788 research outputs found
Impact of flow on ligand-mediated bacterial flocculation
No full textAbstract not availableSarthok Sircar, David M. Bort
Muhammad Ali Sircar the first of the world's officially recognized student-author from British India
No full textBiography of Muhammad Ali Sircar, b. 1923, retired civil servant from Bangladesh, who wrote Assam own copy book, a textbook in English for primary students, while he was a student of class X
Postnatal phencyclidine treatment differentially regulates N-methyl-D-aspartate receptor subunit mRNA expression in developing rat cerebral cortex
No full text‘Mutual aid is present in every crisis’: An Interview with Dean Spade
No full textThe Covid-19 pandemic unravelled a crisis of the modern state, and its legal institutions on the one hand, and on the other hand of our interpretive frames—both philosophical and scientific. It is here that the idea and practice of mutual aid gains significance, both to think about how we can respond to acute crises of planetary scales as well as to the crisis of critique in the discipline of law. The task of mutual aid is not to rehabilitate law out of its crisis or to restore conditions and systems back to a state prior to a crisis. This is because, as Dean Spade says in this interview, ‘they are not broken systems needing to be fixed. They are working exactly as they were designed to work, constantly sharpening violence against targeted populations and enriching a very few people.’ Spade—Wismer Professor of Gender and Diversity at the Seattle University School of Law and a founder of the Sylvia Rivera Law Project—is a key scholar-activist voice on mutual aid in North America and Europe. He is author, most recently, of Mutual Aid: Building Solidarity During this Crisis (And the Next). In this conversation with Oishik Sircar, Spade discusses his theoretical and political influences, how he relates the idea of crisis to critique, his sobering assessment of the limitations not only of law reform but of the role of legal education in radical transformation, his own understandings of mutual aid, his favourite words, why and how he does not see himself only as a legal scholar-activist, and his vision of hope and hopelessness in times of acute and intense crises
Derivative pricing and optimal execution of portfolio transactions in finitely liquid markets
No full textIn real markets, to some degree, every trade will incur a non-zero cost and will influence the price of the asset traded. In situations where a dynamic trading strategy is implemented these liquidity effects can play a significant role. In this thesis we examine two situations in which such trading strategies are inherent to the problem; that of pricing a derivative contingent on the asset and that of executing a large portfolio transaction in the asset.
The asset's finite liquidity has been incorporated explicitly into its price dynamics using the Bakstein-Howison model [4]. Using this model we have derived the no-arbitrage price of a derivative on the asset and have found a true continuous-time equation when the bid-ask spread in the asset is neglected. Focussing on this pure liquidity case we then employ an asymptotic analysis to examine the price of a European call option near strike and expiry where the liquidity effects are shown to be most significant and closed-form expressions for the price are derived in this region. The asset price model is then extended to incorporate the empirical fact that an asset's liquidity mean reverts stochastically. In this situation the pricing equation is analyzed using the multiscale asymptotic technique developed by Fouque, Papanicolaou, and Sircar [22] and a simplified pricing and calibration framework is developed for an asset possessing liquidity risk. Finally, the derivative pricing framework (both with and without liquidity risk) is applied to a new contract termed the American forward which we present as a possible hedge against an asset's liquidity risk.
In the second part of the thesis we investigate how to optimally execute a large transaction of a finitely liquid asset. Using stochastic dynamic programming and attempting only to minimize the transaction's cost, we first find that the optimal strategy is static and contains the naive strategy found in previous studies, but with an extra term to account for interest rates neglected by those studies. Including time risk into the optimization procedure we find expressions for the optimal strategy in the extreme cases when the trader's aversion to this risk is very small and very large. In the former case the optimal strategy is simply the cost-minimization strategy perturbed by a small correction proportional to the trader's level of risk aversion. In the latter case the problem is shown to be much more difficult; we analyze and derive implicit closed-form solutions to the much-simplified perfect liquidity case and show numerical results to demonstrate the agreement of the solution with our intuition
"On Approximation of the Solutions to Partial Differential Equations in Finance"
No full textThis paper proposes a general approximation method for the solutions to second-order parabolic partial differential equations (PDEs) widely used in finance through an extension of Léandre's approach(Léandre (2006,2008)) and the Bismut identiy(e.g. chapter IX-7 of Malliavin (1997)) in Malliavin calculus. We show two types of its applications, new approximations of derivatives prices and short-time asymptotic expansions of the heat kernel. In particular, we provide new approximation formulas for plain-vanilla and barrier option prices under stochastic volatility models. We also derive short-time asymptotic expansions of the heat kernel under general time-homogenous local volatility and local-stochastic volatility models in finance which include Heston (Heston (1993)) and (λ-)SABR models (Hagan et.al. (2002), Labordere (2008)) as special cases. Some numerical examples are shown.
A digital media literacy intervention increases discernment between mainstream and false news in the United States and India
No full textThis is the final version. Available on open access from the National Academy of Sciences via the DOI in this recordData deposition: Data files and scripts necessary to replicate the results in this article are available at the Dataverse repository at https://doi.org/10.7910/DVN/Q5QINN. The US study preanalysis plan is available at https://osf.io/u3sgc. The India study preanalysis plan is available at https://osf.io/97rnz.Widespread belief in misinformation circulating online is a critical challenge for modern societies. While research to date has focused on psychological and political antecedents to this phenomenon, few studies have explored the role of digital media literacy shortfalls. Using data from preregistered survey experiments conducted around recent elections in the United States and India, we assess the effectiveness of an intervention modeled closely on the world's largest media literacy campaign, which provided "tips" on how to spot false news to people in 14 countries. Our results indicate that exposure to this intervention reduced the perceived accuracy of both mainstream and false news headlines, but effects on the latter were significantly larger. As a result, the intervention improved discernment between mainstream and false news headlines among both a nationally representative sample in the United States (by 26.5%) and a highly educated online sample in India (by 17.5%). This increase in discernment remained measurable several weeks later in the United States (but not in India). However, we find no effects among a representative sample of respondents in a largely rural area of northern India, where rates of social media use are far lower.European Union Horizon 2020Facebook Integrity Foundational Research Award
Monodomain Dynamics for Rigid Rod and Platelet Suspensions in Strongly Coupled Coplanar Linear Flow and Magnetic Fields. II. Kinetic theory
No full textWe establish reciprocity relations of the Doi-Hess kinetic theory for rigid rod macromolecular suspensions governed by the strong coupling among an excluded volume potential, linear flow, and a magnetic field. The relation provides a reduction of the flow and field driven Smoluchowski equation: from five parameters for coplanar linear flows and magnetic field, to two field parameters. The reduced model distinguishes flows with a rotational component, which map to simple shear (with rate parameter) subject to a transverse magnetic field (with strength parameter), and irrotational flows, for which the reduced model consists of a triaxial extensional flow (with two extensional rate parameters). We solve the Smoluchowski equation of the reduced model to explore: (i) the effect of introducing a coplanar magnetic field on each sheared monodomain attractor of the Doi-Hess kinetic theory and (ii) the coupling of coplanar extensional flow and magnetic fields. For (i), we show each sheared attractor (steady and unsteady, with peak axis in and out of the shearing plane, periodic and chaotic orbits) undergoes its own transition sequence versus magnetic field strength. Nonetheless, robust predictions emerge: out-of-plane degrees of freedom are arrested with increasing field strength, and a unique flow-aligning or tumbling/ wagging limit cycle emerges above a threshold magnetic field strength or modified geometry parameter value. For (ii), irrotational flows coupled with a coplanar magnetic field yield only steady states. We characterize all (generically biaxial) equilibria in terms of an explicit Boltzmann distribution, providing a natural generalization of analytical results on pure nematic equilibria [P. Constantin, I. Kevrekidis, and E. S. Titi, Arch. Rat. Mech. Anal. 174, 365 (2004); P. Constantin, I. Kevrekidis, and E. S. Titi, Discrete and Continuous Dynamical Systems 11, 101 (2004); P. Constantin and J. Vukadinovic, Nonlinearity 18, 441 (2005); H. Liu, H. Zhang, and P. Zhang, Comm. Math. Sci. 3, 201 (2005); C. Luo, H. Zhang, and P. Zhang, Nonlinearity 18, 379 (2005); I. Fatkullin and V. Slastikov, Nonlinearity 18, 2565 (2005); H. Zhou, H. Wang, Q. Wang, and M. G. Forest, Nonlinearity 18, 2815 (2005)] and extensional flow-induced equilibria [Q. Wang, S. Sircar, and H. Zhou, Comm. Math. Sci. 4, 605 (2005)]. We predict large parameter regions of bi-stable equilibria; the lowest energy state always has principal axis aligned in the flow plane, while another minimum energy state often exists, with primary alignment transverse to the coplanar field. © 2006 American Institute of Physics
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Vyavasthá-chandriká ::a digest of Hindu law, as current in all the provinces of India, except Bengal proper comprising vyavasthás or principles deduced from Sanskrit books of paramount authority, viz: - the Mitákshará, Víra-mitrodaya, Viváda-chintámani, Vyavahára-mayúkha, Smriti-chandriká, & c, with authorities and interpretations, & c, from those books and other sources, annotations from the principles and elements of Hindú law, &c., also precedents of the Privy Council, the late Sudder and Supreme courts, the present High courts of Calcutta, Allahabad, Bombay and Madras, also admitted legal opinions, and responsa prudentum /
No full textSearch for a CP-odd Higgs boson decaying to Zh in pp collisions at root s=8 TeV with the ATLAS detector
No full textSee paper for full list of authors – 13 pages plus author list + cover pages (30 pages total), 5 figures, 2 tables, submitted to Phys. Lett. B, All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HIGG-2013-06/International audienceA search for a heavy, CP-odd Higgs boson, , decaying into a boson and a 125 GeV Higgs boson, , with the ATLAS detector at the LHC is presented. The search uses proton--proton collision data at a centre-of-mass energy of 8 TeV corresponding to an integrated luminosity of 20.3 fb. Decays of CP-even bosons to or pairs with the boson decaying to electron or muon pairs are considered, as well as decays with the boson decaying to neutrinos. No evidence for the production of an boson in these channels is found and the 95% confidence level upper limits derived for \sigma (gg\rightarrow A) \times \mbox{BR}(A \rightarrow Zh) \times \mbox{BR}(h \rightarrow f\bar{f}) are 0.098--0.013 pb for and 0.57--0.014 pb for in a range of 220--1000 GeV. The results are combined and interpreted in the context of two-Higgs doublet models
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