Diego Portales University

Abstract The Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST) will monitor tens of millions of active galactic nuclei (AGNs) for a period of 10 yr with an average cadence of 3 days in six broad photometric bands. This unprecedented data set will enable robust characterizations of AGN UV/optical variability across a wide range of AGN physical properties. However, existing tools for modeling AGN light curves are not yet capable of fully leveraging the volume, cadence, and multiband nature of LSST data. We present EzTaoX , a scalable light-curve modeling tool designed to take advantage of LSST’s multiband observations to simultaneously characterize AGN UV/optical stochastic variability and measure interband time delays. EzTaoX achieves a speed increase of ∼10 2 –10 4 × on CPUs over current tools with similar capabilities, while maintaining equal or better accuracy in recovering simulated variability properties. This performance gain enables continuum time-delay measurements for all AGNs discovered by LSST—both in the Wide Fast Deep survey and the Deep Drilling Fields—thereby opening new opportunities to probe AGN accretion-flow geometries. In addition, EzTaoX ’s multiband capability allows for robust characterization of AGN stochastic variability down to hourly timescales, facilitating the identification of accreting low-mass AGNs—such as those residing in dwarf galaxies—through their distinctive variability signatures.

Abstract Analyses of integral field unit data are typically performed on a per-spaxel basis, with each spectrum modelled independently. For low signal-to-noise ratio (S/N) features such as weak emission lines, estimating properties is difficult and imprecise. Arbitrary binning schemes boost S/N at the cost of resolution, and risk introducing biases. We present a general forward-modeling approach that assumes spectra close on the sky are more similar than distant ones, and so can be modelled jointly. These “spectrospatial” models exploit spatial correlation to provide robust inferences, while simultaneously providing continuous predictions of line properties like strength and kinematics across the sky. Instrumental and calibration systematics are straightforward to include and infer. The model provides a natural trade-off between spatial resolution and S/N in a data-driven way. We apply this to Sloan Digital Sky Survey V Local Volume Mapper (LVM) data of the Rosette Nebula, producing continuous maps of fluxes and kinematics for Balmer, nebular, and auroral lines, as well as weak C ii and N ii recombination lines, demonstrating the approach across 3 orders of magnitude in S/N, including in the very low-S/N regime. The method recovers identical morphologies across different lines tracing similar ionisation volumes, at varying resolutions set by the S/N. We additionally provide a general framework for building and fitting such models in JAX , suitable for many applications. The implementation is fast and memory efficient, scales to large data volumes as in LVM, and can be deployed on hardware accelerators.

Abstract We present the first localized detections of the cold neutral medium (CNM) in IC 10, offering a rare view of dense atomic gas in a low-metallicity ( Z / Z ⊙ ∼ 0.27) dwarf galaxy. As a low-metallicity starburst, IC 10’s interstellar medium conditions could reflect small scale physics conditions that mirror those of early galaxies, providing a unique window into the heating and cooling processes that shaped the interstellar medium in early-Universe environments. Leveraging the high angular (<5″ ∼ 15 pc) and spectral (0.4 km s −1 ) resolution of the Local Group L -band Survey, we searched for H I absorption against nine continuum radio sources and detected absorption along three sightlines corresponding to internal radio emission sources within IC 10. Using Gaussian decomposition and radiative transfer, we characterize the CNM, deriving spin temperatures of ∼30–55 K, column densities of (0.6–3.0) × 10 21 cm −2 , cold H I fractions of ∼21%–37%, and line widths of ∼5.6–13.6 km s −1 . For each individual detection of H I absorption, we find corresponding molecular emission from 12 CO ( J = 1–0), HCO + ( J = 1–0), and HCN ( J = 1–0) at similar velocities and with comparable line widths, indicating a well-mixed cold atomic and molecular medium. In IC 10, the CNM shows a clear kinematic connection to the high-density ISM, implying a stronger dynamical coupling with molecular gas than in the Milky Way, in line with expectations for low-metallicity environments. At the ∼15 pc scales probed by slightly extended H II regions in IC 10, unresolved CNM clouds likely contribute to line blending, so the observed broad H I line widths may partly reflect spatial and kinematic averaging.

Abstract Characterizing dust attenuation is crucial for revealing the intrinsic physical properties of galaxies. We present an analysis of dust attenuation in 18 spectroscopically confirmed star-forming main-sequence galaxies at z = 4.4−5.7 observed with JWST/NIRSpec IFU and NIRCam, selected from the ALPINE and CRISTAL ALMA large programs. We fit the emission-line fluxes from NIRSpec and the broadband photometry from NIRCam with Prospector , using both spatially integrated emission and ∼0.6 kpc pixel-by-pixel measurements. We derive the stellar-to-nebular dust attenuation ratio ( f = E ( B − V ) star / E ( B − V ) neb ) from the SED fits and the Balmer decrement with H α and H β . Although individual galaxies show large scatter, the best-fit value is <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>f</mml:mi> <mml:mo>=</mml:mo> <mml:mn>0.5</mml:mn> <mml:msubsup> <mml:mrow> <mml:mn>1</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.03</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.04</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> , slightly higher than that measured for local starburst galaxies. We find weak correlations of f with galaxy properties, increasing with higher specific star formation rates, younger stellar ages, and more recent star formation. For the range of E ( B − V ) star = 0.009−0.15 mag for in our sample, assuming f = 1 (often adopted in high-redshift studies) instead of f = 0.51 leads to the underestimation of line luminosities and ionizing photon production efficiency ξ ion by ∼3%−36% and ∼4​​​​​​%−46%, respectively. Finally, total stellar masses estimated from spatially integrated SED fits with delayed- τ star formation histories are systematically smaller than the sums of pixel-by-pixel SED fits by a median of ∼0.26 dex, likely because the integrated fits are biased toward luminous young stellar populations.

Incumbency and campaign spending are key determinants of electoral success in legislative elections. In open-list proportional representation systems, their impact might be contingent on the number of open seats in each district. When there are more open seats, incumbents seeking re-election and those who spend more should have higher chances of success. Using data from 2216 candidates in the 2017 and 2021 Chamber of Deputies elections in Chile’s 28 districts, we assess the presence of the mediating effect of open seats. We confirm the importance of incumbency and campaign spending, but the interaction effects of open seats with incumbency and campaign spending are not significant for the chances of winning a seat. The presence of open seats might induce more competitive challengers to enter the race, diluting the expected positive interaction of open seats with incumbency and campaign spending on electoral success.

ABSTRACT The young TOI-451 planetary system, aged 125 Myr, provides a unique opportunity to test theories of planetary internal structures and atmospheric mass-loss through examination of its three transiting planets. We present an exhaustive photometric and spectroscopic follow-up to determine the orbital and physical properties of the system. We perform multidimensional Gaussian Process regression with the code pyaneti on spectroscopic time-series and NGTS/LCO light curves to disentangle the stellar and planetary signal in ESPRESSO radial velocities. We show how contemporaneous photometry serves as an activity indicator to inform RV modelling within a multidimensional Gaussian Processes framework. We argue that this can be exploited when spectroscopic observations are adversely affected by low signal-to-noise and/or poor sampling. We estimate the Doppler semi-amplitudes of $k_{\rm b}=$ $2.6_{-1.2}^{+1.1}$ $\mathrm{m\, s^{-1}}$, $k_{\rm c}=$ $1.2_{-0.8}^{+1.0}$ $\mathrm{m\, s^{-1}}$ , and $k_{\rm d}=$ $2.7 \pm 1.2$ $\mathrm{m\, s^{-1}}$ . This translates in 2$\sigma$ mass estimates for TOI-451 b and d of $M_{\rm b}=$ $4.7_{-2.2}^{+2.1}$ $\mathrm{M_{\rm{\oplus }}}$ and $M_{\rm d}=$ $10.2_{-4.5}^{+4.6}$ $\mathrm{M_{\rm{\oplus }}}$; as well as a mass upper limit for TOI-451 c of $M_{\rm c} \lt 11.5\, M_{\rm{\oplus }}$. The derived planetary properties suggest that planets c and d contain significant hydrogen-rich envelopes. The inferred parameters of TOI-451 b are consistent with either a rocky world that still retains a small hydrogen envelope or a water world. These insights make the TOI-451 system an ideal laboratory for future follow-up studies aimed at measuring atmospheric compositions, detecting atmospheric mass-loss signatures, and further exploring planetary formation and evolution processes.

Abstract. The stochastic and non-stochastic properties of the scouring process at bridges are analysed by coupling synthetic streamflow generations with a scour and fill model considering the upstream sediment supply. Streamflow was generated using the asymmetric moving-average (AMA) scheme that preserves the Hurst-Kolmogorov (HK) dynamics, the second-order dependence structure, time asymmetry, and the first four statistical moments of the marginal distribution. Stationarity, homogeneity, and ergodicity of the streamflow and scouring processes were assumed. Monte Carlo analyses covered 12,000 realisations for each of the three considered scenarios with different upstream sediment supply. Extreme scour events were assessed using annual maxima with GEV fitting and compared against the equilibrium scour. The dependence structure was identified with the climacogram and climacospectrum stochastic tools and fitted with a filtered HK model (FHK-CD). The obtained results show a multi-scale dynamics of the scouring process with rough and weak persistent behaviour (M ≈ 0.40; H ≈ 0.60), while envelopes span from antipersistent to strongly persistent scour regimes (H up to ≈ 0.86) depending on the upstream sediment supply. It is worth noting that the upstream sediment supply reduced the envelope variability and modified the extreme scour values. Additionally, synchronisation between extreme events of streamflow and scour showed a weak correspondence (Critical Success Index ≈ 0.15–0.60), indicating that streamflow extremes do not systematically translate into scour extremes. Finally, scour depths with a given return period (computed from scour time series) increase with upstream sediment supply.

Agroecology is increasingly shaped by the convergence of traditional knowledge, farmers’ lived experiences, and scientific research, fostering a plural dialog that embraces the ecological and socio-political complexity of agricultural systems. Within this framework, soil biodiversity is essential for maintaining ecosystem functions, with soil microbiology, and particularly arbuscular mycorrhizal fungi (AMF), playing a pivotal role in enhancing soil fertility, plant health, and agroecosystem resilience. This review explores the synergy between agroecological practices and AMF by examining their ecological, economic, epistemic, and territorial contributions to sustainable agriculture. Drawing on recent scientific findings and Latin American case studies, it highlights how practices such as reduced tillage, crop diversification, and organic matter inputs foster diverse and functional AMF communities and differentially affect their composition and ecological roles. Beyond their biological efficacy, AMF are framed as relational and socio-ecological agents—integral to networks that connect soil regeneration, food quality, local autonomy, and multi-species care. By bridging ecological science with political ecology and justice in science-based knowledge, this review offers a transdisciplinary lens on AMF and proposes pathways for agroecological transitions rooted in biodiversity, cognitive justice, and territorial sustainability.

Este artículo examina la construcción de la identidad profesional docente de Ivana, educadora de párvulos chilena, a partir de un incidente crítico ocurrido al inicio de su trayectoria profesional -la ingesta accidental de un sorbo de cloro (hipoclorito de sodio) por un niño-. Con una orientación biográfico-narrativa, se produjeron datos mediante entrevistas semiestructuradas, biogramas y journey plots; se realizó un análisis temático guiado por la Teoría del Self Dialógico. Los hallazgos muestran una ecología de posiciones del yo en tensión y coalición —“yo funcionaria novel”, “yo profesional”, “yo sindical”, “yo directora” y “voz institucional”— y describen cómo la voz sindical opera como posición promotora, reconfigurando la atribución de responsabilidad desde la culpabilización individual hacia condiciones organizacionales y normativas. El incidente actúa como punto de inflexión y condensador biográfico, visibiliza tensiones entre cuidado, justicia y gestión del riesgo, habilitando un posicionamiento crítico que transforma afectos disruptivos (culpa, rabia) en responsabilidad situada y agencia. Se discuten implicancias para liderazgos transformadores, entornos de trabajo equitativos y formación centrada en reflexión crítica, justicia social y corresponsabilidad.

ResumoFundamento As doenças cardiovasculares ateroscleróticas — especialmente a doença isquêmica do coração (DIC), o acidente vascular cerebral (AVC) e a doença arterial periférica (DAP) — são a principal causa de mortalidade cardiovascular no Brasil.Objetivos Projetar as tendências de mortalidade por DIC, AVC e DAP no Brasil até 2040.Métodos As contagens anuais de óbitos (1990-2021) por DIC, AVC e DAP entre indivíduos de 40 a 79 anos foram obtidas a partir do estudo Carga Global de Doenças (Global Burden of Disease, GBD) de 2021. Utilizaram-se estimativas populacionais de meio de ano tanto para o período observado (1990-2021) quanto para o projetado (2022-2040). Foram calculadas as taxas de mortalidade brutas e padronizadas por idade. Modelos bayesianos idade-período-coorte foram aplicados para projetar as taxas de mortalidade de 2022 a 2040. Foram computadas as variações percentuais relativas e as estimativas anuais de variação percentual (EAVPs). As projeções (por 100.000 habitantes) são apresentadas como medianas com intervalos de incerteza (IIs) de 95%, e as EAVPs incluem intervalos de confiança (ICs) de 95% derivados por bootstrap.Resultados Entre 1990 e 2040, estima-se que a população brasileira de 40 a 79 anos aumente em 237,82%. A taxa de mortalidade padronizada por idade para DIC deverá apresentar uma redução de 14,16% [de 118,61 em 2021 para 101,82 em 2040 (II 95%, 0,36-203,27)] (EAVP: -0,83% [IC 95%, -0,84 a -0,83]); e, para AVC, uma redução de 17,36% [de 84,58 para 69,90 (II 95%, 0-152,48)] (EAVP: -1,07% [IC 95%, -1,10 a -1,04]). Em contraste, projeta-se que a mortalidade por DAP aumente em 10,99% [de 1,82 para 2,02 (II 95%, 0-5,03)] (EAVP: 0,45% [IC 95%, 0,30-0,59]). Adicionalmente, as taxas de mortalidade padronizadas por idade, específicas por sexo, mostraram variações consideráveis. Para a DIC, projeta-se uma redução de 25,31% entre homens (EAVP, -1,56% [IC 95%, -1,57 a -1,55]), enquanto entre mulheres deverá haver um aumento de 4,12% (EAVP: 0,14% [IC 95%, 0,13-0,16]). A mortalidade por AVC deverá reduzir em 30,00% entre homens (EAVP, -1,94% [IC 95%: -1,96 a -1,91]) e em 4,52% entre mulheres (EAVP: -0,33% [IC 95%, -0,37 a -0,29]). Em contrapartida, a mortalidade por DAP deverá crescer 14,64% entre homens (EAVP, 0,55% [IC 95%: 0,38-0,71]) e 21,92% entre mulheres (EAVP: 0,91% [IC 95%: 0,78-1,02]).Conclusão Embora se preveja redução nas taxas de mortalidade por DIC e AVC, espera-se um aumento na mortalidade por DAP — especialmente entre as mulheres —, o que evidencia a necessidade urgente de intervenções em saúde pública específicas por sexo e por tipo de doença.