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Marketing gag of the “Domaine du Météore” winery turns out to be a real impact crater – Researchers at Goethe University Frankfurt led by Frank Brenker and Andreas Junge disprove science’s decades-old mistake
With the aim of creating an appealing brand, the name of the “Domaine du Météore" winery near the town of Béziers in Southern France points to a local peculiarity: one of its vineyards lies in a round, 200-meter-wide depression that resembles an impact crater. By means of rock and soil analyses, scientists led by cosmochemist Professor Frank Brenker from Goethe University Frankfurt have now established that the crater was indeed once formed by the impact of an iron-nickel meteorite. In doing so, they have disproved a scientific opinion almost 60 years old, because of which the crater was never examined more closely from a geological perspective.
FRANKFURT. Countless meteorites have struck Earth in the past and shaped the history of our planet. It is assumed, for example, that meteorites brought with them a large part of its water. The extinction of the dinosaurs might also have been triggered by the impact of a very large meteorite.
Meteorite craters that are still visible today are rare because most traces of the celestial bodies have long since disappeared again. This is due to erosion and shifting processes in the Earth's crust, known as plate tectonics. The “Earth Impact Database" lists just 190 such craters worldwide. In the whole of Western Europe, only three were previously known: Rochechouart in Aquitaine, France, the Nördlinger Ries between the Swabian Alb and the Franconian Jura, and the Steinheim Basin near Heidenheim in Baden-Württemberg (both in Germany). Thanks to millions of years of erosion, however, for laypersons the three impact craters are hardly recognizable as such.
Geologist and cosmochemist Professor Frank Brenker from Goethe University Frankfurt is convinced: the new meteorite crater will now extend the list. While on holiday, the “Domaine du Météore" winery caught his attention. One of its vineyards lies in a round depression about 220 metres in diameter and 30 meters deep, and the proprietors use the scientific hypothesis that it is the impact crater of a meteorite – seemingly long disproved – as a marketing gag for their wine. Although this hypothesis was proposed by several geologists in the 1950s, it was dismissed by acclaimed colleagues a few years later.
Frank Brenker explains: “Craters can form in many ways, and meteorite craters are indeed very rare. However, I found the various other interpretations of how this depression could have formed unconvincing from a geological perspective." That is why he and his wife collected rock samples for analysis in the labs at Goethe University – and indeed found the first signs of an impact crater. Brenker: “The microanalysis showed that dark-colored layers in one of the shists, which usually simply comprise a larger percentage of mica, might be shock veins produced by the grinding and fracturing of the rock, which in turn could have been caused by an impact." He also found evidence of breccia, angular rock debris held together by a kind of “cement", which can also occur during a meteorite impact.
The following year, Brenker took his colleague Andreas Junge, Professor of Applied Geophysics at Goethe University, and a group of students with him to Southern France to examine the crater in detail. They discovered that Earth's magnetic field is slightly weaker in the crater than in the surrounding area. This is typical for impact craters because the impact shatters or even melts the rock, which can thus contribute less to Earth's magnetic field.
With the help of strong magnets attached to a plate, the researchers also found tiny iron oxide spherules of up to one millimeter in diameter. Such spherules had already been found in other impact craters. Later laboratory analysis showed that the ones here also contained nickel-bearing iron and encased a core of minerals typical for the crater environment. In addition, the researchers discovered numerous shock microdiamonds produced through the high pressure during the meteorite's impact.
Frank Brenker explains: “Such microspheres form either through abrasion of the meteorite in the atmosphere or only upon impact, when a large part of the iron meteorite melts and then reacts with the oxygen in the air. On impact, material shattered at the point of impact might then also be encased. This, together with the lower magnetic field and the other geological and mineralogical finds, allows us to draw hardly any other conclusion: a meteorite did indeed strike here." This makes the crater very exciting for geological laypeople too, says Brenker, because “every visitor can experience here the immense energies released upon such an impact."
Publication/Abstract: Frank E. Brenker, Andreas Junge. Impact origin of the “Domaine du Meteore"-crater, France. Compelling mineralogical and geophysical evidence for an unrecognized destructive event in the heart of Europe. LPSC Houston, #1910 (2023) https://www.hou.usra.edu/meetings/lpsc2023/pdf/1910.pdf
Picture download: https://www.uni-frankfurt.de/132616835
1. The “Trou du Météore": The crater at the “Domaine du Météore" winery really was caused by a meteorite impact. Photo: Frank Brenker, Goethe University Frankfurt
2. Microsphere from the meteorite: The iron oxide spherule found in the “Domaine du Météore" crater has a core composed of minerals typical for the crater environment and also contains a large number of microdiamonds. Photo: Frank Brenker, Goethe University Frankfurt
Professor Frank E. Brenker
NanoGeoscience / Cosmochemistry
Institute for Geosciences
Goethe University Frankfurt
Tel.: +49 151 68109472
Editor: Dr. Markus Bernards, Science Editor, PR & Communication Office, Tel: -49 (0) 69 798-12498, firstname.lastname@example.org
Goethe University’s Provincial Roman Archaeology department disproves previous assumptions during teaching excavation in Bad Ems
In their search for silver ore, the Romans established two military camps in the Bad Ems area near Koblenz in the 1st century AD. This is the result of research carried out as part of a teaching excavation that spanned several years and was carried out by Goethe University's Department of Archaeology and History of the Roman Provinces in cooperation with the federal state of Rhineland-Palatinate. Several surprising findings were made during the process. For one, the exciting research story earned young archaeologist Frederic Auth first place at the Wiesbaden Science Slam.
FRANKFURT: When Prof. Markus Scholz, who teaches archaeology and the history of Roman provinces at Goethe University, returned to Bad Ems toward the end of the excavation work, he was astonished: After all, all the photos sent by his colleague Frederic Auth showed but a few pieces of wood. Not surprisingly, Scholz was ill-prepared for what he saw next: a wooden defense construction consisting of sharpened wooden stakes, designed to prevent the enemy's approach. The martial-looking structure was intended to deter enemies from attacking the camp. Such installations – comparable, if you will, to modern barbed wire – are referenced to in literature from the time. Caesar, for instance, mentioned them. But to date, none had been found. The damp soil of the Blöskopf area obviously provided the ideal conditions: The wooden spikes, which probably extended throughout the entire downward tapering ditch around the camp, were found to be well preserved.
Two previously undiscovered Roman military camps
The work of the Frankfurt archaeologists and Dr. Peter Henrich of the General Directorate for Cultural Heritage of the German federal state of Rhineland-Palatinate, uncovered two previously unknown military camps in the vicinity of Bad Ems, situated on both sides of the Emsbach valley. The excavations were triggered by observations made by a hunter in 2016, who, from his raised hide, spotted color differences in the grain field, indicating the existence of sub-surface structures. A drone photo of the elevation, which bears the beautiful name "Ehrlich" (the German word for “honest"), confirmed the thesis: the field was crisscrossed by a track that could have originated from a huge tractor. In reality, however, it was a double ditch that framed a Roman camp. Geomagnetic prospecting later revealed an eight-hectare military camp with about 40 wooden towers. The archaeological excavations, carried out in two campaigns under the local direction of Dr. Daniel Burger-Völlmecke, revealed further details: the camp, apparently once intended as a solid build, was never completed. Only one permanent building, consisting of a warehouse and storeroom, was located there. The 3,000 soldiers estimated to have been stationed here probably had to sleep in tents. Burn marks show that the camp was burned down after a few years. But why?
It was the student team, led by Frederic Auth, that identified the second, much smaller camp, located some two kilometers away as the crow flies, on the other side of the Emsbach valley. The "Blöskopf" is no blank slate when it comes to archaeology: Exploratory excavations carried out in 1897 uncovered processed silver ore, raising the assumption that a Roman smelting works was once located there. The thesis was further supported by the discovery of wall foundations, fire remains and metal slag. For a long time it was assumed that the smelting works were connected to the Limes, built some 800 meters to the east at around 110 AD. These assumptions, considered valid for decades, have now been disproved: The supposed furnace in fact turned out to be a watchtower of a small military camp holding about 40 men. It was probably deliberately set on fire before the garrison left the camp. The spectacular wooden defense structure was discovered on literally the penultimate day of the excavations – along with a coin minted in 43 AD, proof that the structure could not have been built in connection with the Limes.
Roman tunnels located above the silver deposit
But why did the Romans fail to complete the large camp, instead choosing to abandon both areas after a few years? What were the facilities used for? Archaeologists have found a possible clue in the writings of historian Tacitus: He describes how, under Roman governor Curtius Rufus, attempts to mine silver ore in the area failed in 47 AD. The yield had simply been too low. In fact, the team of Frankfurt archaeologists was able to identify a shaft-tunnel system suggesting Roman origins. The tunnel is located a few meters above the Bad Ems passageway, which would have enabled the Romans to mine silver for up to 200 years – that is, if only they had known about it. In the end, the silver was mined in later centuries only. The Romans' hope for a lucrative precious metal mining operation also explains the military camp's presence: They wanted to be able to defend themselves against sudden raids – not an unlikely scenario given the value of the raw material. "To verify this assumption, however, further research is necessary," says Prof. Scholz. It would be interesting to know, for example, whether the large camp was also surrounded by obstacles meant to hinder an enemy approach. So far, no wooden spikes have been found there, but traces could perhaps end up being discovered in the much drier soil.
Silver mining reserved for later centuries
The fact that the Romans abruptly abandoned an extensive undertaking is not without precedent. Had they known that centuries later, in modern times, 200 tons of silver would be extracted from the ground near Bad Ems, they might not have given up so quickly. The soldiers who were ordered to dig the tunnels obviously had not been too enthusiastic about the hard work: Tacitus reports that they wrote to Emperor Claudius in Rome, asking him to award the triumphal insignia to the commanders in advance so they would not have to make their soldiers slave away unnecessarily.
All considered, an exciting research story, which Frederic Auth, who has led the excavations in Bad Ems since 2019, also knows how to recount in an exciting way. His account won first prize in an interdisciplinary field of applicants at the 21st Wiesbaden Science Slam in early February. The young archaeologist is already booked for further appearances: Auth will perform in Heidelberg on March 2, in Bonn on March 7, and in Mannheim on March 19. More information about the events can be found at: https://www.science-slam.com/ (in German).
The research in Bad Ems was carried out jointly with the Directorate of State Archaeology in the General Directorate for Cultural Heritage of Rhineland-Palatinate, the Institute of Prehistory and Early History at the University of Erlangen-Nuremberg, and the Berlin University of Applied Sciences. Also involved were the hunter and honorary monument conservator Jürgen Eigenbrod and his colleague Hans-Joachim du Roi, as well as several metal detectorists with the necessary permits from the historical monument authorities. The project was financed with support from the Gerhard Jacobi Stiftung, the Society for Archaeology on the Middle Rhine and Moselle, and the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG). The wooden spikes have meanwhile been preserved at the Römisch-Germanisches Zentralmuseum in Mainz.
Publication: A monograph on the archaeological excavations in Bad Ems is currently being prepared.
Images for download: https://www.uni-frankfurt.de/132551146
Image 1: "Tractor Tracks". The excavations in Bad Ems were initiated by J. Eigenbrod, who spotted suspicious traces in the field from his high seat. The traces constitute changes in the vegetation, indicating ground interventions, in this case the ditches of the Roman camp on the "Ehrlich" (Photo: H.-J. du Roi)
Image 2: The geomagnetic prospection confirms the assumption that traces of the former usage of the “Ehrlich" hill would be found under the fields in the soil. (Photo: C. Mischka, FAU Erlangen-Nuremberg).
Image 3: The big surprise for the archaeologists unfolded during the last days of the excavation campaign: A construction of wooden spikes had been preserved in the damp soil of the "Blöskopf" hill, meant to deter potential attackers. (Photo: Auth)
Image 4: Although Caesar had told of comparable obstacles meant to deter the enemy's approach, so far no physical evidence of their existence had been found. For the most part, the wooden defensive constructions did not survive the test of the centuries. (Photo: Auth)
Image 5: Winner among the interdisciplinary field of applicants at the 21st Wiesbaden Science Slam: Goethe University's archaeologist Frederic Auth (3rd from left) with moderator Rainer Holl (from left) and science slammers Maria Bruhnke, Christopher Synatschke, Nina Lanzer and Uwe Gaitzsch. (Photo: science-slam.com)
Prof. Markus Scholz
Archaeology and History of the Roman Provinces
Institute for Archaeological Sciences, Department II
Tel. +49 (0)69 798 32265
Fax +49 (0)69 798 32268
Editor: Dr. Anke Sauter, Science Editor, PR & Communication Office, Tel: +49 (0)69 798-13066, Fax: +49 (0) 69 798-763 12531, email@example.com
Frankfurt microbiologist honored as "Class of 2023 Fellow"
Prof. Volker Müller, a microbiologist at Goethe University Frankfurt, is one of three Germans and a total of 65 scientists from around the world who have now been inducted as fellows into the American Society for Microbiology's (ASM) Academy, the professional society announced. With some 30,000 members, the ASM is one of the world's largest scientific associations in the life sciences. The Academy is ASM's think tank and honorary governing body, and each year appoints 65 excellent microbiologists as fellows.
FRANKFURT Outstanding achievements in their field and a strong commitment to teaching and mentoring – these are the criteria employed by the jury of senior scientists from the American Society for Microbiology to select 65 fellows from among the 148 high-caliber nominations from basic and applied research, teaching, public health, and industry.
Goethe University President Prof. Enrico Schleiff congratulated the new fellow, saying: "In the past year alone, Volker Müller has attracted the scientific community's attention with his high-profile work on the fixation of the greenhouse gas CO2 using bacteria, and with the concept of a hydrogen battery driven by bacterial enzymes. I congratulate him on this great honor. His induction into the Academy is a testimony to the international visibility Goethe University enjoys thanks to outstanding scientists like Volker Müller."
Prof. Volker Müller, Head of the Department of Molecular Microbiology and Bioenergetics at Goethe University, was delighted about the accolade: "The distinction is both a pleasure and an honor. Throughout my career, I have had and continue to have the great fortune and privilege of working with excellent students on exciting questions, ranging from the beginnings of biochemistry and bioenergetics in ancient bacteria on early Earth to the development of these bacteria as production platforms in a CO2-based bio-economy or as catalysts in hydrogen technology. These acetogenic bacteria have been and continue to be a veritable goldmine."
The ASM promotes microbial sciences through conferences, publications, certifications, and educational opportunities. Its goal is to improve laboratory capabilities around the world. The ASM provides a network for scientists from academia, industry, and clinical settings. Its Academy's “Class of 2023 Fellows" is made up of researchers from 11 different countries: Argentina, China, Germany, France, India, Israel, Canada, Austria, Singapore, the United Kingdom, and the United States.
How bacteria gain energy through CO2 fixation
Researchers from Goethe University Frankfurt develop new biobattery for hydrogen storage:
Image for download: https://www.uni-frankfurt.de/128212374
Caption: Prof. Volker Müller of Goethe University Frankfurt (Photo: Uwe Dettmar for Goethe University)
Professor Volker Mueller
Department of Molecular Microbiology & Bioenergetics
Institute for Molecular Biosciences
Tel: 49 (0)69 798-29507
Twitter-Handle: @goetheuni @ASMicrobiology
Three substances fight tumour growth and reduce liver metastases
Iron-dependent cell death (ferroptosis) is a type of programmed cell death by means of which the body kills off diseased, defective or superfluous cells. This process can be used to make immunotherapies against liver cancer more effective. Researchers at Georg-Speyer-Haus, University Hospital Frankfurt and Goethe University Frankfurt have now been able to show this in mice with liver cancer. The combination therapy was also effective against colon cancer metastases that had settled in the liver.
FRANKFURT. Ten years ago, a new type of programmed cell death was discovered: iron-dependent cell death or, to use the scientific term, ferroptosis. Unlike apoptosis, a long-known type of programmed cell death, in ferroptosis the cell absorbs larger amounts of iron. The iron is metabolised in the cell and eventually leads to the destruction of the cell membranes. Such types of cell death are among the body's important control mechanisms, for example in development processes and the elimination of defective or degenerate cells.
For some years now, immunotherapies have established themselves as a treatment option in the battle against cancer. Here, the body's own defence system is stimulated so that it acts against cancer cells. A number of these immunotherapies successfully target key points in the immune system, known as checkpoints, where the immune system is subdued.
Immune checkpoints are a kind of “off switch" on the surface of T cells (cancer-fighting immune cells), with which their activity can be down-regulated. This “off switch" is operated by certain “key" proteins. Many tumours form such “key" proteins to protect themselves against attacks by T cells. That is why blocking the “off switch" by means of drugs, i.e. immune checkpoint inhibitors, are now part of the standard treatment in some types of cancer. Unfortunately, in other types of cancer, such as liver cancer, the response to the immune checkpoint blockade is low.
Researchers at Georg-Speyer-Haus, together with University Hospital Frankfurt and Goethe University Frankfurt, have now observed in mice with colorectal cancer that a substance which triggers ferroptosis leads to the activation of certain immune cells (T cells). Such T cells can systematically kill off cancer cells.
The problem was that two independent mechanisms immediately put a halt again to T cell activity: firstly, the cancer cells formed a “key" protein to operate the “off switch" of the T cells (the immune checkpoint receptor PD-L1). Secondly, other cells of the immune system, known as myeloid suppressor cells, came onto the scene, whose task is equally to subdue the body's immune response.
However, when the researchers gave the diseased mice a triple combination of a ferroptosis activator, an immune checkpoint inhibitor and a substance that prevents the attraction of myeloid suppressor cells, this significantly reduced the liver tumours' growth.
In further tests on mice, the scientists established that the combination therapy was also able to reduce the number of liver metastases originating from a metastasising colorectal tumour. The colorectal tumour itself, however, did not respond to the combination therapy.
Professor Fabian Finkelmeier, one of the two first authors of the study, says: “The combination therapy is apparently dependent on the liver's microenvironment and not on the primary tumour. This indicates that our combination therapy could be effective against liver metastases from any type of cancer."
Dr Claire Conche, the second first author, explains: “With this new combination therapy, we attack the immune system from three sides. First, we make the cancer-fighting T cells reactive towards the tumour cells. Then we remove the obstacles facing the cancer-fighting T cells: the suppression cells and shielding by PD-L1."
Professor Florian Greten, director of Georg-Speyer-Haus and spokesperson for the LOEWE Centre “Frankfurt Cancer Institute", says: “The study underlines the pivotal role of the tumour microenvironment in cancer therapy. We have concentrated here on the immune compartment of the tumour microenvironment and how to modulate the immune system in the direction of a strong anti-tumour response. Our data in preclinical models are an encouraging basis for improving immunotherapy options for patients with hepatocellular carcinoma and liver metastases."
Claire Conche, Fabian Finkelmeier, Marina Pešić, Adele M Nicolas, Tim W. Böttger, Kilian B. Kennel, Dominic Denk, Fatih Ceteci, Kathleen Mohs, Esther Engel, Özge Canli, Yasamin Dabiri, Kai-Henrik Peiffer, Stefan Zeuzem, Gabriela Salinas, Thomas Longerich, Huan Yang, Florian R. Greten: Combining ferroptosis induction with MDSC blockade renders primary tumours and metastases in liver sensitive to immune checkpoint blockade. Gut (2022) http://dx.doi.org/10.1136/gutjnl-2022-327909
The light microscope image shows the liver of a diseased mouse in which many tumours have formed. The tumours are slightly darker in colour, have a rounded shape and are demarcated from the healthy tissue (haematoxylin-eosin stain). The new triple therapy reduced these tumours very significantly. Larger, white areas: preparation artefacts; dark spots: cell nuclei. Photo: Fabian Finkelmeier, University Hospital Frankfurt.
Professor Florian R. Greten
Institute for Tumour Biology and Experimental Therapy / Goethe University Frankfurt
Tel.: +49 (0)69 63395-232
Twitter: @FCI_health, @UK_Frankfurt, @goetheuni
Game Theory Study by theoretical physicist Professor Claudius Gros
Uncontrolled competitions for freely accessible resources such as fish stocks or water can have fatal consequences not only for the resources themselves. In such competitions, investors, too, are ultimately driven to their subsistence level, a new game-theoretical study by Professor Claudius Gros, theoretical physicist at Goethe University, shows.
FRANKFURT. Without regulations for their use, the condition of freely accessible resources such as fish stocks, water or air can deteriorate dramatically. In economics, this is referred to as the "Tragedy of the Commons". In 2009, Elinor Ostrom became the first woman to win the Nobel Prize in Economics for her studies on this topic. Ostrom's question of how to prevent this "tragedy" is just as relevant today as it was some 20 years ago.
Game theory deals with situations in which a number of agents compete with each other, with each participant trying to maximize his or her own profit individually. One speaks of a "Nash equilibrium" if players cannot increase their returns further. The "Tragedy of the Commons" is a game theoretical scenario in which the actors do not compete directly, but indirectly: If someone takes a piece of a common pie, there will be less for everybody else.
Instead of investigating how to avoid the "Tragedy of the Commons", Claudius Gros from Goethe University’s Institute for Theoretical Physics examined the resulting Nash equilibrium, with unexpected results: If a common good is divided more or less equally among N interested parties, then each receives a share of the order 1/N. However, the respective investment costs still need to be deducted. Gros' calculations show that, in equilibrium, the actors increase their engagement until the resulting investment costs almost reach the value of the resources the individual investor can secure for her- or himself. Mathematically, the theoretical physicist was able to show that the final profit of the individual investor scales as 1/N².
The original expectation, that investors each receive a proportional share from the resource, remains correct, as Gros' research shows. However, this does not translate into an overall return of the same proportion, which is smaller by a power in the number of investors. Gros denotes the dramatic deterioration of the net profit as "catastrophic poverty", as it implies that unregulated competition drives the individual actor close to the profitability limit, viz to the subsistence level. Similarly, Gros was able to show that catastrophic poverty can be avoided when the actors cooperate with each other. Cooperation leads to a net profit corresponding to the number of investors in simple power, the classical result.
The result of the investigations is therefore that the "Tragedy of the Commons" can cause substantially more damage than previously assumed. Uncontrolled access not only leads to a potentially excessive exploitation of the resource, a topic that has been the focus of many previous studies. In addition, investors suffer themselves when only maximizing their own profits. Mathematically, Gros was able to show that technological progress intensifies this process and that either all, or the vast majority of participating investors are ultimately affected by catastrophic poverty. If anything, only a few investors – the oligarchs – stand to gain more.
Publication: Claudius Gros, “Generic catastrophic poverty when selfish investors exploit a degradable common resource”, Royal Society Open Science (2023) https://royalsocietypublishing.org/doi/10.1098/rsos.221234
Caption: Professor Claudius Gros, Goethe University Frankfurt. Credit: Uwe Dettmar for Goethe University
Professor Claudius Gros
Institute for Theoretical Physics
Goethe University Frankfurt, Germany
Tel. +49 (0)69 798-47818