XMM-Newton observations of three short period polars: V347 Pav, GG Leo and EU UMa

We present phase-resolved XMM_Newton data of three short period polars: V347 Pav, GG Leo and EU UMa. All three systems show one dominant accretion region which is seen for approximately half of the orbital cycle. GG Leo shows a strong dip feature in its X-ray and UV light curves which is due to absorption of X-rays from the accretion site by the accretion stream. The emission in the case of EU UMa is dominated by soft X-rays: its soft/hard X-ray ratio is amongst the highest seen in these objects. In contrast, GG Leo and V347 Pav shows a ratio consistent with that predicted by the standard shock model. We infer the mass of the white dwarf and explore the affect of restricting the energy range on the derived parameters.Comment: accepted MNRA

Targeting, rhetoric and the failure of grassroots jihad

In this paper I examine the apparent failure of Al Qaeda ideologues, not for want of trying, to incite a widespread campaign of ‘individual jihad’. Not only are instances of genuinely ‘leaderless’ jihadist violence rare, they also tend to be more discriminate and less lethal in their targeting than the operations which Al Qaeda expresses a discursive preference for, and which it attempts to carry out. I argue that an explanation for the rather constrained nature of grassroots jihadist violence can be found, rather paradoxically, in the logic of collective action, which seems to underlie the rhetorical attempts of jihadist ideologues to incite violence. I then briefly examine the possible implications of this for understanding what makes for a successful ‘leaderless’ terrorist campaign.Publisher PD

Can 'quality marking' be used to provide effective feedback within higher education?

Providing written feedback to learners within Higher Education can be a time-consuming and frequently ineffective process, with comments often undervalued or not acted upon. The same concerns exist within the primary sector; marking systems do not always effectively support the principles of Assessment for Learning. This frustration resulted in the development of the 'Quality Marking' model for primary schools (Clarke 1998) which follows an explicit process within which the type of comments, or prompts, used are key. This small scale study has investigated whether 'quality marking' – and in particular the use of scaffold prompts – can be applied to the Higher Education context. A group of final year student teachers within initial teacher training received and acted upon the feedback, as well as completing a series of questionnaires to record their perceptions of the process and its formative value. It is clear from the data gathered that 'quality marking' was viewed as an effective approach. Key identified reasons for this were the likelihood of the feedback to feed forward into future learning, the level of engagement from the learner, the clarity of how to bridge the learning gap, and the beginnings of self-monitoring

Assessment and reduction of the impacts of large freight vehicles on urban traffic corridor performance

Increasing demand for road freight has lead to a widespread adoption of more-productive large freight vehicles (LFVs), such as B-Doubles, by Australia's road freight industry. Individual LFVs have a greater potential to impact traffic efficiency through their greater length and poorer longitudinal performance. However, this is offset to an extent as fewer vehicles are required to perform a given freight task on a tonne-km basis. This research has developed a means of characterising the effects that large freight vehicles have on the performance of an urban arterial corridor managed by signalised intersections. A corridor-level microsimulation model was developed from first principles, which modelled the longitudinal performance of individual vehicles to a greater accuracy than most existing traffic simulation software does. The model was calibrated from traffic counts and GPS-equipped chase car surveys conducted on an urban arterial corridor in Brisbane's southern suburbs. The model was applied to various freight policy and traffic management scenarios, including freight vehicle mode choice, lane utilisation and traffic signal settings; as well as the effectiveness of green time extension for approaching heavy vehicles. Benefits were able to be quantified in terms of reduced travel times and stop rates for both heavy and light vehicles in urban arterial corridors