Research | VALIANT

Fast electromagnetic and RF circuit co-simulation for passive resonator field calculation and optimization in MRI

waddelma — Thu, 26 Mar 2026 20:33:35 +0000

Zhonghao Zhang; Ming Lu; Hao Liang; Zhongliang Zu; Yi Gu; Xiao Wang; Yuankai Huo; Xinqiang Yan (2026).��.��Magnetic Resonance Imaging, 129, 110644.��

This study focuses on improving how passive resonators—devices used in MRI scanners to shape and strengthen radiofrequency (RF) fields—are designed and optimized. Normally, designing these structures requires��full-wave electromagnetic (EM) simulations, which model how RF fields behave in detail. While accurate, these simulations are extremely slow and computationally expensive, especially when many design variables (like different capacitor or inductor values) need to be tested.

To solve this problem, the researchers developed a faster method called a��co-simulation framework, which combines a single detailed EM simulation with simpler circuit-level calculations. In this approach, parts of the resonator are replaced with connection points (“ports”) during the initial simulation, allowing many different electrical configurations to be tested afterward without repeating the costly EM computation. They also integrated a��genetic algorithm��(a search method inspired by natural selection) to automatically explore thousands of design options and find the best configuration for enhancing RF fields in a specific target area.

The method was tested in several scenarios, from simple models to a realistic human head model, and produced results nearly identical to full EM simulations (with less than 1% error). Importantly, the optimization process took less than five minutes, compared to what would normally require extremely long computation times. Overall, this approach offers a much faster and scalable way to design passive MRI components, making it easier to improve image quality without the heavy computational cost of traditional methods.

Fig. 1.��Schematic diagram of the co-simulation principle. Incorporate the optimization stage, indicate the starting point of the method and reorganized the layout.

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Loneliness, Anxiety Symptoms, Depressive Symptoms, and Suicidal Ideation in the All of Us Dataset

waddelma — Thu, 26 Mar 2026 20:17:22 +0000

Katherine Musacchio Schafer; Jacob Franklin; Peter J. Embí; Colin G. Walsh (2026).��.��JAMA Network Open, 9(3), e260596.��

This study examined how feelings of loneliness may help explain the link between anxiety, depression, and��suicidal ideation��(thinking about suicide). Using survey data from over 62,000 adults in the U.S., researchers measured anxiety symptoms, depressive symptoms, loneliness, and suicidal thoughts using standard mental health questionnaires. They found that all three—anxiety, depression, and loneliness—were positively related to suicidal ideation, meaning higher levels of each were associated with more frequent suicidal thoughts.

Importantly, the study showed that��loneliness acts as a mediator, meaning it partly explains��how��anxiety and depression are connected to suicidal ideation. In other words, people with anxiety or depression may be more likely to feel lonely, and that loneliness, in turn, increases the likelihood of suicidal thoughts. While anxiety and depression still had direct effects on suicidal ideation, loneliness accounted for a meaningful portion of this relationship.

Overall, the findings suggest that addressing loneliness could be a key strategy for reducing suicide risk, alongside treating anxiety and depression. By targeting loneliness—through social support, community engagement, or other interventions—it may be possible to interrupt the pathway from mental health symptoms to suicidal thinking.

Figure 1. ��Participant Flowchart From the All of Us Research Program

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Reproducibility and repeatability of the Myoton to quantify sclerotic chronic graft-versus-host disease

waddelma — Thu, 26 Mar 2026 20:16:04 +0000

Nosha Farhadfar; Najla El Jurdi; Kelsey K. Baker; Shramana Ghosh; Mongoljin Bat-Erdene; Heidi Chen; Ruchi Sahu; Rachel Weiss; Jerry Mi; Gabriela Desatnik; Lacey R. Williams; Eric R. Tkaczyk; Stephanie J. Lee (2026).��.��Blood Advances, 10(4), 1145–1152.��

This study evaluates a device called the��Myoton, which is used to measure how stiff or elastic the skin is, as a way to assess��sclerotic chronic graft-versus-host disease (scGVHD)—a condition where donor immune cells attack the patient’s body after a transplant, causing the skin to harden and thicken. Because there is a need for reliable, objective tools to track this condition, the researchers tested how consistent the Myoton’s measurements are when used by different people and at different times.

They measured two key properties of the skin—oscillation frequency��(related to tissue stiffness) and��relaxation time(how quickly tissue returns to normal after being deformed)—at multiple body sites in 36 patients. The results showed excellent consistency between different observers during the same session, meaning different users obtained very similar results. Measurements were also consistent when repeated by the same observer at different times (about six weeks apart), showing good reliability over time.

Importantly, averaging measurements across multiple body sites for each patient gave more consistent results than relying on any single location. Overall, the study demonstrates that the Myoton is a reliable and reproducible tool for measuring skin changes in scGVHD, especially when used to assess overall patient-level skin properties rather than individual spots.

Visual Abstract

Myosin VB is critical for progenitor cell identity and function in the intestine

waddelma — Thu, 26 Mar 2026 20:14:19 +0000

Andreanna Burman; Monica E. Brown; Yilin Yang; Michael Momoh; Francisca Adeniran; Cynthia Ramos; Ken S. Lau; Linda C. Samuelson; Mitchell D. Shub; Joseph T. Roland; Izumi Kaji (2026).��.��Stem Cell Reports, 21(3), 102820.��

This study investigates the role of a protein called��MYO5B (myosin Vb)��in the intestine, particularly in early-stage cells that give rise to the intestinal lining, known as��intestinal stem and progenitor cells. Mutations in MYO5B cause a rare genetic condition called��microvillus inclusion disease (MVID), which leads to severe, lifelong diarrhea because the intestine cannot properly absorb nutrients. While previous research showed that MYO5B is important for forming the brush border (the surface of intestinal cells that helps with absorption), its specific role in stem cells was not well understood.

To explore this, the researchers created specialized mouse models in which MYO5B was gradually lost in intestinal crypt cells—the regions where stem cells reside and continuously produce new intestinal cells. They found that without MYO5B, these stem cells lost their normal identity and instead shifted toward a��transit-amplifying (TA) state, meaning they multiplied rapidly but did not fully mature into functional cells. As a result, the intestinal tissue showed excessive cell growth (hyperproliferation) but poor differentiation (incomplete development into specialized cell types). The study also found disruptions in��mitochondria��(the cell’s energy producers) and��fatty acid metabolism, suggesting that energy processing problems may contribute to these abnormalities.

Importantly, similar patterns were observed in tissue samples from patients with MVID, including an expanded region of rapidly dividing cells and shortened intestinal structures (villus blunting), which impair nutrient absorption. Overall, the findings show that MYO5B plays a crucial role in maintaining healthy intestinal stem cell function, including proper cell growth, maturation, and metabolism, helping explain how its loss leads to disease.

Figure 1��Lrig1^{Δ�ѳ۰�5��}��mice are a model of progressive MYO5B deficiency originating in the small intestinal crypt

(A) Experimental timeline of tamoxifen administration (TMX) on day 0 to induce the��Lrig1-Cre recombinase and the collection of intestinal tissues on days 3 and 5. MYO5B loss and corresponding YFP+ lineage cells are depicted in green.

(B) Changes in mouse body weight following TMX administration. Daily results are presented as mean ± SEM;��N��= 5–9 mice per group.��^∗∗∗∗p��< 0.0001 by two-way ANOVA with Tukey’s test. Asterisk colors depict significances between Lrig1^{Δ�ѳ۰�5��}and M5B f/f (black) or��Lrig1-CreER^T2;��M5B fl/+��(gray).

(D) Duodenal histology with Alcian blue-PAS (AB-PAS) staining and MYO5B immunostaining (inverted). Immunostaining illustrates a decrease in targeted epithelial MYO5B expression, and unclassified non-epithelial signal is evident in MYO5B-deficient lamina propria tissues. Example crypts outlined in yellow dashes. Scale bars, 50 μm.

(E) Quantification of crypt and villus lengths from AB-PAS-stained mouse tissues. Mean ± SEM;��N��= 5–10 mice per group.��^∗∗p��< 0.01,��^∗∗∗p��< 0.001,��^∗∗∗∗p��< 0.0001 by two-way ANOVA with Dunnett’s test vs. control. Asterisk colors indicate significances in villus (gray) or crypt (yellow) values.

(F) Immunostaining for SGLT1, YFP, and ACTG1 in the mouse duodenum. Scale bars, 50 μm.

(G) Control (adult and pediatric) and pediatric MVID patient small intestinal tissues with multiplexed immunostaining for PCNA (proliferative marker), ACTG1 or Ezrin (brush border), CTNNB1 (basolateral membrane), DEF5A (Paneth cell), and nuclei. Scale bars, 50 μm.

Cognitive and Motor Improvements Correlated with Sleep and Activity Following Community-Based Non-contact Boxing in Patients with Parkinson Disease

waddelma — Thu, 26 Mar 2026 20:00:43 +0000

Melanie Leguizamon; Paula Trujillo; Kilian Hett; Colin D. McKnight; Tristan Ponzo; Jason Elenberger; Alexander K. Song; Colleen Bridges; Bailu Yan; Hakmook Kang; Manus J. Donahue; Daniel O. Claassen; Ciaran M. Considine (2026).��.��Archives of Clinical Neuropsychology, 41(2), acaf097.��

This study examined whether a 12-week community exercise program based on non-contact boxing—called��Rock Steady Boxing (RSB)—is practical and beneficial for people with Parkinson’s disease (PD), a condition that affects movement and sometimes thinking abilities. Twenty-six participants completed 24 classes over the study period, and researchers measured their motor (movement-related) and cognitive (thinking and memory) abilities before and after the program. A smaller group also wore��actigraphy devices, which are wearable sensors that track activity levels and sleep patterns.

The results showed clear improvements in motor function, particularly in balance, as measured by a standard clinical test. This suggests that the boxing-based exercise helped participants move more effectively and maintain stability. While there were some signs of improvement in cognitive functions such as memory and attention, these changes were not statistically strong enough to be considered definitive. Additionally, the wearable device data did not show significant changes in daily activity or sleep patterns.

Overall, the study suggests that this type of exercise program is safe, feasible, and beneficial for improving movement in people with Parkinson’s disease, regardless of age or disease severity. There are hints that it might also help cognitive function, but more research with larger groups is needed to confirm this.

Fig. 1

Attrition diagram for Parkinson disease cohort.

Modulation of neurofluid fluctuation frequency by baseline carbon dioxide in awake humans: the role of the autonomic nervous system

waddelma — Thu, 26 Mar 2026 19:59:20 +0000

Xiaole Z. Zhong; Catie Chang; J. Jean Chen (2026).��.��Frontiers in Physiology, 17, 1750101.��

This study investigates how��cerebrospinal fluid (CSF)—the fluid that surrounds and cushions the brain and spinal cord—moves within the brain, and how this movement is influenced by the body’s automatic (autonomic) functions, such as heart rate and breathing. CSF flow is important because it helps remove waste and maintain brain health. While previous research has linked CSF movement to sleep and brain activity, the researchers wanted to isolate the role of the��autonomic nervous system��(the system that controls involuntary processes like heartbeat and respiration).

To do this, they used fMRI scans to observe fluid-related signals in the brain while changing levels of carbon dioxide (CO₂) in participants’ blood—a method that affects blood vessel tone, breathing, and heart function without directly altering brain activity. They found that changes in CSF movement could not be explained simply by physical or mechanical factors. Instead, variations in��heart-rate variability��(natural fluctuations in the time between heartbeats) played a key role in driving slow CSF flow, independent of breathing. Additionally, changes in CO₂ levels mainly affected how frequently heart rate and breathing patterns fluctuated, rather than how strong those fluctuations were.

Overall, the findings suggest that CSF movement is strongly influenced by autonomic regulation, and that both higher and lower-than-normal CO₂ levels can disrupt this process. This highlights a new way to study and potentially control brain fluid dynamics—by adjusting CO₂ levels—without relying on sleep or direct neural activity, offering potential insights into brain health and disease.

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Fig 1: The predictions of CSF flow dynamics across capnias is based on three different physiological pathways: vascular tone, sympathetic tone, and neuronal activity. According to the vascular-tone theory, CSF fluctuations should be maximal at normocapnia. According to the neuronal-activity theory, CSF fluctuations should be maximized at hypocapnia. Lastly, according to the sympathetic-tone theory, CSF fluctuations should be maximized at hypercapnia. These theories will be tested using empirical data involving different capnias, at which all three variables will be altered.

TOI-3862 b: A dense super-Neptune deep in the hot Neptune desert

waddelma — Thu, 26 Mar 2026 19:56:25 +0000

Ilaria Carleo; Amadeo Castro-González; Enric Pallé; Felipe Murgas; Grzegorz Nowak; Gaia Lacedelli; Thomas Masseron; Emily W. Wong; Patrick Eggenberger; Vincent Bourrier; Dawid Jankowski; Krzysztof Goździewski; Douglas R. Alves; James S. Jenkins; Sergio Messina; Keivan G. Stassun; Jose I. Vines; Matteo Brogi; David R. Ciardi; Catherine A. Clark; William Cochran; Karen A. Collins; Hans J. Deeg; Elise Furlan; Davide Gandolfi; Samuel Geraldía González; Artie P. Hatzes; Coel Hellier; Steve B. Howell; Judith Korth; Jorge Lillo-Box; John H. Livingston; Jaume Orell-Miquel; Carina M. Persson; Seth Redfield; Boris Safonov; David Baker; Rafael Delfin Barrena Delgado; Allyson Bieryla; Andrew Boyle; Pau Bosch-Cabot; Núria Casasayas Barris; Stavros Chairetas; Jerome P. De Leon; Izuru Fukuda; Akihiko Fukui; Pere Guerra; Kai Ikuta; Kiyoe Kawauchi; Emil Knudstrup; Florence Libotte; Michael B. Lund; Rafael Luque; Eduardo Lorenzo Martín Guerrero De Escalante; Bob Massey; Edward J. Michaels; Giuseppe Morello; Norio Narita; Hannu Parvianien; Richard P. Schwarz; Avi Shporer; Monika Stangret; Noriharu Watanabe; Cristilyn N. Watkins (2026).��.��Astronomy & Astrophysics, 707, A4.��

This study focuses on a rare type of exoplanet found very close to its star, in a region known as the��“hot Neptune desert.”��This term refers to an area in the relationship between a planet’s size and its orbital period where planets of a certain size (like Neptune) are unexpectedly scarce. Scientists think this is because intense heat from the nearby star can strip away a planet’s atmosphere (atmospheric loss) or because such planets migrate inward in ways that make them unstable. Studying planets that do exist in this region can help explain how planets form and survive under extreme conditions.

The researchers investigated a candidate planet discovered by NASA’s TESS mission, called TOI-3862 b. They confirmed that it is indeed a planet by combining two methods:��transits��(measuring dips in starlight when the planet passes in front of its star) and��radial velocity��(tracking tiny wobbles in the star caused by the planet’s gravity). Using these techniques, they determined that TOI-3862 b is a “super-Neptune,” meaning it is larger and more massive than Neptune but smaller than gas giants like Jupiter. It orbits its star extremely quickly—once every 1.56 days—and has a relatively high density, suggesting it may have a substantial core or has lost part of its atmosphere.

Because TOI-3862 b lies deep within the hot Neptune desert, where few such planets are found, it provides an important case for testing theories about how planets evolve in harsh environments. Its existence suggests that, under certain conditions, planets can resist atmospheric loss or follow unusual evolutionary paths that allow them to survive where most others do not.

Fig. 1 – ��Left: TESS TPF of Sector 22 for TOI-3862. The color bar represents the electron counts for each pixel. The orange squares denote the pixels chosen by the TESS pipeline for aperture photometry. All sources from Gaia DR3 are overlaid on the plot and depicted as circles of varying sizes, corresponding to their G-mag difference relative to the target (as detailed in the legend). This visualization was generated using the��tpfplotter��code (). Gray arrows indicate the proper motion directions for all sources shown in the plot.��Right: TESS heat maps, generated through��TESS-cont��(), showing the percentage of the flux in each pixel that comes from the target star. The five most contaminating Gaia DR3 sources are overlaid with sizes scaling with their emitted fluxes.

Low-Cost and Detunable Wireless Resonator Glasses for Enhanced Eye MRI With Concurrent High-Quality Whole-Brain MRI

waddelma — Thu, 26 Mar 2026 19:52:36 +0000

Ming Lu; Xiaoyue Yang; Jason E. Moore; Pingping Li; Adam W. Anderson; John C. Gore; Seth A. Smith; Xinqiang Yan (2026).��.��Magnetic Resonance in Medicine.��Advance online publication.��

This study introduces a new wearable device—designed like a pair of glasses—that improves the quality of MRI scans of the eyes. MRI image quality is often described using the��signal-to-noise ratio (SNR), which compares the useful signal (clear image information) to background noise; higher SNR means clearer, more detailed images. Imaging the eyes is particularly challenging, especially at very high magnetic field strengths (such as 7 Tesla), where maintaining good image quality across both the eyes and the brain can be difficult.

The researchers created lightweight, 3D-printed “resonator glasses” that contain small electronic components called��LC loop resonators��(circuits that can enhance MRI signal locally). These resonators work wirelessly by interacting with the existing MRI head coil, meaning no modifications to the scanner hardware are needed. The team tested the device in both lab setups (phantoms, which simulate human tissue) and real human scans. They found that the glasses significantly improved image clarity in the eye region—boosting SNR by up to three times—while not reducing image quality in the rest of the brain.

Overall, this device offers a simple, low-cost way to enhance eye imaging during MRI scans without interfering with standard brain imaging. This could make it easier to study eye conditions or perform combined eye–brain imaging in clinical and research settings.

FIGURE 1

Circuit diagram (A) and CAD design (B) of the wireless resonator glasses.

ComCat: Expertise-Guided Context Generation to Enhance Code Comprehension

waddelma — Thu, 26 Mar 2026 19:50:56 +0000

Skyler Grandel; Scott Thomas Andersen; Yu Huang; Kevin Leach (2026).��.��ACM Transactions on Software Engineering and Methodology, 35(3), Article 82.��

Software maintenance makes up a large share of the total cost of software over its lifetime, and a big part of that cost comes from understanding existing code. One way to make code easier to understand is through documentation, especially comments that summarize what the code does or explain why it does it. In this work, we introduce ComCat, a system that uses large language models (LLMs, which are AI models trained on very large amounts of text) together with expert guidance to automatically generate useful comments for source code. ComCat is designed to choose the most relevant and informative comment for a specific piece of code. For C/C++ files, the system works in three steps: it first finds places where comments would be most helpful, then decides what kind of comment is needed, and finally writes the comment. In a study with human participants, ComCat’s comments improved code understanding on three software engineering tasks by up to 13% for most participants. The generated comments were also judged to be at least as accurate and readable as human-written comments, and they were preferred over standard ChatGPT-generated comments for up to 92% of code snippets. We also released a dataset containing code snippets, human-written comments, and human-labeled comment categories. Overall, ComCat shows that LLMs can be used to meaningfully improve how well people understand code.

Fig. 1.

ComCat��pipeline and study procedure. We use three instances of HSR to inform��ComCat’s design (1) and evaluate developer performance (2) and preference (3) with our tool.��ComCat��takes C/C++ code as input, using a Code Parser to identify code Snippets to be commented. These Snippets are classified, and the class of each Snippet is used in combination with our Template Catalog to create a prompt for each Snippet. These prompt ChatGPT, which outputs the commented code. This pipeline is informed by developer expertise, but it is fully automated and requires no human intervention.

Two temperate Earth- and Neptune-sized planets orbiting fully convective M dwarfs

waddelma — Thu, 26 Mar 2026 19:44:35 +0000

Madison G. Scott; Georgina Dransfield; Mathilde Timmermans; Amaury H. M. J. Triaud; Benjamin V. Rackham; Khalid Barkaoui; Adam J. Burgasser; Karen A. Collins; Michaël Gillon; Steve B. Howell; Alan M. Levine; Francisco J. Pozuelos; Keivan G. Stassun; Carl Ziegler; Yilen Gomez Maqueo Chew; Catherine A. Clark; Yasmin Davis; Fatemeh Davoudi; Tansu Daylan; Brice-Olivier Demory; Dax Feliz; Akihiko Fukui; Maximilian N. Günther; Emmanuël Jehin; Florian Lienhard; Andrew W. Mann; Clàudia Janó Muñoz; Norio Narita; Peter P. Pedersen; Richard P. Schwarz; Avi Shporer; Abderahmane Soubkiou; Sebastián Zúñiga-Fernández (2026).��.��Monthly Notices of the Royal Astronomical Society, 547(1), stag070.��

As scientists discover more types of exoplanets (planets outside our solar system), they are rethinking what conditions might allow a planet to be habitable. Traditionally, the “habitable zone” is defined as the range of distances from a star where liquid water could exist on a planet’s surface. In this study, the authors propose a broader concept called the��“temperate zone,”��defined by the amount of stellar energy a planet receives (instellation), specifically between 0.1 and 5 times the amount Earth gets from the Sun. This wider range includes more planets that might potentially support life under different conditions.

The researchers also introduce the TEMPOS survey, which focuses on measuring the sizes of planets orbiting very cool, small stars known as M dwarfs. As part of this effort, they discovered and confirmed two planets: TOI-6716 b and TOI-7384 b. TOI-6716 b is about the same size as Earth, while TOI-7384 b is larger (closer to a “mini-Neptune”). Both orbit relatively cool M dwarf stars and complete an orbit in just a few days. The team used multiple methods—including ground-based observations, high-resolution imaging, and statistical validation—to confirm these planets and precisely measure their sizes.

Both planets receive relatively high levels of stellar energy, placing them near the hotter inner edge of the proposed temperate zone. This means they may be too warm for Earth-like conditions, but they are still valuable for studying planetary environments. Notably, TOI-6716 b could be a promising target for the James Webb Space Telescope, especially for��transmission spectroscopy��(a technique that analyzes starlight passing through a planet’s atmosphere to detect its composition), if it has retained an atmosphere. Overall, this work expands the range of planets considered potentially interesting for habitability studies and contributes new targets for future observation.

Figure 1.

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