Resilient urban design in the foothills of Santiago? Contrast of communal scenarios with seismic risk due to the San Ramón Fault

In recent decades, Santiago has seen a substantial increase in urbanized areas along its eastern foothills, where the San Ramón Fault (FSR) is also located. This has become a new geological risk scenario. Using the unquestionable appeal of the natural setting, the panoramic view of the city, and a healthy environment, luxury housing projects have been promoted that coexist with this seismic risk, something that seems to have been disregarded by communal and metropolitan planning instruments. The purpose of this article is to explore the urban design conditions on Santiago’s foothills to face the San Ramon Fault, through a contrast analysis of two specific sectors located within the potential buffer of the San Ramón Fault - the urban districts of Hospital de Carabineros in Las Condes and El Peral in Puente Alto - and the way these articulate with the natural and built environments, including critical infrastructure. Methodologically speaking, a mixed approach is applied through an analysis matrix of urban design elements that includes three areas of action - built, natural and regulatory - to identify critical situations in the areas studied, where the resilient response is either high or low. It is concluded that contrasting urban design experiences under extreme conditions regarding seismic risk is illustrative, both for permeating the operational layers of risk management such as communal and metropolitan regulations, and to consider the foothills in a resilient way, recognizing the San Ramón Fault as a new base criterion of urban design.Santiago ha experimentado en sus últimas décadas un aumento considerable de áreas urbanizadas en el piedemonte de su borde oriente, donde además se localiza la Falla San Ramón (FSR), de modo que se ha vuelto un nuevo escenario de riesgo geológico. Usando incuestionables atractivos sobre el medio natural, la vista panorámica a la ciudad y un ambiente saludable, se han promocionado proyectos de vivienda de alto costo que conviven con este riesgo sísmico, pero que parecen desestimarlo desde los instrumentos de planificación de nivel comunal y metropolitano. El presente artículo tiene por objetivo explorar las condiciones de diseño urbano que presenta el piedemonte de Santiago para enfrentar la presencia de la Falla San Ramón (FSR), mediante un análisis de contraste de dos sectores específicos localizados dentro de la franja de potencial ruptura superficial (buffer) de la FSR -distrito urbano Hospital de Carabineros en Las Condes y distrito urbano El Peral en Puente Alto-y su forma de articularse con el medio natural y con el medio construido, incluyendo la presencia de infraestructura crítica. Metodológicamente, se aplica un enfoque mixto a través de una matriz de análisis de elementos de diseño urbano que incluye tres ámbitos de acción -construido, natural y normativo- para identificar situaciones críticas de los sectores estudiados, donde se ve elevada o disminuida la respuesta resiliente. Se concluye que contrastar experiencias de diseño urbano en condiciones extremas respecto al riesgo sísmico es ilustrativo, tanto para permear las capas operativas de gestión de riesgo, como normativas comunales y metropolitanas, como para asumir el piedemonte de manera resiliente, reconociendo la Falla San Ramón como un nuevo criterio basal de diseño urbano

Misleading urbanization? The San Ramon fault as a new seismic risk scenario and the sustainability of Santiago, Chile

Santiago, capital city of Chile inhabited by ca. 7 million persons (INE, 2018), is located at the foot of the western flank of the main Andes Cordillera, which is one of the most active mountain chains worldwide. The eastern border of the city, located at the piedmont of the mountain front, experienced an accelerated urbanization in the last four decades with respect to the previous four centuries, with subsequent increased risk associated to geological hazards among of them the possibility for crustal earthquakes along the active San Ramon thrust fault system. Here, we explore this new seismic risk scenario by comparing first order urban mapping at different stages of the horizontal expansion of the city, including the location of the geological structure, with urban policies developed since 1960. Our results show that -at present- urbanization reached 55% of the San Ramon fault trace, evidencing that this active geological structure has not been considered in urban regulations developed for the metropolitan region. We conclude the necessity to unravel normative and knowledge gaps in order to relate the natural geological hazard with the urban planning, as an opportunity to progress toward a sustainable development of the mega-city of Santiago

Aluviones y resiliencia en Atacama. Construyendo saberes sobre riesgos y desastres

Para comprender lo sucedido en la región de Atacama con los aluviones del 2015, se requiere ir más allá del mes de marzo y del contexto regional. Los estudios que se presentan en este libro articulan la situación actual con la precedente, para configurar la complejidad del fenómeno y sus impactos a partir de las señales entregadas por la historia. Tanto la sociedad como la naturaleza han manifestado sus desacoples y sus ajustes, por lo que el conocimiento científico que hemos generado busca también en ellos las explicaciones de lo ocurrido en la actualidad. Así, el análisis de las antiguas y nuevas amenazas se propone en este libro como la llave del conocimiento del riesgo al que se enfrenta la región, con la intención de retratar en el presente también el registro del pasado que lo conforma. Es esta profundidad la que nos permite pensar la experiencia del desastre como una oportunidad de reconocernos colectivamente en sus características, evitando repetir los mismos errores y reinventar las mismas soluciones

Late Holocene precipitation variability recorded in the sediments of Reloncavi Fjord (41 degrees S, 72 degrees W), Chile

Artículo de publicación ISIWe present reconstructions of late Holocene changes in the source of organic matter and siliceous export production in the Relocanvi Fjord (41 degrees S, 72 degrees W), Northern Chilean Patagonia, based on organic carbon content, delta C-13(org), N/C ratio, diatom assemblages and biogenic silica contents from three sediment cores. The age models are based on a combination of Pb-210 profiles, AMS C-14 dating, and on the first occurrence of the diatom Rhizosofenia setigera f. pungens, as a stratigraphic marker in the fjords. The cores span the last 300 to 700 yr. Diatoms dominate the siliceous assemblages in the three cores (98% on average). Our results suggest that precipitation seasonality in the region of Reloncavi was high in CE 1300-1400 and CE 1700-1850, with a clear decreasing trend since CE 1850. The latter trend is in agreement with instrumental records and tree-ring reconstructions. These fluctuations seem to be associated with the Southern Annular Mode (SAM).FONDECYT 11110103 COPAS Sur-Austral Program PFB-31 Hanse-Wissenschaftskolleg in Delmenhorst (Germany

A randomised, blinded, trial of clopidogrel versus aspirin in patients at risk of ischaemic events (CAPRIE). CAPRIE Steering Committee

Many clinical trials have evaluated the benefit of long-term use of antiplatelet drugs in reducing the risk of clinical thrombotic events. Aspirin and ticlopidine have been shown to be effective, but both have potentially serious adverse effects. Clopidogrel, a new thienopyridine derivative similar to ticlopidine, is an inhibitor of platelet aggregation induced by adenosine diphosphate. METHODS: CAPRIE was a randomised, blinded, international trial designed to assess the relative efficacy of clopidogrel (75 mg once daily) and aspirin (325 mg once daily) in reducing the risk of a composite outcome cluster of ischaemic stroke, myocardial infarction, or vascular death; their relative safety was also assessed. The population studied comprised subgroups of patients with atherosclerotic vascular disease manifested as either recent ischaemic stroke, recent myocardial infarction, or symptomatic peripheral arterial disease. Patients were followed for 1 to 3 years. FINDINGS: 19,185 patients, with more than 6300 in each of the clinical subgroups, were recruited over 3 years, with a mean follow-up of 1.91 years. There were 1960 first events included in the outcome cluster on which an intention-to-treat analysis showed that patients treated with clopidogrel had an annual 5.32% risk of ischaemic stroke, myocardial infarction, or vascular death compared with 5.83% with aspirin. These rates reflect a statistically significant (p = 0.043) relative-risk reduction of 8.7% in favour of clopidogrel (95% Cl 0.3-16.5). Corresponding on-treatment analysis yielded a relative-risk reduction of 9.4%. There were no major differences in terms of safety. Reported adverse experiences in the clopidogrel and aspirin groups judged to be severe included rash (0.26% vs 0.10%), diarrhoea (0.23% vs 0.11%), upper gastrointestinal discomfort (0.97% vs 1.22%), intracranial haemorrhage (0.33% vs 0.47%), and gastrointestinal haemorrhage (0.52% vs 0.72%), respectively. There were ten (0.10%) patients in the clopidogrel group with significant reductions in neutrophils (< 1.2 x 10(9)/L) and 16 (0.17%) in the aspirin group. INTERPRETATION: Long-term administration of clopidogrel to patients with atherosclerotic vascular disease is more effective than aspirin in reducing the combined risk of ischaemic stroke, myocardial infarction, or vascular death. The overall safety profile of clopidogrel is at least as good as that of medium-dose aspirin

Apixaban compared with warfarin in patients with atrial fibrillation and previous stroke or transient ischaemic attack: A subgroup analysis of the ARISTOTLE trial

Background: In the ARISTOTLE trial, the rate of stroke or systemic embolism was reduced by apixaban compared with warfarin in patients with atrial fibrillation (AF). Patients with AF and previous stroke or transient ischaemic attack (TIA) have a high risk of stroke. We therefore aimed to assess the efficacy and safety of apixaban compared with warfarin in prespecified subgroups of patients with and without previous stroke or TIA. Methods: Between Dec 19, 2006, and April 2, 2010, patients were enrolled in the ARISTOTLE trial at 1034 clinical sites in 39 countries. 18 201 patients with AF or atrial flutter were randomly assigned to receive apixaban 5 mg twice daily or warfarin (target international normalised ratio 2·0-3·0). The median duration of follow-up was 1·8 years (IQR 1·4-2·3). The primary efficacy outcome was stroke or systemic embolism, analysed by intention to treat. The primary safety outcome was major bleeding in the on-treatment population. All participants, investigators, and sponsors were masked to treatment assignments. In this subgroup analysis, we estimated event rates and used Cox models to compare outcomes in patients with and without previous stroke or TIA. The ARISTOTLE trial is registered with ClinicalTrials.gov, number NTC00412984. Findings: Of the trial population, 3436 (19%) had a previous stroke or TIA. In the subgroup of patients with previous stroke or TIA, the rate of stroke or systemic embolism was 2·46 per 100 patient-years of follow-up in the apixaban group and 3·24 in the warfarin group (hazard ratio [HR] 0·76, 95% CI 0·56 to 1·03); in the subgroup of patients without previous stroke or TIA, the rate of stroke or systemic embolism was 1·01 per 100 patient-years of follow-up with apixaban and 1·23 with warfarin (HR 0·82, 95% CI 0·65 to 1·03; p for interaction=0·71). The absolute reduction in the rate of stroke and systemic embolism with apixaban versus warfarin was 0·77 per 100 patient-years of follow-up (95% CI -0·08 to 1·63) in patients with and 0·22 (-0·03 to 0·47) in those without previous stroke or TIA. The difference in major bleeding with apixaban compared with warfarin was 1·07 per 100 patient-years (95% CI 0·09-2·04) in patients with and 0·93 (0·54-1·32) in those without previous stroke or TIA. Interpretation: The effects of apixaban versus warfarin were consistent in patients with AF with and without previous stroke or TIA. Owing to the higher risk of these outcomes in patients with previous stroke or TIA, the absolute benefits of apixaban might be greater in this population. Funding: Bristol-Myers Squibb and Pfizer. © 2012 Elsevier Ltd

Apixaban versus warfarin in patients with atrial fibrillation

BACKGROUND: Vitamin K antagonists are highly effective in preventing stroke in patients with atrial fibrillation but have several limitations. Apixaban is a novel oral direct factor Xa inhibitor that has been shown to reduce the risk of stroke in a similar population in comparison with aspirin. METHODS: In this randomized, double-blind trial, we compared apixaban (at a dose of 5 mg twice daily) with warfarin (target international normalized ratio, 2.0 to 3.0) in 18,201 patients with atrial fibrillation and at least one additional risk factor for stroke. The primary outcome was ischemic or hemorrhagic stroke or systemic embolism. The trial was designed to test for noninferiority, with key secondary objectives of testing for superiority with respect to the primary outcome and to the rates of major bleeding and death from any cause. RESULTS: The median duration of follow-up was 1.8 years. The rate of the primary outcome was 1.27% per year in the apixaban group, as compared with 1.60% per year in the warfarin group (hazard ratio with apixaban, 0.79; 95% confidence interval [CI], 0.66 to 0.95; P<0.001 for noninferiority; P = 0.01 for superiority). The rate of major bleeding was 2.13% per year in the apixaban group, as compared with 3.09% per year in the warfarin group (hazard ratio, 0.69; 95% CI, 0.60 to 0.80; P<0.001), and the rates of death from any cause were 3.52% and 3.94%, respectively (hazard ratio, 0.89; 95% CI, 0.80 to 0.99; P = 0.047). The rate of hemorrhagic stroke was 0.24% per year in the apixaban group, as compared with 0.47% per year in the warfarin group (hazard ratio, 0.51; 95% CI, 0.35 to 0.75; P<0.001), and the rate of ischemic or uncertain type of stroke was 0.97% per year in the apixaban group and 1.05% per year in the warfarin group (hazard ratio, 0.92; 95% CI, 0.74 to 1.13; P = 0.42). CONCLUSIONS: In patients with atrial fibrillation, apixaban was superior to warfarin in preventing stroke or systemic embolism, caused less bleeding, and resulted in lower mortality. Copyright © 2011 Massachusetts Medical Society. All rights reserved