102 research outputs found

    Verificación del estatus taxonómico del pez altoandino colombiano Grundulus cochae Román - Valencia, Paepke y Pantoja, 2003, (Ostariophysi : Characidae)

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    Grundulus bogotensis y Grundulus cochae son peces de alta montaña aislados geográficamente. G bogotensis es endémica del altiplano Cundiboyacense y G. cochae lo es para la Laguna de Cocha (Nariño). Sin embargo, existen reportes que indican que G. bogotensis fue trasplantada a la Laguna de Cocha en los años 50's, como especie forraje cuando se implementaron los cultivos de la trucha en aguas frías en Colombia, generando duda sobre el estatus taxonómico de la especie.Grundulus bogotensis and Grundulus cochae are high mountains fishes, as well as they are isolated geographically. G. bogotensis is endemic from the Cundiboyacense high plains and G. cochae is endemic from the Laguna de la Cocha (Nariño). There are reports that G. bogotensis was transplanted to the Laguna de la Cocha in the 50's, as a forage species when the trout cultives in cold waters were implemented in Colombia, increasing doubts about the taxonomic status of the specie.Biólogo (a)Pregrad

    Nonmesonic weak decay of Λ hypernuclei: The three-nucleon induced mode

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    The nonmesonic weak decay of 3hypernuclei is studied within a microscopic diagrammatic approach which is extended to include the three-nucleon induced mechanism. We adopt a nuclear matter formalism which, through the local density approximation, allows us to model finite hypernuclei, a one-meson-exchange weak transition potential and a Bonn nucleon–nucleon strong potential. One-, two-and three-nucleon induced weak decay rates are predicted for 123Cby including ground state correlations up to second order in the nucleon–nucleon potential and the recoil of the residual nucleus. Three-nucleon stimulated decays, 3NNN→nNNN(N=nor p), are considered here for the first time. The obtained decay rates compare well with the latest KEK and FINUDA data. The three-nucleon induced rate turns out to be dominated by nnp-and npp-induced decays, it amounts to ∼7%of the total nonmesonic rate and it is ∼1/2of the neutron-induced decay rate. The reduction effect of the nuclear recoil is particularly relevant for the three-nucleon induced rates (∼15%), less important for the two-nucleon induced rates (∼4%) and negligible for the one-nucleon induced rates. Given the non-negligible size of the three-nucleon induced contribution and consequently its importance in the precise determination of the complete set of decay rates, new measurements and/or experimental analysis are encouraged.Facultad de Ciencias Astronómicas y Geofísica

    Nonmesonic weak decay of Λ hypernuclei: The three-nucleon induced mode

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    The nonmesonic weak decay of 3hypernuclei is studied within a microscopic diagrammatic approach which is extended to include the three-nucleon induced mechanism. We adopt a nuclear matter formalism which, through the local density approximation, allows us to model finite hypernuclei, a one-meson-exchange weak transition potential and a Bonn nucleon–nucleon strong potential. One-, two-and three-nucleon induced weak decay rates are predicted for 123Cby including ground state correlations up to second order in the nucleon–nucleon potential and the recoil of the residual nucleus. Three-nucleon stimulated decays, 3NNN→nNNN(N=nor p), are considered here for the first time. The obtained decay rates compare well with the latest KEK and FINUDA data. The three-nucleon induced rate turns out to be dominated by nnp-and npp-induced decays, it amounts to ∼7%of the total nonmesonic rate and it is ∼1/2of the neutron-induced decay rate. The reduction effect of the nuclear recoil is particularly relevant for the three-nucleon induced rates (∼15%), less important for the two-nucleon induced rates (∼4%) and negligible for the one-nucleon induced rates. Given the non-negligible size of the three-nucleon induced contribution and consequently its importance in the precise determination of the complete set of decay rates, new measurements and/or experimental analysis are encouraged.Facultad de Ciencias Astronómicas y Geofísica

    Nonmesonic weak decay of Λ hypernuclei: The ΛN - ΣN coupling

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    The nonmesonic weak decay of Λ hypernuclei is studied within a microscopic diagrammatic approach which is extended to include the ΛN - ΣN strong interaction coupling. We adopt a nuclear matter formalism which, through the local density approximation, allows us to model finite hypernuclei. One-meson-exchange potentials are used for the weak and strong four-baryon interactions. The rates for the neutron- and proton-induced weak decays, ΛN → nN and ΛN → ΣN → nN (N = n or p; Σ = Σ⁻, Σ⁰, and Σ⁺), are predicted for Λ¹²C, Λ²⁸Si, Λ⁵⁶Fe, and Λ²⁰⁸Pb. The ΛN - ΣN coupling turns out to provide a contribution of about 23% (5%) to the total neutron-induced rate (proton-induced rate). Again as an effect of the hyperon coupling, the total one-nucleon-induced rate increases by about 9%, while the Γn/Γp ratio increases by about 17%. The saturation property of the nonmesonic rates with increasing hypernuclear mass number is clearly obtained and explained. The above percentage modifications remain almost unaltered through the hypernuclear mass number. All the non-negligible changes introduced by the ΛN - ΣN coupling lead to a definite improvement of our predictions once compared with the available KEK and FINUDA data.Facultad de Ciencias Astronómicas y GeofísicasFacultad de Ciencias ExactasInstituto de Física La Plat

    ECG study in practical labs for biomedical engineering training

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    Non-invasive biomedical measurements are one of the most important technological contributions whitin the biomedical engineering field. On this paper, a dual laboratory session student oriented is designed to simulate and implement a cardial signal monitor. During the first session, ORCAD PSpice software is used to simulate the whole process. The students can acquire knowledge on the process by configuring and running both the instrumentation amplifier and a passive filter to improve the signal quality. The second session requires from the student basic laboratory skills to use a specific printed circuit board (PCB) to measure its very own cardiac potential. As a result, from this session, the student can visualize the ECG signal acquired directly on the laboratory oscilloscope

    Introducción

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    En los últimos años, las demandas por un conocimiento más conectado con la realidad en economía se han vuelto más frecuentes. Los cuestionamientos a prácticas docentes en las que prima el conocimiento abstracto provienen de múltiples fuentes: estudiantes y profesores han señalado esta necesidad. Sin embargo, la transformación en los currículos de economía y las prácticas de enseñanza de la disciplina no reaccionan rápidamente a estas demandas. No lo hacen porque las lógicas de reproducción de los sistemas de investigación en las universidades y en las revistas académicas exigen un lenguaje común y abordajes estándar de los problemas

    High-throughput sequencing of the 16S rRNA gene to analyze the gut microbiome in juvenile and adult tropical gar (Atractosteus tropicus)

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    Tropical gar (Atractosteus tropicus) is freshwater and estuarine fish, inhabiting the Earth since the Mesozoic era and undergoing limited physiological variation ever since. Besides its recognized cultural and scientific relevance, the species has seen remarkable growth in its economic impact due to pisciculture. In this study, we present the first report of the whole taxonomic composition of microbial communities in gut contents in juveniles and adults of A. tropicus, by sex and origin (wild and cultivated). For this study, 508 genera were identified, with the most and least abundant being Cetobacterium and Paludibacter, respectively. Fusobacteria, Proteobacteria, Firmicutes, and Bacteroidetes phyla are the core gut microbiome of A. tropicus juvenile and adult by sex and origin. Deinococcus-Thermus phylum sequence was only identified in wild-type males. In the phylogenetic trees reconstruction Lactococcus lactis strains CAU929 and CAU6600, Cp6 and CAU9951, Cetobacterium strain H69, Aeromonas hydrophila strain P5 and WR-5-3-2, Aeromonas sobria strain CP DC28 and Aeromonas hydrophila were identified, some of them with probiotic potential within the three dominant phyla in core gut microbiome in A. tropicus adults, especially in wild-type organisms. Myroides genus was recognized in microbiota gut of the cultivated juvenile A. tropicus. Nevertheless, Alpha diversity indicated that the highest gut microbiota abundance and richness is found in cultivated juvenile and wild-type adult A. tropicus female, rather than adult wild-type males and the least gut microbiota abundance and richness is found in a cultivated adult of A. tropicus for both sexes.The authors thank the Mexican National Council of Science and Technology for the postgraduate studies thesis scholarship and the mixed scholarship granted to carry out the research internship at the University of Valencia (Spain). This research received external funding from the Mexican National Council of Science and Technology "Strengthening of the Master's Degree in Environmental Sciences for its Permanence in the National Register of Quality Graduates of CONACYT" Reg. No. TAB-2014-C29-245836 and the Project "Estudio de la fisiología digestiva en larvas y juveniles de pejelagarto (Atractosteus tropicus) con base en técnicas histológicas, bioquímicas y moleculares" Reg. No. CB-2016-01-282765.Peer reviewe

    Obstetricia integral siglo XXI. Tomo II

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    El libro Obstetricia Integral siglo XXI, Tomo II, es una publicación virtual de la Facultad de Medicina, se trata de la continuación sobre el análisis detallado de los principales tópicos en el área de la obstetricia, realizada por un grupo interdisciplinario de investigadores comprometidos con el mejoramiento de la calidad en el cuidado de la salud de la mujer gestante. Se ha procurado un balance entre los aspectos básicos de fisiopatología y las guías de atención clínica soportadas en evidencias científicas, con el ánimo de brindarle al lector un equilibrio entre las bases biopsico-sociales de la salud y la enfermedad y los aspectos prácticos de la atención clínica.Vargas Fiesco, Diana Carolina and Rubio Romero, Jorge Andrés and Ruiz Parra, Ariel Iván and Rodríguez, Luis Martín and Aragón, Miguel Eduardo and Arteaga Díaz, Clara Eugenia and Riaño, Jorge Enrique and Arenas Gamboa, Jaime and Ramírez Martínez, Javier Andrés and Amaya Guío, Jairo and Gaitán , Magda Alexandry and Gallego Arbeláez, Jaime and Cortés Díaz, Daniel Otálvaro and Ángel Müller, Edith and Bracho Ch., Alcides C. and Bautista Charry, Alejandro and Rodríguez Ramos, Marcela and Navarro Milanés, Alfonso and Díaz Cruz, Luz Amparo and Mercado Pedroza, Manuel Esteban and Gaitán Duarte, Hernando and Gómez Sánchez, Pio Iván and Peña, Diana Marcela and Calvo Gómez, José Manuel and Parra Pineda, Mario Orlando and Cárdenas Muñoz, María Luisa (2010) Obstetricia integral siglo XXI. Tomo II. Facultad de Medicina, Universidad Nacional de Colombia, Bogotá. ISBN 978958447618

    Evaluación en época seca de ecosistemas acuáticos y terrestres: componentes de vegetación y faunación. Sector Centro Administrativo PNN El Tuparro (Cumaribo, Vichada)

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    La asignatura Ecología Regional Continental tiene como objetivo el análisis de los procesos ecológicos a escala de paisaje y bioma. A lo largo de su existencia dentro del programa curricular de Biología de la Universidad Nacional de Colombia se han realizado distintos estudios ecológicos en distintas regiones del país, ampliando cada vez más el conocimiento de los estudiantes que toman la asignatura y aportando al conocimiento de zonas poco estudiadas. Durante los últimos periodos, la fase de campo se ha realizado en zonas pertenecientes al Sistema de Parques Nacionales Naturales de Colombia. Es así como se realizó un estudio preliminar durante el segundo semestre de 2010 en el PNN Cueva de Los Guacharos en el departamento del Huila, cumpliendo con el objetivo de una evaluación ecológica rápida a nivel de vegetación y limnología de manera dirigida, además de proyectos de distintos temas sobre aspectos ecológicos de la región. Para este periodo, primer semestre de 2011, la fase de campo se desarrolló en el PNN El Tuparro, ubicado en el departamento del Vichada y se incluyó adicionalmente el componente de faunación. Esta zona del país es poco conocida dado su difícil acceso, por lo que la información obtenida es de gran valor

    Impact of Biological Agents on Postsurgical Complications in Inflammatory Bowel Disease : A Multicentre Study of Geteccu

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    Background: The impact of biologics on the risk of postoperative complications (PC) in inflammatory bowel disease (IBD) is still an ongoing debate. This lack of evidence is more relevant for ustekinumab and vedolizumab. Aims: To evaluate the impact of biologics on the risk of PC. Methods: A retrospective study was performed in 37 centres. Patients treated with biologics within 12 weeks before surgery were considered "exposed". The impact of the exposure on the risk of 30-day PC and the risk of infections was assessed by logistic regression and propensity score-matched analysis. Results: A total of 1535 surgeries were performed on 1370 patients. Of them, 711 surgeries were conducted in the exposed cohort (584 anti-TNF, 58 vedolizumab and 69 ustekinumab). In the multivariate analysis, male gender (OR: 1.5; 95% CI: 1.2-2.0), urgent surgery (OR: 1.6; 95% CI: 1.2-2.2), laparotomy approach (OR: 1.5; 95% CI: 1.1-1.9) and severe anaemia (OR: 1.8; 95% CI: 1.3-2.6) had higher risk of PC, while academic hospitals had significantly lower risk. Exposure to biologics (either anti-TNF, vedolizumab or ustekinumab) did not increase the risk of PC (OR: 1.2; 95% CI: 0.97-1.58), although it could be a risk factor for postoperative infections (OR 1.5; 95% CI: 1.03-2.27). Conclusions: Preoperative administration of biologics does not seem to be a risk factor for overall PC, although it may be so for postoperative infections
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