Density map

密度图
  • 文章类型: Journal Article
    田间小麦穗计数是小麦产量估算的重要步骤,如何在田间环境中解决快速有效的麦穗计数问题,以确保粮食供应的稳定,并为农业管理和政策制定提供更可靠的数据支持,是当前农业领域关注的重点。
    用目前可用的方法解决致密小麦计数问题仍然存在一些瓶颈和挑战。为了解决这些问题,我们提出了一种基于YOLACT框架的新方法,旨在提高致密小麦计数的准确性和效率。用GeM池化层替换CBAM模块中的池化层,然后将密度图引入FPN,这些改进使我们的方法能够更好地应对密集场景中的挑战。
    实验表明,我们的模型改善了复杂背景下的小麦穗计数性能。改进的注意力机制将RMSE从1.75降低到1.57。基于改进的CBAM,通过像素级密度估计,R2从0.9615增加到0.9798,密度图机制准确识别重叠的计数目标,可以提供更精细的信息。
    这些发现证明了我们的智能农业应用框架的实际潜力。
    UNASSIGNED: Field wheat ear counting is an important step in wheat yield estimation, and how to solve the problem of rapid and effective wheat ear counting in a field environment to ensure the stability of food supply and provide more reliable data support for agricultural management and policy making is a key concern in the current agricultural field.
    UNASSIGNED: There are still some bottlenecks and challenges in solving the dense wheat counting problem with the currently available methods. To address these issues, we propose a new method based on the YOLACT framework that aims to improve the accuracy and efficiency of dense wheat counting. Replacing the pooling layer in the CBAM module with a GeM pooling layer, and then introducing the density map into the FPN, these improvements together make our method better able to cope with the challenges in dense scenarios.
    UNASSIGNED: Experiments show our model improves wheat ear counting performance in complex backgrounds. The improved attention mechanism reduces the RMSE from 1.75 to 1.57. Based on the improved CBAM, the R2 increases from 0.9615 to 0.9798 through pixel-level density estimation, the density map mechanism accurately discerns overlapping count targets, which can provide more granular information.
    UNASSIGNED: The findings demonstrate the practical potential of our framework for intelligent agriculture applications.
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  • 文章类型: Journal Article
    背景:自动,精确的枣树产量预测对于果园的管理和资源分配具有重要意义。传统的产量预测技术基于目标检测,预测一个盒子来实现目标统计,但通常用于稀疏目标设置。这些技术,然而,在现实世界中使用特别浓密的枣具有挑战性。盒子标签是劳动力和时间密集的,并且系统的鲁棒性受到严重闭塞的不利影响。因此,迫切需要开发一种基于图像的枣树产量预测方法。但是除了极端的闭塞,由于规模不同,它也具有挑战性,复杂的背景,和照明变化。
    结果:在这项工作中,我们开发了一个简单有效的特征增强引导网络,用于高密度枣的产量估计。它有两个关键的设计:首先,提出了一种基于均匀分布的标签表示方法,与基于高斯核的方法相比,它提供了更好的对象外观表征。这种新方法更易于实现,并显示出更大的成功。其次,我们引入了一个用于红枣计数的特征增强引导网络,包括三个主要组成部分:骨干,密度回归模块,和功能增强模块。特征增强模块在有效感知感兴趣目标和指导密度回归模块做出准确预测方面起着至关重要的作用。值得注意的是,我们的方法利用这个模块来提高我们网络的整体性能。为了验证我们方法的有效性,我们对收集的数据集进行了实验,该数据集包含692张图像,总共包含40344只大枣。结果表明,我们的方法在估计枣数方面具有很高的准确性,平均绝对误差(MAE)为9.62,均方误差(MSE)为22.47。重要的是,我们的方法在很大程度上优于其他最先进的方法,突出了其在枣产量估算中的优越性。
    结论:所提出的方法为预测枣树的产量提供了一种有效的基于图像的技术。该研究将推进人工智能在农林高密度目标识别中的应用。通过利用这种技术,我们的目标是提高种植自动化水平,优化资源配置。
    BACKGROUND: Automatic and precise jujube yield prediction is important for the management of orchards and the allocation of resources. Traditional yield prediction techniques are based on object detection, which predicts a box to achieve target statistics, but are often used in sparse target settings. Those techniques, however, are challenging to use in real-world situations with particularly dense jujubes. The box labeling is labor- and time-intensive, and the robustness of the system is adversely impacted by severe occlusions. Therefore, there is an urgent need to develop a robust method for predicting jujube yield based on images. But in addition to the extreme occlusions, it is also challenging due to varying scales, complex backgrounds, and illumination variations.
    RESULTS: In this work, we developed a simple and effective feature enhancement guided network for yield estimation of high-density jujube. It has two key designs: Firstly, we proposed a novel label representation method based on uniform distribution, which provides a better characterization of object appearance compared to the Gaussian-kernel-based method. This new method is simpler to implement and has shown greater success. Secondly, we introduced a feature enhancement guided network for jujube counting, comprising three main components: backbone, density regression module, and feature enhancement module. The feature enhancement module plays a crucial role in perceiving the target of interest effectively and guiding the density regression module to make accurate predictions. Notably, our method takes advantage of this module to improve the overall performance of our network. To validate the effectiveness of our method, we conducted experiments on a collected dataset consisting of 692 images containing a total of 40,344 jujubes. The results demonstrate the high accuracy of our method in estimating the number of jujubes, with a mean absolute error (MAE) of 9.62 and a mean squared error (MSE) of 22.47. Importantly, our method outperforms other state-of-the-art methods by a significant margin, highlighting its superiority in jujube yield estimation.
    CONCLUSIONS: The proposed method provides an efficient image-based technique for predicting the yield of jujubes. The study will advance the application of artificial intelligence for high-density target recognition in agriculture and forestry. By leveraging this technique, we aim to enhance the level of planting automation and optimize resource allocation.
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  • 文章类型: Journal Article
    低温电子显微镜(Cryo-EM)和低温电子断层扫描(cryo-ET)在一系列分辨率水平下产生生物分子的3-D密度图。模式识别工具对于区分具有可用分辨率的体积图的生物成分非常重要。中等(5-10µ)分辨率的密度图中最明显的特征之一是蛋白质二级结构的可见性。尽管已经开发了计算方法,从低温EM密度图中准确检测螺旋和β链仍然是一个活跃的研究领域。我们开发了一种用于蛋白质二级结构检测和评估中等分辨率3-D低温EM密度图的工具,该工具结合了三种计算方法(SSETracer,StrandTwister,和轴比较)。该计划被整合在UCSFChimera中,cryo-EM社区中流行的可视化软件。在相关工作中,我们开发了BundleTrac,一种从较低分辨率的低温-ET密度图中追踪束中细丝的计算方法。已将其应用于立体纤毛中的肌动蛋白丝追踪,具有良好的准确性,并且可以作为嵌合体中的工具添加。
    Cryo-electron microscopy (Cryo-EM) and cryo-electron tomography (cryo-ET) produce 3-D density maps of biological molecules at a range of resolution levels. Pattern recognition tools are important in distinguishing biological components from volumetric maps with the available resolutions. One of the most distinct characters in density maps at medium (5-10 Å) resolution is the visibility of protein secondary structures. Although computational methods have been developed, the accurate detection of helices and β-strands from cryo-EM density maps is still an active research area. We have developed a tool for protein secondary structure detection and evaluation of medium resolution 3-D cryo-EM density maps which combines three computational methods (SSETracer, StrandTwister, and AxisComparison). The program was integrated in UCSF Chimera, a popular visualization software in the cryo-EM community. In related work, we have developed BundleTrac, a computational method to trace filaments in a bundle from lower resolution cryo-ET density maps. It has been applied to actin filament tracing in stereocilia with good accuracy and can be potentially added as a tool in Chimera.
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  • 文章类型: Review
    膜蛋白存在于水性介质和脂质介质之间的界面处,并且溶解它们的分子结构大部分时间依赖于使用洗涤剂将它们从膜中除去。幸运的是,这种溶解过程不会将它们从所有相关的脂质中剥离出来,单粒子低温透射电子显微镜(SP-TEM)已被证明是可视化蛋白质高分辨率结构和蛋白质的非常好的工具,经常,它的许多相关脂质。在这次审查中,我们观察蛋白质数据库中的膜蛋白结构及其在电子显微镜数据库中的相关图,并确定SP-TEM图如何允许脂质可视化,结合位点的类型,对称性的影响,分辨率和其他因素。我们说明了蛋白质核心周围和内部的脂质可视化,显示核心中的一些脂质双层可以相对于膜移动,以及一些蛋白质如何主动弯曲与它们结合的脂质双层。我们得出的结论是,SP-TEM分辨率的提高可能会使有关脂质与蛋白质结合的作用的更多发现。
    Membrane proteins reside at interfaces between aqueous and lipid media and solving their molecular structure relies most of the time on removing them from the membrane using detergent. Luckily, this solubilization process does not strip them from all the associated lipids and single-particle cryo-transmission electron microscopy (SP-TEM) has proved a very good tool to visualise both protein high-resolution structure and, often, many of its associated lipids. In this review, we observe membrane protein structures from the Protein DataBank and their associated maps in the Electron Microscopy DataBase and determine how the SP-TEM maps allow lipid visualization, the type of binding sites, the influence of symmetry, resolution and other factors. We illustrate lipid visualization around and inside the protein core, show that some lipid bilayers in the core can be shifted with respect to the membrane and how some proteins can actively bend the lipid bilayer that binds to them. We conclude that resolution improvement in SP-TEM will likely enable many more discoveries regarding the role of lipids bound to proteins.
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  • 文章类型: Journal Article
    单粒子电子低温显微镜(cryoEM)已成为研究大分子组装体结构和功能不可或缺的工具。作为冷冻EM结构确定过程的组成部分,已经开发了计算工具,可以直接从密度图构建原子模型,而无需结构模板。大约十年前,我们创造了Pathwalking,一种在近原子分辨率冷冻EM密度图中对蛋白质结构进行从头建模的工具。这里,我们介绍了Pathwalking的最新进展,包括增加概率模型,以及模拟水和配体的配套工具。该软件在2021年CryoEM配体挑战密度图上进行了评估,除了在三个IP3R1密度图中确定配体,分辨率约为3µ至4.1µ。结果清楚地表明,Pathwalking从头建模管道可以构建准确的蛋白质结构,并直接从近原子分辨率图中可靠地定位和识别配体密度。
    Single-particle electron cryomicroscopy (cryoEM) has become an indispensable tool for studying structure and function in macromolecular assemblies. As an integral part of the cryoEM structure determination process, computational tools have been developed to build atomic models directly from a density map without structural templates. Nearly a decade ago, we created Pathwalking, a tool for de novo modeling of protein structure in near-atomic resolution cryoEM density maps. Here, we present the latest developments in Pathwalking, including the addition of probabilistic models, as well as a companion tool for modeling waters and ligands. This software was evaluated on the 2021 CryoEM Ligand Challenge density maps, in addition to identifying ligands in three IP3R1 density maps at ~3 Å to 4.1 Å resolution. The results clearly demonstrate that the Pathwalking de novo modeling pipeline can construct accurate protein structures and reliably localize and identify ligand density directly from a near-atomic resolution map.
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  • 文章类型: Journal Article
    古生物学中的关键问题涉及人类血统中衍生脑特征的出现时间和出现。内分泌是骨性脑箱内部表的副本,在古生物学中被广泛用作重建化石记录中人类大脑进化时间表的代理。准确识别内膜中的脑沟印迹对于评估化石人素中皮质区域的地形延伸和结构组织至关重要。高分辨率成像技术与基于特定人群脑图集的既定方法相结合,为跟踪详细的颅内特征提供了新的机会。这项研究使用基于人群的图集技术在现有的人类内模上提供了大脑上外侧表面的沟模式印记的第一份文献。使用显微CT扫描来自比勒陀利亚骨收集(南非)的人类颅骨。实际上提取了内分泌,和沟是自动检测和手动标记。应用密度图方法将所有标签投影到平均的内膜上,以可视化每个识别的沟纹印记的平均分布。这种方法允许可视化沟纹的个体间变化,例如,额叶沟,与先前的脑MRI研究相关,并且首次在历史上有争议的内膜区域(例如枕叶)中广泛重叠的印记。在提供创新,非侵入性,独立于观察者的方法来研究人类颅内结构组织,我们的分析方案为未来的古神经病学研究和讨论人类认知能力进化的关键假设提供了一个有希望的观点.
    Key questions in paleoneurology concern the timing and emergence of derived cerebral features within the human lineage. Endocasts are replicas of the internal table of the bony braincase that are widely used in paleoneurology as a proxy for reconstructing a timeline for hominin brain evolution in the fossil record. The accurate identification of cerebral sulci imprints in endocasts is critical for assessing the topographic extension and structural organisation of cortical regions in fossil hominins. High-resolution imaging techniques combined with established methods based on population-specific brain atlases offer new opportunities for tracking detailed endocranial characteristics. This study provides the first documentation of sulcal pattern imprints from the superolateral surface of the cerebrum using a population-based atlas technique on extant human endocasts. Human crania from the Pretoria Bone Collection (South Africa) were scanned using micro-CT. Endocasts were virtually extracted, and sulci were automatically detected and manually labelled. A density map method was applied to project all the labels onto an averaged endocast to visualise the mean distribution of each identified sulcal imprint. This method allowed for the visualisation of inter-individual variation of sulcal imprints, for example, frontal lobe sulci, correlating with previous brain-MRI studies and for the first time the extensive overlapping of imprints in historically debated areas of the endocast (e.g. occipital lobe). In providing an innovative, non-invasive, observer-independent method to investigate human endocranial structural organisation, our analytical protocol introduces a promising perspective for future research in paleoneurology and for discussing critical hypotheses on the evolution of cognitive abilities among hominins.
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  • 文章类型: Journal Article
    近年来,深度学习对人群计数进行了广泛的研究。然而,由于透视失真引起的尺度变化,人群计数仍然是一项具有挑战性的任务。在本文中,我们提出了一种密集连接的多尺度金字塔网络(DMPNet),用于计数估计和生成高质量的密度图。我们网络的关键组成部分是多尺度金字塔网络(MPN),在保持输入特征图的分辨率和通道数不变的情况下,能够有效地提取人群的多尺度特征。为了增加网络层之间的信息传递,我们使用密集连接来连接多个MPN。此外,我们还设计了一个新的损失函数,这可以帮助我们的模型实现更好的收敛性。为了评估我们的方法,我们对三个具有挑战性的基准人群计数数据集进行了广泛的实验.实验结果表明,与现有算法相比,DMPNet在参数和结果方面都表现良好。该代码可在以下网址获得:https://github.com/lpfworld/DMPNet。
    Crowd counting has been widely studied by deep learning in recent years. However, due to scale variation caused by perspective distortion, crowd counting is still a challenging task. In this paper, we propose a Densely Connected Multi-scale Pyramid Network (DMPNet) for count estimation and the generation of high-quality density maps. The key component of our network is the Multi-scale Pyramid Network (MPN), which can extract multi-scale features of the crowd effectively while keeping the resolution of the input feature map and the number of channels unchanged. To increase the information transfer between the network layer, we used dense connections to connect multiple MPNs. In addition, we also designed a novel loss function, which can help our model achieve better convergence. To evaluate our method, we conducted extensive experiments on three challenging benchmark crowd counting datasets. Experimental results show that compared with the state-of-the-art algorithms, DMPNet performs well in both parameters and results. The code is available at: https://github.com/lpfworld/DMPNet.
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  • 文章类型: Journal Article
    尽管有丰富的软件工具,在单粒子低温电子显微镜(cryo-EM)中,最佳粒子选择仍然是一个至关重要的问题。不管使用哪种方法,当冰厚度在显微照片上变化时,大多数采摘者都会挣扎。IceBreaker允许用户估计相对冰梯度并通过均衡局部对比度来使其变平。它允许颗粒与背景的区别,并提高整体颗粒拾取性能。此外,我们为每个粒子引入一个与局部冰厚度相对应的附加参数。在处理过程中,可以根据此参数对具有定义冰厚度的粒子进行分组和过滤。这些功能对于实时处理特别有价值,可以从每个显微照片中自动挑选尽可能多的颗粒,并选择最佳区域进行数据收集。最后,估计的冰梯度分布可以单独存储,并用于检查准备样品的质量。
    Despite the abundance of available software tools, optimal particle selection is still a vital issue in single-particle cryoelectron microscopy (cryo-EM). Regardless of the method used, most pickers struggle when ice thickness varies on a micrograph. IceBreaker allows users to estimate the relative ice gradient and flatten it by equalizing the local contrast. It allows the differentiation of particles from the background and improves overall particle picking performance. Furthermore, we introduce an additional parameter corresponding to local ice thickness for each particle. Particles with a defined ice thickness can be grouped and filtered based on this parameter during processing. These functionalities are especially valuable for on-the-fly processing to automatically pick as many particles as possible from each micrograph and to select optimal regions for data collection. Finally, estimated ice gradient distributions can be stored separately and used to inspect the quality of prepared samples.
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  • 文章类型: Journal Article
    The thousand grain weight is an index of size, fullness and quality in crop seed detection and is an important basis for field yield prediction. To detect the thousand grain weight of rice requires the accurate counting of rice. We collected a total of 5670 images of three different types of rice seeds with different qualities to construct a model. Considering the different shapes of different types of rice, this study used an adaptive Gaussian kernel to convolve with the rice coordinate function to obtain a more accurate density map, which was used as an important basis for determining the results of subsequent experiments. A Multi-Column Convolutional Neural Network was used to extract the features of different sizes of rice, and the features were fused by the fusion network to learn the mapping relationship from the original map features to the density map features. An advanced prior step was added to the original algorithm to estimate the density level of the image, which weakened the effect of the rice adhesion condition on the counting results. Extensive comparison experiments show that the proposed method is more accurate than the original MCNN algorithm.
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  • 文章类型: Journal Article
    Cryo-electron microscopy (cryo-EM) has recently emerged as a prominent biophysical method for macromolecular structure determination. Many research efforts have been devoted to produce cryo-EM images, density maps, at near-atomic resolution. Despite many advances in technology, the resolution of the generated density maps may not be sufficiently adequate and informative to directly construct the atomic structure of proteins. At medium-resolution (∼4-10 Å), secondary structure elements (α-helices and β-sheets) are discernible, whereas finding the correspondence of secondary structure elements detected in the density map with those on the sequence remains a challenging problem. In this paper, an automatic framework is proposed to solve α-helix correspondence problem in three-dimensional space. Through modeling of the sequence with the aid of a novel strategy, the α-helix correspondence problem is initially transformed into a complete weighted bipartite graph matching problem. An innovative correlation-based scoring function based on a well-known and robust statistical method is proposed for weighting the graph. Moreover, two local optimization algorithms, which are Greedy and Improved Greedy algorithms, have been presented to find α-helix correspondence. A widely used data set including 16 reconstructed and 4 experimental cryo-EM maps were chosen to verify the accuracy and reliability of the proposed automatic method. The experimental results demonstrate that the automatic method is highly efficient (86.25% accuracy), robust (11.3% error rate), fast (∼1.4 s), and works independently from cryo-EM skeleton.
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