47 research outputs found
Union-net: A deep neural network model adapted to small data sets
In real applications, generally small data sets can be obtained. At present,
most of the practical applications of machine learning use classic models based
on big data to solve the problem of small data sets. However, the deep neural
network model has complex structure, huge model parameters, and training
requires more advanced equipment, which brings certain difficulties to the
application. Therefore, this paper proposes the concept of union convolution,
designing a light deep network model union-net with a shallow network structure
and adapting to small data sets. This model combines convolutional network
units with different combinations of the same input to form a union module.
Each union module is equivalent to a convolutional layer. The serial input and
output between the 3 modules constitute a "3-layer" neural network. The output
of each union module is fused and added as the input of the last convolutional
layer to form a complex network with a 4-layer network structure. It solves the
problem that the deep network model network is too deep and the transmission
path is too long, which causes the loss of the underlying information
transmission. Because the model has fewer model parameters and fewer channels,
it can better adapt to small data sets. It solves the problem that the deep
network model is prone to overfitting in training small data sets. Use the
public data sets cifar10 and 17flowers to conduct multi-classification
experiments. Experiments show that the Union-net model can perform well in
classification of large data sets and small data sets. It has high practical
value in daily application scenarios. The model code is published at
https://github.com/yeaso/union-netComment: 13 pages, 6 figure
Comprehensively Characterizing the Cytological Features of Saccharum spontaneum by the Development of a Complete Set of Chromosome-Specific Oligo Probes
Chromosome-specific identification is a powerful technique in the study of genome structure and evolution. However, there is no reliable cytogenetic marker to unambiguously identify each of the chromosomes in sugarcane (Saccharum spp., Poaceae), which has a complex genome with a high level of ploidy and heterozygosity. In this study, we developed a set of oligonucleotide (oligo)-based probes through bioinformatic design and massive synthetization. These probes produced a clear and bright single signal in each of the chromosomes and their eight homologous chromosomes in the ancient species Saccharum spontaneum (2n = 8x = 64). Thus, they can be used as reliable markers to robustly label each of the chromosomes in S. spontaneum. We then obtained the karyotype data and established a nomenclature based on chromosomal sizes for the eight chromosomes of the octoploid S. spontaneum. In addition, we also found that the 45S and 5S rDNAs demonstrated high copy number variations among different homologous chromosomes, indicating a rapid evolution of the highly repeated sequence after polyploidization. Our fluorescence in situ hybridization (FISH) assay also demonstrated that these probes could be used as cross-species markers between or within the genera of Sorghum and Saccharum. By comparing FISH analyses, we discovered that several chromosome rearrangement events occurred in S. spontaneum, which might have contributed to the basic chromosome number reduction from 10 in sorghum to 8 in sugarcane. Consistent identification of individual chromosomes makes molecular cytogenetic study possible in sugarcane and will facilitate fine chromosomal structure and karyotype evolution of the genus Saccharum
Trisomy 21-induced Dysregulation of Microglial Homeostasis in Alzheimer’s Brains is Mediated by USP25
阿尔茨海默病(Alzheimer’s disease, AD)是一种最为常见的与记忆、认知能力退化相关的渐进性神经退行性疾病。唐氏综合征(Down’s syndrome, DS)是早发型阿尔茨海默病的一个重要风险因素,作为最常见的智力障碍遗传疾病,厦门大学医学院神经科学研究所王鑫教授团队揭示了治疗阿尔茨海默病和唐氏综合征新的治疗靶点,并且在小鼠模型上利用USP25小分子抑制剂成功地改善了阿尔茨海默病小鼠的认知功能,缓解了神经退行性病变的病理进程。该研究工作由王鑫教授指导完成,厦门大学医学院助理教授郑秋阳和博士生李桂林完成主要实验工作,王世华、朱琳、高月、邓青芳、张洪峰、张丽珊、吴美玲、狄安洁参与了部分研究工作。厦门大学医学院许华曦、赵颖俊和孙灏教授在研究过程中给予大力帮助和支持,清华大学董晨教授提供了Usp25基因敲除小鼠,厦门大学附属妇女儿童医院周裕林教授和郑良楷博士帮助收集了脑组织样品。Down syndrome (DS), caused by trisomy of chromosome 21, is the most significant risk factor for early-onset Alzheimer’s disease (AD); however, underlying mechanisms linking DS and AD remain unclear. Here, we show that triplication of homologous chromosome 21 genes aggravates neuroinflammation in combined murine DS-AD models. Overexpression of USP25, a deubiquitinating enzyme encoded by chromosome 21, results in microglial activation and induces synaptic and cognitive deficits, whereas genetic ablation of Usp25 reduces neuroinflammation and rescues synaptic and cognitive function in 5×FAD mice. Mechanistically, USP25 deficiency attenuates microglia-mediated proinflammatory cytokine overproduction and synapse elimination. Inhibition of USP25 reestablishes homeostatic microglial signatures and restores synaptic and cognitive function in 5×FAD mice. In summary, we demonstrate an unprecedented role for trisomy 21 and pathogenic effects associated with microgliosis as a result of the increased USP25 dosage, implicating USP25 as a therapeutic target for neuroinflammation in DS and AD.This work was supported by the National Natural Science Foundation of China (31871077, 81822014, and 81571176 to X.W.; 81701130 to Q.Z.), the National Key R&D Program of China (2016YFC1305900 to X.W.), the Natural Science Foundation of Fujian Province of China (2017J06021 to X.W.), the Fundamental Research Funds for the Chinese Central Universities (20720150061 to X.W.), and the BrightFocus Foundation (A2018214F to Yingjun Zhao).
该研究工作得到国家重点研发计划项目、国家自然科学基金、福建省自然科学基金、厦门大学校长基金的资助和支持
Manure application effects on subsoils: Abundant taxa initiate the diversity reduction of rare bacteria and community functional alterations
Manure application is a significant agriculture practice that can affect the microbial community structure in both topsoil and subsoil. However, how the abundant and rare taxa in the soil profile respond to surface manure application and their ecological roles at different soil depths remain unknown. Based on a soil mesocosm experiment, we used amplicon sequencing and high-throughput quantitative-PCR array to characterize the bacterial community composition and functional traits across soil profiles. Results showed that the relative abundance and diversity of rare taxa increased in the topsoil but decreased in the 40–60 cm soil, where the relative abundance of abundant taxa increased after manure application. Evidence from network analysis, niche width and 16S rRNA operon (rrn) copy number suggest that abundant taxa in subsoils had a greater competitivity for resource mining than rare taxa. Regarding resource utilization strategies, microbial communities under manure treatment preferred to utilize recalcitrant carbon (C) and inorganic phosphorus (P) in the topsoil and labile carbon and organic phosphorus in the subsoil compared with non-manure application. Random Forest regression analysis indicated the relatively greater contribution of abundant taxa to C degradation and fixation in subsoils. These results imply that the manure application effect on microbial resource mining in subsoils is mainly driven by abundant bacteria due to the lower competitiveness of rare taxa for the C sources leached above. Overall, This study linked community functions with the ecological role of abundant and rare taxa in the context of environmental disturbances at different soil depths and shed light on the potential ecological risks of diversity reduction of subsoil rare bacteria
The RING Finger E3 Ligase SpRing is a Positive Regulator of Salt Stress Signaling in Salt-Tolerant Wild Tomato Species
Protein ubiquitination in plants plays critical roles in many biological processes, including adaptation to abiotic stresses. Previously, RING finger E3 ligase has been characterized during salt stress response in several plant species, but little is known about its function in tomato. Here, we report that SpRing, a stress-inducible gene, is involved in salt stress signaling in wild tomato species Solanum pimpinellifolium 'PI365967'. In vitro ubiquitination assay revealed that SpRing is an E3 ubiquitin ligase and the RING finger conserved region is required for its activity. SpRing is expressed in all tissues of wild tomato and up-regulated by salt, drought and osmotic stresses, but repressed by low temperature. Green fluorescent protein (GFP) fusion analysis showed that SpRing is localized at the endoplasmic reticulum. Silencing of SpRing through a virus-induced gene silencing approach led to increased sensitivity to salt stress in wild tomato. Overexpression of SpRing in Arabidopsis thaliana resulted in enhanced salt tolerance during seed germination and early seedling development. The expression levels of certain key stress-related genes are altered both in SpRing-overexpressing Arabidopsis plants and virus-induced gene silenced tomato seedlings. Taken together, our results indicate that SpRing is involved in salt stress and functions as a positive regulator of salt tolerance
Genome-wide analysis of phylogeny, expression profile andsub-cellular localization of SKP1-Like genes in wild tomato
SKP1 is a core component of SCF complex, a major type of E3 ubiquitin ligase catalyzing the last step in ubiquitin-mediated protein degradation pathway. In present study, SKP1 gene family in Solanum pimpinellifolium (SSK), a wild species of tomato, was investigated. A total of 19 SSK genes were identified through homologous search. Their chromosomal locations, gene structures, phylogeny, expression profiles, sub-cellular localizations and protein-protein interaction patterns with putative F-box proteins were analyzed in detail. The high homology and similar expression patterns among clustered SSK genes in chromosome suggested that they may have evolved from duplication events and are functionally redundant. Sub-cellular localization indicated that most of the SSK proteins are distributed in both cytosol and nucleus, except for SSK8, which is detected in cytosol only. Tissue-specific expression patterns suggested that many SSK genes may be involved in tomato fruit development. Furthermore, several SSK genes were found to be responsive to heat stress and salicylic acid treatment. Based on phylogenetic analysis, expression profiles and protein interaction property, we proposed that tomato SSK1 and SSK2 might have similar function to ASK1 and ASK2 in Arabidopsis. (C) 2015 Elsevier Ireland Ltd. All rights reserved
Unveiling the role of dissolved organic matter on phosphorus sorption and availability in a 5-year manure amended paddy soil
Dissolved organic matter (DOM) is an active component of organic manure that is widely used in agroecosystems to increase nutrient availability and consequently enhance crop yields. However, the ways in which soil DOM characteristics are influenced by organic manure and how it contributes to crop yield and soil P availability remains unclear. Here, we conducted a 5-year field experiment and demonstrated that partial replacement of chemical P fertilizer with swine manure could maintain high rice yield and soil available P levels and increase P fertilizer use efficiency (PUE) in comparison to chemical fertilization, even when the total P input was reduced. This suggests that organic manure application can significantly mobilize soil P and increase P availability. Structural equation modeling analysis indicated that the soil pH and humification degree of DOM, rather than DOM content, directly decreased maximum P adsorption capacity. The combined results of the optical spectroscopy and ultrahigh-resolution mass spectroscopy obtained from the laboratory validation experiment based on the DOM-removed soil demonstrated that manure-derived DOM competing with P for adsorption was one of the main reasons for the increase in soil P availability and that the effective DOM components were N-containing lignins, tannins, and condensed polycyclic aromatics with higher O/C and lower H/C ratios. Overall, our results provide solid evidence that soil DOM characteristics are influenced by manure application and facilitate soil P availability, which could help guide the sustainable P management and manure application in agroecosystems
Genome-wide analysis of phylogeny, expression profile and sub-cellular localization of SKP1-Like genes in wild tomato
SKP1 is a core component of SCF complex, a major type of E3 ubiquitin ligase catalyzing the last step in ubiquitin-mediated protein degradation pathway. In present study, SKP1 gene family in Solanum pimpinellifolium (SSK), a wild species of tomato, was investigated. A total of 19 SSK genes were identified through homologous search. Their chromosomal locations, gene structures, phylogeny, expression profiles, sub-cellular localizations and protein-protein interaction patterns with putative F-box proteins were analyzed in detail. The high homology and similar expression patterns among clustered SSK genes in chromosome suggested that they may have evolved from duplication events and are functionally redundant. Sub-cellular localization indicated that most of the SSK proteins are distributed in both cytosol and nucleus, except for SSK8, which is detected in cytosol only. Tissue-specific expression patterns suggested that many SSK genes may be involved in tomato fruit development. Furthermore, several SSK genes were found to be responsive to heat stress and salicylic acid treatment. Based on phylogenetic analysis, expression profiles and protein interaction property, we proposed that tomato SSK1 and SSK2 might have similar function to ASK1 and ASK2 in Arabidopsis. (C) 2015 Elsevier Ireland Ltd. All rights reserved