The lectures are usually presented in the Seminars Room "Gu-Media Center" located at the 2nd floor of the NOC building, University of Athens. Possible exceptions will be announced.
The most recent presentation will be mentioned first.
Directions to the dept. of Informatics & Telecommunications: Click here
Directions to NOC building: http://mc.gunet.gr/access.php
Date: Monday, June 29, 2015, Time: 12:30 | |
Speaker: | Dr. Tassos Bezerianos -
Biosignal Lab, School of Medicine, University of Patras, GR Cognitive Engineering Lab, SINAPSE, National University of Singapore, SG |
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Title: | Complex Networks Theory: Models and applications in brain connectivity and intracellular networks |
Room: | Room E of the department of Informatics and Telecommunications |
Abstract: | Connectivity in organisms comes in many forms - for example, molecular interactions, metabolic pathways, synaptic connections and from micro to meso and macroscopic level of cells, organs and systems. In our talk we will present graph theory models we developed to study: a) the intracellular pathways based on intergromics data and b) time varying brain networks and dynamics from EEG and fMRI data. |
About the speaker: | Anastasios Bezerianos is a Research Professor in the ECE, National University of Singapore, Senior Principal Research Fellow of Singapore Institute for Neurotechnology (SINAPSE) and Professor at the Medical School of Patras University, Greece. He studied Physics at Patras University and Telecommunications at Athens University, and he received his Ph.D. from the University of Patras.
His research interests at large are in Neuroengineering and Systems Medicine and Bioinformatics, and his work is summarized in 110 journal and 175 conference proceedings publications. He has research collaborations with research institutes and universities in Japan, the USA, and Europe, and he is Associate Editor of IEEE TNSRE and the Annals of Biomedical Engineering journals and a reviewer for several international scientific journals. He is a registered expert of the Horizon 2020 program of the European Union and a reviewer of research grant proposals in Greece, Italy, Cyprus and Canada. He is a Senior Member of IEEE and the Founder and Chairman of the biannual International Summer School on Emerging Technologies in Biomedicine.
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Videolecture: | Not yet announced |
Links: | - |
Date: Monday, May 13, 2013, Time: 14:00 | |
Speaker: | Dr. Frederic Cazals - Algorithms-Biology-Structure, INRIA Sophia-Antipolis, France |
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Title: | Modeling Noisy Data with Applications in Structural Bioinformatics |
Room: | Room A1 of the department of Informatics and Telecommunications |
Abstract: | Noisy data are common place in science and engineering, and the importance of developing robust non-parametric models for such data cannot be overstated.
In this talk, we shall review recent concepts and algorithms developed in computational geometry and computational topology for three seemingly unrelated problems in the realm of noisy data modeling, namely reconstructing sampled compact sets from R3, modeling fuzzy (molecular) objects in R3 and, and investigating high dimensional terrains with applications in biophysics and non convex optimization.
Remarkably, we shall see that all solutions follow the same pattern, which consists of three steps, namely (i) defining a generalized distance function, (ii) constructing (a subset of) the Morse-Smale diagram of this function, and (iii) extracting stable features applying topological persistence on the Morse-Smale complex. The benefits of using this framework will be illustrated on the problem of assessing the reconstruction of large protein assemblies. |
About the speaker: | Frédéric Cazals is research director at INRIA Sophia-Antipolis Mediterranee, France, where he leads the group Algorithms - Biology - Structure (ABS,
http://team.inria.fr/abs). He holds an engineering degree in Biological
Sciences from the Institut National Agronomique Paris-Grignon (Paris, France),
a master degree in theoretical computer science from Ecole Normale Superieure and Ecole Polytechnique (Paris, France), and a PhD in theoretical computer science from the University of Paris VII (Paris, France).
His research interests encompass computational structural biology (modeling protein complexes and assemblies, modeling the flexibility of proteins), as well
as geometric and topological modeling (applied differential geometry, computational geometry, computational topology, shape learning).
He recently co-edited the book entitled Modeling in Computational Biology and Biomedicine (Springer), which pitches success stories at the interface biology/medicine - computer science - applied mathematics. |
Videolecture: | http://delos.uoa.gr/opendelos/player?rid=f395a54a http://delos.uoa.gr/opendelos/player?rid=f2b60747 http://delos.uoa.gr/opendelos/player?rid=2d853be5 |
Links: | Personal Web page of the speaker: https://team.inria.fr/abs/team-members/homepage-frederic-cazals/ |
Date: Monday, April 29, 2013, Time: 11:00 | |
Speaker: | Prof. Tulay Adali - IEEE Signal Processing Society Distinguished Lecturer |
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Title: | ICA and IVA: Theory, Connections, and Applications to Medical Imaging |
Room: | Room A2 of the department of Informatics and Telecommunications |
Abstract: | Data-driven methods are based on a simple generative model and hence can minimize the assumptions on the nature of data. They have emerged as promising alternatives to the traditional model-based approaches in many applications where the underlying dynamics are hard to characterize. Independent component analysis (ICA), in particular, has been a popular data-driven approach and an active area of research. Starting from a simple linear mixing model and imposing the constraint of statistical independence on the underlying components, ICA can recover the linearly mixed components subject to only a scaling and permutation ambiguity. It has been successfully applied to numerous data analysis problems in areas as diverse as biomedicine, communications, finance, geophysics, and remote sensing. This talk reviews the fundamentals and properties of ICA, and provides a unified view of two main approaches for achieving ICA, those that make use of non-Gaussianity and sample dependence. Then, the generalization of ICA for analysis of multiple datasets, independent vector analysis (IVA), is introduced and the connections between ICA and IVA are highlighted, especially in the way both approaches make use of signal diversity. Examples are presented to demonstrate the application of ICA and IVA to analysis of functional magnetic resonance imaging data as well as fusion of data from multiple imaging modalities.
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About the speaker: | Tulay Adali received the Ph.D. degrees from North Carolina State University, Raleigh, in 1992 in electrical engineering and joined the faculty at the University of Maryland Baltimore County (UMBC), Baltimore the same year where she currently is a Professor in the Department of Computer Science and Electrical Engineering. She has held visiting positions at Ecole Superieure de Physique et de Chimie Industrielles, Paris, France, Technical University of Denmark, Lyngby, Denmark, Katholieke Universiteit, Leuven, Belgium, and University of Campinas, Brazil.
Prof. Adali assisted in the organization of a number of international conferences and workshops including the IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP), the IEEE International Workshop on Neural Networks for Signal Processing (NNSP), and the IEEE International Workshop on Machine Learning for Signal Processing (MLSP).
She was the General Co-Chair, NNSP (2001--2003); Technical Chair, MLSP (2004--2008); Program Co-Chair, MLSP (2008 and 2009), 2009 International Conference on Independent Component Analysis and Source Separation; Publicity Chair, ICASSP (2000 and 2005); and Publications Co-Chair, ICASSP 2008. Prof. Adali chaired the IEEE Signal Processing Society (SPS) MLSP Technical Committee (2003--2005, 2011--2013), served on the SPS Conference Board (1998--2006), and the Bio Imaging and Signal Processing Technical Committee (2004--2007). She was an Associate Editor for IEEE Transactions on Signal Processing (2003--2006), IEEE Transactions on Biomedical Engineering (2007--2013), IEEE Journal of Selected Areas in Signal Processing (2010-2013), and Elsevier Signal Processing Journal (2007--2010). She is currently serving on the Editorial Boards of the IEEE Proceedings and Journal of Signal Processing Systems for Signal, Image, and Video Technology, and is a member of the IEEE SPS MLSP and Signal Processing Theory and Methods Technical Committees. Prof. Adali is a Fellow of the IEEE and the AIMBE, recipient of a 2010 IEEE Signal Processing Society Best Paper Award, 2013 University System of Maryland Regents' Award for Research, and an NSF CAREER Award. Her research interests are in the areas of statistical signal processing, machinelearning for signal processing, and biomedical data analysis. |
Videolecture: | http://delos.uoa.gr/opendelos/player?rid=84617f0d |
Links: | Personal Web page of the speaker: http://www.csee.umbc.edu/~adali/ |
Date: Wednesday, May 23, 2012, Time: 16:00 | |
Speaker: | Dr. Rachid Deriche - Research Director, Inria |
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Title: | Computational Diffusion MRI : On some recent advances and beyond |
Room: | Room A2 of the department of Informatics and Telecommunications |
Abstract: | Diffusion MRI (dMRI) is the unique Magnetic Resonance Imaging modality able to quantify in vivo and non invasively the average random thermal movement (diffusion) of water molecules in biological tissues such as brain white matter. Using the water diffusion as a probe, dMRI makes it possible to reconstruct white matter fiber pathways and segment major fiber bundles that reflect the structures in the brain which are not visible to other non-invasive imaging modalities. This modern imaging modality, of great interest to neuroscientists and clinicians, has opened a number of challenging problems.
In this talk, the important problems of efficiently acquiring and processing complex dMRI data will be introduced and recently developed solutions and advances will be presented. Applications to computational brain imaging will also be presented and discussed with a particular emphasize on the importance of the Riemannian geometry in the estimation, regularization and segmentation of diffusion images as well as the tracking, the reconstruction and the clustering of the bundles of white matter fibers. High Angular Resolution Diffusion Imaging (HARDI) models will also be presented to go beyond the classical Diffusion Tensor Model, well known to be inadequate in crossing fiber regions. These new algorithms open the possibility of inferring and recovering a more detailed geometric description of the anatomical connectivity between brain areas.
The presentation of some open problems currently being investigated by the dMRI community will conclude the talk.
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About the speaker: | Dr. Rachid Deriche is Research Director at Inria, a public science and technology institution dedicated to computational sciences, where he leads the Project-Team Athena, located at Inria Sophia Antipolis-Méditerranée Research Center (FR).
His research interests include Computational Imaging of the Central Nervous System (CNS), 3D Computer Vision and Mathematical Image Processing, with a particular emphasis on the understanding and the processing of CNS anatomical connectivity through diffusion MRI and its combination with other modalities, such as functional MRI, MEG or EEG.
In recent years, he has been mainly active in developing pioneering algorithms for the analysis and clinical application of diffusion MRI data. Dr Deriche has authored and co-authored more than 250 peer reviewed papers in mathematical image processing, computer vision and computational medical imaging conferences and journals, including over 50 journal publications. Dr. Deriche is an Associate Editor of SIAM Journal on Imaging Sciences (SIIMS) and a member of the editorial board of the Computational Imaging and Vision book series. He recently served as Co-chair of ICPR 2010 Track VI on Bioinformatics and Biomedical Applications, and served for several years as Associate Editor for International Journal of Computer Vision (IJCV). He has also been an area chair for international conferences in computer vision and computational medical imaging, including ECCV, ICCV, CVPR, and MICCAI. Dr Deriche regularly gives invited plenary talks at many conferences and workshops and teaches graduate courses on Biomedical imaging, computer vision and image processing in the Master of Sciences 2: Master of Science in Computational Biology & the engineering school Telecom Sud Paris. |
Videolecture: | http://delos.uoa.gr/opendelos/player?rid=112bf1d |
Links: | Personal Web page of the speaker: http://www-sop.inria.fr/members/Rachid.Deriche/ |
Date: Wednesday, March 28, 2012, Time: 15:00 | |
Speaker: | Leonidas Alexopoulos - Lecturer, Systems Biology and Bioengineering Lab, National Technical University of Athens |
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Title: | Systems Biology for Drug Discovery |
Room: | Room D of the department of Informatics and Telecommunications |
Abstract: | High throughput proteomic technologies and systems biology algorithms
are combined to construct signaling pathways for normal and diseased
cells, identify drug mode of action, and predict drug toxicity and
efficacy.
A major challenge for bringing safe and effective new treatment to
patients is the deep understanding of a disease. Here, we describe
high throughput proteomic technologies and systems biology algorithms
for tackling three milestones in the drug development process:
(i)construction of pathways and comparison between normal or diseased
cells, (ii) identification of drug mode of action (MoA), and (iii)
prediction of drug toxicity and efficacy. With our proposed method,
pathways are created by constraining a generic pathway made of logical
gates to phosphoproteomic data generated by multicombinatorial
treatments of stimuli and inhibitors. Then, knowing the cell's
topology, we monitor drug-induced topology alterations in order to
reveal drug MoA. Our approach that received the 2010 Bio-IT Best
practice award was able to predict the drugs' main target but also
uncovered off-target effects that cannot be revealed by standard
methods. Subsequently, a supervised machine learning algorithms was
able to select MoAs with reduced toxicity and increased efficacy. Our
Systems Biology algorithms and high throughput proteomic data paves
the road for new solutions in the drug discovery process.
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About the speaker: | Leonidas Alexopoulos is a lecturer in the dept of Mechanical Eng at
NTUA. His research is focused on novel
proteomic technologies and Systems Biology tools for construction of
signaling pathways and identification of optimal compounds for
improved efficacy and reduced toxicity.
Dr Alexopoulos has studied at
Aristotle University of Athens (Diploma from the Dept of Mech Eng in
1998), Duke (PhD from Dept of Biomedical Eng in 2004), MIT (postdoc,
dept of Biological Eng 2004-2008), and Harvard Medical School
(postdoc, Dept of Systems Biology 2006-2008). He has worked and
collaborated with major pharma companies (Pfizer, Becton & Dickinson,
Vertex, and Boehringer-Ingelheim) in the area of systems biology for
drug discovery.
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Videolecture: | Not yet available |
Links: | Personal Web page of the speaker: http://users.ntua.gr/leo/ |
Date: Wednesday, November 09, 2011, Time: 16:00 | |
Speaker: | Michael Szardenings - Fraunhofer Institute for Cell Therapy and Immunology, Leipzig, Germany. |
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Title: | How to "improve" amino acid sequences - technical limits of evolution and lab methods |
Room: | Seminars Room Gu-Media Center, 2nd floor of NOC Building, UoA |
Abstract: | When we look at structure function relationships and study them on the basis of known sequence variations or mutational studies, the observed sequence variations are always biased by the limits of the genetic code.
There is rarely any thought spent on the fact that not only there is no structural similarity between some amino acids but that also the genetic distance is enormous, which may be defined as number of necessary base changes in the codon. For the first time I noticed this in my thesis, when the design of a protein by an amino acid exchange, far from being likely on the basis of natural variations in the protein class, gave excellent results. Also in immunology it appears to be a common problem that amino acids cannot easily mutate from one to another, although such drastic changes could have beneficial effects for vaccines and diagnostics.
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About the speaker: | Michael Szardenings studied chemistry in Hamburg and obtained his Ph.D. working in
the field of protein design and genetic engineering at the German
biotechnology institute GBF from the Technical University
Braunschweig.
After postdoctoral years in structural groups Uppsala
and Berlin he joined in 1995 the department of pharmaceutical
pharmacology at the University Uppsala to work on membrane receptors
and the establishment on peptide phage display technologies for
selection on whole cells. From 1998 to 2003 he was CSO of a German
company dedicated to novel methods for peptide phage display.
Thereafter he was in management positions in related drug discovery
biotech companies. In 2009 he became the head of a new group dedicated
to ligand development at the Fraunhofer Institute for Cell Therapy and
Immunology in Leipzig, Germany. Here he has been turning his attention
again to basic developments in peptide phage display. The main
interests of the group are techniques to map immune responses in whole
blood and serum as well as the discovery of peptide ligands to cell
surfaces and the methods required for their application.
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Videolecture: | http://delos.uoa.gr/opendelos/player?rid=119cc11b |
Links: | http://www.izi.fraunhofer.de/index.php?id=liganden-entwicklung-profil&L=1 |
Date: Thursday 12 may 2011, Time: 17:00 -19:00 | |
Title of event: | «Medical Informatics and Bioinformatics - Two new interesting scientific fields with opportunities and challenges» |
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Room: | Room A2 of the department of Informatics and Telecommunications |
Talks: | Elias S. Manolakos, Ass. Professor and Director of the program Brief overview of the ITMB program Dr. Vangelis Karkaletsis, Director of Research, Institute of Informatics and Telecommunications, NCSR Demokritos "Employment Opportunities in NCSR Demokritos in Medical Informatics and Bioinformatics related projects” Dr. Christos Andronis, Director of R@D, Biovista "Applications of Bioinformatics in drug development. The example of Biovista" Dr. Thanos Demiris, Director R@D. micro2gen "Development of integrated molecular diagnostics solutions in Greece – an example of cross-disciplinary R@D activity" |
Event program: | Download the pdf file |
Videolecture: |
http://delos.uoa.gr/opendelos/player?rid=68726d http://delos.uoa.gr/opendelos/player?rid=b93649c3 http://delos.uoa.gr/opendelos/player?rid=b170353 http://delos.uoa.gr/opendelos/player?rid=8dc435e6 |
Date: Friday, April 01, 2011, Time: 14:00 | |
Speaker: | George Vernikos - PhD from the University of Cambridge and The Wellcome Trust Sanger Institute. |
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Title: | Overtake in reverse gear |
Room: | Seminars Room Gu-Media Center, 2nd floor of NOC Building, UoA |
Abstract: | Recently, a new method namely Reverse Vaccinology (RV), that uses a
genomic (instead of cellular) approach has been successfully applied
to the development of vaccines against pathogens that were previously
recalcitrant to such development.
RV is fast and can identify
virtually all potential antigens, irrespective of their concentration,
time of expression and immunogenicity. In this seminar I will discuss
the main concept of RV, the bioinformatics challenge and the possible
application of a Machine methodology with a two-fold aim: Standardise
the algorithmic pipeline and make it generally applicable to other
bacterial species with different population structure; use the
findings of the machine learning in reverse, to understand the global
genomic and proteomic properties of "good" vaccine candidates.
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About the speaker: | George Vernikos holds a PhD from the University of
Cambridge and The Wellcome Trust Sanger Institute.
As a student at the
University of Cambridge he was also a Cambridge European Trust Fellow
and member of the Cambridge University Canoe Club. Before that, he was
member of the Biophysics and Bioinformatics Group at the University of
Athens. Prior to his registration at the University of Athens he was
studying Mechatronics in the Applied Mechanics Laboratory, at the
Technical University of Crete. He is currently working as a Senior
Software Engineer in a private owned company, Qualco SA, located in
Athens while continuing his collaboration with research groups at The
Wellcome Trust Sanger Institute. He is reviewer for the following
journals: Bioinformatics, Nucleic Acids Research and Molecular Biology
and Evolution. He is the author of two stand-alone bioinformatics
softwares: GeneViTo (http://bioinformatics.biol.uoa.gr/GENEVITO) and
alien_hunter (http://www.sanger.ac.uk/resources/software/alien_hunter/).
He is particularly interested in Machine Learning and Microbial
Evolution.
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Videolecture: | http://videolectures.uoa.gr/records/camtasia/di/seminars3/vernikos/vernikos.html |
Links: | - |
Date: Wednesday, March 02, 2011, Time: 13:00 | |
Speaker: | Jiannis Ragoussis - Researcher (Professor Level) in Genomics - University of Oxford and Director of the Genomics Facility at BSRC Al Fleming, Athens. |
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Title: | Integrated multivariate data-mining of miRNA and mRNA profiles identifies independent prognostic miRNAs associated with key Breast cancer progression pathways |
Room: | Room A2 of the department of Informatics and Telecommunications |
Abstract: | We analyzed miRNA and mRNA profiles of 219 breast cancers (BCs) measured using Illumina technology. These data were mined together to discover miRNAs related to specific pathways and prognosis in an integrated multivariate analysis accounting for clinico-pathological population variability.
We confirmed as strongly associated with hypoxia in BC, miRNAs known to be regulated by hypoxia in cell lines, such as miR-210, -122a, -452* and the -23/24/27 clusters. Furthermore, we identified 11 new miRNA associated with hypoxia; some of which were validated by cell line experiments. A comprehensive data-mining was performed to discover miRNAs strongly and independently prognostic for distant-relapse after correction for pathway gene signatures and clinical covariates. We identified 4 in ER-positive and 9 in ER-negative BCs; of these, miR-210, -27b and -150 were strongly prognostic also in triple-negative BCs. Pathways associated with prognostic miRNAs included proliferation, immune response, invasion and hypoxia; confirming in several cases reports from functional studies.
Finally, in some cases these results could be confirmed at the level of gene expression of the precursor and/or predicted targets. For example, in the case of miR-27b, associated with invasion and member of hypoxia-related miR-23/24/27 clusters, the mean expression of targets predicted by 6 published databases was prognostic in univariate and multivariate analyses of distant-relapse in 3 independent large BC series. In conclusion, integrated multivariate data-mining of miRNA and mRNA profiles in a large clinical series could identify independent prognostic miRNAs associated with key BC progression pathways. |
About the speaker: | Born in Athens he studied Biochemistry at the University of Tuebingen
(Germany), where he also received his Doctorate in Biochemistry in 1988.
He received an EMBO fellowship to work with Dr. John Trowsdale at the
Imperial Cancer Research Fund (ICRF) Laboratories in London, where he also
received an ICRF fellowship.
His work has covered the physical mapping and
gene identification in the human Major Histocompatibility Complex. In 1992
he became Lecturer in Molecular Genetics at the Division of Medical
Molecular Genetics of the United Medical and Dental Schools of Guy?s and
St. Thomas London. He became a Senior Lecturer in 1995. In 2001 he moved
to the University of Oxford working at the Wellcome Trust Centre for Human
Genetics, where he is Head of Genomic Research. He is also University
Reader in Genomics. His work covers the application of microarray and next
generation sequencing technologies in genetics, epigenetics and regulation
of transcription.
Since 2010 he has been elected Researcher (Professor Level) in Genomics and
Director of the Genomics Facility at BSRC Al Fleming in Athens.
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Videolecture: | http://videolectures.uoa.gr/records/camtasia/di/itmb/ragousis/ragousis.html |
Links: |
Personal Web page of the speaker: http://www.well.ox.ac.uk/ioannis-ragoussis |
Date: Thursday, January 27, 2011, Time: 15:00 | |
Speaker: | Joseph Nadeau - Director of Research and Academic Affairs, Institute for Systems Biology (ISB), Seattle, USA |
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Title: | From Peas (Genetics) to Disease (Systems Biology): Medicine Transformed as an Information Science |
Room: | Room A2 of the department of Informatics and Telecommunications |
Abstract: | A revolution is underway that is shifting the focus of health care from treatment of disease to diagnosis and prevention. This revolution is based on an integration of genetics, genomics and biology that has led to new field called systems biology and medicine, and that is transforming medicine to an information science.
This revolution is enabled with breakthroughs in technologies and computer sciences that are together leading to an incredible increase in complex information, over time, for millions of individuals. This information must be accessed, analyzed and interpreted in real time to provide effective proactive health care. Analysis of this information, together with parallel studies in model organisms, is creating a deep understanding of the function of biological systems as well as discovery of new ways to maintain health. I will summarize the key elements of this ongoing revolution, and will provide examples of the ways in which an understanding of genetics, systems biology and information sciences can be used to prevent diseases such as cancer and obesity.
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About the speaker: | Joseph Nadeau is formerly James H. Jewel Professor and Chair of Genetics Department at Case Western Reserve University School of Medicine.
He was a founding member of the International Mammalian Genome Society and a founding editor of Mammalian Genome and of Systems Biology and Medicine. He was founder and director of the Mouse Genome Informatics Project and founder of the Mouse Gene Expression Database Project. He has served on review panels and advisory groups at the National Institutes of Health, the National Science Foundation and the Human Genome Database, and has consulted for several biotech and major pharmaceutical companies. His research interests include cancer, metabolic disease and development, with an emphasis on genetic, genomic, computational, bioinformatics, and systems studies of mouse models of human disease. He has won several awards for his work, is an Elected Fellow of the American Association for the Advancement of Science, and was recently recognized with a Pioneer Award from the National Institutes of Health. He is currently Director of Research and Academic Affairs at the Institute for Systems Biology.
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Videolecture: | http://videolectures.uoa.gr/records/camtasia/di/itmb/27-1-2011/27-1-2011.html |
Links: |
Personal Web page of the speaker: http://www.systemsbiology.org/Scientists_and_Research/Faculty_Groups/Nadeau_Group |
Date: Thursday, January 13, 2011, Time: 15:00 | |
Speaker: | Yannis Paschalidis - Professor - Department of Electrical and Computer Engineering and Division of Systems Engineering, Boston University |
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Title: | Optimization Techniques for Protein Docking |
Room: | Seminars Room Gu-Media Center, 2nd floor of NOC Building, UoA |
Abstract: | I shall present my group's recent work motivated by a fundamental and
challenging problem in computational structural biology. Protein-protein interactions play a central role in metabolic control, signal transduction, and gene regulation. Determining the 3-dimensional (3D) structure of a complex from the atomic coordinates of two interacting proteins (the receptor and the ligand) is known as the protein docking problem. Experimental techniques can provide such 3D structures but are time-consuming, expensive, and not universally applicable. As a result, solving these problems computationally is critical and has attracted a lot of attention.
Nature being efficient, protein docking can be formulated as a the problem of minimizing the Gibbs free energy of the complex. Optimization is performed over translations and rotations of the ligand with respect to the receptor (a nonlinear manifold), as well as, over conformational changes (especially side-chains at the interface). However, the free-energy functional is very complex having multiple deep funnels and a huge number of local minima of less depth that are spread over the domain of the function. We present a systematic multi-stage method for performing this optimization. The entire conformational space of ligand translations and rotations is explored using simplified energy potentials to produce clusters of promising conformations. Optimization of side chains is formulated as a combinatorial optimization problem for which we propose a new distributed algorithm based on graph-theoretic ideas. The energy landscape in the space of ligand translations and rotations is explored using dimensionality reduction approaches, which reduces the domain of further optimization.
Finally, cluster refinement is done using a new stochastic global optimization method we have developed, the so called Semi-Definite programming based Underestimation (SDU) method. We will discuss the algorithms, provide convergence guarantees, comparisons with related work, and an array of computational results illustrating our approach. |
About the speaker: | Yannis Paschalidis is a Professor of Electrical & Computer and of Systems Engineering at Boston University, a Co-Director of the Center for Information and Systems Engineering (CISE), and the Academic
Director of the Sensor Network Consortium (SNC) - an industry consortium
he spearheaded which currently consists of 14 companies focusing in
sensor networks.
He obtained a Diploma (1991) from the National Technical University of Athens, and an M.S. (1993) and a Ph.D. (1996) from the Massachusetts Institute of Technology (MIT), all in Electrical Engineering and Computer Science.
In September 1996 he joined Boston University where he has been ever since. His current research interests lie in the fields systems and control, networking, applied probability, optimization, operations research, computational biology, and bioinformatics. Prof. Paschalidis' work on communication networks has been recognized with a CAREER award (2000) from the National Science Foundation and the second prize in the 1997 George E. Nicholson paper competition by INFORMS. He was an invited participant at the 2002 Frontiers of Engineering Symposium, organized by the National Academy of Engineering. His recent work on protein docking has been recognized by a 1st prize in the Protein Interaction Evaluation Meeting (2007) and an invitation to a select workshop at the Institute for Mathematics and Its Applications (IMA) on Molecular and Cellular Biology (2008). He has served in the program/organization committees of many conferences, has been a past associate Editor of the IEEE Trans. on Autom. Control and of the Operations Research Letters, and is currently an associate editor of the SIAM Journal on Control and Optimization. |
Videolecture: | http://videolectures.uoa.gr/records/camtasia/di/itmb/13-1-2011/13-1-2011.html |
Links: | Personal Web page of the speaker: http://ionia.bu.edu/ |