Tyler O'Neal, Staff Editor DEVELOPER TOOLS

Kobe University researchers show the link between temperature, dehydration, tectonic tremors in Alaska

A Kobe University research group has shed light on how low-frequency tectonic tremors occur; these findings will contribute to better predictions of future megathrust earthquakes. The thick blue solid line outlines the Yakutat terrane. The white circle indicates the epicentre of the low-frequency tectonic tremors, and the light blue dashed line shows the area where the tectonic tremors occurred, which is used in Figures 2 to 4. The area inside the pink dashed box is the model region used in this study, and the pink dashed line down the center of the box divides the model region into northeast and southwest areas, and represents the boundary between the subducted Yakutat terrane and the subducted Pacific plate in the model. The black lines indicate the isodepth contours of the upper surface of the subducted oceanic plate (with a contour interval of 20 km), red arrows show the plate motion velocity in the Aleutian Trench, and the red triangles indicate volcanoes. CREDIT Iwamoto, K., Suenaga, N. & Yoshioka, S. Relationship between tectonic tremors and 3-D distributions of thermal structure and dehydration in the Alaska subduction zone. Sci Rep 12, 6234 (2022). https://doi.org/10.1038/s41598-022-10113-2
In addition to the subducting Pacific plate, the Alaska subduction zone is also characterized by a subducting oceanic plateau called the Yakutat terrane. Low-frequency tectonic tremors, which are a type of slow earthquake, have only been detected in the subducted Yakutat terrane area. However, the mechanism by which these events occur is not well understood.

Researchers at Kobe University performed a 3D numerical thermomechanical simulation of thermal convection in the Alaska subduction zone to reveal the mechanism behind these low-frequency tremors. Based on the 3D thermal structure obtained from the simulation, and the indications of hydrous minerals contained in the slab, the researchers calculated the water content distribution and compared the results of these calculations in the area where the tremors occur.

The results revealed high levels of dehydration in the marine sediment layers and ocean crust in the earthquake region. The researchers believe that the reason the tremors only occur in the Yakutat terrane is that the marine sediment layers and ocean crust are thicker there, which means that the level of dehydration is higher than in the western adjacent Pacific plate (where tectonic tremors don’t have to occur).

The Kobe University research group consisted of 2nd year Master’s student IWAMOTO Kaya (Department of Planetology, Graduate School of Science), Academic Researcher SUENAGA Nobuaki, and Professor YOSHIDA Shoichi (both of the Research Center's for Urban Safety and Security).

Main Points

  • Elucidating the mechanism by which low-frequency tremors occur is important for understanding the plate subduction process. It is believed that this will also help illuminate how shallower megathrust earthquakes occur.
  • In this study, the research group constructed a 3D thermomechanical model of the Alaska subduction zone and calculated the subducting plate’s maximum water content and level of dehydration.
  • The dehydration levels from the subducting plate’s marine sediment layers and ocean crust were highest in the region where low-frequency tremors occur. Therefore, it is thought that the water expelled from the subducted plate contributes to the occurrence of these tectonic tremors.

Research Background
An oceanic plateau called the Yakutat terrane is subducting in the Alaska subduction zone. Low-frequency tectonic tremors occur at this subducting plateau. The region where slow earthquakes (such as low-frequency tectonic tremors) occur is deeper and adjacent to the area where megathrust earthquakes occur, which suggests a connection between the two. Revealing the mechanism behind how low-frequency tectonic tremors occur is therefore important for understanding the occurrence of various earthquake events in subduction zones. This research group constructed a 3D thermomechanical model of the Alaska subduction zone so that they could investigate the temperature and level of dehydration in the areas near where low-frequency tremors occur.

Research Methodology
The researchers performed a 3D numerical thermomechanical simulation by the subduction of the Yakutat terrane and Pacific plate in the Alaska subduction zone. It is thought that as the Pacific plate subducts, it brings the hydrous minerals in the slab into the deep high temperature and high-pressure regions, and these conditions cause a dehydration reaction where water is expelled from the hydrous minerals. Based on the 3D thermal structure obtained from the numerical simulation, the researchers determined the dehydration levels of the hydrous minerals in the slab. From these results, it was understood that in the region where low-frequency tremors occur, a large amount of water is expelled due to the high temperature and high-pressure conditions that cause the dehydration degradation reactions. It is thought that low-frequency earthquakes don’t occur in the Pacific plate because it has thin layers and therefore experiences little dehydration. On the other hand, the Yakutat terrane’s ocean crust and marine sediment layers are comparatively thicker, meaning that it experiences high levels of dehydration. The researchers concluded that this is why low-frequency tectonic tremors only occur in the Yakutat terrane.

Further Research
In 1964, a megathrust earthquake occurred in Alaska. This is the biggest earthquake that has occurred in the Alaska subduction zone and the second most powerful earthquake recorded in world history. The low-frequency tectonic tremors that were the subject of this research occurred close to the epicenter of the 1964 earthquake, at the downdip of the plate interface.
Next, the research group will continue to make thermomechanical models of various subduction zones search for universal and regional characteristics of the causal mechanisms behind undersea megathrust earthquakes and slow earthquakes. This research will contribute to improving our understanding of how earthquakes occur and our ability to predict future megathrust earthquakes.

JU prof builds a neurobiological model to better understand creative processes

Tyler O'Neal, Staff Editor DEVELOPER TOOLS

Creativity is understood as the creation of novel, useful and surprising solutions. The researchers argue that the associated cognitive processes, such as the ability to abstract, improvise, or think divergently, involve different brain areas that are interconnected. These areas include the cerebellum, hippocampus, prefrontal cortex, and basal ganglia (see figure). Different areas are activated depending on the type of creativity. The similarities and differences between these types of creativity and their neuronal circuits are described by the model with the help of algorithms. Dopamine plays an essential role as a critical modulator for controlling and optimizing creative neural pathways. Radwa Khalil, Neurobiologist at Jacobs University Bremen.

With this proposed neural network model, the scientists, for the first time, provide a unified framework for seemingly three different forms of creativity. "With this starting point, we hope to thoroughly contribute to a better understanding of the underlying neuronal mechanisms," said Khalil. "The more we know about these mechanisms, the more specifically we can promote creativity and possibly contribute as promising interventions for people with relevant disturbed brain areas." 

With their model, the scientists also want to initiate a discussion about neurobiology and creativity, adds Radwa Khalil. An associate professor, Ahmed A. Moustafa, from the University of Johannesburg and the School of Psychology at Bond University in Australia, is also involved in the research. As a visiting Professor of the German Academic Exchange Service (DAAD), Moustafa will continue his creativity research this summer at Jacobs University, hosted and led by Professor Dr. Ben Godde Professor of Neuroscience at Jacobs University Bremen in Germany.

IRB Barcelona uses ML to expand tumor genome interpretation for personalized cancer treatment

Tyler O'Neal, Staff Editor DEVELOPER TOOLS

Cancer is increasingly prevalent in society and the efforts of the research community, doctors, and administrations to find solutions to this disease are huge. However, it cannot be treated uniformly, as there are more than 200 types of cancer. In addition, the disease in each patient is unique, because the mutations that give rise to the development of each of the tumors are different in each case. Dr. Abel González-Pérez, Dra. Núria López-Bigas, Jordi Deu, Dra. Olivia Tort and Dr. Santiago Demajo

Dr. Núria López-Bigas, ICREA researcher and head of the Biomedical Genomics lab at IRB Barcelona, is leading a European project that seeks to interpret the profiles of mutations in a specific tumor so that medical doctors can choose the most appropriate treatment for each patient. The platform that analyses potential susceptibilities of each tumor is called Cancer Genome Interpreter and it uses machine learning and other computational methods to systematically extract information from mutations observed in thousands of tumors—28,000 tumors from 66 types of cancer analyzed to date—to improve the interpretation of the variants observed in each patient.

“The Cancer Genome Interpreter, which we have been working on for more than five years, has immense potential and, through this project, we intend to optimize it for its use in hospitals and healthcare centers. We want it to be a key instrument to support the decision-making by clinical oncologists, so that each patient, regardless of the hospital in which the diagnosis is made, receives the most appropriate treatment,” explains Dr. López-Bigas.

Spanning five years, the project has been awarded funding of €10M by the European Commission, which has greatly valued its main aim: to provide an answer to an unmet medical need. The European Commission has also highlighted the quality of the platform, the expertise of the partners, and the solid implementation plan presented.

"Driver" and "passenger" mutations in cancer

Tumors are characterized by uncontrolled cell growth and proliferation. Along this process, cells accumulate many mutations (in the order of thousands in the entire genome). However, only a few of these (usually fewer than 10) are relevant for the development of the tumor.

The Cancer Genome Interpreter identifies those mutations that are important for cancer development and those that may be related to the response to a given treatment. On this basis, a prediction can be made of whether a specific drug can be effective against that tumor or whether the tumor is likely to be resistant to the treatment. With this information, the system provides a report to help medical doctors to make decisions about treatment options.

The project also includes the set-up of virtual tumor boards integrated by international experts with whom medical doctors can consult and discuss the report produced by the Cancer Genome Interpreter. The purpose of such meetings is to promote the exchange of knowledge and thus offer optimal treatment management to all patients, particularly those who are treated in smaller healthcare centers and who often do not have access to many specialized oncologists.

Patient-centered

A key pillar of this project is the involvement of people with cancer through two associations that will form part of the project, representing society and patients, with multiple goals. First, the aim is to involve patients so that they can play an active role in the process of personalized cancer medicine. To this end, the system also provides patients with a report, thus informing them about the molecular features of their tumor.

Second, the project seeks to highlight the value of the information and make patients aware that they can help to improve the system by accepting to share the molecular details of their tumors and their clinical information. In its current version, the Cancer Genome Interpreter has been developed from the analysis of the genomes of the tumors of 28,000 patients, covering more than 60 types of cancer, which are available to the scientific community in public repositories. As new sequenced tumors are added to the public domain, machine-learning methods will improve their predictions, thereby enhancing the interpretation of the tumor mutations for new patients.

The ECPC (the European Cancer Patient Coalition) and the Spanish Association Against Cancer will promote the active participation of cancer patients in this research.

17 partners for an ambitious project

As well as patient associations, IRB Barcelona will be collaborating with 17 different types of European organizations, which offer complementary expertise to address the implementation of personalized cancer medicine from all angles.

Nine hospitals and healthcare centers from four European countries are partners of the project and these will be the first to introduce the platform into their systems: the Vall d’Hebron Institute of Oncology (VHIO); the Gustave Roussy; the Leon Berard Centre de Lutte Contre le Cancer;  Uniklinik RWTH AACHEN; Universitätsklinikum Köln AöR; the Manchester Cancer Research Centre; the Girona Biomedical Research Institute Dr. Josep Trueta (IDIBGI); the Fundació Althaia - Hospital Sant Joan de Déu de Manresa and the Andalusian Health Services, as well as the Catalan Institute of Oncology (ICO) and the Fundación Progreso y Salud of the Regional Government of Andalusia.

Regarding research centres, in addition to IRB Barcelona, the Centro Nacional de Análisis Genómico (CNAG – CRG) is participating in the project. The company Alira Health is the partner in charge of ensuring regulatory aspects and the European Association for Cancer Research (EACR) will be managing communication actions associated with the project.