Indian Association for the Cultivation of Science

About: Indian Association for the Cultivation of Science is a education organization based out in Kolkata, India. It is known for research contribution in the topics: Catalysis & Excited state. The organization has 3867 authors who have published 10457 publications receiving 220098 citations.

Radiative contribution to neutrino masses and mixing in μνSSM

Abstract: In an extension of the minimal supersymmetric standard model (popularly known as the μνSSM), three right handed neutrino superfields are introduced to solve the μ-problem and to accommodate the non-vanishing neutrino masses and mixing. Neutrino masses at the tree level are generated through R−parity violation and seesaw mechanism. We have analyzed the full effect of one-loop contributions to the neutrino mass matrix. We show that the current three flavour global neutrino data can be accommodated in the μνSSM, for both the tree level and one-loop corrected analyses. We find that it is relatively easier to accommodate the normal hierarchical mass pattern compared to the inverted hierarchical or quasi-degenerate case, when one-loop corrections are included.

Aspects of linked cluster expansion in general model space many-body perturbation and coupled-cluster theory

Abstract: In this paper, a method of generating separable forms of the wave-operator for incomplete model spaces is discussed. With a time-dependent access to the many-body perturbation and coupled-cluster theories, it is shown how one can extract the regular part of the wave-operator which consists of linked cluster-operators only in the adiabatic limit. The procedure naturally suggests a hierarchy of lower valence model spaces P (k) . once a particular m-valence incomplete model space P (m) is specified. The wave-operator Ω and the effective Hamiltonian H eff are linked in this development and are valence-universal in the sense of being valid for all P (k)' s. 0 k m. We have derived two distinct forms for Ω: (i) Ω = {exp(S)}, with { } as normal order with respect to suitable vacuum, where S are open operators inducing transitions from P (m) to outside it; (ii) Ω N = {exp(S + X)}, where X are additional closed operators which are introduced to maintain isometry of Ω N : P (k) Ω N + Ω N P (k) = P (k) . In neither of these choices do we have intermediate normalization. It is also possible to develop an alternative strategy with the complete model spaces, such that an effective valence-universal operator H may be found which generates roots, only a subset of which are equal to the eigenvalues of H. These subsets are the ones that H eff would have furnished. This may thus be viewed as a Fock-space realization of the intermediate Hamiltonian approach.

Solvation Dynamics of Coumarin 480 in Vesicles

Abstract: Solvation dynamics of Coumarin 480 (C-480) in dimyristoylphosphatidylcholine (DMPC) vesicles in water is studied using picosecond time-resolved Stokes shift. In sonicated unilamellar DMPC vesicles C-480 exhibits wavelength dependent fluorescence decays. At short wavelengths a fast decay is observed while at the long wavelengths a growth in the nanosecond time scale precedes the decay. The solvation dynamics of C-480 in DMPC vesicles is found to be bimodal with two components of 0.6 and 11 ns, which is similar to the solvation dynamics of C-480 in the large water pools of AOT/n-heptane/water (AOT = aerosol OT) microemulsions.

Poly(trehalose) Nanoparticles Prevent Amyloid Aggregation and Suppress Polyglutamine Aggregation in a Huntington's Disease Model Mouse.

Abstract: Prevention and therapeutic strategies for various neurodegenerative diseases focus on inhibiting protein fibrillation, clearing aggregated protein plaques from the brain, and lowering protein-aggregate-induced toxicity. We have designed poly(trehalose) nanoparticles that can inhibit amyloid/polyglutamine aggregation under extra-/intracellular conditions, reduce such aggregation-derived cytotoxicity, and prevent polyglutamine aggregation in a Huntington’s disease (HD) model mouse brain. The nanoparticles have a hydrodynamic size of 20–30 nm and are composed of a 6 nm iron oxide core and a zwitterionic polymer shell containing ∼5–12 wt % covalently linked trehalose. The designed poly(trehalose) nanoparticles are 1000–10000 times more efficient than molecular trehalose in inhibiting protein fibrillation in extra-cellular space, in blocking aggregation of polyglutamine-containing mutant huntingtin protein in model neuronal cells, and in suppressing mutant huntingtin aggregates in HD mouse brain. We show that ...

Solvation Dynamics of DCM in Lipid

Abstract: Solvation dynamics of 4-(dicyanomethylene)-2-methyl-6(p-dimethylaminostyryl)-4H-pyran (DCM) in dimyristoylphosphatidylcholine (DMPC) vesicles in water is studied by using the picosecond time-resolved Stokes shift technique In unilamellar DMPC vesicles, DCM exhibits wavelength-dependent fluorescence decays with a fast decay at the blue end and a slow decay preceded by a distinct growth at the red end of the emission spectrum The solvation dynamics of DCM in DMPC vesicles is found to be biexponential with two components 230 ps (40%) and 16 ns (60%) and is attributed to the relaxation of the water molecules inside the water pool of DMPC vesicles