Indian Institutes of Science Education and Research

About: Indian Institutes of Science Education and Research is a based out in . It is known for research contribution in the topics: Gravitational wave & LIGO. The organization has 584 authors who have published 731 publications receiving 40599 citations. The organization is also known as: IISERs.

Hydrothermal Synthesis, Characterization and Gas Adsorption Study of a Zn(II) Based 1D Coordination Polymer

Abstract: A new 1D co-ordination polymer [Zn(C10H2O8)0.5(C10S2N2H8)·2H2O)] n (1) has been synthesized by in situ formation of a 4-pyt (4-pyridinethiolate) ligand from 4,4′-pyridyldithiol precursor through reductive cleavage of the disulfide bond under hydrothermal conditions. Compound 1 possesses pendent 4-pyt ligands through a Zn–S bond which restricts the framework to expand dimensionality. The compound shows selective CO2 adsorption over N2 at low temperatures.

Aster swarming by symmetry breaking of cortical dynein transport and coupling kinesins

Abstract: Microtubule (MT) radial arrays or asters establish the internal topology of a cell by interacting with organelles and molecular motors. We proceed to understand the general pattern forming potential of aster–motor systems using a computational model of multiple MT asters interacting with motors in cellular confinement. In this model dynein motors are attached to the cell cortex and plus-ended motors resembling kinesin-5 diffuse in the cell interior. The introduction of ‘noise’ in the form of MT length fluctuations spontaneously results in the emergence of coordinated, achiral vortex-like rotation of asters. The coherence and persistence of rotation require a threshold density of both cortical dyneins and coupling kinesins, while the onset is diffusion-limited with relation to the cortical dynein mobility. The coordinated rotational motion emerges due to the resolution of a ‘tug-of-war’ of multiple cortical dynein motors bound to MTs of the same aster by ‘noise’ in the form of MT dynamic instability. This transient symmetry breaking is amplified by local coupling by kinesin-5 complexes. The lack of widespread aster rotation across cell types suggests that biophysical mechanisms that suppress such intrinsic dynamics may have evolved. This model is analogous to more general models of locally coupled self-propelled particles (SPP) that spontaneously undergo collective transport in the presence of ‘noise’ that have been invoked to explain swarming in birds and fish. However, the aster–motor system is distinct from SPP models with regard to the particle density and ‘noise’ dependence, providing a set of experimentally testable predictions for a novel sub-cellular pattern forming system.

Modeling the tunability of the dual-feedback genetic oscillator.

Abstract: Oscillatory gene circuits are ubiquitous to biology and are involved in fundamental processes of cell cycle, circadian rhythms, and developmental systems. The synthesis of small, non-natural oscillatory genetic circuits has been increasingly used to test the fundamental principles of genetic network dynamics. While the ``repressilator'' was used to first demonstrate the proof of principle, a more recently developed dual-feedback, fast, tunable genetic oscillator has demonstrated a greater degree of robustness and control over oscillatory behavior by combining positive- and negative-feedback loops. This oscillator, combining lacI (negative-) and araC (positive-) feedback loops, was, however, modeled using multiple layers of differential equations to capture the molecular complexity of regulation, in order to explain the experimentally measured oscillations. In the search for design principles of such minimal oscillatory circuits, we have developed a reduced model of this dual-feedback loop oscillator consisting of just six differential equations, two of which are delay differential equations. The delay term is optimized, as the only free parameter, to fit the experimental dynamics of the oscillator period and amplitude tunability by the two inducers isopropyl $\ensuremath{\beta}$-D-1-thiogalactopyranoside (IPTG) and arabinose. We proceed to use our reduced and experimentally validated model to redesign the network by comparing the effect of asymmetry in gene expression at the level of (a) DNA copy numbers and the rates of (b) mRNA translation and (c) degradation, since experimental and theoretical work had predicted a need for an asymmetry in the copy numbers of activator (araC) and repressor (lacI) genes encoded on plasmids. We confirm that the minimal period of the oscillator is sensitive to DNA copy number asymmetry, and can demonstrate that while the asymmetry in the translation rate has an identical effect as the plasmid copy numbers, modulating the asymmetry in mRNA degradation can improve the tunability of the period and amplitude of the oscillator. Thus, our model predicts control at the level of translation can be used to redesign such networks, for improved tunability, while at the same time making the network robust to replication ``noise'' and the effects of the host cell cycle. Thus, our model predicts experimentally testable principles to redesign a potentially more robust oscillatory genetic network.

Radios, ringtones, and memory cards or, how the mobile phone became our favourite music playback device

Abstract: This article explores the co-constitution of mobile phones and music consumption in India to examine the changing relationships between music, listeners, playback technologies and music markets. Drawing upon ethnographic research conducted between 2011 and 2013 and archival material from 2003 to 2013, we trace the intersections of vectors such as mobile phone technologies, the digital im/materiality of sound recordings, legal and extralegal economies, practices of listening, sharing and storage. It is the intertwined and reciprocal relationships between these vectors that we elaborate upon in our narrative. In doing so, we are concerned with the rapid emergence in this historical moment of the mobile phone as an exceptionally popular music playback device, the legal and extra-legal practices that afforded this emergence, and the shifts in music-as-commodity as well as music listening that accompany the mobile phone.