Z. Morgan Benowitz-Fredericks

Morgan Benowitz-FredericksEffects of maternal hormones and early environment on the physiology of birds

The scholar who joins our lab for the summer should be interested in studying physiology. They will be involved in multiple projects that seek to understand the interaction between the embryonic and postnatal environment in birds (chickens). Specifically, we experimentally alter hormone levels in eggs and manipulate the posthatch environment to understand how early hormone exposure changes an animal's ability to handle different challenges. We measure traits including growth, behavior, hormone levels, immune function and gene expression. Activities will include a combination of laboratory work and, potentially, animal work. If we have animals, hours can be irregular and may include early mornings, evenings, and weekends (schedules are dictated by the animals/experiments). There is no expectation of specific prior knowledge or skills, but curiosity, enthusiasm and motivation to problem-solve are mandatory! || Learn more about Professor Benowitz-Fredericks.

Karen Castle

Karen Castle Energy Balance in the Martian Atmosphere

The Castle group's current NASA-supported project strives to improve Martian climate models through better understanding the upper atmosphere of Mars. Since this region cools by radiative emission from vibrationally-excited carbon dioxide, efficient collisional energy transfer mechanisms involving the lowest vibrational states of carbon dioxide can have a significant influence on the energy balance of the Martian atmosphere and must be well-understood for proper climate modeling. The Castle group performs laboratory experiments using laser spectroscopy to measure rate coefficients of the important energy transfer processes. The goals of this project are to reduce uncertainty in some rate parameters that are highly uncertain in the literature and to measure others for the first time. || Learn more about Professor Castle.

Charles Clapp

Charles Clapp Studies on Soybean Lipoxygenase

Lipoxygenases are enzymes that catalyze the incorporation of oxygen into polyunsaturated fatty acids. Lipoxygenases are widespread in plants and animals, and they are involved in membrane modification and in the synthesis of signaling molecules. Several human lipoxygenases are targets for drug design. Our lab studies soybean lipoxygenase-1 (SBLO-1), which is more stable than most lipoxygenases and therefore well suited for biochemical studies. Our work has three goals. The first is to understand the basic chemistry of how SBLO-1 binds fatty acids and catalyzes the incorporation of oxygen. The second is to discover and characterize substances that inhibit SBLO-1. These new inhibitors can help guide drug discovery efforts on human lipoxygenases. The third is to modify SBLO-1 so that it will catalyze reactions that natural lipoxygenases will not catalyze. This is done by modifying the DNA that codes for SBLO-1 and then producing protein from this modified DNA. STEM scholars will learn to carry out some of the common procedures used in our lab and will apply these procedures to contribute to achieving the objectives described above. || Learn more about Professor Clapp.

Ken Field

Ken Field The Effects of Farnesyltransferase Inhibitors on the Immune System

The Field group is interested in the effects of farnesyltransferase inhibitors (FTIs) on the immune system in both normal and pathological conditions. This research idea developed during prior research that showed how this class of anti-cancer drugs affects the immune system, even while these drugs blocked certain immune system cancers in mice. The Field group has shown that FTIs can affect the immune regulatory proteins called cytokines that are produced by T cells in mice that are undergoing transplant rejection and that this can delay the rejection of a mismatched skin graft. They are now trying to understand how FTI treatment affects this and other immune responses in mice in order to determine if these experimental drugs might be useful for treating transplant patients. || Learn more about Professor Field.

Erin Jablonski

Erin Jablonski High Efficiency Emulsion-based Liquid-Liquid Extraction 

The Jablonski group has proposed an innovative device that combines milli-fluidic emulsion-based liquid-liquid extraction with a continuous passive emulsion separation technique recently developed in the Jablonski laboratory. These novel fluidic devices allow for the co-current laminar flow of immiscible liquids at the 10­-3 m to 10-­2 m length scale and can process liquids at rates of several mL/min. These co-laminar flow devices have successfully been used to passively separate organic-in-aqueous and aqueous-in-organic emulsions. Early experiments using these co-laminar flow devices for aqueous/ organic liquid-liquid extraction studies to accurately determine mass transfer coefficients have also been successful. The co-laminar flow technique provides an excellent method for determining mass transfer coefficients due to the well-defined interface between the immiscible liquids and the ability to sample the effluent streams immediately upon exiting the device. The proposed milli-fluidic extraction process has improved separation and decreased power requirements when compared with conventional liquid-liquid extraction methods. The proposed method will employ emulsion-forming and co-laminar flow milli-fluidic devices in series, and greater volumetric flow rates will be achieved by stacking several such two-device combinations to operate in parallel. || Learn more about Professor Jablonski.

Rob Jacob

Rob Jacob Icy Debris Fan Research to understand glaciers separating into two sections in alpine regions in response to climate warming

This project is investigating a poorly documented suite of alpine processes and landforms linked to climate change in Alaska and New Zealand. Multiple types of data are being collected at these field sites, such as time-lapse pictures, topographic and geophysical in order to understand these landforms. The student will process, organize, and analyze these datasets. The student will also have the opportunity to collect geophysical data near Bucknell with similar technology as being used in Alaska and New Zealand. It is not necessary for the student to be familiar with the software or the equipment, nor to have prior knowledge about geology. However, an interest in this topic and a willingness to learn are essential. Training will be provided, as needed. The student should be willing to learn various computer programs and will be responsible for creating a database. || Learn more about Professor Jacob.

Chris Martine

Chris Martine Plants are Cool, Too!

In the Martine Lab we explore the biodiversity of life on Earth. Where do species come from -- and what species are still out there to be found? By combining field-based work with lab methods (using new DNA/genomics techniques) we are currently uncovering mysteries related to the evolution of unusual plant reproductive systems, the role of pollinators in maintaining these systems, and the movement of genes across landscapes in northern Australia and the Rocky Mountains. || Learn more about Professor Martine.

Molly McGuire

Molly McGuire The Role of Iron in the Fate and Transport of Water Contaminants in Soil

Clay minerals comprise a large component of the soils and sediments with which groundwater is in contact and are an important source of redox-active Fe in these environments. In laboratory studies, reduced clay minerals have been shown to effect the transformation of a range of likely groundwater pollutants. The McGuire research group uses visible and infrared spectroscopic techniques to understand the changes in electronic and physical structure of these minerals that accompany redox processes in order to discern the relative reactivity of different Fe species. Additionally, because the oxidation state of Fe in the crystal lattice influences the overall volume of the extended structure in these layered minerals - and thereby the accessibility of the interlayer region between the clay layers - we are also interested in the physical changes in the extended clay structure. We have developed a method to use atomic force microscopy (AFM) in situ to investigate the swelling properties of individual clay mineral layers. Understanding the changes in swelling that result from changes in the chemical environment will eventually lead to better predictive models of the fate and transport of common water contaminants and the factors that control the permeability of soils and sediments. || Learn more about Professor McGuire.

Matthew McTammany

Matthew McTammany Connections between Aquatic and Terrestrial Habitats

Research in my lab currently explores connections between aquatic and terrestrial habitats via cross-ecosystem exchanges of materials. Specifically, we are studying roles that adult aquatic insects from rivers play in terrestrial communities and how aquatic insects subsidize diets of predators in terrestrial environments. The STEM Scholar in my program will join a field research team of other students to survey aquatic insects, spiders, and other terrestrial invertebrates at streams and rivers in central Pennsylvania. Following field work, samples will be processed in the laboratory for enumeration and identification of organisms. || Learn more about Professor McTammany.

Le Paliulis

Le Paliulis How Chromosomes Communicate with One Another over a Distance

The Paliulis group studies the key differences between metaphase and anaphase chromosomes, and one project concerns how chromosomes communicate with one another over a distance. A number of organisms have chromosomes that do not pair and stick together in meiosis I but almost always separate correctly from one another. Somehow the position of one chromosome is "communicated" to its partner chromosome. We have been studying this phenomenon in spiders (black widow and yellow sac), showing that partner chromosomes only complete meiosis I when they are correctly positioned relative to one another. We are currently examining Mesostoma ehrenbergii, a flatworm with multiple chromosomes that display distance interactions. || Learn more about Professor Paliulis.

George Shields

George Shields Mechanism for Formation of Secondary Aerosols

In a warming world, the biggest uncertainty in modeling global feedback mechanisms is the formation of clouds. Secondary aerosols form from ions and molecules in the atmosphere, and clouds form from aerosols. In general clouds are thought to be a negative feedback system for global warming, so that as cloud cover increases more incoming sunlight is reflected back into space, thus leading to a cooling effect. However, because the mechanism for secondary aerosol formation is unknown, there is still a very large uncertainty in the feedback mechanisms. The Shields group is using computational chemistry to model the formation of secondary aerosols, and collaborating with experimentalists to fill in the gaps in our uncertainty about these essential processes. || Learn more about Professor Shields, Dean of the College of Arts and Sciences.

Tom Solomon

Tom Solomon The Physics of Chaotic Mixing and Propagating Reaction Fronts 

In a forest fire, the dividing line between burned and unburned trees is called a front. The motion of this front determines how the fire spreads through the forest. Similar front dynamics characterize the spreading of a disease in society, as well as numerous chemical processing applications, biological processes in cells and developing embryos, and plasmas in fusion reactors. We are currently conducting experiments in the Department of Physics & Astronomy that explore how the motion of fronts is affected by fluid mixing, e.g., forced flows in a chemical processor, winds in a forest fire, or the motion of people in society while a disease spreads. Table-top experiments using a simple chemical reaction (the well-known Belousov-Zhabotinsky reaction) focus on how fronts are affected by simple flow patterns -- vortices (whirlpools) and jets. We are currently testing theories of "burning invariant manifolds" that describe front behavior in simple two- and three-dimensional flows. There is a lot of "hands-on" work involved in this project, including the designing, building and testing of the experimental apparatus, mixing chemicals for the reaction, and doing numerous experimental data runs. The experimental work also involves a substantial amount of computer-aided image analysis, almost exclusively on Linux workstations running a program called IDL. || Learn more about Professor Solomon.

Tim Strein

Tim Strein Ionic Migrations and Separation Mechanisms in Capillary Electrophoresis

The Strein Group focuses on analytical chemistry and they are interested in methods of micro- and nano-analysis. The group is particularly interested in techniques that exploit the analytical capabilities of capillary electrophoresis (CE), a methodology that gained wide acceptance when it was used to solve the human genome years ahead of schedule. The work in Strein's lab is aimed at two complementary goals: (1) obtaining a fundamental understanding of ionic migration in non-homogeneous conditions within a capillary (and from within complicated sample matrixes) so that accurate in-capillary mixing conditions can be confidently employed, and (2) understanding CE-based separation mechanisms for both simple ionic systems and more interesting micellar systems capable of chiral separations. The group uses both wet chemical approaches and computer simulation to investigate the capabilities and limitations of CE-based approaches to analyses of importance in clinical and food chemistry, and NMR to characterize intra- and inter-molecular interactions between molecules that give rise to separations. || Learn more about Professor Strein.

Eric Tillman

Eric TillmanConverting Linear Polymers into Macrocycles

In order to convert a linear polymer chain into a cyclic structure, a ring closing reaction must occur. These reactions in our lab involve transforming a polymer chain end into a highly reactive radical. Under properly dilute conditions, a polymer with a radical on each end will undergo ring closure, creating a cyclic polymer or macrocycle. Current research is focused on studying these reactions on model systems. Students would learn polymer synthesis and characterization, and also carry out model reactions of the chain ends of the polymer they produce. || Learn more about Professor Tillman.

Constance Ziemian

Constance Ziemian High velocity impact and bonding of iron-based amorphous metal powders

Amorphous metals, or metallic glasses, are unique non-crystalline metals with disordered atomic structures. Without grain boundaries, metallic glasses often exhibit very high strength, hardness, and wear resistance in comparison with their crystalline metal counterparts. The industrial use of amorphous alloys as structural materials has been somewhat impeded, however, by the difficulties of obtaining cooling rates high enough to produce large gauge glassy material. As a result, the formation of coated material systems composed of a layer of amorphous metal on the surface of conventional metal is being investigated as a means to exploit their superior properties for a wider assortment of applications. In collaboration with the Army Research Laboratory in Aberdeen, Maryland, experimentation is underway to analyze the deformation and bonding of single powder particles of iron-based metallic glass impacted on a mild steel substrate using a kinetic energy-based spray technique. Particle splat morphologies and properties will be characterized as a precursor to comprehensive cold-sprayed coating trials using iron-based metallic glass powder. This project will provide the opportunity for student training and usage of equipment associated with techniques such as X-ray diffraction, laser diffraction, scanning electron microscopy, differential scanning calorimetry, and nanoindentation. || Learn more about Professor Ziemian.



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