1,721,185 research outputs found
Optical characterisation of germanium optical fibres
No full textSemiconductor core optical fibres are currently generating great interest as they promise to be a platform for the seamless incorporation of optoelectronic functionality into a new generation of all-fibre networks [1,2]. Although recent attentions have primarily focused on silicon as the material of choice for semiconductor photonics applications, germanium has some advantages over its counterpart. For example, it has higher nonlinearity, extended infrared transparency and has recently been demonstrated as a direct band gap laser medium [3]. Here we present the first optical characterisation of a germanium core optical fibre. The fibre was fabricated using a chemical micro fluidic deposition process [1] that uses GeH4 (germane) as a precursor to deposit amorphous germanium into the hole of a silica capillary. Figure 1 (a) shows an optical microscope image of the polished end face of a germanium fibre, with a 5.6 µm core diameter, which has been completely filled with the semiconductor material. Optical transmission measurements have been conducted over the wavelength range 2 µm to 11 µm, to confirm the broad mid-infrared operational window, and the guided output at 2.4 µm, imaged using a Spiricon Pyrocam III pyroelectric array camera, is shown in Figure 1 (b). At this wavelength the optical loss has been measured to be 20 dB/cm, which is comparable to losses measured for amorphous silicon fibres in the infrared. The potential for these germanium optical fibres to be used as optical modulators and infrared detectors will be discussed
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
Roles of Cancer Stem Cells in Therapy Resistance and Disease Recurrence
No full textCancer stem cells (CSCs), which can self-renew and differentiate into different kinds of cancer cells, are suggested to be responsible for drug resistance and cancer relapse in a variety of cancer types. Researchers have outlined mechanisms by which CSCs display resistance to therapeutic agents, with the goal of developing agents, which target CSCs and improve treatment success rates and patient outcomes. In this chapter, the key role that CSCs play in various cancers has been outlined, alongside the different mechanisms in which they act by. This has resulted in recent breakthroughs in research, which has fortified the rationale to create agents which target CSCs. This novel strategy for the treatment of different types of cancer could lead to novel anticancer therapeutics which exhibit lower treatment resistance and relapse rates than before the discovery of CSCs.No Full Tex
Cancer Stem Cells in Cancer Initiation and Progression
No full textCancer stem cells (CSCs) are a subclass of cancer cells that can differentiate into various cell types and self-renew, similar to normal stem cells. CSCs play an important role in the initiation and progression of cancer, and as such, there has been extensive research into the molecular and cellular mechanisms underlying the properties of CSCs and how they contribute to the development and spread of cancer. CSCs are thought to be responsible for cancer initiation because they can divide and differentiate into multiple cell types, allowing them to contribute to the formation of a malignant tumor. CSCs are also largely resistant to cancer therapies, which allows them to survive and continue to divide, leading to the growth and progression of the tumor. CSCs can migrate to other body parts and form new tumors, a process known as metastasis. This is one of the major challenges in treating cancer, as it is difficult to eliminate CSCs and prevent the spread of the disease. There is ongoing research into the molecular and cellular mechanisms underlying the properties of CSCs, as well as efforts to develop targeted therapies that specifically target CSCs to improve the treatment of cancer. Some potential therapeutic strategies include inhibiting the pathways that control the self-renewal and viability of CSCs or targeting the microenviron-ment that supports the growth and survival of CSCs.No Full Tex
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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