Top

News

Vicki Sealey named Bolton Professor

Congratulations to Professor Sealey. Learn about the
Bolton Professorship here.

Date, Location: 
2015-12-01

Ms. Emine Guven Ph.D Defense 11/18/2015

Validation of a Predictive Model of Spontaneous Clustering
of Receptors on the Cell Membrane

Date: 11/18/2015
Time: 2:30PM-4:00PM
Place: 121 Armstrong Hall

All are welcome.

Abstract: Membrane receptors are specialized membrane-bound proteins that facili-
tate communication between the intracellular and extracellular membrane.
They control signal initiation in many import cellular signaling pathways.
Cell signaling (or signal transduction) provides the logical inputs individ-
ual cells need in order to perform their role in the context of the organism.
Signaling molecules such as hormones, neurotransmitters or growth factors,
are secreted by cells in the organism as a result of certain conditions; the
cells receiving the signal change (or maintain) their state in response to the
signaling input. The incoming information is processed and the response is
formulated by a complex bio-molecular network.

For many ligand / receptor
families, receptor dimerization or cross-linking is a necessary step for activa-
tion, making signaling pathways sensitive to the distribution of receptors in
the membrane. Microscopic imaging and modern labeling techniques reveal
that certain receptor types tend to co- localize in clusters. The origin of
these clusters is not well understood; they are likely not the result of chemi-
cal binding, but of a pre-existing micro-domain structure of the membrane.
In this work, we validate and implement a spatial stochastic model of clus
tering in order to clarify the mechanism behind cluster formation, as well
as to estimate its effect on signaling based on the hypothesis of pre-existing
domains that have a high affinity for receptors.

We focus on vascular endothelial growth factor (VEGF) receptor. VEGF is
a protein that is involved in the process of the growth of blood vessels and
maintenance. The static snapshots of the clustering of VEGF receptors are
produced by fixing the cells and then labeling them with nano-gold particle.
Then the snapshots of the cell membrane imaged by using high-resolution
transmission electron microscopy. Members of the VEGF family stimulate
cell responses by binding to the membrane-bound receptors (VEGFR), which
in turn stimulates receptor dimerization. In this contribution we develop a
method of defining receptor clustering in the membrane based on their mu-
tual distance, and apply it to a set of transmission microscopy (TEM) images
of VEGF receptor.

We develop domain construction algorithm and apply it
to characteristic length and further describe the clustering domains quanti-
tatively. We estimate the area, perimeter and attractiveness of the clustering
domains. Based on the spatial organization of receptors networks on the cell mem-
brane, we elaborate quantitative criteria to characterize receptor clustering.
We verify that the receptor network based on quantitative relations which are
derived using simple geometrical arguments by performing Monte Carlo sim-
ulations We show that our results are consistent with the observed random
placement of receptors within the clusters and the placement of the clusters
on the cell membrane. We use the pre-existing domain model to calculate the
probability distribution of cluster sizes. We compare experimental results to
estimate the quantitative characteristics of the clustering domains.

Date, Location: 
2015-11-18

Actuarial Science Talk 11/9/2015

Mike Toothman will be available to discuss alternatives for an actuarial
career, how to best prepare for them, and the work that actuaries typically perform

Date: 11/9/2015
Time: 4:30AM-5:30PM
Place: 315 Armstrong Hall

Mike is a Fellow of the Casualty Actuarial Society, (FCAS) and a Member of the American Academy of Actuaries (MAAA). He is a Past President of both the Casualty Actuarial Society (CAS) and the Conference of Consulting Actuaries and is a former Vice President of the American Academy of Actuaries. He has also served on the Boards of Directors for all three of those organizations.

Mike is a leader in the education of actuaries in North America, having served sixteen years in various positions on the CAS Examination Committee, including four years as Vice President responsible for all education and examination processes of the CAS. In addition, for the CAS, he has served on the Board of Directors, as Chairman of both the Long-Range Planning Committee and the Joint Program Committee for the Casualty Loss Reserve Seminar, and on several other committees. Mike served as a member of the Actuarial Board for Counseling and Discipline for six years, from 2004 through 2009, including one term as a Vice-Chair of that Board. Mike also served a two-year term as Chair of the International Association of Consulting Actuaries (IACA), from 2006 to 2008, and subsequently served as a delegate from the International Actuarial Association to the board of IACA.

Date, Location: 
2015-11-09

Miaomiao Han's Prospectus 10/8/2015

Graph Coloring Problems and Group Connectivity

Date: 10/8/2015
Time: 11:20AM-1:00PM
Place: 313 Armstrong Hall

Miaomiao Han

Everyone is invited. Following the talk and any discussion there will be an oral examination by his committee that is otherwise open only to graduate faculty that wish to attend in an observing capacity.

Date, Location: 
2015-10-08

Meet The Dean Candidates!

The Candidates for Dean of the Eberly College of Arts & Sciences
will be visiting Campus in October. More information about the Candidates and their visits .

Date, Location: 
2015-10-07

2015 Welcome Letter

Welcome Letter for new graduate students can be read online here or you
can download the pdf.

Events discussed in the Welcome Letter can also be found in calendar format on the Department Calendar.

If you have any questions do not hesitate to ask.

Date, Location: 
2015-08-18

REU student presentation 7/29-7/30/2015

It is hard to believe that our 8-eight REU program on Combinatorics and Graph Theory is almost over. This program has been sponsored by NSA, NSF and Math Department.

Twelve talented and diligent undergraduate students from 11 different universities have been working with the discrete math group on different challenging research projects. All of them have done a great job and most projects will eventually lead to publications in peer-reviewed discrete math journals. One of our teams won an award at the poster symposium last week.

The students will give their final presentations on Wednesday and Thursday morning. See attachment for the abstracts and schedule. On behalf of the mentors and the REU students, I would like to invite you to come to the talks if you are around. All talks will be in Armstrong 315 from 10:30-12:00 (7/29 and 7/30).

Presentation Schedule: PDF

Date: 07/29/2015 & 7/30/2015
Time: 10:30AM - 12:00PM
Place: 315 Armstrong Hall

Date, Location: 
2015-07-29

Dr. Etienne collaborates with NASA

Black holes are usually thought of as the result of a very massive star that has died. However, black holes millions of times more massive than such stars are thought to exist at the cores of all galaxies, including the Milky Way. How such supermassive black holes gained so much mass remains a mystery. One popular idea is that they were built up through “swallowing up” nearby matter and galaxy collisions.

Read the rest of the article here.

Date, Location: 
2015-07-29

Mr. Meng Zhang Defense 7/17/2015

Spanning Trails and
Spanning Trees

Date: 07/17/2015
Time: 3:30PM
Place: 315 Armstrong Hall

All are welcome.

Date, Location: 
2015-07-17

Mr. Todd Tichenor Defense 6/30/2015

Topics in Graph
Compositions

Date: 06/30/2015
Time: 1:00PM
Place: 315 Armstrong Hall

All are welcome.

Date, Location: 
2015-06-30

Pages

Subscribe to