Stability and passivity analysis of delayed neural networks via an improved matrix-valued polynomial inequality.

The stability and passivity of delayed neural networks are addressed in this paper. A novel Lyapunov-Krasovskii functional (LKF) without multiple integrals is constructed. By using an improved matrix-valued polynomial inequality (MVPI), the previous constraint involving skew-symmetric matrices within the MVPI is removed.

Different mechanisms underlie similar species-area relationships in two tropical archipelagoes.

Despite much research in the field of island biogeography, mechanisms regulating insular diversity remain elusive. Here, we aim to explore mechanisms underlying plant species-area relationships in two tropical archipelagoes in the South China Sea. We found positive plant species-area relationships for both coral and continental archipelagoes.

New sesquiterpenoids from sp.

Five new sesquiterpenoids, including a campherenane-type (), a bergamotane-type (), a drimane-type (), and two bisabolane-type () sesquiterpenoids have been isolated from sp. 71-10-1-1. Their structures were determined by spectroscopic analyses, quantum chemical ECD calculations,C chemical shifts calculations, and X-ray crystallography.

Bacterial genome size and gene functional diversity negatively correlate with taxonomic diversity along a pH gradient.

Bacterial gene repertoires reflect adaptive strategies, contribute to ecosystem functioning and are limited by genome size. However, gene functional diversity does not necessarily correlate with taxonomic diversity because average genome size may vary by community. Here, we analyse gene functional diversity (by shotgun metagenomics) and taxonomic diversity (by 16S rRNA gene amplicon sequencing) to investigate soil bacterial communities along a natural pH gradient in 12 tropical, subtropical, and temperate forests.

Community Assembly of Fungi and Bacteria along Soil-Plant Continuum Differs in a Zoige Wetland.

Distinct plant associated microbiomes live in rhizosphere soil, roots, and leaves. However, the differences in community assembly of fungi and bacteria along soil-plant continuum are less documented in ecosystems. We examined fungal and bacterial communities associated with leaves, roots, and rhizosphere soil of the dominant arbuscular mycorrhizal (AM) plants and and non-AM plant in the Zoige Wetland by using high throughput sequencing techniques.

Lower triangle factor based sliding mode observers design for T-S fuzzy systems with faults.

The paper mainly focuses on the fault estimation for a class of Takagi-Sugeno (T-S) fuzzy systems with faults. A synthetic estimation observer design method is proposed. The synthetic estimation observer can cover the robust observer, adaptive observer and intermediate estimation observer in the existing study work.

Nitrogen fertilisation disrupts the temporal dynamics of arbuscular mycorrhizal fungal hyphae but not spore density and community composition in a wheat field.

Elucidating the temporal dynamics of arbuscular mycorrhizal (AM) fungi is critical for understanding their functions. Furthermore, research investigating the temporal dynamics of AM fungi in response to agricultural practices remains in its infancy. We investigated the effect of nitrogen fertilisation and watering reduction on the temporal dynamics of AM fungi, across the lifespan of wheat.

Two New Diterpenoids from . and Their Activities.

Two new diterpenoids, including a -isopimarane type (1) and an abietane type (2), were isolated from sp. (71-10-1-1). Their structures, including absolute configurations, were elucidated by NMR spectroscopic analyses, X-ray crystallography, C chemical shifts calculations, and ECD calculations.

Tree mycorrhizal type and tree diversity shape the forest soil microbiota.

There is limited knowledge on how the association of trees with different mycorrhizal types shapes soil microbial communities in the context of changing tree diversity levels. We used arbuscular (AM) and ectomycorrhizal (EcM) tree species as con- and heterospecific tree species pairs (TSPs), which were established in plots of three tree diversity levels including monocultures, two-species mixtures and multi-tree species mixtures in a tree diversity experiment in subtropical China. We found that the tree mycorrhizal type had a significant effect on fungal but not bacterial alpha diversity.

Diisoprenyl-cyclohexene/ane-Type Meroterpenoids from sp. and Their Anti-inflammatory Activities.

A secondary metabolites investigation on sp. 71-10-1-1 was carried out, which led to the obtention of nine new diisoprenyl-cyclohexene/ane-type meroterpenoids (-) and two new isoprenylbenzoic acid-type meroterpeniods (-). The structures of these isolates were established on the basis of multispectroscopic analyses, ECD, and C chemical shifts calculations, and single-crystal X-ray diffraction.

Assembly processes lead to divergent soil fungal communities within and among 12 forest ecosystems along a latitudinal gradient.

Latitudinal gradients provide opportunities to better understand soil fungal community assembly and its relationship with vegetation, climate, soil and ecosystem function. Understanding the mechanisms underlying community assembly is essential for predicting compositional responses to changing environments. We quantified the relative importance of stochastic and deterministic processes in structuring soil fungal communities using patterns of community dissimilarity observed within and between 12 natural forests and related these to environmental variation within and among sites.

Soil fungal diversity and community assembly: affected by island size or type?

Fungi have a huge biodiversity and play important roles in soil biogeochemical cycling in island ecosystems. Although island biogeography has been widely studied for macroorganisms, fungal community assembly in true islands and its relationship with island area are less documented. We examined soil fungal communities in 18 oceanic islands of two types (eight non-coral islands and 10 coral islands) using the Illumina MiSeq sequencing technique.

Response of arbuscular mycorrhizal fungal community in soil and roots to grazing differs in a wetland on the Qinghai-Tibet plateau.

Grazing as one of the most important disturbances affects the abundance, diversity and community composition of arbuscular mycorrhizal (AM) fungi in ecosystems, but the AM fungi in response to grazing in wetland ecosystems remain poorly documented. Here, we examined AM fungi in roots and soil in grazing and non-grazing plots in Zoige wetland on the Qinghai-Tibet plateau. Grazing significantly increased AM fungal spore density and glomalin-related soil proteins, but had no significant effect on the extra radical hyphal density of AM fungi.

Sporormielones A-E, bioactive novel C-C coupled orsellinic acid derivative dimers, and their biosynthetic origin.

Sporormielones A-E (1-5), novel C-C coupled orsellinic acid derivative dimers containing tricyclic cores with a dimethylcyclopentenone unit, were obtained, of which 1-3 and 5 showed obvious short-term memory improvement activity in AD flies. Based on transcriptome analysis, C labelling, and gene deletion, their plausible biosynthetic mechanism was proposed.

Host identity is more important in structuring bacterial epiphytes than endophytes in a tropical mangrove forest.

Interactions between plants and microbes are involved in biodiversity maintenance, community stability and ecosystem functioning. However, differences in the community and network structures between phyllosphere epiphytic and endophytic bacteria have rarely been investigated. Here, we examined phyllosphere epiphytic and endophytic bacterial communities of six mangrove species using Illumina MiSeq sequencing of the 16S rRNA gene.

Diversity and community of culturable endophytic fungi from stems and roots of desert halophytes in northwest China.

Halophytes have high species diversity and play important roles in ecosystems. However, endophytic fungi of halophytes in desert ecosystems have been less investigated. In this study, we examined endophytic fungi associated with the stem and root of ten halophytic species colonizing the Gurbantonggut desert.

Community Assembly of Endophytic Fungi in Ectomycorrhizae of Betulaceae Plants at a Regional Scale.

The interaction between aboveground and belowground biotic communities drives community assembly of plants and soil microbiota. As an important component of belowground microorganisms, root-associated fungi play pivotal roles in biodiversity maintenance and community assembly of host plants. The Betulaceae plants form ectomycorrhizae with soil fungi and widely distribute in various ecosystems.

Biocontrol Potential of Fungal Endophytes against f. sp. Causing Wilt in Cucumber.

Endophytic fungi have received much attention as plant growth promoters as well as biological control agents against many plant pathogens. In this study, 30 endophytic fungal species, isolated from various plants in China, were evaluated using dual culture assay against f. sp.

Spororrminone A and 2--spororrminone A, two new chromones from an endolichenic fungus .

Two new chromones, spororrminone A (, ()-5-hydroxy-2-methyl-4-oxo-2-(()-5-oxotetrahydrofuran-2-yl)chroman-7-carboxylic acid) and 2--spororrminone A (, ()-5-hydroxy-2-methyl-4-oxo-2-(()-5-oxotetrahydrofuran-2-yl)chroman-7-carboxylic acid), were isolated from an EtOAc extract of an endolichenic fungal strain (No. 71-11-4-1). The structures of these compounds were identified by spectroscopic analyses.

Late Quaternary climate change explains soil fungal community composition rather than fungal richness in forest ecosystems.

The dramatic climate fluctuations of the late Quaternary have influenced the diversity and composition of macroorganism communities, but how they structure belowground microbial communities is less well known. Fungi constitute an important component of soil microorganism communities. They play an important role in biodiversity maintenance, community assembly, and ecosystem functioning, and differ from many macroorganisms in many traits.

New phthalide derivatives from the Biscogniauxia sp. and their activities.

Five new phthalide derivatives, biscogniphthalides A-D (1, 2, 3a/3b, and 4), were isolated from Biscogniauxia sp. (No. 69-8-7-1), along with one related known phthalide (5).

Phyllosphere epiphytic and endophytic fungal community and network structures differ in a tropical mangrove ecosystem.

Background: Revealing the relationship between plants and fungi is very important in understanding biodiversity maintenance, community stability, and ecosystem functioning. However, differences in the community and network structures of phyllosphere epiphytic and endophytic fungi are currently poorly documented. In this study, we examined epiphytic and endophytic fungal communities associated with the leaves of six mangrove species using Illumina MiSeq sequencing of internal transcribed spacer 2 (ITS2) sequences.

Host plant phylogeny and geographic distance strongly structure Betulaceae-associated ectomycorrhizal fungal communities in Chinese secondary forest ecosystems.

Environmental filtering and dispersal limitation are two of the primary drivers of community assembly in ecosystems, but their effects on ectomycorrhizal (EM) fungal communities associated with wide ranges of Betulaceae taxa at a large scale are poorly documented. In this study, we examined EM fungal communities associated with 23 species from four genera (Alnus, Betula, Carpinus and Corylus) of Betulaceae in Chinese secondary forest ecosystems, using Illumina MiSeq sequencing of the ITS2 region. Effects of host plant phylogeny, soil, climate and geographic distance on EM fungal community were explored.

Convergent Estimation Mechanism Design for Nonlinear Fuzzy Systems With Faults.

The convergent estimation for a class of nonlinear Takagi-Sugeno fuzzy systems is concerned, where time-varying process faults and input disturbances are both involved. A convergent estimation mechanism (CEM) based on a set of fuzzy iterative estimation observers is constructed for the nonlinear fuzzy system; meanwhile, the convergence of the mean sequence of estimation errors (for both states and faults) to zero (vector) is proved. However, in the existing literature, the estimation errors can only be proved to be uniformly ultimately bounded when the fault is time varying.