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New Scientist Profiles

Ten new scientists joined the Weizmann Institute this year. Read about three of them.

Teaching machines to learn

Dr. Ohad Shamir of the Department of Computer Science and Applied Mathematics attempts to answer one of the most difficult questions in science: Will machines ever be able to learn and think like humans? Whereas today’s machine learning mechanisms are becoming increasingly sophisticated and machines are able to acquire knowledge in a more intuitive way, they focus on basic skills acquired by humans at a very early age. In his study, Dr. Shamir focuses on complex learning in environments of resource restraint and uncertainty, such as medical diagnosis, and examines whether it is possible for a machine to function like a human doctor. Furthermore, Dr. Shamir’s research attempts to understand computerized systems that process information like the human brain, by using layered and hierarchical neuron-like connections and networks. These types of networks, if built properly, could mimic human brain functions at a more complex level.
Dr. Shamir earned a BSc summa cum laude in 2007, an MSc in 2008 (as part of a direct PhD track), and a PhD, also summa cum laude, in 2010—all in computer sciences at the Hebrew University of Jerusalem. He joined the Weizmann Institute of Science in October 2013 following a postdoctoral fellowship at Microsoft Research New England in Massachusetts, where he collaborated on several projects and registered three patents in his name.
At the Weizmann Institute, Dr. Shamir will be working side by side with his father, Prof. Adi Shamir, a computer encryption pioneer and Turing Award recipient.

Advancing melanoma research

Dr. Ravid Straussman of the Department of Molecular Cell Biology is a medical doctor who now devotes himself full-time to basic scientific research, focusing on the biological mechanisms that allow cancerous tumors to resist chemotherapy and survive in the human body.
Dr. Straussman decided to pursue this line of study from a non-traditional angle. During his postdoctoral training at the Broad Institute of Harvard and MIT, Straussman concentrated on the role of healthy cells within the microenvironment of the tumor in assisting the tumor’s resistance to treatment. He found that these healthy cells often do assist the cancer cells against chemotherapy by activating their intra-cellular distress mechanisms. One of these mechanisms, a protein called hepatocyte growth factor (HGF), is usually involved in wound healing and, when secreted by cells in the microenvironment of a melanoma tumor, is responsible for developing resistance to the most powerful anti-melanoma drugs in existence today.
Dr. Straussman completed his MD/PhD studies at the Hebrew University Hadassah Medical School and took up research as a postdoctoral fellow in the lab of Prof. Howard Cedar at the Hebrew University of Jerusalem. He then moved to the Broad Institute, where he worked from 2008 until joining the Weizmann Institute of Science in 2013.

 

The connection between eye and brain


Dr. Michal Rivlin of the Department of Neurobiology investigates the neuronal circuitry of the retina, which has a simple layered structure but is able to perform complex computations. Dr. Rivlin, who obtained her PhD in 2009 from the Interdisciplinary Center for Neural Computation at the Hebrew University of Jerusalem, conducted her postdoctoral training at the Department of Molecular and Cell Biology, and the Helen Wills Neuroscience Institute, at the University of California, Berkeley.
During her time at UC Berkeley, Dr. Rivlin discovered that the direction-selective retinal ganglion cells, which are responsible for registering unidirectional motion, can be “trained” to reverse their directionality through short repetitive stimulation with a moving pattern. Dr. Rivlin, who joined the Weizmann Institute of Science in September 2013, intends to explore other specialized cells in the retina and develop new methods to retrain nerve cells, with the hope of better understanding how neuronal information is processed in the retina.
During her postdoctoral research, Dr. Rivlin received a Revson Award from the National Postdoctoral Program for Advancing Women in Science established by the Weizmann Institute.