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1.
IEEE Trans Vis Comput Graph ; 30(6): 2968-2980, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38648150

RESUMO

Visually encoding quantitative information associated with graph links is an important problem in graph visualization. A conventional approach is to vary the thickness of lines to encode the strength of connections in node-link diagrams. In this paper, we present Sticky Links, a novel visual encoding method that draws graph links with stickiness. Taking the metaphor of links with glues, sticky links represent connection strength using spiky shapes, ranging from two broken spikes for weak connections to connected lines for strong connections. We conducted a controlled user study to compare the efficiency and aesthetic appeal of stickiness with conventional thickness encoding. Our results show that stickiness enables more effective and expressive quantitative encoding while maintaining the perception of node connectivity. Participants also found sticky links to be more aesthetic and less visually cluttering than conventional thickness encoding. Overall, our findings suggest that sticky links offer a promising alternative to conventional methods for encoding quantitative information in graphs.

2.
Food Funct ; 15(8): 4389-4398, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38563085

RESUMO

ß-Hydroxy-ß-methylbutyrate (HMB) is a breakdown product of leucine, which promotes muscle growth. Although some studies indicate that HMB activates AKT and mTOR, others show activation of the downstream effectors, P70S6K and S6, independent of mTOR. Our aim was to study the metabolic effect of HMB around the circadian clock in order to determine more accurately the signaling pathway involved. C2C12 myotubes were treated with HMB and clock, metabolic and myogenic markers were measured around the clock. HMB-treated C2C12 myotubes showed no activation of AKT and mTOR, but did show activation of P70S6K and S6. Activation of P70S6K and S6 was also found when myotubes were treated with HMB combined with metformin, an indirect mTOR inhibitor, or rapamycin, a direct mTOR inhibitor. The activation of the P70S6K and S6 independent of AKT and mTOR, was accompanied by increased activation of phospholipase D2 (PLD). In addition, HMB led to high amplitude and advanced circadian rhythms. In conclusion, HMB induces myogenesis in C2C12 by activating P70S6K and S6 via PLD2, rather than AKT and mTOR, leading to high amplitude advanced rhythms.


Assuntos
Ritmo Circadiano , Fibras Musculares Esqueléticas , Fosfolipase D , Valeratos , Valeratos/farmacologia , Animais , Fibras Musculares Esqueléticas/efeitos dos fármacos , Fibras Musculares Esqueléticas/metabolismo , Camundongos , Fosfolipase D/metabolismo , Ritmo Circadiano/efeitos dos fármacos , Linhagem Celular , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Desenvolvimento Muscular/efeitos dos fármacos
3.
Nat Hum Behav ; 8(4): 702-717, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38332339

RESUMO

Mental representations of familiar categories are composed of visual and semantic information. Disentangling the contributions of visual and semantic information in humans is challenging because they are intermixed in mental representations. Deep neural networks that are trained either on images or on text or by pairing images and text enable us now to disentangle human mental representations into their visual, visual-semantic and semantic components. Here we used these deep neural networks to uncover the content of human mental representations of familiar faces and objects when they are viewed or recalled from memory. The results show a larger visual than semantic contribution when images are viewed and a reversed pattern when they are recalled. We further reveal a previously unknown unique contribution of an integrated visual-semantic representation in both perception and memory. We propose a new framework in which visual and semantic information contribute independently and interactively to mental representations in perception and memory.


Assuntos
Rememoração Mental , Redes Neurais de Computação , Semântica , Percepção Visual , Humanos , Feminino , Masculino , Rememoração Mental/fisiologia , Percepção Visual/fisiologia , Adulto , Adulto Jovem , Reconhecimento Psicológico/fisiologia , Reconhecimento Facial/fisiologia , Memória/fisiologia
4.
IEEE Trans Vis Comput Graph ; 29(8): 3519-3534, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35353702

RESUMO

Synthesizing human motion with a global structure, such as a choreography, is a challenging task. Existing methods tend to concentrate on local smooth pose transitions and neglect the global context or the theme of the motion. In this work, we present a music-driven motion synthesis framework that generates long-term sequences of human motions which are synchronized with the input beats, and jointly form a global structure that respects a specific dance genre. In addition, our framework enables generation of diverse motions that are controlled by the content of the music, and not only by the beat. Our music-driven dance synthesis framework is a hierarchical system that consists of three levels: pose, motif, and choreography. The pose level consists of an LSTM component that generates temporally coherent sequences of poses. The motif level guides sets of consecutive poses to form a movement that belongs to a specific distribution using a novel motion perceptual-loss. And the choreography level selects the order of the performed movements and drives the system to follow the global structure of a dance genre. Our results demonstrate the effectiveness of our music-driven framework to generate natural and consistent movements on various dance types, having control over the content of the synthesized motions, and respecting the overall structure of the dance.


Assuntos
Dança , Música , Humanos , Percepção Auditiva , Gráficos por Computador , Movimento
5.
IEEE Trans Image Process ; 31: 3726-3736, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35594231

RESUMO

Convolutional layers are the core building blocks of Convolutional Neural Networks (CNNs). In this paper, we propose to augment a convolutional layer with an additional depthwise convolution, where each input channel is convolved with a different 2D kernel. The composition of the two convolutions constitutes an over-parameterization, since it adds learnable parameters, while the resulting linear operation can be expressed by a single convolution layer. We refer to this depthwise over-parameterized convolutional layer as DO-Conv, which is a novel way of over-parameterization. We show with extensive experiments that the mere replacement of conventional convolutional layers with DO-Conv layers boosts the performance of CNNs on many classical vision tasks, such as image classification, detection, and segmentation. Moreover, in the inference phase, the depthwise convolution is folded into the conventional convolution, reducing the computation to be exactly equivalent to that of a convolutional layer without over-parameterization. As DO-Conv introduces performance gains without incurring any computational complexity increase for inference, we advocate it as an alternative to the conventional convolutional layer. We open sourced an implementation of DO-Conv in Tensorflow, PyTorch and GluonCV at https://github.com/yangyanli/DO-Conv.

6.
IEEE Trans Vis Comput Graph ; 28(7): 2628-2640, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33175679

RESUMO

Static visual attributes such as color and shape are used with great success in visual charts designed to be displayed in static, hard-copy form. However, nowadays digital displays become ubiquitous in the visualization of any form of data, lifting the confines of static presentations. In this article, we propose incorporating data-driven animations to bring static charts to life, with the purpose of encoding and emphasizing certain attributes of the data. We lay out a design space for data-driven animated effects and experiment with three versatile effects, marching ants, geometry deformation and gradual appearance. For each, we provide practical details regarding their mode of operation and extent of interaction with existing visual encodings. We examine the impact and effectiveness of our enhancements through an empirical user study to assess preference as well as gauge the influence of animated effects on human perception in terms of speed and accuracy of visual understanding.

7.
IEEE Trans Vis Comput Graph ; 28(12): 4503-4514, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34170827

RESUMO

Recently, many deep neural networks were designed to process 3D point clouds, but a common drawback is that rotation invariance is not ensured, leading to poor generalization to arbitrary orientations. In this article, we introduce a new low-level purely rotation-invariant representation to replace common 3D Cartesian coordinates as the network inputs. Also, we present a network architecture to embed these representations into features, encoding local relations between points and their neighbors, and the global shape structure. To alleviate inevitable global information loss caused by the rotation-invariant representations, we further introduce a region relation convolution to encode local and non-local information. We evaluate our method on multiple point cloud analysis tasks, including (i) shape classification, (ii) part segmentation, and (iii) shape retrieval. Extensive experimental results show that our method achieves consistent, and also the best performance, on inputs at arbitrary orientations, compared with all the state-of-the-art methods.

8.
IEEE Trans Vis Comput Graph ; 28(12): 4304-4318, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34077360

RESUMO

Rigid registration of partial observations is a fundamental problem in various applied fields. In computer graphics, special attention has been given to the registration between two partial point clouds generated by scanning devices. State-of-the-art registration techniques still struggle when the overlap region between the two point clouds is small, and completely fail if there is no overlap between the scan pairs. In this article, we present a learning-based technique that alleviates this problem, and allows registration between point clouds, presented in arbitrary poses, and having little or even no overlap, a setting that has been referred to as tele-registration. Our technique is based on a novel neural network design that learns a prior of a class of shapes and can complete a partial shape. The key idea is combining the registration and completion tasks in a way that reinforces each other. In particular, we simultaneously train the registration network and completion network using two coupled flows, one that register-and-complete, and one that complete-and-register, and encourage the two flows to produce a consistent result. We show that, compared with each separate flow, this two-flow training leads to robust and reliable tele-registration, and hence to a better point cloud prediction that completes the registered scans. It is also worth mentioning that each of the components in our neural network outperforms state-of-the-art methods in both completion and registration. We further analyze our network with several ablation studies and demonstrate its performance on a large number of partial point clouds, both synthetic and real-world, that have only small or no overlap.

9.
Comput Vis Media (Beijing) ; 6(4): 385-400, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33194253

RESUMO

Visualizing high-dimensional data on a 2D canvas is generally challenging. It becomes significantly more difficult when multiple time-steps are to be presented, as the visual clutter quickly increases. Moreover, the challenge to perceive the significant temporal evolution is even greater. In this paper, we present a method to plot temporal high-dimensional data in a static scatterplot; it uses the established PCA technique to project data from multiple time-steps. The key idea is to extend each individual displacement prior to applying PCA, so as to skew the projection process, and to set a projection plane that balances the directions of temporal change and spatial variance. We present numerous examples and various visual cues to highlight the data trajectories, and demonstrate the effectiveness of the method for visualizing temporal data.

10.
IEEE Trans Vis Comput Graph ; 26(1): 770-779, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31562094

RESUMO

This work proposes Winglets, an enhancement to the classic scatterplot to better perceptually pronounce multiple classes by improving the perception of association and uncertainty of points to their related cluster. Designed as a pair of dual-sided strokes belonging to a data point, Winglets leverage the Gestalt principle of Closure to shape the perception of the form of the clusters, rather than use an explicit divisive encoding. Through a subtle design of two dominant attributes, length and orientation, Winglets enable viewers to perform a mental completion of the clusters. A controlled user study was conducted to examine the efficiency of Winglets in perceiving the cluster association and the uncertainty of certain points. The results show Winglets form a more prominent association of points into clusters and improve the perception of associating uncertainty.

11.
IEEE Trans Pattern Anal Mach Intell ; 42(7): 1791-1797, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31251176

RESUMO

In this paper, we present a novel non-parametric clustering technique. Our technique is based on the notion that each latent cluster is comprised of layers that surround its core, where the external layers, or border points, implicitly separate the clusters. Unlike previous techniques, such as DBSCAN, where the cores of the clusters are defined directly by their densities, here the latent cores are revealed by a progressive peeling of the border points. Analyzing the density of the local neighborhoods allows identifying the border points and associating them with points of inner layers. We show that the peeling process adapts to the local densities and characteristics to successfully separate adjacent clusters (of possibly different densities). We extensively tested our technique on large sets of labeled data, including high-dimensional datasets of deep features that were trained by a convolutional neural network. We show that our technique is competitive to other state-of-the-art non-parametric methods using a fixed set of parameters throughout the experiments.

12.
Crisis ; 41(3): 156-162, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31418311

RESUMO

Background: Victimization by bullying among adolescents is a widespread phenomenon associated with depression and suicidal ideation. Coping with bullying may include aggressive responding and self-blame. Aims: The purpose of this study was to examine the role adolescent self-blame and aggression - representing coping with peer bullying - in depression and suicide ideation. Method: We recruited 97 "pure" victims (41 girls; mean age = 12.69, SD = .80) identified from a sample of 505 adolescents (242 girls; mean age = 12.73, SD = .81) from two Israeli high schools. Self-report questionnaires were used to assess victimization, aggressive responses, self-blame, depression, and suicide ideation. Results: Self-blame in the face of peer bullying was uniquely associated with both depression and suicide ideation. The effect was robust even after controlling for level of victimization. No direct effect of aggressive coping or moderating effects of self-blame or aggression on the association between victimization and depression/suicide ideation were found. Limitations: This study used a cross-sectional design and made exclusive use of self-report measures. Conclusion: Adolescents who blame themselves for being bullied might be at a heightened risk for depression and suicidality compared to adolescents who did not use self-blame.


Assuntos
Adaptação Psicológica , Bullying/estatística & dados numéricos , Depressão/epidemiologia , Grupo Associado , Ideação Suicida , Adolescente , Agressão , Bullying/psicologia , Criança , Vítimas de Crime/psicologia , Vítimas de Crime/estatística & dados numéricos , Estudos Transversais , Depressão/psicologia , Feminino , Humanos , Israel/epidemiologia , Modelos Lineares , Modelos Logísticos , Masculino , Autorrelato
13.
IEEE Comput Graph Appl ; 39(4): 16-27, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31226057

RESUMO

Recently, there has been increasing interest to leverage the competence of neural networks to analyze data. In particular, new clustering methods that employ deep embeddings have been presented. In this paper, we depart from centroid-based models and suggest a new framework, called Clustering-driven deep embedding with PAirwise Constraints (CPAC), for nonparametric clustering using a neural network. We present a clustering-driven embedding based on a Siamese network that encourages pairs of data points to output similar representations in the latent space. Our pair-based model allows augmenting the information with labeled pairs to constitute a semi-supervised framework. Our approach is based on analyzing the losses associated with each pair to refine the set of constraints. We show that clustering performance increases when using this scheme, even with a limited amount of user queries. We demonstrate how our architecture is adapted for various types of data and present the first deep framework to cluster three-dimensional (3-D) shapes.

14.
IEEE Trans Vis Comput Graph ; 25(6): 2217-2227, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29994049

RESUMO

We introduce a data-driven method to generate a large number of plausible, closely interacting 3D human pose-pairs, for a given motion category, e.g., wrestling or salsa dance. With much difficulty in acquiring close interactions using 3D sensors, our approach utilizes abundant existing video data which cover many human activities. Instead of treating the data generation problem as one of reconstruction, either through 3D acquisition or direct 2D-to-3D data lifting from video annotations, we present a solution based on Markov Chain Monte Carlo (MCMC) sampling. Given a motion category and a set of video frames depicting the motion with the 2D pose-pair in each frame annotated, we start the sampling with one or few seed 3D pose-pairs which are manually created based on the target motion category. The initial set is then augmented by MCMC sampling around the seeds, via the Metropolis-Hastings algorithm and guided by a probability density function (PDF) that is defined by two terms to bias the sampling towards 3D pose-pairs that are physically valid and plausible for the motion category. With a focus on efficient sampling over the space of close interactions, rather than pose spaces, we develop a novel representation called interaction coordinates (IC) to encode both poses and their interactions in an integrated manner. Plausibility of a 3D pose-pair is then defined based on the IC and with respect to the annotated 2D pose-pairs from video. We show that our sampling-based approach is able to efficiently synthesize a large volume of plausible, closely interacting 3D pose-pairs which provide a good coverage of the input 2D pose-pairs.

15.
IEEE Trans Pattern Anal Mach Intell ; 41(9): 2273-2279, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-29994700

RESUMO

Multi-dimensional scaling (MDS) plays a central role in data-exploration, dimensionality reduction and visualization. State-of-the-art MDS algorithms are not robust to outliers, yielding significant errors in the embedding even when only a handful of outliers are present. In this paper, we introduce a technique to detect and filter outliers based on geometric reasoning. We test the validity of triangles formed by three points, and mark a triangle as broken if its triangle inequality does not hold. The premise of our work is that unlike inliers, outlier distances tend to break many triangles. Our method is tested and its performance is evaluated on various datasets and distributions of outliers. We demonstrate that for a reasonable amount of outliers, e.g., under 20 percent, our method is effective, and leads to a high embedding quality.

16.
IEEE Trans Pattern Anal Mach Intell ; 40(10): 2529-2537, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-28945589

RESUMO

We present a structure-aware technique to consolidate noisy data, which we use as a pre-process for standard clustering and dimensionality reduction. Our technique is related to mean shift, but instead of seeking density modes, it reveals and consolidates continuous high density structures such as curves and surface sheets in the underlying data while ignoring noise and outliers. We provide a theoretical analysis under a Gaussian noise model, and show that our approach significantly improves the performance of many non-linear dimensionality reduction and clustering algorithms in challenging scenarios.

17.
J Control Release ; 209: 47-56, 2015 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-25910578

RESUMO

Implant-associated bone infections caused by antibiotic-resistant pathogens pose significant clinical challenges to treating physicians. Prophylactic strategies that act against resistant organisms, such as methicillin-resistant Staphylococcus aureus (MRSA), are urgently required. In the present study, we investigated the efficacy of a biodegradable Polymer-Lipid Encapsulation MatriX (PLEX) loaded with the antibiotic doxycycline as a local prophylactic strategy against implant-associated osteomyelitis. Activity was tested against both a doxycycline-susceptible (doxy(S)) methicillin-susceptible S. aureus (MSSA) as well as a doxycycline-resistant (doxy(R)) methicillin-resistant S. aureus (MRSA). In vitro elution studies revealed that 25% of the doxycycline was released from the PLEX-coated implants within the first day, followed by a 3% release per day up to day 28. The released doxycycline was highly effective against doxy(S) MSSA for at least 14days in vitro. A bolus injection of doxycycline mimicking a one day release from the PLEX-coating reduced, but did not eliminate, mouse subcutaneous implant-associated infection (doxy(S) MSSA). In a rabbit intramedullary nail-related infection model, all rabbits receiving a PLEX-doxycycline-coated nail were culture negative in the doxy(S) MSSA-group and the surrounding bone displayed a normal physiological appearance in both histological sections and radiographs. In the doxy(R) MRSA inoculated rabbits, a statistically significant reduction in the number of culture-positive samples was observed for the PLEX-doxycycline-coated group when compared to the animals that had received an uncoated nail, although the reduction in bacterial burden did not reach statistical significance. In conclusion, the PLEX-doxycycline coating on titanium alloy implants provided complete protection against implant-associated MSSA osteomyelitis, and resulted in a significant reduction in the number of culture positive samples when challenged with a doxycycline-resistant MRSA.


Assuntos
Antibacterianos/administração & dosagem , Doxiciclina/administração & dosagem , Staphylococcus aureus Resistente à Meticilina , Osteomielite/prevenção & controle , Infecções Estafilocócicas/prevenção & controle , Animais , Antibacterianos/química , Antibacterianos/uso terapêutico , Doxiciclina/química , Doxiciclina/uso terapêutico , Liberação Controlada de Fármacos , Farmacorresistência Bacteriana , Feminino , Lipídeos/química , Camundongos Endogâmicos C57BL , Polímeros/química , Próteses e Implantes , Coelhos , Titânio
18.
PLoS One ; 8(10): e74970, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24130678

RESUMO

Advanced Glycation End Products (AGEs) are the final products of non-enzymatic protein glycation that results in loss of protein structure and function. We have previously shown that in E. coli AGEs are continually formed as high-molecular weight protein complexes. Moreover, we showed that AGEs are removed from the cells by an active, ATP-dependent secretion and that these secreted molecules have low molecular weight. Taken together, these results indicate that E. coli contains a fraction of low molecular weight AGEs, in addition to the high-molecular weight AGEs. Here we show that the low-molecular weight AGEs originate from high-molecular weight AGEs by proteolytic degradation. Results of in-vitro and in vivo experiments indicated that this degradation is carried out not by the major ATP-dependent proteases that are responsible for the main part of bacterial protein quality control but by an alternative metal-dependent proteolysis. This proteolytic reaction is essential for the further secretion of AGEs from the cells. As the biochemical reactions involving AGEs are not yet understood, the implication of a metalloprotease in breakdown of high molecular weight AGEs and their secretion constitutes an important step in the understanding of AGEs metabolism.


Assuntos
Produtos Finais de Glicação Avançada/metabolismo , Arseniatos/farmacologia , Cloranfenicol/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/metabolismo , Metaloendopeptidases/antagonistas & inibidores
19.
J Chem Theory Comput ; 9(11): 4744-60, 2013 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-26583393

RESUMO

We present a fully numerical multigrid approach for solving the all-electron Kohn-Sham equation in molecules. The equation is represented on a hierarchy of Cartesian grids, from coarse ones that span the entire molecule to very fine ones that describe only a small volume around each atom. This approach is adaptable to any type of geometry. We demonstrate it for a variety of small molecules and obtain high accuracy agreement with results obtained previously for diatomic molecules using a prolate-spheroidal grid. We provide a detailed presentation of the numerical methodology and discuss possible extensions of this approach.

20.
IEEE Comput Graph Appl ; 33(4): 62-72, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24808060

RESUMO

A new system provides a virtual experience akin to trying on clothing. It clones the user's photographic image into a catalog of images of models wearing the desired garments. Simple offline training extracts the user's head. Segmentation accurately separates the face, hair, and background, employing both a three-kernel statistical model and graph cuts. The system adjusts the resulting image's skin color according to a statistical model and relights the head via spherical harmonics. Finally, using a parametric model, the system warps the clone's body dimensions to fit the user's dimensions. This creates high-quality compositions of the user's image and the given garment.

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