About

The Central Arava Branch of the Dead Sea and Arava Science Center operates as an academic platform for applied research, and employs researchers who choose to live in the central Arava. The branch shares a building with the agricultural R & D at the Yair Farm near the Hazeva Field School.

Study fields:

Research at the Central Arava Branch centers on ecology, geology, drug discovery, biochemical pathways under stress conditions, archaeology, education and more.

Dr. Rivka Ofir – Ecology
Dr. Niva Russek-Blum – Neurobiology
Dr. Sarit Ashckenazi-Polivoda – Geology, Microbiology and Ecology (or: The Micro-Paleontology
Dr. Gidon Winters – Ecology

Rivka Ofir

1. Desert plants as source for new leads for drugs; Screening library of desert plants extracts against models for human diseases in c.elegans, zebrafish and cell lines.
   We have a library of ~250 desert plants collected in the Arava between the Red Sea and the Dead Sea. We extract the plant material in various solvents and screen the library of these extracts against in vitro models of cancer diseases (tumors cell lines and cancer stem cells), in vivo  models of neurodegenerative diseases (ALS disease in zebrafish and Alzheimer`s disease in c. elegans). The research will involve identifying  plant extracts with beneficial activities, to identify the active material, to unveil the model of action and cultivate the plants in stress conditions to mimic desert conditions.

2. Desert plants as source for safe fungicides and herbicides; Screening library of desert plants extracts against models for plant fungi and for inhibition of wild weeds.
   We have a library of ~250 desert plants collected in the Arava between the Red Sea and the Dead Sea. We extract the plant material in various solvents and screen the library of these extracts against various fungi isolated in the farms in the Arava.  This library serve also for screening against germination and growth of wheat (Monocotyledon) and bean (Dicotyledon).  The research will involve identifying plant extracts with beneficial activities, to identify the active material, to unveil the model of action and cultivate the plants in stress conditions to mimic desert conditions.

3. Bioprospecting – medicinal metabolites/transcript signatures for growth in desert stress conditions.
   According to our recent studies, the composition of the metabolites in desert plants depend on growth conditions (stress for irrigation, temperature, etc). The research will involve comparing the transcriptome and metabolome of desert plants with medicinal activities like Achillea fragnitisoma, Pulicaria incisa, Boswellia sacra, Commiphora gileadensis.

Niva Russek-Blum

Current research:    

Early macrophages colonization of the brain, their transition to fully differentiated microglia, their effect on neighboring neurons development and behavior and the genetic pathways underlying these processes.

Recent studies on microglial origin indicate that these cells arise early during development from progenitors in the embryonic yolk sac that seed the brain parenchyma and, remarkably, appear to persist there into adulthood. We use the zebrafish, transparent vertebrate whose immunological features resembles ours, to understand the origin, differentiation, and homeostasis, of microglia cells which is expected to provide new insights into their roles in health and disease. We exploit fate mapping procedures to better refine primitive macrophages invasion and colonization of the brain. To define the differentiation process and to be able to find unique markers for these cells, genes that define microglial differentiation are being characterized. The exact role and timing of distinct signaling pathways involved in this process, such as TGF-β, are examined.

The immune perspective of neurodegenerative disorders in the zebrafish brain.

The role of microglia and circulating macrophages in neurodegenerative disorders in a zebrafish model as a mean to get further insights to basic unresolved questions in neuroimmunology and to establish an infrastructure required for the initial screen of potential therapeutic agents.

The impact of inflammatory responses is rapidly assuming major roles in ischemic stroke and neurodegenerative pathologies such as Alzheimer’s disease, Parkinson’s disease, Amyotrophic Lateral Sclerosis (ALS) and Multiple Sclerosis (MS). In recent years, progress has been made in developing new therapies that target the immune system or treatments that use components of the immune system as therapeutic agents.

As part of this inflammatory response in the brain, microglia, yolk-sac -derived macrophages of the CNS, undergo chronic activation promoting both beneficial and toxic effects upon the neuronal network. A great effort is thus now being established in elucidating the process of cell recruitment to the brain and signaling pathways underlying their activation throughout the inflammatory response to neurodegenerative pathologies.

We use the zebrafish, a leading model organism for developmental biology and human disease, as a vertebrate genetic model to study immune mechanisms in the progression of ischemic stroke and ALS. More specifically, we utilize established transgenic lines to track the migration and activation of microglia cells within the healthy vs diseased brain using state-of-the-art live cell imaging and image analysis. We analyze microglia role in synapse turnover and neuronal activity in SOD1 G93R model for ALS and in zebrafish model of ischemic stroke. Furthermore, to establish the signaling pathways underlying the immune response in the brain, genetic modifications are performed to determine the effect of distinct genes on the ischemic and neurodegenerative processes.

A high-throughput screening (HTS) system of zebrafish for the evaluation of potential ALS therapeutics.

Amyotrophic lateral sclerosis (ALS) is an incurable, progressive neurodegenerative disease affecting motor neurons. For rapid screening of potential drugs that will slow/inhibit the progression of the disease, a high-throughput system that will faithfully recapitulate the disease phenotype is required. Zebrafish models for ALS were generated and study results showed that they can complement existing mammal models. Transgenic zebrafish for the major ALS-linked gene superoxide dismutase 1 (SOD1), is utilized in our laboratory. We have established a high throughput screening platform that involves both behavioral and morphological aspects. Drug candidates are added to the water containing the embryos at different days before analysis. We screen libraries of compounds implicated in proper neural development and neuro-protection to be used potentially as a treatment for ALS mutations-carriers.

Dr. Sarit Aschkenazi-Polivoda

Research Assistant: Shiri Rotem

This interdisciplinary field studies fossil and living foraminifera as indicators of ancient and contemporary marine environments. Foraminifera are single-celled organisms that are very common in marine environments. They build calcareous shells that are a major component of marine sedimentary rocks and are well preserved in the geological record. Extensive distribution, rapid evolution and high sensitivity to environmental changes make them an important tool in strata dating and reconstruction of the history of ancient sea environments, as well as important indicators for the health of present ecosystems.

Paleo-ecology is a field within geology that uses fossils to reconstruct ancient ecosystems and environments (paleo = ancient). One of the most effective and useful organisms in paleo-ecology is foraminifera.

The Science Center conducts studies that focus on the history of Late Cretaceous rocks (90-65 mya), the reconstruction of ancient  environmental conditions (oxygen levels, temperature, food supply, etc.), the ecologic and oceanographic conditions during the deposition of rocks rich in organic matter (oil shale) in Israel, and characterization of the living conditions of species of foraminifera in different regions of the world (Texas, the Atlantic and Pacific Oceans). These reconstructions are accomplished by examining foraminifera assemblages and analyzing their stable isotopes. In addition to the environmental aspect, there is also an emphasis on the description and documentation of the various species of planktonic and benthic foraminifera that lived in our region during the Upper Cretaceous period. This information is particularly interesting considering the possible impact of anthropogenic pressures on marine communities over recent years.

Foraminifera are considered to be one of the most powerful tools for marine monitoring because of their sensitivity to environmental changes, anthropogenic influences, and temperature fluctuations. Currently, we are conducting several projects studying temperature changes in modern marine environments. In future we will establish a laboratory to cultivate foraminifera for conducting experiments.

Dr. Gidon Winters

Research Field: Seagrasses

This interdisciplinary research integrates ecology, physiology, remote sensing, GIS, and molecular biology.

Seagrasses are flowering plants that grow in shallow marine environments. The seagrasses evolved from terrestrial plants (i.e., plants with flowers, roots and seeds) that migrated back to the sea some 60-90 million years ago, probably because of rising sea levels. Seagrasses are important to marine ecology and are considered to be one of the most valuable habitats on the planet, valued at $M2.8/km²/yr. The ecological services associated with seaweed include high initial productivity, nutrient recycling and sediment fixation. Because of the high productivity and carrying capacity attributed to these habitats, seagrasses are considered keystone species that affect the environment. Loss of seagrasses not only lowers initial productivity and habitat diversity, but also harms the fishing industry, affecting economically significant fish and invertebrate species. In addition, their disappearance is linked with the accelerated erosional processes of many coasts.

Laboratory research focuses on:

1) Understanding the impact of climate change on seagrasses.

2) Developing indicators for early detection of seagrass stresses.

3) Mapping seagrasses using near and remote sensing.

4) Understanding the mechanisms that make seagrasses resilient to salinity.

These topics are studied in the field (Gulf of Eilat) and in the seagrass lab in Hazeva. Recently, a collaboration with researchers from Cyprus has been initiated; Israeli and Cypriot scientists are conducting a joint field study there.