Estructuras de licuefacción sísmica en el yacimiento romano de La Magdalena, Complutum s. IV AD (Madrid, España)

la antigua ciudad romana de Complutum (Alcalá de Henares, Madrid) fue fundada en el s. I AD y fue una de las ciudades más importantes de Hispania. Complutum fue destruida, abandonada bruscamente, reubicada y reconstruida en una nueva localización en el s. IV AD. Las causas de la destrucción y la nueva localización de la ciudad son aún una incógnita para la arqueología. En este trabajo se muestran diferentes efectos arqueosismológicos de terremotos (EAEs) afectando al yacimiento de La Magdalena (una explotación agrícola situada a 4 km al NE del núcleo urbano de Complutum). El efecto geológico de origen sísmico que afectó al yacimiento es la licuefacción. Se pueden observar diques de arena y cráteres de gravas por explosión afectando a instalaciones romanas, como cisternas, casas o tumbas. Simultáneamente al abandono de La Magdalena también fueron abandonadas de forma brusca la ciudad de Complutum y varias villas romanas a lo largo del valle del Henares, en algunos casos con EAEs que pueden asociarse al mismo evento que destruyó el yacimiento de La Magdalena. Estos EAEs podrían estar generados por un terremoto de Mw = 5.0-6,6, utilizando los límites empíricos de licuefacción y ruptura cosísmica de la fallaInstituto Geológico y Minero de España, EspañaDepartamento de Geología, Escuela Politécnica Superior de Ávila, Universidad Salamanca, EspañaTrébede, Patrimonio Cultural, S.L., EspañaUniversidad de Salamanca, EspañaFacultad de Ciencias, Universidad Autónoma de Madrid, EspañaDepartamento de Ingeniería del Terreno, Escuela Politécnica Superior de Ávila, Universidad de Salamanca, EspañaDepartamento de Edafología, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Politécnica de Madrid, EspañaFacultad de Ciencias, Universidad Nacional de Educación a Distancia, EspañaDepartamento de Geología, Universidad de Alcalá de Henares, Españ

Seismically induced liquefaction structures in La Magdalena archaeological site, the 4th century AD Roman Complutum (Madrid, Spain)

The ancient Roman city of Complutum(Alcalá deHenares,Madrid), founded in the 1st century AD,was one of the most important cities ofHispania. The old Roman citywas destroyed, abruptly abandoned, relocated close by and rebuilt during the late 4th century AD. Destruction of the city and its relocation has not yet been explained by archaeologists. In this paper,with ourmultidisciplinary approach, we identify and characterize earthquake archaeological effects (EAEs) affecting the archaeological site, the La Magdalena, an agricultural holding 4 km from the core of Complutum. The most important EAEs in the site are liquefactions (sand dikes and explosive sand-gravel craters) affecting Roman structures, such as water tanks (cisterns), houses and graves. Ground liquefaction generated significant ground cracks, explosive craters and folds in foundations of buildings. Several other Roman sites throughout the valleywere also abandoned abruptly during the 4th century AD, in some caseswith EAEs of similar origin. This suggests the occurrence of a 5.0–6.6 Mw seismic event in the zone, in accordance with the minimum empirical limit of seismically-induced liquefaction and the maximum surface rupture length of the Henares fault.Instituto Geológico y Minero de España, EspañaDepartamento de Geología, Escuela Politécnica Superior de Ávila, Universidad Salamanca, EspañaFacultad de Ciencias, Universidad Autónoma de Madrid, EspañaTrébede, Patrimonio Cultural, S.L., EspañaDepartamento de Ingeniería del Terreno, Escuela Politécnica Superior de Ávila, Universidad Salamanca, EspañaDepartamento de Edafología, Universidad Politécnica de Madrid, EspañaFacultad de Ciencias, Universidad Nacional de Educación a Distancia, EspañaDepartamento de Geología, Universidad de Alcalá de Henares, Españ

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