1,720,955 research outputs found
Coring Lake Fuxian: A Passageway to Key Paleoclimatic Records
No full textStudying the variations in weather patterns throughout time is fundamental to predicting future climate change. Amongst the greatest influences on climate are the El Niño and La Niña events, which determine global weather patterns. Their formation takes place in the Indo-Pacific Warm Pool (IPWP), and through the El Niño-Southern Oscillation (ENSO), they drive weather patterns throughout the world, especially monsoon-related events. Lakes provide an extensive record of historical data, tracking monsoons over time. At the edge of the IPWP lies Lake Fuxian in Yunnan Province, China, which is strongly affected by the Indian Monsoon. We predict that the sediments of Lake Fuxian, an ancient lake of 2-3 million years, has potentially recorded both monsoonal events and local anthropogenic inputs. We sliced a 31-cm sediment core from Lake Fuxian into 1-cm intervals and analyzed the elemental concentrations of each slice through inductively coupled plasma optical emission spectroscopy (ICP-OES). Peaks in Na concentrations at 9cm, 15cm, 25cm, 26cm,and 28cm represented periods of high evaporation associated with major droughts while peaks at 3cm, 7cm, 16cm,and 19cm denoted periods of major precipitation, a characterization of monsoonal events. Additionally, a shift in concentration found between Pb, Cu, and P from 6cm–2cm provides strong evidence of human activity on the local environment. Through studying these past monsoonal events, we presume that major floods and droughts have occurred multiple times in this region. Decreased freshwater availability is one of the most threatening consequences of climate change to humanity. Lake Fuxian is an important freshwater source, another major drought will prove dangerous to China. Due to China’s influence on the world’s economy, adversity in the country could lead to negative impacts globally. By learning about historical climatic patterns from Lake Fuxian, we come a step closer to making proper climate change predictions and necessary preparations for the future
Monitoring natural and anthropogenic influences on an ancient Chinese lake
No full textAmong the most powerful influences on the state of our freshwater systems include global climate and human interference. We can measure the impact both natural and anthropogenic changes have on freshwater by studying deep sediment cores from ancient lakes. Lake Fuxian, China is one of the few ancient lakes in the world and serves as an important source of drinking water in China. This lake lies along the edge of the Indo-Pacific Warm Pool, home to the formation of El Nino and La Nina events. These events are major drivers of global climate, influencing temperature fluctuations, precipitation patterns, and natural disasters around the world. Recently, industrialization and urbanization in the Yunnan Provence is thought to have influenced the state of Lake Fuxian, increasing anthropogenic influences on the lake. We hypothesized that: (1) this lake could record changes caused by anthropogenic inputs and global climate; and (2) local anthropogenic inputs had a greater impact on the state of the lake than global climatic changes. We have measured the elemental composition of a 30-cm sediment core from this lake through spectroscopy at 1cm intervals, recording approximately 300 years of data. Results to date show cycling in conservative metals through the core, representing switches in global El Nino and La Nina events. An increase in heavy metal concentrations reveal changes caused by anthropogenic influences. Our results provide insight to the difference in severity that both natural and anthropogenic may cause to a freshwater system. The elemental changes of the highest magnitude were caused by global climatic variation, revealing how natural global phenomena can have a greater impact on lakes than local anthropogenic inputs, an important observation for lake management as the threat of the state of freshwater resources is globally on the rise
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
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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