Investigation of long term stability in metal hydrides

It is apparent from the literature and the results of this study that cyclic degradation of AB(5) type metal hydrides varies widely according to the details of how the specimens are cycled. The Rapid Cycle Apparatus (RCA) used produced less degradation in 5000 to 10000 cycles than earlier work with a Slow Cycle Apparatus (SCA) produced in 1500 cycles. Evidence is presented that the 453 K (356 F) Thermal Aging (TA) time spent in the saturated condition causes hydride degradation. But increasing the cooling (saturation) period in the RCA did not greatly increase the rate of degradation. It appears that TA type degradation is secondary at low temperatures to another degradation mechanism. If rapid cycles are less damaging than slow cycles when the saturation time is equal, the rate of hydriding/dehydriding may be an important factor. The peak temperatures in the RCA were about 30 C lower than the SCA. The difference in peak cycle temperatures (125 C in the SCA, 95 C in RCA) cannot explain the differences in degradation. TA type degradation is similar to cyclic degradation in that nickel peaks and line broadening are observed in X ray diffraction patterns after either form of degradation

Biopolitical precarity in the permeable body: the social lives of people, viruses and their medicines

This article is based on multi-sited ethnography that traced a dynamic network of actors (activists, policy-makers, health care systems, pharmaceutical companies) and actants (viruses and medicines) that shaped South African women’s access to, and embodiment of, antiretroviral therapies (ARVs). Using actor network theory and post-humanist performativity as conceptual tools, the article explores how bodies become the meeting place for HIV and ARVs, or non-human actants. The findings centre around two linked sets of narratives that draw the focus out from the body to situate the body in relation to South Africa’s shifting biopolitical landscape. The first set of narratives articulate how people perceive the intra-action of HIV and ARVs in their sustained vitality. The second set of narratives articulate the complex embodiment of these actants as a form biopolitical precarity. These narratives flow into each other and do not represent a totalising view of the effects of HIV and ARVs in the lives of the people with whom I worked. The positive effects of ARVs (as unequivocally essential for sustaining life) were implicit and the precarious vitality of the people in this ethnography was fundamental. However, a related and emergent set of struggles become salient during the study that complicate a view of ARVs as a ‘technofix’. These emergent struggles were biopolitical, and they related first to the intra-action of HIV and ARVs ‘within’ the body; and second, to the ‘outside’ socio-economic context in which people’s bodies were situated

Effects of the neonicotinoid pesticide thiamethoxam at field-realistic levels on microcolonies of Bombus terrestris worker bumble bees

Copyright © 2013 Elsevier. Notice: this is the author’s version of a work that was accepted for publication in Ecotoxicology and Environmental Safety. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Ecotoxicology and Environmental Safety, 2014, Vol. 100, pp. 153-158 at: http://dx.doi.org/10.1016/j.ecoenv.2013.10.027Neonicotinoid pesticides are currently implicated in the decline of wild bee populations. Bumble bees, Bombus spp., are important wild pollinators that are detrimentally affected by ingestion of neonicotinoid residues. To date, imidacloprid has been the major focus of study into the effects of neonicotinoids on bumble bee health, but wild populations are increasingly exposed to alternative neonicotinoids such as thiamethoxam. To investigate whether environmentally realistic levels of thiamethoxam affect bumble bee performance over a realistic exposure period, we exposed queenless microcolonies of Bombus terrestris L. workers to a wide range of dosages up to 98 μg kg−1 in dietary syrup for 17 days. Results showed that bumble bee workers survived fewer days when presented with syrup dosed at 98 μg thiamethoxam kg−1, while production of brood (eggs and larvae) and consumption of syrup and pollen in microcolonies were significantly reduced by thiamethoxam only at the two highest concentrations (39, 98 μg kg−1). In contrast, we found no detectable effect of thiamethoxam at levels typically found in the nectars of treated crops (between 1 and 11 μg kg−1). By comparison with published data, we demonstrate that during an exposure to field-realistic concentrations lasting approximately two weeks, brood production in worker bumble bees is more sensitive to imidacloprid than thiamethoxam. We speculate that differential sensitivity arises because imidacloprid produces a stronger repression of feeding in bumble bees than thiamethoxam, which imposes a greater nutrient limitation on production of brood.Natural Environment Research Council (NERC

Inverse laplace transform for transient-state fluid line network simulation

Inverse Laplace transform methods have a long history in the development of time-domain fluid line models. This paper presents a study combining the new Laplace-domain input/output (I/O) model derived from the network admittance matrix with the Fourier series expansion numerical inverse Laplace transform (NILT) to serve as a time-domain simulation model. A series of theorems are presented demonstrating the stability of the I/O model, which is important for the construction of the NILT method. In the previous work by the first author, the Fourier series expansion algorithm was studied, where qualitative relationships between the parameters and numerical errors were analyzed, and reliable parameter heuristics were developed. These heuristics are used for a series of numerical examples dealing with networks of 11, 35, 51, and 94 pipes by using five different pipe models. The examples are used as the basis from which the accuracy and numerical efficiency of the proposed NILT are compared to the standard method of characteristics (MOCs) model for transient pipeline networks. Findings show that, for all case studies considered, the proposed NILT is numerically efficient for the pipe types involving convolution operations, and it is accurate for networks composed of both linear and nonlinear pipe types.Aaron C. Zecchin, Martin F. Lambert and Angus R. Simpso

Transcriptome profiling defines a novel regulon modulated by the LysR-type transcriptional regulator MexT in Pseudomonas aeruginosa

The LysR-family regulator MexT modulates the expression of the MexEF-OprN efflux system in the human pathogen Pseudomonas aeruginosa. Recently, we demonstrated that MexT regulates certain virulence phenotypes, including the type-three secretion system and early attachment independent of its role in regulating MexEF-OprN. In this study, transcriptome profiling was utilized to investigate the global nature of MexT regulation in P. aeruginosa PAO1 and an isogenic mexEF mutant. Twelve genes of unknown function were highly induced by overexpressing MexT independent of MexEF-OprN. A well-conserved DNA motif was identified in the upstream regulatory region of nine of these genes and upstream of mexE. Reporter fusion analysis demonstrated that the expression of the genes was significantly induced by MexT in P. aeruginosa and a heterogenous Escherichia coli strain and that the conserved sequence was required for this induction. The conserved DNA motif was further characterized as the MexT binding site by site-directed mutagenesis and electrophoretic mobility shift assays. Genes containing this conserved regulatory sequence were identified across other Pseudomonas species, and their expression was activated by MexT. Thus, a novel regulon directly modulated by MexT, that includes but is independent of mexEF-oprN, has been identified

'I didn't used to have much friends': Exploring the friendship concepts and capabilities of a boy with autism and severe learning disabilities

© 2015 John Wiley & Sons Ltd. Accessible summary: This paper looks at the friendships of Ben, (not his real name), a 10-year-old boy with autism and learning disabilities, in his mainstream school. Ben was able to name his friends and showed that he understood some important things about friendship. Adults in the school said that Ben was very keen to have friends and that some of his friendships had lasted for over a year. The study focused on the importance of listening to children with autism and learning disabilities and on the need to highlight their social strengths. Summary: Whilst progress has been made in understanding the friendships of children with autism, research on the friendships of children with additional learning disabilities remains extremely limited. In this research, a qualitative case study approach provided a rich description of the friendship concepts and capabilities of Ben, a 10-year-old boy with autism and severe learning disabilities within the context of a mainstream primary classroom in the United Kingdom. An innovative activity-based strategy was used to gain Ben's own perspectives in relation to friendship. Findings revealed that Ben exhibited a strong desire to have friends, believed himself to have some, demonstrated some understanding in respect of degrees of friendship and displayed a commitment to friendships over relatively long periods of time. Methodological, developmental and capacity perspectives informed the discussion, with a case being made both for a greater focus on the friendship capabilities of children with autism and learning disabilities and their more direct inclusion in the research process

Writing in Britain and Ireland, c. 400 to c. 800

No abstract available

Contemporary Asian Artistic Expressions and Tourism – An Introduction

This introductory chapter presents and critically discusses the various themes underpinning this book. Firstly, it provides an examination of the notion of ‘contemporary art’, including an overview of the existing definitions and debates in the current literature. Secondly, this chapter discusses the nexus between tourism and contemporary art by providing an overview of the past studies conducted on cultural and heritage tourism. In this section, the various themes underpinning the different parts of the literature on art tourism (e.g. identity, authenticity, commoditisation and capitalism) are considered. Thirdly, a discussion on the relationship between tourism and Asian contemporary art is presented, which also includes a part problematising and questioning terms like ‘Asia’ and ‘Asian art’. Finally, an overview of the different chapters that constitute the backbone of this collection is offered alongside the four themes around which the book is structured

Estimates of live-tree carbon stores in the Pacific Northwest are sensitive to model selection

<p>Abstract</p> <p>Background</p> <p>Estimates of live-tree carbon stores are influenced by numerous uncertainties. One of them is model-selection uncertainty: one has to choose among multiple empirical equations and conversion factors that can be plausibly justified as locally applicable to calculate the carbon store from inventory measurements such as tree height and diameter at breast height (DBH). Here we quantify the model-selection uncertainty for the five most numerous tree species in six counties of northwest Oregon, USA.</p> <p>Results</p> <p>The results of our study demonstrate that model-selection error may introduce 20 to 40% uncertainty into a live-tree carbon estimate, possibly making this form of error the largest source of uncertainty in estimation of live-tree carbon stores. The effect of model selection could be even greater if models are applied beyond the height and DBH ranges for which they were developed.</p> <p>Conclusions</p> <p>Model-selection uncertainty is potentially large enough that it could limit the ability to track forest carbon with the precision and accuracy required by carbon accounting protocols. Without local validation based on detailed measurements of usually destructively sampled trees, it is very difficult to choose the best model when there are several available. Our analysis suggests that considering tree form in equation selection may better match trees to existing equations and that substantial gaps exist, in terms of both species and diameter ranges, that are ripe for new model-building effort.</p

How much time do nurses have for patients? a longitudinal study quantifying hospital nurses' patterns of task time distribution and interactions with health professionals

<p>Abstract</p> <p>Background</p> <p>Time nurses spend with patients is associated with improved patient outcomes, reduced errors, and patient and nurse satisfaction. Few studies have measured how nurses distribute their time across tasks. We aimed to quantify how nurses distribute their time across tasks, with patients, in individual tasks, and engagement with other health care providers; and how work patterns changed over a two year period.</p> <p>Methods</p> <p>Prospective observational study of 57 nurses for 191.3 hours (109.8 hours in 2005/2006 and 81.5 in 2008), on two wards in a teaching hospital in Australia. The validated Work Observation Method by Activity Timing (WOMBAT) method was applied. Proportions of time in 10 categories of work, average time per task, time with patients and others, information tools used, and rates of interruptions and multi-tasking were calculated.</p> <p>Results</p> <p>Nurses spent 37.0%[95%CI: 34.5, 39.3] of their time with patients, which did not change in year 3 [35.7%; 95%CI: 33.3, 38.0]. Direct care, indirect care, medication tasks and professional communication together consumed 76.4% of nurses' time in year 1 and 81.0% in year 3. Time on direct and indirect care increased significantly (respectively 20.4% to 24.8%, P < 0.01;13.0% to 16.1%, P < 0.01). Proportion of time on medication tasks (19.0%) did not change. Time in professional communication declined (24.0% to 19.2%, P < 0.05). Nurses completed an average of 72.3 tasks per hour, with a mean task length of 55 seconds. Interruptions arose at an average rate of two per hour, but medication tasks incurred 27% of all interruptions. In 25% of medication tasks nurses multi-tasked. Between years 1 and 3 nurses spent more time alone, from 27.5%[95%CI 24.5, 30.6] to 39.4%[34.9, 43.9]. Time with health professionals other than nurses was low and did not change.</p> <p>Conclusions</p> <p>Nurses spent around 37% of their time with patients which did not change. Work patterns were increasingly fragmented with rapid changes between tasks of short length. Interruptions were modest but their substantial over-representation among medication tasks raises potential safety concerns. There was no evidence of an increase in team-based, multi-disciplinary care. Over time nurses spent significantly less time talking with colleagues and more time alone.</p