Browsing by Author "B. Lal"

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Biochemical and haematological changes following malathion treatment in the freshwater catfish Heteropneustes fossilis (Bloch)
(1986) B. Lal; Amita Singh; Anita Kumari; Neelima Sinha
Male specimens of H. fossilis were exposed to a concentration of 8 mg litre-1 of malathion in their aquarium water for 16 days during the early post-spawning phase. Its effects on glycogen of liver, testes and muscle, glucose and free fatty acids (FFA) in plasma, spleeno-somatic index (SSI), red blood corpuscle (RBC) and haemoglobin (Hb) were examined. Reduced levels of liver and muscle glycogen, associated with increasing plasma glucose, were noticed after 4 and 8 days of treatment but, after 16 days, a recovery was observed. Testicular glycogen did not respond to malathion exposure. Plasma FFA was also unchanged for 4 and 8 days of treatment but a higher level was recorded after 16 days' exposure. RBC and Hb were reduced following the 4-day exposure; however, no apparent change in their level was observed after 8 and 16 days' exposure. The SSI was also reduced during the 4- and 8-day treatments but 16 days' exposure caused the level to return to normal. Thus, this study demonstrates that, after prolonged exposure, H. fossilis develops a tolerance and partially recovers from the stress condition. In the initial stages carbohydrate was used as an energy source to meet the stress situation, while, in the later phase of exposure, FFA served as the major source of energy. © 1986.
Carbaryl-induced thyroid dysfunction in the freshwater catfish Clarias batrachus
(1991) Neelima Sinha; B. Lal; T.P. Singh
Freshwater female catfish, Clarias batrachus, were exposed to sublethal concentrations of carbaryl (12 mg/liter for 96 hr and 5 mg/liter for 16 days) during the prespawning and spawning phases of their annual reproductive cycle. The effects on the levels of thyroxine (T4) and triiodothyronine (T3), the T3 T4 ratio, and the extrathyroidal conversion of T4 to T3 were studied in serum, pharyngeal thyroid, and anterior and posterior kidney. Carbaryl exposure for 96 hr suppressed T4 but elevated T3 and the T3 T4 ratio in serum during both phases of experimentation. However, 16 days exposure caused a decline in T4 as well as in T3 and in the T3 T4 ratio. In the pharyngeal thyroid, carbaryl increased T4 as well as peroxidase activity and decreased T3 and the T3 T4 ratio. Its treatment for 96 hr did not elicit any change in the parameters studied in the anterior kidney, whereas in the posterior kidney it suppressed the levels of T4 and T3, peroxidase activity, and the T3 T4 ratio. However, carbaryl exposure for 16 days provoked increases in T4 and peroxidase activity but decreases in T3 and the T3 T4 ratio in anterior kidney. In posterior kidney, it did not change T4 and peroxidase activity, but decreased T3 and the T3 T4 ratio. It also stimulated extrathyroidal conversion of T4 to T3. © 1991.
Circadian Phase Dependent Thermal Stimulation of Ovarian Recrudescence in Indian Catfish, Clarias batrachus
(Swets en Zeitlinger B.V., 2000) Kaberi Acharia; B. Lal; T.P. Singh; A.K. Pati
Female Clarias batrachus acclimated to long photoperiod (13L:11D), were subjected to 30° ± 1°C thermopulses of either 6-hour or 12-hour duration at different phases of the LD cycle during the late resting phase (first week of January) of their annual reproductive cycle. Six-hour pulses were given either at 0600 or 1200 or 1800 or 0000. Twelve-hour thermopulses were given at 0600 or 1800. The long photoperiods were started at 0530 and that of ambient at 0630 coinciding with the average timing of sunrise that prevailed during the period of the study. The results indicate that exposure to long photoperiod or constant high temperature induced gonadal growth (GSI) and elevated testosterone and oestradiol levels in plasma. The high temperature was significantly more effective in its action. Further, combination of long photoperiod and high temperature produced the strongest gonadal stimulation as gauged from GSI and the levels of steroid hormones. Interestingly, 30°C thermopulses of 12-h duration when given at 0600 to fish held under long photoperiod induced gonadal development of comparable magnitude as observed in response to constant high temperature under long photoperiod. Thermopulses (30°C) of 6-h duration given at 0600 or 1200 also induced significant gonadal recrudescence but of much lesser magnitude. Thermopulses either of 6-h or 12-h duration at 1800 failed to elicit any change in the variables under study. The results of cosinor analysis performed on the responses to 6-h thermopulses also substantiate that there is a rhythm in the sensitivity of C. batrachus to thermopulses. Thus it appears that in this species temperature-induced gonadal recrudescence would occur only following coincidence of high temperature with the thermoinducible phase. The underlying mechanism of this phenomenon might be circadian in nature.
Circadian variation in circulating levels of melatonin, testosterone and estradiol-17β in a tropical freshwater catfish, Clarias batrachus, during different phases of the annual reproductive cycle
(2001) S.M. Roy; B. Lal; T.P. Singh
In the present investigation, daily variations in plasma levels of melatonin, testosterone and estradiol-17β were analysed in the tropical freshwater catfish, Clarias batrachus during early and late-preparatory, pre-spawning, late-spawning and post-spawning phases of its annual reproductive cycle. Plasma melatonin levels exhibited a significant circadian rhythm during all the reproductive phases but peaks were invariably at night. The amplitude of melatonin was high during the early-preparatory phase and low in the pre-spawning phase. Testosterone also displayed significant rhythm during all the studied phases except post spawning phase. Estradiol-17β revealed diurnal rhythm only during preparatory and pre-spawning phases. The peak in the levels of plasma testosterone and estradiol- 17β were recorded during the photophase. During the late-preparatory phase, the rhythm of testosterone coincided with the rhythm of estradiol-17β.
Corrosion inhibition in paper and pulp industry by some organic compounds
(2006) M.A. Quaraishi; B. Lal; Vakil Singh
Paper industries in India face serious problems due to corrosion of structural components and their high cost of replacement and maintenance. Amongst the wide spectrum of preventive measures available, addition of inhibitors is considered to be a reliable and cost effective means for dealing with corrosion problems. The present investigation aims at evaluation of a few organic compounds, namely lauric hydrazide, undecenoic hydrazide, aniline and para anisidine on corrosion behavior of mild steel in simulated corrosive environment, encountered in paper industries, using weight loss and potentiodynamic methods. © University of Manchester and the authors 2006.
Decontamination of coal mine effluent generated at the Rajrappa coal mine using phytoremediation technology
(Taylor and Francis Inc., 2017) Kalpana C. Lakra; B. Lal; T.K. Banerjee
Toxicity of the effluent generated at the Rajrappa coal mine complex under the Central Coalfields Limited (CCL, a subsidiary of Coal India Limited) in Jharkhand, India was investigated. The concentrations (mg L−1) of all the toxic metals (Fe, Mn, Ni, Zn, Cu, Pb, Cr, and Cd) in the coal mine effluent were above the safe limit suggested by the Environmental Protection Agency (EPA 2003). Among these, Fe showed the highest concentration (18.21 ± 3.865), while Cr had the lowest effluent concentration (0.15 ± 0.014). Efforts were also made to detoxify the effluent using two species of aquatic macrophytes namely “‘Salvinia molesta and Pistia stratiotes.” After 10 days of phytoremediation, S. molesta removed Pb (96.96%) > Ni (97.01%) > Cu (96.77%) > Zn (96.38%) > Mn (96.22%) > Fe (94.12%) > Cr (92.85%) > Cd (80.99%), and P. stratiotes removed Pb (96.21%) > Fe (94.34%) > Ni (92.53%) > Mn (85.24%) > Zn (79.51%) > Cr (78.57%) > Cu (74.19%) > Cd (72.72%). The impact of coal mine exposure on chlorophyll content showed a significant decrease of 42.49% and 24.54% from control values in S. molesta and P. stratiotes, respectively, perhaps due to the damage inflicted by the toxic metals, leading to the decay of plant tissues. © 2017 Taylor & Francis Group, LLC.
Diurnal and infradian rhythms in lipid parameters of Indian catfish, Heteropneustes fossilis
(1999) B. Lal; H.N. Singh; T.P. Singh; A.K. Pati
Twentyfour-hour variation in (14C) acetate incorporation in the liver lipid, and lipid concentrations in the liver and muscle tissues were studied during different phases of the annual reproductive cycle in the female freshwater catfish, H. fossilis. A 24-h rhythm in hepatic lipogenic activity was validated. Lipid concentration in liver and muscle also varied in a rhythmic fashion (τ = 24 h). The mesor and amplitude of these rhythms appeared to be modulated by the phase of the annual gonadal cycle of H. fossilis. All three lipid parameters, in addition, exhibited low frequency rhythms with a τ = 6 months or 3 months. The results indicate that the time of the day and month of the year for sampling in any experiment involving examination of lipid metabolism are of critical importance.
Ecological studies on seed germination of Leonotis nepetifolia (L.) Ait. f. in relation to environmental factors, with emphasis on fluoride polluted soils.
(1982) B. Lal; R.S. Ambasht
In the Mirzapur district of Uttar Pradesh, India, Leonotis nepetifolia (Labiatae) is characteristic and dominant in fluoride polluted areas. Fresh seeds are dormant due to the presence of a water-soluble inhibitor in the seed coat. Dormancy naturally ends on dry storage for 6 months between 15-35oC (December to May). Seeds do not germinate at 15-20oC. About 100% seed germination is achieved between 28-32oC and 40-60% soil moisture (rainy season: June-September) in 6 months-old seeds. Seeds withstand high fluoride concentration up to 1500 mu g (as NaF), which made this species very suitable for reclamation of polluted areas. -from Authors
Effect of endosulfan (thiodan) on vitellogenesis and its modulation by different hormones in the vitellogenic catfish Clarias batrachus
(1992) Sharmistha Chakravorty; B. Lal; T.P. Singh
This programme was planned in order to study the reproductive dysfunction caused by endosulfan in the fish Clarias batrachus with special reference to vitellogenesis. Vitellogenin was measured by radioimmunoassay. Endosulfan caused a drastic reduction in the plasma vitellogenin which was partially reversed by estradiol-17β (E2) in intact and ovariectomized fish. Hormones in combination were more effective than any single hormone in overcoming the impact of endosulfan. Triidothyronin (T3), ovine luteinizing hormone releasing hormone (oLHRH) were effective in minimizing the effect of endosulfan whereas cortisol (F) and ovine somatotropic hormone (oStH) did not reduce the effect of endosulfan. Amongst the combined hormone treatments, E2 + oLHRH and E2 + T3 were the most potent in overcoming the effect of endosulfan on vitellogenesis. © 1992.
Effect of endosulfan on thyroid physiology in the freshwater catfish, Clarias batrachus
(1991) Neelima Sinha; B. Lal; T.P. Singh
Effects of endosulfan on thyroid physiology have been studied in the female freshwater catfish, Clarias batrachus during the pre-spawning and spawning phases of its annual reproductive cycle. Effects of endosulfan varied with the length (96 h and 16 days) of exposure, reproductive status of the fish and organ. The 96-h endosulfan exposure significantly increased the level of thyroxine (T4) in serum and pharyngeal thyroid follicles concurrent with induction of peroxidase activity. However, triiodothyronine (T3) level and T3/T4 ratio decreased in serum and pharyngeal thyroid gland. No change was noticed in any of these parameters in the anterior kidney but in the posterior kidney endosulfan reduced T3 and T3/T4 ratio without affecting T4 levels and peroxidase activity. Sixteen days of endosulfan treatment also had a similar impact, except that it did not influence the studied parameters in pharyngeal thyroid. © 1991.
Effect of piscine GH/IGF-I on final oocyte maturation in vitro in Heteropneustes fossilis
(2005) M.K. Sarang; B. Lal
Growth hormone (GH) has recently been identified as co-gonadotropin regulating fish reproduction, hitherto, no effort has been made to see its effect on oocyte maturation in fishes, though some reports demonstrate the role of insulin like growth factor-I (IGF-I) in oocyte maturation in teleosts. Hence, effect of GH on oocyte maturation in post-vitellogenic H. fossilis has been worked out in the present study. Post-vitellogenic follicles in the ovarian tissue were challenged in vitro with H. fossilis pituitary homogenate (fPH), Clarias batrachus GH and GtH, barramundi IGF-I (IGF-I), 17α, 20β-dihydroxy-4-pregnen-3-one (DHP) and testosterone alone, or in combination with IGF-I for 18 h at 26±1°C. Incubation of ovarian tissue with GH in the presence of actinomycin D or cycloheximide or barramundi IGF-I antiserum was also made separately. In general, oocyte maturation was induced by fPH, barramundi IGF-I, GtH, GH and DHP, which was augmented further by addition of barramundi IGF-I. Testosterone had no effect on GVBD. Actinomycin D, cycloheximide and anti barramundi IGF-I abolished the GH induced oocyte maturation. Present study suggests for the first time that GH has a role in egg maturation in fish. © Springer Science+Business Media B.V. 2006.
Effects of cement dust pollution on plants of Psidium guayava
(1980) B. Lal; R.S. Ambasht
[No abstract available]
Electrocatalytic characterization of new La1-xSrxCoO3 films on Pt for use as oxygen anode in alkaline solutions
(2001) R.N. Singh; B. Lal
Pure and Sr-substituted lanthanum cobaltate films have been prepared on Pt by a sol-gel derived route and their physicochemical and electrochemical properties investigated using XRD, IR, cyclic voltammetriy (CV), Tafel-polarization and impedance techniques. The films have been obtained by coating a thick colloidal solution formed by peptization of freshly prepared metal carbonate precipitate in glacial acetic acid and subsequent drying and sintering at 650°C for 2 h. The substitution of La by Sr in the perovskite lattice does not indicate any significant influence on the rate of O2 evolution reaction (OER) in 1M KOH. Values of the Tafel slope and the order for the reaction have been observed to be ∼ 2.303RT/F and ∼ 1, respectively, regardless of the nature of the oxide catalyst. The apparent electrochemical activation energy (ΔHel*) decreases linearly with increasing potential across the oxide/1M KOH interface. Values of the entropy of activation (ΔS*) for the OER are highly negative. Based on electrode kinetic results, the OER is considered to proceed with the formation of adsorbed OH radical as the intermediate in a fast step followed by its electrochemical interaction to yield physisorbed H2O2 in the slow step.
Electrocatalytic properties of CuxCo3-xO4 (0 ≤ x ≤ 1) obtained by a new precipitation method for oxygen evolution
(1999) B. Lal; N.K. Singh; S. Samuel; R.N. Singh
Pure and copper-substituted cobaltites have been prepared by the hydroxide-carbonate-co-precipitation method and investigated in the form of films on nickel for their electrocatalytic properties towards oxygen evolution in alkaline solution. Results showed the marked improvement in the roughness as well as in the apparent electrocatalytic activity of the oxide. However, the substitution of Co by Cu in the spinel lattice did not indicate any significant electrocatalytic influence on the rate of oxygen evolution. Values of the Tafel slope and the reaction order with respect to OH- concentration have been observed to be ≅ 2.3 RT/F and one at low overpotential and 2 × 2.3 RT/F and one at high overpotential with each catalyst regardless of its nature.
Electrocatalytic Properties of Iron Ferrite (Fe3O4) Obtained by Thermal Decomposition Method Using Egg White (Ovalbumin)
(Pleiades Publishing, 2023) P. Chauhan; B. Lal; M. Malviya; A. Soni
Abstract: Nano-sized spinel oxide iron ferrite (Fe3O4) was obtained by thermal decomposition method using egg white (ovalbumin) at 500°C and characterized by physicochemical (TGA, IR, XRD, and SEM) and electrochemical (CV, impedance, and Tafel polarization) techniques. The characteristic vibration bands in FTIR (449–590 cm–1) and XRD powder patterns of decomposed oxide showed the formation of nano-sized (~28 nm) spinel-type oxide. The electrocatalytic performance of iron ferrite was investigated by CV, impedance, and Tafel polarization techniques. Fabricated GC/Fe3O4-electrode showed sluggish kinetic behaviour towards oxygen evolution reaction (OER) in 1 M KOH solution. Tafel slopes for OER at lower and higher overpotential regions were observed at 93–140 mV decade–1, and thermodynamic parameters such as activation energy (E a) and electrochemical entropy of reaction were estimated from the Arrhenius plot, and it was found to be ~23 KJ mol–1 deg–1 and –204 J mol–1 respectively. © 2023, Pleiades Publishing, Ltd.
Electrocatalytic properties of perovskite-type La1-xSr xCoO3 (0≤x≤0.4) obtained by a novel stearic acid sol-gel method for electrocatalysis of O2 evolution in KOH solutions
(2005) B. Lal; M.K. Raghunandan; M. Gupta; R.N. Singh
Lanthanum cobaltate and its strontium-substituted products have been prepared using a novel stearic acid sol-gel method at 600 °C. The oxide catalysts followed the rhombohedral hexagonal crystal geometry. Sr-substitution (0.2-0.4 mol) increased the oxide roughness as well as the apparent electrocatalytic activity greatly. The oxygen evolution on each oxide catalyst showed two Tafel slopes, one (b1≅ 65 mV/decade) at low and the other (b2≅ 103 mV/decade) at higher overpotentials. The reaction order w. r. t. OH- concentration was approximately unity. Values of thermodynamic parameters for the oxygen evolution reaction (OER), namely, the standard enthalpy of activation (ΔH#0) and standard entropy of activation (ΔS#0) were ∼126kJmol-1 and ∼112Jdeg-1mol-1 and ∼109kJmol-1 and ∼144Jdeg-1mol-1 on the base oxide and La0.6Sr 0.4CoO3, respectively. © 2004 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.
Electrocatalytic properties of perovskite-type La1-xSrxMnO3 obtained by a novel sol-gel route for O2 evolution in KOH solutions
(2002) N.K. Singh; B. Lal; R.N. Singh
Perovskite-type La1-xSrxMnO3 were synthesized at 600°C by a sol-gel route involving polyacrylic acid as precursor and investigated as electrocatalysts for the O2-evolution reaction (OER) in KOH solutions. The oxide powders were produced in the form of films on pretreated Ni-supports by an oxide-slurry painting technique. The study showed that Sr-substitution in the oxide matrix did not influence the oxide roughness significantly. The true electrocatalytic activity of the catalyst decreased with increasing Sr-substitution. The reaction order has been found to be approximately unity in OH- concentration. The Tafel slope values at low potential ranged between ∼ 103 and ∼ 116 mV decade-1. The rate of OE increased with increasing temperature following the Arrhenius law. Sr-substitution of 0.4 mol reduced the electrochemical activation energy (ΔHel#0) for OE by 12.9 kJ mol-1. © 2002 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.
Electrocatalytic properties of Sr-doped LaMnO3 obtained by a new sol-gel route in relation to O2 evolution in alkaline solution
(2001) B. Lal; N.K. Singh; R.N. Singh
Lanthanum manganites with molecular formula La1-xSrxMnO3 (0≤×≤0.5) have been synthesized in a powder form at 700°C using citric acid and ethylenediamine as gelling agents. These powders have been reproduced in the film forms on pretreated Ni-supports by an oxide-slurry painting technique. The study has indicated that Sr-substitution increased both the apparent as well as the true catalytic activity of the oxide and that it has no regular effect on the oxide roughness. The Tafel slope and the reaction order with respect to OH- concentrations at low overpotential have been observed to be approximately 2.3 × 2RTIF and unity, respectively. Sr-substitution seems to slightly decrease the apparent electrochemical activation energy (ΔHel#0), while it has no effect on the true electrochemical activation energy (ΔHc#0) and on the entropy of activation (ΔS#0) of the reaction.
Existence of a nitric oxide synthase/nitric oxide system in fish testis and its role in modulation of androgenesis
(Kluwer Academic Publishers, 2013) B. Lal; N. Dubey
Fish testis is equipped with different isoforms of nitric oxide synthase (NOSs) and is capable of producing nitric oxide (NO). Cellular sources of NO in the catfish testis are germ cells, Leydig cells, and macrophages. Production of testicular NO is under endocrine inhibitory control. Expression of NOSs exhibits seasonality and that depends on the reproductive status of fish. Leydig cells are highly sensitive to chemical as well as biological NO. NO inhibits testosterone production by the testis in vivo as well as by the isolated Leydig cells in vitro. © 2012 Springer Science+Business Media B.V.
High surface area lanthanum cobaltate and its A and B sites substituted derivatives for electrocatalysis of O2 evolution in alkaline solution
(2002) R.N. Singh; B. Lal
Co-based perovskite oxides with molecular formulae, La1-xSrxCoO3 (0≤x≤0.5) and La0.7Sr0.3Co1-yBy O3(B = Cu, Fe, Ni, Cr or Mn; 0.05≤y≤0.2) were prepared at 700°C, using a carbonate precipitation method, and reproduced in the film forms on pretreated Ni supports by an oxide slurry painting technique. The study showed that the partial substitution of La by Sr in the LaCoO3 matrix increased the electrochemically effective area (RF), as well as the apparent electrocatalytic activity (ia) but it decreased the true catalytic efficiency (it). Small substitutions at the B site by Ni seemed to slightly improve the electrochemically active area. On the contrary, all other substitutions, namely, Cr, Mn, Fe and Cu had the adverse effect. It is noteworthy that 0.1 mol Fe substitution considerably improved both the apparent as well as the true catalytic activity of the oxide, while other substitutions except Cu, had detrimental effect on the electrocatalysis of O2 evolution. The oxygen evolution reaction (OER) followed first-order kinetics with respect to OH- ion concentration. The Tafel slope (b) values at low potentials ranged between 60 and 80 mV decade-1 and that they increased slightly with increasing temperature. The electrochemical apparent activation energy (ΔHel#) of OE was observed to decrease on increasing the potential across the catalyst/1 M KOH interface. The ΔS# values for the reaction were largely negative. Based on these results a suitable mechanism for O2 evolution is proposed. © 2001 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.