Science Engineering Colloquium

Spring 2018 - Schedule

Delta Science and Mathematics

Location: Delta 241
Time: 12:00 p.m. ‐  1:00 p.m. (Refreshments: 11:45 a.m. ‐ 12:00 p.m.)
Hosted by the College of Science & Computer Engineering

Date Presentation
Privacy in Data Publishing & Social Networks

Dr. Lila Ghemri
Department of Computer Science, Texas Southern University

This talk will present projects that were part of two DHS funded research Centers: the DHS Center of Excellence for Dynamic Data Analysis (DyDan) and the DHS Command, Control and Interoperability Center for Advanced Data Analysis(CCICADA) with Rutgers University as lead.

Anonymization of Sensitive Information and Privacy Preserving Dissemination

In data publishing, a modified, anonymized version of data is usually produced to protect information about entities and individuals in the data, as well as avoid leaking private information about how and from whom the data was collected. Most techniques for privacy protection have focused on highly structured data, in the forms of database tables and contingency tables. Most privacy preserving data mining methods apply transformations to the data that result in the loss of original data and reduces the effectiveness of the underlying mining results. Our goal in this work is to define privacy preserving methods that would reduce the difference between the mining results obtained with the original data and the “anonymized” data.

A Memoryless Social Network Application for Reputation Protection

Since their introduction in the late 90’s, the popularity of social network sites has grown exponentially, encompassing millions of users. As social networks continue to grow and become more popular, users voluntarily post information without an afterthought. The potential risk that users are taking may result in them damaging their reputation and could have dire consequences on their professional and private life. We propose an online social network that uses an expiration mechanism to protect personal data being saved and transmitted to unintended users. The expiration mechanism gives users the freedom to share data without the fear of information getting into the wrong hands.

Space Exploration Technology Drives Innovation

Mr. Chris Culbert
Chief Technologist, NASA Johnson Space Center

Human exploration of space requires a broad range of technologies to enable exploration beyond the planet Earth. This talk will review many of the core technologies needed to enable human exploration, talks about areas of priority for the Johnson Space Center, and reviews areas of joint interest with industry. I’ll close with some discussions about how computing capability has evolved in our human spacecraft and some of the challenges we face providing a computing infrastructure in space.

Mr. Culbert has spent more than 30 years developing technologies and systems for human spaceflight at the Johnson Space Center. He is currently the Chief Technologist for Johnson Space Center, responsible for coordinating center strategies for technology development and supporting agency wide activities for the NASA Office of the Chief Technologist. During his career he has managed the development of advanced technologies in robotics, automation, avionics and software for Space Shuttle, Space Station, and advanced human missions. 


Dr. Luay Nakhleh
Rice University, Department of Computer Science

A phylogeny represents the evolutionary history of a set of taxa from their most recent common ancestor. It provides a powerful framework for organizing, interpreting, and analyzing biological data "in the light of evolution." The post-genomic era has provided the data to make phylogeny reconstruction more accurate. However, this accuracy does not come without modeling and computational challenges. In this seminar, I will describe our efforts in phylogeny reconstruction in two areas: cancer evolution and species evolution. In the case of cancer evolution, I will present our recent work on phylogenetic inference from single -cell genomic data. The challenge here is to carefully account for the noise in the data. In the case of inferring species evolutionary histories, the major challenge is that the evolutionary history of species (and populations and sub-populations) could be incongruent with the evolutionary histories of individual loci within the genomes of these species. I will describe our work on modeling two processes that underlie this incongruence, namely incomplete lineage sorting and gene flow.


Bayou Computing and Engineering

Location: Bayou 2512
Time: 12:00 Noon – 1:00 PM (Refreshments: 11:45 a.m. – 12:00 noon)
Hosted by the College of Science & Computer Engineering

Date Presentation


Root Responses to Iron Deficiency: Metabolic Adaptations and the Role of Flavins

Dr. Ana Flor Lopez Millan
Research Scientist at the USDA Children's Nutrition Research Center

Iron is an essential micronutrient for all living organisms including plants, since it takes part in fundamental biological redox processes such as photosynthesis and respiration. Although Fe is the fourth most abundant element in the earth’s crust, the bioavailability for plants is low, due to its poor solubility in the rhizosphere at neutral or basic pH. Therefore, Fe deficiency is a yield-limiting factor with major implications for field crop production in many agricultural areas of the world. When Fe is scarce, plants develop morphological and biochemical changes in roots leading to an increase in their Fe uptake capacity.

Biochemical changes induced by Fe-deficiency include an activation of the components involved in the root acquisition of this element which include a plasma-membrane Fe(III)-reductase, an Fe(II) transporter and an enhanced proton extrusion capacity mediated by a plasma-membrane ATPase. Research towards the elucidation of the metabolic adaptations occurring in roots in order to sustain the elevated energy requirements of this uptake system will be discussed. In addition, plants grown in Fe-deficient conditions excrete a plethora of organic compounds, including carboxylates, phenolics and flavonoids, that can affect Fe availability and whose roles are still a matter of debate. The root accumulation and excretion patterns of riboflavin and its derivatives in different Fe deficiency conditions and their possible roles in roots and in the rizosphere will also be presented in this seminar.


Macroscopic Quantum Tunneling in Long Josephson Junctions

Dr. Eric Van Mayes
Department of Physical & Applied Sciences
University of Houston-Clear Lake

An investigation of the macroscopic quantum tunneling of bound fractional fluxon pairs is discussed. These fluxons arise due to the time reversal symmetry breaking in a long Josephson junction (LJJ) with two-band superconductors. The spatial dependence of the critical current density can generate magnetic flux in the insulator layer, creating fractional fluxons with large and small fractions of flux quantum. The interaction between the two is repulsive at short distances, but attractive at long distances, causing the formation of what is essentially a fractional fluxon molecule. This molecule can tunnel through a barrier potential at low temperatures when placed in a metastable state formed by a microresistor in the insulator layer and a bias current to the LJJ. These fractional fluxon pairs may be observable if their separation is large enough and the tunneling rate long enough.


Source Identification of Carbon in Size-Fractionated PM and Time-Resolved Bulk PM10 Using Radiocarbon and Molecular Source Markers

Dr. Hyun-Min Hwang
Environmental and Interdisciplinary Sciences
Associate Professor, Texas Southern University

In many urban areas, atmospheric particulate matter (e.g., PM10, PM2.5) has been linked to various health issues such as asthma, lung cancer, and premature death. To improve understanding of the sources of atmospheric carbonaceous particulate matter, size-resolved PM (0.056 to1.8 µm) and time-resolved bulk PM10 collected in Sacramento, California were analyzed for radiocarbon and source markers such as levoglucosan, alkanes, and elemental carbon (EC). The contributions of modern (non-fossil) carbon sources were much greater than that from fossil carbon sources in all samples.

Radiocarbon and source marker measurements confirm that the greater contribution of non-fossil carbon sources in November samples was due to residential wood combustion. The results provide additional evidence that wood combustion was likely a significant source of EC in November samples, and demonstrate that using EC as a diesel emission tracer may not be appropriate in areas where wood combustion could be a confounding source of EC. Levoglucosan to organic carbon (Levo/OC) ratios in all PM10 samples showed a strong negative correlation with fossil carbon content. Fossil originated carbonaceous PM10 could account for about 40% of the total carbonaceous PM10 in the study area when the contribution from wood combustion is zero. The results of the present study demonstrate the value of combining radiocarbon and conventional source markers for more robust and detailed source attributions for ambient PM.


Impact of Hydraulic Fracturing on Environment

Dr. Guoqing Liu
Department of Petroleum Engineering
University of Houston

Over the past decade, hydraulic fracturing in the horizontal well is the critical technology in the shale gas/oil revolution. It has significantly changed the petroleum industry in the United States and the rest of the world. However its potential impacts on the environment has been a public concern for a long time. This presentation is to illustrate the safety and the potential environmental damages of the hydraulic fracturing technology.

The key concept in this presentation is to demonstrate that hydraulic fracturing can be operated in a safe way, but some potential risks needs attention and appropriate management.

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