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Quadratic quasinormal modes at null infinity on a Schwarzschild
No full textThe ringdown of perturbed black holes has been studied since the 1970s, but until recently, studies have focused on linear perturbations. There is now burgeoning interest in nonlinear perturbative effects during ringdown. Here, using a hyperboloidal framework, we provide a complete treatment of linear and quadratic quasinormal modes (QNMs and QQNMs) in second-order perturbation theory, in Schwarzschild spacetime. We include novel methods for extracting QNMs and QQNMs amplitudes using a Laplace transform treatment, allowing for the inclusion of arbitrary initial data. We produce both time- and frequency-domain codes. From these codes, we present new results further exploring the unforeseen dependence of QQNMs amplitudes on the parity of the progenitor system, as demonstrated in our letter [Phys. Rev. Lett. 134, 061401 (2025).]. Our numerical results are restricted to perturbations of a Schwarzschild black hole, but our methods extend straightforwardly to the astrophysically realistic case of a Kerr black hole
Long-Term Exposure to Black Carbon and Incident Asthma and Chronic Obstructive Pulmonary Disease in Adults:The Danish Nurse Cohort
No full textBACKGROUND: Air pollution is a known risk factor for chronic respiratory diseases, including asthma and chronic obstructive pulmonary disease (COPD). However, evidence regarding the role of black carbon (BC) remains mixed and sparse. This study aimed to examine the association of long-term exposure to air pollution, focusing on BC, with incident asthma and COPD in adults.METHOD: We followed 28,731 female nurses from the Danish Nurse Cohort from baseline (1993/1999) until the end of 2018, tracking their first-ever hospital contact (inpatient, outpatient, or emergency visit) for asthma or COPD. Annual mean concentrations of BC, fine particulate matter (PM 2.5), and nitrogen dioxide (NO 2), were modeled since 1979 onward using the Danish DEHM/UBM/AirGIS modeling system and assigned to time-varying residential addresses. Time-varying Cox models were used to assess the association between 3-year running mean air pollution and incident asthma and COPD, adjusting for individual and area-level covariates. RESULTS: Over an average follow-up of 23 years, 633 nurses developed asthma, and 1,145 developed COPD. We found long-term exposure to BC was consistently associated with increased risks of both asthma and COPD, with hazard ratios (HR) per 0.34 μg/m 3 (interquartile range) increase in BC of 1.06 (95% confidence interval: 1.00-1.13) for asthma and 1.04 (0.98-1.11) for COPD. These associations persisted and strengthened after controlling for total PM 2.5 or non-BC PM 2.5. Stronger associations of air pollution were observed among individuals with underlying comorbidity. CONCLUSION: We observed that BC is an independent risk factor for developing chronic respiratory diseases, such as asthma and COPD, and BC may play a more significant role than PM 2.5. This underscored the need for targeted air quality regulations to reduce BC emissions, which may have a greater impact on mitigating the burden of chronic respiratory diseases than focusing solely on PM 2.5. </p
Transient glacio-eustatic fall and its climato-environmental effects during the Frasnian-Famennian transition
No full textThe cause of the Frasnian-Famennian (F F) boundary mass extinction, one of the largest Phanerozoic biocrises, remains uncertain. Here, we infer a short glaciation during the F F transition based on evidence of sea-level fall and major changes in terrestrial inputs and weathering fluxes, suggesting that climatic cooling was the proximate cause of the F F event. This study is based on an integrated elemental-isotopic-organic dataset from the West Valley core, representing prodelta facies of the Catskill Delta in western New York State. The 29-m-thick study interval records a shift from greenish-gray shales of the upper Hanover Formation to dark gray shales of the lower Dunkirk Formation that was accompanied by long-term increases in terrestrial organic and clay fluxes and more reducing watermass conditions. The 15-m interval bracketing the F F boundary shows three shifts from near-marine (background) salinity to low-brackish conditions, implying that sea-level falls caused the study site to transiently shift into the basin's low-salinity surface-water layer. Superimposed on the general lithologic changes in this F F transition section are twelve sedimentary cycles of ∼1–5 m thickness (avg. 2.5 m) characterized by strong variation in TOC and most geochemical proxies. These cycles record climatic variation at an orbital (possibly ∼18-kyr precessional) timescale, resulting in short-term fluctuations in sea level (as shown by salinity proxies) as well as in terrestrial organic and clastic fluxes (as reflected in organic and detrital proxies). Changes in sedimentary proxies at this short timescale show that the organic-rich layers were associated with more humid climatic conditions, higher sea-level stands (consistent with less continental ice mass), and more saline and reducing environmental conditions, whereas organic-poor layers were associated with drier climatic conditions, lower sea-level stands (consistent with more continental ice mass), and less saline and reducing environmental conditions. The F F event, which spans seven such cycles, thus represents a comparatively short glacial episode with a duration of just ∼126 ± 18 kyr, although it is comparable to the more severe Devonian-Carboniferous (D C) boundary glaciation that heralded the onset of the Late Paleozoic Ice Age ∼12 million years later. Both the F F and D C biocrises represent carbon-burial-type events and, although their ultimate cause(s) remain in debate, the existing observations favor a bioevolutionary mechanism linked to the evolution and spread of land plants.</p
Monogamy of Highly Symmetric States
No full textWe investigate the extent to which two particles can be maximally entangled when they are also similarly entangled with other particles on a complete graph, focusing on Werner, isotropic, and Brauer states. To address this, we formulate and solve optimization problems that draw on concepts from many-body physics, computational complexity, and quantum cryptography. We approach the problem by formalizing it as a semi-definite program (SDP), which we solve analytically using tools from representation theory. Notably, we determine the exact maximum values for the projection onto the maximally entangled state and the antisymmetric Werner state, thereby resolving long-standing open problems in the field of quantum extendibility. Our results are achieved by leveraging SDP duality, the representation theory of symmetric, unitary and orthogonal groups, and the Brauer algebra.</p
Refining near-infrared spectroscopy for collagen quantification:A new predictive model for archaeological bone
No full textCollagen is a vital archaeological material, preserving biochemical signatures that provide insights into past environments, diets, and human-animal interactions. However, diagenesis can lead to rapid and inconspicuous collagen degradation. Given the variability in collagen preservation and its significance for analyses such as radiocarbon dating, stable isotope analysis, and ZooMS, researchers have developed prescreening techniques to assess collagen preservation before destructive sampling. Current prescreening approaches, including %N and C:N ratios, typically require sample destruction and access to equipped laboratories. Spectroscopic techniques such as Raman spectroscopy and Fourier Transform Infrared spectroscopy have been explored as alternatives, but they are limited in penetration depth, generalizability (at present at least), and are often still destructive, if minimally. Here, we further develop single-point near-infrared (NIR) spectroscopy as a fully non-destructive, rapid, and field-portable method for prescreening bone for collagen preservation. Unlike FTIR and Raman spectroscopic techniques, NIR light penetrates below the surface of bone, enabling assessment of internal collagen preservation without destructive sample preparation. Using Partial Least Squares Regression (PLSR) and Random Forest (RF) modeling, we trained predictive models on whole bones with known collagen yields and validated the models on an independent archaeological collection. Both PLSR and RF models, when restricted to the 2030–2060 nm range, demonstrate strong and comparable performance while avoiding wavelengths associated with consolidants in our reference library. The models outperform traditional % N-based methods in identifying suitable samples for radiocarbon dating. These models enable the high-throughput screening of large collections of bone, improving sample selection and minimizing unnecessary destructive analysis.</p
Gatemon qubit revisited for improved reliability and stability
No full textThe development of quantum circuits based on hybrid superconductor-semiconductor Josephson junctions holds promise for exploring their mesoscopic physics and for building innovative superconducting devices. The gate-tunable superconducting transmon qubit (gatemon) is the paradigmatic example of such a superconducting circuit; however, gatemons typically suffer from unstable and hysteretic qubit frequencies with respect to the applied gate voltage and reduced coherence times compared to conventional transmons fabricated from aluminum-oxide-based Josephson junctions. Here, we develop methods for characterizing these challenges in gatemons and deploy these methods to compare the impact of shunt-capacitor designs on gatemon performance. Our results indicate a strong frequency-and design-dependent behavior of the qubit stability, hysteresis, and dephasing times. Moreover, we achieve highly reliable tuning of the qubit frequency with 1-MHz precision over a range of several gigahertz, along with improved stability in grounded gatemons compared to gatemons with a floating capacitor design
Global variation in Cr-spinel trace elements
No full textThe major element composition of Cr-spinel [(Mg,Fe2+)(Cr,Al,Fe3+)2O4] has long been used to infer the petrogenesis and tectonic setting of its host rocks. However, overlaps in major element compositions and susceptibility of Mg and Fe2+ to secondary alteration limit its diagnostic utility. In contrast, some trace elements may be particularly diagnostic of certain petrogenic processes or retain primary signatures even when major elements are modified, offering a complementary tool for petrogenetic interpretation. However, a comprehensive evaluation of the systematics of trace elements in Cr-spinel has not yet been undertaken.This study compiles major and trace element data from Cr-spinel-bearing samples worldwide to assess global variability and to identify robust geochemical indicators. Based on a larger, more representative set of Mid-Ocean Ridge Basalt (MORB) spinel data we present new MORB spinel normalization values and a recommended element order for spinel multi-element plots. We document systematic variations in trace elements (Sc, Ga, V, Ni, Mn) with Cr# (Cr# = Cr/(Cr + Al) mol.), particularly in mantle-derived spinels, and show that these trends reflect mantle depletion. Melting models and regression of literature partition coefficients demonstrate that partitioning of Sc, Ga, Ni, Mn, and Ti is likely compositionally controlled.We also show that Cr-spinels from lavas and intrusions can be distinguished based on late-stage re-equilibration with interstitial melt, evident from the low Ru and Cu contents and Sc/Ga ratios in Cr-spinels from intrusions. Our findings highlight the potential of trace element systematics in Cr-spinel as a powerful tool for reconstructing the petrogenesis of mafic-ultramafic rocks
Extra-virgin olive oil and additional cardiovascular outcomes in the PREDIMED Trial:An outcome-wide perspective
No full textBackgroundOlive oil, increasingly consumed in the U.S., has been inversely associated with cardiovascular disease (CVD) risk. However, previous studies did not assess a broad spectrum of CVD outcomes, incorporated repeated annual dietary assessments, or distinguished between polyphenol-rich EVOO and common olive oil (COO), which lacks these compounds.MethodsWe assessed 7102 high-risk participants from the PREDIMED trial (57.5% women; aged 55-80 years), all free of CVD at baseline. Olive oil consumption was assessed annually, and cumulative average intakes of EVOO and COO were calculated. The primary outcome was a composite of myocardial infarction, stroke, peripheral arterial disease, heart failure, atrial fibrillation, or cardiovascular death, whichever occurred first. Individual outcomes were also evaluated. Time-dependent Cox models were adjusted for major confounders, including trial intervention arm.ResultsOver a median follow-up of 4.7 years, 621 participants experienced at least one CVD event. Participants in the highest tertile of cumulative EVOO intake (mean: 49.2 g/d) had a 25% lower risk of the composite outcome (HR: 0.75; 95% CI: 0.60-0.94), with significant reductions in several individual CVD outcomes. In the decile analysis, the highest (mean: 60.9 g/d) versus lowest decile had a 48% lower risk (HR: 0.52; 95% CI: 0.35 to 0.79). COO consumption was not significantly associated with CVD risk when mutually adjusted for EVOO (HRper 10 g/d: 0.93; 95% CI: 0.87-1.00).ConclusionsHigh consumption of EVOO is associated with a substantial reduction in the risk of an outcome-wide composite of CVD events among high-risk individuals. In contrast, COO, which lacks polyphenols, showed weaker associations, highlighting the importance of differentiating olive oil types in CVD prevention strategies.Trial RegistrationThis trial was registered in the ISRCTN registry (ISRCTN 35739639): https://www.isrctn.com/ISRCTN35739639.Background: Olive oil, increasingly consumed in the U.S., has been inversely associated with cardiovascular disease (CVD) risk. However, previous studies did not assess a broad spectrum of CVD outcomes, incorporated repeated annual dietary assessments, or distinguished between polyphenol-rich EVOO and common olive oil (COO), which lacks these compounds. Methods: We assessed 7102 high-risk participants from the PREDIMED trial (57.5% women; aged 55-80 years), all free of CVD at baseline. Olive oil consumption was assessed annually, and cumulative average intakes of EVOO and COO were calculated. The primary outcome was a composite of myocardial infarction, stroke, peripheral arterial disease, heart failure, atrial fibrillation, or cardiovascular death, whichever occurred first. Individual outcomes were also evaluated. Time-dependent Cox models were adjusted for major confounders, including trial intervention arm. Results: Over a median follow-up of 4.7 years, 621 participants experienced at least one CVD event. Participants in the highest tertile of cumulative EVOO intake (mean: 49.2 g/d) had a 25% lower risk of the composite outcome (HR: 0.75; 95% CI: 0.60-0.94), with significant reductions in several individual CVD outcomes. In the decile analysis, the highest (mean: 60.9 g/d) versus lowest decile had a 48% lower risk (HR: 0.52; 95% CI: 0.35 to 0.79). COO consumption was not significantly associated with CVD risk when mutually adjusted for EVOO (HRper 10 g/d: 0.93; 95% CI: 0.87-1.00). Conclusions: High consumption of EVOO is associated with a substantial reduction in the risk of an outcome-wide composite of CVD events among high-risk individuals. In contrast, COO, which lacks polyphenols, showed weaker associations, highlighting the importance of differentiating olive oil types in CVD prevention strategies. Trial Registration: This trial was registered in the ISRCTN registry (ISRCTN 35739639): https://www.isrctn.com/ISRCTN35739639.</p
Anwar Ibrahim: Tenacious in Dissent, Hopeful in Power:Khoo Boo Teik. Kuala Lumpur: Strategic Information and Research Development Centre, 2023.
No full textThe key to bubble-net feeding:how humpback whale morphology functionally differs from other baleen whales
No full textManeuverability in cetaceans is facilitated by pectoral flippers, flukes and spinal flexibility, features that are pronounced in humpback whales (Megaptera novaeangliae). Humpback whales exhibit several foraging tactics requiring high maneuverability not seen in other baleen whales, including bubble-net feeding. We hypothesized that the significant lift force produced by the humpback whale’s uniquely large pectoral flippers will result in them being the only species observed executing the tight, high-speed, sustained turns characteristic of solitary bubble-net feeding. To test this hypothesis, we used a combination of inertial sensor tag data and unoccupied aerial systems (UAS; drone) photogrammetry to quantify the turning performance of solitary bubble-net feeding humpback whales, and compared this to similar data from six other mysticete species. We found that solitary bubble-net feeding humpback whales exhibited centripetal accelerations (0.46 m s−2) that exceeded the upper limit quantified in comparable turns by all six other mysticetes. This enhanced turning performance can be attributed to a substantial lift force generated by the humpback whale’s pectoral flippers (7800±85 N), which contributes to centripetal acceleration and facilitates faster roll rates, allowing humpback whales to more quickly bank inwards and utilize their spinal flexibility to decrease their turning radius. Our findings demonstrate how humpback whales are uniquely adapted to exploit prey patches that might otherwise be insufficient for capture by animals of such a large size.</p