Search

Abstract Background Pituitary adenomas (PAs) are the second most common intracranial tumor. While current diagnostic practices rely primarily on histological testing, they often fail to capture the molecular complexities of pituitary adenomas, underscoring the need for a molecular-based classification to refine therapeutic strategies and prognostic assessments. This study aims to provide a molecularly unbiased classification of pituitary adenomas and explore their unique gene expression patterns and clinical features. Methods We performed unsupervised hierarchical clustering of the gene expression profiles of 117 PA samples to identify three distinct molecular subtypes. Subsequently, we analyzed the compiled transcriptomic profiles of each individual subtype for pathway enrichment. We also validated the new classification with a validation set containing 158 PAs and 24 pituitary adenoma stem cells (PASCs). Results Consensus clustering of transcriptomic data from 117 pituitary adenoma (PA) samples identified three distinct molecular subtypes, each showing unique gene expression patterns and associated biological processes: Group I is enriched in signaling pathways, such as the cAMP signaling pathway and the calcium signaling pathway. Group II is primarily related to metabolic processes, including nitrogen metabolism and arginine biosynthesis in cancer. Group III predominantly shows enrichment in immune responses and potential malignant transformation of the disease, especially through cancer-related pathways such as the JAK–STAT signaling pathway and the PI3K–Akt signaling pathway. The immune profiling revealed distinct patterns for each subtype: Group I had higher dendritic cells and fewer CD8+ T cells, Group II had more monocytes and macrophages, and Group III had elevated levels of T cells. Additionally, there were differences in clinical characteristics and prognosis among the subtypes, with Group III having a worse prognosis, despite the smaller tumor size compared to other groups. Notably, differences in PASCs correlated with the molecular subtypes, with Group III stem cells being enriched in tumorigenesis pathways, PI3K–Akt signaling pathway and Ras signaling pathway. Conclusion Our study introduces a novel molecular classification for pituitary adenomas, independent of traditional histological methods. Each subtype features distinct genetic, molecular, and immunological profiles. We have isolated pituitary adenoma stem-like cells (PASCs), pairing them with tumor tissues for detailed transcriptomic analysis. These PASCs exhibit diverse molecular traits consistent with the new classification.

Abstract Siberian wildrye (Elymus sibiricus) is a xero-mesophytic forage grass with high nutritional quality and stress tolerance. Among its numerous germplasm resources, some possess superior drought resistance. In this study, we firstly investigated the physiological differences between the leaves of drought-tolerant (DT) and drought-sensitive (DS) genotypes under different field water contents (FWC) in soil culture. The results showed that, under drought stress, DT maintained a lower leaf water potential for water absorption, sustained higher photosynthetic efficiency, and reduced oxidative damage in leaves by efficiently maintaining the ascorbic acid-glutathione (ASA-GSH) cycle to scavenge reactive oxygen species (ROS) compared to DS. Secondly, using RNA sequencing (RNA-seq), we analyzed the gene expression profiles of DT and DS leaves under osmotic stress of hydroponics induced by PEG-6000. Through differential analysis, we identified 1226 candidate unigenes, from which we subsequently screened out 115/212 differentially expressed genes (DEGs) that were more quickly induced/reduced in DT than in DS under osmotic stress. Among them, Unigene0005863 (EsSnRK2), Unigene0053902 (EsLRK10) and Unigene0031985 (EsCIPK5) may be involved in stomatal closure induced by abscisic acid (ABA) signaling pathway. Unigene0047636 (EsCER1) may positively regulates the synthesis of very-long-chain (VLC) alkanes in cuticular wax biosynthesis, influencing plant responses to abiotic stresses. Finally, the contents of wax and cutin were measured by GC–MS under osmotic stress of hydroponics induced by PEG-6000. Corresponding to RNA-seq, contents of wax monomers, especially alkanes and alcohols, showed significant induction by osmotic stress in DT but not in DS. It is suggested that limiting stomatal and cuticle transpiration under drought stress to maintain higher photosynthetic efficiency and water use efficiency (WUE) is one of the critical mechanisms that confer stronger drought resistance to DT. This study provides some insights into the molecular mechanisms underlying drought tolerance in E. sibiricus. The identified genes may provide a foundation for the selection and breeding of drought-tolerant crops.

Land conversion to agriculture is an important factor affecting soil ecological processes in the desert grasslands of northern China. However, soil fungal-community structure and function in response to Land conversion remain unclear. In this study, desert grassland, artificial shrubland, and land conversion were investigated in the western part of the Mu Us Sandland (Yanchi, Ningxia; Dingbian, Shaanxi). We found that land conversion significantly increased soil total carbon, nitrogen, and phosphorus, and available phosphorous and potassium contents. In the early stage of conversion to agricultural (April), soil fungal operational taxonomic units and abundance-based coverage estimator were lower than those of dessert grasslands and shrubland plots and had significant correlations with pH, electric conductivity, and available phosphorus and potassium. The dominant phyla strongly correlated with soil physicochemical properties. Concomitantly, the relative abundance of Glomeromycota was significantly lower, and the complexity of the network in the land conversion plots was lower than that in the shrubland plots. In the late stage of land conversion (September), soil fungal operational taxonomic units and abundance-based coverage estimator were lower in the conversion plots than in the desert grassland plots, with more complex network relationships compared to the desert grassland or shrubland plots. Symbiotrophic groups, a functional group of desert grassland soil fungi, can be used as a predictor of environmental change; in addition, land conversion decreases the relative abundance of arbuscular mycorrhizal functional groups. Our study highlights the response of soil fungal communities and functions to human disturbances in desert grasslands. Considering the potential of land conversion to agriculture to influence soil secondary salinization, there is a need for continued observation of soil ecological health over the time continuum of land conversion to agriculture.

Canopy layer urban heat island (CLUHI) is closely related to about 4.7 billion urban residents’ well-being. Compared with sparse observation stations, remote sensing can obtain spatially continuous temperature, which is conducive to intra-annual variation and associated factors of CLUHI over large regions. Such research is scarce, especially from apparent temperature perspective. Thus, the intra-annual spatio-temporal variations and twelve determinants of CLUHI intensities (CLUHIIs) were investigated for 917 urban region agglomerations in China’s five ecological regions, using remotely sensed near-surface air temperature, apparent temperature and other multi-source data, and several spatial analysis and mathematical statistic methods. The findings revealed that annual CLUHIIs by mean temperatures were most between 0.5 and 1.0 ℃, higher in the summer and spring, and larger in North China than South China in the summer. The annual CLUHIIs by maximum temperatures were negative in several cities, especially in rainless West China. North China generally had stronger CLUHIIs by minimum temperatures in all seasons compared to South China. The CLUHIIs by mean apparent temperatures were larger in the summer (most between 0.5 and 2.0 ℃) and varied across ecological regions. Significant positive correlations generally existed among CLUHIIs by various air temperature and land surface temperature indices (p

Soil bacteria are important participants in biogeochemical cycles, and the stability of their community structure is not only affected by fluctuations in time and environment, but also by the participation and regulation of anthropogenic interference. With the increasing reclamation of farmland in the agropastoral transitional zone of northern China, it is imperative to understand the characteristics of soil bacterial communities in response to seasonal variations and anthropogenic reclamation. In this study, desert grassland, artificial shrubland, and desert grassland reclaimed farmland on the western side of the Mu Us Sandy Land were used as research objects. The following main results were obtained through soil sampling in April and September, and physicochemical analyses combined with 16S high-throughput sequencing: seasonal variations increased soil pH and soil water content, whereas land reclamation significantly increased soil total carbon, total phosphorus, soil available phosphorus, and soil available potassium contents. Changes in soil physicochemical properties altered the structure of soil bacterial communities to varying degrees, with Actinobacteriota and Acidobacteriota being the differential phyla among the three sampling sites under seasonal variations (p

The forced sweat cooling of porous media is an effective way to solve the problem of thermal protection of the leading edge of hypersonic vehicles. The pore structure and performance of porous media have a significant impact on its cooling effect and reliability. Therefore，it is very important to prepare porous materials that meet the requirements of forced sweat cooling. Herein，Ti6Al4V pre-alloyed powders were used as raw materials，and porous Ti6Al4V samples with different open porosity were prepared by compression molding combined with high-temperature sintering. The effect of the sintering temperature and holding time on the microstructures，phase compositions and mechanical properties of the samples were investigated. The results show that increasing the sintering temperature and prolonging the holding time will reduce the open porosity of the material. When the open porosity is high，the pores in the material are connected and the seepage rate is high，while the sample strength is low. When the open porosity is low，large pores in the sample are reduced and the seepage rate decreases，but the strength becomes higher. The porous Ti6Al4V sample with an open porosity of 21.8% shows the best comprehensive performance. When the porous Ti6Al4V sample is used as active thermal protection material，it can withstand flame ablation with an average heat flux of 2.5 MW/m2.

Summary: Interfacial investigation for fine-tuning microenvironment has recently emerged as a promising method to optimize the electrochemical CO2 reduction system. The electrical double layer located at the electrode-electrolyte interface presents a particularly significant impact on electrochemical reactions. However, its effect on the activity and selectivity of CO2 electrocatalysis remains poorly understood. Here, we utilized two-dimensional mica flakes, a material with a high dielectric constant, to modify the electrical double layer of Ag nanoparticles. This modification resulted in a significant enhancement of current densities for CO2 reduction and an impressive Faradaic efficiency of 98% for CO production. Our mechanistic investigations suggest that the enhancement of the electrical double layer capacitance through mica modification enriched local CO2 concentration near the reaction interface, thus facilitating CO2 electroreduction.

Oxidative stress-induced apoptosis is an important pathological process in renal ischemia/reperfusion injury (RIRI). Theaflavin (TF) is the main active pigment and polyphenol in black tea. It has been widely reported because of its biological activity that can reduce oxidative stress and protect against many diseases. Here, we explored the role of theaflavin in the pathological process of RIRI. In the present study, the RIRI model of 45 min ischemia and 24 h reperfusion was established in C57BL/6 J male mice, and theaflavin was used as an intervention. Compared with the RIRI group, the renal filtration function, renal tissue damage and antioxidant capacity of the theaflavin intervention group were significantly improved, while the level of apoptosis was reduced. TCMK-1 cells were incubated under hypoxia for 48 h and then reoxygenated for 6 h to simulate RIRI in vitro. The application of theaflavin significantly promoted the translocation of p53 from cytoplasm to nucleus, upregulated the expression of glutathione peroxidase 1 (GPx-1) in cells, and inhibited oxidative stress damage and apoptosis. Transfection with p53 siRNA can partially inhibit the effect of theaflavin. Thus, theaflavin exerted a protective effect against RIRI by inhibiting apoptosis and oxidative stress via regulating the p53/GPx-1 pathway. We conclude that theaflavin has the potential to become a candidate drug for the prevention and treatment of RIRI.

Abstract Medical devices are commonly implanted underneath the skin, but how to real‐time noninvasively monitor their migration, integrity, and biodegradation in human body is still a formidable challenge. Here, the study demonstrates that benzyl violet 4B (BV‐4B), a main component in the FDA‐approved surgical suture, is found to produce fluorescence signal in the first near‐infrared window (NIR‐I, 700–900 nm) in polar solutions, whereas BV‐4B self‐assembles into highly crystalline aggregates upon a formation of ultrasmall nanodots and can emit strong fluorescence in the second near‐infrared window (NIR‐II, 1000–1700 nm) with a dramatic bathochromic shift in the absorption spectrum of ≈200 nm. Intriguingly, BV‐4B‐involved suture knots underneath the skin can be facilely monitored during the whole degradation process in vivo, and the rupture of the customized BV‐4B‐coated silicone catheter is noninvasively diagnosed by NIR‐II imaging. Furthermore, BV‐4B suspended in embolization glue achieves hybrid fluorescence‐guided surgery (hybrid FGS) for arteriovenous malformation. As a proof‐of‐concept study, the solid‐state BV‐4B is successfully used for NIR‐II imaging of surgical sutures in operations of patients. Overall, as a clinically translatable solid‐state dye, BV‐4B can be applied for in vivo monitoring the fate of medical devices by NIR‐II imaging.

As carriers of direct contact between plants and the atmospheric environment, the microbiomes of phyllosphere microorganisms are increasingly recognized as an important area of study. Salt secretion triggered by salt-secreting halophytes elicits changes in the community structure and functions of phyllosphere microorganisms, and often provides positive feedback to the individual plant/community environment. In this study, the contents of Na+ and K+ in the rhizosphere, plant and phyllosphere of Tamarix chinensis were increased under 200 mmol/L NaCl stress. The increase in electrical conductivity, Na+ and K+ in the phyllosphere not only decreased the diversity of bacterial and fungal communities, but also decreased the relative abundance of Actinobacteriota and Basidiomycota. Influenced by electrical conductivity and Na+, the bacteria–fungus co-occurrence network under salt stress has higher complexity. Changes in the structure of the phyllosphere microbial community further resulted in a significant increase in the relative abundance of the bacterial energy source and fungal pathotrophic groups. The relative abundance of Actinobacteriota and Acidobacteriota in rhizosphere showed a decreasing trend under salt stress, while the complexity of the rhizosphere co-occurrence network was higher than that of the control. In addition, the relative abundances of functional groups of rhizosphere bacteria in the carbon cycle and phosphorus cycle increased significantly under stress, and were significantly correlated with electrical conductivity and Na+. This study investigated the effects of salinity on the structure and physicochemical properties of phyllosphere and rhizosphere microbial communities of halophytes, and highlights the role of phyllosphere microbes as ecological indicators in plant responses to stressful environments.

Abstract Background Gonadotrophic pituitary adenoma is a major subtype of pituitary adenoma in the sellar region, but it is rarely involved in the hypersecretion of hormones into blood; thus, it is commonly regarded as “non-functioning.” Its tumorigenic mechanisms remain unknown. The aim of this study was to identify human gonadotrophic pituitary adenoma stem cells (hPASCs) and explore the underlying gene expression profiles. In addition, the potential candidate genes involved in the invasive properties of pituitary adenoma were examined. Methods The hPASCs from 14 human gonadotrophic pituitary adenoma clinical samples were cultured and verified via immunohistochemistry. Genetic profiling of hPASCs and the matched tumor cells was performed through RNA-sequencing and subjected to enrichment analysis. By aligning the results with public databases, the candidate genes were screened and examined in invasive and non-invasive gonadotrophic pituitary adenomas using Real-time polymerase chain reaction. Results The hPASCs were successfully isolated and cultured from gonadotrophic pituitary adenoma in vitro, which were identified as positive for generic stem cell markers (Sox2, Oct4, Nestin and CD133) via immunohistochemical staining. The hPASCs could differentiate into the tumor cells expressing follicle-stimulating hormone in the presence of fetal bovine serum in the culture medium. Through RNA-sequencing, 1352 differentially expressed genes were screened and identified significantly enriched in various gene ontologies and important pathways. The expression levels of ANXA2, PMAIP1, SPRY2, C2CD4A, APOD, FGF14 and FKBP10 were significantly upregulated while FNDC5 and MAP3K4 were downregulated in the invasive gonadotrophic pituitary adenomas compared to the non-invasive ones. Conclusion Genetic profiling of hPASCs may explain the tumorigenesis and invasiveness of gonadotrophic pituitary adenoma. ANXA2 may serve as a potential therapeutic target for the treatment of gonadotrophic pituitary adenoma.

Abstract We aimed to develop a new biocompatible gastrin‐releasing peptide receptor (GRPR) targeted optical probe, IRDye800‐RM26, for fluorescence image‐guided surgery (FGS) of brain malignancies in near‐infrared window II (NIR‐II) imaging. We developed a novel GRPR targeting probe using a nine‐amino‐acid bombesin antagonist analog RM26 combined with IRDye800CW, and explored the fluorescent probe according to optical properties. Fluorescence imaging characterization in NIR‐I/II region was performed in vitro and in vivo. Following simulated NIR‐II image‐guided surgery, we obtained time‐fluorescent intensity curves and time‐signal and background ratio curves. Further, we used histological sections of brain from tumor‐beating mice model to compare imaging specificity between 5‐aminolevulinic acid (5‐ALA) and IRDye800‐RM26, and evaluated biodistribution and biocompatibility. IRDye800‐RM26 had broad emission ranging from 800 to 1200 nm, showing considerable fluorescent intensity in NIR‐II region. High‐resolution NIR‐II imaging of IRDye800‐RM26 can enhance the advantages of NIR‐I imaging. Dynamic and real time fluorescence imaging in NIR‐II region showed that the probe can be used to treat brain malignancies in mice between 12 and 24 h post injection. Its specificity in targeting glioblastoma was superior to 5‐ALA. Biodistribution analysis indicated IRDye800‐RM26 excretion in the kidney and liver. Histological and blood test analyses did not reveal acute severe toxicities in mice treated with effective dose (40 μg) of the probe for NIR‐II imaging. Because of the considerable fluorescent intensity in NIR‐II region and high spatial resolution, biocompatible and excretable IRDye800‐RM26 holds great potentials for FGS, and is essential for translation into human use.

Soil microbes are among the most complex and diverse communities on Earth, actively participating in biogeochemical cycles while responding positively to environmental changes. Saprophytic fungi are important factors in soil carbon cycle, and the response and driving factors in grassland to forestland and grassland to farmland conversion in desert steppe are still poorly understood. Therefore, we analyzed the soil microbial community structure and saprophytic fungal communities in grasslands, shrub lands, and farmlands in typical desert grassland areas of northwest China. It was found that the cultivation of desert steppe plants/crops increased the proportion of silt in soil aggregates while decreasing soil salinity and increasing soil total carbon, nitrogen, and organic matter content. Proteobacteria, Actinobacteriota and Ascomycota were the dominant phyla in desert steppe soils, with Proteobacteria, Gemmatimonadota and Mucoromycota were more responsive to soil environment changes. The co-occurrence network relationship further characterized the process of niche sharing/competition between bacteria and fungi. The complexity of the co-occurrence network was deepened by land use, and fungi occupied more of the niche in shrub planting than in desert steppe and maize planting. Network relationships further characterized the process of niche sharing/competition between bacteria and fungi, and land use deepened the complexity of the co-occurrence network, with soil fungi occupying more ecological niches in shrub cultivation than in grassland and maize cultivation. In addition, saprophytic fungi are the main functional fungi in bacterial-fungal co-occurrence networks and are influenced by soil properties. Random forest analysis further explained the importance of saprophytic fungi in response to environmental changes in desert steppes. The enrichment of soil saprophytic fungi had an obvious correlation with soil aggregate stability, soil physical properties, and soil nutrients, especially in the background of shrub forestation in desert steppes. This study further highlights afforestation as one of the ways to benefit land management in desert steppes, while emphasizing the importance of saprophytic fungi as ecosystem indicators.

This study evaluated the effects of rapeseed meal (RM) and condensed tannins (CT) in diets on largemouth bass (Micropterus salmoides) and examined the possible role of CT on immunity and antioxidants when RM was used in the diets. After 55-days of feeding trials, oxidative stress in largemouth bass differed with dietary RM amount by affecting antioxidant capacity and immune function, changing the health state of the body. More than 5% RM caused oxidative stress, more than 15% RM led to oxidative damage to the liver and intestine, and 25% RM increased the intestinal inflammatory response. High dose of CT dietary supplementation caused oxidative and immune damage of the liver and intestines accompanied by the inflammatory response, while the low dose had the opposite effects, and thus relieved oxidative stress and inflammatory damage. Compared with the effect of contained CT (in RM), the antioxidant capacity and immune function of the groups supplemented with CT were enhanced, and the inflammatory damage effect was reduced at a low dose. In this study, the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) were closely related to the contents of malondialdehyde (MDA), protein carbonyl (PC), oxygen radical, and total antioxidant capacity. Intestinal nuclear factor erythroid 2–related factor 2 (Nrf2) expression was involved in the regulation of antioxidant capacity and altered the expression levels of intestinal inflammatory factors, transforming growth factor beta-1 (TGF-β1), transforming growth factor beta-2 (TGF-β2), and interleukin 6 (IL6). The interaction of anti-nutritional factors in RM may reduce its toxicity to some extent. Thus, largemouth bass could tolerate more CT present in RM than CT alone. CT was not necessary to be removed at levels below 5% of RM in the diet.

Tactile sensing is essential for a variety of daily tasks. Inspired by the event-driven nature and sparse spiking communication of the biological systems, recent advances in event-driven tactile sensors and Spiking Neural Networks (SNNs) spur the research in related fields. However, SNN-enabled event-driven tactile learning is still in its infancy due to the limited representation abilities of existing spiking neurons and high spatio-temporal complexity in the event-driven tactile data. In this paper, to improve the representation capability of existing spiking neurons, we propose a novel neuron model called “location spiking neuron,” which enables us to extract features of event-based data in a novel way. Specifically, based on the classical Time Spike Response Model (TSRM), we develop the Location Spike Response Model (LSRM). In addition, based on the most commonly-used Time Leaky Integrate-and-Fire (TLIF) model, we develop the Location Leaky Integrate-and-Fire (LLIF) model. Moreover, to demonstrate the representation effectiveness of our proposed neurons and capture the complex spatio-temporal dependencies in the event-driven tactile data, we exploit the location spiking neurons to propose two hybrid models for event-driven tactile learning. Specifically, the first hybrid model combines a fully-connected SNN with TSRM neurons and a fully-connected SNN with LSRM neurons. And the second hybrid model fuses the spatial spiking graph neural network with TLIF neurons and the temporal spiking graph neural network with LLIF neurons. Extensive experiments demonstrate the significant improvements of our models over the state-of-the-art methods on event-driven tactile learning, including event-driven tactile object recognition and event-driven slip detection. Moreover, compared to the counterpart artificial neural networks (ANNs), our SNN models are 10× to 100× energy-efficient, which shows the superior energy efficiency of our models and may bring new opportunities to the spike-based learning community and neuromorphic engineering. Finally, we thoroughly examine the advantages and limitations of various spiking neurons and discuss the broad applicability and potential impact of this work on other spike-based learning applications.

Soil microbial taxa have different functional ecological characteristics that influence the direction and intensity of plant–soil feedback responses to changes in the soil environment. However, the responses of soil microbial survival strategies to wet and dry events are poorly understood. In this study, soil physicochemical properties, enzyme activity, and high–throughput sequencing results were comprehensively anal0079zed in the irrigated cropland ecological zone of the northern plains of the Yellow River floodplain of China, where Oryza sativa was grown for a long period of time, converted to Zea mays after a year, and then Glycine max was planted. The results showed that different plant cultivations in a paddy–dryland rotation system affected soil physicochemical properties and enzyme activity, and G. max field cultivation resulted in higher total carbon, total nitrogen, soil total organic carbon, and available nitrogen content while significantly increasing α–glucosidase, β–glucosidase, and alkaline phosphatase activities in the soil. In addition, crop rotation altered the r/K–strategist bacteria, and the soil environment was the main factor affecting the community structure of r/K–strategist bacteria. The co–occurrence network revealed the inter–relationship between r/K–strategist bacteria and fungi, and with the succession of land rotation, the G. max sample plot exhibited more stable network relationships. Random forest analysis further indicated the importance of soil electrical conductivity, total carbon, total nitrogen, soil total organic carbon, available nitrogen, and α–glucosidase in the composition of soil microbial communities under wet–dry events and revealed significant correlations with r/K–strategist bacteria. Based on the functional predictions of microorganisms, wet–dry conversion altered the functions of bacteria and fungi and led to a more significant correlation between soil nutrient cycling taxa and environmental changes. This study contributes to a deeper understanding of microbial functional groups while helping to further our understanding of the potential functions of soil microbial functional groups in soil ecosystems.

The digitization of the national economy and the development of the national network have rapidly increased the amount of data, and research in content storage and forwarding is significant. The existing methods of storing certificates and distributing file content entirely rely on the judgment made by the router, and the forwarding process does not consider the security and legality of the data; at the same time, the traditional peer-to-peer (P2P) forwarding network files cannot be effectively reused, and additional security mechanisms are introduced. It affects the performance of the network itself. To improve the overall network performance, optimize the file forwarding process, and ensure the security of content and the verification of historical information, this paper proposes a method for document content storage and distribution that integrates blockchain technology and Named Data Network (NDN). The advantages of data signature encryption, reverse path forwarding of content, and flexible routing improves the overall performance of the forwarding network. Combined with blockchain decentralization technology, the documents and transaction processes can be stored on the chain to ensure the actual security of the forwarding process. In addition, this paper restricts the forwarding process in the NDN network without making any judgments through smart contract rules to ensure the security of confidential files during the forwarding process and, at the same time, limit the forwarding scope of irrelevant junk files in the private network. Finally, experiments prove that the method proposed in this paper can effectively improve the network’s overall performance, optimize the forwarding process, and make rule judgments on the forwarding process of specific files to ensure the security of files.

Quercus wutaishanica is the dominant tree species in the natural ecosystem restoration of temperate forests in China, and it plays an active role in maintaining ecological balance. However, little is known about how ecosystem versatility develops during the restoration of forest ecosystems dominated by Q. wutaishanica. In this study, we investigated the species composition of the Q. wutaishanica community, soil nutrients, and their functional traits at various restoration stages, and comprehensively analyzed the correlations among them. At the early stage of restoration (10 years of restoration), there were Spiraea pubescens and Syringa pubescens in Q. wutaishanica community (87% of the total species), while had a larger niche width. In the middle of restoration (30 years of restoration), shannon and evenness indices were the largest, while soil total carbon, ammonium nitrogen and chlorophyll content of Q. wutaishanica leaves were the highest; among them, soil total carbon was 15.7% higher than that in 10 years of restoration, 32.4% higher than that in 40 years of restoration, ammonium nitrogen was 71.7% higher than that in 40 years of restoration, and chlorophyll content was 217.9% higher than that in 10 years of restoration, and 51.8% higher than that in 40 years of restoration. At the later stage of restoration (40 years of restoration), Lonicera ferdinandii occupied the dominant ecological niche, and soil available nitrogen, available phosphorus content and leaf thickness were the largest; while AN was 10.9% higher than that of 10 years of restoration, 16.5% higher than that of 30 years of restoration, AP was 60.6% higher than that of 10 years of restoration, 21.6% higher than that of 30 years of restoration, leaf thickness was 22.3% higher than that of 10 years of restoration, 84.9% higher than that of 30 years of restoration. However, the restriction of various soil nutrients was reduced. Our study highlighted the effectiveness of soil resource availability in plant communities during restoration, reduced competition for light among plants, and altered species richness. Furthermore, changes in the interrelationship between plant community composition and leaf functional traits of the dominant species responded positively to community restoration. These results further deepen our understanding of forest management and restoration of forest communities. In the future, it is necessary to comprehensively consider the influence of various factors on forest community restoration.

The relationship between environmental quality and economic growth has been a hot topic for decades. After years of rapid industrialization and urbanization, China’s environmental challenges are approaching a turning point. Following the principles of ecological civilization construction, China is on its way to maintaining high-quality and green economic development. On 10 June 2020, the Chinese Government reported the key findings of the Second National General Survey of Pollution Sources (fiscal year 2017), which provides strong quantitative evidence of progress toward ecological civilization. In terms of our comparison between the two National General Surveys in 2007 and 2017, it was found that environmental pollution, measured in terms of many wastewater and air emission pollutant discharges, is decreasing despite the steady growth in economic activities—and at a noticeably fast pace. Other national and local governments can adopt some of China’s ecological civilization practices, within their own individual contexts.

Abstract This paper proposes a new scheme for locating the faults of three‐terminal double‐circuit transmission line without transposer in the phase domain that is not affected by type of fault. Synchronous voltage and current were measured by phasor measurement units (PMUs) installed at three busbars. Considering the coupling effect of parallel lines, the distribution line model was used to obtain more accurate results and third‐order Taylor series expansion to decouple distributed line model. The phase and branch of all faults on the transmission lines were effectively identified, and various types of faults were accurately located including normal shunt fault, evolving fault and cross‐country fault. The proposed algorithm was tested under different fault locations, resistances, initial angles and types (including cross‐country faults and evolving faults). In addition, the effects of different sampling rates, measurement errors, earth resistivities and transmission line parameter errors were also considered. The simulation calculation was performed in MATLAB software and three‐terminal transmission lines were simulated in PSCAD/EMTP software. The results indicate that maximum estimated error was less than 1.8631%.

Soil microbes act as “players” in regulating biogeochemical cycles, whereas environmental heterogeneity drives microbial community assembly patterns and is influenced by stochastic and deterministic ecological processes. Currently, the limited understanding of soil microbial community assembly patterns and interactions under temperate forest stand differences pose a challenge in studying the soil microbial involvement during the succession from coniferous to broad-leaved forests. This study investigated the changes in soil bacterial and fungal community diversity and community structure at the regional scale and identified the pathways influencing soil microbial assembly patterns and their interactions. The results showed that broad-leaved forest cover in temperate forests significantly increased soil pH, and effectively increased soil water content, total carbon (TC), total nitrogen (TN), and total phosphorus (TP) contents. Both soil bacterial and fungal alpha diversity indices were correlated with soil physicochemical properties, especially in broad-leaved forest. The bacterial and fungal community composition of coniferous forest was dominated by deterministic process (bacteria: 69.4%; fungi: 88.9%), while the bacterial community composition of broad-leaved forest was dominated by stochastic process (77.8%) and the fungal community composition was dominated by deterministic process (52.8%). Proteobacteria, Acidobacteriota, Actinobacteriota, and Verrucomicrobiota were the dominant phyla of soil bacterial communities in temperate forests. Whereas Ascomycota, Mortierellomycota, Basidiomycota, and Rozellomycota were the dominant phyla of soil fungal communities in temperate forests. Most members of dominant phylum were regulated by soil physical and chemical properties. In addition, the succession from temperate coniferous forest to broad-leaved forest was conducive to maintaining the complex network of soil bacteria and fungi, and the top 20 degree of the major taxa in the network reflected the positive response of microbial interactions to the changes of soil nutrients during forest succession. This study not only shows the mechanism by which species differences in temperate forests of northern China affect soil microbial community assembly processes, but also further emphasizes the importance of the soil microbiome as a key ecosystem factor through co-occurrence network analysis.

Urban construction, especially the ongoing large-scale expansion and utilization of underground space, has resulted in massive excavated soil and rock (ESR) from buildings and subways. Therefore, this study aims to explore the technical ways of ESR sintering utilization from the perspective of technology, environment, and policy through qualitative and quantitative methods. The study analyzes the soil properties and distribution of different depths, and the annual production of clay-rich ESR accounts for about 30 million m³ in Shenzhen. More importantly, the comparison between various pollutant concentrations of ESR in Shenzhen and local soil background values showed that the ESR in Shenzhen had no environmental risks. This study can not only provide a scientific basis for ESR as the raw material of sintering but also provide a theoretical basis for the promotion of the pilot of “Zero waste city”.

Objective To investigate the inhibitory effect and mechanism of temozolomide on migration and invasion of U251 human glioma cells enhanced by plumbagin. Methods CCK-8 method was used to study the effects of plumbagin, temozolomide and plumbagin+temozolomide on the proliferation of glioma U251 cells. Cell scratch test was used to detect the migration of U251 cells in the control (DMSO), plumbagin, temozolomide and plumbagin+temozolomide groups for 48h. Transwell assay was used to detect the effect of the combination therapy on the invasion of U251 cells. Western blot was used to detect the relative expression levels of E-cadherin in three groups. Results CCK-8 showed that the proliferation inhibition rate of U251 cells treated with plumbagin (1.25 μmol/L) combined with temozolomide (200 μmol/L) for 48h was 75.69%, significantly higher than that treated with plumbagin alone (P=0.012) or temozolomide alone (P=0.034). Cell scratch assay showed that the combination of plumbagin and temozolomide could significantly enhance the inhibition effect of temozolomide on the migration of U251 cells (P=0.023). Transwell assay showed that the invasion ability of U251 cells was significantly decreased after the combination therapy (P < 0.05). The protein expression of E-cadherin in the combination group was significantly higher than those in plumbagin or temozolomide groups (P < 0.05). Conclusion Plumbagin combined with temozolomide can inhibit the migration and invasion of glioma cells and enhance the sensitivity of glioma cells to temozolomide. And the effect is achieved by the protein expression of E-cadherin.

When plants are subjected to various biotic and abiotic stresses, the root system responds actively by secreting different types and amounts of bioactive compounds, while affects the structure of rhizosphere soil bacterial community. Therefore, understanding plant–soil-microbial interactions, especially the strength of microbial interactions, mediated by root exudates is essential. A short-term experiment was conducted under drought and salt stress to investigate the interaction between root exudates and Nitraria tangutorum rhizosphere bacterial communities. We found that drought and salt stress increased rhizosphere soil pH (9.32 and 20.6%) and electrical conductivity (1.38 and 11 times), respectively, while decreased organic matter (27.48 and 31.38%), total carbon (34.55 and 29.95%), and total phosphorus (20 and 28.57%) content of N. tangutorum rhizosphere soil. Organic acids, growth hormones, and sugars were the main differential metabolites of N. tangutorum under drought and salt stress. Salt stress further changed the N. tangutorum rhizosphere soil bacterial community structure, markedly decreasing the relative abundance of Bacteroidota as r-strategist while increasing that of Alphaproteobacteria as k-strategists. The co-occurrence network analysis showed that drought and salt stress reduced the connectivity and complexity of the rhizosphere bacterial network. Soil physicochemical properties and root exudates in combination with salt stress affect bacterial strategies and interactions. Our study revealed the mechanism of plant–soil-microbial interactions under the influence of root exudates and provided new insights into the responses of bacterial communities to stressful environments.

In conventional photo-thermal-electric conversion systems, the photo-thermal conversion module is coupled to a thermoelectric conversion module. However, the physical contact interface between the modules causes serious energy loss. In order to solve this problem, a novel photo-thermal-electric conversion system with an integrated support material has been developed, with a photo-thermal conversion component at the top, an inside thermoelectric conversion component, and a cooling component at the bottom, surrounded by a water conduction component. The supporting materials of each part are polydimethylsiloxane (PDMS), and there is no apparent physical interface between each part. This integrated support material reduces the heat loss caused by the mechanically coupled interfaces in traditional components. In addition, the confined edge 2D water transport path effectively reduces the heat loss due to water convection. Under 1 sun irradiation, the water evaporation rate and open-circuit voltage of the integrated system reach 2.46 kg m−2 h−1 and 30 mV, respectively, and are nearly 1.4 times and 5.8 times higher than those of non-integrated systems.

Online shopping deliveries are booming, but the environmental cost is not always accounted. Here, the authors examine the impact of delivery services in China from 2007 to 2018 and find that Greenhouse gas emissions surged from 0.3 Mt in 2007 to 13.7 Mt of CO2-equivalent in 2018, they predict that emissions could reach 75 MtCO2e by 2035 if no mitigation measures are adopted.

Optical fiber sensors working at the dispersion turning point (DTP) have served as promising candidates for various sensing applications due to their ultrahigh sensitivity. In this review, recently developed ultrasensitive fiber sensors at the DTP, including fiber couplers, fiber gratings, and interferometers, are comprehensively analyzed. These three schemes are outlined in terms of operation principles, device structures, and sensing applications. We focus on sensitivity enhancement and optical transducers, we evaluate each sensing scheme based on the DTP principle, and we discuss relevant challenges, aiming to provide some clues for future research.

Climate change affects vegetation growth around the world. It has been recognized that the effect of climate change on vegetation growth exhibits hysteresis. However, the duration and intensity of time-lag effect of climate factors on vegetation growth is still difficult to quantify. We analyzed the impacts of climate on vegetation growth in 32 major cities of China from 2010 to 2016. Vegetation growth conditions were characterized using enhanced vegetation index (EVI) datasets from Moderate Resolution Imaging Spectrometer (MODIS). The climate data were extracted from the Daily Value Data Set of China Surface Climate Data (V3.0), including precipitation (PRE; mm), air temperature (TEM; oC), sunshine duration (SSD; h), humidity (RHU; %), and evapotranspiration (EVP; mm). We used the vector autoregressive model (VAR) to analyze the lagged effects of climate factors on EVI, predict vegetation responses to future global changes, and validate its accuracy. Results showed that RHU had the longest (6.13 ± 1.96 months) and strongest (median 0.34 EVI per unit RHU in the first lag period) time-lag effect on EVI, while EVP had the shortest (3.45 ± 1.09 months) and weakest (median −0.02 EVI per unit EVP in the first lag period) time-lag effect on EVI. The time-lag effects of PRE and SSD on EVI were stronger in the south than in the north. Meanwhile, the EVI predicted by the VAR model was highly consistent with the observed EVI (root mean squared error, RMSE

Xerophytes in desert improve their fitness under stress through the development of stems and branches. However, little is known about changes in the structure and function of endophytic microorganisms in response to interactions between desert plants and their environment. In this study, we analyzed the lignification indices of young and mature branches during their development in a typical desert xerophyte, Nitraria tangutorum, and combined 16S and ITS high-throughput sequencing techniques to draw the following conclusions. Nitraria tangutorum accumulated more lignin, cellulose, and hemicellulose content during lignification. In addition, the number of OTUs and diversity of endophytic bacteria and fungi were reduced. Both endophytic bacteria and fungi were governed by stochastic processes during the development of stems and branches of Nitraria tangutorum and were significantly affected by lignification indices. Meanwhile, the development of stems and branches increased the relative abundance of Cyanobacteria and Ascomycota, and the dominant bacterial genera were mostly positively correlated with the lignification indices. In addition, stem and branch lignification reduced endophytic microbial interactions in the relationship between the endophytic bacterial and fungal networks of Nitraria tangutorum. Functional prediction analysis further revealed that lignification of Nitraria tangutorum branches changed the metabolic function of endophytic bacteria. The results of this study indicate that plant endophytic microorganisms play an important role in resisting and adapting to adversity and provide support for related studies on microbial ecology in desert areas.

As porous materials, nano-hydroxyapatite/polyamide 66 (n-HA/PA66) composite scaffolds with both desirable bioactivity and good mechanical properties showed great potential to reconstruct the bone defect. Moreover, the pore size and porosity played a key role in the scaffold architecture and cell or bone ingrowth. To investigate the cytocompatibility of different pore size and porosity of n-HA/PA66 composite scaffolds on differentiation and cytocompatibility of osteogenically induced bone marrow-derived mesenchymal stem cells (BMSCs) and bone conduction in repairing the calvarial critical size defect of Sprague-Dawley rats in vivo, we evaluated three kinds of n-HA/PA66 composite scaffolds according to the pore size and porosity in this study (group A: mean pore size was 214 ± 107.3 μm, and more than 70% were arranged in 100–300 μm; group B: material mean pore size was 375 ± 132.2 μm, and about 60% were distributed in 300–500 μm; group C: mean pore size was 533 ± 169.4 μm, and more than 60% were in 400–700 μm). Osteogenically induced BMSCs were seeded in the three types of n-HA/PA66 material and cultured in vitro, and the variability on cell adhesion, growth, proliferation, osteogenic differentiation was analyzed using scanning electron microscopy alkaline phosphatase (ALP) and collagen type I (COL I) immunohistochemical staining, as well as quantitative real-time PCR (qRT-PCR) analysis on the osteogenesis-related gene expression (alkaline phosphatase, COL I), was done. Three group matrices/BMSC composites were implanted into the cranial defect of Sprague-Dawley rats. The differentiations of osteogenesis in vivo were then evaluated by histological and qRT-PCR analysis on mRNA levels of OPG and RANKL after 4 and 8 weeks, respectively. The in vitro and in vivo results showed that the group B n-HA/PA66 scaffold was more suitable for osteogenically induced BMSC proliferation, differentiation in vitro, and bone conduction in vivo than groups A and C, indicating that the porous n-HA/PA66 matrices with a mean pore size of 375 ± 132.2 μm and porosity 77 ± 2.9% have better cell biocompatibility and bone conduction.

Under the current national network environment, anyone can participate in publishing. As an important information resource, knowledge files reflect the workload of publishers. Moreover, high-quality knowledge files can promote the progress of society. However, pirated inferior files have the opposite effect. At present, most organizations use centralized servers to centrally manage the knowledge files released by users. In addition, it is necessary to introduce an untrusted third party to examine and encrypt the contents of files, which leads to an opaque process of file storage transactions, tampering with intellectual copyright, and the inability to have consistent systems of file management among institutions due to the lack of uniform standards for the same intellectual files. The purpose of this paper is to ensure the safe storage of knowledge files on the one hand and to realize efficient sharing of copyrighted files on the other hand. Therefore, this paper combines NDN (Named Data Network) technology with a distributed blockchain and an Interplanetary File System (IPFS) and proposes a blockchain knowledge file storage and sharing method based on an NDN. The method uses the NDN itself for the file content signature and encryption, thereby separating the file security and transmission process. At the same time, the method uses a flexible NDN reverse path forwarding and routing strategy, combining an IPFS private storage network to improve the safety of the encrypted data storage security. Finally, the method takes advantage of all participating nodes consensus and shares files in the synchronized blockchain to ensure traceability. This paper introduces the structure and principles of the method and describes the process of file upload and transfer. Finally, the performance of the method is compared and evaluated, and the advantages and disadvantages of the method and the future research direction are summarized.

Cynanchum thesioides is a medicinal plant. The complete chloroplast genome sequence of is 158,547 bp in length, contains 131 complete genes, including 85 protein-coding genes (85 PCGs), 8 ribosomal RNA genes (8 rRNAs), and 37 tRNA genes (37 tRNAs). The overall AT content of cp DNA is 62.1%, the corresponding values of the LSC, SSC, and IR regions are 63.7, 67.7, and 56.5%. Phylogenetic tree shows that C. thesioides was identified as the most divergent among the sequenced species of Cynanchum used.

Glycolysis refers to one of the critical phenotypes of tumor cells, regulating tumor cell phenotypes and generating sufficient energy for glioma cells. A range of noticeable genes [such as isocitrate dehydrogenase (IDH), phosphatase, and tensin homolog (PTEN), or Ras] overall impact cell proliferation, invasion, cell cycle, and metastasis through glycolysis. Moreover, long non-coding RNAs (LncRNAs) are increasingly critical to disease progression. Accordingly, this study aimed to identify whether glycolysis-related LncRNAs have potential prognostic value for glioma patients. First, co-expression network between glycolysis-related protein-coding RNAs and LncRNAs was established according to Pearson correlation (Filter: |r| > 0.5 & P < 0.001). Furthermore, based on univariate Cox regression, the Least Absolute Shrinkage and Selection Operator (LASSO) analysis and multivariate Cox regression, a predictive model were built; vital glycolysis-related LncRNAs were identified; the risk score of every single patient was calculated. Moreover, receiver operating characteristic (ROC) curve analysis, gene set enrichment analysis (GSEA), GO and KEGG enrichment analysis were performed to assess the effect of risk score among glioma patients. 685 cases (including RNA sequences and clinical information) from two different cohorts of the Chinese Glioma Genome Atlas (CGGA) database were acquired. Based on the mentioned methods, the risk score calculation formula was yielded as follows: Risk score = (0.19 × EXPFOXD2-AS1) + (−0.27 × EXPAC062021.1) + (−0.16 × EXPAF131216.5) + (−0.05 × EXPLINC00844) + (0.11 × EXPCRNDE) + (0.35 × EXPLINC00665). The risk score was independently related to prognosis, and every single mentioned LncRNAs was significantly related to the overall survival of patients. Moreover, functional enrichment analysis indicated that the biologic process of the high-risk score was mainly involved in the cell cycle and DNA replication signaling pathway. This study confirmed that glycolysis-related LncRNAs significantly impact poor prognosis and short overall survival and may act as therapeutic targets in the future.

To promote the coordinated development between renewable energy and the distribution network, a capacity allocation model of battery energy storage systems (BESS) is proposed to achieve the coordinated optimization for active and reactive power flow, which can reduce the voltage deviation and improve the absorptive capacity for renewable energy. In addition, BESS with four-quadrant operation characteristics, on-load tap changer, and capacitor banks are treated as flexible devices to improve the adaptability for renewable energy fluctuations. In view of the uncertainties of renewable energy caused by the inaccuracy of historical sample data, a set of extreme scenarios with the characteristics of temporal and spatial correlation are considered to obtain a robust BESS configuration decision. The big-M approach and the second-order conic relaxation technique are utilized to convert the BESS capacity allocation model into a mixed-integer linear programming problem. Finally, the IEEE 33-node distribution system is taken as an example to verify the effectiveness of the proposed method.

This study aimed to observe the molecular mechanism underlying the effect of tumor necrosis factor–inducible protein 6 (TSG-6) on the bone morphogenetic protein-4 (BMP-4)/drosophila mothers against decapentaplegic protein(Smad) signaling pathway and mineralization of dental pulp stem cells (DPSCs) in inflammatory environment. Normal and TSG-6 gene–modified DPSCs were cultured in a mineralization-inducing fluid containing 0 or 50 ng/mL TNF-α separately. The real-time polymerase chain reaction was used to measure the expression of TSG-6 and odonto/osteogenic differentiation makers at the mRNA level. Western blot analysis and cellular immunofluorescence were used to observe the odonto/osteogenic differentiation of DPSCs and the variation of BMP-4/Smad signaling pathway at the protein level. Moreover, normal and modified DPSCs combined with hydrogel were used for subcutaneous implantation in nude mice. The levels of odonto/osteogenic markers and BMP-4/Smad-related proteins were lower in Ad-TSG-6 DPSCs than in normal DPSCs after mineralization induction, and were higher in TSG-6-RNAi DPSCs than in normal DPSCs after culturing with mineralization-inducing fluid containing 50 ng/mL TNF-α. The subcutaneous transplantation of normal and modified DPSCs combined with hydrogel in nude mice demonstrated that normal DPSCs were formed in the tissue containing collagen. The tissue formed by Ad-TSG-6 DPSCs was highly variable, and the cells were very dense. We can know that TNF-α regulates the expression of TSG-6, thereby inhibiting the BMP-4/Smad signaling pathway and the odonto/osteogenic differentiation ability of DPSCs.

Superconductors were typically discovered by trial-and-error aided by the knowledge and intuition of individual researchers. In this work, using materials informatics aided by machine learning (ML), we build an ML model of superconductors, which is based on several material descriptors with apparent physical meanings to efficiently predict critical superconducting temperature TC. The descriptors include the average atomic mass of a compound, the average number of electrons in an unfilled shell, the average ground state atomic magnetic moments, the maximum difference of electronegativity, etc. To fully optimize the ML model, we develop a multi-step learning and multi-algorithm cross-verification approach. For known high TC superconductors, our ML model predicts excellent TC values with over 92% confidence. When the ML model is applied to about 2500 layered materials in the inorganic crystal structure database, 25 of them are predicted to be superconductors not known before, including 12 cuprates, 7 iron-based crystals, and 6 others, with TC ranging from ∼32 K to ∼138 K. The findings shed considerable light on the mapping between the material descriptors and TC for layered superconductors. The ML calculates that in our descriptors, the maximum difference of electronegativity is the most important one.

Volatile organic compounds (VOCs) from polypropylene (PP) seriously restricts the application of PP in an automotive field. Herein, the traceability of VOCs from PP resins during manufacturing process and accelerated photoaging degradation was clarified on basis of an accurate characterization method of key VOCs. The influence of PP structures on changing the accelerated photoaging degradation on the VOCs was systematic. The VOCs were identified by means of Gas chromatography (GC) coupled with both a hydrogen flame ion detector (FID) and a mass spectrometry detector (MSD). Results showed that both the molecular structure of PP and the manufacturing process affected the species and contents of VOCs. In addition, the photoaging degradation of PP resulted in a large number of new emerged volatile carbonyl compounds. Our work proposed a possible VOC formation mechanism during the manufacturing and photoaging process. VOCs from PP resins were originated from oligomers and chain random scission during thermomechanical degradation. However, β scission of alkoxy radical and Norrish tape I reactions of ketones via intermediate transition were probably the main VOCs formation routes towards PP during photoaging degradation. This work could provide scientific knowledge on both the accurate traceability of VOCs emissions and new technology for development of low-VOCs PP composites for vehicle.

The development of DC distribution network technology has provided a more efficient way for renewable energy accommodation and flexible power supply. A two-stage stochastic scheduling model for the hybrid AC/DC distribution network is proposed to study the active-reactive power coordinated optimal dispatch. In this framework, the wind power scenario set is utilized to deal with its uncertainty in real time, which is integrated into the decision-making process at the first stage. The charging/discharging power of ESSs and the transferred active/reactive power by VSCs can be adjusted when wind power uncertainty is observed at the second stage. Moreover, the proposed model is transformed into a mixed integer second-order cone programming optimization problem by linearization and second-order cone relaxation techniques to solve. Finally, case studies are implemented on the modified IEEE 33-node AC/DC distribution system and the simulation results demonstrate the effectiveness of the proposed stochastic scheduling model and solving method.

To solve the disadvantages of strong subjectivity for traditional plot methods of grouping discontinuities, such as the pole isodensity map and the occurrence rose graph, and the lack of intuitionism for popular clustering methods, this article introduces a plot method called the membership contour map. Based on the data of the membership matrix obtained through the fuzzy C-mean (FCM) algorithm, the membership contour map is realized by a graphics technique. Due to the full use of membership information in FCM clustering, the membership contour map can show the spatial distribution of the membership degree of each clustering, distinguish discontinuities caused by trivial random factors, and read out clustering centers by the scope form from the membership contour map directly. An application of Sanshandao Gold Mine proves that the membership contour map holds the advantages of both intuitionism and objectivity, and can adapt discontinuities data, which do not have obvious dominant groups.