Neuronal networks provide rapid neuroprotection against spreading toxicity

Acute secondary neuronal cell death, as seen in neurodegenerative disease, cerebral ischemia (stroke) and traumatic brain injury (TBI), drives spreading neurotoxicity into surrounding, undamaged, brain areas. This spreading toxicity occurs via two mechanisms, synaptic toxicity through hyperactivity, and excitotoxicity following the accumulation of extracellular glutamate. To date, there are no fast-acting therapeutic tools capable of terminating secondary spreading toxicity within a time frame relevant to the emergency treatment of stroke or TBI patients. Here, using hippocampal neurons (DIV 15-20) cultured in microfluidic devices in order to deliver a localized excitotoxic insult, we replicate secondary spreading toxicity and demonstrate that this process is driven by GluN2B receptors. In addition to the modeling of spreading toxicity, this approach has uncovered a previously unknown, fast acting, GluN2A-dependent neuroprotective signaling mechanism. This mechanism utilizes the innate capacity of surrounding neuronal networks to provide protection against both forms of spreading neuronal toxicity, synaptic hyperactivity and direct glutamate excitotoxicity. Importantly, network neuroprotection against spreading toxicity can be effectively stimulated after an excitotoxic insult has been delivered, and may identify a new therapeutic window to limit brain damage

Suppression of axionic charge density wave and onset of superconductivity in the chiral Weyl semimetal Ta₂Se₈I

A Weyl semimetal with strong electron-phonon interaction can show axionic coupling in its insulator state at low temperatures, owing to the formation of a charge density wave (CDW). Such a CDW emerges in the linear-chain-compound Weyl semimetal Ta2Se8I below 263 K, resulting in the appearance of the dynamical condensed-matter axion quasiparticle. In this paper, we demonstrate that the interchain coupling in Ta2Se8I can be varied to suppress the CDW formation with pressure, while retaining the Weyl semimetal phase at high temperatures. Above 17 GPa, the Weyl semimetal phase does not survive, and we induce superconductivity, due to the amorphization of the iodine sublattice. Structurally, the quasi-one-dimensional Ta-Se chains remain intact and provide a channel for superconductivity. We highlight that our results show a near-complete suppression of the gap induced by the axionic charge density wave at pressures inaccessible to previous studies. Including this CDW phase, our experiments and theoretical predictions and analysis reveal the complete phase diagram of Ta2Se8I and its relationship to the nearby superconducting state. The results demonstrate Ta2Se8I to be a distinctively versatile platform for exploring correlated topological states. © 2021 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Open access publication funded by the Max Planck Society

PENDAMPINGAN PEMBENTUKAN KESADARAN BELAJAR MELALUI SOSIALISASI PRIMER DAN SEKUNDER BAGI SISWA SEKOLAH DASAR DI DESA OENAK

Masalah terkait kesadaran belajar siswa dalam dunia pendidikan merupakan masalah yang sangat serius untuk diperhatikan. Selain minimnya fasilatas yang menjamin proses belajar, kesadaran belajar siswa sangat diperlukan sebagai landasan dasar untuk memperoleh dan mengasah pengetahuan baik dalam pendidikan formal maupun non formal. Masalah kesadaran belajar siswa ini terjadi karena minimnya sosialisasi primer dan sekunder yang ada dalam keluarga dan masyarakat sebagai bentuk kepedulian terhadap dunia pendidikan anak. Oleh karena itu, untuk mengatasi masalah kesadaran belajar siswa tersrebut, Mahasiswa KKN Universitas Katolik Widya Mandira Kupang melakukan observasi dan analisis terkait pendampingan belajar anak dalam keluarga dan program pendampingan belajar siswa secara personal dalam kelompok dengan metode face to face di Desa Oenak. Berdasarkan hasil observasi dan metode yang dilakukan oleh mahasiswa Universitas Katolik Widya Mandira Kupang, program pendampingan belajar bagi siswa Sekolah Dasar sangat efektif dalam pembentukan kesadaran belajar siswa sekolah dasar di desa Oenak. Tentunya pendampingan ini tidak terlepas dari kreatifitas mahasiwa dalam proses mengajar

Nonlinear coupled magnonics: Terahertz field-driven magnon upconversion

Tailored light excitation and nonlinear control of lattice vibrations have emerged as powerful strategies to manipulate the properties of quantum materials out of equilibrium. Generalizing the exploitation of coherent phonon-phonon interactions to nonlinear couplings among other types of collective modes would open unprecedented opportunities in the design of novel dynamic functionalities in solids. For example, the collective excitations of magnetic order - magnons - can efficiently transfer information via spin current flow, and their coherent and nonlinear control would provide an attractive route to achieve faster signal processing for next-generation information technologies. Here, we discover that intense terahertz (THz) fields can initiate processes of magnon upconversion via coherent magnon-magnon interactions - a phenomenon that opens the paradigm of nonlinear coupled magnonics. By using a suite of advanced spectroscopic tools, including a newly demonstrated two-dimensional (2D) THz polarimetry technique enabled by single-shot detection, we unveil the unidirectional nature of coupling between distinct magnon modes of a canted antiferromagnet. Calculations of spin dynamics further suggest that this coupling is a universal feature of antiferromagnets with canted magnetic moments. These results demonstrate a route to inducing desirable energy transfer pathways between coherent magnons in solids and pave the way for a new era in the development of magnonic signal processing devices

Engineering Anomalously Large Electron Transport in Topological Semimetals

Anomalous transport of topological semimetals has generated significant interest for applications in optoelectronics, nanoscale devices, and interconnects. Understanding the origin of novel transport is crucial to engineering the desired material properties, yet their orders of magnitude higher transport than single-particle mobilities remain unexplained. This work demonstrates the dramatic mobility enhancements result from phonons primarily returning momentum to electrons due to phonon-electron dominating over phonon-phonon scattering. Proving this idea, proposed by Peierls in 1932, requires tuning electron and phonon dispersions without changing symmetry, topology, or disorder. This is achieved by combining de Haas - van Alphen (dHvA), electron transport, Raman scattering, and first-principles calculations in the topological semimetals MX$_2$ (M=Nb, Ta and X=Ge, Si). Replacing Ge with Si brings the transport mobilities from an order magnitude larger than single particle ones to nearly balanced. This occurs without changing the crystal structure or topology and with small differences in disorder or Fermi surface. Simultaneously, Raman scattering and first-principles calculations establish phonon-electron dominated scattering only in the MGe$_2$ compounds. Thus, this study proves that phonon-drag is crucial to the transport properties of topological semimetals and provides insight to further engineer these materials.Comment: 12 pages, 5 figure

RBF-TSS: Identification of Transcription Start Site in Human Using Radial Basis Functions Network and Oligonucleotide Positional Frequencies

Accurate identification of promoter regions and transcription start sites (TSS) in genomic DNA allows for a more complete understanding of the structure of genes and gene regulation within a given genome. Many recently published methods have achieved high identification accuracy of TSS. However, models providing more accurate modeling of promoters and TSS are needed. A novel identification method for identifying transcription start sites that improves the accuracy of TSS recognition for recently published methods is proposed. This method incorporates a metric feature based on oligonucleotide positional frequencies, taking into account the nature of promoters. A radial basis function neural network for identifying transcription start sites (RBF-TSS) is proposed and employed as a classification algorithm. Using non-overlapping chunks (windows) of size 50 and 500 on the human genome, the proposed method achieves an area under the Receiver Operator Characteristic curve (auROC) of 94.75% and 95.08% respectively, providing increased performance over existing TSS prediction methods

Evaluation of the groundnut model PNUTGRO for crop response to water availability, sowing dates, and seasons

Field experiments were conducted during the 1987, 1991 and 1992 rainy seasons at Patancheru (latitude 17°32′N; longitude 78°16′E; elevation 545 m), Andhra Pradesh, India, to collect data to test and validate the hedgerow version of the groundnut model PNUTGRO for predicting phenological development, light interception, canopy growth, dry matter production, pod and seed yields of groundnut (Arachis hypogaea L.) as influenced by row spacing and plant population. The model was calibrated using the crop growth and phenology data of groundnut (cv. Robut 33-1) obtained from the 1987 and 1991 rainy season experiments. In these experiments groundnut was grown at plant populations ranging from 5 to 45 plants/m2 with and without irrigation. Changes were made in the cultivar-specific coefficients related to the light penetration into the crop canopy and dry matter production. The model was validated against independent data obtained from a 1992 rainy season experiment. In 1992, groundnut was grown at plant populations ranging from 10 to 40 plants/m2 and at row spacings of 20, 30 and 60 cm. The model predicted the occurrence of vegetative and reproductive stages, canopy development, total dry matter production and its partitioning to pods and seed accurately. Maximum leaf area index observed during the season was significantly correlated with simulated values (r2 = 0.95). In spite of some incidence of diseases and pests, the correlation between simulated and observed pod yield was significant (r2 = 0.61). It is concluded from this study that the hedgerow version of the groundnut model PNUTGRO can be used to quantify groundnut growth and yields as influenced by plant population and row spacing

Expiratory airflow in late adolescence and early adulthood in individuals born very preterm or with very low birthweight compared with controls born at term or with normal birthweight : a meta-analysis of individual participant data

Background Maximal expiratory airflow peaks early in the third decade of life, then gradually declines with age. The pattern of airflow through adulthood for individuals born very preterm (at 2499 g) or at term. Methods We did a meta-analysis of individual participant data from cohort studies, mostly from the pre-surfactant era. Studies were identified through the Adults born Preterm International Collaboration and by searching PubMed and Embase (search date May 25, 2016). Studies were eligible if they reported on expiratory flow rates beyond 16 years of age in individuals born very preterm or with very low birthweight, as well as controls born at term or with normal birthweight. Studies with highly selected cohorts (eg, only participants with bronchopulmonary dysplasia) or in which few participants were born very preterm or with very low birthweight were excluded. De-identified individual participant data from each cohort were provided by the holders of the original data to a central site, where all the data were pooled into one data file. Any data inconsistencies were resolved by discussion with the individual sites concerned. Individual participant data on expiratory flow variables (FEV1, forced vital capacity [FVC], FEV1/FVC ratio, and forced expiratory flow at 25-75% of FVC [FEF25-75%]) were converted to Z scores and analysed with use of generalised linear mixed models in a one-step approach. Findings Of the 381 studies identified, 11 studies, comprising a total of 935 participants born very preterm or with very low birthweight and 722 controls, were eligible and included in the analysis. Mean age at testing was 21 years (SD 3.4; range 16-33). Mean Z scores were close to zero (as expected) in the control group, but were reduced in the very preterm or very low birthweight group for FEV1 (-0.06 [SD 1.03] vs -0.81 [1.33], mean difference -0.78 [95% CI -0.96 to -0.61], p Interpretation Individuals born very preterm or with very low birthweight are at risk of not reaching their full airway growth potential in adolescence and early adulthood, suggesting an increased risk of chronic obstructive pulmonary disease in later adulthood. Copyright (C) 2019 Elsevier Ltd. All rights reserved.Peer reviewe

Hunt for complex cyanides in protostellar ices with JWST: Tentative detection of CH3_3CN and C2_2H5_5CN

Nitrogen-bearing complex organic molecules have been commonly detected in the gas phase but not yet in interstellar ices. This has led to the long-standing question of whether these molecules form in the gas phase or in ices. $\textit{James Webb}$ Space Telescope ($\textit{JWST}$) offers the sensitivity, spectral resolution, and wavelength coverage needed to detect them in ices and investigate whether their abundance ratios are similar in gas and ice. We report the first tentative detection of CH$_3$CN, C$_2$H$_5$CN, and the simple molecule, N$_2$O, based on the CN-stretch band in interstellar ices toward three (HOPS 153, HOPS 370, and IRAS 20126+4104) out of the five protostellar systems observed as part of the Investigating Protostellar Accretion (IPA) GO program with $\textit{JWST}$-NIRSpec. We also provide upper limits for the two other sources with smaller luminosities in the sample. We detect OCN$^-$ in the ices of all sources with typical CH$_3$CN/OCN$^-$ ratios of around 1. Ice and gas column density ratios of the nitrogen-bearing species with respect to each other are better matched than those with respect to methanol, which are a factor of ${\sim}5$ larger in the ices than the gas. We attribute the elevated ice column densities with respect to methanol to the difference in snowline locations of nitrogen-bearing molecules and of methanol, biasing the gas-phase observations toward fewer nitrogen-bearing molecules. Moreover, we find tentative evidence for enhancement of OCN$^-$, CH$_3$CN, and C$_2$H$_5$CN in warmer ices, although formation of these molecules likely starts along with methanol in the cold prestellar phase. Future surveys combining NIRSpec and MIRI, and additional laboratory spectroscopic measurements of C$_2$H$_5$CN ice, are necessary for robust detection and conclusions on the formation history of complex cyanides.Comment: Accepted for publication in A&