Autobiografía de un banco

El Banco de la República. Antecedentes, evolución y estructura. Banco de la República. Bogotá, 1990, 782 págs

In vitro production of two chitinolytic proteins with an inhibiting effect on the insect coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae) and the fungus Hemileia vastatrix the most limiting pests of coffee crops

Two genes from Streptomyces albidoflavus, one exochitinase (905-bp) and an endochitinase (1100-bp) were functionally expressed in Escherichia coli in form of a fusion protein with a maltose binding protein (MBP). The goal was to produce and test proteins that inhibit both the coffee berry borer insect Hypothenemus hampei and the coffee rust fungus Hemileia vastatrix. Both recombinant proteins MBP/exochitinase and MBP/endochitinase showed chitinolytic activity. When recombinant purified proteins were added to an artificial coffee-based diet for the coffee berry borer, MBP/exochitinase at a concentration of 0.5% W/W caused delayed growth of larvae and 100% mortality between days 8 and 15, while MBP/endochitinase caused 100% mortality at day 35. H. vastatrix urediniospores presented total cell wall degradation in their germinative tubes within 18 h of exposure to the proteins at enzyme concentrations of 5 and 6 mg ml-1, with exochitinase having the greatest effect. The dual deleterious effect of S. albidoflavus chitinases on two of the most limiting coffee pests worldwide, the coffee borer and the coffee rust, make them potential elements to be incorporated in integrated control strategies

Human development, sustainability, and agency

Science for Society Brief #1, May 2023. This brief presents insights from an event co-organized by the United Nations Development Programme (UNDP), the Austrian Academy of Sciences (ÖAW), and the International Institute for Applied Sciences (IIASA) to mark the Austrian launch of the Human Development Report 2021-2022, Uncertain Times, Unsettled Lives: Shaping our Future in a Transforming World

Análisis de un paisaje fragmentado como herramienta para la conservacion de la biodiversidad en áreas de bosque seco y subhumedo tropical en el municipio de pereira, risaralda colombia

El bosque seco tropical en Colombia ha sido reducido a una cobertura de 1200km² de una cobertura original de 80.000km², las áreas de bosque pertenecen a este ecosistema están contenidas en paisajes rurales con intensiva actividad agrícola debido a la fertilidad de los suelos. Tomar decisiones acerca del manejo de paisajes fragmentados para la conservación de la biodiversidad requiere comprender el patrón del mosaico del paisaje; por medio de la implementación de un Sistema de Información Geográfica fue posible calcular medidas e índices que describen el patrón del paisaje en dos escenarios temporales y proponer acciones concretas de manej

Análisis de un paisaje fragmentado como herramienta para la conservacion de la biodiversidad en áreas de bosque seco y subhumedo tropical en el municipio de pereira, risaralda colombia

El bosque seco tropical en Colombia ha sido reducido a una cobertura de 1200km² de una cobertura original de 80.000km², las áreas de bosque pertenecen a este ecosistema están contenidas en paisajes rurales con intensiva actividad agrícola debido a la fertilidad de los suelos. Tomar decisiones acerca del manejo de paisajes fragmentados para la conservación de la biodiversidad requiere comprender el patrón del mosaico del paisaje; por medio de la implementación de un Sistema de Información Geográfica fue posible calcular medidas e índices que describen el patrón del paisaje en dos escenarios temporales y proponer acciones concretas de manej

Pobreza rural y territorio, una discusión abierta

El autor plantea argumentos sobre las características implícitas de las definiciones de pobreza; descubre las posibles falencias de algunas mediciones en boga; propone un enfoque territorial para resolver el problema y escruta en un conjunto de políticas, sus costos y resultado

Keck Planet Imager and Characterizer (KPIC): status update

Here we report on the status of the The Keck Planet Imager and Characterizer (KPIC), which is an on-going series of upgrades to the W.M. Keck II adaptive optics system and instrument suite focused on exoplanet imaging and spectroscopic characterization. The KPIC infrared pyramid wavefront sensor and fiber injection unit to high-resolution infrared spectrograph NIRSPEC have been assembled, integrated and are under-going tests at the University of Hawaii before installation at the Summit in the Fall of 2018

Efficient detection and characterization of exoplanets within the diffraction limit: nulling with a mode-selective photonic lantern

Coronagraphs allow for faint off-axis exoplanets to be observed, but are limited to angular separations greater than a few beam widths. Accessing closer-in separations would greatly increase the expected number of detectable planets, which scales inversely with the inner working angle. The Vortex Fiber Nuller (VFN) is an instrument concept designed to characterize exoplanets within a single beam-width. It requires few optical elements and is compatible with many coronagraph designs as a complementary characterization tool. However, the peak throughput for planet light is limited to about 20%, and the measurement places poor constraints on the planet location and flux ratio. We propose to augment the VFN design by replacing its single-mode fiber with a six-port mode-selective photonic lantern, retaining the original functionality while providing several additional ports that reject starlight but couple planet light. We show that the photonic lantern can also be used as a nuller without a vortex. We present monochromatic simulations characterizing the response of the Photonic Lantern Nuller (PLN) to astrophysical signals and wavefront errors, and show that combining exoplanet flux from the nulled ports significantly increases the overall throughput of the instrument. We show using synthetically generated data that the PLN detects exoplanets more effectively than the VFN. Furthermore, with the PLN, the exoplanet can be partially localized, and its flux ratio constrained. The PLN has the potential to be a powerful characterization tool complementary to traditional coronagraphs in future high-contrast instruments.Comment: 15 pages, 12 figure

First version of the fiber injection unit for the Keck Planet Imager and Characterizer

Coupling a high-contrast imaging instrument to a high-resolution spectrograph has the potential to enable the most detailed characterization of exoplanet atmospheres, including spin measurements and Doppler mapping. The high-contrast imaging system serves as a spatial filter to separate the light from the star and the planet while the high-resolution spectrograph acts as a spectral filter, which differentiates between features in the stellar and planetary spectra. The Keck Planet Imager and Characterizer (KPIC) located downstream from the current W. M. Keck II adaptive optics (AO) system will contain a fiber injection unit (FIU) combining a high-contrast imaging system and a fiber feed to Keck’s high resolution infrared spectrograph NIRSPEC. Resolved thermal emission from known young giant exoplanets will be injected into a single-mode fiber linked to NIRSPEC, thereby allowing the spectral characterization of their atmospheres. Moreover, the resolution of NIRSPEC (R = 37,500 after upgrade) is high enough to enable spin measurements and Doppler imaging of atmospheric weather phenomenon. The module was integrated at Caltech and shipped to Hawaii at the beginning of 2018 and is currently undergoing characterization. Its transfer to Keck is planned in September and first on-sky tests sometime in December