135,699 research outputs found
Data for Variability in Sleep and Affect (Ying et al.)
No full textData for Variability in Sleep and Affect (Ying et al.
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Enantioselective capillary electrophoresis : fundamental aspects and application to the "in vitro" assessment of CYP3A4 mediated ketamine N-demethylation
No full textA large number of pharmaceutical substances are administered as racemates, consisting of two enantiomers with typically different pharmacodynamic and pharmacokinetic profiles. Thus, stereoselective analysis is important in drug development, therapeutic drug monitoring and research. Chiral separation by chromatographic methods such as HPLC and GC require expensive stationary phases. In contrast, in capillary electrophoresis (CE), enantioselective separation can be obtained using one or several chiral selectors which are added to the background electrolyte. Separation of enantiomers is based on different binding affinities with the enantiomers and/or different migration velocities of the formed analyte-selector complexes. High resolution can be achieved by varying type and concentration of chiral selector as well as buffer properties (pH, ionic strength, other additives etc.). Typical chiral selectors are neutral or charged cyclodextrins, proteins and bile acids. The simplicity of the technique makes enantioselective CE an attractive, promising and economic methodology for drug and metabolite analysis in pharmaceutical preparations, body fluids, tissues and microsomal preparations.
In the first part of this thesis, fundamental aspects of enantioselective CE were investigated using computer simulation. Dynamic computer simulators provide insight into the buffer system and improve understanding of the electrophoretic separation process. Simulation allows to predict proper separation and detection conditions for analytes prior to experiments. Using an extended version of the dynamic computer simulator GENTRANS, the interaction of methadone and its main metabolite EDDP with neutral chiral selectors were simulated. Experimentally determined complexation constants and mobilites of the formed complexes were employed as additional input parameters. Simulated electropherograms were qualitatively in good agreement with the experimental results.
In the second and third parts of the thesis, enantioselective CE was applied to study ketamine metabolism in an off-line study. Ketamine is a chiral phencyclidine derivative used in anesthesia. In vitro and also in vivo studies showed a higher affinity for the NMDA-receptors, higher anesthetic potency and shorter recovery time for S-ketamine compared to R-ketamine. The aims in this project were to characterize the kinetics of CYP 3A4 mediated ketamine N-demethylation in vitro including KM, Vmax and to investigate the stereoselective metabolism of this pathway. Furthermore, the inhibition kinetics of this pathway by ketoconazole, a potent CYP3A4 inhibitor, was investigated. Results showed a higher formation rate for S-norketamine after incubation of racemic ketamine as well as incubation of the single enantiomers. Data obtained in the absence of ketoconazole revealed that the N-demethylation occurred stereoselectively. Inhibition kinetics by ketoconazole fitted best to a one-site competitive model and no stereoselectivity could be demonstrated.
In the forth and final part of this thesis, an on-line method was developed to investigate the in vitro N-demethylation of ketamine via CYP3A4, with the incubation performed in-capillary with subsequent electrophoretic separation and detection of the ketamine enantiomers. Kinetic parameters obtained compared well with those of the off-line study mentioned above and the metabolic step was stereoselective, confirming the results of the off-line assay. After additional improvements, the in-capillary method should be widely applicable to assess enzymatic activity in a fast, low-cost and automated way
Religious pathways to coping with personal death anxiety among older adult British Christians and Chinese Buddhists: afterlife beliefs, psychosocial maturity and regret management
No full textReligion was proposed to account for the relatively low personal death anxiety found among older adults. This dissertation sought to examine the influence of religious afterlife beliefs, religiously enhanced psychosocial maturity and religious management of a past major regret on personal death anxiety in later life. Terror Management Theory and Erikson’s Psychosocial Theory were used to describe these three religious pathways to coping with personal death anxiety in later life. The cross-sectional postal survey samples consisted of 143 older adult British Christians and 141 older adult Chinese Buddhists. Structural Equation Modelling results from the British Christian survey study showed that intrinsic religiosity predicted lower personal death anxiety through: (a) fostering more benign afterlife beliefs; (b) enhancing psychosocial maturity; and (c) promoting emotional stability. No significant relationship between belief in reincarnation and personal death anxiety was found in the Chinese Buddhist survey study. Both survey studies failed to support the personal death anxiety buffering power of religious management of a past major life regret, although some religious coping strategies were associated with lower negative emotional appraisal towards the major life regret among older adults. The British survey study has been the first to demonstrate both the personal death anxiety buffering and psychosocial maturity enhancing power of religion in an increasingly secular society. The lack of relationship between Buddhist reincarnation beliefs and personal death anxiety suggests that not all religious afterlife beliefs have death anxiety buffering power as proposed by Terror Management Theory. The development of Buddhist reincarnation belief and Buddhist coping scales is a pioneering step towards developing research on under-explored Eastern non-theistic afterlife beliefs and coping measures. Implications for ways that help religious older adults cope with their personal death anxiety were discussed. Prospective cross cultural and cross-religion studies were recommended to replicate the present survey findings. Finally, self detachment (self negation) was proposed as the basis of an alternative death transcendence theory to be researched in future studies on personal death anxiety
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
COMPOSERS' FORUM Monday, March 8, 1993 8:00 p.m. Lillian H. Duncan Recital Hall
No full textPresented by students of the Shepherd School of MusicPlaylist: Three essays for piano -- Peter Adamczyk / Variations in one frequency -- Pawel Rychwicki / As it was -- Amy Scurria (1973-) / For Li Po -- Feng Yin / Four discovery pieces -- Tse-Ying Koh / The song of the wandering Aengus -- Nathan Davis (1973-)
Author Correction: High gradient terahertz-driven ultrafast photogun
No full textCorrection to: Nature Photonics https://doi.org/10.1038/s41566-024-01441-y, published online 14 May 2024.In the version of this article originally published, Timm Rohwer’s surname appeared incorrectly (Rowher) and has now been corrected in the HTML and PDF versions of the article.Author informationAuthor notes These authors contributed equally: Jianwei Ying, Xie He.Authors and Affiliations Key Laboratory for Laser Plasmas (Ministry of Education), Collaborative Innovation Center of IFSA, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, China Jianwei Ying, Xie He, Dace Su, Lingbin Zheng, Jingui Ma, Peng Yuan & Dongfang Zhang Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron, Hamburg, Germany Tobias Kroh, Timm Rohwer, Moein Fakhari, Günther H. Kassier, Nicholas H. Matlis & Franz X. Kärtner Department of Physics and The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Hamburg, Germany Tobias Kroh & Franz X. KärtnerCorresponding authorsCorrespondence to Franz X. Kärtner or Dongfang Zhang
The Non-Governmental Organizations (NGOs) for Foreign Workers and Foreign Spouses in Taiwan: A Portrayal
No full textDispelling the Myths Behind First-author Citation Counts
No full textWe 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
The construction of Karen Karnak: The multi-author-function
No full textThis thesis is situated within the comparatively recent developments of Web 2.0 and the emergence of interactive WikiMedia, and explores the mode of authorship within a Read/Write culture compared to that of a Read/Only tradition. The hypothesis of this study is that the role of the audience has become merged with the author, and as such, represents new functions and attributes, distinct from a more conventional concept of authorship, in which the roles of audience and author are more separate. Read/Write and participatory culture, as defined by this study, is focused on collaboration, and includes the influences of D.I.Y. culture, Open-Source practices and the production of text by multiple authors. Multi-authorship presents a re-thinking of several concepts which support the notion of the individual author, since the focus of multi-authorship is not on attribution and ownership of a finished text, but on the continued malleability of a text. Modes of multi-authorship, demonstrated in the use of the pseudonyms Alan Smithee and Karen Eliot, represent declarative authors whose names signify multiple origins, whilst concurrently indicating a distinct body of work. The function of these names form an important context to this study, since primary research involves the construction of an experimental mode of multi-authorship utilising WikiMedia technology and the interaction of thirty nine participants, who are invited to create a body of work under the collective pseudonym Karen Karnak. The data generated by this experiment is analysed using aspects of Michel Foucault's author-function to identify and determine power structures inherent in the WikiMedia context. The interplay of power structures, including concepts such as identity, ownership and the body of work, affect the resulting mode of authorship and contribute to the construction of Karen Karnak, suggesting further areas of research into the emerging multi-author
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