Debates in the Digital Humanities Formerly Known as Humanities Computing

published_or_final_versio

The cell-cell junctions of mammalian testes: I. The adhering junctions of the seminiferous epithelium represent special differentiation structures

The seminiferous tubules and the excurrent ducts of the mammalian testis are physiologically separated from the mesenchymal tissues and the blood and lymph system by a special structural barrier to paracellular translocations of molecules and particles: the “blood–testis barrier”, formed by junctions connecting Sertoli cells with each other and with spermatogonial cells. In combined biochemical as well as light and electron microscopical studies we systematically determine the molecules located in the adhering junctions of adult mammalian (human, bovine, porcine, murine, i.e., rat and mouse) testis. We show that the seminiferous epithelium does not contain desmosomes, or “desmosome-like” junctions, nor any of the desmosome-specific marker molecules and that the adhering junctions of tubules and ductules are fundamentally different. While the ductules contain classical epithelial cell layers with E-cadherin-based adherens junctions (AJs) and typical desmosomes, the Sertoli cells of the tubules lack desmosomes and “desmosome-like” junctions but are connected by morphologically different forms of AJs. These junctions are based on N-cadherin anchored in cytoplasmic plaques, which in some subforms appear thick and dense but in other subforms contain only scarce and loosely arranged plaque structures formed by α- and β-catenin, proteins p120, p0071 and plakoglobin, together with a member of the striatin family and also, in rodents, the proteins ZO-1 and myozap. These N-cadherin-based AJs also include two novel types of junctions: the “areae adhaerentes”, i.e., variously-sized, often very large cell-cell contacts and small sieve-plate-like AJs perforated by cytoplasm-to-cytoplasm channels of 5–7 nm internal diameter (“cribelliform junctions”). We emphasize the unique character of this epithelium that totally lacks major epithelial marker molecules and structures such as keratin filaments and desmosomal elements as well as EpCAM- and PERP-containing junctions. We also discuss the nature, development and possible functions of these junctions.German-Israeli Foundation for Scientific Research and Development (GIF grant I-1098-43.11/2010

From “Is” to the (News) World: How Facebook Jeopardized Its Life-Diary Nature and Occupied the Network

This article focuses on self-narratives and identity construction in the context of social networking sites (SNSs). It does so by discussing the findings of a research that had at its core a practice-based module titled “Facebook and Autobiography”, which was designed and taught at a major Hong Kong University. Through a cyber autoethnographic approach, which aligns to the methodological orientation of the second wave in narratology studies, the research explores how the infrastructure of Facebook affects the processes of self-narration in comparison with traditional written dairies. Contrary to previous studies, the interviews with students-participants and the analysis of their Facebook’s profiles suggest that the retrieval on Facebook of even small self-narratives is impaired by the fact that the platform has abandoned its life-diary orientation in favour of a news-based business model where the posthuman connotation of profiles prevails

Engineering stories? A narratological approach to children's book apps

With the rise of smartphones and tablet pcs, children's book apps have emerged as a new type of children's media. While some of them are based on popular children's books such as Mo Willems’ Pigeon books or Beatrix Potter's Peter Rabbit, others were specifically designed as apps. This paper focuses on examining book apps under the aspects of implied user strategies and narrative structure. Using a narratological framework that also takes into account the unique characteristics of the medium, a terminology for the analysis of book apps will be sketched out. Furthermore, an exemplary analysis of iOS books apps for pre- and grade school children comes to the conclusion that, far from offering the child users room for individual creativity, a large number of apps rather train their users in following prescribed paths of reading

Zugang zu elektronischen Ressourcen für externe Benutzer in wissenschaftlichen Bibliotheken

Ausgangspunkt der vorliegenden Arbeit sind Betrachtungen über die zunehmen-de Bedeutung elektronischer Ressourcen und die Auswirkung dieser Entwicklung auf eine serviceorientierte, wissenschaftliche Bibliothek. Es folgt die Darstellung der bei der Nutzung elektronischer Ressourcen zu beachtenden rechtlichen Rahmenbedingungen. Im Ergebnis erweist es sich als notwendig, die vorhandenen Lokalen Bibliothekssysteme (LBS) um eine Komponente für einen rollenbasierten Zugang zu elektronischen Ressourcen zu er-weitern. Dabei sind Kenntnis und Beachtung der in der Arbeit aufgeführten Rechtsnormen und Lizenzverträge nicht nur für Bibliotheken sondern generell für alle Einrichtungen der öffentlichen Hand relevant, die Dienstleistungen über einen Zugang zum Internet oder über die Bereitstellung lizenz- und kosten-pflichtiger elektronischer Ressourcen für die Öffentlichkeit erbringen. Im Rahmen der Arbeit wurde eine entsprechende Erweiterung eines LBS-PICA an der Universitätsbibliothek Rostock implementiert und unter Angabe der wesentlichen Abläufe und Einsatzszenarien sowie eines Aktionsplans für die Einführung dokumentiert. Diese wird neben anderen alternativen, ergänzenden und zukünftigen Lösungen betrachtet und soll einen Einstieg in die Thematik sowie eine Entscheidungshilfe für Planung und Einsatz entsprechender Funktionalitäten und Verfahren sein. Letztlich werden damit Forderungen der DFG umgesetzt, die in den aktuellen Empfehlungen für die Ausstattung von Hochschulbibliotheken mit Lokalen Bibliothekssystemen formuliert sind

Möglichkeitsdenken. Utopie und Dystopie in der Gegenwart

Utopien denken Möglichkeiten von Zukunft. Mit Beginn der historischen Moderne, in der die Erwartung an die Zukunft die Erfahrung der Vergangenheit übersteigt, entstehen in der je aktuellen Gegenwart Entwürfe, die Utopien genannt werden können. Die Temporalisierung der Erfahrung macht Projektionen in die Zukunft möglich (Reinhart Koselleck). Diese sind nie eindeutig. Sie liefern mehrdeutige Wunsch- und Schreckbilder auch in eigentümlichen Verschränkungen. Die Einsicht in diese Dialektik nimmt mit dem Grad der Selbstreferentialität von Zukunftsentwürfen zu; Utopie und Dystopie bedingen sich wechselseitig. – Gegenwärtig leben wir mit außerordentlich unsicheren Zukunftsperspektiven. Haben Utopien nur in Dystopien überlebt? Nach dem Ende des Utopismus-Verdachts am Beginn der 90er Jahre geht es heute um eine Bestandsaufnahme von Zukunftspotentialen, um Diskussionen von Denkformen des Hypothetisch-Möglichen. Bietet die Tradition des utopischen Denkens Anknüpfungspunkte für aktuelle, positiv oder negativ konnotierte Zukunftsbeschreibungen? Wunsch- oder Warnbilder sind noch immer jenem utopischen Impuls verpflichtet, der den Blick aus der Gegenwart in die Zukunft richten will. Die Frage nach der Zukunft utopischen Denkens stellt somit in den Möglichkeiten temporalen, visionären und konjunktivischen Denkens zugleich die Frage nach dem Ort des Gesellschaftlichen und der Gesellschaft heute – und damit die Frage nach der Verbindlichkeit von Tradition, und das heißt auch: nach Traditionen des Utopischen

Zugang zu elektronischen Ressourcen für externe Benutzer in wissenschaftlichen Bibliotheken: Konzeption und praktische Anwendung

Ausgangspunkt der vorliegenden Arbeit sind Betrachtungen über die zunehmende Bedeutung elektronischer Ressourcen und die Auswirkung dieser Entwicklung auf eine serviceorientierte, wissenschaftliche Bibliothek. Es folgt die Darstellung der bei der Nutzung elektronischer Ressourcen zu beachtenden rechtlichen Rahmenbedingungen. Im Ergebnis erweist es sich als notwendig, die vorhandenen Lokalen Bibliothekssysteme (LBS) um eine Komponente für einen rollenbasierten Zugang zu elektronischen Ressourcen zu erweitern. Dabei sind Kenntnis und Beachtung der in der Arbeit aufgeführten Rechtsnormen und Lizenzverträge nicht nur für Bibliotheken, sondern generell für alle Einrichtungen der öffentlichen Hand relevant, die Dienstleistungen über einen Zugang zum Internet oder über die Bereitstellung lizenz- und kostenpflichtiger elektronischer Ressourcen für die Öffentlichkeit erbringen. Im Rahmen der Arbeit wurde eine entsprechende Erweiterung eines LBS-PICA an der Universitätsbibliothek Rostock implementiert und unter Angabe der wesentlichen Abläufe und Einsatzszenarien sowie eines Aktionsplans für die Einführung dokumentiert. Diese wird neben anderen alternativen, ergänzenden und zukünftigen Lösungen betrachtet und soll einen Einstieg in die Thematik sowie eine Entscheidungshilfe für Planung und Einsatz entsprechender Funktionalitäten und Verfahren sein. Letztlich werden damit Forderungen der DFG umgesetzt, die in den aktuellen Empfehlungen für die Ausstattung von Hochschulbibliotheken mit Lokalen Bibliothekssystemen formuliert sind. Diese Veröffentlichung geht zurück auf eine Master-Arbeit im postgradualen Fernstudiengang Master of Arts (Library and Information Science) an der Humboldt-Universität zu Berlin im Sommersemester 2008

Partnerorientierung zwischen Realität und Imagination: Anmerkungen zu einem zentralen Konzept der Dialogtheorie

This paper attempts a critique of the notion of 'dialogue' in dialogue theory as espoused by Linell, Markova, and others building on Bakhtin’s writings. According to them, human communication, culture, language, and even cognition are dialogical in nature. This implies that these domains work by principles of other-orientation and interaction. In our paper, we reject accepting other-orientation as an a priori condition of every semiotic action. Instead, we claim that in order to be an empirically useful concept for the social sciences, it must be shown if and how observable action is other-oriented. This leads us to the following questions: how can we methodically account for other-orientation of semiotic action? Does other-orientation always imply interaction? Is every human expression oriented towards others? How does the other, as s/he is represented in semiotic action, relate to the properties which the other can be seen to exhibit as indexed by their observable behavior? We study these questions by asking how the orientation towards others becomes evident in different forms of communication. For this concern, we introduce ‘recipient design’, ‘positioning’ and ‘intersubjectivity’ as concepts which allow us to inquire how semiotic action both takes the other into account and, reflexively, shapes him/her as an addressee having certain properties. We then specifically focus on actions and situations in which other-orientation is particularly problematic, such as interactions with children, animals, machines, or communication with unknown recipients via mass media. These borderline cases are scrutinized in order to delineate both limits and constitutive properties of other-orientation. We show that there are varieties of meaningful actions which do not exhibit an orientation towards the other, which do not rest on (the possibility of) interaction with the other or which even disregard what their producer can be taken to know about the other. Available knowledge about the other may be ignored in order to reach interactional goals, e. g. in strategical interactions or for concerns of socialization. If semiotic action is otherorientated, its design depends on how the other is available to and matters for their producer. Other-orientation may build on shared biographical experiences with the other, knowledge about the other as an individual and close attention to their situated conduct. However, other-orientation may also rest on (stereo-)typification with respect to institutional roles or group membership. In any case, others as they are represented in semiotic action can never be just others-as-such, but only othersas-perceived-by-the-actor. We conclude that the strong emphasis which dialogue theories put on otherorientation obscures that other-orientation is neither universal in semiotic action, that it must be distinguished from an interactive relationship, and that the ways in which the other figures in semiotic actions is not homogeneous in any of its most general properties. Instead, there is a huge variation in the ways in which the other can be taken into account. Therefore close scrutiny of how the other precisely figures in a certain kind of semiotic action is needed in order to lend the concept of ‘other-orientation’ empirical substance and a definite sense

Transmembrane protein PERP is a component of tessellate junctions and of other junctional and non-junctional plasma membrane regions in diverse epithelial and epithelium-derived cells

Protein PERP (p53 apoptosis effector related to PMP-22) is a small (21.4 kDa) transmembrane polypeptide with an amino acid sequence indicative of a tetraspanin character. It is enriched in the plasma membrane and apparently contributes to cell-cell contacts. Hitherto, it has been reported to be exclusively a component of desmosomes of some stratified epithelia. However, by using a series of newly generated mono- and polyclonal antibodies, we show that protein PERP is not only present in all kinds of stratified epithelia but also occurs in simple, columnar, complex and transitional epithelia, in various types of squamous metaplasia and epithelium-derived tumors, in diverse epithelium-derived cell cultures and in myocardial tissue. Immunofluorescence and immunoelectron microscopy allow us to localize PERP predominantly in small intradesmosomal locations and in variously sized, junction-like peri- and interdesmosomal regions (“tessellate junctions”), mostly in mosaic or amalgamated combinations with other molecules believed, to date, to be exclusive components of tight and adherens junctions. In the heart, PERP is a major component of the composite junctions of the intercalated disks connecting cardiomyocytes. Finally, protein PERP is a cobblestone-like general component of special plasma membrane regions such as the bile canaliculi of liver and subapical-to-lateral zones of diverse columnar epithelia and upper urothelial cell layers. We discuss possible organizational and architectonic functions of protein PERP and its potential value as an immunohistochemical diagnostic marker

Effects of long-term ethanol consumption and Aldh1b1 depletion on intestinal tumourigenesis in mice

Ethanol and its metabolite acetaldehyde have been classified as carcinogens for the upper aerodigestive tract, liver, breast and colorectum. Whereas mechanisms related to oxidative stress and Cyp2e1 induction seem to prevail in the liver, and acetaldehyde has been proposed to play a crucial role in the upper aerodigestive tract, pathological mechanisms in the colorectum have not yet been clarified. Moreover, all evidence for a pro-carcinogenic role of ethanol in colorectal cancer is derived from correlations observed in epidemiological studies or from rodent studies with additional carcinogen application or tumour suppressor gene inactivation. In the current study, wildtype mice and mice with depletion of aldehyde dehydrogenase 1b1 (Aldh1b1), an enzyme which has been proposed to play an important role in acetaldehyde detoxification in the intestines, received ethanol in drinking water for one year. Long-term ethanol consumption led to intestinal tumour development in wildtype and Aldh1b1-depleted mice, but no intestinal tumours were observed in water-treated controls. Moreover, a significant increase in DNA damage was detected in the large intestinal epithelium of ethanol-treated mice of both genotypes compared with the respective water-treated groups, along with increased proliferation of the small and large intestinal epithelium. Aldh1b1 depletion led to increased plasma acetaldehyde levels in ethanol-treated mice, to a significant aggravation of ethanol-induced intestinal hyperproliferation, and to more advanced features of intestinal tumours, but it did not affect intestinal tumour incidence. These data indicate that ethanol consumption can initiate intestinal tumourigenesis without any additional carcinogen treatment or tumour suppressor gene inactivation, and we provide evidence for a role of Aldh1b1 in protection of the intestines from ethanol-induced damage, as well as for both carcinogenic and tumour-promoting functions of acetaldehyde, including increased progression of ethanol-induced tumours.</p