A unified approach to one-dimensional elastic waves by the method of characteristics

Unified approach to one-dimensional elastic waves by method of characteristic

Wave propagation in stepped and joined shells Annual report, 1 Sep. 1968 - 1 Sep. 1969

Shell impact response and wave propagation in cylindrical and conical shells by experimental and analytical method

Molecular techniques reveal cryptic life history and demographic processes of a critically endangered marine turtle

The concept of ‘effective population size’ (Ne), which quantifies how quickly a population will lose genetic variability, is one of the most important contributions of theoretical evolutionary biology to practical conservation management. Ne is often much lower than actual population size: how much so depends on key life history and demographic parameters, such as mating systems and population connectivity, that often remain unknown for species of conservation concern. Molecular techniques allow the indirect study of these parameters, as well as the estimation of current and historical Ne. Here, we use genotyping to assess the genetic health of an important population of the critically endangered hawksbill turtle (Eretmochelys imbricata), a slow-to-mature, difficult-to-observe species with a long history of severe overhunting. Our results were surprisingly positive: we found that the study population, located in the Republic of Seychelles, Indian Ocean, has a relatively large Ne, estimated to exceed 1000, and showed no evidence of a recent reduction in Ne (i.e. no genetic bottleneck). Furthermore, molecular inferences suggest the species' mating system is conducive to maintaining a large Ne, with a relatively large and widely distributed male population promoting considerable gene flow amongst nesting sites across the Seychelles area. This may also be reinforced by the movement of females between nesting sites. Our study underlines how molecular techniques can help to inform conservation biology. In this case our results suggest that this important hawksbill population is starting from a relatively strong position as it faces new challenges, such as global climate change

A cost and CO2 comparison of using trains and higher capacity trucks when UK FMCG companies collaborate

Companies working in a collaboration are able to achieve higher vehicle capacity utilisation and reduced empty running, resulting in lower costs and improved sustainability through reduced emissions and congestion. Collaboration produces higher volumes of goods to be moved than individual companies which means that further efficiencies may be possible by relaxing the freight mode constraints and considering rail and higher capacity vehicles. This paper explains how real world data has been used in a model to quantify the economic and environmental benefits in the FMCG sector delivered through collaboration utilising road and rail freight modes. Data for one month was provided by 10 FMCG companies and included freight transport flows between depots and customers, inter depot movements, and supplier collections. Detailed road and rail costs and operating characteristics were obtained and, with the transport flows, applied to a network design model which was used to validate the company data sets. A strategy examining the potential use of alternative higher capacity vehicles and rail for the flows between nine regional consolidation centres showed cost and CO2 savings. Just under half the inter-regional flows benefited from double deck trailers, longer heavier vehicles for 30% of the flows and rail with different wagon configurations for the rest. In summary there was a 23% reduction in cost with 58% fewer road kilometres and a 46% reduction in CO2 emissions. The ability to backhaul the same mode of transport between most of the regional centres was one of the strengths of this strategy

Anoxic nitrification in marine sediments

Nitrate peaks are found in pore-water profiles in marine sediments at depths considerably below the conventional zone of oxic nitrification. These have been interpreted to represent nonsteady- state effects produced by the activity of nitrifying bacteria, and suggest that nitrification occurs throughout the anoxic sediment region. In this study, ΣNO3 peaks and molecular analysis of DNA and RNA extracted from anoxic sediments of Loch Duich, an organic-rich marine fjord, are consistent with nitrification occurring in the anoxic zone. Analysis of ammonia oxidiser 16S rRNA gene fragments amplified from sediment DNA indicated the abundance of autotrophic ammonia-oxidising bacteria throughout the sediment depth sampled (40 cm), while RT-PCR analysis indicated their potential activity throughout this region. A large non-steady-state pore-water ΣNO3 peak at ~21 cm correlated with discontinuities in this ammonia-oxidiser community. In addition, a subsurface nitrate peak at ~8 cm below the oxygen penetration depth, correlated with the depth of a peak in nitrification rate, assessed by transformation of 15N-labelled ammonia. The source of the oxidant required to support nitrification within the anoxic region is uncertain. It is suggested that rapid recycling of N is occurring, based on a coupled reaction involving Mn oxides (or possibly highly labile Fe oxides) buried during small-scale slumping events. However, to fully investigate this coupling, advances in the capability of high-resolution pore-water techniques are required

Methodology for environmental assessment of agri-environment schemes: the Agri Environmental Footprint Index

End of project reportAgri-environment schemes pay farmers for the provision of environmental services. Such schemes tend to have multiple measures that deliver multiple environmental objectives, and there is a lack of consistent methodology with which to measure the environmental benefits of such schemes. Funded by EU FP6, the Agri-Environment Footprint project (www.footprint.rdg.ac.uk) aimed to address this challenge, and this report provides results from selected components of the project.European Unio

The Hollybank Challenges: AT for People with Profound Disabilities

The use of Assistive Technology with people with profound and multiple disabilities is a specialised subfield. Drawing on its authors' experiences and observations at a UK charitable foundation that offers specialised educational, residential and therapeutic facilities, this paper describes the distinct challenges that present themselves when applying AT to address the needs of this often-overlooked sector of the community. It is hoped that this will help raise awareness and contribute to improving the overall quality of AT provision in this area

The Art of Reason versus the Exactness of Science in Elite Refereeing: Comments on Plessner and Betsch (2001)

Plessner and Betsch’s (2001) investigation into officiating behavior may be representative of a shift from stress-orientated research (Anshel & Weinberg, 1995; Rainey & Winterich, 1995; Stewart & Ellery, 1996) to consideration of decisionmaking (Craven, 1998; Ford, Gallagher, Lacy, Bridwell & Goodwin, 1999; Oudejans, Verheijen, Bakker, Gerrits, Steinbuckner & Beek, 2000), the primary function of referees in any sport. Commendably, Plessner and Betsch have investigated the most important focus of referee performance, the application of the rules (Anshel, 1995). However, methodological weaknesses, together with a fundamental error in the attribution of causation to the findings, significantly dilute this paper’s contribution to extending knowledge in this important area

Elite Refereeing Performance:Developing a Modelfor Sport Science Support

To identify a framework for referee training and selection, based on the key areas of effective performance, we conducted content analyses on Rugby Football Union referee assessor reports, referee training materials, performance profiles from a group of English premier league referees, and a review of published research on sports officiating. The Cornerstones Performance Model of Refereeing emerged, overarched by the psychological characteristics of excellence (see McCaffrey & Orlick, 1989) and featuring four key areas; (a) knowledge and application of the law; (b) contextual judgment; (c) personality and management skills; and (d) fitness, positioning and mechanics. Focus group interviews confirmed the usefulness of the model as an assessment and training tool, which the RFU now use to develop referees throughout Englan