Comment on "Anderson transition in disordered graphene"

We comment on a recent letter by Amini et al. (EPL 87, 37002 (2009)) concerning the existence of a mobility edge in disordered graphene.Comment: 3 pages, 3 figure

Electrostatics of Gapped and Finite Surface Electrodes

We present approximate methods for calculating the three-dimensional electric potentials of finite surface electrodes including gaps between electrodes, and estimate the effects of finite electrode thickness and an underlying dielectric substrate. As an example we optimize a radio-frequency surface-electrode ring ion trap, and find that each of these factors reduces the trapping secular frequencies by less than 5% in realistic situations. This small magnitude validates the usual assumption of neglecting the influences of gaps between electrodes and finite electrode extent.Comment: 9 pages, 9 figures (minor changes

Cytotoxic and antioxidant effect of chrysin on neonate mouse spermatogenic stem cells

Background: So far, many plants have been used for the treatment of infertility. Several studies have revealed that chrysin (as an active metabolite) improves animals' reproduction. Therefore, the objective of this study was to evaluate the effect of chrysin on Balb/C mice spermatogenic stem cells. Materials and Methods: In this in vitro experimental study Balb/C neonate spermatogonia stem cells cultured in DMEM-F12 medium were treated with various concentrations of chrysin (2.5, 5, 10, 20, 40 µg/ml) for 6 and 12 days. Then the cytotoxicity was assessed using MTT, Akredin orange/Propodium Idid, DAPI and antioxidant concentration DCF-DA tests. Results: Chrysin showed no remarkable cytoxicity in concentrations less than 5 µg/ml. While, after 6 days the viability of cells treated with chrysin 10, 20 and 40 µg/ml was decreased to 30, 45 and 56 (P<0.05 and P<0.001, respectiely); after 12 days the viability of cells was decreased to 44, 56 and 65 (P<0.05, P<0.01 and P<0.001, respectiely). DCF-DA results revealed a 80 antioxidant capacity of chrysin in 5 and 2.5µg/ml concentrations. Conclusion: Lower concentrations of chrysin has protective effect on Balb/C mice spermatogenic through improving cell viability, decreasing cells apoptosis and inhibiting free radicals

An assessment of residents’ and fellows’ personal finance literacy: An unmet medical education need

Objectives: This study aimed to assess residents' and fellows' knowledge of finance principles that may affect their personal financial health. Methods: A cross-sectional, anonymous, web-based survey was administered to a convenience sample of residents and fellows at two academic medical centers. Respondents answered 20 questions on personal finance and 28 questions about their own financial planning, attitudes, and debt. Questions regarding satisfaction with one's financial condition and investment-risk tolerance used a 10-point Likert scale (1=lowest, 10=highest). Of 2,010 trainees, 422 (21%) responded (median age 30 years; interquartile range, 28-33). Results: The mean quiz score was 52.0% (SD = 19.1). Of 299 (71%) respondents with student loan debt, 144 (48%) owed over $200,000. Many respondents had other debt, including 86 (21$25,000. Respondents' mean satisfaction with their current personal financial condition was 4.8 (SD = 2.5) and investment-risk tolerance was 5.3 (SD = 2.3). Indebted trainees reported lower satisfaction than trainees without debt (4.4 vs. 6.2, F (1,419) = 41.57, p < .001). Knowledge was moderately correlated with investment-risk tolerance (r=0.41, p < .001), and weakly correlated with satisfaction with financial status (r=0.23, p < .001). Conclusions: Residents and fellows had low financial literacy and investment-risk tolerance, high debt, and deficits in their financial preparedness. Adding personal financial education to the medical education curriculum would benefit trainees. Providing education in areas such as budgeting, estate planning, investment strategies, and retirement planning early in training can offer significant long-term benefits.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Scalable ion traps for quantum information processing

We report on the design, fabrication, and preliminary testing of a 150 zone array built in a `surface-electrode' geometry microfabricated on a single substrate. We demonstrate transport of atomic ions between legs of a `Y'-type junction and measure the in-situ heating rates for the ions. The trap design demonstrates use of a basic component design library that can be quickly assembled to form structures optimized for a particular experiment

Determining the Effect of Guessing on Test Scores

The purpose of this study was to determine the effect of guessing on test scores. The population used for this study consists of twenty (20) pupils of a primary school randomly selected from a total of one hundred (100) primary six pupils in Calabar, Nigeria. Ten (10) multiple choice Chemistry test items were constructed and pilot tested on five (5) primary school pupils of the same grade and age. The result of the study fails to agree with the Perfect Guttman Scale rather it tends to agree with the opinion of Lord (1977). The tests were constructed and applied in the classical test theory pattern and the pupils do not possess the ability demanded by the test items. It is suggested that examiners should give appropriate and clear instructions to the examinees to avoid guessing. In order to assign scores to the responses of the examinees, it is recommended that examiners should adopt the correction of guessing formula. Key Words: Academic Achievement, Classical Test Theory, Electrolysis, Item Difficulty, Item Discrimination, Test score, True Test Theor

Higher Education for All (EFA) in Nigeria: The Promise of Open and Distance Learning (ODL)

The social implication for development of educating all citizens of a country cannot be easily quantified. Education is however, seen as an instrument per excellence by many governments the world over, for social and technological development. This paper discusses the Nigeria Government promise of Education for All (EFA), by the year 2015, following the Dakar Declaration of Education for All in the World Education Summit in Dakar, Senegal in the year 2000. It noted the yawning gap between demand for higher education in Nigeria and the average intake per year using the Joint Admission and Matriculation Board statistics for 2005 to 2009 - a five-year period. It further observed that the conventional universities, with restriction on age of entrants, and the limitations of time, infrastructure and space will not enable Nigeria to meet the target of education for all in 2015. And looking at the advantages and successes of mega universities in other and similar regions of the world, the paper draws the attention of the Nigerian Government to the problem above and suggests the use of Open and Distance Learning as an educational delivery system to reach this lofty goal of Education for All in 2015. It concludes that in doing so, Nigeria will be able to meet that aspect of the Millennial Development Goal (MDG). Keywords: Education for all, higher education, access, open and distance learning, mega universities

Quantum communication between trapped ions through a dissipative environment

We study two trapped ions coupled to the axial phonon modes of a one-dimensional Coulomb crystal. This system is formally equivalent to the "two spin-boson" model. We propose a scheme to dynamically generate a maximally entangled state of two ions within a decoherence-free subspace. Here the phononic environment of the trapped ions, whatever its temperature and number of modes, serves as the entangling bus. The efficient production of the pure singlet state can be exploited to perform short-ranged quantum communication which is essential in building up a large-scale quantum computer.Comment: 4 pages, 2 figure