441 research outputs found

    Understanding the economic barriers to the adoption of agroforestry : A Real Options analysis

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    Acknowledgement Paola Ovando’s contribution to this research was funded by the Macaulay Development Trust’s Fellowship on Natural Capital (2018-21).Peer reviewedPostprin

    Izolacija i sposobnost hvatanja slobodnih radikala cijanidin 3-O-glikozida iz plodova Ribes biebersteinii Berl.

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    The reversed-phase preparative high performance liquid chromatographic purification of the methanol extract of the fruits of Ribes biebersteinii Berl. (Grossulariaceae) afforded five cyanidin glycosides, 3-O-sambubiosyl-5-O-glucosyl cyanidin (1), cyanidin 3-O-sambubioside (2), cyanidin 3-O-glucoside (3), cyanidin 3-O-(2G-xylosyl)-rutinoside (4) and cyanidin 3-O-rutinoside (5). They showed considerable free-radical-scavenging properties in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay with the RC50 values of 9.29 × 106, 9.33 × 106, 8.31 × 106, 8.96 × 106 and 9.55 × 106 mol L1, respectively. The structures of these compounds were elucidated by various chemical hydrolyses and spectroscopic means. The total anthocyanin content was 1.9 g per 100 g dried fruits on cyanidin 3-glucoside basis.Pet cijanidin glikozida, 3-O-sambubiozil-5-O-glukozil cijanidin (1), cijanidin 3-O-sambubiozid (2), cijanidin 3-O-glukozid (3), cijanidin 3-O-(2G-ksilozil)-rutinozid (4) i cijanidin 3-O-rutinosid (5) izolirani su iz metanolnog ekstrakta plodova Ribes biebersteinii Berl. (Grossulariaceae) koristeći reverzno-faznu preparativnu tekućinsku kromatografiju visoke učinkovitosti. Cijanidin glikozidi pokazali su sposobnost hvatanja slobodnih radikala u pokusu s 2,2-difenil-1-pikrilhidrazilom (DPPH). Dobivene su sljedeće RC50 vrijednosti: 9,29 × 106, 9,33 × 106, 8,31 × 106, 8,96 × 106, odnosno 9,55 × 106 mol L1. Strukture glikozida određene su kemijskom hidrolizom i spektroskopijom masa. Ukupni sadržaj antocijanina bio je 1,9 g na 100 g suhih plodova preračunato na cijanidin 3-glukozid

    DEVELOPING NEW APPROACHES TO GLOBAL STOCK STATUS ASSESSMENT AND FISHERY PRODUCTION POTENTIAL OF THE SEAS

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    Stock status is a key parameter for evaluating the sustainability of fishery resources and developing corresponding management plans. However, the majority of stocks are not assessed, often as a result of insufficient data and a lack of resources needed to execute formal stock assessments. The working group involved in this publication focused on two approaches to estimating fisheries status: one based on single-stock status, and the other based on ecosystem production.JRC.G.4-Maritime affair

    Computational identification of anthocyanin-specific transcription factors using a rice microarray and maximum boundary range algorithm

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    This study identifies 2,617 candidate genes related to anthocyanin biosynthesis in rice using microarray analysis and a newly developed maximum boundary range algorithm. Three seed developmental stages were examined in white cultivar and two black Dissociation insertion mutants. The resultant 235 transcription factor genes found to be associated with anthocyanin were classified into nine groups. It is compared the 235 genes by transcription factor analysis and 593 genes from among clusters of COGs related to anthocyanin functions. Total 32 genes were found to be expressed commonly. Among these, 9 unknown and hypothetical genes were revealed to be expressed at each developmental stage and were verified by RT-PCR. These genes most likely play regulatory roles in either anthocyanin production or metabolism during flavonoid biosynthesis. While these genes require further validation, our results underline the potential usefulness of the newly developed algorithm

    Evaluación continua y su importancia en el proceso de enseñanza-aprendizaje de Climatología en la carrera de Agronomía

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    La evaluación tradicionalmente se ha centrado en la etapa final del proceso de enseñanza-aprendizaje llevando en muchos casos a que los alumnos se enfoquen más en aprobar la asignatura que en lograr un aprendizaje significativo. Sin embargo, el docente no debe sólo evaluar al final del curso, sino que debe hacerlo en cada uno de los bloques de conocimiento para facilitar el aprovechamiento y el aprendizaje progresivo de los contenidos de la asignatura. Al aplicar la evaluación continua, el profesor puede detectar los problemas de aprendizaje del estudiante y realizar una valoración integral del proceso de enseñanza-aprendizaje. El objetivo del trabajo fue evaluar la identificar los temas que presentan más dificultades en el proceso de enseñanza – aprendizaje mediante la evaluación continua. Se implementó un proceso de evaluación continua con la finalidad de facilitar la asimilación y el desarrollo progresivos de los contenidos de la asignatura Climatología correspondiente al primer cuatrimestre del segundo año de la carrera de Ingeniería Agronómica. Se utilizó como fuente de datos un cuestionario estructurado, al inicio de la clase práctica, se evalúan los fundamentos teóricos a emplearse en el práctico. Éstas evaluaciones constituyen el 30% de la nota del parcial correspondiente.En el presente trabajo se presentan los resultados observados a lo largo de 7 ciclos lectivos (2012 a 2018). Las unidades que presentaron menor porcentaje de acierto fueron Bio y Agrometeorología, Radiación y Balance Hidrológico (con 42, 47 y 47%, respectivamente) y aquellas de mejor desempeño fueron Introducción, Vientos y Heladas (con 59; 60 y 64%, respectivamente). Los temas con menores porcentajes de aciertos pueden ser debidos a dificultad y el tiempo de aprendizaje. La evaluación continua le permite al estudiante recibir información sobre su ritmo de aprendizaje, y puede de esta manera reorientar su aprendizaje. A los docentes, les permite identificar las fortalezas y las dificultades, del tema desarrollado

    Rising atmospheric methane: 2007-2014 growth and isotopic shift

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    From 2007 to 2013, the globally averaged mole fraction of methane in the atmosphere increased by 5.7±1.2ppb yr1^{-1}. Simultaneously, δ13\delta^{13}CCH4_\text{CH4} (a measure of the 13^{13}C/12^{12}C isotope ratio in methane) has shifted to significantly more negative values since 2007. Growth was extreme in 2014, at 12.5±0.4ppb, with a further shift to more negative values being observed at most latitudes. The isotopic evidence presented here suggests that the methane rise was dominated by significant increases in biogenic methane emissions, particularly in the tropics, for example, from expansion of tropical wetlands in years with strongly positive rainfall anomalies or emissions from increased agricultural sources such as ruminants and rice paddies. Changes in the removal rate of methane by the OH radical have not been seen in other tracers of atmospheric chemistry and do not appear to explain short-term variations in methane. Fossil fuel emissions may also have grown, but the sustained shift to more 13^{13}C-depleted values and its significant interannual variability, and the tropical and Southern Hemisphere loci of post-2007 growth, both indicate that fossil fuel emissions have not been the dominant factor driving the increase. A major cause of increased tropical wetland and tropical agricultural methane emissions, the likely major contributors to growth, may be their responses to meteorological change.This work was supported by the UK Natural Environment Research Council projects NE/N016211/1 The Global Methane Budget, NE/M005836/1 Methane at the edge, NE/K006045/1 The Southern Methane Anomaly and NE/I028874/1 MAMM. We thank the UK Meteorological Office for flask collection and hosting the continuous measurement at Ascension, the Ascension Island Government for essential support, and Thumeka Mkololo for flask collection in Cape Tow

    Postharvest characteristics of Ataulfo mango grown in Soconusco, Chiapas

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    Objective: To determine the main evolution indexes of the postharvest ripening of the Ataulfo mango variety grown in Soconusco, Chiapas, Mexico.Design/Methodology/Approach: The variables determined were, mango skin color (B*, a*, and b*), starch index, total soluble solids (TSS) (°Brix), pH, fruit firmness, and color/skin firmness correlation.Results: As the fruit ripeness evolution advances from stage 1 to stage 5, the values of the B*, a*, and b* (color) variables, the TSS, and the pH also increase; however, starch concentration and skin firmness decrease. The negative correlation between the B*, a*, and b* (color) and the fruit firmness,suggests the use of the color variable to measure the ripeness of the Ataulfo variety.Study Limitations/Implications: The ripeness evolution of mango has been the subject of several studies, focused on different varieties (e.g., Tommy Atkins, Keitt, Alphonso, etc.), particularly in Ataulfo mangoes grown in different regions of Mexico. Understanding the physicochemical evolution of the Ataulfo mango grown in Soconusco, Chiapas is fundamental for the producers.Finding/Conclusions: The results obtained could help to determine the ripeness state of the Ataulfo mango, under the environmental conditions of Soconusco, Chiapas

    Etnobotánica de las calabazas cultivadas (cucurbita spp.) En valles centrales de oaxaca, méxico

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    Pumpkins (Cucurbita spp.) (Cucurbitaceae) are plants that have been part of man’s diet in America for more than 10 000 years; they are part of the basic food production system known as milpa. These plants, together with many other useful plant species, have found a very efficient medium for distribution and commercialization in the system of markets in Oaxaca’s Central Valleys, México. Four species domesticated in Mesoamerica can be found in Oaxaca’s Central Valley markets, from which tender and mature fruits are sold, as well as toasted and raw seeds, vines to be used as vegetable and male flowers. They are cultivated in association with other plants as part of the milpa or as a single crop, rainfed or with irrigation; the latter is the case for the production of zucchini from improved varieties and calabaza huicha, a landrace that competes favorably with the improved varieties

    Ages and metallicities of globular clusters in M81 using GTC/OSIRIS spectra

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    We here present the results of an analysis of the optical spectroscopy of 42 globular cluster (GC) candidates in the nearby spiral galaxy M81 (3.61~Mpc). The spectra were obtained using the long-slit and MOS modes of the OSIRIS instrument at the 10.4~m Gran Telescopio Canarias (GTC) at a spectral resolution of \sim1000. We used the classical Hβ\beta vs [MgFe]' index diagram to separate genuine old GCs from clusters younger than 3 Gyr. Of the 30 spectra with continuum signal-to-noise ratio >10>10, we confirm 17 objects to be classical GCs (age >10>10~Gyr, 1.4<-1.4<[Fe/H]<<-0.4), with the remaining 13 being intermediate-age clusters (1-7.5~Gyr). We combined age and metallicity data of other nearby spiral galaxies (18\lesssim18~Mpc) obtained using similar methodology like the one we have used here to understand the origin of GCs in spiral galaxies in the cosmological context. We find that the metal-poor ([Fe/H]<-1) GCs continued to form up to 6~Gyr after the first GCs were formed, with all younger systems (age <8<8~Gyr) being metal-rich.Comment: 16 pages, 13 figures, 8 tables; Accepted for publication in MNRA
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