1,722,061 research outputs found
Atmospheric destabilization leads to Arctic Ocean winter surface wind intensification
Get PDFThe surface-amplified winter warming over the Arctic Ocean is accompanied by a pronounced intensification of near-surface winds, simulated by climate models and emerging in reanalysis data. Here, the influences of sea-ice decline, wind changes aloft, and atmospheric stability are revisited based on CMIP6 historical and high-emission scenario and ERA5 reanalysis data. Spatial trend patterns suggest that near-surface wind intensification over the inner Arctic Ocean in winter is largely driven by an increasing downward momentum transfer due to a weakening atmospheric stratification. In contrast, a near-surface wind intensification in summer appears to be largely driven by accelerating winds aloft, amplified in a high-emission future by decreasing surface roughness due to sea-ice decline. In both seasons, differences in near-surface wind-speed trends are closely linked to atmospheric stability trends. Models suggest that by 2100 the lower troposphere may become as unstable in winter as in summer, implying a fundamental regime shift of the Arctic winter boundary layer
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Genetic and diet effects on <it>Ppar-α </it>and <it>Ppar-γ </it>signaling pathways in the Berlin Fat Mouse Inbred line with genetic predisposition for obesity
No full textAbstract Background The Berlin Fat Mouse Inbred (BFMI) line is a new mouse model for obesity, which was long-term selected for high fatness. Peroxisome proliferator-activated receptors (PPARs) are involved in the control of energy homeostasis, nutrient metabolism and cell proliferation. Here, we studied the expression patterns of the different Ppar genes and the genes in the PPAR pathway in the BFMI line in comparison to physiological changes. Results At the age of 10 weeks, the BFMI mice exhibited marked obesity with enlarged adipocytes and high serum triglycerides concentrations in comparison to the often used mouse line C57BL/6 (B6). Between these two lines, gene expression analyses revealed differentially expressed genes belonging to the PPAR pathway, in particular genes of the lipogenesis and the fatty acid transport. Conclusion Surprisingly, the Ppar-α gene expression was up-regulated in liver and Ppar-γ gene expression was down-regulated in the white adipose tissue, indicating the activation of a mechanism that counteracts the rise of obesity.</p
Variations on the Author
Get PDF“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
Get PDFWe 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
Ice Edge Verification -- Measuring the skill in our forecasts and disagreement in our observations
No full textSea ice is one of the most crucial components of the polar system. Alongside its effects on the climate and weather, it also impacts human lives and operations in these regions. Climate scientists, as well as other stakeholders (such as marine industries, mining operations, governmental authorities as well as local/aboriginal population), have a high interest in getting accurate observation and prediction of sea ice presence, and its effective border – the ice edge. In this context, this thesis is focused on the verification of ice presence and ice edge, across different datasets. We do this by describing a new method of generating reference forecasts of the ice edge (as benchmark for predictions at sub-seasonal to seasonal timescales), analysing initial state errors in forecasts and analysis from ECMWF, and comparing the ice presence and ice edge difference between several observational and analysis datasets.
Operational systems generating sea ice forecasts at sub-seasonal timescales are mostly compared against simple references based solely on climatological or initial states, which can lead to a potential overestimation of their prediction skill. In chapter 1, we describe the Spatial Damped Anomaly Persistence (SDAP) method, which combines historical sea ice probability with the initial ice edge anomalies to generate probabilistic reference forecasts of the ice edge. The SDAP forecasts outperform both traditional references, as well as most dynamical forecast models from the Sub-seasonal to Seasonal (S2S) project at long lead times, establishing a more challenging benchmark for operational forecast systems.
Within the S2S database, forecasts from the European Centre for Medium- Range Weather Forecasts (ECMWF) have the highest prediction skill compared to both traditional references and SDAP forecasts, but show significant initial error. In chapter 2, we analyse this initial state issue in the ECMWF forecasts, as well as corresponding analysis from ORAS5, by measuring the errors against observations from OSISAF. We find that the initial state errors are partly due to interpolation issues, and partly systematic underestimation, especially in the summer. We show the spatial distribution of the mean bias and provide evidence that between 10 to 20% of the error can be reduced simply by subtracting the mean bias.
While forecast verification methods assume observations to be ‘the truth’, observational records also have inconsistencies that have previously only been discussed in concentration or ice extent terms. In chapter 3, we analyse differences in ice presence between several observational and analysis datasets by measuring the Integrated Ice Edge Error and bias between each pair. We find significant mismatch between observations, particularly in the summer, and identify regions where certain observations disagrees with all other. Our results show that observational records from OSISAF potentially overestimate ice presence, while those from AMSR-E/2 potentially underestimate it.
In the last chapter, we discuss the results from the different studies in context of each other and mention how the inconsistencies in observations cast doubt on the forecast errors we initially measured, offering the possibility of a probabilistic observation and reemphasizing the need for accurate sea ice edge measurements and forecasts
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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