1,721,688 research outputs found
Development of automated nucleic acid technologies for marine point of sample diagnostics
No full textUnsafe water, poor hygiene and inadequate sanitation are responsible for about 90% of diarrheal associated deaths worldwide, which are the second leading cause of death in children under five, globally (1.2 million deaths in 2005). The economic cost associated with unsafe water is also significant, with the World Bank estimating that a lack of access to safe water and sanitation amount to equivalent global economic losses of US$260 billion, annually. Coastal communities also face challenges from harmful algal blooms, which deplete oxygen and essential nutrients, and produce toxins that threaten human health; this impacts on locally important industries such as aquaculture, mariculture, leisure and tourism. Current, widely used methods for the detection of biological hazards in water sources rely on culturing or visual inspection of water samples via light microscopy. These techniques are time consuming, require well stocked laboratories and expensive equipment, are dependent on highly trained technical staff, and are often unable to differentiate morphologically similar organisms. Molecular techniques, on the other hand can provide better discrimination between related taxonomical groups, and are suited for miniaturisation and automation, enabling the analysis to be undertaken outside of the laboratory, and by minimally trained personnel.Recent advances in microfluidic technologies have demonstrated that molecular-biology techniques (e.g. genetic sequence amplification and detection) can be applied using lab-on-a-chip (LOC) systems for testing samples for the target organisms at the ‘point of sample’ or ‘point of care’. Nucleic acid sequence-based amplification (NASBA) and recombinase polymerase amplification (RPA) are particularly attractive for LOC applications as, unlike the current gold standard Polymerase Chain Reaction (PCR), they require simple, isothermal heating and a generally lower reaction temperature. NASBA is also attractive for LOC-based methods targeting RNA (e.g. RNA viruses) as it directly amplifies RNA removing the need for an additional reverse transcription step. This study indicates several, novel advances towards the provision of point of sample genetic testing for a range of harmful microorganisms and viruses. For the first time, the isothermal amplification of a fragment of the Hepatitis E virus using NASBA is reported with comparable sensitivity to a clinically relevant PCR-based assay. Further, amplification of a fragment of the Alexandrium minutum ITS1-5.8s-ITS2 rRNA gene region via RPA was achieved with a limit of detection of 10 cells exceeding the required sensitivity of 40 cells L-1 for statutory A. minutum surveillance in seawater. In addition to this, two methods for the long-term, dry storage of amplification reagents are presented. Trehalose and sucrose sugars combined with lyophilisation were sufficient to retain reagent activity after storage for four weeks at room temperature. Air drying in the presence of pullulan maintained reagent functionality for six weeks. Alongside these advances, a portable, handheld prototype concept for nucleic acid amplification was developed and tested, with the A. minutum ITS1-5.8s-ITS2 RPA assay being successfully performed on the handheld device achieving the same sensitivity as when performed on laboratory equipment. These advances demonstrate that nucleic acid amplification on a miniaturised device is possible, and that in future, rapid, specific and sensitive testing for harmful species may be able to be performed at the point of sample by non-technically trained operators
Evaluating the effect of data and data uncertainity on predictions of flood inundation
No full textIn the light of uncertain climate change, there is a need to assess flood risk outside the realm of current experience. Flood inundation models allow river discharge upstream to be related directly to flood extent downstream. They are, therefore, potentially very useful tools that can be used in a variety of real and “what-if” scenarios. However, flood inundation models are limited by the availability and use of appropriate data. In this thesis, the effect of data and data uncertainty on the prediction of flood inundation was assessed, using the two dimensional model, LISFLOOD-FP. Simulations were conducted on two sites in the United Kingdom. Specifically, the objective of the research was to use LISFLOOD-FP to (i) assess the suitability of elevation data available nationally in the UK (and via equivalents globally) for use in the prediction of flood inundation and (ii) assess the role of land cove in predicting inundation extent. Research assessed (i) several sources of elevation data and the effect that they had on the prediction of inundation extent, (ii) the effects of prediction uncertainty in interpolated elevation data and (iii) the use of remotely sensed land cover to predict spatially distributed friction coefficients on the floodplain and model sensitivity to them. At the scale of modelling undertaken, the most accurate predictions of inundation extent were obtained using photogrammetric elevation. The effects of prediction uncertainty in interpolated elevation data were found to increase both with distance downstream and throughout the simulation. Remotely sensed estimates of land cover were found to be useful for generating spatially distributed friction coefficients. However, predicted flood inundation using LISFLOOD-FP was insensitive to floodplain friction.</p
Replication Data for: Geographical Coverage in Political Science Research
No full textWe describe and analyze patterns in the geographical focus of political science research across more than a century. Using a new database of titles and abstracts from 27,690 publications in eight major political science journals from their inception, we demonstrate that, historically, political scientists concentrated their studies on a limited number of countries situated in North America and Western Europe. While a strong focus on Western countries remains today, we detail how this picture has changed somewhat over recent decades, with political science research becoming increasingly ‘globalized’. Still, several countries have received almost no attention, and geographical citation patterns differ by subfield. For example, we find indications of a greater focus on the United States and large Western European countries in international relations than in comparative politics publications. In extension, we analyze several correlates of a country being the focus of political science research, including the country’s predominant languages, income, population size, democracy level, and conflict experience, and show systematic variation in the geographic focus of research. This unequal focus, we argue, has important implications regarding the applicability of extant descriptive and causal claims, as well as the development of theories in political science
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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