Floquet analysis of a driven Kitaev chain in presence of a quasiperiodic potential

The interplay of topology and disorder in non-equilibrium quantum systems is an intriguing subject. Here, we look for a suitable platform that enables an in-depth exploration of the topic. To this end, we analyze the topological and localization properties of a dimerized one-dimensional Kitaev chain in the presence of an onsite quasiperiodic potential whose amplitude is modulated periodically in time. The topological features have been explored via computing the real-space winding numbers corresponding to both the Majorana zero and the $\pi$ energy modes. We enumerate the scenario at different driving frequencies. In particular, at either low or intermediate frequency regimes, the phase diagram concerning the zero mode involves two distinct phase transitions, one from a topologically trivial to a non-trivial phase, and another from a topological phase to an Anderson localized phase. On the other hand, the study of the $\pi$ modes reveals the emergence of a unique topological phase, where both the bulk and the edge modes are fully localized, which may be called as the Floquet topological Anderson phase. Moreover, while the low and high-frequency regimes host extended and localized states, respectively, at intermediate frequencies, the states can be extended, critical (or multifractal), and localized. Inverse and normalized participation ratios are used as tools to characterize the extended and the localized states. Further, the intermediate frequency regime is thoroughly enumerated via a finite-size scaling analysis of the fractal dimension

Ergodicity-breaking phase diagram and fractal dimensions in long-range models with generically correlated disorder

Models with correlated disorders are rather common in physics. In some of them, like the Aubry-Andr\'e (AA) model, the localization phase diagram can be found from the (self)duality with respect to the Fourier transform. In the others, like the all-to-all translation-invariant Rosenzweig-Porter (TI RP) ensemble or the Hilbert-space structure of the many-body localization, one needs to develop more sophisticated and usually phenomenological methods to find the localization transition. In addition, such models contain not only localization but also the ergodicity-breaking transition, giving way to the non-ergodic extended phase of states with non-trivial fractal dimensions $D_q$. In this work, we suggest a method to calculate both the above transitions and a lower bound to the fractal dimensions $D_2$ and $D_\infty$, relevant for physical observables. In order to verify this method, we apply it to the class of long-range (self-)dual models, interpolating between AA and TI RP ones via both power-law dependences of on-site disorder correlations and hopping terms, and, thus, being out of the validity range of the previously developed methods. We show that the interplay of the correlated disorder and the power-law decaying hopping terms leads to the emergence of the two types of fractal phases in an entire range of parameters, even without having any quasiperiodicity of the AA potential. The analytical results of the above method are in full agreement with the extensive numerical calculations

Colonial legacies and contemporary urban planning practices in Dhaka, Bangladesh

Effective urban planning is said to be crucial for ensuring liveable, equitable and viable urban areas progress towards sustainability. This study combines a review of the relevant literature, key informant interviews and field observations to explore contemporary planning practices in Dhaka, Bangladesh. We problematize ineffective urban planning practice in Dhaka as a prime expression and reproduction of colonial planning, which manifests itself through institutional bureaucracy and centralization, technocracy, and ad hoc planning. We argue that these imprints have rendered planning institutions weak and fostered dependency on imported ideologies and practices. The situation, we further argue, not only stifles local planning creativity but also makes the planning profession unattractive. Apart from limited local innovations and political aspirations for meeting global development targets, urban planning and city management have followed a reductionist approach under neoliberalism. With little to no social resonance, attempts at creating ordered spaces are, instead, contributing to increased spatial fragmentation and segregation, informality, and widespread urban poverty. To promote urban sustainability, this paper urges the contextualization of colonial ideologies and practices against the social, political and economic realities of urban Bangladesh

Shop Talk: Annual Drosophila Research Conference, 2010

This year, the Genetics Society of America (GSA) received a record-breaking number of registrants to the conference. Despite low attendance at other scientific meetings, according to GSA Meetings Manager, Suzy Brown, this year’s conference had the ‘‘largest number of registrants than any other previous years.’’ There were 170 talks, more than 850 posters and 13 workshops; so there was a range of information that people could pick according to their interests

Comparison of Antibacterial Efficacy of Combination of Turmeric and Calcium Hydroxide with Three Intracanal Medicaments against Various Endodontic Bacteria: An in vitro Study

Introduction: An intracanal medicament have an antibacterial effect on the root canal flora. The effectiveness of different available intracanal medicaments and search for new antibacterial agents to use as intracanal medicament to ensure success of our treatment is today’s need. Curcumin (diferuloymthane) main yellow bioactive component of turmeric has wide spectrum of biological actions and this provides a basis for exploring its endodontic applications. Aim: To determine antibacterial efficacy of Curcuma longa (turmeric) against root canal microorganism and compare its  efficacy with calcium hydroxide, calcium hydroxide+ turmeric and metapex. Materials and methods: For an antibacterial assessment samples were divided into four groups as group 1 calciumhydroxide group 2 calcium hydroxide + turmeric oleoresin group 3 turmeric oleoresin group 4 metapex. Each group was tested against following root canal pathogens S. aureas, E. coli, E. feacalis by agar well diffusion method. Inhibition zone was recorded at 24, 48 and 72 hours. Results were tabulated andsent for statistical analysis. Result: Maximum inhibition of E.feacalis, E.coli, S. aureas is shown by combination of turmeric oleoresin and calcium hydroxide, i.e., group 2 followed by group metapex and then calcium hydroxide. Conclusion: Turmeric extract has substantial antibacterial effect and its combination with calcium hydroxide increases its antibacterial efficacy against all important root canal pathogens. So turmeric has great potential to be used as intracanal medicament&nbsp

STUDY OF ANALGESIC AND ANTIDIARRHOEAL ACTIVITIES OF Sonneratia caseolaris (LINN.) LEAF AND STEM USING DIFFERENT SOLVENT SYSTEM.

The different fractions of crude ethanol extract of leaf and stem of S. caseolaris (Linn.) (Sonneratiaceae) were screened for its analgesic and antidiarrhoeal activities. The different fraction of crude extract was obtained by using four different solvent systems. The different fractions of crude extract produced significant writhing inhibition in acetic acid induced writhing in mice at dose of 250 and 500mg/kg BW comparable to the standard drug diclofenac sodium at the dose of 25mg/kg BW. When tested for its antidiarrhoeal effects on castor oil induced diarrhea in mice, it increased mean latent period and decreased the frequency of defecation significantly at the dose of 250 and 500mg/kg BW comparable to the standard drug loperamide at the dose of 50mg/kg BW. The overall results tend to suggest the analgesic and antidiarrhoeal activities of the different fractions of crude extract. Both ethyl acetate fraction of stem and chloroform fraction of leaf have significant analgesic activity. Again between the two fractions of crude ethanol extract ethyl acetate fraction of S.caseolaris stem have most significant antidiarrhoeal activity.Key words: analgesic, antidiarrhoeal, S.caseolaris, diclofenac sodium, loperamide