The Influence of German-Speaking Émigrés on the Emergence of Cognitive Science as a New Interdisciplinary Field

During the 1950s, the scientific world experienced a shift in the study of the mind in what is now called the cognitive revolution. While common belief claims a rise of novel approaches, this is only partially true. A number of notions which built the foundation for cognitive studies were already present in the prior century in German schools. Research of developments of these traditions and concepts leading up to the cognitive revolution also showed that certain key figures in psychology and mathematics taught in Germany and by means of often forced emigration carried over the ideas that sparked in early German research centres. This article gives an overview of the development leading up to the cognitive revolution and the émigrés involved

Exclusive multipotency and preferential asymmetric divisions in post-embryonic neural stem cells of the fish retina.

The potency of post-embryonic stem cells can only be addressed in the living organism, by labeling single cells after embryonic development and following their descendants. Recently, transplantation experiments involving permanently labeled cells revealed multipotent neural stem cells (NSCs) of embryonic origin in the medaka retina. To analyze whether NSC potency is affected by developmental progression, as reported for the mammalian brain, we developed an inducible toolkit for clonal labeling and non-invasive fate tracking. We used this toolkit to address post-embryonic stem cells in different tissues and to functionally differentiate transient progenitor cells from permanent, bona fide stem cells in the retina. Using temporally controlled clonal induction, we showed that post-embryonic retinal NSCs are exclusively multipotent and give rise to the complete spectrum of cell types in the neural retina. Intriguingly, and in contrast to any other vertebrate stem cell system described so far, long-term analysis of clones indicates a preferential mode of asymmetric cell division. Moreover, following the behavior of clones before and after external stimuli, such as injuries, shows that NSCs in the retina maintained the preference for asymmetric cell division during regenerative responses. We present a comprehensive analysis of individual post-embryonic NSCs in their physiological environment and establish the teleost retina as an ideal model for studying adult stem cell biology at single cell resolution.This is the final version of the article. It has been published by The Company of Biologists Ltd in Development here: http://dev.biologists.org/content/early/2014/08/19/dev.109892.long

Repulsive cues combined with physical barriers and cell-cell adhesion determine progenitor cell positioning during organogenesis.

International audienceThe precise positioning of organ progenitor cells constitutes an essential, yet poorly understood step during organogenesis. Using primordial germ cells that participate in gonad formation, we present the developmental mechanisms maintaining a motile progenitor cell population at the site where the organ develops. Employing high-resolution live-cell microscopy, we find that repulsive cues coupled with physical barriers confine the cells to the correct bilateral positions. This analysis revealed that cell polarity changes on interaction with the physical barrier and that the establishment of compact clusters involves increased cell-cell interaction time. Using particle-based simulations, we demonstrate the role of reflecting barriers, from which cells turn away on contact, and the importance of proper cell-cell adhesion level for maintaining the tight cell clusters and their correct positioning at the target region. The combination of these developmental and cellular mechanisms prevents organ fusion, controls organ positioning and is thus critical for its proper function

Photovoltaische Energieversorgungsanlagen. Phase 3. Schlussbericht. T. 1 Berichtszeitraum 01.01.1987 bis 31.12.1990

The development-project Photovoltaik Energy Supply Systems, is the third phase of a development of low-cost-solargenerators based on crystalline silicon-solar cells. Based on the results obtained from phase II the installation of an experimental production line was completed. The development keypoints had been the optimization of the production processes and the transfer of laboratory results to production scale with the general goal of cost reduction of solar cell generators. With new additional production processes and optimizations of established processes an average efficiency of 12,5% has been reached. (orig./BWI)Das Vorhaben Photovoltaische Energieversorgungsanlagen stellt die dritte Phase der Entwicklung von kostenguenstigen Solargeneratoren auf der Basis kristalliner Siliciumzellen dar. Aufbauend auf den in der Phase II erreichten Zielen wurde die Solarzellen- und Modulversuchsfertigung fertiggestellt. Wesentliche Entwicklungsschwerpunkte waren dabei die Optimierung der Fertigungsprozesse sowie die Ueberfuehrung von Laborergebnissen in den Fertigungsmassstab mit dem generellen Ziel der Kostenreduktion von terrestrischen Solargeneratoren. Mit neu eingefuehrten Fertigungsschritten und den Optimierungsarbeiten an bestehenden Prozessen wird ein mittlerer Wirkungsgrad von 12,5% erreicht. (orig./BWI)SIGLEAvailable from TIB Hannover: F94B0133+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman

Prdm6 Is Essential for Cardiovascular Development In Vivo

Prdm6 Is Essential for Cardiovascular Development In Viv

Selective disruption of <i>Prdm6</i> in vascular smooth muscle cells results in perinatal lethality.

<p>(<b>A</b>) <i>Prdm6</i>^wt/del;SM22-Cre mice were crossed with <i>Prdm6</i>^flox/flox mice, and the genotypes of the offspring were analyzed at three weeks of age. The <i>Prdm6</i>^flox/del;SM22-Cre genotype leads to deletion of Prdm6 in the SMC lineage. The frequencies of the resulting genotypes were calculated from a total of 28 offspring animals and compared to the expected Mendelian frequencies. (<b>B</b>) Newborn mice from the same crosses as in (A) were observed at day 1 and day 2 after birth and subsequently were genotyped. (<b>C</b>) Lungs from newborn <i>Prdm6</i>^flox/del control animals (viable) and SMC-conditional <i>Prdm6</i>^flox/del;SM22-Cre animals (deceasing) were embedded in paraffin, and sections were stained with hematoxylin and eosin. Scale bars correspond to 100 µm.</p