Space Science News: from archive to teaching resource, the secret life of newspapers

Worldwide, science education reform is aiming to promote 'scientific literacy' among young people. Typically, this is taken to include empowering them to engage critically with science in news media. This study explored the extent and nature of secondary science teachers' use of newspapers. It found that, though a great many use the resource, the majority do so incidentally and with the intention of showing the relevance of the subject rather than developing their students' criticality.

Symmetry, delocalization, and molecular conductance

Molecules bonded between two metal contacts form the simplest possible molecular devices. Coupled by the molecule, the left and right contact-based states form symmetric and antisymmetric pairs near the Fermi level. We relate the size of the resulting energy splitting DeltaE to the symmetry and degree of delocalization of the coupling molecular orbital. Qualitative trends in molecular conductances are then estimated from the variations in DeltaE. We examine benzenedithiol and other molecules of interest in transport. (C) 2005 American Institute of Physics.

Broken symmetry and pseudogaps in ropes of carbon nanotubes

Since the discovery of carbon nanotubes, it has been speculated that these materials should behave like nanoscale wires with unusual electronic properties and exceptional strength. Recently, 'ropes' of close-packed single-wall nanotubes have been synthesized in high yield. The tubes in these ropes are mainly of the (10,10) type3, which is predicted to be metallic. Experiments on individual nanotubes and ropes indicate that these systems indeed have transport properties that qualify them to be viewed as nanoscale quantum wires at low temperature. It has been expected that the close-packing of individual nanotubes into ropes does not change their electronic properties significantly. Here, however, we present first-principles calculations which show that a broken symmetry of the (10,10) tube caused by interactions between tubes in a rope induces a pseudogap of about 0.1 eV at the Fermi level. This pseudogap strongly modifies many of the fundamental electronic properties: we predict a semimetal-like temperature dependence of the electrical conductivity and a finite gap in the infrared absorption spectrum. The existence of both electron and hole charge carriers will lead to qualitatively different thermopower and Hall-effect behaviours from those expected for a normal metal.

Broken symmetry and pseudogaps in ropes of carbon nanotubes

We investigate the influence of tube-tube interactions in ropes of (10,10) carbon nanotubes, and find that these effects induce a pseudogap in the density of state (DOS) of the rope of width 0.1 eV at the Fermi level. In an isolated (n,n) carbon nanotube there are two bands that cross in a linear fashion at the Fermi level, making the nanotube metallic with a DOS that is constant in a 1.5 eV wide window around the Fermi energy. The presence of the neighbouring tubes causes these two bands to repel, opening up a band gap that can be as large as 0.3 eV. The small dispersion in the plane perpendicular to the rope smears out this gap for a rope with a large cross-sectional area, and we see a pseudogap at the Fermi energy in the DOS where the DOS falls to one third of its value for the isolated tube. This phenomenon should affect many properties of the behavior of ropes of (n,n) nanotubes, which should display a more semimetallic character than expected in transport and doping experiments, with the existence of both hole and electron carriers leading to qualitatively different thermopower and Hall-effect behaviors from those expected for a normal metal. Band repulsion like this can be expected to occur for any tube perturbed by a sufficiently strong interaction, for example, from contact with a surface or with other tubes.

The ABC for Life Programme - Teaching Basic Life Support in Schools

Background Less than 1% of the general public know how to assess or manage someone who has collapsed. It has been estimated that if 15–20% of the population were capable of performing cardiopulmonary resuscitation (CPR), mortality of out of hospital cardiac arrest could be decreased significantly. Training basic life support (BLS) skills to school children would be the most cost effective way of achieving this goal and ensuring that a large proportion of the population acquire basic life saving skills. Aims To assess retention of knowledge of basic life support 6 months after a single course of instruction in cardiopulmonary resuscitation designed specifically for school children. Setting School pupils in a rural location in one region of the United Kingdom. Methods A course of instruction in cardiopulmonary resuscitation – the ‘ABC for life’ programme – specifically designed to teach 10–12-year-old school children basic life support skills. The training session was given to school pupils in a rural location in Northern Ireland. A 22 point questionnaire was used to assess acquisition and retention of basic life support knowledge. Results Children instructed in cardiopulmonary resuscitation showed a highly significant increase in level of knowledge following the training session. While their level of knowledge decreased over a period of 6 months it remained significantly higher than that of a comparable group of children who had never been trained. Conclusion A training programme designed and taught as part of the school curriculum would have a significant impact on public health.