Similar Maps Research Articles

Uncovering CNS access of lipidated exendin-4 analogues by quantitative whole-brain 3D light sheet imaging

Peptide-based drug development for CNS disorders is challenged by poor blood-brain barrier (BBB) penetrability of peptides. While acylation protractions (lipidation) have been successfully applied to increase circulating half-life of therapeutic peptides, little is known about the CNS accessibility of lipidated peptide drugs. Light-sheet fluorescence microscopy (LSFM) has emerged as a powerful method to visualize whole-brain 3D distribution of fluorescently labelled therapeutic peptides at single-cell resolution. Here, we applied LSFM to map CNS distribution of the clinically relevant GLP-1 receptor agonist (GLP-1RA) exendin-4 (Ex4) and lipidated analogues following peripheral administration. Mice received an intravenous dose (100 nmol/kg) of IR800 fluorophore-labelled Ex4 (Ex4), Ex4 acylated with a C16-monoacid (Ex4_C16MA) or C18-diacid (Ex4_C18DA). Other mice were administered C16MA-acylated exendin 9-39 (Ex9-39_C16MA), a selective GLP-1R antagonist, serving as negative control for GLP-1R mediated agonist internalization. Two hours post-dosing, brain distribution of Ex4 and analogues was predominantly restricted to the circumventricular organs, notably area postrema and nucleus of the solitary tract. However, Ex4_C16MA and Ex9-39_C16MA also distributed to the paraventricular hypothalamic nucleus and medial habenula. Notably, Ex4_C18DA was detected in deeper-lying brain structures such as dorsomedial/ventromedial hypothalamic nuclei and the dentate gyrus. Similar CNS distribution maps of Ex4_C16MA and Ex9-39_C16MA suggest that brain access of lipidated Ex4 analogues is independent on GLP-1 receptor internalization. The cerebrovasculature was devoid of specific labelling, hence not supporting a direct role of GLP-1 RAs in BBB function. In conclusion, peptide lipidation increases CNS accessibility of Ex4. Our fully automated LSFM pipeline is suitable for mapping whole-brain distribution of fluorescently labelled drugs.

Quantitative Relations between Morphostructural Similarity Degree and Map Scale Change in Contour Clusters in Multi-Scale Map Space

This paper aims to propose a new approach to calculate the quantitative relations between morphostructural similarity degree and map scale change in multi-scale contour clusters for automatic contour generalization. Terrain lines were extracted by pre-processing of unclosed contour lines, and an indirect quantitative expression method of morphostructural similarity relation was proposed based on terrain line hierarchical trees. Thirteen groups of multi-scale contour clusters with different drainage areas of loess geomorphy were employed to explore the changing regularity of morphostructural similarity indices with map scale. Finally, the quantitative relations between morphostructural similarity degree and map scale change were calculated using 52 groups of points. The results show that power function is the best fit among the candidate functions, and the quantitative relations between the morphostructural similarity degree and map scale change can be expressed using the same power function, which facilitates the automation of contour generalization.

Myocardial tissue microstructure with and without stress-induced ischemia assessed by T1 mapping in patients with stable coronary artery disease

BackgroundStress-induced myocardial ischemia seems not to be associated with cardiovascular events. However, its effects on myocardial tissue characteristics remain under debate. Thus, we sought to assess whether documented stress-induced ischemia is associated with changes in myocardial microstructure evaluated by magnetic resonance native T1 map and extracellular volume fraction (ECV). MethodsThis is a single-center, analysis of the previously published MASS V Trial. Multivessel patients with a formal indication for myocardial revascularization and with documented stress-induced ischemia were included in this study. Native T1 and ECV values evaluated by cardiac magnetic resonance imaging of ischemic and nonischemic myocardial segments at rest and after stress were compared. Myocardial ischemia was detected by either nuclear scintigraphy or stress magnetic cardiac resonance protocol. ResultsBetween May 2012 and March 2014, 326 prospective patients were eligible for isolated CABG or PCI and 219 were included in the MASS V trial. All patients underwent resting cardiac magnetic resonance imaging. Of a total of 840 myocardial segments, 654 were nonischemic segments and 186 were ischemic segments. Native T1 and ECV values of ischemic segments were not significantly different from nonischemic segments, both at rest and after stress induction. In addition, native T1 and ECV values of myocardial segments supplied by vessels with obstructive lesions were similar to those supplied by nonobstructive ones. Conclusion and relevanceIn this study, cardiac magnetic resonance identified similar T1 mapping values between ischemic and nonischemic myocardial segments. This finding suggests integrity and stability of myocardial tissue in the presence of stress-induced ischemia.

An Efficient Phase Unwrapping Method Based on Unscented Kalman Filter

In this paper, we proposed a phase unwrapping method which combines with unscented Kalman filter, pixel classification and an efficient path-following strategy. The characteristics of proposed method as: (1) the path-following strategy speeds up the process of phase unwrapping without decreasing the accuracy; (2) the reliability of each pixel will be graded according to the position of residue and pixel classification strategy; (3) different from the traditional methods, the proposed method can perform filtering and phase unwrapping at the same time to prevent global propagation of error. In addition, we also introduce a signal model which can obtain a similar correlation map by only using a wrapped phase image when without the master-slave image. The results on synthetic data and real data show that the proposed method can obtain better results.

Comparative Maps of Safety Features for Fission and Fusion Reactors

Abstract The differences between nuclear fission and fusion have been discussed widely in the literature. However, little has been done to investigate the key differences in safety designs and regulatory requirements between the nuclear reactor types. In this study, an innovative methodology was successfully developed to map nuclear safety features to the fundamental safety principles set out by the nuclear regulators. Three safety cases were assessed in the mapping study, a research fusion reactor (Joint European Torus), a research fission reactor (Tsing Hua Open-pool Reactor) and a commercial fission reactor (Hinkley Point C). The graphical representation allowed a comparative analysis of the safety features and fundamental principles which revealed differences between the hazard profiles of fission and fusion reactors and provided important insights for the creation of a similar map for a future commercial fusion device.

Deriving the number of salience maps an observer has from the number and quality of concurrent centroid judgments

[C. Koch, S. Ullman, Hum. Neurobiol.4, 219-227 (1985)] proposed a 2D topographical salience map that took feature-map outputs as its input and represented the importance "saliency" of the feature inputs at each location as a real number. The computation on the map, "winner-take-all," was used to predict action priority. We propose that the same or a similar map is used to compute centroid judgments, the center of a cloud of diverse items. [P. Sun, V. Chu, G. Sperling, Atten. Percept. Psychophys.83, 934-955 (2021)] demonstrated that following a 250-msec exposure of a 24-dot array of 3 intermixed colors, subjects could accurately report the centroid of each dot color, thereby indicating that these subjects had at least three salience maps. Here, we use a postcue, partial-report paradigm to determine how many more salience maps subjects might have. In 11 experiments, subjects viewed 0.3-s flashes of 28 to 32 item arrays composed of M, M = 3,...,8, different features followed by a cue to mouse-click the centroid of items of just the post-cued feature. Ideal detector response analyses show that subjects utilized at least 12 to 17 stimulus items. By determining whether a subject's performance in (M-1)-feature experiments could/could-not predict performance in M-feature experiments, we conclude that one subject has at least 7 and the other two have at least five salience maps. A computational model shows that the primary performance-limiting factors are channel capacity for representing so many concurrently presented groups of items and working-memory capacity for so many computed centroids.

Chronic hypoxia disrupts memory T regulatory cell phenotype which contributes to the pathogenesis of pulmonary hypertension

Pulmonary hypertension (PH) caused by chronic hypoxia (CH) is a multifaceted disease most often caused by sleep apnea, prolonged high-altitude exposure, or chronic obstructive pulmonary disease (COPD), with minimal treatment options, leading to right heart failure and death. One major contributor in the pathogenesis of PH that requires more characterization is the accompanying immune response.Our previous studies have demonstrated the importance of inflammation and self-immunity in CH-induced PH. We demonstrated pulmonary-perivascular localization of pro-inflammatory Th17 cells as well as an increase in total Th17 cells in the lung, while finding no overall changes in the number of anti-inflammatory T regulatory (Treg) cells present in the lung. Imbalance between Th17 and Treg cells has been shown to drive multiple inflammatory and metabolic diseases. One area of interest related to this balance has been the recent discovery and attempted characterization of exTregs, or cells that, at one point in time, were Tregs but lost their phenotype transitioning to pro-inflammatory Th17 cells, due to decreases in the expression of the transcription factor FoxP3. Therefore, we hypothesized that the increase in Th17 cells seen in CH is due to a decrease in Tregs and Treg suppressive capacity as well as a switching of Tregs to Th17 cells. Using a mouse model that allows the study of lineage stability and genetic mapping of Tregs, together with single-cell RNA sequencing (scRNA SEQ), we initially established that CH resulted in a gene expression profile consistent with exTregs or Tregs with less suppressive activity, such as downregulation of Il2ra gene and upregulation of Tnfrsf4 (adjusted p-value 0.03). To further establish a loss in Tregs as well as an increase in exTregs following CH exposure, we performed spectral flow cytometry of splenocytes on a Cytek Aurora to look for changes in protein expression and cell prevalence. Finally, we used a similar lineage mapping mouse model to look at Th17 cells. Following these experiments, we found supporting evidence of our scRNA SEQ data, finding a decrease in Tregs in both male and female mice following CH exposure, as well as an increase in exTregs in both groups exposed to CH. We also further supported this data finding Th17 cells tracked through our model to be increased following CH. These results support the importance of immune cell balance and inflammation in the pathogenesis of CH-induced PH. R56 HL153065-01 NIH, AHA 18TPA34170037, AHA967925 & T32 HL07736 NIH This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Study of turbulent transport in magnetized plasmas with flow using symplectic maps

Turbulent transport in a magnetized plasma of the kind found in tokamaks is modeled by a 2D wave spectrum that allows reduction to a symplectic map. The properties of particle transport when chaos sets in are analyzed in various circumstances including finite Larmor radius (FLR) effects and a background plasma flow. For large wave amplitudes, regular particle orbits become chaotic, which represents a type of Lagrangian turbulence. When chaos becomes global, it leads to the loss of particle confinement. Poloidal flows tend to decrease the chaos in some regions, and they can give rise to the formation of transport barriers. FLR effects not only reduce chaos but also give rise to non-local behavior. Thus, when the particles have a thermal distribution of Larmor radii, a non-Gaussian particle distribution function in space is obtained. However, the transport preserves its diffusive scaling when there is no flow. Previous results about the dependence of the diffusion coefficient with amplitude are re-derived analytically and numerically taking into account FLR effects. In the presence of general poloidal flows, the transport has to be described by a two-step map. They modify the nature of transport in the direction of the flow from diffusive to ballistic to super-ballistic, depending on the type of flow. The transverse transport, in turn, shows suppression of the oscillations with wave amplitude that are present in the absence of flow. When the plasma flow varies linearly with radius, the transport can be studied with a similar single-step map, and the transverse diffusion coefficient is reduced while parallel transport can become super-ballistic. For non-monotonic flows, there are accelerating modes that can produce ballistic-like particles while the bulk of the particles behaves diffusively.

PO-01-164 CATHETER ABLATION WITH MORPHOLOGIC REPETITIVENESS ABLATION ON PERSISTENT ATRIAL FIBRILLATION: A PROSPECTIVE MULTICENTER TRIAL

Catheter ablation for persistent atrial fibrillation (AF) has shown limited success. AF drivers could be accurately identified by PeRIodicity and SiMilarity (PRISM) mapping and ablated. We aimed to determine whether PRISM mapping can improve ablation results for persistent AF when added to pulmonary vein isolation (PVI). This PRISM trial was an investigator-initiated, multicenter, prospective, single-blinded trial conducted at three centers across Asia. Patients with persistent AF referred for ablation were enrolled from June 2019 to December 2020. Patients were assigned to the PRISM-guided approach (Group 1, Figure) or the conventional approach (Group 2) at a 1:1 ratio. Outcome assessments were blinded to the treatment received. The primary outcome was freedom from AF for longer than 30 seconds at 6 and 12 months. 170 patients (age 62.0 ± 12.3 years; 136 men) were enrolled. We assigned 85 patients to group 1 and 85 patients to group 2. There were more group 1 patient who achieved freedom of AF at 12 months compared with group 2 patients. (71.6% [60/85] vs. 47.1% [40/85], p=0.003). Multivariate analysis indicated that the PRISM-guided approach was associated with freedom from the recurrence of AF [hazard ratio: 0.531, 95% confidence interval: 0.331-0.852, p=0.009]. Complication rates between the two groups were not significantly different. Our study showed that for persistent AF ablation, a specified substrate modification guided by PRISM mapping could eliminate AF sources and maintain sinus rhythm for 12 months.

Surface Maps via Adaptive Triangulations

AbstractWe present a new method to compute continuous and bijective maps (surface homeomorphisms) between two or more genus‐0 triangle meshes. In contrast to previous approaches, we decouple the resolution at which a map is represented from the resolution of the input meshes. We discretize maps via common triangulations that approximate the input meshes while remaining in bijective correspondence to them. Both the geometry and the connectivity of these triangulations are optimized with respect to a single objective function that simultaneously controls mapping distortion, triangulation quality, and approximation error. A discrete‐continuous optimization algorithm performs both energy‐based remeshing as well as global second‐order optimization of vertex positions, parametrized via the sphere. With this, we combine the disciplines of compatible remeshing and surface map optimization in a unified formulation and make a contribution in both fields. While existing compatible remeshing algorithms often operate on a fixed pre‐computed surface map, we can now globally update this correspondence during remeshing. On the other hand, bijective surface‐to‐surface map optimization previously required computing costly overlay meshes that are inherently tied to the input mesh resolution. We achieve significant complexity reduction by instead assessing distortion between the approximating triangulations. This new map representation is inherently more robust than previous overlay‐based approaches, is less intricate to implement, and naturally supports mapping between more than two surfaces. Moreover, it enables adaptive multi‐resolution schemes that, e.g., first align corresponding surface regions at coarse resolutions before refining the map where needed. We demonstrate significant speedups and increased flexibility over state‐of‐the art mapping algorithms at similar map quality, and also provide a reference implementation of the method.

Reference‐based Screentone Transfer via Pattern Correspondence and Regularization

AbstractAdding screentone to initial line drawings is a crucial step for manga generation, but is a tedious and human‐laborious task. In this work, we propose a novel data‐driven method aiming to transfer the screentone pattern from a reference manga image. This not only ensures the quality, but also adds controllability to the generated manga results. The reference‐based screentone translation task imposes several unique challenges. Since manga image often contains multiple screentone patterns interweaved with line drawing, as an abstract art, this makes it even more difficult to extract disentangled style code from the reference. Also, finding correspondence for mapping between the reference and the input line drawing without any screentone is hard. As screentone contains many subtle details, how to guarantee the style consistency to the reference remains challenging. To suit our purpose and resolve the above difficulties, we propose a novel Reference‐based Screentone Transfer Network (RSTN). We encode the screentone style through a 1D stylegram. A patch correspondence loss is designed to build a similarity mapping function for guiding the translation. To mitigate the generated artefacts, a pattern regularization loss is introduced in the patch‐level. Through extensive experiments and a user study, we have demonstrated the effectiveness of our proposed model.

FSConv: Flexible and separable convolution for convolutional neural networks compression

Because of limited computation resources, convolutional neural networks (CNNs) are difficult to deploy on mobile devices. To overcome this issue, many methods have successively reduced parameters in CNNs with the idea of removing redundancy among feature maps. We observe similarities between feature maps at the same layer but not complete consistency. Intuitively, the difference between similar feature maps is an essential ingredient for the success of CNNs. Therefore, we propose a flexible and separable convolution (FSConv) in a different perspective to embrace redundancy while requiring less computation, which can implicitly cluster feature maps into different clusters without introducing similarity measurements. Our proposed model extracts intrinsic information from the representative part through ordinary convolution in each cluster and reveals tiny hidden details from the redundant part through groupwise/depthwise convolution. Experimental results demonstrate that FSConv-equipped networks always perform better than previous state-of-the-art CNNs compression algorithms. Code is available at https://github.com/Clarkxielf/FSConv-Flexible-and-Separable-Convolution-for-Convolutional-Neural-Networks-Compression.

Analytic structures and harmonic measure at bifurcation locus

We study conformal quantities at generic parameters with respect to the harmonic measure on the boundary of the connectedness loci Md for unicritical polynomials fc(z)=zd+c. It is known that these parameters are structurally unstable and have stochastic dynamics. We prove C1+α2d+α−ϵ-conformality, α=2−HD(Jc0), of the parameter-phase space similarity maps ϒc0(z):C↦C at typical c0∈∂Md and establish that globally quasiconformal similarity maps ϒc0(z), c0∈∂Md, are C1-conformal along external rays landing at c0 in C∖Jc0 mapping onto the corresponding rays of Md. This conformal equivalence leads to the proof that the z-derivative of the similarity map ϒc0(z) at typical c0∈∂Md is equal to 1/T(c0), where T(c0)=∑n=0∞(D(fc0n)(c0))−1 is the transversality function.The paper builds analytical tools for a further study of the extremal properties of the harmonic measure on ∂Md, [27]. In particular, we will explain how a non-linear dynamics creates abundance of hedgehog neighborhoods in ∂Md effectively blocking a good access of ∂Md from the outside.

Accurate few-shot object counting with Hough matching feature enhancement.

Given some exemplars, few-shot object counting aims to count the corresponding class objects in query images. However, when there are many target objects or background interference in the query image, some target objects may have occlusion and overlap, which causes a decrease in counting accuracy. To overcome the problem, we propose a novel Hough matching feature enhancement network. First, we extract the image feature with a fixed convolutional network and refine it through local self-attention. And we design an exemplar feature aggregation module to enhance the commonality of the exemplar feature. Then, we build a Hough space to vote for candidate object regions. The Hough matching outputs reliable similarity maps between exemplars and the query image. Finally, we augment the query feature with exemplar features according to the similarity maps, and we use a cascade structure to further enhance the query feature. Experiment results on FSC-147 show that our network performs best compared to the existing methods, and the mean absolute counting error on the test set improves from 14.32 to 12.74. Ablation experiments demonstrate that Hough matching helps to achieve more accurate counting compared with previous matching methods.

From Maps to 3D Models: Reconstructing the Urban Landscape of San Cristóbal de La Laguna in the 16th Century

The use of 3D visualization technologies offers a unique opportunity to reconstruct historical cities that no longer exist or have been substantially modified. In this paper, we use the oldest preserved map of the city of San Cristóbal de La Laguna, created in 1588 by the engineer Leonardo Torriani, as the basis for its 3D virtual recreation. This map shows the first non-fortified Spanish colonial city whose plan provided a model for the colonial cities in America. These distinct features made San Cristóbal de La Laguna a UNESCO world heritage site. In our work, we present a map-based workflow for 3D reconstruction that balances fidelity to the original map with the integration of other historical sources and the current status of the city. This leads to the development of several 3D models from those distinct sources whose integration provides the 3D reconstruction of the city in the 16th century. The results of this project can be applied to other similar maps that were created in Europe at that time.

A novel network core structure extraction algorithm utilized variational autoencoder for community detection

Community detection technologies have the general research significance in complex networks, in which the topology information of network is worthy to be the focus for its widely application. It is the definition of community structure that the connection of nodes in the community is dense with the connection of nodes outside the community is sparse, which is corresponding to the core structure in the complex real networks is represented by a compact and dense set of connected nodes. While all the notes in the network are considered by the traditional topology, it is hard to extract the core structure with the continuous, exponential growth of community networks. In this paper, a novel network core structure extraction algorithm utilized variational autoencoder for community detection(CSEA) is proposed for finding the community structure more accurately. Firstly, the K-truss algorithm is used to find the core structure information in the network, and the similarity matrix is generated by similarity mapping combined with local information. Secondly, the variational autoencoder is used to extract and reduce the dimension of the similarity matrix containing the core structure of the network, and the low-dimensional feature matrix is obtained. Finally, the K-means clustering algorithm is utilized to obtain the community structure information. We compare CSEA algorithm with 18 different types of community detection algorithms using 4 evaluation metrics on 19 complex real networks. By extensively evaluating our algorithm on large real-world datasets, we show that CSEA algorithm has an excellent community division effect in dense complex real networks, especially in small and medium-sized networks, and it can accurately divide the complex real networks with unknown community structure. Simultaneously, CSEA algorithm also reveals some efficiency advantage in its on-line test.

Material and textural features-based retrieval using feature similarity mapping for synthetic images

Content Based image retrieval (CBIR) is one of the prominent application of image processing where image retrieval from the database is made automatic based on the content in it. The materialist details of the images contains high degree of information and can serve as important toll for analysis. Different variant of content based image retrieval work by locating an object in the image and then retrieving images with similar object in it. The method works using different similarity assessment techniques. In this research work, we have developed a new material feature and HMMD space CBIR technique which works by transforming the domain to HMMD space and then finding the material and Texture Features along with other relevant features. These features forms he feature vector and are then deployed to assess the similarity of the two images which then generates a relevant and irrelevant image search. The system has higher accuracy of assessment as verified by experimentation for precision, productivity and precision agriculture.

Multivalent Cartographic Accessibility: Tactile Maps for Collaborative Decision-Making

Conventional visual maps present significant accessibility challenges for blind or low vision users, leaving them with few or no options for interpreting spatial data. This need not be the case: tactile maps, designed to be read through touch, have been published for more than a century. But they have most often been categorized as a navigation tool, or mere “tactile graphics” (i.e., not as expressly spatial documents). Tactile maps that allow their users to explore and synthesize thematic spatial data are rare, as are studies evaluating them. As our world continues to face existential threats that are spatial in nature—pandemics, supply chain disruptions, floods, etc.—maps will continue to provide critical information in ways that other media are unable to match. In the absence of accessible thematic maps, blind people will not only be left out of the loop, but their capacity for contributing valuable input will be severely diminished. In response, I describe here a study that evaluates the potential of thematic tactile maps for providing blind users an accessible means of analyzing spatial data when working in collaboration with sighted partners. Findings indicate that while the maps did not prove to be useful tools on their own, they did facilitate collaboration between blind or low vision participants and sighted participants. This suggests that, with some refinements, similar maps could be feasibly distributed as a means for people with visual disabilities to meaningfully participate in an otherwise inaccessible process that requires the synthesis of thematic spatial information.

SWSEL: Sliding Window-based Selective Ensemble Learning for class-imbalance problems

For class-imbalance problems, traditional supervised learning algorithms tend to favor majority instances (also called negative instances). Therefore, it is difficult for them to accurately identify the minority instances (also called positive instances). Ensemble learning is a common method to solve the class-imbalance problem. They build multiple classifier systems on the training dataset to improve the recognition accuracy of minority instances. Sliding window is a commonly used method for processing data stream. Few researchers have used sliding windows to select majority instances and construct ensemble learning models. Traditional ensemble learning methods use some or all of the majority instances for modeling by oversampling or undersampling. However, they also inherit the drawbacks of the preprocessing methods. Therefore, in this paper, we try to use similarity mapping to construct pseudo-sequences of majority instances. Then, according to the sliding window idea, we fully use all existing majority instances, and a novel sliding window-based selective ensemble learning method (SWSEL) is proposed to deal with the class-imbalance problem. This method uses the idea of distance alignment in multi-view alignment to align the centers of the minority instances with the majority instances, and slide to select the majority instances on the sequence of pseudo-majority instances. In addition, to prevent too many classifiers from leading to long running times, we use distance metric to select a certain number of base classifiers to build the final ensemble learning model. Extensive experimental results on various real-world datasets show that using SVM, MLP and RF as the base classifier, SWSEL achieves a statistically significant performance improvement on two evaluation metrics, AUC and G-mean, compared to state-of-the-art methods.

The Metropolis in Latin America, 1830–1930: Cityscapes Photographs Debates

The Metropolis in Latin America, 1830–1930: Cityscapes Photographs Debates