Smad4 and Trim33/Tif1γ Redundantly Regulate Neural Stem Cells in the Developing Cortex

During central nervous system (CNS) development, proliferation and differentiation of neural stem cells (NSCs) have to be regulated in a spatio-temporal fashion. Here, we report different branches of the transforming growth factor β (TGFβ) signaling pathway to be required for the brain area-specific control of NSCs. In the midbrain, canonical TGFβ signaling via Smad4 regulates the balance between proliferation and differentiation of NSCs. Accordingly, Smad4 deletion resulted in horizontal expansion of NSCs due to increased proliferation, decreased differentiation, and decreased cell cycle exit. In the developing cortex, however, ablation of Smad4 alone did not have any effect on proliferation and differentiation of NSCs. In contrast, concomitant mutation of both Smad4 and Trim33 led to an increase in proliferative cells in the ventricular zone due to decreased cell cycle exit, revealing a functional redundancy of Smad4 and Trim33. Furthermore, in Smad4-Trim33 double mutant embryos, cortical NSCs generated an excess of deep layer neurons concurrent with a delayed and reduced production of upper layer neurons and, in addition, failed to undergo the neurogenic to gliogenic switch at the right developmental stage. Thus, our data disclose that in different regions of the developing CNS different aspects of the TGFβ signaling pathway are required to ensure proper developmen

Infrared absorption of porous silicon layers and silicon particle films

Using TaC filaments for a hot-wire chemical vapor deposition (HWCVD) compact material (substrate temperatures 220°C) and porous, non-compact or void-rich layers (120°C) were produced in a silane-hydrogen atmosphere in the pressure range from 1 Pa to 30 Pa. For high pressures the adhesion of the layers was weak. In this case the thus pulverized silicon particles could be removed from the substrate by an ultrasonic process in an isopropanol bath. The suspension of these silicon particles was spread to form a continuous film, namely a "particle-film". The infrared (IR) spectra of the compact solid, the original porous layers and a series of temper stages of the particle-films are compared and discussed. The role of H and O atoms in the silicon network is investigated. Thus those structural properties, which may be found out by infrared tools, e.g. the bonding configurations of the Si related bonds of the said materials and some possible chemical reactions are explained

Visual short‐term memory‐related EEG components in a virtual reality setup

Virtual reality (VR) offers a powerful tool for investigating cognitive processes, as it allows researchers to gauge behaviors and mental states in complex, yet highly controlled, scenarios. The use of VR head-mounted displays in combination with physiological measures such as EEG presents new challenges and raises the question whether established findings also generalize to a VR setup. Here, we used a VR headset to assess the spatial constraints underlying two well-established EEG correlates of visual short-term memory: the amplitude of the contralateral delay activity (CDA) and the lateralization of induced alpha power during memory retention. We tested observers' visual memory in a change detection task with bilateral stimulus arrays of either two or four items while varying the horizontal eccentricity of the memory arrays (4, 9, or 14 degrees of visual angle). The CDA amplitude differed between high and low memory load at the two smaller eccentricities, but not at the largest eccentricity. Neither memory load nor eccentricity significantly influenced the observed alpha lateralization. We further fitted time-resolved spatial filters to decode memory load from the event-related potential as well as from its time-frequency decomposition. Classification performance during the retention interval was above-chance level for both approaches and did not vary significantly across eccentricities. We conclude that commercial VR hardware can be utilized to study the CDA and lateralized alpha power, and we provide caveats for future studies targeting these EEG markers of visual memory in a VR setup.Bundesministerium für Bildung und Forschung http://dx.doi.org/10.13039/501100002347Cooperation between the Max Planck Society and the Fraunhofer GesellschaftDeutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659Peer Reviewe

Role of Eddies in the Carbon Pump of Eastern Boundary Upwelling Systems, REEBUS, Cruise No. M156, 03.07. – 01.08.2019 Mindelo (Cap Verde) – Mindelo

Summary The major goal of the RV METEOR cruise M156 to Cape Verdian waters and the Mauritanian upwelling area off West Africa was to contribute to a better quantitative understanding of the effects of mesoscale eddies on CO2 source/sink mechanisms and the biological carbon pump in eastern boundary upwelling areas as well as their effects to the oligotrophic periphery including the deep-sea floor. The cruise M156 (MOSES Eddy Study I) was conducted within the framework of the BMBF funded REEBUS project (Role of Eddies in the Carbon Pump of Eastern Boundary Upwelling Systems) by a consortium of physical, biological (benthic microbiology, bacterial plankton, protists) and biogeochemical oceanographers. Specific aims were i. the quantification of solute and particle fluxes within and at the periphery of eddies; ii. to determine the turnover of carbon species, air-sea gas exchange of CO2, iii. the determination of the protistan and bacterial plankton community structures in the surface layers of an eddy, and iv. to quantify the magnitude and variability of material fluxes to the seabed and turnover in the sediment underneath the eddy passage. To achieve these aims, the cruise had two major observing strategies: i. an intense benthic/pelagic program along the zonal eddy passage at 18°N. Along this corridor ranging from 24°20’ to 16°30’W, five benthic/pelagic stations (E1 to E5) in different water depths and distances from the Mauritanian coast were performed. The motivation for this survey has been to resolve zonal gradients in pelagic element cycling as well as of organic matter degradation and burial in the seabed, which in turn could potentially be linked with changes in eddy induced primary- and export production. ii. the detailed investigation of an individual eddy to investigate physical, biogeochemical and biological processes on meso- to submeso-scales (100km to 10m). Satellite data analysis was performed before and during the cruise to identify a suitable eddy from a combination of sea-level anomaly, ocean color as Chl-a proxy, and sea-surface temperature supplemented with shipboard current velocity measurements. A total of 171 stations were sampled. The water column program consists of 59 CTD casts, 29 MSS and 20 Marine Snow Catcher deployments. For biogeochemical measurements at the sea surface two deployments of a Lagrangian Surface Drifter and one Waveglider deployment were conducted. At the seafloor, we conducted 10 BIGO deployments. Ten seafloor imaging surveys were performed using the towed camera system OFOS, supplemented with 7 Multibeam and 1 Sidescan surveys. In deviation from the cruise proposal, the planned long-term deployment of a Lander, which was planned to record a time series of oxygen fluxes during the passage of an eddy, was not deployed due to a major delay in its design and manufacturing. The planned AUV (Girona 500) deployments at the shallow E5 station close to the Mauritanian coast station did also not take place. Despite moderate weather conditions, all deployments were successful, hence all the data and sample material aimed for has been achieved. It is to expect that as planned all scientific questions can be addressed. Especially in the synthesis of all REEBUS cruises and the consideration of data from earlier cruises (MSM17/4, M107) into this region a high scientific potential can be expected

Pallimängude organisatsioon Eestis

Uuringuaruanne Eesti Vabariigi KultuuriministeeriumileSportmängude organisatsiooni tegevuse efektiivsust käsitletakse käesoleva uurimuse raames eraldi. Seda mitte sellepärast, et sportmängude alaliitude ja klubide tegevus oleks kardinaalselt erinev nn individuaalspordialade organisatsioonide tegevusest. Peamine põhjus, lähtudes meie uurimuse kesksest paradigmast, ressursside teooriast, on seotud tõdemusega, et sportmängude rahvusvahelise konkurentsivõime saavutamiseks on vaja rohkem ressursse. Organisatsioonilistest ressurssidest on lisaks individuaalspordialade alaliitude efektiivse tegevuse ressurssidele vajalikud mitmed sellised ressursid, mida individuaalalade edukuse saavutamiseks vaja ei ole.http://www.spordiinfo.ee/est/g22s17