faculty and student research

Green Chemistry	Biodiversity in Fragmented Tropical Forests	Biodiversity of Deep Sea Mollusks	Lasers to Integrate Photonics with Electronics
Renewable Energy Chemistry	Electronic Field Guide Project	Chemical Sensors and ECOShuttle to Study the Coastal Ocean	Cuticular Hardening and Insect Immunity
Translational Regulation of Gene Expression during Spermatogenesis	Reducing the Flow of Mercury to the Environment	Photonics Technology	Maintaining Error-Free Databases

Green Chemistry

Green chemistry involves an ecologically sustainable view of chemical research, development and manufacture, and is dedicated to chemistry to benefit society. Toxicological understanding and environmental fate are necessary components to understanding the entire "molecular life cycle" of any commercial endeavor. The Green Chemistry Ph.D. is a Track within the Environmental Sciences Department, and is administered by the Chemistry Department. It is the first such program in the world. Students obtaining a degree from this program will be prepared for conventional chemistry jobs in industry, government and academia. In addition to traditional training in the chemical sciences, required and elective courses in the Biology and Environmental, Earth and Ocean Sciences (EEOS) Departments provide graduates with the tools and experience to assess human impact on health and the environment.

Timothy Dransfield, Department of Chemistry (back to top)

Biodiversity in Fragmented Tropical Forests

Tropical deforestation and forest fragmentation raise many global environmental concerns, including potential loss of biodiversity as a result of habitat alteration. Professor Kamal Bawa of the Biology Department directs a multifaceted, interdisciplinary research project focused on these changes. One major goal of the project is to improve the conservation of tropical forests by understanding the biological and socioeconomic reasons for their decline. Another major goal is to identify the effects of habitat degradation on the biodiversity of forest trees. He and molecular geneticist Richard Kesseli are approaching this problem by using genetic markers to study genetic diversity and patterns of gene flow in contiguous and fragmented Costa Rican forests.

Professor Bawa is working with non-governmental organizations, conservationists, and the Soligas who inhabit a tropical forest in India to develop locally managed enterprises, based on such non-timber forest products as honey, fruit, and herbal medicines, that are both economically and ecologically sustainable. The Bawa and Kesseli work will provide essential information that can be used by forest managers and conservationists to mitigate the effects of forest fragmentation and help maintain genetic diversity.

Supported by the National Science Foundation, National Institutes of Health, MacArthur Foundation, World Wildlife Fund, and International Plant Genetics Institute.

Kamaljit S. Bawa, Department of Biology
Richard V. Kesseli, Department of Biology (back to top)

Biodiversity of Deep Sea Mollusks

Drs. Ron J. Etter and Michael A. Rex of the Biology Department are conducting the first molecular genetic study of population differentiation and speciation in the deep sea. The deep sea is the largest and least known ecosystem on Earth. Recent exploration has revealed a surprisingly varied and dynamic environment, and quite unexpectedly high biodiversity. While a picture of ecological patterns is emerging, the evolutionary origin of this rich and highly endemic fauna is unknown. This represents a huge gap in our understanding of basic evolutionary phenomena and presents a number of major theoretical challenges. The primary evidence of evolutionary divergence in other environments is genetic populations structure.

This research is providing important clues about how life evolved in the deep ocean. It also has implications for conservation of biodiversity in an environment that is targeted for massive international exploitation for petroleum exploration, mining and waste disposal.

Supported by the National Science Foundation.

Ron E. Etter, Department of Biology
Michael A. Rex, Department of Biology (back to top)

Lasers to Integrate Photonics with Electronics

In the less than four decades that have elapsed since their inception, laser devices have revolutionized many technologies due to their high power, coherence, and spectral purity. Professor Greg Sun of the Engineering Program is working on the development of a tunable intersubband Raman laser, part of a new family of semiconductor lasers that, unlike conventional lasers, can operate in the range of mid-to-far infrared and bridge the wide frequency gap between electronics and optics. Recently Dr. Sun has begun to expand the idea of intersubband lasing to the quantum structures of silicon-based materials, establishing models for the quantum confined phonons in these material systems as well as their interactions with carriers which determines the intersubband lasing lifetimes.

Although silicon is the most readily available semiconductor material for electronics, it has inefficient light emitting properties when used in conventional semiconductor devices. The development of efficient silicon-based intersubband lasers opens up the important possibility of achieving the ultimate goal of monolithic integration of photonic devices with electronics. Dr. Sun's work, therefore, has major implications for current microelectronics technology.

Supported by the Air Force Office of Scientific Research of the Department of Defense.

Greg Sun, Engineering Program (back to top)

Renewable Energy Chemistry

This Research probe environmentally benign methods of generating, storing, distributing and utilizing natural energy resources, as well as the economic consequences of the use of alternative fuels. Renewable energy sources utilize natural processes, such as those originating from solar, wind, water, and geothermal sources. Many of these sources are intermittent and/or energetically diffuse, and supporting processes also need to be explored to efficiently store, concentrate and distribute these energy sources. Laboratories at the University of Massachusetts Boston explore efficient capture and conversion of solar energy, effective generation, distribution and use of hydrogen fuel, green battery chemistries which store greater energy and have less impact on the environment, new fuel cell studies, and the fate and distribution of pollutants resulting from new and traditional energy generation sources.

Deyang Qu, Department of Chemistry (back to top)

Electronic Field Guide Project

The Electronic Field Guide Project, directed by Drs. Robert Morris, Mathematics and Computer Science and Robert Stevenson, Biology, will make it possible to identify biological specimens in the field using a web-accessible, distributed object-oriented database. Taxonomic, environmental, and ecological information in the database will aid identification by building a context for each observation. The database will also support the recording of multiple observations, so that larger-scale ecological studies can be carried out using the data.

The flexible electronic field guide can have its user interface tailored to the target audience--school children documenting the biodiversity of their schoolyard; professional biologists documenting species loss; governmental agencies supervising environmental impact studies; etc. It can communicate with other biodiversity databases via the Internet so that researchers, governmental and non-governmental agencies, and teachers can access and compare information worldwide.

Supported by the National Science Foundation.

Robert Morris, Department of Computer Science
Robert Stevenson, Department of Biology (back to top)

Cuticular Hardening and Insect Immunity

Insects have a great impact on agriculture, the food industry, and health sciences. Professor Manickam Sugumaran, Biology Department is studying several processes that are essential for the survival of insects: cuticular sclerotization (hardening), melanization, immunity, and wound healing. By elucidating the molecular mechanisms underlying these vital physiological processes, his laboratory is working toward the development of new and novel insecticides that are environmentally safe. They have discovered unsuspected pathways, key enzymes, and crosslinking molecules involved in cuticular hardening and insect immunity. In collaboration with INBIO in Costa Rica, Sugumaran and colleague Kamal Bawa are looking in the tropical rain forests for new molecules to expand this biochemical work, focusing on inhibitors that would disrupt the action of key enzymes such as phenoloxidase, quinone isomerase, dopachrome isomerase, and quinone methide isomerase.

The findings are currently being transformed into biological control measures for agricultural pests and noxious insects that spread such dreaded diseases as malaria. The basic research findings are also being applied in diverse other ways: natural hair color; prevention of oxidative browning in food products; biological glues and novel polymers; skin color lightening agents; toughening of silk; and antimelanoma drugs.

Supported by the National Institutes of Allergy and Infectious Diseases, Fogerty International Institute, and Lawrence M. Gelb Research Foundation

Manickam Sugumaran, Department of Biology (back to top)

Chemical Sensors and ECOShuttle
to Study the Coastal Ocean

Real-time chemical sensors are being developed in the ECOS Department to study the dynamic and highly variable coastal ocean. To date, Dr. Robert Chen and his students have developed a shipboard fluorescence spectroscopy system that uses a fiber optic sensor that can measure directly from seawater every 10 seconds. They have used it in Boston Harbor, Chesapeake Bay, and San Diego Bay as well as on 10-day expeditions across the continental shelf. In collaboration with Bernie Gardner and other ECOS colleagues, Chen has also developed an undulating vehicle called the ECOShuttle. When towed behind a research vessel, ECOShuttle can map the physical and chemical properties of seawater in three dimensions, sensing plumes and pools of organic matter or pollution as small as several meters.

Sensitive, real-time geochemical measurements of coastal waters have myriad environmental applications. Chen and his students are now analyzing the largest data set ever taken of two important contaminants: measurements in Boston Harbor of pyrene, an EPA priority pollutant, and in the Mid-Atlantic Bight of total dissolved organic carbon, a large, critical, and relatively unknown pool of carbon that may affect the magnitude of global warming.

Supported by the Department of Energy, the Office of Naval Research, and MIT SeaGrant.

Robert Chen, Department of Environmental, Earth and Ocean Sciences    (back to top)

Translational Regulation of Gene
Expression during Spermatogenesis

Translation is the process by which the sequence of bases in messenger RNA (mRNA) is decoded into the sequence of amino acids in a protein. In most mammalian cells, the vast majority of mRNAs are translated into proteins, but this is not the case for developing sperm cells. These highly specialized cells express few of the proteins found in other cells, a condition achieved by mechanisms that block the initiation of translation of virtually all mRNA. Sperm cells also have other regulatory mechanisms that alter the rate of translation of individual mRNAs. Professor Kenneth Kleene of the Biology Department is using transgenic mice to study the mechanisms that regulate translation of one of the small group of mRNAs that are known to undergo developmental changes in the rate of translation in sperm cells. The mRNA selected for study carries code for a protein called SMPC, which is found in the keratinous outer mitochondrial membranes of spermatozoa. Kleene is investigating proteins hypothesized to block translation when bound to specific sequences of bases in the mRNA.

The identification of mechanisms that regulate the efficiency of mRNA translation during spermatogenesis provides models of similar regulatory processes in other systems. The work can be extended to help explain the rapid responses of cells to environmental changes. It can also be used to understand defects that arise during embryonic development because of failures in genetic translation.

Supported by the National Science Foundation.

Kenneth Kleene, Department of Biology (back to top)

Reducing the Flow of Mercury to the Environment

Source reduction technologies are methods for removing a chemical from the waste stream before it leaves the building where it is generated or used. These technologies are being developed in the Environmental, Coastal and Ocean Sciences Department to prevent a variety of potentially toxic chemicals from leaving industries, hospitals, and universities and entering our environment. Dr. Gordon Wallace is focusing on mercury, a toxic metal that has historically entered hospital sewage at high levels from medicines, analytical chemicals, and such broken instruments as thermometers, manometers and pressure gauges. Working with several Massachusetts industries and the state's Executive Office of Environmental Affairs to reduce concentrations of mercury in sewage, Wallace and his laboratory provide technical and analytical support for field-testing source reduction technologies aimed at removing mercury from hospital waste streams before discharge.

The sensitive, reliable measurements and timely analysis provided by Dr. Wallace have refined source reduction technologies for hospital-generated mercury waste and can be extended to other metal-contaminated waste streams (e.g. metal plating industries, circuit board production facilities). The work has also led to a better understanding of metal chelation in complex chemical environments and to the improvement of analytical measurement techniques for use in the presence of potentially interfering matrices.

Supported by the UMass/Executive Office of Environmental Affairs STEP Program.

Gordon Wallace, Department of Environmental, Earth and Ocean Sciences  (back to top)

Photonics Technology

Ultrafast laser pulse techniques are being used to study nonlinear optical properties of organic materials in the laboratory of Dr. Gopal Rao of the Physics Department. The work provides basic physical information on the molecules selected for study, such as energy states and lifetimes, saturable or reverse saturable absorption, and two-photon absorption. These properties are then exploited in diverse applications. Bacteriorhodopsin and related environmentally friendly molecules from biological materials are under investigation as new candidate materials for applications in photonics technology. Modern techniques of synthetic chemistry and molecular bioengineering are used to tailor the linear and nonlinear optical properties of these molecules as required by specific applications.

Some porphyrin materials studied by Rao were found to be good candidates for laser eye protection because of their nonlinear absorption: a thin film coating eyeglass lets in ordinary light but very rapidly becomes opaque when hit by an intense laser beam, quickly reverting to normal mode when the beam is no longer present. The US Army is using the porphyrin work to build a prototype for a tank periscope that will protect the eyes of soldiers from laser damage. The new techniques developed with biochemical molecules hold promise for applications in medical imaging, such as sharpening the edges of a diffuse X-ray or CT scan. Two patents have recently been granted for applications developed in this laboratory.

Supported by the US Army Natick Labs.

Gopal Rao, Department of Physics  (back to top)

Maintaining Error-Free Databases

Users face a tradeoff between speed of access and maintenance of data integrity as database values are frequently read and updated. The execution of multiple transactions requires them to be interleaved in ways that prevent erroneous values from entering. Software engineers work with a standard known as the serializability rule which stipulates that each execution of multiple transactions must have the same effect as executing the same transactions in serial order. Drs. Patrick O'Neil and Elizabeth O'Neil, Mathematics and Computer Science, are working on a new generation of transaction programs that gain speed yet execute correctly on less-than-serializable systems, developing methods to test for correctness when these schedulers are used under a variety of conditions.

The O'Neils have applied their results to the snapshot isolation method used by Oracle, the largest vendor of database servers. Snapshot isolation is interesting because it gains high performance by working from a "snapshot" of the pertinent data at transaction start time while allowing other transactions to read and write the data. Their work will provide tools that can be used to identify the anomalous conditions that limit use of the snapshot isolation method.

Supported by the National Science Foundation.

Patrick O'Neil, Department of Computer Science
Elizabeth O'Neil, Department of Computer Science  (back to top)