scholarly journals Rapid imaging of special nuclear materials for nuclear nonproliferation and terrorism prevention

2021 ◽  
Vol 7 (21) ◽  
pp. eabg3032
Author(s):  
Jana Petrović ◽  
Alf Göök ◽  
Bo Cederwall
Keyword(s):  
Nuclear Physics ◽  
Imaging Modality ◽  
Three Dimensional ◽  
Nuclear Fission ◽  
Machine Learning Techniques ◽  
Nuclear Materials ◽  
Prototype System ◽  
Fast Time ◽  
Gamma Emission ◽  
Special Nuclear Materials

We introduce a neutron-gamma emission tomography (NGET) technique for rapid detection, three-dimensional imaging, and characterization of special nuclear materials like weapons-grade plutonium and uranium. The technique is adapted from fundamental nuclear physics research and represents a previously unexplored approach to the detection and imaging of small quantities of these materials. The method is demonstrated on a radiation portal monitor prototype system based on fast organic scintillators, measuring the characteristic fast time and energy correlations between particles emitted in nuclear fission processes. The use of these correlations in real time in conjunction with modern machine learning techniques provides unprecedented imaging efficiency and high spatial resolution. This imaging modality addresses global security threats from terrorism and the proliferation of nuclear weapons. It also provides enhanced capabilities for addressing different nuclear accident scenarios and for environmental radiological surveying.

scholarly journals Optical Coherence Tomography for Patients with Developmental Disabilities: A Preliminary Study

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7940
Author(s):  
Kimberly Espinoza ◽  
Juri Hayashi ◽  
Yasushi Shimada ◽  
Junji Tagami ◽  
Alireza Sadr
Keyword(s):  
Optical Coherence Tomography ◽  
Developmental Disabilities ◽  
Rating Scale ◽  
Imaging Modality ◽  
Three Dimensional ◽  
Prototype System ◽  
Optical Coherence ◽  
Persons With Disabilities ◽  
Dental Radiographs ◽  
Pain Rating Scale

Dental radiographs are essential for diagnosis and treatment planning, but are sometimes difficult to acquire for patients with developmental disabilities (PDD). Optical Coherence Tomography (OCT) is a non-ionizing imaging modality that has the potential application as an alternative to dental radiographs for PDD. This study aimed to determine the feasibility of intraoral OCT imaging for PDD. Ten participants were recruited in the Dental Education in the Care of Persons with Disabilities (DECOD) Clinic to explore the utility of dental OCT. The prototype system (Yoshida Dental) creates in-depth and three-dimensional images of teeth. The participants indicated their degree of pain during imaging on the Wong-Baker FACES Pain Rating Scale, and the degree of discomfort after imaging on a visual analog scale. OCT can be used for patients with developmental disabilities with minimal levels of pain and discomfort, without ionizing radiation.

The Age of Innocence

2018 ◽  
Author(s):  
Roger H. Stuewer
Keyword(s):  
Nuclear Physics ◽  
Nuclear Reactions ◽  
Alpha Decay ◽  
Nuclear Fission ◽  
Theoretical Physics ◽  
Lise Meitner ◽  
Artificial Radioactivity ◽  
The Great Depression ◽  
Nuclear Disintegration ◽  
Quantum Mechanical Theory

Nuclear physics emerged as the dominant field in experimental and theoretical physics between 1919 and 1939, the two decades between the First and Second World Wars. Milestones were Ernest Rutherford’s discovery of artificial nuclear disintegration (1919), George Gamow’s and Ronald Gurney and Edward Condon’s simultaneous quantum-mechanical theory of alpha decay (1928), Harold Urey’s discovery of deuterium (the deuteron), James Chadwick’s discovery of the neutron, Carl Anderson’s discovery of the positron, John Cockcroft and Ernest Walton’s invention of their eponymous linear accelerator, and Ernest Lawrence’s invention of the cyclotron (1931–2), Frédéric and Irène Joliot-Curie’s discovery and confirmation of artificial radioactivity (1934), Enrico Fermi’s theory of beta decay based on Wolfgang Pauli’s neutrino hypothesis and Fermi’s discovery of the efficacy of slow neutrons in nuclear reactions (1934), Niels Bohr’s theory of the compound nucleus and Gregory Breit and Eugene Wigner’s theory of nucleus+neutron resonances (1936), and Lise Meitner and Otto Robert Frisch’s interpretation of nuclear fission, based on Gamow’s liquid-drop model of the nucleus (1938), which Frisch confirmed experimentally (1939). These achievements reflected the idiosyncratic personalities of the physicists who made them; they were shaped by the physical and intellectual environments of the countries and institutions in which they worked; and they were buffeted by the profound social and political upheavals after the Great War: the punitive postwar treaties, the runaway inflation in Germany and Austria, the Great Depression, and the greatest intellectual migration in history, which encompassed some of the most gifted experimental and theoretical nuclear physicists in the world.

scholarly journals Combining Virtual Reality and Organizational Neuroscience for Leadership Assessment

2021 ◽  
Vol 11 (13) ◽  
pp. 5956
Author(s):  
Elena Parra ◽  
Irene Alice Chicchi Giglioli ◽  
Jestine Philip ◽  
Lucia Amalia Carrasco-Ribelles ◽  
Javier Marín-Morales ◽  
...  
Keyword(s):  
Machine Learning ◽  
Eye Tracking ◽  
Ecological Validity ◽  
Objective Assessment ◽  
Leadership Skills ◽  
Three Dimensional ◽  
Machine Learning Techniques ◽  
Future Research ◽  
Promising Tool ◽  
Future Research Agenda

In this article, we introduce three-dimensional Serious Games (3DSGs) under an evidence-centered design (ECD) framework and use an organizational neuroscience-based eye-tracking measure to capture implicit behavioral signals associated with leadership skills. While ECD is a well-established framework used in the design and development of assessments, it has rarely been utilized in organizational research. The study proposes a novel 3DSG combined with organizational neuroscience methods as a promising tool to assess and recognize leadership-related behavioral patterns that manifest during complex and realistic social situations. We offer a research protocol for assessing task- and relationship-oriented leadership skills that uses ECD, eye-tracking measures, and machine learning. Seamlessly embedding biological measures into 3DSGs enables objective assessment methods that are based on machine learning techniques to achieve high ecological validity. We conclude by describing a future research agenda for the combined use of 3DSGs and organizational neuroscience methods for leadership and human resources.

scholarly journals Magnetic particle imaging of particle dynamics in complex matrix systems

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sebastian Draack ◽  
Meinhard Schilling ◽  
Thilo Viereck
Keyword(s):  
Magnetic Particle ◽  
Imaging Modality ◽  
Three Dimensional ◽  
Local Environment ◽  
Relaxation Mechanism ◽  
Harmonic Spectrum ◽  
Magnetic Particle Imaging ◽  
Matrix Interactions ◽  
Tracer Distribution ◽  
Particle Imaging

Abstract Magnetic particle imaging (MPI) is a young imaging modality for biomedical applications. It uses magnetic nanoparticles as a tracer material to produce three-dimensional images of the spatial tracer distribution in the field-of-view. Since the tracer magnetization dynamics are tied to the hydrodynamic mobility via the Brownian relaxation mechanism, MPI is also capable of mapping the local environment during the imaging process. Since the influence of viscosity or temperature on the harmonic spectrum is very complicated, we used magnetic particle spectroscopy (MPS) as an integral measurement technique to investigate the relationships. We studied MPS spectra as function of both viscosity and temperature on model particle systems. With multispectral MPS, we also developed an empirical tool for treating more complex scenarios via a calibration approach. We demonstrate that MPS/MPI are powerful methods for studying particle-matrix interactions in complex media.

Acceleration of the EM-like reconstruction method for diffuse optical tomography with ordered-subsets method

2014 ◽  
Vol 22 (3) ◽  
Author(s):  
Caifang Wang
Keyword(s):  
Numerical Experiments ◽  
Imaging Modality ◽  
Random Medium ◽  
Optical Tomography ◽  
Back Propagation ◽  
Three Dimensional ◽  
Diffuse Optical Tomography ◽  
Optical Parameters ◽  
Reconstruction Method ◽  
Boundary Measurements

Abstract.Diffuse optical tomography (DOT) is an optical imaging modality, which provides the spatial distribution of the optical parameters inside a random medium. A propagation back-propagation method named EM-like reconstruction method for stationary DOT problem has been proposed yet. This method is really time consuming. Hence the ordered-subsets (OS) technique for this reconstruction method is studied in this paper. The boundary measurements of DOT are grouped into nonoverlapping and overlapping ordered sequence of subsets with random partition, sequential partition and periodic partition, respectively. The performance of OS methods is compared with the standard EM-like reconstruction method with two-dimensional and three-dimensional numerical experiments. The numerical experiments indicate that reconstruction of nonoverlapping subsets with periodic partition, overlapping subsets with periodic partition and standard EM-like method provide very similar acceptable reconstruction results. However, reconstruction of nonoverlapping subsets with periodic partition spends a minimum of time to get proper results.

scholarly journals Accuracy of Commonly-Used Imaging Modalities in Assessing Left Atrial Appendage for Interventional Closure: Review Article

2018 ◽  
Vol 7 (11) ◽  
pp. 441 ◽  
Author(s):  
Ramez Morcos ◽  
Haider Al Taii ◽  
Priya Bansal ◽  
Joel Casale ◽  
Rupesh Manam ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Transesophageal Echocardiography ◽  
Left Atrial ◽  
Left Atrial Appendage ◽  
Imaging Modality ◽  
Three Dimensional ◽  
Atrial Appendage ◽  
Imaging Modalities ◽  
Three Dimensional Printing ◽  
Dimensional Printing

Periprocedural imaging assessment for percutaneous Left Atrial Appendage (LAA) transcatheter occlusion can be obtained by utilizing different imaging modalities including fluoroscopy, magnetic resonance imaging (MRI), computed tomography (CT), and ultrasound imaging. Given the complex and variable morphology of the left atrial appendage, it is crucial to obtain the most accurate LAA dimensions to prevent intra-procedural device changes, recapture maneuvers, and prolonged procedure time. We therefore sought to examine the accuracy of the most commonly utilized imaging modalities in LAA occlusion. Institutional Review Board (IRB) approval was waived as we only reviewed published data. By utilizing PUBMED which is an integrated online website to list the published literature based on its relevance, we retrieved thirty-two articles on the accuracy of most commonly used imaging modalities for pre-procedural assessment of the left atrial appendage morphology, namely, two-dimensional transesophageal echocardiography, three-dimensional transesophageal echocardiography, computed tomography, and three-dimensional printing. There is strong evidence that real-time three-dimensional transesophageal echocardiography is more accurate than two-dimensional transesophageal echocardiography. Three-dimensional computed tomography has recently emerged as an imaging modality and it showed exceptional accuracy when merged with three-dimensional printing technology. However, real time three-dimensional transesophageal echocardiography may be considered the preferred imaging modality as it can provide accurate measurements without requiring radiation exposure or contrast administration. We will present the most common imaging modality used for LAA assessment and will provide an algorithmic approach including preprocedural, periprocedural, intraprocedural, and postprocedural.

scholarly journals Recent advances in echocardiography for valvular heart disease

F1000Research ◽  
2015 ◽  
Vol 4 ◽  
pp. 914 ◽  
Author(s):  
Rebecca Hahn
Keyword(s):  
Heart Disease ◽  
Current Literature ◽  
Valvular Heart Disease ◽  
Patient Population ◽  
Imaging Modality ◽  
Three Dimensional ◽  
Fusion Imaging ◽  
Intracardiac Echocardiography ◽  
Dimensional Echocardiography ◽  
Three Dimensional Echocardiography

Echocardiography is the imaging modality of choice for the assessment of patients with valvular heart disease. Echocardiographic advancements may have particular impact on the assessment and management of patients with valvular heart disease. This review will summarize the current literature on advancements, such as three-dimensional echocardiography, strain imaging, intracardiac echocardiography, and fusion imaging, in this patient population.

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