Dynamical synapses in the retina

National audienc

Genome scale model reconstruction of the methylotrophic yeast Ogataea polymorpha

Ogataea polymorpha is a thermotolerant, methylotrophic yeast with significant industrial applications. It is a promising host to generate platform chemicals from methanol, derived e.g. from carbon capture and utilization streams. Full development of the organism into a production strain requires additional strain design, supported by metabolic modeling on the basis of a genome-scale metabolic model. However, to date, no genome-scale metabolic model is available for O. polymorpha. To overcome this limitation, we used a published reconstruction of the closely related yeast Pichia pastoris as reference and corrected reactions based on KEGG annotations. Additionally, we conducted phenotype microarray experiments to test O. polymorpha’s metabolic capabilities to grown on or respire 192 different carbon sources. Over three-quarter of the substrate usage was correctly reproduced by the model. However, O. polymorpha failed to metabolize eight substrates and gained 38 new substrates compared to the P. pastoris reference model. To enable the usage of these compounds, metabolic pathways were inferred from literature and database searches and potential enzymes and genes assigned by conducting BLAST searches. To facilitate strain engineering and identify beneficial mutants, gene-protein-reaction relationships need to be included in the model. Again, we used the P. pastoris model as reference to extend the O. polymorpha model with this relevant information. The final metabolic model of O. polymorpha supports the engineering of synthetic metabolic capabilities and enabling the optimization of production processes, thereby supporting a sustainable future methanol econom

The Role of Dynamical Synapses in Retinal Surprise Coding

International audience• Stimulation of a dissected retina with a sequence of periodic dark flashes. • Extracellular spike recordings. 2. Identification of necessary components via pharmacological inhibition of synaptic transmission onto : • ON bipolar cells via mGluR6 receptor antagonist LAP-4. • OFF bipolar cells via AMPA receptor antagonist ACET. Results ON BC inhibition cancels the OSR

Dynamical Synapses in Retinal Surprise coding

International audience• Stimulation a dissected retina with a sequence of periodic dark flashes • Extracellular spike recordings. 2. Identification of necessary components via pharmacological inhibition of synaptic transmission onto : • ON bipolar cells via mGluR6 receptor antagonist LAP-4. • OFF bipolar cells via AMPA receptor antagonist ACET. Results ON BC inhibition cancels the OSR

Temporal pattern recognition in retinal ganglion cells is mediated by dynamical inhibitory synapses

A fundamental task for the brain is to generate predictions of future sensory inputs, and signal errors in these predictions. Many neurons have been shown to signal omitted stimuli during periodic stimulation, even in the retina. However, the mechanisms of this error signaling are unclear. Here we show that depressing inhibitory synapses enable the retina to signal an omitted stimulus in a flash sequence. While ganglion cells, the retinal output, responded to an omitted flash with a constant latency over many frequencies of the flash sequence, we found that this was not the case once inhibition was blocked. We built a simple circuit model and showed that depressing inhibitory synapses were a necessary component to reproduce our experimental findings. We also generated new predictions with this model, that we confirmed experimentally. Depressing inhibitory synapses could thus be a key component to generate the predictive responses observed in many brain areas

Asymptotic safety of gravity and the Higgs boson mass

There are indications that gravity is asymptotically safe. The Standard Model (SM) plus gravity could be valid up to arbitrarily high energies. Supposing that this is indeed the case and assuming that there are no intermediate energy scales between the Fermi and Planck scales we address the question of whether the mass of the Higgs boson $m_H$ can be predicted. For a positive gravity induced anomalous dimension $A_\lambda>0$ the running of the quartic scalar self interaction $\lambda$ at scales beyond the Planck mass is determined by a fixed point at zero. This results in $m_H=m_{\rm min}=126$ GeV, with only a few GeV uncertainty. This prediction is independent of the details of the short distance running and holds for a wide class of extensions of the SM as well. For $A_\lambda <0$ one finds $m_H$ in the interval $m_{\rm min}< m_H < m_{\rm max}\simeq 174$ GeV, now sensitive to $A_\lambda$ and other properties of the short distance running. The case $A_\lambda>0$ is favored by explicit computations existing in the literature.Comment: 8 pages, typos corrected, references added. Journal versio

myomiR-dependent switching of BAF60 variant incorporation into Brg1 chromatin remodeling complexes during embryo myogenesis

Myogenesis involves the stable commitment of progenitor cells followed by the execution of myogenic differentiation, processes that are coordinated by myogenic regulatory factors, microRNAs and BAF chromatin remodeling complexes. BAF60a, BAF60b and BAF60c are structural subunits of the BAF complex that bind to the core ATPase Brg1 to provide functional specificity. BAF60c is essential for myogenesis; however, the mechanisms regulating the subunit composition of BAF/Brg1 complexes, in particular the incorporation of different BAF60 variants, are not understood. Here we reveal their dynamic expression during embryo myogenesis and uncover the concerted negative regulation of BAF60a and BAF60b by the muscle-specific microRNAs (myomiRs) miR-133 and miR-1/206 during somite differentiation. MicroRNA inhibition in chick embryos leads to increased BAF60a or BAF60b levels, a concomitant switch in BAF/Brg1 subunit composition and delayed myogenesis. The phenotypes are mimicked by sustained BAF60a or BAF60b expression and are rescued by morpholino knockdown of BAF60a or BAF60b. This suggests that myomiRs contribute to select BAF60c for incorporation into the Brg1 complex by specifically targeting the alternative variants BAF60a and BAF60b during embryo myogenesis, and reveals that interactions between tissue-specific non-coding RNAs and chromatin remodeling factors confer robustness to mesodermal lineage determination

Разработка информационной системы учета и анализа проектной деятельности студента

В статье показан процесс проектирования информационной системы учета и анализа проектной деятельности студента. Проектная деятельность является на сегодняшний день актуальным методом ведения учебной деятельности, который активно внедряется в университеты, в том числе и в ТПУ

Home and preschool learning environments and their relations to the development of early numeracy skills

This study examined the influence of the quality of home and preschool learning environments on the development of early numeracy skills in Germany, drawing on a sample of 532 children in 97 preschools. Latent growth curve models were used to investigate early numeracy skills and their development from the first (average age: 3 years) to the third year (average age: 5 years) of preschool. Several child and family background factors (e.g., gender, maternal education, socioeconomic status), measures of the home learning environment (e.g., literacy- and numeracy-related activities), and measures of preschool structural and process quality (e.g., ECERS-E, ECERS-R) were tested as predictors of numeracy skills and their development. The analyses identified child and family background factors that predicted numeracy skills in the first year of preschool and their development over the three points of measurement — particularly gender, parental native language status (German/other), socioeconomic status, and mother’s educational level. The quality of the home learning environment was strongly associated with numeracy skills in the first year of preschool, and this advantage was maintained at later ages. In contrast, the process quality of the preschool was not related to numeracy skills at the first measurement, but was significantly related to development over the period observed. The results underline the differential impact of the two learning environments on the development of numeracy skills. Interaction effects are explored and discussed

Introducing HCI in Corporate IT Department in a Large Company in Brazil

Abstract. This paper describes the introduction of human-computer interaction activities in the Corporate IT Department in a large energy company in Brazil. It is certified by ISO 9001:2000, and thus has a set of norms that IT employees must follow during the software development process. We discuss the introduction of HCI activities into these norms