Z2 spin liquid in S=1/2 Heisenberg model on Kagome lattice: A projective symmetry group study of Schwinger-fermion mean-field states

With strong geometric frustration and quantum fluctuations, S=1/2 quantum Heisenberg antiferromagnets on the Kagome lattice has long been considered as an ideal platform to realize spin liquid (SL), a novel phase with no symmetry breaking and fractionalized excitations. A recent numerical study of Heisenberg S=1/2 Kagome lattice model (HKLM) show that in contrast to earlier studies, the ground state is a singlet-gapped SL with signatures of Z2 topological order. Motivated by this numerical discovery, we use projective symmetry group to classify all 20 possible Schwinger-fermion mean-field states of Z2 SLs on Kagome lattice. Among them we found only one gapped Z2 SL (which we call Z2[0,\pi]\beta state) in the neighborhood of U(1)-Dirac SL state, whose energy is found to be the lowest among many other candidate SLs including the uniform resonating-valentce-bond states. We thus propose this Z2[0,\pi]\beta state to be the numerically discovered SL ground state of HKLM.Comment: 12 pages, 2 figures, revtex4, published versio

A real interlocutor in elicitation techniques: does it matter?

This study investigates whether adding a real interlocutor to elicitation techniques would result in requests that are different from those gathered through versions with a hypothetical interlocutor. For this purpose, a written method is chosen. One group of 40 students receive a written discourse completion task (DCT) with two situations that ask respondents to write emails on paper to an imaginary professor. This data is compared to earlier data collected from 27 students, where a group of students composed emails for the same situations and sent them electronically to their professor. Thus, while one group write emails to a hypothetical professor, the other group is provided with a real interlocutor. The data is analyzed for the inclusion of opening and closing moves, density, the level of directness and the choices of moves in the opening and closing sequences, as well as the choices of supportive moves. Results indicate significant differences in (the) level of directness, and the choices of moves in the opening and closing sequences. The other analyses do not show significant differences. The findings reveal that the addition of a real interlocutor does make a difference, albeit not a drastic one. The results have implications for the design of elicitation techniques that aim to simulate real life

Exact controllability of multiplex networks

Date of Acceptance: 11/09/2014Peer reviewedPublisher PD

The experience and attitude of TMU faculty and researchers toward predatory journals and research productivity

A questionnaire related to journal submission was sent to researchers for a 2-week period to investigate the submission status as well as the problems faced by Taipei Medical University faculties and researchers. This study has two major findings including the Experience of predatory journal and Calculations of academic performance point and discuss about users’ cognition and their needs from the library and the university, as well as the library policy and services related to predatory journals. It is authors’ hope that the research results can serve as reference for other medical libraries planning to provide relevant services

Use of sodium bicarbonate for acute dizziness after minor head injury

AbstractObjectiveDizziness after minor head injury (mHI) is common. In some eastern countries, it is treated with 7% sodium bicarbonate solution (SB). This prospective study evaluated the clinical efficacy of SB compared with normal saline (NS).Material and methodsFrom April 2009 to April 2010, we performed a prospective observational study on 228 patients (68% female, 32% male) with acute dizziness after mHI. At the emergency physician’s discretion, intravenous SB (1 mL/kg) in NS (250 mL) or NS (250 mL) was administered to 166 patients and 62 patients, respectively, as empiric antidizziness therapy. Outcome measures were severity of dizziness and treatment response, which were measured by a visual analog scale. Various characteristics were compared between treatment groups. Any continued dizziness of the patients during follow-up was also compared with their pre-injury condition, such as prior psychiatric disorders and the presence of vertigo.ResultsThe SB group had their visual analog scale scores reduced by 25.4% compared with 24.6% in the NS group. Both groups showed a statistically significant reduction in dizziness (p < 0.001); however, the dizziness improvement did not differ significantly between the two treatment groups (p = 0.699). Sixty-four patients (28.1%) suffered from continued dizziness during follow-up (mean period, 22.4 ± 28.9 days). The prevalence of continued dizziness was higher in patients with prior psychiatric disorders, although this was not statistically significant (40% vs. 27.2%, p = 0.276), whereas patients with prior vertigo did not experience a higher dizziness relapse rate (27% vs. 28.2%).ConclusionsSB and NS administrations are both effective individually when treating patients with acute dizziness from mHI; however, both results may be attributable to the placebo effect. Therefore more research is necessary to understand the complex conditions that determine the effects of SB on this disorder