bluuebunny/crossref_metadata_2025 huggingface dataset:
Exertion-aware path generation
Authors: Li Wanwan , Xie Biao , Zhang Yongqi , Meiss Walter , Huang Haikun , Yu Lap-Fai
Published: August 2020

We propose a novel approach for generating paths with desired exertion properties, which can be used for delivering highly realistic and immersive virtual reality applications that help users achieve exertion goals. Given a terrain as input, our optimization-based approach automatically generates feasible paths on the terrain which users can bike to perform body training in virtual reality. The approach considers exertion properties such as the total work and the perceived level of path difficulty in generating the paths. To verify our approach, we applied it to generate paths on a variety of terrains with different exertion targets and constraints. To conduct our user studies, we built an exercise bike whose force feedback was controlled by the elevation angle of the generated path over the terrain. Our user study results showed that users found exercising with our generated paths in virtual reality more enjoyable compared to traditional exercising approaches. Their energy expenditure in biking the generated paths also matched with the specified targets, validating the efficacy of our approach.
Fast and deep facial deformations
Authors: Bailey Stephen W. , Omens Dalton , Dilorenzo Paul , O'Brien James F.
Published: August 2020

Film-quality characters typically display highly complex and expressive facial deformation. The underlying rigs used to animate the deformations of a character's face are often computationally expensive, requiring high-end hardware to deform the mesh at interactive rates. In this paper, we present a method using convolutional neural networks for approximating the mesh deformations of characters' faces. For the models we tested, our approximation runs up to 17 times faster than the original facial rig while still maintaining a high level of fidelity to the original rig. We also propose an extension to the approximation for handling high-frequency deformations such as fine skin wrinkles. While the implementation of the original animation rig depends on an extensive set of proprietary libraries making it difficult to install outside of an in-house development environment, our fast approximation relies on the widely available and easily deployed TensorFlow libraries. In addition to allowing high frame rate evaluation on modest hardware and in a wide range of computing environments, the large speed increase also enables interactive inverse kinematics on the animation rig. We demonstrate our approach and its applicability through interactive character posing and real-time facial performance capture.
PolyFit
Authors: Dominici Edoardo Alberto , Schertler Nico , Griffin Jonathan , Hoshyari Shayan , Sigal Leonid , Sheffer Alla
Published: August 2020

Raster clip-art images, which consist of distinctly colored regions separated by sharp boundaries typically allow for a clear mental vector interpretation. Converting these images into vector format can facilitate compact lossless storage and enable numerous processing operations. Despite recent progress, existing vectorization methods that target such data frequently produce vectorizations that fail to meet viewer expectations. We present
PolyFit
, a new clip-art vectorization method that produces vectorizations well aligned with human preferences. Since segmentation of such inputs into regions had been addressed successfully, we specifically focus on fitting piecewise smooth vector curves to the raster input region boundaries, a task prior methods are particularly prone to fail on. While perceptual studies suggest the criteria humans are likely to use during mental boundary vectorization, they provide no guidance as to the exact interaction between them; learning these interactions directly is problematic due to the large size of the solution space. To obtain the desired solution, we first approximate the raster region boundaries with coarse intermediate polygons leveraging a combination of perceptual cues with observations from studies of human preferences. We then use these intermediate polygons as auxiliary inputs for computing piecewise smooth vectorizations of raster inputs. We define a finite set of potential polygon to curve primitive maps, and learn the mapping from the polygons to their best fitting primitive configurations from human annotations, arriving at a compact set of local raster and polygon properties whose combinations reliably predict human-expected primitive choices. We use these primitives to obtain a final globally consistent spline vectorization. Extensive comparative user studies show that our method outperforms state-of-the-art approaches on a wide range of data, where our results are preferred three times as often as those of the closest competitor across multiple types of inputs with various resolutions.
Adaptive merging for rigid body simulation
Authors: Coevoet Eulalie , Benchekroun Otman , Kry Paul G.
Published: August 2020

We reduce computation time in rigid body simulations by merging collections of bodies when they share a common spatial velocity. Merging relies on monitoring the state of contacts, and a metric that compares the relative linear and angular motion of bodies based on their sizes. Unmerging relies on an inexpensive single iteration projected Gauss-Seidel sweep over contacts between merged bodies, which lets us update internal contact forces over time, and use the same metrics as merging to identify when bodies should unmerge. Furthermore we use a contact ordering for graph traversal refinement of the internal contact forces in collections, which helps to correctly identify all the bodies that must unmerge when there are impacts. The general concept of merging is similar to the common technique of sleeping and waking rigid bodies in the inertial frame, and we exploit this too, but our merging is in moving frames, and unmerging takes place at contacts between bodies rather than at the level of bodies themselves. We discuss the previous relative motion metrics in comparison to ours, and evaluate our method on a variety of scenarios.
One shot 3D photography
Authors: Kopf Johannes , Matzen Kevin , Alsisan Suhib , Quigley Ocean , Ge Francis , Chong Yangming , Patterson Josh , Frahm Jan-Michael , Wu Shu , Yu Matthew , Zhang Peizhao , He Zijian , Vajda Peter , Saraf Ayush , Cohen Michael
Published: August 2020

3D photography is a new medium that allows viewers to more fully experience a captured moment. In this work, we refer to a
3D photo
as one that displays parallax induced by moving the viewpoint (as opposed to a stereo pair with a fixed viewpoint). 3D photos are static in time, like traditional photos, but are displayed with interactive parallax on mobile or desktop screens, as well as on Virtual Reality devices, where viewing it
also
includes stereo. We present an end-to-end system for creating and viewing 3D photos, and the algorithmic and design choices therein. Our 3D photos are captured in a single shot and processed directly on a mobile device. The method starts by estimating depth from the 2D input image using a new monocular depth estimation network that is optimized for mobile devices. It performs competitively to the state-of-the-art, but has lower latency and peak memory consumption and uses an order of magnitude fewer parameters. The resulting depth is lifted to a layered depth image, and new geometry is synthesized in parallax regions. We synthesize color texture and structures in the parallax regions as well, using an inpainting network, also optimized for mobile devices, on the LDI directly. Finally, we convert the result into a mesh-based representation that can be efficiently transmitted and rendered even on low-end devices and over poor network connections. Altogether, the processing takes just a few seconds on a mobile device, and the result can be instantly viewed and shared. We perform extensive quantitative evaluation to validate our system and compare its new components against the current state-of-the-art.
Robust fitting of parallax-aware mixtures for path guiding
Authors: Ruppert Lukas , Herholz Sebastian , Lensch Hendrik P. A.
Published: August 2020

Effective local light transport guiding demands for high quality guiding information, i.e., a precise representation of the directional incident radiance distribution at every point inside the scene. We introduce a parallax-aware distribution model based on parametric mixtures. By parallax-aware warping of the distribution, the local approximation of the 5D radiance field remains valid and precise across large spatial regions, even for close-by contributors. Our robust optimization scheme fits parametric mixtures to radiance samples collected in previous rendering passes. Robustness is achieved by splitting and merging of components refining the mixture. These splitting and merging decisions minimize and bound the expected variance of the local radiance estimator. In addition, we extend the fitting scheme to a robust, iterative update method, which allows for incremental training of our model using smaller sample batches. This results in more frequent training updates and, at the same time, significantly reduces the required sample memory footprint. The parametric representation of our model allows for the application of advanced importance sampling methods such as radiance-based, cosine-aware, and even product importance sampling. Our method further smoothly integrates next-event estimation (NEE) into path guiding, avoiding importance sampling of contributions better covered by NEE. The proposed robust fitting and update scheme, in combination with the parallax-aware representation, results in faster learning and lower variance compared to state-of-the-art path guiding approaches.
Character controllers using motion VAEs
Authors: Ling Hung Yu , Zinno Fabio , Cheng George , Van De Panne Michiel
Published: August 2020

A fundamental problem in computer animation is that of realizing purposeful and realistic human movement given a sufficiently-rich set of motion capture clips. We learn data-driven generative models of human movement using autoregressive conditional variational autoencoders, or Motion VAEs. The latent variables of the learned autoencoder define the action space for the movement and thereby govern its evolution over time. Planning or control algorithms can then use this action space to generate desired motions. In particular, we use deep reinforcement learning to learn controllers that achieve goal-directed movements. We demonstrate the effectiveness of the approach on multiple tasks. We further evaluate system-design choices and describe the current limitations of Motion VAEs.
Example-driven virtual cinematography by learning camera behaviors
Authors: Jiang Hongda , Wang Bin , Wang Xi , Christie Marc , Chen Baoquan
Published: August 2020

Designing a camera motion controller that has the capacity to move a virtual camera automatically in relation with contents of a 3D animation, in a cinematographic and principled way, is a complex and challenging task. Many cinematographic rules exist, yet practice shows there are significant stylistic variations in how these can be applied.

In this paper, we propose an example-driven camera controller which can extract camera behaviors from an example film clip and re-apply the extracted behaviors to a 3D animation, through learning from a collection of camera motions. Our first technical contribution is the design of a low-dimensional cinematic feature space that captures the essence of a film's cinematic characteristics (camera angle and distance, screen composition and character configurations) and which is coupled with a neural network to automatically extract these cinematic characteristics from real film clips. Our second technical contribution is the design of a cascaded deep-learning architecture trained to (i) recognize a variety of camera motion behaviors from the extracted cinematic features, and (ii) predict the future motion of a virtual camera given a character 3D animation. We propose to rely on a Mixture of Experts (MoE) gating+prediction mechanism to ensure that distinct camera behaviors can be learned while ensuring generalization.

We demonstrate the features of our approach through experiments that highlight (i) the quality of our cinematic feature extractor (ii) the capacity to learn a range of behaviors through the gating mechanism, and (iii) the ability to generate a variety of camera motions by applying different behaviors extracted from film clips. Such an example-driven approach offers a high level of controllability which opens new possibilities toward a deeper understanding of cinematographic style and enhanced possibilities in exploiting real film data in virtual environments.
Continuous multiple importance sampling
Authors: West Rex , Georgiev Iliyan , Gruson Adrien , Hachisuka Toshiya
Published: August 2020

Multiple importance sampling (MIS) is a provably good way to combine a finite set of sampling techniques to reduce variance in Monte Carlo integral estimation. However, there exist integration problems for which a continuum of sampling techniques is available. To handle such cases we establish a continuous MIS (CMIS) formulation as a generalization of MIS to uncountably infinite sets of techniques. Our formulation is equipped with a base estimator that is coupled with a provably optimal balance heuristic and a practical stochastic MIS (SMIS) estimator that makes CMIS accessible to a broad range of problems. To illustrate the effectiveness and utility of our framework, we apply it to three different light transport applications, showing improved performance over the prior state-of-the-art techniques.
A massively parallel and scalable multi-GPU material point method
Authors: Wang Xinlei , Qiu Yuxing , Slattery Stuart R. , Fang Yu , Li Minchen , Zhu Song-Chun , Zhu Yixin , Tang Min , Manocha Dinesh , Jiang Chenfanfu
Published: August 2020

Harnessing the power of modern multi-GPU architectures, we present a massively parallel simulation system based on the Material Point Method (MPM) for simulating physical behaviors of materials undergoing complex topological changes, self-collision, and large deformations. Our system makes three critical contributions. First, we introduce a new particle data structure that promotes coalesced memory access patterns on the GPU and eliminates the need for complex atomic operations on the memory hierarchy when writing particle data to the grid. Second, we propose a kernel fusion approach using a new Grid-to-Particles-to-Grid (
G2P2G
) scheme, which efficiently reduces GPU kernel launches, improves latency, and significantly reduces the amount of global memory needed to store particle data. Finally, we introduce optimized algorithmic designs that allow for efficient sparse grids in a shared memory context, enabling us to best utilize modern multi-GPU computational platforms for hybrid Lagrangian-Eulerian computational patterns. We demonstrate the effectiveness of our method with extensive benchmarks, evaluations, and dynamic simulations with elastoplasticity, granular media, and fluid dynamics. In comparisons against an open-source and heavily optimized CPU-based MPM codebase [Fang et al. 2019] on an elastic sphere colliding scene with particle counts ranging from 5 to 40 million, our GPU MPM achieves over 100x per-time-step speedup on a workstation with an Intel 8086K CPU and a single Quadro P6000 GPU, exposing exciting possibilities for future MPM simulations in computer graphics and computational science. Moreover, compared to the state-of-the-art GPU MPM method [Hu et al. 2019a], we not only achieve 2x acceleration on a single GPU but our kernel fusion strategy and Array-of-Structs-of-Array (
AoSoA
) data structure design also generalizes to multi-GPU systems. Our multi-GPU MPM exhibits near-perfect weak and strong scaling with 4 GPUs, enabling performant and large-scale simulations on a 1024
3
grid with close to 100 million particles with less than 4 minutes per frame on a single 4-GPU workstation and 134 million particles with less than 1 minute per frame on an 8-GPU workstation.
Local motion phases for learning multi-contact character movements
Authors: Starke Sebastian , Zhao Yiwei , Komura Taku , Zaman Kazi
Published: August 2020

Training a bipedal character to play basketball and interact with objects, or a quadruped character to move in various locomotion modes, are difficult tasks due to the fast and complex contacts happening during the motion. In this paper, we propose a novel framework to learn fast and dynamic character interactions that involve multiple contacts between the body and an object, another character and the environment, from a rich, unstructured motion capture database. We use one-on-one basketball play and character interactions with the environment as examples. To achieve this task, we propose a novel feature called local motion phase, that can help neural networks to learn asynchronous movements of each bone and its interaction with external objects such as a ball or an environment. We also propose a novel generative scheme to reproduce a wide variation of movements from abstract control signals given by a gamepad, which can be useful for changing the style of the motion under the same context. Our scheme is useful for animating contact-rich, complex interactions for real-time applications such as computer games.
RoboCut
Authors: Duenser Simon , Poranne Roi , Thomaszewski Bernhard , Coros Stelian
Published: August 2020

Hot-wire cutting is a subtractive fabrication technique used to carve foam and similar materials. Conventional machines rely on straight wires and are thus limited to creating piecewise ruled surfaces. In this work, we propose a method that exploits a dual-arm robot setup to actively control the shape of a flexible, heated rod as it cuts through the material. While this setting offers great freedom of shape, using it effectively requires concurrent reasoning about three tightly coupled sub-problems: 1) modeling the way in which the shape of the rod and the surface it sweeps are governed by the robot's motions; 2) approximating a target shape through a sequence of surfaces swept by the equilibrium shape of an elastic rod; and 3) generating collision-free motion trajectories that lead the robot to create desired sweeps with the deformable tool. We present a computational framework for robotic hot wire cutting that addresses all three sub-problems in a unified manner. We evaluate our approach on a set of simulated results and physical artefacts generated with our robotic fabrication system.
Catch & Carry
Authors: Merel Josh , Tunyasuvunakool Saran , Ahuja Arun , Tassa Yuval , Hasenclever Leonard , Pham Vu , Erez Tom , Wayne Greg , Heess Nicolas
Published: August 2020

We address the longstanding challenge of producing flexible, realistic humanoid character controllers that can perform diverse whole-body tasks involving object interactions. This challenge is central to a variety of fields, from graphics and animation to robotics and motor neuroscience. Our physics-based environment uses realistic actuation and first-person perception - including touch sensors and egocentric vision - with a view to producing active-sensing behaviors (e.g. gaze direction), transferability to real robots, and comparisons to the biology. We develop an integrated neural-network based approach consisting of a motor primitive module, human demonstrations, and an instructed reinforcement learning regime with curricula and task variations. We demonstrate the utility of our approach for several tasks, including goal-conditioned box carrying and ball catching, and we characterize its behavioral robustness. The resulting controllers can be deployed in real-time on a standard PC.
1
Compositional neural scene representations for shading inference
Authors: Granskog Jonathan , Rousselle Fabrice , Papas Marios , Novák Jan
Published: August 2020

We present a technique for adaptively partitioning neural scene representations. Our method disentangles lighting, material, and geometric information yielding a scene representation that preserves the orthogonality of these components, improves interpretability of the model, and allows compositing new scenes by mixing components of existing ones. The proposed adaptive partitioning respects the uneven entropy of individual components and permits compressing the scene representation to lower its memory footprint and potentially reduce the evaluation cost of the model. Furthermore, the partitioned representation enables an in-depth analysis of existing image generators. We compare the flow of information through individual partitions, and by contrasting it to the impact of additional inputs (G-buffer), we are able to identify the roots of undesired visual artifacts, and propose one possible solution to remedy the poor performance. We also demonstrate the benefits of complementing traditional forward renderers by neural representations and synthesis, e.g. to infer expensive shading effects, and show how these could improve production rendering in the future if developed further.
Skeletal tissue regulation by catalase overexpression in mitochondria
Authors: Schreurs Ann-Sofie , Torres Samantha , Truong Tiffany , Moyer Eric L. , Kumar Akhhilesh , Tahimic Candice G. T. , Alwood Joshua S. , Globus Ruth K.
Published: August 2020

Accumulation of oxidative damage from excess reactive oxygen species (ROS) may contribute to skeletal aging and mediate adverse responses to physiological challenges. Wild-type (WT) mice and transgenic mice (male, 16 wk of age) with human catalase targeted to the mitochondria (mCAT) were analyzed for skeletal responses to the remodeling stimuli of combined hind-limb unloading and exposure to ionizing radiation (137Cs, 2 Gy). Treatment for 2 wk caused lipid peroxidation in the bones WT but not mCAT mice, showing that transgene expression mitigated oxidative stress. Ex vivo osteoblast colony growth rate was 95% greater in mCAT than WT mice and correlated with catalase activity levels ( P < 0.005, r = 0.67), although terminal osteoblast and osteoclast differentiation were unaffected. mCAT mice had lower cancellous bone volume and cortical size than WT mice. Ambulatory control mCAT animals also displayed reduced cancellous and cortical structural properties compared with control WT mice. In mCAT but not WT mice, treatment caused an unexpectedly rapid radial expansion (+8% cortical area, +22% moment of inertia), reminiscent of compensatory bone growth during advancing age. In contrast, treatment caused similar structural deficits in cancellous tissue of mCAT and WT mice. In sum, mitochondrial ROS signaling via H2O2 was important for the acquisition of adult bone structure and catalase overexpression failed to protect cancellous tissue from treatment. In contrast, catabolic stimuli caused radial expansion in mCAT not WT mice, suggesting that mitochondrial ROS in skeletal cells act to suppress tissue turnover in response to remodeling challenges.
Moving human muscle physiology research forward: an evaluation of fiber type-specific protein research methodologies
Authors: Tobias Irene S. , Galpin Andrew J.
Published: August 2020

Human skeletal muscle is a heterogeneous tissue composed of multiple fiber types that express unique contractile and metabolic properties. While analysis of mixed fiber samples predominates and holds value, increasing attention has been directed toward studying proteins segregated by fiber type, a methodological distinction termed “fiber type-specific.” Fiber type-specific protein studies have the advantage of uncovering key molecular effects that are often missed in mixed fiber homogenate studies but also require greater time and resource-intensive methods, particularly when applied to human muscle. This review summarizes and compares current methods used for fiber type-specific protein analysis, highlighting their advantages and disadvantages for human muscle studies, in addition to recent advances in these techniques. These methods can be grouped into three categories based on the initial processing of the tissue: 1) muscle-specific fiber homogenates, 2) cross sections of fiber bundles, and 3) isolated single fibers, with various subtechniques for performing fiber type identification and protein quantification. The relative implementation for each unique methodological approach is analyzed from 83 fiber type-specific studies of proteins in live human muscle found in the literature to date. These studies have investigated several proteins involved in a wide range of cellular functions that are important to muscle tissue. The second half of this review summarizes key findings from this ensemble of fiber type-specific human protein studies. We highlight examples of where this analytical approach has helped to improve understanding of important physiological topics such as insulin sensitivity, muscle hypertrophy, muscle fatigue, and adaptation to different exercise programs.
Generation and optimization of highly pure motor neurons from human induced pluripotent stem cells via lentiviral delivery of transcription factors
Authors: Sepehrimanesh Masood , Ding Baojin
Published: August 2020

Generation of neurons from human induced pluripotent stem cells (hiPSCs) overcomes the limited access to human brain samples and greatly facilitates the progress of research in neurological diseases. However, it is still a challenge to generate a particular neuronal subtype with high purity and yield for determining the pathogenesis of diseased neurons using biochemical approaches. Motor neurons (MNs) are a specialized neuronal subtype responsible for governing both autonomic and volitional movement. Dysfunctions in MNs are implicated in a variety of movement diseases, such as amyotrophic lateral sclerosis (ALS). In this study, we generated functional MNs from human iPSCs via lentiviral delivery of transcription factors. Moreover, we optimized induction conditions by using different combinations of transcription factors and found that a single lentiviral vector expressing three factors [neurogenin-2 (NGN2), insulin gene enhancer 1 (ISL1), and LIM/homeobox 3 (LHX3)] is necessary and sufficient to induce iPSC-derived MNs (iPSC-MNs). These MNs robustly expressed general neuron markers [microtubule-associated protein 2 (MAP2), neurofilament protein (SMI-32), and tubulin β-3 class III (TUBB3)] and MN-specific markers [HB9 and choline acetyltransferase (ChAT)] and showed electrical maturation and firing of action potentials within 3 wk. This approach significantly improved the neuronal survival, yield, and purity, making it feasible to obtain abundant materials for biochemical studies in modeling movement diseases.
Simulated stool for assessment of anorectal physiology
Authors: Chen Ssu-Chi , Futaba Kaori , Leung Wing Wa , Wong Cherry , Mak Tony , Ng Simon , Gregersen Hans
Published: August 2020

Fecal continence is maintained by several mechanisms including anatomical factors, anorectal sensation, rectal compliance, stool consistency, anal muscle strength, mobility, and psychological factors. The homeostatic balance is easily disturbed, resulting in symptoms including fecal incontinence and constipation. Current technologies for assessment of anorectal function have limitations. Overlap exist between data obtained in different patient groups, and there is lack of correlation between measurements and symptoms. This review describes a novel technology named Fecobionics for assessment of anorectal physiology. Fecobionics is a simulated stool, capable of dynamic measurements of a variety of variables during defecation in a single examination. The data facilitate novel analysis of defecatory function as well as providing the foundation for modeling studies of anorectal behavior. The advanced analysis can enhance our physiological understanding of defecation and future interdisciplinary research for unraveling defecatory function, anorectal sensory-motor disorders, and symptoms. This is a step in the direction of improved diagnosis of anorectal diseases.
First contact: the role of respiratory cilia in host-pathogen interactions in the airways
Authors: Kuek Li Eon , Lee Robert J.
Published: August 2020

Respiratory cilia are the driving force of the mucociliary escalator, working in conjunction with secreted airway mucus to clear inhaled debris and pathogens from the conducting airways. Respiratory cilia are also one of the first contact points between host and inhaled pathogens. Impaired ciliary function is a common pathological feature in patients with chronic airway diseases, increasing susceptibility to respiratory infections. Common respiratory pathogens, including viruses, bacteria, and fungi, have been shown to target cilia and/or ciliated airway epithelial cells, resulting in a disruption of mucociliary clearance that may facilitate host infection. Despite being an integral component of airway innate immunity, the role of respiratory cilia and their clinical significance during airway infections are still poorly understood. This review examines the expression, structure, and function of respiratory cilia during pathogenic infection of the airways. This review also discusses specific known points of interaction of bacteria, fungi, and viruses with respiratory cilia function. The emerging biological functions of motile cilia relating to intracellular signaling and their potential immunoregulatory roles during infection will also be discussed.
Functional sympatholysis is preserved in healthy young Black men during rhythmic handgrip exercise
Authors: Barbosa Thales C. , Young Benjamin E. , Stephens Brandi Y. , Nandadeva Damsara , Kaur Jasdeep , Keller David M. , Fadel Paul J.
Published: August 2020

Black men have attenuated increases in forearm vascular conductance (FVC) and forearm blood flow (FBF) during moderate- and high-intensity rhythmic handgrip exercise compared with White men, but the underlying mechanisms are unclear. Here, we tested for the first time the hypothesis that functional sympatholysis (i.e., attenuation of sympathetic vasoconstriction in the exercising muscles) is impaired in Black men compared with White men. Thirteen White and 14 Black healthy young men were studied. FBF (duplex Doppler ultrasound) and mean arterial pressure (MAP; Finometer) were measured at rest and during rhythmic handgrip exercise at 30% maximal voluntary contraction. FVC was calculated as FBF/MAP. Sympathetic activation was induced via lower body negative pressure (LBNP) at −20 Torr for 2 min at rest and from the 3rd to the 5th min of handgrip. Sympathetic vasoconstriction was assessed as percent reductions in FVC during LBNP. The groups presented similar resting FVC, FBF, and MAP. During LBNP at rest, reductions in FVC were not different between White (−35 ± 10%) and Black men (−32 ± 14%, P = 0.616), indicating similar reflex-induced sympathetic vasoconstriction. During handgrip exercise, there were minimal reductions in FVC with LBNP in either group (White: −1 ± 7%; Black: +1 ± 8%; P = 0.523), indicating functional sympatholysis in both groups. Thus, contrary to our hypothesis, our findings indicate a preserved functional sympatholysis in healthy young Black men compared with White men, suggesting that this mechanism does not appear to contribute to reduced exercise hyperemia during moderate-intensity rhythmic handgrip in this population.
Representation of the observer’s predicted outcome value in mirror and nonmirror neurons of macaque F5 ventral premotor cortex
Authors: Pomper Joern K. , Spadacenta Silvia , Bunjes Friedemann , Arnstein Daniel , Giese Martin A. , Thier Peter
Published: August 2020

Both the populations of F5 mirror neurons and nonmirror neurons represent the predicted value of an outcome resulting from the observation of a grasping action. Value-dependent motivation, arousal, and attention directed at the observed action do not provide a better explanation for this representation. The population activity’s metric suggests an optimal scaling of value representation to task setting.
Elvitegravir/Cobicistat/Emtricitabine/Tenofovir Alafenamide in the Treatment of HIV-Infected Patients: Experience with the First 100 Patients from Qatar
Authors: Al Soub Hussam , Al-khal A. Latif M. , Alsoub Deema , Awouda Waleed
Published: August 2020

Background. To describe our experience with the use of Elvitegravir/Cobicistat/Emtricitabine/Tenofovir Alafenamide (EVG/COBI/FTC/TAF) in the treatment of HIV-infected patients in Qatar including both naïve and treatment experienced. We also report the reasons for switching to EVG/COBI/FTC/TAF in treatment-experienced patients, response to treatment, and tolerability. Method. Review of the medical records of the first 100 HIV-infected patients treated with EVG/COBI/FTC/TAF. Results. Among the 100 HIV-infected patients who were treated with EVG/COBI/FTC/TAF, 64 were Qatari and the rest were from other nationalities. 80 patients were males and 20 were females. 29 were treatment naïve, and 71 were treatment experienced. Among treatment-experienced patients, the most common reasons for switch to EVG/COBI/FTC/TAF were safety concerns, followed by regimen simplification and adverse drug reaction of the previous regimen (40%, 14%, and 13%, respectively). Treatment response to EVG/COBI/FTC/TAF leading to undetectable viral load in naïve patients was 69%, and in treatment-experienced patients, it was 83% with an overall response among all patients of 79%. Excluding those who left the country and whose data were not available, the response rate will be 86%. Tolerability was excellent with mild side effects and no discontinuation due to side effects. Conclusion. Experience with the use of EVG/COBI/FTC/TAF in 100 patients with HIV infection in Qatar was favourable both in treatment naïve patients and in those who were treatment experienced with an excellent tolerability.
Clustering by Detecting Density Peaks and Assigning Points by Similarity-First Search Based on Weighted K-Nearest Neighbors Graph
Authors: Diao Qi , Dai Yaping , An Qichao , Li Weixing , Feng Xiaoxue , Pan Feng
Published: August 2020

This paper presents an improved clustering algorithm for categorizing data with arbitrary shapes. Most of the conventional clustering approaches work only with round-shaped clusters. This task can be accomplished by quickly searching and finding clustering methods for density peaks (DPC), but in some cases, it is limited by density peaks and allocation strategy. To overcome these limitations, two improvements are proposed in this paper. To describe the clustering center more comprehensively, the definitions of local density and relative distance are fused with multiple distances, including K-nearest neighbors (KNN) and shared-nearest neighbors (SNN). A similarity-first search algorithm is designed to search the most matching cluster centers for noncenter points in a weighted KNN graph. Extensive comparison with several existing DPC methods, e.g., traditional DPC algorithm, density-based spatial clustering of applications with noise (DBSCAN), affinity propagation (AP), FKNN-DPC, and K-means methods, has been carried out. Experiments based on synthetic data and real data show that the proposed clustering algorithm can outperform DPC, DBSCAN, AP, and K-means in terms of the clustering accuracy (ACC), the adjusted mutual information (AMI), and the adjusted Rand index (ARI).
Bearing Characteristics of Moso Bamboo Micropile‐Composite Soil Nailing System in Soft Soil Areas
Authors: Cheng Zhihe , Deng Yousheng
Published: August 2020

Based on the characteristics of moso bamboo including high short‐term strength, stable performance, and ability to provide temporary support for shallow foundation pits in soft soil, the stress characteristics and supporting effects of the ecological composite supporting system have been explored through model tests and numerical calculation analysis of the moso bamboo micropile‐composite soil nailing structure. The results showed that the bamboo pile can effectively control the horizontal deformation of the side wall of the foundation pit and the ground surface settlement, achieving a relatively satisfactory supporting effect. Furthermore, the bamboo pile has visibly bent in middle and lower parts, where the regional shear point is most likely to appear, the axial force of the soil nail is distributed in an oval pattern with a smaller force on both sides and a larger force in the middle part, the maximum axial strain is 447.3 με, and the axial force of the soil nails in each row follows a similar trend. The synergy of piles and soil nails can delay the formation of the slip surface, therefore enhancing the overall bearing capacity of the foundation pit. These results can shed light on the support mechanism and engineering design of bamboo piles in shallow soft soil foundation pits.
Changes in the Clinical Characteristics of 62 Patients Who Died from Coronavirus Disease 2019
Authors: Chen Jingli , Ye Jishi , Li Hui , Xia Zhongyuan , Yan Hong
Published: August 2020

Background. Since the first reports of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infections in December 2019 in Wuhan, China, the virus has spread to other parts of China and across the world. Although a few studies have assessed the clinical course of coronavirus disease 2019 (COVID‐19), the changes in clinical characteristics during disease progression remain unclear. Methods. We retrospectively analyzed the clinical characteristics of 62 patients who died from COVID‐19 at the Central Hospital of Wuhan between January 26 and February 17, 2020. We compared the clinical features on admission and at the last follow‐up before death. Results. Of the 62 patients with COVID‐19, 41 (66%) patients were male, and 21 (34%) were female. The median age was 72 years (interquartile range (IQR), 54‐88), and 45 (72.5%) patients had preexisting conditions. The median time from symptom onset to the first visit at the clinic was three days, while the median time from symptom onset to death was 18.5 days. During disease progression, the amounts of arterial gases worsened, and liver, renal, and heart dysfunction was observed. Due to the cytokine storm, infection‐related biomarkers, including lactic acid, C‐reactive protein, and interleukine‐6, gradually worsened during hospitalization. Conclusion. Our findings suggest that during hospitalization, many COVID‐19 patients experienced multiple organ dysfunction and cytokine storm. The time from symptom onset to death was only 18.5 days, highlighting the disease’s rapid progression. The better understanding of the clinical changes during disease progression might provide further insight into the COVID‐19 pathophysiology.
Analysis of Land Surface Temperature Evolution Based on Regional Road Scope
Authors: Liu Fabao , Jia Xingli , Li Wenbin , Du Ao , Wang Dang
Published: August 2020

To balance sustainable road construction and environmental impact, intrinsic relationships between regional road networks and land surface temperature (LST) along the roads must be examined. In this study, we hypothesize that expanding road networks can affect the LST within a given region. Thus, we determined the influence of varying road grades on the surrounding LST. Using an improved single‐window algorithm with reasonably adjusted water vapor parameters, LST data for the relevant areas were extracted from Landsat 8 data. Analyzing these data revealed that, in the improved single‐window algorithm, the MOD05 L2 water vapor parameter could obtain results, indicating that road grades are positively correlated with LST changes when road network mileage is increased. In addition, we found that LST was increased by highways and low‐grade roads over distances of 180 m and 150 m compared with the surrounding area, respectively. Furthermore, LST was affected by road interchanges over a distance of 300 m and by intersections formed by low‐grade roads over 150 m; both have a linear nonuniform influence on the propagation models. Finally, we determined that different highways in the LST radiation range can interact to form an LST concentration zone, resulting in further LST increases.
Robust T-S Fuzzy Control of Electrostimulation for Paraplegic Patients considering Norm-Bounded Uncertainties
Authors: Covacic Márcio Roberto , Minhoto Teixeira Marcelo Carvalho , Augusto de Carvalho Aparecido , Cardim Rodrigo , Assunção Edvaldo , Sanches Marcelo Augusto Assunção , Fujimoto Henrique Shuiti , Mineo Maxwell Simões , Biazeto Anderson Ross , Gaino Ruberlei
Published: August 2020

This manuscript presents a Takagi–Sugeno fuzzy control for a mathematical model of the knee position of paraplegic patients using functional electrical stimulation (FES). Each local model of the fuzzy system is represented considering norm-bounded uncertainties. After obtaining the model of FES with norm-bounded uncertainties, the fuzzy control strategy is designed through the solution of linear matrix inequalities (LMIs) using the conditions available in the literature, which consider these norm-bounded uncertainties. The strategy considers decay rate and constraints on the input signal. The model is simulated in the Matlab environment using the numerical parameters measured by experimental tests from a paraplegic patient.
Surface Geometry of Four Conventional Nanohybrid Resin‐Based Composites and Four Regular Viscosity Bulk Fill Resin‐Based Composites after Two‐Step Polishing Procedure
Authors: Granat Mateusz , Cieloszyk Janusz , Kowalska Urszula , Buczkowska-Radlińska Jadwiga , Łagocka Ryta
Published: August 2020

Objectives. The aim of the study was to determine the quantitative and qualitative surface structure of contemporary RBCs in posterior teeth reconstructions: regular viscosity bulk fill and conventional composites, obtained after two‐stage polishing procedure. Materials and Methods. Four conventional nanohybrid composites (Tetric EvoCeram, GrandioSO, Filtek Z550, and Ceram·X Mono) and four regular viscosity bulk fill composites (Tetric EvoCeram Bulk Fill, X‐tra fil, Filtek Bulk Fill Posterior, and QuixFil) were tested. Samples of each RBC were prepared using PMMA cylindrical mold. After two‐step polishing procedure, a surface geometry was evaluated under profilometry (Turbowave v. 7.36, Hommel‐Etamic) and SEM (VEGA 3, Tescan Analytics). To evaluate differences between values, the following nonparametric tests were used: Friedman’s ANOVA, Wilcoxon’s matched‐pair test, ANOVA Kruskal‐Wallis, and Mann‐Whitney U. Results. All conventional RBCs showed Ra values in the range of 0.20‐0.26 μm. Bulk fill showed higher values in range of 0.49‐1.36 μm except for Filtek Bulk Fill Posterior, which achieved 0.23 μm Ra value. SEM images of conventional RBCs were described as smooth surfaces with slight damage except for TEC, which presented smooth surface with no damage. Bulk fill composites showed rough surface, except for TBF, which presented smooth surface with slight damage. Conclusions. Regular viscosity bulk fill composites do not constitute a homogeneous group regarding surface roughness after polishing. They obtain, for the most part, poorer smoothness values after polishing than conventional RBCs.
2‐(6‐Hydroxyhexylthio)‐5,8‐dimethoxy‐1,4‐naphthoquinone Induces Apoptosis through ROS‐Mediated MAPK, STAT3, and NF‐κB Signalling Pathways in Lung Cancer A549 Cells
Authors: Shen Gui-Nan , Wang Cheng , Luo Ying-Hua , Wang Jia-Ru , Wang Rui , Xu Wan-Ting , Zhang Yi , Zhang Yu , Zhang Dong-Jie , Jin Cheng-Hao
Published: August 2020

Two novel compounds, 2‐(2‐hydroxyethylthio)‐5,8‐dimethoxy‐1,4‐naphthoquinone (HEDMNQ) and 2‐(6‐hydroxyhexylthio)‐5,8‐dimethoxy‐1,4‐naphthoquinone (HHDMNQ), were synthesized to investigate the kill effects and mechanism of 1,4‐naphthoquinone derivatives in lung cancer cells. The results of the CCK‐8 assay showed that HEDMNQ and HHDMNQ had significant cytotoxic effects on A549, NCI‐H23, and NCI‐H460 NSCLC cells. Flow cytometry and western blot results indicated that HHDMNQ induced A549 cell cycle arrest at the G2/M phase by decreasing the expression levels of cyclin‐dependent kinase 1/2 and cyclin B1. Fluorescence microscopy and flow cytometry results indicated that HHDMNQ could induce A549 cell apoptosis, and western blot analysis showed that HHDMNQ induced apoptosis through regulating the mitochondria pathway, as well as the MAPK, STAT3, and NF‐κB signalling pathways. Flow cytometry results showed that intracellular reactive oxygen species (ROS) levels were increased after HHDMNQ treatment, and western blot showed that ROS could modulate the intrinsic pathway and MAPK, STAT3, and NF‐κB signalling pathways. These effects were blocked by the ROS inhibitor N‐acetyl‐L‐cysteine in A549 cells. Our findings suggest that compared with HEDMNQ, HHDMNQ had the stronger ability to inhibit the cell viability of lung cancer cells and induce apoptosis by regulating the ROS‐mediated intrinsic pathway and MAPK/STAT3/NF‐κB signalling pathways. Thus, HHDMNQ might be a potential antitumour compound for treating lung cancer.
An In Vitro Evaluation Study of the Geometric Changes of Root Canal Preparation and the Quality of Endodontic Treatment
Authors: Razumova Svetlana , Brago Anzhela , Howijieh Ammar , Barakat Haydar , Manvelyan Ashot , Kozlova Yuliya
Published: August 2020

Introduction. The geometry of root canals differs in different parts, especially in the apical region, and it is affected by different preparation techniques. The aim of this study was to evaluate the geometric changes of root canal preparation by general dentists regardless of the endodontic instrumentation systems and to study the quality of endodontic treatment by evaluating the untouched areas after mechanical preparation and the smear layer removal. Materials and Methods. 100 extracted maxillary canines were collected for the in vitro study from 10 dentists, and the dentists were asked to treat the teeth endodontically. The teeth then were separated and examined under an optical microscope to evaluate the root canal final diameter and the untouched areas. Then, the teeth were examined under a scanned electronic microscope to evaluate the smear layer in coronal, middle, and third parts of the canal. Statistical significance was set as P<0.05. Results. The mean diameter of the root canal after instrumentation in the coronal and middle thirds was 2.50 ± 1.12 and 1.75 ± 1.24 mm, respectively, and the untouched area percentage observed in the apical thirds was 71%. For smear layer removal, it was better in the coronal and middle thirds than in the apical (P<0.05). Conclusion. The changes in the diameter of the root canal, the percentage of untouched areas after mechanical preparation, and the percentage of smear layer were observed in a higher percent in the apical third than in the coronal and middle thirds, and this raises the question of changing the technique of processing the root canal, especially in the apical third.