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2. The Integrated Forward-Forward Algorithm: Integrating Forward-Forward and Shallow Backpropagation With Local Losses

Author

Tang, Desmond Y. M.

Subjects
Computer Science - Neural and Evolutionary Computing, Computer Science - Artificial Intelligence
Abstract

The backpropagation algorithm, despite its widespread use in neural network learning, may not accurately emulate the human cortex's learning process. Alternative strategies, such as the Forward-Forward Algorithm (FFA), offer a closer match to the human cortex's learning characteristics. However, the original FFA paper and related works on the Forward-Forward Algorithm only mentioned very limited types of neural network mechanisms and may limit its application and effectiveness. In response to these challenges, we propose an integrated method that combines the strengths of both FFA and shallow backpropagation, yielding a biologically plausible neural network training algorithm which can also be applied to various network structures. We applied this integrated approach to the classification of the Modified National Institute of Standards and Technology (MNIST) database, where it outperformed FFA and demonstrated superior resilience to noise compared to backpropagation. We show that training neural networks with the Integrated Forward-Forward Algorithm has the potential of generating neural networks with advantageous features like robustness.

Published
2023

3. Event‐based modeling in temporal lobe epilepsy demonstrates progressive atrophy from cross‐sectional data

Author

Lopez, Seymour M, Aksman, Leon M, Oxtoby, Neil P, Vos, Sjoerd B, Rao, Jun, Kaestner, Erik, Alhusaini, Saud, Alvim, Marina, Bender, Benjamin, Bernasconi, Andrea, Bernasconi, Neda, Bernhardt, Boris, Bonilha, Leonardo, Caciagli, Lorenzo, Caldairou, Benoit, Caligiuri, Maria Eugenia, Calvet, Angels, Cendes, Fernando, Concha, Luis, Conde‐Blanco, Estefania, Davoodi‐Bojd, Esmaeil, de Bézenac, Christophe, Delanty, Norman, Desmond, Patricia M, Devinsky, Orrin, Domin, Martin, Duncan, John S, Focke, Niels K, Foley, Sonya, Fortunato, Francesco, Galovic, Marian, Gambardella, Antonio, Gleichgerrcht, Ezequiel, Guerrini, Renzo, Hamandi, Khalid, Ives‐Deliperi, Victoria, Jackson, Graeme D, Jahanshad, Neda, Keller, Simon S, Kochunov, Peter, Kotikalapudi, Raviteja, Kreilkamp, Barbara AK, Labate, Angelo, Larivière, Sara, Lenge, Matteo, Lui, Elaine, Malpas, Charles, Martin, Pascal, Mascalchi, Mario, Medland, Sarah E, Meletti, Stefano, Morita‐Sherman, Marcia E, Owen, Thomas W, Richardson, Mark, Riva, Antonella, Rüber, Theodor, Sinclair, Ben, Soltanian‐Zadeh, Hamid, Stein, Dan J, Striano, Pasquale, Taylor, Peter N, Thomopoulos, Sophia I, Thompson, Paul M, Tondelli, Manuela, Vaudano, Anna Elisabetta, Vivash, Lucy, Wang, Yujiang, Weber, Bernd, Whelan, Christopher D, Wiest, Roland, Winston, Gavin P, Yasuda, Clarissa Lin, McDonald, Carrie R, Alexander, Daniel C, Sisodiya, Sanjay M, Altmann, Andre, Bargalló, Núria, Bartolini, Emanuele, O’Brien, Terence J, and Thomas, Rhys H

Subjects
Brain Disorders, Epilepsy, Neurodegenerative, Neurosciences, Clinical Research, Biomedical Imaging, Aetiology, 2.1 Biological and endogenous factors, Neurological, Good Health and Well Being, Atrophy, Biomarkers, Cross-Sectional Studies, Epilepsy, Temporal Lobe, Hippocampus, Humans, Magnetic Resonance Imaging, Sclerosis, disease progression, duration of illness, event-based model, MTLE, patient staging, ENIGMA-Epilepsy Working Group, Clinical Sciences, Neurology & Neurosurgery
Abstract

ObjectiveRecent work has shown that people with common epilepsies have characteristic patterns of cortical thinning, and that these changes may be progressive over time. Leveraging a large multicenter cross-sectional cohort, we investigated whether regional morphometric changes occur in a sequential manner, and whether these changes in people with mesial temporal lobe epilepsy and hippocampal sclerosis (MTLE-HS) correlate with clinical features.MethodsWe extracted regional measures of cortical thickness, surface area, and subcortical brain volumes from T1-weighted (T1W) magnetic resonance imaging (MRI) scans collected by the ENIGMA-Epilepsy consortium, comprising 804 people with MTLE-HS and 1625 healthy controls from 25 centers. Features with a moderate case-control effect size (Cohen d ≥ .5) were used to train an event-based model (EBM), which estimates a sequence of disease-specific biomarker changes from cross-sectional data and assigns a biomarker-based fine-grained disease stage to individual patients. We tested for associations between EBM disease stage and duration of epilepsy, age at onset, and antiseizure medicine (ASM) resistance.ResultsIn MTLE-HS, decrease in ipsilateral hippocampal volume along with increased asymmetry in hippocampal volume was followed by reduced thickness in neocortical regions, reduction in ipsilateral thalamus volume, and finally, increase in ipsilateral lateral ventricle volume. EBM stage was correlated with duration of illness (Spearman ρ = .293, p = 7.03 × 10-16 ), age at onset (ρ = -.18, p = 9.82 × 10-7 ), and ASM resistance (area under the curve = .59, p = .043, Mann-Whitney U test). However, associations were driven by cases assigned to EBM Stage 0, which represents MTLE-HS with mild or nondetectable abnormality on T1W MRI.SignificanceFrom cross-sectional MRI, we reconstructed a disease progression model that highlights a sequence of MRI changes that aligns with previous longitudinal studies. This model could be used to stage MTLE-HS subjects in other cohorts and help establish connections between imaging-based progression staging and clinical features.

Published
2022

4. Topographic divergence of atypical cortical asymmetry and atrophy patterns in temporal lobe epilepsy

Author

Park, Bo-yong, Larivière, Sara, Rodríguez-Cruces, Raul, Royer, Jessica, Tavakol, Shahin, Wang, Yezhou, Caciagli, Lorenzo, Caligiuri, Maria Eugenia, Gambardella, Antonio, Concha, Luis, Keller, Simon S, Cendes, Fernando, Alvim, Marina KM, Yasuda, Clarissa, Bonilha, Leonardo, Gleichgerrcht, Ezequiel, Focke, Niels K, Kreilkamp, Barbara AK, Domin, Martin, von Podewils, Felix, Langner, Soenke, Rummel, Christian, Rebsamen, Michael, Wiest, Roland, Martin, Pascal, Kotikalapudi, Raviteja, Bender, Benjamin, O’Brien, Terence J, Law, Meng, Sinclair, Benjamin, Vivash, Lucy, Kwan, Patrick, Desmond, Patricia M, Malpas, Charles B, Lui, Elaine, Alhusaini, Saud, Doherty, Colin P, Cavalleri, Gianpiero L, Delanty, Norman, Kälviäinen, Reetta, Jackson, Graeme D, Kowalczyk, Magdalena, Mascalchi, Mario, Semmelroch, Mira, Thomas, Rhys H, Soltanian-Zadeh, Hamid, Davoodi-Bojd, Esmaeil, Zhang, Junsong, Lenge, Matteo, Guerrini, Renzo, Bartolini, Emanuele, Hamandi, Khalid, Foley, Sonya, Weber, Bernd, Depondt, Chantal, Absil, Julie, Carr, Sarah JA, Abela, Eugenio, Richardson, Mark P, Devinsky, Orrin, Severino, Mariasavina, Striano, Pasquale, Parodi, Costanza, Tortora, Domenico, Hatton, Sean N, Vos, Sjoerd B, Duncan, John S, Galovic, Marian, Whelan, Christopher D, Bargalló, Núria, Pariente, Jose, Conde-Blanco, Estefania, Vaudano, Anna Elisabetta, Tondelli, Manuela, Meletti, Stefano, Kong, Xiang‐Zhen, Francks, Clyde, Fisher, Simon E, Caldairou, Benoit, Ryten, Mina, Labate, Angelo, Sisodiya, Sanjay M, Thompson, Paul M, McDonald, Carrie R, Bernasconi, Andrea, Bernasconi, Neda, and Bernhardt, Boris C

Subjects
Epilepsy, Neurodegenerative, Clinical Research, Brain Disorders, Neurosciences, Aetiology, 2.1 Biological and endogenous factors, Neurological, Adult, Atrophy, Connectome, Epilepsy, Temporal Lobe, Hippocampus, Humans, Magnetic Resonance Imaging, temporal lobe epilepsy, asymmetry, cortical thickness, multi-site, gradients, Medical and Health Sciences, Psychology and Cognitive Sciences, Neurology & Neurosurgery
Abstract

Temporal lobe epilepsy, a common drug-resistant epilepsy in adults, is primarily a limbic network disorder associated with predominant unilateral hippocampal pathology. Structural MRI has provided an in vivo window into whole-brain grey matter structural alterations in temporal lobe epilepsy relative to controls, by either mapping (i) atypical inter-hemispheric asymmetry; or (ii) regional atrophy. However, similarities and differences of both atypical asymmetry and regional atrophy measures have not been systematically investigated. Here, we addressed this gap using the multisite ENIGMA-Epilepsy dataset comprising MRI brain morphological measures in 732 temporal lobe epilepsy patients and 1418 healthy controls. We compared spatial distributions of grey matter asymmetry and atrophy in temporal lobe epilepsy, contextualized their topographies relative to spatial gradients in cortical microstructure and functional connectivity calculated using 207 healthy controls obtained from Human Connectome Project and an independent dataset containing 23 temporal lobe epilepsy patients and 53 healthy controls and examined clinical associations using machine learning. We identified a marked divergence in the spatial distribution of atypical inter-hemispheric asymmetry and regional atrophy mapping. The former revealed a temporo-limbic disease signature while the latter showed diffuse and bilateral patterns. Our findings were robust across individual sites and patients. Cortical atrophy was significantly correlated with disease duration and age at seizure onset, while degrees of asymmetry did not show a significant relationship to these clinical variables. Our findings highlight that the mapping of atypical inter-hemispheric asymmetry and regional atrophy tap into two complementary aspects of temporal lobe epilepsy-related pathology, with the former revealing primary substrates in ipsilateral limbic circuits and the latter capturing bilateral disease effects. These findings refine our notion of the neuropathology of temporal lobe epilepsy and may inform future discovery and validation of complementary MRI biomarkers in temporal lobe epilepsy.

Published
2022

5. The ENIGMA‐Epilepsy working group: Mapping disease from large data sets

Author

Sisodiya, Sanjay M, Whelan, Christopher D, Hatton, Sean N, Huynh, Khoa, Altmann, Andre, Ryten, Mina, Vezzani, Annamaria, Caligiuri, Maria Eugenia, Labate, Angelo, Gambardella, Antonio, Ives‐Deliperi, Victoria, Meletti, Stefano, Munsell, Brent C, Bonilha, Leonardo, Tondelli, Manuela, Rebsamen, Michael, Rummel, Christian, Vaudano, Anna Elisabetta, Wiest, Roland, Balachandra, Akshara R, Bargalló, Núria, Bartolini, Emanuele, Bernasconi, Andrea, Bernasconi, Neda, Bernhardt, Boris, Caldairou, Benoit, Carr, Sarah JA, Cavalleri, Gianpiero L, Cendes, Fernando, Concha, Luis, Desmond, Patricia M, Domin, Martin, Duncan, John S, Focke, Niels K, Guerrini, Renzo, Hamandi, Khalid, Jackson, Graeme D, Jahanshad, Neda, Kälviäinen, Reetta, Keller, Simon S, Kochunov, Peter, Kowalczyk, Magdalena A, Kreilkamp, Barbara AK, Kwan, Patrick, Lariviere, Sara, Lenge, Matteo, Lopez, Seymour M, Martin, Pascal, Mascalchi, Mario, Moreira, José CV, Morita‐Sherman, Marcia E, Pardoe, Heath R, Pariente, Jose C, Raviteja, Kotikalapudi, Rocha, Cristiane S, Rodríguez‐Cruces, Raúl, Seeck, Margitta, Semmelroch, Mira KHG, Sinclair, Benjamin, Soltanian‐Zadeh, Hamid, Stein, Dan J, Striano, Pasquale, Taylor, Peter N, Thomas, Rhys H, Thomopoulos, Sophia I, Velakoulis, Dennis, Vivash, Lucy, Weber, Bernd, Yasuda, Clarissa Lin, Zhang, Junsong, Thompson, Paul M, McDonald, Carrie R, Abela, Eugenio, Absil, Julie, Adams, Sophia, Alhusaini, Saud, Alvim, Marina, Balestrini, Simona, Bender, Benjamin, Bergo, Felipe, Bernardes, Tauana, Calvo, Anna, Carreno, Mar, Cherubini, Andrea, David, Philippe, Davoodi‐Bojd, Esmaeil, Delanty, Norman, Depondt, Chantal, Devinsky, Orrin, Doherty, Colin, França, Wendy Caroline, Franceschet, Leticia, Hibar, Derrek P, Ishikawa, Akari, Kaestner, Erik, Langner, Soenke, Liu, Min, Mirandola, Laura, Naylor, Jillian, and Nazem‐Zadeh, Mohammad‐reza

Subjects
Brain Disorders, Biomedical Imaging, Neurosciences, Epilepsy, Neurodegenerative, 2.1 Biological and endogenous factors, Aetiology, Neurological, covariance, deep learning, DTI, event-based modeling, gene expression, genetics, imaging, MRI, quantitative, rsfMRI, ENIGMA Consortium Epilepsy Working Group, Cognitive Sciences, Experimental Psychology
Abstract

Epilepsy is a common and serious neurological disorder, with many different constituent conditions characterized by their electro clinical, imaging, and genetic features. MRI has been fundamental in advancing our understanding of brain processes in the epilepsies. Smaller-scale studies have identified many interesting imaging phenomena, with implications both for understanding pathophysiology and improving clinical care. Through the infrastructure and concepts now well-established by the ENIGMA Consortium, ENIGMA-Epilepsy was established to strengthen epilepsy neuroscience by greatly increasing sample sizes, leveraging ideas and methods established in other ENIGMA projects, and generating a body of collaborating scientists and clinicians to drive forward robust research. Here we review published, current, and future projects, that include structural MRI, diffusion tensor imaging (DTI), and resting state functional MRI (rsfMRI), and that employ advanced methods including structural covariance, and event-based modeling analysis. We explore age of onset- and duration-related features, as well as phenomena-specific work focusing on particular epilepsy syndromes or phenotypes, multimodal analyses focused on understanding the biology of disease progression, and deep learning approaches. We encourage groups who may be interested in participating to make contact to further grow and develop ENIGMA-Epilepsy.

Published
2022

6. Structural network alterations in focal and generalized epilepsy assessed in a worldwide ENIGMA study follow axes of epilepsy risk gene expression

Author

Larivière, Sara, Royer, Jessica, Rodríguez-Cruces, Raúl, Paquola, Casey, Caligiuri, Maria Eugenia, Gambardella, Antonio, Concha, Luis, Keller, Simon S, Cendes, Fernando, Yasuda, Clarissa L, Bonilha, Leonardo, Gleichgerrcht, Ezequiel, Focke, Niels K, Domin, Martin, von Podewills, Felix, Langner, Soenke, Rummel, Christian, Wiest, Roland, Martin, Pascal, Kotikalapudi, Raviteja, O’Brien, Terence J, Sinclair, Benjamin, Vivash, Lucy, Desmond, Patricia M, Lui, Elaine, Vaudano, Anna Elisabetta, Meletti, Stefano, Tondelli, Manuela, Alhusaini, Saud, Doherty, Colin P, Cavalleri, Gianpiero L, Delanty, Norman, Kälviäinen, Reetta, Jackson, Graeme D, Kowalczyk, Magdalena, Mascalchi, Mario, Semmelroch, Mira, Thomas, Rhys H, Soltanian-Zadeh, Hamid, Davoodi-Bojd, Esmaeil, Zhang, Junsong, Winston, Gavin P, Griffin, Aoife, Singh, Aditi, Tiwari, Vijay K, Kreilkamp, Barbara AK, Lenge, Matteo, Guerrini, Renzo, Hamandi, Khalid, Foley, Sonya, Rüber, Theodor, Weber, Bernd, Depondt, Chantal, Absil, Julie, Carr, Sarah JA, Abela, Eugenio, Richardson, Mark P, Devinsky, Orrin, Severino, Mariasavina, Striano, Pasquale, Tortora, Domenico, Kaestner, Erik, Hatton, Sean N, Vos, Sjoerd B, Caciagli, Lorenzo, Duncan, John S, Whelan, Christopher D, Thompson, Paul M, Sisodiya, Sanjay M, Bernasconi, Andrea, Labate, Angelo, McDonald, Carrie R, Bernasconi, Neda, and Bernhardt, Boris C

Subjects
Neurodegenerative, Genetics, Neurosciences, Brain Disorders, Epilepsy, Aetiology, 2.1 Biological and endogenous factors, Neurological, Adult, Connectome, Epilepsy, Generalized, Epilepsy, Temporal Lobe, Gene Expression, Humans, Immunoglobulin E, Magnetic Resonance Imaging, Nerve Net
Abstract

Epilepsy is associated with genetic risk factors and cortico-subcortical network alterations, but associations between neurobiological mechanisms and macroscale connectomics remain unclear. This multisite ENIGMA-Epilepsy study examined whole-brain structural covariance networks in patients with epilepsy and related findings to postmortem epilepsy risk gene expression patterns. Brain network analysis included 578 adults with temporal lobe epilepsy (TLE), 288 adults with idiopathic generalized epilepsy (IGE), and 1328 healthy controls from 18 centres worldwide. Graph theoretical analysis of structural covariance networks revealed increased clustering and path length in orbitofrontal and temporal regions in TLE, suggesting a shift towards network regularization. Conversely, people with IGE showed decreased clustering and path length in fronto-temporo-parietal cortices, indicating a random network configuration. Syndrome-specific topological alterations reflected expression patterns of risk genes for hippocampal sclerosis in TLE and for generalized epilepsy in IGE. These imaging-transcriptomic signatures could potentially guide diagnosis or tailor therapeutic approaches to specific epilepsy syndromes.

Published
2022

7. Artificial intelligence for classification of temporal lobe epilepsy with ROI-level MRI data: A worldwide ENIGMA-Epilepsy study

Author

Gleichgerrcht, Ezequiel, Munsell, Brent C, Alhusaini, Saud, Alvim, Marina KM, Bargalló, Núria, Bender, Benjamin, Bernasconi, Andrea, Bernasconi, Neda, Bernhardt, Boris, Blackmon, Karen, Caligiuri, Maria Eugenia, Cendes, Fernando, Concha, Luis, Desmond, Patricia M, Devinsky, Orrin, Doherty, Colin P, Domin, Martin, Duncan, John S, Focke, Niels K, Gambardella, Antonio, Gong, Bo, Guerrini, Renzo, Hatton, Sean N, Kälviäinen, Reetta, Keller, Simon S, Kochunov, Peter, Kotikalapudi, Raviteja, Kreilkamp, Barbara AK, Labate, Angelo, Langner, Soenke, Larivière, Sara, Lenge, Matteo, Lui, Elaine, Martin, Pascal, Mascalchi, Mario, Meletti, Stefano, O'Brien, Terence J, Pardoe, Heath R, Pariente, Jose C, Rao, Jun Xian, Richardson, Mark P, Rodríguez-Cruces, Raúl, Rüber, Theodor, Sinclair, Ben, Soltanian-Zadeh, Hamid, Stein, Dan J, Striano, Pasquale, Taylor, Peter N, Thomas, Rhys H, Vaudano, Anna Elisabetta, Vivash, Lucy, von Podewills, Felix, Vos, Sjoerd B, Weber, Bernd, Yao, Yi, Yasuda, Clarissa Lin, Zhang, Junsong, Thompson, Paul M, Sisodiya, Sanjay M, McDonald, Carrie R, Bonilha, Leonardo, Group, ENIGMA-Epilepsy Working, Altmann, Andre, Depondt, Chantal, Galovic, Marian, Thomopoulos, Sophia I, and Wiest, Roland

Subjects
Biomedical Imaging, Neurodegenerative, Neurosciences, Brain Disorders, Prevention, Epilepsy, 2.1 Biological and endogenous factors, Aetiology, Neurological, Artificial Intelligence, Brain, Epilepsy, Temporal Lobe, Hippocampus, Humans, Magnetic Resonance Imaging, Sclerosis, Support Vector Machine, Temporal lobe epilepsy, Machine learning, Artificial inteligence, ENIGMA-Epilepsy Working Group
Abstract

Artificial intelligence has recently gained popularity across different medical fields to aid in the detection of diseases based on pathology samples or medical imaging findings. Brain magnetic resonance imaging (MRI) is a key assessment tool for patients with temporal lobe epilepsy (TLE). The role of machine learning and artificial intelligence to increase detection of brain abnormalities in TLE remains inconclusive. We used support vector machine (SV) and deep learning (DL) models based on region of interest (ROI-based) structural (n = 336) and diffusion (n = 863) brain MRI data from patients with TLE with ("lesional") and without ("non-lesional") radiographic features suggestive of underlying hippocampal sclerosis from the multinational (multi-center) ENIGMA-Epilepsy consortium. Our data showed that models to identify TLE performed better or similar (68-75%) compared to models to lateralize the side of TLE (56-73%, except structural-based) based on diffusion data with the opposite pattern seen for structural data (67-75% to diagnose vs. 83% to lateralize). In other aspects, structural and diffusion-based models showed similar classification accuracies. Our classification models for patients with hippocampal sclerosis were more accurate (68-76%) than models that stratified non-lesional patients (53-62%). Overall, SV and DL models performed similarly with several instances in which SV mildly outperformed DL. We discuss the relative performance of these models with ROI-level data and the implications for future applications of machine learning and artificial intelligence in epilepsy care.

Published
2021

8. Network-based atrophy modeling in the common epilepsies: A worldwide ENIGMA study

Author

Larivière, Sara, Rodríguez-Cruces, Raúl, Royer, Jessica, Caligiuri, Maria Eugenia, Gambardella, Antonio, Concha, Luis, Keller, Simon S, Cendes, Fernando, Yasuda, Clarissa, Bonilha, Leonardo, Gleichgerrcht, Ezequiel, Focke, Niels K, Domin, Martin, von Podewills, Felix, Langner, Soenke, Rummel, Christian, Wiest, Roland, Martin, Pascal, Kotikalapudi, Raviteja, O’Brien, Terence J, Sinclair, Benjamin, Vivash, Lucy, Desmond, Patricia M, Alhusaini, Saud, Doherty, Colin P, Cavalleri, Gianpiero L, Delanty, Norman, Kälviäinen, Reetta, Jackson, Graeme D, Kowalczyk, Magdalena, Mascalchi, Mario, Semmelroch, Mira, Thomas, Rhys H, Soltanian-Zadeh, Hamid, Davoodi-Bojd, Esmaeil, Zhang, Junsong, Lenge, Matteo, Guerrini, Renzo, Bartolini, Emanuele, Hamandi, Khalid, Foley, Sonya, Weber, Bernd, Depondt, Chantal, Absil, Julie, Carr, Sarah JA, Abela, Eugenio, Richardson, Mark P, Devinsky, Orrin, Severino, Mariasavina, Striano, Pasquale, Tortora, Domenico, Hatton, Sean N, Vos, Sjoerd B, Duncan, John S, Whelan, Christopher D, Thompson, Paul M, Sisodiya, Sanjay M, Bernasconi, Andrea, Labate, Angelo, McDonald, Carrie R, Bernasconi, Neda, and Bernhardt, Boris C

Subjects
Mental Health, Brain Disorders, Epilepsy, Clinical Research, Neurosciences, Neurodegenerative, Aetiology, 2.1 Biological and endogenous factors, Neurological
Abstract

Epilepsy is increasingly conceptualized as a network disorder. In this cross-sectional mega-analysis, we integrated neuroimaging and connectome analysis to identify network associations with atrophy patterns in 1021 adults with epilepsy compared to 1564 healthy controls from 19 international sites. In temporal lobe epilepsy, areas of atrophy colocalized with highly interconnected cortical hub regions, whereas idiopathic generalized epilepsy showed preferential subcortical hub involvement. These morphological abnormalities were anchored to the connectivity profiles of distinct disease epicenters, pointing to temporo-limbic cortices in temporal lobe epilepsy and fronto-central cortices in idiopathic generalized epilepsy. Negative effects of age on atrophy further revealed a strong influence of connectome architecture in temporal lobe, but not idiopathic generalized, epilepsy. Our findings were reproduced across individual sites and single patients and were robust across different analytical methods. Through worldwide collaboration in ENIGMA-Epilepsy, we provided deeper insights into the macroscale features that shape the pathophysiology of common epilepsies.

Published
2020

9. White matter abnormalities across different epilepsy syndromes in adults: an ENIGMA-Epilepsy study

Author

Hatton, Sean N, Huynh, Khoa H, Bonilha, Leonardo, Abela, Eugenio, Alhusaini, Saud, Altmann, Andre, Alvim, Marina KM, Balachandra, Akshara R, Bartolini, Emanuele, Bender, Benjamin, Bernasconi, Neda, Bernasconi, Andrea, Bernhardt, Boris, Bargallo, Núria, Caldairou, Benoit, Caligiuri, Maria E, Carr, Sarah JA, Cavalleri, Gianpiero L, Cendes, Fernando, Concha, Luis, Davoodi-bojd, Esmaeil, Desmond, Patricia M, Devinsky, Orrin, Doherty, Colin P, Domin, Martin, Duncan, John S, Focke, Niels K, Foley, Sonya F, Gambardella, Antonio, Gleichgerrcht, Ezequiel, Guerrini, Renzo, Hamandi, Khalid, Ishikawa, Akari, Keller, Simon S, Kochunov, Peter V, Kotikalapudi, Raviteja, Kreilkamp, Barbara AK, Kwan, Patrick, Labate, Angelo, Langner, Soenke, Lenge, Matteo, Liu, Min, Lui, Elaine, Martin, Pascal, Mascalchi, Mario, Moreira, José CV, Morita-Sherman, Marcia E, O’Brien, Terence J, Pardoe, Heath R, Pariente, José C, Ribeiro, Letícia F, Richardson, Mark P, Rocha, Cristiane S, Rodríguez-Cruces, Raúl, Rosenow, Felix, Severino, Mariasavina, Sinclair, Benjamin, Soltanian-Zadeh, Hamid, Striano, Pasquale, Taylor, Peter N, Thomas, Rhys H, Tortora, Domenico, Velakoulis, Dennis, Vezzani, Annamaria, Vivash, Lucy, von Podewils, Felix, Vos, Sjoerd B, Weber, Bernd, Winston, Gavin P, Yasuda, Clarissa L, Zhu, Alyssa H, Thompson, Paul M, Whelan, Christopher D, Jahanshad, Neda, Sisodiya, Sanjay M, and McDonald, Carrie R

Subjects
Genetics, Neurodegenerative, Epilepsy, Clinical Research, Brain Disorders, Neurosciences, Biomedical Imaging, Aetiology, 2.1 Biological and endogenous factors, Neurological, Adult, Brain, Diffusion Magnetic Resonance Imaging, Epileptic Syndromes, Female, Humans, Image Interpretation, Computer-Assisted, Male, Middle Aged, White Matter, epilepsy, diffusion tensor imaging, multisite analysis, white matter, Medical and Health Sciences, Psychology and Cognitive Sciences, Neurology & Neurosurgery
Abstract

The epilepsies are commonly accompanied by widespread abnormalities in cerebral white matter. ENIGMA-Epilepsy is a large quantitative brain imaging consortium, aggregating data to investigate patterns of neuroimaging abnormalities in common epilepsy syndromes, including temporal lobe epilepsy, extratemporal epilepsy, and genetic generalized epilepsy. Our goal was to rank the most robust white matter microstructural differences across and within syndromes in a multicentre sample of adult epilepsy patients. Diffusion-weighted MRI data were analysed from 1069 healthy controls and 1249 patients: temporal lobe epilepsy with hippocampal sclerosis (n = 599), temporal lobe epilepsy with normal MRI (n = 275), genetic generalized epilepsy (n = 182) and non-lesional extratemporal epilepsy (n = 193). A harmonized protocol using tract-based spatial statistics was used to derive skeletonized maps of fractional anisotropy and mean diffusivity for each participant, and fibre tracts were segmented using a diffusion MRI atlas. Data were harmonized to correct for scanner-specific variations in diffusion measures using a batch-effect correction tool (ComBat). Analyses of covariance, adjusting for age and sex, examined differences between each epilepsy syndrome and controls for each white matter tract (Bonferroni corrected at P

Published
2020

12. Stimulated emission from NV centres in diamond

Author

Jeske, Jan, Lau, Desmond W. M., McGuinness, Liam P., Reineck, Philip, Johnson, Brett C., McCallum, Jeffrey C., Jelezko, Fedor, Volz, Thomas, Cole, Jared H., Gibson, Brant C., and Greentree, Andrew D.

Subjects
Quantum Physics, Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Materials Science, Physics - Atomic Physics, Physics - Optics
Abstract

Stimulated emission is the process fundamental to laser operation, thereby producing coherent photon output. Despite negatively-charged nitrogen-vacancy (NV$^-$) centres being discussed as a potential laser medium since the 1980's, there have been no definitive observations of stimulated emission from ensembles of NV$^-$ to date. Reasons for this lack of demonstration include the short excited state lifetime and the occurrence of photo-ionisation to the neutral charge state by light around the zero-phonon line. Here we show both theoretical and experimental evidence for stimulated emission from NV$^-$ states using light in the phonon-sidebands. Our system uses a continuous wave pump laser at 532 nm and a pulsed stimulating laser that is swept across the phononic sidebands of the NV$^-$. Optimal stimulated emission is demonstrated in the vicinity of the three-phonon line at 700 nm. Furthermore, we show the transition from stimulated emission to photoionisation as the stimulating laser wavelength is reduced from 700nm to 620 nm. While lasing at the zero-phonon line is suppressed by ionisation, our results open the possibility of diamond lasers based on NV centres, tuneable over the phonon-sideband. This broadens the applications of NV magnetometers from single centre nanoscale sensors to a new generation of ultra-precise ensemble laser sensors, which exploit the contrast and signal amplification of a lasing system.

Published
2016
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13. Remote Nanodiamond Magnetometry

Author

Ruan, Yinlan, Simpson, David A., Jeske, Jan, Ebendorff-Heidepriem, Heike, Lau, Desmond W. M., Ji, Hong, Johnson, Brett C., Ohshima, Takeshi, V., Shahraam Afshar, Hollenberg, Lloyd, Greentree, Andrew D., Monro, Tanya M., and Gibson, Brant C.

Subjects
Physics - Optics
Abstract

Optical fibres have transformed the way people interact with the world and now permeate many areas of science. Optical fibres are traditionally thought of as insensitive to magnetic fields, however many application areas from mining to biomedicine would benefit from fibre-based remote magnetometry devices. In this work, we realise such a device by embedding nanoscale magnetic sensors into tellurite glass fibres. Remote magnetometry is performed on magnetically active defect centres in nanodiamonds embedded into the glass matrix. Standard optical magnetometry techniques are applied to initialize and detect local magnetic field changes with a measured sensitivity of 26 micron Tesla/square root(Hz). Our approach utilizes straight-forward optical excitation, simple focusing elements, and low power components. We demonstrate remote magnetometry by direct reporting of the magnetic ground states of nitrogen-vacancy defect centres in the optical fibres. In addition, we present and describe theoretically an all-optical technique that is ideally suited to remote fibre-based sensing. The implications of our results broaden the applications of optical fibres, which now have the potential to underpin a new generation of medical magneto-endoscopes and remote mining sensors., Comment: 10 pages,4 figures

Published
2016

14. Direct measurement and modelling of internal strains in ion-implanted diamond

Author

Bosia, Federico, Argiolas, Nicola, Bazzan, Marco, Fairchild, Barbara A., Greentree, Andrew D., Lau, Desmond W. M., Olivero, Paolo, Picollo, Federico, Rubanov, Sergey, and Prawer, Steven

Subjects
Condensed Matter - Materials Science
Abstract

We present a phenomenological model and Finite Element simulations to describe the depth variation of mass density and strain of ion-implanted single-crystal diamond. Several experiments are employed to validate the approach: firstly, samples implanted with 180 keV B ions at relatively low fluences are characterized using high-resolution X-ray diffraction (HR-XRD); secondly, the mass density variation of a sample implanted with 500 keV He ions well above its amorphization threshold is characterized with Electron Energy Loss Spectroscopy (EELS). At high damage densities, the experimental depth profiles of strain and density display a saturation effect with increasing damage and a shift of the damage density peak towards greater depth values with respect to those predicted by TRIM simulations, which are well accounted for in the model presented here. The model is then further validated by comparing TEM-measured and simulated thickness values of a buried amorphous carbon layer formed at different depths by implantation of 500 keV He ions through a variable-thickness mask to simulate the simultaneous implantation of ions at different energies., Comment: 40 pages, 9 figures, submitted to Physical Review B

Published
2013
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15. Wafer-scale two-dimensional semiconductors from printed oxide skin of liquid metals

Author

Benjamin J. Carey, Jian Zhen Ou, Rhiannon M. Clark, Kyle J. Berean, Ali Zavabeti, Anthony S. R. Chesman, Salvy P. Russo, Desmond W. M. Lau, Zai-Quan Xu, Qiaoliang Bao, Omid Kavehei, Brant C. Gibson, Michael D. Dickey, Richard B. Kaner, Torben Daeneke, and Kourosh Kalantar-Zadeh

Subjects
Science
Abstract

One of the key challenges 2D materials still face is their uniform wafer-scale deposition. Here, the authors present a deposition method for post-transition metal dichalcogenides, based on transformation of an ultra-thin oxide layer on the surface of liquid elemental gallium onto an oxide-coated substrate.

Published
2017
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16. Stimulated emission from nitrogen-vacancy centres in diamond

Author

Jan Jeske, Desmond W. M. Lau, Xavier Vidal, Liam P. McGuinness, Philipp Reineck, Brett C. Johnson, Marcus W. Doherty, Jeffrey C. McCallum, Shinobu Onoda, Fedor Jelezko, Takeshi Ohshima, Thomas Volz, Jared H. Cole, Brant C. Gibson, and Andrew D. Greentree

Subjects
Science
Abstract

Here Jeskeet al. show both theoretical and experimental evidence for stimulated emission from negatively charged nitrogen vacancy centres using light in the phonon sidebands around 700 nm, demonstrating its suitability as a laser medium.

Published
2017
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22. Prevalence and Characteristics of Phantom Limb Pain and Residual Limb Pain in the Long Term after Upper Limb Amputation

Author

Desmond, Deirdre M. and MacLachlan, Malcolm

Abstract

This study aims to describe the prevalence and characteristics of phantom limb pain and residual limb pain after upper limb amputation. One-hundred and forty-one participants (139 males; mean age 74.8 years; mean time since amputation 50.1 years) completed a self-report questionnaire assessing residual and phantom limb pain experience. Prevalence of phantom limb pain during the week preceding assessment was 42.6% (60 of 141). Prevalence of residual limb pain was 43.3% (61 of 141). More than one third of these had some pain constantly or most days. Phantom limb pain was commonly described as "discomforting" (31 of 60) and associated with "a little bit" of lifestyle interference (23 of 60). Residual limb pain was most often described as "discomforting" (27 of 61) or "distressing" (19 of 61) and was typically associated with low to moderate levels of lifestyle interference. Assessment of multiple dimensions of postamputation pain in the long term after upper limb amputation is warranted.

Published
2010
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23. Assets, Challenges, and the Potential of Technology for Nutrition Education in Rural Communities

Author

Atkinson, Nancy L., Desmond, Sharon M., Saperstein, Sandra L., Billing, Amy S., Gold, Robert S., and Tournas-Hardt, Amy

Abstract

Objective: To examine assets of and challenges to getting adequate nutrition and physical activity among low-income rural residents, and the potential for technology to provide health education. Methods: Environmental scans and community stakeholder interviews were conducted in 5 rural counties in Maryland. During environmental scans, stakeholders guided tours around each county to explore community services and resources for nutrition, physical activity and technology. In-depth interviews with stakeholders (n = 58) focused on nutrition, physical activity, and technology issues. Results: Low-income residents both benefit from and face challenges in rural settings. Besides attitude and knowledge barriers, lack of affordable resources and public transportation contributed to inattention to nutrition and physical activity. Stakeholders' reactions to a proposed Internet-based intervention were mostly favorable, but questions emerged about providing computers and Internet to individual families. Conclusions and Implications: Internet-based education may be a viable option to help low-income rural residents overcome barriers to nutrition and physical activity. (Contains 3 tables.)

Published
2010
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24. Safety and Efficacy of Tenecteplase and Alteplase in Patients With Tandem Lesion Stroke: A Post Hoc Analysis of the EXTEND-IA TNK Trials.

Author

Yogendrakumar, Vignan, Churilov, Leonid, Mitchell, Peter J., Kleinig, Timothy J., Yassi, Nawaf, Thijs, Vincent, Wu, Teddy, Shah, Darshan, Bailey, Peter, Dewey, Helen M., Choi, Philip M.C., Ma, Alice, Wijeratne, Tissa, Garcia-Esperon, Carlos, Cloud, Geoffrey, Chandra, Ronil V., Cordato, Dennis J., Yan, Bernard, Sharma, Gagan, and Desmond, Patricia M.

Published
2023
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25. Tenecteplase Treatment and Thrombus Characteristics Associated With Early Reperfusion: An EXTEND-IA TNK Trials Analysis.

Author

Yogendrakumar, Vignan, Churilov, Leonid, Guha, Prodipta, Beharry, James, Mitchell, Peter J., Kleinig, Timothy J., Yassi, Nawaf, Thijs, Vincent, Wu, Teddy Y., Brown, Helen, Dewey, Helen M., Wijeratne, Tissa, Yan, Bernard, Sharma, Gagan, Desmond, Patricia M., Parsons, Mark W., Donnan, Geoffrey A., Davis, Stephen M., Campbell, Bruce C.V., and Dowling, Richard

Published
2023
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28. Correction: Corrigendum: Wafer-scale two-dimensional semiconductors from printed oxide skin of liquid metals

Author

Benjamin J. Carey, Jian Zhen Ou, Rhiannon M. Clark, Kyle J. Berean, Ali Zavabeti, Anthony S. R. Chesman, Salvy P. Russo, Desmond W. M. Lau, Zai-Quan Xu, Qiaoliang Bao, Omid Kavehei, Brant C. Gibson, Michael D. Dickey, Richard B. Kaner, Torben Daeneke, and Kourosh Kalantar-Zadeh

Subjects
Science
Abstract

Nature Communications 8: Article number: 14482; published: 17 February 2017; Updated: 22 March 2017 The original version of this Article contained a typographical error in the spelling of the author Omid Kavehei, which was incorrectly given as Omid Kevehei. This has now been corrected in both the PDF and HTML versions of the Article.

Published
2017
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32. Reduced Severity of Tissue Injury Within the Infarct May Partially Mediate the Benefit of Reperfusion in Ischemic Stroke.

Author

Ng, Felix C., Churilov, Leonid, Yassi, Nawaf, Kleinig, Timothy J., Thijs, Vincent, Wu, Teddy Y., Shah, Darshan G., Dewey, Helen M., Sharma, Gagan, Desmond, Patricia M., Yan, Bernard, Parsons, Mark W., Donnan, Geoffrey A., Davis, Stephen M., Mitchell, Peter J., Leigh, Richard, Campbell, Bruce C.V., and EXTEND-IA TNK Part 1 and 2 Investigators

Published
2022
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34. Rural eHealth Nutrition Education for Limited-Income Families: An Iterative and User-Centered Design Approach

Author

Atkinson, Nancy L, Saperstein, Sandra L, Desmond, Sharon M, Gold, Robert S, Billing, Amy S, and Tian, Jing

Subjects
Computer applications to medicine. Medical informatics, R858-859.7, Public aspects of medicine, RA1-1270
Abstract

Background Adult women living in rural areas have high rates of obesity. Although rural populations have been deemed hard to reach, Internet-based programming is becoming a viable strategy as rural Internet access increases. However, when people are able to get online, they may not find information designed for them and their needs, especially harder to reach populations. This results in a “content gap” for many users. Objective User-centered design is a methodology that can be used to create appropriate online materials. This research was conducted to apply a user-centered approach to the design and development of a health promotion website for low-income mothers living in rural Maryland. Methods Three iterative rounds of concept testing were conducted to (1) identify the name and content needs of the site and assess concerns about registering on a health-related website; (2) determine the tone and look of the website and confirm content and functionality; and (3) determine usability and acceptability. The first two rounds involved focus group and small group discussions, and the third round involved usability testing with individual women as they used the prototype system. Results The formative research revealed that women with limited incomes were enthusiastic about a website providing nutrition and physical activity information targeted to their incomes and tailored to their personal goals and needs. Other priority content areas identified were budgeting, local resources and information, and content that could be used with their children. Women were able to use the prototype system effectively. Conclusions This research demonstrated that user-centered design strategies can help close the “content gap” for at-risk audiences.

Published
2009
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36. Microvascular Dysfunction in Blood-Brain Barrier Disruption and Hypoperfusion Within the Infarct Posttreatment Are Associated With Cerebral Edema.

Author

Ng, Felix C., Churilov, Leonid, Yassi, Nawaf, Kleinig, Timothy J., Thijs, Vincent, Wu, Teddy Y., Shah, Darshan G., Dewey, Helen M., Sharma, Gargan MCA, Desmond, Patricia M., Yan, Bernard DMedSci, Parsons, Mark W., Donnan, Geoffrey A., Davis, Stephen M., Mitchell, Peter J. MMed, Leigh, Richard, Campbell, Bruce C.V., Sharma, Gargan, Yan, Bernard, and Mitchell, Peter J

Published
2022
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37. Safety and Efficacy of Tenecteplase in Older Patients With Large Vessel Occlusion: A Pooled Analysis of the EXTEND-IA TNK Trials.

Author

Yogendrakumar, Vignan, Churilov, Leonid, Mitchell, Peter J. MMed, Kleinig, Timothy J., Yassi, Nawaf, Thijs, Vincent, Wu, Teddy Y., Shah, Darshan G., Ng, Felix C., Dewey, Helen M., Wijeratne, Tissa, Yan, Bernard DMedSc, Desmond, Patricia M., Parsons, Mark W., Donnan, Geoffrey Alan, Davis, Stephen M., Campbell, Bruce C.V., Mitchell, Peter J, Yan, Bernard, and EXTEND-IA TNK Investigators

Published
2022
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42. A multicentre, randomized, double-blinded, placebo-controlled Phase III study to investigate EXtending the time for Thrombolysis in Emergency Neurological Deficits (EXTEND)

Author

Ma, Henry, Parsons, Mark W., Christensen, Soren, Campbell, Bruce C. V., Churilov, Leonid, Connelly, Alan, Yan, Bernard, Bladin, Chris, Phan, Than, Barber, Alan P., Read, Stephen, Hankey, Graeme J., Markus, Romesh, Wijeratne, Tissa, Grimley, R., Mahant, N., Kleinig, Tim, Sturm, John, Lee, A., Blacker, D., Gerraty, Richard, Krause, M., Desmond, P. M., McBride, S. J., Carey, Leanne, Howells, David W., Hsu, C. Y., Davis, Stephen M., and Donnan, Geoffrey A.

Published
2012
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