Begeistert digitalisieren: Die Arbeit in und an einer E-Commerce-Plattform

Dieser Artikel basiert auf meiner ethnografischen Feldforschung in einer Preisvergleichsplattform, die ich als Promotionsprojekt durchgeführt habe. Zunächst strukturiere ich den Arbeitsbegriff am englischen Begriffspaar labour, das eher auf die erfahrbare Ebene von (digitalem) Wandel verweist, und work, das eher das praktische becoming of und damit die Herstellung von (digitalem) Wandel bezeichnet. In einem Dreischritt zeige ich danach, wie beide Ebenen analytisch ernst zu nehmen sind: (1) Mitarbeitende begeistern sich für die Arbeit an der Plattform und schaffen hieraus (2) Infrastrukturen, die Waren und User im Unternehmen versammeln. (3) Hieraus entstehen E-Commerce-Märkte, auf welchen sich auch die Preisvergleichsplattform bewegt. Dieser Beitrag plädiert dafür, dass Vermittlung als ein Produktionsprozess verstanden werden sollte, indem die Arbeit in und an einer Plattform fokussiert wird.This article is based on my dissertation, in which I conducted field research in a price comparison platform. I outline a contrast between labour, which refers to the layer of experience of (digital) transformation, and work, which refers more to the practical becoming of (digital) transformation. I will then show in three steps, how both layers interfere: (1) Employees enthuse themselves for working on the platform and produce by that (2) infrastructures, which assemble commodities and users. (3) This intermediation constructs an e-commerce-market. This article claims that intermediation should be understood as a production process by itself and by that focusing on the work in and on a platform

Woran arbeiten wir? E-Commerce-Plattformen ethnografisch verstehen

Plattformen werden im gesellschaftlichen Diskurs häufig als maßgebendes Merkmal des digitalen Kapitalismus unserer Gegenwart genannt. Doch werden selten Einblicke in diesen Kapitalismus ermöglicht, die nicht nur als Berichte der Mitarbeitenden zu bewerten sind. Der Autor führt in dieser Ethnografie Gesprächsnotizen und Praktiken von Mitarbeitenden der Plattformökonomie zusammen. Er zeigt damit, dass die digitale Ökonomisierung den Menschen entgegen gängiger Annahmen nicht überflüssig macht. Im Gegenteil sind wir selbst diejenigen, die mit Begeisterung neue Wertschöpfungsmodelle schaffen, indem wir unsere Bedürfnisse digitalisieren und damit neue Absatzmärkte in Form von E-Commerce-Märkten erschließen

Die Bedeutung von Vorleistungsimporten und nichtpreislicher Wettbewerbsfähigkeit für den deutschen Leistungsbilanzsaldo

Deutschland weist seit mehreren Jahren einen anhaltenden Leistungsbilanzüberschuss auf. Im Vorfeld der Finanz- und Wirtschaftskrise stieg der Überschuss über mehrere Jahre deutlich an und hatte im Jahr 2007 über 7 Prozent des Bruttoinlandsprodukts (BIP) erreicht. Neben Deutschland wiesen auch weitere EU-Länder, z.B. Österreich, Schweden oder Finnland anhaltende und steigende Leistungsbilanzüberschüsse auf. Gleichzeitig hatten andere, vor allem südeuropäische, EU-Länder wachsende und anhaltende Leistungsbilanzdefizite. Seit 2007 haben sich zwar die Leistungsbilanzsalden fast aller europäischen Länder wieder verringert, Deutschland verzeichnet jedoch nach wie vor einen Überschuss von 6 bis 7 Prozent des BIP. Leistungsbilanzungleichgewichte sind oftmals Ausdruck unterschiedlicher Wettbewerbsfähigkeit. Gerade Deutschland wird häufig vorgeworfen, seine Wettbewerbsfähigkeit mittels übermäßiger Lohnzurückhaltung gestärkt zu haben. Deutschlands Exporte seien dadurch relativ preiswert geworden und der Leistungsbilanzüberschuss gewachsen. Gleichzeitig hätten andere Länder an Wettbewerbsfähigkeit verloren (z.B. durch zu hohe Lohnabschlüsse). Ihre Exporte seien deshalb relativ teuer geworden und ihre Leistungsbilanzdefizite gewachsen. So hätten die Ungleichgewichte zugenommen. [...]This study analyzes to what extend the rising share of foreign value added in exports and various factors of non-price competitiveness are related to exports and current account balances in the European Union and other large exporting economies. It also asks whether Germany is special with regard to these relationships. We answer these questions by means of descriptive and econometric analyses. In particular, we carry out export regressions for 12 manufacturing industries in a sample of 14 EU countries and in a sample of 8 large exporting economies. Moreover, we carry out regressions for the current account balance in 14 EU countries. The study looks at the period 1995 to 2007. We calculate an indicator for the share of foreign value added in exports (degree of vertical specialization) based on the World Input Output Database (WIOD). The indicator is calculated for individual industries and countries. Using the WIOD, it is possible to allocate the actual imported value added to the respective origin country, irrespective of whether it has been channeled through other countries in previous stages of the production process. Hence, we can distinguish the imported intermediates by country of origin. In this study, we distinguish between imports from high-wage countries, low-wage countries, and Central and Eastern European countries (CEECs). The share of imported value added from CEECs is particularly high in Germany. It has also grown most strongly in Germany. [...

Wall roughness induces asymptotic ultimate turbulence

Turbulence is omnipresent in Nature and technology, governing the transport of heat, mass, and momentum on multiple scales. For real-world applications of wall-bounded turbulence, the underlying surfaces are virtually always rough; yet characterizing and understanding the effects of wall roughness for turbulence remains a challenge, especially for rotating and thermally driven turbulence. By combining extensive experiments and numerical simulations, here, taking as example the paradigmatic Taylor-Couette system (the closed flow between two independently rotating coaxial cylinders), we show how wall roughness greatly enhances the overall transport properties and the corresponding scaling exponents. If only one of the walls is rough, we reveal that the bulk velocity is slaved to the rough side, due to the much stronger coupling to that wall by the detaching flow structures. If both walls are rough, the viscosity dependence is thoroughly eliminated in the boundary layers and we thus achieve asymptotic ultimate turbulence, i.e. the upper limit of transport, whose existence had been predicted by Robert Kraichnan in 1962 (Phys. Fluids {\bf 5}, 1374 (1962)) and in which the scalings laws can be extrapolated to arbitrarily large Reynolds numbers

Order-of-magnitude speedup for steady states and traveling waves via Stokes preconditioning in Channelflow and Openpipeflow

Steady states and traveling waves play a fundamental role in understanding hydrodynamic problems. Even when unstable, these states provide the bifurcation-theoretic explanation for the origin of the observed states. In turbulent wall-bounded shear flows, these states have been hypothesized to be saddle points organizing the trajectories within a chaotic attractor. These states must be computed with Newton's method or one of its generalizations, since time-integration cannot converge to unstable equilibria. The bottleneck is the solution of linear systems involving the Jacobian of the Navier-Stokes or Boussinesq equations. Originally such computations were carried out by constructing and directly inverting the Jacobian, but this is unfeasible for the matrices arising from three-dimensional hydrodynamic configurations in large domains. A popular method is to seek states that are invariant under numerical time integration. Surprisingly, equilibria may also be found by seeking flows that are invariant under a single very large Backwards-Euler Forwards-Euler timestep. We show that this method, called Stokes preconditioning, is 10 to 50 times faster at computing steady states in plane Couette flow and traveling waves in pipe flow. Moreover, it can be carried out using Channelflow (by Gibson) and Openpipeflow (by Willis) without any changes to these popular spectral codes. We explain the convergence rate as a function of the integration period and Reynolds number by computing the full spectra of the operators corresponding to the Jacobians of both methods.Comment: in Computational Modelling of Bifurcations and Instabilities in Fluid Dynamics, ed. Alexander Gelfgat (Springer, 2018

ContDist: a tool for the analysis of quantitative gene and promoter properties

<p>Abstract</p> <p>Background</p> <p>The understanding of how promoter regions regulate gene expression is complicated and far from being fully understood. It is known that histones' regulation of DNA compactness, DNA methylation, transcription factor binding sites and CpG islands play a role in the transcriptional regulation of a gene. Many high-throughput techniques exist nowadays which permit the detection of epigenetic marks and regulatory elements in the promoter regions of thousands of genes. However, so far the subsequent analysis of such experiments (e.g. the resulting gene lists) have been hampered by the fact that currently no tool exists for a detailed analysis of the promoter regions.</p> <p>Results</p> <p>We present ContDist, a tool to statistically analyze quantitative gene and promoter properties. The software includes approximately 200 quantitative features of gene and promoter regions for 7 commonly studied species. In contrast to "traditionally" ontological analysis which only works on qualitative data, all the features in the underlying annotation database are quantitative gene and promoter properties.</p> <p>Utilizing the strong focus on the promoter region of this tool, we show its usefulness in two case studies; the first on differentially methylated promoters and the second on the fundamental differences between housekeeping and tissue specific genes. The two case studies allow both the confirmation of recent findings as well as revealing previously unreported biological relations.</p> <p>Conclusion</p> <p>ContDist is a new tool with two important properties: 1) it has a strong focus on the promoter region which is usually disregarded by virtually all ontology tools and 2) it uses quantitative (continuously distributed) features of the genes and its promoter regions which are not available in any other tool. ContDist is available from <url>http://web.bioinformatics.cicbiogune.es/CD/ContDistribution.php</url></p

A Study of the Influence of Sex on Genome Wide Methylation

Sex differences in methylation status have been observed in specific gene-disease studies and healthy methylation variation studies, but little work has been done to study the impact of sex on methylation at the genome wide locus-to-locus level or to determine methods for accounting for sex in genomic association studies. In this study we investigate the genomic sex effect on saliva DNA methylation of 197 subjects (54 females) using 20,493 CpG sites. Three methods, two-sample T-test, principle component analysis and independent component analysis, all successfully identify sex influences. The results show that sex not only influences the methylation of genes in the X chromosome but also in autosomes. 580 autosomal sites show strong differences between males and females. They are found to be highly involved in eight functional groups, including DNA transcription, RNA splicing, membrane, etc. Equally important is that we identify some methylation sites associated with not only sex, but also other phenotypes (age, smoking and drinking level, and cancer). Verification was done through an independent blood cell DNA methylation data (1298 CpG sites from a cancer panel array). The same genomic site-specific influence pattern and potential confounding effects with cancer were observed. The overlapping rate of identified sex affected genes between saliva and blood cell is 81% for X chromosome, and 8% for autosomes. Therefore, correction for sex is necessary. We propose a simple correction method based on independent component analysis, which is a data driven method and accommodates sample differences. Comparison before and after the correction suggests that the method is able to effectively remove the potentially confounding effects of sex, and leave other phenotypes untouched. As such, our method is able to disentangle the sex influence on a genome wide level, and paves the way to achieve more accurate association analyses in genome wide methylation studies

DNA Methylation and Gene Expression Changes in Monozygotic Twins Discordant for Psoriasis: Identification of Epigenetically Dysregulated Genes

Monozygotic (MZ) twins do not show complete concordance for many complex diseases; for example, discordance rates for autoimmune diseases are 20%–80%. MZ discordance indicates a role for epigenetic or environmental factors in disease. We used MZ twins discordant for psoriasis to search for genome-wide differences in DNA methylation and gene expression in CD4+ and CD8+ cells using Illumina's HumanMethylation27 and HT-12 expression assays, respectively. Analysis of these data revealed no differentially methylated or expressed genes between co-twins when analyzed separately, although we observed a substantial amount of small differences. However, combined analysis of DNA methylation and gene expression identified genes where differences in DNA methylation between unaffected and affected twins were correlated with differences in gene expression. Several of the top-ranked genes according to significance of the correlation in CD4+ cells are known to be associated with psoriasis. Further, gene ontology (GO) analysis revealed enrichment of biological processes associated with the immune response and clustering of genes in a biological pathway comprising cytokines and chemokines. These data suggest that DNA methylation is involved in an epigenetic dysregulation of biological pathways involved in the pathogenesis of psoriasis. This is the first study based on data from MZ twins discordant for psoriasis to detect epigenetic alterations that potentially contribute to development of the disease

Re-examining the Unified Theory of Acceptance and Use of Technology (UTAUT): Towards a Revised Theoretical Model

YesBased on a critical review of the Unified Theory of Acceptance and Use of Technology (UTAUT), this study first formalized an alternative theoretical model for explaining the acceptance and use of information system (IS) and information technology (IT) innovations. The revised theoretical model was then empirically examined using a combination of meta-analysis and structural equation modelling (MASEM) techniques. The meta-analysis was based on 1600 observations on 21 relationships coded from 162 prior studies on IS/IT acceptance and use. The SEM analysis showed that attitude: was central to behavioural intentions and usage behaviours, partially mediated the effects of exogenous constructs on behavioural intentions, and had a direct influence on usage behaviours. A number of implications for theory and practice are derived based on the findings