Press releases

 

May 28 2015
12:31

Reconstruction of Arctic climate conditions in the Cretaceous period

The Arctic: Interglacial period with a break

FRANKFURT. Scientists at the Goethe University Frankfurt and at the Senckenberg Biodiversity and Climate Research Centre working together with their Canadian counterparts, have reconstructed the climatic development of the Arctic Ocean during the Cretaceous period, 145 to 66 million years ago. The research team comes to the conclusion that there was a severe cold snap during the geological age known for its extreme greenhouse climate. The study published in the professional journal Geology is also intended to help improve prognoses of future climate and environmental development and the assessment of human influence on climate change.

The Cretaceous, which occurred approximately 145 million to 66 million years ago, was one of the warmest periods in the history of the earth. The poles were devoid of ice and average temperatures of up to 35 degrees Celsius prevailed in the oceans. "A typical greenhouse climate; some even refer to it as a 'super greenhouse' ", explains Professor Dr. Jens Herrle of the Goethe University and Senckenberg Biodiversity and Climate Research Centre, and adds: "We have now found indications in the Arctic that this warm era 112 to 118 million years ago was interrupted for a period of about 6 million years."

In cooperation with his Canadian colleague Professor Claudia Schröder-Adams of the Carleton University in Ottawa, the Frankfurt palaeontologist sampled the Arctic Fjord Glacier and the Lost Hammer diapir locality on Axel Heiberg Island in 5 to 10 metre intervals. "In so doing, we also found so-called glendonites", Herrle recounts. Glendonite refers to star-shaped calcite minerals, which have taken on the crystal shape of the mineral ikaite. "These so-called pseudomorphs from calcite to ikaite are formed because ikaite is stable only below 8 degrees Celsius and metamorphoses into calcite at warmer temperatures", explains Herrle and adds: "Thus, our sedimentological analyses and age dating provide a concrete indication for the environmental conditions in the cretaceous Arctic and substantiate the assumption that there was an extended interruption of the interglacial period in the Arctic Ocean at that time."

In two research expeditions to the Arctic undertaken in 2011 and 2014, Herrle brought 1700 rock samples back to Frankfurt, where he and his working group analysed them using geochemical and paleontological methods. But can the Cretaceous rocks from the polar region also help to get a better understanding of the current climate change? "Yes", Herrle thinks, elaborating: "The polar regions are particularly sensitive to global climatic fluctuations. Looking into the geological past allows us to gain fundamental knowledge regarding the dynamics of climate change and oceanic circulation under extreme greenhouse conditions. To be capable of better assessing the current man-made climate change, we must, for example, understand what processes in an extreme greenhouse climate contribute significantly to climate change." In the case of the Cretaceous cold snap, Herrle assumes that due to the opening of the Atlantic in conjunction with changes in oceanic circulation and marine productivity, more carbon was incorporated into the sediments. This resulted in a decrease in the carbon dioxide content in the atmosphere, which in turn produced global cooling.

The Frankfurt scientist's newly acquired data from the Cretaceous period will now be correlated with results for this era derived from the Atlantic, "in order to achieve a more accurate stratigraphic classification of the Cretaceous period and to better understand the interrelationships between the polar regions and the subtropics", is the outlook Herrle provides.

Publication

Jens O. Herrle, Claudia J., Schröder-Adams, William Davis, Adam T. Pugh, Jennifer M. Galloway, and Jared Fath: Mid-Cretaceous High Arctic stratigraphy, climate, and Oceanic Anoxic Events, in: Geology, 19 Mai 2015, 10.1130/G36439.1 Open Access

http://geology.gsapubs.org/cgi/content/abstract/G36439.1v1

Pictures are available for download here: www.senckenberg.de/presse

Information:  Prof. Dr. Jens O. Herrle,  Senckenberg Biodiversity and Climate Research Centre, Faculty of Geoscience and Geography, Goethe University Frankfurt, Phone +49 (0)69 798 40180, jens.herrle@em.uni-frankfurt.de

 

May 21 2015
11:31

Two out of ten plastic rings release chemicals with hormone-like effect

Endocrine disrupting chemicals in baby teethers

FRANKFURT.     In laboratory tests, two out of ten teethers, plastic toys used to sooth babies’ teething ache, release endocrine disrupting chemicals. One product contains parabens, which are normally used as preservatives in cosmetics, while the second contains six so-far unidentified endocrine disruptors. The findings were reported by researchers at the Goethe University in the current issue of the Journal of Applied Toxicology.

"The good news is that most of the teethers we analyzed did not contain any endocrine disrupting chemicals.  However, the presence of parabens in one of the products is striking because these additives are normally not used in plastic toys", says Dr. Martin Wagner, of the Department Aquatic Ecotoxicology at the Goethe University. The substances detected – methyl, ethyl and propyl parabens – can act like natural oestrogen in the body and, in addition, inhibit the effects of androgens such as testosterone. The EU Commission recently banned two parabens in certain baby cosmetics, because of concerns over their health effects.

"Our study shows that plastic toys are a source of undesirable chemicals. Manufacturers, regulatory agencies and scientists should investigate the chemical exposure from plastic toys more thoroughly", Wagner concludes from the study. The additives have only limited benefits for the quality of the product, but can represent a potential health issue. This is especially true for babies and infants, whose development is orchestrated by a delicately balanced hormonal control and who are more susceptible to chemicals exposures than adults.

Publication:

Elisabeth Berger, Theodoros Potouridis, Astrid Haeger, Wilhelm Püttmann and Martin Wagner: Effect-directed identification of endocrine disruptors in plastic baby teethers, in: Journal of Applied Toxicology, 18.5.2015, DOI: 10.1002/jat.3159

Information:  Dr. Martin Wagner, Department Aquatic Ecotoxicology, Goethe University, Phone: +49 (0) 69 798-42149, wagner@bio.uni-frankfurt.de; Elisabeth Berger, Phone: +49 (0) 60516 1954-3117, elisabeth.berger@senckenberg.de

 

May 12 2015
12:54

Neurobiologist Amparo Acker-Palmer receives an ERC Advanced Grant of 2.5 million Euros for five years

How Do Neurons and Blood Vessels “Talk” to Each Other?

FRANKFURT. Neurons and blood vessels often traverse the body side by side, a fact observed as early as the 16th century by the Flemish anatomist Andreas Vesalius. Only over the last ten years, however, researchers have discovered that the growth of neuronal and vascular networks is controlled by the same molecules. Prof. Amparo Acker-Palmer, a pioneer in this area, performs groundbreaking research on the communication between neurons and blood vessel cells in the brain. She hopes to use her findings to gain important insights into brain diseases such as dementia and mental illness. The European Research Council will fund her project with an Advanced Investigator Grant of 2.5 million Euros over the next five years.

“Most interesting is the interaction between neurons and blood vessels in the cerebral cortex. To date, we know very little about how neurons communicate with endothelial cells in order to structure a functional network in the brain.” explains Acker-Palmer. She plans to assess these processes in the layering of the cerebral cortex during embryonic development. Here, neuronal cells migrate in an inside out manner, while blood vessels grow in the opposite direction, from the pial surface towards the ventricular surface. Since these two growth processes are coordinated, Acker-Palmer suspects that they are controlled by the same signaling molecules. How dysfunction in the crosstalk may lead to cognitive impairments is one of the focuses of her research.

As model organisms her team uses genetically altered mice and zebrafish. Translucent zebrafish are the best suitable vertebrate model to visualize in vivo the dynamic events of cell-to-cell communication at the neurovascular interface. High-resolution electron microscopes will also be used to study these close connections between endothelial cells in the blood capillaries and glial cells at the blood-brain barrier. Glial cells wrap around the blood capillaries and prevent harmful substances from the blood stream from entering the brain.. Acker-Palmer and her team aim at deciphering the molecular signaling pathways regulating the neurovascular interface. “If we can intervene in the mechanism and temporarily open the blood-brain barrier, we can insert active agents and find new approaches for treating dementia and mental illness,” says the neurobiologist.

Amparo Acker-Palmer, born in Sueca, Valencia, Spain in 1968, studied biology and biochemistry at the University of Valencia, where she obtained her PhD in 1996. Then she moved to the European Molecular Biology Laboratory (EMBL) in Heidelberg to perform her postdoctoral work. In 2001, she moved to Martinsried, near Munich, to head an independent junior research group on signal transduction at the Max Planck Institute for Neurobiology. In 2007, she became Professor at the “Macromolecular Complexes” Center of Excellence at the Goethe University Frankfurt. Acker-Palmer is the Chair of the Molecular and Cellular Neurobiology Department at Goethe University Frankfurt since 2011. She received a Gutenberg Research College (GRC) fellowship from Johannes Gutenberg University Mainz in 2012, and she one of the leading scientists in the Rhine-Main Neuroscience Network (rmn2). In 2014, Acker-Palmer joined the Max Planck Society as Max Planck Fellow at the MPI for Brain Research in Frankfurt. Amparo Acker-Palmer is member of the Leopoldina German Academy of Natural Scientists and the Academia Europaea. She received the Paul Ehrlich Award for Young Scientists in 2010.

Pictures are available for download here: www.uni-frankfurt.de/55539781

Captions

Prof. Amparo Acker-Palmer.

Mouse brain: The microscope image of a mouse brain illustrates the close interaction between neurons (green), astrocytes (blue), and blood vessels (red) in the brain. The various cell populations appear in a specific pattern and interact with the neighboring cells.

Zebrafish:  In vivo-Imaging of the blood circulation system in a three-day-old zebrafish larva. The left picture shows a side view of the head, the middle picture a side view of the trunk and the right picture a back view of the head. Fluorescent reporter genes reveal that the blood vessels (green) are fully formed at this point. The individual blood cells (red) can also be seen circulating in the blood vessels.

Information:  Prof. Amparo Acker-Palmer, Institute of Cellular Biology and Neuroscience, Buchmann Institute of Molecular Life Sciences, Campus Riedberg, Tel.: (069) 798-42563, Acker-Palmer@bio.uni-frankfurt.de.

 

May 12 2015
12:53

Biologist Stefanie Dimmeler receives an ERC Advanced Grant of 2.5 million Euros for five years

From Heart Attacks to Cancer: What Role Do Long, Non-Coding RNAs Play?

FRANKFURT. About 70 percent of our genes provide the blueprint for biomolecules whose function is only now being discovered – non-coding RNAs. Instead of being translated into proteins, they seem to perform steering functions in the body. Stefanie Dimmeler was one of the first researchers to prove that the sub-group of micro-RNAs plays a role in regenerating blood vessels. She has now received the coveted ERC Advanced Investigator Grant from the European Research Council (ERC), which will allow her to study another large group of non-coding RNAs. She believes that this group plays a role in creating heart attacks, strokes and cancer. ERC has awarded her 2.5 million Euros over the next five years.

“If you asked me what was special about the evolutionary development of human beings, I would say it´s the more than 30,000 non-coding RNA, most of which we only share with primates,” says Stefanie Dimmeler. From the perspective of her research area, cardiovascular regeneration, it is especially noteworthy that vascular illnesses like arteriosclerosis, which causes heart attacks, only occur in their typical form in humans. There are many indicators that long, non-coding RNAs, lncRNAs for short, control these illnesses. They affect the inside layer of the blood vessels, known as endothelial cells, and help supply the organs and tissues with oxygen and nutrients.

The technologies used to track these lncRNAs and their complex functions are much more complicated than finding proteins. Dimmeler and her working group identified two candidates, Angiolnc1 and Angiolnc2, that regulate the functions of endothelial cells. Now she wants to study the molecular epigenetic mechanisms that these two lncRNAs use to trigger vascular illnesses. The goal of this research is to identify new treatments for preventing arteriosclerosis, in order to reduce the incidence of heart attacks and strokes.

In the third part of her project, Dimmeler will study whether ring-shaped lncRNAs, which have special protection once they are released into the blood, can be used as biomarkers for identifying illnesses in the vascular system or the heart. To this end, she will work with her group to develop tests that can be used to find these biomolecules in patients’ blood during the various stages of cardiovascular illnesses.

Prof. Stefanie Dimmeler, born in 1967, studied Biology at the University of Constance, where she received her doctorate in 1993. After two years as a research assistant at the University of Cologne, she went to Goethe University, where she was promoted to professor in 1998 in the Department of Experimental Medicine. In 2001, she accepted a position as a professor in the Molecular Cardiology Department at Goethe University. She has been the Director of the Institute of Cardiovascular Regeneration, in the Center for Molecular Medicine, since 2008. She is the co-speaker of the DFG-funded “Cardiopulmonary Systems” Excellence Cluster, the “LOEWE Center for Cell and Genetic Therapy” funded by the State of Hesse, and the German Center for Cardiovascular Research (DZHK) funded by the German Ministry for Education and Research (BMBF) at the Rhine-Main site. She is a member of the Macromolecular Complexes Excellence Cluster as well as several specialized research areas. From 2008 to 2012, she was a member of the German Ethics Commission. Stefanie Dimmeler has received numerous research prizes, including the renowned Gottfried Wilhelm Leibniz Prize from the German Research Foundation and the Ernst Jung Prize for Medicine.

Pictures are available for download here: www.uni-frankfurt.de/55538604

Captions

Prof. Stefanie Dimmeler.

Blood vessels: An image of blood vessels in the heart (shown in red). The large vessel is surrounded by smaller vessels (capillaries). The nuclei are shown in blue, and the neurons are green.

Information:  Prof. Stefanie Dimmeler, Institute for Cardiovascular Regeneration, Niederrad Campus, Main Office: Claudia Herfurth, Tel.: (069) 6301-6667, herfurth@med.uni-frankfurt.de.

 

May 4 2015
16:59

Physicists in Frankfurt have found the long sought-after Efimov state in the helium trimer/ article published in Science

Quantum mechanical helium trio

FRANKFURT. A quantum state predicted by the Russian theoretician Vitaly Efimov 40 years ago has been discovered by physicists of the Goethe University in a molecule consisting of three helium atoms. The molecule is of enormous spatial extent and exists mainly in the classically forbidden tunneling region, explain the researchers in the current edition of the journal “Science”.

In 1970, Vitaly Efimov analysed a three-body quantum system in which the attraction between two bodies reduced such that they become unbound. His prediction was that instead of breaking up, the molecule consisting of three particles can support an infinite number of bound states with huge distances between the binding partners. "Every classical notion as to why such a structure remains stable fails here", explains Prof. Reinhard Dörner, head of the research group at the Institute for Nuclear Physics.

This counter-intuitive prediction led to the currently booming field of "Efimov physics". It soon became apparent that a system consisting of three helium atoms, a so-called trimer, would be the prime example of this quantum mechanical effect. But all experiments conducted to prove the existence of the gigantic, extremely weakly bound helium system failed.

In 2006, physicists at the University of Innsbruck first found indirect indications of Efimov systems in cold quantum gases of caesium atoms. In the atom traps they used, the interaction between the particles can be externally controlled. Efimov systems, however, as soon as they appear, are ejected from the artificial environment of the trap and fall apart unseen.

The Frankfurt physicist Dr. Maksim Kunitski, of the research group of Prof. Dörner has now produced a stable Efimov system consisting of three helium atoms, by pressing gaseous helium at a temperature of only eight degrees above absolute zero through a tiny nozzle  into a vacuum. In this ultracold molecular beam, helium molecules with two, three or more helium atoms are formed. By diffraction of the molecular beam at a super-fine transmission grating, the physicist was able to spatially separate the trimers.

The researchers created an exploded view of this Efimov state which directly show the structure of and, in particular, the distances between the atoms in the trimer. They ionized each helium atom of the molecule with the help of a laser beam. Due to the electrostatic repulsion, the now triply positively charged trimer broke apart explosively. Subsequently, using the COLTRIMS microscope developed at the Goethe University, researchers measured the momenta of the helium ions in three-dimensions, which allowed to reconstruct the geometry of the trimer. 

In collaboration with the theoretician Doerte Blume of Washington State University in the USA, Maksim Kunitski found out that only one of the many possible Efimov states had in fact occurred naturally in the molecular beam. The distances between bonds in the huge molecule extend to more than 100 angstroms (compared to a mere two angstroms in a water molecule). Thereby, the helium atoms do not form an isosceles triangle, but are arranged asymmetrically. That correlates well with the theoretical predictions that have already existed for many years.

"This is the first stable Efimov system that has ever been discovered. The three-body system flies through the laboratory inside the vacuum chamber without further interaction and without the need for external fields", Dörner explains. "Maksim Kunitski has conducted this ground breaking work in a laser laboratory at the Goethe University Frankfurt. He did not need a big machine to accomplish this."

"The Efimov state is not an exotic special case, but rather an example of a universal quantum effect that plays an essential role in many areas of physics", Kunitski explains. Examples of this are cold atoms, clusters, nuclear physics and recently also solid-state physics. Moreover, there are also first reports about its significance in biology.

Reinhard Dörner could afford to tackle a research project that was so risky with respect to its prospects of success because in 2009 the German Research Foundation (DFG) made 1.25 million Euros available as part of its Koselleck programme. "It was a rather bold plan", says Dörner in retrospect, "but now, at the end of the project and really only because the DFG provided me with this large amount for a risky project without detailed planning – the search was successful."

Publication:

M. Kunitski et al.: Observation of the Efimov state of the helium trimer, in Science, 1. Mai 2015, DOI: 10.1126/science.aaa5601

You can find images for downloading at: link

Captions:

1)  Efimov trimer in a gas beam of other particles.  The three helium atoms form an acute triangle, their distance from the quantum cloud, shown in yellow, amounts to a hundredfold of the size of the atoms.    

2) Dr. Maksim Kunitski at the Frankfurt COLTRIMS microscope with which he discovered the Efimov state of the helium trimer.

Information: Prof. Reinhard Dörner, Institut für Kernphysik, Campus Riedberg, Phone +49 (0)69 798-47003, doerner@atom.uni-frankfurt.de.