一类含星S_3之粘接图S_3⊙G的niche数

星S3=K1,3是无穷niche图.但是本文通过星S3与几个简单图类之粘接图的niche数以及星与一般图之粘接图的niche数等问题的研究表明:许多粘接图S3⊙G都是有限niche图.

Deer antler stem cell niche: An interesting perspective

In recent years,there has been considerable exploration into methods aimed at enhancing the regenerative capacity of transplanted and/or tissue-resident cells.Biomaterials,in particular,have garnered significant interest for their potential to serve as natural scaffolds for cells.In this editorial,we provide commentary on the study by Wang et al,in a recently published issue of World J Stem Cells,which investigates the use of a decellularized xenogeneic extracellular matrix(ECM)derived from antler stem cells for repairing osteochondral defects in rat knee joints.Our focus lies specifically on the crucial role of biological scaffolds as a strategy for augmenting stem cell potential and regenerative capabilities,thanks to the establishment of a favorable microenvironment(niche).Stem cell differen-tiation heavily depends on exposure to intrinsic properties of the ECM,including its chemical and protein composition,as well as the mechanical forces it can generate.Collectively,these physicochemical cues contribute to a bio-instructive signaling environment that offers tissue-specific guidance for achieving effective repair and regeneration.The interest in mechanobiology,often conceptualized as a form of“structural memory”,is steadily gaining more validation and momen-tum,especially in light of findings such as these.

Distribution and dynamics of niche and interspecific association of dominant phytoplankton species in the Feiyun River basin,Zhejiang,China

To investigate the dominant species and interspecific association in the phytoplankton community of the Feiyun River basin in Zhejiang Province,East China,the main stream and the Shanxi Zhaoshandu Reservoir in the downstream were chosen as the study area,for which 22 sampling sites were designated.Sampling was conducted in September 2021,January,May,and July 2022.Phytoplankton species were identified from both quantitative samples and in-vivo observations.Phytoplankton was quantified by direct counting.Results show that there were 98 species belonging to 6 phyla and 78 genera.In addition,to clarify the niches of the dominant phytoplankton species and their interspecific association,the dominance index was calculated,and a comprehensive analysis was conducted including niche width,niche overlap value,ecological response rate,overall association,chi-square test,and the stability.The phytoplankton community exhibited characteristics of a Cyanobacteria-Chlorophyta-Diatom type community,showing higher diversity in spring and lower diversity in summer.Among 11 dominants phytoplankton species from 3 phyla,both frequency and dominance degree varied seasonally,of which Microcystis sp.was the dominant species in Spring,Autumn,and Winter.The niche widths of the dominant species ranged from 0.234 to 0.933,and were categorized into three groups.The niche overlap values of the 11 dominant species ranged from 0.359 to 0.959,exhibiting significant seasonal differences-highest in winter followed by autumn,spring,and summer in turn.The overall correlation among dominant species in all four seasons revealed a non-significant negative association,resulting in an unstable community structure.A significant portion(84.2%)of species pairs displayed positive associations,suggesting a successional pattern where Diatoms dominated while other dominant species shared resources and space.Despite this pattern,stability measurements indicated that the dominant species community remained unstable.Therefore,careful monitoring is recommended for potential water environment issues arising from abnormal proliferation of dominant species in the watershed during winter.This research built a theoretical foundation with a data support to the early warning of eutrophication and provided a reference for water resources management in similar watersheds along the eastern coast of China.

Post-disaster spatial reconstruction from the perspective of a rural settlement niche in the upper reaches of the Minjiang River

Post-disaster recovery and reconstruction provide an effective way to reduce the disaster vulnerability of, and promote leapfrog development in, an affected area. To date, studies that have used administrative boundaries to investigate the reconstruction of settlement space have not been able to clearly define the real boundaries of land use changes or quantify the degree of response to the ‘Build-Back-Better’ initiative, and have lacked any consideration of the fourth reconstruction stage–development period(10 years). This study constructed a mountain settlement niche and analyzed the characteristics, spatial reconstruction, and drivers of rural settlements during 2009–2019 in the upper reaches of the Minjiang River, southwest China. The results showed the following:(1) Natural factors were the basis for the formation and development of mountain settlement niches. The scale of the settlement niche and its land use structure depended on the physical geography features and the ethnic farming and grazing traditions. The settlement niche provided a realistic boundary for the spatial reconstruction.(2) The layout of residential land around cropland was the common feature of the mountain settlement niche. Of all the land use types, the roads and rural residential lands showed the most change over the 10 years;13,860 residential patches increased in size and 4,742 patches were abandoned.(3) The area of orchards, planted to reconstruct the economy in the mountains, increased by nearly 2.5 times.(4) Collapses, landslides, and debris flow disasters and the ecological red line influenced the spatial reconstruction. While the main focus of post-disaster recovery is spatial reconstruction, initiatives should include economic and spiritual recovery, and should also achieve sustainable development of the region.

A Single-Cell Landscape of Human Liver Transplantation Reveals a Pathogenic Immune Niche Associated with Early Allograft Dysfunction

Liver transplantation(LT)is the standard therapy for individuals afflicted with end-stage liver disease.Despite notable advancements in LT technology,the incidence of early allograft dysfunction(EAD)remains a critical concern,exacerbating the current organ shortage and detrimentally affecting the prognosis of recipients.Unfortunately,the perplexing hepatic heterogeneity has impeded characterization of the cellular traits and molecular events that contribute to EAD.Herein,we constructed a pioneering single-cell transcriptomic landscape of human transplanted livers derived from non-EAD and EAD patients,with 12 liver samples collected from 7 donors during the cold perfusion and portal reperfusion stages.Comparison of the 75231 cells of non-EAD and EAD patients revealed an EAD-associated immune niche comprising mucosal-associated invariant T cells,granzyme B^(+)(GZMB^(+))granzyme K^(+)(GZMK^(+))natural killer cells,and S100 calcium binding protein A12^(+)(S100A12^(+))neutrophils.Moreover,we verified this immune niche and its association with EAD occurrence in two independent cohorts.Our findings elucidate the cellular characteristics of transplanted livers and the EAD-associated pathogenic immune niche at the single-cell level,thus,offering valuable insights into EAD onset.

Distribution,abundance,and realized niches of meroplankton by two different mesh size nets during spring 2017 in the Southern Yellow Sea,China

Meroplankton play a crucial role in both benthic and pelagic ecosystems.Existing quantitative research on estimating the quantities of meroplankton groups is both underrepresented and inaccurate.To investigate and evaluate the influence of varying mesh sizes(505 and 160μm)on the sampling efficiency of meroplankton,we conducted an examination using two commonly used plankton nets during the spring season in the Southern Yellow Sea(SYS).Our study revealed a total of 12 meroplankton groups,with 9 groups identified in the 505-μm mesh nets and 11 groups in the 160-μm mesh nets.The results demonstrated the superior collection efficiency of the 160-μm net compared to the 505-μm net across the majority of meroplankton groups.Furthermore,we focused on exploring the abundance,distribution patterns,and realized niches of meroplankton collected by the two mesh size nets,and observed that the distribution of meroplankton closely resembled the distribution of possible benthic adults in the SYS.Correlation analysis of the six dominant groups collected in the 160-μm mesh nets revealed that seawater temperature and salinity emerged as the key environmental factors driving variations in meroplankton abundance within the SYS.This study also found that a smaller mesh size net does not necessarily capture meroplankton more comprehensively.A comprehensive understanding of the ecological characteristics of meroplankton requires the combination of two types of nets for research.Our research significantly advances our understanding of the quantification,abundance,and distribution of meroplankton,serving as a valuable contribution to the broader landscape of detailed quantitative meroplankton studies.

A Reference Vector-Assisted Many-Objective Optimization Algorithm with Adaptive Niche Dominance Relation

It is still a huge challenge for traditional Pareto-dominatedmany-objective optimization algorithms to solve manyobjective optimization problems because these algorithms hardly maintain the balance between convergence and diversity and can only find a group of solutions focused on a small area on the Pareto front,resulting in poor performance of those algorithms.For this reason,we propose a reference vector-assisted algorithmwith an adaptive niche dominance relation,for short MaOEA-AR.The new dominance relation forms a niche based on the angle between candidate solutions.By comparing these solutions,the solutionwith the best convergence is found to be the non-dominated solution to improve the selection pressure.In reproduction,a mutation strategy of k-bit crossover and hybrid mutation is used to generate high-quality offspring.On 23 test problems with up to 15-objective,we compared the proposed algorithm with five state-of-the-art algorithms.The experimental results verified that the proposed algorithm is competitive.

四类粘接图的niche数

粘接图Ｇ１（ｕ）○·Ｇ２（ｖ）是将图Ｇ１的顶点ｕ与图Ｇ２的顶点ｖ重合而得到的一个图．本文证明Ｐｍ（ｕ）○·Ｋｎ（ｕ是Ｐｍ的起点或终点，ｎ≥２），Ｋｍ○·Ｋｎ（ｍ，ｎ≥２），Ｐｍ（ｕ）○·Ｃｎ（ｎ≥３）和Ｋｍ○·Ｃｎ（ｍ≥２，ｎ≥３）这四类图都是ｎｉｃｈｅ图．

Multiple Spatial Scale Analysis of the Niche Characteristics of the Rhododendron dauricum Plant Communities in Northeast China

This study aims to verify the concept of niches at multiple spatial scales in plant communities.To this end,we analyzed the niche characteristic of Rhododendron dauricum plant communities in Northeast China at three spatial scales.At the local scale,we calculated the Importance Value(IV)of species in five communities in the north of the Da Hinggan Mountains.At the intermediate scale,we examined five communities in their entirety,calculated the niche breadth of the species,and integrated niche overlap and interspecific association to analyze interspecific relationships.Further,the generalized additive model(GAM)was used to analyze the impact of topography and soil factors on niche characteristics.At the regional scale,we analyzed the geographical distribution of dominant species of R.dauricum plant communities in Northeast China and used principal component analysis(PCA)to analyze the impact of geographical and climate factors on species distribution.The results show that at the local scale,the IV of the species in each community varies widely.At the intermediate scale,species with a wide niche breadth tend to have a high value for IV.Larix gmelinii,Betula platyphylla,R.dauricum,Ledum palustre,and Vaccinium vitis-idaea had a relatively wide niche breadth and a high niche overlap,and the interspecific associations were almost all positive.Elevation and soil nutrients were the most dominant environmental factors.At the regional scale,species with a wide niche breadth tend to have a wide range of distribution,and temperature and precipitation were the most dominant environmental factors.This study suggests that the niche characteristics at three scales are both related and different.Niche characteristics at the local scale were various and labile,and niche characteristics at the intermediate and regional scales were relatively regular.These results show some degree of consistency with previous studies from an evolutionary perspective.The action mechanisms of these communities are related to differences in the dominant environmental factors.In addition,the integration of niche overlap and interspecific association determine interspecific relationships more accurately.

Niches of dominant fish in the waters surrounding the Taishan Islands, China

An index of relative importance(IRI) was employed to screen for dominant fish in the waters surrounding the Taishan Islands, China, using data from four seasonal trawl surveys undertaken between 2012 and 2013. Niche breadth and niche overlap were measured using the Feinsinger and Morisita-Horn indices, respectively, and the characteristics and seasonal variations in the niches of dominant fish were assessed via non-metric multidimensional scaling(NMDS) and cluster analysis. A total of 80 fish species, including 16 dominant species, were recorded. Only A mblychaeturichthys hexanema was dominant in all seasons. According to niche breadth values and NMDS, the 16 dominant species were grouped into the following three types:(1) wide niche breadth species, including Cynoglossus macrolepidotus, A. hexanema, and Trypauchen vagina, among others;(2) medium niche breadth species, including Setipinna taty and Johnius belangerii; and(3) narrow niche breadth species, including A trobucca nibe and Coilia mystus. Most species with a wider niche breadth were demersal fish with a lower swimming capability and even distribution. The niche breadth of migrating fish was narrower than that of settled fish. At a given spatial scale, fish with stronger swimming capabilities had a narrower niche breadth. Niche overlap, which is associated with niche specialization, ranged from 0.000 to 0.886 and had an annual mean value of 0.314. In summer and autumn, niche overlap was relatively high within species of the Sciaenidae family and within species of the Gobiidae in autumn. Dif ferences in thermophily, feeding habits, food organism abundance/distribution and predator-prey relationships af fected the niche overlap of fish in this area. Cluster analysis revealed that species with the narrowest niche breadth and lowest niche overlap values usually displayed lower aggregation and greater distribution dif ferences compared with other species.

一类复合图的niche数上界

研究证明：在一定条件下，两个有限ｎｉｃｈｅ 图 Ｇ１ 和 Ｇ２ 的两点粘接图的ｎｉｃｈｅ 数 ｎ（ Ｇ１∶ Ｇ２（ ｕ１＝ ｖ１ ，ｕ２ ＝ ｖ２）） ≤ｎ（ Ｇ１） ＋ ｎ（ Ｇ２） － ｒ，其中ｒ ＝ ０ ，１ 。

含星S_3之并图的niche数

众所周知 ,星S3=K1,3是一个无有限niche数的图 .而本文的研究证明 :S3与许多图类的并图都是有有限niche数的图 .

复合图G1(u)⊙uv⊙G2(v)的niche数

复合图Ｇ１（ｕ）⊙ｕｖ⊙Ｇ２（ｖ）是将简单图Ｇ１的顶点ｕ与简单图Ｇ２的顶点ｖ用边ｕｖ连接成的图．本文证明：若Ｇ１和Ｇ２都是有限ｎｉｃｈｅ图，则当连接点ｕ，ｖ满足一定的条件时，复合图Ｇ１（ｕ）⊙ｕｖ⊙Ｇ２（ｖ）也是有限ｎｉｃｈｅ图，且ｎ（Ｇ１（ｕ）⊙ｕｖ⊙Ｇ２（ｖ））≤ｎ（Ｇ１）＋ｎ（Ｇ２）－ｒ其中，ｒ＝０，１，２．

Euler图C_m⊙C_n的niche数

研究了图 C_m⊙C_n 的 niche 数,证明所有 Euler 图 C_m⊙C_n 的 niche 数n(C_m⊙C_n)都不超过1,且当(m,n)不属于{(4,6),(4,7),(4,8),(4,9),(5,8),(5,9)}时,C_m⊙C_n 都是 niche 图.

Lineage Diversification and Niche Evolution in the Chinese Cobra Naja atra (Elapidae)

Theroleof nicheevolution(niche conservatism or niche divergence)in lineage diversification is a poorly studied area.The Chinese cobra Naja atra(Elapidae)has diverged into three lineages:Lineage E in eastern China,Lineage S in southern China and Vietnam,and Lineage W in western China.However,whether the ecological niche is conserved or divergent among these three lineages is unknown.In the present study,we used ecological niche models in geographical space to study the ecological differences among lineages.We compared the niche overlap in environmental space to test niche conservatism and niche divergence.Our results showed that the three lineages of N.atra shared an ecological niche space between Lineages E and S/W,with the climatic niches of Lineages S and W representing a specialized fraction of the climatic niche of Lineage E.We speculated that the niche divergence between Lineages S and W was a consequence of geographical barriers limitinggeneflow.Ourstudyprovides evidence for lineage diversification associated with both geographical isolation and climatic niche evolution,suggesting that early niche divergence between Lineages S and W,followed by niche conservatism,causes niche divergence among lineages.

干细胞niche与肿瘤干细胞产生和发展的关系

肿瘤干细胞学说认为大部分肿瘤来源于肿瘤干细胞。肿瘤干细胞与正常干细胞一样具有自我更新能力,能够产生肿瘤组织团块中的各种增殖和分化的细胞。肿瘤干细胞可能来源于正常干细胞或分化细胞。干细胞niche是干细胞生存的微环境,通过提供抑制细胞增殖和生长的信号来维持干细胞于静止状态。干细胞niche功能异常会导致niche的数量增加,以及干细胞功能异常和数量增加。肿瘤干细胞可能在异常的niche中存活,打破这种异常的niche就会削弱肿瘤干细胞的自我更新,从而抑制肿瘤的生长。靶向肿瘤干细胞异常微环境的治疗策略可能是癌症治疗的一个方向。

益气补肾方调控胃癌干细胞niche及Notch信号通路抗转移分子机制研究

[目的]探讨益气补肾方调控胃癌肿瘤干细胞(cancer stem cells,CSC)niche及Notch信号通路抗胃癌增殖转移的分子机制,为临床应用提供实验依据。[方法]采用人胃癌细胞株NCI-N87建立胃癌CSC富集裸鼠荷瘤模型。裸鼠随机分为阴性对照组、模型对照组、氟尿嘧啶组(5-Fu组)、益气补肾方组(益气补肾组)及益气补肾方+氟尿嘧啶组(协同组)。每组药物干预6周,观察裸鼠体质量变化及瘤体生长情况,比较各组肿瘤增殖及远处转移情况;采用ELISA法检测瘤体血管内皮生长因子受体-1(vascular endothelial growth factor receptor-1,VEGFR-1)、骨桥蛋白(osteopontin,OPN)、缺氧诱导因子-1α(hypoxia-inducible factor-1α,HIF-1α)、CXC趋化因子受体4(CXC chemokine receptor 4,CXCR4)表达;采用免疫组化法检测肿瘤组织中CD24、CD44、上皮细胞粘附分子(epithelial cell adhesion molecule,Ep CAM)的表达;采用Western blot检测肿瘤组织Notch1、Jagged1蛋白表达。[结果]给药6周后,益气补肾组、协同组及阴性对照组裸鼠体质量均明显重于模型对照组、5-Fu组,差异均有统计学意义(P<0.01);模型对照组与阴性对照组裸鼠的瘤体均重于5-Fu组、益气补肾组及协同组,差异有统计学意义(P<0.01)。5-Fu组、益气补肾组及协同组裸鼠的肝脏、腹壁、淋巴结及肺的总转移率明显少于模型对照组,差异有统计学意义(P<0.05)。与模型对照组比,5-Fu组、益气补肾组及协同组瘤体内VEGFR-1、OPN、HIF-1α、CXCR4的表达下调,差异有统计学意义(P<0.05,P<0.01)。益气补肾组与协同组CD24、CD44的表达均低于模型对照组及5-Fu组,差异有统计学意义(P<0.05)。益气补肾组Ep CAM的表达低于模型对照组及5-Fu组,差异有统计学意义(P<0.05)。益气补肾组及协同组瘤体组织中Notch1、Jagged1蛋白表达均低于模型对照组,差异有统计学意义(P<0.05)。[结论]益气补肾方具有显著的抗胃癌细胞增殖转移的作用,其机制可能是通过调控CSC niche及Notch信号通路,进而下调胃癌CSC表面标志物CD24、CD44、Ep CAM的表达,诱导胃癌CSC良性分化,从而降低瘤体内CSC比例。

Population Dynamics and Breeding Space Niche of Four Heron Species in Tanghai Wetlands

The population dynamics and breeding behaviors of Black-crowned Night Herons （ Nycticorax nycticorax ）, Egrets （Egtetta garzetta）, Chinese Pond Herons （Ardeola bacchus） and Great Egrets （Casmerodius albus） were observed in Tanghai Wetlands, Hebei Province from August 2004 to July 2005. Further, we studied the relationship of nest space distribution and directly calculated the nest density of vertical and horizontal levels, the niche overlapping index and the niche breadth. The results showed that there were two breeding areas, named Area Ⅰ and Area Ⅱ . The maximum population occurred in the period from April to September and was approximately 5800 individuals. Area Ⅰ was occupied earlier than Area Ⅱ by approximately half a month. In the breeding period, Black-crowned Night Herons were dominant in numbers and most occupied the upper nests of the core areas. Great Egrets also took the upper nests but they have the smallest population. Most Egrets took the middle nests of the edges of the area. Chinese Pond Herons, with a smaller population than the Egret, mostly nested in the edges, but some of them also took the lower nests of the core area. On the whole, the vertical niche of Egrets is the widest, the horizontal niche of Black-crowned Night Herons is the widest and the niche breadth of Chinese Pond Herons is the largest. The nest distribution pattern is the most similar between Chinese Pond Herons and Black-crowned Night Herons, and the niche overlapping index of Chinese Pond Herons and Egrets is the largest. Black-crowned Night Herons and Great Egrets control Egrets and Chinese Pond Herons in competition. Rich food and the optimal ecological environments lead to plenty of herons in the wetlands. In addition, it is a distinguishing feature of the four species that nests are built in poplar trees over 22 m tall.

Research Progress and Thoughts of Habitat Suitability Evaluation of Citrus Based on Niche Theory

[Objective] This study was to overview the research progress and thoughts of habitat suitability evaluation of citrus based on ecological niche theory. [Method] The research progress on habitat suitability evaluation and ecological niche theory to the niche selection of crops were comprehensively analyzed. [Result] The research thoughts of using niche theory to evaluate the habitat suitability of citrus with quality constraint were put forward, including collection and expression of citrus ecological environment and quality factors, interactive response study of the citrus ecological environment and quality, and habitat suitability evaluation and adaptation mechanism study of citrus based on quality constraint. [Conclusion] This study provided references for the development of citrus industrialization.

成体干细胞Niche与肺脏修复

肺脏是个开放的复杂器官,覆盖其表面的上皮细胞持续暴露在病原微生物和大气污染物中,最易受到损伤,因而关于它的结构和功能修复问题一直是研究的热点。成体干细胞具有多向分化潜能,在不同niche的作用下可以分化成不同的细胞。肺脏的不同区域含有不同的干细胞,而且这些上皮干细胞在某些特定的条件下可以产生增殖和转分化,因而这些不同水平的干细胞可以通过不同的修复方式来实施肺脏结构和功能的维持和修复,但这些干细胞的来源及其在肺脏修复中的作用和机制并不十分清楚。因此对肺脏成体干细胞的研究进展进行综述以期对肺脏的修复有一个新的认识。