48 research outputs found
Precision Improvement of Power-Efficient Capacitive Senor Readout Circuit Using Multi-Nested Clocks
Volcanism, redox conditions, and microbialite growth linked with the end-Permian mass extinction: Evidence from the Xiajiacao section (western Hubei Province), South China
Ā© 2017. A new Permian-Triassic boundary microbialite (PTBM) is described from the Xiajiacao section of western Hubei Province, South China. The new microbialite, 3.16. m thick, comprises a thin layer of stromatolite and a thick thrombolite unit. An irregular contact separates the uppermost Permian skeletal packstone from the post-extinction stromatolite, but it is not yet possible to discriminate whether it was formed by submarine solution in the wake of ocean acidification or subaerial exposure due to regional regression, or a combination of both. The stromatolite shows "cabbage-like" morphology, and the thrombolite is characterized by centimetric clotted texture. Abundant columns of the microproblematica structure Gakhumella, coccoid-like spheroids, bacterial clump-like spheroids, and hollow spheroids are recognized in both stromatolites and thrombolites and may have played an important role in accretion of the microbialites. Pyrite framboid analysis indicates that microbialites may have been affected by lower dysoxic to upper dysoxic conditions in the immediate aftermath of the Permian-Triassic extinction. Stratigraphic abundance of both high-temperature grains (Ī²-quartz and glassy balls) peaked ~. 20. cm below the biotic extinction horizon, implying that either intensive volcanic eruption occurred only just prior to biotic extinction, or volcanism was still intensive during biotic extinction, but volcanic grains were not deposited in the Xiajiacao locality, likely due to the shallow, agitated environment caused by the regional regression. Overall, microbial bloom, indicated by the widespread PTBMs, seems to have been little affected by the contemporaneous volcanism.We thank both anonymous reviewers and editor Thomas Algeo for critical
comments and constructive suggestions, which have greatly improved the quality of
the paper. This study is partly supported by the 111 Program of China (B08030), two
NSFC grants (41572091, 41402089), and one research grant from the State Key
Laboratory of Biogeology and Environmental Geology (BGEG), China University of
Geosciences (GBL11206). It is a contribution to the IGCP 630 āPermianāTriassic
climatic and environmental extremes and biotic responseā
Sclerotinia sclerotiorum Thioredoxin Reductase Is Required for Oxidative Stress Tolerance, Virulence, and Sclerotial Development
Sclerotinia sclerotiorum is a destructive ascomycete plant pathogen with worldwide distribution. Extensive research on different aspects of this pathogenās capability to cause disease will help to uncover clues about new ways to safely control Sclerotinia diseases. The thioredoxin (Trx) system consists of Trx and thioredoxin reductase (TrxR), which play critical roles in maintenance of cellular redox homeostasis. In this study, we functionally characterized a gene encoding a TrxR (SsTrr1) in S. sclerotiorum. The amino acids of SsTrr1 exhibited high similarity with reported TrxRs in plant pathogens and targeted silencing of SsTrr1 lead to a decrease in TrxR activities of mycelium. SsTrr1 showed high expression levels during hyphae growth, and the levels decreased at the different stages of sclerotial development. SsTrr1 gene-silenced strains produced a smaller number of larger sclerotia on potato dextrose agar medium. The observations were consistent with the inhibitory effects on sclerotial development by the TrxR inhibitor, anrunofin. The expression of SsTrr1 showed a dramatic increase under the oxidative stress and the hyphal growth of gene-silenced strains showed more sensitivity to H2O2. SsTrr1 gene-silenced strains also showed impaired virulence in different hosts. Taken together, our results suggest that SsTrr1 encodes a TrxR that is of great important for oxidative stress tolerance, virulence, and sclerotial development of S. sclerotiorum
Complete biotic and sedimentary records of the Permian-Triassic transition from Meishan section, South China:Ecologically assessing mass extinction and its aftermath
Systematic biases in determining dust attenuation curves through galaxy SED fitting
While the slope of the dust attenuation curve () is found to
correlate with effective dust attenuation () as obtained through spectral
energy distribution (SED) fitting, it remains unknown how the fitting
degeneracies shape this relation. We examine the degeneracy effects by fitting
SEDs of a sample of local star-forming galaxies (SFGs) selected from the Galaxy
And Mass Assembly survey, in conjunction with mock galaxy SEDs of known
attenuation parameters. A well-designed declining starburst star formation
history is adopted to generate model SED templates with intrinsic UV slope
() spanning over a reasonably wide range. The best-fitting
for our sample SFGs shows a wide coverage, dramatically differing from the
limited range of for a starburst of constant star formation. Our
results show that strong degeneracies between , , and in
the SED fitting induce systematic biases leading to a false --
correlation. Our simulation tests reveal that this relationship can be well
reproduced even when a flat -- relation is taken to build the
input model galaxy SEDs. The variations in best-fitting are dominated
by the fitting errors. We show that assuming a starburst with constant star
formation in SED fitting will result in a steeper attenuation curve, smaller
degeneracy errors, and a stronger -- relation. Our findings
confirm that the -- relation obtained through SED fitting is
likely driven by the systematic biases induced by the fitting degeneracies
between , , and .Comment: 21 pages, 13 figures, accepted for publication in the MNRAS, Comments
welcome
PyPose v0.6: The Imperative Programming Interface for Robotics
PyPose is an open-source library for robot learning. It combines a
learning-based approach with physics-based optimization, which enables seamless
end-to-end robot learning. It has been used in many tasks due to its
meticulously designed application programming interface (API) and efficient
implementation. From its initial launch in early 2022, PyPose has experienced
significant enhancements, incorporating a wide variety of new features into its
platform. To satisfy the growing demand for understanding and utilizing the
library and reduce the learning curve of new users, we present the fundamental
design principle of the imperative programming interface, and showcase the
flexible usage of diverse functionalities and modules using an extremely simple
Dubins car example. We also demonstrate that the PyPose can be easily used to
navigate a real quadruped robot with a few lines of code
Loop-Mediated Isothermal Amplification for the Rapid Detection of the Mutation of Carbendazim-Resistant Isolates in <i>Didymella bryoniae</i>
Gummy stem blight (GSB) caused by Didymella bryoniae (D. bryoniae) is a worldwide fungal soil-borne disease that can cause severe yield reduction of watermelon. To shorten the monitoring time of carbendazim-resistant strains of D. bryoniae in the field, in this study, we developed a loop-mediated isothermal amplification (LAMP) assay for rapid detection of carbendazim-resistant strains of D. bryoniae. The Ī²-tubulin gene of carbendazim-resistant strains was selected as the target for primer design. Based on the color change of hydroxy naphthol blue (HNB) and gel electrophoresis, the optimal reaction conditions for LAMP were determined at 65 Ā°C for 50 min. In specificity tests, the LAMP assay was able to distinguish between carbendazim-resistant and sensitive strains of D. bryoniae. Moreover, in sensitivity tests, the detection limit was 1 ng/Ī¼L D. bryoniae DNA of the carbendazim-resistant strain. In addition, the LAMP method was successfully applied to detect carbendazim-resistant strains in D. bryoniae-infested samples. Therefore, the developed LAMP assay provides a new method for the rapid detection of carbendazim-resistant strains of D. bryoniae