Search

Your search keyword '"Carson, Richard"' showing total 3,263 results
Start Over Author "Carson, Richard"
3,263 results on '"Carson, Richard"'

1. Understanding and valuing human connections to deep-sea methane seeps off Costa Rica

Author

Pereira, Olívia S, Jacobsen, Mark, Carson, Richard, Cortés, Jorge, and Levin, Lisa A

Subjects
Economics, Applied Economics, Life on Land, Choice modelling, Deep sea, Ecosystem services, Existence value, Methane seeps, Environmental Science and Management, Other Economics, Agricultural Economics & Policy, Ecology, Applied economics, Other economics
Published
2024

2. Random Utility Models with Skewed Random Components: the Smallest versus Largest Extreme Value Distribution

Author

Carson, Richard T., Sun, Derrick H., and Sun, Yixiao

Subjects
Economics - Econometrics
Abstract

At the core of most random utility models (RUMs) is an individual agent with a random utility component following a largest extreme value Type I (LEVI) distribution. What if, instead, the random component follows its mirror image -- the smallest extreme value Type I (SEVI) distribution? Differences between these specifications, closely tied to the random component's skewness, can be quite profound. For the same preference parameters, the two RUMs, equivalent with only two choice alternatives, diverge progressively as the number of alternatives increases, resulting in substantially different estimates and predictions for key measures, such as elasticities and market shares. The LEVI model imposes the well-known independence-of-irrelevant-alternatives property, while SEVI does not. Instead, the SEVI choice probability for a particular option involves enumerating all subsets that contain this option. The SEVI model, though more complex to estimate, is shown to have computationally tractable closed-form choice probabilities. Much of the paper delves into explicating the properties of the SEVI model and exploring implications of the random component's skewness. Conceptually, the difference between the LEVI and SEVI models centers on whether information, known only to the agent, is more likely to increase or decrease the systematic utility parameterized using observed attributes. LEVI does the former; SEVI the latter. An immediate implication is that if choice is characterized by SEVI random components, then the observed choice is more likely to correspond to the systematic-utility-maximizing choice than if characterized by LEVI. Examining standard empirical examples from different applied areas, we find that the SEVI model outperforms the LEVI model, suggesting the relevance of its inclusion in applied researchers' toolkits.

Published
2024

3. Performance Characteristics of the NeuroEXPLORER, a Next-Generation Human Brain PET/CT Imager.

Author

Li, Hongdi, Badawi, Ramsey, Cherry, Simon, Fontaine, Kathryn, He, Liuchun, Henry, Shannan, Hillmer, Ansel, Hu, Lingzhi, Khattar, Nikkita, Leung, Edwin, Li, Tiantian, Li, Yusheng, Liu, Chi, Liu, Peng, Lu, Zhenrui, Majewski, Stanislaw, Matuskey, David, Morris, Evan, Mulnix, Tim, Omidvari, Negar, Samanta, Suranjana, Selfridge, Aaron, Sun, Xishan, Toyonaga, Takuya, Volpi, Tommaso, Zeng, Tianyi, Jones, Terry, Qi, Jinyi, and Carson, Richard

Subjects
DOI, NEMA, NeuroEXPLORER, brain PET, high resolution
Abstract

The collaboration of Yale, the University of California, Davis, and United Imaging Healthcare has successfully developed the NeuroEXPLORER, a dedicated human brain PET imager with high spatial resolution, high sensitivity, and a built-in 3-dimensional camera for markerless continuous motion tracking. It has high depth-of-interaction and time-of-flight resolutions, along with a 52.4-cm transverse field of view (FOV) and an extended axial FOV (49.5 cm) to enhance sensitivity. Here, we present the physical characterization, performance evaluation, and first human images of the NeuroEXPLORER. Methods: Measurements of spatial resolution, sensitivity, count rate performance, energy and timing resolution, and image quality were performed adhering to the National Electrical Manufacturers Association (NEMA) NU 2-2018 standard. The systems performance was demonstrated through imaging studies of the Hoffman 3-dimensional brain phantom and the mini-Derenzo phantom. Initial 18F-FDG images from a healthy volunteer are presented. Results: With filtered backprojection reconstruction, the radial and tangential spatial resolutions (full width at half maximum) averaged 1.64, 2.06, and 2.51 mm, with axial resolutions of 2.73, 2.89, and 2.93 mm for radial offsets of 1, 10, and 20 cm, respectively. The average time-of-flight resolution was 236 ps, and the energy resolution was 10.5%. NEMA sensitivities were 46.0 and 47.6 kcps/MBq at the center and 10-cm offset, respectively. A sensitivity of 11.8% was achieved at the FOV center. The peak noise-equivalent count rate was 1.31 Mcps at 58.0 kBq/mL, and the scatter fraction at 5.3 kBq/mL was 36.5%. The maximum count rate error at the peak noise-equivalent count rate was less than 5%. At 3 iterations, the NEMA image-quality contrast recovery coefficients varied from 74.5% (10-mm sphere) to 92.6% (37-mm sphere), and background variability ranged from 3.1% to 1.4% at a contrast of 4.0:1. An example human brain 18F-FDG image exhibited very high resolution, capturing intricate details in the cortex and subcortical structures. Conclusion: The NeuroEXPLORER offers high sensitivity and high spatial resolution. With its long axial length, it also enables high-quality spinal cord imaging and image-derived input functions from the carotid arteries. These performance enhancements will substantially broaden the range of human brain PET paradigms, protocols, and thereby clinical research applications.

Published
2024

4. Tractography derived quantitative estimates of tissue microstructure depend on streamline length: A characterization and method of adjustment

Author

Carson, Richard G. and Leemans, Alexander

Subjects
Quantitative Biology - Quantitative Methods
Abstract

Tractography algorithms are used extensively to delineate white matter structures, by operating on the voxel-wise information generated through the application of diffusion tensor imaging (DTI) or other models to diffusion weighted (DW) magnetic resonance imaging (MRI) data. We demonstrate that these methods commonly yield systematic streamline length dependent distortions of tractography derived tissue microstructure parameters, such as fractional anisotropy (FA). This dependency may be described as piecewise linear. For streamlines shorter than an inflection point (determined for a group of tracts delineated for each individual brain), estimates of tissue microstructure exhibit a positive linear relation with streamline length. For streamlines longer than the point of inflection, the association is weaker, with the slope of the relationship between streamline length and tissue microstructure differing only marginally from zero. As the dependency is most pronounced for a range of streamline lengths encountered typically in DW imaging of the human brain (less than ~100 mm), our results suggest that some previous estimates of tissue microstructure should be treated with considerable caution. A method is described, whereby an Akaike information weighted average of linear, Blackman and piecewise linear model predictions, may be used to compensate effectively for the dependence of FA (and other estimates of tissue microstructure) on streamline length, across the entire range of streamline lengths present in each specimen., Comment: 8 figures in main text; 7 figures in Supplementary Material

Published
2024

6. An update on the use of image-derived input functions for human PET studies: new hopes or old illusions?

Author

Volpi, Tommaso, Maccioni, Lucia, Colpo, Maria, Debiasi, Giulia, Capotosti, Amedeo, Ciceri, Tommaso, Carson, Richard, DeLorenzo, Christine, Hahn, Andreas, Knudsen, Gitte, Lammertsma, Adriaan, Price, Julie, Sossi, Vesna, Wang, Guobao, Zanotti-Fregonara, Paolo, Bertoldo, Alessandra, and Veronese, Mattia

Subjects
Blood sampling, High sensitivity, Image-derived input function, Long axial field of view, Total-body PET
Abstract

BACKGROUND: The need for arterial blood data in quantitative PET research limits the wider usability of this imaging method in clinical research settings. Image-derived input function (IDIF) approaches have been proposed as a cost-effective and non-invasive alternative to gold-standard arterial sampling. However, this approach comes with its own limitations-partial volume effects and radiometabolite correction among the most important-and varying rates of success, and the use of IDIF for brain PET has been particularly troublesome. MAIN BODY: This paper summarizes the limitations of IDIF methods for quantitative PET imaging and discusses some of the advances that may make IDIF extraction more reliable. The introduction of automated pipelines (both commercial and open-source) for clinical PET scanners is discussed as a way to improve the reliability of IDIF approaches and their utility for quantitative purposes. Survey data gathered from the PET community are then presented to understand whether the fields opinion of the usefulness and validity of IDIF is improving. Finally, as the introduction of next-generation PET scanners with long axial fields of view, ultra-high sensitivity, and improved spatial and temporal resolution, has also brought IDIF methods back into the spotlight, a discussion of the possibilities offered by these state-of-the-art scanners-inclusion of large vessels, less partial volume in small vessels, better description of the full IDIF kinetics, whole-body modeling of radiometabolite production-is included, providing a pathway for future use of IDIF. CONCLUSION: Improvements in PET scanner technology and software for automated IDIF extraction may allow to solve some of the major limitations associated with IDIF, such as partial volume effects and poor temporal sampling, with the exciting potential for accurate estimation of single kinetic rates. Nevertheless, until individualized radiometabolite correction can be performed effectively, IDIF approaches remain confined at best to a few tracers.

Published
2023

8. Author Correction: Synaptic loss and its association with symptom severity in Parkinson’s disease

Author

Holmes, Sophie E., Honhar, Praveen, Tinaz, Sule, Naganawa, Mika, Hilmer, Ansel T., Gallezot, Jean-Dominique, Dias, Mark, Yang, Yanghong, Toyonaga, Takuya, Esterlis, Irina, Mecca, Adam, Van Dyck, Christopher, Henry, Shannan, Ropchan, Jim, Nabulsi, Nabeel, Louis, Elan D., Comley, Robert, Finnema, Sjoerd J., Carson, Richard E., and Matuskey, David

Published
2024
Full Text
View/download PDF

10. The regional pattern of age-related synaptic loss in the human brain differs from gray matter volume loss: in vivo PET measurement with [11C]UCB-J

Author

Toyonaga, Takuya, Khattar, Nikkita, Wu, Yanjun, Lu, Yihuan, Naganawa, Mika, Gallezot, Jean-Dominique, Matuskey, David, Mecca, Adam P., Pittman, Brian, Dias, Mark, Nabulsi, Nabeel B., Finnema, Sjoerd J., Chen, Ming-Kai, Arnsten, Amy, Radhakrishnan, Rajiv, Skosnik, Patrick D., D’Souza, Deepak Cyril, Esterlis, Irina, Huang, Yiyun, van Dyck, Christopher H., and Carson, Richard E.

Published
2024
Full Text
View/download PDF

11. Integrating Non-Targeted Ecosystem Services into Assessment of Natural Stormwater Treatment Systems

Author

Le, Jennifer T, Gonzalez, Jennifer P, Carson, Richard T, Ambrose, Richard F, and Levin, Lisa A

Subjects
Environmental Sciences, Engineering, Environmental Management, Environmental Engineering, urban runoff, urban ecology, nature-based solutions, natural treatment systems, biofilters, ecosystem services, monitoring and evaluation, planning and management
Abstract

Natural stormwater treatment systems (NTS) are built ecosystems designed to capture and treat stormwater runoff via natural processes. Although NTS design typically targets water services, the biological communities associated with NTS (i.e., plants, animals, and microbes) can provide non-targeted functions that can result in ecosystem services, such as biodiversity, pollination, and climate regulation, or in some cases disservices. Additional co-benefits of NTS include recreation, education and outreach opportunities, and aesthetic value. A review of NTS ecosystem services and co-benefits is provided with specific examples from Los Angeles County, highlighting the need for ecosystem services indicators, standard measurements, and monitoring. As NTS become globally widespread, best practices must include the ability to holistically assess NTS performance in ways that extend beyond water treatment services. Three models are presented that can be used to evaluate NTS performance. Such information can be important in advancing NTS design, choosing spatial placement, and making choices between NTS and more traditional stormwater treatment options.

Published
2023

12. Imaging the fetal nonhuman primate brain with SV2A positron emission tomography (PET)

Author

Rossano, Samantha, Toyonaga, Takuya, Berg, Eric, Lorence, Isabella, Fowles, Krista, Nabulsi, Nabeel, Ropchan, Jim, Li, Songye, Ye, Yunpeng, Felchner, Zachary, Kukis, David, Huang, Yiyun, Benveniste, Helene, Tarantal, Alice F, Groman, Stephanie, and Carson, Richard E

Subjects
Reproductive Medicine, Biomedical and Clinical Sciences, Biomedical Imaging, Neurosciences, Pediatric, Brain Disorders, Perinatal Period - Conditions Originating in Perinatal Period, Reproductive health and childbirth, Neurological, Animals, Brain, Macaca mulatta, Membrane Glycoproteins, Nerve Tissue Proteins, Positron-Emission Tomography, Synaptogenesis, In utero, Positron emission tomography, SV2A, Nonhuman primate, Other Physical Sciences, Clinical Sciences, Nuclear Medicine & Medical Imaging, Clinical sciences
Abstract

PurposeExploring synaptic density changes during brain growth is crucial to understanding brain development. Previous studies in nonhuman primates report a rapid increase in synapse number between the late gestational period and the early neonatal period, such that synaptic density approaches adult levels by birth. Prenatal synaptic development may have an enduring impact on postnatal brain development, but precisely how synaptic density changes in utero are unknown because current methods to quantify synaptic density are invasive and require post-mortem brain tissue.MethodsWe used synaptic vesicle glycoprotein 2A (SV2A) positron emission tomography (PET) radioligands [11C]UCB-J and [18F]Syn-VesT-1 to conduct the first assessment of synaptic density in the developing fetal brain in gravid rhesus monkeys. Eight pregnant monkeys were scanned twice during the third trimester at two imaging sites. Fetal post-mortem samples were collected near term in a subset of subjects to quantify SV2A density by Western blot.ResultsImage-derived fetal brain SV2A measures increased during the third trimester. SV2A concentrations were greater in subcortical regions than in cortical regions at both gestational ages. Near term, SV2A density was higher in primary motor and visual areas than respective associative regions. Post-mortem quantification of SV2A density was significantly correlated with regional SV2A PET measures.ConclusionWhile further study is needed to determine the exact relationship of SV2A and synaptic density, the imaging paradigm developed in the current study allows for the effective in vivo study of SV2A development in the fetal brain.

Published
2022

17. Synthesizing Multi-Tracer PET Images for Alzheimer's Disease Patients using a 3D Unified Anatomy-aware Cyclic Adversarial Network

Author

Zhou, Bo, Wang, Rui, Chen, Ming-Kai, Mecca, Adam P., O'Dell, Ryan S., Van Dyck, Christopher H., Carson, Richard E., Duncan, James S., and Liu, Chi

Subjects
Electrical Engineering and Systems Science - Image and Video Processing, Computer Science - Artificial Intelligence, Computer Science - Computer Vision and Pattern Recognition
Abstract

Positron Emission Tomography (PET) is an important tool for studying Alzheimer's disease (AD). PET scans can be used as diagnostics tools, and to provide molecular characterization of patients with cognitive disorders. However, multiple tracers are needed to measure glucose metabolism (18F-FDG), synaptic vesicle protein (11C-UCB-J), and $\beta$-amyloid (11C-PiB). Administering multiple tracers to patient will lead to high radiation dose and cost. In addition, access to PET scans using new or less-available tracers with sophisticated production methods and short half-life isotopes may be very limited. Thus, it is desirable to develop an efficient multi-tracer PET synthesis model that can generate multi-tracer PET from single-tracer PET. Previous works on medical image synthesis focus on one-to-one fixed domain translations, and cannot simultaneously learn the feature from multi-tracer domains. Given 3 or more tracers, relying on previous methods will also create a heavy burden on the number of models to be trained. To tackle these issues, we propose a 3D unified anatomy-aware cyclic adversarial network (UCAN) for translating multi-tracer PET volumes with one unified generative model, where MR with anatomical information is incorporated. Evaluations on a multi-tracer PET dataset demonstrate the feasibility that our UCAN can generate high-quality multi-tracer PET volumes, with NMSE less than 15% for all PET tracers., Comment: Accepted at MICCAI 2021

Published
2021

18. Consensus for experimental design in electromyography (CEDE) project: Checklist for reporting and critically appraising studies using EMG (CEDE-Check)

Author

Besomi, Manuela, Devecchi, Valter, Falla, Deborah, McGill, Kevin, Kiernan, Matthew C., Merletti, Roberto, van Dieën, Jaap H., Tucker, Kylie, Clancy, Edward A., Søgaard, Karen, Hug, François, Carson, Richard G., Perreault, Eric, Gandevia, Simon, Besier, Thor, Rothwell, John C., Enoka, Roger M., Holobar, Aleš, Disselhorst-Klug, Catherine, Wrigley, Tim, Lowery, Madeleine, Farina, Dario, and Hodges, Paul W.

Published
2024
Full Text
View/download PDF

19. Perceptions of the seriousness of major public health problems during the COVID-19 pandemic in seven middle-income countries

Author

Carson, Richard T., Hanemann, Michael, Köhlin, Gunnar, Adamowicz, Wiktor, Sterner, Thomas, Amuakwa-Mensah, Franklin, Alpizar, Francisco, Khossravi, Emily A., Jeuland, Marc, Bonilla, Jorge A., Tan-Soo, Jie-Sheng, Nam, Pham Khanh, Ndiritu, Simon Wagura, Wadehra, Shivani, Chegere, Martin Julius, Visser, Martine, Chukwuone, Nnaemeka Andegbe, and Whittington, Dale

Published
2023
Full Text
View/download PDF

20. Local molecular and global connectomic contributions to cross-disorder cortical abnormalities

Author

Hansen, Justine Y, Shafiei, Golia, Vogel, Jacob W, Smart, Kelly, Bearden, Carrie E, Hoogman, Martine, Franke, Barbara, van Rooij, Daan, Buitelaar, Jan, McDonald, Carrie R, Sisodiya, Sanjay M, Schmaal, Lianne, Veltman, Dick J, van den Heuvel, Odile A, Stein, Dan J, van Erp, Theo GM, Ching, Christopher RK, Andreassen, Ole A, Hajek, Tomas, Opel, Nils, Modinos, Gemma, Aleman, André, van der Werf, Ysbrand, Jahanshad, Neda, Thomopoulos, Sophia I, Thompson, Paul M, Carson, Richard E, Dagher, Alain, and Misic, Bratislav

Subjects
Neurosciences, Pediatric, Brain Disorders, Mental Health, Aetiology, Underpinning research, 2.1 Biological and endogenous factors, 1.1 Normal biological development and functioning, Mental health, Neurological, Brain, Brain Diseases, Connectome, Humans, Magnetic Resonance Imaging, Neural Pathways
Abstract

Numerous brain disorders demonstrate structural brain abnormalities, which are thought to arise from molecular perturbations or connectome miswiring. The unique and shared contributions of these molecular and connectomic vulnerabilities to brain disorders remain unknown, and has yet to be studied in a single multi-disorder framework. Using MRI morphometry from the ENIGMA consortium, we construct maps of cortical abnormalities for thirteen neurodevelopmental, neurological, and psychiatric disorders from N = 21,000 participants and N = 26,000 controls, collected using a harmonised processing protocol. We systematically compare cortical maps to multiple micro-architectural measures, including gene expression, neurotransmitter density, metabolism, and myelination (molecular vulnerability), as well as global connectomic measures including number of connections, centrality, and connection diversity (connectomic vulnerability). We find a relationship between molecular vulnerability and white-matter architecture that drives cortical disorder profiles. Local attributes, particularly neurotransmitter receptor profiles, constitute the best predictors of both disorder-specific cortical morphology and cross-disorder similarity. Finally, we find that cross-disorder abnormalities are consistently subtended by a small subset of network epicentres in bilateral sensory-motor, inferior temporal lobe, precuneus, and superior parietal cortex. Collectively, our results highlight how local molecular attributes and global connectivity jointly shape cross-disorder cortical abnormalities.

Published
2022

25. Consensus for experimental design in electromyography (CEDE) project: Application of EMG to estimate muscle force

Author

J. M. Dick, Taylor, Tucker, Kylie, Hug, François, Besomi, Manuela, van Dieën, Jaap H., Enoka, Roger M., Besier, Thor, Carson, Richard G., Clancy, Edward A., Disselhorst-Klug, Catherine, Falla, Deborah, Farina, Dario, Gandevia, Simon, Holobar, Aleš, Kiernan, Matthew C., Lowery, Madeleine, McGill, Kevin, Merletti, Roberto, Perreault, Eric, Rothwell, John C., Søgaard, Karen, Wrigley, Tim, and Hodges, Paul W.

Published
2024
Full Text
View/download PDF

28. WTO must ban harmful fisheries subsidies

Author

Sumaila, U Rashid, Skerritt, Daniel J, Schuhbauer, Anna, Villasante, Sebastian, Cisneros-Montemayor, Andrés M, Sinan, Hussain, Burnside, Duncan, Abdallah, Patrízia Raggi, Abe, Keita, Addo, Kwasi A, Adelsheim, Julia, Adewumi, Ibukun J, Adeyemo, Olanike K, Adger, Neil, Adotey, Joshua, Advani, Sahir, Afrin, Zahidah, Aheto, Denis, Akintola, Shehu L, Akpalu, Wisdom, Alam, Lubna, Alava, Juan José, Allison, Edward H, Amon, Diva J, Anderies, John M, Anderson, Christopher M, Andrews, Evan, Angelini, Ronaldo, Anna, Zuzy, Antweiler, Werner, Arizi, Evans K, Armitage, Derek, Arthur, Robert I, Asare, Noble, Asche, Frank, Asiedu, Berchie, Asuquo, Francis, Badmus, Lanre, Bailey, Megan, Ban, Natalie, Barbier, Edward B, Barley, Shanta, Barnes, Colin, Barrett, Scott, Basurto, Xavier, Belhabib, Dyhia, Bennett, Elena, Bennett, Nathan J, Benzaken, Dominique, Blasiak, Robert, Bohorquez, John J, Bordehore, Cesar, Bornarel, Virginie, Boyd, David R, Breitburg, Denise, Brooks, Cassandra, Brotz, Lucas, Campbell, Donovan, Cannon, Sara, Cao, Ling, Cardenas Campo, Juan C, Carpenter, Steve, Carpenter, Griffin, Carson, Richard T, Carvalho, Adriana R, Castrejón, Mauricio, Caveen, Alex J, Chabi, M Nicole, Chan, Kai MA, Chapin, F Stuart, Charles, Tony, Cheung, William, Christensen, Villy, Chuku, Ernest O, Church, Trevor, Clark, Colin, Clarke, Tayler M, Cojocaru, Andreea L, Copeland, Brian, Crawford, Brian, Crépin, Anne-Sophie, Crowder, Larry B, Cury, Philippe, Cutting, Allison N, Daily, Gretchen C, Da-Rocha, Jose Maria, Das, Abhipsita, de la Puente, Santiago, de Zeeuw, Aart, Deikumah, Savior KS, Deith, Mairin, Dewitte, Boris, Doubleday, Nancy, Duarte, Carlos M, Dulvy, Nicholas K, Eddy, Tyler, Efford, Meaghan, Ehrlich, Paul R, Elsler, Laura G, and Fakoya, Kafayat A

Subjects
General Science & Technology
Published
2021

30. Multiparametric Cardiac 18F-FDG PET: Pilot Comparison of FDG Delivery Rate with 82Rb Myocardial Blood Flow

Author

Zuo, Yang, Lopez, Javier E., Smith, Thomas W., Foster, Cameron C., Carson, Richard E., Badawi, Ramsey D., and Wang, Guobao

Subjects
Physics - Medical Physics
Abstract

Myocardial blood flow (MBF) and flow reserve are usually quantified in the clinic with positron emission tomography (PET) using a perfusion-specific radiotracer (e.g. 82Rbchloride). However, the clinical accessibility of existing perfusion tracers remains limited. Meanwhile, 18F-fluorodeoxyglucose (FDG) is a commonly used radiotracer for PET metabolic imaging without similar limitations. In this paper, we explore the potential of 18F-FDG for myocardial perfusion imaging by comparing the myocardial FDG delivery rate K1 with MBF as determined by dynamic 82Rb PET in fourteen human subjects with heart disease. Two sets of FDG K1 were derived from one-hour dynamic FDG scans. One was the original FDG K1 estimates and the other was the corresponding K1 values that were linearly normalized for blood glucose levels. A generalized Renkin-Crone model was used to fit FDG K1 with Rb MBF, which then allowed for a nonlinear extraction fraction correction for converting FDG K1 to MBF. The linear correlation between FDG-derived MBF and Rb MBF was moderate (r=0.79) before the glucose normalization and became much improved (r>0.9) after glucose normalization. The extraction fraction of FDG was also similar to that of Rb-chloride in the myocardium. The results from this pilot study suggest that dynamic cardiac FDG-PET with tracer kinetic modeling has the potential to provide MBF in addition to its conventional use for metabolic imaging.

Published
2020
Full Text
View/download PDF

32. What is the function of inter-hemispheric inhibition?

Author

Carson, Richard G.

Subjects
Quantitative Biology - Neurons and Cognition
Abstract

It is widely supposed that following unilateral brain injury, there arises an asymmetry in inter-hemispheric inhibition which has an adverse influence upon motor control. I argue that this 'inter-hemispheric imbalance' model arises from a fundamental misunderstanding of the roles played by inter-hemispheric (callosal) projections in mammalian brains. Drawing upon a large body of empirical data, derived largely from animal models, and associated theoretical modeling, it is demonstrated that inter-hemispheric projections perform contrast enhancing and integrative functions via mechanisms such as surround/lateral inhibition. The principal functional unit of callosal influence comprises a facilitatory centre and a depressing peripheral zone, that together shape the influence of converging inputs to pyramidal neurons. Inter-hemispheric inhibition is an instance of a more general feature of mammalian neural systems, whereby inhibitory interneurons act not simply to prevent over-excitation but to sculpt the output of specific circuits. The narrowing of the excitatory focus that occurs through crossed surround inhibition is a highly conserved motif of transcallosal interactions in mammalian sensory and motor cortices. A case is presented that the notion of 'inter-hemispheric imbalance' has been sustained, and clinical interventions derived from this model promoted, by erroneous assumptions concerning that revealed by investigative techniques such as transcranial magnetic stimulation (TMS). The alternative perspective promoted by the present analysis, also permits the basis of positive (e.g. post stroke) associations between the structural integrity of transcallosal projections and motor capability to be better understood., Comment: 45 pages (including references and figure legends), 4 figures

Published
2020
Full Text
View/download PDF

33. Circular-SWAT for deep learning based diagnostic classification of Alzheimer's disease: application to metabolome data

Author

Kaddurah-Daouk, Rima, Kueider-Paisley, Alexandra, Doraiswamy, P. Murali, Blach, Colette, Moseley, Arthur, Thompson, Will, St John-Williams, Lisa, Mahmoudiandehkhordi, Siamak, Tenenbaum, Jessica, Welsh-Balmer, Kathleen, Plassman, Brenda, Saykin, Andrew J., Nho, Kwangsik, Risacher, Shannon L., Kastenmüller, Gabi, Arnold, Matthias, Han, Xianlin, Baillie, Rebecca, Knight, Rob, Dorrestein, Pieter, Brewer, James, Mayer, Emeran, Labus, Jennifer, Baldi, Pierre, Gupta, Arpana, Fiehn, Oliver, Barupal, Dinesh, Meikle, Peter, Mazmanian, Sarkis, Rader, Dan, Kling, Mitchel, Shaw, Leslie, Trojanowski, John, van Duijin, Cornelia, Nevado-Holgado, Alejo, Bennett, David, Krishnan, Ranga, Keshavarzian, Ali, Vogt, Robin, Ikram, Arfan, Hankemeier, Thomas, Thiele, Ines, Price, Nathan, Funk, Cory, Baloni, Priyanka, Jia, Wei, Wishart, David, Brinton, Roberta, Chang, Rui, Farrer, Lindsay, Au, Rhoda, Qiu, Wendy, Würtz, Peter, Koal, Therese, Mangravite, Lara, Krumsiek, Jan, Suhre, Karsten, Newman, John, Moreno, Herman, Foroud, Tatania, Sacks, Frank, Jansson, Janet, Weiner, Michael W., Aisen, Paul, Petersen, Ronald, Jack, Clifford R., Jr., Jagust, William, Trojanowki, John Q., Toga, Arthur W., Beckett, Laurel, Green, Robert C., Morris, John C., Perrin, Richard J., Shaw, Leslie M., Khachaturian, Zaven, Carrillo, Maria, Potter, William, Barnes, Lisa, Bernard, Marie, Gonzalez, Hector, Ho, Carole, Hsiao, John K., Jackson, Jonathan, Masliah, Eliezer, Masterman, Donna, Okonkwo, Ozioma, Perrin, Richard, Ryan, Laurie, Silverberg, Nina, Fleisher, Adam, Sacrey, Diana Truran, Fockler, Juliet, Conti, Cat, Veitch, Dallas, Neuhaus, John, Jin, Chengshi, Nosheny, Rachel, Ashford, Miriam, Flenniken, Derek, Kormos, Adrienne, Montine, Tom, Rafii, Michael, Raman, Rema, Jimenez, Gustavo, Donohue, Michael, Gessert, Devon, Salazar, Jennifer, Zimmerman, Caileigh, Cabrera, Yuliana, Walter, Sarah, Miller, Garrett, Coker, Godfrey, Clanton, Taylor, Hergesheimer, Lindsey, Smith, Stephanie, Adegoke, Olusegun, Mahboubi, Payam, Moore, Shelley, Pizzola, Jeremy, Shaffer, Elizabeth, Sloan, Brittany, Harvey, Danielle, Forghanian-Arani, Arvin, Borowski, Bret, Ward, Chad, Schwarz, Christopher, Jones, David, Gunter, Jeff, Kantarci, Kejal, Senjem, Matthew, Vemuri, Prashanthi, Reid, Robert, Fox, Nick C., Malone, Ian, Thompson, Paul, Thomopoulos, Sophia I., Nir, Talia M., Jahanshad, Neda, DeCarli, Charles, Knaack, Alexander, Fletcher, Evan, Tosun-Turgut, Duygu, Chen, Stephanie Rossi, Choe, Mark, Crawford, Karen, Yushkevich, Paul A., Das, Sandhitsu, Koeppe, Robert A., Reiman, Eric M., Chen, Kewei, Mathis, Chet, Landau, Susan, Cairns, Nigel J., Householder, Erin, Franklin, Erin, Bernhardt, Haley, Taylor-Reinwald, Lisa, Korecka, Magdalena, Figurski, Michal, Neu, Scott, Apostolova, Liana G., Shen, Li, Foroud, Tatiana M., Nudelman, Kelly, Faber, Kelley, Wilmes, Kristi, Thal, Leon, Silbert, Lisa C., Lind, Betty, Crissey, Rachel, Kaye, Jeffrey A., Carter, Raina, Dolen, Sara, Quinn, Joseph, Schneider, Lon S., Pawluczyk, Sonia, Becerra, Mauricio, Teodoro, Liberty, Dagerman, Karen, Spann, Bryan M., Vanderswag, Helen, Ziolkowski, Jaimie, Heidebrink, Judith L., Zbizek-Nulph, Lisa, Lord, Joanne L., Mason, Sara S., Albers, Colleen S., Knopman, David, Johnson, Kris, Villanueva-Meyer, Javier, Pavlik, Valory, Pacini, Nathaniel, Lamb, Ashley, Kass, Joseph S., Doody, Rachelle S., Shibley, Victoria, Chowdhury, Munir, Rountree, Susan, Dang, Mimi, Stern, Yaakov, Honig, Lawrence S., Mintz, Akiva, Ances, Beau, Winkfield, David, Carroll, Maria, Stobbs-Cucchi, Georgia, Oliver, Angela, Creech, Mary L., Mintun, Mark A., Schneider, Stacy, Geldmacher, David, Love, Marissa Natelson, Griffith, Randall, Clark, David, Brockington, John, Marson, Daniel, Grossman, Hillel, Goldstein, Martin A., Greenberg, Jonathan, Mitsis, Effie, Shah, Raj C., Lamar, Melissa, Samuels, Patricia, Duara, Ranjan, Greig-Custo, Maria T., Rodriguez, Rosemarie, Albert, Marilyn, Onyike, Chiadi, Farrington, Leonie, Rudow, Scott, Brichko, Rottislav, Kielb, Stephanie, Smith, Amanda, Raj, Balebail Ashok, Fargher, Kristin, Sadowski, Martin, Wisniewski, Thomas, Shulman, Melanie, Faustin, Arline, Rao, Julia, Castro, Karen M., Ulysse, Anaztasia, Chen, Shannon, Sheikh, Mohammed O., Singleton-Garvin, Jamika, Petrella, JeffreyR., James, Olga, Wong, Terence Z., Borges-Neto, Salvador, Karlawish, Jason H., Wolk, David A., Vaishnavi, Sanjeev, Clark, Christopher M., Arnold, Steven E., Smith, Charles D., Jicha, Gregory A., Raslau, Flavius D., Lopez, Oscar L., Oakley, MaryAnn, Simpson, Donna M., Porsteinsson, Anton P., Martin, Kim, Kowalski, Nancy, Keltz, Melanie, Goldstein, Bonnie S., Makino, Kelly M., Ismail, M. Saleem, Brand, Connie, Thai, Gaby, Pierce, Aimee, Yanez, Beatriz, Sosa, Elizabeth, Witbracht, Megan, Kelley, Brendan, Nguyen, Trung, Womack, Kyle, Mathews, Dana, Quiceno, Mary, Levey, Allan I., Lah, James J., Hajjar, Ihab, Cellar, Janet S., Burns, Jeffrey M., Swerdlow, Russell H., Brooks, William M., Silverman, Daniel H.S., Kremen, Sarah, Apostolova, Liana, Tingus, Kathleen, Lu, Po H., Bartzokis, George, Woo, Ellen, Teng, Edmond, Graff-Radford, Neill R., Parfitt, Francine, Poki-Walker, Kim, Farlow, Martin R., Hake, Ann Marie, Matthews, Brandy R., Brosch, Jared R., Herring, Scott, van, Christopher H., Mecca, Adam P., Good, Susan P., MacAvoy, Martha G., Carson, Richard E., Varma, Pradeep, Chertkow, Howard, Vaitekunis, Susan, Hosein, Chris, Black, Sandra, Stefanovic, Bojana, Heyn, Chris (Chinthaka), Robin Hsiung, Ging-Yuek, Kim, Ellen, Mudge, Benita, Sossi, Vesna, Feldman, Howard, Assaly, Michele, Finger, Elizabeth, Pasternak, Stephen, Rachinsky, Irina, Kertesz, Andrew, Drost, Dick, Rogers, John, Grant, Ian, Muse, Brittanie, Rogalski, Emily, Robson, Jordan, Mesulam, M.-Marsel, Kerwin, Diana, Wu, Chuang-Kuo, Johnson, Nancy, Lipowski, Kristine, Weintraub, Sandra, Bonakdarpour, Borna, Pomara, Nunzio, Hernando, Raymundo, Sarrael, Antero, Rosen, Howard J., Miller, Bruce L., Perry, David, Turner, Raymond Scott, Johnson, Kathleen, Reynolds, Brigid, MCCann, Kelly, Poe, Jessica, Sperling, Reisa A., Johnson, Keith A., Marshall, Gad A., Yesavage, Jerome, Taylor, Joy L., Chao, Steven, Coleman, Jaila, White, Jessica D., Lane, Barton, Rosen, Allyson, Tinklenberg, Jared, Belden, Christine M., Atri, Alireza, Clark, Kelly A., Zamrini, Edward, Sabbagh, Marwan, Killiany, Ronald, Stern, Robert, Mez, Jesse, Kowall, Neil, Budson, Andrew E., Obisesan, Thomas O., Ntekim, Oyonumo E., Wolday, Saba, Khan, Javed I., Nwulia, Evaristus, Nadarajah, Sheeba, Lerner, Alan, Ogrocki, Paula, Tatsuoka, Curtis, Fatica, Parianne, Maillard, Pauline, Olichney, John, Carmichael, Owen, Bates, Vernice, Capote, Horacio, Rainka, Michelle, Borrie, Michael, Lee, T.-Y., Bartha, Dr Rob, Johnson, Sterling, Asthana, Sanjay, Carlsson, Cynthia M., Perrin, Allison, Burke, Anna, Scharre, Douglas W., Kataki, Maria, Tarawneh, Rawan, Hart, David, Zimmerman, Earl A., Celmins, Dzintra, Miller, Delwyn D., BolesPonto, Laura L., Smith, Karen Ekstam, Koleva, Hristina, Shim, Hyungsub, Nam, Ki Won, Schultz, Susan K., Williamson, Jeff D., Craft, Suzanne, Cleveland, Jo, Yang, Mia, Sink, Kaycee M., Ott, Brian R., Drake, Jonathan, Tremont, Geoffrey, Daiello, Lori A., Drake, Jonathan D., Ritter, Aaron, Bernick, Charles, Munic, Donna, O'Connelll, Abigail, Mintzer, Jacobo, Wiliams, Arthur, Masdeu, Joseph, Shi, Jiong, Garcia, Angelica, Newhouse, Paul, Potkin, Steven, Salloway, Stephen, Malloy, Paul, Correia, Stephen, Kittur, Smita, Pearlson, Godfrey D., Blank, Karen, Anderson, Karen, Flashman, Laura A., Seltzer, Marc, Hynes, Mary L., Santulli, Robert B., Relkin, Norman, Chiang, Gloria, Lee, Athena, Lin, Michael, Ravdin, Lisa, Petersen, Ron, Neylan, Thomas, Grafman, Jordan, Danowski, Sarah, Nguyen-Barrera, Catherine, Hayes, Jacqueline, Finley, Shannon, Bernstein, Matthew, Senjem, Matt, Foster, Norm, Kim, Sungeun, Sood, Ajay, Blanchard, Kimberly S., Fleischman, Debra, Arfanakis, Konstantinos, Varon, Daniel, Greig, Maria T., Petrella, Jeffrey R., Goldstein, Bonnie, Martin, Kimberly S., Reist, Christopher, Sadowsky, Carl, Martinez, Walter, Villena, Teresa, Rosen, Howard, Marshall, Gad, Peskind, Elaine R., Petrie, Eric C., Li, Gail, Mackin, Scott, Jimenez-Maggiora, Gustavo, Drake, Erin, Donohue, Mike, Nelson, Craig, Bickford, David, Butters, Meryl, Zmuda, Michelle, Reyes, Denise, Faber, Kelley M., Nudelman, Kelly N., Au, Yiu Ho, Scherer, Kelly, Catalinotto, Daniel, Stark, Samuel, Ong, Elise, Fernandez, Dariella, Jo, Taeho, Kim, Junpyo, Bice, Paula, Huynh, Kevin, Wang, Tingting, Meikle, Peter J., and Giles, Corey

Published
2023
Full Text
View/download PDF

36. Retraction Note: Cannabinoid type 1 receptor availability in the amygdala mediates threat processing in trauma survivors

Author

Pietrzak, Robert H, Huang, Yiyun, Corsi-Travali, Stefani, Zheng, Ming-Qiang, Lin, Shu-fei, Henry, Shannan, Potenza, Marc N, Piomelli, Daniele, Carson, Richard E, and Neumeister, Alexander

Subjects
Biological Psychology, Psychology, Medical and Health Sciences, Psychology and Cognitive Sciences, Psychiatry, Neurosciences, Biological psychology
Abstract

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Published
2020

37. Mapping neurotransmitter systems to the structural and functional organization of the human neocortex

Author

Hansen, Justine Y., Shafiei, Golia, Markello, Ross D., Smart, Kelly, Cox, Sylvia M. L., Nørgaard, Martin, Beliveau, Vincent, Wu, Yanjun, Gallezot, Jean-Dominique, Aumont, Étienne, Servaes, Stijn, Scala, Stephanie G., DuBois, Jonathan M., Wainstein, Gabriel, Bezgin, Gleb, Funck, Thomas, Schmitz, Taylor W., Spreng, R. Nathan, Galovic, Marian, Koepp, Matthias J., Duncan, John S., Coles, Jonathan P., Fryer, Tim D., Aigbirhio, Franklin I., McGinnity, Colm J., Hammers, Alexander, Soucy, Jean-Paul, Baillet, Sylvain, Guimond, Synthia, Hietala, Jarmo, Bedard, Marc-André, Leyton, Marco, Kobayashi, Eliane, Rosa-Neto, Pedro, Ganz, Melanie, Knudsen, Gitte M., Palomero-Gallagher, Nicola, Shine, James M., Carson, Richard E., Tuominen, Lauri, Dagher, Alain, and Misic, Bratislav

Published
2022
Full Text
View/download PDF

39. A Novel Loss Function Incorporating Imaging Acquisition Physics for PET Attenuation Map Generation using Deep Learning

Author

Shi, Luyao, Onofrey, John A., Revilla, Enette Mae, Toyonaga, Takuya, Menard, David, Ankrah, Jo-seph, Carson, Richard E., Liu, Chi, and Lu, Yihuan

Subjects
Electrical Engineering and Systems Science - Image and Video Processing, Computer Science - Computer Vision and Pattern Recognition, Computer Science - Machine Learning, Physics - Medical Physics
Abstract

In PET/CT imaging, CT is used for PET attenuation correction (AC). Mismatch between CT and PET due to patient body motion results in AC artifacts. In addition, artifact caused by metal, beam-hardening and count-starving in CT itself also introduces inaccurate AC for PET. Maximum likelihood reconstruction of activity and attenuation (MLAA) was proposed to solve those issues by simultaneously reconstructing tracer activity ($\lambda$-MLAA) and attenuation map ($\mu$-MLAA) based on the PET raw data only. However, $\mu$-MLAA suffers from high noise and $\lambda$-MLAA suffers from large bias as compared to the reconstruction using the CT-based attenuation map ($\mu$-CT). Recently, a convolutional neural network (CNN) was applied to predict the CT attenuation map ($\mu$-CNN) from $\lambda$-MLAA and $\mu$-MLAA, in which an image-domain loss (IM-loss) function between the $\mu$-CNN and the ground truth $\mu$-CT was used. However, IM-loss does not directly measure the AC errors according to the PET attenuation physics, where the line-integral projection of the attenuation map ($\mu$) along the path of the two annihilation events, instead of the $\mu$ itself, is used for AC. Therefore, a network trained with the IM-loss may yield suboptimal performance in the $\mu$ generation. Here, we propose a novel line-integral projection loss (LIP-loss) function that incorporates the PET attenuation physics for $\mu$ generation. Eighty training and twenty testing datasets of whole-body 18F-FDG PET and paired ground truth $\mu$-CT were used. Quantitative evaluations showed that the model trained with the additional LIP-loss was able to significantly outperform the model trained solely based on the IM-loss function., Comment: Accepted at MICCAI 2019

Published
2019

41. Consensus for experimental design in electromyography (CEDE) project: Single motor unit matrix

Author

Martinez-Valdes, Eduardo, Enoka, Roger M., Holobar, Aleš, McGill, Kevin, Farina, Dario, Besomi, Manuela, Hug, François, Falla, Deborah, Carson, Richard G., Clancy, Edward A., Disselhorst-Klug, Catherine, van Dieën, Jaap H., Tucker, Kylie, Gandevia, Simon, Lowery, Madeleine, Søgaard, Karen, Besier, Thor, Merletti, Roberto, Kiernan, Matthew C., Rothwell, John C., Perreault, Eric, and Hodges, Paul W.

Published
2023
Full Text
View/download PDF

44. Effects of Age and BMI on Histamine H3 Receptor Availability in Healthy Humans

Author

Yang, Yanghong, primary, Ibrahim, Waleed, additional, Gravel, Paul, additional, Pittman, Brian, additional, Hoye, Jocelyn, additional, Cool, Ryan, additional, Sadabad, Faranak Ebrahimian, additional, Pittenger, Christopher, additional, Gallezot, Jean-Dominique, additional, Carson, Richard E., additional, Huang, Henry, additional, Radhakrishnan, Rajiv, additional, and Matuskey, David, additional

Published
2024
Full Text
View/download PDF

45. Connecting the Dots: Approaching a Standardized Nomenclature for Molecular Connectivity Combining Data and Literature

Author

Reed, Murray Bruce, primary, Cocchi, Luca, additional, Knudsen, Gitte Moos, additional, Sander, Christin, additional, Gryglewski, Gregor, additional, Chen, Jingyuan, additional, Volpi, Tommaso, additional, Fisher, Patrick, additional, Khattar, Nikkita, additional, Silberbauer, Leo R, additional, Murgas, Matej, additional, Godbersen, Godber Mathis, additional, Nics, Lukas, additional, Walter, Martin, additional, Hacker, Marcus, additional, Hammers, Alexander, additional, Ogden, Todd R, additional, Mann, Joseph J, additional, Biswal, Bharat, additional, Rosen, Bruce, additional, Carson, Richard, additional, Price, Julie, additional, Lanzenberger, Rupert, additional, and Hahn, Andreas, additional

Published
2024
Full Text
View/download PDF

46. Pilot PET study of vaginally administered bioadhesive nanoparticles in cynomolgus monkeys: Kinetics and safety evaluation

Author

Grun, Molly K., primary, Honhar, Praveen, additional, Wang, Yazhe, additional, Rossano, Samantha, additional, Khang, Minsoo, additional, Suh, Hee Won, additional, Fowles, Krista, additional, Kliman, Harvey J., additional, Cavaliere, Alessandra, additional, Carson, Richard E., additional, Marquez‐Nostra, Bernadette, additional, and Saltzman, W. Mark, additional

Published
2024
Full Text
View/download PDF

47. 37. The Structural Connectome Constrains in Vivo Synaptic Density Loss in Schizophrenia

Author

Chopra, Sidhant, primary, Worhunsky, Patrick, additional, Naganawa, Mika, additional, Angarita, Gustavo, additional, Cosgrove, Kelly, additional, D'Souza, Deepak, additional, Matuskey, David, additional, Nabulsi, Nabeel, additional, Huang, Yiyun, additional, Carson, Richard E., additional, Esterlis, Irina, additional, Skosnik, Patrick D., additional, Holmes, Avram, additional, and Radhakrishnan, Rajiv, additional

Published
2024
Full Text
View/download PDF

50. Measuring Synaptic Density and Dopamine Transporter Availability in Parkinson's Disease: A PET Imaging Study with 11C-UCB-J and 18F-FE-PE2I (P7-3.007)

Author

Saadabad, Faranak Ebrahimian, primary, Volpi, Tommaso, additional, Honhar, Praveen, additional, Naganawa, Mika, additional, Cayir, Salih, additional, Tinaz, Sule, additional, Gallezot, Jean-Dominique, additional, angarita, Gustavo, additional, Holmes, Sophie, additional, Carson, Richard, additional, Finnema, Sjoerd, additional, and Matuskey, David, additional

Published
2024
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results