1,720,984 research outputs found
Raw Data for: Rapid generation of homozygous fluorescent knock-in human cells using CRISPR/Cas9 genome editing and validation by automated imaging and digital PCR screening. Authors: Andrea Callegari, Moritz Kueblbeck, Beatriz Serrano-Solano, Natalia Rosalia Morero and Jan Ellenberg.
No full textRaw Data for: Rapid generation of homozygous fluorescent knock-in human cells using CRISPR/Cas9 genome editing and validation by automated imaging and digital PCR screening. Authors: Andrea Callegari, Moritz Kueblbeck, Beatriz Serrano-Solano, Natalia Rosalia Morero and Jan Ellenberg.</p
Chromophore-Assisted Laser Inactivation of α- and γ-Tubulin SNAP-tag Fusion Proteins inside Living Cells
No full textChromophore-assisted laser inactivation (CALI) can help to unravel localized activities of target proteins at defined times and locations within living cells. Covalent SNAP-tag labeling of fusion proteins with fluorophores such as fluorescein is a fast and highly specific tool to attach the photosensitizer to its target protein in vivo for selective inactivation of the fusion protein. Here, we demonstrate the effectiveness and specificity of SNAP-tag-based CALI by acute inactivation of α-tubulin and γ-tubulin SNAP-tag fusions during live imaging assays of cell division. Singlet oxygen is confirmed as the reactive oxygen species that leads to loss of fusion protein function. The major advantage of SNAP-tag CALI is the ease, reliability, and high flexibility in labeling: the genetically encoded protein tag can be covalently labeled with various dyes matching the experimental requirements. This makes SNAP-tag CALI a very useful tool for rapid inactivation of tagged proteins in living cells
Gradual changes during mouse preimplantation development could affect chromosome segregation fidelity.
No full textAfter meiosis I, the fully differentiated oocyte is fertilized by the sperm and resumes meiosis II. The two divisions are very asymmetric to maintain a large cytoplasmic volume for storage. During both meiotic divisions, transcription is inactive and protein expression is translationally and post-translationally regulated. Because centrosomes are degraded during early oogenesis [26], multiple acentriolar MTOCs functionally replace them in meiotic spindle assembly [19,27]. Thereby, multipolar spindle intermediates preferentially form during prometaphase. Also the duration of the division phase in the cell cycle (M-phase) is very long: meiosis I can take up to 10 hours and meiosis II can be especially delayed due to a metaphase arrest until fertilization [28]. Therefore, the totipotent zygote undergoes the first mitosis under unusual conditions, and the described and depicted parameters only gradually change during the early divisions: in every cleavage, the cell size is halved, whereas the genomic content should remain constant [25]. Through stored and activated mRNA, the zygote is still entirely under maternal translational control [23]. Only from the two-cell stage onwards—when transcription of the embryonic genome becomes activated—maternal control gets replaced by embryonic control [29]. Fewer and fewer MTOCs organize the mitotic spindle until centrosomes form de novo at the blastocyst stage. Until then, spindle assembly passes through less marked multipolar organization [30,31]. Also, M-phase duration changes: after very lengthy and even halted meiosis, the zygotic mitosis is still prolonged (approximately 90 to 120 minutes) compared to somatic mitosis [32,33]. Thereafter, the duration decreases until it reaches the timing of a normal somatic cell mitosis. These gradual changes during preimplantation development might contribute to decreased chromosome segregation fidelity during cleavage divisions. MTOC, microtubule organizing center.</p
Misalignment of the two spindles in murine zygotic mitosis can result in binucleated blastomeres.
No full textIn murine zygotic mitosis, two independent spindles assemble around the parental pronuclei [42]. If these two spindles fail to align in parallel prior to anaphase—e.g., in case the pronuclei are too far apart from each other at mitotic entry—two-cell embryos with blastomeres containing two nuclei can form.</p
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
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