108 research outputs found

    Biodiversity of network modules drives ecosystem functioning in biochar-amended paddy soil

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    IntroductionSoil microbes are central in governing soil multifunctionality and driving ecological processes. Despite biochar application has been reported to enhance soil biodiversity, its impacts on soil multifunctionality and the relationships between soil taxonomic biodiversity and ecosystem functioning remain controversial in paddy soil.MethodsHerein, we characterized the biodiversity information on soil communities, including bacteria, fungi, protists, and nematodes, and tested their effects on twelve ecosystem metrics (including functions related to enzyme activities, nutrient provisioning, and element cycling) in biochar-amended paddy soil.ResultsThe biochar amendment augmented soil multifunctionality by 20.1 and 35.7% in the early stage, while the effects were diminished in the late stage. Moreover, the soil microbial diversity and core modules were significantly correlated with soil multifunctionality.DiscussionOur analysis revealed that not just soil microbial diversity, but specifically the biodiversity within the identified microbial modules, had a more pronounced impact on ecosystem functions. These modules, comprising diverse microbial taxa, especially protists, played key roles in driving ecosystem functioning in biochar-amended paddy soils. This highlights the importance of understanding the structure and interactions within microbial communities to fully comprehend the impact of biochar on soil ecosystem functioning in the agricultural ecosystem

    Relationship Between Dispersion Metric and Properties of PMMA/SWNT Nanocomposites

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    Particle spatial dispersion is a crucial characteristic of polymer composite materials and this property is recognized as especially important in nanocomposite materials due to the general tendency of nanoparticles to aggregate under processing conditions. We introduce dispersion metrics along with a specified dispersion scale over which material homogeneity is measured and consider how the dispersion metrics correlate quantitatively with the variation of basic nanocomposite properties. We then address the general problem of quantifying nanoparticle spatial dispersion in model nanocomposites of single wall carbon nanotubes (SWNT) dispersed in poly(methyl methacrylate) (PMMA) at a fixed SWNT concentration of 0.5 % using a \u27coagulation\u27 fabrication method. Two methods are utilized to measure dispersion, UV-Vis spectroscopy and optical confocal microscopy. Quantitative spatial dispersion levels were obtained through image analysis to obtain a \u27relative dispersion index\u27 (RDI) representing the uniformity of the dispersion of SWNTs in the samples and through absorbance. We find that the storage modulus, electrical conductivity, and flammability containing the same amount of SWNTs, the relationships between the quantified dispersion levels and physical properties show about four orders of magnitude variation in storage modulus, almost eight orders of magnitude variation in electric conductivity, and about 70 % reduction in peak mass loss rate at the highest dispersion level used in this study. The observation of such a profound effect of SWNT dispersion indicates the need for objective dispersion metrics for correlating and understanding how the properties of nanocomposites are determined by the concentration, shape and size of the nanotubes

    Cytosolic PLA2 is required for CTL-mediated immunopathology of celiac disease via NKG2D and IL-15

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    IL-15 and NKG2D promote autoimmunity and celiac disease by arming cytotoxic T lymphocytes (CTLs) to cause tissue destruction. However, the downstream signaling events underlying these functional properties remain unclear. Here, we identify cytosolic phospholipase A2 (cPLA2) as a central molecule in NKG2D-mediated cytolysis in CTLs. Furthermore, we report that NKG2D induces, upon recognition of MIC+ target cells, the release of arachidonic acid (AA) by CTLs to promote tissue inflammation in association with target killing. Interestingly, IL-15, which licenses NKG2D-mediated lymphokine killer activity in CTLs, cooperates with NKG2D to induce cPLA2 activation and AA release. Finally, cPLA2 activation in intraepithelial CTLs of celiac patients provides an in vivo pathophysiological dimension to cPLA2 activation in CTLs. These results reveal an unrecognized link between NKG2D and tissue inflammation, which may underlie the emerging role of NKG2D in various immunopathological conditions and define new therapeutic targets

    Evolution of cellular diversity in primary motor cortex of human, marmoset monkey, and mouse

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    Comparative cellular analysis of motor cortex in human, marmoset and mouse

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    The primary motor cortex (M1) is essential for voluntary fine-motor control and is functionally conserved across mammals1. Here, using high-throughput transcriptomic and epigenomic profiling of more than 450,000 single nuclei in humans, marmoset monkeys and mice, we demonstrate a broadly conserved cellular makeup of this region, with similarities that mirror evolutionary distance and are consistent between the transcriptome and epigenome. The core conserved molecular identities of neuronal and non-neuronal cell types allow us to generate a cross-species consensus classification of cell types, and to infer conserved properties of cell types across species. Despite the overall conservation, however, many species-dependent specializations are apparent, including differences in cell-type proportions, gene expression, DNA methylation and chromatin state. Few cell-type marker genes are conserved across species, revealing a short list of candidate genes and regulatory mechanisms that are responsible for conserved features of homologous cell types, such as the GABAergic chandelier cells. This consensus transcriptomic classification allows us to use patch-seq (a combination of whole-cell patch-clamp recordings, RNA sequencing and morphological characterization) to identify corticospinal Betz cells from layer 5 in non-human primates and humans, and to characterize their highly specialized physiology and anatomy. These findings highlight the robust molecular underpinnings of cell-type diversity in M1 across mammals, and point to the genes and regulatory pathways responsible for the functional identity of cell types and their species-specific adaptations

    A multimodal cell census and atlas of the mammalian primary motor cortex

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    ABSTRACT We report the generation of a multimodal cell census and atlas of the mammalian primary motor cortex (MOp or M1) as the initial product of the BRAIN Initiative Cell Census Network (BICCN). This was achieved by coordinated large-scale analyses of single-cell transcriptomes, chromatin accessibility, DNA methylomes, spatially resolved single-cell transcriptomes, morphological and electrophysiological properties, and cellular resolution input-output mapping, integrated through cross-modal computational analysis. Together, our results advance the collective knowledge and understanding of brain cell type organization: First, our study reveals a unified molecular genetic landscape of cortical cell types that congruently integrates their transcriptome, open chromatin and DNA methylation maps. Second, cross-species analysis achieves a unified taxonomy of transcriptomic types and their hierarchical organization that are conserved from mouse to marmoset and human. Third, cross-modal analysis provides compelling evidence for the epigenomic, transcriptomic, and gene regulatory basis of neuronal phenotypes such as their physiological and anatomical properties, demonstrating the biological validity and genomic underpinning of neuron types and subtypes. Fourth, in situ single-cell transcriptomics provides a spatially-resolved cell type atlas of the motor cortex. Fifth, integrated transcriptomic, epigenomic and anatomical analyses reveal the correspondence between neural circuits and transcriptomic cell types. We further present an extensive genetic toolset for targeting and fate mapping glutamatergic projection neuron types toward linking their developmental trajectory to their circuit function. Together, our results establish a unified and mechanistic framework of neuronal cell type organization that integrates multi-layered molecular genetic and spatial information with multi-faceted phenotypic properties

    Thermal Performance of a Cylindrical Lithium-Ion Battery Module Cooled by Two-Phase Refrigerant Circulation

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    It is important for the safety and good performance of a Li-ion battery module/pack to have an efficient thermal management system. In this paper, a battery thermal management system with a two-phase refrigerant circulated by a pump was developed. A battery module consisting of 240 18650-type Li-ion batteries was fabricated based on a finned-tube heat-exchanger structure. This structural design offers the potential to reduce the weight of the battery thermal management system. The cooling performance of the battery module was experimentally studied under different charge/discharge C-rates and with different refrigerant circulation pump operation frequencies. The results demonstrated the effectiveness of the cooling system. It was found that the refrigerant-based battery thermal management system could maintain the battery module maximum temperature under 38 degrees C and the temperature non-uniformity within 2.5 degrees C for the various operation conditions considered. The experimental results with 0.5 C charging and a US06 drive cycle showed that the thermal management system could reduce the maximum temperature difference in the battery module from an initial value of 4.5 degrees C to 2.6 degrees C, and from the initial 1.3 degrees C to 1.1 degrees C, respectively. In addition, the variable pump frequency mode was found to be effective at controlling the battery module, functioning at a desirable constant temperature and at the same time minimizing the pump work consumption
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