Unconventional superconductivity in CuxBi2Se3

We report point contact measurements in high quality single crystals of Cu0.2Bi2Se3. We observe three different kinds of spectra: (1) Andreev-reflection spectra, from which we infer a superconducting gap size of 0.6mV; (2) spectra with a large gap which closes above Tc at about 10K; and (3) tunneling-like spectra with zero-bias conductance peaks. These tunneling spectra show a very large gap of ~2meV (2Delta/KTc ~ 14)

Proximity induced superconductivity by Bi in topological Bi2Te2SeBi_2Te_2Se and Bi2Se3Bi_2Se_3 films: Evidence for a robust zero energy bound state possibly due to Majorana Fermions

Point contact conductance measurements on topological $Bi_2Te_2Se$ and $Bi_2Se_3$ films reveal a signature of superconductivity below 2-3 K. In particular, critical current dips and a robust zero bias conductance peak are observed. The latter suggests the presence of zero energy bound states which could be assigned to Majorana Fermions in an unconventional topological superconductor. We attribute these novel observations to proximity induced local superconductivity in the films by small amounts of superconducting Bi inclusions or segregation to the surface, and provide supportive evidence for these effects.Comment: Accepted for publication in Physical Review B (Dec. 20, 2011), 15 figures. Version V1: arXiv:1111.3445v1 [cond-mat.supr-con] 15 Nov 201

The problem of scale : the city, the territory, the planetary

University of Technology, Sydney. Faculty of Design, Architecture and Building.Since they cannot secure themselves in common notions of value, classical definitions of scale grounded in systems of proportion can no longer be considered relevant. The thesis therefore sets out a way of understanding scalar genesis or individuation. Drawing on the work of Gilles Deleuze, Gilbert Simondon, Manuel Delanda and Michel Foucault it attends to this scalar genesis across three registers: the ontological, the epistemological and the discursive. Using a series of case studies such as an urban design project by Oscar Niemeyer in Lebanon, an experiment in cybernetic management in Chile, and the present issues surrounding the modeling and politics of the earths climate as exemplars of individuation at the scale of the city, the territory and the planetary, the thesis concludes by suggesting that every event of scalar genesis links together unique problematics across ontological, epistemological and discursive registers, in what is described as a chain of immanence. It concludes by suggesting that the political question of value with respect to scale can now return, but only in so far as this value is immanent to the scalar problematic in question

Improved method for the determination of strontium-90 in oyster flesh.

The method for the determination of strontium-90 in environmental materials used in this laboratory has been found to be subject to interference from the large concentration of zinc in oyster flesh. This report deals with the development of a suitable solvent extraction procedure that will remove zinc without itself interfering in the determination. The method selected was the extraction of the thiocyanate complex of zinc from a hydrochloric acid solution into diethyl ether. This procedure removed greater than 95 per cent of zinc and produced no undesirable complications. Normal recovery of strontium was raised to better than 90 per cent

Improved method for the determination of strontium-90 in soils and sands.

The method for the determination of strontium-90 in environmental materials used in this laboratory has been found to be subject to interference from large concentrations of iron and aluminium in soil extracts. This report deals with the development of a suitable solvent extraction procedure that will remove iron and aluminium without itself interfering in the determination. The method selected was the extraction of iron and aluminium acetylacetonates into chloroform at controlled values of pH. This procedure removed better than 95 per cent of both iron and aluminium and produced no undesirable complications. Normal recovery of strontium was better than 80 per cent

An informational pathway to the development of a contamination-related memory bias

Background and Objectives: Following from previous work in which post-encoding suggestions of threat led to the development of a memory bias (in the presumed absence of an attentional bias; Senn & Radomsky, 2012), we sought to examine whether the development of a similar threat-relevant memory bias could be fostered via a purely informational pathway. Methods: A vignette about a classroom interaction was read aloud to (n = 96) undergraduate participants who then completed a post-encoding recall test. Participants were then told that the experimenter forgot to read the last sentence of the vignette, and were then randomly assigned either to the Threat condition, in which the additional statement indicated that a character in the vignette had a highly contagious flu, or to the No-Threat condition, in which the additional statement indicated that a character in the vignette had been accepted to graduate school. A second recall test was then administered. Results: Participants in the Threat condition (but not those in the No-Threat condition) demonstrated a proportional memory bias in favour of threatening information. This bias was not evident at the initial recall test. Limitations: Time spent engaging in active recall was not assessed. Also, although the study was designed to minimize demand characteristics, it is possible that these played a role. Conclusions: An explicit memory bias for threat can be created through informational means alone, even when no threat was present at encoding. Results are discussed in terms of pathways to fear and of cognitive approaches to understanding and treating anxiety disorders

Probing the surface states in Bi2Se3 using the Shubnikov-de Haas effect

Shubnikov-de Haas (SdH) oscillations are observed in Bi2Se3 flakes with high carrier concentration and low bulk mobility. These oscillations probe the protected surface states and enable us to extract their carrier concentration, effective mass and Dingle temperature. The Fermi momentum obtained is in agreement with angle resolved photoemission spectroscopy (ARPES) measurements performed on crystals from the same batch. We study the behavior of the Berry phase as a function of magnetic field. The standard theoretical considerations fail to explain the observed behavior.Comment: 6 pages, 8 figures. Accepted to Physical Review

Knowledge of pharmacists and parents towards antibiotic use in pediatrics: a cross-sectional study in Lebanon

Objectives: to assess the knowledge of both parents and community pharmacists regarding antibiotics use and resistance in pediatrics in Lebanon. Methods: A cross-sectional study was conducted between June and August 2017 in community pharmacies. A pre-established questionnaire targeting knowledge of parents and pharmacists regarding antibiotics use/misuse was carried out. An index of knowledge was computed to assess factors associated with good knowledge on antibiotics use/misuse. Results: The study showed that 28.7% of pharmacists did not know which factors may contribute to antimicrobial resistance. Concerning the misuse of antibiotics, pharmacists blamed at first parents (90.1%), at second level physicians (72.8%), and third themselves (59.4%). Furthermore, pharmacists believed that the socioeconomic problems of the country (86.1%), the level of resistance to the molecule of choice (80.8%), the lack of consultation time (71.2%) and the lack of national guidelines/recommendations (66.3%) might be additional factors contributing to antimicrobial resistance. In case of acute otitis media, the majority of pharmacists chose the correct treatment, dose and duration according to international guidelines; this was in contrast to the results obtained in case of pharyngitis. Female pharmacists had a significantly higher knowledge score compared to their male counterparts (ORa=2.51). Half of parents (42.6%) declared that antibiotics act against both viruses and bacteria, 55.9% still believe that the presence of fever requires the administration of antibiotics, 50% didn’t know the consequences of antibiotics misuse, 58.4% said that it is okay to give their child antibiotics without a physician's advice or based on a pharmacist’s recommendation, and 66.7% trusted the pharmacist in the antibiotic prescription. Parents with a university level of education or a master’s degree had significantly better knowledge compared to illiterate ones (ORa=9.04 and ORa=16.46, respectively). Conclusions: Based on the results obtained, it would be necessary to implement educational campaigns in order to increase awareness on antibiotics misuse and resistance in pediatrics