当前共找到 1317 篇文献分享,本页显示第 841 - 860 篇。
841.
彬
(2022-11-30 23:31):
#paper doi: 10.3168/jds.2009-2581. Conte G , Mele M , Chessa S , et al. Diacylglycerol acyltransferase 1, stearoyl-CoA desaturase 1, and sterol regulatory element binding protein 1 gene polymorphisms and milk fatty acid composition in Italian Brown cattle[J]. Journal of Dairy Science, 2010, 93(2):753-763. 该研究对意大利褐牛群的SCD1、DGAT1和SREBP1基因进行分型,并研究了这3个基因分型是否与乳中脂肪酸组成相关。结果显示意大利褐牛SCD1、SREBP1和DGAT1这3个基因的基因频率分别为82%、84%和98%,表现出等位基因分布不平衡,SCD1和DGAT1基因多态性与牛奶脂肪酸组分显著相关,而SREBP1基因多态性与牛奶脂肪酸组分关联不显著。
Abstract:
Several lipogenic genes have been shown to have effects on lipid metabolism: stearoyl CoA desaturase 1 (SCD1) catalyzes the desaturation of several fatty acids (FA) in the cis-Delta(9) position in …
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Several lipogenic genes have been shown to have effects on lipid metabolism: stearoyl CoA desaturase 1 (SCD1) catalyzes the desaturation of several fatty acids (FA) in the cis-Delta(9) position in mammary glands of ruminant animals, diacylglycerol acyltransferase 1 (DGAT1) is a key enzyme in triacylglycerol synthesis in the mammary gland, and sterol regulatory element binding protein (SREBP-1) is a transcription factor that regulates expression levels of the SCD1 gene and other genes relevant to lipid and FA metabolism in adipose tissue and mammary gland. In this work, 351 Italian Brown cows were genotyped for polymorphisms in the SCD1, SREBP-1, and DGAT1 genes to reveal the allelic distribution in the population. Subsequently, effects on individual milk FA composition and on cis-9 unsaturated/saturated FA ratios, a proxy of mammary stearoyl CoA desaturase activity, were investigated. The genotypes of SCD1 (A293V) and DGAT1 (K232A) were determined by an approach based on the ligation detection reaction and a universal array, whereas the genotype of SREBP-1 (84-bp insertion-deletion) was revealed by PCR amplification of intron 5. The genotype analysis showed an unbalanced distribution of alleles within all genes, being the allele with higher gene frequency at 82, 84, and 98% for SCD1, SREBP-1, and DGAT1, respectively. Significant associations between SCD1 and DGAT1 polymorphisms and milk FA composition were found, whereas SREBP-1 polymorphism was not associated with milk FA composition. In particular, SCD1 showed significant association with C14:1 cis-9 and C14:1 cis-9/C14:0, which is considered the best proxy of the desaturation activity in mammary gland. The DGAT1 polymorphism had the strongest association with milk FA composition, which confirmed the key role of DGAT1 in lipid metabolism of mammary gland. However, the unbalanced distribution of alleles in all polymorphisms investigated suggested that the size of population should be increased to confirm the results of the present study.
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842.
Ricardo
(2022-11-30 23:24):
#paper http://dx.doi.org/10.1016/j.neuroimage.2017.07.008 Quicksilver: Fast predictive image registration – A deep learning approach 介绍了一种快速变形图像配准方法——Quicksilver。图像对的配准通过直接基于图像外观的变形模型的patch-wise预测工作。采用深度编码器-解码器网络作为预测模型。虽然预测策略是通用的,但作者主要关注大变形Diffeomorphic Metric Mapping (LDDMM)模型的预测。具体地说,作者预测了LDDMM的动量参数化,这促进了patch-wise预测策略,同时保持了LDDMM的理论性质,如保证微分同胚映射以获得足够强的正则化。作者还提供了预测网络的概率版本,可以在测试期间进行采样,以计算预测变形的不确定性。最后,作者引入了一种新的修正网络,它大大提高了现有预测网络的预测精度。
Abstract:
This paper introduces Quicksilver, a fast deformable image registration method. Quicksilver registration for image-pairs works by patch-wise prediction of a deformation model based directly on image appearance. A deep encoder-decoder …
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This paper introduces Quicksilver, a fast deformable image registration method. Quicksilver registration for image-pairs works by patch-wise prediction of a deformation model based directly on image appearance. A deep encoder-decoder network is used as the prediction model. While the prediction strategy is general, we focus on predictions for the Large Deformation Diffeomorphic Metric Mapping (LDDMM) model. Specifically, we predict the momentum-parameterization of LDDMM, which facilitates a patch-wise prediction strategy while maintaining the theoretical properties of LDDMM, such as guaranteed diffeomorphic mappings for sufficiently strong regularization. We also provide a probabilistic version of our prediction network which can be sampled during the testing time to calculate uncertainties in the predicted deformations. Finally, we introduce a new correction network which greatly increases the prediction accuracy of an already existing prediction network. We show experimental results for uni-modal atlas-to-image as well as uni-/multi-modal image-to-image registrations. These experiments demonstrate that our method accurately predicts registrations obtained by numerical optimization, is very fast, achieves state-of-the-art registration results on four standard validation datasets, and can jointly learn an image similarity measure. Quicksilver is freely available as an open-source software.
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843.
muton
(2022-11-30 23:19):
#paper https://science.org/doi/10.1126/ sciadv.abm3829 Science Advances,2022,Higher-dimensional neural representations predict better episodic memory
情景记忆使人类能够编码并随后生动地检索有关我们丰富经历的信息,但怎样的神经表征可以支持这一心理能力?作者让被试学习人脸图片和词语的配对,使用表征维度的分析方法,对由脑成像得到的神经相似性矩阵进行PCA分析,得到每个主成分的eigenvalue,通过对eigenvalue的处理得到RD(representational dimensionality)值,来分析面孔选择区和其他相关脑区的差异,结果发现,面孔选择区保留了高维表征,重要的是,RD值越大,记忆效应就越好。本文提供了新的神经表征分析方法。
Abstract:
Episodic memory enables humans to encode and later vividly retrieve information about our rich experiences, yet the neural representations that support this mental capacity are poorly understood. Using a large …
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Episodic memory enables humans to encode and later vividly retrieve information about our rich experiences, yet the neural representations that support this mental capacity are poorly understood. Using a large fMRI dataset ( = 468) of face-name associative memory tasks and principal component analysis to examine neural representational dimensionality (RD), we found that the human brain maintained a high-dimensional representation of faces through hierarchical representation within and beyond the face-selective regions. Critically, greater RD was associated with better subsequent memory performance both within and across participants, and this association was specific to episodic memory but not general cognitive abilities. Furthermore, the frontoparietal activities could suppress the shared low-dimensional fluctuations and reduce the correlations of local neural responses, resulting in greater RD. RD was not associated with the degree of item-specific pattern similarity, and it made complementary contributions to episodic memory. These results provide a mechanistic understanding of the role of RD in supporting accurate episodic memory.
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844.
张贝
(2022-11-30 22:20):
#paper DOI: 10.1038/s41586-020-1969-6 Nature
. 2020 Feb;578(7793):82-93 Pan-cancer analysis of whole genomes
本文是泛癌全基因组分析(PCAWG)联盟在nature上发表的一篇文章,对ICGC和TCGA的38种常见癌症的2658例肿瘤及其配对正常组织样本的全基因组测序数据进行系统整合分析。癌症基因组平均有4-5个驱动突变(结合编码和非编码基因元件);约有5%的病例未发现驱动突变,表明癌症驱动基因的发现仍未完全;常见和罕见的遗传变异会影响体细胞突变的模式,包括点突变、结构变异和体细胞反转录转座。同时文章描述了非编码突变、识别了导致碱基替换、小片段插入和缺失以及结构变异的突变过程的新特征;分析了肿瘤演化的时机和模式;描述了体细胞突变对剪接、表达水平、融合基因和启动子活性的多种转录结果;并评估了癌症基因组的一系列特征。
Abstract:
Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale. Here we report the integrative analysis …
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Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation; analyses timings and patterns of tumour evolution; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity; and evaluates a range of more-specialized features of cancer genomes.
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845.
周周复始
(2022-11-30 21:53):
#paper https://doi.org/10.1007/978-3-031-17117-8_4 Chen, L., Wu, J., Wu, Q., Wei, H., Zhang, Y. (2022). Continuous Longitudinal Fetus Brain Atlas Construction via Implicit Neural Representation. In: Licandro, R., Melbourne, A., Abaci Turk, E., Macgowan, C., Hutter, J. (eds) Perinatal, Preterm and Paediatric Image Analysis. PIPPI 2022. Lecture Notes in Computer Science, vol 13575. Springer, Cham. 纵向胎儿脑图谱是了解和表示胎儿大脑复杂发育过程的工具。现有的胎儿脑图谱的创建通常是平均每个时间的脑模版,时间点也是离散的。但由于样本在不同时间点的个体遗传趋势不同,所得到的图谱存在时间上的不一致性,可能导致大脑发育特征参数在时间轴上出现误差。因此本文提出了一个多阶段深度学习框架来解决时间不一致性的问题,将时间不一致性问题转换为4D图像数据去噪任务。利用隐式神经表示,创建了连续无噪声的胎儿纵向脑图谱,并将其作为4D时空坐标函数。并用两个公开的胎儿大脑图谱(CRL和FBA-Chinese图谱)做实验。结果表明,该方法在保留胎儿大脑结构表示的同时,显著提高了图谱的时间一致性。此外,连续的胎儿纵向脑图谱可广泛应用于生成更精细的4D时空分辨率图谱。
Abstract:
Longitudinal fetal brain atlas is a powerful tool for understanding and characterizing the complex process of fetus brain development. Existing fetus brain atlases are typically constructed by averaged brain images …
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Longitudinal fetal brain atlas is a powerful tool for understanding and characterizing the complex process of fetus brain development. Existing fetus brain atlases are typically constructed by averaged brain images on discrete time points independently over time. Due to the differences in onto-genetic trends among samples at different time points, the resulting atlases suffer from temporal inconsistency, which may lead to estimating error of the brain developmental characteristic parameters along the timeline. To this end, we proposed a multi-stage deep-learning framework to tackle the time inconsistency issue as a 4D (3D brain volume + 1D age) image data denoising task. Using implicit neural representation, we construct a continuous and noise-free longitudinal fetus brain atlas as a function of the 4D spatial-temporal coordinate. Experimental results on two public fetal brain atlases (CRL and FBA-Chinese atlases) show that the proposed method can significantly improve the atlas temporal consistency while maintaining good fetus brain structure representation. In addition, the continuous longitudinal fetus brain atlases can also be extensively applied to generate finer 4D atlases in both spatial and temporal resolution.
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846.
林海onrush
(2022-11-30 21:51):
#paper,https://doi.org/10.48550/arXiv.2211.16197,FJMP: Factorized Joint Multi-Agent Motion Prediction over Learned Directed Acyclic Interaction Graphs,该研究针对自动驾驶轨迹预测生成问题,提出了FJMP,一种学习有向无环相互作用图的因子分解多智能体联合运动预测框架.使用未来场景交互动力学作为稀疏有向交互图,边缘表示agent之间的显式交互,修剪图成有向无环图(DAG)并分解联合预测任务,根据 DAG 的部分排序,其中联合未来轨迹使用有向无环图神经网络DAGNN。在INTERACTION和Argoverse2数据集上,证明了FJMP与非因子化相比能得到准确且场景一致的联合轨迹预测。FJMP在交互的多智能体INTERACTION基准测试上取得SOTA。
arXiv,
2022.
DOI: 10.48550/arXiv.2211.16197
Abstract:
Predicting the future motion of road agents is a critical task in an autonomous driving pipeline. In this work, we address the problem of generating a set of scene-level, or …
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Predicting the future motion of road agents is a critical task in an autonomous driving pipeline. In this work, we address the problem of generating a set of scene-level, or joint, future trajectory predictions in multi-agent driving scenarios. To this end, we propose FJMP, a Factorized Joint Motion Prediction framework for multi-agent interactive driving scenarios. FJMP models the future scene interaction dynamics as a sparse directed interaction graph, where edges denote explicit interactions between agents. We then prune the graph into a directed acyclic graph (DAG) and decompose the joint prediction task into a sequence of marginal and conditional predictions according to the partial ordering of the DAG, where joint future trajectories are decoded using a directed acyclic graph neural network (DAGNN). We conduct experiments on the INTERACTION and Argoverse 2 datasets and demonstrate that FJMP produces more accurate and scene-consistent joint trajectory predictions than non-factorized approaches, especially on the most interactive and kinematically interesting agents. FJMP ranks 1st on the multi-agent test leaderboard of the INTERACTION dataset.
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847.
魏魏魏
(2022-11-30 21:50):
#paper doi:10.1111/cdep.12279 Child Development Perspectives, (2018), The Development of Self and Identity in Adolescence: Neural Evidence and Implications for a Value-Based Choice Perspective on Motivated Behavior.
青少年的自我意识和自我同一性发展是重要发展任务,这将影响他们的自主性和社会关系。与自我过程相关的神经影像学研究发现在青少年阶段与自我同一性关系密切的腹侧前额叶皮层的活动更多,这意味着青少年基于价值观和动机的行为及决策会出现进步。在本文中,作者提出了青少年基于动机的行为会受到基于价值观的决策过程的影响的观点,而基于价值观的决策过程以腹侧前额叶皮层为中心。作者的观点形成了一个独特的青少年神经发育模型,这一模型聚焦奖励的敏感性和认知控制,同时认为青少年发展中的自我和自我同一性会产生重要的作用。本文中作者重点阐述了这一模型和青少年自我发展的关系,为青少年自我和行为研究提供了新的思路。
Abstract:
Following a key developmental task of childhood-building a foundation of self-knowledge in the form of domain-specific self-concepts-adolescents begin to explore their emerging identities in ways that foster autonomy and connectedness. …
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Following a key developmental task of childhood-building a foundation of self-knowledge in the form of domain-specific self-concepts-adolescents begin to explore their emerging identities in ways that foster autonomy and connectedness. Neuroimaging studies of self-related processes demonstrate enhanced engagement of the ventromedial prefrontal cortex in adolescence, which may facilitate and reflect the development of identity by integrating the value of potential actions and choices. Drawing from neuroeconomic and social cognitive accounts, we propose that motivated behavior during adolescence can be modeled by a general value-based decision-making process centered around value accumulation in the ventromedial prefrontal cortex. This approach advances models of adolescent neurodevelopment that focus on reward sensitivity and cognitive control by considering more diverse value inputs, including contributions of developing self- and identity-related processes. It also considers adolescent decision making and behavior from adolescents' point of view rather than adults' perspectives on what adolescents should value or how they should behave.
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848.
王昊
(2022-11-30 19:37):
#paper https://cis.temple.edu/tagit/presentations/A%20Path%20Towards%20Autonomous%20Machine%20Intelligence.pdf. A Path Towards Autonomous Machine Intelligence. LeCun. A Path Towards Autonomous Machine Intelligence Version 0.9.2, 2022-06-27. 62. Yann LeCun指明下一代AI方向:自主机器智能。 LeCun在本文中提出了一套认知的架构,以及训练其中world model的方法。主要包括以下模块: (1)配置器(Configurator)模块负责执行控制(executive control):给定要执行的任务,可以通过调整这些模块的参数来预先配置感知模块(perception module)、世界模型(world model)、成本(cost)和当前任务的 actor。(2)感知模块(Perception module)接收来自传感器的信号并估计当前世界的状态,对于给定的任务,只有一小部分感知到的世界状态是相关和有用的。配置器模块启动感知系统,从感知中提取相关信息,完成手头的任务。(3)世界模型(World model)的作用是双重的:(1)估计感知未提供的关于世界状态的缺失信息;(2)预测合理的未来世界状态。(4)成本模块(Cost module)计算单个标量的输出,该输出预测智能体的不适(discomfort)程度。(5)Actor 模块计算动作序列的提议。(6)短期记忆模块(Short-term memory module)跟踪当前和预测的世界状态以及相关成本。
2022.
Abstract:
How could machines learn as efficiently as humans and animals? How could machines learn to reason and plan? How could machines learn representations of percepts and action plans at multiple …
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How could machines learn as efficiently as humans and animals? How could machines learn to reason and plan? How could machines learn representations of percepts and action plans at multiple levels of abstraction, enabling them to reason, predict, and plan at multiple time horizons? This position paper proposes an architecture and training paradigms with which to construct autonomous intelligent agents. It combines concepts such as configurable predictive world model, behavior driven through intrinsic motivation, and hierarchical joint embedding architectures trained with self-supervised learning.
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849.
哪有情可长
(2022-11-30 19:24):
#paper THP9 enhances seed protein content and nitrogen-use efficiency in maize, Nature 2022 October, https://doi.org/10.1038/s41586-022-05441-2. 鉴定未驯化的野生型玉米大刍草的蛋白发现其要比现代玉米籽粒蛋白含量高,由于玉米大刍草的基因型复杂,其参考基因组一直没有被组装,作者通过构建已知参考基因组B73和大刍草杂交后代,测定后代基因型去掉已知的参考基因组B73进行组装大刍草的参考基因组,将两套参考基因组进行共线性分析发现存在大量的结构变异,推测蛋白含量的高低可能是由于结构变异引起。作者们继续构建群体,通过BSA鉴定到了控制籽粒蛋白含量的基因THP9,该基因在现代品种中存在48bp的缺失,导致剪切位点发生变化后导致基因翻译提前终止,最终导致现代玉米籽粒蛋白含量降低。作者又利用525份自然群体进行GWAS分析,也鉴定到该基因所处的区间。对525份材料按照基因型可以分成三种单倍型,Hap1跟野生型基因型一致,作者又通过转基因验证该基因的确能够提高蛋白含量,又通过构建NIL群体,继续验证该基因的功能,发现当籽粒蛋白含量高时,根部的氮吸收效率高,该基因也是首次在玉米中鉴定的第一个高蛋白基因。
Abstract:
Teosinte, the wild ancestor of maize (Zea mays subsp. mays), has three times the seed protein content of most modern inbreds and hybrids, but the mechanisms that are responsible for …
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Teosinte, the wild ancestor of maize (Zea mays subsp. mays), has three times the seed protein content of most modern inbreds and hybrids, but the mechanisms that are responsible for this trait are unknown. Here we use trio binning to create a contiguous haplotype DNA sequence of a teosinte (Zea mays subsp. parviglumis) and, through map-based cloning, identify a major high-protein quantitative trait locus, TEOSINTE HIGH PROTEIN 9 (THP9), on chromosome 9. THP9 encodes an asparagine synthetase 4 enzyme that is highly expressed in teosinte, but not in the B73 inbred, in which a deletion in the tenth intron of THP9-B73 causes incorrect splicing of THP9-B73 transcripts. Transgenic expression of THP9-teosinte in B73 significantly increased the seed protein content. Introgression of THP9-teosinte into modern maize inbreds and hybrids greatly enhanced the accumulation of free amino acids, especially asparagine, throughout the plant, and increased seed protein content without affecting yield. THP9-teosinte seems to increase nitrogen-use efficiency, which is important for promoting a high yield under low-nitrogen conditions.
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850.
Vincent
(2022-11-30 19:09):
#paper https://doi.org/10.1038/s41467-020-15298-6 nature communication, 2020, Integrative differential expression and gene set enrichment analysis using summary statistics for scRNA-seq studies. 基因表达差异分析和基因集富集分析是单细胞领域两个最常用的分析方式,但是两种分析往往是独立进行的,由于单细胞数据噪声较大,这样单独分析会造成统计效力的降低以及不同的数据集(或者使用不同方法分析同一套数据)得到的分析结果不一致。另一方面差异分析和富集分析其实在内部是紧密相连的,差异分析的结果是富集分析的基础,同时基因集富集分析反过来也可以反哺差异分析(基因之间并非独立,如果某基因差异表达了,与之相关的基因也可能差异表达),这意味着将两者结合起来同时分析能够提高统计效力并且使得分析结果更加稳健和可重复。这篇文章提出了一种新方法iDEA,该方法使用了层次贝叶斯模型,将差异分析和富集分析整合起来综合分析,通过仿真实验和真实数据分析,文章发现该方法较现有的差异或者富集方法有更高的统计效力,更一致的差异分析结果和更准确的富集分析结论
Abstract:
Differential expression (DE) analysis and gene set enrichment (GSE) analysis are commonly applied in single cell RNA sequencing (scRNA-seq) studies. Here, we develop an integrative and scalable computational method, iDEA, …
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Differential expression (DE) analysis and gene set enrichment (GSE) analysis are commonly applied in single cell RNA sequencing (scRNA-seq) studies. Here, we develop an integrative and scalable computational method, iDEA, to perform joint DE and GSE analysis through a hierarchical Bayesian framework. By integrating DE and GSE analyses, iDEA can improve the power and consistency of DE analysis and the accuracy of GSE analysis. Importantly, iDEA uses only DE summary statistics as input, enabling effective data modeling through complementing and pairing with various existing DE methods. We illustrate the benefits of iDEA with extensive simulations. We also apply iDEA to analyze three scRNA-seq data sets, where iDEA achieves up to five-fold power gain over existing GSE methods and up to 64% power gain over existing DE methods. The power gain brought by iDEA allows us to identify many pathways that would not be identified by existing approaches in these data.
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851.
LXJ
(2022-11-30 18:56):
#paper https://doi.org/10.1080/22221751.2022.2132880 Emerging Microbes & Infections 2022. Population genomics of emerging Elizabethkingia anophelis pathogens reveals potential outbreak and rapid global dissemination. 按蚊伊丽莎白菌是一种新兴的条件致病菌,这种细菌可能导致严重的新生儿脑膜炎、菌血症、眼部感染和呼吸系统等疾病。目前,有关按蚊伊丽莎白菌的地理分布,系统发育结构以及在全球,特别是在亚洲传播方面的研究很少。该菌的流行病学、传播和进化机制尚不清楚。未知的发病机制和耐药机制、较少的基因组信息,使得该致病菌缺乏有效的治疗方案,给按蚊伊丽莎白菌感染的处理带来了挑战。进一步阐明这种新兴病原体的上述问题有助于临床对该菌的治疗和预防。该研究通过细菌的全基因组测序确定了按蚊伊丽莎白菌的全球种群框架、系统发育结构、地理分布和传播评估,揭示了按蚊伊丽莎白菌引起大规模暴发和快速全球传播的潜在可能性。
IF:8.400Q1
Emerging microbes & infections,
2022-Dec.
DOI: 10.1080/22221751.2022.2132880
PMID: 36197077
Abstract:
is an emerging species and has increasingly been reported to cause life-threatening infections and even outbreaks in humans. Nevertheless, there is little data regarding the geographical distribution, phylogenetic structure, and …
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is an emerging species and has increasingly been reported to cause life-threatening infections and even outbreaks in humans. Nevertheless, there is little data regarding the geographical distribution, phylogenetic structure, and transmission across the globe, especially in Asia. We utilize whole-genome sequencing (WGS) data to define a global population framework, phylogenetic structure, geographical distribution, and transmission evaluation of pathogens. The geographical distribution diagram revealed the emerging pathogenic bacteria already distributed in various countries worldwide, especially in the USA and China. Strikingly, phylogenetic analysis showed a part of our China original shared the same ancestor with the USA outbreak strain, which implies the possibility of localized outbreaks and global spread. These closer related strains also contained ICEEaI, which might insert into a disrupted DNA repair gene and made the strain more liable to mutation and outbreak infection. BEAST analysis showed that the most recent common ancestor for ICEEaI was dated twelve years ago, and China might be the most likely recent source of this bacteria. Our study sheds light on the potential possibility of causing the large-scale outbreak and rapid global dissemination. Continued genomic surveillance of the dynamics of populations will generate further knowledge for optimizing future prevent global outbreak infections.
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852.
小年
(2022-11-30 18:38):
https://doi.org/10.1038/s41467-021-21865-2 nature communications, 2021, Single cell transcriptomic analysis of murine lung development on hyperoxia-induced damage. 本文构建高氧损伤小鼠肺模型模拟支气管肺发育不良,进行单细胞转录组测序分析研究,评估小鼠肺单细胞发育动态。按3个时间节点,捕获了36只小鼠肺的超66,000个单细胞。分别从肺泡上皮、基质成纤维细胞、毛细血管内皮和巨噬细胞等亚群方面阐述肺损伤小鼠随着时间发育在细胞数目和基因层面的变化,通路分析和细胞动态串扰预测表明炎症信号是高氧诱导变化的主要驱动因素。本文提供了一个较广泛的健康小鼠和肺受损小鼠发育过程中的细胞组成图谱,但细胞类型较为受限,更为精细的细胞亚群注释依赖于亚群marker和细胞形态学认识的提升。
Abstract:
During late lung development, alveolar and microvascular development is finalized to enable sufficient gas exchange. Impaired late lung development manifests as bronchopulmonary dysplasia (BPD) in preterm infants. Single-cell RNA sequencing …
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During late lung development, alveolar and microvascular development is finalized to enable sufficient gas exchange. Impaired late lung development manifests as bronchopulmonary dysplasia (BPD) in preterm infants. Single-cell RNA sequencing (scRNA-seq) allows for assessment of complex cellular dynamics during biological processes, such as development. Here, we use MULTI-seq to generate scRNA-seq profiles of over 66,000 cells from 36 mice during normal or impaired lung development secondary to hyperoxia with validation of some of the findings in lungs from BPD patients. We observe dynamic populations of cells, including several rare cell types and putative progenitors. Hyperoxia exposure, which mimics the BPD phenotype, alters the composition of all cellular compartments, particularly alveolar epithelium, stromal fibroblasts, capillary endothelium and macrophage populations. Pathway analysis and predicted dynamic cellular crosstalk suggest inflammatory signaling as the main driver of hyperoxia-induced changes. Our data provides a single-cell view of cellular changes associated with late lung development in health and disease.
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853.
白鸟
(2022-11-30 11:26):
#paper https://doi.org/10.1016/j.cell.2022.05.013 Cell 2022. Mapping information-rich genotype-phenotype landscapes with genome-scale Perturb-seq. 遗传学的一个核心目标是研究遗传变化(基因型)和表型之间的关系。主要有两种研究思路,正向遗传学和反向遗传学。正向遗传以表型为中心的“正向遗传”,即揭示驱动表型的基因变化(果因论);而反向遗传是以基因为中心,对确定的遗传变化引起的不同表型进行解析(因果论)。为了揭示基因扰动的功能后果和基因型-表型关系,文章团队构建了一套可实践的方法论。本文利用单细胞高通量CRISPR 筛选技术Perturb-seq,针对对K562和RPE1细胞系超过250万个细胞进行了单个基因的CRISPR扰动(即1个细胞只包含一种基因的 sgRNA),通过单一基因型的变化,查看在转录组层面表型的变化,构建了一个基因型-表型综合图谱。研究团队根据基因的共同调控将其聚类到特定表达程序中,并计算每个扰动簇中每个基因表达程序的平均活性。分析结果包含多个与基因干扰相关的已知表达程序,包括蛋白酶体功能障碍导致的蛋白酶体亚基上调、 ESCRT蛋白缺失时NF-kB信号通路的激活,以及胆固醇生物合成上调对囊泡运输缺陷的反应等。它的意义在于单细胞CRISPR筛选为系统探索遗传和细胞功能提供了一个研究工具,构建和分析丰富的基因型-表现型图谱,以作为系统探索遗传和细胞功能的驱动力。可以构建全基因组的基因敲除细胞池,定向的研究,关键基因的敲除对下游转录调控表型的生物学功能。重点学习文章中grna的数据质控和归一化等细节处理。
Abstract:
A central goal of genetics is to define the relationships between genotypes and phenotypes. High-content phenotypic screens such as Perturb-seq (CRISPR-based screens with single-cell RNA-sequencing readouts) enable massively parallel functional …
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A central goal of genetics is to define the relationships between genotypes and phenotypes. High-content phenotypic screens such as Perturb-seq (CRISPR-based screens with single-cell RNA-sequencing readouts) enable massively parallel functional genomic mapping but, to date, have been used at limited scales. Here, we perform genome-scale Perturb-seq targeting all expressed genes with CRISPR interference (CRISPRi) across >2.5 million human cells. We use transcriptional phenotypes to predict the function of poorly characterized genes, uncovering new regulators of ribosome biogenesis (including CCDC86, ZNF236, and SPATA5L1), transcription (C7orf26), and mitochondrial respiration (TMEM242). In addition to assigning gene function, single-cell transcriptional phenotypes allow for in-depth dissection of complex cellular phenomena—from RNA processing to differentiation. We leverage this ability to systematically identify genetic drivers and consequences of aneuploidy and to discover an unanticipated layer of stress-specific regulation of the mitochondrial genome. Our information-rich genotype-phenotype map reveals a multidimensional portrait of gene and cellular function.
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854.
洪媛媛
(2022-11-29 16:40):
#paper https://doi.org/10.1016/j.ccell.2022.10.022 Cancer Cell 2022. Evaluation of cell-free DNA approaches for multi-cancer early detection. 这篇文章介绍了Grail CCGA研究的substudy 1结果。比较了WGBS平台的全基因组甲基化、基因靶向测序平台的SNV和白细胞配对SNV、WGS平台的拷贝数变异、白细胞配对拷贝数变异、片段末端、片段长度、等位基因不平衡和临床特征,这些不同方法的性能,结果显示不管在训练集还是验证集,全基因组甲基化在癌症检测性能和肿瘤溯源能力上最好,衍生出来的甲基化靶向测序使用于CCGA substudy 2和3。
Abstract:
In the Circulating Cell-free Genome Atlas (NCT02889978) substudy 1, we evaluate several approaches for a circulating cell-free DNA (cfDNA)-based multi-cancer early detection (MCED) test by defining clinical limit of detection …
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In the Circulating Cell-free Genome Atlas (NCT02889978) substudy 1, we evaluate several approaches for a circulating cell-free DNA (cfDNA)-based multi-cancer early detection (MCED) test by defining clinical limit of detection (LOD) based on circulating tumor allele fraction (cTAF), enabling performance comparisons. Among 10 machine-learning classifiers trained on the same samples and independently validated, when evaluated at 98% specificity, those using whole-genome (WG) methylation, single nucleotide variants with paired white blood cell background removal, and combined scores from classifiers evaluated in this study show the highest cancer signal detection sensitivities. Compared with clinical stage and tumor type, cTAF is a more significant predictor of classifier performance and may more closely reflect tumor biology. Clinical LODs mirror relative sensitivities for all approaches. The WG methylation feature best predicts cancer signal origin. WG methylation is the most promising technology for MCED and informs development of a targeted methylation MCED test.
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855.
钟鸣
(2022-11-29 00:04):
#paper https://doi.org/10.3389/fvets.2020.00252 ,Frontiers in Veterinary Science,Contagious Yawning in African Elephants (Loxodonta africana): Responses to Other Elephants and Familiar Humans
你可能知道,打哈欠是会传染的,即当看到/听到/想到别人打哈欠时,也会不由自主跟着打哈欠。不仅如此,打哈欠也会在物种间相互传染,目前已知的是人与狗、人与黑猩猩间存在种间传染性打哈欠现象。虽然传染性打哈欠的发生机制和作用还不清楚,但据推测与个体间的社会沟通有关。大象具有高度发达的大脑,且社会化程度很高,为探究大象与人是否存在种间传染性哈欠,本文作者设计了一系列观察实验。实验对象是公园里的7头大象,它们每天按例与饲养员沟通,还要与游客互动。
在正式试验前,作者记录了大象打哈欠的频率:在觉醒时平均18小时打一个哈欠,这表明觉醒时自发打哈欠的频率很低。在正式试验中,饲养员在执行日常训练任务时,直视大象并且做出打哈欠动作(嘴巴缓慢张开、呆住,随后迅速闭合),对照试验为张嘴动作(缓慢张开、缓慢闭合)。结论是观察到了人象之间的种间传染性哈欠。
Abstract:
While spontaneous yawning is common across all vertebrate classes, contagious yawning is less common and has been observed only in a few species of social animals. Interspecific contagious yawning in …
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While spontaneous yawning is common across all vertebrate classes, contagious yawning is less common and has been observed only in a few species of social animals. Interspecific contagious yawning in response to yawning by humans has been observed only by chimpanzees and dogs. After confirming additional occurrences of intraspecific contagious yawning in a group of captive African elephants previously studied, we further investigated the potential for the same group of elephants to engage in interspecific contagious yawning with familiar human handlers. Ten captive African elephants, most of whom had been previously studied, were observed over 13 nights for evidence of intraspecific contagious yawning. Seven of these elephants were also involved in trials where familiar handlers performed staged yawns, as well as trials with staged non-yawning gapes, or trials with no yawns or gapes. Incorporating previously collected contagious yawning data, we describe nine instances of intraspecific contagious yawning in the elephants. Three of the seven elephants yawned contagiously in response to humans during the interspecific yawning trials. This is the first report of interspecific contagious yawning by elephants in response to yawns by familiar humans.
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856.
DeDe宝
(2022-11-28 23:47):
#paper https://doi.org/10.1038/s41562-019-0811-3 Nature Human Behaviour volume 4, pages397–411 (2020) Multimodal mapping of the face connectome
面部处理支持人脸识别和情感理解的能力,这依赖于脑区网络分布,但目前研究者对脑区的相互作用知之甚少。本篇文章结合解剖、功能连接测量与行为分析,建立了面部连接体的全脑模型,探明了模型的关键特征,如脑网络拓扑结构和纤维束构成。研究者提出了具有三个核心流的神经认知模型,面部处理流程沿着这些核心流并行或交互处理。虽然长程神经纤维束是很重要,但面部脑网络由短程神经纤维束主导,最后,研究者提供了面部处理流程右偏侧化是由于半球内和半球间连接不平衡的证据。总之,面部脑网络依赖于高度结构化的神经纤维束之间的动态链接,使支持行为和认知的面部处理流程成为可能。
Abstract:
Face processing supports our ability to recognize friend from foe, form tribes and understand the emotional implications of changes in facial musculature. This skill relies on a distributed network of …
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Face processing supports our ability to recognize friend from foe, form tribes and understand the emotional implications of changes in facial musculature. This skill relies on a distributed network of brain regions, but how these regions interact is poorly understood. Here we integrate anatomical and functional connectivity measurements with behavioural assays to create a global model of the face connectome. We dissect key features, such as the network topology and fibre composition. We propose a neurocognitive model with three core streams; face processing along these streams occurs in a parallel and reciprocal manner. Although long-range fibre paths are important, the face network is dominated by short-range fibres. Finally, we provide evidence that the well-known right lateralization of face processing arises from imbalanced intra- and interhemispheric connections. In summary, the face network relies on dynamic communication across highly structured fibre tracts, enabling coherent face processing that underpins behaviour and cognition.
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857.
尹志
(2022-11-28 21:20):
#paper https://doi.org/10.1093/bib/bbab344 Briefings in Bioinformatics, 22(6), 2021, 1-11:Molecular design in drug discovery: a comprehensive
review of deep generative models. 一篇基于深度生成模型的药物发现中的分子设计的综述。看年份是比较新的,但其实已经完全不sota了啊,哈哈哈哈哈。但是作为科普是很好的。文章介绍了基于深度生成模型的分子设计这个在药物发现领域的重要主题。综述了两种主流的分子表示:SMILES-based和图based。然后在每个表示下,分别介绍了基于VAE,GAN,RNN,Flow几种深度生成模型的分子设计。同时也介绍了目前市面上主要的de novo的分子设计的数据集。文章的结尾还从数据、模型、评价指标的角度讨论了分子设计目前存在的挑战。不过作者在写这篇综述的时候,可能是万万没想到今年diffusion model会在生成模型领域大杀四方吧,哈哈哈哈
Abstract:
Deep generative models have been an upsurge in the deep learning community since they were proposed. These models are designed for generating new synthetic data including images, videos and texts …
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Deep generative models have been an upsurge in the deep learning community since they were proposed. These models are designed for generating new synthetic data including images, videos and texts by fitting the data approximate distributions. In the last few years, deep generative models have shown superior performance in drug discovery especially de novo molecular design. In this study, deep generative models are reviewed to witness the recent advances of de novo molecular design for drug discovery. In addition, we divide those models into two categories based on molecular representations in silico. Then these two classical types of models are reported in detail and discussed about both pros and cons. We also indicate the current challenges in deep generative models for de novo molecular design. De novo molecular design automatically is promising but a long road to be explored.
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858.
惊鸿
(2022-11-28 10:33):
#paper CRISPRing future medicinesExpert Opin. Drug Discov.PubDate:2021-01-03DOI:10.1080/17460441.2021.1850687Laure Grand Moursel 1 , Mijke Visser 1 , Geraldine Servant 1 , Selvi Durmus 1 , Anne-Marie Zuurmond 1这是以快速且具有成本效益的方式设计哺乳动物基因组的能力导致 CRISPR 技术在生物医学研究中的快速适应。基于 CRISPR 的工程具有加速药物发现、支持降低药物开发中的高损耗率以及促进细胞和基因疗法的开发的潜力。CRISPR 技术正迅速成为基因组工程的首选工具,如今很难想象没有这项技术的药物发现管道。随着未来几年,CRISPR 技术无疑将得到进一步完善,并将蓬勃发展成为一项成熟的技术,它将在支持药物发现管道以及细胞和基因治疗开发中的基因组工程要求方面发挥关键作用。
IF:6.000Q1
Expert opinion on drug discovery,
2021-04.
DOI: 10.1080/17460441.2021.1850687
PMID: 33322954
Abstract:
: The ability to engineer mammalian genomes in a quick and cost-effective way has led to rapid adaptation of CRISPR technology in biomedical research. CRISPR-based engineering has the potential to …
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: The ability to engineer mammalian genomes in a quick and cost-effective way has led to rapid adaptation of CRISPR technology in biomedical research. CRISPR-based engineering has the potential to accelerate drug discovery, to support the reduction of high attrition rate in drug development and to enhance development of cell and gene-based therapies.: How CRISPR technology is transforming drug discovery is discussed in this review. From target identification to target validation in both and models, CRISPR technology is positively impacting the early stages of drug development by providing a straightforward way to genome engineering. This property also attracted attention for CRISPR application in the cell and gene therapy area.: CRISPR technology is rapidly becoming the preferred tool for genome engineering and nowadays it is hard to imagine the drug discovery pipeline without this technology. With the years to come, CRISPR technology will undoubtedly be further refined and will flourish into a mature technology that will play a key role in supporting genome engineering requirements in the drug discovery pipeline as well as in cell and gene therapy development.
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859.
前进
(2022-11-28 10:25):
#paper Zhu Y , Lu S . Swin-VoxelMorph: A Symmetric Unsupervised Learning Model forDeformable Medical Image Registration Using Swin Transformer[C]// International Conference on Medical Image Computing and Computer-Assisted Intervention. Springer, Cham, 2022.
可变形医学图像配准广泛应用于医学图像处理中,具有可逆一对一的映射。虽然最先进的图像配准方法是基于卷积神经网络,但很少有人尝试用Transformer的方法。现有的模型忽略了在嵌入学习中使用注意机制来处理远程交叉图,限制了这种方法来识别解剖结构的语义上有意义的对应关系。这些方法虽然实现了快速的图像配准,但也忽略了变换的拓扑保存和可逆性。在本文中,提出了一种新的基于Swin Transformer对称无监督学习网络,它可以最小化图像之间的差异,并同时估计正变换和逆变换像相关性.具体地说,本文提出了三维Swin-UNet,它应用具有Shfited window的分层Swin Transformer作为编码器来提取上下文特征。设计了一种基于patch expanding的symmetric swin Transformer解码器,进行上采样操作,估计配准场。此外,目标损失函数可以保证预测变换的实质性微分性质。本文在ADNI和PPMI两个数据集上验证了该方法,并在保持理想的微分性质的同时实现了最先进的配准精度。
Abstract:
Deformable medical image registration is widely used in medical image processing with the invertible and one-to-one mapping between images. While state-of-the-art image registration methods are based on convolutional neural networks, …
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Deformable medical image registration is widely used in medical image processing with the invertible and one-to-one mapping between images. While state-of-the-art image registration methods are based on convolutional neural networks, few attempts have been made with Transformers which show impressive performance on computer vision tasks. Existing models neglect to employ attention mechanisms to handle the long-range cross-image relevance in embedding learning, limiting such approaches to identify the semantically meaningful correspondence of anatomical structures. These methods also ignore the topology preservation and invertibility of the transformation although they achieve fast image registration. In this paper, we propose a novel, symmetric unsupervised learning network Swin-VoxelMorph based on the Swin Transformer which minimizes the dissimilarity between images and estimates both forward and inverse transformations simultaneously. Specifically, we propose 3D Swin-UNet, which applies hierarchical Swin Transformer with shifted windows as the encoder to extract context features. And a symmetric Swin Transformer-based decoder with patch expanding layer is designed to perform the up-sampling operation to estimate the registration fields. Besides, our objective loss functions can guarantee substantial diffeomorphic properties of the predicted transformations. We verify our method on two datasets including ADNI and PPMI, and it achieves state-of-the-art registration accuracy while maintaining desirable diffeomorphic properties.
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860.
林李泽强
(2022-11-27 19:25):
#paper https://doi.org/10.1002/hbm.25980 Human Brain Mapping, 2022:
Voxel-wise intermodal coupling analysis of two or more modalities using local covariance decomposition. 这篇文章提出了一种新的多模态耦合的方法——基于协方差特征分解的耦合方法,这种方法解决了先前相关的研究中耦合值不对称以及仅限两种模态的缺点(Vandekar et al., 2016)。 该方法使用局部协方差分解(主成分分析中的最大特征值的方差占比)来定义对两个或多个模态有效的对称体素耦合值,较大的值表明体素的跨模态的局部协方差矩阵可以在单个维度中很好地概括。此外,作者还验证中这个指标的生物相关性,即验证该指标与年龄或性别的相关性。
Abstract:
When individual subjects are imaged with multiple modalities, biological information is present not only within each modality, but also between modalities - that is, in how modalities covary at the …
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When individual subjects are imaged with multiple modalities, biological information is present not only within each modality, but also between modalities - that is, in how modalities covary at the voxel level. Previous studies have shown that local covariance structures between modalities, or intermodal coupling (IMCo), can be summarized for two modalities, and that two-modality IMCo reveals otherwise undiscovered patterns in neurodevelopment and certain diseases. However, previous IMCo methods are based on the slopes of local weighted linear regression lines, which are inherently asymmetric and limited to the two-modality setting. Here, we present a generalization of IMCo estimation which uses local covariance decompositions to define a symmetric, voxel-wise coupling coefficient that is valid for two or more modalities. We use this method to study coupling between cerebral blood flow, amplitude of low frequency fluctuations, and local connectivity in 803 subjects ages 8 through 22. We demonstrate that coupling is spatially heterogeneous, varies with respect to age and sex in neurodevelopment, and reveals patterns that are not present in individual modalities. As availability of multi-modal data continues to increase, principal-component-based IMCo (pIMCo) offers a powerful approach for summarizing relationships between multiple aspects of brain structure and function. An R package for estimating pIMCo is available at: https://github.com/hufengling/pIMCo.
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