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USIS: Unsupervised Semantic Image Synthesis [article]

George Eskandar, Mohamed Abdelsamad, Karim Armanious, Bin Yang
2021 arXiv   pre-print
Semantic Image Synthesis (SIS) is a subclass of image-to-image translation where a photorealistic image is synthesized from a segmentation mask. SIS has mostly been addressed as a supervised problem. However, state-of-the-art methods depend on a huge amount of labeled data and cannot be applied in an unpaired setting. On the other hand, generic unpaired image-to-image translation frameworks underperform in comparison, because they color-code semantic layouts and feed them to traditional
more » ... ional networks, which then learn correspondences in appearance instead of semantic content. In this initial work, we propose a new Unsupervised paradigm for Semantic Image Synthesis (USIS) as a first step towards closing the performance gap between paired and unpaired settings. Notably, the framework deploys a SPADE generator that learns to output images with visually separable semantic classes using a self-supervised segmentation loss. Furthermore, in order to match the color and texture distribution of real images without losing high-frequency information, we propose to use whole image wavelet-based discrimination. We test our methodology on 3 challenging datasets and demonstrate its ability to generate multimodal photorealistic images with an improved quality in the unpaired setting.
arXiv:2109.14715v1 fatcat:3dgcw4ei5nc47o4e3qo47toc4a

GLPU: A Geometric Approach For Lidar Pointcloud Upsampling [article]

George Eskandar, Janaranjani Palaniswamy, Karim Guirguis, Barath Somashekar, Bin Yang
2022 arXiv   pre-print
In autonomous driving, lidar is inherent for the understanding of the 3D environment. Lidar sensors vary in vertical resolutions, where a denser pointcloud depicts a more detailed environment, albeit at a significantly higher cost. Pointcloud upsampling predicts high-resolution pointclouds from sparser ones to bridge this performance gap at a lower cost. Although many upsampling frameworks have achieved a robust performance, a fair comparison is difficult as they were tested on different
more » ... s and metrics. In this work, we first conduct a consistent comparative study to benchmark the existing algorithms on the KITTI dataset. Then, we observe that there are three common factors that hinder the performance: an inefficient data representation, a small receptive field, and low-frequency losses. By leveraging the scene geometry, a new self-supervised geometric lidar pointcloud upsampling (GLPU) framework is proposed to address the aforementioned limitations. Our experiments demonstrate the effectiveness and superior performance of GLPU compared to other techniques on the KITTI benchmark.
arXiv:2202.03901v1 fatcat:vude3xxhovfmjcgeqetbi6azbi

An Unsupervised Domain Adaptive Approach for Multimodal 2D Object Detection in Adverse Weather Conditions [article]

George Eskandar, Robert A. Marsden, Pavithran Pandiyan, Mario Döbler, Karim Guirguis, Bin Yang
2022 arXiv   pre-print
Integrating different representations from complementary sensing modalities is crucial for robust scene interpretation in autonomous driving. While deep learning architectures that fuse vision and range data for 2D object detection have thrived in recent years, the corresponding modalities can degrade in adverse weather or lighting conditions, ultimately leading to a drop in performance. Although domain adaptation methods attempt to bridge the domain gap between source and target domains, they
more » ... o not readily extend to heterogeneous data distributions. In this work, we propose an unsupervised domain adaptation framework, which adapts a 2D object detector for RGB and lidar sensors to one or more target domains featuring adverse weather conditions. Our proposed approach consists of three components. First, a data augmentation scheme that simulates weather distortions is devised to add domain confusion and prevent overfitting on the source data. Second, to promote cross-domain foreground object alignment, we leverage the complementary features of multiple modalities through a multi-scale entropy-weighted domain discriminator. Finally, we use carefully designed pretext tasks to learn a more robust representation of the target domain data. Experiments performed on the DENSE dataset show that our method can substantially alleviate the domain gap under the single-target domain adaptation (STDA) setting and the less explored yet more general multi-target domain adaptation (MTDA) setting.
arXiv:2203.03568v1 fatcat:e2kthdczbjbzfi6zmowyey2pba

Human anterior cingulate neurons and the integration of monetary reward with motor responses

Ziv M Williams, George Bush, Scott L Rauch, G Rees Cosgrove, Emad N Eskandar
2004 Nature Neuroscience  
The human dorsal anterior cingulate cortex (dACC) has been implicated in cognitive processes that have been proposed to play a role in integrating contextual information needed to select or modify appropriate motor responses. In humans, however, there has been little direct evidence tying the dACC to the integration of contextual information and behavioral response. We used single-neuron recordings from human subjects to evaluate the role of the dACC in reward-based decision making. Subjects
more » ... ergoing planned surgical cingulotomy performed a task where they were instructed to make specific movements in response to changing monetary rewards. In many neurons, activity increased in response to a diminished reward, and was also predictive of the movement ultimately made. After dACC ablation, subjects made selectively more errors when they were required to change movement based on reward reduction. These findings suggest that the dACC in humans plays an important role in linking rewardrelated information with alternative actions.
doi:10.1038/nn1354 pmid:15558064 fatcat:inymrhmt3bebzkatdwi74kcbbm

Investigating How Calcium Diffusion Affects Metabolic Oscillations and Synchronization of Pancreatic Beta Cells

George Eskandar, Jennifer Houser, Ellen Prochaska, Jessica Wojtkiewicz, Teresa Lebair, Bradford E. Peercy, Margaret Watts, Arthur Sherman
2016 Spora A Journal of Biomathematics  
Co-author George Eskandar was supported, in part, by the UMBC National Security Agency (NSA) Scholars Program through a contract with the NSA.  ... 
doi:10.30707/spora2.1eskandar fatcat:uslqfspsmjdm7d74scjuz5t7xu

Epithelial Uptake and Transport of Cell-Free Human Immunodeficiency Virus Type 1 and gp120-Coated Microparticles

Andreas Kage, Eskandar Shoolian, Katharina Rokos, Muhsin Özel, Rolf Nuck, Werner Reutter, Eckart Köttgen, Georg Pauli
1998 Journal of Virology  
Cell-free human immunodeficiency virus type 1 (HIV-1) can be taken up and released by a monolayer of primary human gingival cells and remain infectious for CD4+ cells. Virus-sized latex particles covalently coated with purified native HIV-1 envelope glycoprotein gp120 are also transported through the primary epithelial cells. This process is significantly stimulated by increasing the intracellular cyclic AMP (cAMP) concentration. Inhibition experiments with mannan and α-methyl-mannopyranoside
more » ... dicated that mannosyl groups are involved in the interaction between gp120 and gingival cells. An increase of cellular oligomannosyl receptors by incubation with the mannosidase inhibitor deoxymannojirimycin augmented transcellular transport of the gp120-coated particles. The results suggest that infectious HIV can penetrate gingival epithelia by a cAMP-dependent transport mechanism involving interaction of the lectin-like domain of gp120 and mannosyl residues on glycoproteins on the mucosal surface. Penetration of HIV could be inhibited by soluble glycoconjugates present in oral mucins.
doi:10.1128/jvi.72.5.4231-4236.1998 fatcat:3536zarlqnfvdhvd7p6oqbgie4

Endometrial Thermal Balloon Ablation with the ThermaChoice System: Effect of Intrauterine Pressure and Duration of Treatment

George A. Vilos, Fatma A. Aletebi, Mamdoh A. Eskandar
2000 The Journal of the American Association of Gynecologic Laparoscopists  
Menorrhagia is a common problem, with a worldwide prevalence as high as 19% in women of reproductive age. 1 It can cause discomfort and disrupt life, and its impact on women's social, economic, and psychologic well-being can be severe. During the past decade endometrial ablation proved to be an effective alternative to hysterectomy. Worldwide experience indicates that the success rate of hysteroscopic endometrial ablation is in the range of 70% to 90%. [2] [3] [4] Although the procedure is
more » ... tive and is associated with reduced morbidity, mortality, hospitalization, convalescence, and health care cost compared with hysterectomy, it requires additional training and surgical expertise involving a significant learning curve. 5,6 Furthermore, the operative complication rate ranged from 6% for patients undergoing their first endometrial ablation to 15% for repeat procedures. [7] [8] [9] A thermal uterine balloon system was introduced and evaluated to minimize these potential risks and complications 10-12 and proved to be safe as well as 325 Abstract Study Objective. To determine the safety and efficacy of thermal balloon therapy under variable intrauterine pressures and durations of treatment. Design. Retrospective cohort study. (Canadian Task Force classification II-1). Setting. University-affiliated teaching hospital. Patients. Sixty-six women with menorrhagia. Intervention. Eighteen patients were treated with the ThermaChoice thermal balloon system for 8 minutes at 80 to 150 mm Hg pressure, 15 were treated for 8 minutes at 151 to 180 mm Hg, and 33 were treated for 12 to 16 minutes at 151 to 180 mm Hg. Measurements and Main Results. No intraoperative complications occurred and postoperative morbidity was minimal. At 12 to 24 months follow-up, persistent menorrhagia was reported in 56% of women treated at 80 to 150 mm Hg compared with 20% treated at 151 to 180 mm Hg for 8 minutes (p = 0.01), and in 24% treated for 12 to 16 minutes at 151 to 180 mm Hg (p = 0.1). Conclusion. Thermal balloon endometrial ablation is a safe and effective treatment for menorrhagia. Balloon pressure greater than 150 mm Hg increased the effectiveness of treatment. Success was not affected or influenced by increasing the duration of treatment from 8 to 12 minutes or more. posting of electronic files on the Internet, transferring electronic files to other persons, distributing printed output, and photocopying. To order multiple reprints of an individual article or request authorization to make photocopies, please contact the AAGL. Endometrial Ablation with the ThermaChoice System Vilos et al FIGURE 1. Pressure-volume curves for nine patients. The balloon was inflated in 1-ml increments of 5% dextrose in water solution.
doi:10.1016/s1074-3804(05)60474-4 pmid:10924625 fatcat:oenemjno3vdz3ilucsxaxhlr6m

Two modes of inhibitory neuronal shutdown distinctly amplify seizures in humans [article]

Omar J Ahmed, Tibin T John, Shyam Kumar Sudhakar, Ellen KW Brennan, Alcides Lorenzo Gonzalez, Jason S Naftulin, Emad Eskandar, Joseph R Madsen, G. Rees Cosgrove, Andrew S Blum, N Stevenson Potter, George A Mashour (+2 others)
2020 medRxiv   pre-print
Inhibitory neurons are critical for normal brain function but dysregulated in disorders such as epilepsy. At least two theories exist for how inhibition may acutely decrease during a seizure: hyperpolarization of fast-spiking (FS) inhibitory neurons by other inhibitory neurons, or depolarization block (DB) of FS neurons resulting in an inability to fire action potentials. Firing rate alone is unable to disambiguate these alternatives. Here, we show that human FS neurons can stop firing due to
more » ... th hyperpolarization and DB within the same seizure. However, only DB of FS cells is associated with dramatic increases in local seizure amplitude, unobstructed traveling waves, and transient increases in excitatory neuronal firing. This result is independent of seizure etiology or focus. Computational models of DB reproduce the in vivo human biophysics. These methods enable intracellular decoding using only extracellular recordings in humans and explain the otherwise ambiguous inhibitory neuronal control of human seizures.
doi:10.1101/2020.10.09.20204206 fatcat:qo4ek4jrtbffvpngjqgoxme5ty

Multi-tensor investigation of orbitofrontal cortex tracts affected in subcaudate tractotomy

Jimmy C. Yang, George Papadimitriou, Ryan Eckbo, Edward H. Yeterian, Lichen Liang, Darin D. Dougherty, Sylvain Bouix, Yogesh Rathi, Martha Shenton, Marek Kubicki, Emad N. Eskandar, Nikos Makris
2014 Brain Imaging and Behavior  
Subcaudate tractotomy (SCT) is a neurosurgical lesioning procedure that can reduce symptoms in medically intractable obsessive compulsive disorder (OCD). Due to the putative importance the orbitofrontal cortex (OFC) in symptomatology, fibers that connect the OFC, SCT lesion, and either the thalamus or brainstem were investigated with two-tensor tractography using an unscented Kalman filter approach. From this dataset, fibers were warped to Montreal Neurological Institute space, and probability
more » ... aps with center-of-mass analysis were subsequently generated. In comparing fibers from the same OFC region, including medial OFC (mOFC), central OFC (cOFC), and lateral OFC (lOFC), the area of divergence for fibers connected with the thalamus versus the brainstem is posterior to the anterior commissure. At the anterior commissure, fibers connected with the thalamus run dorsal to those connected with the brainstem. As OFC fibers travel through the ventral aspect of the internal capsule, lOFC fibers are dorsal to cOFC and mOFC fibers. Using neuroanatomical comparison, tracts coursing between the OFC and thalamus are likely part of the anterior thalamic radiations, while those between the OFC and brainstem likely belong to the medial forebrain bundle. These data support the involvement of the OFC in OCD and may be relevant to creating differential lesional procedures of specific tracts or to developing deep brain stimulation programming paradigms. Keywords psychosurgery; diffusion tensor imaging; diffusion tractography; obsessive-compulsive disorder; deep brain stimulation Yang et al.
doi:10.1007/s11682-014-9314-z pmid:25103312 pmcid:PMC4320992 fatcat:lmwtpv6ekfaovdtnbjevfl7wfe

Diffusion-weighted imaging uncovers likely sources of processing-speed deficits in schizophrenia

Peter Kochunov, Laura M. Rowland, Els Fieremans, Jelle Veraart, Neda Jahanshad, George Eskandar, Xiaoming Du, Florian Muellerklein, Anya Savransky, Dinesh Shukla, Hemalatha Sampath, Paul M. Thompson (+1 others)
2016 Proceedings of the National Academy of Sciences of the United States of America  
Schizophrenia, a devastating psychiatric illness with onset in the late teens to early 20s, is thought to involve disrupted brain connectivity. Functional and structural disconnections of cortical networks may underlie various cognitive deficits, including a substantial reduction in the speed of information processing in schizophrenia patients compared with controls. Myelinated white matter supports the speed of electrical signal transmission in the brain. To examine possible neuroanatomical
more » ... rces of cognitive deficits, we used a comprehensive diffusion-weighted imaging (DWI) protocol and characterized the white matter diffusion signals using diffusion kurtosis imaging (DKI) and permeability-diffusivity imaging (PDI) in patients (n = 74), their nonill siblings (n = 41), and healthy controls (n = 113). Diffusion parameters that showed significant patient-control differences also explained the patient-control differences in processing speed. This association was also found for the nonill siblings of the patients. The association was specific to processing-speed abnormality but not specific to working memory abnormality or psychiatric symptoms. Our findings show that advanced diffusion MRI in white matter may capture microstructural connectivity patterns and mechanisms that govern the association between a core neurocognitive measureprocessing speed-and neurobiological deficits in schizophrenia that are detectable with in vivo brain scans. These non-Gaussian diffusion white matter metrics are promising surrogate imaging markers for modeling cognitive deficits and perhaps, guiding treatment development in schizophrenia. diffusion-weighted imaging | schizophrenia | processing speed | cognitive deficits | endophenotypes
doi:10.1073/pnas.1608246113 pmid:27834215 pmcid:PMC5127361 fatcat:df6wgink2jb7nj5ceclivarnc4

The common genetic influence over processing speed and white matter microstructure: Evidence from the Old Order Amish and Human Connectome Projects

Peter Kochunov, Paul M. Thompson, Anderson Winkler, Mary Morrissey, Mao Fu, Thomas R. Coyle, Xiaoming Du, Florian Muellerklein, Anya Savransky, Christopher Gaudiot, Hemalatha Sampath, George Eskandar (+8 others)
2016 NeuroImage  
Speed with which brain performs information processing influences overall cognition and is dependent on the white matter fibers. To understand genetic influences on processing speed and white matter FA, we assessed processing speed and diffusion imaging fractional anisotropy (FA) in related individuals from two populations. Discovery analyses were performed in 146 individuals from large Old Order Amish (OOA) families and findings were replicated in 485 twins and siblings of the Human Connectome
more » ... Project (HCP). The heritability of processing speed was h 2 =43% and 49% (both p < 0.005), while the heritability of whole brain FA was h 2 =87% and 88% (both p < 0.001), in the OOA and HCP, respectively. Whole brain FA was significantly correlated with processing speed in the two cohorts. Quantitative genetic analysis demonstrated a significant degree to which common genes influenced joint variation in FA and brain processing speed. These estimates suggested common sets of genes influencing variation in both phenotypes, consistent * Corticospinal tract -L and R combined (CST) 0.67+0.37 (p=0.08) 0.66±0.05 (p=1×10 −18 ) * Analyses in both cohorts were corrected for age, age 2 , age×sex and age 2 ×sex. Bolded values are significant at p≤0.05. * Values that are significant after correction for multiple (N=11) comparisons.
doi:10.1016/j.neuroimage.2015.10.050 pmid:26499807 pmcid:PMC4691385 fatcat:jdf424leijdmpnjfzc5heos46u

Variability and anatomical specificity of the orbitofrontothalamic fibers of passage in the ventral capsule/ventral striatum (VC/VS): precision care for patient-specific tractography-guided targeting of deep brain stimulation (DBS) in obsessive compulsive disorder (OCD)

Nikolaos Makris, Yogesh Rathi, Palig Mouradian, Giorgio Bonmassar, George Papadimitriou, Wingkwai I. Ing, Edward H. Yeterian, Marek Kubicki, Emad N. Eskandar, Lawrence L. Wald, Qiuyun Fan, Aapo Nummenmaa (+2 others)
2015 Brain Imaging and Behavior  
Eskandar are named inventors on patents related to improved targeting and delivery of deep brain stimulation.  ... 
doi:10.1007/s11682-015-9462-9 pmid:26518214 pmcid:PMC4851930 fatcat:obzhfn75lbgpdlwjzf4xd5c7ke

Iran Guards its Wildlife

1972 Oryx  
Some were sent to Dr Georg von Opel in Germany to build up a captive breeding herd (which now numbers 16 pure-bred animals) and a new park was created on land presented by HIH Prince Abdorreza, where,  ...  Iran Guards its Wildlife The great care and interest that Iran takes in her wildlife is evident in Conservation and Wildlife Management in Iran, by Eskandar Firouz, published by the Iran Game and Fish  ... 
doi:10.1017/s0030605300010693 fatcat:2njjigbtxfcotbglu3ek4vbbcy

Author Index

2022 ICASSP 2022 - 2022 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)  
201 Erraguntla, Madhav ......................................... 1136 Escalante-B., Alberto N. ................................... 7407 Esfandiari, Majdoddin ..................................... 5023 Eskandar  ...  , George ............................................. 1760 Eskimez, Sefik Emre .............. 271, 356, 6032, 9271 Esmaeilpour, Mohammad ................................ 2869 Espinosa, Sebastian .....  ... 
doi:10.1109/icassp43922.2022.9747046 fatcat:yunx4yqzrvepxcnhfrzw7rzama

Investigating the Role and Importance of Persian Crown Jewels in Economic and Political Developments in Shah Abbas I Era (1587-1629)

Sayed Masud Sayed Bonakdar, Hussein Mir Jafari, Loghman Dehghan Niri
2012 Asian Culture and History  
Better than the high quality minting of the coins, it was their imprint which interested him because he had presumably mistaken the figure of Saint George on the coins with that of Imam Ali.  ...  These gifts were sometimes granted to poets to whom Shah Abbas gave gold equal to their weight (Eskandar Beyk Turkaman, v. 2, p. 516, 1382) .  ... 
doi:10.5539/ach.v4n2p146 fatcat:ziomtoe7szdx5eshetcx2wlxni
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