261 research outputs found
Visit of Subra Suresh, President of Nanyang Technological University, Distinguished University Professor from Singapore
No full textProfessor Subra Suresh, President, Nanyang Technological University, Distinguished University Professor, Singapor
A World of Changes Prepares Subra Suresh to Tackle Change at NSF
No full textLast week, in his first public interview since taking office, the new director of the U.S. National Science Foundation, Subra Suresh, discussed his plans for the agency in the current politically charged climate.</jats:p
Investigation of Human Diseases at the Intersections of Engineering, Natural Sciences and Medicine
No full textPresented on September 20, 2011 at 11:00 a.m. in the IBB Atrium on the Georgia Tech Campus.Subra Suresh was sworn in as director of the National Science Foundation on October 18, 2010,
and is the Vannevar Bush Professor of Engineering (on leave) at the Massachusetts Institute of
Technology. He holds joint faculty appointments in Materials Science and Engineering,
Mechanical Engineering, Biological Engineering, and Health Sciences and Technology. Suresh’s
work as a researcher, educator, and academic administrator across a wide range of disciplines
—including mechanical engineering, materials science, and biomedical engineering—have been
recognized by academic and professional organizations around the world. His experimental and
computational modeling work on the mechanical properties of structural and functional materials,
his innovations in materials design and characterization, and his discoveries regarding the
connections between cellular nanomechanics and human diseases such as malaria have shaped
new fields at the intersections of traditional disciplines. More than 100 students, post-doctoral
associates, and research scientists who trained in his group occupy prominent positions in
academe, industry, and government throughout the world. He has authored or co-authored three
books: Fatigue of Materials, Fundamentals of Functionally Graded Materials, and Thin Film
Materials. Suresh made far-reaching contributions as a graduate student, parent, faculty
member, and dean over three decades at MIT. While serving as department head in Materials
Science and Engineering from 2000 to 2006, he renovated highly visible spaces along the
Infinite Corridor to give the general public an insider’s view of modern materials research and
instruction, and, in partnership with the Physics Department, he helped launch the Physics-
DMSE-Spectroscopy-Infrastructure (PDSI) project. Suresh was founding chair of the first
Singapore-MIT Alliance (SMA) Programme on Advanced Materials for Micro and Nano Systems
and was the Institute’s lead coordinator on the creation of the Singapore-MIT Alliance for
Research and Technology (SMART) Center. Suresh’s interests in international, inter-institutional,
and inter-disciplinary collaboration led in 2005 to the creation of Global Enterprise for
MicroMechanics and Molecular Medicine (GEM4), whose membership now includes more than
12 institutions from around the world. During Suresh’s tenure as Dean the School of Engineering
added more than 50 new faculty members to its ranks—more than 10% of its total. Under his
leadership, the School pioneered new interdepartmental faculty searches and recruited high
numbers of women and under-represented minorities to the faculty; in 2009-10, for the first time
in its history, more women than men joined the faculty of MIT’s School of Engineering. Suresh
also oversaw the creation of a several new initiatives: the Center for Computational Engineering,
the Transportation@MIT initiative, the Bernard Gordon Engineering Leadership Program, the
creation and renovation of a number of laboratory facilities, and the MIT Flexible Engineering
Degree Program.Runtime: 71:31 minutesMajor advances in various branches of engineering and natural sciences, together with
transformational developments in information technology, computational modeling and simulation,
genetics, genomics, and nanotechnology, have provided unprecedented opportunities to explore
human health and diseases at the cellular and molecular levels. Such developments have also
facilitated new opportunities to study fundamental mechanistic processes with the goal of
developing basic scientific understanding, new diagnostic tools, and novel therapeutics for a
range of human diseases and disorders. This presentation will provide an overview of some
recent accomplishments and opportunities for future exploration. Specific examples are drawn
from the study of infectious diseases, hereditary blood disorders, and cancer
Introduction à la géopolitique de Philippe Subra : Synthèse et critique
No full textCet article vise à faire le point sur les travaux théoriques et méthodologiques de Philippe Subra. Il vise à montrer comment ceux-ci viennent renouveler la théorie géopolitique, en mettant en leur centre la question des phénomènes dits locaux ; phénomènes qui n’ont pas, jusqu’à maintenant, reçu toute l’attention qu’ils méritent des géopoliticiens. À notre connaissance, les travaux de Philippe Subra – relativement récents – n’ont pas encore bénéficié d’un travail de synthèse conséquent, et surtout de la discussion critique si nécessaire à l’épanouissement des nouvelles idées et orientations académiques. Ces travaux sont pourtant susceptibles d’apporter une nouvelle impulsion à la théorie géopolitique et, plus particulièrement, à l’analyse des conflits dans le champ de l’aménagement et du développement. À l’instar des travaux menés par l’école géographique, ceux de Philippe Subra montrent que l’analyse des représentations est un outil indispensable d’une analyse géopolitique des projets d’aménagement et de développement. De fait, les représentations permettent d’appréhender les relations au territoire et surtout de comprendre la nature des rivalités rencontrées. En somme, en nous appuyant sur les principaux travaux théoriques et méthodologiques de Philippe Subra, c’est à cet effort de synthèse et de critique que nous souhaitons contribuer. Cet article d’introduction à la géopolitique de Philippe Subra aborde d’abord sa lecture de l’aménagement et du développement comme questions géopolitiques. Puis, l’article présente sa typologie des conflits. Il introduit ensuite à ses concepts clés. L’article permet finalement de revenir sur le travail accompli par l’auteur jusqu’à présent, et d’en offrir une appréciation critique, qui se veut méliorative.This article presents the theoretical and methodological work of Philippe Subra. It aims to show how they are renewing geopolitical theory by putting the question of so-called ‘ local ’ phenomena at the centre ; phenomena that have not, until now, received the attention they deserve from geopoliticians. To our knowledge, the works of Philippe Subra – which are relatively recent – have not yet benefited from synthesis work, or from the critical discussion so necessary to the blossoming of new ideas and academic orientations. However, this work is likely to bring a new impetus to geopolitical theory and, more particularly, to the analysis of conflicts in the field of planning and development. Like the work done by the Geographical School, Philippe Subra's work shows that the analysis of the representations is an indispensable tool of geopolitical analysis for projects of planning and development. In fact, the representations make it possible to appreciate relations within the territory, and especially to understand the nature of the rivalries that arise. In short, by drawing on Philippe Subra's main theoretical and methodological works, we wish to contribute to this effort of synthesis and criticism. This introductory article to the geopolitics of Philippe Subra first addresses his reading of planning and development as geopolitical issues. Then, the article presents its typology of conflicts. He then introduces his key concepts. Finally, the article allows us to review the work accomplished by the author so far, and to offer a critical appreciation of it, which is intended to be meliorative
Quantifying the biophysical characteristics of Plasmodium-falciparum- parasitized red blood cells in microcirculation
No full textThe pathogenicity of Plasmodium falciparum (Pf) malaria results from the stiffening of red blood cells (RBCs) and its ability to adhere to endothelial cells (cytoadherence). The dynamics of Pf-parasitized RBCs is studied by three-dimensional mesoscopic simulations of flow in cylindrical capillaries in order to predict the flow resistance enhancement at different parasitemia levels. In addition, the adhesive dynamics of Pf-RBCs is explored for various parameters revealing several types of cell dynamics such as firm adhesion, very slow slipping along the wall, and intermittent flipping. The parasite inside the RBC is modeled explicitly in order to capture phenomena such as “hindered tumbling” motion of the RBC and the sudden transition from firm RBC cytoadherence to flipping on the endothelial surface. These predictions are in quantitative agreement with recent experimental observations, and thus the three-dimensional modeling method presented here provides new capabilities for guiding and interpreting future in vitro and in vivo studies of malaria.National Institutes of Health (U.S.) (NIH) Grant R01HL094270)National Science Foundation (U.S.) (NSF) Grant CBET-0852948)Singapore-MIT Alliance for Research and Technology (Interdisciplinary Research Group on Infectious Diseases
Multiscale Modeling of Red Blood Cell Mechanics and Blood Flow in Malaria
No full textRed blood cells (RBCs) infected by a Plasmodium parasite in malaria may lose their membrane deformability with a relative membrane stiffening more than ten-fold in comparison with healthy RBCs leading to potential capillary occlusions. Moreover, infected RBCs are able to adhere to other healthy and parasitized cells and to the vascular endothelium resulting in a substantial disruption of normal blood circulation. In the present work, we simulate infected RBCs in malaria using a multiscale RBC model based on the dissipative particle dynamics method, coupling scales at the sub-cellular level with scales at the vessel size. Our objective is to conduct a full validation of the RBC model with a diverse set of experimental data, including temperature dependence, and to identify the limitations of this purely mechanistic model. The simulated elastic deformations of parasitized RBCs match those obtained in optical-tweezers experiments for different stages of intra-erythrocytic parasite development. The rheological properties of RBCs in malaria are compared with those obtained by optical magnetic twisting cytometry and by monitoring membrane fluctuations at room, physiological, and febrile temperatures. We also study the dynamics of infected RBCs in Poiseuille flow in comparison with healthy cells and present validated bulk viscosity predictions of malaria-infected blood for a wide range of parasitemia levels (percentage of infected RBCs with respect to the total number of cells in a unit volume).United States. National Institutes of Health (Grant R01HL094270)National Science Foundation (U.S.). (Grant CBET-0852948)Singapore-MIT Alliance for Research and Technology Cente
Refractive index maps and membrane dynamics of human red blood cells parasitized by Plasmodium falciparum
No full textParasitization by malaria-inducing Plasmodium falciparum leads to structural, biochemical, and mechanical modifications to the host red blood cells (RBCs). To study these modifications, we investigate two intrinsic indicators: the refractive index and membrane fluctuations in A falciparum-invaded human RBCs (Pf-RBCs). We report experimental connections between these intrinsic indicators and pathological states. By employing two noninvasive optical techniques, tomographic phase microscopy and diffraction phase microscopy, we extract three-dimensional maps of refractive index and nanoscale cell membrane fluctuations in isolated RBCs. Our systematic experiments cover all intraerythrocytic stages of parasite development under physiological and febrile temperatures. These findings offer potential, and sufficiently general, avenues for identifying, through cell membrane dynamics, pathological states that cause or accompany human diseases.
Lipid bilayer and cytoskeletal interactions in a red blood cell
No full textWe study the biomechanical interactions between the lipid bilayer and the cytoskeleton in a red blood cell (RBC) by developing a general framework for mesoscopic simulations. We treated the lipid bilayer and the cytoskeleton as two distinct components and developed a unique whole-cell model of the RBC, using dissipative particle dynamics (DPD). The model is validated by comparing the predicted results with measurements from four different and independent experiments. First, we simulated the micropipette aspiration and quantified the cytoskeletal deformation. Second, we studied the membrane fluctuations of healthy RBCs and RBCs parasitized to different intraerythrocytic stages by the malaria-inducing parasite Plasmodium falciparum. Third, we subjected the RBC to shear flow and investigated the dependence of its tank-treading frequency on shear rate. Finally, we simulated the bilayer–cytoskeletal detachment in channel flow to quantify the strength of such interactions when the corresponding bonds break. Taken together, these experiments and corresponding systematic DPD simulations probe the governing constitutive response of the cytoskeleton, elastic stiffness, viscous friction, and strength of bilayer–cytoskeletal interactions as well as membrane viscosities. Hence, the DPD simulations and comparisons with available independent experiments serve as validation of the unique two-component model and lead to useful insights into the biomechanical interactions between the lipid bilayer and the cytoskeleton of the RBC. Furthermore, they provide a basis for further studies to probe cell mechanistic processes in health and disease in a manner that guides the design and interpretation of experiments and to develop simulations of phenomena that cannot be studied systematically by experiments alone.National Institutes of Health (U.S.) (Grant R01HL094270)United States. Dept. of Energy (Collaboratory on Mathematics and Mesoscopic Modeling of Materials)Singapore-MIT Alliance for Research and Technology CenterSingapore-MIT Allianc
Obama's Nominee to Lead NSF Lauded for Science and Management Skills
No full textSubra Suresh, dean of engineering at the Massachusetts Institute of Technology, was nominated last week to become the next director of the National Science Foundation.</jats:p
NSF Creates Fast Track for Out-of-the-Box Proposals
No full textLast week, National Science Foundation Director Subra Suresh unveiled an initiative that aims to roll the dice on a relative handful of researchers with unorthodox ideas about how to tackle complex problems.</jats:p
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