Estudio, diseño de prototipo general de sistema fotovoltaico para proyecto centro urbano de bienestar y oportunidades (CUBO)

El proyecto de los CUBOS son una iniciativa del gobierno salvadoreño que se enfoca en brindar servicios básicos y acceso a la tecnología a comunidades rurales y urbanas de bajos ingresos. Hasta ahora, los CUBOS han dependido exclusivamente de un diseño de suministro eléctrico convencional. Nuestro objetivo es presentar una propuesta que pueda implementarse para mejorar el ahorro económico a largo plazo y, sobre todo, reducir el impacto ambiental. Esta iniciativa busca servir como un incentivo para que se amplíe o adapte a más instituciones gubernamentales. Además, promovemos el uso de la energía solar fotovoltaica (SFV) debido a su carácter de energía renovable y limpia, así como su alta eficiencia. Este sistema podría funcionar durante todo el año, sin importar las interrupciones en el suministro eléctrico por parte de las empresas distribuidoras

Geochronology of the Lower Cretaceous volcanism from the Coastal Range (29°20’-30°S), Chile.

24 pages, 10 figures, 4 tables.40Ar/39Ar age data (laser and furnace step heating) on plagioclase from Lower Cretaceous volcanic sequences from the Arqueros Formation in two sections of the Coastal Range at the latitude of La Serena (≈29°S) have been obtained. Due to the partial alteration of plagioclase crystals, disturbed age spectra in the furnace experiments have been observed, whereas laser heating determinations involving a much smaller quantity of grains carefully selected, could display plateau ages corresponding to pure plagioclase, as demonstrated by a constant 37ArCa/39ArK ratio. Plateau ages of 114.1±0.5 Ma (sample ARQ99-4), 111.3±0.9 Ma (sample TC99-5a), and 91.0±0.6 Ma (sample TC99-2) were found in lava fl ows, and 84.3±1.3 Ma on a dyke (sample ARQ99-7). These new 40Ar/39Ar ages, together with those previously published in central Chile, allow a constriction of the extensional magmatism during the Early Cretaceous in the Coastal Range of central and north-central Chile. All these data are in accordance with a long lived Early Cretaceous Magmatic Province (119-84 Ma), that could have started with a brief and huge magmatic event, mostly developed in the central part of the Coastal Range, followed by discrete magmatic pulses at further northern latitudes.Geocronología del volcanismo del Cretácico Inferior en la Cordillera de la Costa (29°20'-30°S), Chile. Se han obtenido edades 40Ar/39Ar (calentamiento por pasos en horno y mediante láser) en plagioclasas de secuencias volcánicas de dos secciones del Cretácico Inferior de la Cordillera de la Costa (Formación Arqueros) a la latitud de La Serena (≈29°S). Debido a la alteración parcial de los cristales de plagioclasa, se han observado espectros de edades perturbados en las medidas realizadas en horno. Sin embargo, en las determinaciones realizadas mediante láser en unos pocos granos de plagioclasa meticulosamente seleccionados se han obtenido edades plateau correspondientes a plagioclasa primaria, como lo evidencian los valores constantes de la relación 37ArCa/39ArK. Se han obtenido edades plateau de 114,1±0,5 Ma (muestra ARQ99-4), 111,3±0,9 Ma (muestra TC99-5a) y 91,0±0,6 Ma (muestra TC99-2) en diferentes coladas de lava, y de 84,3±1,3 Ma en un dique (muestra ARQ99-7). Estas nuevas edades 40Ar/39Ar, junto a las ya publicadas en Chile central, permiten constreñir mejor la duración del evento magmático extensional durante el Cretácico Inferior en la Cordillera de la Costa del centro y centro-norte de Chile. Estos datos están de acuerdo con la existencia de una Provincia Magmática del Cretácico Inferior (119-84 Ma), que habría comenzado con un breve e intenso evento magmático en la zona central de la Cordillera seguido de pulsos magmáticos discretos hacia latitudes más septentrionales.This study was supported by the Departamento de Investigación y Desarrollo (DID), Universidad de Chile, Project I001-99/2, FONDECYT Projects 1031000, 7040160 and 7050282, the Spanish project BTE-2003- 06265 (Ministry of Science and Technology/Ministry of Education and Science and FEDER), the RNM 131 of Junta de Andalucía and the ‘Plan Propio’ of GranadaPeer reviewe

Successional patterns along soil development gradients formed by glacier retreat in the Maritime Antarctic, King George Island

Background: Maritime Antarctica is severely affected by climate change and accelerating glacier retreat forming temporal gradients of soil development. Successional patterns of soil development and plant succession in the region are largely unknown, as are the feedback mechanisms between both processes. Here we identify three temporal gradients representing horizontal and vertical glacier retreat, as well as formation of raised beaches due to isostatic uplift, and describe soil formation and plant succession along them. Our hypotheses are (i) plants in Antarctica are able to modulate the two base parameters in soil development, organic C content and pH, along the temporal gradients, leading to an increase in organic carbon and soil acidity at relatively short time scales, (ii) the soil development induces succession along these gradients, and (iii) with increasing soil development, bryophytes and Deschampsia antarctica develop mycorrhiza in maritime Antarctica in order to foster interaction with soil.  Results: All temporal gradients showed soil development leading to differentiation of soil horizons, carbon accumulation and increasing pH with age. Photoautptroph succession occurred rapidly after glacier retreat, but occurrences of mosses and lichens interacting with soils by rhizoids or rhizines were only observed in the later stages. The community of ground dwelling mosses and lichens is the climax community of soil succession, as the Antarctic hairgrass D. antarctica was restricted to ornithic soils. Neither D. antarctica nor mosses at the best developed soils showed any sign of mycorrhization.  Conclusion: Temporal gradients formed by glacier retreat can be identified in maritime Antarctic, where soil development and plant succession of a remarkable pace can be observed, although pseudo-succession occurs by fertilization gradients caused by bird feces. Thus, the majority of ice-free surface in Antarctica is colonized by plant communities which interact with soil by litter input rather than by direct transfer of photoassimilates to soil

COMPORTAMIENTO DE PLAT YXANTHUS ORBIGNYI EXTRAÍDOS DE LA PLAYA LOS PESCADORES DE CHORRILLOS AL SUMERGIRLOS EN DIFERENTES PH

Las múltiples fuentes de contaminación del agua tienen consecuencias devastadoras para la vida marina. Los peces, mamíferos marinos,crustáceos y moluscos en la parte superior de la cadena alimentaria están expuestos a niveles más altos de toxinas por su exposición tanto al agua contaminada como por alimentarse de los peces también expuestos a ella. Los animales marinos que dependen de la grasa para regular la temperatura del cuerpo tienen altos niveles de toxinas. Muchas toxinas se almacenan en la grasa. Debido a que ciertos animales tienen grandes cantidades de grasa, en las que se acumulan muchas toxinas. Por esta razón que surgió la necesidad investigar el comportamiento de uno de estos animales a condiciones extremas de acidez , para tal fin se seleccionó al Platyxanthus orbignyi (cangrejo) puesto que este animal vive en tierra y en el agua. Se sometió a los animales con soluciones desde pH = 2,4 hasta pH= 3,5; encontrándose a pH mayores a 3,0 efectos de coloración en zonas específicas como la hepatopancreatica y gonodas ; pero a pH menores a 3,0 los efectos fueron devastadores, tal es así que muchos órganos como los intestinos, branquias, etc. resultaron totalmente cocidos. Si consideramos que los desechos tóxicos vertidos al mar muchas veces son ácidos , podemos imaginarnos el grave daño que sufre la vida acuática

Impulse oscillometry reference values and bronchodilator response in three- to five-year old children living at high altitude

Q2Q1Introduction: Impulse oscillometry (IOS) is used to measure airway impedance. It is an effective tool for diagnosing and treating respiratory diseases, and it has the advantage that it does not require forced respiratory maneuvers. IOS reference values are required for each population group. Objective: This study aimed to determine the IOS reference values and bronchodilator response in healthy preschool children living in Bogotá, Colombia. Methods: We performed a cross-sectional study in preschool children who had no history of respiratory disease; 96 children fit the parameters for testing to determine normal values according to the American Thoracic Society and European Respiratory Society criteria. Results: Values for respiratory resistance (Rrs) and reactance (Xrs) at 5, 10, and 20 Hz, respiratory impedance (Zrs, and resonance frequency (Fres) were established. Height was the most influential independent variable for IOS values; an increase in height led to a reduction in Rrs5 and Rrs20 and an increase in Xrs5. After the administration of 400 mcg of salbutamol the values for Rrs5(-17.48%), Rrs20(-8.63%), Fres (-10.68%), and area of reactance (-35.44%) were reduced, meanwhile Xrs5 (15.35%) was increased. Conclusions: Normal IOS values before and after the administration of 400 mcg of salbutamol were determined for a population of children aged 3-5 years at 2,640 m. Reference IOS equations for these children are presented. A relative change of up to -28% and 36% after the use of salbutamol for respiratory resistance and reactance, respectively, should be considered as an upper limit of the normal range, and possible appropriate cut-off values for defining significant response for evaluating therapeutic interventions. Keywords: children; cross-sectional studies; high altitude; oscillometry; reference values; respiratory function tests.N/

Diseño de aeronave de combate no tripulada de quinta generación para el apoyo aéreo cercano

La evolución en el diseño de aeronaves de combate se ha visto modificada por la inclusión de nuevos parámetros de alta exigencia, dentro de los cuales se incluyen las áreas de investigación relacionadas con la aerodinámica, la furtividad y la optimización en los procesos de operación. El presente artículo contempla el diseño de un Vehículo de Combate Aéreo no Tripulado (UCAV) para la ejecución de misiones de Apoyo Aéreo Cercano (CAS por sus siglas en inglés) en las próximas décadas. Los resultados obtenidos demuestran las habilidades de los UCAV como aeronaves de quinta generación para el reemplazo de flotas reconocidas a nivel mundial (A-10 Thunderbolt II y Sukhoi Su-25) y, además, garantiza su utilidad y viabilidad en los futuros entornos de combate. Así mismo, la investigación se enfoca en una de las variables de mayor discusión respecto a la supervivencia en el combate aéreo, se trata de la furtividad por fenómenos electromagnéticos, con la cual se obtuvieron valores de Sección Equivalente de Radar (RCS) iguales a -24,18 dBsm o representables en un área de detectabilidad de 0,0038 m2 en configuración limpia, de modo que este valor es inferior al de aeronaves furtivas como lo es el Northrop Grumman B-2 Spirit.  Finalmente, el diseño permite la operación con un máximo peso de despegue de 61,900 lb y una carga paga de 11,240 lb que se acondicionan a una configuración alar y de estabilizadores para rangos transónicos

Avances en la lista roja de las plantas de Colombia

A complete Red List of Colombian Plants is one of the main targets of the National Strategy for Plant Conservation (NSPC) and is fundamental for plant conservation planning in the country. The Red Book of Plants of Colombia made the first major contribution to the Red List of plants of the country, and since 2014 a team associated with the NSPC and the Colombian Plant Specialist Group (CPSG) from the IUCN has coordinated efforts to maintain progress in this task. By the end of 2022 the national Red List achieved a coverage of 12% of the species reported in the country, and it is expected that in 2025 this coverage will reach at least 25%. Based on the assessments completed to this date, 37% of assessed species are threatened, but this proportion reaches 48% when considering only endemic ones. This article presents an analysis of the taxonomic, ecological, and geographical patterns in the risk of extinction of the species assessed to date and discuss perspectives to complete the Red List of Colombian Plants.Completar la Lista Roja de las Plantas de Colombia es una de las metas principales de la Estrategia Nacional para la Conservación de Plantas (ENCP) y es crucial para la planificación de la conservación de la flora del país. La serie del Libro Rojo de Plantas de Colombia realizó la primera contribución importante a la Lista Roja nacional, y desde el 2014 un equipo de trabajo asociado a la ENCP y el Grupo de Especialistas de Plantas de Colombia (GEPC) de la UICN han coordinado esfuerzos para seguir avanzando en esta tarea. Al final del 2022 la Lista Roja de Plantas a nivel nacional alcanzó un 12 % de cobertura de las especies reportadas en el país y para el año 2025 esta cobertura alcanzará al menos un 25 %. Según las evaluaciones finalizadas hasta el momento, el 37 % de las plantas evaluadas se encuentran amenazadas, pero la cifra es del 48 % si se consideran solamente las especies endémicas. Aquí se presenta un análisis de los patrones taxonómicos, ecológicos y geográficos en el riesgo de extinción de las especies evaluadas hasta el momento y se discuten perspectivas para completar la Lista Roja de las Plantas de Colombia

Role of age and comorbidities in mortality of patients with infective endocarditis

[Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. [Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk. [Results]: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39–1.88),and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality. [Conclusion]: There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030