No Evidence for “Break-Induced Replication” in a Higher Plant – But Break-Induced Conversion May Occur

“Break-induced replication” (BIR) is considered as one way to repair DNA double-strand breaks (DSBs). BIR is defined as replication of the proximal break-ends up to the end of the broken chromosome using an undamaged (homologous) double-stranded template and mimicking a non-reciprocal translocation. This phenomenon was detected by genetic experiments in yeast. BIR is assumed to occur also in mammals, but experimental evidence is not yet at hand. We have studied chromosomes of the field bean, Vicia faba L., with respect to the occurrence of BIR after DSB induction during S and G2 phase. Simultaneous incorporation of the base analog ethynyldeoxyuridine (EdU) revealed no chromosomal replication pattern indicative of BIR. Thus, if occurring at all, BIR does not play a major role in DSB repair in higher plants with large chromosome arms. However, the frequency of interstitial asymmetric EdU incorporation within heterochromatic regions, visible on metaphase chromosomes, increased after chromosome breakage during S and G2 phase. Such asymmetric labeling could be interpreted as conservative replication up to the next replicon, circumventing a DSB, and yielding an interstitial conversion-like event

Visual-Inertial Mapping with Non-Linear Factor Recovery

Cameras and inertial measurement units are complementary sensors for ego-motion estimation and environment mapping. Their combination makes visual-inertial odometry (VIO) systems more accurate and robust. For globally consistent mapping, however, combining visual and inertial information is not straightforward. To estimate the motion and geometry with a set of images large baselines are required. Because of that, most systems operate on keyframes that have large time intervals between each other. Inertial data on the other hand quickly degrades with the duration of the intervals and after several seconds of integration, it typically contains only little useful information. In this paper, we propose to extract relevant information for visual-inertial mapping from visual-inertial odometry using non-linear factor recovery. We reconstruct a set of non-linear factors that make an optimal approximation of the information on the trajectory accumulated by VIO. To obtain a globally consistent map we combine these factors with loop-closing constraints using bundle adjustment. The VIO factors make the roll and pitch angles of the global map observable, and improve the robustness and the accuracy of the mapping. In experiments on a public benchmark, we demonstrate superior performance of our method over the state-of-the-art approaches

Influence of Carrier Gas Composition on the Stress of Al2O3 Coatings Prepared by the Aerosol Deposition Method

Al2O3 films were prepared by the aerosol deposition method at room temperature using different carrier gas compositions. The layers were deposited on alumina substrates and the film stress of the layer was calculated by measuring the deformation of the substrate. It was shown that the film stress can be halved by using oxygen instead of nitrogen or helium as the carrier gas. The substrates were annealed at different temperature steps to gain information about the temperature dependence of the reduction of the implemented stress. Total relaxation of the stress can already be achieved at 300 °C. The XRD pattern shows crystallite growth and reduction of microstrain while annealing

Organizing R&D Consortia for Path Creation and Extension: The Case of Semiconductor Manufacturing Technologies

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Taking issue with the classical theory of path dependence, we capture the active agency involved in collective efforts aimed at extending a current technological path and, in parallel, at creating a new path in the field of leading-edge international semiconductor manufacturing. We apply structuration theory in order to analyse the practices of path constitution that traditional evolutionary views of lock-in and irreversibility in path processes have neglected. Drawing on 96 interviews since 2003 and extensive secondary sources in the field of semiconductor manufacturing in Europe, Japan and the United States, we perform a qualitative, longitudinal and multi-level case analysis; in this analysis we trace, in particular, the strategic development of a path-extending technological option besides a potentially path-breaking new generation of lithography for chip manufacturing systems. Our results provide deep insights into the collective and collaborative dimension of organizing R&D in processes of technology development. Thereby, we contribute to a theory of technological paths that considers collective embedded agency and takes into account interorganizational forms for an understanding of the innovation dynamics in science-based industries such as semiconductor manufacturing

The Case of Semiconductor Manufacturing Technologies

Taking issue with the classical theory of path dependence, we capture the active agency involved in collective efforts aimed at extending a current technological path and, in parallel, at creating a new path in the field of leading-edge international semiconductor manufacturing. We apply structuration theory in order to analyse the practices of path constitution that traditional evolutionary views of lock-in and irreversibility in path processes have neglected. Drawing on 96 interviews since 2003 and extensive secondary sources in the field of semiconductor manufacturing in Europe, Japan and the United States, we perform a qualitative, longitudinal and multi-level case analysis; in this analysis we trace, in particular, the strategic development of a path- extending technological option besides a potentially path-breaking new generation of lithography for chip manufacturing systems. Our results provide deep insights into the collective and collaborative dimension of organizing R&D; in processes of technology development. Thereby, we contribute to a theory of technological paths that considers collective embedded agency and takes into account interorganizational forms for an understanding of the innovation dynamics in science-based industries such as semiconductor manufacturing

Towards Feature-based Product Line Engineering of Technical Systems

AbstractThe development of today's technical products (e.g., in automation) is characterized by high customer expectations regarding the product individualization, which causes a wide range of product variants. Original equipment manufacturers (OEMs) can apply classical approaches from product line engineering, like feature modeling, to cope with the variability and the induced develop- ment complexity. Our tool support for feature models integrates a variety of feature model extensions like feature attributes and properties, logical constraints between features and feature properties, and the distinction between features and feature realiza- tions. Beyond that, technical products have geometrical dimensions. The OEM specifies Computer Aided Design (CAD) models to consider these geometrical dimensions and to virtually layout particular product variants. Geometrical assembly constraints specify how parts of the product can be arranged in a CAD model. However, a potential product customer cannot configure an individual product variant and virtually layout this variant in the same software tool since the respective information stems from different sources. In order to cope with this problem, we present in this paper an extension of our tool support for feature models to specify geometrical assembly constraints. Based on the proposed extension, we outline our research roadmap to consider these constraints in an online shop of an e-commerce system, in which a potential customer shall be able to configure a product variant and to virtually layout it according to the assembly constraints

Serological testing of cattle experimentally infected with Mycoplasma mycoides subsp. mycoides Small Colony using four different tests reveals a variety of seroconversion patterns

<p>Abstract</p> <p>Background</p> <p>To study the specific antibody response to infection with <it>Mycoplasma mycoides </it>subsp. <it>mycoides </it>Small Colony (<it>Mmm</it>SC), the agent of Contagious Bovine Pleuropneumonia (CBPP), we examined three panels of sera collected during three experimental infection trials in African cattle. The methods used included an in-house complement fixation test (CFT), a commercially available CFT, a competitive antibody ELISA (cELISA) and the immunoblotting test (IBT). In addition, lung tissue samples were examined by culture.</p> <p>Results</p> <p>A total of 89% (51/59) of all experimentally infected animals tested positive on at least one of the serological tests throughout the trial. The specific antibody titres to the <it>Mmm</it>SC infection became positive first by CFT (6 to 9 days post infection [dpi]), followed by IBT (9 to 13 dpi) and cELISA (13 to 16 dpi). Individual animals were found to display remarkably distinct seroconversion patterns, which allowed their classification into i) early high responders, ii) late high responders, and iii) low responders. In accordance with other studies, none of the present serological tests was capable of detecting all CBPP infected animals.</p> <p>Conclusion</p> <p>Comparison of the assays' performance in terms of sensitivity and specificity raises serious questions as to their reliability for identification of infected individuals in the field. In view of these limitations, a combination of CFT and cELISA can markedly improve CBPP diagnosis at single-animal level.</p

Influence of Oxygen Partial Pressure during Processing on the Thermoelectric Properties of Aerosol-Deposited CuFeO2

In the field of thermoelectric energy conversion, oxide materials show promising potential due to their good stability in oxidizing environments. Hence, the influence of oxygen partial pressure during synthesis on the thermoelectric properties of Cu-Delafossites at high temperatures was investigated in this study. For these purposes, CuFeO2 powders were synthetized using a conventional mixed-oxide technique. X-ray diffraction (XRD) studies were conducted to determine the crystal structures of the delafossites associated with the oxygen content during the synthesis. Out of these powders, films with a thickness of about 25 µm were prepared by the relatively new aerosol-deposition (AD) coating technique. It is based on a room temperature impact consolidation process (RTIC) to deposit dense solid films of ceramic materials on various substrates without using a high-temperature step during the coating process. On these dense CuFeO2 films deposited on alumina substrates with electrode structures, the Seebeck coefficient and the electrical conductivity were measured as a function of temperature and oxygen partial pressure. We compared the thermoelectric properties of both standard processed and aerosol deposited CuFeO2 up to 900 °C and investigated the influence of oxygen partial pressure on the electrical conductivity, on the Seebeck coefficient and on the high temperature stability of CuFeO2. These studies may not only help to improve the thermoelectric material in the high-temperature case, but may also serve as an initial basis to establish a defect chemical model