At Stromboli Volcano, Italy, very long period (VLP) seismic signals and Strombolian eruptions have been attributed to the unsteady flow of gas slugs through the shallow plumbing system followed by explosive slug bursting at a free surface. In data from a 2018 seismo-acoustic deployment, similar to 92% of events in two main VLP multiplets do not coincide in time with impulsive infrasonic signals (the expected signal of explosive slug bursting); we term these "silent VLPs." The lack of infrasonically detected explosions relative to repeating VLPs does not support the commonly invoked "gas slug" model. We propose that VLPs may be generated when gas bubbles move into a weak semi-solid plug in the uppermost portion of the conduit. The plug then acts as a mechanical filter in which pathways vary and guide or trap ascending gas slugs, allowing for passive (silent) gas release and explosive escape mechanisms decoupled in time from VLPs.

Estimates of intruded magma volume are critical for forecasting volcanic unrest. Geodetic modeling can provide such estimates but is of limited use in submarine and highly vegetated settings. A complementary approach could be to use estimates of seismic moment release. In this study, we examine the moment-volume scaling of several proximal volcanic earthquake sequences and compare it to that of injection-induced seismicity. We find a notable similarity in scaling between the volcanic sequences, which contrasts with the broad range of responses exhibited by anthropogenic injection-induced sequences. This may imply an underlying similarity in the geologic conditions for volcanoes that is distinct from induced seismicity settings. It could also allow for estimates of intruded volume to be made without geodetic information. This provides further insight into the factors controlling seismogenesis in these different settings and has implications for volcano seismology and injection-induced seismicity hazard estimation.

IntroductionContinental hydrothermal systems (CHSs) are geochemically complex, and they support microbial communities that vary across substrates. However, our understanding of these variations across the complete range of substrates in CHS is limited because many previous studies have focused predominantly on aqueous settings. MethodsHere we used metagenomes in the context of their environmental geochemistry to investigate the ecology of different substrates (i.e., water, mud and fumarolic deposits) from Solfatara and Pisciarelli. Results and DiscussionResults indicate that both locations are lithologically similar with distinct fluid geochemistry. In particular, all substrates from Solfatara have similar chemistry whereas Pisciarelli substrates have varying chemistry; with water and mud from bubbling pools exhibiting high SO42- and NH4+ concentrations. Species alpha diversity was found to be different between locations but not across substrates, and pH was shown to be the most important driver of both diversity and microbial community composition. Based on cluster analysis, microbial community structure differed significantly between Pisciarelli substrates but not between Solfatara substrates. Pisciarelli mud pools, were dominated by (hyper)thermophilic archaea, and on average, bacteria dominated Pisciarelli fumarolic deposits and all investigated Solfatara environments. Carbon fixation and sulfur oxidation were the most important metabolic pathways fueled by volcanic outgassing at both locations. Together, results demonstrate that ecological differences across substrates are not a widespread phenomenon but specific to the system. Therefore, this study demonstrates the importance of analyzing different substrates of a CHS to understand the full range of microbial ecology to avoid biased ecological assessments.

Context. The current architecture of a given multi-planetary system is a key fingerprint of its past formation and dynamical evolution history. Long-term follow-up observations are key to complete their picture. Aims. In this paper, we focus on the confirmation and characterization of the components of the TOI-969 planetary system, where TESS detected a Neptune-size planet candidate in a very close-in orbit around a late K-dwarf star. Methods. We use a set of precise radial velocity observations from HARPS, PFS, and CORALIE instruments covering more than two years in combination with the TESS photometric light curve and other ground-based follow-up observations to confirm and characterize the components of this planetary system. Results. We find that TOI-969 b is a transiting close-in (P-b similar to 1.82 days) mini-Neptune planet (m(b) = 9.1(-1.0)(+1.1) M-Phi, R-b = 2.765(-0.097)(+0.088) R-Phi), placing it on the lower boundary of the hot-Neptune desert (T-eq,T-b = 941 +/- 31 K). The analysis of its internal structure shows that TOI-969 b is a volatile-rich planet, suggesting it underwent an inward migration. The radial velocity model also favors the presence of a second massive body in the system, TOI-969 c, with a long period of P-c = 1700(-280)(+290) days, a minimum mass of m(c) sin i(c) = 11.3(-0.9)(+1.1) M-Jup, and a highly eccentric orbit of e(c) = 0.628(-0.036)(+0.043). Conclusions. The TOI-969 planetary system is one of the few around K-dwarfs known to have this extended configuration going from a very close-in planet to a wide-separation gaseous giant. TOI-969 b has a transmission spectroscopy metric of 93 and orbits a moderately bright (G = 11.3 mag) star, making it an excellent target for atmospheric studies. The architecture of this planetary system can also provide valuable information about migration and formation of planetary systems.

The geological units on the floor of Jezero crater, Mars, are part of a wider regional stratigraphy of olivine-rich rocks, which extends well beyond the crater. We investigated the petrology of olivine and carbonate-bearing rocks of the Seitah formation in the floor of Jezero. Using multispectral images and x-ray fluorescence data, acquired by the Perseverance rover, we performed a petrographic analysis of the Bastide and Brac outcrops within this unit. We found that these outcrops are composed of igneous rock, moderately altered by aqueous fluid. The igneous rocks are mainly made of coarsegrained olivine, similar to some martian meteorites. We interpret them as an olivine cumulate, formed by settling and enrichment of olivine through multistage cooling of a thick magma body.

Northwest China has experienced a warming-wetting climate featured by increasing temperature and precipitation during the past six decades. Recent studies suggested that the climate may have shifted from wetting to drying after the 1990s if changes in energy supply were considered. However, how the change in energy supply affects the dryness remains unclear. In this study, we quantified the dryness in Northwest China based on the Standardized Precipitation Evapotranspiration Index (SPEI) which considers the impact of potential evapotranspiration estimated by the Penman-Monteith equation on dryness during 1961-2018. Then, the contributions of changes in meteorological variables (precipitation, temperature, relative humidity, wind speed, and net radiation) to the dryness changes were estimated using a detrending technique. The results indicated that Northwest China experienced a wetting period (1961-1989) and then a drying period (1989-2018). During 1961-1989, increased precipitation and slowed wind were the main drivers of the wetting trend. During 1989-2018, although the increased precipitation and decline in solar radiation favored a wetting condition, warmer temperature, drier air (decrease in relative humidity), together with rebounded wind speed offset the wetting trend and resulted in significantly increasing dryness in Northwest China. The dryness would further increase if current climate trends continue in the future, which may have important implications for water management in Northwest China.

The identification of factors that may be forcing ecological observations to approach the upper boundary provides insight into potential mechanisms affecting driver-response relationships, and can help inform ecosystem management, but has rarely been explored. In this study, we propose a novel framework integrating quantile regression with interpretable machine learning. In the first stage of the framework, we estimate the upper boundary of a driver-response relationship using quantile regression. Next, we calculate "potentials " of the response variable depending on the driver, which are defined as vertical distances from the estimated upper boundary of the relationship to observations in the driver-response variable scatter plot. Finally, we identify key factors impacting the potential using a machine learning model. We illustrate the necessary steps to implement the framework using the total phosphorus (TP)-Chlorophyll a (CHL) relationship in lakes across the continental US. We found that the nitrogen to phosphorus ratio (N:P), annual average precipitation, total nitrogen (TN), and summer average air temperature were key factors impacting the potential of CHL depending on TP. We further revealed important implications of our findings for lake eutrophication management. The important role of N:P and TN on the potential highlights the co-limitation of phosphorus and nitrogen and indicates the need for dual nutrient criteria. Future wetter and/or warmer climate scenarios can decrease the potential which may reduce the efficacy of lake eutrophication management. The novel framework advances the application of quantile regression to identify factors driving observations to approach the upper boundary of driver-response relationships.

The clinical and largely unpredictable heterogeneity of phenotypes in patients with mitochondrial disorders demonstrates the ongoing challenges in the understanding of this semi-autonomous organelle in biology and disease. Previously, we used the gene-breaking transposon to create 1200 transgenic zebrafish strains tagging protein-coding genes (Ichino et al., 2020), including the lrpprc locus. Here, we present and characterize a new genetic revertible animal model that recapitulates components of Leigh Syndrome French Canadian Type (LSFC), a mitochondrial disorder that includes diagnostic liver dysfunction. LSFC is caused by allelic variations in the LRPPRC gene, involved in mitochondrial mRNA polyadenylation and translation. lrpprc zebrafish homozygous mutants displayed biochemical and mitochondrial phenotypes similar to clinical manifestations observed in patients, including dysfunction in lipid homeostasis. We were able to rescue these phenotypes in the disease model using a liver-specific genetic model therapy, functionally demonstrating a previously under-recognized critical role for the liver in the pathophysiology of this disease.

The thermal equation of states for fcc iridium (Ir) is obtained from first-principles molecular dynamics up to 3000 K and 540 GPa. The equation of state (EoS) is globally fitted to a simplified free-energy model and various parameters are derived. The theoretical principal Hugoniot is compared with shock wave experiments, where discrepancy suggests formation of new Ir phases. A few representative EoS parameters, such as bulk modulus KT, thermal expansivity alpha, Gruneisen parameter gamma, constant pressure capacity CP, and Debye temperature OD, are computed to compare with experimental data.

The recent discovery of SPINDLY (SPY)-catalyzed protein O-fucosylation revealed a novel mechanism for regulating nucleocytoplasmic protein functions in plants. Genetic evidence indicates the important roles of SPY in diverse developmental and physiological processes. However, the upstream signal controlling SPY activity and the downstream substrate proteins O-fucosylated by SPY remain largely unknown. Here, we demonstrated that SPY mediates sugar-dependent growth in Arabidopsis (Arabidopsis thaliana). We further identified hundreds of O-fucosylated proteins using lectin affinity chromatography followed by mass spectrometry. All the O-fucosylation events quantified in our proteomic analyses were undetectable or dramatically decreased in the spy mutants, and thus likely catalyzed by SPY. The O-fucosylome includes mostly nuclear and cytosolic proteins. Many O-fucosylated proteins function in essential cellular processes, phytohormone signaling, and developmental programs, consistent with the genetic functions of SPY. The O-fucosylome also includes many proteins modified by O-linked N-acetylglucosamine (O-GlcNAc) and by phosphorylation downstream of the target of rapamycin (TOR) kinase, revealing the convergence of these nutrient signaling pathways on key regulatory functions such as post-transcriptional/translational regulation and phytohormone responses. Our study identified numerous targets of SPY/O-fucosylation and potential nodes of crosstalk among sugar/nutrient signaling pathways, enabling future dissection of the signaling network that mediates sugar regulation of plant growth and development.