A regulatory role for repeated decoy transcription factor binding sites in target gene expression

Repetitive stretches of DNA that contain transcription factor (TF) binding sites can act as decoys that sequester TFs. This study shows that these decoy sites can have important indirect effects on transcriptional regulation by altering the dose–response between a TF and its target promoter

Topics in double field theory

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 199-204).The existence of momentum and winding modes of closed string on a torus leads to a natural idea that the field theoretical approach of string theory should involve winding type coordinates as well as the usual space-time coordinates. Recently developed double field theory is motivated from this idea and it implements T-duality manifestly by doubling the coordinates. In this thesis we will mainly focus on the double field theory formulation of different string theories in its low energy limit: bosonic, heterotic, type II and its massive extensions, and M = 1 super-gravity theory. In chapter 2 of the thesis we study the equivalence of different formulations of double field theory. There are three different formulations of double field theory: background field E formulation, generalized metric H formulation, and frame field EAM formulation. Starting from the frame field formalism and choosing an appropriate gauge, the equivalence of the three formulations of bosonic theory are explicitly verified. In chapter 3 we construct the double field theory formulation of heterotic strings. The global symmetry enlarges to O(D, D + n) for heterotic strings and the enlarged generalized metric features this symmetry. The structural form of bosonic theory can directly be applied to the heterotic theory with the enlarged generalized metric. In chapter 4 we develop a unified framework of double field theory for type II theories. The Ramond-Ramond potentials fit into spinor representations of the duality group 0(D, D) and the theory displays Spin+(D, D) symmetry with its self-duality relation. For a specific form of RR 1-form the theory reduces to the massive deformation of type IIA theory due to Romans. In chapter 5 we formulate the K = 1 supersymmetric extension of double field theory including the coupling to n abelian vector multiplets. This theory features a local 0(1, 9 + n) x 0(1, 9) tangent space symmetry under which the fermions transform.by Seung Ki Kwak.Ph.D

Accepted by...........................................................

Cancer is a leading cause of death worldwide, accounting for at least 10 % of all deaths globally. Current therapies for cancer include surgical excision, chemotherapy and immunotherapy. CD8 * T cells are adaptive immune cells responsible for eradicating tumor cells. However, these T cells can be rendered ineffective through tolerance. Yet in various mouse models and human patients, tolerant T cells persist. The aim of this project is to identify factors that support T cell persistence in a tolerizing tumor environment. Using a spontaneous prostate cancer model, we study antigen-specific T cells that have been shown to be locally tolerant in the prostate tumor environment. In this thesis, I compare the immune response in normal, antigen-bearing, tumor transgenic and tumor-antigen transgenic mouse models. Results show that T cell infiltration and persistence in the tolerizing prostate environment is dependent on the presence o

Design and Implementation of a Sector-Based Airspace Model for the MIT Extensible Air Network Simulation Design and Implementation of a Sector-Based Airspace Model for the MIT Extensible Air Network Simulation by

Abstract The MIT Extensible Air Network Simulation (MEANS) is a tool that has been designed to assist airline schedulers and air traffic managers in predicting flight delays for given air traffic scenarios. One aspect of the simulation, the determination of flight times, has received criticism from the MEANS users as being too simplistic for their needs. Currently, MEANS predicts flight times based on a historical distribution of observed flight times between city pairs. This system ignores the effects of flight level winds and airspace congestion, two major determiners of flight time. The replacement flight time model presented divides the airspace into discrete sectors based on existing divisions in air traffic control. Each sector has its own wind conditions and capacity limitations which affect passing flights. Results show that, after some calibration, the new flight time model produces accurate flight times when the airspace is divided into ARTCC domains and does not introduce additional errors into other parts of the simulation. Additionally, test scenarios show that the new system is capable of modeling airspace capacity events, such as a radar failure. Comparative results reveal that the old, distribution model produces surprisingly accurate flight times for typical wind conditions and airspace utilization. Emily Egan for everything. And my family for being there for me