Publications by authors named "Encalada A"

Mercury is a highly toxic element present in water, soil, air, and biota. Anthropogenic activities, such as burning fossil fuels, mining, and deforestation, contribute to the presence and mobilization of mercury between environmental compartments. Although current research on mercury pathways has advanced our understanding of the risks associated with human exposure, limited information exists for remote areas with high diversity of fauna, flora, and indigenous communities.

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DNA barcoding, based on mitochondrial markers, is widely applied in species identification and biodiversity studies. The aim of this study was to establish a barcoding reference database of fishes inhabiting the Cube River from Western Ecuador in the Chocó-Darien Global Ecoregion (CGE), a threatened ecoregion with high diversity and endemism, and evaluate the applicability of using barcoding for the identification of fish species. Barcode sequences were obtained from seven orders, 17 families, 23 genera and 26 species, which were validated through phylogenetic analysis, morphological measurements, and literature review.

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Rhyacoglanis pulcher is a rare Neotropical rheophilic bumblebee catfish known only from the type locality in the Cis-Andean Amazon region, Ecuador, and the type-species of the genus. So far, the three syntypes collected in 1880 were the only specimens unambiguously associated to the name R. pulcher available in scientific collections.

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The giant mottled eel (Anguilla marmorata) is distributed mostly in the Indo-West Pacific. However, a few records indicate the presence of this eel in the Tropical Central and East Pacific. In April 2019, an eel specimen was caught in a small stream in San Cristobal Island, Galápagos.

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Life history of benthic faunas of tropical high-altitude cold environments are poorly studied. Here, monthly larval and adult data are presented for at Saltana Stream in Ecuador. In cold conditions throughout the year (6 °C), this species showed an asynchronous and continuous production.

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Article Synopsis
  • Amazonian environments are facing severe degradation due to industrial and agricultural activities, threatening its biodiversity and ecosystem services.
  • The primary threats include regional deforestation driven by export demands and the impacts of global climate change.
  • Urgent political action is needed to implement known policies to protect the Amazon, as failure to do so will have dire consequences for both the region and the global environment.
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Temperatures have increased around the globe, affecting many ecosystems, including high-elevation Andean streams where important aquatic insect species coexist. Depending on the magnitude of change, warming could lead to the mortality of sensitive species, and those tolerant to rising water temperatures may exhibit differences in growth rates and development. Taxon-specific optimal temperature ranges for growth determine how high or low temperatures alter an organism's body size.

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Over the life course, persons with disabilities require a range of supports to be integrated into their communities, to participate in activities that are meaningful and necessary, and to have access, on an equal basis to persons without disabilities, to community living. We conducted a scoping review of the peer-reviewed and grey literature on community support for persons with disabilities in low- and middle-income countries (LMICs). The main findings of this review concern the following: there are gaps in access to community support for persons with disabilities in LMICs; there are barriers to the provision of such support; formal and informal strategies and interventions for the provision of community support exist across the life cycle and different life domains, but evidence concerning their effectiveness and coverage is limited; and the role of community-based rehabilitation and Organisations of Persons with Disabilities in the assessment of needs for, and the development and provision of, community support, needs to be more clearly articulated.

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Article Synopsis
  • - Proposed hydropower dams in the Amazon Basin need careful consideration of environmental trade-offs, as the ecosystem services provided by this diverse area can be affected differently depending on dam placements.
  • - Multiobjective optimization is utilized to find a balance that minimizes negative impacts on essential aspects like river flow, fish diversity, and greenhouse gas emissions while still achieving energy production targets.
  • - Uncoordinated dam construction has led to lost ecosystem benefits, highlighting the need for collaborative approaches among Amazonian countries to better manage hydropower development across the entire region.
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  • The study investigates how the diversity of detritivores (organisms that break down dead organic material) affects the decomposition of litter in streams across a global scale, involving 38 streams in 23 countries.
  • Results show a positive correlation between detritivore diversity and litter decomposition, with this effect being particularly strong in tropical regions.
  • The findings highlight the potential impact of detritivore extinctions on decomposition processes, especially in tropical areas where diversity is already low and environmental stressors are common.
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Running waters contribute substantially to global carbon fluxes through decomposition of terrestrial plant litter by aquatic microorganisms and detritivores. Diversity of this litter may influence instream decomposition globally in ways that are not yet understood. We investigated latitudinal differences in decomposition of litter mixtures of low and high functional diversity in 40 streams on 6 continents and spanning 113° of latitude.

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The status of the species present in the Galapagos Islands (Odonata, Libellulidae) has been the subject of a long-standing debate among odonatologists. Here, we use molecular and morphological data to analyze a series of specimens from this genus collected in 2018 from the Islands of San Cristobal, Isabela, and Santa Cruz, with the aim of determining their relationship with Muttkowski and with their currently considered senior synonym Hagen. We combined sequencing of mitochondrial and nuclear DNA with morphological examination of several specimens of , including representatives of continental and .

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Two specimens of Micromyzon akamai, an eyeless and miniaturized species previously known only from the deep channels of the eastern Amazon basin in Brazil, are reported from the Curaray River, a tributary of the Napo River in Ecuador. The new specimens are the first records of Micromyzon in the headwaters of the Amazon River and the first records of M. akamai outside Brazil.

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A fundamental gap in climate change vulnerability research is an understanding of the relative thermal sensitivity of ectotherms. Aquatic insects are vital to stream ecosystem function and biodiversity but insufficiently studied with respect to their thermal physiology. With global temperatures rising at an unprecedented rate, it is imperative that we know how aquatic insects respond to increasing temperature and whether these responses vary among taxa, latitudes, and elevations.

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Anthropogenic threat maps are commonly used as a surrogate for the ecological integrity of rivers in freshwater conservation, but a clearer understanding of their relationships is required to develop proper management plans at large scales. Here, we developed and validated empirical models that link the ecological integrity of rivers to threat maps in a large, heterogeneous and biodiverse Andean-Amazon watershed. Through fieldwork, we recorded data on aquatic invertebrate community composition, habitat quality, and physical-chemical parameters to calculate the ecological integrity of 140 streams/rivers across the basin.

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Tropical montane rivers (TMR) are born in tropical mountains, descend through montane forests, and feed major rivers, floodplains, and oceans. They are characterized by rapid temperature clines and varied flow disturbance regimes, both of which promote habitat heterogeneity, high biological diversity and endemism, and distinct organisms' life-history adaptations. Production, transport, and processing of sediments, nutrients, and carbon are key ecosystem processes connecting high-elevation streams with lowland floodplains, in turn influencing soil fertility and biotic productivity downstream.

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Carrot residues were upgraded as pectin-enriched fractions (PEFs) useful for functional food formulation due to co-extracted antioxidants (α- and β-carotenes, lutein, α-tocopherol), and gelling effect. High power ultrasound (US)-enzyme assisted extraction was applied for efficiency and sustainability. Carrot powder (CP) in citrate-buffer (pH 5.

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Global patterns of biodiversity have emerged for soil microorganisms, plants and animals, and the extraordinary significance of microbial functions in ecosystems is also well established. Virtually unknown, however, are large-scale patterns of microbial diversity in freshwaters, although these aquatic ecosystems are hotspots of biodiversity and biogeochemical processes. Here we report on the first large-scale study of biodiversity of leaf-litter fungi in streams along a latitudinal gradient unravelled by Illumina sequencing.

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Article Synopsis
  • River ecosystems play a crucial role in processing terrestrial organic carbon, and this process is heavily influenced by microbial activity.
  • A global study involving over 1000 river and riparian sites revealed distinct carbon processing patterns across different biomes, showing slower processing at higher latitudes and faster rates near the equator.
  • The findings suggest temperature and environmental factors affect carbon processing rates, providing a foundation for future biomonitoring efforts to assess environmental impacts on ecosystems worldwide.
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Species richness is greatest in the tropics, and much of this diversity is concentrated in mountains. Janzen proposed that reduced seasonal temperature variation selects for narrower thermal tolerances and limited dispersal along tropical elevation gradients [Janzen DH (1967) 101:233-249]. These locally adapted traits should, in turn, promote reproductive isolation and higher speciation rates in tropical mountains compared with temperate ones.

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Food resource availability varies along gradients of elevation where riparian vegetative cover exerts control on the relative availability of allochthonous and autochthonous resources in streams. Still, little is known about how elevation gradients can alter the availability and quality of resources and how stream food webs respond. We sampled habitat characteristics, stable isotope signatures (δC, δN, δΗ) and the carbon, nitrogen and phosphorus composition of basal food resources and insects in 11 streams of similar size along an elevation gradient from 1260 to 4045 m on the northeastern slope of the Ecuadorian Andean-Amazon region.

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Andes-to-Amazon river connectivity controls numerous natural and human systems in the greater Amazon. However, it is being rapidly altered by a wave of new hydropower development, the impacts of which have been previously underestimated. We document 142 dams existing or under construction and 160 proposed dams for rivers draining the Andean headwaters of the Amazon.

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Article Synopsis
  • Plant litter plays a crucial role in stream ecosystems, with its decomposition influenced by various litter traits that may vary with latitude.
  • A global study assessed litter quality in 151 species across 24 regions, revealing that litter quality tends to be higher at higher latitudes, while tropical regions exhibit lower quality and different nutrient ratios.
  • Findings indicate that environmental factors primarily drive litter trait variation rather than phylogeny, which suggests that the lower quality litter in the tropics contributes to a greater reliance on microbial decomposition over detritivore-mediated processes.
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