KLF1 (formerly known as EKLF) regulates the development of erythroid cells from bi-potent progenitor cells via the transcriptional activation of a diverse set of genes. Mice lacking Klf1 die in utero ...prior to E15 from severe anemia due to the inadequate expression of genes controlling hemoglobin production, cell membrane and cytoskeletal integrity, and the cell cycle. We have recently described the full repertoire of KLF1 binding sites in vivo by performing KLF1 ChIP-seq in primary erythroid tissue (E14.5 fetal liver). Here we describe the KLF1-dependent erythroid transcriptome by comparing mRNA-seq from Klf1(+/+) and Klf1(-/-) erythroid tissue. This has revealed novel target genes not previously obtainable by traditional microarray technology, and provided novel insights into the function of KLF1 as a transcriptional activator. We define a cis-regulatory module bound by KLF1, GATA1, TAL1, and EP300 that coordinates a core set of erythroid genes. We also describe a novel set of erythroid-specific promoters that drive high-level expression of otherwise ubiquitously expressed genes in erythroid cells. Our study has identified two novel lncRNAs that are dynamically expressed during erythroid differentiation, and discovered a role for KLF1 in directing apoptotic gene expression to drive the terminal stages of erythroid maturation.
Achieving the highest precision for theoretical predictions at the LHC requires the calculation of hard-scattering cross sections that include perturbative QCD corrections up to (N)NNLO and ...electroweak (EW) corrections up to NLO. Parton distribution functions (PDFs) need to be provided with matching accuracy, which in the case of QED effects involves introducing the photon parton distribution of the proton,
x
γ
(
x
,
Q
2
)
. In this work a determination of the photon PDF from fits to recent ATLAS measurements of high-mass Drell–Yan dilepton production at
s
=
8
TeV is presented. This analysis is based on the xFitter framework, and has required improvements both in the APFEL program, to account for NLO QED effects, and in the aMCfast interface to account for the photon-initiated contributions in the EW calculations within MadGraph5_aMC@NLO. The results are compared with other recent QED fits and determinations of the photon PDF, consistent results are found.
A theoretical model of photoacoustic response signal formation from laser-irradiated metal membranes is proposed with allowance for the excitation of defect states. Theoretical results obtained for ...197-μm-thick aluminum membranes in a frequency range from 20 Hz to 7 kHz are compared to experimental data for membranes excited by laser radiation at a 660-nm wavelength. The proposed theoretical model provides quite adequate coincidence with experiment for membrane oscillations under the assumption of a purely surface character of laser radiation absorption.
The experimental study of behavior of laser-ultrasonic signals in the vicinity of a hole in dielectric silicon nitride ceramics under the action of mechanical stresses has been implemented. The key ...discrepancy between the obtained results and similar results that we obtained earlier for metals was found, along with their quantitative mismatch with the predictions of the thermodynamic model for generation of thermoelastic signals in prestressed materials. An explanation of the observed discrepancies has been proposed based on a model of thermal excitation of defect states in a lattice that we have previously proposed.
Recent progress in quantum electrodynamics (QED) calculations of highly charged ions is reviewed. The theoretical predictions for the binding energies, the hyperfine splittings, and the g factors are ...presented and compared with available experimental data. Special attention is paid to tests of bound‐state QED at strong field regime. Future prospects for tests of QED at the strongest electric and magnetic fields as well as for determination of the fine structure constant and the nuclear magnetic moments with heavy ions are discussed.
Recent progress in quantum electrodynamics (QED) calculations of highly charged ions is reviewed. The theoretical predictions for the binding energies, the hyperfine splittings, and the g factors are presented and compared with available experimental data. Special attention is paid to tests of bound‐state QED at strong field regime. Future prospects for tests of QED at the strongest electric and magnetic fields as well as for determination of the fine structure constant and the nuclear magnetic moments with heavy ions are discussed.
The processes of heat removal from multijunction solar cells on a germanium substrate to AlN ceramics through a solder layer were studied by thermal wave photodeflection methods. Two types lead-free ...solder based on SnBi and SnAgCu were used under various pressure soldering conditions. The thermal conductivity and thermal resistance of the solder layers are compared. It is shown that the thermal conductivities of the solder layers differ from the reference data for the corresponding metal alloys, and in some cases may depend on the pressure during the brazing process.
We investigate the impact of displaced heavy-quark matching scales in a global fit. The heavy-quark matching scale
μ
m
determines at which energy scale
μ
the QCD theory transitions from
N
F
to
N
F
+
...1
in the variable flavor number scheme (VFNS) for the evolution of the parton distribution functions (PDFs) and strong coupling
α
S
(
μ
)
. We study the variation of the matching scales, and their impact on a global PDF fit of the combined HERA data. As the choice of the matching scale
μ
m
effectively is a choice of scheme, this represents a theoretical uncertainty; ideally, we would like to see minimal dependence on this parameter. For the transition across the charm quark (from
N
F
=
3
to 4), we find a large
μ
m
=
μ
c
dependence of the global fit
χ
2
at NLO, but this is significantly reduced at NNLO. For the transition across the bottom quark (from
N
F
=
4
to 5), we have a reduced
μ
m
=
μ
b
dependence of the
χ
2
at both NLO and NNLO as compared to the charm. This feature is now implemented in xFitter 2.0.0, an open source QCD fit framework.
In designing mine spillways without a profiled water drain surface that operates in the absence of contact of the water jet with the concrete within a funnel and transitional section, the problem ...arises of calculating the trajectory of an annular jet, taking into account the vacuum in the space under the jet. A hydraulic method for such calculation using a virtual jet is described. Calculated dependences are given. The results of calculations are compared to test results, confirming the operability of the proposed method.
The maximum mixed stress intensity factors that control the growth of mode I cracks for a circular disk with a subsurface radial crack under a model contact load unidirectionally moving along its ...edge are studied. The load contains a tangential component, which makes it possible to account for the forces of sliding friction between the rolling bodies. By comparing the stress intensity factors with the crack resistance characteristics of steels of KP-2 and KP-T railroad wheels, their fracture is predicted.
Laser generation of ultrasound in metals with internal mechanical stresses has been analyzed. The characteristics of a photoacoustic signal in the vicinity of a hole in a D16 alloy plate under the ...action of mechanical stresses have been studied. The discrepancy between the experimental results and predictions of the thermodynamic model for the dependence of the thermal expansion coefficient on mechanical stresses was found. For proper description of the signal characteristics in real metals, we have proposed to take into account the influence of the electron subsystem on laser generation of acoustic waves.
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