1,664 research outputs found

    Estimación de la posición 3D de un quadrotor basado en visión

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    En este documento se explica el desarrollo de un sistema de estimación de la posición y orientación para un quadrotor utilizando técnicas de visión por computador. Los objetivos de este sistema son lograr realizar la estimación mediante la captura de imágenes que realiza el vehiculo con la cámara que incorpora. Para la implementación de este sistema se ha utilizado la librería ARToolKitPlus y se ha evaluado su rendimiento tomando como referencia un dataset público de imágenes. Los resultados obtenidos por este sistema, muestran que este sistema es robusto en la detección de las referencias para realizar la estimación. Y que esta estimacion depende de la distancia entre la cámara que captura las imágenes y los patrones de referencias.This paper explains the development of a system to estimate the pose and position of a quadrotor using computer vision techniques. The goals of this system are achieved estimation by mean of images captured with the camera installed on the quadrotor. For this system implementation was used the ARToolKitPlus library and was evaluated its performance compared to a public dataset. The results obtained for this system show that it is robust to detect the references to perform the estimation. And this estimation depends on the distance between the camera which capture the images and the reference pattern.En aquest document s'explica el desenvolupament d'un sistema d'estimació de la posició i orientació per a un quadrotor utilitzant tècniques de visió per computador. Els objectius d'aquest sistema són aconseguir realitzar l'estimació mitjançant la captura d'imatges que realitza el vehicle amb la càmera que incorpora. Per a la implementació d'aquest sistema s'ha utilitzat la llibreria ARToolKitPlus i s'ha avaluat el seu rendiment prenent com a referència un dataset públic d'imatges. Els resultats obtinguts per aquest sistema, mostren que aquest sistema és robust en la detecció de les referències per a realitzar l'estimació. I que aquesta estimació depèn de la distància entre la càmera que captura les imatges i els patrons de referències

    Legume Overseeding along with P Fertilization Increase Forage Production of Temperate Natural Grasslands

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    Legume overseeding along with P fertilization is a common practice used in natural temperate and subtropical grasslands to increase forage production. This practice has been evaluated at experimental plots but not at the paddocks level of commercial farms. The latter are realistic evaluation units to generate knowledge for livestock management. In this study, the enhanced vegetation index (EVI), a proxy of forage production, was used to evaluate the effect of this practice on grazed paddocks in Uruguay. Twenty paired paddocks under similar grazing conditions were selected with natural grassland (NG) and natural grassland with legume overseeding and P fertilization (NG-LP). Paired paddocks were compared in terms of EVI mean and its temporal variability. After nine years of the intensification practice, mean annual EVI of NG-LP was 4% higher than that of NG, while the mean winter–spring EVI of NG-LP was 7.5% higher. EVI intra- and inter-annual variability of NG-LP was 8–11% higher than that of NG. Additionally, forage production was estimated using a radiative transfer model. Differences between NG-LP and NG were amplified six to seven times. Legume overseeding along with P fertilization increased forage production in pastoral livestock paddocks, particularly in the period of forage deficit, while it also increased intra and inter-annual variability of forage production.Fil: Rama, Gonzalo. Universidad de la República; UruguayFil: Oyarzabal, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Cardozo, Gerónimo. Universidad de la República; UruguayFil: Lezama, Felipe. Universidad de la República; UruguayFil: Baeza, Santiago. Universidad de la República; Urugua

    Neuroimaging reveals distinct brain glucose metabolism patterns associated with morphine consumption in Lewis and Fischer 344 rat strains.

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    Vulnerability to addiction may be given by the individual's risk of developing an addiction during their lifetime. A challenge in the neurobiology of drug addiction is understanding why some people become addicted to drugs. Here, we used positron emission tomography (PET) and statistical parametric mapping (SPM) to evaluate changes in brain glucose metabolism in response to chronic morphine self-administration (MSA) in two rat strains with different vulnerability to drug abuse, Lewis (LEW) and Fischer 344 (F344). Four groups of animals were trained to self-administer morphine or saline for 15 days. 2-deoxy-2-[18F]-fluoro-D-glucose (FDG)-PET studies were performed on the last day of MSA (acquisition phase) and after 15 days of withdrawal. PET data were analyzed using SPM12. LEW-animals self-administered more morphine injections per session than F344-animals. We found significant brain metabolic differences between LEW and F344 strains in the cortex, hypothalamus, brainstem, and cerebellum. In addition, the different brain metabolic patterns observed after the MSA study between these rat strains indicate differences in the efficiency of neural substrates to translate the drug effects, which could explain the differences in predisposition to morphine abuse between one individual and another. These findings have important implications for the use of these rat strains in translational morphine and opiate research.MLS was supported by the Ministerio de Ciencia e Innovación, Instituto de Salud Carlos III (projects PI17/01766, and grant BA21/00030), co-funded by the European Regional Development Fund (ERDF), “A way to make Europe”, CIBERSAM, Delegación del Gobierno para el Plan Nacional sobre Drogas (2017/085), Fundación Mapfre, and Fundación Alicia Koplowitz. EA was supported by grants from Ministerio de Sanidad, Servicios Sociales e Igualdad and Red de Trastornos Adictivos del Instituto de Salud Carlos III (RTA-RD16/020/0022), Delegación del Gobierno para el Plan Nacional sobre Drogas (2016I073), Ministerio de Ciencia e Innovación (PSI2016-80541-P), UNED (Plan de Promoción de la Investigación 2018–2020), and the European Union´s Justice Programme – Drugs Policy Initiatives (JUST-2017-AG-DRUGS- 806996-JUSTSO). NLR was supported by Instituto de Investigación Sanitaria Gregorio Marañón, "Programa Intramural de Impulso a la I + D + I 2019″. MD work was supported by Ministerio de Ciencia e Innovación (MCIN) and Insituto de Salud Carlos III (ISCIII) (PT20/00044). The CNIC is supported by the Instituto de Salud Carlos III (ISCIII), the Ministerio de Ciencia e Innovación (MCIN), and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence (SEV‐2015‐0505).S

    Natural grassland remnants in dynamic agricultural landscapes: identifying drivers of fragmentation

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    Grasslands have been subject to contraction and fragmentation processes worldwide, mainly due to their transformation into commercial tree plantations and agricultural lands. Identifying the remaining grasslands areas and the drivers of its fragmentation constitute an important step towards their appreciation, conservation and sustainability monitoring. The Eastern Plains of Uruguay constitute a region of recognized national and international conservation importance, but rice cultivation has spread extensively over the last 60 years, resulting in a strong transformation of its natural biomes. Our objectives were to map natural grasslands remnants in this complex landscape characterized by a high presence of different post-agricultural stages of vegetation; to quantify grassland fragmentation and its spatial variability in the landscape; and to identify the main drivers of the fragmentation process. We intersected a current supervised classification of the Eastern Plains of Uruguay (743,600 ha) with a mask of croplands from the previous ten years to discriminate grasslands remnants. We quantified the landscape fragmentation and described the relative contribution of different biophysical and anthropogenic factors in grasslands spatial configuration. Our results showed that natural grassland currently occupies only 21% of the Eastern Plains surface and it is in an advanced stage of fragmentation, comparable to that of the most historically transformed regions of the Rio de la Plata Grasslands. A few variables that determine the expansion of agriculture (large cadastral parcels size, high road network density and low topographical variation) drive the fragmentation process, relegating grassland to places with unfavorable characteristics for the development of rice cultivation

    Paclitaxel mitigates structural alterations and cardiac conduction system defects in a mouse model of Hutchinson-Gilford progeria syndrome.

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    Hutchinson-Gilford progeria syndrome (HGPS) is an ultrarare laminopathy caused by expression of progerin, a lamin A variant, also present at low levels in non-HGPS individuals. HGPS patients age and die prematurely, predominantly from cardiovascular complications. Progerin-induced cardiac repolarization defects have been described previously, although the underlying mechanisms are unknown. We conducted studies in heart tissue from progerin-expressing LmnaG609G/G609G (G609G) mice, including microscopy, intracellular calcium dynamics, patch-clamping, in vivo magnetic resonance imaging, and electrocardiography. G609G mouse cardiomyocytes showed tubulin-cytoskeleton disorganization, t-tubular system disruption, sarcomere shortening, altered excitation-contraction coupling, and reductions in ventricular thickening and cardiac index. G609G mice exhibited severe bradycardia, and significant alterations of atrio-ventricular conduction and repolarization. Most importantly, 50% of G609G mice had altered heart rate variability, and sinoatrial block, both significant signs of premature cardiac aging. G609G cardiomyocytes had electrophysiological alterations, which resulted in an elevated action potential plateau and early afterdepolarization bursting, reflecting slower sodium current inactivation and long Ca+2 transient duration, which may also help explain the mild QT prolongation in some HGPS patients. Chronic treatment with low-dose paclitaxel ameliorated structural and functional alterations in G609G hearts. Our results demonstrate that tubulin-cytoskeleton disorganization in progerin-expressing cardiomyocytes causes structural, cardiac conduction, and excitation-contraction coupling defects, all of which can be partially corrected by chronic treatment with low dose paclitaxel.Work in V.A.’s laboratory is supported by grants from the Spanish Ministerio de Ciencia e Innovacio´n (MCIN) (SAF2016-79490-R, PID2019-108489RBI00) and the Instituto de Salud Carlos III (ISCIII) (AC17/00067) with cofunding from the European Regional Development Fund/Fondo Europeo de Desarrollo Regional (ERDF/FEDER, ‘Una manera de hacer Europa’), and the Progeria Research Foundation (Award PRF 2019–77). Work in J.J.’s laboratory is supported by the National Heart, Lung, and Blood Institute (R01 Grant HL122352), a CNIC ‘Severo Ochoa’ intramural competitive grant, and Fondos FEDER, Madrid, Spain. Work in D.F.-R.’s laboratory is supported by the Spanish MCIN (SAF2016-80324-R) and the ISCIII (AC17/00053). The CNIC is supported by the MCIN, the ISCIII, and the Pro CNIC Foundation.S

    Generation and characterization of a novel knockin minipig model of Hutchinson-Gilford progeria syndrome

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    Hutchinson-Gilford progeria syndrome (HGPS) is an extremely rare genetic disorder for which no cure exists. The disease is characterized by premature aging and inevitable death in adolescence due to cardiovascular complications. Most HGPS patients carry a heterozygous de novo LMNA c.1824C > T mutation, which provokes the expression of a dominant-negative mutant protein called progerin. Therapies proven effective in HGPS-like mouse models have yielded only modest benefit in HGPS clinical trials. To overcome the gap between HGPS mouse models and patients, we have generated by CRISPR-Cas9 gene editing the first large animal model for HGPS, a knockin heterozygous LMNA c.1824C > T Yucatan minipig. Like HGPS patients, HGPS minipigs endogenously co-express progerin and normal lamin A/C, and exhibit severe growth retardation, lipodystrophy, skin and bone alterations, cardiovascular disease, and die around puberty. Remarkably, the HGPS minipigs recapitulate critical cardiovascular alterations seen in patients, such as left ventricular diastolic dysfunction, altered cardiac electrical activity, and loss of vascular smooth muscle cells. Our analysis also revealed reduced myocardial perfusion due to microvascular damage and myocardial interstitial fibrosis, previously undescribed readouts potentially useful for monitoring disease progression in patients. The HGPS minipigs provide an appropriate preclinical model in which to test human-size interventional devices and optimize candidate therapies before advancing to clinical trials, thus accelerating the development of effective applications for HGPS patients.This project was mainly supported by an Established Investigator Award from the Progeria Research Foundation (2014-52), and from the Spanish Ministerio de Ciencia, Innovación y Universidades (MCIU), and the European Regional Development Fund (FEDER, “A way to build Europe”) (SAF2016-79490-R, CB16/11/00405). Ana Barettino has a predoctoral contract from MCIU (BES-2017-079705). Work at Universidad de Murcia is supported by Fundación Seneca-Agencia de Ciencia y Tecnología de la Región de Murcia (20040/GERM/16). The CNIC is supported by the MCIU and the Pro-CNIC Foundation and is a Severo Ochoa Center of Excellence (SEV-2015-0505).S

    Reflections Magazine of the Faculty of Education. Volume 4 No. 7 December 1988

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    La Revista de la Facultad de Educación Preescolar de la Universidad Autónoma de Bucaramanga recibe para su publicación trabajos sobre Educación, Infancia, Formación de Docentes, Trabajo Comunitario, Psicología Infantil y temas afines.The Magazine of the Faculty of Preschool Education of the Autonomous University of Bucaramanga receives for its publication works on Education, Childhood, Teacher Training, Community Work, Child Psychology and related topics.Modalidad Presencia

    Emergence and spread of a B.1.1.28-derived P.6 lineage with Q675H and Q677H spike mutations in Uruguay

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    Uruguay controlled the viral dissemination during the first nine months of the SARS-CoV-2 pandemic. Unfortunately, towards the end of 2020, the number of daily new cases exponentially increased. Herein, we analyzed the country-wide genetic diversity of SARS-CoV-2 between November 2020 and April 2021. We identified that the most prevalent viral variant during the first epidemic wave in Uruguay (December 2020–February 2021) was a B.1.1.28 sublineage carrying Spike mutations Q675H + Q677H, now designated as P.6, followed by lineages P.2 and P.7. P.6 probably arose around November 2020, in Montevideo, Uruguay’s capital department, and rapidly spread to other departments, with evidence of further local transmission clusters; it also spread sporadically to the USA and Spain. The more efficient dissemination of lineage P.6 with respect to P.2 and P.7 and the presence of mutations (Q675H and Q677H) in the proximity of the key cleavage site at the S1/S2 boundary suggest that P.6 may be more transmissible than other lineages co-circulating in Uruguay. Although P.6 was replaced by the variant of concern (VOC) P.1 as the predominant lineage in Uruguay since April 2021, the monitoring of the concurrent emergence of Q675H + Q677H in VOCs should be of worldwide interest
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