Convolutional neural networks (CNNs) have been widely used in the field of remote sensing (RS) scene classification, which have achieved remarkable results. In RS scene classification, local key ...objects are particularly crucial for classification results. However, most existing CNN methods directly utilize the deep-level global features of CNN, ignoring object-level information in shallow features or leading to redundant and erroneous information when using shallow features. To fully utilize the important information in shallow features, we proposed an end-to-end contextual spatial-channel attention network (CSCANet) to learn multilayer feature representations and further improve classification performance by employing shallow object-level semantic information. First, ResNet34 is pretrained to extract different levels of features. Second, a contextual spatial-channel attention module (CSCAM) is constructed to generate contextual spatial-channel attention features by exploiting features at different levels. Finally, the triple loss function is combined with the central loss function to guide the model training. Experiments on three public RS scene classification datasets UC-Merced (UCM), aerial image dataset (AID), and NWPU-RESISC45 (NWPU) demonstrate that the proposed method achieves highly competitive results.
The spikelet number per spike (SNS) contributes greatly to grain yield in wheat. Identifying various genes that control wheat SNS is vital for yield improvement. This study used a recombinant inbred ...line population genotyped by the Wheat55K single-nucleotide polymorphism array to identify two major and stably expressed quantitative trait loci (QTLs) for SNS. One of them (QSns.sau-2SY-2D.1) was reported previously, while the other (QSns.sau-2SY-7A) was newly detected and further analyzed in this study. QSns.sau-2SY-7A had a high LOD value ranging from 4.46 to 16.00 and explained 10.21–40.78％ of the phenotypic variances. QSns.sau-2SY-7A was flanked by the markers AX-110518554 and AX-110094527 in a 4.75-cM interval on chromosome arm 7AL. The contributions and interactions of both major QTLs were further analyzed and discussed. The effect of QSns.sau-2SY-7A was successfully validated by developing a tightly linked kompetitive allele specific PCR marker in an F2:3 population and a panel of 101 high-generation breeding wheat lines. Furthermore, several genes including the previously reported WHEAT ORTHOLOG OF APO1 (WAPO1), an ortholog of the rice gene ABERRANT PANICLE ORGANIZATION 1 (APO1) related to SNS, were predicted in the interval of QSns.sau-2SY-7A. In summary, these results revealed the genetic basis of the multi-spikelet genotype of wheat line 20828 and will facilitate subsequent fine mapping and breeding utilization of the major QTLs.
Elymus breviaristatus and Elymus sinosubmuticus are perennial herbs, not only morphologically similar but also sympatric distribution. The genome composition of E. sinosubmuticus has not been ...reported, and the relationship between E. sinosubmuticus and E. breviaristatus is still controversial. We performed artificial hybridization, genomic in situ hybridization, and phylogenetic analyses to clarify whether the two taxa were the same species.
The high frequency bivalent (with an average of 20.62 bivalents per cell) at metaphase I of pollen mother cells of the artificial hybrids of E. breviaristatus (StYH) × E. sinosubmuticus was observed. It illustrated that E. sinosubmuticus was closely related to E. breviaristatus. Based on genomic in situ hybridization results, we confirmed that E. sinosubmuticus was an allohexaploid, and the genomic constitution was StYH. Phylogenetic analysis results also supported that this species contained St, Y, and H genomes. In their F
hybrids, pollen activity was 53.90%, and the seed setting rate was 22.46%. Those indicated that the relationship between E. sinosubmuticus and E. breviaristatus is intersubspecific rather than interspecific, and it is reasonable to treated E. sinosubmuticus as the subspecies of E. breviaristatus.
In all, the genomic constitutions of E. sinosubmuticus and E. breviaristatus were StYH, and they are species in the genus Campeiostachys. Because E. breviaristatus was treated as Campeistachys breviaristata, Elymus sinosubmuticus should be renamed Campeiostachys breviaristata (Keng) Y. H. Zhou, H. Q. Zhang et C. R. Yang subsp. sinosubmuticus (S. L. Chen) Y. H. Zhou, H. Q. Zhang et L. Tan.
Benzoylecgonine (BZE) is the major toxic metabolite of cocaine and is responsible for the long‐term cocaine‐induced toxicity owing to its long residence time in humans. BZE is also the main ...contaminant following cocaine consumption. Here, we identified the bacterial cocaine esterase (CocE) as a BZE‐metabolizing enzyme (BZEase), which can degrade BZE into biological inactive metabolites (ecgonine and benzoic acid). CocE was redesigned by a reactant‐state‐based enzyme design theory. An encouraging mutant denoted as BZEase2, presented a >400‐fold improved catalytic efficiency against BZE compared with wild‐type (WT) CocE. In vivo, a single dose of BZEase2 (1 mg kg−1, IV) could eliminate nearly all BZE within only two minutes, suggesting the enzyme has the potential for cocaine overdose treatment and BZE elimination in the environment by accelerating BZE clearance. The crystal structure of a designed BZEase was also determined.
Benzoylecgonine (BZE) is the major toxic metabolite of cocaine and is responsible for cocaine‐induced long‐term toxicity owing to its long residence time in humans. We computationally identified, re‐designed, and crystallized a novel BZEase. The obtained BZEase mutant shows a 427‐fold improved catalytic efficiency toward BZE compared to WT BZEase. In vivo tests prove that the BZEase mutant is a promising treatment for BZE detoxification.
Background
Elymus atratus
(Nevski) Hand.-Mazz. is perennial hexaploid wheatgrass. It was assigned to the genus
Elymus
L. sensu stricto based on morphological characters. Its genome constitution has ...not been disentangled yet.
Objective
To identify the genome constitution and origin of
E. atratus
.
Methods
In this study, genomic in situ hybridization and fluorescence in situ hybridization, and phylogenetic analysis based on the
Acc1, DMC1
and
matK
sequences were performed.
Results
Genomic in situ hybridization and fluorescence in situ hybridization results reveal that
E. atratus
2n = 6x = 42 is composed of 14
St
genome chromosomes, 14
H
genome chromosomes, and 14
Y
genome chromosomes including two
H
-
Y
type translocation chromosomes, suggesting that the genome formula of
E. atratus
is
StStYYHH
. The phylogenetic analysis based on
Acc1
and
DMC1
sequences not only shows that the
Y
genome originated in a separate diploid, but also suggests that
Pseudoroegneria
(
St
),
Hordeum
(
H
), and a diploid species with
Y
genome were the potential donors of
E. atratus
. Data from chloroplast DNA showed that the maternal donor of
E. atratus
contains the
St
genome.
Conclusion
Elymus atratus
is an allohexaploid species with
StYH
genome, which may have originated through the hybridization between an allotetraploid
Roegneria
(
StY
) species as the maternal donor and a diploid
Hordeum
(
H
) species as the paternal donor.
The level and pattern of nucleotide variation in duplicate gene provide important information on the evolutionary history of polyploids and divergent process between homoeologous loci within ...lineages. Kengyilia is a group of allohexaploid species with the StYP genomic constitutions in the wheat tribe. To investigate the evolutionary dynamics of the Pgk1 gene in Kengyilia and its diploid relatives, three copies of Pgk1 homoeologues were isolated from all sampled hexaploid Kengyilia species and analyzed with the Pgk1 sequences from 47 diploid taxa representing 18 basic genomes in Triticeae. Sequence diversity patterns and genealogical analysis suggested that (1) Kengyilia species from the Central Asia and the Qinghai-Tibetan plateau have independent origins with geographically differentiated P genome donors and diverged levels of nucleotide diversity at Pgk1 locus; (2) a relatively long-time sweep event has allowed the Pgk1 gene within Agropyron to adapt to cold climate triggered by the recent uplifts of the Qinghai-Tibetan Plateau; (3) sweep event and population expansion might result in the difference in the d(N)/d(S) value of the Pgk1 gene in allopatric Agropyron populations, and this difference may be genetically transmitted to Kengyilia lineages via independent polyploidization events; (4) an 83 bp MITE element insertion has shaped the Pgk1 loci in the P genome lineage with different geographical regions; (5) the St and P genomes in Kengyilia were donated by Pseudoroegneria and Agropyron, respectively, and the Y genome is closely related to the Xp genome of Peridictyon sanctum. The interplay of evolutionary forces involving diverged natural selection, population expansion, and transposable events in geographically differentiated P genome donors could attribute to geographical differentiation of Kengyilia species via independent origins.
A discrete element method (DEM) model of the crushing process of a toothed double-roll crusher (TDRC) is established using the bonded particle model. DEM results and experimental data are compared ...quantitatively and a relatively good agreement is observed. The effects of rotation speed and structure of crushing rolls on the performance of TDRC are investigated numerically. The results show that when the rolls' speed is relatively high, the nipping condition would be improved, and more cracks could be created to release the increasing strain energy, generating more fractions of small sizes in the products. But, when rolls' speed exceeds 150 rpm, the crushing performance would not be significantly improved. A reasonable working gap and better nipping behaviour are obtained using the spiral-tooth-roll or the staggered-tooth-roll. The validated DEM model could be applied to gain a fundamental understanding of the crushing mechanisms of TDRC.
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•A DEM model of a toothed double-roll crusher was established based on bonded particle model.•Validation in terms of product size distribution was conducted for three groups of tests.•The effects of rotation speed and structure of rolls on the crushing process were investigated.•The breakage mechanism of the particle was discussed based on fracture dynamics.
To investigate the pattern of chloroplast genome variation in Triticeae, we comprehensively analyzed the indels in protein-coding genes and intergenic sequence, gene loss/pseudonization, intron ...variation, expansion/contraction in inverted repeat regions, and the relationship between sequence characteristics and chloroplast genome size in 34 monogenomic Triticeae plants. Ancestral genome reconstruction suggests that major length variations occurred in four-stem branches of monogenomic Triticeae followed by independent changes in each genus. It was shown that the chloroplast genome sizes of monogenomic Triticeae were highly variable. The chloroplast genome of
,
,
,
,
,
,
, and
in Triticeae had evolved toward size reduction largely because of pseudogenes elimination events and length deletion fragments in intergenic. The
/
complex,
,
,
,
, and
in Triticeae had a larger chloroplast genome size. The large size variation in major lineages and their subclades are most likely consequences of adaptive processes since these variations were significantly correlated with divergence time and historical climatic changes. We also found that several intergenic regions, such as
N-
C and
E-
L containing unique genetic information, which can be used as important tools to identify the maternal relationship among Triticeae species. Our results contribute to the novel knowledge of plastid genome evolution in Triticeae.
With the acceleration of the aging process of society, stroke has become a major health problem in the middle-aged and elderly population. A number of new stroke risk factors have been recently ...found. It is necessary to develop a predictive risk stratification tool using multidimensional risk factors to identify people at high risk for stroke.
The study included 5,844 people (age ≥ 45 years) who participated in the China Health and Retirement Longitudinal Study in 2011 and its follow-up up to 2018. The population samples were divided into training set and validation set according to 1:1. A LASSO Cox screening was performed to identify the predictors of new-onset stroke. A nomogram was developed, and the population was stratified according to the score calculated through the X-tile program. Internal and external verifications of the nomogram were performed by ROC and calibration curves, and the Kaplan-Meier method was applied to identify the performance of the risk stratification system.
The LASSO Cox regression screened out 13 candidate predictors from 50 risk factors. Finally, nine predictors, including low physical performance and the triglyceride-glucose index, were included in the nomogram. The nomogram's overall performance was good in both internal and external validations (AUCs at 3-, 5-, and 7-year periods were 0.71, 0.71, and 0.71 in the training set and 0.67, 0.65, and 0.66 in the validation set, respectively). The nomogram was proven to excellently discriminate between the low-, moderate-, and high-risk groups, with a prevalence of 7-year new-onset stroke of 3.36, 8.32, and 20.13%, respectively (
< 0.001).
This research developed a clinical predictive risk stratification tool that can effectively identify the different risks of new-onset stroke in 7 years in the middle-aged and elderly Chinese population.
Roegneria is a polyploid perennial genus in the tribe Triticeae. Some species of Roegneria are morphologically similar to genus Elymus and have been classified in Elymus. To investigate the ...delimitation and phylogenetic relationships of Roegneria, nuclear (ITS, Acc1, and Pgk1) and chloroplast (trnL–trnF) DNA regions were sequenced for 38 allopolyploid species and 32 diploid species of Triticeae. Phylogenetic analyses of nuclear DNA revealed that all Roegneria species were included in the St and Y genome clades, and that the Y genome was closely related to the V and Xp genomes. The chloroplast DNA dataset showed that Roegneria species were grouped with Pseudoroegneria species. The Pseudoroegneria species from the Middle East (P. libanotica and P. tauri) and Central Asia (P. strigosa) were more closely related to Roegneria species. The results suggested that: (i) the species containing the St and Y genomes should be segregated from Elymus and treated as a distinct genus, Roegneria, based on the genomic constitution; (ii) P. libanotica, P. tauri, and/or P. strigosa potentially served as the maternal donor of the St genome in Roegneria; (iii) The Y genome of Roegneria originated from a diploid Y genome species, and the V and Xp genomes may have contributed to Y genome formation; (iv) among Roegneria species of previously uncertain genomic constitution, R. seriotina was tetraploid and possessed the StY genomes, E. calcicolus was hexaploid with the StYH genomic constitution and should be classified in Campeiostachys, R. glaucifolia possessed the StStY genomes, and R. tschimganica had the genomic constitution St1St2Y.
Bayesian tree and parsimony network were inferred from the Pgk1 sequences of Roegneria and its closely related species. Phylogenetic analyses have revealed that all Roegneria species were included in the St and Y genome clades, and that the Y genome was closely related to the V and Xp genomes. The Pseudoroegneria species from the Middle East (P. libanotica and P. tauri) and Central Asia (P. strigosa) were more closely related to Roegneria species.
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