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¶Ù²¹³Ù±ð:Ìý1/16/14

³§±è±ð²¹°ì±ð°ù:ÌýAlex Hopkins

¶Ù±ð±è²¹°ù³Ù³¾±ð²Ô³Ù:ÌýChemistry

°Õ¾±³Ù±ô±ð:ÌýMan vs. bacteria: Our failing weapons and how to make more

´¡²ú²õ³Ù°ù²¹³¦³Ù:ÌýAntibiotic resistance genes are ubiquitous in the environment. The use of antibiotics naturally selects for bacteria with resistance genes that allow them to survive in the presence of antibiotic drugs. These resistant bacteria can share their resistance genes with other bacteria, enabling the spread of resistance across species. These and other mechanisms have led to the emergence of multi-drug resistant pathogens, which no longer respond to the current arsenal of antibiotic treatments. To combat this growing problem, scientists seek out novel targets for the development of new antibiotic drugs.

I will discuss current antibiotics and their mechanisms of action, the rise of antibiotic resistance, and the Sousa lab’s approaches to define new targets for the next generation of antibiotics.

¶Ù²¹³Ù±ð:Ìý1/28/14

³§±è±ð²¹°ì±ð°ù:ÌýKaty Barnhart

¶Ù±ð±è²¹°ù³Ù³¾±ð²Ô³Ù:ÌýGeology

°Õ¾±³Ù±ô±ð:ÌýSea ice and arctic coasts

´¡²ú²õ³Ù°ù²¹³¦³Ù:ÌýI will discuss whole-Arctic sea ice change and associated coastal impacts and details of coastal erosion at Drew Point, Beaufort Sea, Alaska.

Coasts form the dynamic interface of the terrestrial and oceanic systems. In the Arctic, and in much of the world, the coast is a zone of relatively high population, infrastructure, biodiversity, and ecosystem services. A significant difference between Arctic and temperate coasts is the presence of sea ice. Sea ice influences Arctic coasts in two main ways: (1) the length of the sea ice-free season controls the length of time over which nearshore water can interact with the land, and (2) the sea ice edge controls the fetch over which storm winds can blow over open water, resulting in changes in nearshore water level and wave field. The resulting nearshore hydrodynamic environment impacts all aspects of the coastal system.

Arctic coastlines are responding rapidly to climate change. Remotely sensed observations of coastline position indicate that the mean annual erosion rate along a 60-km reach of Alaska’s Beaufort Sea coast, characterized by high ice content and small grain size, doubled from 7 m yr -1 for the period 1955-1979 to 14 m yr -1 for 2002-2007. Over the last 30 years the duration of the open water season expanded from ∼45 days to ∼95 days. Time-lapse photography indicates that coastal erosion in this environment is a halting process: the most significant erosion occurs during storm events in which local water level is elevated by surge, during which instantaneous submarine erosion rates can reach 1-2 m/day. In contrast, at times of low water, or when sea ice is present, erosion rates are negligible.

I use a combination of field and remotely sensed observations to understand the process of coastal erosion in this environment and consider how ice-rich coasts will respond to a changing Arctic.

¶Ù²¹³Ù±ð:Ìý2/13/14

³§±è±ð²¹°ì±ð°ù:ÌýMatthieu Talpe

¶Ù±ð±è²¹°ù³Ù³¾±ð²Ô³Ù:ÌýAerospace Engineering

°Õ¾±³Ù±ô±ð:ÌýDefying gravity... into telling us about the Earth

´¡²ú²õ³Ù°ù²¹³¦³Ù:ÌýAs the story goes, the fall of an apple on the head of a man named Isaac Newton triggered the first formulation of the gravitational attraction. Historical accuracy aside, gravity, an intrinsic property of mass, is commonly known to equal approximately 9.8 m/s^2 at the surface of Earth. However, higher fidelity measurements of the Earth's gravity obtained from satellites have become both so precise and accurate that the motion of mass at the surface of the Earth is clearly detectable. Two of the largest examples of surface mass motion are the seasonal filling and draining of the Amazon basin and the melt of the Antarctica and Greenland ice sheets. In this seminar, I will talk about NASA's designated gravity-observing spacecraft and how its measurements contribute to monitoring the Earth's dynamic environment and, most notably, the recent climate change.

¶Ù²¹³Ù±ð:Ìý3/13/14

³§±è±ð²¹°ì±ð°ù:ÌýJen Gifford

¶Ù±ð±è²¹°ù³Ù³¾±ð²Ô³Ù:ÌýChemistry

°Õ¾±³Ù±ô±ð:ÌýContinuing the antibiotics conversation: M. smegmatis growth inhibition with thiol-modified Au nanoparticles

´¡²ú²õ³Ù°ù²¹³¦³Ù:ÌýAs discussed previously this semester, the emergence of multi-drug resistance (MDR) by pathogenic bacteria has become a significant global public health threat. Our laboratory uses a small molecule variable ligand display (SMVLD) method to develop novel and highly potent nanoparticle antibiotics for various pressing bacterial concerns. These conjugates have been shown to delay resistance mechanisms, have similar effective concentrations as many commercially available drugs, and lack cytotoxicity. In particular, I will discuss my research on the application of our method to M. smegmatis, a non-infectious model for M. tuberculosis.

¶Ù²¹³Ù±ð:Ìý4/1/14

³§±è±ð²¹°ì±ð°ù:ÌýChelsea Cook

¶Ù±ð±è²¹°ù³Ù³¾±ð²Ô³Ù:ÌýEcology and Evolutionary Biology

°Õ¾±³Ù±ô±ð:Ìý Stay cool: Social context influences a thermoregulatory fanning behavior in honeybees

´¡²ú²õ³Ù°ù²¹³¦³Ù:ÌýOn January 25 th 2014, a headline from The Australian, Australia’s main newspaper, stated that the country would likely have to import honey from China as they were in the midst of a honey shortage. The reason: due to the hottest year on record, honeybees were spending too much time cooling their hive and not enough time collecting nectar. If the hive gets too hot, then the developing bees inside may die. To cool their hive, honeybees stand at the entrance and fan their wings. This helps to circulate cooler air. But how do honeybees know when it is the most efficient time to fan? I explore how social context changes the performance of this fanning behavior, and how this fits into the larger organization of division of labor in the honeybee society. Understanding how groups perform jobs efficiently furthers our understanding about societies in general, from bacteria to humans.

¶Ù²¹³Ù±ð:Ìý4/17/14

³§±è±ð²¹°ì±ð°ù:ÌýSarah Grover

¶Ù±ð±è²¹°ù³Ù³¾±ð²Ô³Ù:ÌýPsychology

°Õ¾±³Ù±ô±ð:ÌýGroup problem-solving in a threatening environment: Women’s math expertise is discounted in male dominated groups

´¡²ú²õ³Ù°ù²¹³¦³Ù:ÌýResearchers in social psychology and allied fields have conducted over 300 experiments on stereotype threat, which is the threat of being judged or treated in terms of a stereotype, or the fear that one will inadvertently behave in a manner to confirm a stereotype. Stereotype threat has been shown to lead to consequential negative outcomes for the academic achievement of women and minorities (e.g., impaired test performance, de-identification with the academic domain). I will provide a brief overview of nearly 20 years of stereotype threat research, including causes, consequences and interventions to mitigate stereotype threat. After providing some relevant background on stereotype threat research, I will introduce some new research that I have been conducting with my advisors Bernadette Park and Tiffany Ito examining the effects of cues known to elicit stereotype threat in a group problem-solving context. Specifically we vary the gender composition of the groups to be either male dominated (three male and one female) or all female (four female participants) and examine how group gender composition affects self and others' perceptions of a female participant with task-relevant expertise. I encourage you all to attend so that we can have a lively discussion of the research over some tasty pizza.

¶Ù²¹³Ù±ð:Ìý5/1/14

³§±è±ð²¹°ì±ð°ù:ÌýChristine Fanchiang

¶Ù±ð±è²¹°ù³Ù³¾±ð²Ô³Ù:ÌýAerospace Engineering

°Õ¾±³Ù±ô±ð:ÌýThe human element: Quantifying human spacecraft design impacts on crew performance

´¡²ú²õ³Ù°ù²¹³¦³Ù:ÌýThe design of a system has a considerable influence on the performance and behavior of the users. While this concept applies to any tool or system used in everyday life, the effects are magnified when applied to more complex systems such as the Space Shuttle. The added challenges faced by astronauts increase the need for careful and well-planned spacecraft designs. This presentation reviews the history of human spacecraft design and provides a general methodology for quantifying the impacts of human spacecraft design choices on the crew's performance.