Experimental determination of the particle motions associated with the low order acoustic modes in enclosures

A procedure for experimentally determining, in terms of the particle motions, the shapes of the low order acoustic modes in enclosures is described. The procedure is based on finding differentiable functions which approximate the shape functions of the low order acoustic modes when these modes are defined in terms of the acoustic pressure. The differentiable approximating functions are formed from polynomials which are fitted by a least squares procedure to experimentally determined values which define the shapes of the low order acoustic modes in terms of the acoustic pressure. These experimentally determined values are found by a conventional technique in which the transfer functions, which relate the acoustic pressures at an array of points in the enclosure to the volume velocity of a fixed point source, are measured. The gradient of the function which approximates the shape of a particular mode in terms of the acoustic pressure is evaluated to give the mode shape in terms of the particle motion. The procedure was tested by using it to experimentally determine the shapes of the low order acoustic modes in a small rectangular enclosure

What Kind of ’Big Government’ is the Big Society? A Reply to Bulley and Sokhi-Bulley

This article is a reply to Bulley and Sokhi-Bulley's recent article on the Big Society. We put forward two main criticisms of Bulley and Sokhi-Bulley's governmentality-focused approach in our alternative reading of the Big Society. Firstly, we argue that, given the ethopolitical strategies Bulley and Sokhi-Bulley focus their attention on are unlikely to produce the kind of transformation in the ethical outlook of citizens they suppose, the real historical significance of the Big Society must lie elsewhere. Secondly, we argue that Bulley and Sokhi-Bulley overlook the lines of continuity and discontinuity linking the Big Society to the forms of neo-liberal governmentality that have preceded it in British politics. In the final section of the article, we argue that the Cameron project amounts to both a partial continuation of the type of neo-liberal governmental rationality characteristic of the New Labour project and a partial reversion to a more rudimentary Thatcherite form of neo-liberal governmentality

The Chromospheric Activity and Ages of M Dwarf Stars in Wide Binary Systems

We investigate the relationship between age and chromospheric activity for 139 M dwarf stars in wide binary systems with white dwarf companions. The age of each system is determined from the cooling age of its white dwarf component. The current limit for activity-age relations found for M dwarfs in open clusters is 4 Gyr. Our unique approach to finding ages for M stars allows for the exploration of this relationship at ages older than 4 Gyr. The general trend of stars remaining active for a longer time at later spectral type is confirmed. However, our larger sample and greater age range reveals additional complexity in assigning age based on activity alone. We find that M dwarfs in wide binaries older than 4 Gyr depart from the log-linear relation for clusters and are found to have activity at magnitudes, colors and masses which are brighter, bluer and more massive than predicted by the cluster relation. In addition to our activity-age results, we present the measured radial velocities and complete space motions for 161 white dwarf stars in wide binaries.Comment: 22 pages including 9 figures and 5 tables. Accepted for publication in The Astronomical Journa

Prevalence of sulfonamide resistance genes in bacterial isolates from manured agricultural soils and pig slurry in the United Kingdom

Prevalence of three sulfonamide resistance genes, sul1, sul2 and sul3 and sulfachloropyridazine (SCP) resistance was determined in bacteria isolated from UK manured agricultural clay soils and slurry samples, over a two year period. Slurry from tylosin-fed pigs amended with SCP and oxytetracycline (OTC) was used for manuring. Sul gene positive isolates were further screened for the presence of class 1 and 2 integrons. Phenotypic resistance to SCP was significantly higher in pig slurry and post application soil than in pre-application soil. Of 5isolates, 23 % carried sul1, 18 % sul2 and 9 % sul3 only. Two percent of isolates contained all three sul genes. Class 1 and class 2 integrons were identified in 5 % and 11.7 % of sul positive isolates. In previous reports, sul1 was linked to class 1 integrons, but in this study only 8 % of sul1 positive isolates carried the intI1 gene. Sulfonamide resistant pathogens were identified in slurry amended soil and soil leachate, including Shigella flexneri, Aerococcus spp. and Acinetobacter baumanni, suggesting a potential environmental reservoir. Sulfonamide resistance in Psychrobacter, Enterococcus and Bacillus spp. is reported for the first time, and this study also provides the first description of the genotype sul1, sul2 and sul3 outside the Enterobacteriacae, and in the soil environment

Integron prevalence and diversity in manured soil

Integron abundance and diversity were studied in soil amended with pig slurry. Real-time PCR illustrated a significant increase in class 1 integron prevalence post slurry-application with increased prevalence still evident at 10 months post-application. Culture dependent data revealed 10 genera, including putative human pathogens, carrying class 1 and 2 integrons

How did they get here from there? Detecting changes of direction in terrestrial ranging

Efficient exploitation of large-scale space is crucial to many species of animal, but the difficulties of studying how animals decide on travel routes in natural environments have hampered scientific understanding of environmental cognition. Field experiments allow researchers to define travel goals for their subjects, but practical difficulties restrict large-scale studies. In contrast, data on natural travel patterns are abundant and easy to record, but hard to interpret without circularity and subjectivity when making inferences about when and why an animal began heading to a particular location. We present a method of determining objectively the point at which an animal’s travel path becomes directed at a location, for instance a distant feeding site, based on the statistical characteristics of its route. We evaluate this method and illustrate how it can be tailored to particular problems, using data that is (a) synthetic; (b) from baboons, where travel is from a single sleeping site in an overlapping home range, and (c) from chimpanzees, where sleeping sites are unlimited within a large territory. We suggest that this ‘change- point test’ might usefully become a routine first step in interpreting the decision- making behind animal travel under natural conditions

The effects of transcranial direct current stimulation on within- and cross-paradigm transfer following multi-session backward recall training.

Transcranial direct current stimulation (tDCS) has been shown to enhance the efficacy and generalisation of working memory (WM) training, but there has been little systematic investigation into how coupling task-specific WM training with stimulation impacts more specifically on transfer to untrained tasks. This randomised controlled trial investigated the boundary conditions to transfer by testing firstly whether the benefits of training on backward digit recall (BDR) extend to untrained backward recall tasks and n-back tasks with different materials, and secondly which, if any, form of transfer is enhanced by tDCS. Forty-eight participants were allocated to one of three conditions: BDR training with anodal (10 min, 1 mA) or sham tDCS, or visual search training with sham tDCS, applied over the left dorsolateral prefrontal cortex. Transfer was assessed on within- (backward recall with digits, letters, and spatial locations) and cross-paradigm (n-back with digits and letters) transfer tests following three sessions of training and stimulation. On-task training gains were found, with transfer to other backward span but not n-back tasks. There was little evidence that tDCS enhanced on-task training or transfer. These findings indicate that training enhances paradigm-specific processes within WM, but that tDCS does not enhance these gains

Understanding how institutions may support the development of transdisciplinary approaches to sustainability research

This article analyses the approaches of academics seeking to engage with private, public and community-based stakeholders through transdisciplinary research about pressing sustainability challenges and, in particular, climate change; it outlines aspects of the institutional factors which influence transdisciplinary research. A qualitative approach was employed in conducting 10 semi-structured interviews to analyse the challenges and motivations of academic researchers when working with a range of other stakeholders through transdisciplinary practice. Two key contributions are made through this work. First, this article adds to the existing literature on motivations and challenges for undertaking research with private, public and community stakeholders in a cross-disciplinary manner. Second, the current institutional circumstances influencing such research practices are outlined, alongside potential ways forward. The research presented here has been undertaken in light of the experiences of the two lead co-authors as early career researchers coming from the disciplines of sociology and energy engineering, engaging in transdisciplinary research within a local community context in relation to a regional energy transition project

Climate models underestimate dynamic cloud feedbacks in the tropics

We acknowledge funding from the UK Natural Environment Research Council for the CIRCULATES project (Grant NE/T006315/1). Mark Webb was supported by the Met Office Hadley Centre Climate Programme funded by BEIS and Defra. We also acknowledge the World Climate Research Programme, which, through its Working Group on Coupled Modelling, coordinated and promoted CMIP6.Cloud feedbacks are the leading cause of uncertainty in climate sensitivity. The complex coupling between clouds and the large-scale circulation in the tropics contributes to this uncertainty. To address this problem, the coupling between clouds and circulation in the latest generation of climate models is compared to observations. Significant biases are identified in the models. The implications of these biases are assessed by combining observations of the present day with future changes predicted by models to calculate observationally constrained feedbacks. For the dynamic cloud feedback (i.e., due to changes in circulation), the observationally constrained values are consistently larger than the model-only values. This is due to models failing to capture a nonlinear minimum in cloud brightness for weakly descending regimes. Consequently, while the models consistently predict that these regimes increase in frequency in association with a weakening tropical circulation, they underestimate the positive cloud feedback associated with this increase.Publisher PDFPeer reviewe