Implicaciones metodológicas e inconsistencias de la Tercera Comunicación Nacional sobre Cambio Climático de Colombia

Las Comunicaciones Nacionales sobre Cambio Climático (CNCC) son un mecanismo para que los países informen sus avances en mitigación y adaptación, y constituyen uno de los elementos de base para la política sobre cambio climático a escala nacional. Colombia ha emitido tres CNCC. La tercera plantea un escenario que considera las proyecciones de diversos modelos incluidos en la quinta fase del Proyecto de Comparación de Modelos Acoplados (Coupled Model Intercomparison Project, CMIP), el cual se estima como el promedio de las proyecciones correspondientes a las cuatro trayectorias de concentración representativa (Representative Concentration Pathways,RCP) presentadas en el quinto reporte de evaluación del Panel Intergubernamental sobre Cambio Climático. Cada una de estas RCP representa una trayectoria de concentración de gases de efecto invernadero (GEI) para un escenario particular de crecimiento poblacional, económico y tecnológico que conduce a una posible trayectoria de evolución del sistema climático. En este estudio se comparan las proyecciones presentadas en la Tercera CNCC con las obtenidas directamente de los modelos empleados. Nuestros resultados demuestran que al utilizarse un promedio de RCP se pierden escenarios alternos que podrían ser importantes a la hora de considerar posibles futuros diferentes y anulan la utilidad de plantear diversas trayectorias de emisiones de GEI. Más aun, una comparación entre la Segunda y la Tercera CNCC muestra proyecciones de precipitación opuestas para diferentes regiones del país, lo cual es de particular importancia, pues el escenario de cambio climático planteado en la Tercera CNCC sirve de referencia para la toma de decisiones en materia de cambio climático a nivel nacional

Global Spatial Risk Assessment of Sharks Under the Footprint of Fisheries

Effective ocean management and conservation of highly migratory species depends on resolving overlap between animal movements and distributions and fishing effort. Yet, this information is lacking at a global scale. Here we show, using a big-data approach combining satellite-tracked movements of pelagic sharks and global fishing fleets, that 24% of the mean monthly space used by sharks falls under the footprint of pelagic longline fisheries. Space use hotspots of commercially valuable sharks and of internationally protected species had the highest overlap with longlines (up to 76% and 64%, respectively) and were also associated with significant increases in fishing effort. We conclude that pelagic sharks have limited spatial refuge from current levels of high-seas fishing effort. Results demonstrate an urgent need for conservation and management measures at high-seas shark hotspots and highlight the potential of simultaneous satellite surveillance of megafauna and fishers as a tool for near-real time, dynamic management

Sensibilidad de bacterias procedentes de pasifloras a antibióticos y productos cúpricos

La gulupa (Passiflora edulis Sims) es una importante fruta en cuanto a exportaciones en Colombia, esta es atacada por bacterias, entre ellas Xanthomonas axonopodis, pero las alternativas de control basadas en productos cúpricos y antibióticos no han sido eficientes, suponiendo adquisición de resistencia a estos productos por parte de dichos microorganismos. A partir de 111 aislamientos bacterianos asociados a bacteriosis en gulupa y maracuyá (Passiflora edulis var. flavicarpa Deg.) obtenidos en nueve regiones productoras de Colombia, se evaluó por medio de ensayos in vitro la sensibilidad a ampicilina, cloranfenicol, kasugamicina, oxitetraciclina, sulfato de estreptomicina, sulfato de kanamicina y validamicina, y a dos bactericidas cúpricos, oxicloruro y sulfato de cobre. Los resultados indicaron que los mayores porcentajes de sensibilidad a antibióticos, excluyendo el cloranfenicol que no es de uso agrícola, fueron obtenidos con sulfato de estreptomicina (25 mg L-1) con un 79% de aislamientos sensibles. Toda la población evaluada fue sensible a sulfato de cobre en una concentración de 750 mg L-1, y por el contrario, con oxicloruro de cobre (100% de la población) presentó resistencia. En general, aproximadamente el 47,9% de los aislamientos presentó resistencia a los productos evaluados, lo cual correspondería al uso de otras alternativas de control de enfermedades fitobacterianas en el cultivo

Computational Simulation of Colorectal Cancer Biomarker Particle Mobility in a 3D Model

Even though some methods for the detection of colorectal cancer have been used clinically, most of the techniques used do not consider the in situ detection of colorectal cancer (CRC) biomarkers, which would favor in vivo real-time monitoring of the carcinogenesis process and consequent studies of the disease. In order to give a scientific and computational framework ideal for the evaluation of diagnosis techniques based on the early detection of biomarker molecules modeled as spherical particles from the computational point of view, a computational representation of the rectum, stool and biomarker particles was developed. As consequence of the transport of stool, there was a displacement of CRC biomarker particles that entered the system as a result of the cellular apoptosis processes in polyps with a length lower than 1 cm, reaching a maximum velocity of 3.47×10−3 m/s. The biomarkers studied showed trajectories distant to regions of the polyp of origin in 1 min of simulation. The research results show that the biomarker particles for CRC respond to the variations in the movements of the stool with trajectories and speeds that depend on the location of the injury, which will allow locating the regions with the highest possibilities of catching particles through in situ measurement instruments in the future

pH-Sensitive Acrylic Terpolymers for the Coating of Orally Administered Drugs Used for Colonic Release

Polymeric coatings are a promising option for the development of delivery systems for orally administered drugs. However, the gastrointestinal conditions to which they are subjected, which include low pH and solubility as well as peristaltic movements, can limit their applications. In this work, different formulations of polymeric coatings were produced using pH-sensitive materials consisting of copolymers of methyl acrylate, methyl methacrylate, and methacrylic acid. The polymers were synthesized by the emulsion polymerization technique, obtaining small average particle sizes (56-190 nm), molecular weights between 200,000 and 400,000 g/mol, and a glass transition temperature above 35 °C, which are suitable for film formation at room temperature. Thus, they were assessed as coatings for hydroxypropyl methylcellulose capsules (HPMC) using the immersion method, showing adequate capacity to protect the capsule at gastric pH (pH 1.2) and dissolve at the simulated intestinal pH (pH= 7.2). In particular, the higher the content of the acidic monomer, the higher the release time of the test molecule contained in the acrylic terpolymer-coated HPMC capsules proposed, which was a curcuminoid derivative due to their bright color and potential medical benefits. In addition, a minimum number of immersions was required for coating the HPMC capsules at high acidic concentrations, which further facilitates the delayed release needed for colonic treatment. However, too high proportions of methacrylic acid may result in cytotoxicity issues. Consequently, a biocompatible formulation containing a proportion of methyl acrylate, methyl methacrylate, and methacrylic acid of 7:3:3 is proposed as the most adequate for colonic release. Thus, by chemically modulating the molar percentages of the acrylic monomers, it was possible to obtain tailored acrylic terpolymer coatings with different characteristics and desired properties in order to modulate the release kinetics of an active substance in a colonic environment.The authors thank D. P. Rosenblatt for proofreading the manuscript. The work was funded by the University of Antioquia, MINCIENCIAS through the program Ecosistema Cientifico (Alianza NanoBiocáncer Cod. FP44842-211-2018, project number 58962). Instituto de Salud Carlos III funded this research through Consorcio Centro de Investigación Biomédica en Red (CIBER) with the project “Gels4ACT” (Nr. BBN20PIV02). The authors are also grateful for the financial support received from the Spanish Ministry of Science and Innovation (PID2020-115296RA-I00 and the “Ramón y Cajal” program (RYC-2017-22614)). The work was also supported by the Max Planck Society through the Max Planck Partner Group “Dynamic Biomimetics for Cancer Immunotherapy” in collaboration with the Max Planck Institute for Medical Research (Heidelberg, Germany). The authors acknowledge financial support from the Spanish Ministry of Science and Innovation through the “Severo Ochoa” Programme for Centres of Excellence in R&D (CEX2019-000917-S). This work has been developed inside the “Materials Science” PhD program of UAB (Spain).With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe

Estudio in vitro de permeabilidad, porosidad y crecimiento celular en membranas electrohiladas para prótesis vasculares

Introducción y objetivos: En la actualidad la posibilidad de fabricación de implantes vasculares mediante la técnica de electrospinning ha ganado interés para vasos sanguíneos de diámetros pequeños. El potencial en aplicaciones vasculares reside en su capacidad de generar estructuras microporosas con gran área superficial. Sin embargo, poco se conoce del efecto de dicha microestructura y su espesor, tanto en las propiedades de transporte de masa como en la proliferación celular. El propósito de este trabajo es analizar la permeabilidad, la porosidad y el crecimiento celular en membranas electrohiladas para prótesis vasculares. Métodos: mediante electrohilado se fabricaron membranas para implantes de poliuretano con memoria de forma (Irogran) en dos espesores, muestra 0 entre 0,2 mm y 0,9 mm y muestra +1 entre 0,9 mm y 1,0 mm, sobre las cuales se sembraron fibroblastos cardiacos humanos por un periodo de incubación hasta de 10 días. La porosidad y permeabilidad se evaluaron mediante la norma ISO 7198 y la proliferación celular se analizó a través de microscopia óptica y electrónica de barrido (SEM). El número total de muestras fue 12 para cada espesor de referencia. El análisis de datos se llevó a cabo mediante una prueba tipo ANOVA. Resultados: las muestras +1 presentaron permeabilidad promedio de 55,5% menor que las 0, reducción de la porosidad de 10,24%, asociado a mayor crecimiento celular, evidenciado por sincitios celulares. Conclusiones: La variación de estructuras microporosas de gran área superficial para obtener implantes con la técnica de electrospinning, incide en el crecimiento celular y subsecuentemente en la permeabilidad y la porosidad, hecho que abre una gran oportunidad para su uso potencial en aplicaciones vasculares de diámetros pequeños

Development of a fortified drink from the mixture of small colombian native fruits

Strawberry (Fragaria ananassa), blackberry (Rubus glaucus), Peruvian cherry (Physalis peruviana L.) and purple passion fruit (Passiflora edulis Sims) are important fruit crops in Colombia, due to their organoleptic properties and nutritional qualities, making them attractive for international markets. This study was undertaken to characterize the physicochemical properties of these four fruits and to present an alternative for their use. To achieve this goal, the moisture, pH, soluble solids, acidity, color, iron and vitamin C concentration were determined, and a fortified mixed fruit drink was developed. All of the fruits can be classified as high acidity products dueto the acidity results. Purple passion fruit and Peruvian cherry presented the highest content of soluble solids, while blackberry, purple passion fruit and Peruvian cherry did not exhibit statistically significant differences in their iron contents, and strawberry exhibited the highest contribution of vitamin C.La fresa (Fragaria ananassa), la mora (Rubus glaucus), la uchuva (Physalis peruviana L.)y la gulupa (Passiflora edulis Sims)son cultivos frutales importantes en Colombia por sus propiedades organolépticas y nutritivas. Este estudio se realizó para caracterizar las propiedades fisicoquímicas de estos cuatro frutos y presentar una alternativa para su uso. Para lograr este objetivo, se caracterizaron las cuatro frutas determinando humedad, pH, sólidos solubles, acidez, color, contenido de hierro y la concentración de vitamina C. Posteriormente se desarrolló una bebida fortificada de frutas. De acuerdo a los resultados de acidez, todos losfrutos se pueden clasificar como productos de alta acidez. La gulupa y la uchuva, presentaron el mayor contenido de sólidos solubles, mientras que la mora, la gulupa y la uchuva, no presentaron diferencias estadísticamente significativas en su contenido de hierro. La fresa presentó la mayor contribución de la vitamina C

Study of the Velocity-Selection Satellites Present in the 5p3 / 2 → 6pj(J = 1/2, 3/2) Electric Quadrupole Transitions in Atomic Rubidium

International audienceThis article presents detailed experimental and theoretical studies of the satellite fluorescence lines observed when the 5P3 / 2 → 6PJ, (J = 1/2, 3/2) electric quadrupole transition (E2) is excited in a room temperature vapor of rubidium atoms. The initial state of nthis E2 transition is prepared by a narrow linewidth laser locked to one of the dominant 5S1 / 2 → 5P3 / 2 D2 hyperfine excitations for zero velocity atoms. Effects due to the selection of different atomic velocity classes in this preparation step are responsible for the presence of several satellite lines that can be found in the fluorescence decay spectra of both 85Rb and 87Rb. Compared to the main lines, these satellites do not show a strong dependence on the relative linear polarization directions of the lasers used in the preparation and the electric quadrupole steps. The relative intensities of the satellites decrease as the intensity of the preparation laser increases. Results of a rate equation calculation that explicitly includes selection-of-velocity effects indicate that optical pumping plays a central role in determining the relative intensities and the polarization dependence of the satellite lines. When the preparation laser is locked to the 5S1 / 2F1 = 1 → 5P3 / 2F2 = 0 low F cyclic transition in 87Rb, six lines were found in addition to the 5P3 / 2F2 = 0 → 6P3 / 2F3 = 2 lone electric quadrupole transition for zero velocity atoms. In this case, the calculated spectrum is necessary for the correct interpretation of the experimental results, clearly indicating that optical pumping and selection of velocities are responsible for these six additional electric quadrupole lines