Net gen or not gen? Student and Staff Evaluations of the use of Podcasts/Audio Files and an Electronic Voting System (EVS) in a Blended Learning Module.

At the authors’ institution, blended learning is defined as “educational provision where high quality e-learning opportunities and excellent campus-based learning are combined or blended in coherent, reflective and innovative ways so that learning is enhanced and choice is increased. Students are at the centre of this vision”. This paper outlines work undertaken to investigate the impact of integrating podcasts/audio file downloads and use of an electronic voting system (EVS) to transform module delivery from a traditional mode to a blended delivery. The purpose being to introduce a measure of flexibility in how, when and where students study; to increase interactivity and engagement in classroom sessions, and to enhance students' learning. The student cohort is diverse in respect of age – the majority or students are direct entry students of the so-called net generation, whilst a significant number of students (35%) are mature students. Would age be an influencing factor on the students’ preference for the learning methods employed, or their willingness or ability to engage with the technologies? An interim student evaluation was undertaken at the midpoint of the taught module, to provide formative, illustrative data to the module leader and teaching team about student opinion of the teaching methods and learning technologies. Given the option of returning to the traditional delivery method, 77.5% of students either “agreed” or “strongly agreed” that the module should continue to run in its blended format. The final evaluation discovered no discernable differences in the behaviour of the direct entry students compared to the mature students. Both groups accessed the podcasts easily, generally at home, and spent longer than if blended learning technologies had not been used. It was discovered that 16% of the mature and 24% of the direct entry students would have preferred lectures to podcasts, although the students were positive about the flexibility offered. Both groups of students were virtually unanimous on the benefits of the EVS to support learning. The teaching team concluded that the blended learning technologies increased the students’ engagement with their learning

Incorporating learning technologies into undergraduate radiography education

Original article can be found at: http://www.sciencedirect.com/science/journal/10788174 Copyright The College of RadiographersThis study investigated the impact of integrating podcasts/audio file downloads and use of an electronic voting system (EVS) on a previously traditionally taught module. Both student (direct entry and mature) and staff satisfaction with the modified structure were evaluated.Peer reviewe

Evidence for chaotic behaviour in pulsar spin-down rates

We present evidence for chaotic dynamics within the spin-down rates of 17 pulsars originally presented by Lyne et al. Using techniques that allow us to re-sample the original measurements without losing structural information, we have searched for evidence of a strange attractor in the time series of frequency derivatives for each of the 17 pulsars. We demonstrate the effectiveness of our methods by applying them to a component of the Lorenz and R\"ossler attractors that were sampled with similar cadence to the pulsar time series. Our measurements of correlation dimension and Lyapunov exponent show that the underlying behaviour appears to be driven by a strange attractor with approximately three governing non-linear differential equations. This is particularly apparent in the case of PSR B1828$-$11 where a correlation dimension of 2.06\pm0.03 and a Lyapunov exponent of $(4.0\pm0.3)\times10^{-4}$ inverse days were measured. These results provide an additional diagnostic for testing future models of this behaviour.Comment: 15 pages, 18 figures, 2 tables, Accepted to MNRA

Discovery of Five New Pulsars in Archival Data

Reprocessing of the Parkes Multibeam Pulsar Survey has resulted in the discovery of five previously unknown pulsars and several as-yet-unconfirmed candidates. PSR J0922-52 has a period of 9.68 ms and a DM of 122.4 pc cm^-3. PSR J1147-66 has a period of 3.72 ms and a DM of 133.8 pc cm^-3. PSR J1227-6208 has a period of 34.53 ms, a DM of 362.6 pc cm^-3, is in a 6.7 day binary orbit, and was independently detected in an ongoing high-resolution Parkes survey by Thornton et al. and also in independent processing by Einstein@Home volunteers. PSR J1546-59 has a period of 7.80 ms and a DM of 168.3 pc cm^-3. PSR J1725-3853 is an isolated 4.79-ms pulsar with a DM of 158.2 pc cm^-3. These pulsars were likely missed in earlier processing efforts due to their high DMs and short periods and the large number of candidates that needed to be looked through. These discoveries suggest that further pulsars are awaiting discovery in the multibeam survey data.Comment: 12 pages, 2 figures, 2 tables, accepted to Ap

On the detectability of extragalactic fast radio transients

Recent discoveries of highly dispersed millisecond radio bursts by Thornton et al. in a survey with the Parkes radio telescope at 1.4 GHz point towards an emerging population of sources at cosmological distances whose origin is currently unclear. Here we demonstrate that the scattering effects at lower radio frequencies are less than previously thought, and that the bursts could be detectable at redshifts out to about $z=0.5$ in surveys below 1 GHz. Using a source model in which the bursts are standard candles with bolometric luminosities $\sim 8 \times 10^{44}$ ergs/s uniformly distributed per unit comoving volume, we derive an expression for the observed peak flux density as a function of redshift and use this, together with the rate estimates found by Thornton et al. to find an empirical relationship between event rate and redshift probed by a given survey. The non-detection of any such events in Arecibo 1.4 GHz survey data by Deneva et al., and the Allen Telescope Array survey by Simeon et al. is consistent with our model. Ongoing surveys in the 1--2 GHz band should result in further discoveries. At lower frequencies, assuming a typical radio spectral index $\alpha=-1.4$, the predicted peak flux densities are 10s of Jy. As a result, surveys of such a population with current facilities would not necessarily be sensitivity limited and could be carried out with small arrays to maximize the sky coverage. We predict that sources may already be present in 350-MHz surveys with the Green Bank Telescope. Surveys at 150 MHz with 30 deg$^2$ fields of view could detect one source per hour above 30 Jy.Comment: 5 pages, 2 figures, Accepted for publication in MNRAS on 2013 July 25. Received 2013 July 24; in original form 2013 May 3

Timing of pulsars found in a deep Parkes multibeam survey

We have carried out a sensitive radio pulsar survey along the northern Galactic plane ($50^{\circ} < l < 60^{\circ}$ and |b| \lapp 2^{\circ}) using the Parkes 20-cm multibeam system. We observed each position for 70-min on two separate epochs. Our analyses to date have so far resulted in the detection of 32 pulsars, of which 17 were previously unknown. Here we summarize the observations and analysis and present the timing observations of 11 pulsars and discovery parameters for a further 6 pulsars. We also present a timing solution for the 166-ms bursting pulsar, PSR~J1938+2213, previously discovered during an Arecibo drift-scan survey. Our survey data for this pulsar show that the emission can be described by a steady pulse component with bursting emission, which lasts for typically 20--25 pulse periods, superposed. Other new discoveries are the young 80.1-ms pulsar PSR~J1935+2025 which exhibits a significant amount of unmodeled low-frequency noise in its timing residuals, and the 4.2-ms pulsar PSR~J1935+1726 which is in a low-mass binary system with a 90.7-day circular orbit.Comment: 6 pages, 2 figures, accepted for publication in MNRA

Gravitational wave background from rotating neutron stars

The background of gravitational waves produced by the ensemble of rotating neutron stars (which includes pulsars, magnetars and gravitars) is investigated. A formula for \Omega(f) (commonly used to quantify the background) is derived, properly taking into account the time evolution of the systems since their formation until the present day. Moreover, the formula allows one to distinguish the different parts of the background: the unresolvable (which forms a stochastic background) and the resolvable. Several estimations of the background are obtained, for different assumptions on the parameters that characterize neutron stars and their population. In particular, different initial spin period distributions lead to very different results. For one of the models, with slow initial spins, the detection of the background can be rejected. However, other models do predict the detection of the background by the future ground-based gravitational wave detector ET. A robust upper limit for the background of rotating neutron stars is obtained; it does not exceed the detection threshold of two cross-correlated Advanced LIGO interferometers. If gravitars exist and constitute more than a few percent of the neutron star population, then they produce an unresolvable background that could be detected by ET. Under the most reasonable assumptions on the parameters characterizing a neutron star, the background is too faint. Previous papers have suggested neutron star models in which large magnetic fields (like the ones that characterize magnetars) induce big deformations in the star, which produce a stronger emission of gravitational radiation. Considering the most optimistic (in terms of the detection of gravitational waves) of these models, an upper limit for the background produced by magnetars is obtained; it could be detected by ET, but not by BBO or DECIGO.Comment: 25 pages, 15 figure

A Search for Sub-millisecond Pulsations in Unidentified FIRST and NVSS Radio Sources

We have searched 92 unidentified sources from the FIRST and NVSS 1400 MHz radio survey catalogs for radio pulsations at 610 MHz. The selected radio sources are bright, have no identification with extragalactic objects, are point-like and are more than 5% linearly polarized. Our search was sensitive to sub-millisecond pulsations from pulsars with dispersion measures (DMs) less than 500 pc cm-3 in the absence of scattering. We have detected no pulsations from these sources and consider possible effects which might prevent detection. We conclude that as a population, these sources are unlikely to be pulsars.Comment: 8 pages, including 2 tables and 1 figure. Accepted for publication in A

Strengthening the role of civil society in water sector governance towards climate change adaptation in African cities – Durban, Maputo, Nairobi

Water resources management is one of the most important climate change-related issues on international, national and urban public policy agendas. Income inequality in South Africa, Mozambique, and Kenya is among the largest in the world; in all three countries, equity struggles related to water are growing in social, political and ecological significance, which is both a symptom and a cause of urban vulnerabilities related to climate change. Democratic mediation of these conflicts, and sustainable long-term management of water resources in the face of climate change, requires public participation. But those most affected by water issues such as scarcity and flooding are also those least likely to be able to participate in governance and policy institutions. In particular, members of economically disadvantaged groups – especially women, in general – tend to be gravely impacted by poor water management, but also face great difficulties in participating effectively in governance bodies. This project responded to that particular need, and has developed practical strategies for strengthening urban governments in planning investments in climate change adaptation. The project linked university researchers with community-based NGOs conducting environmental education and organizing participatory workshops in low-income urban areas with pressing climate change and water-related problems; built on proven methods of community-university collaboration to strengthen urban watershed governance; increased equity in public participation processes related to urban climate change adaptation; and fostered progressive local, national and international policy development on climate change-related water management – while training students, university researchers, NGO staff members, and community participants. The major research outcome of the project is its contribution to understanding effective ways of strengthening local governments, NGOs and civil society organizations involved in environmental education and organizing for improved public participation in watershed governance and climate change adaptation in African urban areas.This research was supported by the International Development Research Centre, grant number IDRC GRANT NO. 106002-00