), 80 (optimal) and 120 (supra-optimal) kgN ha−1. Foliar spray of GA3 was effectiveonly when plants received sufficient N (80 kgN ha−1). GA3 sprays significantly enhancedplant dry mass, leaf area, carbon dioxide exchange rate, plant growth rate,cropgrowth rate and relative growth rate. GA3 -treated plants showedenhanced nitrogen-use efficiency through redistribution of N to seeds.

A successful mass translocation of commensal rhesus monkeys Macaca mulatta in Vrindaban, India

Abstract: Rhesus monkeys Macaca mulatta and people have coexisted for many years in Vrindaban in Mathura District, Uttar Pradesh, India. The monkeys are highly valued both by locals and pilgrims to the area, in part because of their quasi sacred status, but during the last two decades the increasing human and monkey populations of the township have led to severe human-monkey conflict and a decrease in people's respect for the monkeys. To ease this situation one of the world's largest ever translocations of monkeys was undertaken. In 1995, 30 groups of rhesus monkeys, comprising an estimated 1,338 individuals, were recorded in Vrindaban. Of these, 12 groups, a total of 600 individuals, were translocated in January 1997 to eight sites in seminatural forested areas within the same District. A post-translocation study indicated that the translocated monkeys were settled and appeared to be exhibiting normal behaviour. This study indicates that translocation of commensal monkeys to forested areas can be a successful technique for their rehabilitation.

Heavy metal toxicity in legume-microsymbiont system

Abstract: A pot study was conducted to investigate the toxicity of cadmium (Cd), lead (Pb), copper (Cu), zinc (Zn), chromium (Cr), and nickel (Ni) added separately or in combination on chickpea (Cicer arietinum L.)-Rhizobium and greengram (Vigna radiata (L.) Wilczek)-Bradyrhizobium systems and metal uptake pattern by legume grains. Chickpea-Rhizobium system was comparatively more sensitive to heavy metal toxicity than greengram-Bradyrhizobium system in terms of decreased yield, low nitrogen content in plant tissues, and the protein content in grains. The phytotoxicity was apparently due to the susceptibility of the symbiotic apparatus against toxic doses of heavy metals. Metal uptake by grains seemed to be directly related to the concentration of heavy metals and was greater in the case of an individual metal added separately than in combination.

Non-union of the humeral shaft treated by internal fixation

Abstract: We reviewed 40 cases with non-union of the humeral shaft. There were 31 men and nine women patients with an average age of 38.5 (35–65) years. Thirty-four non-unions were of the atrophic type. Non-union was most often found at the transition of the middle third to the lower third of the humeral shaft. Six fractures were classified as open at the time of the initial injury. All patients were treated by open reduction and internal fixation with a dynamic compression plate (DCP). Cancellous bone graft was used in all atrophic non-unions. In one patient an additional fibular graft was used. The average follow-up was 13 (6–18) months. Final results were available for 34 patients. Thirty-one fractures (91%) healed in an average of 4.5 (3–9) months. Main complications were temporary radial nerve palsy in two patients and deep infection in one.

A Study of Some New Acidizing Inhibitors on Corrosion of N-80 Alloy in 15% Boiling Hydrochloric Acid

Abstract: Three new organic inhibitors, namely, dicinnamylidene acetone (DCA), disalicylidene acetone (DSA), and divanillidene acetone (DVA), were synthesized in the laboratory and their inhibiting ...

Dithiazolidines—A New Class of Heterocyclic Inhibitors for Prevention of Mild Steel Corrosion in Hydrochloric Acid Solution

Abstract: Heterocyclic compounds, namely 3,5-diphenyl-imino-1,2,4-dithiazolidine (DPID); 3-phenyl-imino-5-chlorophenyl-imino-1,2,4-dithiazolidine (PCID); 3-phenyl-imino-5-tolyl-imino-1,2,4-dithiazolidine (PTID); and 3-phenyl-imino-5-anisidyl-imino-1,2,4-dithiazolidine (PAID), were synthesized in the laboratory. Their influence on the inhibition of corrosion of mild steel in 1 N hydrochloric acid (HCl) was investigated by weight loss and potentiodynamic polarization techniques. The inhibition efficiency of these compounds was found to vary with concentration, temperature, and immersion time. Good inhibition efficiency (>90%) was evidenced even at a concentration of 25 ppm. Potentiodynamic polarization results revealed that three of the inhibitors, DPID, PCID, and PAID, are cathodic inhibitors while PTID is a mixed-type inhibitor. Adsorption on the metal surface obeyed Temkin's adsorption isotherm.

Seasonal variation in bacterial flora of the wastewater and soil in the vicinity of industrial area.

Abstract: Environmental pollution is one of the major problems being facedtoday due to the advent of extensive industrialization. Heavy metals are the most important contaminants in wastewater that are present in abundance and are toxic. Heavy metal contentsof sewage in the industrial estate of Aligarh (U.P.) have beendetermined by atomic absorption spectrophotometry. The analysisof samples collected from six different locations revealedsignificantly high levels of Fe, Zn, Cu, Cr and Ni. Certainbacteriological (Total bacterial count, Total coliform, Fecal coliform, and Fecal Streptococci) parameters of domestic and industrial sewage as well as soils were monitored from March1990 to January 1993. Total bacterial count, total coliform,fecal coliform and fecal streptococci were found to be lowestin all the samples of industrial wastewater compared to thosein domestic sewage and soil systems. The soil however, contained highest total culturable bacterial population. In view of the common practice of the application of sewage to agricultural land in the neighbouring area, the discharge ofindustrial wastewater without proper treatment into public sewers should be strictly prohibited.

Plasmid incidence in bacteria from agricultural and industrial soils

Abstract: Heavy metal contents of agricultural and industrial soils were determined by atomic absorption spectrophotometry The analysis of the samples collected from two different locations revealed significantly high levels of Fe, Zn, Cu, Cr and Ni Certain microbiological parameters (total aerobic heterotrophs, asymbiotic N2-fixers, total Actinomycetes and fungi) were also monitored from these soils A total of 70 bacterial isolates from agricultural and industrial soils were examined for plasmid DNA content and resistance to the antibiotics amoxycillin, cloxacillin, chloramphenicol, doxycycline methicillin, nalidixic acid, and tetracycline Minimum inhibitory concentrations (MICs) of Cu, Cr, Pb, Cd, Hg, Zn, and Ni for each isolate were also determined Resistance was most frequent to methicillin (485%), cloxacillin (457%), and nalidixic acid (40%) for all isolates of bacteria The highest MICs observed were 100 μg/ml for mercury, 800 μg/ml for Ni and 1600 μg/ml for other metals The incidences of metal resistance and MICs of metals for bacteria from industrial soil were significantly different to those of agricultural soil On a percentage basis, 914% of the total bacterial isolates from industrial soil were found to harbour plasmids whereas 40% of the isolates from agricultural soil contained plasmids