Corrección en el artículo de R.G. Espinosa et al. « Optimización de código para un simulador de estructuras aporticadas y su implementación como herramienta productiva »

Peer Reviewe

New archaeomagnetic directions from Portugal and evolution of the geomagnetic field in Iberia from Late Bronze Age to Roman Times

This study presents new archaeomagnetic results from 33 combustion structures (kilns and hearths) from the archaeological sites of Castelinho, Crestelos, Olival Poço da Barca and Fonte do Milho in NE Portugal. The age of the investigated structures ranges from 1210 BC to 200 AD according to calibrated radiocarbon dating, thermoluminescence dating and archaeological constraints. Stepwise thermal and alternating field demagnetization isolate a single, stable, characteristic remanence component with very well defined directions. Rock magnetic analyses suggest low-Ti titanomagnetite/maghemite as the main magnetic carrier of the remanence. Mean directions are well grouped in most structures. The effect of thermoremanent anisotropy on mean directions has been evaluated and was found to be important. Inclination increases of between 2° and 13° after applying the anisotropy correction at specimen level. This highlights the requirement of evaluating this effect on the directions of small and flattened thin kilns and hearths. The 31 new directional data improve both the temporal and spatial distribution of the Iberian archaeomagnetic dataset from Late Bronze Age to Roman Times. Finally, a new directional palaeosecular variation curve for Iberia for the last twelve centuries BC is proposed. The curve has been computed using the bootstrap method and includes data coming from sites within 900 km of Madrid. The new palaeodirectional secular variation curve for Iberia is consistent with the Western European palaeosecular variation curve and with the prediction of regional European models

Updated Iberian archeomagnetic catalogue: new full vector paleosecular variation curve for the last three millennia

In this work, we present 16 directional and 27 intensity high‐quality values from Iberia. Moreover, we have updated the Iberian archeomagnetic catalogue published more than 10 years ago with a considerable increase in the database. This has led to a notable improvement of both temporal and spatial data distribution. A full vector paleosecular variation curve from 1000 BC to 1900 AD has been developed using high‐quality data within a radius of 900 km from Madrid. A hierarchical bootstrap method has been followed for the computation of the curves. The most remarkable feature of the new curves is a notable intensity maximum of about 80 μT around 600 BC, which has not been previously reported for the Iberian Peninsula. We have also analyzed the evolution of the paleofield in Europe for the last three thousand years and conclude that the high maximum intensity values observed around 600 BC in the Iberian Peninsula could respond to the same feature as the Levantine Iron Age Anomaly, after travelling westward through Europe

Effect of sitagliptin on cardiovascular outcomes in type 2 diabetes

BACKGROUND: Data are lacking on the long-term effect on cardiovascular events of adding sitagliptin, a dipeptidyl peptidase 4 inhibitor, to usual care in patients with type 2 diabetes and cardiovascular disease. METHODS: In this randomized, double-blind study, we assigned 14,671 patients to add either sitagliptin or placebo to their existing therapy. Open-label use of antihyperglycemic therapy was encouraged as required, aimed at reaching individually appropriate glycemic targets in all patients. To determine whether sitagliptin was noninferior to placebo, we used a relative risk of 1.3 as the marginal upper boundary. The primary cardiovascular outcome was a composite of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for unstable angina. RESULTS: During a median follow-up of 3.0 years, there was a small difference in glycated hemoglobin levels (least-squares mean difference for sitagliptin vs. placebo, -0.29 percentage points; 95% confidence interval [CI], -0.32 to -0.27). Overall, the primary outcome occurred in 839 patients in the sitagliptin group (11.4%; 4.06 per 100 person-years) and 851 patients in the placebo group (11.6%; 4.17 per 100 person-years). Sitagliptin was noninferior to placebo for the primary composite cardiovascular outcome (hazard ratio, 0.98; 95% CI, 0.88 to 1.09; P<0.001). Rates of hospitalization for heart failure did not differ between the two groups (hazard ratio, 1.00; 95% CI, 0.83 to 1.20; P = 0.98). There were no significant between-group differences in rates of acute pancreatitis (P = 0.07) or pancreatic cancer (P = 0.32). CONCLUSIONS: Among patients with type 2 diabetes and established cardiovascular disease, adding sitagliptin to usual care did not appear to increase the risk of major adverse cardiovascular events, hospitalization for heart failure, or other adverse events

Optimización de código para un simulador de estructuras aporticadas y su implementación como una herramienta productiva

In this paper the optimization of the program &quot;Processor&quot; is presented. The &quot;processor&quot; is a finite element program used by the tool &quot;Portal of Damage&quot; (http://portaldeporticos.ula.ve), coded in Fortran-90, and based in the lumped damage mechanics. This program allows the simulation and modelling of the inelastic behaviour and damage in reinforced concrete structures under static or dynamic loads. To decrease the computing time of the structure analysis, the library UCSparceLib (University of Carabobo Sparse) was included, and to make even more efficient, to improve the performance of the Processor is implemented a queue manager in the cluster where the Portal is lodged. The queue manager is designed under discrete events simulation paradigm. The experimental results show a reduction in the computing time of more than 80% for the examples. Finally, an implementation using OpenMP is done in a shared memory computer

On the reliability of archaeomagnetic dating in Iberia: two case studies from Portugal and Zamora

Archaeomagnetic investigations have been carried out on 22 combustion structures from Portugal and Spain, along the Duero River Valley at the archaeological sites of Crestelos and Olival Poço da Barca (NE Portugal) and at El Castillón (NW Spain). The age of most of the investigated structures at Portuguese sites ranges from the 3rd century BC up to Roman times according to archaeological information. At El Castillón the investigated kilns are considered to cover the 5th – 7th centuries AD. Stepwise thermal and alternating field demagnetization isolated a single, stable, characteristic remanence component with very well defined directions. Mean site directions were well grouped in most sites. Only the two most poorly preserved structures showed a relatively high directional dispersion. Classical Thellier paleointensity experiments were conducted on pilot specimens. Successful results were obtained in specimens from el Castillón and from Olival Poço da Barca. In contrast, alterations occurred during thermal treatment at Crestelos kilns and hearths. Archaeomagnetic dating was conducted in all sites by using six reference Palaeosecular Variation (PSV) curves provided by local studies (from Iberia and France) and by regional (SCHA.DIF.3k) and global models (ARCH3k.1 and SHA.DIF.14k). The best PSV master curves for dating purposes on the investigated structures are the French curve for the old structures (older than 200 AD) and the regional SCHA.DIF.3k model for the younger structures. The new archaeomagnetic dating results suggest that the Crestelos site was active since 265±87 BC up to 252±138 AD, with a mean occupation period between 198 BC-43 AD. There could have been a previous occupation of the site but it could not be precisely dated. Distributions of the directions from Crestelos describe a PSV trend consistent with the French curve, suggesting that the archaeomagnetic dating tool could be improved in the near future by dating selected structures by independent methods. Archaeomagnetic dating at El Castillón site provide two phases of occupation of the site, at 441±12 AD and 488±53 AD, consistent with recent radiocarbon ages from the site. The effect of TRM anisotropy on directions has been evaluated, with the results highlighting the necessity for TRM anisotropy corrections if accurate dating is to be obtained