networks

Networks
  • 文章类型: Journal Article
    大多数癌症类型缺乏有针对性的治疗选择,当一线靶向治疗可用时,治疗抵抗是一个巨大的挑战。最近的技术进步使得能够以高通量方式在患者组织上使用具有测序(ATAC-seq)和RNA测序(RNA-seq)的转座酶可接近染色质的测定。这里,我们提出了一种计算方法,该方法利用这些数据集来基于肿瘤谱系识别药物靶标.我们使用机器学习方法构建了针对22种癌症类型的371名患者的基因调控网络,该方法使用三维基因组数据进行了增强子与启动子接触的训练。接下来,我们确定了这些网络中的关键转录因子(TFs),用于发现治疗漏洞,通过直接靶向TFs或与之相互作用的蛋白质。我们验证了四个确定为神经内分泌的候选人,肝脏,和肾癌,目前的治疗方案预后不佳。
    Most cancer types lack targeted therapeutic options, and when first-line targeted therapies are available, treatment resistance is a huge challenge. Recent technological advances enable the use of assay for transposase-accessible chromatin with sequencing (ATAC-seq) and RNA sequencing (RNA-seq) on patient tissue in a high-throughput manner. Here, we present a computational approach that leverages these datasets to identify drug targets based on tumor lineage. We constructed gene regulatory networks for 371 patients of 22 cancer types using machine learning approaches trained with three-dimensional genomic data for enhancer-to-promoter contacts. Next, we identified the key transcription factors (TFs) in these networks, which are used to find therapeutic vulnerabilities, by direct targeting of either TFs or the proteins that they interact with. We validated four candidates identified for neuroendocrine, liver, and renal cancers, which have a dismal prognosis with current therapeutic options.
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  • 文章类型: Journal Article
    草地被认为是土壤生物多样性的重要蓄水池。牲畜放牧是一种草地管理策略,旨在改善土壤质量并增强植物多样性。土壤微生物群落在草地生态系统中起着举足轻重的作用,因此,检查放牧行为是否会影响土壤微生物组非常重要。以前关于放牧的研究主要集中在细菌和真菌上,忽视了一个重要的群体原生生物。原生生物在土壤微生物群中至关重要,因为它们驱动着养分的可利用性和营养相互作用。确定放牧对原生生物的影响及其与细菌和真菌群落的关系对于了解放牧生态系统中的土壤微生物组动态非常重要。在这项研究中,我们调查了土壤细菌,真菌,和四个放牧等级以下的原生社区:不放牧,适度使用放牧,充分利用放牧,和大量使用的放牧。我们的结果表明,大量放牧导致特定群体的原生生物多样性更大,比如Discoba和Conosa,越来越丰富。我们还发现原生生物和细菌/真菌成员之间有很强的联系,表明它们在土壤微生物组中的复杂关系。例如,在放牧下,捕食性原生生物的丰度增加,而丛枝菌根真菌减少。值得注意的是,丛枝菌根与掠食性群体呈负相关。此外,我们观察到微生物网络的复杂性随着放牧强度的增加而增加,真菌成员在网络中发挥着重要作用。总的来说,我们的研究报告了时间放牧强度对土壤微生物动态的影响,并强调了在评估放牧对草地生态系统地下群落的影响时考虑原生生物生态学的重要性。
    目的:本研究的意义在于探索时间放牧强度对土壤微生物组动态的影响,特别关注原生生物经常被忽视的作用。我们的发现提供了对原生生物之间复杂关系的见解,细菌,和真菌,强调它们对土壤中营养相互作用的影响。更好地了解这些动态对于制定有效的草地管理和保护战略至关重要,强调将原生生物生态学纳入草原微生物组研究的重要性。
    Grasslands are recognized as important reservoirs of soil biodiversity. Livestock grazing is implemented as a grassland management strategy to improve soil quality and enhance plant diversity. Soil microbial communities play a pivotal role in grassland ecosystems, so it is important to examine whether grazing practices affect the soil microbiome. Previous studies on grazing have primarily focused on bacteria and fungi, overlooking an important group-protists. Protists are vital in soil microbiomes as they drive nutrient availability and trophic interactions. Determining the impact of grazing on protists and their relationships with bacterial and fungal communities is important for understanding soil microbiome dynamics in grazed ecosystems. In this study, we investigated soil bacterial, fungal, and protist communities under four grazing levels: no grazing, moderate-use grazing, full-use grazing, and heavy-use grazing. Our results showed that heavy grazing led to a greater diversity of protists with specific groups, such as Discoba and Conosa, increasing in abundance. We also found strong associations between protist and bacterial/fungal members, indicating their intricate relationships within the soil microbiome. For example, the abundance of predatory protists increased under grazing while arbuscular mycorrhizal fungi decreased. Notably, arbuscular mycorrhizae were negatively associated with predatory groups. Furthermore, we observed that microbial network complexity increased with grazing intensity, with fungal members playing an important role in the network. Overall, our study reports the impact of temporal grazing intensity on soil microbial dynamics and highlights the importance of considering protist ecology when evaluating the effects of grazing on belowground communities in grassland ecosystems.
    OBJECTIVE: The significance of this study lies in its exploration of the effects of temporal grazing intensity on the dynamics of the soil microbiome, specifically focusing on the often-neglected role of protists. Our findings provide insights into the complex relationships between protists, bacteria, and fungi, emphasizing their impact on trophic interactions in the soil. Gaining a better understanding of these dynamics is essential for developing effective strategies for grassland management and conservation, underscoring the importance of incorporating protist ecology into microbiome studies in grasslands.
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  • 文章类型: Journal Article
    列举美国无家可归的人,联邦住房和城市发展部(HUD)授权其指定的地方司法管辖区定期对该人口进行粗略的人口普查。此时间点(PIT)身体计数,通常在一月的晚上由志愿者用手电筒和剪贴板进行,通常是用单独的便利样本进行采访。这里,我们建议采用基于网络的(同行推荐)应答者驱动抽样(RDS)方法来生成无庇护人群的代表性样本,伴随着一种新颖的方法来生成司法管辖区无庇护人数的统计估计。首先,我们对RDS调查的样本量进行了功效分析,以统计无家可归的无庇护人群。然后,我们在金县进行了三次大规模的人口代表性样本,西澳(西雅图地铁),2022年,2023年和2024年。我们描述了数据收集和新方法的应用,将2020年PIT计数(在金县进行的最后一次视觉PIT计数)与新方法2022年和2024年PIT计数进行比较。我们最后讨论和未来的方向。
    To enumerate people experiencing homelessness in the U.S., the federal Department of Housing and Urban Development (HUD) mandates its designated local jurisdictions regularly conduct a crude census of this population. This Point-in-Time (PIT) body count, typically conducted on a January night by volunteers with flashlights and clipboards, is often followed by interviews with a separate convenience sample. Here, we propose employing a network-based (peer-referral) respondent-driven sampling (RDS) method to generate a representative sample of unsheltered people, accompanied by a novel method to generate a statistical estimate of the number of unsheltered people in the jurisdiction. First, we develop a power analysis for the sample size of our RDS survey to count unsheltered people experiencing homelessness. Then, we conducted three large-scale population-representative samples in King County, WA (Seattle metro) in 2022, 2023, and 2024. We describe the data collection and the application of our new method, comparing the 2020 PIT count (the last visual PIT count performed in King County) to the new method 2022 and 2024 PIT counts. We conclude with a discussion and future directions.
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  • 文章类型: Journal Article
    用烯丙氧基羰基(alloc)保护的赖氨酸选择性修饰卷曲螺旋成束肽,在其侧链上含有烯烃的非天然氨基酸。该烯烃从卷曲螺旋表面的特异性显示具有蛋白质样特异性,使该残基能够用作共价连接,用于创建具有可控特性的肽网络,或用作将成束剂自组装成意外的物理连接,由侧链的疏水性质驱动的复杂晶格。对于网络形成,用alloc保护的赖氨酸和半胱氨酸氨基酸修饰肽,用于溶液组装成溶剂溶胀的膜,随后通过硫醇-烯光点击反应进行共价交联。网络交联的程度,通过流变仪测定,通过改变捆绑者积木颗粒上反应基团的特定空间显示来微调,在束内和束间交联之间过渡。来自捆扎器构造块中心的alloc组的设计显示也促使颗粒自组装成具有多孔形态的意想不到的复杂晶格。使用透射电子显微镜在各种溶液条件下研究了晶格,低温透射电子显微镜,和小角度X射线散射。通过使用粗粒度建模和机器学习优化技术以及实验方法来确定晶格中的近似粒子排列。拟议的桁架状面心立方填料的alloc功能化捆扎器与实验结果非常吻合。
    Coiled-coil \'bundlemer\' peptides were selectively modified with allyloxycarbonyl (alloc)-protected lysine, a non-natural amino acid containing an alkene on its side chain. The specific display of this alkene from the coiled-coil surface with protein-like specificity enabled this residue to be used as a covalent linkage for creating peptide networks with controllable properties or as a physical linkage for the self-assembly of bundlemers into unexpected, intricate lattices driven by the hydrophobic nature of the side chain. For network formation, peptides were modified with both alloc-protected lysine and cysteine amino acids for solution assembly into solvent-swollen films and subsequent covalent cross-linking via thiol-ene photo click reactions. The degree of network cross-linking, as determined by rheometry, was finely tuned by varying the specific spatial display of reactive groups on the bundlemer building block particles, transitioning between intrabundle and interbundle cross-linking. The designed display of alloc groups from the center of the bundlemer building block also prompted particle self-assembly into an unexpected intricate lattice with a porous morphology. The lattices were studied in a variety of solution conditions using transmission electron microscopy, cryotransmission electron microscopy, and small-angle X-ray scattering. The approximate particle arrangement in the lattice was determined by using coarse-grained modeling and machine learning optimization techniques along with experimental methods. The proposed truss-like face-centered cubic packing of the alloc-functionalized bundlemers agrees well with the experimental results.
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  • 文章类型: Journal Article
    我们考虑了从流行病学过程中观察到的节点状态推断联系网络的问题。在黑盒贝叶斯优化框架中,此问题简化为可能网络集合上的离散似然优化。该组的基数随着网络节点的数量而组合增长,这使得这种优化在计算上具有挑战性。对于每个网络,它的可能性是观察到的数据在这个网络上的流行病学过程的演变过程中出现的概率。这个概率可能很小,特别是如果网络与地面实况网络有很大不同,观察到的数据实际上是从那里出现的。常用的随机模拟算法努力恢复罕见事件,因此估计小概率和可能性。在本文中,我们用求解所有网络状态概率的化学主方程来代替随机模拟。因为这个方程也遭受了维度的诅咒,我们应用张量训练近似来克服它,并实现快速准确的计算。数值模拟证明了网络的有效黑盒贝叶斯推理。
    We consider a problem of inferring contact network from nodal states observed during an epidemiological process. In a black-box Bayesian optimisation framework this problem reduces to a discrete likelihood optimisation over the set of possible networks. The cardinality of this set grows combinatorially with the number of network nodes, which makes this optimisation computationally challenging. For each network, its likelihood is the probability for the observed data to appear during the evolution of the epidemiological process on this network. This probability can be very small, particularly if the network is significantly different from the ground truth network, from which the observed data actually appear. A commonly used stochastic simulation algorithm struggles to recover rare events and hence to estimate small probabilities and likelihoods. In this paper we replace the stochastic simulation with solving the chemical master equation for the probabilities of all network states. Since this equation also suffers from the curse of dimensionality, we apply tensor train approximations to overcome it and enable fast and accurate computations. Numerical simulations demonstrate efficient black-box Bayesian inference of the network.
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  • 文章类型: Journal Article
    将复杂系统表示为网络已成为许多科学领域的关键工具。在物理网络的背景下,比如生物神经网络,血管网络,或网络液体,其中节点和边缘在三维空间中占据体积,它们如何变得密集的问题特别重要。这里,我们研究了一个模型网络液体,已知通过两个连续的液-液相转变(LLPT)致密化。我们阐明了由网络中结合的颗粒形成的环状循环路径的重要性,以及它们的空间分布,以了解支撑LLPT密度增加的结构变化。我们的分析表明,这些网络的致密化主要是由连接环的形成驱动的,和LLPT对应于拓扑转换的层次结构,其中环形成基本构建块。我们设想纠缠作为致密化的一般机制出现,对物理网络的嵌入有着广泛的影响,尤其是在密闭空间。
    The representation of complex systems as networks has become a critical tool across many fields of science. In the context of physical networks, such as biological neural networks, vascular networks, or network liquids where the nodes and edges occupy volume in three-dimensional space, the question of how they become densely packed is of special importance. Here, we investigate a model network liquid, which is known to densify via two successive liquid-liquid phase transitions (LLPTs). We elucidate the importance of rings-cyclic paths formed by bonded particles in the networks-and their spatial disposition in understanding the structural changes that underpin the increase in density across the LLPTs. Our analyses demonstrate that the densification of these networks is primarily driven by the formation of linked rings, and the LLPTs correspond to a hierarchy of topological transitions where rings form the fundamental building blocks. We envisage entanglement to emerge as a general mechanism for densification, with wide implications for the embedding of physical networks, especially in confined spaces.
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  • 文章类型: Journal Article
    目的:本研究的目的是检查多种健康行为的时间动态(身体活动,酒精消费,健康饮食,香烟消费,娱乐性药物使用,vaping),和大流行相关的健康行为(例如,洗手,物理距离)使用网络心理测量学。
    方法:国际COVID-19意识和反应评估(iCARE)研究是一项关于公众意识的国际多波观察队列研究,态度,以及为减少COVID-19在世界各地人群中的传播而实施的公共卫生政策。对来自加拿大人(n=254)的纵向数据的子样本进行了四波分析(2020年2月至7月)。
    方法:我们使用时间网络模型来拟合时间网络,同时代的网络,以及来自iCARE调查项目的受试者间网络。
    结果:在体力活动和健康饮食之间观察到时间上的正相关,户外口罩使用和vaping之间存在明显的双向关系。一个同期的网络揭示了消费行为(vaping,香烟使用,酒精使用,和娱乐性药物使用),体力活动和药物使用之间的负面关联,健康饮食和吸烟。
    结论:健康行为是相互关联的,可以建模为网络或行为系统。将时间网络分析应用于多种健康行为的研究非常适合解决该领域的关键研究问题,例如“多种健康行为如何随时间相互变化”。未来的研究使用时间序列数据和测量行为的情感和认知媒介,除了健康行为,有可能贡献有价值的假设生成见解。
    OBJECTIVE: The aim of this study was to examine the temporal dynamics of multiple health behaviours (physical activity, alcohol consumption, healthy eating, cigarette consumption, recreational drug use, vaping), and pandemic-related health behaviours (e.g., hand washing, physical distancing) using network psychometrics.
    METHODS: The International COVID-19 Awareness and Responses Evaluation (iCARE) study is an international multi-wave observational cohort study of public awareness, attitudes, and responses to public health policies implemented to reduce the spread of COVID-19 on people around the world. A sub-sample of longitudinal data from Canadians (n = 254) was analysed across four waves (February-July 2020).
    METHODS: We used temporal network models to fit temporal networks, contemporaneous networks, and between-subject networks from items within the iCARE survey.
    RESULTS: Positive temporal associations were observed between physical activity and healthy eating, and a bidirectional relationship was evident between outdoor mask use and vaping. A contemporaneous network revealed positive associations between consumption behaviours (vaping, cigarette use, alcohol use, and recreational drug use), and negative associations between physical activity and drug use, and healthy eating and cigarette use.
    CONCLUSIONS: Health behaviours are interconnected and can be modelled as networks or behavioural systems. The application of temporal network analysis to the study of multiple health behaviours is well suited to address key research questions in the field such as \'how do multiple health behaviours co-vary with one another over time\'. Future research using time series data and measuring affective and cognitive mediators of behaviour, in addition to health behaviours, has the potential to contribute valuable hypothesis-generating insights.
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  • 文章类型: Journal Article
    熵测量越来越多地用于分析通过功能磁共振成像(fMRI)观察到的神经活动的结构,静息态网络(RSN)因其对大脑功能结构的可重现性描述而受到关注。时间相关性显示出这些网络之间的二分法:那些与环境互动的网络,被称为外在,其中包括视觉和感觉运动网络;以及与执行控制和自我参考相关的网络,被称为内在的,其中包括默认模式网络和额叶控制网络。虽然这些体素之间的时间相关性可以评估各个网络组件之间的同步性,熵测量引入了体素内评估,该评估量化了每个血氧水平依赖性(BOLD)时间序列中编码的信号特征。因此,该框架提供了理解fMRI信号中信息的表示和处理的见解。已提出多尺度熵(MSE)作为用于表征跨不同时间尺度的神经活动熵的有用度量。BOLD数据中的时间熵度量取决于时间序列的长度;因此,需要具有细粒度时间分辨率和足够数量的时间帧的高质量数据来提高熵精度。我们将MSE应用于午夜扫描俱乐部,一个高度采样和特征明确的公开数据集,分析RSN的熵分布并评估其区分不同功能网络的能力。在时间尺度和RSN上比较熵谱。我们的结果表明,在慢速频率(0.005-0.1Hz)下,熵的空间分布再现了已知的RSN分割。我们发现内在和外在RSN之间存在复杂性层次结构,内在网络强健地表现出比外在网络更高的熵。最后,我们发现了新的证据,表明小脑后部熵的地形表现出与内在RSN相当的高水平熵。
    Entropy measures are increasingly being used to analyze the structure of neural activity observed by functional magnetic resonance imaging (fMRI), with resting-state networks (RSNs) being of interest for their reproducible descriptions of the brain\'s functional architecture. Temporal correlations have shown a dichotomy among these networks: those that engage with the environment, known as extrinsic, which include the visual and sensorimotor networks; and those associated with executive control and self-referencing, known as intrinsic, which include the default mode network and the frontoparietal control network. While these inter-voxel temporal correlations enable the assessment of synchrony among the components of individual networks, entropic measures introduce an intra-voxel assessment that quantifies signal features encoded within each blood oxygen level-dependent (BOLD) time series. As a result, this framework offers insights into comprehending the representation and processing of information within fMRI signals. Multiscale entropy (MSE) has been proposed as a useful measure for characterizing the entropy of neural activity across different temporal scales. This measure of temporal entropy in BOLD data is dependent on the length of the time series; thus, high-quality data with fine-grained temporal resolution and a sufficient number of time frames is needed to improve entropy precision. We apply MSE to the Midnight Scan Club, a highly sampled and well-characterized publicly available dataset, to analyze the entropy distribution of RSNs and evaluate its ability to distinguish between different functional networks. Entropy profiles are compared across temporal scales and RSNs. Our results have shown that the spatial distribution of entropy at infra-slow frequencies (0.005-0.1 Hz) reproduces known parcellations of RSNs. We found a complexity hierarchy between intrinsic and extrinsic RSNs, with intrinsic networks robustly exhibiting higher entropy than extrinsic networks. Finally, we found new evidence that the topography of entropy in the posterior cerebellum exhibits high levels of entropy comparable to that of intrinsic RSNs.
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  • 文章类型: Journal Article
    痴呆症是全球公共卫生问题。这项研究的重点是痴呆症的遗传因素。我们分析了台中退伍军人总医院的电子病历(EMR),台湾,以确认痴呆和非痴呆患者之间的差异。这项工作得到了台北医科大学[TMU111-AE1-B45]的支持。
    Dementia is a global public health concern. This study focuses on the genetic factors underlying dementia. We analyzed electronic medical records (EMR) from Taichung Veterans General Hospital, Taiwan, to confirm differences between dementia and non-dementia patients. This work was supported by Taipei Medical University [TMU111-AE1-B45].
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  • 文章类型: Journal Article
    蜜蜂(Apismellifera)是对全球农业至关重要的关键传粉媒介,面对来自各种压力源的威胁,包括外寄生虫瓦螨(Varroadestructor)。以前的研究已经确定了瓦螨和蜜蜂之间的共享细菌,然而,目前尚不清楚这些细菌是否在两个物种中相似地组装。这项研究建立在现有知识的基础上,通过调查瓦螨和蜜蜂的微生物群中的共同发生模式,照亮潜在的相互作用。利用16SrRNA数据集,我们进行了共现网络分析,探索核心关联网络(CAN)并评估网络稳健性。比较网络分析揭示了蜜蜂和螨微生物组之间的结构差异,以及共同的核心特征和微生物图案。螨网络表现出较低的鲁棒性,表明与蜜蜂相比,对类群扩展的抵抗力较小。此外,对预测的功能分析和分类群贡献的分析表明,代谢网络中的常见中心途径具有不同的分类群,有助于瓦螨和蜜蜂微生物群。结果表明,虽然两种微生物系统都表现出功能冗余,其中不同的分类单元有助于生态系统的功能稳定性和恢复力,有证据表明,生态位特化导致对该宿主-寄生虫系统每个部分的特定途径的独特贡献。分类单元对关键途径的贡献的特异性为Varroa微生物组管理和保护蜜蜂微生物组提供了有针对性的方法。我们的发现为微生物相互作用提供了有价值的见解,在瓦螨感染增加的情况下,帮助农民和养蜂人维持健康和有弹性的蜂群。
    The honeybee (Apis mellifera) is a key pollinator critical to global agriculture, facing threats from various stressors, including the ectoparasitic Varroa mite (Varroa destructor). Previous studies have identified shared bacteria between Varroa mites and honeybees, yet it remains unclear if these bacteria assemble similarly in both species. This study builds on existing knowledge by investigating co-occurrence patterns in the microbiomes of both Varroa mites and honeybees, shedding light on potential interactions. Leveraging 16S rRNA datasets, we conducted co-occurrence network analyses, explored Core Association Networks (CAN) and assess network robustness. Comparative network analyses revealed structural differences between honeybee and mite microbiomes, along with shared core features and microbial motifs. The mite network exhibited lower robustness, suggesting less resistance to taxa extension compared to honeybees. Furthermore, analyses of predicted functional profiling and taxa contribution revealed that common central pathways in the metabolic networks have different taxa contributing to Varroa mites and honeybee microbiomes. The results show that while both microbial systems exhibit functional redundancy, in which different taxa contribute to the functional stability and resilience of the ecosystem, there is evidence for niche specialization resulting in unique contributions to specific pathways in each part of this host-parasite system. The specificity of taxa contribution to key pathways offers targeted approaches to Varroa microbiome management and preserving honeybee microbiome. Our findings provide valuable insights into microbial interactions, aiding farmers and beekeepers in maintaining healthy and resilient bee colonies amid increasing Varroa mite infestations.
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