79 research outputs found

    Performance Analysis of Piezoelectric Energy Harvesting System.

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    [EN] This paper analyzes a piezoelectric system made of a smart lead zirconate material. The system is composed of a monolithic PZT (piezoelectric ceramic) plate made of a ceramic-based piezoelectric material. The experiment was conducted on a test stand with a GUNT HM170 wind tunnel and a special measurement system. The developed bluff-body shape mounted on an elastic beam with a piezoelectric was mounted on a mast with arms. Springs were fixed on the arms to limit the movement of the test object. Air flow velocity in the wind tunnel and forced vibration frequencies were changed during the tests. The recorded parameters were an output voltage signal from the piezoelectric element and linear accelerations at selected points of the test object. The highest energy efficiency of the tested system was specified from mechanical vibrations and air flow. The results of the tests are a resonance curve for the tested system and a correlation of RMS voltage and acceleration as a function of the velocity of air flow for the excitation frequency f ranging from 1 to 6 Hz. The tests specified the area where the highest output voltage under the given excitation conditions is generated.Publication was supported by the program of the Polish Ministry of Science and Higher Education under the project DIALOG 0019/DLG/2019/10 in the years 2019¿2021.Ambrozkiewicz, B.; Czyz, Z.; Staczek, P.; Tiseira, A.; Garcia Tiscar, J. (2022). Performance Analysis of Piezoelectric Energy Harvesting System. Advances in Science and Technology Research Journal. 16:179-185. https://doi.org/10.12913/22998624/1562151791851

    Srsf1 and Elavl1 act antagonistically on neuronal fate choice in the developing neocortex by controlling TrkC receptor isoform expression

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    The seat of higher-order cognitive abilities in mammals, the neocortex, is a complex structure, organized in several layers. The different subtypes of principal neurons are distributed in precise ratios and at specific positions in these layers and are generated by the same neural progenitor cells (NPCs), steered by a spatially and temporally specified combination of molecular cues that are incompletely understood. Recently, we discovered that an alternatively spliced isoform of the TrkC receptor lacking the kinase domain, TrkC-T1, is a determinant of the corticofugal projection neuron (CFuPN) fate. Here, we show that the finely tuned balance between TrkC-T1 and the better known, kinase domain-containing isoform, TrkC-TK+, is cell type-specific in the developing cortex and established through the antagonistic actions of two RNA-binding proteins, Srsf1 and Elavl1. Moreover, our data show that Srsf1 promotes the CFuPN fate and Elavl1 promotes the callosal projection neuron (CPN) fate in vivo via regulating the distinct ratios of TrkC-T1 to TrkC-TK+. Taken together, we connect spatio-temporal expression of Srsf1 and Elavl1 in the developing neocortex with the regulation of TrkC alternative splicing and transcript stability and neuronal fate choice, thus adding to the mechanistic and functional understanding of alternative splicing in vivo

    Ire1α-Regulated Rate of mRNA Translation is Required for Acquisition of Identity and Polarity in Upper Layer Cortical Neurons

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    Evolutionary expansion of the neocortex is associated with the increase in upper layer neurons. Here, we present Inositol-Requiring Enzyme 1α, Ire1α, as an essential determinant of upper layer fate, neuronal polarization and cortical lamination. We demonstrate a non-canonical function of Ire1α in the regulation of global translation rates in the developing neocortex through its dynamic interaction with the ribosome and regulation of eIF4A1 and eEF-2 expression. Inactivation of Ire1α engenders lower protein synthesis rates associated with stalled ribosomes and decreased number of translation start sites. We show unique sensitivity of upper layer fate to translation rates. Whereas eEF-2 is required for cortical lamination, eIF4A1 regulates acquisition of upper layer fate downstream of Ire1α in a mechanism of translational control dependent on 5’UTR-embedded structural elements in fate determinant genes. Our data unveil developmental regulation of ribosome dynamics as post-transcriptional mechanisms orchestrating neuronal diversity establishment and assembly of cortical layers

    Optimizing Nervous System-Specific Gene Targeting with Cre Driver Lines: Prevalence of Germline Recombination and Influencing Factors.

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    The Cre-loxP system is invaluable for spatial and temporal control of gene knockout, knockin, and reporter expression in the mouse nervous system. However, we report varying probabilities of unexpected germline recombination in distinct Cre driver lines designed for nervous system-specific recombination. Selective maternal or paternal germline recombination is showcased with sample Cre lines. Collated data reveal germline recombination in over half of 64 commonly used Cre driver lines, in most cases with a parental sex bias related to Cre expression in sperm or oocytes. Slight differences among Cre driver lines utilizing common transcriptional control elements affect germline recombination rates. Specific target loci demonstrated differential recombination; thus, reporters are not reliable proxies for another locus of interest. Similar principles apply to other recombinase systems and other genetically targeted organisms. We hereby draw attention to the prevalence of germline recombination and provide guidelines to inform future research for the neuroscience and broader molecular genetics communities

    The architecture of protein synthesis in the developing neocortex at near-atomic resolution reveals Ebp1-mediated neuronal proteostasis at the 60S tunnel exit

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    Protein synthesis must be finely tuned in the nervous system, as it represents an essential feature of neurodevelopmental gene expression, and dominant pathology in neurological disease. However, the architecture of ribosomal complexes in the developing mammalian brain has not been analyzed at high resolution. This study investigates the architecture of ribosomes ex vivo from the embryonic and perinatal mouse neocortex, revealing Ebp1 as a 60S peptide tunnel exit binding factor at near-atomic resolution by multiparticle cryo-electron microscopy. The impact of Ebp1 on the neuronal proteome was analyzed by pSILAC and BONCAT coupled mass spectrometry, implicating Ebp1 in neurite outgrowth proteostasis, with in vivo embryonic Ebp1 knockdown resulting in dysregulation of neurite outgrowth. Our findings reveal Ebp1 as a central component of neocortical protein synthesis, and the 60S peptide tunnel exit as a focal point of gene expression control in the molecular specification of neuronal morphology

    Adhesion dynamics in the neocortex determine the start of migration and the post-migratory orientation of neurons.

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    peer reviewedThe neocortex is stereotypically organized into layers of excitatory neurons arranged in a precise parallel orientation. Here we show that dynamic adhesion both preceding and following radial migration is essential for this organization. Neuronal adhesion is regulated by the Mowat-Wilson syndrome-associated transcription factor Zeb2 (Sip1/Zfhx1b) through direct repression of independent adhesion pathways controlled by Neuropilin-1 (Nrp1) and Cadherin-6 (Cdh6). We reveal that to initiate radial migration, neurons must first suppress adhesion to the extracellular matrix. Zeb2 regulates the multipolar stage by transcriptional repression of Nrp1 and thereby downstream inhibition of integrin signaling. Upon completion of migration, neurons undergo an orientation process that is independent of migration. The parallel organization of neurons within the neocortex is controlled by Cdh6 through atypical regulation of integrin signaling via its RGD motif. Our data shed light on the mechanisms that regulate initiation of radial migration and the postmigratory orientation of neurons during neocortical development

    Timed global reorganization of protein synthesis during neocortex neurogenesis at codon resolution

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    Translation modulates the timing and amplification of gene expression after transcription. Development of the brain’s neocortex requires precisely timed and spatially targeted gene expression, but the relationship between mRNA vs. protein synthesis throughout the genome is unknown. We perform a comprehensive analysis of the reactants, synthesis, and products of mRNA translation spanning mouse neocortex neurogenesis. Ribosome number in the cortical plate decreases sharply at mid-neurogenesis during a transition in neuronal subtype specification, shifting the fundamental kinetics of protein synthesis, with mRNA and protein levels frequently divergent. Satb2, which drives an essential neuronal subtype-specific program, is a highly dynamically translated mRNA with surprisingly broad transcription across diverse neuronal lineages. Satb2 protein achieves its neuronal subtype expression through timed regulation by the RNA-binding protein Pumilio2. Thus, the refinement of transcriptional programs by protein synthesis is a widespread feature of neuronal specification. Developmental neocortex translatome data are provided in an open-source resource: https://shiny.mdc-berlin.de/cortexomics/
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