Inventario de Daños y Efectos Geológicos Co y/o Post-Sísmicos del Sismo Ocurrido el 18 de mayo de 1875, en la Frontera entre Colombia y Venezuela

On the border between Colombia and Venezuela, have occurred seismic events with important records of damage in both countries. In this paper, we study the historical earthquake that took place on May 18, 1875 between 11.15 and 11.30 in the morning (the time was the same for communities in both countries since there was no time zone difference), which is catalogued as a border earthquake due to the report of damages in the cities of both nations. The community of San José de Cúcuta, current capital of the Northern State of Santander, Colombia, registered the greatest number of deaths and damage to buildings. An inventory of the geological damage and co -seismic and postseismic effects was created based on information of previous studies and data obtained from archival primary sources from Colombia and Venezuela. The result is a bi-national database, which includes the summaries of historical descriptions with the effects in the persons and objects, the geological damages and effects observed during the seismic event. These data has led to the creation of a table of MM and EMS-98 intensities, which enables the identification and delimitation of the regions of greater damages. The maximum level intensity is I=10 in the cities of San José de Cúcuta, Villa del Rosario, Pueblo de Cúcuta (San Luis) in Colombia and San Antonio, San Juan de Ureña in Venezuela. Moreover, we formulated a table of intensities using the ESI-2007 INQUA scale, based on the information of geological observations described in historical documents. These data are related to the epicentral zone with an approximate radius of 30 km.Published105-2635T. Sismologia, geofisica e geologia per l'ingegneria sismicaN/A or not JC

Controllable Strain-driven Topological Phase Transition and Dominant Surface State Transport in High-Quality HfTe5 Samples

Controlling materials to create and tune topological phases of matter could potentially be used to explore new phases of topological quantum matter and to create novel devices where the carriers are topologically protected. It has been demonstrated that a trivial insulator can be converted into a topological state by modulating the spin-orbit interaction or the crystal lattice. However, there are limited methods to controllably and efficiently tune the crystal lattice and at the same time perform electronic measurements at cryogenic temperatures. Here, we use large controllable strain to demonstrate the topological phase transition from a weak topological insulator phase to a strong topological insulator phase in high-quality HfTe5 samples. After applying high strain to HfTe5 and converting it into a strong topological insulator, we found that the sample's resistivity increased by more than two orders of magnitude (24,000%) and that the electronic transport is dominated by the topological surface states at cryogenic temperatures. Our findings show that HfTe5 is an ideal material for engineering topological properties, and it could be generalized to study topological phase transitions in van der Waals materials and heterostructures. These results can pave the way to create novel devices with applications ranging from spintronics to fault-tolerant topologically protected quantum computers

Complexity in water and carbon dioxide fluxes following rain pulses in an African savanna

The idea that many processes in arid and semi-arid ecosystems are dormant until activated by a pulse of rainfall, and then decay from a maximum rate as the soil dries, is widely used as a conceptual and mathematical model, but has rarely been evaluated with data. This paper examines soil water, evapotranspiration (ET), and net ecosystem CO2 exchange measured for 5 years at an eddy covariance tower sited in an Acacia–Combretum savanna near Skukuza in the Kruger National Park, South Africa. The analysis characterizes ecosystem flux responses to discrete rain events and evaluates the skill of increasingly complex “pulse models”. Rainfall pulses exert strong control over ecosystem-scale water and CO2 fluxes at this site, but the simplest pulse models do a poor job of characterizing the dynamics of the response. Successful models need to include the time lag between the wetting event and the process peak, which differ for evaporation, photosynthesis and respiration. Adding further complexity, the time lag depends on the prior duration and degree of water stress. ET response is well characterized by a linear function of potential ET and a logistic function of profile-total soil water content, with remaining seasonal variation correlating with vegetation phenological dynamics (leaf area). A 1- to 3-day lag to maximal ET following wetting is a source of hysteresis in the ET response to soil water. Respiration responds to wetting within days, while photosynthesis takes a week or longer to reach its peak if the rainfall was preceded by a long dry spell. Both processes exhibit nonlinear functional responses that vary seasonally. We conclude that a more mechanistic approach than simple pulse modeling is needed to represent daily ecosystem C processes in semiarid savannas

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

Clinical assessment using an algorithm based on fuzzy C-means clustering

The Fuzzy c-means (FCM) algorithms define a grouping criterion from a function, which seeks to minimize iteratively the function up to until an optimal fuzzy partition is obtained. In the execution of this algorithm each element to the clusters is related to others that belong in the same n-dimensional space, which means that an element can belong to more than one clusters. This proposal aims to define a fuzzy clustering algorithm which allows the patient classifications based on the clinical assessment of the medical staff. In this work 30 cases were studied using the Glasgow Coma Scale to measure the level of awareness for each one which were prioritized by triage Manchester method. After applying the FCM algorithm the data is separated data into two clusters, thus, verified the fuzzy grouping in patients with a degree of membership that specifies the level of prioritization.</p

FPGA-Based Online PQD Detection and Classification through DWT, Mathematical Morphology and SVD

Power quality disturbances (PQD) in electric distribution systems can be produced by the utilization of non-linear loads or environmental circumstances, causing electrical equipment malfunction and reduction of its useful life. Detecting and classifying different PQDs implies great efforts in planning and structuring the monitoring system. The main disadvantage of most works in the literature is that they treat a limited number of electrical disturbances through personal computer (PC)-based computation techniques, which makes it difficult to perform an online PQD classification. In this work, the novel contribution is a methodology for PQD recognition and classification through discrete wavelet transform, mathematical morphology, decomposition of singular values, and statistical analysis. Furthermore, the timely and reliable classification of different disturbances is necessary; hence, a field programmable gate array (FPGA)-based integrated circuit is developed to offer a portable hardware processing unit to perform fast, online PQD classification. The obtained numerical and experimental results demonstrate that the proposed method guarantees high effectiveness during online PQD detection and classification of real voltage/current signals

Full-thickness macular hole after LASIK for the correction of myopia

Purpose: To describe 19 patients (20 eyes) who developed a macular hole (MH) after undergoing bilateral LASIK for the correction of myopia. Design: Noncomparative, interventional, retrospective, multicenter case series. Participants: Nineteen patients (20 eyes) who developed an MH after bilateral LASIK for the correction of myopia at 10 institutions in Venezuela, Colombia, Puerto Rico, Spain, and the United States. Methods: Chart review. Main Outcome Measure: Macular hole development. Results: The MH formed between 1 to 83 months after LASIK (mean, 12.1). In 60% of cases, the MH developed ?6 months after LASIK, and in 30% of cases it developed less than 1 year after LASIK. Eighteen of 19 (94.7%) patients were female. Mean age was 46 years (range, 25-65). All eyes were myopic (range, -0.50 to -19.75 diopters [mean, -8.9]). Posterior vitreous detachment was not present before and was documented after LASIK in 55% of eyes. A vitrectomy closed the MH on the 14 eyes that underwent surgical management, with an improvement of final best-corrected visual acuity in 13 of 14 (92.8%) patients. Our 20 eyes with a full-thickness MH after LASIK reflect an incidence of approximately 0.02% (20/83938). Conclusion: An MH may infrequently develop after LASIK for the correction of myopia. Our study shows that vitreoretinal surgery can be successful in restoring vision for most myopic eyes with an MH after LASIK. Vitreoretinal interface changes may play a role in MH formation after LASIK for the correction of myopia. © 2005 by the American Academy of Ophthalmology

Full-thickness macular hole after LASIK for the correction of myopia

Purpose: To describe 19 patients (20 eyes) who developed a macular hole (MH) after undergoing bilateral LASIK for the correction of myopia. Design: Noncomparative, interventional, retrospective, multicenter case series. Participants: Nineteen patients (20 eyes) who developed an MH after bilateral LASIK for the correction of myopia at 10 institutions in Venezuela, Colombia, Puerto Rico, Spain, and the United States. Methods: Chart review. Main Outcome Measure: Macular hole development. Results: The MH formed between 1 to 83 months after LASIK (mean, 12.1). In 60% of cases, the MH developed ?6 months after LASIK, and in 30% of cases it developed less than 1 year after LASIK. Eighteen of 19 (94.7%) patients were female. Mean age was 46 years (range, 25-65). All eyes were myopic (range, -0.50 to -19.75 diopters [mean, -8.9]). Posterior vitreous detachment was not present before and was documented after LASIK in 55% of eyes. A vitrectomy closed the MH on the 14 eyes that underwent surgical management, with an improvement of final best-corrected visual acuity in 13 of 14 (92.8%) patients. Our 20 eyes with a full-thickness MH after LASIK reflect an incidence of approximately 0.02% (20/83938). Conclusion: An MH may infrequently develop after LASIK for the correction of myopia. Our study shows that vitreoretinal surgery can be successful in restoring vision for most myopic eyes with an MH after LASIK. Vitreoretinal interface changes may play a role in MH formation after LASIK for the correction of myopia. © 2005 by the American Academy of Ophthalmology