The elements in the Universe are synthesized primarily in stars and supernovae, where nuclear fusion favours the production of even-Z elements. In contrast, odd-Z elements are less abundant and their yields are highly dependent on detailed stellar physics, making theoretical predictions of their cosmic abundance uncertain. In particular, the origin of odd-Z elements such as phosphorus (P), chlorine (Cl) and potassium (K), which are important for planet formation and life, is poorly understood. While the abundances of these elements in Milky Way stars are close to solar values, supernova explosion models systematically underestimate their production by up to an order of magnitude, indicating that key mechanisms for odd-Z nucleosynthesis are currently missing from theoretical models. Here we report the observation of P, Cl and K in the Cassiopeia A supernova remnant using high-resolution X-ray spectroscopy with X-Ray Imaging and Spectroscopy Mission data, with the detection of K at above the 6 sigma level being the most significant finding. Supernova explosion models of normal massive stars cannot explain the element abundance pattern, especially the high abundances of Cl and K, while models that include stellar rotation, binary interactions or shell mergers agree closely with the observations. Our observations suggest that such stellar activity plays an important role in supplying these elements to the Universe.
In this Letter, we present a compelling and robust argument for the roles of neutrino fast flavor conversion (FFC) in the explosion mechanism of core-collapse supernova (CCSN), combining the multi-angle FFC subgrid model rooted in quantum kinetic theory with the multi-dimensional four-species Boltzmann neutrino radiation hydrodynamics. Employing various progenitor masses and the nuclear equations of states, we find that the effect of FFC on CCSN explosion is bifurcated depending on the progenitors. For the lowest-mass progenitor, FFC facilitates the shock revival and enhances the explosion energy, whereas for higher-mass progenitors its impact is inhibitory. We identify the mass accretion rate as the key determinant governing this bifurcation. When the mass accretion rate is low (high), the contribution of FFC to neutrino heating becomes positive (negative), because the heating efficiency enhancement via FFC-driven spectral hardening of electron-type neutrinos dominates over (is outweighed by) the concurrent reduction in neutrino luminosity. Our results further highlight the limitations of approximate neutrino transport, and demonstrate that a multi-angle treatment is essential for accurately capturing FFC effects; otherwise, FFCs are missed and even generated spuriously.
As demonstrated, heart rate variability (HRV) biofeedback (HRVB) is effective in managing chronic conditions. However, reviews specifically addressing HRVB effects on cardiac autonomic dysfunction in patients with cardiovascular diseases (CVDs) are lacking. We evaluated HRVB effects on autonomic, hemodynamic, and psychological outcomes in such patients. This systematic review and meta-analysis of randomized controlled trials (RCTs) searched MEDLINE, CINAHL, Web of Science, Cochrane Central Register of Controlled Trials, and Igaku Chuo Zasshi from inception to April 2025. We included RCTs on HRVB in CVD populations and excluded those without HRV, clinical, or psychological outcomes. Two reviewers independently screened, extracted data, and assessed risk of bias using Cochrane RoB 2 tool. Random-effects models were applied to HRV indices, blood pressure, respiratory rate, and psychological outcomes. From 2402 records, 13 RCTs (965 participants; 795 analyzed) were included. HRVB significantly improved the standard deviation of NN interval; low-frequency (LF) and logLF increased, high-frequency (HF) and logHF showed no significant changes. Both systolic (mean difference [MD] = − 3.08, 95
We present extended gas kinematic maps of the Perseus cluster based on a combination of five new XRISM/Resolve pointings observed in 2025 with four performance verification datasets from 2024, totaling a net exposure of 745 ks. To date, Perseus remains the only cluster that has been extensively mapped out to similar or equal to 0.7r(2500) by XRISM/Resolve, while simultaneously offering sufficient spatial resolution to resolve gaseous substructures driven by mergers and active galactic nucleus (AGN) feedback. Our observations cover multiple radial directions and a broad range of dynamical scales, enabling us to characterize the kinematic properties of the intracluster medium up to a scale of similar to 500 kpc. In the measurements, we detected high-velocity dispersions (similar or equal to 300km s(-1)) in the eastern region of the cluster that are spatially coincident with the extended X-ray surface brightness excess and correspond to a nonthermal pressure fraction of similar or equal to 7 - 13%. The velocity field outside the AGN-dominant region can be effectively described by a single, large-scale kinematic driver based on the velocity structure function, which statistically favors an energy injection scale of at least a few hundred kpc. The estimated turbulent dissipation energy is comparable to the gravitational potential energy released by a recent merger, implying a significant role of turbulent cascade in the merger energy conversion. In the bulk velocity field, we observed a dipole-like pattern along the east-west direction with an amplitude of similar or equal to +/- 200 - 300 km s(-1), indicating rotational motions induced by the recent merger event. This feature constrains the viewing direction to similar or equal to 30 degrees -50 degrees relative to the normal of the merger plane. Our hydrodynamic simulations suggest that Perseus has experienced at least two energetic mergers since redshift z similar to 1, the most recent of which is associated with the radio galaxy IC310, in agreement with recent SRG/eROSITA findings. This study showcases exciting scientific opportunities for future missions with high-resolution spectroscopic capabilities (e.g., HUBS, LEM, and NewAthena).
Q(t) measurement has been developed as a diagnostic technique for electrical insulators in DC applications, and is widely used to compare the relative properties of polymeric samples under high voltage; however, its conventional usage is limited to analyzing the charge amount compared to the space charge phenomenon. Conversely, Q(t) measurement can also serve as a diagnostic tool for leakage current through insulation materials because of its relatively high precision; hence, this study focuses on utilizing this method as an online abnormal detector. However, first, noisy data resulting from variable circumstances remains a challenge, even when simple low-pass filters are applied. This study ensures noise reduction by assuming an ordinary differential equation model and applying Kalman filters/Rauch–Tung–Striebel (RTS) smoothers to the experimental data of a polyimide sheet sample. Filtering/smoothing reduces the noise level to less than 1/900 of the simple first-difference data when an RTS smoother is applied, according to the comparison method that utilizes linearly-approximated data. Then, fixed-lag smoothers are applied, generally obtaining more smoothed data than that of the Kalman filter. Through the filtered results and Kalman filters’ property as an adaptive low-pass filter, a direction for filter designing is proposed, which depends on ‘process noise to the 2nd power’ / ‘observation noise.’ The filtering/evaluation/designing methods utilized in this study are beneficial for more precise diagnoses and are expected to provide a foundation for online leakage current detection.
