2011-12 Science Seminar Series

This year-long series hosts preeminent women scientist from a broad spectrum of STEM disciplines. The scientific lectures are free and open to the public.

 
Fall 2011

October 13

Sofya Raskhodnikova, Penn State hosted by Anna Lysyanskaya, Computer Science
Understanding Global Properties of Data Sets from Local Observations CIT 368, 4PM
Abstract: Suppose we are given a list of numbers and we wish to determine whether it is sorted in increasing order. That problem obviously requires reading the entire list. However, it turns out that if we know in advance that our list is either sorted or far from sorted, we can perform the test by examining only a small portion of the list. This is an example of a global property of a data set that we can understand by making a few local observations.

As data of all types gets easier to obtain and cheaper to store, data sets are becoming increasingly large. Consequently, there is a need to perform computational tasks on massive data sets. What useful computations can be performed on a data set when reading all of it is prohibitively expensive? This question, fundamental to several fields, is at the heart of a research area, called Sublinear Algorithms, that has provided important insights into fast approximate computation.

In this talk, we will give a few examples of specific problems that can be solved while making only local observations, starting with the sorting example and moving on to simple analysis of images, comparing and compressing documents, and understanding properties of functions. We will also present an application of these ideas to an area (namely, data privacy), where extreme efficiency is not a requirement per se, but helps to guarantee other properties.

   
Spring 2012
February 17

V. Faye McNeill, Columbia hosted by Meredith Hastings, Geological Sciences
Atmospheric Aerosols: Chemistry, Clouds, and Climate MacMillan Hall 317, 12PM
Abstract: The chemistry of atmospheric aerosols influences their direct and indirect effects on climate. Recent laboratory studies show that particle-phase
chemical reactions between organics and inorganic salts can lead to secondary organic products which absorb light in the UV and visible, thus
changing the optical properties of the particle. McNeill will introduce a model of coupled gas and aqueous aerosol chemistry -- developed to study
the formation of secondary organic aerosol material in aerosol water and the associated changes in aerosol optical properties. The lab also studies
the sources and properties of surface-active organic species in aerosols. Organic films at the gas-aerosol interface can reduce aerosol surface
tension, potentially enhancing the ability of small particles to nucleate cloud droplets (CCN activity). Their work has shown that uptake of methylglyoxal, acetaldehyde, and formaldehyde from the gas phase driven by aqueous-phase oligomerization chemistry is a potentially significant source of surface-active organic material in aerosols. Aerosol chamber studies of the CCN activity of particles exposed to gas-phase surfactants will be presented.

   
February 28

Susanne Moser, Susanne Moser Research & Consulting hosted by Heather Leslie, Center for Environmental Studies
Barriers to Adaptation:  The Challenges of Managing Climate Risks Foxboro Auditorium, Kassar House, 4PM
Abstract: Adaptation to climate change has risen sharply on the scientific and policy agendas in recent years. How communities can adapt to the projected impacts of climate change, and what may hinder them from doing so is both of academic interest and pressing practical concern. This presentation will take a close look at the efforts of communities in coastal California (San Francisco Bay) in understanding, planning, and preparing for expected climate change risks, the barriers they face, and the strategies they pursue to overcome those obstacles. The implications of the research findings are both challenging some conventional notions of adaptive capacity, especially in wealthy nations such as the US, but also offer practical insights for assisting local communities as they try to manage the consequences of climate change locally.

   
March 1 Carol Padden, UC San Diego hosted by Laura Kertz, Cognitive, Linguistic, & Psychological Sciences
From gesture to language Salomon 001, 4PM
Abstract: Because they can be created spontaneously with little outside influence, new sign languages are natural laboratories for understanding the emergence of linguistic properties. Unlike established sign languages like American Sign Language, or British Sign Language (each are at least 200 years old), new sign languages are only one to three generations old, yet they are fully communicative and already exhibit linguistic structure. We find that signers of one new sign language, Al-Sayyid Bedouin Sign Language, have consistent word order, and lexical categories by the second generation. However, the phonological or formational properties of the new sign language are still developing. How do such languages begin life, in their earliest years? I will describe studies our research group has carried out with hearing non-signers' novel use of gestures and gesture strings. Rudimentary word order can be found in their gesture strings and some very basic gesture types are consistently used. Our work offers a different view of how linguistic structure can emerge in a short time, in contrast to some claims offered about the course of language evolution.
   
March 14 Yishi Jin, HHMI hosted by Anne Hart, Neuroscience
Common themes and emerging regulators of axon regeneration:  insights from C. elegans Nathan Marcuvitz Auditorium, Sidney Frank Hall, 12PM
   
April 5 Susan Solomon, NOAA hosted by Meredith Hastings, Geological Sciences
A tale for our times: Something for everyone about climate change and the reasons for climate gridlock MacMillan 115, 4PM
Abstract: This talk aims to provide scientific information that can be useful for everyone who wants to better understand the dual challenges of science and climate change, and why international agreement on climate change policy has proven particularly difficult. Manmade greenhouse gases are slowly forcing the climate system to change. Carbon dioxide emissions from fossil fuel burning are the dominant factor causing current climate changes now and for the next century, and some of today’s emissions will still be in the atmosphere in a thousand years or more. On the human side, global increases of greenhouse gases arise from a mix of different countries, both developed and developing, with different current emissions, infrastructure capabilities and past commitments that are among the factors influencing policy discussions. Comparisons will be briefly drawn
between the success of policy on ozone depletion (Montreal Protocol) versus the apparent gridlock on climate change, and the lessons that may thereby be learned.
   
April 9 Margaret Wright, New York University hosted by Jill Pipher, Mathematics
Non-derivative optimization: the sound, the fury, and the bottom line Foxboro Auditorium, 4PM
Abstract:    For nearly 60 years, the role of non-derivative (derivative-free) methods within mainstream optimization has varied wildly, from untrustworthy outlier to solid citizen. These changes of opinion are largely due to the increasing ``mathematization'' of optimization, since early non-derivative methods were proposed without accompanying rigorous analysis. In contrast, practitioners (meaning people whose primary wish is to compute a solution) have never wavered in their fondness for these methods. Significant progress has been made since the late 1980s concerning theoretical underpinnings, but, despite hundreds of papers proving a variety of theorems, controversy continues about which methods are most effective on real-world applications. This talk will summarize selected recent highlights, both mathematical and practical.
   
April 19

Lilian Alessa, University of Alaska hosted by Heather Leslie, Center for Environmental Studies
Water, Technology, and Sustainability: Are We Engineering Vulnerability? UEL 106, 12PM
Water resources continue to challenge societies around the world. As part of the solution, water technologies ranging from reclamation, to storage to household level conservation hardware have been implemented. In this talk we will discuss the role of technology in achieving water sustainability and question the increasing effort to 'engineer' water efficiency. We will also present concrete examples and tools from the emerging field of computational social science which may better inform our goals of achieving resilience through a human hydrological perspective.

   
April 20 Tracey Holloway, University of Wisconsin-Madison hosted by Meredith Hastings, Geological Sciences
Energy Options for Cleaner Air MacMillan 115, 12PM
Choice of U.S. energy systems, from electricity production to transportation, impact health-damaging air pollution across the country. These changes are intertwined with climate change, international development, and regulatory policy. As we consider strategies that move toward renewable, domestic resources, one of the most direct environmental benefits is clean air. Holloway and her research group focus on processes
controlling ground-level ozone and particulate matter, from emission sources to chemistry and meteorology. Using advanced computer models, satellite data, and ground-based measurements, she works to evaluate the air quality and public health impacts of energy conservation, renewable electricity, and transportation alternatives.
   
May 3 Barbara Meyer, Berkeley hosted by Erica Larschan, Molecular Biology, Cell Biology, & Biochemistry
Repressing and Tethering Chromosomes through Molecular Machine Nathan Marcuvitz Auditorium, Sidney Frank Hall, 12PM
   
June 12 Susan Mango, Harvard hosted by Erica Larschan, Molecular Biology, Cell Biology, & Biochemistry
How are cells instructed to form organs? Nathan Marcuvitz Auditorium, Sidney Frank Hall, 12PM