Fall 2014 STEMinar Schedule
ٲٱ:9/2/14
:Noah Williams
ٱ貹ٳԳ:Mathematics
վٱ:Mathematics and the genome rearrangement problem
ٰ:Mathematics can be used to help biologists understand evolutionary relationships and diseases such as Neurofibromatosis. In this talk, we will investigate the genome rearrangement problem, whose goal is to find the best way to transform one collection of DNA into another. In particular, we will discuss the Double Cut and Join (DCJ) and Deletion-Insertion models for genome rearrangement and some results pertaining to the distribution of genomes under DCJ distance.
ٲٱ:9/18/14
:Osama Bilal
ٱ貹ٳԳ:Aerospace Engineering
վٱ:PhoNonic materials: The mystery of missing frequencies and their applications
ٰ:Transmission of everyday sound and heat can be tracked back to a physical particle named “phoNon”. Understanding, analyzing and manipulating such particle across multiple scales/disciplines can be achieved using phononic materials. That is a class of material systems composed of a basic building block that repeats in space (i.e. unit cell). Among many features, it exhibits distinct frequency characteristics such as band gaps, where certain frequencies are prohibited from propagation. These properties can lead to tremendous range of applications, ranging from vibration isolation, converting heat waste into electricity to acoustic cloaking. In this seminar, I will give an introduction to the field, explain the main concepts, potential applications and shed some light on its design and optimization.
ٲٱ:9/30/14
:Kristen Brown
ٱ貹ٳԳ:Mechanical Engineering
վٱ:Internalizing air quality and greenhouse gas externalities in the US energy system
ٰ:This study provides a unique analysis of how the US energy system might be transformed if energy costs internalized the damages caused by air pollution. The US energy system is modeled including fees on emissions that are based on estimates of the external cost of those emissions. The externalities that are internalized include health and environmental effects as well as climate change. Placing fees on emissions provides more of an incentive to reduce pollution than fees on energy use. This interdisciplinary work incorporates knowledge from engineering, babyֱapps, mathematics, medicine, climate research, and atmospheric chemistry.
ٲٱ:10/16/14
:Sarah Welsh-Huggins
ٱ貹ٳԳ:Civil Engineering
վٱ:Integrating green and resilient building design for enhanced disaster recovery
ٰ:Increased worldwide urbanization in recent years has led to greater vulnerability from seismic and other natural hazards. Integrating performance based design and assessment of green and hazard resilient buildings, however, offers alternatives for urban disaster recovery. Performance based earthquake engineering aims to reduce the dollars, deaths, and downtime associated with a hazard event. Green design, meanwhile, strives to minimize use of natural resources and provide babyֱapp gains associated with reduced operating energy or greater occupant productivity. My dissertation research proposes a new life cycle assessment methodology that links the distinct fields of sustainability and hazard resilience, advancing building design and identifying leverage points for improved disaster mitigation and recovery. The “green resilience” framework presented here can be used to analyze the implications of disaster mitigation and reconstruction. The methodology quantifies environmental metrics and sociobabyֱapp indicators of building performance over its lifetime and accounts for potential risk of hazard events. The utility of the framework will be illustrated with a case study of the design and seismic assessment of a hypothetical commercial building in Los Angeles, CA, U.S.A.
ٲٱ:10/28/14
:Helen McCreery
ٱ貹ٳԳ:Ecology and Evolutionary Biology
վٱ:Collaborating with ants: basic bio, shared lessons, and cooperative transport
ٰ:Ant colonies consist of autonomous, simple units capable of remarkable problem solving through cooperation. Ants build massive, complex, underground nests, and many species work together to transport objects hundreds of thousands of times their own weight. How does this complex coordination emerge from groups of simple individuals? This question is inherently interdisciplinary, and there is a long history of collaboration and shared lessons among ant biologists, computer scientists, and mathematicians. For example, algorithms inspired by ants and other social insects are used in swarm robots. In this STEMinar, I will give a brief introduction to ant biology and cooperation, and discuss my interdisciplinary research on cooperative transport.
ٲٱ:11/6/14
:Maya Fabrikant
ٱ貹ٳԳ:Physics
վٱ:Frozen molecules and space chemistry
ٰ:Cooling molecules allows us to study what kind of chemistry happens at temperatures characteristic of interstellar atmospheres. More practically, cold environments can stabilize very reactive molecules like radicals, which can allow us to study difficult to observe reactions. Exotic ultracold molecules like KrB have been created in the lab with the help of laser cooling and photoassociation, but sufficiently cooling molecules more commonly encountered in nature, like the CH and NH radicals, presents its own unique challenges. I will talk about methods for cooling and detecting these more mundane molecules and what kind of chemistry we might expect to observe.
ٲٱ:11/18/14
:Marianne Reddan
ٱ貹ٳԳ:Psychology
վٱ:Developing neural signatures for discrete emotional states
ٰ:Despite its research popularity and societal importance, emotion remains elusive to neuroscience. Progress is slowed by the field’s concern with local representation, a one to one mapping of structure and function. This has led to the identification of many correlates of emotion (e.g. amydala threat, nucleus accumbens reward), but the complexity and distributed nature of emotional experiences remain neglected. Our laboratory employs a novel and promising approach to the problem of emotion: We apply machine learning to neuroimaging data in order to identify sensitive and specific signatures of emotional responses. We have successfully developed signatures of pain and negative emotion, which have strong implications for the treatment and diagnosis of emotional disorders. In this talk, I will discuss (1) a ongoing study which aims to classify nuanced emotional experiences, and (2) my work investigating the neural representation of threat anticipation, and how imagination can change its expression.
ٲٱ:12/4/14
:Joey Hubbard
ٱ貹ٳԳ:Ecology and Evolutionary Biology
վٱ:Genetic and environmental contributions to a divergent plumage trait in barn swallows
ٰ:A central theme of evolutionary research is to understand the source and function of phenotypic variation. For most phenotypic traits, sources of variation can be partitioned into genetic or environmental variation. Identifying the proportion of variance due to these components allows for predictions regarding phenotypic responses to variable environments and selection to be made. Barn swallow subspecies have divergent phenotypes and it appears that the focal trait for female preferences has also diverged. We examined the sources of phenotypic variation of melanin based ventral plumage in two populations of barn swallows: North America (babyֱapp) and Europe (Czech Republic). In North America, male coloration is the target of sexual selection with darker males achieving higher reproductive success. However, it is unclear what role coloration plays in mate choice decision for our study population in the Czech Republic. In both populations, we found that coloration is explained by both genetic and environmental variation. However, the genetic covariance structure of color traits differed. Together, these results demonstrate that coloration is influenced by developmental environment more than genetic environment. Thus, in North America, where females prefer males with dark plumage, coloration serves as a better signal of developmental conditions than genetic quality. Moreover, divergent selection on plumage coloration may explain the phenotypic differences among these populations, suggesting a role of sexual selection in the diversification of the barn swallow species complex.