Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

It is well known that the dynamics of a quantum system is always nonadiabatic in passage through a quantum critical point and the defect density in the final state following a quench shows a power-law scaling with the rate of quenching. However, we propose here a possible situation where the dynamics of a quantum system in passage across quantum critical regions is adiabatic and the defect density decays exponentially. This is achieved by incorporating additional interactions which lead to quantum critical behavior and gapless phases but do not participate in the time evolution of the system. To illustrate the general argument, we study the defect generation in the quantum critical dynamics of a spin-1/2 anisotropic quantum XY spin chain with three spin interactions and a linearly driven staggered magnetic field. © 2010 The American Physical Society.

World University root node

Department of Physics

Fulltext

Physical Review E - Statistical, Nonlinear, and Soft Matter Physics

Adiabatic dynamics in passage across quantum critical lines and gapless phases

In this work, we study the adhesion of multicomponent vesicle membrane to both flat and curved substrates, based on the conventional Helfrich bending energy for multicomponent vesicles and adhesion potentials of different forms. A phase field formulation is used to describe the different components of the vesicle. For the axisymmetric case, a number of representative equilibrium vesicle shapes are computed and a few energy diagrams are presented which reveal the dependence of the calculated shapes and solution branches on various parameters including both bending moduli and spontaneous curvatures as well as the adhesion potential constants. Our computation also confirms a recent experimental observation that the adhesion may promote phase separation in two-component vesicle membranes. © 2010 The American Physical Society.

Department of Mechanical Engineering

Adhesion of multicomponent vesicle membranes

Effect of a room temperature ionic liquid (RTIL) and water on the ultrafast excited state proton transfer (ESPT) of pyranine (8-hydroxypyrene-1,3,6- trisulfonate, HPTS) inside a microemulsion is studied by femtosecond up-conversion. The microemulsion consists of the surfactant, triton X-100 (TX-100) in benzene (bz) and contains the RTIL, 1-pentyl-3-methyl-imidazolium tetrafluoroborate ([pmim] [BF4]) as the polar phase. In the absence of water, HPTS undergoes ultrafast ESPT inside the RTIL microemulsion (RTIL/TX-100/bz) and the deprotonated form (RO-) exhibits three rise components of 0.3, 14, and 375 ps. It is proposed that in the RTIL microemulsion, HPTS binds to the TX-100 at the interface region and participates in ultrafast ESPT to the oxygen atoms of TX-100. On addition of water an additional slow rise of 2150 ps is observed. Similar long rise component is also observed in water/TX-100/benzene reverse micelle (in the absence of [pmim] [BF4]). It is suggested that the added water molecules preferentially concentrate (trapped) around the palisade layer of the RTIL microemulsion. The trapped water molecules remain far from the HPTS both in the presence and absence of ionic liquid and gives rise to the slow component (2150 ps) of ESPT. Replacement of H2 O by D2 O causes an increase in the time constant of the ultraslow rise to 2350 ps. © 2010 American Institute of Physics.

Department of Chemistry

Journal of Chemical Physics

Ultrafast and ultraslow proton transfer of pyranine in an ionic liquid microemulsion

The need for efficient usage of the scarce electromagnetic spectrum has resulted in the growth of cognitive radios (CRs). The primary task in any CR network is to dynamically sense the radio spectrum so as to reliably determine portion(s) of the frequency band that may be used for communication link(s). Recently spectrum sensing for CRs based on filter banks have been suggested in literature. It was suggested that using filter banks for spectrum sensing will enable multi-carrier communications at no extra cost. This paper presents a study of the requirements and challenges of digital filter banks from a CR perspective in contrast to traditional filter banks for wireless communications. The current state-ofthe- art filter banks are discussed, with both advantageous and disadvantageous and how such filter banks can be altered to meet the essential requirements of CR systems.

Department of Electrical Engineering

APSIPA ASC 2010 - Asia-Pacific Signal and Information Processing Association Annual Summit and Conference

Challenges in digital filter bank implementation from a cognitive radio perspective - A review

We show that data from recent experiments carried out on the kinetics of DNA escape from α -hemolysin nanopores [M. Wiggin, C. Tropini, C. T. Cossa, N. N. Jetha, and A. Marziali, Biophys. J. 95, 5317 (2008)] may be rationalized by a model of chain dynamics based on the anomalous diffusion of a particle moving in a harmonic well in the presence of a delta function sink. The experiments of Wiggin found, among other things, that the occasional occurrence of unusually long escape times in the distribution of chain trapping events led to nonexponential decays in the survival probability, S(t), of the DNA molecules within the nanopore. Wiggin ascribed this nonexponentiality to the existence of a distribution of trapping potentials, which they suggested was the result of stochastic interactions between the bases of the DNA and the amino acids located on the surface of the nanopore. Based on this idea, they showed that the experimentally determined S(t) could be well fit in both the short and long time regimes by a function of the form (1+t/τ)-α (the so called Becquerel function). In our model, S(t) is found to be given by a Mittag-Leffler function at short times and by a generalized Mittag-Leffler function at long times. By suitable choice of certain parameter values, these functions are found to fit the experimental S(t) even better than the Becquerel function. Anomalous diffusion of DNA within the trap prior to escape over a barrier of fixed height may therefore provide a second, plausible explanation of the data, and may offer fresh perspectives on similar trapping and escape problems. © 2010 American Institute of Physics.

Anomalous reaction-diffusion as a model of nonexponential DNA escape kinetics

Systemic lupus erythematosus (SLE) is a complex systemic autoimmune disease that predominant-ly affects the kidneys in the form of lupus nephri-tis, although multiple organs can be involved. Lu-pus nephritis is characterized by the deposition in glomeruli of immune complexes formed by IgG, IgM and IgA autoantibodies (which collectively are called antinuclear antibodies). These autoanti-bodies are directed toward ubiquitous nuclear an-tigens, particularly double-stranded DNA. 1 De-position of these complexes can result in renal failure and even death. Several mechanisms are known to contribute to the pathogenesis of lupus nephritis, including those mediated by type 1 helper T (Th1) and type 17 helper T (Th17) cells. 2 Although humoral re-sponses in the form of autoreactive antibodies (also known as immunoglobulins) are effector mediators of lupus nephritis and the presence of IgE autoantibodies has been reported in some patients, the way in which type 2 helper T (Th2) cells and B cells are activated in the pathogenesis of lupus nephritis has not been clear. Charles and colleagues 3 shed some light on the question through experiments involving mice with " hyperactive " B cells. Specifically, Lyn, a protein tyrosine kinase that negatively regulates B-cell activation, was absent in these mice. Autoim-mune disease developed spontaneously in the mice fairly late in life (at 32 to 40 weeks). This disease shared features with SLE: the mice had anti−double-stranded DNA antibodies, deposition of immune complexes in glomeruli and kidney damage. In additional experiments with other types of knockout mice, Charles et al. concluded that lupuslike nephritis and the production of antinuclear antibodies and anti−double-stranded DNA immunoglobulins in the Lyn-deficient mice were dependent on both interleukin-4 and IgE (Fig. 1), thus suggesting a role for the Th2 envi-ronment. This conclusion shone the spotlight on basophils and mast cells, the two major cell types implicated in Th2-dependent pathogenesis. The authors observed that the induced deficiency of mast cells in the Lyn-deficient mice did not mod-ify the autoimmune process, whereas a depletion of basophils led to markedly reduced numbers of circulating autoreactive IgGs, splenic plasma cells and levels of proinflammatory mediators (such as interleukin-4) in the kidneys. How then would basophils promote lupus ne-phritis? Basophils express Fc$\epsilon$RI (a high-affinity receptor for IgE antibodies), the binding of which (by the IgE immune complex) leads to activation of basophils. Charles et al. found that Lyn-defi-cient mice indeed contained autoreactive IgE and IgE immune complex in the circulation that both mediated the activation of basophils and their homing to secondary lymphoid organs. Through their secretion of interleukin-4 in these organs, the basophils promote Th2 differentiation (Fig. 1). Th2 cells, in cooperation with interleukin-6 and B-cell−activating factor (bound to the basophil Figure 1 (facing page). The Basophil and Lupus Nephritis. Charles et al. 3 recently described a study providing support for a model of pathogenesis of nephritis in systemic lupus erythematosus (SLE). IgE-containing immune complexes in both mice with " hyperactive " B cells (Lyn-deficient mice) and persons with SLE trig-ger circulating basophils to express a secondary lym-phoid organ−homing receptor (CD62L, also known as L-selectin) and the antigen-presenting molecule, ma-jor-histocompatibility-complex (MHC) class II. In sec-ondary lymphoid organs, these activated basophils secrete interleukin-4 and thus promote type 2 helper T (Th2) cell differentiation. Th2 cells — in cooperation with basophil-derived interleukin-6 and basophil mem-brane-bound B-cell−activating factor (BAFF) — enhance B-cell differentiation and survival and produc-tion of autoreactive antibodies. The immune complexes of which these autoreactive antibodies are part are de-posited in glomeruli and cause lupus nephritis.

Biological Sciences and Engineering

New England Journal of Medicine

Basophils and nephritis in lupus

Recent reports demonstrate that basophils act as antigen presenting cells to drive Th2 and IgE responses against protease and protein allergens and helminth parasites. Through MHC class II-dependent cognate interactions with CD4+ T cells in the context of co-stimulatory molecules, and through secretion of IL-4, IL-13 and thymic stromal lymphopoietin, basophils drive antigen-specific Th2 responses. These results have uncovered previously unknown functions of basophils, and should aid in designing novel therapeutic strategies for asthma and allergic conditions. © 2009 Elsevier Ltd. All rights reserved.

Trends in Immunology

Basophils as antigen presenting cells

Mycobacterium tuberculosis, the causative agent of pulmonary tuberculosis, infects one-third of the world's population. Activation of host immune responses for containment of mycobacterial infections involves participation of innate immune cells, such as dendritic cells (DCs). DCs are sentinels of the immune system and are important for eliciting both primary and secondary immune responses to pathogens. In this context, to understand the molecular pathogenesis of tuberculosis and host response to mycobacteria and to conceive prospective vaccine candidates, it is important to understand how cell wall Ags of M. tuberculosis and, in particular, the proline-glutamic acid-polymorphic guanine-cytosine-rich sequence (PE-PGRS) family of proteins modulate DC maturation and function. In this study, we demonstrate that two cell wall-associated/secretory PE-PGRS proteins, PE-PGRS 17 (Rv0978c) and PE-PGRS 11 (Rv0754), recognize TLR2, induce maturation and activation of human DCs, and enhance the ability of DCs to stimulate CD4+ T cells. We further found that PE-PGRS protein-mediated activation of DCs involves participation of ERK1/2, p38 MAPK, and NF-κB signaling pathways. Priming of human DCs with IFN-γ further augmented PE-PGRS 17 or PE-PGRS 11 Ag-induced DC maturation and secretion of key proinflammatory cytokines. Our results suggest that by activating DCs, PE-PGRS proteins, important mycobacterial cell wall Ags, could potentially contribute in the initiation of innate immune responses during tuberculosis infection and hence regulate the clinical course of tuberculosis. Copyright ©2010 by The American Association of Immunologists, Inc. All rights reserved.

Journal of Immunology

PE-PGRS antigens of mycobacterium tuberculosis induce maturation and activation of human dendritic cells

We study positive solutions to the steady state reaction diffusion equation with Dirichlet boundary condition of the form: {-Δu=au-bu2-c up/1+up - K, x ∈ ω u=0, x ∈ ∂ω Here Δu = div(▽u) is the Laplacian of u, a,b,c,p,K are positive constants with p ≥ 2 and ω is a smooth bounded region with ∂ω in C2. This model describes the steady states of a logistic growth model with grazing and constant yield harvesting. It also describes the dynamics of the fish population with natural predation and constant yield harvesting. We study the existence of positive solutions to this model. We prove our results by the method of sub-super solutions.}, references={Amann, H., Fixed point equations and nonlinear eigenvalue problems in ordered banach spaces (1976) SIAM Rev., 18, pp. 620-709; Berestycki, H., Caffarelli, L.A., Nirenberg, L., Inequalities for second-order elliptic equations with applications to unbounded domains (1996) Duke Mathematical Journal, 81 (2), pp. 467-494. , DOI 10.1215/S0012-7094-96-08117-X; Clement, Ph., Peletier, L.A., An anti-maximum principle for second order elliptic operators (1979) J. Diff. Eqns., 34 (2), pp. 218-229; Lions, P.L., On the existence of positive solutions of semilinear elliptic equations (1982) SIAM Rev., 24, pp. 441-467; May, R.M., Thresholds and breakpoints in ecosystems with a multiplicity of stable states (1977) Nature, 269, pp. 471-477; Noy-Meir, I., Stability of grazing systems an application of predator-prey graphs (1975) Journal of Ecology, 63, pp. 459-482; Oruganti, S., Shi, J., Shivaji, R., Diffusive equations with constant yield harvesting, I: Steady states (2002) Trans. Amer. Math. Soc., 354, pp. 3601-3619; Steele, J.H., Henderson, E.W., Modelling long term fluctuations in fish stocks (1984) Science, 224, pp. 985-987}, correspondence_address1={Causey, R.; Department of Mathematics and Statistics, , Mississippi State 39759, United States; email: rmc107@msstate.edu}, publisher={Belgian Mathematical Society}, issn={13701444}, language={English}, abbrev_source_title={Bull. Belg. Math. Soc. Simon Stevin}, document_type={Article}, source={Scopus},

Department of Mathematics

Bulletin of the Belgian Mathematical Society - Simon Stevin

An ecological model with grazing and constant yield harvesting

In this article we give a characterization of the convergence of projection methods which are useful for approximating the Moore-Penrose inverse of a closed densely defined operator between Hilbert spaces. We illustrate the main theorem with an example. Also a procedure for constructing the admissible sequence of projections is discussed. © 2010 The Indian National Science Academy.