1,721,320 research outputs found
Artificial chiral materials
No full textIn 1898 Acharya J C Bose, a researcher from Calcutta, India, wrote in the Proceedings of the Royal Society of London: 'In order to imitate the rotation by liquids like sugar solutions, I made elements of "molecules" of twisted jute, of two varieties, one kind being twisted to the right (positive) and the other twisted to the left (negative).... The twisted structure produces an optical twist of the plane of polarization'. This paper[1], published 111 years ago and reporting experimental microwave tests on the optical activity of the artificial chiral medium, was the first publication on what has now become a flourishing and dynamic field of metamaterials - man-made media with all sorts of unusual functionalities that can be achieved by artificial structuring smaller than the wavelength scale of the external stimulus. An increasing number of researchers are currently designing, fabricating and studying artificial metamaterials composed of tailored chiral building blocks that may be viewed as 'artificial chiral molecules'. This special section is devoted to this vibrant and emerging research direction and has a special emphasis on the theory of light interactions with artificial chiral media
Efficacy of foramsulfuron plus thiencarbazone-methyl towards different development stages of weed species in sugar beet cultivation
No full textThe currently available weed control system in sugar beet cultivation has low flexibility due to the necessity of applications at the cotyledon stage of the weeds. The aim of the present study was to evaluate a new herbicide providing more flexibility in terms of application time. In 2013 and 2014, efficacy of an ALS-inhibiting herbicide (foramsulfuron + thiencarbazone-methyl) was evaluated in six field trials in Germany. Sugar beet varieties not sensitive to ALS-inhibiting herbicides are currently in the breeding process. The herbicide was tested on five weed species in different development stages (later than cotyledon stage). In the trials, only weeds but no sugar beet were sown. The herbicide was applied with three dosages at five development stages of the weeds. Efficacy towards Brassica napus L. and Galium aparine L. was nearly 100%. Efficacy towards Chenopodium album L., Matricaria chamomilla L. and Polygonum onvolvulus L. was reduced due to unfavorable weather conditions and with decreasing dosages and increasing development stages. Efficacy was lowest in case of Chenopodium album being close to 95% at BBCH 14 and 16 with 0.50 L/ha and 1.00 L/ha, respectively. It was thus concluded that the herbicide can be applied later than at cotyledon stage. This implies more flexibility of application timing than current herbicides. To develop a comprehensive evaluation of the weed control system, further studies regarding selectivity, duration of efficacy and resistance risks are necessary.Bayer CropScience A
Efficacy of foramsulfuron plus thiencarbazone-methyl towards different development stages of weed species in sugar beet cultivation
No full textThe currently available weed control system in sugar beet cultivation has low flexibility due to the necessity of applications at the cotyledon stage of the weeds. The aim of the present study was to evaluate a new herbicide providing more flexibility in terms of application time. In 2013 and 2014, efficacy of an ALS-inhibiting herbicide (foramsulfuron + thiencarbazone-methyl) was evaluated in six field trials in Germany. Sugar beet varieties not sensitive to ALS-inhibiting herbicides are currently in the breeding process. The herbicide was tested on five weed species in different development stages (later than cotyledon stage). In the trials, only weeds but no sugar beet were sown. The herbicide was applied with three dosages at five development stages of the weeds. Efficacy towards Brassica napus L. and Galium aparine L. was nearly 100%. Efficacy towards Chenopodium album L., Matricaria chamomilla L. and Polygonum onvolvulus L. was reduced due to unfavorable weather conditions and with decreasing dosages and increasing development stages. Efficacy was lowest in case of Chenopodium album being close to 95% at BBCH 14 and 16 with 0.50 L/ha and 1.00 L/ha, respectively. It was thus concluded that the herbicide can be applied later than at cotyledon stage. This implies more flexibility of application timing than current herbicides. To develop a comprehensive evaluation of the weed control system, further studies regarding selectivity, duration of efficacy and resistance risks are necessary.Bayer CropScience A
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
- …
