Acoustic-Sensing-Based Attribute-Driven Imbalanced Compensation for Anomalous Sound Detection without Machine Identity.

Acoustic sensing provides crucial data for anomalous sound detection (ASD) in condition monitoring. However, building a robust acoustic-sensing-based ASD system is challenging due to the unsupervised nature of training data, which only contain normal sound samples. Recent discriminative models based on machine identity (ID) classification have shown excellent ASD performance by leveraging strong prior knowledge like machine ID. However, such strong priors are often unavailable in real-world applications, limiting these models. To address this, we propose utilizing the imbalanced and inconsistent attribute labels from acoustic sensors, such as machine running speed and microphone model, as weak priors to train an attribute classifier. We also introduce an imbalanced compensation strategy to handle extremely imbalanced categories and ensure model trainability. Furthermore, we propose a score fusion method to enhance anomaly detection robustness. The proposed algorithm was applied in our DCASE2023 Challenge Task 2 submission, ranking sixth internationally. By exploiting acoustic sensor data attributes as weak prior knowledge, our approach provides an effective framework for robust ASD when strong priors are absent.

Diversity and antimicrobial activities of culturable actinomycetes from Odontotermes formosanus (Blattaria: Termitidae).

BACKGROUND: Actinomycetes are important microbes, and they are very important for developing active substances for useful drugs. Actinomycetes are numerous inhabitants, and they are widely distributed in the nest of fungus-growing termites. Previously, we isolated and purified numerous actinomycetes from the combs of Odontotermes formosanus and obtained a variety of valuable natural products. RESULTS: Here, we isolated and purified actinomycetes from fungus-growing termite Odontotermes formosanus using medium-based cultures. Among the eight media tested, M7 and I-HV media were found suitable for isolating actinomycetes. Further, 84 actinomycetes, including 79 Streptomyces isolates, were isolated and purified from O. formosanus and its combs, which belong to four genera (Streptomyces, Kribbella, Amycolatopsis, and Cellulosimicrobium). Then, the type and quantity of actinomycetes were positively correlated with the activity range of termites. Twenty-two actinomycetes strains showed antimicrobial activities. Among them, the BYF18, BYF48, BYF70, and BYF106 strains exhibited antifungal activities against five pathogenic fungi, with zone of inhibition (ZOI) values ranging from 3 to 21 mm. Grincamycin N was isolated and purified from the metabolites of Streptomyces lannensis (BYF106), and it displayed antibacterial activities against Staphylococcus aureus (ZOI = 13.82 ± 0.52 mm) and Micrococcus tetragenus (ZOI = 17.6 ± 0.5 mm) (gentamycin sulfate, as the positive control, had ZOI values of 19.9 ± 0.5 mm and 30.83 ± 0.75 mm, against S. aureus and M. tetragenus, respectively). CONCLUSIONS: Our results confirmed that the actinomycetes associated with O. formosanus are important sources of new active substances.

Temporal and spatial pattern of endophytic fungi diversity of Camellia sinensis (cv. Shu Cha Zao).

BACKGROUND: The experimental materials were a 60-year-old tea tree (Camellia sinensis cv. Shu Cha Zao; SCZ) (the mother plant) and 1-year-old and 20-year-old plants of SCZ that originated as mother plant cuttings. The aim of this study was to use high-throughput sequencing to study the spatial and dynamic distribution of endophytic fungi in different leaf niches (upper leaves, middle leaves, lower leaves) and rhizosphere soil on tea plants of different ages in the same garden. RESULTS: Ascomycota (83.77%), Basidiomycota (11.71%), and Zygomycota (3.45%) were the dominant fungal phyla in all samples. Cladosporium (12.73%), Zymoseptoria (9.18%), and Strelitziana (13.11%) were the dominant genera in the leaf. Alpha diversity analysis revealed that endophytic communities in leaves differed from those in rhizosphere soil and different leaf niches had similar fungal diversity. Shannon's indices and NMDS analysis indicated significant differences in fungal diversity and composition among the SCZ trees of different ages (p ≤ 0.01). The abundance of Cladosporium and Zymoseptoria decreased with increasing SCZ age, whereas the abundance of Strelitziana increased. CONCLUSIONS: The results illustrate variation in endophytic fungi among different niches on tea plants of different ages. The distribution of endophytic fungi in leaves of C. sinensis shows spatiotemporal variation.

Reidentification of Sex Pheromones of Tea Geometrid Ectropis obliqua Prout (Lepidoptera: Geometridae).

Tea geometrid Ectropis obliqua Prout (Lepidoptera: Geometridae) is an important defoliator of the tree crop Camellia sinensis L. in China. The sex pheromones of E. obliqua have not been identified, but have potential importance relative to the biological control of this predator. In this study, the female sex pheromones of E. obliqua were identified and evaluated for use in the monitoring and mass trapping of this pest. The sex pheromone extracts were subjected to gas chromatography-electroantennographic detection and gas chromatography-mass spectrometry. The identified chemicals were synthesized and applied to wind-tunnel tests and field experiments. (Z,Z,Z)-3,6,9-octadecatriene and 6,7-epoxy-(Z,Z)-3,9-octadecadiene were determined to be the primary sex pheromones produced by the female E. obliqua; the latter elicits the strongest electroantennogram responses from male E. obliqua antennae. However, males did not respond to single components in the wind-tunnel tests. The results of a field-trapping experiment indicated that a 4:6 v/v blend of (Z,Z,Z)-3,6,9-octadecatriene and 6,7-epoxy-(Z,Z)-3,9-octadecadiene was highly effective in attracting male moths.

Phylogenetic and functional analysis of gut microbiota of a fungus-growing higher termite: Bacteroidetes from higher termites are a rich source of ß-glucosidase genes.

Fungus-growing termites, their symbiotic fungi, and microbiota inhibiting their intestinal tract comprise a highly efficient cellulose-hydrolyzing system; however, little is known about the role of gut microbiota in this system. Twelve fosmid clones with ß-glucosidase activity were previously obtained by functionally screening a metagenomic library of a fungus-growing termite, Macrotermes annandalei. Ten contigs containing putative ß-glucosidase genes (bgl1-10) were assembled by sequencing data of these fosmid clones. All these contigs were binned to Bacteroidetes, and all these ß-glucosidase genes were phylogenetically closed to those from Bacteroides or Dysgonomonas. Six out of 10 ß-glucosidase genes had predicted signal peptides, indicating a transmembrane capability of these enzymes to mediate cellulose hydrolysis within the gut of the termites. To confirm the activities of these ß-glucosidase genes, three genes (bgl5, bgl7, and bgl9) were successfully expressed and purified. The optimal temperature and pH of these enzymes largely resembled the environment of the host's gut. The gut microbiota composition of the fungus-growing termite was also determined by 454 pyrosequencing, showing that Bacteroidetes was the most dominant phylum. The diversity and the enzyme properties of ß-glucosidases revealed in this study suggested that Bacteroidetes as the major member in fungus-growing termites contributed to cello-oligomer degradation in cellulose-hydrolyzing process and represented a rich source for ß-glucosidase genes.

Bioinspired Artificial Intelligence Applications 2023.

With rapid development of Artificial Intelligence (AI), researchers have found many bioinspired AI applications, such as bioinspired images and speech processing, which can increase accuracy [...].

Rolling forms the diversities of small molecular nonvolatile metabolite profile and consequently shapes the bacterial community structure for Keemun black tea.

The detailed dynamics of small molecular nonvolatile chemical and bacterial diversities, as well as their relationship are still unclear in the manufacturing process of Keemun black tea (KMBT). Herein, mass spectrometry-based untargeted metabolomics, Feature-based Molecular Networking (FBMN) and bacterial DNA amplicon sequencing were used to investigate the dense temporal samples of the manufacturing process. For the first time, we reveal that the pyrogallol-type catechins are oxidized asynchronously before catechol-type catechins during the black tea processing. Rolling is the key procedure for forming the small molecular nonvolatile metabolite profile (SMNMetProf), increasing the metabolite richness, and then shaping the bacterial community structure in the KMBT manufacturing process, which decreases both molecular weight and molecular polarity of the small molecular nonvolatile metabolites. The SMNMetProf of black tea is formed by the endogenous enzymatic oxidation of tea leaves, rather than bacterial fermentation.

Profiling the metatranscriptome of the protistan community in Coptotermes formosanus with emphasis on the lignocellulolytic system.

The symbiotic protists in the hindgut of lower termites are critical for lignocellulose decomposition. Due to the unculturability of these protists, information on lignocellulases and their abundance within the gut is unavailable. The advent of high-throughput sequencing technologies enables an investigation of the gene expression profile in this community without culturing these organisms. Here, we carried out 454 pyrosequencing to profile the metatranscriptome of the protistan community in Coptotermes formosanus. In total, 223,477 reads were obtained by sequencing the enriched protistan mRNA. Phagocytosis and cytoskeletal homeostasis pathways were highly represented in the metatranscriptome. Among the metabolic pathways, starch and sucrose metabolism were dominant. A detailed analysis combining Pfam and KEGG annotation identified 118 glycosyl hydrolases belonging to 18 different glycosyl hydrolase families (GHFs). Subsequently, a novel GHF10 endo-1,4-beta-xylanase was functionally characterized to complement our understanding of the protistan hemicellulases.

Dynamic Changes in the Microbial Community and Metabolite Profile during the Pile Fermentation Process of Fuzhuan Brick Tea.

The pile fermentation process of Fuzhuan brick tea is unique in that it involves preheating without the use of starter cultures. The detailed metabolite changes and their drivers during this procedure are not known. Characterizing these unknown changes that occur in the metabolites and microbes during pile fermentation of Fuzhuan brick tea is important for industrial modernization of this traditional fermented food. Using microbial DNA amplicon sequencing, mass spectrometry-based untargeted metabolomics, and feature-based molecular networking, we herein reveal that significant changes in the microbial community occur before changes in the metabolite profile. These changes were characterized by a decrease in Klebsiella and Aspergillus, alongside an increase in Bacillus and Eurotium. The decrease in lysophosphatidylcholines, unsaturated fatty acids, and some astringent flavan-3-ols and bitter amino acids, as well as the increase in some less astringent flavan-3-ols and sweet or umami amino acids, contributed importantly to the overall changes observed in the metabolite profile. The majority of these changes was caused by bacterial metabolism and the corresponding heat generated by it.

Bacillus cereus (EG-Q3) in the Gut of Ectropis grisescens Contributes to Host Response to Starvation Conditions.

The gut bacteria of insects play an important role in their nutrition, maintenance, and ecological adaption. Ectropis grisescens is the most important leaf-feeding pest in tea gardens in China. In order to explore whether E. grisescens adaptation under starvation stress is related to its gut bacteria, we used a culture-independent method to compare the composition and diversity of their gut bacteria under starvation treatment. The results revealed no significant changes in core gut bacteria composition and diversity within 24 h of starvation. However, non-core gut bacterial Bacillus increased significantly under starvation conditions. B. cereus strain EG-Q3 isolated from the gut of E. grisescens in carbon source-selected medium showed the ability to degrade fat bodies from E. grisescens in vitro and in vivo. Moreover, the fat-lowering ratio of E. grisescens fed with B. cereus strain EG-Q3 (6.76 ± 1.281%) was significantly higher than that of the control group (3.96 ± 0.801%, t = 4.15, df = 8, p < 0.01) after starvation for 4 h. These findings suggest that non-core gut bacterial B. cereus strain EG-Q3 contributes to host adaptation to starvation. Together, this research provides evidence that E. grisescens may benefit from non-core gut bacteria under starvation conditions.

Analysis of the Humoral Immunal Response Transcriptome of Ectropis obliqua Infected by Beauveria bassiana.

Ectropis obliqua is a destructive masticatory pest in China's tea gardens. Beauveria bassiana as microbial insecticides can effectively control E. obliqua larvae; however, the immune response of this insect infected by B. bassiana are largely unknown. Here, after isolating a highly virulent strain of B. bassiana from E. obliqua, the changes in gene expression among different tissues, including hemocytes and fat bodies, of E. obliqua larvae infected by the entomopathogen were investigated using transcriptome sequencing. A total of 5877 co-expressed differentially expressed genes (DEGs) were identified in hemocytes and fat bodies, of which 5826 were up-regulated in hemocytes and 5784 were up-regulated in fat bodies. We identified 249 immunity-related genes, including pattern recognition receptors, immune effectors, signal modulators, and members of immune pathways. A quantitative real-time PCR analysis confirmed that several pattern recognition receptors were upregulated in hemocytes and fat bodies; however, others were downregulated. The investigated immune effectors (ATT and PPO-1) were suppressed. The results showed that there were tissue differences in the expression of immune genes. This study provides a large number of immunity-related gene sequences from E. obliqua after being infected by B. bassiana, furthering the understanding of the molecular mechanisms of E. obliqua defenses against B. bassiana.

Microbial and Nonvolatile Chemical Diversities of Chinese Dark Teas Are Differed by Latitude and Pile Fermentation.

Understanding the microbial and chemical diversities, as well as what affects these diversities, is important for modern manufacturing of traditional fermented foods. In this work, Chinese dark teas (CDTs) that are traditional microbial fermented beverages with relatively high sample diversity were collected. Microbial DNA amplicon sequencing and mass spectrometry-based untargeted metabolomics show that the CDT microbial ß diversity, as well as the nonvolatile chemical α and ß diversities, is determined by the primary impact factors of geography and manufacturing procedures, in particular, latitude and pile fermentation after blending. A large number of metabolites sharing between CDTs and fungi were discovered by Feature-based Molecular Networking (FBMN) on the Global Natural Products Social Molecular Networking (GNPS) web platform. These molecules, such as prenylated cyclic dipeptides and B-vitamins, are functionally important for nutrition, biofunctions, and flavor. Molecular networking has revealed patterns in metabolite profiles on a chemical family level in addition to individual structures.

Wolbachia Strain wGri From the Tea Geometrid Moth Ectropis grisescens Contributes to Its Host's Fecundity.

Members of the Wolbachia genus manipulate insect-host reproduction and are the most abundant bacterial endosymbionts of insects. The tea Geometrid moth Ectropis grisescens (Warren) (Lepidoptera: Geometridae) is the most devastating insect pest of tea plants [Camellia sinensis (L.) O. Kuntze] in China. However, limited data on the diversity, typing, or phenotypes of Wolbachia in E. grisescens are available. Here, we used a culture-independent method to compare the gut bacteria of E. grisescens and other tea Geometridae moths. The results showed that the composition of core gut bacteria in larvae of the three Geometridae moth species was similar, except for the presence of Wolbachia. Moreover, Wolbachia was also present in adult female E. grisescens samples. A Wolbachia strain was isolated from E. grisescens and designated as wGri. Comparative analyses showed that this strain shared multilocus sequence types and Wolbachia surface protein hypervariable region profiles with cytoplasmic incompatibility (CI)-inducing strains in supergroup B; however, the wGri-associated phenotypes were undetermined. A reciprocal cross analysis showed that Wolbachia-uninfected females mated with infected males resulted in 100% embryo mortality (0% eggs hatched per female). Eggs produced by mating between uninfected males and infected females hatched normally. These findings indicated that wGri induces strong unidirectional CI in E. grisescens. Additionally, compared with uninfected females, Wolbachia-infected females produced approximately 30-40% more eggs. Together, these results show that this Wolbachia strain induces reproductive CI in E. grisescens and enhances the fecundity of its female host. We also demonstrated that wGri potential influences reproductive communication between E. grisescens and Ectropis obliqua through CI.

Short-time speaker verification with different speaking style utterances.

In recent years, great progress has been made in the technical aspects of automatic speaker verification (ASV). However, the promotion of ASV technology is still a very challenging issue, because most technologies are still very sensitive to new, unknown and spoofing conditions. Most previous studies focused on extracting target speaker information from natural speech. This paper aims to design a new ASV corpus with multi-speaking styles and investigate the ASV robustness to these different speaking styles. We first release this corpus in the Zenodo website for public research, in which each speaker has several text-dependent and text-independent singing, humming and normal reading speech utterances. Then, we investigate the speaker discrimination of each speaking style in the feature space. Furthermore, the intra and inter-speaker variabilities in each different speaking style and cross-speaking styles are investigated in both text-dependent and text-independent ASV tasks. Conventional Gaussian Mixture Model (GMM), and the state-of-the-art x-vector are used to build ASV systems. Experimental results show that the voiceprint information in humming and singing speech are more distinguishable than that in normal reading speech for conventional ASV systems. Furthermore, we find that combing the three speaking styles can significantly improve the x-vector based ASV system, even when only limited gains are obtained by conventional GMM-based systems.

Feature-Based Molecular Networking Analysis of the Metabolites Produced by In Vitro Solid-State Fermentation Reveals Pathways for the Bioconversion of Epigallocatechin Gallate.

Dark teas are prepared by a microbial fermentation process. Flavan-3-ol B-ring fission analogues (FBRFAs) are some of the key bioactive constituents that characterize dark teas. The precursors and the synthetic mechanism involved in the formation of FBRFAs are not known. Using a unique solid-state fermentation system with ß-cyclodextrin inclusion complexation as well as targeted chromatographic isolation, spectroscopic identification, and Feature-based Molecular Networking on the Global Natural Products Social Molecular Networking web platform, we reveal that dihydromyricetin and the FBRFAs, including teadenol A and fuzhuanin A, are derived from epigallocatechin gallate upon exposure to fungal strains isolated from Fuzhuan brick tea. In particular, the strains from subphylum Pezizomycotina were key drivers for these B-/C-ring oxidation transformations. These are the same transformations seen during the fermentation process of dark teas. These discoveries set the stage to enrich dark teas and other food products for these health-promoting constituents.

Positive Effects of the Tea Catechin, (-)-Epigallocatechin-3-Gallate, on Gut Prophenoloxidase and the Survival of Ectropis obliqua (Lepidoptera: Geometridae).

Ectropis obliqua Prout is the main pest of the tea plant Camellia sinensis (L.) O. Kuntze in China, affecting an annual area of more than one million acres. (-)-Epigallocatechin-3-gallate (EGCG) is the major catechin in tea leaves. Here, we show that EGCG is highly efficient in increasing the survival rate of E. obliqua larvae. We also compared the gut peroxidase (PO) activity between EGCG-fed and control larvae. EGCG-fed larvae had significantly greater PO activity levels than control larvae. Western blotting validated these results. Gut PO activity levels of larvae fed an artificial diet gradually decreased and disappeared completely by day 5. We hypothesize that the increased survival rate of EGCG-fed larvae was associated with increased PO activity. This research provides evidence that E. obliqua larvae have adapted to, and may even benefit from, secondary compounds found in tea leaves.

Positive effects of the tea catechin (-)-epigallocatechin-3-gallate on gut bacteria and fitness of Ectropis obliqua Prout (Lepidoptera: Geometridae).

Ectropis obliqua Prout (Lepidoptera: Geometridae) is the most devastating insect pest of tea plants in China and infests thousands of hectares of tea plantations in China annually. (-)-Epigallocatechin-3-gallate (EGCG) is a major phenolic compound in tea leaves and has a strong antibacterial function. Here, we show that EGCG can effectively improve the fitness of E. obliqua larvae and present the reason by which EGCG promotes larval fitness. In this study, we compared the fitness difference among Control, Antibiotic and Treatment of larvae. The fitness of larvae treated with EGCG and antibiotic was similar and better than that of control group. We also demonstrated that EGCG treatment could significantly reduce species richness and abundance of gut bacteria in E. obliqua larvae. Hence that we speculate that EGCG promotes larval fitness and is associated with ECGG antimicrobial activity. In short, our study provides evidence of the E. obliqua larvae have adapted to secondary compounds found in tea leaves, and may even benefit from these compounds. Our study also contributes to a greater understanding of the reason involved in plant-insect interactions.

A new anti-proliferative acylated flavonol glycoside from Fuzhuan brick-tea.

Fuzhuan brick-tea (FBT) is unique for a fungal fermentation stage in its manufacture process and is classified in dark tea. A new acylated flavonol glycoside, kaempferol 3-O-[E-p-coumaroyl-(→2)][α-l-arabinopyranosyl-(1→3)][α-l-rhamnopyranosyl(1→6)]-ß-d-glucopyranoside, which was trivially named as camellikaempferoside A (1), was isolated from FBT along with camelliquercetiside C (2). Their structures were unambiguously elucidated by combination of spectroscopic and chemical methods. Compound 1 showed anti-proliferative activity against MCF-7 and MDA-MB-231 cells with IC50 values of 7.83 and 19.16 µM, respectively.

Filled pause refinement based on the pronunciation probability for lecture speech.

Nowadays, although automatic speech recognition has become quite proficient in recognizing or transcribing well-prepared fluent speech, the transcription of speech that contains many disfluencies remains problematic, such as spontaneous conversational and lecture speech. Filled pauses (FPs) are the most frequently occurring disfluencies in this type of speech. Most recent studies have shown that FPs are widely believed to increase the error rates for state-of-the-art speech transcription, primarily because most FPs are not well annotated or provided in training data transcriptions and because of the similarities in acoustic characteristics between FPs and some common non-content words. To enhance the speech transcription system, we propose a new automatic refinement approach to detect FPs in British English lecture speech transcription. This approach combines the pronunciation probabilities for each word in the dictionary and acoustic language model scores for FP refinement through a modified speech recognition forced-alignment framework. We evaluate the proposed approach on the Reith Lectures speech transcription task, in which only imperfect training transcriptions are available. Successful results are achieved for both the development and evaluation datasets. Acoustic models trained on different styles of speech genres have been investigated with respect to FP refinement. To further validate the effectiveness of the proposed approach, speech transcription performance has also been examined using systems built on training data transcriptions with and without FP refinement.

Metagenomic insights into metabolic capacities of the gut microbiota in a fungus-cultivating termite (Odontotermes yunnanensis).

Macrotermitinae (fungus-cultivating termites) are major decomposers in tropical and subtropical areas of Asia and Africa. They have specifically evolved mutualistic associations with both a Termitomyces fungi on the nest and a gut microbiota, providing a model system for probing host-microbe interactions. Yet the symbiotic roles of gut microbes residing in its major feeding caste remain largely undefined. Here, by pyrosequencing the whole gut metagenome of adult workers of a fungus-cultivating termite (Odontotermes yunnanensis), we showed that it did harbor a broad set of genes or gene modules encoding carbohydrate-active enzymes (CAZymes) relevant to plant fiber degradation, particularly debranching enzymes and oligosaccharide-processing enzymes. Besides, it also contained a considerable number of genes encoding chitinases and glycoprotein oligosaccharide-processing enzymes for fungal cell wall degradation. To investigate the metabolic divergence of higher termites of different feeding guilds, a SEED subsystem-based gene-centric comparative analysis of the data with that of a previously sequenced wood-feeding Nasutitermes hindgut microbiome was also attempted, revealing that SEED classifications of nitrogen metabolism, and motility and chemotaxis were significantly overrepresented in the wood-feeder hindgut metagenome, while Bacteroidales conjugative transposons and subsystems related to central aromatic compounds metabolism were apparently overrepresented here. This work fills up our gaps in understanding the functional capacities of fungus-cultivating termite gut microbiota, especially their roles in the symbiotic digestion of lignocelluloses and utilization of fungal biomass, both of which greatly add to existing understandings of this peculiar symbiosis.