Departmental Seminars

Fall 2017

 

Aug 21, 2017
10:30 AM
Room 1011, EB1
Dr. Marc Lavine
Science Magazine

There is a strong desire, often driven by real or perceived pressures, to publish research in a top tier journal like Science.  However, with a rejection rate above 90%, it is a difficult process.  When a paper gets rejected without referee comments, it is hard to know why the paper failed to get past the initial screening process.  In this talk, I will describe the publication process at Science, within the broader context of developing skills for more effective scientific communication.  Aside from publishing in high impact journals, good communication tools are essential for forming scientific collaborations, bypassing research obstacles, avoiding conflicts during scientific presentations and explaining scientific research to funding bodies and the public at large, who are the primary source of financial support for scientific research.

Aug 28, 2017
10:30 AM
Room 1011, EB1
Dr. Moti Herskowitz
Ben-Gurion University of the Negev, Israel

Among critical challenges facing modern society, conversion of waste liquids and gases to renewable, eco-friendly, socially-acceptable, economically-competitive, sustainable and fungible liquid fuels for transportation to replace fuels produced from crude oil is one of the most urgent tasks. In spite of major investment in R&D and significant scientific progress in this field, the current progress is very limited. Sustainable and renewable fuels account for <10% of the total transportation fuels.The Blechner Center (http://www.bgu.ac.il/indcat/) has developed, over the past two decades, a wide variety of technologies in the area of alternative fuels and chemicals. Integrated catalytic technologies for conversion of CO2/CO/H2 mixtures to fuels and chemicals are ready for demonstration and commercialization.The seminar will focus on existing and foreseeing catalytic processes for converting waste liquids and gases to liquid fuels and chemicals.

Sep 11, 2017
10:30 AM
Room 1011, EB1

Dr. Roe-Hoan Yoon
Virginia Tech

The stability of colloids, foams, and wetting films is controlled by the surface forces in the thin liquid films (TLFs) of water confined between macroscopic surfaces. The classical DLVO theory uses the van der Waals and double-layer forces to predict the stability of mildly hydrophobic colloids with contact angles (θ) of up to ~60o. For colloids of stronger hydrophobicity, it is necessary to extend the theory by considering contributions from hydrophobic forces.1 Many investigators actually measured the hydrophobic forces directly using the surface force apparatus (SFA) and atomic force microscope (AFM), while others showed evidences that they are artifacts resulting from Nano-bubbles, drying effect, charge correlation, etc. The debate on hydrophobic forces has been ongoing for more than a generation now, but its origin is still unknown.

At Virginia Tech, we have been measuring the hydrophobic forces that may be present in three different types of TLFs, i.e., colloid, foam, and wetting films, and have obtained thermodynamically consistent results. It has been shown that hydrophobic interactions at macroscopic length scale are enthalpic involving enthalpy-entropy compensation.2,3 This finding is contrary to what is known for the hydrophobic interactions at molecular scale, e.g., self-assembly of hydrocarbon chains, but is consistent with predictions from the molecular dynamic simulations reported in the literature. More recently, we have developed a method which measures both hydrodynamic and surface forces present in wetting films using an air bubble effectively as a sensor and confirms the results by direct force measurement using a cantilever spring.4,5 The results have been used to determine the free energies (DG) of film thinning and rupture using the Frumkin-Derjaguin isotherm. If time permits, thermodynamic evidences for the hydrophobic forces of molecular origin will also be discussed briefly.

  1. Xu, Z. and Yoon, R.-H., J. Colloid and Interface Sci., 134, 427 (1990)
  2. Wang, J., Eriksson, J.C., and Yoon, R.-H., J. Colloid and Interface Sci., 364, 257 (2011)
  3. Li, Z. and Yoon, R-H., Langmir, 30, 13312 (2014)
  4. Pan, L., Jung, S., Yoon, R.-H., J. Colloid and Interface Sci. 361, 321 (2011)
  5. Pan, L. and Yoon, R.-H., Minerals Engineering 98, 240 (2016) 
Sep 18, 2017
10:30 AM
Room 1011, EB1

Dr. Nikhil Nair
Tufts University

Efforts in synthetic biology and metabolic engineering have largely focused on improving biosynthetic productivity and yields of biological processes under the assumption that that nutrient uptake rates and assimilation into central metabolism are not limiting. These assumptions are not valid in biological systems engineered to utilize non-native nutrients. For example, non-native C5 sugar (viz. xylose, arabinose) metabolism in the yeast S. cerevisiae and C1 (viz. CO2, methanol) utilization in E. coli are non-optimal, even after extensive engineering efforts, compared to that of native C6 sugar substrates like glucose and galactose. Thus, there is significant need to answer the following questions:

  • Why have current designs implementations of non-native nutrient assimilation pathways not been more successful?
  • How do we engineer biological systems to better assimilate nutrients they did not natural evolve to utilize?
  • What are the merits of success when evaluating the designs?

In this talk, I will present our recent advances in answering these questions using pentose assimilation by S. cerevisiae as a test case. Insights from these work will significantly advance future efforts in synthetic biological focused on valorizing low value feedstocks into high-value products.

In addition, I will briefly discuss our recent efforts in developing a united platform to treat a large family of orphan diseases called inborn errors of metabolism (IEM). IEMs are a family of >500 disorders that individually affect less than 1 in 10,000 newborns but cumulatively affect nearly 1 in 1000 infants. Most of these disorders have no current treatment options and our goal is to leverage the gut microbiota as a modulator of metabolism to alleviate chronic and acute pathologies associated with these disorders. I will discuss results from our work in developing engineered gut bacteria and synthetic enzymes as novel therapeutics to treat 9 distinct disorders within this family.

Sep 25, 2017
10:30 AM
Room 1011, EB1

Dr. Benjamin McCool
ExxonMobil

Oct 2, 2017
10:30 AM
Room 1011, EB1
TBD
Oct 9, 2017
10:30 AM
Room 1011, EB1

Dr. David Kofke
University at Buffalo

Oct 16, 2017
10:30 AM
Room 1011, EB1

Dr. George Petekidis
University of Crete, Greece

Oct 23, 2017
10:30 AM
Room 1011, EB1
Undergraduate Student Award
Oct 30, 2017
10:30 AM
Room 1011, EB1
TBD
Nov 20, 2017
10:30 AM
Room 1011, EB1
TBD
Nov 27, 2017
10:30 AM
Room 1011, EB1
TBD