IntroducingNew Scientists 2009-2010

Table of Contents

Support for New Scientists is Vital for Israel’s Future 1

Dr. Jakub (Kobi) Abramson 2

Dr. Ido Amit 4

Dr. Michal Armoni 6

Dr. Gad Asher 8

Dr. Eran Bouchbinder 10

Dr. Ofer Feinerman 12

Dr. Dmitry Gourevitch 14

Dr. Jacob Hanna 16

Dr. Zohar Komargodski 18

Dr. Valery Krizhanovsky 20

Dr. Anat Levin 22

Dr. David Margulies 24

Dr. Eran Ofek 26

Dr. Yael Shwartz 28

Dr. Oren Tal 30

Dr. Assaf Vardi 32

Dr. Karina Yaniv 34

Dr. Ofer Yizhar 36

New Scientist Funds and Gifts 38

1

In recruiting new faculty members, the Weizmann Institute looks for promising researchers with

innovative ideas who are opening up new directions in science. To help a new scientist come

to Israel, the Institute offers a commitment of at least three years of funding to establish the

scientist’s new laboratory. The costs average from $1 to $2 million dollars, depending upon

the field of research, and can reach $4 million in the special case of creating an entirely new

stem cell lab for one of the young researchers featured here. Hiring bright young scientists is an

investment in our future competitiveness and success.

We have included brief profiles of the young scientists who have been hired in 2009 and 2010 to

join the faculty of the Weizmann Institute of Science. We are fortunate to add three M.D.s, who

bring medical and clinical perspectives to their research. Four of our new recruits are women,

including one who worked abroad as a Sara Lee Schupf Post-Doctoral awardee in 2007. They

are a truly outstanding group of young researchers – with the curiosity to learn something

radically new; and the drive, creative ideas, and ambition to change the world.

Friends of the Weizmann Institute of Science worldwide have rallied to help with our need to

equip and fund our newest scientists. They use tools from electron microscopes to the world’s

most powerful telescopes, and research models from ants to zebrafish. Strong philanthropic

support for each new generation of scientists at the Institute is continually needed to ensure

Israel’s intellectual edge in science and technology. Thank you to the many friends of the

Weizmann Institute who have invested in the future of science.

Support for New Scientists is Vital for Israel’s Future

Prof. Daniel Zajfman, President

2

Dr. Jakub (Kobi) AbramsonDepartment of Immunology

Dr. Jakub (Kobi) Abramson’s immunology research offers new insights into how the body learns to tolerate its own agents, while attacking invaders.

M.Sc. Biochemistry (2000), Institute of Chemical Technology (ICT), Prague; Ph.D. Immunology (2005), Weizmann Institute of Science; Postdoc: Joslin Diabetes Center, Department of Pathology, Harvard Medical School, Boston, MA, USA.

Dr. Celia Zwillenberg-Fridman andDr. Lutz Zwillenberg Career Development Chair

3

The tiny thymus is the source of the body’s

T cells – immune system cells that patrol the

bloodstream looking for foreign invaders. Dr.

Jakub (Kobi) Abramson studies how these

powerful immune system defenders learn

tolerance, a process that begins in their

nursery in the thymus. They must be “taught”

not only how to recognize a foe, but also

how to tolerate the body’s own components. If

T cells don’t learn these lessons well, damaging

autoimmune reactions or autoimmune diseases

can result, as the T cells will attack the body instead

of protecting it. The first critical steps in the process of

teaching tolerance to T-cells are regulated primarily by a single

gene, which encodes a protein called the Autoimmune regulator (Aire). It not only drives

expression of thousands of genes ectopically – i.e., in a place where they are not normally found

– but it interacts with a very large set of major protein partners. Dr. Abramson’s in-depth search

found more than 40 proteins active in four key areas of cellular activity (see illustration). He seeks

insights into how immunologic tolerance is established and how autoimmunity is prevented, so

that he can suggest ways to restore immunological tolerance once it has been lost or impaired,

a possibility that has implications for a host of autoimmune disorders.

4

Ido Amit is one of the young researchers actively redefining what the world of science knows about gene regulation and immunology.

B.Sc.(1998) and M.Sc. summa cum laude (2002) Life Sciences, Bar Ilan University; Ph.D. Biological Regulation (2007), Weizmann Institute of Science; Postdoc: Broad Institute of MIT and Harvard, Cambridge, MA, USA.

Dr. Ido AmitDepartment of Immunology

5

Dr. Ido Amit is investigating one of the

fundamental questions in human biology,

how the body defends itself, using the

Toll-like receptor (TLR) pathway as a

model for understanding how biological

networks generate appropriate responses.

Uncontrolled immune responses underlie

many autoimmune and inflammatory diseases

such as cancer, inflammatory bowel disease,

rheumatoid arthritis, Type I diabetes, and Lupus.

Toll-like receptors sense invading pathogens and trigger

signaling and transcriptional networks that respond to the

threat. Dendritic cells, critical innate immune cells that function as sentinels, and orchestrate

the body’s adaptive immune response, use TLR to detect invading pathogens. Dr. Amit and

his colleagues recently revealed that the dendritic cell response circuit has two major arms: an

inflammatory arm, which initiates a system-wide immune response to bacterial infections; and

an anti-viral arm, which coordinates a more focused response tailored to viruses. Together,

these arms encompass about 100 regulators — roughly four times as many as were previously

known. Dr. Amit hopes to take this groundbreaking work (selected by the journal Science as a

Research Breakthrough of the Year) farther by using next-generation genomic technologies to

create detailed interactive maps and models to help scientists to discover and predict therapeutic

targets for inflammatory disorders and possibly for creating new vaccines.

6

Dr. Michal Armoni is shaping new tools and curricula to improve and extend computer science education.

B.A. (1989) summa cum laude and M.Sc. Computer Science Technion-Israel Institute of Technology (1991); Ph.D. School of Education, Tel Aviv University. Postdocs: Department of Education in Technology and Science, Technion-Israel Institute of Technology, and Department of Science Teaching, Weizmann Institute of Science, Rehovot, Israel.

Dr. Michal ArmoniDepartment of Science Teaching

7

Dr. Michal Armoni is researching the various aspects

of teaching and learning computer science, from

junior high school to undergraduate levels. Her specific

focus is on identifying and conveying the fundamental

ideas of computer science. This involves extensive research

and development projects, aimed at (1) studying computer science

learning and teaching and their development, (2) producing and implementing improved and

up-to-date learning and teaching materials that integrate the use of modern technologies, and

(3) providing professional development for computer science teachers all over Israel.

Her work is based on an underlying philosophy that considers curriculum development and

implementation, teacher professional development, research and evaluation as interrelated and

continuous long-term activities. Dr. Armoni’s research studies focus on cognitive, socio-cultural

and affective aspects of learning. She approaches teaching and learning to teach computer

science using quantitative, qualitative, and mixed research methods.

8

Dr. Gad Asher brings the perspective of a medical practitioner to the study of the body’s circadian rhythms.

B.Sc. and M.D. Sackler School of Medicine, Tel Aviv University (1998); Residency in Internal Medicine, Tel Aviv Sourasky Medical Center; Ph.D. Molecular Genetics (2006), Weizmann Institute of Science; Postdoc: Department of Molecular Biology, University of Geneva, Switzerland.

Dr. Gad AsherDepartment of Biological Chemistry

9

Dr. Gad Asher is fascinated by the

body’s internal clocks. There are millions

of molecular-level clocks at work in the body

– in brain and other major organs and in nearly

every single cell. Scientists have been able to show

daily rhythms of gene expression even in cultured cells (see

graph showing daily rhythms of gene expression in cultured cell). Dr. Asher is curious about

what happens on the molecular and cellular level as the body’s 24-hour circadian (from Latin:

circa diem) clocks regulate our daily metabolism, and behavior. The journal Cell Press called one

of his recent discoveries the “missing link” between the body’s circadian clock and metabolism.

His findings suggest the possibility that novel drugs could be developed to modulate the body’s

biological clock and repair it in diseases such as chronic sleep disturbances, or under altered

physiological conditions as in cases of jet-lag.

10

Dr. Bouchbinder works at the point of intersection between fields such as non-linear and non-equilibrium statistical physics, solid mechanics, materials science, and applied mathematics.

B.A. Physics and Philosophy, Tel Aviv University, summa cum laude (1999). M.Sc. (2002) and Ph.D. Theoretical Physics Weizmann Institute of Science (2007). Postdoc: Racah Institute of Physics, Hebrew University Jerusalem.

Dr. Eran BouchbinderDepartment of Chemical Physics

11

Understanding of the dynamics of the

failure of materials is a major technological

and scientific challenge. Dr. Eran Bouchbinder

plans to focus especially on amorphous systems,

such as glasses (structural, metallic, and polymeric),

granular media, and soft materials such as foams, colloids, and

emulsions; but also to consider more ordered materials like crystalline or polycrystalline solids.

He began with efforts to understand the dynamics of cracks propagating in brittle materials.

This is a major challenge in condensed matter physics and materials science. He developed

conformal mapping techniques to construct physical models for cracking problems that involved

interactions between geometry and mechanics. These works demonstrated how the physics

that occur on a small scale near the tip of a propagating crack may affect the macroscopic

failure behavior of materials. However, Dr. Bouchbinder is not content to simply describe the

breaking point of materials. He wants to be able to find a working theory that will bring together

experimental data and the principles of theoretical physics, the chemical structure of materials,

and the laws of thermodynamics.

A microscopic photo of the tip

of a crack moving through a

brittle gel used for measuring

the movement of the materials

involved.

12

Dr. Ofer Feinerman is a physicist with a fascination for biological systems that is producing new insights into life.

B.Sc. Physics and Mathematics (1996) and M.Sc. Physics (1999) at the Hebrew University of Jerusalem; Ph.D. Physics of Complex Systems (2006), Weizmann Institute of Science; Postdoc: Computational Biology and Immunology at the Memorial Sloan Kettering Cancer Center and “group of living matter” at the Rockefeller University, New York, USA.

Dr. Ofer FeinermanDepartment of Physics of Complex Systems

13

Having studied the nervous system, the cells of the

immune system, and an ant colony from the point

of view of a physicist, Dr. Ofer Feinerman marvels at

how such reliable and effective biological systems can

be made from so many smaller, individually less reliable

components. In his doctoral work at the Weizmann Institute,

Dr. Feinerman helped build artificial logic circuits made of nerve cells

(see branching network at right) and studied their signal processing. The ant colony can also be

regarded as a processing network with a “fluid-like” information flow that senses environmental

conditions while simultaneously resolving them. Randomness, noise, heterogeneity, reliability,

information processing, and computational capabilities are common themes in neuroscience,

immunology, and social insect behavior. Dr. Feinerman brings the tools of theoretical physics

to study these issues in ants. He plans to study the native Israeli ant cataglyphis niger (above)

in artificial nest-like structures in the lab, using radio and visual ID tags to individually track and

manipulate each ant in a colony of hundreds.

14

Dr. Dmitry GourevitchDepartment of Mathematics

Dr. Dmitry Gourevitch works in a highly abstract field of mathematics known as representation theory.

B.Sc. Mathematics with honors, Tel Aviv University (2000) M.Sc. (2005) and Ph.D. (2009) in Mathematics at the Weizmann Institute of Science. Postdocs: Institute for Advanced Study at Princeton and the Department of Mathematics at Rutgers University in New Jersey.

15

Dr. Dmitry Gourevitch specializes in a field of mathematics known as representation theory.

Representation theory is a powerful tool because it reduces problems in abstract algebra to

more “solvable” problems in linear algebra. The field has numerous applications to physics

(in particular quantum mechanics), and computer science, as well as to other areas of

mathematics. For his Ph.D. thesis at the Weizmann Institute, working under Profs. Joseph

Bernstein and Prof. Stephen Gelbart, Dr. Gourevitch concentrated on relative representation

theory of pairs of groups. In particular, he studied special types of pairs of groups such as

“Gelfand pairs,” “symmetric pairs,” and “spherical pairs.” He has contributed to extending

the concept of Schwartz functions and distributions (named after the French mathematician

Laurent-Moïse Schwartz 1915-2002), which play an important role in representation theory. His

other area of concentration is devoted to “multiplicity one theorems,” which form a quite modern

topic in representation theory of reductive groups and has important applications to the field of

automorphic forms. Automorphic forms is a deep, but fast-developing area of mathematics that

connects several fundamental areas, such as algebraic geometry, representation theory and

number theory. Eventually, Dr. Gourevitch hopes to use all of these mathematical tools to make

his own unique contributions to representation theory. Dr. Gourevitch will join the Department of

Mathematics at the Weizmann Institute of Science as a Senior Scientist in January 2011.

His wife, Anna, is also a mathematician, with a Ph.D. in Mathematics from Tel Aviv University.

Diagram of deformation

possibilities from: A. Gourevitch,

D. Gourevitch: "Geometry of

obstructed equisingular families

of algebraic hypersurfaces"

Journal of Pure and Applied

Algebra 213, no. 9 (2009)

16

Dr. Jacob (Yaqub) Hanna is a highly promising young stem cell researcher who is pioneering techniques in induced pluipotency and reprogramming of adult cells.

B.Sc. Medical Sciences summacum laude (2001), M.Sc. Microbiology and Immunology, (2003) Ph.D. / MD summa cum laude Clinical Medicine (2007), all at the Hebrew University of Jerusalem; Postdoc: The Whitehead Institute for Biomedical Research, MIT, Cambridge, MA, USA.

Dr. Jacob HannaDepartment of Molecular Genetics

17

Induced pluripotent stem cells (IPS) have regenerative

properties almost identical to those of embryonic stem

as they can differentiate into all cell types in the human

body. However, iPSCs can be directly created from adult

cells by expressing defined genes without using an egg or

fetal material. Dr. Jacob Hanna worked in one of the first three labs

worldwide to successfully reprogram mouse skin cells into IPS cells. He was the lead researcher

in a study that showed how further-modified IPS cells could be used to treat sickle-cell anemia

in mice, the first proof of concept of the therapeutic application of IPS (see illustration of a

strategy to correct sickle cell anemia in mice by creating induced pluripotent stem cells above).

In his new lab, Jacob will utilize multiple analytical tools to define key insights into the molecular

mechanisms of reprogramming and how stem cells execute key choices as they differentiate. In

addition, by generating iPSCs from specific patients with a variety of disorders, his work offers

the promise of establishing powerful new research models for studying human genetic and

autoimmune diseases, such as Niemann-Pick disease and Type 1 diabetes.

18

Dr. Zohar KomargodskiDepartment of Particle Physics and Astrophysics

Dr. Zohar Komargodski is a theoretical physicist working on extensions of the Standard Model of particle physics, in particular, supersymmetry.

B.Sc. Physics and Mathematics, summa cum laude, Tel Aviv University (2004), M.Sc. Physics, summa cum laude, Weizmann Institute (2006), Ph.D. Physics, summa cum laude, Weizmann Institute (2008); Postdoc: Institute for Advanced Study, School of Natural Science, Princeton, NJ, USA.

19

Dr. Zohar Komargodski is one of the theoretical

physicists closely watching the results of the

high-energy physics experiments conducted

within the Large Hadron Collider (LHC) at

CERN. To make the so-called Standard

Model of particle physics consistent with

the rules of quantum mechanics, physicists

have long postulated the addition of at least

one particle, the Higgs boson. This is the only

standard model particle that has not yet been

seen, and physicists have only a rough idea what

its characteristics are. Experiments at the LHC are

expected to provide the first experimental evidence

of the existence or non-existence of the Higgs boson. If

the Higgs particle does not exist, it would have far-reaching

consequences for the most basic postulates in modern physics.

Theoretical physicists like Dr. Kormogodski are using the data deriving

from the LHC experiments, such as the ones relating to the Higgs boson,

and other large-scale physics initiatives worldwide to formulate a single unifying

theory that explains all physical phenomena – from the behavior of subatomic particles to the

formation of the universe. One of the leading proposals for such a unified theory is based on

``Supersymmetry (SUSY).’’ Supersymmetry is a particularly appealing enlargement of the Standard

Model that offers interesting explanations for the Higgs question, posed above, as well as some

predictions for the LHC experiments. On the theoretical side, the discovery of supersymmetry

will revolutionize our understanding of space-time. At the age of 27, Dr. Komargodski has

already made creative scientific contributions related to aspects of Supersymmetric theories.

One of the equations from

"Comments on the Fayet-

Iliopoulos term in field theory

and supergravity" by Zohar

Komargodski and Nathan

Seiberg from the Journal of High

Energy Physics 2009.

Dr. Valery Krizhanovsky Department of Molecular Cell Biology

Carl and Frances Korn Career

Development Chair in the Life Sciences

Dr. Valery Krizhanovsky’s work

in cellular senescence has

major implications for the study

of disease and aging.

B.Sc. Clinical Nutrition (1995);

M.Sc. Biochemistry and

Nutrition (1999), Ph.D. / MD

Developmental Neuro-Genetics,

Institute of Life Sciences (2005), all

at Hebrew University of Jerusalem;

Postdoc: Cell Biology and Cancer

Research at Cold Spring Harbor

Laboratory, New York, NY USA.

21

Dr. Valery Krizhanovsky is exploring the role

of cellular senescence which occurs in

both disease and in aging when cells keep

functioning but stop reproducing. Once

thought to occur only in tissue cultures outside

the body, studies since 2005, including his

most recent findings, demonstrate that

cellular senescence occurs naturally as part

of a number of responses to stress or injury,

and operates as a braking mechanism to limit

tissue damage and tumor formation. In his

postdoctoral research, Dr. Krizhanovsky was the

first to demonstrate the protective role of cellular

senescence in liver fibrosis and cirrhosis. Using

this disease as a model, he showed that senescent

cells accumulate in fibrotic mouse livers. He seeks to

understand the role of cellular senescence in the body’s

response to tissue damage, including in long-term damage, in

the initiation of cancer, as well as in the process of aging. He hopes

that this knowledge will ultimately lead to better strategies for disease

prevention and treatment in patients.

22

Dr. Anat Levin’s research focuses – quite literally – on improving digital photography and computerized vision.

B.Sc. Mathematics and Computer Science, (2000) M.Sc., (2001) and Ph.D. Computer Science (2006) all at the Hebrew University of Jerusalem; Postdoc: Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology (MIT) Cambridge, MA, USA.

Dr. Anat LevinDepartment of Mathematics and Computer ScienceHelena Rubinstein Career Development Chair

23

The emerging field of

computational photography

exploits digital technology to introduce

computation between the light array and the

final image. Dr. Anat Levin aims to understand the limitations

to the amount of information a camera can hope to collect. She plans to use that information

to design next-generation cameras that overcome traditional digital photography and computer

vision challenges. Dr. Levin and her colleagues helped develop several recent post-exposure

applications such as transparency, colorization, matting, and segmentation. They have also

applied these principles to the design of novel cameras, such as the coded aperture camera,

which acquires depth information in addition to a full-resolution image from a single shot; and

the motion invariant camera, which can overcome motion blur distortions. Dr. Levin was named

by the Institute of Electrical and Electronics Engineering’s Intelligent Systems magazine as one of

ten top researchers in 2008 and the 2009 Pazy Award for the most outstanding BSF-supported

project in mathematics and computer science.

A prototype

camera that

overcomes

motion blurring

by taking two

images at once.

24

Dr. David Margulies uses biomimetics to imitate the ways that proteins recognize and signal the presence of biomolecules to create exciting new prospects for science, medicine, and technology.

B.Sc. Chemistry, Hebrew University (1998), M.Sc (2001) and Ph.D. Organic Chemistry, Weizmann Institute (2006), Postdoc: Department of Chemistry, Yale University, New Haven, CT, USA.

Dr. David MarguliesDepartment of Organic ChemistryJudith and Martin Freedman Career Development Chair

25

Dr. David Margulies focuses on the design of artificial

receptors that can recognize specific biomolecules

and modulate natural recognition processes. These

artificial receptors can be used as the basis for

drugs, sensors, or other molecular-scale devices.

In his graduate and postdoctoral research, Dr.

Margulies designed a number of groundbreaking

biomimetic systems, such as the first molecule

to add and subtract numbers; a molecular “ATM-

machine” security system that recognizes password

entries; synthetic receptors that can switch off cancer-

related malignant biological pathways; and biomimetic

“sniffers” capable of astoundingly rapid detection of various

proteins. Dr. Margulies plans to take molecular recognition a step further: Not only will his

synthesized receptors bind, detect, and regulate biological targets; they will also be capable of

dynamically adapting to biochemical changes. A current project involves the design of a simple,

versatile, and efficient analytical system that mimics the way proteins recognize and signal the

presence of biomolecules. Another study addresses a significant challenge in drug design by

regulating protein functions using molecules that mimic their dynamic structures.

26

Dr. Eran Ofek has shown tremendous creativity and insight in devising ways to explore the outer limits of the solar system, and the history of stars.

B.Sc. (1997) and M.Sc. magna cum laude Physics (2000), Ph.D. School of Physics and Astronomy, (2005), all at Tel Aviv University; Postdoc: California Institute of Technology (Caltech), Pasadena, CA, USA.

Dr. Eran OfekDepartment of Particle Physics and Astrophysics

27

Dr. Eran Ofek wants to explore one of the

solar system’s last unobserved frontiers – the

Oort Cloud, as well as some of our near galactic

neighbors. Astronomers have been looking for tangible

evidence of ice and rocks that orbit between about 5,000 and

50,000 astronomical units from the sun (1 AU = the mean distance of Earth from the Sun, or

~150 million kilometers) ever since 1950, when Dutch astronomer Jan Oort theorized that they

must be the source of very long-period comets (those with orbits longer than 200 years). So

far, no direct observation of an object in the Oort cloud has yet been reported. Dr. Eran Ofek, is

interested in the Oort Cloud and its closer cousin, the Kuiper Belt, because these primitive relics

still preserve evidence about the composition and dynamics of the formation of the solar system

about 4.6 billion years ago. (See NASA illustration above, depicting the size and distance of the

Oort Cloud and Kuiper Belt relative to the Sun).

28

Dr. Yael Shwartz’s research focuses on scientific literacy, coherence and knowledge integration, integrating thinking skills, and improving formal and informal chemistry education.

B.Sc. Chemistry, Bar-Ilan University (1989); Teaching Diploma Weizmann Institute of Science (1992); Ph.D. Science Education, Weizmann Institute of Science (2004, direct track). Postdocs: Department of Science Teaching, Weizmann Institute of Science, and School of Education, University of Michigan, Ann Arbor, MI, USA.

Dr. Yael ShwartzDepartment of Science Teaching

29

Dr. Yael Shwartz is engaged in all facets

of chemistry education and curriculum

development, with special emphasis on the

professional development of high-school

chemistry teachers. This includes research

on encouraging chemical literacy, student

understanding of chemistry concepts, learning

in the chemistry laboratory, and how chemistry

teachers interact with their students. Her current

research also focuses on how students conceptualize

the multiple facets of energy and the interactions of

energy and matter. She is investigating student attitudes

towards science and what influences students to choose (or

not) chemistry as a major, to get a deeper insight into student

motivation to learn science.

Dr. Shwartz facilitates a leadership course for chemistry teachers and

mentors teachers as part of the Rothschild-Weizmann program. She studies how

teachers and students function in digital on-line environments to learn what kind of support is

needed in order for teachers to improve their classes’ use of today’s multiple digital learning

environments and resources. She is also developing both chemistry and interdisciplinary science

learning modules, integrating scientific inquiry practices with the science content.

ריםחומ

ם הבעול

ם שרי

וקסים

יח

משרד החינוךהאגף לתכנון ולפיתוח תוכניות לימודים

מטה מל"מהמרכז הישראלי לחינוך מדעי טכנולוגי

על–שם עמוס דה-שליט

המחלקה להוראת המדעים

יחסים וקשריםבעולם החומרים

זיוה בר-דביעל שורץ תמי לוי נחום

30

Dr. Oren Tal is one of the young pioneers in the emerging fields of molecular electronics and “spintronics.”

B.Sc., magna cum laude Chemistry University of Tel Aviv (1996). M.Sc. Chemical Physics, Weizmann Institute of Science (2001), Ph.D. Physical Electronics, Tel Aviv University (2006) Postdoc: Leiden Institute of Physics, The Netherlands.

Dr. Oren TalDepartment of Chemical PhysicsAlvin and Gertrude Levine Career Development Chair

31

Dr. Oren Tal has learned to build bridges – made of a single

atom or molecule – between two nanoscale electrical contacts.

(see picture at right). A single molecule bridging between two

electrodes serves as a perfect test bed for exploring the fundamental principles and properties of

matter, such as the transport of electrical current, electron spin current, or molecular vibrations,

on a very controllable, atomic level. The information gained is laying groundwork for future

directions in spin based electronics (spintronics) – which promises more computing power for

considerably less energy than conventional means. Dr. Tal studied the interactions between

molecular vibrations in a single water molecule, and was part of the team to investigate the

properties of benzene, the first single organic molecule tested to achieve close to the “quantum

of conductance,” the theoretical maximum conductance possible for a single electron channel.

This overcomes a major barrier towards creating ultra-low-energy molecular electronic devices.

32

Dr. Assaf Vardi examines the basic biochemistry of the algae that form the basis for the global food chain.

B.Sc. Biology magna cum laude (1994), M.Sc. (1999), and Ph.D. Molecular Ecology (2004), all at the Hebrew University of Jerusalem; Postdocs: École Normale Supérieure, Paris, France, and Institute of Marine and Coastal Sciences, Rutgers University, NJ, USA.

Dr. Assaf VardiDepartment of Plant SciencesEdith and Nathan Goldenberg Career Development Chair

33

Dr. Assaf Vardi is a marine molecular ecologist

who studies phytoplankton, the single-celled,

microscopic algae that are the base of the marine

food chain. Their activity accounts for roughly half

of global photosynthesis and oxygen production.

He has developed advanced molecular methods

to investigate communications signals among

phytoplankton cells (such as the diatoms pictured

at right) and between them and marine viruses, and

how these signals regulate the fate of phytoplankton

populations. Dr. Vardi found that injured phytoplankton

release mediator compounds, which he terms infochemicals,

into their surroundings. Damaged cells can respond to these

chemical signals by triggering “cell suicide” on a massive scale. This can create algal blooms,

huge aggregations of concentrated phytoplankton that can cover many square kilometers of the

ocean or a lake’s surface, killing fish and fouling drinking water. In healthier cells, however, the

signal leads to activation of processes designed to deal with stress. Algae can also produce a

significant amount of lipids that can be turned into biofuel. Algae are far more efficient than crop

plants in the production of oil per land area, and take up carbon dioxide in the process; thus, Dr.

Vardi’s insights into may help in producing clean biofuels.

34

Dr. Karina Yaniv is a biologist who studies the lymphatic system, which is essential for immune responses, fluid homeostasis, and fat absorption.

B.Sc. Chemistry and Biology Hebrew University of Jerusalem (1994). Ph.D. Developmental Biology Hadassah-Hebrew University Medical School (2004). Postdoc: Laboratory of Molecular Genetics at the National Institutes of Health (NIH), Bethesda, MD, USA.

Dr. Karina YanivDepartment of Biological Regulation

35

Dr. Karina Yaniv studies the critical role

played by the formation of blood vessels

during embryonic development. Recent research

has shown that many of the signaling pathways

involved in this early vascular development are reactivated in

disease stages of blood vessel formation (angiogenesis); or vessel regression, such as coronary

heart disease and cancer. Absent or damaged lymphatic vessels can lead to lymphedema,

localized fluid retention and tissue damage. Impairment of the lymph system has also been

found to promote the metastatic spread of cancer cells to distant organs. Dr. Yaniv uses the

zebrafish, a small tropical fish whose transparent embryonic stage offers distinct advantages for

studying vessel formation in vivo. Using two-photon time-lapse imaging of transgenic zebrafish,

she was able to trace the formation of lymphatic vessels in the living embryo, determining for

the first time the origin and development of this system, a controversial question that eluded

resolution for the last century. Dr. Yaniv’s long-term research goal is to elucidate the cellular

and molecular mechanisms underlying the formation of blood and lymphatic vessels during

embryonic development. She hopes that her work will open new venues for research, as well as

uncover potential therapeutic targets for treating vascular diseases.

36

Dr. Ofer YizharDepartment of Neurobiology

Dr. Ofer Yizhar, has made important contributions in the revolutionary light-driven approach to brain research called optogenetics.

B.Sc. Biology with distinction, Hebrew University of Jerusalem (2001). Ph.D. Neurobiology with distinction, Tel Aviv University (2008). Postdoc: Bioengineering, Stanford University, California, USA.

37

Neuroscientists worldwide are excited about the

potential of optogenetics, a field invented in 2005

when scientists were first able to create neurons

that respond to light. They did this by introducing

light-sensitive proteins, first into cultured nerve cells and

later into living brains. These light-sensitive proteins are

called “microbial rhodopsins” and are produced by a set of

microbial “opsin” genes normally found in certain green algae and

photosynthetic bacteria. Dr. Ofer Yitzhar contributed to the development

of several new optogenetic tools. The first were “step-function opsins” (SFOs), which researchers

now use with light delivered by optical fibers (see picture), to turn “on” particular types of nerve

cells and increase the level of activity of a specific area of the brain – an ability that has important

implications for a number of mental health issues, from depression to schizophrenia. He also

helped refine “ChETA” – a super-fast-responding opsin that allows scientists to activate fast-

spiking cells with high precision, and a novel set of channelrhodopsins, the most potent known

so far, that can be activated with yellow light and used to stimulate neurons deep in brain tissue.

Recently, Dr. Yizhar completed a set of new optogenetic tools, called “C1V1 variants,” that can

be activated using multi-photon excitation and can be used to activate neurons with single-cell

resolution, He uses these new tools to study patterns of neural activity in the prefrontal cortex, a

region of the brain that is crucial for higher cognitive function and is often impaired in psychiatric

diseases such as schizophrenia.

Photograph by Darren Braun

November 2010,

ScientificAmerican.com

New Scientist Funds and Gifts The Weizmann Institute

of Science has received

substantial gifts for the benefit

of new scientists from the

following individuals, families

and funds, and wishes to

express its appreciation to

them:

• Abramson Family Center for Young Scientists

• Abisch-Frenkel Foundation for the Promotion

of Life Sciences

• Ruth and Herman Albert Scholars Program

• Alberto Moscona-Nissim, AMN Foundation

for Science and the Arts in Israel

• Asher and Jeannette Alhadeff Research

Award

• Candice Appleton Family Trust

• Gerhard and Hannah Bacharach Charitable

Trust

• Estate of David Arthur Barton

• Miriam Berman Presidential Development

Chair

• Andrew and Froma Benerofe New Scientist

Fund

• Leo M. Bernstein Family Foundation

• Edith C. Blum Foundation

• Estate of Shlomo (Stanislav) and Sabine

Bierzwinsky

• Frances Brody Young Scientists Fund

• Mr. and Mrs. Raymond Burton, CBE

• Carolito Stiftung

• Chais Family Fellows Program for New

Scientists

• Lester Crown Brain Research Fund

• Clore Israel Foundation

• Sir Charles Clore Research Prize

• Sir Harry S. Djanogly, CBE

• Rena Dweck New Scientist Endowment Fund

• Mel and Joyce Eisenberg Keefer Professional

Chair for New Scientists

• Judith and Martin Freedman Career

Development Chair

• Meir and Jeanette Friedman Research

Fellowship

• Estelle Funk Foundation President’s Fund for

Biomedical Research

• Fusfeld Research Fund

• Peter and Patricia Gruber Awards

• IPA New Scientist Prize

• J & R Foundation

• Nancy and Dr. Joseph Jacobson Family

Presidential Development Chair

• Enid Barden and Aaron J. Jade Presidential

Development Chair for New Scientists in

Memory of Cantor John Y. Jade

• Liz and Alan Jaffe Endowment

• Jarndyce Foundation

• Mitchell T. Kaplan and Marilyn E. Jones

• Sanford Kaplan

• Koret Foundation

• Prof. Daniel E. Koshland, Jr.

• Larson Charitable Foundation New Scientist

Fund

• Mr. and Mrs. Gary Leff

• Alvin and Gertrude Levine Career

Development Chair

• Mr. and Mrs. Howard Levine

• Estate of Lela London

• Loundy Fund for New Scientists in memory of

Jeanette and Mason Loundy

• Rhoda R. Mancher

• Ilana and Pascal-Olivier Mantoux

• Mrs. Judith Marks

• Dr. Karen Mashkin

• Rina Mayer

• Janice Montana

• Morse Family Fund

• Alberto Moscona-Nissim, Mexico, A.M.N.

Fund for the Promotion of Science, Culture

and the Arts in Israel

• Dr. Ernst Nathan Fund for Biomedical

Research

• William Z. and Eda Bess Novick New

Scientists Fund

• Estate of Paul Ouriff

• Robert Rees Applied Research Fund

• Henry S. & Anne S. Reich Research Fund for

• Mental Health

• Abraham and Sonia Rochlin Foundation

• Mrs. Clara Clarisse Roman

• Lois Rosen New Scientist Fund

• Hana and Julius Rosen Fund

• Mr. and Mrs. Louis Rosenmayer

• Rosenzweig-Coopersmith Foundation

• Lord Sieff of Brimpton Memorial Fund

• Skirball Chair for New Scientists

• Samuel M. Soref & Helene K. Soref

• Foundation

• South Florida Committee for the Weizmann

• Institute of Science “Brain Gain Fund”

• Mr. and Mrs. Walter Strauss

• Swiss Society of Friends of the Weizmann

Institute of Science

• Mrs. Sara Z. De Usansky

• Sarah and Rolando Uziel

• Nathan, Shirley, Philip and Charlene Vener

New Scientist Fund

• Dr. Albert Wilner

• Wolfson Family Charitable Trust New

Investigator Laboratories

• Jacques and Anita Zagury

• Natalie Zinn Haar Foundation

• Dr. Celia Zwillenberg-Fridman Fund for

Young Scientists