148 research outputs found
Infrared diagnostics of the solar magnetic field with Mg I 12 m lines: forward-model results
The Mg I 12.32 and 12.22 m lines are a pair of emission lines that
present a great advantage for accurate solar magnetic field measurement. They
potentially contribute to the diagnosis of solar atmospheric parameters through
their high magnetic sensitivity. The goal of this study is to understand the
radiation transfer process of these lines in detail and explore the ability of
magnetic field diagnosis in the infrared. We calculated the Stokes profiles and
response functions of the two Mg I 12 m lines based on one-dimensional
solar atmospheric models using the Rybicki-Hummer (RH) radiative transfer code.
The integration of these profiles with respect to the wavelength was used to
generate calibration curves related to the longitudinal and transverse fields.
The traditional single-wavelength calibration curve based on the weak-field
approximation was also tested to determine if it is suitable for the infrared.
The 12.32 m line is more suitable for a magnetic field diagnosis because
its relative emission intensity and polarization signal are stronger than that
of the 12.22 m line. The result from the response functions illustrates
that the derived magnetic field and velocity with 12.32 m line mainly
originate from the height of 450 km, while that for the temperature is about
490 km. The calibration curves obtained by the wavelength-integrated method
show a nonlinear distribution. For the Mg I 12.32 m line, the longitudinal
(transverse) field can be effectively inferred from Stokes V/I (Q/I and U/I) in
the linear range below G ( G) in quiet regions and below
G ( G) in penumbrae. Within the given linear range, the
method is a supplement to the magnetic field calibration when the Zeeman
components are incompletely split.Comment: 12 pages, 10 figures, accepted for publication in A&
Controllable Weyl nodes and Fermi arcs in a light-irradiated carbon allotrope
The precise control of Weyl physics in realistic materials oers a promising
avenue to construct accessible topological quantum systems, and thus draw
widespread attention in condensed-matter physics. Here, based on rst-principles
calculations, maximally localized Wannier functions based tight-binding model,
and Floquet theorem, we study the light-manipulated evolution of Weyl physics
in a carbon allotrope C6 crystallizing a face-centered orthogonal structure
(fco-C6), an ideal Weyl semimetal with two pairs of Weyl nodes, under the
irradiation of a linearly polarized light (LPL). We show that the positions of
Weyl nodes and Fermi arcs can be accurately controlled by changing light
intensity. Moreover, we employ a low-energy eective k p model to understand
light-controllable Weyl physics. The results indicate that the symmetry of
light-irradiated fco-C6 can be selectively preserved, which guarantees that the
light-manipulated Weyl nodes can only move in the highsymmetry plane in
momentum space. Our work not only demonstrates the ecacy of employing periodic
driving light elds as an ecient approach to manipulate Weyl physics, but also
paves a reliable pathway for designing accessible topological states under
light irradiation
Persistent Upflows and Downflows at Active Region boundaries Observed by SUTRI and AIA
Upflows and downflows at active region (AR) boundaries have been frequently
observed with spectroscopic observations at extreme ultraviolet (EUV)
passbands. In this paper, we report the coexistence of upflows and downflows at
the AR boundaries with imaging observations from the Solar Upper Transition
Region Imager (SUTRI) and the Atmospheric Imaging Assembly (AIA). With their
observations from 2022 September 21 to 2022 September 30, we find 17 persistent
opposite flows occurring along the AR coronal loops. The upflows are prominent
in the AIA 193 \AA images with a velocity of 50-200 km/s, while the downflows
are best seen in the SUTRI 465 \AA and AIA 131 \AA images with a slower
velocity of tens of kilometers per second (characteristic temperatures (log
T(K)) for 193 \AA, 465 \AA and 131 \AA are 6.2, 5.7, 5.6, respectively). We
also analyze the center-to-limb variation of the velocities for both upflows
and downflows. The simultaneous observations of downflows and upflows can be
explained by the chromosphere-corona mass-cycling process, in which the
localized chromospheric plasma is impulsively heated to coronal temperature
forming a upflow and then these upflows experience radiative cooling producing
a downflow with the previously heated plasma returning to the lower atmosphere.
In particular, the persistent downflows seen by SUTRI provide strong evidence
of the cooling process in the mass cycle. For upflows associated with open
loops, part of the plasma is able to escape outward and into the heliosphere as
solar wind
Immunization against inhibin DNA vaccine as an alternative therapeutic for improving follicle development and reproductive performance in beef cattle
The objective of the present study was to investigate the potential role of immunization against INH on follicular development, serum reproductive hormone (FSH, E2, and P4) concentrations, and reproductive performance in beef cattle. A total of 196 non-lactating female beef cattle (4-5 years old) with identical calving records (3 records) were immunized with 0.5, 1.0, 1.5, or 2.0 mg [(T1, n = 58), (T2, n = 46), (T3, n = 42) and (T4, n = 36), respectively] of the pcISI plasmid. The control (C) group (n = 14) was immunized with 1.0 mL 0.9% saline. At 21d after primary immunization, all beef cattle were boosted with half of the primary immunization dose. On day 10 after primary immunization, the beef cattle immunized with INH DNA vaccine evidently induced anti-INH antibody except for the T1 group. The T3 group had the greatest P/N value peak among all the groups. The anti-INH antibody positive rates in T2, T3 and T4 groups were significantly higher than that in C and T1 groups. RIA results indicated that serum FSH concentration in T2 group increased markedly on day 45 after booster immunization; the E2 amount in T3 group was significantly increased on day 10 after primary immunization, and the levels of E2 also improved in T2 and T3 groups after booster immunization; the P4 concentration in T2 group was significantly improved on day 21 after primary immunization. Ultrasonography results revealed that the follicles with different diameter sizes were increased, meanwhile, the diameter and growth speed of ovulatory follicle were significantly increased. Furthermore, the rates of estrous, ovulation, conception, and twinning rate were also significantly enhanced. These findings clearly illustrated that INH DNA vaccine was capable of promoting the follicle development, thereby improving the behavioral of estrous and ovulation, eventually leading to an augment in the conception rates and twinning rate of beef cattle
Whole-Genome Sequencing Uncovers Two Loci for Coronary Artery Calcification and Identifies Arse as a Regulator of Vascular Calcification
Coronary artery calcification (CAC) is a measure of atherosclerosis and a well-established predictor of coronary artery disease (CAD) events. Here we describe a genome-wide association study (GWAS) of CAC in 22,400 participants from multiple ancestral groups. We confirmed associations with four known loci and identified two additional loci associated with CAC (ARSE and MMP16), with evidence of significant associations in replication analyses for both novel loci. Functional assays of ARSE and MMP16 in human vascular smooth muscle cells (VSMCs) demonstrate that ARSE is a promoter of VSMC calcification and VSMC phenotype switching from a contractile to a calcifying or osteogenic phenotype. Furthermore, we show that the association of variants near ARSE with reduced CAC is likely explained by reduced ARSE expression with the G allele of enhancer variant rs5982944. Our study highlights ARSE as an important contributor to atherosclerotic vascular calcification, and a potential drug target for vascular calcific disease
Genetic drivers of heterogeneity in type 2 diabetes pathophysiology
Type 2 diabetes (T2D) is a heterogeneous disease that develops through diverse pathophysiological processes1,2 and molecular mechanisms that are often specific to cell type3,4. Here, to characterize the genetic contribution to these processes across ancestry groups, we aggregate genome-wide association study data from 2,535,601 individuals (39.7% not of European ancestry), including 428,452 cases of T2D. We identify 1,289 independent association signals at genome-wide significance (P < 5 × 10-8) that map to 611 loci, of which 145 loci are, to our knowledge, previously unreported. We define eight non-overlapping clusters of T2D signals that are characterized by distinct profiles of cardiometabolic trait associations. These clusters are differentially enriched for cell-type-specific regions of open chromatin, including pancreatic islets, adipocytes, endothelial cells and enteroendocrine cells. We build cluster-specific partitioned polygenic scores5 in a further 279,552 individuals of diverse ancestry, including 30,288 cases of T2D, and test their association with T2D-related vascular outcomes. Cluster-specific partitioned polygenic scores are associated with coronary artery disease, peripheral artery disease and end-stage diabetic nephropathy across ancestry groups, highlighting the importance of obesity-related processes in the development of vascular outcomes. Our findings show the value of integrating multi-ancestry genome-wide association study data with single-cell epigenomics to disentangle the aetiological heterogeneity that drives the development and progression of T2D. This might offer a route to optimize global access to genetically informed diabetes care.</p
Genetic Drivers of Heterogeneity in Type 2 Diabetes Pathophysiology
Type 2 diabetes (T2D) is a heterogeneous disease that develops through diverse pathophysiological processes1,2 and molecular mechanisms that are often specific to cell type3,4. Here, to characterize the genetic contribution to these processes across ancestry groups, we aggregate genome-wide association study data from 2,535,601 individuals (39.7% not of European ancestry), including 428,452 cases of T2D. We identify 1,289 independent association signals at genome-wide significance (P \u3c 5 × 10-8) that map to 611 loci, of which 145 loci are, to our knowledge, previously unreported. We define eight non-overlapping clusters of T2D signals that are characterized by distinct profiles of cardiometabolic trait associations. These clusters are differentially enriched for cell-type-specific regions of open chromatin, including pancreatic islets, adipocytes, endothelial cells and enteroendocrine cells. We build cluster-specific partitioned polygenic scores5 in a further 279,552 individuals of diverse ancestry, including 30,288 cases of T2D, and test their association with T2D-related vascular outcomes. Cluster-specific partitioned polygenic scores are associated with coronary artery disease, peripheral artery disease and end-stage diabetic nephropathy across ancestry groups, highlighting the importance of obesity-related processes in the development of vascular outcomes. Our findings show the value of integrating multi-ancestry genome-wide association study data with single-cell epigenomics to disentangle the aetiological heterogeneity that drives the development and progression of T2D. This might offer a route to optimize global access to genetically informed diabetes care
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