236 research outputs found
Ästhetische Zeitkonzeptionen der zwanziger Jahre: László Moholy-Nagy und El Lissitzky
Das erste Viertel des 20. Jahrhunderts ist eine Phase intensiver Auseinandersetzung mit dem Phänomen Zeit. In unterschiedlichen Gebieten wie Mathematik, Physik, Literatur und Philosophie ebenso wie in der Alltagswelt gewannen temporale Aspekte besondere Relevanz und entwickelten sich zu einem virulenten Diskussionsgegenstand vielschichtiger Prägung. Lässt sich diese Sensibilisierung für alles, was mit der Zeit zusammenhängt, nun auch für die Diskurse in der bildenden Kunst belegen? Während die Frage der Temporalität für die Arbeiten des Kubismus und Futurismus vielfach diskutiert wurde, fehlt eine ähnliche Untersuchung für den Konstruktivismus und sein Umfeld in den 20er Jahren ebenso wie ganz konkret für die in dieser Arbeit thematisierten Künstler, László Moholy-Nagy und El Lissitzky. Die Arbeit liefert in diesem Sinn einen ergänzenden und erweiternden Beitrag einer breiteren Analyse der Rolle von Zeitkonzeptionen in der für dieses Thema so wichtigen Phase der Kunst des beginnenden 20. Jahrhunderts. Sie nimmt zudem die Frage in den Blick, ob und wie die Diskussion des Temporalen am Schauplatz Kunst mit dem Netzwerk der Zeitdiskurse dieser Periode interagiert. Es kann gezeigt werden, dass sich in Moholys wie in Lissitzkys Arbeit nicht einzelne Zeitaspekte artikulieren, sondern Zeitenkonvolute, die aus unmittelbaren, symptomatischen, messbaren Momenten von Zeit ebenso wie aus mittelbaren Momenten des Zeitlichen bestehen. Letztere sind immer dort gegeben, wo die Zeit nicht als visualisierter Fakt, zu zeigendes Sujet oder messbare Quantität im Werk gedacht wird, sondern als Movens, als dem Werk a priori zugehörige Kategorie, als stets mitzudenkende Qualität von Wahrnehmung und Erkenntnis. Sie bezeugen, dass das Werkverständnis auf einem Denkmodell beruht, für das die Kategorie Zeit unverzichtbar ist. Hieraus resultiert der in der Arbeit etablierte Begriff der temporalen Qualitäten, der gleichzeitig einen veränderten Modus für das Sprechen über das Verhältnis von Zeit und Bild überhaupt in Anschlag bringt und der zu einer veränderten Fragestellung zum Auffinden und Verorten von Zeitaspekten im Kunstwerk führt. Insbesondere lässt sich im konkreten Fall so zeigen, dass die Frage nach dem Temporalen bei Moholy wie Lissitzky weit über sich hinaus weist auf das grundsätzliche Verständnis von ‚Werk‘ respektive der Beziehung zwischen Künstler, Werk und Betrachter
Towards a Taxonomy of Concepts Describing IT Outside the IT Department
Due to technological advances, IT is increasingly introduced and managed outside of (or even hidden from) an organization\u27s IT department. Researchers and practitioners have created multiple concepts describing different facets and trends of this development. While the individual concepts typically focus on different aspects, there are overlaps between these concepts. This effect hampers research progress as it creates redundancies and separate streams of knowledge development. To close this gap, we propose a taxonomy of the concepts Lightweight IT, IT Consumerization, Bring Your Own Device, Shadow IT, and Business-Managed IT based on a structured literature review. For this purpose, we derive characterizing dimensions of each concept from existing studies and analyze literature according to the usage of terms. As a result, we can describe and delineate the concepts. Thus, we contribute a taxonomy of IT outside the IT department to improve the transfer of research results from between research streams
Reconstructing the deep-branching relationships of the papilionoid legumes
Resolving the phylogenetic relationships of the deep nodes of papilionoid legumes (Papilionoideae) is essential to understanding the evolutionary history and diversification of this economically and ecologically important legume subfamily. The early-branching papilionoids include mostly Neotropical trees traditionally circumscribed in the tribes Sophoreae and Swartzieae. They are more highly diverse in floral morphology than other groups of Papilionoideae. For many years, phylogenetic analyses of the Papilionoideae could not clearly resolve the relation- ships of the early-branching lineages due to limited sampling. In the eight years since the publication of Legumes of the World, we have seen an extraordinary wealth of new molecular data for the study of Papilionoideae phylogeny, enabling increasingly greater resolution and many surprises. This study draws on recent molecular phylogenetic studies and a new comprehensive Bayesian phylogenetic analysis of 668 plastid matK sequences. The present matK phylogeny resolves the deep-branching relationships of the papilionoids with increased support for many clades, and suggests that taxonomic realignments of some genera and of numerous tribes are necessary. The potentially earliest-branching papilionoids fall within an ADA clade, which includes the recircumscribed monophyletic tribes Angylocalyceae, Dipterygeae, and Amburanae. The genera Aldina and Amphimas represent two of the nine main but as yet unresolved lineages comprising the large 50-kb inversion clade. The quinolizidine-alkaloid-accumulating Genistoid s.l. clade is expanded to include Dermatophyllum and a strongly supported and newly circumscribed tribe Ormosieae. Sophoreae and Swartzieae are dramatically reorganized so as to comprise mono-phyletic groups within the Core Genistoid clade and outside the 50-kb inversion clade, respectively. Acosmium is excluded from the Genistoids s.l. and strongly resolved within the newly circumscribed tribe Dalbergieae. By providing a better resolved phylogeny of the earliest-branching papilionoids, this study, in combination with other recent evidence, will lead to a more stable phylogenetic classification of the Papilionoideae.Web of Scienc
A First Glimpse of Wild Lupin Karyotype Variation As Revealed by Comparative Cytogenetic Mapping
Insight into plant genomes at the cytomolecular level provides useful information about their karyotype structure, enabling inferences about taxonomic relationships and evolutionary origins. The Old World lupins (OWL) demonstrate a high level of genomic diversification involving variation in chromosome numbers (2n = 32-52), basic chromosome numbers (x = 5-7, 9, 13) and in nuclear genome size (2C DNA = 0.97-2.68 pg). Lupins comprise both crop and wild species and provide an intriguing system to study karyotype evolution. In order to investigate lupin chromosome structure, heterologous FISH was used. Sixteen BACs that had been generated as chromosome markers for the reference species, Lupinus angustifolius, were used to identify chromosomes in the wild species and explore karyotype variation. While all “single-locus” in L. angustifolius, in the wild lupins these clones proved to be “single-locus,” “single-locus” with additional signals, “repetitive” or had no detectable BAC-FISH signal. The diverse distribution of the clones in the targeted genomes suggests a complex evolution history, which possibly involved multiple chromosomal changes such as fusions/fissions and repetitive sequence amplification. Twelve BACs were sequenced and we found numerous transposable elements including DNA transposons as well as LTR and non-LTR retrotransposons with varying quantity and composition among the different lupin species. However, at this preliminary stage, no correlation was observed between the pattern of BAC-FISH signals and the repeat content in particular BACs. Here, we describe the first BAC-based chromosome-specific markers for the wild species: L. cosentinii, L. cryptanthus, L. pilosus, L. micranthus and one New World lupin, L. multiflorus. These BACs could constitute the basis for an assignment of the chromosomal and genetic maps of other lupins, e.g., L. albus and L. luteus. Moreover, we identified karyotype variation that helps illustrate the relationships between the lupins and the extensive cytological diversity within this group. In this study we premise that lupin genomes underwent at least two rounds of fusion and fission events resulting in the reduction in chromosome number from 2n = 52 through 2n = 40 to 2n = 32, followed by chromosome number increment to 2n = 42
Meltwater circulation and permeability of Arctic summer sea ice derived from hydrological field experiments
Membrane transporters studied by EPR spectroscopy: structure determination and elucidation of functional dynamics
During their mechanistic cycles membrane transporters often undergo extensive conformational changes, sampling a range of orientations, in order to complete their function. Such membrane transporters present somewhat of a challenge to conventional structural studies; indeed, crystallization of membrane-associated proteins sometimes require conditions that vary vastly from their native environments. Moreover, this technique currently only allows for visualization of single selected conformations during any one experiment. EPR spectroscopy is a magnetic resonance technique that offers a unique opportunity to study structural, environmental and dynamic properties of such proteins in their native membrane environments, as well as readily sampling their substrate-binding-induced dynamic conformational changes especially through complementary computational analyses. Here we present a review of recent studies that utilize a variety of EPR techniques in order to investigate both the structure and dynamics of a range of membrane transporters and associated proteins, focusing on both primary (ABC-type transporters) and secondary active transporters which were key interest areas of the late Professor Stephen Baldwin to whom this review is dedicated
Characterizing Aquifer Heterogeneity Using Bacterial and Bacteriophage Tracers
Gravel aquifers act as important potable water sources in Central Western Europe, yet are
subject to numerous contamination pressures. Compositional and textural heterogeneity
makes protection zone delineation around groundwater supplies in these units challenging.
Artificial tracer testing aids character ization. This paper re-appraises tracer test results,
presented in Mallèn et al. (2005), in light of new geological and microbiological data.
Comparative passive gradient testing, employing a fluorescent solute (Uranine), virus (H40/1
bacteriophage) and comparably-sized bacterial tracers Escherichia coli (E.coli) and
Pseudomonas putida (P.putida), was used to investigate a calcareous gravel aquifer’s ability
to remove microbiological contaminants at a test site near Munich, Germany. Test results
revealed E.coli relative recoveries could exceed those of H40/1 at monitoring wells, 10m and
20m from an injection well, by almost four times; P.putida recoveries varied by a factor of up
to three between wells. Application of filtration theory suggested greater attenuation of
H40/1, relative to similarly-charged E.coli occurred due to differences in microorganism size,
while estimated collision efficiencies appeared comparable. By contrast, more positively
charged P.putida experienced greater attenuation at one monitoring point, while lower
attenuation rates at the second location indicated the influence of geochemical heterogeneity.
Test findings proved consistent with observations from nearby fresh outcrops that suggested
thin open framework gravel beds dominated mass transport in the aquifer, while discrete
intervals containing stained clasts reflect localized geochemical heterogeneity. Study results
highlight the utility of reconciling outcrop observations with artificial tracer test responses,
using microbiological tracers with well-defined properties, to characterize aquifer
heterogeneity
Documentation of time-scales for onset of natural attenuation in an aquifer treated by a crude-oil recovery system
Tracer tests, hydrochemical and microbiological investigations as a basis for groundwater protection in a remote tropical mountainous karst area, Vietnam
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