Artículos científicos

URI permanente para esta colecciónhttp://10.0.96.45:4000/handle/11056/14837

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Biological Activity of Extracts of Trichilia Species and the Limonoid Hirtin Against Lepidopteran Larvae
(Elsevier Science Ltd, 1994) Xie, Y. S.; Isman, M. B.; Gunning, P.; Mackinnon, S.; Arnason, J. T.; Taylor, D. R.; Sánchez. V, P.; Hasbun, C; Towers, G. H. N.
Crude extracts of several Trichilia species (Meliaceae) were evaluated for their behavioral and physiological effects on the polyphagous lepidopterans Peridroma saucia and Spodoptera litura. A majority of extracts of nine Trichilia species, collected primarily from Costa Rica, significantly deter larval growth of P. saucia. Extracts of wood and bark are generally more active than those of foliage. Effects of various tissue extracts from T. connaroides on P. saucia and S. litura were comparatively studied. Extracts of bark, the most active tissue compared to those of wood, seed, exocarp and leaf, reduced larval growth of P. saucia and S. litura by 50% at dietary concentrations of 29.1 and 185.1 ppm, respectively. The limonoid hirtin, a constituent of Trichilia hirta, significantly inhibited larval growth of P. saucia in a dose-dependent manner, with a dietary EC50 (effective concentration to inhibit growth by 50% relative to controls) of 13.0 ppm. Hirtin and various extracts from T. connaroides significantly reduced larval growth and consumption rates, as well as dietary utilization, indicating that these substances possess both behavioral effects and post-ingestive toxicity.
Q’eqchi’ Maya healers’ traditional knowledge in prioritizing conservation of medicinal plants: culturally relative conservation in sustaining traditional holistic health promotion
(Springer Nature, 2009-07-30) Pesek, Todd; Abramiuk, Marc; Fini, Nick; Otarola Rojas, Marco; Collins, Sean; Cal, Víctor; Sánchez Vindas, Pablo; Poveda Álvarez, Luis; Arnason, John T.
This ethnobotanical study in the spirit of transdisciplinarity, and in collaboration with Q’eqchi’ Maya traditional healers, compares traditional Q’eqchi’ Maya ecosystem constructs or environmental zones with scientific ecosystems. To determine which categorization method better accommodates Q’eqchi’ Maya medicinal plant diversity, we analized 26 transects representing 160 medicinal plant occurrences. Our transect array encompasses a representative sampling of Q’eqchi’ Maya medicinal plant repertoire with use values broadly distributed over 17 usage categories. With a cumulative frequency of 2,235 medicinal plants through ecological zones, we conducted one-way ANOVA on the mean number of medicinal plant species identified in transects of the two conceptual schemes being contested. Our analysis reveals the Q’eqchi Maya environmental zones are the most salient. That is, knowledge of the Q’eqchi’ Maya environmental zones improves one’s ability to predict whether there will be a high or low abundance of Q’eqchi’ Maya medicinal plant species in a particular region, whereas knowledge of scientific ecosystems does not accomplish this feat as well. This is a notable finding as it suggests that if indeed Q’eqchi’ Maya medicinal plant diversity is better accounted for by the zones as envisioned by the Q’eqchi’ Maya, then it should be this mode of conceptualization that should be adopted by scientists and conservationists when trying to locate and protect regional Q’eqchi’ Maya medicinal plant diversity. These efforts serve as a model internationally in the conservation of medicinal plant biodiversity supportive of culturally relative holistic health promotion.
Spatial Distribution and Chemical Composition of Road Dust in Two High-Altitude Latin American Cities
(Universidad Nacional de Costa Rica, 2021-08-28) Vanegas, Sebastián; Trejos, Ericka M.; Aristizábal, Beatriz H.; Pereira, Guilherme M.; Hernández, Julio M.; Herrera-Murillo, Jorge; Ramírez, Omar; Amato, Fulvio; Silva, Luis F. O.; Rojas, Néstor Y.; Zafra, Carlos; Pachón, Jorge E.
Road dust (RD) resuspension is one of the main sources of particulate matter in cities with adverse impacts on air quality, health, and climate. Studies on the variability of the deposited PM10 fraction of RD (RD10) have been limited in Latin America, whereby our understanding of the central factors that control this pollutant remains incomplete. In this study, forty-one RD10 samples were collected in two Andean cities (Bogotá and Manizales) and analyzed for ions, minerals, and trace elements. RD10 levels varied between 1.8–45.7 mg/m2, with an average of 11.8 mg/m2, in Bogotá and between 0.8–26.7 mg/m2, with an average of 5.7 mg/m2, in Manizales. Minerals were the most abundant species in both cities, with a fraction significantly larger in Manizales (38%) than Bogotá (9%). The difference could be explained mainly by the complex topography and the composition of soil derived from volcanic ash in Manizales. The volcanic activity was also associated with SO4􀀀2 and Cl􀀀. Enrichment factors and principal component analysis were conducted to explore potential factors associated to sources of RD10. Elements such as Cu, Pb, Cr, Ni, V, Sb, and Mo were mainly associated with exhaust and non-exhaust traffic emissions.
The summertime Boreal forest field measurement intensive (HUMPPA-COPEC-2010): an overview of meteorological and chemical influences
(Copernicus Publications, 2011-10-27) Williams, J; Crowley, J.; Fischer, H.; Harder, H.; Martinez, M.; Petäjä. T.; Rinne, J.; Bäck, Jaana; Boy, M.; Dal Maso, M.; Hakala, J.; Kajos, M.; Keronen, P.; Rantala, P.; Aalto, J.; Aaltonen, H.; Paatero, J.; Vesala, T.; Hakola, H.; Levula, J.; Pohja, J.; Herrmann, F.; Auld, J.; Mesarchaki, E.; Song, W.; Yassaa, M.; Nölscher, A.; Johnson, A. M.; Custer, T.; Sinha, V.; Thieser, J.; Pouvesle, V.; Taraborrelli, D.; Tang, M. J.; Bozem, H.; Hosaynali-Beygi, Z.; Axinte, R.; Oswald, R.; Novelli, A.; Kubistin, D.; Hens, K.; Javed, U.; Trawny, K; Breitenberger, C.; Hidalgo, P.J.; Ebben, C.J.; Geiger, F.M.; Corrigan, A.L.; Russell, M.L.; Ouwersloot, H.G.; Vilà-Guerau de Arellano, J.; Ganzeveld, L.; Vogel, A.; Beck, M.; Bayerle, A.; Kampf, C.J.; Bertelmann, M.; Köllner, F.; Hoffmann, T.; Valverde, J.; González, D.; Riekkola, M.L,; Kulmala, M.; Lelieveld, j.
This paper describes the background, instrumentation, goals, and the regional influences on the HUMPPACOPEC intensive field measurement campaign, conducted at the Boreal forest research station SMEAR II (Station for Measuring Ecosystem-Atmosphere Relation) in HyytiäLä, Finland from 12 July–12 August 2010. The prevailing meteorological conditions during the campaign are examined and contrasted with those of the past six years. Back trajectory analyses show that meteorological conditions at the site in 2010 were characterized by a higher proportion of southerly flow than in the other years studied. As a result the summer of 2010 was anomalously warm and high in ozone making the campaign relevant for the analysis of possible future climates. A comprehensive land use analysis, provided on both 5 and 50 km scales, shows that the main vegetation types surrounding the site on both the regional and local scales are: coniferous forest (Scots pine and/or Norway spruce); mixed forest (Birch and conifers); and woodland scrub (e.g. Willows, Aspen); indicating that the campaign results can be taken as representative of the Boreal forest ecosystem. In addition to the influence of biogenic emissions, the measurement site was occasionally impacted by sources other than vegetation. Specific tracers have been used here to identify the time periods when such sources have impacted the site namely: biomass burning (acetonitrile and CO), urban anthropogenic pollution (pentane and SO2) and the nearby Korkeakoski sawmill (enantiomeric ratio of chiral onoterpenes). None of these sources dominated the study period, allowing the Boreal forest summertime emissions to be assessed and contrasted with various other source signatures.

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