Quantum-coherence-free precision metrology by means of difference-signal amplification

The novel weak-value-amplification (WVA) scheme of precision metrology is deeply rooted in the quantum nature of destructive interference between the pre- and post-selection states. And, an alternative version, termed as joint WVA (JWVA), which employs the difference-signal from the post-selection accepted and rejected results, has been found possible to achieve even better sensitivity (two orders of magnitude higher) under some technical limitations (e.g. misalignment errors). In this work, after erasing the quantum coherence, we analyze the difference-signal amplification (DSA) technique, which serves as a classical counterpart of the JWVA, and show that similar amplification effect can be achieved. We obtain a simple expression for the amplified signal, carry out characterization of precision, and point out the optimal working regime. We also discuss how to implement the post-selection of a classical mixed state. The proposed classical DSA technique holds similar technical advantages of the JWVA and may find interesting applications in practice.Comment: 7pages, 5 figures. arXiv admin note: text overlap with arXiv:2207.0366

Ncapg dynamically coordinates the myogenesis of fetal bovine tissue by adjusting chromatin accessibility

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. NCAPG is a subunit of condensin I that plays a crucial role in chromatin condensation during mitosis. NCAPG has been demonstrated to be associated with farm animal growth traits. However, its role in regulating myoblast differentiation is still unclear. We used myoblasts derived from fetal bovine tissue as an in vitro model and found that NCAPG was expressed during myogenic differentiation in the cytoplasm and nucleus. Silencing NCAPG prolonged the mitosis and impaired the differentiation due to increased myoblast apoptosis. After 1.5 days of differentiation, silencing NCAPG enhanced muscle-specific gene expression. An assay for transposase-accessible chromatinhigh throughput sequencing (ATAC-seq) revealed that silencing NCAPG altered chromatin accessibility to activating protein 1 (AP-1) and its subunits. Knocking down the expression of the AP-1 subunits fos-related antigen 2 (FOSL2) or junB proto-oncogene (JUNB) enhanced part of the muscle-specific gene expression. In conclusion, our data provide valuable evidence about NCAPG’s function in myogenesis, as well as its potential role in gene expression

bta-miR-23a Regulates the Myogenic Differentiation of Fetal Bovine Skeletal Muscle-Derived Progenitor Cells by Targeting MDFIC Gene

miR-23a, a member of the miR-23a/24-2/27a cluster, has been demonstrated to play pivotal roles in many cellular activities. However, the mechanisms of how bta-miR-23a controls the myogenic differentiation (MD) of PDGFRalpha(-) bovine progenitor cells (bPCs) remain poorly understood. In the present work, bta-miR-23a expression was increased during the MD of (PDGFRalpha-) bPCs. Moreover, bta-miR-23a overexpression significantly promoted the MD of (PDGFRalpha-) bPCs. Luciferase reporter assays showed that the 3\u27-UTR region of MDFIC (MyoD family inhibitor domain containing) could be a promising target of bta-miR-23a, which resulted in its post-transcriptional down-regulation. Additionally, the knockdown of MDFIC by siRNA facilitated the MD of (PDGFRalpha-) bPCs, while the overexpression of MDFIC inhibited the activating effect of bta-miR-23a during MD. Of note, MDFIC might function through the interaction between MyoG transcription factor and MEF2C promoter. This study reveals that bta-miR-23a can promote the MD of (PDGFRalpha-) bPCs through post-transcriptional downregulation of MDFIC

A laboratory nanoseismological study on deep-focus earthquake micromechanics

Global earthquake occurring rate displays an exponential decay down to ~300 km and then peaks around 550 to 600 km before terminating abruptly near 700 km. How fractures initiate, nucleate, and propagate at these depths remains one of the greatest puzzles in earth science, as increasing pressure inhibits fracture propagation. We report nanoseismological analysis on high-resolution acoustic emission (AE) records obtained during ruptures triggered by partial transformation from olivine to spinel in Mg2GeO4, an analog to the dominant mineral (Mg,Fe)2SiO4 olivine in the upper mantle, using state-of-the-art seismological techniques, in the laboratory. AEs’ focal mechanisms, as well as their distribution in both space and time during deformation, are carefully analyzed. Microstructure analysis shows that AEs are produced by the dynamic propagation of shear bands consisting of nanograined spinel. These nanoshear bands have a near constant thickness (~100 nm) but varying lengths and self-organize during deformation. This precursory seismic process leads to ultimate macroscopic failure of the samples. Several source parameters of AE events were extracted from the recorded waveforms, allowing close tracking of event initiation, clustering, and propagation throughout the deformation/transformation process. AEs follow the Gutenberg-Richter statistics with a well-defined b value of 1.5 over three orders of moment magnitudes, suggesting that laboratory failure processes are self-affine. The seismic relation between magnitude and rupture area correctly predicts AE magnitude at millimeter scales. A rupture propagation model based on strain localization theory is proposed. Future numerical analyses may help resolve scaling issues between laboratory AE events and deep-focus earthquakes

BMP4 and rosiglitazone improves adipogenesis of bovine fetal muscle derived progenitor cells

peer reviewedIntramuscular fat (IMF) content is one of the most important factors determining beef quality and price. Intramuscular adipocytes develop from mesenchymal stem cells (MSCs) in mesoderm. The mechanisms of preadipocytes differentiate into mature adipocytes to a great extent are clear, but the commitment of MSCs to preadipocytes is largely unknown. In this study, the Platelet-derived growth factor receptor α (PDGFRα) positive progenitor cells were isolated from the longissimus dorsi muscle (LM) of fetal bovine and induced adipogenesis. To optimize the in vitro IMF differentiation model, the effects of bone morphogenic protein 4 (BMP4) and rosiglitazone during differentiation were studied. Comparing with control group, progenitor cells treated with BMP4 or rosiglitazone accumulated more intracellular lipid. Furthermore, the mRNA expression level of adipocyte-specific genes also increased significantly in BMP4 or rosiglitazone treated cells. The result indicated that BMP4 and rosiglitazone could promote adipogenesis and be applied in adipogenic differentiation of fetal bovine derived progenitor cells

Enhancing Optical Up-Conversion Through Electrodynamic Coupling with Ancillary Chromophores

In lanthanide-based optical materials, control over the relevant operating characteristics–for example transmission wavelength, phase and quantum efficiency–is generally achieved through the modification of parameters such as dopant/host combination, chromophore concentration and lattice structure. An alternative avenue for the control of optical response is through the introduction of secondary, codoped chromophores. Here, such secondary centers act as mediators, commonly bridging the transfer of energy between primary absorbers of externally sourced optical input and other sites of frequency-converted emission. Utilizing theoretical models based on experimentally feasible, three-dimensional crystal lattice structures; a fully quantized theoretical framework provides insights into the locally modified mechanisms that can be implemented within such systems. This leads to a discussion of how such effects might be deployed to either enhance, or potentially diminish, the efficiency of frequency up-conversion

Fault Orientation Determination for the 4 March 2008 Taoyuan Earthquake from Dense Near-Source Seismic Observations

On 4 March 2008, a moderate earthquake (ML = 5.2) occurred in southern Taiwan and named as the Taoyuan earthquake, preceded by foreshocks and followed by numerous aftershocks. This earthquake sequence occurred during the TAIGER (TAiwan Integrated GEodynamics Research) controlled-source seismic experiment. Consequently, several seismic networks were deployed in the Taiwan area at this time and many stations recorded this earthquake sequence in the near-source region. We archived and processed near-source observations to determine the fault orientation. To locate the events more accurately, station corrections, waveform cross-correlation to pick seismic phases, and a double-difference earthquake location algorithm were used to compute earthquake hypocenters. Over a 50-hour recording period, beginning half an hour before the start of the main shock, 2340 events were identified within the earthquake sequence. The identified aftershocks reveal a clear fault plane with a strike of N37°E and a dip of 45°SE. This plane corresponds to one of the focal mechanism nodal planes determined by the Broadband Array in Taiwan for Seismology (BATS) (strike = 37°, dip = 48°, and rake = 96°). Based on the main shock focal mechanism, the aftershock distribution, and the regional geological reports, we suggest that faulting on the northern extension of the major regional active fault, the Chishan Fault, caused the Taoyuan earthquake sequence