Removal of mismatched bases from synthetic genes by enzymatic mismatch cleavage

The success of long polynucleotide de novo synthesis is largely dependent on the quality and purity of the oligonucleotides used. Generally, the primary product of any synthesis reaction is directly cloned, and clones with correct products have to be identified. In this study, a novel strategy has been established for removing undesired sequence variants from primary gene synthesis products. Single base-pair mismatches, insertions and deletions were cleaved with specific endonucleases. Three different enzymes—T7 endonuclease I, T4 endonuclease VII and Escherichia coli endonuclease V—have been tested. As a model, a synthetic polynucleotide encoding the bacterial chloramphenicol-acetyltransferase (cat) was synthesized using different methods for one step polynucleotide synthesis based on ligation of oligonucleotides. The influence of enzymatic mismatch cleavage (EMC) as an error correction step on the frequency of correct products was analyzed by functional cloning of the synthetic cat and comparing the error rate with that of untreated products. Significant reduction of all mutation types was observed. Statistical analysis revealed that the T4 and E.coli endonucleases reduced the occurrence of mutations in cloned synthetic gene products. The EMC treatment was successful especially in the removal of deletions and insertions from the primary ligation products

Characterisation of friction behaviour of intact soft solid foods and food boli

Methodologies to quantify friction forces between soft solid foods or food boli and (model) oral surfaces are desired to better understand how changes in food properties during oral processing affect sensory perception. In this short communication, friction forces (FF) occurring between polydimethylsiloxane (PDMS) surfaces and intact soft solid foods/boli were quantified. As models for intact foods, we used gelatine gels varying in composition and particle size, and sausages were used as an example for real foods. Friction forces measured during the relative motion of intact foods against a rough PDMS surface (“oral surface”), strongly depended on the composition of the food. Friction forces were significantly lower for PDMS against emulsion-filled gels, than for PDMS against unfilled gels, likely due to the lubricating effect of released oil from the gel. Moreover, sausages, displayed significantly higher friction forces than gelatine gels when moving against the PDMS probe, presumably linked to differences in the surface of the foods. The friction forces observed for the PDMS probe moving against food boli were dependent on particle size and saliva quantity; boli with larger particle sizes showed significantly lower friction forces, whereas the addition of saliva to food boli first increased friction forces, but with increasing amount decreased the friction forces significantly. We conclude that the presented methodology is able to quantify the friction behaviour of intact soft solid foods and boli directly, taking into account (i) the effect of composition and added fillers, (ii) serum or oil release and (iii) bolus particle size.</p

Dimensionalisierung, Gruppenbildung und Wahrscheinlichkeitsübergang: zur Identifizier- und Interpretierbarkeit multivariater Beziehungen zwischen Milieu, Beruf und Weiterbildung an SOEP-Daten

'Der Artikel behandelt Fragen der Milieu- und Bildungsbeteiligungsforschung primär unter methodischen Gesichtspunkten der Auswertung aus verschiedenen Erhebungen des SOEP (Erhebungen 1994 und 1999). Im Zentrum steht die Frage, in welcher Weise Milieuzugehörigkeit und Weiterbildungsbeteiligung aufeinander bezogen werden können. Die Rekonstruktion des Zusammenhangs erfolgt auf der Grundlage multivariater Verfahren der Objekt- und Variablenklassifikation. Gezeigt wird, dass mittels einer gezielten, auf die Analyse von Milieus zugeschnittenen Kombination solcher Verfahren die Unterscheidung milieuspezifischer von milieuunspezifischen Bestimmungsfaktoren der Weiterbildungsbeteiligung gelingen kann. Auf diese Weise ist es möglich, eine inhaltliche und methodische Schwäche der bildungsbezogenen Milieuforschung sichtbar zu machen: Nicht nur die innere Unterscheidbarkeit von Milieus, sondern auch die Unterscheidung von Milieu und Nicht- Milieu ist eine für die Einschätzung von Milieus als unabhängige Variable inhaltlich und methodisch erforderliche Operation.' (Autorenreferat)'The article deals with issues from milieu research and research on participation in education, primarily looking at methodological aspects in the analysis of various surveys from the SOEP (surveys 1994 and 1999). The central question is how milieu and participation in further education are related to each another. The relationship is reconstructed on the basis of multivariate procedures for classifying objects and variables. It will be shown that milieu-specific factors for participation in further education can be distinguished from milieu-non-specific factors, namely by systematically combining these multivariate procedures in such a way that the combination is tailored to the analysis of milieus. Thus a weakness regarding content and methodology can be made visible in milieu research focusing on education: in order to assess milieus as an independent variable, both matter and methodology require not only a differentiation between various types of milieus, but also between milieu and non-milieu.' (author's abstract)

Numerical methods for drift-diffusion models

The van Roosbroeck system describes the semi-classical transport of free electrons and holes in a self-consistent electric field using a drift-diffusion approximation. It became the standard model to describe the current flow in semiconductor devices at macroscopic scale. Typical devices modeled by these equations range from diodes, transistors, LEDs, solar cells and lasers to quantum nanostructures and organic semiconductors. The report provides an introduction into numerical methods for the van Roosbroeck system. The main focus lies on the Scharfetter-Gummel finite volume discretization scheme and recent efforts to generalize this approach to general statistical distribution functions

Numerical methods for drift-diffusion models

The van Roosbroeck system describes the semi-classical transport of free electrons and holes in a self-consistent electric field using a drift-diffusion approximation. It became the standard model to describe the current flow in semiconductor devices at macroscopic scale. Typical devices modeled by these equations range from diodes, transistors, LEDs, solar cells and lasers to quantum nanostructures and organic semiconductors. The report provides an introduction into numerical methods for the van Roosbroeck system. The main focus lies on the Scharfetter-Gummel finite volume disretization scheme and recent efforts to generalize this approach to general statistical distribution functions

Helmholtz Open Science Workshop „Zugang zu und Nachnutzung von wissenschaftlicher Software“ #hgfos16, Report; November 2016

Der Report des Helmholtz Open Science Workshops „Zugang zu und Nachnutzung von wissenschaftlicher Software“ #hgfos16 behandelt die Themen Standards und Qualitätssicherung; Reproduzierbarkeit; Lizenzierung und weitere rechtliche Aspekte; Zitation und Anerkennung; Sichtbarkeit und Modularität; Geschäftsmodelle; Personal, Ausbildung, Karrierewege. Diese Themen sind eng miteinander verzahnt. Für jeden Themenbereich werden jeweils die Relevanz, Fragestellungen, Herausforderungen, mögliche Lösungsansätze und Handlungsempfehlungen betrachtet

The bioinspired construction of an ordered carbon nitride array for photocatalytic mediated enzymatic reduction

A carbon nitride array (CNA) material has been constructed using a sacrificial diatom template. A regular carbon nitride nanorod array could be replicated from the periodic and regular nanochannel array of the template. The directional charge transport properties and high light harvesting capability of the CNA gives much better performance in splitting water to give hydrogen than its bulk counterpart. Furthermore, by combining with a rhodium complex as a mediator, the nicotinamide adenine dinucleotide (NADH) cofactor of many enzymes could be photocatalytically regenerated by the CNA. The rate of the in situ NADH regeneration is high enough to reverse the biological pathway of the three dehydrogenase enzymes, which then leads to the sustainable conversion of formaldehyde to methanol and also the reduction of carbon dioxide into methanol

Exoplanet imaging data challenge: benchmarking the various image processing methods for exoplanet detection

The Exoplanet Imaging Data Challenge is a community-wide effort meant to offer a platform for a fair and common comparison of image processing methods designed for exoplanet direct detection. For this purpose, it gathers on a dedicated repository (Zenodo), data from several high-contrast ground-based instruments worldwide in which we injected synthetic planetary signals. The data challenge is hosted on the CodaLab competition platform, where participants can upload their results. The specifications of the data challenge are published on our website https://exoplanet-imaging-challenge.github.io/. The first phase, launched on the 1st of September 2019 and closed on the 1st of October 2020, consisted in detecting point sources in two types of common data-set in the field of high-contrast imaging: data taken in pupil-tracking mode at one wavelength (subchallenge 1, also referred to as ADI) and multispectral data taken in pupil-tracking mode (subchallenge 2, also referred to as ADI+mSDI). In this paper, we describe the approach, organisational lessons-learnt and current limitations of the data challenge, as well as preliminary results of the participants’ submissions for this first phase. In the future, we plan to provide permanent access to the standard library of data sets and metrics, in order to guide the validation and support the publications of innovative image processing algorithms dedicated to high-contrast imaging of planetary systems

[Insulin pump therapy and continuous glucose monitoring].

This Guideline represents the recommendations of the Austrian Diabetes Association (ÖDG) on the use of diabetes technology (insulin pump therapy; continuous glucose monitoring, CGM; hybrid closed-loop systems, HCL; diabetes apps) and access to these technological innovations for people with diabetes mellitus based on current scientific evidence

Das digitale Ich. Zwischen Gemeinschaft und Abgrenzung - drei Fallstudien

Dieses E-Book enthält drei sozialwissenschaftliche Fallstudien, die Studierende der Hochschule der Medien Stuttgart im Wintersemester 2015/16 in einem Master-Kurs erstellt haben. Die Projekte behandelten neue Trends in der zunehmend digitalisierten Gesellschaft. Thematisch umfassen die drei Teilstudien das "Vertrauen in der Sharing Economy", die "digitale Diaspora" am Beispiel polnischstämmiger Migranten und die "Ethik der Privatheit"