Some thoughts on the importance of open source and open access for emerging digital scholarship

Both the open source and the open access movements have their roots in the ‘hard’ sciences rather than in the social Sciences and Humanities (SSH). They have been concerned, traditionally, with open access to source code for computational data processing and with open access to scienti?c information published as journal articles. Still, the basic assumption of the present contribution is that there is a specific open source and open access agenda within the SSH and that this may affect these disciplines—once such an agenda is fully in place — in a way hardly conceivable in the ‘hard’ sciences. However, understanding the full impact and potential of such approaches in the SSH requires reflection upon broader methodological issues. Two vectors or primary oppositions are of specific interest in this respect: the scholarly information continuum as a whole and its evolution from print based to electronic working paradigms and the revolutionary changes that can be foreseen as a consequence the speci?c difference of the SSH as opposed to the Science-TechnologyMedicine (STM) culture of relating signi?ers to signi?cates and the specific impact of the digital revolution resulting from this specific difference. Exploring these two vectors this contribution will try to indicate constituent elements of an ‘open’ agenda for the digital humanities

Digital document and interpretation : re-thinking "text" and scholarship in electronic settings

The contribution starts from outlining the evolution of the scholarly production flow from the print based paradigm to the digital age and in this context it explores the opposition of digital versus analog representation modes. It then develops on the triple paradigm shift caused by genuine digital publishing and its specific consequences for the social sciences and humanities (SSH) which in turn results in re-constituting basic scholarly notions such as 'text' and 'document'. The paper concludes with discussing the specific value that could be added in systematically using digital text resources as a basis for scholarly work and also states some of the necessary conditions for such a 'digital turn' to be successful in the SSH.Der Beitrag beginnt mit einem Überblick zur Evolution des wissenschaftlichen Informationskontinuums auf dem Weg vom druckbasierten Paradigma in das digitale Zeitalter und geht in diesem Zusammenhang näher auf die Unterscheidung 'digitaler' und 'analoger' Repräsentationsmodi ein. Anschließend behandeln wir den als Folge des Übergangs zu genuin digitalen Publikationsformen erwartbaren dreifachen Paradigmenwechsel und dessen spezifische Konsequenzen für die Geistes- und Sozialwissenschaften sowie als deren Folge wiederum die Re-Konstitution elementarer Kernbegriffe geisteswissenschaftlichen Arbeitens wie 'Text' und 'Dokument'. Der Beitrag schließt mit einer Betrachtung des spezifischen Mehrwerts, der sich aus dem systematischen Rekurs auf digitale Textressourcen in den Geisteswissenschaften ergeben könnte und geht dabei auch auf die erforderlichen Vorbedingungen eines solcherart erfolgreichen 'digital turn' in den Geistes- und Sozialwissenschaften ein

Influence of magnetic fields on the spin reorientation transition in ultra-thin films

The dependence of the spin reorientation transition in ultra-thin ferromagnetic films on external magnetic fields is studied. For different orientations of the applied field with respect to the film, phase diagrams are calculated within a mean field theory for the classical Heisenberg model. In particular we find that the spin reorientation transition present in this model is not suppressed completely by an applied field, as the magnetization component perpendicular to the field may show spontaneous order in a certain temperature interval.Comment: 11 pages(LaTeX2e), 6 figures(eps), submitted to Phil. Mag. B. See also http://www.thp.Uni-Duisburg.DE/Publikationen/Publist_Us_R.htm

Magic bullets and moving targets : antibiotic resistance and experimental chemotherapy, 1900-1940

It was in the 1940s that antibiotic resistance arose as an object of study for clinical medicine. Somewhat earlier it had become an important analytical tool for bacterial geneticists. However, the concept of antibiotic resistance as an induced and inheritable trait of microbial species was introduced a generation earlier in the years preceding the First World War. The paper reconstructs the concept that was put forward by the German immunologist Paul Ehrlich in 1907. He came across the phenomenon when trying to develop chemotherapies for trypa n osomiasis, the best known of which is African sleeping sickness. However, resistance was studied by him for other than therapy-related purposes. It provided a productive laboratory model for the study of cell functions. Induced resistance to chemicals facilitated the development of ideas on the relation of a parasite's cellular metabolism and of drug action, i.e. by providing a negative proof for the existence of chemoreceptors on the surfaces of parasite cells. This approach does also serve to explain why British and German researchers continued to study the phenomenon of induced resistance in microbes for decades -despite it being absent from clinical medicine. After all, there existed very few chemotherapies of infectious diseases prior to the arrival of the sulfa drugs. Moreover, resistance to such medicines was rarely observed. However, being part and parcel of Ehrlich's theories, his views on resistance were also criticised together with these. It was in particular Henry Dale who would challenge Ehrlich's views of resistance being an inheritable and stable trait of microbes. Instead he insisted that understanding this «wholly mysterious phenomenon» required taking into account some host interaction. Induced resistance, which had come into being as a chance discovery on the chemotherapy of sleeping sickness, thus became one of the more important laboratory models of twentieth-century immunological research. Its early history is largely discontinuous with later work, and antimicrobial resistance as it evolved from 1900 to 1940 followed other trajectories than those which became relevant after 1940

Metastability in Monte Carlo simulation of 2D Ising films and in Fe monolayer strips

Effective Curie temperatures measured in Fe monolayer strips agree reasonable with computer sinulations of two-dimensional Ising model strips. The simulations confirm the domain structure seen already by Albano et al.Comment: 3 pages, plain tex, 5 postscript figure

Ion Selectivity and Competition in Channelrhodopsins

AbstractChannelrhodopsins are light-gated ion channels of green algae. They are widely used for the analysis of neuronal networks using light in the emerging field of optogenetics. Under steady-state light conditions, the two open states, O1 and O2, mediate the photocurrents with different ion conductance and selectivity. To understand the conducting process as well as its optogenetic applications, it is important to study ion binding and transport of this promiscuous cation channel. Here, we present an enzyme kinetic algorithm that allowed us to calculate the ion composition of the initial and steady-state photocurrents for multication media. The approach is based on current-voltage relations determined for the individual ions H+, Na+, Ca2+, and Mg2+. We identify and quantify the widely different competition of the ions in wild-type channelrhodopsin-2 and two high-performing channelrhodopsin variants CatCh+ and C1V1. Both variants show enhanced Ca2+ conductance, but only CatCh+ displays high steady-state Ca2+ currents at neutral pH due to reduced H+ competition and low inactivation. We demonstrate that for optogenetic applications, one should always take into account that the variable equilibria of the two open states depend on light intensity, voltage, and the ionic composition of the medium