Press releases

 

Nov 29 2018
08:27

The exchange of water between the North and South Atlantic became significantly larger fifty-nine million years ago

Scientists discover how the Atlantic Ocean became part of the global circulation at a climatic tipping point

A team of scientists, led by Dr Sietske Batenburg at the University of Oxford’s Department of Earth Sciences, in close collaboration with Goethe University and other German and UK institutions, have discovered that the exchange of water between the North and South Atlantic became significantly larger fifty-nine million years ago. 

The scientists made this discovery when they compared neodymium isotope signatures of deep sea sediment samples from both regions of the Atlantic. Their paper – ‘Major intensification of Atlantic overturning circulation at the onset of Paleogene greenhouse warmth’ – published today in Nature Communications, reveals that the more vigorous circulation together with an increase in atmospheric CO2 led to a climatic tipping point. With a resulting more even distribution of heat over the earth, a long-term cooling phase ended and the world headed into a new greenhouse period. 

Neodymium (Nd) isotopes are used as a tracer of water masses and their mixing. Surface waters acquire a Nd-isotope signature from surrounding land masses through rivers and wind-blown dust. When surface waters sink to form a deep-water mass, they carry their specific Nd-isotope signature with them. As a deep-water mass flows through the ocean and mixes with other water masses, its Nd-isotope signature is incorporated into sediments. Deep sea sediments are valuable archives of ocean circulation and past climates.

The story revealed in this paper begins at the end of the Cretaceous period (ending 66 million years ago), when the world was between two greenhouse states. Climate had been cooling for tens of millions of years since the peak hothouse conditions of the mid-Cretaceous, around 90 million years ago. Despite long-term cooling, temperatures and sea level at the end of the Cretaceous period were higher than at present day.

Dr Sietske Batenburg says: ‘Our study is the first to establish how and when a deep-water connection formed. At 59 million years ago, the Atlantic Ocean truly became part of the global thermohaline circulation, the flow that connects four of the five main oceans.’

The Atlantic Ocean was still young, and the North and South Atlantic basins were shallower and narrower than today. The equatorial gateway between South America and Africa only allowed a shallow, surface-water connection for much of the late Cretaceous period. Active volcanism formed underwater mountains and plateaus that blocked deep-water circulation. In the South Atlantic, the Walvis Ridge barrier formed above an active volcanic hotspot. This ridge was partially above sea level and formed a barrier for the flow of deep-water masses.

As the Atlantic Ocean continued to open, the oceanic crust cooled and subsided. Basins became deeper and wider, and submarine plateaus and ridges sank, along with the crust. At some point, deep water from the Southern Ocean was able to flow north across the Walvis Ridge and fill the deeper parts of the Atlantic basins.

From 59 million years ago onwards, Nd-isotope signatures from the North and South Atlantic were remarkably similar. This may indicate that one deep-water mass, likely originating from the south, made its way through the Atlantic Ocean and filled the basin from deep to intermediate depths. The enhanced deep water exchange, together with increasing atmospheric CO2, may have enabled a more efficient distribution of heat over the planet.

This study shows that to understand the role of ocean circulation in past greenhouse climates, it is important to understand the different roles of geography and climate.

The current rate of climate change by CO2 emissions from human activity by far surpasses the rate of warming during past greenhouse climates. Studying ocean circulation during the most recent greenhouse interval in the geologic past may provide clues as to how ocean circulation might develop in the future, and how heat will be distributed over the planet by ocean currents.

This research is the result of an international collaboration with the Goethe-University Frankfurt; the Ruprecht-Karls-University of Heidelberg; the GEOMAR Helmholtz Centre for Ocean Research Kiel; the Federal Institute for Geosciences and Natural Resources in Hannover; the Royal Holloway University of London and the University of Oxford.

The sediments for this study were all taken from long ocean drill cores. The International Ocean Discovery Program (IODP) coordinates scientific expeditions to drill the ocean floor to recover these sediments, and stores the sediment cores so that they are available to the whole scientific community.

Publication: S.J. Batenburg, S. Voigt, O. Friedrich, A.H. Osborne, A. Bornemann, T. Klein1, L. Pérez-Díaz und M. Frank: Major intensification of Atlantic overturning circulation at the onset of Paleogene greenhouse warmth, in: Nature Communications, DOI: 10.1038/s41467-018-07457-7

Images may be downloaded at: www.uni-frankfurt.de/74972308; Credit: Sietske Batenburg

Further information: Professor Silke Voigt, Institute for Geosciences, Geology, Riedberg Campus, Tel.: +49 69 798-40190, s.voigt@em.uni-frankfurt.de.

 

Nov 26 2018
11:41

Surprising discovery of a chimeric protein that combines both ion pump and ion channel

How does potassium enter cells?

FRANKFURT. For decades it was assumed that protein channels and protein pumps fulfilled completely different functions and worked independently of each other. Researchers at Goethe University Frankfurt and University Groningen have now elucidated the transport path of a protein complex that combines both mechanisms: it first receives potassium from the channel and then transfers it to the pump, from where it is transported to the cell. 

A balanced potassium household is critical for the survival of both people and bacteria. As bacteria are exposed to much greater fluctuations in environmental conditions, the controlled intake of potassium often poses a particular challenge. Since the cell membrane is impenetrable for potassium ions, it has to be translocated through specific membrane transport proteins. 

On the one hand, potassium channels enable the rapid, but passive influx of potassium ions. This stops as soon as an electrochemical equilibrium between the cell and its environment has been reached. To attain intracellular concentrations beyond this, potassium is transported into the cell actively through potassium pumps, with energy being consumed in the form of ATP.

Since both protein families – channels and pumps – carry out very different functions, they have always been described as separate from each other. This, however, is contradicted by the observation that KdpFABC, a highly affine, active potassium uptake system of bacteria, does not represent a simple pump, but is constructed of a total of four different proteins. One of these is derived from a typical pump, while another one resembles a potassium channel.

Inga Hänelt, Assistant Professor for biochemistry at Goethe University, and her colleague Cristina Paulino from University of Groningen, the Netherlands, therefore decided to take a closer look at the membrane protein KdpFABC through the microscope – or, more specifically, the cryo-electron microscope. They were surprised by the result: “All earlier hypotheses were wrong,” states Inga Hänelt. “Although we had all the data in front of us, it took us a while to understand the pathway potassium takes through the complex into the cell.”

First, a channel-like protein binds the potassium and transports it through the first tunnel to the pump. Once it has arrived, the first, outward-facing tunnel closes, while a second, inward-facing tunnel opens. This tunnel also extends between both proteins and ultimately ends in the interior of the cell. “The complex essentially combines the best qualities of both protein families,” explains Charlott Stock, doctoral candidate in Inge Hänelt’s research group. “The channel-like protein binds potassium, at first very specifically and with high affinity, while the pump enables an active transport that can enrich potassium in the cell by 10,000-fold.”

The data, recently published in Nature Communications, impressed the scientists with how diverse transport through membranes can be. “We have learned that when investigating various membrane transport proteins, we shouldn’t rely on seemingly incontrovertible mechanisms, but have to be ready for surprises,” summarises Inga Hänelt.

Publication:Charlott Stock, Lisa Hielkema, Igor Tascon, Dorith Wunnicke, Gert T. Oostergetel,  Mikel Azkargorta, Cristina Paulino, Inga Hänelt, Cryo-EM structures of KdpFABC suggest a K+ transport mechanism via two inter-subunit half-channels, in: Nature Communications, 10.1038/s41467-018-07319-2 

An image may be downloaded at: www.uni-frankfurt.de/75137139
Caption: Outward and inward opening structures of KdpFABC in the cell membrane. Credit: Inga Hänelt research group.

Further information: Dr. Inga Hänelt, Institute for Biochemistry, Faculty 14, Riedberg Campus, Telephone: +49 69 798-29262, haenelt@biochem.uni-frankfurt.de 

 

Nov 21 2018
09:18

Friedrich Merz Visiting Professor Donald Ingber cultivates miniature organs on microchips

What are the alternatives to animal testing?

FRANKFURT. How predictive are animal models for the human body? Which human organs can be recreated in vitro? How can personalized medicine benefit from patient-specific organ systems in the future? These questions are the focus of this year’s Friedrich Merz Visiting Fellowship Endowment with Donald Ingber, who will visit Goethe University from Harvard University for one week at the beginning of December. Ingber develops miniature, living organ systems of human cells for investigating diseases and testing new therapies. 

The bioengineering expert developed methods for engineering living human cells on microchips as miniature, three-dimensional organs. These models often deliver more precise results than animal tests, whose predictability for the human body is limited. In addition, they represent a trendsetting option for testing novel drug substances in the laboratory. In cancer therapy, patient-specific tumor cells are cultivated in vitro in order to find a personalized and effective treatment of the individual cancerous disease. 

Professor Ingber and Professor Maike Windbergs, who investigates alternatives to animal testing at Goethe University, will present these fascinating new approaches in a clear and understandable way using film material and examples from research and clinical practice in a podium discussion for the general public

Podium discussion: Human organs and diseases in vitro – fiction or realistic alternative to animal testing?
When: 6th December (Thursday) at 6:00 pm
Where: the Arkadensaal at Goethe House, Großer Hirschgraben 23-25, 60311 Frankfurt. 

Additional podium guests include State Animal Welfare Officer for Hessen Dr. Madeleine Martin and Merz Chief Scientific Officer Dr. Stefan Albrecht. Merz is among the pioneers in the development of in vitro tests for Botolinum toxin.

In a symposium on Wednesday 5th December, international experts will discuss “Modelling health and diseases; form in vitro design to future therapies” (Location: Biozentrum, Riedberg Campus, Hörsaal B1, 9 am – 5 pm). The experts include Professor Andries von der Meer from the Twente University in Enschede, Netherlands. He designs artificial blood vessels on chips and uses them to replicate the process of thrombosis. Professor Ernst Reichmann from the Children’s Clinic in Zurich will present clinical studies on the development of artificial skins for burn victims. The presentation by Professor Stefan Hippenstiel from the Charité in Berlin will discuss the use of human lung tissue to simulate infections in the lung.

Goethe University will be represented by the following experts: Professor Florian Greten, Speaker of the Frankfurt Cancer Institute, who will talk about the use of test systems with human cancer cells for preclinical substance tests and in personalized medicine. Dr. Manuel Kaulich from the Institute for Biochemistry II will report on how he uses the gene scissors CRISPR/Cas for the large-scale screening of substances in order to counter resistances in cancer treatment. Professor Ernst Stelzer from the Buchmann Institute for Molecular Life Sciences at Goethe University and his research group investigates spheroids based on pancreatic cells to test new therapies for type I diabetes. For the first time, three young postdoctoral students in pharmacy and medicine will introduce their work in brief presentations.

Donald Ingber will also give a lecture for students on 6th December at 10:00 am on the same topics (location: Otter-Stern-Centre, Riedberg Campus, HS 3). It will be followed by a one-hour discussion with questions prepared by pharmacy students in their 8th semester.

Professor Donald Ingber is founding director of the Wyss Institute for Biologically Inspired Engineering at Harvard University. Tissue engineering is just one of his many areas of research, which also encompass mechanobiology, tumor angiogenesis, systems biology and nanobiotechnology and translational medicine. He has received numerous awards for his creative ideas. In 2015, the journal “Foreign Policy” elected him as “Leading Global Thinker” and his “Organ-on-the-Chip” technology was awarded “Design of the Year” by the London Design Museum. Ingber holds 150 patents and has founded five companies.

Members of the press will have the opportunity to interview Donald Ingber and other experts on the day of the symposium (5th December). Please contact Professor Maike Windbergs for scheduling: +49 (0) 69 798-42715, windbergs@em.uni-frankfurt.de .

Further information: Professor Maike Windbergs, Institut für Pharmazeutische Technologie, Faculty 14, Riedberg Campus, Tel.: +49 (0) 69 798-42715, windbergs@em.uni-frankfurt.de.
http://www.uni-frankfurt.de/Friedrich-Merz-Stiftungsgastprofessur

 

Nov 19 2018
10:15

Successful cooperation between De Gruyter, the FID Jewish Studies (Specialized Information Services Program) and Knowledge Unlatched Frankfurt/Berlin

Open Access: 20 Titles from the field Jewish Studies now openly accessible

FRANKFURT/BERLIN. The Fachinformationsdienst (FID) Jewish Studies and De Gruyter present 20 titles from the field of Jewish Studies Open Access. The e-books have been made openly accessible through Knowledge Unlatched and its "KU Reverse" model. The title list contains important works from the fields of history, Jewish studies and literature, including fundamental works such as the "Handbuch der deutsch-jüdischen Literatur" (Handbook of German-Jewish Literature) edited by Hans Otto Horch and "Die Sprache der Judenfeindschaft im 21. Jahrhundert" (The Language of Antisemitism in the 21st Century) by Monika Schwarz-Friesel and Jehuda Reinharz. The titles can be accessed on Open Access portals such as OAPEN and library catalogues. Together with other freely accessible ebooks, the 20 titles can be found on the publisher's website.

The FID Jewish Studies at the JCS University Library Frankfurt/Main is directed by Dr. Rachel Heuberger and has replaced the former special collections "Science of the Jews" and "Israel". The aim is to provide the specialist community with research-relevant literature, but also to develop innovative research tools. "The free provision of these titles was particularly important to us, as they are used by our scientists in cooperation with other institutions all over the world. The acquisition barrier has previously made academic work more difficult," says Dr. Rachel Heuberger, head of FID Jewish Studies at Frankfurt University Library.

"The cooperation with FID Jewish Studies is a promising start for us to further expand Open Access in this programme segment. We look forward to continuing to work constructively on new models in future in dialogue with our partners in order to promote the idea of free accessibility and easy retrieval of scientific results," says Martin Rethmeier, Editorial Director History at De Gruyter.

Further information:
FID Jewish Studies: Dr. Rachel Heuberger Head of FID Jewish Studies Phone: +49 69 798 39665 r.heuberger@ub.uni-frankfurt.de www.jewishstudies.de
De Gruyter Eric Merkel-Sobotta Communications Phone: +49 30 260 05 304 mailto:ems@degruyter.com www.degruyter.com 
Knowledge Unlatched: Philipp Hess Phone: +49 176 239 230 94 philipp@knowledgeunlatched.org; www.knowledgeunlatched.org

FID Jewish Studies: The Fachinformationsdienst Jüdische Studien der Frankfurter Universitätsbibliothek (Jewish Studies Special Information Service of the Frankfurt University Library) provides subject-specific information as well as electronic and printed resources for science and research. The search portal (www.jewishstudies.de) offers central access to the entire spectrum of Jewish Studies / Israel Studies and thus enables optimal research.

De Gruyter: De Gruyter has been publishing first-class scientific works for over 260 years. The international publishing house is headquartered in Berlin and has further offices in Boston, Beijing, Basel, Warsaw, Vienna and Munich. De Gruyter publishes over 1,300 new book titles and more than 900 journals annually in the humanities, social sciences, medicine, mathematics, technology, computer sciences, natural sciences and law, and also offers a wide range of digital media. The publishing group includes the imprints De Gruyter Akademie Forschung, Birkhäuser, De Gruyter Mouton, De Gruyter Oldenbourg, De Gruyter Saur, De|G Press, Deutscher Kunstverlag (DKV), Düsseldorf University Press and the publishing service provider Sciendo. For further information, please visit: www.degruyter.com.

Knowledge Unlatched: Knowledge Unlatched (KU) is committed to free access to academic content for readers around the world. The KU online platform serves as a central point of contact for libraries worldwide to support Open Access models, publication collections of leading publishing houses, and new Open Access initiatives. For more information, please visit: http://www.knowledgeunlatched.

 

Nov 12 2018
08:57

The cosmochemist Professor Alexander Krot (University of Hawaii) is coming to Goethe University as recipient of the Humboldt Research Award

Improving understanding of how the solar system is formed

FRANKFURT. The observatory on Mauna Kea in Hawaii is world-famous. Less well-known is the fact that the Hawaiian Islands are home to one of the leading institutes for cosmochemistry, the Institute for Geophysics and Planetology (HIGP). One of its scientists is the renowned cosmochemist Professor Alexander Krot, and he is now coming to Goethe University for half a year as Humboldt researcher. 

Professor Frank Brenker, geophysicist at Goethe University has been working successfully with Professor Alexandor Kort for years. This gave Krot the impetus to temporarily take leave from his Institute for Geophyscis and Planetology (HIGP) on Hawaii, where a large number of powerful measuring instruments are at his disposal for the examination of extraterrestrial material. As recipient of the Humboldt Research Award he will be working in Frankfurt am Main for six months. 

At the Institute for Geosciences at Goethe University, Krot will be working both in teaching and research. He is especially interested in nanoscale analytical methods using transmission electron microscopy and synchrotron radiation, an area in which Frank Brenker specializes. 

Alexander Krot made a particular name for himself through his work on the formation of the first solid bodies of our solar system. Numerous fundamental insights into the childhood of the solar nebula are based on his research. With more than 160 publications, of which 14 are in “Nature” or “Science”, his scientific body of work is impressive. 

Krot is not only one of the most influential and successful researchers in the area of cosmochemistry, the science of the formation and distribution of chemical elements and compounds in the solar system – he is also an excellent teacher. He can now pass on his knowledge directly in several bachelor and master projects at the same time. “It’s a unique opportunity for our students to be able to work with such an internationally successful researcher this early in their careers,” reports Brenker with pleasure. “Some of them are already familiar with Mr. Krot from his many groundbreaking publications, and it is naturally exciting for them to now be able to discuss things directly with him.”

Images to download can be found at: http://www.uni-frankfurt.de/74667310
Captions:
Image1: Prof. Dr. Alexander Krot (Copyright: Krot)
Image 2: Off-colour image with magnesium in red, calcium in green, and aluminum in blue. This colour selection was introduced by Alexander Krot for an optimal depiction of the early formations in the solar system. Pictured here is a calcium-aluminum-rich inclusion in the meteorite Efremovka. CAIs are the oldest solid body formation in our solar system. They are 4.567 billion years old, the same age as our solar system. (Copyright: Krot)
Image 3: An artist’s depiction of the solar nebula. (Copyright: NASA/JPL)

Further information: Professor Frank Brenker, Institute for Geosciences, Mineralogy, Riedberg Campus, Tel.: +49(0)69 798-40134, f.brenker@em.uni-frankfurt.de