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Accelerating growth and global expansion of antimicrobial resistance has deepened the need for discovery of novel antimicrobial agents. Antimicrobial peptides have clear advantages over conventional antibiotics which include slower emergence of resistance, broad-spectrum antibiofilm activity, and the ability to favourably modulate the host immune response. Broad bacterial susceptibility to antimicrobial peptides offers an additional tool to expand knowledge about the evolution of antimicrobial resistance. Structural and functional limitations, combined with a stricter regulatory environment, have hampered the clinical translation of antimicrobial peptides as potential therapeutic agents. Existing computational and experimental tools attempt to ease the preclinical and clinical development of antimicrobial peptides as novel therapeutics. This Review identifies the benefits, challenges, and opportunities of using antimicrobial peptides against multidrug-resistant pathogens, highlights advances in the deployment of novel promising antimicrobial peptides, and underlines the needs and priorities in designing focused development strategies taking into account the most advanced tools available. © 2020 Elsevier Ltd

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S.e realizó una comparación simultánea de cuatro métodos para la extracción de ADN plasmídico. De los resultados experimentales se concluyó que únicamente con la técnica de Kronstad, en las condiciones ensayadas y con cultivos de cepas de Rhizobium leguminosarum bv Viceae en fase de crecimiento logarítmica temprana, se visualizaron 3 plásmidos para la cepa SEMIA 335 y un plásmido para la cepa B.

12 p. En el presente artículo, el fenómeno de interacción fluido-estructura fue simulado gracias a la herramienta computacional COMSOL® Multiphysics, empleando como caso de estudio el movimiento reciprocante propio del diafragma integrado a una microbomba de vacío, al modelar este elemento como una estructura deformable, capaz de deflectarse bajo una carga aplicada, y cuya interacción con el fluido implica un cambio de trayectoria en el flujo. Detallando para este caso el proceso de análisis mecánico y simulación numérica. Analizando el desempeño de dicho modelo de microbomba en relación a otros prototipos ofertados por el actual estado del arte. In this article, the fluid-structure interaction phenomena was simulated by the computational tool COMSOL ® Multiphysics, using as case of study the reciprocating motion from the integrated diaphragm of a vacuum micropump, modeling this element as a deformable structure, able to deflect itself under an applied load, and whose interaction with the fluid involves a change in the flow path. Detailing for this study the process of mechanical analysis and numerical simulation. Analyzing the performance of the micropump model relative to other prototypes offered by the current state of the art. Bucaramanga

Incorporation mechanism of sulfate groups in major calcium carbonates (calcite, aragonite and vaterite) is investigated using first-principles quantum-mechanical calculations. For each mineral, the stable structure of the substituted site is determined. In calcite and aragonite, a tilting of the sulfate-group with respect to the orientation of planar carbonate groups is observed. The theoretical vibrational properties of the sulfate-bearing carbonates are determined together with those of anhydrite (CaSO4) and isolated SO2 molecule. Comparison with experimental data supports the substitution of sulfate for carbonate groups in carbonate minerals. The energetic of sulfate incorporation is increasingly unfavorable in the order vaterite, calcite, and aragonite. Regarding isotopic fractionation properties, our calculations suggest that the equilibrium S-34/S-32 isotopic fractionation factor between vaterite and calcite is small (similar to 0.5% at 0 degrees C). A slightly larger fractionation factor (similar to 1% at 0 degrees C) is expected between aragonite and calcite; whereas a negative fractionation (similar to-1.5% at 0 degrees C) is expected between anhydrite and calcite. Finally, it is suggested that the isotopic fractionation between calcite and aqueous sulfate is smaller than 4%.

Mg isotope analyses of mantle rocks and minerals revealed large variations. Systematic differences in δ26Mg found between minerals from mantle xenoliths offer the potential for this isotopic system as an isotope geothermometer. However, results from other studies reveal a more complicated picture, where isotopic variability was found in similar samples (San Carlos olivines). To date, the cause for the observed variability remains uncertain. We explore the role of inter-mineral Mg isotope fractionation at upper mantle conditions. Experiments were done at 2 GPa and 00°C for 167 to 185 hours to investigate isotope partitioning between forsterite (Fo) and enstatite (En). Mg isotopes of coexisting En and Fo were analysed by MC-ICP-MS. The experiments were complemented by analyses of olivine and orthopyroxene from a SC xenolith and by theoretical estimations of equilibrium inter-mineral Mg isotope fractionation, based on vibrational frequency calculations and minimization of the total free energy of the solids. First experimental results revealed no Mg isotope fractionation between En and Fo beyond analytical precision at 00°C, 2 GPa (∆26MGEn-Fo = -0.02‰±0.12 (2SD); -0.03‰±0.).This result is consistent with our measurement on the SC xenolith (∆26Mgopx-ol = -0.08‰±0.11) and is close to the theoretical estimate (0.21‰). The absence of equilibrium inter-mineral Mg isotope fractionation suggests that the variability observed in various mantle-derived rocks is caused by other processes, such as diffusion-induced kinetic isotope fractionation as previously observed for Li isotopes. This is supported by a co-variation between Li and Mg isotopes found by others in a global peridotite dataset, implying both Li and Mg isotopes are affected by the same process. Hence, a combined Mg and Li isotope approach has the potential to better understand processes leading to the observed isotopic variability.

Presented at the 2002 AVIRIS Workshop, JPL-NASA, Pasadena, California, March 5-8th, 2002, Invasive species are rapidly becoming a threat to the world’s biota. In the United States alone, non-native species are causing environmental damage and economic losses estimated to exceed $100 billion per year (Pimentel et al., 2000). Morse et al. (1995) estimate that approximately 5,000 plant species that have escaped from cultivation have subsequently invaded natural ecosystems in the United States. One of these species, leafy spurge (Euphorbia esula L.), entered North America from Eurasia in 1829 (Council for Agricultural Science and Technology (CAST), 2000). Some years later, during the Homestead Period, it found its way into North Dakota and subsequently has spread throughout the upper Midwest and northern Rocky Mountain States, causing estimated annual losses of revenue in excess of $200 million. Leafy spurge causes severe ecosystem degradation due to its aggressive growth relative to that of native flora, its ability to invade non-infested habitats, and its persistence once established. It forms nearly monotypic stands and has the capacity to alter ecological processes and visitor perceptions of Theodore Roosevelt National Park and the surrounding region (Trammell, 1994).

Las clasificaciones de ocupación de suelo en las que interviene de forma significativa el olivar producen una tasa de error muy alta debido, por un lado, a la cobertura parcial del suelo por parte del arbolado, y por otro, a la variación de esa misma cobertura dependiente de factores como el marco de plantación, la orientación relativa de la superficie con relación a la posición del sensor y la posición relativa de la zona observada con relación al nadir de la escena. El objetivo de este trabajo es aportar un procedimiento de corrección radiométrica de cara a mejorar la identificación de este tipo de superficies a partir de imágenes adquiridas por sensores multiespectrales Digital image classifications of predominant olive tree land covers give high error levels due to several reasons: the partial soil cover by the trees, variations of the cover rate with the spatial inter tree frames, the variations in relative positions between the observed plot, the scene nadir and the remote sensor. The aim of this work is to show a new radiometric correction procedure to improve the identification of olive tree crops when using multispectral images.