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3d space

Misun Kim, Eleanor A Maguire
Humans commonly operate within 3D environments such as multifloor buildings and yet there is a surprising dearth of studies that have examined how these spaces are represented in the brain. Here, we had participants learn the locations of paintings within a virtual multilevel gallery building and then used behavioral tests and fMRI repetition suppression analyses to investigate how this 3D multicompartment space was represented, and whether there was a bias in encoding vertical and horizontal information. We found faster response times for within-room egocentric spatial judgments and behavioral priming effects of visiting the same room, providing evidence for a compartmentalized representation of space...
March 15, 2018: Cerebral Cortex
Nitish Padmanaban, Timon Ruban, Vincent Sitzmann, Anthony M Norcia, Gordon Wetzstein
Virtual reality systems are widely believed to be the next major computing platform. There are, however, some barriers to adoption that must be addressed, such as that of motion sickness - which can lead to undesirable symptoms including postural instability, headaches, and nausea. Motion sickness in virtual reality occurs as a result of moving visual stimuli that cause users to perceive self-motion while they remain stationary in the real world. There are several contributing factors to both this perception of motion and the subsequent onset of sickness, including field of view, motion velocity, and stimulus depth...
April 2018: IEEE Transactions on Visualization and Computer Graphics
Chiara Nicoletti, Mattia Forcato, Silvio Bicciato
In all organisms, chromatin is packed to fulfil structural constraints and functional requirements. The hierarchical model of chromatin organization in the 3D nuclear space encompasses different topologies at diverse scale lengths, with chromosomes occupying distinct volumes, further organized in compartments, inside which the chromatin fibers fold into large domains and short-range loops. In the recent years, the combination of chromosome conformation capture (3C) techniques and high-throughput sequencing allowed probing chromatin spatial organization at the whole genome-scale...
March 15, 2018: Current Opinion in Biotechnology
Tatsuya Soeno, Tomoharu Mochizuki, Osamu Tanifuji, Hiroshi Koga, Takayuki Murayama, Hiroki Hijikata, Yuki Takahashi, Naoto Endo
INTRODUCTION: Instability after total knee arthroplasty is a critical problem. The purpose of this study was to clarify the stability of implanted knees during walking by comparing differences in dynamic instability during knee acceleration between individuals with or without previously experienced subjective instability, as measured by self-reported questionnaire. MATERIALS AND METHODS: We examined 92 knees with medial pivot implants. Mean patient age and follow-up duration were 78...
2018: PloS One
Sen Wang, Xinxin Zuo, Chao Du, Runxiao Wang, Jiangbin Zheng, Ruigang Yang
This paper deals with the 3D reconstruction problem for dynamic non-rigid objects with a single RGB-D sensor. It is a challenging task as we consider the almost inevitable accumulation error issue in some previous sequential fusion methods and also the possible failure of surface tracking in a long sequence. Therefore, we propose a global non-rigid registration framework and tackle the drifting problem via an explicit loop closure. Our novel scheme starts with a fusion step to get multiple partial scans from the input sequence, followed by a pairwise non-rigid registration and loop detection step to obtain correspondences between neighboring partial pieces and those pieces that form a loop...
March 16, 2018: Sensors
Yu Onodera, Ryo Akimoto, Hiroto Suzuki, Masayuki Okada, Masaki Nakane, Kaneyuki Kawamae
BACKGROUND: Although clinical studies of the high-flow nasal cannula (HFNC) and its effect on positive end-expiratory pressure (PEEP) have been done, the washout effect has not been well evaluated. Therefore, we made an experimental respiratory model to evaluate the respiratory physiological effect of HFNC. METHODS: An airway model was made by a 3D printer using the craniocervical 3D-CT data of a healthy 32-year-old male. CO2 was infused into four respiratory lung models (normal-lung, open- and closed-mouth models; restrictive- and obstructive-lung, open-mouth models) to maintain the partial pressure of end-tidal CO2 (PET CO2 ) at 40 mmHg...
March 15, 2018: Intensive Care Medicine Experimental
Qiang Chen, Sijie Niu, Wangyi Fang, Yuanlu Shuai, Wen Fan, Songtao Yuan, Qinghuai Liu
BACKGROUND AND OBJECTIVE: The measurement of choroidal volume is more related with eye diseases than choroidal thickness, because the choroidal volume can reflect the diseases comprehensively. The purpose is to automatically segment choroid for three-dimensional (3D) spectral domain optical coherence tomography (SD-OCT) images. METHODS: We present a novel choroid segmentation strategy for SD-OCT images by incorporating the enhanced depth imaging OCT (EDI-OCT) images...
May 2018: Computer Methods and Programs in Biomedicine
Andrew MacQuarrie, Anthony Steed
360° images and video have become extremely popular formats for immersive displays, due in large part to the technical ease of content production. While many experiences use a single camera viewpoint, an increasing number of experiences use multiple camera locations. In such multi-view 360° media (MV360M) systems, a visual effect is required when the user transitions from one camera location to another. This effect can take several forms, such as a cut or an image-based warp, and the choice of effect may impact many aspects of the experience, including issues related to enjoyment and scene understanding...
April 2018: IEEE Transactions on Visualization and Computer Graphics
Geng Lyu, Xukun Shen, Taku Komura, Kartic Subr, Lijun Teng
Displays that can portray environments that are perceivable from multiple views are known as multiscopic displays. Some multiscopic displays enable realistic perception of 3D environments without the need for cumbersome mounts or fragile head-tracking algorithms. These automultiscopic displays carefully control the distribution of emitted light over space, direction (angle) and time so that even a static image displayed can encode parallax across viewing directions (Iightfield). This allows simultaneous observation by multiple viewers, each perceiving 3D from their own (correct) perspective...
April 2018: IEEE Transactions on Visualization and Computer Graphics
Fatimah Alahmari, Bambar Davaasuren, Abdul-Hamid Emwas, Alexander Rothenberger
The new thioaluminogermanate Na(AlS2 )(GeS2 )4 (1) was successfully synthesized by a direct combination reaction. The compound crystallizes in the monoclinic space group P21 / n (no. 14) with unit cell parameters a = 6.803(3) Å, b = 38.207(2) Å, c = 6.947(4) Å, and β = 119.17(3)°. The crystal structure is composed of a [(AlS2 )(GeS2 )4 ]- 3D polyanionic network, in which Al and Ge atoms share the atomic positions and Na cations occupy the channels and voids formed by the connection of (Ge/Al)S4 tetrahedra...
March 14, 2018: Inorganic Chemistry
Sarah J Trenfield, Atheer Awad, Alvaro Goyanes, Simon Gaisford, Abdul W Basit
3D printing (3DP) is forecast to be a highly revolutionary technology within the pharmaceutical sector. In particular, the main benefits of 3DP lie in the production of small batches of medicines, each with tailored dosages, shapes, sizes and release characteristics. The manufacture of medicines in this way may finally lead to the concept of personalised medicines becoming a reality. In the shorter term, 3DP could be extended throughout the drug development process, ranging from preclinical development and clinical trials, through to frontline medical care...
March 10, 2018: Trends in Pharmacological Sciences
Anna Tauro, Jelena Jovanovik, Colin John Driver, Clare Rusbridge
OBJECTIVE:  Abnormalities within the spinal arachnoid space are often treated surgically, but they can be challenging to detect with conventional magnetic resonance imaging (MRI) sequences. 3D-CISS sequences are considered superior in evaluating structures surrounded by cerebrospinal fluid (CSF) due to the high signal-to-noise ratio, high contrast-to-noise ratio and intrinsic insensitivity to motion with minimal signal loss due to CSF pulsations. Our objective was to describe findings and advantages in adding 3D-CISS sequences to routine MRI in patients affected by spinal arachnoid diverticula (SAD) or arachnoid adhesions...
February 2018: Veterinary and Comparative Orthopaedics and Traumatology: V.C.O.T
Wataru Jomoto, Masao Tanooka, Hiroshi Doi, Keisuke Kikuchi, Chiemi Mitsuie, Yusuke Yamada, Toru Suzuki, Toshiko Yamano, Reiichi Ishikura, Noriko Kotoura, Shingo Yamamoto
We sought to develop a surgical navigation system using magnetic resonance angiography (MRA) and a three-dimensional (3D) printer for robot-assisted radical prostatectomy (RARP). Six patients with pathologically proven localized prostate cancer were prospectively enrolled in this study. Prostate magnetic resonance imaging (MRI), consisting of T2-weighted sampling perfection with application-optimized contrasts using different flip-angle evolutions (SPACE) and true fast imaging with steady-state precession (true FISP), reconstructed by volume rendering, was followed by dynamic contrast-enhanced MRA performed with a volumetric interpolated breath-hold examination (VIBE) during intravenous bolus injection of gadobutrol...
January 2, 2018: Curēus
Tarek Zghaib, Ashkan A Malayeri, Esra G Ipek, Mohammadali Habibi, Dong Huang, Muhammad A Balouch, David A Bluemke, Hugh Calkins, Saman Nazarian, Stefan L Zimmerman
BACKGROUND: Ablation-induced left atrial (LA) edema may result in procedural failure due to reversible pulmonary vein (PV) isolation. Conventional T2-weighted magnetic resonance edema imaging is limited by low spatial resolution. OBJECTIVE: In this pilot study, our goal was to 1) optimize and validate a 3D-SPACE sequence for quantification of T2-signal in the LA and 2) apply in recently ablated patients, comparing myocardial edema on T2-SPACE to tissue damage on late gadolinium-enhancement (LGE) imaging...
March 9, 2018: Heart Rhythm: the Official Journal of the Heart Rhythm Society
Jay Burmeister, Adrian Nalichowski, Michael Snyder, Robert Halford, Geoff Baran, Brian Loughery, Ahmad Hammoud, Joe Rakowski, Todd Bossenberger
We describe the commissioning of the first dedicated commercial total body irradiation (TBI) unit in clinical operation. The Best Theratronics GammaBeam 500 is a Co-60 teletherapy unit with extended field size and imaging capabilities. Radiation safety, mechanical and imaging systems, and radiation output are characterized. Beam data collection, calibration, and external dosimetric validation are described. All radiation safety and mechanical tests satisfied relevant requirements and measured dose distributions meet recommendations of American Association of Physicists in Medicine (AAPM) Report #17...
March 11, 2018: Journal of Applied Clinical Medical Physics
Xiaokang Yu, Na Lei, Yalin Wang, Xianfeng Gu
3D dynamic surface tracking is an important research problem and plays a vital role in many computer vision and medical imaging applications. However, it is still challenging to efficiently register surface sequences which has large deformations and strong noise. In this paper, we propose a novel automatic method for non-rigid 3D dynamic surface tracking with surface Ricci flow and Teichmüller map methods. According to quasi-conformal Teichmüller theory, the Techmüller map minimizes the maximal dilation so that our method is able to automatically register surfaces with large deformations...
October 2017: Proceedings
Majid Malboubi, Asier Jayo, Maddy Parsons, Guillaume Charras
Cell migration plays a key role in many physiological and pathological conditions during which cells migrate primarily in the 3D environments formed by tissues. Microfluidics enables the design of simple devices that can mimic in a highly controlled manner the geometry and dimensions of the interstices encountered by cells in the body. Here we describe the design, fabrication, and implementation of an array of channels with a range of cross sections to investigate migration of cells and cell clusters through confined spaces...
2018: Methods in Molecular Biology
Carl Barton, Sandro Morganella, Øyvind Ødegård-Fougner, Stephanie Alexander, Jonas Ries, Tomas Fitzgerald, Jan Ellenberg, Ewan Birney
The 3D structure of chromatin plays a key role in genome function, including gene expression, DNA replication, chromosome segregation, and DNA repair. Furthermore the location of genomic loci within the nucleus, especially relative to each other and nuclear structures such as the nuclear envelope and nuclear bodies strongly correlates with aspects of function such as gene expression. Therefore, determining the 3D position of the 6 billion DNA base pairs in each of the 23 chromosomes inside the nucleus of a human cell is a central challenge of biology...
March 9, 2018: PLoS Computational Biology
Lixia Ni, Zhenxing Li, Haifeng Li, Xu Liu
This paper proposes a 360-deg large-scale multiprojection light-field 3D display system, which can reconstruct the light field of models in real space. The reconstructed contents can be observed by multiple viewers from different angles and positions simultaneously. In this system, 360 projectors project images onto a cylindrical light-field diffusion screen whose height is 1.8 m and diameter is 3 m. When moving around the system, viewers can see 3D scenes with smooth-motion parallax, and the frame rate can reach 30 fps and above...
March 10, 2018: Applied Optics
Ingvild E Bjerke, Martin Øvsthus, Eszter A Papp, Sharon C Yates, Ludovico Silvestri, Julien Fiorilli, Cyriel M A Pennartz, Francesco S Pavone, Maja A Puchades, Trygve B Leergaard, Jan G Bjaalie
The Human Brain Project (HBP), an EU Flagship Initiative, is currently building an infrastructure that will allow integration of large amounts of heterogeneous neuroscience data. The ultimate goal of the project is to develop a unified multi-level understanding of the brain and its diseases, and beyond this to emulate the computational capabilities of the brain. Reference atlases of the brain are one of the key components in this infrastructure. Based on a new generation of three-dimensional (3D) reference atlases, new solutions for analyzing and integrating brain data are being developed...
March 5, 2018: European Psychiatry: the Journal of the Association of European Psychiatrists
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