The Massachusetts Institute of Technology is a private research university in Cambridge, Massachusetts. Founded in 1861 in response to the increasing industrialization of the United States, MIT adopted a European polytechnic university model and stressed laboratory instruction in applied science and engineering. Researchers worked on computers, radar, and inertial guidance during World War II and the Cold War. Post-war defense research contributed to the rapid expansion of the faculty and campus under James Killian. The current 168-acre campus opened in 1916 and extends over 1 mile along the northern bank of the Charles River basin.MIT, with five schools and one college which contain a total of 32 departments, is traditionally known for research and education in the physical science and engineering, and more recently in biology, economics, linguistics, and management as well. The "Engineers" sponsor 31 sports, most teams of which compete in the NCAA Division III's New England Women's and Men's Athletic Conference; the Division I rowing programs compete as part of the EARC and EAWRC.MIT is often cited as among the world's top universities. As of 2014, 81 Nobel laureates, 52 National Medal of Science recipients, 45 Rhodes Scholars, 38 MacArthur Fellows, and 2 Fields Medalists have been affiliated with MIT. MIT has a strong entrepreneurial culture and the aggregated revenues of companies founded by MIT alumni would rank as the eleventh-largest economy in the world. Wikipedia.
The Broad Institute Inc., Massachusetts Institute of Technology and President And Fellows Of Harvard College | Date: 2017-03-22
The invention provides for systems, methods, and compositions for manipulation of sequences and/or activities of target sequences. Provided are vectors and vector systems, some of which encode one or more components of a CRISPR complex, as well as methods for the design and use of such vectors. Also provided are methods of directing CRISPR complex formation in eukaryotic cells and methods for selecting specific cells by introducing precise mutations utilizing the CRISPR-Cas system.
Massachusetts Institute of Technology | Date: 2017-03-01
Embodiments related to cation-disordered lithium metal oxide compounds, their methods of manufacture, and use are described. In one embodiment, a cation-disordered lithium metal oxide includes LiMMO_(2) with a greater than 1. M includes at least one redox-active species with a first oxidation state n and an oxidation state n greater than n, and M is chosen such that a lithium-M oxide having a formula LiMO_(2) forms a cation-disordered rocksalt structure. M includes at least one charge-compensating species that has an oxidation state y that is greater than n.
Ebert M.S.,Massachusetts Institute of Technology
Cell | Year: 2012
Biological systems use a variety of mechanisms to maintain their functions in the face of environmental and genetic perturbations. Increasing evidence suggests that, among their roles as posttranscriptional repressors of gene expression, microRNAs (miRNAs) help to confer robustness to biological processes by reinforcing transcriptional programs and attenuating aberrant transcripts, and they may in some network contexts help suppress random fluctuations in transcript copy number. These activities have important consequences for normal development and physiology, disease, and evolution. Here, we will discuss examples and principles of miRNAs that contribute to robustness in animal systems. Copyright © 2012 Elsevier Inc. All rights reserved.
Centola D.,Massachusetts Institute of Technology
Science | Year: 2010
How do social networks affect the spread of behavior? A popular hypothesis states that networks with many clustered ties and a high degree of separation will be less effective for behavioral diffusion than networks in which locally redundant ties are rewired to provide shortcuts across the social space. A competing hypothesis argues that when behaviors require social reinforcement, a network with more clustering may be more advantageous, even if the network as a whole has a larger diameter. I investigated the effects of network structure on diffusion by studying the spread of health behavior through artificially structured online communities. Individual adoption was much more likely when participants received social reinforcement from multiple neighbors in the social network. The behavior spread farther and faster across clustered-lattice networks than across corresponding random networks.
Guarente L.,Massachusetts Institute of Technology
Genes and Development | Year: 2013
Calorie or dietary restriction (CR) has attracted attention because it is the oldest and most robust way to extend rodent life span. The idea that the nutrient sensors, termed sirtuins, might mediate effects of CR was proposed 13 years ago and has been challenged in the intervening years. This review addresses these challenges and draws from a great body of new data in the sirtuin field that shows a systematic redirection of mammalian physiology in response to diet by sirtuins. The prospects for drugs that can deliver at least a subset of the benefits of CR seems very real. © 2013 Guarente.
Guarente L.,Massachusetts Institute of Technology
New England Journal of Medicine | Year: 2011
Sirtuins were originally identified as antiaging proteins in model genetic organisms and have emerged as mediators of the beneficial effects of calorie restriction in mammals. The mammalian Sir2 orthologue, SIRT1, is an NAD-dependent deacetylase that is involved in many central pathways governing physiology and stress management. Genetic or pharmacologic activation of SIRT1 can benefit numerous diseases in murine models. Indeed, two different SIRT1-activating compounds are now in a diverse set of phase 1 or phase 2 human trials (ClinicalTrials.gov numbers, NCT00937326, NCT00964340, NCT01014117, NCT01018017, NCT01018628, NCT01262911, NCT01031108, and NCT01154101). Beyond SIRT1, there are six other mammalian sirtuins (SIRT2, 3, 4, 5, 6, and 7), and all may turn out to have therapeutic potential with the use of activators or inhibitors. Among these sirtuins, SIRT3 is extremely interesting, because it appears to suppress one of the contributing causes of aging itself, reactive oxygen species in mitochondria. Indeed, genetic polymorphisms in the SIRT3 promoter have been associated with extreme longevity in an Italian population,89,90 although these studies will have to be replicated in other groups. In conclusion, sirtuins are a unique class of proteins that link protein acetylation to metabolism and exert profound effects on mammalian physiology and diseases of aging. The development of drugs that target sirtuins to treat these diseases is ongoing. Copyright © 2011 Massachusetts Medical Society.
Guarente L.,Massachusetts Institute of Technology
Cell | Year: 2014
The 40thanniversary of Cell coincides with that of the National Institute on Aging (NIA). Indeed, Cell papers on NIA-funded research helped move the field into a genetic and molecular era. Now is a fair time to ask whether we are far down a trail leading to a deep understanding of aging or whether we are still tiptoeing cautiously at the trailhead. © 2014 Elsevier Inc.
Nocera D.G.,Massachusetts Institute of Technology
Accounts of Chemical Research | Year: 2012
To convert the energy of sunlight into chemical energy, the leaf splits water via the photosynthetic process to produce molecular oxygen and hydrogen, which is in a form of separated protons and electrons. The primary steps of natural photosynthesis involve the absorption of sunlight and its conversion into spatially separated electron-hole pairs. The holes of this wireless current are captured by the oxygen evolving complex (OEC) of photosystem II (PSII) to oxidize water to oxygen. The electrons and protons produced as a byproduct of the OEC reaction are captured by ferrodoxin of photosystem I. With the aid of ferrodoxin-NADP + reductase, they are used to produce hydrogen in the form of NADPH. For a synthetic material to realize the solar energy conversion function of the leaf, the light-absorbing material must capture a solar photon to generate a wireless current that is harnessed by catalysts, which drive the four electron/hole fuel-forming water-splitting reaction under benign conditions and under 1 sun (100 mW/cm 2) illumination.This Account describes the construction of an artificial leaf comprising earth-abundant elements by interfacing a triple junction, amorphous silicon photovoltaic with hydrogen- and oxygen-evolving catalysts made from a ternary alloy (NiMoZn) and a cobalt-phosphate cluster (Co-OEC), respectively. The latter captures the structural and functional attributes of the PSII-OEC. Similar to the PSII-OEC, the Co-OEC self-assembles upon oxidation of an earth-abundant metal ion from 2+ to 3+, may operate in natural water at room temperature, and is self-healing. The Co-OEC also activates H 2O by a proton-coupled electron transfer mechanism in which the Co-OEC is increased by four hole equivalents akin to the S-state pumping of the Kok cycle of PSII. X-ray absorption spectroscopy studies have established that the Co-OEC is a structural relative of Mn 3CaO 4-Mn cubane of the PSII-OEC, where Co replaces Mn and the cubane is extended in a corner-sharing, head-to-tail dimer.The ability to perform the oxygen-evolving reaction in water at neutral or near-neutral conditions has several consequences for the construction of the artificial leaf. The NiMoZn alloy may be used in place of Pt to generate hydrogen. To stabilize silicon in water, its surface is coated with a conducting metal oxide onto which the Co-OEC may be deposited. The net result is that immersing a triple-junction Si wafer coated with NiMoZn and Co-OEC in water and holding it up to sunlight can effect direct solar energy conversion via water splitting. By constructing a simple, stand-alone device composed of earth-abundant materials, the artificial leaf provides a means for an inexpensive and highly distributed solar-to-fuels system that employs low-cost systems engineering and manufacturing. Through this type of system, solar energy can become a viable energy supply to those in the non-legacy world. © 2012 American Chemical Society.
Autor D.H.,Massachusetts Institute of Technology
Science | Year: 2014
The singular focus of public debate on the "top 1 percent" of households overlooks the component of earnings inequality that is arguably most consequential for the "other 99 percent" of citizens: the dramatic growth in the wage premium associated with higher education and cognitive ability. This Review documents the central role of both the supply and demand for skills in shaping inequality, discusses why skill demands have persistently risen in industrialized countries, and considers the economic value of inequality alongside its potential social costs. I conclude by highlighting the constructive role for public policy in fostering skills formation and preserving economic mobility.
Bazant M.Z.,Massachusetts Institute of Technology
Accounts of Chemical Research | Year: 2013
Advances in the fields of catalysis and electrochemical energy conversion often involve nanoparticles, which can have kinetics surprisingly different from the bulk material. Classical theories of chemical kinetics assume independent reactions in dilute solutions, whose rates are determined by mean concentrations. In condensed matter, strong interactions alter chemical activities and create variations that can dramatically affect the reaction rate. The extreme case is that of a reaction coupled to a phase transformation, whose kinetics must depend not only on the order parameter but also on its gradients at phase boundaries. Reaction-driven phase transformations are common in electrochemistry, when charge transfer is accompanied by ion intercalation or deposition in a solid phase. Examples abound in Li-ion, metal-air, and lead-acid batteries, as well as metal electrodeposition-dissolution. Despite complex thermodynamics, however, the standard kinetic model is the Butler-Volmer equation, based on a dilute solution approximation. The Marcus theory of charge transfer likewise considers isolated reactants and neglects elastic stress, configurational entropy, and other nonidealities in condensed phases.The limitations of existing theories recently became apparent for the Li-ion battery material LixFePO4 (LFP). It has a strong tendency to separate into Li-rich and Li-poor solid phases, which scientists believe limits its performance. Chemists first modeled phase separation in LFP as an isotropic "shrinking core" within each particle, but experiments later revealed striped phase boundaries on the active crystal facet. This raised the question: What is the reaction rate at a surface undergoing a phase transformation? Meanwhile, dramatic rate enhancement was attained with LFP nanoparticles, and classical battery models could not predict the roles of phase separation and surface modification.In this Account, I present a general theory of chemical kinetics, developed over the past 7 years, which is capable of answering these questions. The reaction rate is a nonlinear function of the thermodynamic driving force, the free energy of reaction, expressed in terms of variational chemical potentials. The theory unifies and extends the Cahn-Hilliard and Allen-Cahn equations through a master equation for nonequilibrium chemical thermodynamics. For electrochemistry, I have also generalized both Marcus and Butler-Volmer kinetics for concentrated solutions and ionic solids.This new theory provides a quantitative description of LFP phase behavior. Concentration gradients and elastic coherency strain enhance the intercalation rate. At low currents, the charge-transfer rate is focused on exposed phase boundaries, which propagate as "intercalation waves", nucleated by surface wetting. Unexpectedly, homogeneous reactions are favored above a critical current and below a critical size, which helps to explain the rate capability of LFP nanoparticles. Contrary to other mechanisms, elevated temperatures and currents may enhance battery performance and lifetime by suppressing phase separation. The theory has also been extended to porous electrodes and could be used for battery engineering with multiphase active materials.More broadly, the theory describes nonequilibrium chemical systems at mesoscopic length and time scales, beyond the reach of molecular simulations and bulk continuum models. The reaction rate is consistently defined for inhomogeneous, nonequilibrium states, for example, with phase separation, large electric fields, or mechanical stresses. This research is also potentially applicable to fluid extraction from nanoporous solids, pattern formation in electrophoretic deposition, and electrochemical dynamics in biological cells. © 2013 American Chemical Society.