To better understand��protoplanetary disks—the disks of gas and dust around young stars where planets form—scientists need models that can explain both their��spectra��(how they emit light at different wavelengths) and their physical structure. In earlier work, the authors developed a combined approach called the��EaRTH Disk Model, which links observational data from infrared spectra with��radiative transfer models��(simulations of how light moves through and interacts with matter).

In this study, they improve one part of that model: how temperature is distributed across the disk. Instead of using a more complex method that requires breaking the disk into many small pieces for calculation, they introduce a simpler mathematical description that still captures how temperature varies with location. This new approach uses an empirical (data-driven) relationship between spatial properties of the disk, making it easier for models to fit real observations while staying physically realistic.

They tested the updated model using infrared data from the��Spitzer Space Telescope, focusing on��transition disks��(disks with gaps or holes that may indicate planet formation). The results provide insights into the disks’ composition (mineralogy) and structure, including evidence for��grain growth and processing—key steps in the early stages of planet formation.

Figure 1.��Model fit plots of TZTD empirical mineralogical analysis of Spitzer/IRS spectra of targets indicated in Table��. Red: cool-disk component constituents; blue: warm-disk component constituents; see Figure Set��in the����for legend of dust components.

]]> /valiant/2026/04/29/blinded-by-the-beam-a-unified-real-time-defense-against-laser-based-attacks-on-navigational-perception-of-autonomous-vehicles/ Wed, 29 Apr 2026 04:17:53 +0000 /valiant/?p=6594 Solanki, Abhijeet; Amiri, Wesam Al; Hasan, Syed Rafay; Guo, Terry N. (2026).��.��IEEE Access.��

Autonomous vehicles (AVs) use multiple sensors—especially��cameras�����Ի���LiDAR��(a laser-based system that measures distance)—to understand their surroundings. However, camera systems can be tricked by��laser-based attacks, where directed light creates misleading patterns in images. Earlier versions of these attacks required constant adjustment, making them difficult to use in real time. This study introduces a simpler and more practical method: a��static laser attackthat does not need continuous tuning but can still disrupt how the vehicle detects objects.

The researchers analyzed how these laser attacks affect images by examining their visual patterns using statistical measures, image-processing techniques, and machine learning methods. They found that even fixed laser interference can reduce object recognition accuracy and interfere with how camera and LiDAR data are combined (sensor fusion). Some attacks create obvious artifacts that can be detected using basic image filters and color-based analysis, while more subtle ones require more advanced, geometry-aware detection methods.

To address both types, the authors developed a lightweight detection system that combines statistical and geometric features to identify these attacks in real time. Their approach achieved over 90% detection accuracy on a compact computing device, showing that it is both effective and practical for use in real-world autonomous systems.

FIGURE 1.��

Static attack visualization. Each row shows a normal clean image (top) and its corresponding attacked version (bottom). Static AdvLB introduces consistent bright streaks, while Static AdvLS adds reproducible neon-green circular patterns. These fixed-parameter attacks are real-time deployable and highly reproducible.

The Sloan Digital Sky Survey V (SDSS-V) is carrying out the first full-sky survey of stars in the Milky Way’s��stellar halo(the extended, sparse region surrounding the galaxy) using low-resolution��spectroscopy��(analyzing starlight to learn about stars’ properties). This study describes the data-processing system used for this survey, which combines multiple types of observations—stellar spectra, brightness measurements (photometry), and distance information from��parallax—to estimate key properties such as a star’s temperature, chemical composition (metallicity), abundance of certain elements (like��alpha elements, which trace stellar history), and distance.

The resulting dataset, called the��BOSS-MINESweeper catalog, was carefully tested by comparing its results with well-studied star clusters and more precise, high-resolution surveys. The catalog proves powerful for several types of research: it can identify unusual stars with rare chemical signatures, reveal previously unknown structures in the distant halo, and map how stars move across the galaxy on very large scales.

Overall, this work provides a major new resource for studying the formation and evolution of the Milky Way. The catalog is publicly available and will continue to grow with future data releases.

Figure 1.��Top: distribution of SDSS-V halo stars observed up through 2024, in Galactic coordinates. This figure includes data observed from both APO and LCO, although only APO data are released in DR19. Bottom: stellar distribution in Gaia color–magnitude space, colored by median SNR (in the 4750−5500 Å region) of the co-added BOSS spectrum. Contours of target density are overlaid. The displayed color range corresponds to stellar temperatures from ≈3800 to 6500 K.

Many real-world systems—like social networks, recommendation platforms, and traffic systems—can be represented as��dynamic graphs, where connections between entities change over time. Predicting future connections (link prediction) in these systems is challenging because existing models often miss subtle changes in interaction order, struggle to capture long-term patterns, and do not fully account for how specific pairs of nodes relate to each other over time.

To address this, the authors propose��Graph2Video, a new approach inspired by how videos are processed in computer vision. Instead of looking at a graph as a static snapshot, the method treats the evolving neighborhood around a potential connection as a sequence of “graph frames” (like frames in a video). These frames are stacked into a “graph video,” allowing the model to capture both short-term changes and long-term trends using techniques originally developed for video analysis. The method then creates a compact representation (an��embedding, or numerical summary) for each potential link, which can be easily integrated into existing models.

Experiments show that Graph2Video improves prediction accuracy compared to current leading methods. Overall, the study demonstrates that adapting ideas from video processing is an effective way to better understand and predict how connections evolve in complex, time-changing networks

.

Vienneau, Emelina P.; Weeks, Abbie E.; Pan, Ying-Chun; Shema, Peggy M.; Morgan, Victoria L.; Byram, Brett C. (2026).��.��IEEE Transactions on Biomedical Engineering.��

This study examines whether the size of the��pulmonary artery (PA)—the blood vessel that carries blood from the heart to the lungs—measured on��CT scans��can help indicate the presence and severity of��pulmonary hypertension (PH), a condition where blood pressure in the lungs is abnormally high. Earlier research linked enlarged PA size to more severe PH, but it was unclear how well this relationship holds for milder cases or what it means for patient outcomes.

Researchers analyzed data from nearly 700 individuals with different types of PH and compared them with similar people without the condition. They found that larger PA size, as well as the ratio of PA size to the nearby aorta (PA:aorta ratio), was strongly associated with higher��mean pulmonary artery pressure (mPAP)—a key measure of disease severity obtained through an invasive test called��right heart catheterization. Importantly, PA size increased steadily from people without PH to those with mild and then more severe disease.

The study also showed that larger PA measurements were linked to worse outcomes: patients with bigger pulmonary arteries had a higher risk of needing a heart or lung transplant or dying over time. While PA size alone is not a perfect diagnostic tool, it provides useful, noninvasive information that can help assess disease severity and prognosis. Overall, these findings suggest that simple measurements from routine CT scans can offer valuable insight into both the presence and progression of pulmonary hypertension.

Figure 1

Measurement of the axial PA and aorta diameters (top left), tubular PA area (top right), right PA diameter and area (bottom left), and left PA diameter and area (bottom right). Abbreviations: Ao, aorta; LPA, left pulmonary artery; PA, main pulmonary artery; RPA, right pulmonary artery.

New treatments for Alzheimer’s disease that target��amyloid-beta (Aβ)—a protein that builds up in the brain—are changing how the disease is diagnosed and managed. This study examined real-world data from Mayo Clinic health records (2019–2025) to see how testing and treatment patterns have shifted with the introduction of a drug called��lecanemab, which is given by infusion.

After insurance coverage expanded, use of lecanemab increased rapidly. At the same time, there were notable changes in how patients are tested: traditional methods like��cerebrospinal fluid (CSF) testing��declined, while blood-based tests—especially��plasma p-tau217��(a marker linked to Alzheimer’s-related brain changes)—rose sharply. Brain scans using��PET imaging��to detect amyloid also increased. All patients who received lecanemab were confirmed to have amyloid buildup through PET or CSF testing.

The study also found that women were more likely to test positive for amyloid across different testing methods. Genetic testing showed that many patients carried the��APOE-ε4 variant, a gene associated with higher Alzheimer’s risk, but those with two copies of this variant were less likely to start lecanemab treatment. Overall, the findings show that the arrival of anti-amyloid therapies is rapidly reshaping both diagnostic approaches and treatment use in real-world clinical care.

FIGURE 1

Regulatory milestones of Alzheimer’s disease biomarkers and treatments from 2012 through 2025. Aβ, amyloid-beta; AD, Alzheimer’s disease; CMS, Centers for Medicare & Medicaid Services; CSF, cerebrospinal fluid; PET, positron emission tomography; pTau, phosphorylated tau.

]]> /valiant/2026/04/29/toi-1080-b-a-temperate-rocky-planet-orbiting-a-quiet-m4v-host/ Wed, 29 Apr 2026 03:59:15 +0000 /valiant/?p=6576 Gómez Maqueo Chew, Yadira; Dransfield, George; Barkaoui, Khalid; Cadieux, Charles; Ducrot, Elsa; Rackham, Benjamin V.; Timmermans, Maarten; Burgasser, Adam J.; Segura, Antígona; Stassun, Keivan G.; Ziegler, Carl; Soubkiou, Ahmed; Almenara, José M.; Demory, Brice O.; Gillon, Michaël; Jenkins, Jon M.; Jofré, Ezequiel; Khandelwal, Ankit; Páez, Sebastián; Petrucci, Roberto; Parc, Loïc; Pichardo Marcano, María; Plauchu-Frayn, Isabelle; Schroffenegger, Urs; Schwarz, Reinhard; Tan, Thiam G.; Triaud, Amaury H. M. J.; Benkhaldoun, Zouhair; Bonfils, Xavier; Bouchy, François; Collins, Karen A.; Davoudi, Farzaneh; Doyon, René; Gachaoui, Mohammed; Hooton, Matthew J.; Jehin, Emmanuël; Pozuelos, Francisco J.; Scott, Matthew G.; Yalçınkaya, Selçuk; Zong Lang, Feng; Zúñiga-Fernández, Sebastián; De Medeiros, José R.; González-Hernández, Jonay I.; Santos, Nuno C. (2026).��.��Monthly Notices of the Royal Astronomical Society, 548(1).��

This study reports the discovery and confirmation of a small, Earth-sized��exoplanet��(a planet outside our solar system) called��TOI-1080 b, which orbits its star every ~4 days. The host star is a nearby, relatively quiet��M dwarf��(a small, cool type of star) located about 25.6 parsecs (~83 light-years) away. The planet was first detected by the TESS space telescope using the��transit method��(observing dips in starlight as the planet passes in front of the star) and confirmed with additional space- and ground-based observations.

TOI-1080 b has a radius about 1.2 times that of Earth and a moderate��equilibrium temperature��of around 368 K (about 95°C), placing it in a “temperate” range compared to many hotter close-in planets. Measurements of the star’s motion (radial velocity) suggest the planet’s mass is less than about 10.7 times Earth’s mass. The researchers also ruled out the presence of other nearby planets of similar size in short orbits around the same star.

Because it is relatively small, nearby, and orbits a quiet star, TOI-1080 b is an excellent candidate for further study—especially for examining its possible��atmosphere��using powerful telescopes like the James Webb Space Telescope (JWST). It is considered a high-priority target for ongoing programs focused on detailed studies of rocky, Earth-like worlds.

Figure 1.

FIRE spectrum of TOI-1080. The target spectrum (red) is shown alongside that of the��SPEX��SXD spectrum of the M3.5 V standard Luyten’s Star (GJ 273; grey). The higher spectral resolution of the FIRE spectrum gives it a more jagged appearance. Strong M-dwarf spectral features and spectral regions with strong tellurics are indicated. The figure shows the normalized flux of the planet host TOI-1080 as a function of wavelength, between 0.9 to 2.35 microns.

Brown dwarfs (BDs)��are objects with masses between planets and stars, making them useful for understanding how properties change across this range. In this study, researchers report the discovery of two such objects—TOI-4776 b�����Ի���TOI-5422 b—identified using data from the TESS space telescope. Both are��transiting systems, meaning the brown dwarf passes in front of its host star, causing a small, measurable dip in brightness that reveals its size and orbit. Although the two objects have similar masses, they differ in age and physical properties.

TOI-4776 b is younger and larger, orbiting its star every ~10 days, and appears��“i�Դڱ����ٱ��”—its radius is bigger than expected based on standard models of how brown dwarfs evolve. In contrast, TOI-5422 b is older, smaller, and orbits more quickly (about every 5 days). It appears slightly����вԻ������ܳ����Դdzܲ�,”��meaning it emits less light than models predict, which is unusual for objects like this.

The study also found that the star hosting TOI-5422 b shows brightness variations linked to its rotation, suggesting the brown dwarf may be influencing the star’s spin. The alignment between the star’s rotation and the brown dwarf’s orbit indicates a close dynamical relationship. Overall, these two systems provide valuable examples for testing and refining models of how brown dwarfs form and evolve over time.

Figure 1.��Detrended TESS light curve of TOI-5422 shown as dark blue points. The star was observed at 10 minute cadence in TESS Sectors 43, 44, and 45, and 2 minute cadence in Sectors 71 and 72. Removed TESS data in Sectors 43–45 are shown as gray points. The binning shown here as yellow points uses bin sizes of 90 minutes. This star also exhibits photometric variations likely due to stellar rotation; these effects have been removed for the transit analysis. The red line is the fitted model from��EXOFASTv2.

]]> /valiant/2026/04/29/barriers-and-facilitators-to-implementing-a-shared-decision-making-tool-for-anticoagulant-related-drug-drug-interactions-a-qualitative-study-across-three-academic-medical-centres-in-the-usa/ Wed, 29 Apr 2026 03:56:36 +0000 /valiant/?p=6570

Becker, Robert A.; Bonnet, Kemberlee; Shah, Mauli V.; Dang, Elizabeth; Ancker, Jessica S.; Malone, Daniel C.; Trinkley, Katy E.; Gomez-Lumbreras, Ainhoa; Del Fiol, Guilherme; Kawamoto, Kensaku; Tawfik, Abdelrahman G.; Cornia, Ryan; Jones, Aubrey E.; Mitchell, James; Reese, Thomas J. (2026).��.��BMJ Open, 16(3).��