Jump-starting transition? Catalysing grassroots action on climate change

The potential for community-led local sustainability initiatives to play a key role in a transition towards a low-carbon economy has been acknowledged by both policymakers and researchers. To date, such initiatives have predominantly been established through the efforts of volunteers, resulting in a scattered uptake across towns, cities and other communities in the UK and further afield. In a context where local and national Government are increasingly seeking to deliver local action on climate change in partnership with community organisations, is it possible or desirable for Government and other publicly funded bodies to successfully set up these grassroots initiatives “from the outside” where none exist already? This paper describes a project which explored this question through the provision of a 2-year programme of support for local action on climate change in a sub-region of the UK. Community development strategies were employed with a view to establishing new grassroots climate change initiatives in a range of different communities. The results indicate some potential for the strategy to meet with success, with several new groups and small-scale projects being established as a result. However, the short lifespan of many of the organisations set up and the relatively low impact on carbon emission reduction of their activities raises questions about the effectiveness of grassroots initiatives and how support of their activities can be delivered most effectively to maximise impact and improve cost effectiveness.     

Optical Properties and London Dispersion Forces of Amorphous Silica Determined by Vacuum Ultraviolet Spectroscopy and Spectroscopic Ellipsometry

Precise and accurate knowledge of the optical properties of amorphous silica is important because of the increasing application of SiO₂ in optical and electrooptical devices, including photolithography masks for semiconductor fabrication, recently as a potential 157 nm mask substrate. The optical properties in the vacuum ultraviolet (VUV) region have been investigated, because they convey detailed information on the electronic structure and interatomic bonding of the material. In this work, we have combined spectroscopic ellipsometry and VUV spectroscopy to directly determine the optical functions of SiO₂ in this range, thereby reducing the uncertainty in the low-energy extrapolation of the data, essential for Kramers–Kronig analysis of VUV reflectance. We report the complex optical properties of SiO₂, over the range of 1.5 to 42 eV, showing improved agreement with theory when contrasted with earlier results. In addition to the features previously reported at 10.4, 11.6, 14.03, and 17.10 eV, new interband transitions have been observed at 21.3 eV along with O 2 s transitions at 32 eV. We found the bulk plasma peak to be 23.7 eV in the energy loss function spectrum. Based on the magnitude of these new results, the Hamaker constant for SiO₂|Vacuum|SiO₂ is 71.6 zJ, which is larger than the previously reported value of 66 zJ.     

Corticomotoneuronal contribution to the fractionation of muscle activity during precision grip in the monkey

1. During independent finger movements, the intrinsic muscles of the hand show a fractionated pattern of activity in which the timing and amplitude of electromyographic (EMG) activity varies considerably from one muscle to another. It has been suggested that, in the macaque monkey, corticomotoneuronal (CM) cells that produce postspike facilitation (PSF) of EMG in these muscles contribute to this fractionation. To test this hypothesis, we have investigated the relationship between the pattern of PSF exerted by a CM cell and the pattern of activity shown by the cell and by its target muscles. 2. The activity of 15 identified CM cells was recorded from two monkeys that performed a precision grip task. Spike-triggered averaging of rectified EMG during the hold period of this task showed that each cell produced PSF in at least two intrinsic hand muscles. 3. Segments of data were selected from the initial movement period of the task in which the EMG activity in one target muscle was substantially greater than that of the other, and the mean firing rate of each CM cell was determined for these periods. 4. CM cells showed bursts of activity in the movement period. Most of them (13/15) had a significantly (P < 0.001) higher firing rate when one of its target muscles was more active than the other. For nine of these cells (identified as set A), this muscle was the one receiving the larger PSF. In four cases (set B), the reverse was true. Two cells (set C), which produced PSF of equal size in their target muscles, showed no change in firing rate across the periods of fractionated EMG activity. 5. All set A and set B cells fired at significantly (P < 0.001) higher rates during the movement period, in association with fractionation of EMG activity, than in the hold period, in which a cocontracted pattern of muscle activity was observed. 6. There were pronounced differences in the strength of PSF exerted by the CM cells on their target muscles during the fractionation periods. One CM cell exerted PSF of a muscle during one period of fractionation, but postspike suppression of the same muscle during the other period. 7. It is suggested that changes in the firing rate of a CM cell and in the degree of facilitation it exerts could both contribute to the fractionation of activity in its target muscles. Cells of set A appear to be specifically recruited in a manner that directly reflects the pattern of facilitation they exert on the sampled target muscles. These results may explain why the CM system is so important for the performance of relatively independent finger movements.     

Exercise VO2 estimation using recovery sampling

Various situations present a challenge to determine oxygen uptake (VO2) accurately simply because of the restrictions imposed by the equipment employed. This investigation was undertaken to 1) compare a select number of recovery VO2 measurements with respect to their accuracy in estimating actual exercise VO2 and 2) to determine whether absolute workload or VO2max affect this relationship. Fifteen subjects [8 highly trained (HT), VO2max +/- SD = 70.2 +/- 3.5 ml/kg . min-1 and 7 untrained (UT), VO2max = 49.7 +/- 3.8 ml/kg . min-1] completed a number of 5 min workbouts on a bicycle ergometer at 25-70% VO2max (VO2 = .899--3.879 l . min-1). VO2 and VCO2 (l . min-1) were monitored continuously throughout the exercise and for 5 min of recovery via a breath-by-breath system. The results indicated that 1) exercise VO2 +/- Sy.x can be estimated from several recovery collection periods, the first breath y = .953X + .441 +/- .319, the first two breaths y = 1.046X + .327 +/- .270, the first three breaths y = 1.089X + .260 +/- .241, and the second three breaths y = 1.101X + .387 +/- .234, and 2) VO2max does not affect this relationship (p greater than 0.05) while increasing absolute workload produces a greater exercise VO2 underestimation (p less than 0.05). It was concluded that using this method exercise VO2 can be estimated with reasonable accuracy (Sy.x = .234--.319, r = .92--.94, p less than 0.01).     

An Empirical Bayes Approach to Reliability

A Bayesian reliability estimation technique known as the ``empirical Bayes approach' is developed which uses previous experience nce to get a Bayesian point estimator. The techniques require no knowledge of the form of the unknown prior distribution and are robust to assumptions about its form. Empirical Bayes techniques are applicable to situations in which prior, independent observations of the random variable X from the random couple (?, X) are available where ? is the observed parameter of interest distributed in accordance with the unknown prior distribution. Performance comparisons of the empirical Bayes and other well established techniques are developed by examples for the binomial, exponential, Normal, and Poisson situations which often occur in reliability problems. In all cases the empirical Bayes estimator performed better than the classical estimator in minimizing the average squared error.     

Centrifugal Lacquering

The main features of centrifugal lacquering machines and their method of operation are briefly described. The types of coating material that are suitable for use are mentioned, including cellulose lacquers, gum lacquers and staying and air drying synthetic finishes, and the articles suitable for centrifugal lacquering, such as nuts, springs and buttons, are listed.     

Localization of bacterial DNA polymerase: evidence for a factory model of replication

Two general models have been proposed for DNA replication. In one model, DNA polymerase moves along the DNA (like a train on a track); in the other model, the polymerase is stationary (like a factory), and DNA is pulled through. To distinguish between these models, we visualized DNA polymerase of the bacterium Bacillus subtilis in living cells by the creation of a fusion protein containing the catalytic subunit (PolC) and green fluorescent protein (GFP). PolC-GFP was localized at discrete intracellular positions, predominantly at or near midcell, rather than being distributed randomly. These results suggest that the polymerase is anchored in place and thus support the model in which the DNA template moves through the polymerase.