Browsing by Issue Date, starting with "2007"

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Attractiveness of Varanasi as a tourist destination: perspective of foreign tourists
(2007) Debadyuti Das; Pratap K.J. Mohapatra; Sushil Kumar Sharma; Ashutosh Sarkar
The present paper examines the attractiveness of Varanasi as a tourist destination from the perspective of foreign tourists considering several important dimensions simultaneously. These are demographic characteristics of tourists, their expectation on touristic attributes of the destination as also satisfaction with the same and finally holistic impressions of the destination. A factor analysis carried out on 24 touristic attributes pertaining to the expectation of visitors gives rise to seven meaningful constructs. Results of step-wise multiple regression analysis between the perceived attractiveness and the above seven constructs reveal the importance of each of these seven constructs in explaining the perceived attractiveness of the destination. Holistic impressions of Varanasi reveal that it is a city embodying the essence of Indian spiritualism and mysticism with Ganges and Ghats forming the heart of the city. © 2007 Inderscience Enterprises Ltd.
Water table fluctuation between drains in the presence of exponential recharge and depth-dependent evapotranspiration
(2007) R.M. Singh; K.K. Singh; Shivaraj R. Singh
A linearized form of the Boussinesq equation was solved analytically to predict the water table fluctuation in subsurface drained farmland in the presence of recharge and evapotranspiration (ET). The recharge was assumed to be variable with time and the ET considered decreasing linearly with a decrease in the water table height above the drains. The proposed analytical solution was verified for special cases with the existing solutions. There was a close match between the solutions. Applications of the solution in prediction of the water table height in a drainage system are illustrated with the help of physical examples. © 2007 ASCE.
Radiotracer technique in adsorption studies Part XVIII: Uptake of Ce(III) from aqueous solutions by hydrous manganese and stannic oxides
(2007) S.P. Mishra; Vijaya
The removal of Ce(III) from aqueous solutions by hydrous manganese oxide (HMO) and hydrous stannic oxide (HSO) was studied as a function of concentrations (10-2-10-7 mol·dm-3) and pH (1.2-10.0) by using the radiotracer technique. The effects of co-ions and irradiation of HMO and HSO were also studied. The uptake of Ce(III) fitted well with the Freundlich adsorption isotherm. No significant desorption of pre-adsorbed Ce(III) in the studied temperature range (303-333 K) indicates that both the solids may be good adsorbents for the removal of Ce(III). © 2007 Springer Science+Business Media, Inc.
Freeze-out volume of hot dense fireball
(2007) M. Mishra; C.P. Singh
A thermodynamically consistent excluded volume model is proposed to account for the particle multiplicities obtained from lowest SIS energies to the highest RHIC energies. The chemical freeze-out volumes lying in a slice of one unit of rapidity for pions and kaons are separately inferred from this analysis and the results are compared with the corresponding thermal freeze-out volumes obtained from the Hanbury-Brown Twiss (HBT) pion interferometry. Furthermore, we extract the variations of freeze-out number densities for pions and nucleons with the center-of-mass energy in our model and compare them with the HBT data. © 2007 Elsevier B.V. All rights reserved.
Single stage repair of anovestibular fistula in neonate
(2007) Vijay D. Upadhyaya; S.C. Gopal; D.K. Gupta; A.N. Gangopadhyaya; S.P. Sharma; Vijayendra Kumar
Anorectal malformations are one of the most common congenital defects. This study is conducted to evaluate the result of single stage anterior sagittal anorectovaginoplasty (ASARVP) in cases of vestibular anus (AVF) in neonatal age group without thorough gut preparation. All the patients of AVF admitted during 2003-2006 were included in this study. Single stage ASARVP was done in these patients without preparing the bowel in the lithotomy position, the fistula was freed and sufficient length of anorectum was dissected and vagina was separated. Midline incision at the proposed anal site was made, then a plane was dissected between the muscle complex going anteriorly. The mobilized anorectum was pulled to the proposed anal site and proper anoplasty was done. The results were evaluated for duration of surgery, need of bowel preparation, commencement of feed and hospital stay and follow-up (assessment of continence and anal dilatation). A total of 27 patients were included in our study. All patients were less than 1-month-old. Operative time ranges from 50 to 70 min. Bowel preparation was not needed. Per oral feed was started after 48 h in all patients and average duration of hospital stay was 3- 4 days. Postoperative regular anal dilatation was commenced after 1 week of operation. Continence results according to Kelly's method were good in 70%, fair in 21% and poor 9%. Single-stage anorectovaginoplasty in neonates has a good result in cases of AVF and avoids the need of bowel preparation. © 2007 Springer-Verlag.
Role of antibiotics in meconium aspiration syndrome
(2007) Sriparna Basu; Ashok Kumar; B.D. Bhatia
Background: Meconium aspiration syndrome (MAS) is a major cause of severe respiratory distress in newborns and the role of antibiotics in its management is not well defined. Objective: To determine the role of routine antibiotic therapy in the management of MAS. Methods: After excluding the possibility of sepsis, 144 patients with MAS were randomised into two groups. Group A (study group) received ampicillin and gentamicin for 7 days, commencing between 24 and 36 hours of life, and group B, the controls, received no antibiotics. Both groups received similar supportive management. The primary outcome measure was the development of infection. Details of clinical progress during hospitalisation were recorded. All were followed up for a minimum of 3 months. Results: The patient profiles were similar in both groups. Five patients (three in the study group, two controls) developed culture-positive sepsis during their hospital stay. No significant difference was detected between the groups regarding period of oxygen dependency (5.8 vs 5.9 days), day of starting feeds (4.0 vs 4.2), day of achievement of full feeds (9.4 vs 9.3), clearance of chest radiograph (11.7 vs 12.9 days) or duration of hospital stay (13.7 vs 13.5 days). The most common radiological features were parenchymal infiltrates followed by hyperinflation. The incidence of complications was similar in both groups. Conclusion: Routine antibiotic therapy is not necessary for managing MAS. © 2007 The Liverpool School of Tropical Medicine.
Shape evolution in76,78Kr nuclei at high spins in tilted axis cranking Hartree-Fock-Bogoliubov approach
(2007) A. Ansari; P. Sharma; U.R. Jakhar; H.L. Yadav
A two-dimensional tilted axis cranking Hartree-Fock-Bogoliubov (CHFB) calculation is performed for 76Kr and 78Kr nuclei up to high spins J = 30 employing a pairing-plus-quadrupole (PPQ) model interaction Hamiltonian. Intricate details of the evolution of single particle structures and shapes as a function of spin have been investigated. The results show the existence of energy levels with high K quantum numbers lying close to the yrast line in both the nuclei. Such high K states should exhibit isomeric characteristics due to the K-selection rules for the γ-decays. Moreover, in 78Kr a new band with J = 20-30 lying below the observed ground band is predicted. © Indian Academy of Sciences.
Microstructures and microtextures of natural cokes: A case study of heat-affected coking coals from the Jharia coalfield, India
(Elsevier B.V., 2007) Ashok K. Singh; Mahendra P. Singh; Mamta Sharma; Sunil K. Srivastava
In Jharia coalfield, nearly 1250 Mt of coking coal has been devolatilized due to igneous intrusives and ∼ 1900 Mt due to mine fires. This paper is an effort to investigate the effect of carbonization in two intrusive affected coal seams of Ena (seam XIII) and Alkusa (seam XIV) collieries of this coalfield. Through petrographic studies by microscopy, characterization of normal and heat-affected coals was carried out. The microstructures and microtextures produced due to extraneous heat have been related to nature and extent of heat, location of heating source, and quality and quantity of natural coke produced. Based on the results of this study and earlier studies, an effort has been made to study the classification scheme for microtextures of natural cokes generated through in-situ carbonization of the coal seams. It has been observed that in case of such heat effects under overburden pressure, the anisotropy is much more pronounced as compared to laboratory-carbonized cokes. In the mildly carbonized coals (pre-plastic phase, < 300 °C) the vitrinite attained higher reflectance than normal vitrinite, liptinite started disappearing, and inertinite remained unaffected. In the moderately affected coals (plastic phase, 300-500 °C), mesophase spheres and fused natural cokes were generated from the reactives (vitrinite and liptinite maceral groups), the liptinites disappeared, and structurally, the inertinites remained almost unchanged with slight increase in the reflectance value. In the severely heat-affected coals (post plastic phase, > 500 °C) the identified microtextures were mesophase spheres, different shapes and sizes of natural cokes, graphitic sphaeroliths, pyrolytic carbons, inerts with morpho-structural changes and slightly higher reflectance values, and altered and unaltered mineral matters. A gradual change in the heat-affected coals with increasing temperature was observed with respect to location of intrusive body. It has been concluded that, barring the effect of pressure, the changes due to heat effect on coking coals, whether in situ or laboratory carbonization, are almost similar. Organic and inorganic constituents undergoing changes at a particular temperature are nearly similar in both conditions. In case of pronounced overburden pressure, flow structures develop in the natural coke groundmass. Higher reflectance and very strong anisotropy, as evidenced in completely baked coking coals with fine to very coarse mosaic structures, may be a good criterion to explore these heat altered coals for the carbon artifact industry and further efforts are required to be made in this line. © 2006 Elsevier B.V. All rights reserved.
Boerhaavia diffusa: An over-exploited plant of medicinal importance in eastern Uttar Pradesh [8]
(2007) Arvind Singh
[No abstract available]
Microfacies analysis of transgressive condensed sequence: A study from the oxfordian of Kachchh Basin, Gujarat
(2007) R.N. Tiwari; Diwakar Mishra
1-9 m thick Dhosa Oolite Member of Chari Formation exposed in Kachchh Mainland, western India, represents a condensed transgressive sequence of the Oxfordian age. It is composed of hard and compact, fossiliferous, sandy/conglomeratic oolitic limestone interbedded with friable, thinly bedded calcareous siltstone/fine sandstone. Field & petrographic studies revealed six microfacies namely; (i) sandy/pebbly ironstone (A1); (ii) conglomeratic fossiliferous ironstone (A2); (iii) conglomeratic fossiliferous oolitic packstone (B1); (iv) sandy oolitic packstone (B2); (v) siltstone (C1); (vi) fine grained sandstone (C2). These microfacies are grouped in to three microfacies assemblages namely: (i) sandy oolitic packstone - siltstone assemblage (B2-C1), (ii) siltstone - fine grained sandstone assemblage (C1 - C2) and (iii) conglomeratic fossiliferous oolitic packstone - fine grained sandstone assemblage (C2-B1). The study of microfacies suggests that the deposition of the Dhosa Oolite Member took place in an open marine shallow shelf environment with clear proximal-to-distal trend from southeast to northwest. Two transgressive pulses were responsible for its formation. An earlier slow and frequently interrupted transgression together with subsidence is recorded by abrupt change in clastic grain size, mixing of two lithologies and abundance of siliciclastics in each microfacies. Later, rapid transgression is suggested by the extremely reduced thickness, erosive to irregular contacts, development of intraformational conglomerates, multiphase reworked sediments, an increase in the abundance of carbonates and ammonites and negligible sediment input. Lateral variation in the microfacies and their assemblages together with variable extent of marine mega fauna (ammonites) from southeast to northwest marks the depositional slope of the basin towards northwest during studied interval. The mixed lithologies in this condensed sequence together with the bioturbated nature of sediments suggest that the rate of sedimentation was extremely slow. © Geol. Soc. India.
The real greenhouse effect [1]
(Medknow Publications and Media Pvt. Ltd, 2007) Sanjay Singh
[No abstract available]
Upconversion and concentration quenching in Er3+-doped TeO2-Na2O binary glasses
(2007) Kaushal Kumar; S.B. Rai; D.K. Rai
The spectroscopic properties of Er3+-doped alkali tellurite TeO2-Na2O glasses are investigated. Infrared-to-visible upconversion emission bands are observed at 410, 525, 550 and 658 nm using 797 nm excitation wavelength. These bands are assigned to the 2H9/2 → 4I15/2, 2H11/2 → 4I15/2, 4S3/2 → 4I15/2 and 4F9/2 → 4I15/2 transition, respectively. The power dependence study reveals that the 2H9/2 → 4I15/2 transition involves a three-step process while the other upconversion transitions involve only two steps. An excitation with 532 nm wavelength, two upconversion bands are observed in the UV region at 380 and 404 nm in addition to bands in the visible region at 410, 475, 525, 550, 658 and 843 nm. These bands are ascribed to 4G11/2 → 4I15/2, 2P3/2 → 4I13/2, 2H9/2 → 4I15/2, 2P3/2 → 4I11/2, 2H11/2 → 4I15/2, 4S3/2 → 4I15/2, 4F9/2 → 4I15/2 and 4S3/2 → 4I13/2 transition, respectively. Increasing Er3+ concentration leads to a rapid growth in the intensity of red emission relative to that for the green emission. An explanation for this observation has been suggested. The temperature dependence profile for the two thermally coupled levels (2H11/2, 4S3/2) shows that they can be used for measuring the temperature. © 2007 Elsevier B.V. All rights reserved.
Electrochemical characterization of composite films of polypyrrole and la1-xSrxCoO3 (0 ≤ × ≤ 0.4) for electrocatalysis of O2 reduction
(2007) R.N. Singh; M. Malviya; Anindita
Sandwich-type composite films of polypyrrole (PPy) and La 1-xSrxCoO3(0 ≤×<0.4) on a conductive graphite support (G) have been obtained by electropolymerization for electrocatalysis of the oxygen reduction reaction (ORR). The composite films have been characterized by SEM, EDAX, cyclic voltammetry, impedance and Tafel polarization techniques. The studies show that the composite electrodes are greatly active for the ORR than the non-composite one. The higher Sr substitutions (>0.2 mol) have an adverse effect on the electrocatalytic activity. The rate for the ORR at the composite film has been found to decrease with decreasing pH of the electrolyte. Among all the four composite electrodes studied, the G/PPy/PPy(La0.8Sr0.2CoO3)/PPy electrode in 0.5 mol dm-3 K2SO4 plus 5 m moldm-3 KOH at 25°C exhibits the highest electrocatalytic activity towards the ORR.
Visceral leishmaniasis: What are the needs for diagnosis, treatment and control?
(2007) François Chappuis; Shyam Sundar; Asrat Hailu; Hashim Ghalib; Suman Rijal; Rosanna W. Peeling; Jorge Alvar; Marleen Boelaert
Visceral leishmaniasis (VL) is a systemic protozoan disease that is transmitted by phlebotomine sandflies. Poor and neglected populations in East Africa and the Indian sub-continent are particularly affected. Early and accurate diagnosis and treatment remain key components of VL control. In addition to improved diagnostic tests, accurate and simple tests are needed to identify treatment failures. Miltefosine, paromomycin and liposomal amphotericin B are gradually replacing pentavalent antimonials and conventional amphotericin B as the preferred treatments in some regions, but in other areas these drugs are still being evaluated in both mono- and combination therapies. New diagnostic tools and new treatment strategies will only have an impact if they are made widely available to patients.
Authors' reply [2]
(2007) Mallika Tewari; Hari Shukla
[No abstract available]
Age and sex dependent alteration in presenilin expression in mouse cerebral cortex
(2007) Mahendra Kumar Thakur; Soumi Ghosh
(1) Presenilin (PS) expression is regulated by several cellular and extracellular factors which change with age and sex. Both age and sex are key risk factors for Alzheimer's disease (AD), which is linked to mutations in PS genes. (2) We have analyzed the effect of age and sex on PS expression by northern hybridization and western blot analysis using the cerebral cortex of adult (24 ± 2 weeks) and old (65 ± 5 weeks) mice. (3) Our results demonstrate that PS1 was downregulated and PS 2 was upregulated in old mice of both sexes. The level of PS 1 was relatively higher and that of PS 2 was lower in female than male mice of same age group. Taken together, these findings show age and sex dependent alteration in PS expression, which in turn may influence the signal transduction pathways and consequently brain functions. © 2007 Springer Science+Business Media, LLC.
Benzyl N′-(2-methoxy-benzo-yl)hydrazine-carbo-dithio-ate
(2007) N.K. Singh; Mamata Singh; Ray J. Butcher
The title dithio ester, C16H16N2O2S2, was synthesized by the reaction of potassium N′-(2-methoxy-benzo-yl)hydra-zine-carbodithio-ate and benzyl chloride in chloro-form. The dihedral angle between the 2-methoxy-phenyl ring and the benzyl ring is 85.06 (2) Å. In the crystal structure, intra- and inter-molecular hydrogen bonding stabilizes the mol-ecule and the crystal packing. © International Union of Crystallography 2007.
Evolutionary genetics of Drosophila ananassae: Evidence for trade-offs among several fitness traits
(2007) Jay P. Yadav; Bashisth N. Singh
Correlated responses to bi-directional selection on thorax length, examined on several life-history traits and chromosome inversion polymorphisms, have revealed apparent novel trade-offs in Drosophila ananassae. We provide evidence of trade-offs between hatching time and pupal period, pupal period and egg-pupa development time, and pupal period and larval development time (LDT). Body size shows positive correlations with ovariole number, LDT and DT (egg-fly). We provide evidence of sexual dimorphism for trade-offs between longevity and body size and starvation and longevity in females only. Trade-offs between wing/thorax (W/T) ratio and longevity, W/T ratio and starvation, and DT (egg- fly) and longevity are evident in males only. Sexual dimorphism is also evident for inversion polymorphism with body size and longevity. A longevity assay suggests that low line females outlived high line females whereas high line males outlived low line males. The mean longevity in males is negatively correlated with the 2L-ST and 3R-ST arrangement frequencies whereas the 3L-ST arrangement frequency is positively correlated with the mean longevity in males but opposite arrangements are found in females. Absolute starvation resistance is negatively correlated with 2L-ST and 3R-ST chromosome arrangements and results in a trade-off between longevity and absolute starvation resistance in females. Analyses of fecundity, hatchability, and viabilities based on age intervals in both G10 and G13 suggest that the early reproduction is favoured in D. ananassae. The productivity percentage is highest in the high line and there is no effect of late reproduction on it. Overall, we provide some unravelled trade-offs and striking sex differences, which may help in understanding the life-history evolution of the species. © 2007 The Linnean Society of London.
Lamotrigine in pregnancy: Safety profile and the risk of malformations
(2007) Prakash; L.V. Prabhu; M.A. Nasar; R. Rai; S. Madhyastha; G. Singh
The use of antiepileptic drugs in pregnancy always presents challenges to doctors and their patients as it may have deleterious effects on the developing embryo. Lamotrigine is most commonly prescribed drug among the newer antiepileptic drugs; hence, it has been selected for the present review. A number of studies pertaining to the safety of lamotrigine use during pregnancy have been reported, with differing results. Contradictory results have been reported in animals regarding lamotrigine teratogenicity, and human studies have also proven inconclusive. In many countries, human pregnancy registries are maintained to establish the safety of antiepileptic drugs during pregnancy, as all the different suggestions favour some over others, with specific antiepileptic combinations still being questioned. It is our hope that the present work may integrate the available disparate relevant facts into a directed effort towards minimising the risk of foetal compromise.
Microbial production of 7-aminocepahlosporanic acid and new generation cephalosporins (cephalothin) by different processing strategies
(2007) Kumar Gaurav; Kanika Kundu; Subir Kundu
The development of β-lactam antibiotics has been a continious battle of the design of new compounds to withstand inactivation by the ever-increasing diversity of β-lactamases. Semisynthetic cephalosporins like cephalothin were synthesized from 7-Amino cephalosporanic acid (7-ACA), and thiophene-2-actetic acid using cephalosporin-C acylase enzyme was studied. The production of cephalosporin-C acylase by Pseudomonas diminuta was used and the growth kinetics studied. The optimum condition of enzyme activity was determined by using response surface methodology. A 23 full-factorial composite design was employed for experimental design and the result analyzed. The pH value and temperature for optimum activity were 6.5 and 32°C, respectively. The structural analog compound similar to the side-chain of semisynthetic cephalosporins, e.g., thiophene-2-actetic acid, was added. HPLC data analysis indicate that the concentration of cephalothin was 1.6 mg/mL. Copyright © Informa Healthcare.