Network model

网络模型
  • 文章类型: Journal Article
    正常情况下纹状体的主要细胞,中型多刺神经元(MSN),显示结构化的细胞组装活动模式,该模式在几分钟的超长时间尺度上顺序交替。重要的是要了解这种活动,因为它在多种病理中被破坏,如帕金森病和运动障碍,并且被认为是由MSN到MSN的横向抑制连接以及皮质对MSN的兴奋强度和分布的改变引起的。为了理解这些长时间尺度是如何产生的,我们扩展了以前的MSN细胞网络模型,以包括具有短期可塑性的突触,参数取自最近详细的纹状体连接体研究。我们首先使用非线性降维技术证实了顺序切换细胞簇的存在,统一流形逼近和投影(UMAP).我们发现,该网络可以产生非平稳活动模式,在生物现实条件下,以分钟的速度非常缓慢地变化。接下来,我们使用基于仿真的推理(SBI)来训练深度网络,以将MSN网络生成的单元组装活动的特征映射到MSN网络参数。我们使用经过训练的SBI模型从离体脑切片钙成像数据估计MSN网络参数。我们发现,最佳拟合网络参数非常接近其生理观察值。另一方面,从帕金森估计的网络参数,脱皮和运动障碍的离体切片制剂是不同的。我们的工作可能会为从尖峰数据中诊断基底神经节病理学以及设计药理学治疗提供一条管道。
    Under normal conditions the principal cells of the striatum, medium spiny neurons (MSNs), show structured cell assembly activity patterns which alternate sequentially over exceedingly long timescales of many minutes. It is important to understand this activity since it is characteristically disrupted in multiple pathologies, such as Parkinson\'s disease and dyskinesia, and thought to be caused by alterations in the MSN to MSN lateral inhibitory connections and in the strength and distribution of cortical excitation to MSNs. To understand how these long timescales arise we extended a previous network model of MSN cells to include synapses with short-term plasticity, with parameters taken from a recent detailed striatal connectome study. We first confirmed the presence of sequentially switching cell clusters using the non-linear dimensionality reduction technique, Uniform Manifold Approximation and Projection (UMAP). We found that the network could generate non-stationary activity patterns varying extremely slowly on the order of minutes under biologically realistic conditions. Next we used Simulation Based Inference (SBI) to train a deep net to map features of the MSN network generated cell assembly activity to MSN network parameters. We used the trained SBI model to estimate MSN network parameters from ex-vivo brain slice calcium imaging data. We found that best fit network parameters were very close to their physiologically observed values. On the other hand network parameters estimated from Parkinsonian, decorticated and dyskinetic ex-vivo slice preparations were different. Our work may provide a pipeline for diagnosis of basal ganglia pathology from spiking data as well as for the design pharmacological treatments.
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  • 文章类型: Journal Article
    空间转录组学的进展为揭示生物学系统的结构和功能提供了前所未有的机会。然而,当前的算法未能解决空间转录组学数据的异质性和可解释性。这里,我们提出了一个多层网络模型,用于通过联合学习识别空间转录数据中的空间域。我们证明了空间域可以通过细胞网络的拓扑结构来精确地表征和区分,促进空间域的识别和可解释性,优于最先进的基线。此外,我们证明了网络模型为各种平台的空间转录数据的综合分析提供了一种有效和高效的策略。
    Advances in spatial transcriptomics provide an unprecedented opportunity to reveal the structure and function of biology systems. However, current algorithms fail to address the heterogeneity and interpretability of spatial transcriptomics data. Here, we present a multi-layer network model for identifying spatial domains in spatial transcriptomics data with joint learning. We demonstrate that spatial domains can be precisely characterized and discriminated by the topological structure of cell networks, facilitating identification and interpretability of spatial domains, which outperforms state-of-the-art baselines. Furthermore, we prove that network model offers an effective and efficient strategy for integrative analysis of spatial transcriptomics data from various platforms.
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  • 文章类型: Journal Article
    简介:有关自主神经系统(ANS)活动的信息可能会提供有关房颤(AF)进展的见解,并支持个性化的AF治疗,但无法从ECG轻松获取。在这项研究中,我们提出了一种基于ECG评估房室结不应期和传导延迟时呼吸调节的新方法.方法:训练1维卷积神经网络(1D-CNN),以从RR系列的1分钟片段中估计AV节传导特性的呼吸调制,呼吸信号,和心房纤颤率(AFR)使用复制临床ECG数据的合成数据。使用AV节点的网络模型和4百万个独特的模型参数集来生成合成数据。然后使用1D-CNN分析28例房颤患者的临床深呼吸测试数据中的呼吸调制,其中使用基于周期性分量分析的新颖方法提取ECG导出的呼吸信号。结果:我们使用合成数据证明,1D-CNN可以单独估计RR系列的呼吸调制,皮尔逊样本相关性为r=0.805,并且添加任一呼吸信号(r=0.830),AFR(r=0.837),或两者(r=0.855)改善了估计。讨论:ECG数据分析的初步结果表明,我们提出的呼吸诱导自主神经调制的估计,一个RESP,是可重复的和足够灵敏的监测变化和检测个体差异。然而,需要进一步的研究来验证可重复性,灵敏度,以及resp的临床意义。
    Introduction: Information about autonomic nervous system (ANS) activity may offer insights about atrial fibrillation (AF) progression and support personalized AF treatment but is not easily accessible from the ECG. In this study, we propose a new approach for ECG-based assessment of respiratory modulation in atrioventricular (AV) nodal refractory period and conduction delay. Methods: A 1-dimensional convolutional neural network (1D-CNN) was trained to estimate respiratory modulation of AV nodal conduction properties from 1-minute segments of RR series, respiration signals, and atrial fibrillatory rates (AFR) using synthetic data that replicates clinical ECG-derived data. The synthetic data were generated using a network model of the AV node and 4 million unique model parameter sets. The 1D-CNN was then used to analyze respiratory modulation in clinical deep breathing test data of 28 patients in AF, where an ECG-derived respiration signal was extracted using a novel approach based on periodic component analysis. Results: We demonstrated using synthetic data that the 1D-CNN can estimate the respiratory modulation from RR series alone with a Pearson sample correlation of r = 0.805 and that the addition of either respiration signal (r = 0.830), AFR (r = 0.837), or both (r = 0.855) improves the estimation. Discussion: Initial results from analysis of ECG data suggest that our proposed estimate of respiration-induced autonomic modulation, a resp, is reproducible and sufficiently sensitive to monitor changes and detect individual differences. However, further studies are needed to verify the reproducibility, sensitivity, and clinical significance of a resp.
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  • 文章类型: Journal Article
    美国存在明显的心理健康治疗差距。努力弥合这一差距,提高资源的可获取性,心理健康自我评估的临床验证工具。理论上,这些屏幕是信息搜索的宝贵组成部分,代表这一过程的准备和面向行动的阶段,同时改变或加强个人在线信息时的搜索内容和语言。因此,这项工作调查了屏幕完成与心理健康相关搜索行为的关联.来自N=7,572名MicrosoftBing用户的三年互联网搜索历史与他们各自的抑郁症配对,焦虑,双相情感障碍,或精神病在线屏幕完成和社会人口统计数据可通过美国心理健康获得。数据被转换为网络表示,以将查询建模为离散步骤,并具有从一种搜索类型过渡到另一种搜索类型的概率和时间。还使用马尔可夫链对屏幕完成后的搜索数据进行建模,以模拟不同搜索类型随时间的似然轨迹。观察到查询动态相对于屏幕完成的差异,涉及治疗的搜索,诊断,自杀意念,自杀意图通常成为寻求终点的最高概率行为信息。此外,结果表明,精神病理学的低风险状态与向极端临床结果过渡的关联(即,主动自杀意图)。未来的研究需要得出关于屏幕和搜索行为之间因果关系的明确结论。
    There is an appreciable mental health treatment gap in the United States. Efforts to bridge this gap and improve resource accessibility have led to the provision of online, clinically-validated tools for mental health self-assessment. In theory, these screens serve as an invaluable component of information-seeking, representing the preparative and action-oriented stages of this process while altering or reinforcing the search content and language of individuals as they engage with information online. Accordingly, this work investigated the association of screen completion with mental health-related search behaviors. Three-year internet search histories from N=7,572 Microsoft Bing users were paired with their respective depression, anxiety, bipolar disorder, or psychosis online screen completion and sociodemographic data available through Mental Health America. Data was transformed into network representations to model queries as discrete steps with probabilities and times-to-transition from one search type to another. Search data subsequent to screen completion was also modeled using Markov chains to simulate likelihood trajectories of different search types through time. Differences in querying dynamics relative to screen completion were observed, with searches involving treatment, diagnosis, suicidal ideation, and suicidal intent commonly emerging as the highest probability behavioral information seeking endpoints. Moreover, results pointed to the association of low risk states of psychopathology with transitions to extreme clinical outcomes (i.e., active suicidal intent). Future research is required to draw definitive conclusions regarding causal relationships between screens and search behavior.
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  • 文章类型: Journal Article
    地表水养分污染,富营养化的主要原因,尽管政府间努力调节营养源,但仍然是伊利湖西部的主要环境问题。莫美河流域一直是最大的营养贡献者。两种主要的营养来源是施用于农田的无机肥料和牲畜粪便,后来通过径流和土壤侵蚀被带到溪流中。先前对营养源归属的研究集中在年度时间尺度上的大型流域或县。在更精细的时空尺度上进行来源归因,这使得更有效的营养管理,仍然是一个巨大的挑战。本研究旨在通过在分水岭尺度(12位水文单位代码)上开发用于磷源归属的通用贝叶斯网络模型来解决这一挑战。由于磷的释放是不确定的,我们结合了来自肥料和肥料施用的过量磷和作物吸收数据,SWAT模型模拟的流量信息,并使用近似贝叶斯计算对河流中的水质进行测量,以得出将磷的贡献归因于亚流域的后验。我们的结果表明,亚分水岭规模的磷释放存在显着差异,而粗尺度的归因却失去了磷。归因于小流域的磷贡献平均低于环境机构目前采用的养分平衡方法估计的过量磷。肥料比粪肥贡献更多的可溶性活性磷,而粪肥贡献了大部分的非活性磷。虽然是针对莫美河流域的特定背景而开发的,我们的轻量级和可推广的模型框架可以适应其他地区和污染物,并有助于为有针对性的环境监管和执法提供信息。
    Surface water nutrient pollution, the primary cause of eutrophication, remains a major environmental concern in Western Lake Erie despite intergovernmental efforts to regulate nutrient sources. The Maumee River Basin has been the largest nutrient contributor. The two primary nutrient sources are inorganic fertilizer and livestock manure applied to croplands, which are later carried to the streams via runoff and soil erosion. Prior studies of nutrient source attribution have focused on large watersheds or counties at annual time scales. Source attribution at finer spatiotemporal scales, which enables more effective nutrient management, remains a substantial challenge. This study aims to address this challenge by developing a generalizable Bayesian network model for phosphorus source attribution at the subwatershed scale (12-digit Hydrologic Unit Code). Since phosphorus release is uncertain, we combine excess phosphorus derived from manure and fertilizer application and crop uptake data, flow information simulated by the SWAT model, and in-stream water quality measurements using Approximate Bayesian Computation to derive a posterior that attributes phosphorus contributions to subwatersheds. Our results show significant variability in subwatershed-scale phosphorus release that is lost in coarse-scale attribution. Phosphorus contributions attributed to the subwatersheds are on average lower than the excess phosphorus estimated by the nutrient balance approach currently adopted by environmental agencies. Fertilizer contributes more soluble reactive phosphorus than manure, while manure contributes most of the unreactive phosphorus. While developed for the specific context of Maumee River Basin, our lightweight and generalizable model framework could be adapted to other regions and pollutants and could help inform targeted environmental regulation and enforcement.
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  • 文章类型: Journal Article
    鉴于广泛的工作创造了多种预测多发性硬化症(MS)疾病病程的技术,本文试图对这些方法进行概述,并提出一种预测疾病进展的替代方法。为此,现有的估计和预测病程的方法已分为临床,放射学,生物,和基于计算或人工智能的标记。权衡这些预后组的弱点和优势是一种深刻的方法,目前还需要这种方法,并且直接在患病的连接水平上起作用。因此,我们建议将计算模型与已建立的连接组结合使用,作为MS疾病轨迹的预测工具。通过检查这些研究,基本的基于传导的Hodgkin-Huxley模型很有希望。Hodgkin-Huxley模型的优点是连接体的某些特性,例如神经元连接权重,空间距离,和信号传输速率的调整,可以考虑。正是这些特性在MS中特别改变,并且对加工具有强烈的影响,传输,和神经元信号模式的相互作用。Hodgkin-Huxley(HH)方程作为点神经元模型用于小型网络内部的信号传播。目的是改变神经元模型的传导参数,复制MS中髓磷脂特性的变化,并观察信号在网络中传播的动力学。该模型最初针对不同的长度进行了验证,传导值,和连接权重通过三个节点连接。稍后,这些单独的因素被整合到一个小的网络中,并模拟模拟MS的状况。在网络中的某些节点处引起传导参数的变化之后观察信号传播模式,并将其与在将变化应用于网络之前获得的控制模型模式进行比较。通过适应输入条件,信号传播模式如预期的那样变化。同样,当模型应用于连接体时,模式的变化可以提供对疾病进展的洞察。这种方法开辟了一条探索MS疾病进展的新途径。工作处于初步状态,但是随着未来将这种方法应用于连接体的愿景,提供更好的临床工具。
    In light of extensive work that has created a wide range of techniques for predicting the course of multiple sclerosis (MS) disease, this paper attempts to provide an overview of these approaches and put forth an alternative way to predict the disease progression. For this purpose, the existing methods for estimating and predicting the course of the disease have been categorized into clinical, radiological, biological, and computational or artificial intelligence-based markers. Weighing the weaknesses and strengths of these prognostic groups is a profound method that is yet in need and works directly at the level of diseased connectivity. Therefore, we propose using the computational models in combination with established connectomes as a predictive tool for MS disease trajectories. The fundamental conduction-based Hodgkin-Huxley model emerged as promising from examining these studies. The advantage of the Hodgkin-Huxley model is that certain properties of connectomes, such as neuronal connection weights, spatial distances, and adjustments of signal transmission rates, can be taken into account. It is precisely these properties that are particularly altered in MS and that have strong implications for processing, transmission, and interactions of neuronal signaling patterns. The Hodgkin-Huxley (HH) equations as a point-neuron model are used for signal propagation inside a small network. The objective is to change the conduction parameter of the neuron model, replicate the changes in myelin properties in MS and observe the dynamics of the signal propagation across the network. The model is initially validated for different lengths, conduction values, and connection weights through three nodal connections. Later, these individual factors are incorporated into a small network and simulated to mimic the condition of MS. The signal propagation pattern is observed after inducing changes in conduction parameters at certain nodes in the network and compared against a control model pattern obtained before the changes are applied to the network. The signal propagation pattern varies as expected by adapting to the input conditions. Similarly, when the model is applied to a connectome, the pattern changes could give an insight into disease progression. This approach has opened up a new path to explore the progression of the disease in MS. The work is in its preliminary state, but with a future vision to apply this method in a connectome, providing a better clinical tool.
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  • 文章类型: Journal Article
    Aquatic invasive species (AIS) are one of the greatest threats to the functioning of aquatic ecosystems worldwide. Once an invasive species has been introduced to a new region, many governments develop management strategies to reduce further spread. Nevertheless, managing AIS in a new region is challenging because of the vast areas that need protection and limited resources. Spatial heterogeneity in invasion risk is driven by environmental suitability and propagule pressure, which can be used to prioritize locations for surveillance and intervention activities. To better understand invasion risk across aquatic landscapes, we developed a simulation model to estimate the likelihood of a waterbody becoming invaded with an AIS. The model included waterbodies connected via a multilayer network that included boater movements and hydrological connections. In a case study of Minnesota, we used zebra mussels (Dreissena polymorpha) and starry stonewort (Nitellopsis obtusa) as model species. We simulated the impacts of management scenarios developed by stakeholders and created a decision-support tool available through an online application provided as part of the AIS Explorer dashboard. Our baseline model revealed that 89% of new zebra mussel invasions and 84% of new starry stonewort invasions occurred through boater movements, establishing it as a primary pathway of spread and offering insights beyond risk estimates generated by traditional environmental suitability models alone. Our results highlight the critical role of interventions applied to boater movements to reduce AIS dispersal.
    Modelo del riesgo de la invasión de especies acuáticas dispersadas por movimiento de botes y conexiones entre ríos Resumen Las especies acuáticas invasoras (EAI) son una de las principales amenazas para el funcionamiento de los ecosistemas acuáticos a nivel mundial. Una vez que una especie invasora ha sido introducida a una nueva región, muchos gobiernos desarrollan estrategias de manejo para disminuir la dispersión. Sin embargo, el manejo de las especies acuáticas invasoras en una nueva región se complica debido a las amplias áreas que necesitan protección y los recursos limitados. La heterogeneidad espacial de un riesgo de invasión es causada por la idoneidad ambiental y la presión de propágulo, que puede usarse para priorizar la ubicación de las actividades de vigilancia e intervención. Desarrollamos una simulación para estimar la probabilidad de que un cuerpo de agua sea invadido por EAI para tener un mejor entendimiento del riesgo de invasión en los paisajes acuáticos. El modelo incluyó cuencas conectadas a través de una red multicapa que incluía movimiento de botes y conexiones hidrológicas. Usamos como especies modelo a Dreissena polymorpha y a Nitellopsis obtusa en un estudio de caso en Minnesota. Simulamos el impacto de los escenarios de manejo desarrollado por los actores y creamos una herramienta de decisiones por medio de una aplicación en línea proporcionada como parte del tablero del Explorer de EAI. Nuestro modelo de línea base reveló que el 89% de las invasiones nuevas de D. polymorpha y el 84% de las de N. obtusa ocurrieron debido al movimiento de los botes, lo que lo estableció como una vía primaria de dispersión y nos proporcionó información más allá de las estimaciones de riesgo generadas por los modelos tradicionales de idoneidad ambiental. Nuestros resultados resaltan el papel crítico de las intervenciones aplicadas al movimiento de los botes para reducir la dispersión de especies acuáticas invasoras.
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  • 文章类型: Journal Article
    执行职能(EF)对学术成就至关重要,身体健康,和心理健康。以前使用结构方程模型的研究揭示了EF的发展性组织,从童年的一个因素演变为成人的三个因素:抑制,认知灵活性,和更新。最近的网络模型研究证实了从童年到成年的这种差异。重新分析了1019名儿童(7.8至15.3岁;50.4%的女性;59.1%的白人,15.0%拉丁裔,14.3%双种族,6.7%非洲裔美国人,4.2%亚裔美国人,0.6%其他),本研究比较了三种探索EF发展的分析方法:结构方程模型,网络模型,和新的潜变量网络模型。所有方法都支持细粒度的EF特定轨迹和整个开发过程中的差异,抑制在童年是中心,在青春期早期更新。
    Executive functions (EFs) are crucial for academic achievement, physical health, and mental well-being. Previous studies using structural equation models revealed EFs\' developmental organization, evolving from one factor in childhood to three factors in adults: inhibition, cognitive flexibility, and updating. Recent network model studies confirmed this differentiation from childhood to adulthood. Reanalyzing previously published data from 1019 children (aged 7.8 to 15.3; 50.4% female; 59.1% White, 15.0% Latinx, 14.3% Bi-racial, 6.7% African American, 4.2% Asian American, 0.6% Other), this study compared three analytical methods to explore EF development: structural equation model, network model, and the novel latent variable network model. All approaches supported fine-grained EF-specific trajectories and differentiation throughout development, with inhibition being central in childhood and updating in early adolescence.
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  • 文章类型: Journal Article
    本研究旨在通过网络分析评估社交恐惧症量表(SPIN)的心理测量特征,验证性因素分析,和多体Rasch模型。收集了一个由1,530名参与者组成的横截面数据集,959名女性,571名男性。引导探索图分析揭示了二维的存在,项目17、15、5、14、6和9表现出最高的强度中心性指数。值得注意的是,网络比较测试表明,女性和男性网络在网络不变性和全球强度方面没有差异.此外,验证性因素分析结果表明,两个提取的维度显示出可接受的拟合优度。此外,可靠性系数值是可以接受的,超过0.70的阈值。Rasch分析结果表明总体拟合,但是有些项目表现出重叠,暗示他们的潜在移除。此外,建议开发新项目,以解决现有项目之间的差距,特别是用于衡量社会焦虑障碍的较低水平。总之,这些发现提供了有力的证据,支持SPIN作为衡量阿尔及利亚社会焦虑障碍的工具的信度和效度.
    This study aimed to evaluate the psychometric characteristics of the Social Phobia Inventory (SPIN) by employing network analysis, confirmatory factor analysis, and the Polytomous Rasch Model. A cross-sectional data set was collected comprising 1,530 participants, with 959 being women and 571 being men. The Bootstrap Exploratory Graph Analysis unveiled the presence of two dimensions, with Items 17, 15, 5, 14, 6, and 9 exhibiting the highest strength centrality index. Notably, the Network Comparison Test indicated no differences in Network Invariance and global strength between the networks of women and men. Furthermore, the confirmatory factor analysis results demonstrated that the two extracted dimensions displayed an acceptable goodness of fit. In addition, the reliability coefficient values were acceptable, exceeding the threshold of 0.70. The Rasch analysis results suggested an overall fit, but some items exhibited overlap, suggesting their potential removal. Furthermore, it was recommended to develop new items to address gaps between existing items, particularly for measuring the lower levels of Social Anxiety Disorder. In conclusion, these findings provide robust evidence supporting the reliability and validity of the SPIN as a tool for measuring Social Anxiety Disorder in Algeria.
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  • 文章类型: Journal Article
    面部情感表达在人际交往中起着核心作用;这些显示用于预测和影响他人的行为。尽管它们很重要,量化和分析简短的面部情感表达的动态仍然是一个研究不足的方法论挑战。这里,我们提出了一种利用机器学习和网络建模来评估面部表情动态的方法。使用临床访谈的视频记录,我们在96名被诊断患有精神病的人和116名从未患有精神病的成年人的样本中证明了这种方法的实用性.被诊断为精神分裂症的参与者倾向于从中性表达转变为不常见的表达(例如,恐惧,惊喜),而被诊断患有其他精神病的参与者(例如,有精神病的情绪障碍)转向悲伤的表达。该方法在研究正常和改变的情绪表达方面具有广泛的应用,并且可以与远程医疗集成以改善精神病评估和治疗。
    Facial emotion expressions play a central role in interpersonal interactions; these displays are used to predict and influence the behavior of others. Despite their importance, quantifying and analyzing the dynamics of brief facial emotion expressions remains an understudied methodological challenge. Here, we present a method that leverages machine learning and network modeling to assess the dynamics of facial expressions. Using video recordings of clinical interviews, we demonstrate the utility of this approach in a sample of 96 people diagnosed with psychotic disorders and 116 never-psychotic adults. Participants diagnosed with schizophrenia tended to move from neutral expressions to uncommon expressions (e.g., fear, surprise), whereas participants diagnosed with other psychoses (e.g., mood disorders with psychosis) moved toward expressions of sadness. This method has broad applications to the study of normal and altered expressions of emotion and can be integrated with telemedicine to improve psychiatric assessment and treatment.
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