UNC PHYSICS AND
ASTRONOMY WEEKLY CALENDAR
MONDAY, FEBRUARY 8
4:00
p.m., Room 265, Phillips Hall
(UNC-CH)
(Refreshments
at 3:30 p.m., Room 277, Phillips Hall)
Physics
and Astronomy Colloquium
Edwin
Bergin (University. of Michigan)
“The Formation and Survival of Water in the
Terrestrial-Planet Forming Zone”
Abstract: Despite its fundamental importance for life,
the origin of water on
our planet remains a mystery. Recent astronomical
observations
have revealed what may prove to be the ubiquity of water vapor during
the early stages of planet formation. In this talk we will explore
a
simple solution that shows that this water vapor forms in situ and is
capable of protecting itself from molecule-destroying stellar ultraviolet
radiation.
We will outline new aspects regarding the dominance of Lyman alpha photons
in the radiation field and how the water chemistry is compensates for
water destruction by these photons. We will also discuss some of the
implications of this result. The absorption of this radiation
can control the gas thermodynamics in the upper layers of the protoplanetary
disk. Similar to the Earth's ozone layer, which shelters the chemistry of
life,
the water layer protects other molecules and allows for the presence of a rich
organic chemistry. More broadly, the
survival of thousands of oceans in the natal
habitable zone potentially allows it to be incorporated into forming planetesimals.
TUESDAY, FEBRUARY 9
No Event Scheduled
WEDNESDAY, FEBRUARY 10
No Event Scheduled
THURSDAY, FEBRUARY 11
3:00 p.m., Room
258, Phillips Hall (UNC-CH)
UNC Condensed Matter Physics Seminar
Professor Robert Riehn (Department
of Physics, North Carolina
State University)
“A Nanofluidic Toolbox for DNA
Analysis”
Abstract: DNA stretching in nanofluidic
channels that are round 100 nm in diameter and 100's of microns long is an
emerging technique for the genetic analysis of long nucleic acid
molecules. We will explain why nanofluidic stretching
differs from other single-molecule techniques, in particular how the ability to
measure individuality is greatly enhanced by the fundamentally different
averaging properties. We will present an overview of the basic physics that
enables this exciting new technique, and discuss
proof-of-principle
experiments that have demonstrated how genetic information can be gathered by
the technique.
We will then describe progress in
a number of ongoing projects that are based on the basic idea of nanofluidic manipulation of DNA. In particular, we have
begun to develop a toolbox for connecting nanochannels
into networks, and control the motion of single molecules by creating a
spatially and
temporally
modulated energy landscape. In context
we also discovered that polyelectrolytes in good
solvents can be both stretched and contracted in a.c.
electric fields if certain conditions are met.
We further studies the fluctuation spectrum of nanoconfined polymers. The second branch of our current
research is the application of nanofluidic
confinement to biological problems. In particular we will describe progress in
reading the epigenetic code of chromatin, and work towards electric sequencing
of DNA.
FRIDAY, FEBRUARY 12
No Event Scheduled