Epileptiform discharge upregulates p-ERK1/2, growth-associated protein 43 and synaptophysin in cultured rat hippocampal neurons

AbstractExtracellular signal-regulated protein kinase, ERK1/2 is activated by phosphorylation (p-ERK1/2) during environmental stress such as epileptiform discharge. We investigated the role of ERK1/2 in abnormal axon growth and synapse reorganization in cultured neurons displaying epileptiform activity.The cultured neurons displaying epileptiform activity were treated with magnesium-free extracellular fluid for 3h and monitored epileptiform discharges using whole-cell patch clamp. Two study groups, neurons displaying epileptiform activity and the same neurons treated with ERK1/2 inhibitor U0126, were studied at six time points, 0min, 30min, 2h, 6h, 12h, and 24h following discharge. The expressions of p-ERK1/2, C-fos, growth-associated protein 43 (GAP-43) and synaptophysin (SYP), as markers of axon growth and synapse reorganization, were investigated by double-label immunofluorescence and western blotting.In the neurons displaying epileptiform activity, p-ERK1/2 was detected immediately following discharge, and expression peaked at 30min. The expression of C-fos, GAP-43 and SYP followed the same pattern as p-ERK1/2. In the treated group, p-ERK1/2 was inhibited completely, and C-fos, GAP-43 and SYP were reduced.These findings indicate that epileptiform discharge activates ERK1/2 which regulates C-fos in cultured neurons displaying epileptiform activity, and this cascade may upregulate GAP-43 and SYP to contribute to axon growth and synapse reorganization to potentiate epileptic activities

Creation of Chiral Interface Channels for Quantized Transport in Magnetic Topological Insulator Multilayer Heterostructures

One-dimensional (1D) topologically protected states are usually formed at the interface between two-dimensional (2D) materials with different topological invariants. Therefore, 1D chiral interface channels (CICs) can be created at the boundary of two quantum anomalous Hall (QAH) insulators with different Chern numbers. Such a QAH junction can function as a chiral edge current distributer at zero magnetic field, but its realization remains challenging. Here, by employing an in-situ mechanical mask, we use molecular beam epitaxy (MBE) to synthesize QAH insulator junctions, in which two QAH insulators with different Chern numbers are connected along a 1D junction. For the junction between C = 1 and C = -1 QAH insulators, we observe quantized transport and demonstrate the appearance of the two parallel propagating CICs along the magnetic domain wall at zero magnetic field. Moreover, since the Chern number of the QAH insulators in magnetic topological insulator (TI)/TI multilayers can be tuned by altering magnetic TI/TI bilayer periods, the junction between two QAH insulators with arbitrary Chern numbers can be achieved by growing different periods of magnetic TI/TI on the two sides of the sample. For the junction between C = 1 and C = 2 QAH insulators, our quantized transport shows that a single CIC appears at the interface. Our work lays down the foundation for the development of QAH insulator-based electronic and spintronic devices, topological chiral networks, and topological quantum computations.Comment: 20 pages, 4 figures, comments are welcom

Probing Primordial Gravitational Waves: Ali CMB Polarization Telescope

In this paper, we will give a general introduction to the project of Ali CMB Polarization Telescope (AliCPT), which is a Sino-US joint project led by the Institute of High Energy Physics (IHEP) and has involved many different institutes in China. It is the first ground-based Cosmic Microwave Background (CMB) polarization experiment in China and an integral part of China's Gravitational Waves Program. The main scientific goal of AliCPT project is to probe the primordial gravitational waves (PGWs) originated from the very early Universe. The AliCPT project includes two stages. The first stage referred to as AliCPT-1, is to build a telescope in the Ali region of Tibet with an altitude of 5,250 meters. Once completed, it will be the worldwide highest ground-based CMB observatory and open a new window for probing PGWs in northern hemisphere. AliCPT-1 telescope is designed to have about 7,000 TES detectors at 90GHz and 150GHz. The second stage is to have a more sensitive telescope (AliCPT-2) with the number of detectors more than 20,000. Our simulations show that AliCPT will improve the current constraint on the tensor-to-scalar ratio $r$ by one order of magnitude with 3 years' observation. Besides the PGWs, the AliCPT will also enable a precise measurement on the CMB rotation angle and provide a precise test on the CPT symmetry. We show 3 years' observation will improve the current limit by two order of magnitude.Comment: 11 pages, 7 figures, 2 table

Hawking radiation of black holes in the z=4z = 4 Horava-Lifshitz gravity

We investigate the Hawking radiation of 3+1 and 4+1 dimensional black holes in the $z = 4$ Horava-Lifshitz gravity with fermion tunnelling. It turns out that the Hawking temperatures are recovered and are in consistence with those obtained by calculating surface gravity of the black holes. For the 3+1 dimensional black holes, the Hawking temperatures are related to the fundamental parameters of Horava-Lifshitz gravity.Comment: V2: references added, typo corrected, 16page

Observation of Fractionally Quantized Anomalous Hall Effect

The integer quantum anomalous Hall (QAH) effect is a lattice analog of the quantum Hall effect at zero magnetic field. This striking transport phenomenon occurs in electronic systems with topologically nontrivial bands and spontaneous time-reversal symmetry breaking. Discovery of its putative fractional counterpart in the presence of strong electron correlations, i.e., the fractional quantum anomalous Hall (FQAH) effect, would open a new chapter in condensed matter physics. Here, we report the direct observation of both integer and fractional QAH effects in electrical measurements on twisted bilayer MoTe$_2$. At zero magnetic field, near filling factor $\nu = -1$ (one hole per moir\'e unit cell) we see an extended integer QAH plateau in the Hall resistance $R_\text{xy}$ that is quantized to $h/e^2 \pm 0.1 \%$ while the longitudinal resistance $R_\text{xx}$ vanishes. Remarkably, at $\nu=-2/3$ and $-3/5$ we see plateau features in $R_\text{xy}$ at $3h/2e^2 \pm 1\%$ and $5h/3e^2 \pm 3\%$, respectively, while $R_\text{xx}$ remains small. All these features shift linearly in an applied magnetic field with slopes matching the corresponding Chern numbers $-1$, $-2/3$, and $-3/5$, precisely as expected for integer and fractional QAH states. In addition, at zero magnetic field, $R_\text{xy}$ is approximately $2h/e^2$ near half filling ($\nu = -1/2$) and varies linearly as $\nu$ is tuned. This behavior resembles that of the composite Fermi liquid in the half-filled lowest Landau level of a two-dimensional electron gas at high magnetic field. Direct observation of the FQAH and associated effects paves the way for researching charge fractionalization and anyonic statistics at zero magnetic field.Comment: 15 pages, 4 figures for main text. 8 extended data figure

Antibody-mediated Prevention of Fusarium Mycotoxins in the Field

Fusarium mycotoxins directly accumulated in grains during the infection of wheat and other cereal crops by Fusarium head blight (FHB) pathogens are detrimental to humans and domesticated animals. Prevention of the mycotoxins via the development of FHB-resistant varieties has been a challenge due to the scarcity of natural resistance against FHB pathogens. Various antibodies specific to Fusarium fungi and mycotoxins are widely used in immunoassays and antibody-mediated resistance in planta against Fusarium pathogens has been demonstrated. Antibodies fused to antifungal proteins have been shown to confer a very significantly enhanced Fusarium resistance in transgenic plants. Thus, antibody fusions hold great promise as an effective tool for the prevention of mycotoxin contaminations in cereal grains. This review highlights the utilization of protective antibodies derived from phage display to increase endogenous resistance of wheat to FHB pathogens and consequently to reduce mycotoxins in field. The role played by Fusarium-specific antibody in the resistance is also discussed

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13