Cyberbullying

Technology now allows people — often children — to bully online. Social messaging sites can open up the user to a variety of bullying techniques outside of the playground. How parents and other adults can help reduce bullying over the Internet is examined in this NebGuide. ... What can a parent do about cyberbullying? First, it’s important that parents and youth not reply or respond in any way to cyberbullies. Research indicates that being responsive may, in fact, escalate the activity. Instead, parents will need to think like a detective or lawyer. Document the activity with dates and times and print out any offensive materials. Keep the original email or other digital information, which can help computer specialists find the digital source. Use this information to report the activity to appropriate authorities, such as the school, local police department, state patrol, Federal Bureau of Investigation (FBI), your Internet service provider (ISP), and/or groups like WiredSafety

Sulphur hexaflouride: low energy (e,2e) experiments and molecular three-body distorted wave theory

Experimental and theoretical triple differential ionisation cross-sections (TDCS’s) are presented for the highest occupied molecular orbital of sulphur hexafluoride. These measurements were performed in the low energy regime, with outgoing electron energies ranging from 5 to 40 eV in a coplanar geometry, and with energies of 10 and 20 eV in a perpendicular geometry. Complementary theoretical predictions of the TDCS were calculated using the molecular three-body distorted wave formalism. Calculations were performed using a proper average over molecular orientations as well as the orientation-averaged molecular orbital approximation. This more sophisticated model was found to be in closer agreement with the experimental data, however neither model accurately predicts the TDCS over all geometries and energies

Hydrodynamic Equation for the Breakdown of the Quantum Hall Effect in a Uniform Current

The hydrodynamic equation for the spatial and temporal evolution of the electron temperature T_e in the breakdown of the quantum Hall effect at even-integer filling factors in a uniform current density j is derived from the Boltzmann-type equation, which takes into account electron-electron and electron-phonon scatterings. The derived equation has a drift term, which is proportional to j and to the first spatial derivative of T_e. Applied to the spatial evolution of T_e in a sample with an abrupt change of the width along the current direction, the equation gives a distinct dependence on the current direction as well as a critical relaxation, in agreement with the recent experiments.Comment: 4 pages, 1 Postscript figure, corrected equations, to be published in J. Phys. Soc. Jpn. 70 (2001) No.

Hydrodynamic Equations in Quantum Hall Systems at Large Currents

Hydrodynamic equations (HDEQs) are derived which describe spatio-temporal evolutions of the electron temperature and the chemical potential of two-dimensional systems in strong magnetic fields in states with large diagonal resistivity appearing at the breakdown of the quantum Hall effect. The derivation is based on microscopic electronic processes consisting of drift motions in a slowly-fluctuating potential and scattering processes due to electron-electron and electron-phonon interactions. In contrast with the usual HDEQs, one of the derived HDEQs has a term with an energy flux perpendicular to the electric field due to the drift motions in the magnetic field. As an illustration, the current distribution is calculated using the derived HDEQs.Comment: 10 pages, 2 Postscript figures, to be published in J. Phys. Soc. Jpn. 71 (2002) No.

Spectroscopy of the Potential Profile in a Ballistic Quantum Constriction

We present a theory for the nonlinear current-voltage characteristics of a ballistic quantum constriction. Nonlinear features first develop because of above-barrier reflection from the potential profile, created by impurities in the vicinity of the constriction. The nonlinearity appears on a small voltage scale and makes it possible to determine distances between impurities as well as the magnitude of the impurity potentials.Comment: 3 pages, 4 figures (availiable upon request), REVTEX, Applied Physics Report 93-5

Tenofovir treatment augments anti-viral immunity against drug-resistant SIV challenge in chronically infected rhesus macaques

BACKGROUND: Emergence of drug-resistant strains of human immunodeficiency virus type 1 (HIV-1) is a major obstacle to successful antiretroviral therapy (ART) in HIV-infected patients. Whether antiviral immunity can augment ART by suppressing replication of drug-resistant HIV-1 in humans is not well understood, but can be explored in non-human primates infected with simian immunodeficiency virus (SIV). Rhesus macaques infected with live, attenuated SIV develop robust SIV-specific immune responses but remain viremic, often at low levels, for periods of months to years, thus providing a model in which to evaluate the contribution of antiviral immunity to drug efficacy. To investigate the extent to which SIV-specific immune responses augment suppression of drug-resistant SIV, rhesus macaques infected with live, attenuated SIVmac239Δnef were treated with the reverse transcriptase (RT) inhibitor tenofovir, and then challenged with pathogenic SIVmac055, which has a five-fold reduced sensitivity to tenofovir. RESULTS: Replication of SIVmac055 was detected in untreated macaques infected with SIVmac239Δnef, and in tenofovir-treated, naïve control macaques. The majority of macaques infected with SIVmac055 experienced high levels of plasma viremia, rapid CD4(+ )T cell loss and clinical disease progression. By comparison, macaques infected with SIVmac239Δnef and treated with tenofovir showed no evidence of replicating SIVmac055 in plasma using allele-specific real-time PCR assays with a limit of sensitivity of 50 SIV RNA copies/ml plasma. These animals remained clinically healthy with stable CD4(+ )T cell counts during three years of follow-up. Both the tenofovir-treated and untreated macaques infected with SIVmac239Δnef had antibody responses to SIV gp130 and p27 antigens and SIV-specific CD8(+ )T cell responses prior to SIVmac055 challenge, but only those animals receiving concurrent treatment with tenofovir resisted infection with SIVmac055. CONCLUSION: These results support the concept that anti-viral immunity acts synergistically with ART to augment drug efficacy by suppressing replication of viral variants with reduced drug sensitivity. Treatment strategies that seek to combine immunotherapeutic intervention as an adjunct to antiretroviral drugs may therefore confer added benefit by controlling replication of HIV-1, and reducing the likelihood of treatment failure due to the emergence of drug-resistant virus, thereby preserving treatment options

Electron-beam propagation in a two-dimensional electron gas

A quantum mechanical model based on a Green's function approach has been used to calculate the transmission probability of electrons traversing a two-dimensional electron gas injected and detected via mode-selective quantum point contacts. Two-dimensional scattering potentials, back-scattering, and temperature effects were included in order to compare the calculated results with experimentally observed interference patterns. The results yield detailed information about the distribution, size, and the energetic height of the scattering potentials.Comment: 7 pages, 6 figure

Effective measures of tailored learning support for Engineering Work-Based Learners in HE: A Case study

Since 2004, Aston University has been delivering work-based learning (WBL) engineering degrees to key UK Energy sector employers, such as National Grid. National measures for widening participation in HE, such as the Degree Apprenticeship Levy, have led to significant changes in learning background diversity of WBL cohorts, consequently increasing student requirement for additional learning-support in HE Institutions (HEIs). To address these challenges, an intervention strategy was formulated in collaboration with Aston University's Learning Development Centre. Our methodology gradually embedded a provision of tailored learning-support sessions/workshops in mathematics and effective communication skills within WBL curricula. Integrating this support has led to marked increases in student engagement,grade-attainment, and stakeholder satisfaction. This case study is pertinent to HE's current STEM sector focus on developing WBL programmes, where the flexible methodologies established here can serve as practical models for other HEIs in the delivery of ‘in-employment’ education, in response to the fast-changing workplace