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The adoption of maize as a dietary staple shaped human societies. While a reliable carbohydrate-rich source, its inherent nutritional limitations posed substantial challenges. Maize is deficient in lysine, an essential amino acid crucial for maintaining balanced health. Maize-dependent diets, therefore, necessitated complementary dietary strategies. We report amino acid stable carbon isotope data from 39 directly dated humans from southern Belize (6,100-1,100 BP) to investigate how early populations mitigated nutritional deficiencies. Concentration-dependent mixing model results indicate that protein supplementation from maize-eating animals contributed maize-derived lysine to human diets through trophic magnification (elevated proportions of isotopically distinct nutrients in tissues from trophic transfer). Our results indicate that such strategies were in place by 6,100 BP, consistent with evidence of early maize cultivation but predating reliance by ~2,000 years. Our findings highlight early coevolutionary dynamics linking maize cultivation and human-animal provisioning relationships, deepening understandings of adaptive food systems during agricultural transitions and offering insights into nutritional strategies underpinning sustainable subsistence. 

Abstract This study investigates impacts of the May 2024 superstorm on the mid‐latitude Global Positioning System (GPS) scintillation and position errors. Using 1‐Hz GPS receiver data, we identified position errors in PPP mode reaching up to 70 m in the Central United States during the storm main phase on May 10. The PPK solution becomes unstable following the arrival of storm and lasted till the recovery phase, coinciding with reported GPS outages of farming equipment. The large position errors were attributed to strong scintillation and carrier phase cycle slips around the equatorward boundary of the ionosphere trough, where large total electron content (TEC) gradients and irregularities were present. In the Southwestern United States, position errors of 10–20 m were associated with the storm‐enhanced density and equatorial ionization anomaly. Scintillation and cycle slips in this region were minor, and bending of the GPS signal paths (refractive effect) is suggested to cause the position errors. PPP outages were also associated with sudden changes in the geometric distributions of available GPS satellites used in position calculations. On May 11, energetic particle precipitation during substorms led to abrupt jumps in TEC and scintillation, resulting in rapidly evolving position errors of up to 10 m. These findings highlight the critical role of storm‐time plasma transport, precipitation, and irregularity formation in degrading GPS performance. The study underscores the need for accurate ionospheric state specification, improved signal processing technique, real‐time ionospheric corrections, and optimized satellite selection algorithms, to enhance navigation resilience during severe space weather events. 

Abstract This study investigates the impact of high‐latitude ionospheric irregularities on global positioning system (GPS) position accuracy during the 10–11 May 2024 geomagnetic storm. Using data from ground‐based GPS receivers and an all‐sky camera in Antarctica, we examined evolution of GPS vertical total electron content, phase fluctuations, and precise point positioning (PPP) errors. Results reveal that auroral precipitation associated with the coronal mass ejection shock induced significant GPS phase fluctuations and positioning errors in the dayside cusp region. Tongues of ionization (TOIs) had the largest and most sustained impact on signal disruptions and degraded position accuracy, with a peak position error reaching 28 m. Furthermore, dawnside auroral activity during the substorms and poleward boundary intensifications (PBIs) caused localized disturbances in the auroral oval. Despite sufficient satellite visibility, these irregularities significantly compromised GPS positioning performance. 

Abstract BackgroundHeavy ion radiotherapy offers distinct advantages over conventional treatments due to its superior dose distribution and enhanced biological effectiveness. However, the microdosimetric characteristics of high linear energy transfer (LET) ions, particularly near the Bragg peak, remain poorly characterized. Most experimental microdosimetry has been conducted at lower LETs, leaving a critical gap in high‐LET microdosimetric data. PurposeThis study aims to extend microdosimetry to several different high‐LET ions (700–2500 keV/µm) using the novel ENCORE detector. MethodsMicrodosimetry was performed at the Florida State University John D. Fox Accelerator Laboratory using the ENCORE detector, a multi‐sampling ionization chamber filled with low‐pressure tissue‐equivalent gas capable of resolving energy deposition from approximately 200 keV to 3 MeV.¹²C,¹⁶O, and²⁸Si beams were accelerated to 17–55 MeV and delivered to the segmented detector. Energy deposition patterns near the Bragg peak were recorded, and microdosimetric spectra were reconstructed. Monte Carlo was used to model the experimental setup. From each measured and simulated spectra, dose‐mean lineal energy () was calculated and compared. ResultsThe 16 strips of the ENCORE corresponded to a tissue‐equivalent thickness of 17.6 µm, enabling resolution of energy deposition immediately proximal and distal to the Bragg peak. In six measurement configurations, the ion beam stopped within this range, allowing precise mapping of the profile around the peak; in the remaining configurations, the beam fully traversed the detector. Across all beams, difference between measured and simulated averaged 12%, based on one measurement per strip. Peak measured reached 920 ± 220, 1240 ± 206, and 2460 ± 620 keV/µm for¹²C,¹⁶O, and²⁸Si beams, respectively. ConclusionThis study demonstrated that ENCORE can resolve microdosimetric spectra with high spatial and LET resolution across a range of ion energies. Measured values reasonably agreed with Monte Carlo simulations, validating the potential of ENCORE for position‐resolved microdosimetry and model benchmarking in particle therapy. 

The middle-late Holocene in Southern Belize saw shifts in subsistence strategies including the introduction of managed plants and animals. Botanical and stable isotopic data have been used to track the introduction of agricultural products into diet with maize first consumed before 7,000 cal. BP. However, the timing of the introduction of managed animals is less understood because early faunal assemblages are rare. Carbon isotope (d13C) analysis of amino acids (CSIA-AA) is a powerful tool that allows researchers to track biochemical origins of individual amino acids into consumer tissues. CSIA-AA analysis of directly dated human skeletons from two rockshelters spanning the transition to agriculture show a trend of increasing d13Clysine values indicating a C4 lysine origin in individuals by the Classic Maya period. Additionally, individuals that date to the middle Holocene demonstrate higher than expected incorporation of C4-derived lysine. Based on the low abundance of lysine in maize (C4-plant) and daily lysine requirements in humans, these results are only possible through trophic concentration of C4-derived lysine, obtained by consuming maize-eating animals. We propose that human d13Clysine values can be used to track the incorporation of managed, but not necessarily domesticated, animals into neotropical diets during the transition to agriculture. 

Novel quantum materials offer the opportunity to expand next-generation computers, high-precision sensors, and new energy technologies. Among the most important factors influencing the development of quantum materials research is the ability of inorganic and materials chemists to grow high-quality single crystals. Here, the synthesis, structure characterization and magnetic properties of Na2Cu3(SeO3)4 are reported. It exhibits a novel two-dimensional (2D) structure with isolated layers of Cu nets. Single crystals of Na2Cu3(SeO3)4 were grown using a low-temperature hydrothermal method. Single-crystal X-ray diffraction reveals that Na2Cu3(SeO3)4 crystallizes in the monoclinic crystal system and has space group symmetry of P21/n (No.14) with a unit cell of a = 8.1704(4) Å, b = 5.1659(2) Å, c = 14.7406(6) Å, β = 100.86(2), V = 611.01(5) Å3 and Z = 2. Na2Cu3(SeO3)4 comprises a 2D Cu-O-Cu lattice containing two unique copper sites, a CuO6 octahedra and a CuO5 square pyramid. The SeO3 groups bridge the 2D Cu-O-Cu layers isolating the neighboring Cu-O-Cu layers, thereby enhancing their 2D nature. Magnetic properties were determined by measuring the magnetic susceptibility of an array of randomly oriented single crystals of Na2Cu3(SeO3)4. The temperature-dependent magnetic measurement shows an antiferromagnetic transition at TN = 4 K. These results suggest the fruitfulness of hydrothermal synthesis in achieving novel quantum materials and encourage future work on the chemistry of transition metal selenite. 

Phase-pure polycrystalline Ba4RuMn2O10 was prepared and determined to adopt the noncentrosymmetric polar crystal structure (space group Cmc21) based on results of second harmonic generation, convergent beam electron diffraction, and Rietveld refinements using powder neutron diffraction data. The crystal structure features zigzag chains of corner-shared trimers, which contain three distorted face-sharing octahedra. The three metal sites in the trimers are occupied by disordered Ru/Mn with three different ratios: Ru1:Mn1 = 0.202(8):0.798(8), Ru2:Mn2 = 0.27(1):0.73(1), and Ru3:Mn3 = 0.40(1):0.60(1), successfully lowering the symmetry and inducing the polar crystal structure from the centrosymmetric parent compounds Ba4T3O10 (T = Mn, Ru; space group Cmca). The valence state of Ru/Mn is confirmed to be +4 according to X-ray absorption near-edge spectroscopy. Ba4RuMn2O10 is a narrow bandgap (∼0.6 eV) semiconductor exhibiting spin-glass behavior with strong magnetic frustration and antiferromagnetic interactions. 

ABSTRACT We conducted a GPU-accelerated reprocessing of $$\sim 87~{{\ \rm per\ cent}}$$ of the archival data from the High Time Resolution Universe South Low Latitude (HTRU-S LowLat) pulsar survey by implementing a pulsar search pipeline that was previously used to reprocess the Parkes Multibeam Pulsar Survey (PMPS). We coherently searched the full 72-min observations of the survey with an acceleration search range up to $$|50|\, \rm m\, s^{-2}$$, which is most sensitive to binary pulsars experiencing nearly constant acceleration during 72 min of their orbital period. Here we report the discovery of 71 pulsars, including six millisecond pulsars, of which five are in binary systems, and seven pulsars with very high dispersion measures (DM $$\gt 800 \, \rm pc \, cm^{-3}$$). These pulsar discoveries largely arose by folding candidates to a much lower spectral signal-to-noise ratio than in previous surveys and by exploiting the coherence of folding over the incoherent summing of the Fourier components to discover new pulsars as well as candidate classification techniques. We show that these pulsars could be fainter and on average more distant as compared with both the previously reported 100 HTRU-S LowLat pulsars and the background pulsar population in the survey region. We have assessed the effectiveness of our search method and the overall pulsar yield of the survey. We show that through this reprocessing we have achieved the expected survey goals, including the predicted number of pulsars in the survey region, and discuss the major causes why these pulsars were missed in previous processing of the survey.