1,933 research outputs found
Leptin Induces Proliferation and Notch Expression In Pancreatic Cancer
Pancreatic adenocarcinoma (PA) is an aggressive cancer. It develops in a way that causes almost no detectable symptoms, which leads to a rapid progression and a short survival rate.
Researchers have discovered a link between pancreatic cancer (and other cancer types) and obesity. High levels of leptin, an appetite hormone secreted by adipocytes, have been found in obese people. Studies have shown that the absence of leptin in the body or severe leptin resistance can lead to uncontrolled eating and weight gain, hence, its connection to obesity. Consequently, our lab is analyzing the relationship between obesity and leptin and what effects they have on pancreatic cancer progression.
We hypothesize that in PA cells, leptin induces proliferation, tumorigenesis, and increased levels of Notch and related molecules. These effects are reversed by our leptin antagonist linked to iron nanoparticles, IONP-LPrA2 (iron oxidized nanoparticles leptin peptide receptor antagonist). We’re mainly focused on 4 cell lines: Panc-1, MiaPaCa-2, and BxPc3 (derived from primary tumors) and AsPc-1 (from a metastatic tumor). Of the primary tumors, Panc-1 and MiaPaCa-2 are more aggressive and BxPc-3 is less aggressive.
We expect results validating that leptin will induce proliferation (in Panc-1 and AsPc-1cells by MTT assay), expression of Notch and other molecules (in BxPc3 and MiaPaCa-2 cells by flow cytometry and Western Blot), and tumorsphere formation (in Panc-1). Leptin may also induce Notch expression in Panc-1 tumorspheres.
In conclusion, this project will demonstrate the involvement of leptin in PA progression. Leptin\u27s effects will be abrogated by the inhibitor of leptin signaling, IONP-LPrA2
Speculative parallelism in Intel Cilk Plus
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 37).Certain algorithms can be effectively parallelized at the cost of performing some redundant work. One example is searching an unordered tree graph for a particular node. Each subtree can be searched in parallel by a separate thread. Once a single thread is successful, however, the work of the others is unneeded and should be ended. This type of computation is known as speculative parallelism. Typically, an abort command is provided in the programming language to provide this functionality, but some languages do not. This thesis shows how support for the abort command can be provided as a user-level library. A parallel version of the alpha beta search algorithm demonstrates its effectivenesss.by Ruben Perez.M.Eng
UMTS radio-over-fiber pico-cell interconnection employing uncooled DFB lasers for multi-mode fibre modulation bandwidth enhancement
This paper analyzes experimentally the use of distributed feedback lasers (DFB) in order to increase modulation bandwidth in multimode fibres, enabling 3 km bidirectional radio-over-multimode fibre UMTS transmission in a frequency-division duplexing (FDD) configuration
The continuous star formation history of a giant HII region in M101
We present results about the star formation process in the giant HII region
NGC 5471 in the outskirts of M101. From resolved HST/WPFC2 photometry we find
that star formation has been going for the last 70 Myr. We further compare
previous results from integrated infrared-optical photometry with the stellar
resolved CMD and we discuss the star formation properties of this region and
its individual knots, as well as characterizing the different stellar content.
This result has very important consequences in our understanding of the burst
versus continuous star formation activity in spiral galaxies.Comment: 2 pages, 2 figures. Proceeding of the conference From Stars to
Galaxies: Building the pieces to build up the Universe (Venice, Italy
Cosmological constraints for a two brane-world system with single equation of state
We present the study of two 3-brane system embedded in a 5-dimensional
space-time in which the fifth dimension is compactified on a
orbifold. Assuming isotropic, homogeneous, and static branes, it can be shown
that the dynamics of one brane is dominated by the other one when the metric
coefficients have a particular form. We study the resulting cosmologies when
one brane is dominated by a given single-fluid component.Comment: This work was presented at the VIII Taller of the DGFM, Tuxtla
Gutierrez, Chiapas, Mexico noviembre 22-26, 201
Two-brane system in a vacuum bulk with a single equation of state
We study the cosmology of a two-brane model in a five-dimensional spacetime,
where the extra spatial coordinate is compactifed on an orbifold. Additionally,
we consider the existence on each brane of matter fields that evolve in time.
Solving the Einstein equations in a vacuum bulk, we can show how the matter
fields in both branes are connected and they do not evolve independentlyComment: This work was presented at the IX Taller de la Division de
Gravitacion y Fisica Matematica, Colima 201
Intrinsic noise profoundly alters the dynamics and steady state of morphogen-controlled bistable genetic switches
During tissue development, patterns of gene expression determine the spatial
arrangement of cell types. In many cases, gradients of secreted signaling
molecules - morphogens - guide this process. The continuous positional
information provided by the gradient is converted into discrete cell types by
the downstream transcriptional network that responds to the morphogen. A
mechanism commonly used to implement a sharp transition between two adjacent
cell fates is the genetic toggle switch, composed of cross-repressing
transcriptional determinants. Previous analyses emphasize the steady state
output of these mechanisms. Here, we explore the dynamics of the toggle switch
and use exact numerical simulations of the kinetic reactions, the Chemical
Langevin Equation, and Minimum Action Path theory to establish a framework for
studying the effect of gene expression noise on patterning time and boundary
position. This provides insight into the time scale, gene expression
trajectories and directionality of stochastic switching events between cell
states. Taking gene expression noise into account predicts that the final
boundary position of a morphogen-induced toggle switch, although robust to
changes in the details of the noise, is distinct from that of the deterministic
system. Moreover, stochastic switching introduces differences in patterning
time along the morphogen gradient that result in a patterning wave propagating
away from the morphogen source. The velocity of this wave is influenced by
noise; the wave sharpens and slows as it advances and may never reach steady
state in a biologically relevant time. This could explain experimentally
observed dynamics of pattern formation. Together the analysis reveals the
importance of dynamical transients for understanding morphogen-driven
transcriptional networks and indicates that gene expression noise can
qualitatively alter developmental patterning
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