44 research outputs found

    Theoretical Analysis of Noise and Vibration Generated by Gas Pressure Pulsation in Hermetic Compressors

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    Due to the intermittent nature of discharge flow in hermetic compressors, gas pulsation is a major source of noise, vibration and harshness (NVH) effects. In the presented study on gas pulsation noise of hermetic compressors, a model was developed where the thermodynamics aspects of the compression process and the vibro-acoustics aspects are coupled together. The vibro-acoustics submodel is based on finite element method, and it describes the two-way coupled interaction of compressor cavity acoustics and shell vibration. The thermodynamics submodel is based on compressor model developed in previous studies, PDSim. It is used to compute the discharge gas pulsations that excite the cavity. Meanwhile, the acoustics response in the cavity is coupled with the thermodynamics submodel though proper modeling of discharge valves. Simulations were conducted to validate the models developed in the current work as well as the to demonstrate how these modeling tools can help compressor manufacturers to gain better understanding of the physical reasons behind NVH effects of compressors. These tools can also provide guidelines on NVH oriented design optimization of compressors

    Modification of m5C regulators in sarcoma can guide different immune infiltrations as well as immunotherapy

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    BackgroundRecent studies have found that 5-methylcytosine (m5C) modulators are associated with the prognosis and treatment of cancer. However, the relevance of m5C modulators in sarcoma prognosis and the tumour microenvironment is unclear.MethodsWe selected 15 m5C regulators and performed unsupervised clustering to identify m5C modification patterns and differentially expressed genes associated with the m5C phenotype in The Cancer Genome Atlas (TCGA) sarcomas. The extent of immune cell infiltration in different clustering groups was explored using single-sample gene set enrichment analysis and estimation algorithms. A principal component analysis algorithm-based m5C scoring protocol was performed to assess the m5C modification patterns of individual tumors.ResultsWe identified two distinct m5C modification patterns in the TCGA sarcoma cohort, which possess different clinical outcomes and biological processes. Tumour microenvironment analysis revealed two groups of immune infiltration patterns highly consistent with m5C modification patterns, classified as immune inflammatory and immune desert types. We constructed m5C scores and found that high m5C scores were closely associated with leiomyosarcoma and other subtypes, and were associated with poorer prognosis, lower PD-L1 expression, and poorer immunotherapy outcomes. The best application was validated against the m5C database.ConclusionWe constructed an m5C score for sarcoma based on the TCGA database and identified a poorer prognosis in the high m5c score group. The stability and good prognostic predictive power of the m5C score was verified by an external database. We found that sarcomas in the low m5C score group may have a better response to immunotherapy

    WS-Snapshot: An effective algorithm for wide-field and large-scale imaging

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    The Square Kilometre Array (SKA) is the largest radio interferometer under construction in the world. The high accuracy, wide-field and large size imaging significantly challenge the construction of the Science Data Processor (SDP) of SKA. We propose a hybrid imaging method based on improved W-Stacking and snapshots. The w range is reduced by fitting the snapshot uvuv plane, thus effectively enhancing the performance of the improved W-Stacking algorithm. We present a detailed implementation of WS-Snapshot. With full-scale SKA1-LOW simulations, we present the imaging performance and imaging quality results for different parameter cases. The results show that the WS-Snapshot method enables more efficient distributed processing and significantly reduces the computational time overhead within an acceptable accuracy range, which would be crucial for subsequent SKA science studies.Comment: 10 pages, 10 figures, 6 tables, accepted by MNRA

    Calculation of Sound Insulation for Hybrid CLT Fabricated with Lumber and LVL and comparison with experimental data.

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    The insulated predictions were carried out for LVL, CLT and HCLT in order to evaluate their sound properties, in which the theoretical value of sound insulation was predicted by regarding the substances in wood cell wall as equivalence to specific medium based on Biot model, and the wood anatomical characteristics, such as the length and diameter of tracheid, diameter of pit, and porosity, were taken into account for determining the equivalent density and bulk modulus of elasticity of wood cell wall. By comparing the tested and predicted values of sound insulation, the conclusion were drawn as follows: the predicted values of sound insulation were significantly correlated with the tested values for LVL, CLT and HCLT. As for Masson pine and Southern pine, the adjacent of earlywood and latewood was considered as sandwich structure for the calculation of sound insulation. Meanwhile, the bonding interface was creatively introduced to improve the accuracy of sound insulation prediction. The transfer function involved in sound insulation prediction provide an effective method to characterize the sound insulation volume of wood composite in construction and decoration areas

    Rapid appearance quality of rice based on machine vision and convolutional neural network research on automatic detection system

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    IntroductionIn the process of rice production and storage, there are many defects in the traditional detection methods of rice appearance quality, but using modern high-precision instruments to detect the appearance quality of rice has gradually developed into a new research trend at home and abroad with the development of agricultural artificial intelligence.MethodsIn this study, we independently designed a fast automatic rice appearance quality detection system based on machine vision technology by introducing convolutional neural network and image processing technology. In this study, NIR and RGB images were generated into five-channel image data by superposition function, and image are preprocessed by combining the Watershed algorithm with the Otus adaptive threshold function. Different grains in the samples were labeled and put in the convolutional neural network for training. The rice grains were classified and the phenotype data were analyzed by selecting the optimal training model to realize the detection of rice appearance quality.Results and discussionThe experimental results showed that the resolution of the system could reach 92.3%. In the detection process, the system designed with this method not only reduces the subjectivity problems caused by different detection environments, visual fatigue caused large sample size and the inspector’s personal factors, but also significantly improves the detection time and accuracy, which further enhances the detection efficiency of rice appearance quality, and has positive significance for the development of the rice industry

    Sciences of the USA 1418 -1421 ͉ PNAS

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    The discovery of the block-like structure of linkage disequilibrium (LD) in human populations holds the promise of delineating the etiology of common diseases. However, understanding the magnitude, mechanism, and utility of between-population LD sharing is critical for future genome-wide association studies. In this study, substantial LD sharing between six non-African populations was observed, although much less between African-American and non-African, based on 20,000 SNPs of chromosome 21. We also demonstrated the respective roles of recombination and demographic events in shaping LD sharing. Furthermore, we showed that the haplotype-tagged SNPs chosen from one population are portable to the others in East Asia. Therefore, we concluded that the magnitude of LD sharing between human populations justifies the use of representative populations for selecting haplotypetagged SNPs in genome-wide association studies of complex diseases. bottleneck ͉ genetic distance ͉ association study ͉ common disease ͉ genetic variant C omprehensive testing of the association between genetic variations in the human genome and common diseases holds the promise of delineating the genetic architecture of these diseases (1-5). Substantial sharing of the boundaries and specific haplotypes of linkage disequilibrium (LD) blocks between populations was observed (6). However, variations of haplotype and LD across populations were also reported, raising concerns on its practical hindrance for genomewide testing of association (7-9). Conflicting observations on the magnitude of LD sharing between human populations, therefore, call for a careful examination of the following three questions, which are fundamental in developing strategies for genomewide testing of association. First, measurement of LD sharing between populations should be made independent of the definition of LD blocks, which introduce inconsistent block boundaries (10). Second, the mechanisms that shape LD sharing between populations are yet to be fully explored although the roles of recombination hotspots and demographic events have been implicated To address the aforementioned questions, we typed Ͼ20,000 SNPs on chromosome 21 in seven populations: three representative continental populations [African-American (AFR), European (EUR), and Han Chinese (HAN)] and four other major East Asian (EA) populations. This design allows a close examination of LD sharing between continental groups as well as those within East Asia. In this report, we measured the LD sharing between populations independent of the definition of LD block; and we showed that bottleneck events play a critical role in shaping the LD sharing between Africans and nonAfricans, but much less so between non-Africans. An important question for applying HapMap results to disease studies is how tagSNPs selected from a HapMap population will be ported to disease studies performed in other populations. In this study, we showed that tagSNPs selected from representative continental populations are indeed portable to the others in the same continent for association studies, at least in East Asia, with reasonable efficiency. In addition, we proposed a simple guideline that allows a quick evaluation of the portability of tagSNPs between populations by typing a small number of SNPs. Results Overall 26,112 SNPs were selected and typed in this study, and the data from 19,060 SNPs passed the quality control criteria and were used for further analyses. The SNPs and quality control criteria for SNP selection are described in Materials and Methods. Seven world populations, including EUR, AFR, and five EA populations, were studied. The five EA populations, i.e., HAN, Miao (HMJ), Zhuang (CCY), Wa (WBM), and Uighur (UIG), represent five major linguistic families spoken in East Asia. Preservation of LD between populations, i.e., LD sharing (S, or S AB when the population A was given as reference), is measured by the proportion of SNP pairs in LD in one population (population A or the reference) that are also in LD in another (population B). In this study, LD sharing was estimated without invoking the inference of haplotype blocks; therefore, the measure is independent of the definition of haplotype blocks. LD between two loci was measured in r 2 (16). Detail for the measure of LD sharing is described in Materials and Methods. LD sharing between EAs ranges from 63-74% for r 2 Ն 0.1 and 70-84% for r 2 Ն 0.5 (se

    Chromosome-level genome assembly of a regenerable maize inbred line A188.

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    BACKGROUND The maize inbred line A188 is an attractive model for elucidation of gene function and improvement due to its high embryogenic capacity and many contrasting traits to the first maize reference genome, B73, and other elite lines. The lack of a genome assembly of A188 limits its use as a model for functional studies. RESULTS Here, we present a chromosome-level genome assembly of A188 using long reads and optical maps. Comparison of A188 with B73 using both whole-genome alignments and read depths from sequencing reads identify approximately 1.1 Gb of syntenic sequences as well as extensive structural variation, including a 1.8-Mb duplication containing the Gametophyte factor1 locus for unilateral cross-incompatibility, and six inversions of 0.7 Mb or greater. Increased copy number of carotenoid cleavage dioxygenase 1 (ccd1) in A188 is associated with elevated expression during seed development. High ccd1 expression in seeds together with low expression of yellow endosperm 1 (y1) reduces carotenoid accumulation, accounting for the white seed phenotype of A188. Furthermore, transcriptome and epigenome analyses reveal enhanced expression of defense pathways and altered DNA methylation patterns of the embryonic callus. CONCLUSIONS The A188 genome assembly provides a high-resolution sequence for a complex genome species and a foundational resource for analyses of genome variation and gene function in maize. The genome, in comparison to B73, contains extensive intra-species structural variations and other genetic differences. Expression and network analyses identify discrete profiles for embryonic callus and other tissues
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