Two News Scripps Faculty Appointed

Amro Hamdoun and Dave Stegman join the Scripps Faculty

Scripps Institution of Oceanography/University of California, San Diego

Amro Hamdoun and Dave Stegman were recently appointed as the newest faculty members of Scripps Institution of Oceanography at UC San Diego. Hamdoun is a newly appointed assistant professor of marine cell biology in Scripps' Marine Biology Research Division. His general interests are in the fields of ecological developmental biology and cell biology. His current research focuses on the defense and survival mechanisms of embryos and the biology of the accumulation and elimination of chemicals in marine animal cells.

It's a privilege to be at this historic oceanographic institution and dynamic UC campus,” said Hamdoun. “The impact of these institutions on environmental science, biology, and medicine, to name a few, is humbling. It will be a major boon for our research to be part of these outstanding programs.

In an effort to learn more about the biology of protective mechanisms in cells and embryos, Hamdoun, who joined Scripps in July 2009, primarily studies sea urchins, animals that produce millions of eggs that can be easily manipulated in the laboratory. Sea urchin embryos have large cells that can be used to characterize the biochemical changes and intracellular movements of proteins that protect cells from environmental chemicals.  Hamdoun and his laboratory team are applying advanced light microscopy technologies to understand how fine-scale changes in location of intracellular proteins during embryonic development can alter embryo physiology and susceptibility or resistance of the embryo to environmental chemicals.

These studies are providing basic insights into the mechanisms of regulation of cellular defenses and predictive insights into how chemicals move from the environment into marine animal cells. Many of these studies underscore the close relationship between the oceans and human health.

Hamdoun was a National Institutes of Health (NIH) National Research Service Award postdoctoral fellow at Hopkins Marine Station of Stanford University and is currently an NIH Career Development Award recipient. He received his Ph.D. in physiology from the University of California at Davis in 2003.

Stegman is a newly appointed assistant professor of geophysics in Scripps’ Cecil H. and Ida M. Green Institute of Geophysics and Planetary Physics. He uses high-performance computing and advanced four-dimensional visualization systems to explore the intricate details of how planets evolve and why plate tectonics are unique to Earth.

His current research investigates global scale dynamics by reconstructing the history of where tectonic plates have been recycled into the earth’s mantle over the past 300 million years. This research aims to address many of the most important geodynamic events over the past 200 million years, including a 35-million-year phase during the Cretaceous period when the magnetic field stopped reversing, increased production of volcanic greenhouse gases led to a warmer climate and several planetary reorientations of the entire solid Earth, known as true polar wander, occurred.

I live for those moments of scientific discovery and that excitement of scientific exploration that I feel while working together with students and other scientists.  So it's an immense honor and privilege to join the faculty at Scripps Institution of Oceanography, which draws together such a talented group of people who share that enthusiasm,” said Stegman. “I can think of no better place to pursue my scientific ambitions and dedicate myself to continuing Scripps' world-class tradition in geophysics and tectonics.”<

Research Fellow at the University of Melbourne, and previous to that was at Monash University where he was an Australian Research Council postdoctoral fellow. During his time in Australia, he pioneered 3-D numerical models of free subduction, which address questions of why tectonic plates move, how plate boundaries evolve, and how features in the earth's deep interior develop.

In 2003, Stegman received his Ph.D from the University of California at Berkeley, where he developed one of the first 3-D spherical models of thermo-chemical convection to investigate the thermal evolution of Earth, the Moon, and Mars with an emphasis on the important role of chemically distinct materials. In 2009, renewed interest in this area of planetary geodynamics led to a new model for explaining many of the enigmatic features on Enceladus, an icy moon of Saturn.

Stegman collaborates widely with several groups across Australia, as well as the U.S., Europe, and Japan and has published on diverse topics, including on global and regional geodynamics, an enigmatic icy moon of Saturn, known as Enceladus, and high performance computing.

— Shannon Casey

August 14, 2009