Interaction of Coupled Higher Order Nonlinear SCHR\"Odinger Equation Solitons

The novel inelastic collision properties of two-soliton interaction for an $n$-component coupled higher order nonlinear Schr\"odinger equation are studied. Some interesting features of three soliton interactions, related to the integrability of the $n$-component coupled higher order nonlinear Schr\"odinger equation are also discussed.Comment: 6 pages, 4 figures, revtex

Soliton solutions, Liouville integrability and gauge equivalence of Sasa Satsuma equation

Exact integrability of the Sasa Satsuma eqation (SSE) in the Liouville sense is established by showing the existence of an infinite set of conservation laws. The explicit form of the conserved quantities in term of the fields are obtained by solving the Riccati equation for the associated 3x3 Lax operator. The soliton solutions in particular, one and two soliton solutions, are constructed by the Hirota's bilinear method. The one soliton solutions is also compared with that found through the inverse scattering method. The gauge equivalence of the SSE with a generalized Landau Lifshitz equation is established with the explicit construction oComment: 14 pages, to be published in J. Math. Phys. April-May, 199

Linear interference and systematic soliton shape modulation by engineering plane wave background and soliton parameters

We investigate linear interference of a plane wave with different localised waves using coupled Fokas-Lenells equation(FLE) with four wave mixing (FWM) term. We obtain localised wave solution of the coupled FLE by linear superposition of two distinctly independent wave solutions namely plane wave and one soliton solution & plane wave and two soliton solution. We obtain several nonlinear profiles depending on the relative phase induced by soliton parameters. We analyse the linear interference profile under four different conditions on the spatial and temporal phase coefficients of interfering waves. We further investigate the interaction of two soliton solution and a plane wave. In this case we notice that asymptotically, two solitons profile may be similar or different from each other depending on the choices of soliton parameters in the two cases. The results obtained by us might be useful for applications in soliton control, a fiber amplifier, all optical switching, and optical computing. Further we believe that the present investigation would be useful to study the linear interference pattern of other localised waves of FLE.Comment: 14 pages, 18 figure

OXIDATIVE STRESS-BASED HEPATOTOXICITY OF DULOXETINE IN WISTAR RATS

Objective: Duloxetine, a selective serotonin and noradrenaline reuptake inhibitor used in major depressive disorders, urinary incontinence and diabetic peripheral neuropathic pain. It is reported to be associated with several types of liver injuries, including hepatocellular, cholestatic and mixed hepatocellular-cholestatic patterns. The objective of this study was to assess the effect of duloxetine or its metabolites on oxidative stress-induced liver damages.Methods: In this study, animals were divided into five groups. In the first group, the only vehicle was given orally for 21 d. The second group has been considered as hepatotoxic control group where Erythromycin was given orally for 14 d and remaining three groups have been considered as test groups where duloxetine, fluvoxamine and duloxetine along with fluvoxamine were administered orally for 21 d. Liver GSH, oxidised lipid (malonaldehyde MDA), superoxide dismutase (SOD), catalase (CAT), protein carbonyl (PC) and plasma alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) levels were measured to determine the level of hepatotoxicity. Scanning electron microscopy (SEM) study of liver tissues was also performed to examine the liver injuries.Results: GSH and SOD levels were found to be decreased in duloxetine-treated groups with respect to the hepatotoxic control group, whereas increased level of MDA, CAT and PC signify the damages of liver cells. Increased level of plasma ALT, AST and ALP at the same time indicated liver tissue damage. Opposite effects were observed in the case of duloxetine and fluvoxamine-treated groups. SEM of liver tissues revealed that the tissue injury occurred in Duloxetin treated groups, whereas the restoration of normal tissue architecture took place due to the administration of duloxetine and fluvoxamine-treated groups.Conclusion: Our results collectively indicated that hydroxylated and epoxide metabolites of duloxetine might have hepatotoxic potential due to oxidative stress produced by the release of free radicals or reactive oxygen species

Inverse scattering method and vector higher order nonlinear Schrodinger equation

A generalised inverse scattering method has been developed for arbitrary n dimensional Lax equations. Subsequently, the method has been used to obtain N soliton solutions of a vector higher order nonlinear Schrodinger equation, proposed by us. It has been shown that under suitable reduction, vector higher order nonlinear Schrodinger equation reduces to higher order nonlinear Schrodinger equation. The infinite number of conserved quantities have been obtained by solving a set of coupled Riccati equation. A gauge equivalence is shown between the vector higher order nonlinear Schrodinger equation and the generalized Landau Lifshitz equation and the Lax pair for the latter equation has also been constructed in terms of the spin field, establishing direct integrability of the spin system.Comment: 28 page

Inverse scattering approach to coupled higher order nonlinear Schr\"odinger equation and N-soliton solutions

A generalized inverse scattering method has been applied to the linear problem associated with the coupled higher order nonlinear schr\"odinger equation to obtain it's $N$-soliton solution. An infinite number of conserved quantities have been obtained by solving a set of coupled Riccati equations. It has been shown that the coupled system admits two different class of solutions, characterised by the number of local maxima of amplitude of the soliton.Comment: 23 page

"The fruits of independence": Satyajit Ray, Indian nationhood and the spectre of empire

Challenging the longstanding consensus that Satyajit Ray's work is largely free of ideological concerns and notable only for its humanistic richness, this article shows with reference to representations of British colonialism and Indian nationhood that Ray's films and stories are marked deeply and consistently by a distinctively Bengali variety of liberalism. Drawn from an ongoing biographical project, it commences with an overview of the nationalist milieu in which Ray grew up and emphasizes the preoccupation with colonialism and nationalism that marked his earliest unfilmed scripts. It then shows with case studies of Kanchanjangha (1962), Charulata (1964), First Class Kamra (First-Class Compartment, 1981), Pratidwandi (The Adversary, 1970), Shatranj ke Khilari (The Chess Players, 1977), Agantuk (The Stranger, 1991) and Robertsoner Ruby (Robertson's Ruby, 1992) how Ray's mature work continued to combine a strongly anti-colonial viewpoint with a shifting perspective on Indian nationhood and an unequivocal commitment to cultural cosmopolitanism. Analysing how Ray articulated his ideological positions through the quintessentially liberal device of complexly staged debates that were apparently free, but in fact closed by the scenarist/director on ideologically specific notes, this article concludes that Ray's reputation as an all-forgiving, ‘everybody-has-his-reasons’ humanist is based on simplistic or even tendentious readings of his work