846 research outputs found
Long-Term Organic Farming Manipulated Rhizospheric Microbiome and Bacillus Antagonism Against Pepper Blight (Phytophthora capsici)
Soil-borne diseases are often less severe in organic farms, possibly because of the recruitment of beneficial microorganisms by crops. Here, the suppressiveness of organic, integrated, and conventionally managed soils to pepper blight (Phytophthora capsici) was studied in growth chamber experiments. Disease incidence was 41.3 and 34.1% lower in the soil from an organic farming system than in either the soil from the integrated or from the conventional farming systems, respectively. Beta-diversity of rhizospheric microbial communities differed among treatments, with enrichment of Bacillus, Sporosarcina, Acidobacteria Gp5, Gp6, Gp22, and Ignavibacterium by the organic soil. Cultivation-dependent analysis indicated that 50.3% of in vitro antagonists of P. capsici isolated from the rhizosphere of healthy peppers were affiliated to Bacillus. An integration of in vitro antagonists and bacterial diversity analyses indicated that Bacillus antagonists were higher in the rhizosphere of pepper treated by the organic soil. A microbial consortium of 18 in vitro Bacillus antagonists significantly increased the suppressiveness of soil from the integrated farming system against pepper blight. Overall, the soil microbiome under the long-term organic farming system was more suppressive to pepper blight, possibly owing to Bacillus antagonism in the rhizosphere. This study provided insights into microbiome management for disease suppression under greenhouse conditions
Unlocking Low-Light-Rainy Image Restoration by Pairwise Degradation Feature Vector Guidance
Rain in the dark is a common natural phenomenon. Photos captured in such a
condition significantly impact the performance of various nighttime activities,
such as autonomous driving, surveillance systems, and night photography. While
existing methods designed for low-light enhancement or deraining show promising
performance, they have limitations in simultaneously addressing the task of
brightening low light and removing rain. Furthermore, using a cascade approach,
such as ``deraining followed by low-light enhancement'' or vice versa, may lead
to difficult-to-handle rain patterns or excessively blurred and overexposed
images. To overcome these limitations, we propose an end-to-end network called
which can jointly handle low-light enhancement and deraining. Our
network mainly includes a Pairwise Degradation Feature Vector Extraction
Network (P-Net) and a Restoration Network (R-Net). P-Net can learn degradation
feature vectors on the dark and light areas separately, using contrastive
learning to guide the image restoration process. The R-Net is responsible for
restoring the image. We also introduce an effective Fast Fourier - ResNet
Detail Guidance Module (FFR-DG) that initially guides image restoration using
detail image that do not contain degradation information but focus on texture
detail information. Additionally, we contribute a dataset containing synthetic
and real-world low-light-rainy images. Extensive experiments demonstrate that
our outperforms existing methods in both synthetic and complex
real-world scenarios
Data-constrained Magnetohydrodynamic Simulation of an Intermediate Solar Filament Eruption
Solar eruptive activities could occur in weak magnetic field environments and
over large spatial scales, especially relevant to eruptions involving
intermediate or quiescent solar filaments. To handle the large scales, we
implement and apply a flux rope embedding method using regularized Biot-Savart
laws in the spherical coordinate system. Combined with a potential field source
surface model and a magneto-frictional method, a nonlinear force-free field
comprising a flux rope embedded in a potential field is constructed. Using the
combined nonlinear force-free field as the initial condition, we then perform a
zero- data-constrained magnetohydrodynamic (MHD) simulation for an M8.7
flare at 03:38 UT on 2012 January 23. The MHD model reproduces the eruption
process, flare ribbon evolution (represented by the quasi-separatrix layer
evolution) and kinematics of the flux rope. This approach could potentially
model global-scale eruptions from weak field regions.Comment: 23 pages, 7 figures, accepted for publicaiton in Ap
Effect of a Zn impurity on T_c and its implication to pairing symmetry in LaFeAsOF
The effect of non-magnetic Zn impurity on superconductivity in
LaFeZnAsOF system is studied systematically. In the
presence of Zn impurity, the superconducting transition temperature increases
in the under-doped regime, remains unchanged in the optimally doped regime, and
is severely suppressed in the over-doped regime. Our results suggest a switch
of the symmetry of the superconducting order parameters from a -wave to
or -wave states as the charge carrier doping increases in
FeAs-based superconductors.Comment: 4 pages, 4 figures. Format changed and a few revisons mad
Derivation and Characterization of Hepatic Progenitor Cells from Human Embryonic Stem Cells
The derivation of hepatic progenitor cells from human embryonic stem (hES) cells is of value both in the study of early human liver organogenesis and in the creation of an unlimited source of donor cells for hepatocyte transplantation therapy. Here, we report for the first time the generation of hepatic progenitor cells derived from hES cells. Hepatic endoderm cells were generated by activating FGF and BMP pathways and were then purified by fluorescence activated cell sorting using a newly identified surface marker, N-cadherin. After co-culture with STO feeder cells, these purified hepatic endoderm cells yielded hepatic progenitor colonies, which possessed the proliferation potential to be cultured for an extended period of more than 100 days. With extensive expansion, they co-expressed the hepatic marker AFP and the biliary lineage marker KRT7 and maintained bipotential differentiation capacity. They were able to differentiate into hepatocyte-like cells, which expressed ALB and AAT, and into cholangiocyte-like cells, which formed duct-like cyst structures, expressed KRT19 and KRT7, and acquired epithelial polarity. In conclusion, this is the first report of the generation of proliferative and bipotential hepatic progenitor cells from hES cells. These hES cell–derived hepatic progenitor cells could be effectively used as an in vitro model for studying the mechanisms of hepatic stem/progenitor cell origin, self-renewal and differentiation
(E)-N′-(4-Nitrobenzylidene)-4-(8-quinolyloxy)butanohydrazide
In the title compound, C20H18N4O4, conformation along the bond sequence linking the benzene and quinoline rings, which have a mean interplanar dihedral angle of 2.7 (5)°, is trans–(+)gauche–trans–trans–(−)gauche–trans–trans. In the crystal structure, a pair of intermolecular N—H⋯O hydrogen bonds links the molecules into centrosymmetric cyclic R
2
2(8) dimers, which are aggregated via π–π interactions into parallel sheets [quinoline–benzene ring centroid separation = 3.6173 (16)–3.6511 (16) Å]. The sheets are further connected through weak C—H⋯O interactions, giving a supramolecular two-dimensional network
Human herpesvirus 6A induces apoptosis of primary human fetal astrocytes via both caspase-dependent and -independent pathways
<p>Abstract</p> <p>Background</p> <p>Human herpesvirus 6 (HHV-6) is a T-lymphtropic and neurotropic virus that can infect various types of cells. Sequential studies reported that apoptosis of glia and neurons induced by HHV-6 might act a potential trigger for some central nervous system (CNS) diseases. HHV-6 is involved in the pathogenesis of encephalitis, multiple sclerosis (MS) and fatigue syndrome. However, the mechanisms responsible for the apoptosis of infected CNS cells induced by HHV-6 are poorly understood. In this study, we investigated the cell death processes of primary human fetal astrocytes (PHFAs) during productive HHV-6A infection and the underlying mechanisms.</p> <p>Results</p> <p>HHV-6A can cause productive infection in primary human fetal astrocytes. Annexin V-PI staining and electron microscopic analysis indicated that HHV-6A was an inducer of apoptosis. The cell death was associated with activation of caspase-3 and cleavage of poly (ADP-ribose) polymerase (PARP), which is known to be an important substrate for activated caspase-3. Caspase-8 and -9 were also significantly activated in HHV-6A-infected cells. Moreover, HHV-6A infection led to Bax up-regulation and Bcl-2 down-regulation. HHV-6A infection increased the release of Smac/Diablo, AIF and cytochrome c from mitochondria to cytosol, which induced apoptosis via the caspase-dependent and -independent pathways. In addition, we also found that anti-apoptotic factors such as IAPs and NF-κB decreased in HHV-6A infected PHFAs.</p> <p>Conclusion</p> <p>This is the first demonstration of caspase-dependent and -independent apoptosis in HHV-6A-infected glial cells. These findings would be helpful in understanding the mechanisms of CNS diseases caused by HHV-6.</p
Catalytically efficient Ni-NiOₓ-Y₂O₃ interface for medium temperature water-gas shift reaction
The metal-support interfaces between metals and oxide supports have long been studied in catalytic applications, thanks to their significance in structural stability and efficient catalytic activity. The metal-rare earth oxide interface is particularly interesting because these early transition cations have high electrophilicity, and therefore good binding strength with Lewis basic molecules, such as H2O. Based on this feature, here we design a highly efficient composite Ni-Y2O3 catalyst, which forms abundant active Ni-NiOx-Y2O3 interfaces under the water-gas shift (WGS) reaction condition, achieving 140.6 μmolCO gcat-1 s-1 rate at 300 °C, which is the highest activity for Ni-based catalysts. A combination of theory and ex/in situ experimental study suggests that Y2O3 helps H2O dissociation at the Ni-NiOx-Y2O3 interfaces, promoting this rate limiting step in the WGS reaction. Construction of such new interfacial structure for molecules activation holds great promise in many catalytic systems
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