High-Field Shubnikov-de Haas Oscillations in the Topological Insulator Bi2_2Te2_2Se

We report measurements of the surface Shubnikov de Haas oscillations (SdH) on crystals of the topological insulator Bi$_2$Te$_2$Se. In crystals with large bulk resistivity ($\sim$4 $\Omega$cm at 4 K), we observe $\sim$15 surface SdH oscillations (to the $n$ = 1 Landau Level) in magnetic fields $B$ up to 45 Tesla. Extrapolating to the limit $1/B\to 0$, we confirm the $\frac12$-shift expected from a Dirac spectrum. The results are consistent with a very small surface Lande $g$-factor.Comment: Text expanded, slight changes in text, final version; Total 6 pages, 6 figure

DNA methylation of ESR-1 and N-33 in colorectal mucosa of patients with Ulcerative Colitis (UC)

Introduction: Epigenetic marking such as DNA methylation influence gene transcription and chromosomal stability and may also be affected by environmental exposures. Few studies exist on alteration in DNA methylation profiles (genomic and gene specific methylation) in patients with Ulcerative Colitis (UC) and none assessing its relationship with lifestyle exposures. Aims & Methods: To assess genomic methylation and promoter methylation of the ESR-1 (oestrogen receptor - 1) and N-33 (tumour suppressor candidate-3) genes in the macroscopically normal mucosa of UC patients as well as to investigate effects of anthropometric and lifestyle exposures on DNA methylation. Sixty eight subjects were recruited (24 UC and 44 age and sex matched controls). Colorectal mucosal biopsies were obtained and DNA was extracted. Genomic DNA methylation was quantified using the tritium-labelled cytosine extension assay (3[H] dCTP) whilst gene specific methylation was quantified using the COBRA method. Results: The methylation level of both ESR-1 and N-33 genes were significantly higher in UC subjects compared with controls (7.9% vs 5.9%; p = 0.015 and 66% vs 9.3%; p < 0.001 respectively). There was no detectable difference in global DNA methylation between patients with UC and age and sex matched controls. No associations between indices of DNA methylation and anthropometric measures or smoking patterns were detected. Conclusions: For the first time, we have shown increased methylation in the promoter regions of the putative tumour suppressor gene N-33 in macroscopically normal mucosa of patients with UC. In addition, we have confirmed that methylation of ESR-1 promoter is higher in UC patients compared with age and sex matched controls. These findings suggests that, inactivation through methylation of the putative tumour suppressor genes N-33 and ESR-1, may not be associated with colorectal carcinogenesis in UC

Adoption of innovative e-learning support for teaching: A multiple case study at the University of Waikato

In response to recent social, economic, and pedagogical challenges to tertiary-level teaching and learning, universities are increasingly investigating and adopting elearning as a way to engage and motivate students. This paper reports on the first year of a two-year (2009-2010) qualitative multiple case study research project in New Zealand. Using perspectives from activity theory and the scholarship of teaching, the research has the overall goal of documenting, developing, and disseminating effective and innovative practice in which e-learning plays an important role in tertiary teaching. A “snapshot” of each of the four 2009 cases and focused findings within and across cases are provided. This is followed by an overall discussion of the context, “within” and “across” case themes, and implications of the research

Field Evaluation of Four Insecticides for the Control of the Mango Leaf-cutting Weevil, Deporaus marginatus Pasco

In an insecticidal trial for the control of the leaf-cutting weevil of mango, Deporaus marginatus Pasc., deltamethrin was the most effective insecticide followed by etrimfos, acephate and dicrotophos in that order. A persistency study of deltamethrin in the field showed that the insecticide was effective for up to two weeks

Signal processing by opto-optical interactions between self-localized and free propagating beams in liquid crystals

The reorientational nonlinearity of nematic liquid crystals enables a self-localized spatial soliton and its waveguide to be deflected or destroyed by a control beam propagating across the cell. We demonstrate a simple all-optical readdressing scheme by exploiting the lens-like perturbation induced by an external beam on both a nematicon and a co-polarized guided signal of different wavelength. Angular steering as large as 2.2 degrees was obtained for control powers as low as 32mW in the near infrared

In vitro synergy and enhanced murine brain penetration of saquinavir coadministered with mefloquine.

Highly active antiretroviral therapy has substantially improved prognosis in human immunodeficiency virus (HIV). However, the integration of proviral DNA, development of viral resistance, and lack of permeability of drugs into sanctuary sites (e.g., brain and lymphocyte) are major limitations to current regimens. Previous studies have indicated that the antimalarial drug chloroquine (CQ) has antiviral efficacy and a synergism with HIV protease inhibitors. We have screened a panel of antimalarial compounds for activity against HIV-1 in vitro. A limited efficacy was observed for CQ, mefloquine (MQ), and mepacrine (MC). However, marked synergy was observed between MQ and saquinavir (SQV), but not CQ in U937 cells. Furthermore, enhancement of the antiviral activity of SQV and four other protease inhibitors (PIs) by MQ was observed in MT4 cells, indicating a class specific rather than a drug-specific phenomenon. We demonstrate that these observations are a result of inhibition of multiple drug efflux proteins by MQ and that MQ also displaces SQV from orosomucoid in vitro. Finally, coadministration of MQ and SQV in CD-1 mice dramatically altered the tissue distribution of SQV, resulting in a >3-fold and >2-fold increase in the tissue/blood ratio for brain and testis, respectively. This pharmacological enhancement of in vitro antiviral activity of PIs by MQ now warrants further examination in vivo

Respiratory distress in a newborn

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