(Press-News.org) Research Background:
Turbulence in nature refers to the complex, time-dependent, and spatially varying fluctuations that develop in fluids such as water, air, and plasma. It is a universal phenomenon that appears across a vast range of scales and systems—from atmospheric and oceanic currents on Earth, to interstellar gas in stars and galaxies, and even within jet engines and blood flow in human arteries. Turbulence is not merely chaotic; rather, it consists of an evolving hierarchy of interacting vortices, which may organize into large-scale structures or produce coherent flow patterns over time.
In nuclear fusion plasmas, turbulence plays a crucial role in regulating the confinement of thermal energy and the mixing of fuel particles, thereby directly impacting the performance of fusion reactors. Unlike simple fluid turbulence, plasma turbulence involves the simultaneous evolution of multiple physical fields, such as density, temperature, magnetic fields, and electric currents. These quantities are interwoven, forming a state where multiple flows and vortices are intricately entangled. Understanding and decoding the fundamental mechanisms of such complex, multi-field turbulence is essential for the control and optimization of future fusion reactors.
Traditionally, studies of plasma turbulence have focused on analyzing fluctuations of individual physical quantities. A standard method involves decomposing turbulence into a superposition of spatially uniform waves and then examining the distribution and transfer of fluctuation energy across scales. However, this wave-based decomposition becomes inadequate when the turbulence forms localized vortex structures or when multiple field quantities interact strongly. There has thus been a growing need for a new analysis framework—one that can capture localized structures and reveal the intertwined behavior of multiple fluctuating fields in a unified and physically meaningful way.
Research Results:
To investigate how vortices and flows emerge, localize, and interact within plasma turbulence, Go Yatomi of the National Institute for Fusion Science (a graduate student at SOKENDAI at the time of submission) and Associate Professor Motoki Nakata of Komazawa University (also a visiting researcher at RIKEN iTHEMS) have developed a novel analytical method called multi-field singular value decomposition (MFSVD). This technique extends the mathematical framework of singular value decomposition to multiple physical quantities, enabling the decomposition of complex turbulence into a set of common spatial patterns (or bases) that capture correlated fluctuations across different fields such as density, temperature, and electric potential.
MFSVD makes it possible to analyze how these multi-variable fluctuations collectively drive the formation and evolution of turbulent structures, such as vortices and large-scale flows, from a unified perspective. From the shared spatial modes extracted via MFSVD, the researchers further defined two new measures based on information entropy, concepts originally rooted in quantum mechanics and quantum information theory. The first is the von Neumann entropy (vNE), which quantifies the structural complexity and diversity of turbulent fluctuations. The second is entanglement entropy (EE), which measures the degree of coupling—or "entanglement"—between different turbulent structures, indicating how strongly they interact. Both quantities are derived from a mathematically constructed density matrix that parallels its counterpart in quantum theory, demonstrating a natural and powerful analogy between quantum states and turbulent systems.
By applying these information-theoretic quantities to numerical simulations of a plasma turbulence model, the research team identified a previously overlooked transition in turbulence states—one that cannot be detected through traditional energy-based analysis. This newly discovered transition reflects an abrupt shift in the collective patterns of vortices that occurs behind the scenes of major energy flows (Fig.1). Such pattern transitions can significantly influence macroscopic flow stability and are thus critical for understanding plasma confinement and transport processes.
Moreover, the entanglement entropy allowed the team to express detailed interactions, such as when and where specific patterns transfer energy or fluctuations to others, in a single measure. In conventional analysis, capturing such dynamics would require examining vast datasets. In contrast, these entropy-based quantities offer a new lens through which the essential features of nonlinear turbulent interactions can be distilled and studied efficiently.
Significance and Future Outlook:
The approach proposed in this study—analyzing turbulence transitions and interactions from the perspective of information entropy—holds promise not only for interpreting numerical simulation data but also for application to experimental measurements. Even in situations where only a limited number of sensors or diagnostic tools are available, this method can serve as a powerful guide to determine “how much measurement data is sufficient to capture essential turbulence features” and “which vortex structures should be prioritized for observation.”
Importantly, the entropy-based framework developed here is not limited to plasma turbulence. It is expected to be applicable to a broad range of complex systems involving multi-scale flows and coupled fluctuations across many physical quantities—such as in atmospheric and oceanic sciences, traffic and transportation networks, and social systems. Looking ahead, the research team aims to deepen the theoretical correspondence between information entropy in turbulence and principles in quantum information theory, while also advancing the application of these methods to real-world measurement data. By combining the perspectives of both energy and information, this work opens a new avenue toward understanding the essential dynamics of turbulence and other complex phenomena.
END
Information entropy untangles vortices and flows in turbulent plasmas
A turbulence analysis inspired by quantum information theory
2025-06-02
ELSE PRESS RELEASES FROM THIS DATE:
Overall survival and quality-of-life superiority in modern phase 3 oncology trials
2025-06-01
About The Study: Although phase 3 trials are often interpreted as demonstrating superiority, overall survival and quality of life (QOL), which may be the most relevant end points to patients, are uncommonly improved. To increase the meaningfulness of late-phase research, future trial designs and regulatory processes should be refocused toward overall survival and QOL improvements.
Corresponding Author: To contact the corresponding author, Alexander D. Sherry, MD, email alexanderdsherry@gmail.com.
To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/
(doi:10.1001/jamaoncol.2025.1002)
Editor’s ...
Not-so-tasty: Plastic particles found in food could harm the body
2025-06-01
Results from a new animal study suggest that microscopic plastic particles found in food and beverages may affect glucose metabolism and harm organs such as the liver. The findings raise concerns about potential health risks in people and point to the need for more research.
As plastic breaks down, it forms micro- (<5 mm) and nanoparticles (<100 nm), which can enter the food chain and end up in seafood and other foods people eat. Studies estimate that a person may ingest around 40,000 ...
For heart health, food quality matters more than cutting carbs or fat
2025-06-01
A new study that followed almost 200,000 people for several decades has found that when it comes to heart health, the quality of food consumed matters as much as following a low-carbohydrate or low-fat diet. The results suggest that choosing healthy, high-quality foods is key to protecting the heart.
In the past two decades, low-carbohydrate and low-fat diets have been promoted for their potential health benefits, such as weight management and improved blood sugar and cholesterol levels. However, the impact of these diets on reducing heart disease risk has remained an ongoing debate.
“We found that what you eat on low-carb or low-fat ...
Study suggests obesity contributes to anxiety and cognitive impairment
2025-06-01
With rates of obesity and anxiety both on the rise—especially among younger Americans—new research suggests that the two conditions may be connected through interactions between the gut and the brain. The study, conducted in mice, links diet-induced obesity with anxiety-like symptoms, alterations in brain signaling and differences in gut microbes that may contribute to impaired brain functioning.
“Several studies have pointed to a link between obesity and anxiety, though it is still unclear whether obesity directly causes anxiety or if the association is influenced by societal pressures,” said Desiree ...
Higher linoleic acid levels linked to lower heart disease and diabetes risk
2025-06-01
New research that used blood markers to measure linoleic acid levels and their relation to cardiometabolic risk adds evidence that this omega-6 fatty acid may help to lower risks for heart disease and type 2 diabetes. The findings challenge claims that seed oils are harmful to cardiometabolic health.
Linoleic acid, which is found in vegetable oils—especially seed oils like soybean and corn oil—and plant foods, is the primary omega-6 fatty acid consumed in the diet.
“There has been increasing ...
Dual-target CAR T cell therapy slows growth of aggressive brain cancer
2025-06-01
CHICAGO – A dual-target CAR T cell therapy approach shows promise for slowing tumor growth in a notoriously aggressive and fast-growing brain cancer. Tumors became smaller after the experimental CAR T cell therapy in nearly two-thirds of patients. While survival data is still accumulating, several patients lived 12 months or longer after receiving the investigational therapy, which is notable given the typical survival for this patient population is less than a year.
The findings were presented today at the 2025 American Society of ...
Adding immune checkpoint inhibitor to standard chemotherapy regimen improves outcomes in stage 3 colon cancer, study finds
2025-06-01
BOSTON, June 1, 2025 – Combining standard adjuvant chemotherapy with an immune checkpoint inhibitor (atezolizumab) leads to a significant improvement in disease-free survival in a subset of patients with stage 3 colon cancer that is deficient in DNA mismatch repair (dMMR), Dana-Farber Cancer Institute investigator Dr. Jeffrey Meyerhardt and his colleagues report at the 2025 American Society of Clinical Oncology (ASCO) meeting.
These results stem from the ATOMIC trial, a phase 3 multicenter, randomized, ...
Diet influences survival after stage iii colon cancer, Dana-Farber study finds
2025-06-01
BOSTON, June 1, 2025 – Patients with colon cancer who consumed an anti-inflammatory diet during a phase 3 clinical trial showed longer overall survival post-treatment compared to those on a proinflammatory diet, according to a Dana-Farber Cancer Institute analysis. Engaging in higher levels of physical activity may amplify the positive influence on survival.
“One of the most common questions that patients ask is what they should do after treatment to maximally reduce their risk of cancer recurrence and improve survival,” says first author Dr. Sara Char, a clinical fellow in Hematology and Oncology at Dana-Farber ...
Switch to experimental drug after liquid biopsy detection of breast cancer recurrence improves outcomes
2025-06-01
A large prospective, randomized clinical trial in patients with advanced breast cancer has found that the use of liquid biopsy blood tests for early detection of a treatment-resistance mutation, followed by a switch to a new type of treatment, substantially extends the period of tumor control compared to standard care.
The SERENA-6 study, published June 1 in the New England Journal of Medicine and presented concurrently at the annual meeting of the American Society for Clinical Oncology, was conducted at multiple medical centers, principally in Europe, East Asia and the United States, including at Weill ...
Alliance presents results from phase III ATOMIC trial combining atezolizumab with chemotherapy for patients with stage III dMMR colon cancer at ASCO 2025
2025-06-01
June 1, 2025 — The Alliance for Clinical Trials in Oncology announced today results from ATOMIC (A021502), a phase III trial evaluating standard chemotherapy alone or combined with atezolizumab (Tecentriq®) in treating patients who have surgically resected stage III colon cancer and deficient deoxyribonucleic acid (DNA) mismatch repair (dMMR). The study, sponsored by the National Cancer Institute (NCI) and conducted in partnership with Genentech, a member of the Roche Group, met its primary endpoint, demonstrating a statistically ...
LAST 30 PRESS RELEASES:
Cannabis extract could treat fungal diseases
Pancreatic cancer spreads to liver or lung thanks to this protein
Eating an array of smaller fish could be nutrient-dense solution to overfishing
Han studying potential of next generation telepresence
Emory study finds molecular link between air pollution and pregnancy risks
Controlling bacteria with light: from tackling antibiotic resistance to “bacterial robots”
Johns Hopkins study shows how scientists can use black holes as supercolliders
Being incarcerated and living in areas where more have gone to jail is associated with higher death rates
New insights into long-term dysfunction of edited blood stem cells and how to overcome it
Severe maternal morbidity by race and ethnicity and birth mode
Individual- and area-level incarceration and mortality
New tool to generate aneuploidies and analyze their impact on development
SwRI-led research finds particles energized by magnetic reconnection in the nascent solar wind
Aging increases brain’s sensitivity to hypoxia and blood-brain barrier damage in mice
Eating more phytosterols could lower your risk of heart disease and diabetes
Eating more sweet food may not sway sweet preference
Scientists propose new approach for classifying processed foods
New study: Daily mango intake may support postmenopausal heart and metabolic health
Study finds daily cup of beans boosts heart and metabolic health
Freshwater fish in US carry introduced human-infecting parasites
Sanaria reports positive initial safety results for groundbreaking PfSPZ-LARC2 malaria vaccine
FAU study explores barriers and trends in cannabis use disorder treatment
Semi-automated manufacturing process for cost-efficient quantum cascade laser modules
First direct observation of the trapped waves that shook the world
New mRNA vaccine is more effective and less costly to develop, Pitt study finds
DNA floating in the air tracks wildlife, viruses — even drugs
Targeting viral enzymes to strengthen brain immunity against HSV-1
Online game, developed at Harvard, proven to reduce partisan animosity
Two plant species invent the same chemically complex and medically interesting substance
Clinical research on psychedelics gets a boost from new study
[Press-News.org] Information entropy untangles vortices and flows in turbulent plasmasA turbulence analysis inspired by quantum information theory