Complex organic matter degradation by secondary consumers in chemolithoautotrophy-based subsurface geothermal ecosystems.

Microbial communities in terrestrial geothermal systems often contain chemolithoautotrophs with well-characterized distributions and metabolic capabilities. However, the extent to which organic matter produced by these chemolithoautotrophs supports heterotrophs remains largely unknown. Here we compared the abundance and activity of peptidases and carbohydrate active enzymes (CAZymes) that are predicted to be extracellular identified in metagenomic assemblies from 63 springs in the Central American and the Andean convergent margin (Argentinian backarc of the Central Volcanic Zone), as well as the plume-influenced spreading center in Iceland. All assemblies contain two orders of magnitude more peptidases than CAZymes, suggesting that the microorganisms more often use proteins for their carbon and/or nitrogen acquisition instead of complex sugars. The CAZy families in highest abundance are GH23 and CBM50, and the most abundant peptidase families are M23 and C26, all four of which degrade peptidoglycan found in bacterial cells. This implies that the heterotrophic community relies on autochthonous dead cell biomass, rather than allochthonous plant matter, for organic material. Enzymes involved in the degradation of cyanobacterial- and algal-derived compounds are in lower abundance at every site, with volcanic sites having more enzymes degrading cyanobacterial compounds and non-volcanic sites having more enzymes degrading algal compounds. Activity assays showed that many of these enzyme classes are active in these samples. High temperature sites (> 80°C) had similar extracellular carbon-degrading enzymes regardless of their province, suggesting a less well-developed population of secondary consumers at these sites, possibly connected with the limited extent of the subsurface biosphere in these high temperature sites. We conclude that in < 80°C springs, chemolithoautotrophic production supports heterotrophs capable of degrading a wide range of organic compounds that do not vary by geological province, even though the taxonomic and respiratory repertoire of chemolithoautotrophs and heterotrophs differ greatly across these regions.

Ultrahigh-precision noble gas isotope analyses reveal pervasive subsurface fractionation in hydrothermal systems.

Mantle-derived noble gases in volcanic gases are powerful tracers of terrestrial volatile evolution, as they contain mixtures of both primordial (from Earth's accretion) and secondary (e.g., radiogenic) isotope signals that characterize the composition of deep Earth. However, volcanic gases emitted through subaerial hydrothermal systems also contain contributions from shallow reservoirs (groundwater, crust, atmosphere). Deconvolving deep and shallow source signals is critical for robust interpretations of mantle-derived signals. Here, we use a novel dynamic mass spectrometry technique to measure argon, krypton, and xenon isotopes in volcanic gas with ultrahigh precision. Data from Iceland, Germany, United States (Yellowstone, Salton Sea), Costa Rica, and Chile show that subsurface isotope fractionation within hydrothermal systems is a globally pervasive and previously unrecognized process causing substantial nonradiogenic Ar-Kr-Xe isotope variations. Quantitatively accounting for this process is vital for accurately interpreting mantle-derived volatile (e.g., noble gas and nitrogen) signals, with profound implications for our understanding of terrestrial volatile evolution.

Chemolithoautotroph distributions across the subsurface of a convergent margin.

Subducting oceanic crusts release fluids rich in biologically relevant compounds into the overriding plate, fueling subsurface chemolithoautotrophic ecosystems. To understand the impact of subsurface geochemistry on microbial communities, we collected fluid and sediments from 14 natural springs across a ~200 km transect across the Costa Rican convergent margin and performed shotgun metagenomics. The resulting 404 metagenome-assembled genomes (MAGs) cluster into geologically distinct regions based on MAG abundance patterns: outer forearc-only (25% of total relative abundance), forearc/arc-only (38% of total relative abundance), and delocalized (37% of total relative abundance) clusters. In the outer forearc, Thermodesulfovibrionia, Candidatus Bipolaricaulia, and Firmicutes have hydrogenotrophic sulfate reduction and Wood-Ljungdahl (WL) carbon fixation pathways. In the forearc/arc, Anaerolineae, Ca. Bipolaricaulia, and Thermodesulfovibrionia have sulfur oxidation, nitrogen cycling, microaerophilic respiration, and WL, while Aquificae have aerobic sulfur oxidation and reverse tricarboxylic acid carbon fixation pathway. Transformation-based canonical correspondence analysis shows that MAG distribution corresponds to concentrations of aluminum, iron, nickel, dissolved inorganic carbon, and phosphate. While delocalized MAGs appear surface-derived, the subsurface chemolithoautotrophic, metabolic, and taxonomic landscape varies by the availability of minerals/metals and volcanically derived inorganic carbon. However, the WL pathway persists across all samples, suggesting that this versatile, energy-efficient carbon fixation pathway helps shape convergent margin subsurface ecosystems.

PAUSA: Resultados de un programa de proximidad dirigido a personas con prácticas de chemsex en la ciudad de Madrid / PAUSA: Results of an outreach programme aimed at people with chemsex practices in the city of Madrid

Introducción: El Instituto de Adicciones de Madrid Salud (Ayuntamiento de Madrid) utiliza habitualmenteestrategias de acercamiento orientadas a diferentes grupos de población. En 2020 se impulsó un nuevoprograma de acercamiento dirigido a usuarios con prácticas de chemsex, cuyo diseño y resultadosiniciales se presentan en este trabajo. Objetivos: El programa de acercamiento PAUSA se proponeacceder a usuarios de chemsex que todavía no han demandado atención profesional, ofreciéndolesapoyo desde fases más tempranas para: reducir los riesgos de estas prácticas, programar un descansode las mismas, o facilitar un mejor acceso y enlace a los servicios públicos y comunitarios especializadosen chemsex en la ciudad de Madrid. Materiales y métodos: El diseño del programa exploró diferentesopciones de acercamiento a usuarios de chemsex en activo, incluyendo estrategias de difusión onliney a través de tarjetas y cartelería. Se ofrecieron a los usuarios dos tipos de intervenciones, breves yestructuradas. Las primeras se desarrollaron vía chat. Las segundas mediante cita programada presencialo por Skype/Zoom. Resultados: Durante el periodo de actividad analizado se realizaron un total de 739intervenciones breves por chat, beneficiando a un total de 442 usuarios. Se realizaron además un totalde 190 citas estructuradas, presenciales u online, de una hora de duración. Un total de 115 usuariosfueron derivados a centros de atención a las adicciones. La atención recibida por parte del programarecibió excelentes evaluaciones. Conclusiones: El modelo de intervención implementado en el programaPAUSA resultó efectivo para contactar con usuarios de chemsex en fases más tempranas. La captaciónonline en aplicaciones de contactos gais fue la estrategia de acercamento de mayor éxito. Los usuariosatendidos mostraron una alta aceptabilidad de este formato de intervención. (AU)

Introduction: The Institute of Addictions of Madrid Health (City Council of Madrid) routinely employsoutreach strategies aimed at different population groups. In 2020, a new outreach programme wasinitiated targeting individuals engaged in chemsex practices. This paper presents the design and initialoutcomes of this programme. Objectives: The PAUSE outreach programme aims to engage chemsexusers who have not yet sought professional help, providing them support at earlier stages to mitigatethe risks associated with these practices, introduce breaks from them, or facilitate better access andlinkage to public and community services specialised in chemsex within the city of Madrid. Materialsand Methods: The programme’s design explored various approaches to engage active chemsex users,including online dissemination strategies and through cards and posters. Users were offered twotypes of interventions: brief and structured. The former were conducted via chat, while the latterwere scheduled either for in-person meetings or through Skype/Zoom. Results: During the analysedactivity period, a total of 739 brief interventions were conducted via chat, benefiting 442 users in total.Additionally, 190 structured sessions, either in-person or online, lasting an hour each were carriedout. A total of 115 users were referred to addiction care centres. The programme’s services receivedexcellent evaluations. Conclusions: The intervention model implemented in the PAUSE programmeproved effective in reaching users engaged in chemsex during early stages. Online outreach throughgay contact apps emerged as the most successful engagement strategy. Users served demonstrated ahigh acceptability of this intervention format. (AU)

High 3He/4He in central Panama reveals a distal connection to the Galápagos plume.

It is well established that mantle plumes are the main conduits for upwelling geochemically enriched material from Earth's deep interior. The fashion and extent to which lateral flow processes at shallow depths may disperse enriched mantle material far (>1,000 km) from vertical plume conduits, however, remain poorly constrained. Here, we report He and C isotope data from 65 hydrothermal fluids from the southern Central America Margin (CAM) which reveal strikingly high 3He/4He (up to 8.9RA) in low-temperature (≤50 °C) geothermal springs of central Panama that are not associated with active volcanism. Following radiogenic correction, these data imply a mantle source 3He/4He >10.3RA (and potentially up to 26RA, similar to Galápagos hotspot lavas) markedly greater than the upper mantle range (8 ± 1RA). Lava geochemistry (Pb isotopes, Nb/U, and Ce/Pb) and geophysical constraints show that high 3He/4He values in central Panama are likely derived from the infiltration of a Galápagos plume-like mantle through a slab window that opened ∼8 Mya. Two potential transport mechanisms can explain the connection between the Galápagos plume and the slab window: 1) sublithospheric transport of Galápagos plume material channeled by lithosphere thinning along the Panama Fracture Zone or 2) active upwelling of Galápagos plume material blown by a "mantle wind" toward the CAM. We present a model of global mantle flow that supports the second mechanism, whereby most of the eastward transport of Galápagos plume material occurs in the shallow asthenosphere. These findings underscore the potential for lateral mantle flow to transport mantle geochemical heterogeneities thousands of kilometers away from plume conduits.

[Myotonic dystrophy and bundle-branch re-entrant tachycardia]. / Distrofia miotónica y taquicardia ventricular por reentrada rama-rama.

We report the case of a 37-year-old man diagnosed with myotonic dystrophy who presented atrial fibrillation with high ventricular rate. While being treated with amiodarone, he suffered cardiac arrest. The electrophysiological study disclosed bundle-branch reentrant ventricular tachycardia and ventricular fibrillation. Catheter ablation of the right bundle branch was performed and a bicameral defibrillator was implanted. The mechanisms and treatment of arrhythmias in these patients are discussed.

Manual de evaluación en Clínica Integral / Manual of evaluation in Integral Clinic

Presenta el sistema de evaluación de la Clínica Integral, la evaluación semestral, la evaluación para graduación y los procedimientos de evaluación por área clínica