Repositorio Digital Ikiam (Univ. Regional Amazónica)
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Estudio de la cámara magmática principal del volcán Sumaco mediante tomografía sísmica
Get PDFThe back-arc (Eastern sub-Andean belt) of the Ecuadorian Andes encompass four volcanoes:
Reventador, Yanaurco, Pan de Azúcar, and Sumaco. Despite the proximity of these volcanoes,
Sumaco volcanic materials are distinctly SiO2-undersaturated alkalines. Through seismic travel
time tomography, three velocity models (, ∆, /
) were generated to identify the
primary magmatic reservoir of the Ecuadorian back-arc. The inverse problem was solved using
the INSIGHT computer code package in a gridded parallelepiped box with a cell size of 5 km in
the horizontal direction and 2 km in the vertical direction. This study finds the principal
magmatic chamber located below the Sumaco volcano but slightly shared with the extinct Pan
de Azúcar and Yanaurco volcanoes.
Sumaco Fault extension is also recognizable and is expected to be responsible for the rapid
ascent of the magma towards the surface before an eruption.
As a conclusion, a significant factor that could lead to the differentiation of the Sumaco lavas
is a hypothetical flat slab block below the volcan
Síntesis y evaluación del potencial antitumoral y antimicrobiano de pequeños péptidos catiónicos bioinspirados en fosfolipasas de venenos de serpientes
Get PDFEl cáncer y la resistencia a los antibióticos son algunos de los principales
problemas de salud y desafíos que actualmente enfrenta la humanidad, por ello la
comunidad científica se ha enfocado en descubrir nuevas moléculas terapéuticas y en
base a ellas diseñar nuevos fármacos que mitiguen esta problemática. Los péptidos
bioinspirados en fosfolipasas (PLA2) derivados del veneno de serpientes han surgido
como una alternativa innovadora para la inhibición de tumores y de poblaciones
microbianas patógenas. En este estudio se sintetizaron tres péptidos derivados de tres
PLA2s Asp49 básicas: Bmje (YNKKYRYHLKSCKKADK), Bmtxj (YNKKYMKH LKPCKKA) y
Cergo (NLRTYKKRYMFY). Dichas secuencias fueron analizadas por programas
bioinformáticos tales como AMPA, PepDraw, I-TASSER, HemoPI, ToxinPred y NetWheels
para determinar sus propiedades físico-químicas y su toxicidad in silico. Posteriormente,
las secuencias seleccionadas fueron sintetizadas, purificadas por cromatografía FLASH e
identificadas mediante espectrometría de masas MALDI-TOF MS. El grado de pureza se
determinó mediante cromatografía líquida de alta eficiencia en fase reversa (RP-HPLC).
Seguidamente, el potencial antitumoral de los péptidos fue evaluado mediante el
ensayo de viabilidad celular por reducción de MTT en tres líneas celulares de carcinoma
humano (Caco II, Hep-G2 y MCF-7), mientras que el potencial antimicrobiano fue
evaluado en tres cepas bacterianas de interés clínico (Escherichia coli, Staphylococcus
aureus y Candida albicans). Se observó una actividad antitumoral moderada del péptido
Bmje contra MFC-7 con una concentración letal media (CL50) de 464,85 M, mientras
que Cergo presento actividad antimicrobiana contra E. coli con un CMI de 75 M y Bmtxj
contra S. aureus con un CMI de 37,5 M. Adicionalmente, ninguno de los tres péptidos
evaluados presentó un carácter hemolítico. Estos resultados evidencian que las
fosfolipasas representan un grupo de toxinas que puede funcionar como arquetipos
adecuados para el diseño de moléculas bioactivas prometedoras contra problemas de
salud pública
Measuring Floodplain Inundation Using DielAmplitude of Temperature
Get PDFAssessment of inundation patterns across large and remote floodplains is challenging andcostly. Inexpensive loggers that record the damping of the diel amplitude of temperature (DAT)when submerged compared to overlying air can indirectly indicate inundation. We assessed theefficacy of this approach in tropical, subtropical, and temperate floodplains by comparing directwater level measurements using pressure transducers with the indirect indication of inundationascertained from the DAT at the same location. The approach worked better in tropical than insubtropical and temperate floodplains. However, the relatively small DATs of air in humid anddensely vegetated settings made estimation of inundation more challenging compared to the drier andless vegetated settings, where a large diel range of air temperature was markedly damped beneath thewater. The indirect temperature approach must be calibrated for a particular ecosystem using directwater-level measurements to define DAT thresholds that are indicative of submergence of the sensors.Temperature provides an inexpensive indicator of duration of inundation that can be particularlyuseful in studies of large and remote floodplains, although the development of inexpensive sensorsthat directly measure submergence (e.g., by resistivity) will likely become a better option in the future
Microbiota of Wild Fruits from the Amazon Region of Ecuador: Linking Diversity and Functional Potential of Lactic Acid Bacteria with Their Origin
Get PDFSubtropical wild fruits are a reservoir of microbial diversity and represent a potential source of beneficial microorganisms. Wild fruits provide essential nutrients, minerals, and antioxidants that contribute to human health. Many of these wild fruits are used by indigenous peoples for medicine and food, but there is yet an unexplored potential in the study of their properties and benefits. Wild fruits from the Amazon region and their associated active substances or bacterial communities can prevent disease, provide appropriate nutrition, contribute to new sources of income, and improve lives. Despite its condition as a megabiodiverse country, Ecuador suffers from limited access to its genetic resources, and particularly for research. A total of 41 isolates were obtained from six wild Amazonian fruit species and were molecularly classified into the genera Lactiplantibacillus (31 isolates), Lactococcus (3 isolates), Weissella (3 isolates), and Enterococcus (1 isolate). Three isolates showed large divergence in sequence variability and were not identified by the taxonomic assignment algorithm. Inferred phylogenies on the 16S rRNA gene explained the relationship between lineages and their origin. Carbohydrate metabolism and antimicrobial profiles were evaluated, and the isolates were classified from a functional perspective. Antimicrobial profiles showed a wide-range spectrum against several Gram-positive and Gram-negative bacteria. To our knowledge, this is the first study assessing the diversity of LAB in native tropical fruits from the Amazon region of Ecuador and their promising functional properties. The obtained isolates and their assessed properties are valuable genetic resources to be further investigated for industrial and pharmaceutical applications
Coarse Woody Debris’ Invertebrate Community Is Affected Directly by Canopy Type and Indirectly by Thinning in Mixed Scots Pine— European Beech Forests
Get PDFAbstract: Research Highlights: Thinning and tree species alter the forest floor microclimate by
modifying canopy cover, radiation, wind, and humidity. Thus, forest management can directly
influence the edaphic mesofauna responsible for decomposing coarse woody debris (CWD).
Background and Objectives: This research was carried out in the Southwestern Pyrenees Mountains
(Northern Spain) and aimed to determine the influence of forest thinning and canopy type (pure
Pinus sylvestris L. or a mix of P. sylvestris and Fagus sylvatica L.) on CWD colonization by edaphic
fauna. Materials and Methods: CWD samples were collected belonging to intermediate and advanced
decomposition stages, 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 replications 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: 19 taxonomic groups were recorded, the most
abundant being the mesofauna (mites and Collembola). Mixed canopy type had a significant
positive influence on richness, whereas advanced decay class had a positive significant influence on
total abundance and richness. In addition, there were non-significant decreasing trends in richness
and abundance with increasing thinning intensity. However, interactions among thinning intensity,
canopy type, and decay class significantly affected mesofauna. Furthermore, some taxonomic
groups showed differential responses to canopy type. CWD water content was positively correlated
with total invertebrate abundance and some taxonomic groups. Our results suggest that stand
composition has the potential to directly affect invertebrate communities in CWD, whereas stand
density influence is indirect and mostly realized through changes in CWD moisture. As mesofauna
is related to CWD decomposition rates, these effects should be accounted for when planning forest
management transition from pure to mixed forests
New record of a feral population of Lithobates catesbeianus Shaw, 1802 in a protected area (Santay Island) in the Ecuadorian coast
Get PDFThe American bullfrog (Lithobates catesbeianus Shaw, 1802), an amphibian
species native to eastern North America, is considered one of the 100 most harmful
invasive species in the world. Previous studies document several feral populations
in the Amazon and Andean regions of Ecuador. However, only few adults have
been reported in the Coast region, despite some evidence suggesting its introduction
31 years ago. Using visual and auditory cues, we explored a 490-hectare wetland
area at Santay Island, a protected sanctuary and a Ramsar site on the Ecuadorian
Coast. Bullfrogs were detected in seven out of 15 sampled ponds in all types of
habitats except for mangroves. The low abundance of adults and juveniles suggests
a recently established population. This is the first record of a feral population inside
a protected area or Ramsar site in Ecuador. In accordance with the Ramsar Convention
mission of preserving wetlands, we propose two strategies to manage bullfrogs at
Santay Island
Etnobotánica y etnofarmacología de Ilex guayusa en Ecuador: uso potencial de “wayusa” en Amazonía
Get PDFIlex guayusa pertenece a la familia Aquifoliaceae y
es un árbol de 10 m de altura nativo en Amazonía del
Ecuador [1], su grado de manejo cultural indica que
la planta es silvestre y cultivada. La investigación se
realizó en tres comunidades Kichwa, localizadas en
la provincia de Napo
2,100 years of human adaptation to climate change in the High Andes
Get PDFHumid montane forests are challenging environments for human habitation. We used high-resolution fossil pollen, charcoal, diatom and sediment chemistry data from the iconic archaeological setting of Laguna de los Condores, Peru to reconstruct changing land uses and climates in a forested Andean valley. Forest clearance and maize cultivation were initiated during periods of drought, with periods of forest recovery occurring during wetter conditions. Between ad 800 and 1000 forest regrowth
was evident, but this trend was reversed between ad 1000 and 1200 as drier conditions coincided with renewed land clearance,
the establishment of a permanent village and the use of cliffs overlooking the lake as a burial site. By ad 1230 forests
had regrown in the valley and maize cultivation was greatly reduced. An elevational transect investigating regional patterns
showed a parallel, but earlier, history of reduced maize cultivation and forest regeneration at mid-elevation. However, a lowland site showed continuous maize agriculture until European conquest but very little subsequent change in forest cover. Divergent, climate-sensitive landscape histories do not support categorical assessments that forest regrowth and peak carbon sequestration
coincided with European arrival
Biología reproductiva del cacao blanco (Theobroma bicolor Humb. & Bonpl.) en Napo Ecuador
Get PDFEl cacao blanco (Theobroma bicolor) posee una amplia distribución en el
neotrópico, con una variedad de nombres y usos. Su semilla presenta valores nutricionales
para su aprovechamiento y comercialización internacional. Con el objetivo de contribuir al
conocimiento de la biología reproductiva de T. bicolor en Ecuador se estudiaron aspectos
sobre la biología floral, la fenología reproductiva y las restricciones bióticas sobre la
reproducción de la especie. El estudio fue realizado en la provincia de Napo, cantón Tena.
A partir de la observación de 80 flores se describió la morfología de la flor; de la observación
de 35 botones florales la proporción entre óvulos y polen; mediante el monitoreo en campo
de 260 flores, se determinaron las etapas florales y la receptividad del estigma utilizando
para esto peróxido de hidrógeno. Para conocer la fenología reproductiva (floración y
fructificación) se monitorearon mensualmente 55 árboles durante los meses de julio de
2019 a febrero de 2020. Se determinaron las correlaciones entre la floración y fructificació
Ecosystem Service Multifunctionality: Decline and Recovery Pathways in the Amazon and ChocóLowland Rainforests
Get PDFThe balance between the supply of multiple ecosystem services (ES) and the fulfillment of society demands is a challenge, especially in the tropics where different land use transition phases emerge. These phases are characterized by either a decline (from intact old-growth to logged forests) or a recovery of ES (successional forests, plantations, and agroforestry systems). This highlights the importance of ecosystem service multifunctionality (M) assessments across these land use transition phases as a basis for forest management and conservation. We analyzed synergies and trade-offs of ES to identify potential umbrella ES. We also evaluated the impact of logging activities in the decline of ES and M, and the influence of three recovery phases in the supply of ES and M. We installed 156 inventory plots (1600 m2) in the Ecuadorian Central Amazon and the Chocó. We estimated indicators for provisioning, regulating, supporting services and biodiversity. M indicator was estimated using the multifunctional average approach. Our results show that above-ground carbon stocks can be considered as an umbrella service as it presented high synergetic relations with M and various ES. We observed that logging activities caused a decline of 16–18% on M, with high impacts for timber volume and above-ground carbon stocks, calling for more sustainable practices with stricter post-harvesting control to avoid a higher depletion of ES and M. From the recovery phases it is evident that, successional forests offer the highest level of M, evidencing high potential to recover multiple ES after human disturbance