In late 2019 a new virus reported in Wuhan, China, identified as SARS-CoV-2 spread rapidly challenging the healthcare system around the world. The need for rapid, timely and accurate detection was critical to the prevention of community outbreaks of the virus. However, the high global demand for reagents during the years 2020 and 2021 generated a bottleneck in kits used for detection, greatly affecting developing countries, lagging their ability to diagnose and control the virus in the population. The difficulty in importing reagents, high costs and limited public access to the SARS-CoV-2 detection test led to the search for alternative methods. In this framework, different commercial nucleic acid extraction methodologies were evaluated and compared against heat shock as an alternative method for SARS-CoV-2 detection by RT-PCR, in order to determine the diagnostic yield and its possible low-cost compared to other methodologies. Nasopharyngeal samples were used where the diagnostic efficiency of the alternative method was 70 to 73%. The evaluation of the discriminatory efficacy of the method took the sensitivity and specificity to establish its cut-off point, being 0.73 to 0.817, which allows discriminating between COVID-19 positives and negatives. As for the diagnostic effectiveness expressed as the proportion of subjects correctly classified, it is between 80 and 84%. On the other hand, in terms of the costs necessary to carry out the detection, the alternative method is more economical and accessible in terms of direct cost close to 47 and 49 USD, and indirect cost around 35 and 50 USD compared to the commercial methods available in this comparison and evaluation, being possible its implementation in developing countries with high infection rates, allowing access to the diagnostic test with a reliable and low-cost method. Keywords: COVID-19, RT-PCR, Viral RNA.
Habitat disturbance leads to biodiversity decline and modifications in the landscape structure and composition, affecting both dispersal movements and ecological processes at different temporal and spatial scales. The Ecuadorian Tropical Andes harbour suitable habitats for the distribution of a wide variety of species; however, there is a lack of studies focused on mammal diversity and its association with the habitat attributes in the central- eastern slopes. Here, we reported the diversity of terrestrial mammals recorded between 2019 and 2021 in a camera-trap monitoring study in the Candelaria and Machay reserves in the upper basin of the Pastaza River, Ecuador. We performed site-occupancy probability analysis to assess the influence of spatial variables in the species’ occurrence and also, based on natural marks, we reported preliminary findings in Andean bear individual identification. We detected 22 species of terrestrial mammals. Alpha diversity was similar between reserves with slightly higher species richness in Machay. Evenness indices showed unequal species distribution, with the Andean bear and domestic dogs exhibiting greater dominance. In addition, species composition was dissimilar between reserves, where the species turnover mostly explained the beta diversity. We observed that Andean bear and puma detections increased according to the natural vegetation cover. Conversely, domestic dogs were frequently detected in cells with an increasing proportion of pastures and crops. Additionally, we identified 26 Andean bears and six individuals recaptured during our study. Our results caution about the disturbance derived from human activities since we recorded unprecedented detections of domestic dogs in wild habitats. Nonetheless, it highlights the importance of private conservation areas (e.g. Candelaria, Machay and others) for supporting the occurrence and dispersal of terrestrial mammal species between larger areas in the upper basin of the Pastaza River.
In a time of rapid global change, the question of what determines patterns in species abundance distribution remains a priority for understanding the complex dynamics of ecosystems. The constrained maximization of information entropy provides a framework for the understanding of such complex systems dynamics by a quantitative analysis of important constraints via predictions using least biased probability distributions. We apply it to over two thousand hectares of Amazonian tree inventories across seven forest types and thirteen functional traits, representing major global axes of plant strategies. Results show that constraints formed by regional relative abundances of genera explain eight times more of local relative abundances than constraints based on directional selection for specific functional traits, although the latter does show clear signals of environmental dependency. These results provide a quantitative insight by inference from large-scale data using cross-disciplinary methods, furthering our understanding of ecological dynamics.
Geodiversity is considered the abiotic equivalent of biodiversity; it can be explained in three main fields such as scientific, educational, and tourism. In sixteen geosites of Napo Sumaco Geopark, a quantitative assessment of geodiversity was carried out using the methodology proposed by Brilha (Brilha, Geoheritage 8:119–134, 2016). This work has a field data collection phase in the geosites Shunku Rumi and Pungarayacu Quarry, where for the first time a geological sketch and stratigraphic columns were made. Regarding the quantitative assessment, it was found that the geosites Sumaco Volcano and Guagua Sumaco Lagoon and Outlook have a high scientific value, the geosite Pungarayacu Quarry has a high potential for educational use, and the Puerto Misahualli’s Bookcase has a high potential touristic use. In terms of degradation risk assessment, Pungarayacu Quarry and Hollin River geosites have a high and moderate degradation risk respectively. The remaining fourteen geosites show a low risk of degradation because there are no activities that cause degradation, and are protected by the people of communities and local guides. Finally, this work shows the need for more scientific research, improvement in the security conditions, promotion of the geosites, and development of didactic material.
The Napo River basin, which is situated within the Upper Amazon archaeological region, is one of the most speciose forests in Greater Amazonia. Standard thinking in scholarship and science holds that these forests are essentially pristine because any Indigenous impacts in the past would have been minimal, seedbanks would have been nearby, and natural forests would have reappeared after the humans left, died out, or dispersed. Inventory research in 2019 on three ridgetop forests in Waorani territory inside the Curaray basin (which drains to the right margin of the Napo River) and a comparable inventory on one control site forest along the Nushiño River (also in the Curaray basin) show human impacts from about the late nineteenth century to about 1960; they occurred during the period of wartime among Waorani themselves and between Wao people and outsiders. The human impacts resulted in the high basal-area presence of two long-lived species with important Waorani cultural uses: cacao ( Theobroma cacao L.) and ungurahua palm ( Oenocarpus bataua Mart.). These species have high frequency and dominance values and do not occur in the control site, which is comparable in terms of elevation above the flood zone of the rivers in the sample. These findings mean that alpha diversity in the right margin sector (or south) of the Napo River basin cannot a priori be explained by reference to traditionally, biologically accepted patterns of ecological succession but may require knowledge of historical patterns of Indigenous land use and secondary landscape transformation over time due to human (specifically Waorani) impacts of the past.
The two most important sources of global information on species distributions show dramatic differences in the estimation of global richness patterns of threatened vertebrates in marine islands. Abstract Aim: The most popular sources of information on species distributions are the expert-derived maps and georeferenced occurrences, mainly those compiled by the Global Biodiversity Information Facility (GBIF). These sources have been constantly used with biogeographical and conservation goals. However, their degree of accuracy in representing geographical biodiversity patterns remains poorly understood. Here, we compared both sources of information on species distributions to estimate global patterns of richness and species composition of threatened vertebrates on marine islands. Location: Global. Taxon: Terrestrial vertebrates. Methods: We gathered distributional data of all threatened terrestrial vertebrate species inhabiting 22,471 marine islands worldwide from GBIF and expert derived maps. Then, to assess strengths and biases from each source, using geographical information systems, we calculated and compared: (a) species richness per island, (b) general patterns of richness and (c) the number of shared species from both sources per island.
Organochlorine pesticides (OCPs) have been intensively used without proper regulation and control in Latin America due to the prevalence of diseases and pests, thus posing potential risks to nontarget organisms. Initiatives for ecosystem preservation, such as to designate protected areas, may not be enough to avoid contamination by OCPs, considering that protected areas tend to be permeable to diffuse sources. Here, we investigate multi-level responses of the oyster Crassostrea virginica to OCPs in Laguna de Términos, a RAMSAR coastal lagoon in the southern Gulf of Mexico. For this aim, OCPs occurrence and concentrations in the water, sediment, and in oysters from 3 settlement banks were assessed. Enzymatic and non-enzymatic biochemical biomarkers were quantified in the oysters' mantle and digestive gland, and the human health risk due to oyster consumption was also evaluated. OCPs in water were below detection limits. Fourteen OCPs were detected in sediments (∑OCPs mean of 49 ngg-1) and 7 in oyster tissues (∑OCPs mean of 121 ngg-1). The occurrence of OCPs was related to the land uses along the watersheds of the rivers that drain into the lagoon. Biochemical responses were correlated with OCPs (∑HCH, ∑DDT, heptachlor and endosulfan) in sediment, and oyster tissues. OCPs in oyster tissues showed a strong association with pro-oxidant forces and oxidative stress responses (Superoxide dismutase, Catalase, Glutathione Peroxidase, and lipid peroxidation), and neurotoxicity (Acetylcholinesterase), suggesting that the current OCPs contamination exerts significant stress. Our study also shows that the consumption of oysters from the lagoon increases the potential human health risk. Considering that Laguna de Términos is a protected Ramsar site, we suggest that environmental protection measures should be increased and that a monitoring program for OCPs exposure is necessary to assess the effects on this ecosystem.
This study evaluated the antioxidant properties and chemical composition of the seeds, pulp and peels of Ungurahua (Oenocarpus bataua) and Pasu (Gustavia macarenensis)—fruits, native to the Ecuadorian Amazon. The antioxidant capacity was measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and cyclic voltammetry (antioxidant index 50 (AI50)) assays; differential pulse voltammetry was used to evaluate antioxidant power using the electrochemical index. The total phenolic content, as well as the yellow flavonoid and anthocyanin content, were quantified via spectrophotometry. In addition, the trans-resveratrol and ascorbic acid content were evaluated through high performance liquid chromatography (HPLC). Ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) was used to identify secondary metabolites with possible therapeutic properties. Results showed that the Pasu peel and seed extracts had the highest antioxidant capacity, followed by the Ungurahua peel; these results were consistent for both spectroscopic and electrochemical assays. HPLC and UPLC-MS analysis suggest that Oenocarpus bataua and Gustavia macarenensis are important sources of beneficial bioactive compounds.
In the Ecuadorian Amazonia, there is a concern about the presence of high concentrations of cadmium (Cd) in rivers and sediments because of changes in land use and anthropogenic activities, e.g., mining and oil exploitation. Hence, the research related to water treatment processes to meet environmental standards has gained relevance. The use of biochar (BC) as adsorbent is considered a promising and low-cost alternative to improve the water quality in developing countries. In this work, lignocellulosic wastes from Guadua angustifolia were transformed through thermochemical treatments, into a promising carbonaceous material, such as BC. BC samples were prepared by pyrolysis (termed pyrochar, PC) and hydrothermal carbonization (termed hydrochar, HC). Their physicochemical properties were correlated with the Cd adsorption removal performance, analyzing the effect of adsorbent dosage, initial solution pH, adsorption kinetics and adsorption isotherms. HC showed the highest Cd adsorption performance, due to the presence of a higher number of oxygenated functional groups, as confirmed by FTIR, XPS and Raman spectroscopy. This research has proposed a sustainable alternative for the recovery of an available waste, contributing to mitigate the effects of the presence of metals on the health and economy of the most vulnerable sectors of society.
The Cordillera del Cóndor (CC) mountain range, located parallel to the Eastern Andes and bordering both Ecuador and Peru, is a discontinuous formation whose elevation spans 190–3200 m a.s.l., with unique geology and vegetation, and a wide variety of climates. Here, based on a thorough revision of databases, the scientific literature and on field work, we evaluate the importance of the CC to the species diversity of amphibians and reptiles. We update species richness and composition information, analyze their spatial and elevation distributions, review their conservation status and compare their species richness and composition with those of eight other cordilleras in South America. A total of 165 amphibian species and 137 reptile species have been recorded for the CC. The spatial distribution of the collection localities is notably biased toward a few zones in the cordillera, and the greatest species richness occurs between 1400 and 1800 m a.s.l. Close to 12% of the amphibian species and 3% of the reptile species of the CC are threatened; however, for 22% of the species, either the data are insufficient to assign a risk category or their conservation status has not been evaluated. Of the nine cordilleras compared, the CC has the greatest number of amphibian species and reptile species recorded, and its species composition is similar to that of the Kutukú and Kampankis cordilleras. The CC is an area of enormous importance at the regional level in terms of amphibian and reptile diversity and should be a high conservation priority.
Peptide engineering has gained attraction as a source of new cationicity-enhanced analogues with high potential for the design of next-generation antibiotics. In this context, cruzioseptin-1 (CZS-1), a peptide identified from Cruziohyla calcarifer, is recognized for its antimicrobial potency. However, this amidated-peptide is moderately hemolytic. In order to reduce toxicity and increase antimicrobial potency, 3 peptide analogues based on cruzioseptin-1 were designed and evaluated. [K4K15]CZS-1, an analogue with increased cationicity and reduced hydrophobicity, showed antibacterial, antifungal and antiproliferative properties. In addition, [K4K15]CZS-1 is less hemolytic than CZS-1. The in silico and scanning electron microscopy analysis reveal that [K4K15]CZS-1 induces a membranolytic effect on bacteria. Overall, these results confirm the potential of CZS-1 as source of inspiration for design new selective antimicrobial analogues useful for development of new therapeutic agents.
Emerging contaminants in water bodies is an issue of concern due to their impact on the ecosystem and human health. The COVID-19 pandemic has forced the implementation of protective measures such as social distancing, lockdowns, and remote work, which have affected the tourism influx. This study aimed to evaluate the occurrence of emerging pollutants in bodies of water in Esmeraldas, a coastal province of Ecuador, before and during the COVID-19 pandemic in a highly touristic region. For this purpose, surface waters from 14 beaches and ten river mouths were sampled at two-time points in November 2019 and November 2020. Compounds widely consumed in Ecuador: acetaminophen, caffeine, sodium diclofenac, trimethoprim, and sulfamethoxazole were extracted from water samples by solid phase extraction SPE and detected with a UPLC-QTOF-MS system. We found a decrease in the occurrence of caffeine from 100 % to 4.2 % of caffeine and 25 % to 0 % of diclofenac, likely related to the decline in tourist afflux due to the lockdown measures. Most of the compounds diminished in terms of frequency and/or concentration; however, as COVID-19 treatments make use of different pharmaceutical compounds such as antivirals, antibiotics, antiparasitics, or glucocorticoids, future studies should include these to assess their environmental impact.
Dwarf caimans (Alligatoridae: Paleosuchus palpebrosus and Paleosuchus trigonatus), are small crocodilians exhibiting cryptic behaviour and complex habitat use that occur throughout the Amazon region. Our goals were to evaluate individual home range, habitat occupancy and movement patterns where they occur in sympatry in relation to seasonal water-level variation. We tracked five P. palpebrosus and seven P. trigonatus using VHS radio transmitters along the shores of two streams directly influenced by the flooding pulse of the Purus River. Paleosuchus palpebrosus individuals moved greater distances on a daily basis and had larger home ranges than P. trigonatus, and the species had different responses to increases in water levels. Paleosuchus palpebrosus moved into flooded forests, as do their principle prey species. Conversely, larger P. trigonatus individuals usually remained near the main stream, and were relatively sedentary. Intraspecific home-range overlap was higher than interspecific overlap in both species. Thus, habitat occupancy patterns as a function of water-level variation might facilitate coexistence of the two species of dwarf caimans in the same location. This study shows that when living in sympatry under a seasonal flooding regime, Paleosuchus species show a degree of habitat partitioning evidenced by different daily movement rates, home-range sizes and home-range locations.
The amerophidian snake radiation is a Late Cretaceous superfamily that encompasses two families: Aniliidae, pipe snakes, and Tropidophiidae, dwarf boas. We describe a new dwarf boa snake species, from the Tropidophiidae family, from the cloud forest in northeastern Ecuador. Tropidophis cacuangoae sp. nov. can be diagnosed from its congeners based on external and osteological morphology. The new species inhabits eastern tropical piedmont and lower evergreen montane forests, in the Amazon Tropical Rainforest biome, and is likely to be an Ecuadorian endemic. We also discuss the relationships of the new species with South American tropidophiids and provide a key to the identification of mainland South American dwarf boas.
Remaining immobile for an unpredictable time following contact with a predator (postcontact immobility) is a successful tactic to reduce predation. However, the mechanisms that may cause this variation are poorly known. We explored whether size, personality, substrate type and predation risk influence the duration of postcontact immobility in antlion larvae. Using field experiments on a large number of larvae, we detected a highly unpredictable postcontact immobility duration. This suggests that motor routines selected to improve the performance of this sit-and-wait predator larvae, such as staying immobile for an indefinite period, can also be adaptive to avoid predation. Postcontact immobility showed similar duration between low- and high-predation risk levels and was unrelated to larvae size. However, larvae showed longer postcontact immobility on compact soils than on loose soils. Antlions took longer to bury themselves in compact substrate, increasing the probability of being detected by a predator. Hence, it seems reasonable that, on compact soils, larvae showed longer postcontact immobility. On the other hand, larvae showed some degree of consistency in presenting short or long postcontact immobility independently of the nature of the treatments. Since repeated inductions of postcontact immobility in the same prey by a predator are rare, unpredictable variation at the population level may be an emergent property of consistency in postcontact immobility duration at the individual level. We conclude that factors generating unpredictable postcontact immobility duration may be intrinsic or extrinsic but are often associated with traits that predators cannot easily detect in advance, reinforcing the adaptive value of playing dead as an antipredator strategy.
Colour is an important component of many different defensive strategies, but signal efficacy and detectability will also depend on the size of the coloured structures, and how pattern size interacts with the background. Consequently, size-dependent changes in colouration are common among many different species as juveniles and adults frequently use colour for different purposes in different environmental contexts. A widespread strategy in many species is switching from crypsis to conspicuous aposematic signalling as increasing body size can reduce the efficacy of camouflage, while other antipredator defences may strengthen. Curiously, despite being chemically defended, the gold-striped frog (Lithodytes lineatus, Leptodactylidae) appears to do the opposite, with bright yellow stripes found in smaller individuals, whereas larger frogs exhibit dull brown stripes. Here, we investigated whether size-dependent differences in colour support distinct defensive strategies. We first used visual modelling of potential predators to assess how colour contrast varied among frogs of different sizes. We found that contrast peaked in mid-sized individuals while the largest individuals had the least contrasting patterns. We then used two detection experiments with human participants to evaluate how colour and body size affected overall detectability. These experiments revealed that larger body sizes were easier to detect, but that the colours of smaller frogs were more detectable than those of larger frogs. Taken together our data support the hypothesis that the primary defensive strategy changes from conspicuous aposematism to camouflage with increasing size, implying size-dependent differences in the efficacy of defensive colouration. We discuss our data in relation to theories of size-dependent aposematism and evaluate the evidence for and against a possible size-dependent mimicry complex with sympatric poison frogs (Dendrobatidae).
Micrurus is a medically relevant genus of venomous snakes composed of 85 species. Bites caused by coral snakes are rare, but they are usually associated with very severe and life-threatening clinical manifestations. Ecuador is a highly biodiverse country with a complex natural environment, which is home to approximately 20% of identified Micrurus species. Additionally, it is on the list of Latin American countries with the highest number of snakebites. However, there is no local anti-venom available against the Ecuadorian snake venoms, and the biochemistry of these venoms has been poorly explored. Only a limited number of samples collected in the country from the Viperidae family were recently characterised. Therefore, this study addressed the compositional patterns of two coral snake venoms from Ecuador, M. helleri and M. mipartitus, using venomics strategies, integrating sample fractionation, gel electrophoresis, and mass spectrometry. Chromatographic and electrophoretic profiles of these snake venoms revealed interspecific variability, which was ascertained by mass spectrometry. The two venoms followed the recently recognised dichotomic toxin expression trends displayed by Micrurus species: M. helleri venom contains a high proportion (72%) of phospholipase A2, whereas M. mipartitus venom is dominated by three-finger toxins (63%). A few additional protein families were also detected in these venoms. Overall, these results provide the first comprehensive views on the composition of two Ecuadorian coral snake venoms and expand the knowledge of Micrurus venom phenotypes. These findings open novel perspectives to further research the functional aspects of these biological cocktails of PLA2s and 3FTxs and stress the need for the preclinical evaluation of the currently used antivenoms for therapeutic purposes in Ecuador.
This study aimed to give lights for establishing a psychrophilic BMP test by three approaches for inoculum acclimation under 25 °C. The first test was run using stabilized mesophilic (25 °C) and psychrophilic (15 °C) inoculums to digest cellulose. Second was based on temperature acclimatization of inoculum just by time, from 30 to 10 and 20 °C. The third was running a consecutive BMP under psychrophilic temperatures (23 °C). Cellulose psychrophilic BMP using stabilized psychrophilic inoculum achieve similar results to those obtained at mesophilic conditions with stabilized mesophilic inoculum. Time acclimatization of inoculum improve BMP results respect non-adapted (from 0.47 to 055 Nm³ CH4 kg⁻¹ SV at 20 °C, from 0.31 to 0.44 Nm³ CH4 kg⁻¹ SV at 10 °C). Consecutive BMP under psychrophilic conditions shows better results for inoculum acclimatization to run assays at low temperatures. There is a need to develop and standardize a procedure to run psychrophilic BMP.
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Vía Tena - Muyuna Kilómetro 7, Tena, Napo, Ecuador
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