Natural disasters such as landslides often occur on soil slopes in seasonally frozen areas that undergo freeze‒thaw cycling. Ecological slope protection is an effective way to prevent such disasters. ...To explore the change in the mechanical properties of soil under the influence of both root reinforcement and freeze‒thaw cycles and its influence on slope stability, the Baijiabao landslide in the Three Gorges Reservoir area was taken as an example. The mechanical properties of soil under different confining pressures, vegetation coverages (VCs) and numbers of freeze‒thaw cycles were studied via mechanical tests, such as triaxial compression tests, wave velocity tests and FLAC3D simulations. The results show that the shear strength of a root-soil composite increases with increasing confining pressure and VC and decreases with increasing number of freeze‒thaw cycles. Bermuda grass roots and confining pressure jointly improve the durability of soil under freeze‒thaw conditions. However, with an increase in the number of freeze‒thaw cycles, the resistance of root reinforcement to freeze‒thaw action gradually decreases. The observed effect of freeze‒thaw cycles on soil degradation was divided into three stages: a significant decrease in strength, a slight decrease in strength and strength stability. Freeze‒thaw cycles and VC mainly affect the cohesion of the soil and have little effect on the internal friction angle. Compared with that of a bare soil slope, the safety factor of a slope covered with plants is larger, the maximum displacement of a landslide is smaller, and it is less affected by freezing and thawing. These findings can provide a reference for research on ecological slope protection technology.
The marine ciliate Mesodinium rubrum is famous for its ability to acquire and exploit chloroplasts and other cell organelles from some cryptophyte algal species. We sequenced genomes and ...transcriptomes of free-swimming Teleaulax amphioxeia, as well as well-fed and starved M. rubrum in order to understand cellular processes upon sequestration under different prey and light conditions. From its prey, the ciliate acquires the ability to photosynthesize as well as the potential to metabolize several essential compounds including lysine, glycan, and vitamins that elucidate its specific prey dependency. M. rubrum does not express photosynthesis-related genes itself, but elicits considerable transcriptional control of the acquired cryptophyte organelles. This control is limited as light-dependent transcriptional changes found in free-swimming T. amphioxeia got lost after sequestration. We found strong transcriptional rewiring of the cryptophyte nucleus upon sequestration, where 35% of the T. amphioxeia genes were significantly differentially expressed within well-fed M. rubrum. Qualitatively, 68% of all genes expressed within well-fed M. rubrum originated from T. amphioxeia. Quantitatively, these genes contributed up to 48% to the global transcriptome in well-fed M. rubrum and down to 11% in starved M. rubrum. This tertiary endosymbiosis system functions for several weeks, when deprived of prey. After this point in time, the ciliate dies if not supplied with fresh prey cells. M. rubrum represents one evolutionary way of acquiring photosystems from its algal prey, and might represent a step on the evolutionary way towards a permanent tertiary endosymbiosis.
Extensive adenosine-to-inosine (A-to-I) editing of nuclear-transcribed mRNAs is the hallmark of metazoan transcriptional regulation. Here, by profiling the RNA editomes of 22 species that cover major ...groups of Holozoa, we provide substantial evidence supporting A-to-I mRNA editing as a regulatory innovation originating in the last common ancestor of extant metazoans. This ancient biochemistry process is preserved in most extant metazoan phyla and primarily targets endogenous double-stranded RNA (dsRNA) formed by evolutionarily young repeats. We also find intermolecular pairing of sense-antisense transcripts as an important mechanism for forming dsRNA substrates for A-to-I editing in some but not all lineages. Likewise, recoding editing is rarely shared across lineages but preferentially targets genes involved in neural and cytoskeleton systems in bilaterians. We conclude that metazoan A-to-I editing might first emerge as a safeguard mechanism against repeat-derived dsRNA and was later co-opted into diverse biological processes due to its mutagenic nature.
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•A-to-I editing is a regulatory innovation originating in the ancestor of metazoans•Evolutionarily young repetitive elements are the primary targets of A-to-I editing•Editing on pairing regions of sense-antisense transcripts is common in some species•Recoding editing convergently targets neural and cytoskeleton systems in Bilateria
Zhang et al. profile the RNA editomes of 22 species that cover major groups of Holozoa. Their findings support ADAR-mediated A-to-I editing as a metazoan innovation, which might have first emerged as a safeguard mechanism against repeat-derived dsRNA and was later co-opted into other biological processes due to its mutagenic nature.
Ventriculomegaly with cystic kidney disease (VMCKD) is a rare and severe disorder characterized by cerebral ventriculomegaly, greatly elevated maternal serum alpha-fetoprotein (MSAFP) or amniotic ...fluid alpha-fetoprotein (AFAFP) levels and kidney disease similar to Finnish congenital nephrosis. Recessive mutations in the CRB2 (NM_173689) gene have been shown to cause the syndrome. Here, we described a nonconsanguineous Chinese family with two fetuses affected with VMCKD. A novel compound heterozygous mutation was identified in the CRB2 gene with co-segregation. One mutation c.1960G>C (p.A654P) was inherited from the father, while another mutation c.3078_c.3093delGGCGCGGCCCCGGCCC (p.L1026Lfs*110) was inherited from the mother. Preimplantation genetic testing for monogenic disease (PGT-M) was performed for the carrier couple with full informed consent and successfully blocked the inheritance of the disease. Our study has important implications on molecular diagnosis and genetic counseling for VMCKD and extends the mutation spectrum in CRB2 gene.
In order to research the new sub-synchronous oscillation (SSO) phenomenon caused by the wind power, first, this work studied the characteristics of the wind turbine in the frequency of the SSO, ...considering the characteristics of the wind controller simultaneously, and established the wind turbine and the power grid transmission model under the SSO propagation path. Then, the non-infinite equivalent model of the grid power model was proposed in order to change the strengthening degree. Third, a comprehensive evaluation index based on the oscillation energy was presented, and the capacity of the wind power from the frequency limit of the SSO was evaluated; meanwhile, the constraints of the SSO have been studied to maintain the stability of the power network. Finally, the rationality and effectiveness of the method were verified based on the IEEE 39-node model.
High throughput sequencing has previously identified differentially expressed genes (DEGs) and enriched signalling networks in human myometrium for term (≥37 weeks) gestation labour, when defined as ...a singular state of activity at comparison to the non-labouring state. However, transcriptome changes that occur during transition from early to established labour (defined as ≤3 and >3 cm cervical dilatation, respectively) and potentially altered by fetal membrane rupture (ROM), when adapting from onset to completion of childbirth, remained to be defined. In the present study, we assessed whether differences for these two clinically observable factors of labour are associated with different myometrial transcriptome profiles. Analysis of our tissue ('bulk') RNA-seq data (NCBI Gene Expression Omnibus: GSE80172) with classification of labour into four groups, each compared to the same non-labour group, identified more DEGs for early than established labour; ROM was the strongest up-regulator of DEGs. We propose that lower DEGs frequency for early labour and/or ROM negative myometrium was attributed to bulk RNA-seq limitations associated with tissue heterogeneity, as well as the possibility that processes other than gene transcription are of more importance at labour onset. Integrative analysis with future data from additional samples, which have at least equivalent refined clinical classification for labour status, and alternative omics approaches will help to explain what truly contributes to transcriptomic changes that are critical for labour onset. Lastly, we identified five DEGs common to all labour groupings; two of which (AREG and PER3) were validated by qPCR and not differentially expressed in placenta and choriodecidua.
Aims
The aim of this study was to analyze changes in emission of water-soluble ions in fine particulate matter over time and in different southwest forest areas in China based on China’s Forestry ...Statistical Yearbook and MODIS satellite fire point data.
Methods
We took 6 dominant tree species samples in the southwestern forest region of China and simulated combustion using controllable biomass combustion devices. Based on the spatial analysis method of ArcGIS, combining satellite fire point data and official statistical yearbooks, we analyzed the spatial and temporal dynamics of emissions of water-soluble ions in PM2.5 released by forest fires in southwestern forest areas from 2004 to 2021.
Results
The total amount of forest biomass combusted in southwest forest areas was 64.43 kt. Among the different forest types, the proportion of burnt subtropical evergreen broad-leaved forest was the largest (60.49%) followed by subtropical mixed coniferous and broad-leaved forest (22.78%) and subtropical evergreen coniferous forest (16.72%). During the study period, 61.19 t of water-soluble ions were released in PM
2.5
from forest fires, and the emissions of Li
+
, Na
+
, NH
4
+
, K
+
, Mg
2+
, Ca
2+
, F
−
, Cl
−
, Br
−
, NO
3
−
, PO
4
3−
and SO
4
2−
were 0.48 t, 11.54 t, 2.51 t, 19.44 t, 2.12 t, 2.92 t, 1.94 t, 12.70 t, 1.12 t, 1.18 t, 1.17 t and 4.07 t, respectively. Yunnan was the province with the highest emissions of water-soluble ions in PM
2.5
in the southwest forest areas, and the concentration K
+
was the highest. Emission of water-soluble ions in Yunnan and Sichuan all showed a significant downward trend, while the overall decrease in Tibet, Chongqing and Guizhou was not significant. The peak emission of water-soluble ions in PM
2.5
during forest fires appeared in spring and winter, which accounted for 87.66% of the total emission.
Discussion
This study reveals the spatiotemporal changes in water-soluble ion emissions from forest fires, by studying the spatiotemporal dynamics of water-soluble ions in PM
2.5
, we can better understand the sources, distribution, and change patterns of these ions, as well as their impact on the atmospheric environment, ecosystems, and climate change. This information is crucial for predicting and managing air pollution, as well as developing effective forest management and environmental protection policies to respond to fires; and hence concerted fire prevention efforts should be made in each province, taking into account the season with higher probability of fire occurrence to reduce the potential impact of fire-related pollutions.
The high-voltage DC transmission (HVDC) technology has become more and more popular for grid integration of large and remote wind farms. There was the new form of SSO appeared in Xinjing Grid which ...was the PMSG integration through an HVDC system, so the SSO was studied. The detailed model of the wind power transmission system through the two-terminal HVDC system was established. With the small signal method in case of the SSO fed into the system, due to the characteristics of the PMSG and HVDC topology, the expressions of the output signal of SSO were derived. Based on the ideal model，a control scheme for SSO suppression was proposed from the perspective of the PMSG controller. Finally, verified the rationality and effectiveness of the method based on the simplified Xinjiang grid model.
In this letter, we propose a novel low-rank-representation (LRR) based manifold-regularization approach for zero-shot learning (ZSL). Most existing regularization-based ZSL approaches perform the ...alignment between visual feature space and semantic space based on the affinity matrix constructed from the test instances. The affinity matrix plays a significant role in exploiting the manifold structures of visual feature space, hence we propose to use the LRR to guide the affinity-matrix construction by exploring the subspace structures of data. Considering the locality and similarity information among data, we incorporate a Laplacian regularization term to the LRR framework to ensure that the learned affinity matrix can capture the local geometric structures in data. We also explicitly impose the nonnegative sparse constraint on the affinity matrix to facilitate the learning of local manifold structures. Moreover, we use an effective manifold-regularization methodology to learn discriminative semantic representations of test instances, leading to significant improvements in classification performance over the unseen classes. Extensive experiments on three benchmark datasets demonstrate that the proposed approach outperforms the state of the arts.
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