Repositorio Digital Ikiam (Univ. Regional Amazónica)
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Comercio internacional desigual y pérdida de autosuficiencia alimentaria en Sudamérica
Get PDFEl objetivo central de esta investigación es examinar las repercusiones del modelo de desarrollo orientado hacia la exportación
de productos primarios y alimentos en los ámbitos económicos,
ambientales y nutricionales en los países sudamericanos en el
periodo 1986-2018. El modelo primario-exportador ha provocado impactos negativos en términos económicos, sociales y ambientales (dependencia, ampliación del extractivismo y de los
monocultivos agrícolas), además, ha coadyuvado a una pérdida
de autosuficiencia alimentaria en algunos productos, así como a
modificaciones en la dieta alimentaria. A partir del comercio internacional desigual en todas sus facetas (precios, ecológico y
calórico), se aporta a la comprensión del consumo interno.
Entre 1986 y 2018, Sudamérica presentó un intercambio desigual en precios, junto con una reprimarización del sector externo, desindustrialización y escasos encadenamientos productivos. Las relaciones asimétricas se trasladan al intercambio
ecológicamente desigual (ied) y al intercambio calórico desigual
(icd). Por una parte, se registran persistentes déficits o pérdidas
físicas, es decir, se exportan más toneladas de materiales de las
que se importan (intercambio ecológicamente desigual). De esta
manera, se pierden recursos naturales en forma del suelo y nutrientes comprometidos, además de generarse conflictos sociales
y ambientales en las zonas de extracción o producción de monocultivos. Por otra parte, se exportan calorías baratas con alto
contenido nutricional y se importan calorías caras con bajo contenido nutricional (intercambio calórico desigual)
Bioaccumulation and toxicity of microplastics and pesticides in Fiddler crabs from a ramsar site in the estuary of Guayas river
Get PDFPesticides and Microplastics (MPs) pose a major threat to ecosystem functionality and to biodiversity
15 in estuarine ecosystem. In this study, we assessed two objectives. 1) The concentration of organophosphate
16 pesticides (OPs) and MPs in water and sediments from the burrows, and tissues of the fiddler crabs Leptuca
17 festae and Minuca ecuadoriensis. Both species from Isla Santay, a Ramsar site in the estuary of the Guayas
18 River, Ecuador. 2) The effects of the exposure experiment to microplastic (MP) and its interaction with
19 malathion (MLT) in the survival of M. ecuadoriensis and MPs bioaccumulation. MPs concentrations in the
burrows were up 660 ± 174.36 items kg-1 wet weight and 26 items L-1
20 in collected sediments and water,
21 respectively. Regarding OPs, water and sediment concentrations were up to 26 times above the United States
22 Environmental Protection Agency (US EPA) thresholds for chronic exposure. The highest abundance of MPs
23 in the tissues was found in the gills. OPs concentrations in tissues were below the detection limits. The results
24 of the exposure experiment showed a higher decrease in the survival in MLT+MP treatment (80%) compared
25 to MLT (20%), MP (0%), and control (8%). The bioaccumulation of MPs was reported in the gills, digestive
26 tract, and hepatopancreas. However, the higher concentration of MPs was reported in the MLT+MP treatment.
27 Because MPs can increase the toxicity of malathion in fiddler crabs, which are chronically exposed to MPs
28 and OPs, they represent suitable bioindicators to monitor Isla Santay and to comprehend the effects of human
29 activities on the coastal environment of Ecuador
Trametes coccinea IDEA, un hongo súper productor de lacasa aislado de un lago natural de asfalto: Tolerancia y biotransformación de hidrocarburos policíclicos aromáticos
Get PDF: Los hidrocarburos policíclicos aromáticos (HPAs) son compuestos tóxicos que no se degradan fácilmente bajo
condiciones naturales tales como fenómenos físicos (fotooxidación, volatilización), químicos (intercambio iónico, complejación,
transformación) y biológicos (degradación por microorganismos autóctonos) que además, dependen de la temperatura, humedad
y niveles de oxígeno. El objetivo del presente trabajo fue aislar, identificar y caracterizar fenotípicamente hongos hidrocarbono
clásticos de ambientes extremos que sean capaces de tolerar HPAs, tales como Trametes coccinea IDEA, que se aisló del
Lago de asfalto natural de Guanoco en Venezuela. A fin de estudiar su tolerancia a los HPAs, el hongo se expuso a diferentes
concentraciones de naftaleno, fenantreno y pireno (0, 2.5, 25, 50, 100, 200, 400, 800 y 1600 mg/L). Posteriormente, en ensayo
en medio de cultivo líquido, se procedió a estudiar el efecto de los HPAs sobre la actividad de enzimas del sistema enzimático
de degradación de lignina (SEDL), así como sobre la posible variación en los niveles de toxicidad empleando Lactuca sativa
como bioindicador. Los resultados mostraron una mayor tolerancia al pireno, seguido por el naftaleno y fenantreno. Se observó
una fuerte inducción de la actividad lacasa en presencia de naftaleno (167.96 U/mgP) y pireno (124.89 U/mgP) con respecto
al control, mientras que con fenantreno se obtuvo una baja actividad (88.67 U / mgP). De manera interesante, se evidenció
una generación de sub-productos más tóxicos cuando el naftaleno y el fenantreno fueron biotratados por el hongo, mientras
que el nivel de toxicidad del pireno disminuyó significativamente. T. coccinea IDEA tiene un alto potencial para ser utilizado en
estrategias de biorremediación de hidrocarburos, las cuales deben ser monitoreadas mediante análisis ecotoxicológicos para
detectar posibles variaciones de toxicidad de los productos parcialmente biotransformados
Invertebrate Community of Scots Pine Coarse Woody Debris in the Southwestern Pyrenees under Different Thinning Intensities and Tree Species †
Get PDFBackground and Objectives: The forest in the Southwestern Pyrenees Mountains (North ern Spain) is mainly composed of pure Pinus sylvestris L. or a mix of P. sylvestris and Fagus
sylvatica L. The most common forest management technique to harvest pine is the application of
forest thinning with different intensities. It promotes a change in the forest composition and struc ture. Taking into consideration this region as a site specific research about this topic, we aimed to
understand the CWD invertebrate composition response to different thinning intensities and can opy type of these tree species. Materials and Methods: CWD samples were collected belonging to
intermediate and advanced decay classes, approximately 10 cm long and 5 cm in diameter. Using a
design of three thinning intensities (0%, 20%, and 40% of basal area removed), with three replica tions per treatment (nine plots in total), four samples were taken per plot (two per canopy type) to
reach 36 samples in total. Meso- and macrofauna were extracted from CWD samples with Berlese–
Tullgren funnels, and individuals were counted and identified. Results: Most of the taxonomic
groups belonged to mesofauna, mainly to Acari and Collembola orders. On the other hand, the
macrofauna represented a minimum percentage of the community composition. Our results indi cated that although thinning intensities did not significantly affect the invertebrate community, can opy type and CWD water content influenced significantly. It is imperative to consider in forest
management the responses of canopy type and thinning intensities in CWD water content, this dis turbance could also slow down the organic matter decomposition process in the soil, thus affecting
in the long term the natural cycle of nutrients
Red List assessment of amphibian species of Ecuador: A multidimensional approach for their conservation
Get PDFEcuador is one of the most biodiverse countries in the world, but faces severe pressures and threats to its natural ecosystems. Numerous species have declined and require to be objectively evaluated and quantified, as a step towards the development of conservation strategies. Herein, we present an updated National Red List Assessment for amphibian species of Ecuador, with one of the most detailed and complete coverages for any Ecuadorian taxonomic group to date. Based on standardized methodologies that integrate taxonomic work, spatial analyses, and ecological niche modeling, we assessed the extinction risk and identified the main threats for all Ecuadorian native amphibians (635 species), using the IUCN Red List Categories and Criteria. Our evaluation reveals that 57% (363 species) are categorized as Threatened, 12% (78 species) as Near Threatened, 4% (26 species) as Data Deficient, and 27% (168 species) as Least Concern. Our assessment almost doubles the number of threatened species in comparison with previous evaluations. In addition to habitat loss, the expansion of the agricultural/cattle raising frontier and other anthropogenic threats (roads, human settlements, and mining/oil activities) amplify the incidence of other pressures as relevant predictors of ecological integrity. Potential synergic effects with climate change and emergent diseases (apparently responsible for the sudden declines), had particular importance amongst the threats sustained by Ecuadorian amphibians. Most threatened species are distributed in montane forests and paramo habitats of the Andes, with nearly 10% of them occurring outside the National System of Protected Areas of the Ecuadorian government. Based on our results, we recommend the following actions: (i) An increase of the National System of Protected Areas to include threatened species. (ii) Supporting the ex/in-situ conservation programs to protect species considered like Critically Endangered and Endangered. (iii) Focalizing research efforts towards the description of new species, as well as species currently categorized as Data Deficient (DD) that may turn out to be threatened. The implementation of the described actions is challenging, but urgent, given the current conservation crisis faced by amphibians
GH Biplot in Reduced-Rank Regression Based on Partial Least Squares
Get PDFOne of the challenges facing statisticians is to provide tools to enable researchers to interpret and present theirdata and conclusions in ways easily understood by the scientific community. One of the tools available for this purpose is amultivariate graphical representation called reduced rank regression biplot. This biplot describes how to construct a graphicalrepresentation in nonsymmetric contexts such as approximations by least squares in multivariate linear regression models ofreduced rank. However multicollinearity invalidates the interpretation of a regression coefficient as the conditional effect of aregressor, given the values of the other regressors, and hence makes biplots of regression coefficients useless. So it was, in thesearch to overcome this problem, Alvarez and Griffin [1], presented a procedure for coefficient estimation in a multivariateregression model of reduced rank in the presence of multicollinearity based on PLS (Partial Least Squares) and generalizedsingular value decomposition. Based on these same procedures, a biplot construction is now presented for a multivariateregression model of reduced rank in the presence of multicollinearity. This procedure, called PLSSVD GH biplot, provides auseful data analysis tool which allows the visual appraisal of the structure of the dependent and independent variables. Thispaper defines the procedure and shows several of its properties. It also provides an implementation of the routines in R andpresents a real life application involving data from the FAO food database to illustrate the procedure and its properties
Structural, enzymatic and pharmacological profiles of AplTX-II - A basic sPLA2 (D49) isolated from the Agkistrodon piscivorus leucostoma snake venom
No full textA basic sPLA2 (D49) from the venom of snake Agkistrodon piscivorus leucostoma (AplTX-II) was isolated, purified and characterized. We determined the enzymatic and pharmacological profiles of this toxin. AplTX-II was isolated with a high level of purity through reverse phase chromatography and molecular exclusion. The enzyme showed pI 9.48 and molecular weight of 14,003 Da. The enzymatic activity of the AplTX-II depended on Ca2+ pH and temperature. The comparison of the primary structure with other sPLA2s revealed that AplTX-II presented all the structural reasons expected for a basic sPLA2s. Additionally, we have resolved its structure with the docked synthetic substrate NOBA (4-nitro-3-octanoyloxy benzoic acid) by homology modeling, and performed MD simulations with explicit solvent. Structural similarities were found between the enzyme's modeled structure and other snake sPLA2 X-Ray structures, available in the PDB database. NOBA and active-site water molecules spontaneously adopted stable positions and established interactions in full agreement with the reaction mechanism, proposed for the physiological substrate, suggesting that NOBA hydrolysis is an excellent model to study phospholipid hydrolysis
Impact of individual protected areas on deforestation and carbon emissions in Acre, Brazil
Get PDFIn Quito, climate change has shifted average temperatures, increased flooding during the rainy season, and intensified fires during the dry season. The city of Quito is committed to reducing its emissions at a 5% annual rate until 2025. For this purpose, Quito has developed specific plans like the “Vision 2040” and the “Resilience Strategy.” The present paper results from an award-winning proposal to the “Mi barrio ejemplar y sostenible” [My exemplary and sustainable neighborhood] urban competition and is based on developing the “Vision 2040” for San Enrique de Velasco, a typical peri-urban district of Quito. This proposal was developed considering a co-design process using both traditional methodologies and an innovative tool based on collaborative urbanism. Against a deprived and segregated district, where the lack of green areas and access to nature is now affecting the daily life of residents, the proposal considers using nature-based solutions (NBS) as a main driver for rehabilitating pride and a cohesive spirit among neighbors, developing the local economy, recovering the important natural assets of the area, solving issues like stormwater management and lack of comfort in public areas with ecological means, and developing a new landscape
Bothrops atrox from Ecuadorian Amazon: Initial analyses of venoms from individuals
Get PDFBothrops atrox is the most clinically relevant snake species within the Amazon region, which includes Ecuadorian territories. It comprises a large distribution, which could contribute to the genetic and venomic variation identified in the species. The high variability and protein isoform diversity of its venom are of medical interest, since it can influence the clinical manifestations caused by envenomation and its treatment. However, in Ecuador there is insufficient information on the diversity of venomic phenotypes, even of relevant species such as B. atrox. Here, we characterized the biochemical and toxicological profiles of the venom of six B. atrox individuals from the Ecuadorian Amazon. Differences in catalytic activities of toxins, elution profiles in liquid chromatography, electrophoretic patterns, and toxic effects among the analyzed samples were identified. Nonetheless, in the preclinical testing of antivenom, two samples from Mera (Pastaza) required a higher dose to achieve total neutralization of lethality and hemorrhage. Taken together, these data highlight the importance of analyzing individual venoms in studies focused on the outcomes of envenoming
Influencia de la rugosidad del terreno en los incendios forestales
Get PDFObjetivo: Comprobar la hipótesis de que la rugosidad del terreno influye en los regímenes
de incendios de dos maneras (i) valores altos de rugosidad funcionan como barreras
naturales que evitan la propagación de los incendios y (ii) el fuego no es una característica
aleatoria en el paisaje.
Ubicación: Siete sitios en la cordillera de los Andes tropicales entre 2°77’ y 13°60’ de latitud.
Métodos: Se utilizaron modelos de elevación digital, imágenes satelitales y datos de
incendios para analizar las relaciones entre incendios y la rugosidad del terreno en cada
sitio de estudio. Examinamos la ocurrencia de incendios como una relación entre el
Normalized Difference Vegetation Index (NDVI) y el Índice de Rugosidad del Terreno (TRI).
Además, analizamos la distribución de los incendios basados en las características del TRI:
áreas donde hubo fuego (TRIfire), donde no hubo fuego (TRInofire), y todo el sitio (TRItotal).
Resultados: (i) La vegetación aumenta consistentemente con el TRI. Las regiones analizadas
mostraron que, terrenos rugosos son más propensos a retener la vegetación que los
terrenos planos. (ii) La ocurrencia de incendios no es un proceso aleatorio, ya que
encontramos diferencias significativas entre TRIfire, TRInofire y TRItotal (p-value <= 2.2e-16).
TRIfire.
Conclusiones principales: La rugosidad del terreno influye en la dinámica de los incendios,
ya que controla su ocurrencia y modula cómo se propagan en el paisaje. Zonas de alta
rugosidad son más propensas a regenerar la vegetación después de los incendios. En el
contexto del cambio climático, las regiones con alto TRI podrían funcionar como refugios
para la biota