Repositorio Digital Ikiam (Univ. Regional Amazónica)
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Microplastic contamination along the Tena River, Napo, Ecuador
Get PDFLos residuos plásticos han terminado en el ambiente, donde se acumulan, fragmentan
y transportan, provocando impactos sociales y ambientales. Sin embargo, la
investigación sobre la contaminación por microplástico (MP) en los ríos interiores de la
cuenca del Amazonas aún es escasa, especialmente en áreas escasamente
urbanizadas, como el río Tena, ubicado en la Amazonía ecuatoriana. Analizamos el río
Tena desde zonas vírgenes, hasta su paso por toda una zona urbana y evaluamos los
patrones de distribución de microplásticos en agua, sedimentos y materia en
suspensión, también evaluamos la influencia de factores externos (origen antrópico) e
internos (velocidad del río y tamaño del sedimento) en los patrones de distribución de
MP. En el laboratorio, los microplásticos fueron cuantificados y descritos por
microscopía y los tipos de polímeros fueron identificados por espectroscopía infrarroja.
Se encontraron más microplásticos en el sedimento (promedio 753 partículas kg⁻¹) y la
mayoría de ellos fueron microplásticos pequeños (63-250 µm representando 66.36%),
que en materia suspendida (promedio 129 partículas L-1
) y en el agua superficial
(media 94 partículas L
-1
). Encontramos que la densidad de población humana influye
en la distribución de microplásticos en los sedimentos (r2=0,9962, valor p=9,987e-05) y
en la materia suspendida (r2= 0,7375, valor p= 0,06232). En las aguas superficiales,
las cantidades de microplástico se ven afectadas en menor medida por la densidad de
población (r2=0,3806, p-value= 0,2677) y la velocidad del río (r2= 0,2914, p-value=
0,3477). Se encontraron fibras (87,37%), colores azules y transparentes (54,59%) y los
tipos de microplásticos fueron celofán, poliacrilamida, resina de poliéster insaturada y
poliestireno. El tipo y los colores encontrados indican que los microplásticos proceden
principalmente de actividades antropogénicas como la pesca, la lavandería y la
agricultura. Llegamos a la conclusión de que, tras el paso por zonas urbanas, se ha
multiplicado por 2 a 5 la cantidad de PM en todas las matrices evaluadas. Esto indica
una mala gestión de los residuos sólidos, incluso en las pequeñas ciudades de las
zonas menos urbanizadas, en las regiones amazónicas.Tutor: Rodrigo Eduardo Espinosa Barrera ; Co-Tutura Mariana Capparell
Revisión crítica sobre plantas de la familia FABACEAE con registro de uso y producción de triterpenoides en la Amazonía Ecuatoriana
Get PDFLos triterpenoides son metabolitos especializados altamente distribuidos en la naturaleza y son usados por sus múltiples actividades biológicas. La familia Fabaceae es una de las que más reportes de triterpenoides presenta. En esta revisión se recopiló información relevante acerca de las plantas de la familia Fabaceae de la Amazonía ecuatoriana con registro de uso, en las cuales se han reportado triterpenoides o que presenten genes relacionados a su biosíntesis. Se realizó una búsqueda sin restricción de año en las bases de datos de
SciELO Citation Index, WorldWide Science, PubMed/Medline, Researchgate y Google Scholar, usando las palabras claves: triterpenoids, triterpenes, oxidosqualene cyclase (OSC), cytochrome P450 monooxygenase (CYP) y los nombres de las especies de los géneros con mayor ocurrencia para cada subfamilia. Además, se determinó su distribución usando el software QGIS3.16 y se analizó los avances biotecnológicos de producción de triterpenoides y aprovechamiento de los recursos genéticos. De las 13 especies objetivo se
identificaron 93 triterpenoides agrupados en cuatro esqueletos principales (oleanano, lupano, ursano, friedelano). Además, no se encontraron estudios de genes de CYPs u OSCs en las especies objetivo, a excepción de P. vulgaris que posee CYPs de los clanes CYP71 (36%), CYP72 (43%) y CYP85 (21%). A pesar de que el material vegetal usado en los estudios procede en su mayoría de países diferentes al Ecuador, a excepción de B. tarapotensis, estas especies se distribuyen en la Amazonía ecuatoriana. La comprensión del potencial medicinal de estas especies aumentará la generación de estudios de propagación y aplicaciones de ingeniería genética, edición génica y biología sintética.Tutora: Fukushima, Ery Odett
Uso pecuario intensivo, propiedades químicas del suelo y sostenibilidad en los Andes al norte del Ecuador
Get PDF(Pennisetum clandestinum), ryegrass (Lolium perenne, Lolium multiflorum) and clover
(Trifolium repens), grows on Mollisols of long term agricultural use (pre-Inca), derived
from volcanic ash, without mineral fertilization, depending on the recycling of nutrients
from animal excretion. The impact of intensive livestock between 2008-2017 on the
chemical properties of the soil was analyzed, repeating soil analyzes in both years
following standard laboratory procedures, and based on the diagnosis, recommendations
are made to improve the agricultural system. The pH from 6.1 to 6.5), K and Na (250%)
and S (420%) increased significantly (p≤0.01), while Ca, Mg and micronutrients did not
present significant differences in the evaluated period, and MOS, N, P and S contents were
kept very low for local edaphoclimatic conditions. Total N and extractable P reserves in
the soil was calculated at 5.2 Mg.ha-1
and 8,3 kg.ha1-
, respectively, equivalent to about 11
times the estimated annual contribution of 413,2N and10% of the contribution of 83,7P
kg.ha1-
in excreta + urine. To improve the sustainability of the production system, and
reducing risks of environmental impact, we suggest establishing a silvopastoral system
(SSP), semi-stabulate the cattle and compost the excreta, increase the cultivation of oats,
maiz and forage barley to optimize the diet of the cattle and apply biofertilizers to the
pasture based on mycorrhizal fungi and nitrifying bacteria
Local hydrological conditions influence tree diversity and composition across the Amazon basin
Get PDFTree diversity and composition in Amazonia are known to be strongly determined by the water supplied by precipitation.
Nevertheless, within the same climatic regime, water availability is modulated by local topography and soil characteristics
(hereafter referred to as local hydrological conditions), varying from saturated and poorly drained to well-drained and poten tially dry areas. While these conditions may be expected to influence species distribution, the impacts of local hydrological
conditions on tree diversity and composition remain poorly understood at the whole Amazon basin scale. Using a dataset of
443 1-ha non-flooded forest plots distributed across the basin, we investigate how local hydrological conditions influence 1)
tree alpha diversity, 2) the community-weighted wood density mean (CWM-wd) – a proxy for hydraulic resistance and 3) tree
species composition. We find that the effect of local hydrological conditions on tree diversity depends on climate, being more
evident in wetter forests, where diversity increases towards locations with well-drained soils. CWM-wd increased towards bet ter drained soils in Southern and Western Amazonia. Tree species composition changed along local soil hydrological gradients
in Central-Eastern, Western and Southern Amazonia, and those changes were correlated with changes in the mean wood den sity of plots. Our results suggest that local hydrological gradients filter species, influencing the diversity and composition of
Amazonian forests. Overall, this study shows that the effect of local hydrological conditions is pervasive, extending over wide
Amazonian regions, and reinforces the importance of accounting for local topography and hydrology to better understand the
likely response and resilience of forests to increased frequency of extreme climate events and rising temperatures
Human health risk assessment of metals and metalloids in mining areas of the Northeast Andean foothills of the Ecuadorian Amazon
Get PDFGold mining (GM) is a major source of metals and metalloids in rivers, causing severe environmental pollution and increasing the exposure risks to the residents of surrounding areas. Mining in Ecuadorian Amazonia has dramatically increased in recent years, but its impacts on Indigenous local populations that make use of rivers are still unknown. The aim of this study was to assess the risks to adults and children caused by the exposure to metals and metalloids in freshwater ecosystems contaminated with tailings released by GM activities in 11 sites of the upper Napo River basin, Ecuador. We selected a carcinogenic and a noncarcinogenic risk assessment method to estimate the hazard index (HI) and total cancer risk (TCR). The concentration of Ag, Al, As, Cd, Cu, Fe, Mn, Pb, Zn, B, and V in water and sediment samples was considered to assess the risks to human health. The calculated HI was 23-352 times greater than the acceptable limits in all sites for both children and adults. Mn and Fe were the main contributors (75% in water and 99% in sediment) to the total calculated risk based on the HI. The calculated TCR for children and adults exceeded approximately one to three times the permissible threshold in all sites. As and Pb contributed up to 93% of the total calculated risk based on TCR for both children and adults. This study demonstrates that the emission and mobilization of metals and metalloids caused by mining activities increase the risk to human health, to which we recommend further monitoring of freshwater contamination in the area and the implementation of preventive health management measures. Integr Environ Assess Manag 2022;00:1-11. © 2022 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC)
Evaluation of methane production from the anaerobic co-digestion of manure of guinea pig with lignocellulosic Andean residues
Get PDFThe objective of this research was to evaluate anaerobic co-digestion of guinea pig manure (GP) with Andean agricultural
residues such as amaranth (AM), quinoa (QU) and wheat (TR) in batch biodigesters under mesophilic conditions (37 0
C) for
40 days. As microbial inoculum, sewage treatment sludge was used in two inoculum/substrate ratios (ISR of 1 and 2). In terms of
methane production, the best results occurred in treatments containing AM and QU as co-substrate and an ISR of 2. Thus, the
highest methane production yield in the GP:AM biodigesters (25:75) and GP:QU (25:75) with 341.86 mlCH4/g VS added and
341.05 mlCH4/g VS added, respectively. On the other hand, the results showed that methane production with an ISR of 2
generated higher yields for guinea pig waste and the methane fraction of the biogas generated was in a range from 57 to 69%.
Methane production kinetics from these raw materials was studied using five kinetic models: modified Gompertz, logistic
equation, transfer, cone and Richards. The cone model adjusted best to the experimental values with those observed with r2 of
0.999 and RMSE of 1.16 mlCH4/g VS added. Finally, the highest biodegradability (experimental yield/theoretical yield) was
obtained in the GP-AM biodigesters (25:75) with 67.92%
Priorities of action and research for the protection of biodiversity and ecosystem services in continental Ecuador
Get PDFEcuador belongs to the megadiverse countries of the world. However, the high diversity in species, ecosystems and their services are under threat by land use changes, invasive species, overexploitation, pollution and climate change. There is a need to monitor, manage, protect and improve biodiversity and ecosystem services (BES) in Ecuador; however, Ecuador is marginally represented in the international policy-science interface for the protection of BES. We analyzed 266 international peer-reviewed papers that were published between 2000 and 2020 to assess the current impact of human disturbance and climate change on BES in continental Ecuador. We found that there were more studies available on the impact of human disturbance on BES than on climate change effects. Birds represented the most studied taxon in Ecuador (70 studies), whereas the total amount of available international scientific publications for other Ecuadorian plant and animal taxa were rather low (< 34 studies) and spatially and thematically scattered. Among ecosystem services, water provision was analyzed relatively often. Our literature review revealed that there is a need to conduct more studies on impacts of human disturbance and climate change on BES. Further research is needed; particularly in the coastal hinterland, in the central Andes and in the Amazon. We suggest that the investment of time, resources and effort into the documentation, standardization, sharing, and publishing of data are key towards supporting the monitoring and maintenance of BES
Toward food sovereignty and self-sufficiency in Latin America and the Caribbean: opportunities for agricultural complementarity Hacia una soberanía y autosuficiencia alimentaria en América Latina y el Caribe: oportunidades de complementariedad agrícola
Get PDFFood self-sufficiency is a relevant political issue in many countries, developed and developing,
particularly to satisfy the internal nutritional needs of the population and face situations in which the prices
of basic products are unstable or when a country faces an external shock. Improving resilience involves
strengthening local rural communities to meet demand with domestic production. The member countries of
Latin America and the Caribbean (LCN) produce enough food to sustain their population and to be one of the
world’s largest food exporters. From the theoretical discussion and using data from FAO, the research shows
that there is a potential to improve food sovereignty and to define food and agricultural policies through
agricultural complementarity among the LCN countries. Diverting part of the current trade with third parties
to intraregional trade, for products in which the region has a comparative advantage, would mean that LCN
countries could save up to 2.7 billion dollars per year, that is, 6.8% of total imports of food in 2018, avoiding
the outflow of foreign currency and promoting greater economic integration between countries
Deciphering the Limitations and Antibacterial Mechanism of Cruzioseptins
Get PDFAntimicrobial peptides consist mainly of membrane-active sequences, which are potentially relevant to antibiotic resistance era. In this context, a novel family of peptides isolated from the skin secretion of Cruziohyla calcarifer have been recently identified with wide and efficient antimicrobial effects. However, the mechanism underlying their antibacterial action remains unknown, as well as their activity under salt concentrations. For the primary purpose, spectrofluorometric and microscopic assays were performed using fluorescent intercalating agents. In silico study also were performed aiming to confirm the nature and energetics of the membranolytic interactions. The influence of proteolytic enzymes and salt concentrations was accessed by broth microdilution approach, mimicking physiological conditions. Cruzioseptins showed detergent-like properties, acting by a similar lytic mechanism characterized for others cationic peptides. An increase of up to three times the minimum inhibitory concentration was observed in presence of salts or serum. This represents an important challenge for the clinical use of peptide-based drugs. Overall, we ratify the antimicrobial potential of cruzioseptins and suggest paradigms that should be considered for translational medicine
700,000 years of tropical Andean glaciation
Get PDFOur understanding of the climatic teleconnections that drove ice-age cycles has been
limited by a paucity of well-dated tropical records of glaciation that span several
glacial–interglacial intervals. Glacial deposits ofer discrete snapshots of glacier extent
but cannot provide the continuous records required for detailed interhemispheric
comparisons. By contrast, lakes located within glaciated catchments can provide
continuous archives of upstream glacial activity, but few such records extend beyond
the last glacial cycle. Here a piston core from Lake Junín in the uppermost Amazon
basin provides the frst, to our knowledge, continuous, independently dated archive of
tropical glaciation spanning 700,000 years. We fnd that tropical glaciers tracked
changes in global ice volume and followed a clear approximately 100,000-year
periodicity. An enhancement in the extent of tropical Andean glaciers relative to global
ice volume occurred between 200,000 and 400,000 years ago, during sustained
intervals of regionally elevated hydrologic balance that modifed the regular
approximately 23,000-year pacing of monsoon-driven precipitation. Millennial-scale
variations in the extent of tropical Andean glaciers during the last glacial cycle were
driven by variations in regional monsoon strength that were linked to temperature
perturbations in Greenland ice cores1
; these interhemispheric connections may have
existed during previous glacial cycles