Insulator Version Apk Download Extra Quality

We study the effects of opening the band gap on the double exchange ferromagnetism. Applying the density-matrix renormalization group method and an analytical expansion from the dimer limit to the one-dimensional double exchange model, we demonstrate for a relevant region of the exchange coupling that, in the weak dimerization regime, the Peierls gap opens in the fully spin-polarized conduction band without affecting its ferromagnetism, whereas in the strong dimerization regime, the ferromagnetism is destroyed, and the Mott gap opens instead, leading the system to the antiferromagnetic quasi-long-range order. An insulator version of double exchange ferromagnetism is thus established.

In this article, we use Cr-doped (BiSb)2Te3 films to study QAHE and its related phase diagram. Due to the highly insulating bulk state achieved by the non-equilibrium molecular beam epitaxy (MBE) growth, we observe the giant longitudinal resistance peak and zero Hall conductance plateau at the coercive field in the six quintuple-layer (QL) (Cr0.12Bi0.26Sb0.62)2Te3 film. Such zero Hall plateau manifests the presence of the unique QAHE insulating state, which may be understood within the magnetic multi-domain network context. Moreover, by studying the angle-dependent quantum transport behaviours, the 2D massive Dirac fermion-featured QAHE phase diagram is mapped out to show that the QAHE state with the first Chern number C1=1 is transitioned into the C1=0 insulating state, and the conductance tensor (tag_hash_110xx, tag_hash_112xy) follows a universal semicircle relation, regardless of the applied magnetic field strength. The presence of the zero Hall plateau and the realization of the metal-to-insulator switching in the 2D QAHE regime expand the insights of the critical quantum transport phenomena, and may also pave the way for low-power dissipation spintronics applications.

Insulator Version Apk Download

Download Zip 🔥 https://urlgoal.com/2y3LzF 🔥

In conclusion, we study the QAHE phase transition for the 2D hybridized magnetic TI system. We show that such QAH metal-to-insulator switching can only be achieved in high-quality samples with truly bulk insulating state and 2D quantum confinement. The observations of the zero Hall plateaus and double-split longitudinal conductance are consistent with the proposed microscopic multi-domain network model where the vanishing of the magnetic exchange gap tag_hash_114M at the coercive field causes the topology change, yet the temperature-dependent and size scaling behaviours of the QAHE plateau transition needs further investigations to reveal the nature of this exotic state of matter. It is noted that a recent work by Y. Feng el al. also reported the observation of the zero Hall plateau (although the sample was not fully quantized) in a back-gated 5QL Cr-doped magnetic TI sample49. At the same time, from both the field-dependent and angle-dependent magneto-transport results, we map out the global QAHE phase diagram which can be described by a single semicircle curve continuously connecting the (0, 0) and (0, e2/h) in the (tag_hash_119xx, tag_hash_121xy) conductance plot. Additionally, we achieve the QAHE insulator regime by making either (B= tag_hash_1240HC, tag_hash_126=90) or (B>B0, tag_hash_129=180) at relatively small magnetic fields. The discovered universal phase transition rule is significant for the understanding of the QAHE system and our results open new avenues for the exploration of novel QAHE-related phenomena and applications.

Using a new ultrafast electron calorimetry technique, JILA researchers in the Kapteyn-Murnane group discovered a new state in a standard material called tantalum diselenide. Starting in a standard insulating state (left frame), in which the atoms (gold) are arranged in a star formation, the group blasted the material with an ultrafast IR laser (red). This ultrafast laser heats the electrons, thus expanding their probably distribution (blue). This expansion destabilizes the insulator state and allows the atoms to rush out, eventually reaching a metastable insulating state (right frame).

Tantalum diselenide (TaSe2) is a semiconductor built from one layer of atomically thin tantalum sandwiched between two layers of selenide. When cold, the atoms in this material bunch together into a star shape. This shape shackles the electrons to the atoms and impedes the flow of electricity, therefore rendering the material as an insulator. But warm this material and insulator melts into a conductor like ice melting to water.

Chromatin insulators are responsible for orchestrating long-range interactions between enhancers and promoters throughout the genome and align with the boundaries of Topologically Associating Domains (TADs). Here, we demonstrate an association between gypsy insulator proteins and the phosphorylated histone variant H2Av (H2Av), normally a marker of DNA double strand breaks. Gypsy insulator components colocalize with H2Av throughout the genome, in polytene chromosomes and in diploid cells in which Chromatin IP data shows it is enriched at TAD boundaries. Mutation of insulator components su(Hw) and Cp190 results in a significant reduction in H2Av levels in chromatin and phosphatase inhibition strengthens the association between insulator components and H2Av and rescues H2Av localization in insulator mutants. We also show that H2Av, but not H2Av, is a component of insulator bodies, which are protein condensates that form during osmotic stress. Phosphatase activity is required for insulator body dissolution after stress recovery. Together, our results implicate the H2A variant with a novel mechanism of insulator function and boundary formation.

The DNA in eukaryotic genomes is folded into domains called Topologically Associating Domains (TADs), which promote gene specific transcription regulation. Insulator proteins are DNA binding proteins that bind at the boundaries between adjacent TADs. Loop extrusion is a mechanism by which insulators promote TAD formation in vertebrate genomes, but the mechanism by which insulator proteins facilitate the formation of boundaries in Drosophila is not well understood. In this work we show that there is an association between Drosophila gypsy insulator proteins and the phosphorylated version of the histone variant H2Av (H2Av). H2Av has been traditionally linked to the mechanism of DNA repair, but our data shows that gypsy insulator components colocalize with H2Av throughout the genome, and that H2Av is also enriched at TAD boundaries. Mutation of genes encoding insulator proteins su(Hw) and Cp190 results in a significant reduction in H2Av levels, and inhibition of the phosphatase activity that removes phosphate from H2Av strengthens the association between insulator proteins and H2Av. We also show that H2Av is a component of insulator bodies, which are protein condensates that form during osmotic stress. Together, our results implicate the H2A variant with a novel mechanism of insulator function and boundary formation.

Citation: Simmons JR, An R, Amankwaa B, Zayac S, Kemp J, Labrador M (2022) Phosphorylated histone variant H2Av is associated with chromatin insulators in Drosophila. PLoS Genet 18(10): e1010396.

Drosophila melanogaster has an array of different insulator complexes, with each complex being recruited to different sequences in the genome by a DNA binding insulator protein [9,10]. One insulator site, located within the gypsy retrotransposon, has been thoroughly characterized for its ability to block enhancer promoter communications [4]. A number of gypsy retrotransposons are present throughout the Drosophila genome [11], and insertion or transposition of gypsy to a new locus may interrupt local transcriptional activity and chromatin dynamics [4,12]. Insulator proteins are recruited to gypsy through a 460-bp sequence composed of 12 binding sites for Suppressor of Hairy Wing (Su(Hw)) [4]. Su(Hw) specifically recruits an isoform of modifier of mdg4 (Mod(mdg4)67.2) [13]. Another protein, Centrosomal Protein 190 (CP190), is found as an essential part of different insulator complexes [9] and is recruited to the gypsy insulator through interactions with Mod(mdg4)67.2 [14] and the amino terminal domain of HIPP1 (HP1 and insulator partner protein 1) [15].

Our laboratory previously demonstrated an accumulation of phosphorylated H2Av (H2Av) signal in the ovaries of su(Hw) mutants and the presence of chromosomal aberrations in actively dividing larval neuroblasts lacking Su(Hw), suggesting a possible connection between Su(Hw) activity and genome stability [24]. Furthermore, disruption of Mei-41/ATR, a kinase responsible for phosphorylating H2Av among other targets upon DNA damage [39], partially rescues the defective oogenesis phenotype associated with mutation of su(Hw) [24]. While insulator-binding proteins have been described for their role in genome organization and regulation in Drosophila, the mechanisms linking their activity to DNA repair remain elusive.

In this work, we show that H2Av is present at Su(Hw)-binding sites throughout the genome, including at gypsy retrotransposons, and that mutation of several gypsy insulator components disrupts normal distribution of H2Av in chromosomes. We show that H2Av is a component of insulator bodies formed under osmotic stress and that dephosphorylation of H2Av is required for efficient dissolution of these bodies during recovery. Chromatin immunoprecipitation data reveal extensive genome-wide colocalization between Su(Hw) and H2Av and enrichment for both at TAD boundaries. This association also extends to insulator function as flies doubly heterozygous for His2Av810 and mutant alleles of su(Hw) showed a partial rescue of phenotypes for yellow2 and cut6, two gypsy insulator induced phenotypes. Collectively, these findings point to a model in which H2Av works with insulators to coordinate genome function and perhaps genome-wide responses to genotoxic stress. 2351a5e196