72 research outputs found
Skeleton based action recognition using translation-scale invariant image mapping and multi-scale deep cnn
This paper presents an image classification based approach for skeleton-based
video action recognition problem. Firstly, A dataset independent
translation-scale invariant image mapping method is proposed, which transformes
the skeleton videos to colour images, named skeleton-images. Secondly, A
multi-scale deep convolutional neural network (CNN) architecture is proposed
which could be built and fine-tuned on the powerful pre-trained CNNs, e.g.,
AlexNet, VGGNet, ResNet etal.. Even though the skeleton-images are very
different from natural images, the fine-tune strategy still works well. At
last, we prove that our method could also work well on 2D skeleton video data.
We achieve the state-of-the-art results on the popular benchmard datasets e.g.
NTU RGB+D, UTD-MHAD, MSRC-12, and G3D. Especially on the largest and challenge
NTU RGB+D, UTD-MHAD, and MSRC-12 dataset, our method outperforms other methods
by a large margion, which proves the efficacy of the proposed method
The bacterial and fungal microbiomes of ectomycorrhizal roots from stone oaks and Yunnan pines in the subtropical forests of the Ailao Mountains of Yunnan
Ectomycorrhizal (ECM) symbioses play an important role in tree biology and forest ecology. However, little is known on the composition of bacterial and fungal communities associated to ECM roots. In the present study, we surveyed the bacterial and fungal microbiome of ECM roots from stone oaks (Lithocarpus spp.) and Yunnan pines (Pinus yunnanensis) in the subtropical forests of the Ailao Mountains (Yunnan, China). The bacterial community was dominated by species pertaining to Rhizobiales and Acidobacteriales, whereas the fungal community was mainly composed of species belonging to the Russulales and Thelephorales. While the bacterial microbiome hosted by ECM roots from stone oaks and Yunnan pines was very similar, the mycobiome of these host trees was strikingly distinct. The microbial networks for bacterial and fungal communities showed a higher complexity in Lithocarpus ECM roots compared to Pinus ECM roots, but their modularity was higher in Pinus ECM roots. Seasonality also significantly influenced the fungal diversity and their co-occurrence network complexity. Our findings thus suggest that the community structure of fungi establishing and colonizing ECM roots can be influenced by the local soil/host tree environment and seasonality. These results expand our knowledge of the ECM root microbiome and its diversity in subtropical forest ecosystems
Electrochemical hydrogenation of mixed-phase TiO₂ nanotube arrays enables remarkably enhanced photoelectrochemical water splitting performance
We first report that photoelectrochemical (PEC) performance of electrochemically hydrogenated TiO2 nanotube arrays (TNTAs) as high-efficiency photoanodes for solar water splitting could be well tuned by designing and adjusting the phase structure and composition of TNTAs. Among various TNTAs annealed at different temperature ranging from 300 to 700 °C, well-crystallized single anatase (A) phase TNTAs-400 photoanode shows the best photoresponse properties and PEC performance due to the favorable crystallinity, grain size and tubular structures. After electrochemical hydrogenation (EH), anatase-rutile (A-R) mixed phase EH-TNTAs-600 photoanode exhibits the highest photoactivity and PEC performance for solar water splitting. Under simulated solar illumination, EH-TNTAs-600 achieves the best photoconversion efficiency of up to 1.52% and maximum H2 generation rate of 40.4 µmol h−1 cm−2, outstripping other EH-TNTAs photoanodes. Systematic studies reveal that the signigicantly enhanced PEC performance for A-R mixed phaes EH-TNTAs-600 photoanode could be attributed to the synergy of A-R mixed phases and intentionally introduced Ti3+ (oxygen vacancies) which enhances the photoactivity over both UV and visible-light regions, and boosts both charge separation and transfer efficiencies. These findings provide new insight and guidelines for the construction of highly efficient TiO2-based devices for the application of solar water splitting.This work was supported by the National Natural Science Foundation
of China (51402078, 21702041, and 11674354), the
National Basic Research Program of China (2014CB660815), and
the Fundamental Research Funds for the Central Universities
(JZ2016HGTB0711, JZ2016HGTB0719, and JZ2017HGPA0167)
The chemical profiling of Salvia plebeia during different growth periods and the biosynthesis of its main flavonoids ingredients
Salvia plebeia (Lamiaceae) is a valuable medicinal plant widely distributed across Asia and Oceania. However, the composition and accumulation patterns of its active ingredients in different organs during the growth and their biosynthetic mechanism remain unknown. Therefore, we conducted metabolite profiling, transcriptomic analysis, and biological functional verification to explore the distribution, accumulation, and biosynthesis mechanisms of flavonoids in S. plebeia. We identified 70 metabolites including 46 flavonoids, 16 phenolic acids, seven terpenoids, and one organic acid, of which 21 were previously unreported in S. plebeia. Combining metabolomic-transcriptomic analysis and biological functional verification, we identified the key genes involved in biosynthesis of its main active ingredients, hispidulin and homoplantaginin, including SpPAL, SpC4H, Sp4CL2, Sp4CL5, SpCHS1, SpCHI, SpFNS, SpF6H1, SpF6OMT1, SpF6OMT2, SpUGT1, SpUGT2, and SpUGT3. Using the identified genes, we reconstructed the hispidulin and homoplantaginin biosynthesis pathways in Escherichia coli, and obtained a yield of 5.33 and 3.86 mg/L for hispidulin and homoplantaginin, respectively. Our findings provide valuable insights into the changes in chemical components in different organs of S. plebeia during different growth and harvest stages and establishes a foundation for identifying and synthesizing its active components
Toward a natural classification of Botryosphaeriaceae : a study of the type specimens of Botryosphaeria sensu lato
The genus Botryosphaeria includes more than 200 epithets, but only the type
species, Botryosphaeria dothidea and a dozen or more other species have been
identified based on DNA sequence data. The taxonomic status of the other species
remains unconfirmed because they lack either morphological information or DNA
sequence data. In this study, types or authentic specimens of 16 “Botryosphaeria”
species are reassessed to clarify their identity and phylogenetic position. nuDNA
sequences of four regions, ITS, LSU, tef1-a and tub2, are analyzed and considered
in combination with morphological characteristics. Based on the multigene phylogeny
and morphological characters, Botryosphaeria cruenta and Botryosphaeria hamamelidis
are transferred to Neofusicoccum. The generic status of Botryosphaeria aterrima and
Botryosphaeria mirabile is confirmed in Botryosphaeria. Botryosphaeria berengeriana
var. weigeliae and B. berengeriana var. acerina are treated synonyms of B. dothidea.
Botryosphaeria mucosa is transferred to Neodeightonia as Neodeightonia mucosa, and
Botryosphaeria ferruginea to Nothophoma as Nothophoma ferruginea. Botryosphaeria
foliicola is reduced to synonymy with Phyllachorella micheliae. Botryosphaeria abuensis,
Botryosphaeria aesculi, Botryosphaeria dasylirii, and Botryosphaeria wisteriae are
tentatively kept in Botryosphaeria sensu stricto until further phylogenetic analysis is
carried out on verified specimens. The ordinal status of Botryosphaeria apocyni,
Botryosphaeria gaubae, and Botryosphaeria smilacinina cannot be determined, and
tentatively accommodate these species in Dothideomycetes incertae sedis. The
study demonstrates the significance of a polyphasic approach in characterizing type
specimens, including the importance of using of DNA sequence data.Supplementary Figure 1 | Botryosphaeria gaubae (W 1992-05937,
holotype). (A,B) Ascomata erumpent through the lower side of the leaf. (C)
Squash showing cylindrical or broadly cylindrical asci in cotton blue. (D) Part of
the peridium. (E) Septate pseudoparaphyses in cotton blue. (F-H) Aseptate,
fusiform to ellipsoid ascospores in cotton blue. Scale bars: (A) = 1 mm,
(B) = 200 mm, (C) = 50 mm, (E) = 20 mm, (D,F-H) = 10 m m.Supplementary Figure 2 | Laestadia apocyni (MICH 14281, isotype). (A)
Ascomata erumpent through a piece of twig epidermis. (B) Released, hyaline,
1-septate ascospores. (C) Ascus in water. (D) Line drawing of ascus in water.
Scale bars: (A) = 200 mm, (B-D) = 20 m m.Supplementary Figure 3 | Sphaeria smilacinina (NYS f2818, holotype). (A)
Ascomata erumpent through the twig epidermis. (B,C) Immature asci. (D)
Released ascospores. (E) Line drawing of broadly clavate ascus. Scale bars:
(A) = 500 mm, (B-D) = 20 mm, (E) = 40 m m.Supplementary Figure 4 | One of the most parsimonious trees obtained from
combined ITS, LSU, tub2, and tef1-a sequence data of Botryosphaeria spp.
Outgroup taxa are Neofusicoccum luteum and Neofusicoccum parvum. Maximum
parsimony (MP) support values above 70% and Bayesian posterior probabilities
(PP) support above 80% are shown with MP bootstrap followed by Bayesian PP
(MP/PP) values at the nodes. The species characterized in this study
are in boldface.Supplementary Figure 5 | One of the most parsimonious trees obtained based
on combined ITS, tef1-a, and tub2 sequence data of Neofusicoccum spp.
Outgroup taxon are Botryosphaeria dothidea and B. corticis. Maximum parsimony
(MP) support values above 60% and Bayesian posterior probabilities (PP) support
above 80% are shown with MP/PP, values at the nodes. The species
characterized in this study are in boldface.Supplementary Figure 6 | One of the most parsimonious trees obtained from
LSU sequence dataset of Neofusicoccum spp. Outgroup taxa are Botryosphaeria
corticis and B. dothidea. Maximum parsimony (MP) support values above 70%
and Bayesian posterior probabilities (PP) support above 80% are shown with MP
bootstrap followed by Bayesian PP (MP/PP) values at the nodes. The species
characterized in this study are in boldface.Supplementary Figure 7 | One of the most parsimonious trees obtained from
ITS and LSU sequence dataset of Nothophoma spp. Outgroup taxa is Didymella
calidophila. Maximum likelihood (ML) support values above 50%, Maximum
parsimony (MP) support values above 50%, and Bayesian posterior probabilities
(PP) support above 95% are shown with ML and MP bootstrap followed by
Bayesian PP (MP/PP/ML) values at the nodes. The species characterized in this
study are in boldface.Supplementary Table 1 | Species, specimens and GenBank accession numbers
of sequences used in this study (newly generated sequences are
indicated in bold).The National Natural Science Foundation of China and NSFC Projects of International Cooperation and Exchanges.http://www.frontiersin.org/Microbiologyam2022Forestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog
Using CRISPR Interference as a Therapeutic Approach to Treat TGFβ2-Induced Ocular Hypertension and Glaucoma
Purpose: Primary open angle glaucoma (POAG) is a leading cause of blindness worldwide with elevated intraocular pressure (IOP) as the most important risk factor. POAG IOP elevation is due to pathological changes in the trabecular meshwork (TM). Elevated TGFβ2 contributes to these changes and increases IOP. We have shown that histone hyperacetylation is associated with TGFβ2 elevation in the TM. In this study, we determined if clustered regularly interspaced short palindromic repeats (CRISPR) interference could specifically deacetylate histones and decrease TGFβ2 in the TM.
Methods: We tested the efficiency of different promoters in driving KRAB-dCAS9 expression in human TM cells. We also screened and determined the optimal sgRNA sequence in the inhibition of TGFβ2. Chromatin immunoprecipitation-qPCR was used to determine the binding of KRAB-dCAS9. An adenovirus-mediated TGFβ2-induced ocular hypertension (OHT) mouse model was used to determine the effect of the CRISPR interference system in vivo.
Results: We found that the CRISPR interference system inhibited TGFβ2 expression in human TM cells, and properly designed sgRNA targeted the promoter of the TGFβ2 gene. Using sgRNA targeting the CMV promoter of the Ad5-CMV-TGFβ2 viral vector, we found that lentivirus-mediated KRAB-dCAS9 and sgRNA expression was able to inhibit Ad5-CMV-TGFβ2-induced OHT in C57BL/6J female and male mice eyes. This inhibition of OHT was associated with decreased levels of TGFβ2 and extracellular matrix proteins in the mouse eye.
Conclusions: Our results indicate that CRISPR interference is a useful tool for gene inhibition and may be a therapeutic approach to treat TGFβ2-induced OHT
Three-Dimensional Flat Bands and Dirac Cones in a Pyrochlore Superconductor
Emergent phases often appear when the electronic kinetic energy is comparable
to the Coulomb interactions. One approach to seek material systems as hosts of
such emergent phases is to realize localization of electronic wavefunctions due
to the geometric frustration inherent in the crystal structure, resulting in
flat electronic bands. Recently, such efforts have found a wide range of exotic
phases in the two-dimensional kagome lattice, including magnetic order,
time-reversal symmetry breaking charge order, nematicity, and
superconductivity. However, the interlayer coupling of the kagome layers
disrupts the destructive interference needed to completely quench the kinetic
energy. Here we experimentally demonstrate that an interwoven kagome network--a
pyrochlore lattice--can host a three dimensional (3D) localization of electron
wavefunctions. In particular, through a combination of angle-resolved
photoemission spectroscopy, fundamental lattice model and density functional
theory (DFT) calculations, we present the novel electronic structure of a
pyrochlore superconductor, CeRu. We find striking flat bands with
bandwidths smaller than 0.03 eV in all directions--an order of magnitude
smaller than that of kagome systems. We further find 3D gapless Dirac cones
predicted originally by theory in the diamond lattice space group with
nonsymmorphic symmetry. Our work establishes the pyrochlore structure as a
promising lattice platform to realize and tune novel emergent phases
intertwining topology and many-body interactions.Comment: 12 pages, 3 figure
Reversible Non-Volatile Electronic Switching in a Near Room Temperature van der Waals Ferromagnet
The ability to reversibly toggle between two distinct states in a
non-volatile method is important for information storage applications. Such
devices have been realized for phase-change materials, which utilizes local
heating methods to toggle between a crystalline and an amorphous state with
distinct electrical properties. To expand such kind of switching between two
topologically distinct phases requires non-volatile switching between two
crystalline phases with distinct symmetries. Here we report the observation of
reversible and non-volatile switching between two stable and closely-related
crystal structures with remarkably distinct electronic structures in the near
room temperature van der Waals ferromagnet FeGeTe. From a
combination of characterization techniques we show that the switching is
enabled by the ordering and disordering of an Fe site vacancy that results in
distinct crystalline symmetries of the two phases that can be controlled by a
thermal annealing and quenching method. Furthermore, from symmetry analysis as
well as first principle calculations, we provide understanding of the key
distinction in the observed electronic structures of the two phases:
topological nodal lines compatible with the preserved global inversion symmetry
in the site-disordered phase, and flat bands resulting from quantum destructive
interference on a bipartite crystaline lattice formed by the presence of the
site order as well as the lifting of the topological degeneracy due to the
broken inversion symmetry in the site-ordered phase. Our work not only reveals
a rich variety of quantum phases emergent in the metallic van der Waals
ferromagnets due to the presence of site ordering, but also demonstrates the
potential of these highly tunable two-dimensional magnets for memory and
spintronics applications
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
- …