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Volatile organic compounds (VOCs) are often subject to synergistic oxidation by different oxidants in the atmosphere. However, the exact synergistic-oxidation mechanism of atmospheric VOCs and its role in particle formation remain poorly understood. In particular, the reaction kinetics of the key reactive intermediates, organic peroxy radicals (RO2), during synergistic oxidation is rarely studied. Here, we conducted a combined experimental and kinetic modeling study of the nocturnal synergistic oxidation of α-pinene (the most abundant monoterpene) by O3 and NO3 radicals as well as its influences on the formation of highly oxygenated organic molecules (HOMs) and particles. We find that in the synergistic O3 + NO3 regime, where OH radicals are abundantly formed via decomposition of ozonolysis-derived Criegee intermediates, the production of CxHyOz HOMs is substantially suppressed compared to that in the O3-only regime, mainly because of the depletion of α-pinene RO2 derived from ozonolysis and OH oxidation by those arising from NO3 oxidation via cross reactions. Measurement–model comparisons further reveal that the cross-reaction rate constants of NO3-derived RO2 with O3-derived RO2 are on average 10–100 times larger than those of NO3-derived RO2 with OH-derived RO2. Despite a strong production of organic nitrates in the synergistic-oxidation regime, the substantial decrease in CxHyOz HOM formation leads to a significant reduction in ultralow- and extremely low-volatility organic compounds, which significantly inhibits the formation of new particles. This work provides valuable mechanistic and quantitative insights into the nocturnal synergistic-oxidation chemistry of biogenic emissions and will help to better understand the formation of low-volatility organic compounds and particles in the atmosphere.

Abstract Previous studies arguing for parental care in dinosaurs have been primarily based on fossil accumulations of adults and hatchlings, perinatal and post-hatchlings in nests and nest areas, and evidence of brooding, the majority of which date to the Late Cretaceous. Similarly, the general body proportions of preserved embryonic skeletons of the much older Early Jurassic Massospondylus have been used to suggest that hatchlings were unable to forage for themselves. Here, we approach the question of parental care in dinosaurs by using a combined morphological, chemical, and biomechanical approach to compare early embryonic and hatchling bones of the Early Jurassic sauropodomorph Lufengosaurus with those of extant avian taxa with known levels of parental care. We compare femora, the main weight-bearing limb bone, at various embryonic and post-embryonic stages in a precocious and an altricial extant avian dinosaur with those of embryonic and hatchling Lufengosaurus, and find that the rate and degree of bone development in Lufengosaurus is closer to that of the highly altricial Columba (pigeon) than the precocious Gallus (chicken), providing strong support for the hypothesis that Lufengosaurus was fully altricial. We suggest that the limb bones of Lufengosaurus hatchlings were not strong enough to forage for themselves and would likely need parental feeding.

Abstract This study asked if combining different motor learning mechanisms—adaptation and reinforcement—could produce immediate improvements in over ground walking after stroke. Fifteen adults with stroke engaged in three conditions: (1) reinforcement following adaptation, (2) reinforcement alone, and (3) adaptation alone. Adaptation involved split-belt treadmill walking to produce after-effects that reduce step asymmetry. Reinforcement involved the use of real-time auditory feedback about step length asymmetry. Auditory feedback was binary, signaling whether steps were asymmetric or equal, but not whether to shorten or lengthen either step. Change in step length asymmetry was the outcome assessed during over ground walking. Reinforcement following adaptation led to reductions in step length asymmetry that persisted into an immediate retention period. Importantly, it led to the desired pattern of lengthening the shorter step in a majority of participants. Reinforcement alone led to no significant change in step length asymmetry, and sometimes produced a non-optimal pattern of shortening the longer step. Our control condition of adaptation alone led to more transient reductions in step length asymmetry. These findings reveal the potential for utilizing serial delivery of adaptation and reinforcement to influence a complex movement in the real-world context of over ground walking, in people with stroke.

Discussions of 'diversity' in higher education are often limited to structural diversity (i.e. access to higher education based on demographic variables), which is just one form of diversity that impacts student learning outcomes. Others include curricular diversity (a measure of the interdisciplinary of the coursework) and interactional diversity (a measure of informal interaction). This study aims to explore the effects of all three categories of diversity on the academic performance of college students. Using data from a top higher education institution in Taiwan, we construct indicators of curricular diversity (i.e. curricular evenness (CE), ratio of elective credits (REC), ratio of inter-collegiate credits (RIC), and interdisciplinary experience (IDE). Interactional diversity was measured using student's participation in activities involving interaction with others, and structural diversity was measured by student's personal and contextual characteristics. Our goal was to determine which of these forms of diversity impacted students' self-reported skills in interdisciplinary communication (ICS) and collaborative problem solving (CPS). Results show that curricular diversity is significantly associated with interactional diversity. In terms of learning outcomes, curricular and structural diversity are associated with both ICS and CPS, while interactional diversity is associated with CPS. Interactional diversity also moderates the relationships between curricular diversity and ICS as well as CPS. This research implies that institutions of higher education need to promote curricular and interactive diversity to fix systemic biases that limit or relate to structural diversity.

Abstract The mechanical function of the myocardium is defined by cardiomyocyte contractility and the biomechanics of the extracellular matrix (ECM). Understanding this relationship remains an important unmet challenge due to limitations in existing approaches for engineering myocardial tissue. Here, they established arrays of cardiac microtissues with tunable mechanics and architecture by integrating ECM‐mimetic synthetic, fiber matrices, and induced pluripotent stem cell‐derived cardiomyocytes (iPSC‐CMs), enabling real‐time contractility readouts, in‐depth structural assessment, and tissue‐specific computational modeling. They found that the stiffness and alignment of matrix fibers distinctly affect the structural development and contractile function of pure iPSC‐CM tissues. Further examination into the impact of fibrous matrix stiffness enabled by computational models and quantitative immunofluorescence implicates cell‐ECM interactions in myofibril assembly, myofibril maturation, and notably costamere assembly, which correlates with improved contractile function of tissues. These results highlight how iPSC‐CM tissue models with controllable architecture and mechanics can elucidate mechanisms of tissue maturation and disease.

Summary: Diet significantly influences the human gut microbiota, a key player in health. We analyzed shotgun metagenomic sequencing data from healthy individuals with long-term dietary patterns—vegan, flexitarian, or omnivore—and included detailed dietary surveys and blood biomarkers. Dietary patterns notably affected the bacterial community composition by altering the relative abundances of certain species but had a minimal impact on microbial functional repertoires. However, diet influenced microbial functionality at the strain level, with diet type linked to strain genetic variations. We also found molecular signatures of selective pressure in species enriched by specific diets. Notably, species enriched in omnivores exhibited stronger positive selection, such as multiple iron-regulating genes in the meat-favoring bacterium Odoribacter splanchnicus, an effect that was also validated in independent cohorts. Our findings offer insights into how diet shapes species and genetic diversity in the human gut microbiota.

This study aimed to investigate the performance of Multicarrier Phase Coding (MCPC) and P4-encoded waveforms. Researchers explored the unique properties of these signals, focusing on aspects like phase distribution, autocorrelation, power spectral density for P4 encoding, and aperiodic autocorrelation and ambiguity function for MCPC signals. The findings identified optimal MCPC sequences with reduced peak-to-mean envelope power ratios (PMEPR), improving signal performance. Complementary codes based on permutation were also generated and analyzed for MCPC sequences. The study utilized an improved genetic algorithm to develop new and improved waveforms, underscoring the importance of techniques like optimal sequence permutation, complementary sequences, and classical window frequency weighting in enhancing signal performance.

Volatile organic compounds (VOCs) affect secondary pollutant formation via active chemistry. Proton-transfer-reaction mass spectrometry (PTR-MS) is one of the most important techniques to study the highly variable spatial and temporal characteristics of VOCs. The response of protonated, adduct, and fragmented ions in PTR-MS in changing instrument settings and varying relative humidity (RH) requires rigorous characterization. Herein, we present dedicatedly designed laboratory experiments conducted to investigate the response of these ions for 21 VOCs, including 12 oxygenated VOCs and 2 nitriles, using the recently developed Vocus PTR-MS. Our results show that the focusing ion–molecule reactor (FIMR) axial voltage increases sensitivity by 3 to 4 orders of magnitude but does not significantly change the fractions of protonated ions. Reducing the FIMR pressure, however, substantially increases fragmentation. Applying a high radio frequency (RF) amplitude radially to the FIMR can enhance sensitivity by 1 to 2 orders of magnitude without affecting the protonated ion fractions. The change in big segmented quadrupole (BSQ) amplitude mainly affects sensitivity and protonated ion fraction by modifying ion transmission. The relationship between sensitivity and proton-transfer reaction rate constant is complicated by the influences from both ion transmission and protonated ion fraction. The protonated ions of most VOCs studied (19 out of 21) show less than 15 % variations in sensitivity as RH increases from ∼ 5% to ∼ 85 %, except for some long-chain aldehydes which show a positive RH variation of up to 30 %. Our results suggest that the Vocus PTR-MS can reliably quantify the majority of VOCs under ambient conditions with varying RH. However, caution is advised for small oxygenates such as formaldehyde and methanol due to their low sensitivity and for long-chain aldehydes due to their slight RH dependence and fragmentation.

Abstract Synthetic biologists seek to engineer intelligent living systems capable of decision-making, communication, and memory. Separate technologies exist for each tenet of intelligence; however, the unification of all three properties in a living system has not been achieved. Here, we engineer completely intelligent Escherichia coli strains that harbor six orthogonal and inducible genome-integrated recombinases, forming Molecularly Encoded Memory via an Orthogonal Recombinase arraY (MEMORY). MEMORY chassis cells facilitate intelligence via the discrete multi-input regulation of recombinase functions enabling inheritable DNA inversions, deletions, and genomic insertions. MEMORY cells can achieve programmable and permanent gain (or loss) of functions extrachromosomally or from a specific genomic locus, without the loss or modification of the MEMORY platform – enabling the sequential programming and reprogramming of DNA circuits within the cell. We demonstrate all three tenets of intelligence via a probiotic (Nissle 1917) MEMORY strain capable of information exchange with the gastrointestinal commensal Bacteroides thetaiotaomicron.

Introduction: Emergency medicine (EM) is one of few specialties with variable training lengths. Hiring a three-year graduate to continue fellowship training in a department that supports a four-year residency program can lead to conflicts around resident supervision. We sought to understand hiring and clinical supervision, or staffing, patterns of non-Accreditation Council for Graduate Medical Education (ACGME) fellowships hosted at institutions supporting four-year residency programs. Methods: We performed a web-based, cross-sectional survey of non-ACGME fellowship directors (FD) hosted at institutions supporting four-year EM residency programs. We calculated descriptive statistics. Our primary outcome was the proportion of programs with four-year EM residencies that hire non-ACGME fellows graduating from three-year EM residencies. Results: Of 119 eligible FDs, 88 (74%) completed the survey. Seventy FDs (80%) indicated that they hire graduates of three-year residencies. Fifty-six (80%) indicated that three-year graduates supervise residents. Most FDs (74%) indicated no additional requirements exist to supervise residents outside of being hired as faculty. The FDs cited department policy, concerns about quality and length of training, and resident complaints as reasons for not hiring three-year graduates. A majority (10/18, 56%) noted that not hiring fellows from three-year programs negatively impacts recruitment and gives them access to a smaller applicant pool. Conclusion: Most non-ACGME fellowships at institutions with four-year EM programs recruit three-year graduates and allow them to supervise residents. This survey provides programs information on how comparable fellowships recruit and staff their departments, which may inform policies that fit the needs of their learners, the fellowship, and the department.

Nowadays, photogrammetrically derived point clouds are widely used in many civilian applications due to their low cost and flexibility in acquisition. Typically, photogrammetric point clouds are assessed through reference data such as LiDAR point clouds. However, when reference data are not available, the assessment of photogrammetric point clouds may be challenging. Since these point clouds are algorithmically derived, their accuracies and precisions are highly varying with the camera networks, scene complexity, and dense image matching (DIM) algorithms, and there is no standard error metric to determine per-point errors. The theory of internal reliability of camera networks has been well studied through first-order error estimation of Bundle Adjustment (BA), which is used to understand the errors of 3D points assuming known measurement errors. However, the measurement errors of the DIM algorithms are intricate to an extent that every single point may have its error function determined by factors such as pixel intensity, texture entropy, and surface smoothness. Despite the complexity, there exist a few common metrics that may aid the process of estimating the posterior reliability of the derived points, especially in a multi-view stereo (MVS) setup when redundancies are present. In this paper, by using an aerial oblique photogrammetric block with LiDAR reference data, we analyze several internal matching metrics within a common MVS framework, including statistics in ray convergence, intersection angles, DIM energy, etc. We associate these metrics to the per-point errors evaluated through LiDAR reference data and discuss their potential contributions in estimating internal reliabilities of point clouds derived from DIM algorithms. The experimental results show that ray convergence and DIM energy are relevant indicators for the accuracy of the generated point clouds. Initial investigation shows that these two indicators could be further utilized to infer the measurement errors without reference data, which could potentially estimate the reliabilities of point clouds through error propagation.

In this publication, the potential non-gadolinium magnetic resonant imaging agent—nanoparticulate K2Mn[Fe(CN)6]—its comparison sample KFe[Co(CN)6], as well as their reference samples were measured and analyzed using Mn, Co and Fe L-edge X-ray absorption spectroscopy (L XAS). From the information obtained, we conclude that K2Mn[Fe (CN)6] has a high spin (hs)-Mn(II) and a low spin (ls)-Fe(II), while KFe[Co(CN)6] has an hs-Fe(II) and an ls-Co(III). In these Prussian blue (PB) analog structures, the L XAS analysis also led to the conclusion that the hs-Mn(II) in K2Mn[Fe(CN)6] or the hs-Fe(II) in KFe[Co(CN)6] bonds to the N in the [M(CN)6]4−/3− ions (where M = Fe(II) or Co(III)), while the ls-Fe(II) in K2Mn[Fe(CN)6] or the ls-Co(III) in KFe[Co(CN)6] bonds to the C in the [M(CN)6]4−/3− ion, suggesting the complexed metalloligand [Mn(II) or Fe(II)] occupies the N-bound site in PB. Then, nuclear resonant vibrational spectroscopy (NRVS) was used to confirm the results from the L XAS measurements: the Mn(II), Eu(III), Gd(III), Fe(II) cations complexed by [M(CN)6]n−-metalloligand all take the N-bound site in PB-like structures. Our NRVS studies also prove that iron in the K2Mn[Fe(CN)6] compound has a 2+ oxidation state and is surrounded by the C donor atoms in the [M(CN)6]n− ions.

Medium entropy alloys (MEAs) have a high potential in industrial applications due to their excellent mechanical properties. Here we report a strategy to improve the ductility of the Ni40Co30Cr20Al5Ti5 MEAs by rapid solidification (RS). The as-cast alloy is composed of dendritic structure and L12 nano-precipitates. After RS, the lattice misfit of precipitate and matrix is reduced from 0.251 % to 0.167 %, and the size of the precipitate decreases from 85 nm to 28 nm. Meanwhile, RS also reduces the grain size of matrix. Gliding dislocation can cut through precipitates with low lattice misfit and smaller size, which can avoid strain accumulation and prevent crack initiation at the precipitate-matrix interfaces. Compared with the as-cast alloy, the ductility of the RS alloy is increased by 17 %–42 % without a decrease in strength. Our results can provide a guidance for other experiments using the RS technology (laser cladding, magnetron sputtering, etc.) to achieve the strength-ductility balance in the MEAs.

Acylperoxy radicals (RO2) are key intermediates in the atmospheric oxidation of organic compounds and different from the general alkyl RO2 radicals in reactivity. However, direct probing of the molecular identities and chemistry of acyl RO2 remains quite limited. Here, we report a combined experimental and kinetic modeling study of the composition and formation mechanisms of acyl RO2, as well as their contributions to the formation of highly oxygenated organic molecules (HOMs) during ozonolysis of α-pinene. We find that acyl RO2 radicals account for 67 %, 94 %, and 32 % of the highly oxygenated C7, C8, and C9 RO2, respectively, but only a few percent of C10 RO2. The formation pathway of acyl RO2 species depends on their oxygenation level. The highly oxygenated acyl RO2 (oxygen atom number ≥6) are mainly formed by the intramolecular aldehydic H shift (i.e., autoxidation) of RO2, while the less oxygenated acyl RO2 (oxygen atom number ) are basically derived from the C–C bond cleavage of alkoxy (RO) radicals containing an α-ketone group or the intramolecular H shift of RO containing an aldehyde group. The acyl-RO2-involved reactions explain 50 %–90 % of C7 and C8 closed-shell HOMs and 14 % of C10 HOMs, respectively. For C9 HOMs, this contribution can be up to 30 %–60 %. In addition, acyl RO2 contribute to 50 %–95 % of C14–C18 HOM dimer formation. Because of the generally fast reaction kinetics of acyl RO2, the acyl RO2 + alkyl RO2 reactions seem to outcompete the alkyl RO2 + alkyl RO2 pathways, thereby affecting the fate of alkyl RO2 and HOM formation. Our study sheds lights on the detailed formation pathways of the monoterpene-derived acyl RO2 and their contributions to HOM formation, which will help to understand the oxidation chemistry of monoterpenes and sources of low-volatility organic compounds capable of driving particle formation and growth in the atmosphere.

Abstract Transport properties of silicate melts control magma ocean dynamics on the early terrestrial planets and rocky exoplanets. Here we calculate the viscosity (transport of momentum) of peridotite liquid at potential magma ocean conditions (0–159 GPa, 2,200–6,000 K) using ab initio molecular dynamics simulations. We find that, unlike MgSiO3 or basaltic melts, the viscosity of the highly depolymerized peridotite liquid (a) increases monotonically with pressure without an anomalous drop and (b) is lower than those of other melts over the entire mantle pressure range. Low viscosity would promote fractional crystallization in a less polymerized magma ocean and thus contribute to mantle heterogeneity from its earliest stage. Given the compositional dependence of magma ocean properties, emphasis on multicomponent bulk silicate Earth‐like composition, instead of simple end‐members, are rendered necessary, in order to better understand high‐energy planetary accretion processes and their aftermaths.

Organic aerosol (OA) is a significant part of urban fine particulate matter (PM2.5), and a lack of detailed knowledge of their sources has increasingly hindered the improvement of air quality in China in recent years, as significant reductions have been achieved in inorganic ion constituents. In this study, a wide range of organic molecular markers in PM2.5 were monitored with a bi-hourly time resolution using a thermal desorption aerosol gas chromatograph system (TAG) in urban Shanghai in winter 2019. The molecular marker data have provided a unique source tracking ability in characterizing the evolution of organic aerosols during nine wintertime episodic events. Episodes primarily influenced by local air masses were characterized with higher proportions in PM2.5 and mass increments of both primary and secondary OA. Rapid increases in both the absolute mass concentration and relative proportion were observed for primary and secondary OA markers, indicative of vehicle emissions (e.g., alkanes, hopanes, and 2,3-dihydroxy-4-oxopentanoic acid) and cooking activities (e.g., saturated and unsaturated fatty acids and C9 acids). In comparison, episodes under significant influences of transported air mass were typically associated with a predominant PM2.5 contribution from secondary inorganic aerosols and enhanced OA contribution from biomass burning activities. The latter was evident from the tracer data (e.g., levoglucosan, aromatic polycarboxylic acids, and nitroaromatic compounds). Secondary OA markers associated with later-generation products of the hydrocarbon oxidation process, such as C3−5 dicarboxylic acids, were the most deficient during local episodes, while notably enhanced during the episodes under the influence of transported air masses, reflecting the different extent and pathways of atmospheric aging processing. The ability to distinguish the variations in the OA evolution during different types of episodes demonstrates the value of online organic molecular measurements for episodic analysis. The results indicate that control of local urban sources such as vehicular and cooking emissions would lessen severity of local episodes, while regional control of precursors for secondary inorganic aerosols and biomass burning activities would reduce PM2.5 episodes under synoptic conditions conducive for regional transport.

Abstract Coral reefs in the Central Indo-Pacific region comprise some of the most diverse and yet threatened marine habitats. While reef monitoring has grown throughout the region in recent years, studies of coral reef benthic cover remain limited in spatial and temporal scales. Here, we analysed 24,365 reef surveys performed over 37 years at 1972 sites throughout East Asia by the Global Coral Reef Monitoring Network using Bayesian approaches. Our results show that overall coral cover at surveyed reefs has not declined as suggested in previous studies and compared to reef regions like the Caribbean. Concurrently, macroalgal cover has not increased, with no indications of phase shifts from coral to macroalgal dominance on reefs. Yet, models incorporating socio-economic and environmental variables reveal negative associations of coral cover with coastal urbanisation and sea surface temperature. The diversity of reef assemblages may have mitigated cover declines thus far, but climate change could threaten reef resilience. We recommend prioritisation of regionally coordinated, locally collaborative long-term studies for better contextualisation of monitoring data and analyses, which are essential for achieving reef conservation goals.

Reactive organic gases (ROGs), as important precursors of secondary pollutants, are not well resolved as their chemical complexity has challenged their quantification in many studies. Here, a near-complete speciation of ROG emissions from residential combustion was developed by the combination of proton transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) with a gas chromatography system equipped with a mass spectrometer and a flame ionization detector (GC-MS/FID), including 1049 species in all. Among them, 125 identified species, ∼ 90 % of the total ROG masses, were applied to evaluate their emission characteristics through real combustion samplings in rural households of China. The study revealed that with 55 species, mainly oxygenated species, higher hydrocarbons with ≥8 carbon atoms, and nitrogen-containing species, previously un- and under-characterized, ROG emissions from residential coal and biomass combustion were underestimated by 44.3 % ± 11.8 % and 22.7 % ± 3.9 %, respectively, which further amplified the underestimation of secondary organic aerosol formation potential (SOAP) as high as 70.3 % ± 1.6 % and 89.2 % ± 1.0 %, respectively. The hydroxyl radical reactivity (OHR) of ROG emissions was also undervalued significantly. The study provided a feasible method for the near-complete speciation of ROGs in the atmosphere and highlighted the importance of acquiring completely speciated measurement of ROGs from residential emissions, as well as other processes.

We report an observation of ultrahigh-energy (UHE) gamma rays from the Galactic center (GC) region, using 7 yr of data collected by the High-Altitude Water Cherenkov (HAWC) Observatory. The HAWC data are best described as a point-like source (HAWC J1746-2856) with a power-law spectrum ( ${d}N/{d}E=\phi {\left(E/26\,\mathrm{TeV}\right)}^{\gamma }$ ), where γ = −2.88 ± 0.15 _stat − 0.1 _sys and ϕ = 1.5 × 10 ^−15 (TeV cm ^2 s) ^−1 $\pm {0.3}_{\mathrm{stat}}{\,}_{-{0.13}_{\mathrm{sys}}}^{+{0.08}_{\mathrm{sys}}}$ extending from 6 to 114 TeV. We find no evidence of a spectral cutoff up to 100 TeV using HAWC data. Two known point-like gamma-ray sources are spatially coincident with the HAWC gamma-ray excess: Sgr A* (HESS J1745-290) and the Arc (HESS J1746-285). We subtract the known flux contribution of these point sources from the measured flux of HAWC J1746-2856 to exclude their contamination and show that the excess observed by HAWC remains significant (>5 σ ), with the spectrum extending to >100 TeV. Our result supports that these detected UHE gamma rays can originate via hadronic interaction of PeV cosmic-ray protons with the dense ambient gas and confirms the presence of a proton PeVatron at the GC.

Identification of enteric bacteria species by whole genome sequence (WGS) analysis requires a rapid and an easily standardized approach. We leveraged the principles of average nucleotide identity using MUMmer (ANIm) software, which calculates the percent bases aligned between two bacterial genomes and their corresponding ANI values, to set threshold values for determining species consistent with the conventional identification methods of known species. The performance of species identification was evaluated using two datasets: the Reference Genome Dataset v2 (RGDv2), consisting of 43 enteric genome assemblies representing 32 species, and the Test Genome Dataset (TGDv1), comprising 454 genome assemblies which is designed to represent all species needed to query for identification, as well as rare and closely related species. The RGDv2 contains six Campylobacter spp., three Escherichia/Shigella spp., one Grimontia hollisae, six Listeria spp., one Photobacterium damselae, two Salmonella spp., and thirteen Vibrio spp., while the TGDv1 contains 454 enteric bacterial genomes representing 42 different species. The analysis showed that, when a standard minimum of 70% genome bases alignment existed, the ANI threshold values determined for these species were ≥95 for Escherichia/Shigella and Vibrio species, ≥93% for Salmonella species, and ≥92% for Campylobacter and Listeria species. Using these metrics, the RGDv2 accurately classified all validation strains in TGDv1 at the species level, which is consistent with the classification based on previous gold standard methods.

Aromatic carbonyls (e.g., methoxybenzaldehydes), an important class of photosensitizers, are abundant in the atmosphere. Photosensitization and nitrate-mediated photo-oxidation can occur simultaneously, yet studies about their interactions, particularly for aqueous secondary organic aerosol (aqSOA) formation, remain limited. This study compared non-phenolic (3,4-dimethoxybenzaldehyde, DMB) and phenolic (vanillin, VL) methoxybenzaldehydes as photosensitizers for aqSOA formation via guaiacol (GUA) oxidation in the absence and presence of ammonium nitrate (AN) under atmospherically relevant cloud and fog conditions. GUA oxidation by triplet excited states of DMB (3DMB∗) (GUA + DMB) was ∼ 4 times faster and exhibited greater light absorption than oxidation by 3VL∗ (GUA + VL). Both GUA + DMB and GUA + VL formed aqSOA composed of oligomers, functionalized monomers, oxygenated ring-opening species, and N-containing products in the presence of AN. The observation of N-heterocycles such as imidazoles indicates the participation of ammonium in the reactions. The majority of generated aqSOA comprises potential brown carbon (BrC) chromophores. Oligomerization and functionalization dominated in GUA + DMB and GUA + VL, but functionalization appeared to be more important in GUA + VL due to contributions from VL itself. AN did not significantly affect the oxidation kinetics, but it had distinct effects on the product distributions, likely due to differences in the photosensitizing abilities and structural features of DMB and VL. In particular, the more extensive fragmentation in GUA + DMB than in GUA + VL likely generated more N-containing products in GUA + DMB + AN. In GUA + VL + AN, the increased oligomers may be due to VL-derived phenoxy radicals induced by ⚫OH or ⚫NO2 from nitrate photolysis. Furthermore, increased nitrated products observed in the presence of both DMB or VL and AN than in AN alone imply that photosensitized reactions may promote nitration. This work demonstrates how the structural features of photosensitizers affect aqSOA formation via non-carbonyl phenol oxidation. Potential interactions between photosensitization and AN photolysis were also elucidated. These findings facilitate a better understanding of photosensitized aqSOA formation and highlight the importance of AN photolysis in these reactions.

Oxygenated organic molecules (OOMs) are dominated by the N-containing species in polluted urban environments. As N-containing OOMs, especially those with more than one nitrogen atom, prevail in the high m/z (mass-to-charge) range (m/z> 350 Th), unambiguous identification of N-containing OOMs is highly desirable for understanding of their formation processes, precursors and influencing factors. To achieve this, we applied an ultra-high-resolution chemical-ionization Orbitrap (CI-Orbitrap) in a field campaign and found that OOMs contain one (1N-OOMs), two (2N-OOMs) and three (3N-OOMs) nitrogen atoms comprised 50 %, 26 % and 4 %, respectively, of total OOMs. More interestingly, the fraction of 2N-OOMs increased with the increase in carbon number (nC) and was dominated by the ones derived from aliphatic precursors (2N-OOMAli, 64.2 %), indicating the importance of multistep oxidation. Plausible precursors of 2N-OOMs were aliphatics (2N-OOMAli, 64.2 %), aromatics (2N-OOMAro, 16 %) and monoterpenes (2N-OOMMT, 15.4 %). The absolute concentrations of 2N-OOMs were greatly affected by the pollution level for most cases. The 2N-OOMAli was the most abundant 2N-OOM, and its fraction even increased on the polluted day with an enhanced proportion of the ones with nC >10. While 2N-OOMAli and 2N-OOMAro were dominated by daytime photochemical production, nighttime NO3-initiated oxidation played a comparable role to the daytime photochemistry in the formation of 2N-OOMMT. The 2N-OOMAro species were of the highest oxygenation level, followed by 2N-OOMMT and 2N-OOMAli, which were affected by photochemistry and NOx concentrations. These results highlight the significant formation of 2N-OOMs and the influencing factors on their formation in polluted urban environments, where various volatile organic compound (VOC) precursors and atmospheric oxidants are present.

Abstract The Chinese economy upheld a frail recovery in 2022 under the triple superposition of contraction of demand, disruption in supply, and weakening expectations, aggravated by unanticipated adverse shocks in the midst of global turmoil. Over the year, rising income uncertainty set off by the pandemic shock continued depressing household consumption and housing demand. Trade also saw slowing growth, along with consumption and investment, with sluggish residential investment awaiting policy stimulus to take force. Unemployment rate remained high, and was much higher for youth engendered by severe structural imbalances in the labor market. Local government debt burden worsened while revenue shrinking, only to exacerbate the local fiscal financial risk. It fared better on the price side. While growth in producer price index kept falling, consumer price index maintained steady growth. Renminbi depreciated against USD through fluctuations with larger swings, but the exchange rate remained in a manageable band. The Institute for Advanced Research‐China Macroeconomic Model projects the baseline growth rate in real gross domestic product to be 5.4% in 2023. We have also used the model to conduct alternative scenario analyses and policy simulations to assess the impacts of potential downside risks or favorable situations. Our findings call for a focus on economic construction with deepening reform and opening up more comprehensively and initiatively. Only by doing so can China spur market vitality, strengthen business confidence, and forge competitive advantages.

Understanding the gas–particle partitioning of semivolatile organic compounds (SVOCs) is of crucial importance in the accurate representation of the global budget of atmospheric organic aerosols. In this study, we quantified the gas- vs. particle-phase fractions of a large number of SVOCs in real time in an urban area of East China with the use of a CHemical Analysis of aeRosols ONline (CHARON) inlet coupled to a high-resolution proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS). We demonstrated the use of the CHARON inlet for highly efficient collection of particulate SVOCs while maintaining the intact molecular structures of these compounds. The collected month-long dataset with hourly resolution allows us to examine the gas–particle partitioning of a variety of SVOCs under ambient conditions. By comparing the measurements with model predictions using instantaneous equilibrium partitioning theory, we found that the dissociation of large parent molecules during the PTR ionization process likely introduces large uncertainties to the measured gas- vs. particle-phase fractions of less oxidized SVOCs, and therefore, caution should be taken when linking the molecular composition to the particle volatility when interpreting the PTR-ToF-MS data. Our analysis suggests that understanding the fragmentation mechanism of SVOCs and accounting for the neutral losses of small moieties during the molecular feature extraction from the raw PTR mass spectra could reduce, to a large extent, the uncertainties associated with the gas–particle partitioning measurement of SVOCs in the ambient atmosphere.

Current chemical transport models fail to reproduce both the concentrations and temporal variations of organic aerosol (OA), especially the secondary organic aerosol (SOA), hindering the identification of major contribution sources. The fact that precursors of intermediate-volatility and semivolatile organic compounds (I/SVOCs) are not included in models has a significant impact on the performance of SOA simulation. Herein, we establish a high-resolution emission inventory of I/SVOCs and by incorporating it into the CMAQ model, concentrations, temporal variations, and spatial distributions of POA and SOA originating from different sources in the Yangtze River Delta (YRD) region of China were simulated. By incorporating I/SVOC emissions into the model, the modeled average SOA concentrations in the region increased by 148 %. Significant model improvements in the simulations of different OA components were demonstrated by comparison with comprehensive observation data. Furthermore, spatial and seasonal variations of different source contributions to OA production have been identified. We found that cooking emissions are predominant sources of POA in the densely populated urban area of the region. I/SVOC emissions from industrial sources are dominant contributors to the SOA formation, followed by those from mobile sources. Our results indicate that future control measures should be specifically tailored on an intraregional scale based on the different source characteristics to achieve the national goal of continuous improvement in air quality. In addition, local source profiles and emission factors of I/SVOCs, as well as SOA formation mechanisms in the model framework must urgently be updated to further improve the model performance and thus the accuracy of source identifications.

IntroductionCutaneous squamous cell carcinoma of the head and neck (cSCCHN) can metastasize by invading nerves and spread toward the central nervous system. This metastatic process is called perineural invasion (PNI) and spread (PNS). An in vivo sciatic nerve mouse model is used for cSCCHN PNI/PNS. Here we describe a complementary whisker pad model which allows for molecular studies investigating drivers of PNI/PNS in the head and neck environment.MethodsA431 cells were injected into the whisker pads of BALB/c Foxn1nu and NSG-A2 mice. Tumor progression was monitored by bioluminescence imaging and primary tumor resection was performed. PNI was detected by H&E and IHC. Tumor growth and PNI were assessed with inducible ablation of LOXL2.ResultsThe rate of PNI development in mice was 10%-28.6%. Tumors exhibited PNI/PNS reminiscent of the morphology seen in the human disease. Our model’s utility was demonstrated with inducible ablation of LOXL2 reducing primary tumor growth and PNI.DiscussionThis model consists in a feasible way to test molecular characteristics and potential therapies, offers to close a gap in the described in vivo methods for PNI/PNS of cSCCHN and has uses in concert with the established sciatic nerve model.

Aerosol acidity plays a key role in regulating the chemistry and toxicity of atmospheric aerosol particles. The trend of aerosol pH and its drivers is crucial in understanding the multiphase formation pathways of aerosols. Here, we reported the first trend analysis of aerosol pH from 2011 to 2019 in eastern China, calculated with the ISORROPIA model based on observed gas and aerosol compositions. The implementation of the Air Pollution Prevention and Control Action Plan led to −35.8 %, −37.6 %, −9.6 %, −81.0 % and 1.2 % changes of PM2.5, SO42-, NHx, non-volatile cations (NVCs) and NO3- in the Yangtze River Delta (YRD) region during this period. Different from the drastic changes of aerosol compositions due to the implementation of the Air Pollution Prevention and Control Action Plan, aerosol pH showed a minor change of −0.24 over the 9 years. Besides the multiphase buffer effect, the opposite effects from the changes of SO42- and non-volatile cations played key roles in determining this minor pH trend, contributing to a change of +0.38 and −0.35, respectively. Seasonal variations in aerosol pH were mainly driven by the temperature, while the diurnal variations were driven by both temperature and relative humidity. In the future, SO2, NOx and NH3 emissions are expected to be further reduced by 86.9 %, 74.9 % and 41.7 % in 2050 according to the best health effect pollution control scenario (SSP1-26-BHE). The corresponding aerosol pH in eastern China is estimated to increase by ∼0.19, resulting in 0.04 less NO3- and 0.12 less NH4+ partitioning ratios, which suggests that NH3 and NOx emission controls are effective in mitigating haze pollution in eastern China.

Oxygenated organic molecules (OOMs) are crucial for atmospheric new particle formation and secondary organic aerosol (SOA) growth. Therefore, understanding their chemical composition, temporal behavior, and sources is of great importance. Previous studies on OOMs mainly focus on environments where biogenic sources are predominant, yet studies on sites with dominant anthropogenic emissions, such as megacities, have been lacking. Here, we conducted long-term measurements of OOMs, covering four seasons of the year 2019, in urban Beijing. The OOM concentration was found to be the highest in summer (1.6×108 cm−3), followed by autumn (7.9×107 cm−3), spring (5.7×107 cm−3) and winter (2.3×107 cm−3), suggesting that enhanced photo-oxidation together with the rise in temperature promote the formation of OOMs. Most OOMs contained 5 to 10 carbon atoms and 3 to 7 effective oxygen atoms (nOeff=nO-2×nN). The average nOeff increased with increasing atmospheric photo-oxidation capacity, which was the highest in summer and the lowest in winter and autumn. By performing a newly developed workflow, OOMs were classified into the following four types: aromatic OOMs, aliphatic OOMs, isoprene OOMs, and monoterpene OOMs. Among them, aromatic OOMs (29 %–41 %) and aliphatic OOMs (26 %–41 %) were the main contributors in all seasons, indicating that OOMs in Beijing were dominated by anthropogenic sources. The contribution of isoprene OOMs increased significantly in summer (33 %), which is much higher than those in the other three seasons (8 %–10 %). Concentrations of isoprene (0.2–5.3×107 cm−3) and monoterpene (1.1–8.4×106 cm−3) OOMs in Beijing were lower than those reported at other sites, and they possessed lower oxygen and higher nitrogen contents due to high NOx levels (9.5–38.3 ppbv – parts per billion by volume) in Beijing. With regard to the nitrogen content of the two anthropogenic OOMs, aromatic OOMs were mainly composed of CHO and CHON species, while aliphatic OOMs were dominated by CHON and CHON2 ones. Such prominent differences suggest varying formation pathways between these two OOMs. By combining the measurements and an aerosol dynamic model, we estimated that the SOA growth rate through OOM condensation could reach 0.64, 0.61, 0.41, and 0.30 µg m−3 h−1 in autumn, summer, spring, and winter, respectively. Despite the similar concentrations of aromatic and aliphatic OOMs, the former had lower volatilities and, therefore, showed higher contributions (46 %–62 %) to SOA than the latter (14 %–32 %). By contrast, monoterpene OOMs and isoprene OOMs, limited by low abundances or high volatilities, had low contributions of 8 %–12 % and 3 %–5 %, respectively. Overall, our results improve the understanding of the concentration, chemical composition, seasonal variation, and potential atmospheric impacts of OOMs, which can help formulate refined restriction policy specific to SOA control in urban areas.

Atrial fibrillation (AF), is the most common sustained cardiac arrhythmia. It was once thought to be benign as long as the ventricular rate was controlled, however, AF is associated with significant cardiac morbidity and mortality. Increasing life expectancy driven by improved health care and decreased fertility rates has, in most of the world, resulted in the population aged ≥65 years growing more rapidly than the overall population. As the population ages, projections suggest that the burden of AF may increase more than 60% by 2050. Although considerable progress has been made in the treatment and management of AF, primary prevention, secondary prevention, and prevention of thromboembolic complications remain a work in progress. This narrative review was facilitated by a MEDLINE search to identify peer-reviewed clinical trials, randomized controlled trials, meta-analyses, and other clinically relevant studies. The search was limited to English-language reports published between 1950 and 2021. Atrial fibrillation was searched via the terms primary prevention, hyperthyroidism, Wolff-Parkinson-White syndrome, catheter ablation, surgical ablation, hybrid ablation, stroke prevention, anticoagulation, left atrial occlusion and atrial excision. Google and Google scholar as well as bibliographies of identified articles were reviewed for additional references. In these two manuscripts, we discuss the current strategies available to prevent AF, then compare noninvasive and invasive treatment strategies to diminish AF recurrence. In addition, we examine the pharmacological, percutaneous device and surgical approaches to prevent stroke as well as other types of thromboembolic events.

In the summer of 2020, multiple efforts were undertaken to establish safe and effective vaccines to combat the spread of the coronavirus disease (COVID-19). In the United States (U.S.), Operation Warp Speed (OWS) was the program designated to coordinate such efforts. OWS was a partnership between the Department of Health and Human Services (HHS), the Department of Defense (DOD), and the private sector, that aimed to help accelerate control of the COVID-19 pandemic by advancing development, manufacturing, and distribution of vaccines, therapeutics, and diagnostics. The U.S. Department of Veterans Affairs’ (VA) was identified as a potential collaborator in several large-scale OWS Phase III clinical trial efforts designed to evaluate the safety and efficacy of various vaccines that were in development. Given the global importance of these trials, it was recognized that there would be a need for a coordinated, centralized effort within VA to ensure that its medical centers (sites) would be ready and able to efficiently initiate, recruit, and enroll into these trials.The manuscript outlines the partnership and start-up activities led by two key divisions of the VA's Office of Research and Development's clinical research enterprise. These efforts focused on site and enterprise-level requirements for multiple trials, with one trial serving as the most prominently featured of these studies within the VA. As a result, several best practices arose that included designating clinical trial facilitators to study sites to support study initiation activities and successful study enrollment at these locations in an efficient and timely fashion.

Summary: Mouse models are key tools for investigating host-microbiome interactions. However, shotgun metagenomics can only profile a limited fraction of the mouse gut microbiome. Here, we employ a metagenomic profiling method, MetaPhlAn 4, which exploits a large catalog of metagenome-assembled genomes (including 22,718 metagenome-assembled genomes from mice) to improve the profiling of the mouse gut microbiome. We combine 622 samples from eight public datasets and an additional cohort of 97 mouse microbiomes, and we assess the potential of MetaPhlAn 4 to better identify diet-related changes in the host microbiome using a meta-analysis approach. We find multiple, strong, and reproducible diet-related microbial biomarkers, largely increasing those identifiable by other available methods relying only on reference information. The strongest drivers of the diet-induced changes are uncharacterized and previously undetected taxa, confirming the importance of adopting metagenomic methods integrating metagenomic assemblies for comprehensive profiling.

Bacteroides species are prominent members of the human gut microbiota. Here the authors develop a platform technology (consortium transcriptional programming) in five human donor Bacteroides chassis cells—enabling complex decision-making within said community, which can be used for the development of living therapeutics.

Refractory black carbon (rBC) aerosols play an important role in air quality and climate change, yet highly time-resolved and detailed investigations on the physicochemical properties of rBC and its associated coating are still scarce. In this work, we used a laser-only Aerodyne soot particle aerosol mass spectrometer (SP-AMS) to exclusively measure rBC-containing (rBCc) particles, and we compared their properties with those of the total nonrefractory submicron particles (NR-PM1) measured in parallel by a high-resolution AMS (HR-AMS) in Shanghai. Observations showed that, overall, rBC was thickly coated, with an average mass ratio of coating to rBC core (RBC) of ∼5.0 (±1.7). However, the ratio of the mass of the rBC-coating species to the mass of those species in NR-PM1 was only 19.1 (±4.9) %; sulfate tended to condense preferentially on non-rBC particles, so the ratio of the sulfate on rBC to the NR-PM1 sulfate was only 7.4 (±2.2) %, while the majority (72.7±21.0 %) of the primary organic aerosols (POA) were associated with rBC. Positive matrix factorization revealed that organics emitted from cooking did not coat rBC, and a portion of the organics that coated rBC was from biomass burning; such organics were unidentifiable in NR-PM1. Small rBCc particles were predominantly from traffic, while large-sized ones were often mixed with secondary components and typically had a thick coating. Sulfate and secondary organic aerosol (SOA) species were generated mainly through daytime photochemical oxidation (SOA formation, likely associated with in situ chemical conversion of traffic-related POA to SOA), while nocturnal heterogeneous formation was dominant for nitrate; we also estimated an average time of 5–19 h for those secondary species to coat rBC. During a short period that was affected by ship emissions, particles were characterized as having a high vanadium concentration (on average 6.3±3.1 ng m−3) and a mean vanadium/nickel mass ratio of 2.0 (±0.6). Furthermore, the size-resolved hygroscopicity parameter (κrBCc) of rBCc particles was obtained based on their full chemical characterization, and was parameterized as κrBCc(x)=0.29–0.14 × exp⁡(-0.006×x) (where x ranges from 150 to 1000 nm). Under critical supersaturations (SSC) of 0.1 % and 0.2 %, the D50 values were 166 (±16) and 110 (±5) nm, respectively, and 16 (±3) % and 59 (±4) %, respectively, of the rBCc particles by number could be activated into cloud condensation nuclei (CCN). Our findings are valuable for advancing the understanding of BC chemistry as well as the effective control of atmospheric BC pollution.

Abstract Background Persistent atrial fibrillation (AF) is associated with high recurrence rates of AF and atypical atrial flutters or tachycardia (AFT) postablation. Laser balloon (LB) ablation of the pulmonary vein (PV) ostia has similar efficacy as radiofrequency wide area circumferential ablation (RF‐WACA); however, an approach of LB wide area circumferential ablation (LB‐WACA) may further improve success rates. Objective To evaluate freedom from atrial tachyarrhythmia (AFT/AF) recurrence postablation using RF‐WACA versus LB‐WACA in persistent AF patients. Methods This was a retrospective multicenter study. Patients were followed for up to 24 months via office visits, Holter, and/or device monitoring. The primary endpoint was freedom from AFT/AF after a single ablation procedure. Secondary endpoints included freedom from AF, freedom from AFT, first‐pass isolation of all PVs, and procedural complications. Results Two hundred and four patients were studied (LB‐WACA: n = 103; RF‐WACA: n = 101). Patients’ baseline characteristics were similar except patients in the RF‐WACA group were older (64 vs. 68, p = .03). First‐pass isolation was achieved more often during LBA (LB‐WACA: 88% vs. RF‐WACA 75%; p = .04). Procedure (p = .36), LA dwell (p = .41), and fluoroscopy (p = .44) time were similar. The mean follow‐up was 506 ± 279 days. Sixty‐six patients had arrhythmic events including 24 AFT and 59 AF recurrences. LB‐WACA group had higher arrhythmia‐free survival (p = .009) after single ablation procedures. In the multivariate Cox regression model, RF‐WACA was associated with a higher recurrence of AFT compared with LB‐WACA (Adjusted HR 3.16 [95% CI: 1.13–8.83]; p = .03). Conclusions LB‐WACA was associated with higher freedom from atrial arrhythmias mostly driven by the lower occurrence of AFT compared with RF‐WACA.

Abstract China's economy underwent a steady recovery in 2021. Investment grew steadily with structural improvement. Exports and imports surged while trade surplus expanded. On the other hand, although labor market conditions improved, income distribution worsened, contributing to sluggish growth in consumption, whereas the gap between consumer price index and producer price index widened, and the profits of enterprises of different sizes diverged, which may go beyond how they are correlated with the locations of the enterprises in the chain of production and trade. While proper liquidity was maintained with prudent monetary policy, risk spillover rose in the financial system, particularly for small and medium‐sized banks. Household and local government debts remained at relatively high levels, further dragging down growth in consumption and infrastructure investment. The “dual carbon” goals exerted downward pressure on near‐term growth in trading off their long‐term benefits. The economy also faced challenges in its external environment in the midst of the prolonged COVID‐19 pandemic aboard, trade protectionism, and the readjustment of the global value chain. Moreover, excessive supervision and inadequate implementation disturbed China's economy, resulting in declined market vitality and confidence of market participants. Based on the Institute for Advanced Research‐China Macroeconomic Model, the baseline real gross domestic product growth rate is projected to be 5.5% in 2022. Alternative scenario analyses and policy simulations are conducted, in addition to the benchmark forecast, to reflect the influences of various risks and possible favorable situations. The findings suggest that China should deepen reform and open up more comprehensively and initiatively, while special effort should be placed on providing accommodative policy and friendly public opinion environment, to facilitate steady growth and propel high‐quality development. A comprehensive macroeconomic governance framework with Chinese characteristics must be developed from systems thinking, to resolve the various issues, internal and external, cyclical and secular, structural and institutional, in an all‐inclusive and coherent manner.

Long-term human path forecasting in crowds is critical for autonomous moving platforms (like autonomous driving cars and social robots) to avoid collision and make high-quality planning. It is not easy for prediction systems to successfully take into account social interactions and predict a distribution of future possible path in a highly interactive and dynamic circumstance. In this paper, we develop a data-driven model for long-term trajectory prediction, which naturally takes into account social interactions through a spatio-temporal graph representation and predicts multi-modes of future trajectories. Different from generative adversarial network (GAN) based models which generate samples and then provide distributions of samples, we use mixture density functions to describe human motion and intuitively map the distribution of future path with explicit densities. To prevent the model from collapsing into a single mode and truly capture the intrinsic multi-modality, we further use a Winner-Takes-All (WTA) loss instead of computing loss over all modes. Extensive experiments over several trajectory prediction benchmarks demonstrate that our method is able to capture the multi-modality of human motion and forecast the distributions of plausible futures in complex scenarios.

Structure from motion using uncalibrated multi-camera systems is a challenging task. This paper proposes a bundle adjustment solution that implements a baseline constraint respecting that these cameras are static to each other. We assume these cameras are mounted on a mobile platform, uncalibrated, and coarsely synchronized. To this end, we propose the baseline constraint that is formulated for the scenario in which the cameras have overlapping views. The constraint is incorporated in the bundle adjustment solution to keep the relative motion of different cameras static. Experiments were conducted using video frames of two collocated GoPro cameras mounted on a vehicle with no system calibration. These two cameras were placed capturing overlapping contents. We performed our bundle adjustment using the proposed constraint and then produced 3D dense point clouds. Evaluations were performed by comparing these dense point clouds against LiDAR reference data. We showed that, as compared to traditional bundle adjustment, our proposed method achieved an improvement of 29.38%.

We examine a century of radial velocity, visual magnitude, and astrometric observations of the nearest red supergiant, Betelgeuse, in order to reexamine the century-old assertion that Betelgeuse might be a spectroscopic binary. These data reveal Betelgeuse varying stochastically over years and decades due to its boiling, convective envelope, periodically with a 5.78 yr long secondary period (LSP), and quasiperiodically from pulsations with periods of several hundred days. We show that the LSP is consistent between astrometric and radial velocity data sets, and argue that it indicates a low-mass companion to Betelgeuse, less than a solar mass, orbiting in a 2110 day period at a separation of just over twice Betelgeuse’s radius. The companion star would be nearly 20 times less massive and a million times fainter than Betelgeuse, with similar effective temperature, effectively hiding it in plain sight near one of the best-studied stars in the night sky. The astrometric data favor an edge-on binary with orbital plane aligned with Betelgeuse’s measured spin axis. Tidal spin–orbit interaction drains angular momentum from the orbit and spins up Betelgeuse, explaining the spin–orbit alignment and Betelgeuse’s anomalously rapid spin. In the future, the orbit will decay until the companion is swallowed by Betelgeuse in the next 10,000 yr.

We cross-check the Hubble Space Telescope (HST) Cepheid/Type Ia supernova (SN Ia) distance ladder, which yields the most precise local H _0 , against early James Webb Space Telescope (JWST) subsamples (∼1/4 of the HST sample) from SH0ES and CCHP, calibrated only with NGC 4258. We find HST Cepheid distances agree well (∼1 σ ) with all combinations of methods, samples, and telescopes. The comparisons explicitly include the measurement uncertainty of each method in NGC 4258, an oft-neglected but dominant term. Mean differences are ∼0.03 mag, far smaller than the 0.18 mag “Hubble tension.” Combining all measures produces the strongest constraint yet on the linearity of HST Cepheid distances, 0.994 ±0.010, ruling out distance-dependent bias or offset as the source of the tension at ∼7 σ . However, current JWST subsamples produce large sampling differences in H _0 whose size and direction we can directly estimate from the full HST set. We show that Δ H _0 ∼ 2.5 km s ^−1 Mpc ^−1 between the CCHP JWST program and the full HST sample is entirely consistent with differences in sample selection. We combine all JWST samples into a new distance-limited set of 16 SNe Ia at D ≤ 25 Mpc. Using JWST Cepheids, JAGB, and tip of the red giant branch, we find 73.4 ± 2.1, 72.2 ± 2.2, and 72.1 ± 2.2 km s ^−1 Mpc ^−1 , respectively. Explicitly accounting for common supernovae, the three-method JWST result is H _0 = 72.6 ± 2.0, similar to H _0 = 72.8 expected from HST Cepheids in the same galaxies. The small JWST sample trivially lowers the Hubble tension significance due to small-sample statistics and is not yet competitive with the HST set (42 SNe Ia and 4 anchors), which yields 73.2 ± 0.9. Still, the joint JWST sample provides important cross-checks that the HST data pass.

Obtaining a cohesive understanding of performance in protonic-ceramic electrolysis cells is difficult due to the wide operating space coupled with low-throughput diagnostic techniques, sluggish system dynamics, and cell degradation. In this work, design of experiments (DOEs) methods are implemented to provide an efficient framework for understanding the phenomena that most strongly dictate cell performance. In addition to a more robust description of cell-level phenomena, mathematical equations are generated that accurately describe the complex relationship between the cell operating variables and cell performance metrics such as faradaic efficiency, cell potential, resistances, and energy conversion efficiency. Here, DOE is realized without the need to pre-select the most important operating variables based on a priori rationalizations. This is particularly valuable for system-level and technoeconomic analyses where the accurate prediction of cell/stack response over many operating conditions is required. The demonstrated experimental framework consists of a screening design and subsequent optimization design. The Plackett–Burman factor-screening design identifies temperature, current density, and steam content as having the largest impacts on cell performance, particularly faradaic efficiency. Increasing the electrolytic current density from 0.2 to 0.5 A cm ^−2 decreases polarization resistances by 74% due in large part to a negative-capacitance element that dominates at low frequency and high electrolysis bias. Impedance data highlights the connection of this negative feature to electronic leakage through the electrolyte and gas diffusion limitations. Additionally, increasing cell temperature from 500 to 600 ^∘ C is shown to decrease faradaic efficiency by 9% due to electrolyte dehydration and oxygen incorporation at high temperatures. The Box–Behnken optimization design then enables generation of regression equations to be used in response surfaces for data visualization and cohesive, multivariate analysis of cell operation.

Galactic gamma-ray diffuse emission (GDE) is emitted by cosmic rays (CRs), ultra-relativistic protons, and electrons, interacting with gas and electromagnetic radiation fields in the interstellar medium. Here we present the analysis of teraelectronvolt diffuse emission from a region of the Galactic plane over the range in longitude of l ∈ [43°, 73°], using data collected with the High Altitude Water Cherenkov (HAWC) detector. Spectral, longitudinal, and latitudinal distributions of the teraelectronvolt diffuse emission are shown. The radiation spectrum is compatible with the spectrum of the emission arising from a CR population with an index similar to that of the observed CRs. When comparing with the DRAGON base model , the HAWC GDE flux is higher by about a factor of 2. Unresolved sources such as pulsar wind nebulae and teraelectronvolt halos could explain the excess emission. Finally, deviations of the Galactic CR flux from the locally measured CR flux may additionally explain the difference between the predicted and measured diffuse fluxes.

The giant spiral galaxy M101 is host to the nearest recent Type Ia supernova (SN 2011fe) and thus has been extensively monitored in the near-infrared to study the late-time light curve of the SN. Leveraging this existing baseline of observations, we derive the first Mira-based distance to M101 by discovering and classifying a sample of 211 Miras with periods ranging from 240–400 days in the SN field. Combined with new Hubble Space Telescope (HST) WFC3/IR channel observations, our data set totals 11 epochs of F110W (HST YJ ) and 13 epochs of F160W (HST H ) data spanning ∼2900 days. We adopt absolute calibrations of the Mira period–luminosity relation based on geometric distances to the Large Magellanic Cloud and the water megamaser host galaxy NGC 4258, and find μ _M101 = 29.10 ± 0.06 mag. This distance is in 1 σ agreement with most other recent Cepheid and tip of the red giant branch distance measurements to M101. Including the previous Mira SN Ia host, NGC 1559, and SN 2005df, we determine the fiducial SN Ia peak luminosity, ${M}_{B}^{0}=-19.27\,\pm \,0.09$ mag. With the Hubble diagram of supernovae Ia, we derive H _0 = 72.37 ± 2.97 km s ^−1 Mpc ^−1 , a 4.1% measurement of H _0 using Miras. We find excellent agreement with recent Cepheid distance ladder measurements of H _0 and confirm previous indications that the local universe value of H _0 is higher than the early universe value at ∼95% confidence. Currently, the Mira-based H _0 measurement is still dominated by the statistical uncertainty in the SN Ia peak magnitude.

We study stars in the J-regions of the asymptotic giant branch (JAGB) of near-infrared color–magnitude diagrams in the maser host NGC 4258 and four hosts of six Type Ia supernovae (SNe Ia): NGC 1448, NGC 1559, NGC 5584, and NGC 5643. These clumps of stars are readily apparent near 1.0 < F150W − F277W < 1.5 and m _F150W = 22–25 mag with James Webb Space Telescope NIRCam photometry. Various methods have been proposed to assign an apparent reference magnitude to this recently proposed standard candle, including the mode, median, sigma-clipped mean, or a modeled luminosity function parameter. We test the consistency of these by measuring intrahost variations, finding differences of up to ∼0.2 mag that significantly exceed statistical uncertainties. Brightness differences appear intrinsic, and are further amplified by the nonuniform shape of the JAGB luminosity function, also apparent in the LMC and SMC. We follow a “many methods” approach to measure consistently JAGB magnitudes and distance moduli to the SN Ia host sample calibrated by NGC 4258. We find broad agreement with distance moduli measured from Cepheids, tip of the red giant branch, and Miras. However, the SN host mean distance modulus estimated via the JAGB method necessary to estimate H _0 differs by ∼0.19 mag among the above definitions, the result of different levels of luminosity function asymmetry. The methods yield a full range of 71−78 km s ^−1 Mpc ^−1 , i.e., a fiducial result of H _0 = 74.7 ± 2.1(stat) ± 2.3(sys, ±3.1 if combined in quadrature) km s ^−1 Mpc ^−1 , with systematic errors limited by the differences in methods. Future work may seek to standardize and refine this promising tool further, making it more competitive with established distance indicators.

Galactic cosmic rays (GCRs) are charged particles that reach the heliosphere almost isotropically in a wide energy range. In the inner heliosphere, the GCR flux is modulated by solar activity so that only energetic GCRs reach the lower layers of the solar atmosphere. In this work, we propose that high-energy GCRs can be used to explore the solar magnetic fields at low coronal altitudes. We used GCR data collected by the High-Altitude Water Cherenkov observatory to construct maps of GCR flux coming from the Sun’s sky direction and studied the observed GCR deficit, known as Sun shadow (SS), over a 6 yr period (2016–2021) with a time cadence of 27.3 days. We confirm that the SS is correlated with sunspot number, but we focus on the relationship between the photospheric solar magnetic field measured at different heliolatitudes and the relative GCR deficit at different energies. We found a linear relationship between the relative deficit of GCRs represented by the depth of the SS and the solar magnetic field. This relationship is evident in the observed energy range of 2.5–226 TeV, but is strongest in the range of 12.4 33.4 TeV, which implies that this is the best energy range to study the evolution of magnetic fields in the low solar atmosphere.

HESS J1809-193 is an unidentified TeV source, first detected by the High Energy Stereoscopic System (H.E.S.S.) collaboration. The emission originates in a source-rich region that includes several supernova remnants (SNRs) and pulsars including SNR G11.1+0.1, SNR G11.0-0.0, and the young radio pulsar PSR J1809-1917. Originally classified as a pulsar wind nebula candidate, recent studies show the peak of the TeV region overlapping with a system of molecular clouds. This resulted in the revision of the original leptonic scenario to look for alternate hadronic scenarios. Marked as a potential PeVatron candidate, this region has been studied extensively by H.E.S.S. due to its emission extending up to several tens of TeV. In this work, we use 2398 days of data from the High Altitude Water Cherenkov (HAWC) observatory to carry out a systematic source search of the HESS J1809-193 region. We were able to resolve emission detected as an extended component (modelled as a symmetric Gaussian with a 1 σ radius of 0.°21) with no clear cutoff at high energies and emitting photons up to 210 TeV. We model the multiwavelength observations for the region around HESS J1809-193 using a time-dependent leptonic model and a lepto-hadronic model. Our model indicates that both scenarios could explain the observed data within the region of HESS J1809-193.

This paper investigates the origin of the γ -ray emission from MGRO J1908+06 in the GeV–TeV energy band. By analyzing the data collected by the Fermi Large Area Telescope, the Very Energetic Radiation Imaging Telescope Array System, and High Altitude Water Cherenkov, with the addition of spectral data previously reported by LHAASO, a multiwavelength study of the morphological and spectral features of MGRO J1908+06 provides insight into the origin of the γ -ray emission. The mechanism behind the bright TeV emission is studied by constraining the magnetic field strength, the source age, and the distance through detailed broadband modeling. Both spectral shape and energy-dependent morphology support the scenario that inverse Compton emission of an evolved pulsar wind nebula associated with PSR J1907+0602 is responsible for the MGRO J1908+06 γ -ray emission with a best-fit true age of T = 22 ± 9 kyr and a magnetic field of B = 5.4 ± 0.8 μ G, assuming the distance to the pulsar d _PSR = 3.2 kpc.

We present the most precise measurements to date for the spatial extension and energy spectrum of the γ -ray region between a pulsar’s wind nebula and the interstellar medium, better known as the halo, present around Geminga and PSR B0656+14 (Monogem) using ∼2398 days of >1 TeV data collected by the HAWC observatory. We interpret the data using a physically motivated model for the diffuse γ -ray emission generated from positrons and electrons (e ^± ) injected by the pulsar wind nebula and inverse Compton scattering with interstellar radiation fields. We find the morphologies of the regions inside these halos are characterized by an inhibited diffusion that are approximately three orders of magnitudes smaller than the Galactic average. We also obtain the e ^± emission efficiencies of 6.6% and 5.1%, respectively, for Geminga and Monogem. These results have remarkable consequences for the study of the particle diffusion in the region between the pulsar wind nebulae and the interstellar medium, and for the interpretation of the flux of positrons measured by the AMS-02 experiment above 10 GeV.

The first TeV γ -ray source with no lower energy counterparts, TeV J2032+4130, was discovered by HEGRA. It appears in the third HAWC catalog as 3HWC J2031+415 and it is a bright TeV γ -ray source whose emission has previously been resolved as two sources: HAWC J2031+415 and HAWC J2030+409. While HAWC J2030+409 has since been associated with the Fermi Large Area Telescope Cygnus Cocoon, no such association for HAWC J2031+415 has yet been found. In this work, we investigate the spectrum and energy-dependent morphology of HAWC J2031+415. We associate HAWC J2031+415 with a γ -ray binary system containing the pulsar PSR J2032+4127 and its companion MT91 213. We study HAWC data to observe their periastron in 2017. Additionally, we perform a combined multiwavelength analysis using radio, X-ray, and γ -ray emission. We conclude that HAWC J2031+415 and, by extension, TeV J2032+4130 are most probably a pulsar wind nebula powered by PSR J2032+4127.