323,012 research outputs found
Advanced EBSD-EDS methodologies
No full textThis data is a companion to the manuscript 'Advancing analytical electron microscopy methodologies to characterise microstructural features in superalloys' submitted to Ultramicroscopy by B. Schulz, N. Haghdadi, T. Leitner, M. Hafok and S. Primig [1].
It includes algorithms that were developed to automatically analyse large electron backscatter diffraction (EBSD) datasets using the MTEX toolbox for Matlab. Further, sample datasets and tutorials are provided to illustrate how to apply the developed methodologies. The developed methodologies allow to:
3-1) Correct γ/γ' interface artefacts in combined EBSD/Electron dispersive X-ray spectroscopy measurements
3-2-1) Classify recrystallised grains based on their location
3-2-2) Identify recrystallisation nucleation mechanism at distorted twins
3-3-1) Describe the evolution of twin boundaries during hot compression
3-3-2) Visualise the coherence and grain boundary planes of Σ3 twins
The numbering of the tutorials corresponds with the section numbers in the paper.
Explanation of the underlying methodologies are published here: [1] B. Schulz, N. Haghdadi, T. Leitner, M. Hafok, S. Primig, Advancing analytical electron microscopy methodologies to characterise microstructural features in superalloys, Ultramicroscopy (2023), 113699, https://doi.org/10.1016/j.ultramic.2023.113699.
This work © 2022 by B. Schulz et al. is licensed under a GNU General Public License v3.0 (GPL-3.0-or-later). To attribute the material to the creators, please cite the above mentioned paper B. Schulz et al. [1].If you use this software, please cite it as below
Analysis of the transcriptional program governing meiosis and gametogenesis in yeast and mammals
Full text linkDuring meiosis a competent diploid cell replicates its DNA once and then undergoes two consecutive divisions followed by haploid gamete differentiation. Important aspects of meiotic development that distinguish it from mitotic growth include a highly increased rate of recombination, formation of the synaptonemal complex that aligns the homologous chromosomes, as well as separation of the homologues and sister chromatids during meiosis I and II without an intervening S-phase. Budding yeast is an excellent model organism to study meiosis and gametogenesis and accordingly, to date it belongs to the best studied eukaryotic systems in this context. Knowledge coming from these studies has provided important insights into meiotic development in higher eukaryotes. This was possible because sporulation in yeast and spermatogenesis in higher eukaryotes are analogous developmental pathways that involve conserved genes. For budding yeast a huge amount of data from numerous genome-scale studies on gene expression and deletion phenotypes of meiotic development and sporulation are available. In contrast, mammalian gametogenesis has not been studied on a large-scale until recently. It was unclear if an expression profiling study using germ cells and testicular somatic control cells that underwent lengthy purification procedures would yield interpretable results. We have therefore carried out a pioneering expression profiling study of male germ cells from Rattus norvegicus using Affymetrix U34A and B GeneChips. This work resulted in the first comprehensive large-scale expression profiling analysis of mammalian male germ cells undergoing mitotic growth, meiosis and gametogenesis. We have identified 1268 differentially expressed genes in germ cells at different developmental stages, which were organized into four distinct expression clusters that reflect somatic, mitotic, meiotic and post-meiotic cell types. This included 293 yet uncharacterized transcripts whose expression pattern suggests that they are involved in spermatogenesis and fertility. A group of 121 transcripts were only expressed in meiotic (spermatocytes) and postmeiotic germ cells (round spermatids) but not in dividing germ cells (spermatogonia),
Sertoli
cells or two somatic control tissues (brain
and skeletal muscle). Functional analysis reveals
that most of the known genes in this
group fulfill essential functions during meiosis,
spermiogenesis (the process of sperm maturation)
and fertility. Therefore it is highly possible
that some of the �30 uncharacterized transcripts
in this group also contribute to these
processes. A web-accessible database (called
reXbase, which was later on integrated into
GermOnline) has been developed for our expression
profiling study of mammalian male
meiosis, which summarizes annotation information
and shows a graphical display of expression
profiles of every gene covered in our
study.
In the budding yeast Saccharomyces cerevisiae
entry into meiosis and subsequent progression
through sporulation and gametogenesis
are driven by a highly regulated transcriptional
program activated by signal pathways
responding to nutritional and cell-type cues.
Abf1p, which is a general transcription factor,
has previously been demonstrated to participate
in the induction of numerous mitotic as
well as early and middle meiotic genes. In
the current study we have addressed the question
how Abf1p transcriptionally coordinates
mitotic growth and meiotic development on a
genome-wide level. Because ABF1 is an essential
gene we used the temperature-sensitive
allele abf1-1. A phenotypical analysis of mutant
cells revealed that ABF1 plays an important
role in cell separation during mitosis,
meiotic development, and spore formation. In
order to identify genes whose expression depends
on Abf1p in growing and sporulating
cells we have performed expression profiling
experiments using Affymetrix S98 GeneChips
comparing wild-type and abf1-1 mutant cells
at both permissive and restrictive temperature.
We have identified 504 genes whose normal expression
depends on functional ABF1. By combining
the expression profiling data with data
from genome-wide DNA binding assays (ChIPCHIP)
and in silico predictions of potential
Abf1p-binding sites in the yeast genome, we
were able to define direct target genes. Expression
of these genes decreases in the absence
of functional ABF1 and whose promotors are
bound by Abf1p and/or contain a predicted
binding site.
Among 352 such bona fide direct target genes
we found many involved in ribosome biogenesis,
translation, vegetative growth and meiotic
developement and therefore could account for
the observed growth and sporulation defects of
abf1-1 mutant cells. Furthermore, the fact that
two members of the septin family (CDC3 and
CDC10 ) were found to be direct target genes
suggests a novel role for Abf1p in cytokinesis.
This was further substantiated by the observation
that chitin localization and septin ring
formation are perturbed in abf1-1 mutant cells
Diffusive author(s), cohesive author: Analysis of S/N (1994)
No full textThis study indicates the ways in which various aspects of the author(s) are brought forth in Dumb type’s performance art, the S/N production. Previous research has suggested a non-hierarchical organization of Dumb type and the absence of a “privileged author” in Dumb type’s collaborative work, S/N. However, the results that I have investigated from member’s interviews on the creative process of S/N along with my analysis of the recorded images of S/N, indicate a different aspect of the author(s). First, S/N was created through, so to speak, the collective ideas of the members of Dumb type. Further, S/N has at least nine quotations from previous performances, installations, and printed writings, besides the work-in-progress technique. Explicating one of the “author functions” as given by Michel Foucault, each text has plural subjects of the author. However, it has been revealed from members’ interviews that Teiji Furuhashi had a decision-making role in selecting the members’ ideas within the performance. Since then, S/N has had plural subjects of creation; however, Furuhashi is one of the subjects of creation along with the “privileged author.” S/N has plural authors (diffusive authors) yet at the same time, it has a “privileged author,” Teiji Furuhashi (cohesive author)
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
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
Author's address:
No full textCan archives of audiovisual TV interviews be used to make authors more visible to students, and thereby reduce the learning gap between native and non-native language speakers in college classes? We examined students in a college course who learned about one scholar's ideas through watching an audiovisual TV interview (i.e., visible author format) and about another scholar's ideas through reading a formal text description (i.e., invisible author format). For the invisible author, native language speakers scored significantly higher than the non-native language speakers on a corresponding exam question (i.e., a cognitive measure), generated more words on the exam question (i.e., a motivational measure), and mentioned the author's name more often in answering the exam question (i.e., an affective measure). For the visible author, the groups did not differ on any of these measures. These findings provide evidence for the idea that making the author visible through audiovisual TV interviews can eliminate the learning gap between native and non-native language speakers. 3 Universities around the world serve students who are non-native speakers of th
The vanishing author in computer-generated works: a critical analysis of recent Australian case law
Full text linkAbstract
The use of software is ubiquitous in the creation of many copyright works, yet the requirement in copyright law that every work have a human author who engages in independent intellectual effort means that its use may prevent copyright subsistence. Several recent Australian cases have refocused attention on authorship as an essential criterion of copyright subsistence, and these cases suggest that much computer-produced output may be authorless and thus lack copyright protection. This article, the first in a two-part series, analyses how each case deals with the question of authorship of computer-produced works and why the use of software diminishes copyright protection for a significant number of computer-generated works. The article critiques the application of conventional notions of human authorship developed in the pre-computer age to modern productions and suggests alternative approaches to authorship that satisfy both the major objectives of copyright policy and the need to adapt to the computer age. The article argues that, without a broader judicial approach to authorship of computer-generated works, Parliament must remedy the lacuna in protection for these ‘authorless’ works. Possible solutions for reform are suggested. In a forthcoming article, the author comprehensively examines those reform proposals
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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