Cyber security education is as essential as “The Three R’s”

Smartphones have diffused rapidly across South African society and constitute the most dominant information and communication technologies in everyday use. That being so, it is important to ensure that all South Africans know how to secure their smart devices. This requires a high level of security awareness and knowledge. As yet, there is no formal curriculum addressing cyber security in South African schools. Indeed, it seems to be left to Universities to teach cyber security principles, and they currently only do this when students take computing-related courses. The outcome of this approach is that only a very small percentage of South Africans, i.e. those who take computing courses at University, are made aware of cyber security risks and know how to take precautions. Moreover, because this group is overwhelmingly male, this educational strategy disproportionately leaves young female South Africans vulnerable to cyber attacks. We thus contend that cyber security ought to be taught as children learn the essential “3 Rs” – delivering requisite skills at University level does not adequately prepare young South Africans for a world where cyber security is an essential skill. Starting to provide awareness and knowledge at primary school, and embedding it across the curriculum would, in addition to ensuring that people have the skills when they need them, also remove the current gender imbalance in cyber security awareness

Pulsar emission in the very-high-energy regime

The vast majority of the pulsars detected by the Fermi Large Area Telescope (LAT) display spectra with exponential cutoffs falling in a narrow range around a few GeV. Early spectral modelling predicted spectral cutoff energies of up to 100 GeV. More modern studies estimated spectral cutoff energies in the 1-20 GeV range. It was therefore not expected that pulsars would be visible in the very-high-energy (VHE; >100 GeV) regime. The VERITAS detection (confirmed by MAGIC) of pulsed emission from the Crab pulsar up to 400 GeV (and now possibly up to 1 TeV) therefore raised important questions about our understanding of the electrodynamics and local environment of pulsars. H.E.S.S. has now detected pulsed emission from the Vela pulsar in the 20-120 GeV range, making this the second pulsar detected by a ground-based Cherenkov telescope. We will review the latest developments in VHE pulsar science, including an overview of recent observations and refinements to radiation models and magnetic field structures. This will assist us in interpreting the VHE emission detected from the Crab and Vela pulsars, and predicting the level of VHE emission expected from other pulsars, which will be very important for the upcoming CTA.Comment: 10 pages, 5 figures, "To appear in the Proceedings of the 3rd Annual Conference on High Energy Astrophysics in Southern Africa (HEASA2015), 18-20 June 2015, Johannesburg, South Africa, Eds. M. Boettcher, D. Buckley, S. Colafrancesco, P. Meintjes and S. Razzaque.

A Cosmic Ray Positron Anisotropy due to Two Middle-Aged, Nearby Pulsars?

Geminga and B0656+14 are the closest pulsars with characteristic ages in the ran ge of 100 kyr to 1 Myr. They both have spindown powers of the order 3e34 erg/s at present. The winds of these pulsars had most probably powered pulsar wind nebulae (PWNe) that broke up less than about 100 kyr after the birth of the pulsars. Assuming that leptonic particles accelerated by the pulsars were confined in th e PWNe and were released into the interstellar medium (ISM) on breakup of the PW Ne, we show that, depending on the pulsar parameters, both pulsars make a non-ne gligible contribution to the local cosmic ray (CR) positron spectrum, and they m ay be the main contributors above several GeV. The relatively small angular dist ance between Geminga and B0656+14 thus implies an anisotropy in the local CR po sitron flux at these energies. We calculate the contribution of these pulsars to the locally observed CR electr on and positron spectra depending on the pulsar birth period and the magnitude o f the local CR diffusion coefficient. We further give an estimate of the expecte d anisotropy in the local CR positron flux. Our calculations show that within the framework of our model, the local CR posit ron spectrum imposes constraints on pulsar parameters for Geminga and B0656+14, notably the pulsar period at birth, and also the local interstellar diffusion co efficient for CR leptons.Comment: accepted for publication in ApJ

The Effect of Different Magnetospheric Structures on Predictions of Gamma-ray Pulsar Light Curves

The second pulsar catalogue of the Fermi Large Area Telescope (LAT) will contain in excess of 100 gamma-ray pulsars. The light curves (LCs) of these pulsars exhibit a variety of shapes, and also different relative phase lags with respect to their radio pulses, hinting at distinct underlying emission properties (e.g., inclination and observer angles) for the individual pulsars. Detailed geometric modelling of the radio and gamma-ray LCs may provide constraints on the B-field structure and emission geometry. We used different B-field solutions, including the static vacuum dipole and the retarded vacuum dipole, in conjunction with an existing geometric modelling code, and constructed radiation sky maps and LCs for several different pulsar parameters. Standard emission geometries were assumed, namely the two-pole caustic (TPC) and outer gap (OG) models. The sky maps and LCs of the various B-field and radiation model combinations were compared to study their effect on the resulting LCs. As an application, we compared our model LCs with Fermi LAT data for the Vela pulsar, and inferred the most probable configuration in this case, thereby constraining Vela's high-altitude magnetic structure and system geometry.Comment: 6 pages, 4 figures, conference article, appears in Proceedings of SAIP2012, the 57th Annual Conference of the South African Institute of Physics, edited by Johan Janse van Rensburg, ISBN: 978-1-77592-070-

An analysis of U.K. property funds classified according to U.S. styles: Core, value-added, and opportunistic

This analysis explores the feasibility of sorting UK funds into the three categories that are widely used in the US, and then compares the performance of these styles between the UK and US. Following an overview of several factors’ impact on the expected risk and return of a property fund, we use Loan-to-Value ratio (LTV) as the dominant factor in a preliminary style-classification, defining funds with no debt as core, funds with LTV lower than 40% as value-added, and funds with higher than 50% LTV ratios as opportunistic. Then the study makes some adjustments to this classification based on the observation of the funds’ attributes other than LTV, and the classification ends up with 19 core funds, 22 value-added funds and 21 opportunistic funds. After that, we find two major differences between the UK and US funds. First, the core approach represents a smaller portion of the UK funds than the US funds and the opposite is true for the value-added approach. One way to improve the feasibility of researchers comparing funds within these two countries is introducing a fourth style, core-plus. Second, the US opportunistic funds are better performing with similar leverage than their UK counterparts, while future studies would help draw more precise conclusions about the performance comparisons