49 research outputs found
Servicios ecosistémicos de la cuenca alta del río Fucha
112 páginasEl presente estudio, desarrollado por un grupo de estudiantes del Colegio Técnico José Félix Restrepo IED, busca reinterpretar los servicios ecosistémicos de las coberturas vegetales de la cuenca alta del río Fucha, entre las carreras sexta y sexta Este. Este fue el tema principal de la investigación. Contiene información de los recursos naturales que nos ofrecen y que nos benefician no solo a los seres humanos, sino a toda a la biodiversidad que se encuentra sobre la cuenca del río. Entre los servicios se encuentran, por ejemplo, el agua potable limpia y los procesos de descomposición de desechos. Estos se pueden dividir en cuatro categorías amplias como aprovisionamientos (es decir la producción de agua y de alimentos), regulación (el control del clima y de las enfermedades), polinización de cultivos de aves e insectos y, finalmente, la cultural, de la que nos beneficiamos los estudiantes, vecinos y demás personas que hacemos uso de
los servicios ecosistémicos que nos ofrece la cuenca.
Con esta investigación se busca, por otra parte, conocer un poco más de los grandes beneficios que podemos recibir de la naturaleza y que hacen que la vida humana sea posible
The dynamic geophysical environment of (101955) Bennu based on OSIRIS-REx measurements
The top-shaped morphology characteristic of asteroid (101955) Bennu, often found among fast-spinning asteroids and binary asteroid primaries, may have contributed substantially to binary asteroid formation. Yet a detailed geophysical analysis of this morphology for a fast-spinning asteroid has not been possible prior to the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission. Combining the measured Bennu mass and shape obtained during the Preliminary Survey phase of the OSIRIS-REx mission, we find a notable transition in Bennu’s surface slopes within its rotational Roche lobe, defined as the region where material is energetically trapped to the surface. As the intersection of the rotational Roche lobe with Bennu’s surface has been most recently migrating towards its equator (given Bennu’s increasing spin rate), we infer that Bennu’s surface slopes have been changing across its surface within the last million years. We also find evidence for substantial density heterogeneity within this body, suggesting that its interior is a mixture of voids and boulders. The presence of such heterogeneity and Bennu’s top shape are consistent with spin-induced failure at some point in its past, although the manner of its failure cannot yet be determined. Future measurements by the OSIRIS-REx spacecraft will provide insight into and may resolve questions regarding the formation and evolution of Bennu’s top-shape morphology and its link to the formation of binary asteroids
Evidence for widespread hydrated minerals on asteroid (101955) Bennu
Early spectral data from the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission reveal evidence for abundant hydrated minerals on the surface of near-Earth asteroid (101955) Bennu in the form of a near-infrared absorption near 2.7 µm and thermal infrared spectral features that are most similar to those of aqueously altered CM-type carbonaceous chondrites. We observe these spectral features across the surface of Bennu, and there is no evidence of substantial rotational variability at the spatial scales of tens to hundreds of metres observed to date. In the visible and near-infrared (0.4 to 2.4 µm) Bennu’s spectrum appears featureless and with a blue (negative) slope, confirming previous ground-based observations. Bennu may represent a class of objects that could have brought volatiles and organic chemistry to Earth
Effects of alirocumab on types of myocardial infarction: insights from the ODYSSEY OUTCOMES trial
Aims The third Universal Definition of Myocardial Infarction (MI) Task Force classified MIs into five types: Type 1, spontaneous; Type 2, related to oxygen supply/demand imbalance; Type 3, fatal without ascertainment of cardiac biomarkers; Type 4, related to percutaneous coronary intervention; and Type 5, related to coronary artery bypass surgery. Low-density lipoprotein cholesterol (LDL-C) reduction with statins and proprotein convertase subtilisin–kexin Type 9 (PCSK9) inhibitors reduces risk of MI, but less is known about effects on types of MI. ODYSSEY OUTCOMES compared the PCSK9 inhibitor alirocumab with placebo in 18 924 patients with recent acute coronary syndrome (ACS) and elevated LDL-C (≥1.8 mmol/L) despite intensive statin therapy. In a pre-specified analysis, we assessed the effects of alirocumab on types of MI. Methods and results Median follow-up was 2.8 years. Myocardial infarction types were prospectively adjudicated and classified. Of 1860 total MIs, 1223 (65.8%) were adjudicated as Type 1, 386 (20.8%) as Type 2, and 244 (13.1%) as Type 4. Few events were Type 3 (n = 2) or Type 5 (n = 5). Alirocumab reduced first MIs [hazard ratio (HR) 0.85, 95% confidence interval (CI) 0.77–0.95; P = 0.003], with reductions in both Type 1 (HR 0.87, 95% CI 0.77–0.99; P = 0.032) and Type 2 (0.77, 0.61–0.97; P = 0.025), but not Type 4 MI. Conclusion After ACS, alirocumab added to intensive statin therapy favourably impacted on Type 1 and 2 MIs. The data indicate for the first time that a lipid-lowering therapy can attenuate the risk of Type 2 MI. Low-density lipoprotein cholesterol reduction below levels achievable with statins is an effective preventive strategy for both MI types.For complete list of authors see http://dx.doi.org/10.1093/eurheartj/ehz299</p
Effect of alirocumab on mortality after acute coronary syndromes. An analysis of the ODYSSEY OUTCOMES randomized clinical trial
Background: Previous trials of PCSK9 (proprotein convertase subtilisin-kexin type 9) inhibitors demonstrated reductions in major adverse cardiovascular events, but not death. We assessed the effects of alirocumab on death after index acute coronary syndrome. Methods: ODYSSEY OUTCOMES (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab) was a double-blind, randomized comparison of alirocumab or placebo in 18 924 patients who had an ACS 1 to 12 months previously and elevated atherogenic lipoproteins despite intensive statin therapy. Alirocumab dose was blindly titrated to target achieved low-density lipoprotein cholesterol (LDL-C) between 25 and 50 mg/dL. We examined the effects of treatment on all-cause death and its components, cardiovascular and noncardiovascular death, with log-rank testing. Joint semiparametric models tested associations between nonfatal cardiovascular events and cardiovascular or noncardiovascular death. Results: Median follow-up was 2.8 years. Death occurred in 334 (3.5%) and 392 (4.1%) patients, respectively, in the alirocumab and placebo groups (hazard ratio [HR], 0.85; 95% CI, 0.73 to 0.98; P=0.03, nominal P value). This resulted from nonsignificantly fewer cardiovascular (240 [2.5%] vs 271 [2.9%]; HR, 0.88; 95% CI, 0.74 to 1.05; P=0.15) and noncardiovascular (94 [1.0%] vs 121 [1.3%]; HR, 0.77; 95% CI, 0.59 to 1.01; P=0.06) deaths with alirocumab. In a prespecified analysis of 8242 patients eligible for ≥3 years follow-up, alirocumab reduced death (HR, 0.78; 95% CI, 0.65 to 0.94; P=0.01). Patients with nonfatal cardiovascular events were at increased risk for cardiovascular and noncardiovascular deaths (P<0.0001 for the associations). Alirocumab reduced total nonfatal cardiovascular events (P<0.001) and thereby may have attenuated the number of cardiovascular and noncardiovascular deaths. A post hoc analysis found that, compared to patients with lower LDL-C, patients with baseline LDL-C ≥100 mg/dL (2.59 mmol/L) had a greater absolute risk of death and a larger mortality benefit from alirocumab (HR, 0.71; 95% CI, 0.56 to 0.90; Pinteraction=0.007). In the alirocumab group, all-cause death declined wit h achieved LDL-C at 4 months of treatment, to a level of approximately 30 mg/dL (adjusted P=0.017 for linear trend). Conclusions: Alirocumab added to intensive statin therapy has the potential to reduce death after acute coronary syndrome, particularly if treatment is maintained for ≥3 years, if baseline LDL-C is ≥100 mg/dL, or if achieved LDL-C is low. Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01663402
Comparación de un programa de restricción alimenticia diurna y nocturna en pollos de engorde de la línea Arbor Acres Plus®
14 p.La restricción alimenticia es una práctica utilizada en la avicultura para reducir los porcentajes de mortalidad causados por síndromes metabólicos y para mejorar la eficiencia alimenticia en pollos de engorde. El objetivo fue comparar el rendimiento en el peso corporal, consumo acumulado de alimento, ganancia de peso, índice de conversión alimenticia, mortalidad y relación costo/beneficio de un programa de restricción alimenticia diurna y nocturna en pollos de engorde sexados de la línea genética Arbor Acres Plus®. Se utilizó un galpón con 3,024 aves, dividido en 14 bloques distribuidos en un diseño de bloques completos al azar, utilizando cuatro tratamientos: hembras ayuno de día, machos ayuno de día, hembras ayuno de noche y machos ayuno de noche. A los cuatro tratamientos se les proporcionó una hora de ayuno en la fase 1 (día 3-7), cuatro horas en la fase 2 (día 8-14), seis horas en la fase 3 (día 15-28), y ocho horas en la fase 4 (día 29-32). Se realizó un análisis de varianza por medio del modelo lineal general y separación de medias con la prueba de Duncan´s Multiple Range (P ≤ 0.05). El peso corporal y la ganancia de peso fueron mayores en las aves bajo restricción alimenticia diurna. El índice de conversión alimenticia fue similar en las aves con el programa de restricción alimenticia diurna y nocturna. Los machos con restricción alimenticia diurna presentaron mayor consumo de alimento acumulado y mayor porcentaje de mortalidad. El programa de restricción alimenticia diurna presentó una mejor relación de costo/beneficio
Aneurisma de la arteria comunicante posterior y parálisis del III nervio craneal. Caso clínico y revisión de la literatura
Objective: Case report of posterior communicating artery aneurysm (ACoP) related unilateral oculomotor nerve palsy (ONP). Introduction: The ACoP aneurysms represents the 25% of all aneurysms. It could cause ONP because of his close relation of the aneurysm and the oculomotor nerve. The treatment in symptomatic patients should be the exclusion of the aneurysm. Case report: 38-year-old woman with headache of 15 days of evolution and acute ONP. CT angiography shows a 3x7 mm ACoP aneurysm. Microsurgery and clipping were considered the best treatment and were realized without complications. The patient evolves with complete recovery of his ONP with complete exclusion of the aneurysm. Discussion: ACoP aneurysm should be considered in ONP working diagnosis. The treatment is exclusion of the aneurism either by endovascular or microsurgical techniques. Microsurgical clipping has shown better functional outcomes than endovascular therapy
Cruise control system for the DLSU eco car team 2014 battery electric vehicle
Fuel efficiency is one of the concepts in the automobile industry that has made itself noticed by vehicle owners. One of the events that allow student groups and enthusiast to showcase their enthusiasm and eagerness in the development of this concept is the Shell Eco-Marathon competition, which is basically a competition of greatest mileage. To win the race, the participants of the competition must be able to design vehicles of great efficiency, however, a great part of winning the race is the drivers ability to follow a race strategy that, as theoretically determined, will yield the greatest mileage for the vehicle. The group proposed the implementation of a cruise control system to address this issue.
The cruise control system applied (1) implements the cruise control on a predetermined race strategy, (2) incorporates the use of a PID controller for the system, (3) implements it in a computing device, which is either a minicomputer or a microcontroller. Along with the predefined course for testing, the determination of the race strategy is aided by the use of a motor test bench. The electrical system as a whole also acquires GPS and IMU data as additional vehicle parameters.
A tool to such as the PID controller was used in optimizing the desired motor speed. For this case, the parameters used are as follows: Kp = 0.135, Ki = 0.14, and Kd = 0.037. Data gathered from various tests had shown that the proportional, integral and derivative values are needed to stabilize the response of the controller. The results also proved that the use of PID allows the feeding of throttle voltage to the motor to be responsive faster than if it were manually controlled.
In conclusion, the group was able to meet all the required objectives of the thesis project. The cruise control system was implemented in a test battery electric vehicle. The results of the experimentations showed that the system yielded greater mileage as composed to running the vehicle through manual driving. The testing of the cruise control using the entire track length resulted to a rise time of 2.676 s, settling time of 13.036 s, overshoot of 13.67% and steady-state error of 2.27%
Control Clasico E Inteligente De Temperatura En Un Prototipo De Invernadero Hidroponico
El presente artículo tiene como objetivo la creación de un sistema de control de temperatura de un invernadero hidropónico portátil, utilizando la tarjeta NodeMCU como tarjeta de adquisición y tratamiento de datos. Se comparan diferentes métodos de control clásico y control inteligente, se seleccionan los de mejor comportamiento y con ayuda de las redes neuronales serán clonados. Finalmente, todos los pasos realizados nos ayudaran a determinar cuál es el mejor controlador para aplicar en el invernadero hidropónico.