Estimating trophic link density from quantitative but incomplete diet data

The trophic link density and the stability of food webs are thought to be related, but the nature of this relation is controversial. This article introduces a method for estimating the link density from diet tables which do not cover the complete food web and do not resolve all diet items to species level. A simple formula for the error of this estimate is derived. Link density is determined as a function of a threshold diet fraction below which diet items are ignored (

Self-aligning wireless link using modulated backscatter

A self-tracking (aligning) radio communications system based on the principle of modulated backscatter detection is presented here. Using amplitude-modulated backscatter from a co-operating target, a modified IQ demodulation scheme is used to reproduce automatically and in real time both the received and conjugate of the received phase of an incoming signal. The phase conjugated demodulated IF signal can have incoming backscattered data removed and new data are inserted before being up-converted using IQ single side-band generation so that retro-directive re-transmission can be made to occur. In the absence of the backscattered modulation signal, no phase conjugation and hence no retro-directed re-transmission can occur. The system reported is therefore inherently self-authenticating a facility not readily available from previously reported retro-directive self-tracking systems. © 2010 © The Institution of Engineering and Technology.

Science Literacy and media Literacy: a missing link?

The study of science in the media is increasingly highlighted within science programmes and represents an authentic context for interdisciplinary collaboration. Yet the literature on ‘media across the curriculum’ makes surprisingly little mention of links to science and cross-curricular approaches to teaching about and with science-based media resources is an area that is under-explored. This research study focuses on science in the news. The project involved 28 teachers from seven schools and brought together science and English teachers to explore collaborative working with the aim of promoting critical engagement with media reports with a science component. Teachers planned, developed and implemented a school-based activity with an emphasis on ‘connected learning’ rather than the compartmentalised learning that tends to accompany the discrete treatment of science matters in science class and media matters in English class. Not only did the project raise teachers’ awareness of science in the media as a potential, purposeful and profitable area for collaborative working, but it demonstrated how the synergy of the different experiences and expertise of science and English teachers produced very varied approaches to a programme of activities with an enhanced capacity to promote criticality in relation to science literacy and media literacy.

The metamorphosis of supernova SN 2008D/XRF 080109: A link between supernovae and GRBs/hypernovae

The only supernovae (SNe) to show gamma-ray bursts ( GRBs) or early x-ray emission thus far are overenergetic, broad- lined type Ic SNe ( hypernovae, HNe). Recently, SN 2008D has shown several unusual features: (i) weak x-ray flash (XRF), (ii) an early, narrow optical peak, (iii) disappearance of the broad lines typical of SN Ic HNe, and (iv) development of helium lines as in SNe Ib. Detailed analysis shows that SN 2008D was not a normal supernova: Its explosion energy (E approximate to 6 x 10(51) erg) and ejected mass [similar to 7 times the mass of the Sun ( M.)] are intermediate between normal SNe Ibc and HNe. We conclude that SN 2008D was originally a similar to 30 M. star. When it collapsed, a black hole formed and a weak, mildly relativistic jet was produced, which caused the XRF. SN 2008D is probably among the weakest explosions that produce relativistic jets. Inner engine activity appears to be present whenever massive stars collapse to black holes.

The use of interactive video in teaching teachers: an evaluation of a link with a primary school

This paper presents an evaluation of the use of videoconferencing in learning and teaching in a United Kingdom higher education institution involved in initial teacher education. Students had the opportunity to observe naturalistic teaching practices without physically being present in the classroom. The study consisted of semi-structured interviews with the co-ordinator of the link, the head of ICT services in Stranmillis University College and the teacher of the classroom being observed. Students were invited to complete an online questionnaire. The views of the students, the co-ordinator of the link, the teacher of the classroom being observed and the head of ICT services in Stranmillis University College were then triangulated to gain an overall view of the effectiveness of the videoconferencing link. Interviews suggested students benefited in terms of pedagogy. In the early stages of the project, the teacher thought it acted as a form of classroom control. Technical problems were encountered initially and camera control was modified in the light of these. The online questionnaire suggested that students viewed this experience in a positive way and were impressed with the content, technical quality, and potential benefits of the use of this example of new technologies.

The link between logic, mathematics and imagination: evidence from children with developmental dyscalculia and mathematically gifted children

This study examined performance on transitive inference problems in children with developmental dyscalculia (DD), typically developing controls matched on IQ, working memory and reading skills, and in children with outstanding mathematical abilities. Whereas mainstream approaches currently consider DD as a domain-specific deficit, we hypothesized that the development of mathematical skills is closely related to the development of logical abilities, a domain-general skill. In particular, we expected a close link between mathematical skills and the ability to reason independently of one's beliefs. Our results showed that this was indeed the case, with children with DD performing more poorly than controls, and high maths ability children showing outstanding skills in logical reasoning about belief-laden problems. Nevertheless, all groups performed poorly on structurally equivalent problems with belief-neutral content. This is in line with suggestions that abstract reasoning skills (i.e. the ability to reason about content without real-life referents) develops later than the ability to reason about belief-inconsistent fantasy content.A video abstract of this article can be viewed at http://www.youtube.com/watch?v=90DWY3O4xx8.

The palliative care link nurse role in nursing homes: barriers and facilitators

Aim. This paper is a report of a study to explore link nurses' views and experiences regarding the development, barriers and facilitators to the implementation of the role in palliative care in the nursing home.
Background. The delivery of palliative care in nursing homes is widely advocated; one approach is to develop the link nurse role to cascade good practice and training to nurses and other care staff to enhance patient care.
Method. A descriptive qualitative study was conducted with a purposive sample of 14 link nurses from 10 nursing homes in Northern Ireland during 2006. Three focus groups, composed of all Registered Nurses currently acting as link nurses in their nursing homes participated, and the data were audio recorded, fully transcribed and content analysed.
Findings. The link nurse system shows potential to enhance palliative care within nursing homes. However, link nurses experienced a number of difficulties in implementing education programmes. Facilitators of the role included external support, monthly meetings, access to a resource file and peer support among link nurses themselves. Lack of management support, a transient workforce and lack of adequate preparation for link nurses were barriers to fulfilling this role.
Conclusion. Whilst palliative care link nurses can improve care for residents in nursing homes, consideration must be given to overcome the types of barriers identified in order to enable the link nurse system to function effectively. © 2008 The Authors.