Carlos Aguirre-Nuñez

Despite the importance of adaptive reuse for urban renewal, municipal records of changes in property destinations remain an untapped resource for understanding regulatory barriers. This study develops an interpretable machine learning (ML) framework to screen historical administrative non-approval using 42,350 municipal records from a mid-sized city in southern Chile spanning 2010 to 2025. Historical memory features were constructed exclusively from outcomes available before each application, thereby preventing temporal leakage. Records from 2010–2022 were used for training, 2023 was reserved for validation, and 2024–2025 constituted a locked test set. A logistic regression model combining auditable risk flags derived from GIRO (declared economic or functional activity) with historical property, address, and activity category information was selected by maximizing the F1-score (the harmonic mean of precision and recall) subject to a recall ≥ 0.85. At the validation-selected threshold of 0.285, the model achieved a receiver operating characteristic area under the curve (ROC-AUC) of 0.778, a precision–recall area under the curve (PR-AUC) of 0.720, an F1-score of 0.719, recall of 0.887, and precision of 0.604. The model flagged 66.8% of applications for prioritized review. The proposed framework supports human-in-the-loop screening and institutional learning; it neither determines regulatory compliance nor automates municipal decisions.

Este artículo propone una lectura multiescalar del microbioma del entorno construido, examinando cómo las comunidades microbianas de las viviendas se relacionan con procesos que abarcan desde la escala metropolitana hasta las prácticas cotidianas. A partir de una revisión interdisciplinaria y del estudio exploratorio de un conjunto de vivienda social incremental en Renca, se analizan las relaciones entre estructura urbana, entorno barrial, transformaciones domésticas y diversidad microbiológica. Viviendas originalmente homogéneas han desarrollado condiciones diferenciadas mediante ampliaciones y formas de ocupación. Mediante la secuenciación de muestras de cocinas y salas de estar-comedor, se caracterizaron comunidades bacterianas y fúngicas. Los resultados muestran una alta variabilidad entre viviendas y recintos, asociada al uso, la ocupación, la ventilación, la humedad y el intercambio con el exterior. La vivienda emerge como una instancia de mediación entre procesos urbanos, ambientales, sociales y biológicos, situando el microbioma doméstico como una condición sociomaterial relevante para la cohabitación multiespecie y los ambientes saludables.

Este artículo contrasta y refuta empíricamente la explicación neoliberal del alza de los precios de la vivienda en la ciudad de Concepción, Chile entre 2010 y 2021; y adelanta una interpretación acerca de cómo funcionan los mercados de suelo y vivienda – alternativa a la “historia oficial” que se ofrece para explicar dichas alzas. Cierra con tres hipótesis sobre el funcionamiento de los mercados de vivienda en Concepción. El alza de los precios de la vivienda, muy por encima del crecimiento demográfico y a pesar del incremento de viviendas construidas, se atribuye a dos formas en que la promoción inmobiliaria fabrica escasez de suelo y rentas: los ciclos inmobiliarios localizados y la economía urbana del monocultivo.

Background/Objectives: Cardiovascular diseases (CVD) in Chile are profoundly shaped by place-based determinants of diet. This study examines the association between food deserts—areas with structurally limited access to nutritious, affordable food—and population-level cardiovascular risk across Chile’s three largest metropolitan areas (Santiago, Valparaíso, Concepción). Methods: We constructed a geospatial food desert index combining OpenStreetMap-derived retail accessibility with census information, and linked it to georeferenced cardiovascular health records. To overcome the limitations of global models that assume spatial stationarity, we applied Multiscale Geographically Weighted Regression (MGWR) to allow coefficients to vary across space and to recover variable-specific process scales. Results: The MGWR results indicate pronounced spatial non-stationarity in the food desert–CVD association. The relationship is predominantly positive across Gran Valparaíso, predominantly negative in Gran Concepción, and highly mixed within Gran Santiago, evidencing divergent local mechanisms rather than a single national pattern. Conclusions: The observed heterogeneity undermines “one-size-fits-all” national interventions and supports place-sensitive, equity-oriented strategies. Policy implications include territorially tailored food-retail regulation and primary-care outreach, co-designed with local actors, with MGWR providing a critical analytic basis for actionable, context-specific public health planning.

Urban verticalisation is a defining feature of metropolitan growth, yet its dynamics in Latin American cities remain underexplored, particularly regarding project-level traits and broader urban context. This study analyses verticalisation in Santiago, Chile, identifying spatial patterns, urban drivers, and links to socio-economic and regulatory conditions. Using a mixed-methods approach, 892 high-rise residential permits (2010–19) are grouped into six clusters through principal component and cluster analyses. Logistic and ordered logistic regressions assess the influence of urban attributes on vertical development. Results show that proximity to major public transport hubs significantly increases verticalisation likelihood, aligning with global transit-oriented trends. However, lower land values and regulatory flexibility encourage dense projects in areas such as Estación Central, while wealthier zones resist vertical growth due to high land prices and community opposition. The findings highlight verticalisation’s dual nature: it optimises land use and expands housing supply, but also reinforces existing inequalities, segregation and overcrowding. This challenges the assumption that verticalisation responds primarily to luxury demand, linking it instead to affordability, market dynamics and uneven urban governance. POLICY RELEVANCE Evidence reveals how urban verticalisation in Santiago is shaped by affordability and regulatory flexibility rather than luxury demand. High-rise projects are a spatially uneven urban development: they are concentrated in areas with lower land values and weaker planning instruments, while wealthier municipalities resist vertical growth through higher land prices and organised opposition. For policymakers and practitioners, these findings underline the risks of unbalanced densification: overcrowded micro-apartments, limited access to green areas and reinforced socio-spatial segregation. Opportunities exist to align vertical development with sustainability goals. Strategic interventions include strengthening planning frameworks, integrating transit-oriented development with quality standards, and ensuring equitable access to housing and urban amenities. Yet the extent to which they can reduce segregation and protect vulnerable groups depends on the broader social, economic and political dynamics of Latin American urban governance, where regulatory fragmentation and market power often constrain public action.

The COVID-19 pandemic has spurred discussions on reimagining cities based on principles of public health and reducing spatially expressed inequalities. In this context, the concept of the 15-minute city has emerged as a priority for municipal authorities in the case of Chile. However, the implementation of this model faces challenges, including the dominant presence of the market in the production and capitalisation of urban life in Chilean cities. This article was published open access under a CC BY-NC-ND licence: https://creativecommons.org/licenses/by-nc-nd/4.0/ .

Timber construction is increasingly promoted in Chile as a route to low-carbon, energy-efficient housing, yet public acceptance remains decisive for its diffusion. This study reports the first large-scale perception survey of timber buildings in Greater Concepción (N = 200) and contrasts key results with an earlier identical survey in Valdivia. Concepción residents strongly recognise timber’s thermal comfort attributes and associate wood housing with lower winter heating demand, a perception markedly stronger than in Valdivia. Conversely, 73% of Concepción respondents believe timber homes burn easily, but a majority also accept that modern engineering can mitigate this risk, indicating scope for targeted technical communication. Environmental perceptions are more ambivalent: although respondents value wood’s renewable origin, 42% doubt that timber construction reduces climate change, and many equate it with deforestation, echoing controversies around Chile’s plantation model. Cluster analysis reveals a techno-optimist subgroup coupling enthusiasm for energy savings with confidence in fire-safety innovations, suggesting a strategic constituency for demonstration projects. By situating end-user attitudes within national decarbonisation goals, this paper argues that region-specific outreach—emphasising verified energy-efficiency gains, certified sustainable forestry and visible fire-safety performance—can convert passive approval into active demand and accelerate Chile’s transition to a net-zero housing stock.

The effectiveness of ozone (O₃) in eliminating various types of microorganisms, as well as in oxidizing a wide range of contaminants present in wastewater, and drinking water, is extensively documented in the literature, along with the required concentrations, contact times (Ct values), reaction mechanisms for different pollutants, and overall efficiency. This article presents a comprehensive review on the use of aqueous O₃ for treatment and disinfection, specifically for low-contaminant domestic greywater (LGW), providing information for its integration into the design of small-scale treatment systems. Additionally, to complement the theoretical findings, experimental tests were conducted using a portable O₃ generator in an operational facility treating greywater (GW) from handwashing sinks. The results confirmed that O₃ concentration increases over time but decreases as the volume of water to be treated increases. Water analysis results showed significant reductions in BOD₅, turbidity, and total suspended solids after treatment. Furthermore, the results demonstrated that the presence of microorganisms in LGW is minimal, as in the case of fecal coliforms, ensuring a 1 Log disinfection level in this type of system. O₃, as the sole treatment and disinfection system, with an oxidation potential nearly twice that of chlorine, proved to be highly effective in small-scale treatment systems, promoting sustainable practices, water resource conservation, environmental protection, and public health.