639 research outputs found
Tackling climate change with blockchain
Concern about the carbon footprint of Bitcoin is not holding back blockchain developers from leveraging the technology for action on climate change. Although blockchain technology is enabling individuals and businesses to manage their carbon emissions, the social and environmental costs and benefits of doing so remain unclear
Economies of space and the school geography curriculum
This paper is about the images of economic space that are found in school curricula. It suggests the importance for educators of evaluating these representations in terms of the messages they contain about how social processes operate. The paper uses school geography texts in Britain since the 1970s to illustrate the different ways in which economic space has been represented to students, before exploring some alternative resources that could be used to provide a wider range of representations of economic space. The paper highlights the continued importance of understanding the politics of school knowledge
Integrated acoustic immunoaffinity-capture (IAI) platform for detection of PSA from whole blood samples.
On-chip detection of low abundant protein biomarkers is of interest to enable point-of-care diagnostics. Using a simple form of integration, we have realized an integrated microfluidic platform for the detection of prostate specific antigen (PSA), directly in anti-coagulated whole blood. We combine acoustophoresis-based separation of plasma from undiluted whole blood with a miniaturized immunoassay system in a polymer manifold, demonstrating improved assay speed on our Integrated Acoustic Immunoaffinity-capture (IAI) platform. The IAI platform separates plasma from undiluted whole blood by means of acoustophoresis and provides cell free plasma of clinical quality at a rate of 10 uL/min for an online immunoaffinity-capture of PSA on a porous silicon antibody microarray. The whole blood input (hematocrit 38-40%) rate was 50 μl min(-1) giving a plasma volume fraction yield of ≈33%. PSA was immunoaffinity-captured directly from spiked female whole blood samples at clinically significant levels of 1.7-100 ng ml(-1) within 15 min and was subsequently detected via fluorescence readout, showing a linear response over the entire range with a coefficient of variation of 13%
Where do high‐risk drinking occasions occur more often? A cross‐sectional, cross‐country study
Introduction
The current paper examines the proportion of drinking occasions and total alcohol consumed that takes place at off-premise locations. Comparisons are made between high-income countries: Australia, New Zealand, England and Scotland, and across drinker-types: high-risk and lower-risk.
Methods
Data were taken from the International Alcohol Control study in Australia (N = 1789), New Zealand (N = 1979), England (N = 2844) and Scotland (N = 1864). The cross-national survey measures location and beverage-specific alcohol consumption. The number of drinking occasions and mean consumption across on- and off-premise locations and the proportion of drinking occasions that high- and lower-risk drinkers had at on- and off-premise locations was estimated for each country.
Results
The majority of drinking occasions among high-risk drinkers occurred at off-premise locations across all four countries; Australia 80.1%, New Zealand 72.0%, England 61.7% and Scotland 60.7%. High-risk drinkers in Australia had significantly larger proportions of drinking occasions occurring at off-premise locations compared to England and Scotland. Across all countries, high-risk drinkers and lower-risk drinkers consumed significantly larger quantities of alcohol per occasion at off-premise locations compared to on-premises locations. Finally, the majority of total alcohol consumed occurred at off-premise locations across all countries for high- and lower-risk drinkers.
Discussion and Conclusions
As the accessibility to alcohol outside of licensed premises continues to increase, particularly with the expansion of home delivery services, it is important to be mindful of the high proportion of heavy drinking occasions that occur off-premise
Please mind the gap: students’ perspectives of the transition in academic skills between A-level and degree level geography
This paper explores first-year undergraduates’ perceptions of the transition from studying geography at pre-university level to studying for a degree. This move is the largest step students make in their education, and the debate about it in the UK has been reignited due to the government’s planned changes to A-level geography. However, missing from most of this debate is an appreciation of the way in which geography students themselves perceive their transition to university. This paper begins to rectify this absence. Using student insights, we show that their main concern is acquiring the higher level skills required for university learning
Impacts of invasive ants on pollination of native plants are similar in invaded and restored plant communities
This is the final version. Available on open access from Elsevier via the DOI in this recordData availability:
Data will be made available on request.Ants are amongst the most successful invaders worldwide and can markedly modify invaded communities through biotic interactions. Invasive ants, for example, can compete with native pollinators for resources, act as legitimate pollinators, or disrupt plant-pollinator mutualistic interactions, thereby affecting native plant reproduction. Ecological restoration aims to mitigate the impact of invasive species and restore ecological communities and ecosystem functioning. Here we investigated the combined effects of two invasive ant species, the yellow crazy ant (Anoplolepis gracilipes) and white-footed ant (Technomyrmex albipes), on the pollination and reproduction of native plants in the context of a large-scale plant community restoration experiment. We conducted ant exclusion experiments and pollinator observations to obtain data on plant reproduction and pollination of four plant species. The experiments were conducted across eight granitic inselbergs on the island of Mahé, Seychelles, four of which are undergoing restoration since 2011 and four remained as invaded control sites (unrestored). Our findings indicate that native plants on Seychelles’ inselbergs relied primarily on flying flower visitors for pollination, considering that the contribution of ants to fruit set was generally small and substantially lower than that of flying pollinators. Moreover, while flying pollinators approached flowering plants irrespective of invasive ant presence, the number of probed flowers per visit was reduced, in both restored and unrestored communities. Therefore, native plant reproduction was negatively affected by the presence of invasive ants and this effect was similar in restored and unrestored plant communities. Our research suggests that invasive ants may contribute to changes in plant communities by deterring legitimate pollinators of native plants, an impact that is unlikely to be alleviated through early stages of ecological restoration.Deutsche Forschungsgemeinschaft (DFG)Portuguese Foundation for Science and Technolog
Paper II: Calibration of the Swift ultraviolet/optical telescope
The Ultraviolet/Optical Telescope (UVOT) is one of three instruments onboard
the Swift observatory. The photometric calibration has been published, and this
paper follows up with details on other aspects of the calibration including a
measurement of the point spread function with an assessment of the orbital
variation and the effect on photometry. A correction for large scale variations
in sensitivity over the field of view is described, as well as a model of the
coincidence loss which is used to assess the coincidence correction in extended
regions. We have provided a correction for the detector distortion and measured
the resulting internal astrometric accuracy of the UVOT, also giving the
absolute accuracy with respect to the International Celestial Reference System.
We have compiled statistics on the background count rates, and discuss the
sources of the background, including instrumental scattered light. In each case
we describe any impact on UVOT measurements, whether any correction is applied
in the standard pipeline data processing or whether further steps are
recommended.Comment: Accepted for publication in MNRAS. 15 pages, 21 figures, 4 table
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A genome annotation-driven approach to cloning the human ORFeome.
We have developed a systematic approach to generating cDNA clones containing full-length open reading frames (ORFs), exploiting knowledge of gene structure from genomic sequence. Each ORF was amplified by PCR from a pool of primary cDNAs, cloned and confirmed by sequencing. We obtained clones representing 70% of genes on human chromosome 22, whereas searching available cDNA clone collections found at best 48% from a single collection and 60% for all collections combined.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Robust Dropping Criteria for F-norm Minimization Based Sparse Approximate Inverse Preconditioning
Dropping tolerance criteria play a central role in Sparse Approximate Inverse
preconditioning. Such criteria have received, however, little attention and
have been treated heuristically in the following manner: If the size of an
entry is below some empirically small positive quantity, then it is set to
zero. The meaning of "small" is vague and has not been considered rigorously.
It has not been clear how dropping tolerances affect the quality and
effectiveness of a preconditioner . In this paper, we focus on the adaptive
Power Sparse Approximate Inverse algorithm and establish a mathematical theory
on robust selection criteria for dropping tolerances. Using the theory, we
derive an adaptive dropping criterion that is used to drop entries of small
magnitude dynamically during the setup process of . The proposed criterion
enables us to make both as sparse as possible as well as to be of
comparable quality to the potentially denser matrix which is obtained without
dropping. As a byproduct, the theory applies to static F-norm minimization
based preconditioning procedures, and a similar dropping criterion is given
that can be used to sparsify a matrix after it has been computed by a static
sparse approximate inverse procedure. In contrast to the adaptive procedure,
dropping in the static procedure does not reduce the setup time of the matrix
but makes the application of the sparser for Krylov iterations cheaper.
Numerical experiments reported confirm the theory and illustrate the robustness
and effectiveness of the dropping criteria.Comment: 27 pages, 2 figure
Photometric Calibration of the Swift Ultraviolet/Optical Telescope
We present the photometric calibration of the Swift UltraViolet/Optical
Telescope (UVOT) which includes: optimum photometric and background apertures,
effective area curves, colour transformations, conversion factors for count
rates to flux, and the photometric zero points (which are accurate to better
than 4 per cent) for each of the seven UVOT broadband filters. The calibration
was performed with observations of standard stars and standard star fields that
represent a wide range of spectral star types. The calibration results include
the position dependent uniformity, and instrument response over the 1600-8000A
operational range. Because the UVOT is a photon counting instrument, we also
discuss the effect of coincidence loss on the calibration results. We provide
practical guidelines for using the calibration in UVOT data analysis. The
results presented here supersede previous calibration results.Comment: Minor improvements after referees report. Accepted for publication in
MNRA
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