Oleas Gallo, Nora Helena
Thumbnail Image
Preferred name
Oleas Gallo, Nora Helena
Main Affiliation
Quito
Email
noraoleas@uti.edu.ec
ORCID
Scopus Author ID
12645534600

Research Output

Filters

19
Reset filters

Settings
Now showing 1 - 10 of 19
No Thumbnail Available
Publication

Evolutionary history of CAM photosynthesis in Neotropical Clusia: Insights from genomics, anatomy, physiology and climate

2022 , Luján, M. , Oleas Gallo, Nora Helena , Winter, K.

Clusia is a remarkable genus of Neotropical woody plants as its members engage in either C3 photosynthesis or employ, to varying degrees, crassulacean acid metabolism (CAM) photosynthesis. Information about the evolutionary history of CAM in Clusia is scarce. Restriction site-associated sequencing of 64 species (20% of the genus) provided strong support for most of the previously recognized nine lineages. Ancestral reconstruction using maximum parsimony or maximum likelihood under a one-rate model suggested that CAM evolved at least four times independently from a most recent common ancestor (MRCA) with C3, whereas a maximum likelihood two-rate model suggested that CAM was already present in the MRCA followed by reversions to C3 in several lineages. Phylogenetic generalized least square analysis assessed variation in seven leaf anatomical traits and CAM activity measured as δ13C. Results indicate that CAM is highly correlated with palisade mesophyll layer thickness and cell size. In addition, correlation between 19 bioclimatic variables and δ13C was evaluated. It was found that CAM is positively correlated with habitats with a more severe dry season and greater precipitation seasonality. Since CAM is weakly and/or only periodically expressed in many Clusia spp., and thus not readily reflected in δ13C, future analysis of phylogenetically-informed CAM expression in Clusia must include physiological measurements such as CO2 exchange and/or diel changes in leaf acidity for each species under investigation. © 2021 The Linnean Society of London,.

View
No Thumbnail Available
Publication

Community voices: the importance of diverse networks in academic mentoring

2022 , Deanna, R. , Merkle, B.G. , Chun, K.P. , Navarro-Rosenblatt, D. , Baxter, I. , Oleas Gallo, Nora Helena , Bortolus, A. , Geesink, P. , Diele-Viegas, L. , Aschero, V. , de Leone, M.J. , Oliferuk, S. , Zuo, R. , Cosacov, A. , Grossi, M. , Knapp, S. , Lopez-Mendez, A. , Welchen, E. , Ribone, P. , Auge, G.

[No abstract available]

View
No Thumbnail Available
Publication

In vitro and in silico analysis of galanthine from Zephyranthes carinata as an inhibitor of acetylcholinesterase

2022 , Sierra, K. , de Andrade, J.P. , R. Tallini, L. , Osorio, E.H. , Yañéz, O. , Osorio, M.I. , Oleas Gallo, Nora Helena , García-Beltrán, O. , de S. Borges, W. , Bastida, J. , Osorio, E. , Cortes, N.

Zephyranthes carinata Herb., a specie of the Amaryllidoideae subfamily, has been reported to have inhibitory activity against acetylcholinesterase. However, scientific evidence related to their bioactive alkaloids has been lacking. Thus, this study describes the isolation of the alkaloids of this plant, and their inhibition of the enzymes acetylcholinesterase (eeAChE) and butyrylcholinesterase (eqBuChE), being galanthine the main component. Additionally, haemanthamine, hamayne, lycoramine, lycorine, tazettine, trisphaeridine and vittatine/crinine were also isolated. The results showed that galanthine has significant activity at low micromolar concentrations for eeAChE (IC50 = 1.96 μg/mL). The in-silico study allowed to establish at a molecular level the high affinity and the way galanthine interacts with the active site of the TcAChE enzyme, information that corroborates the result of the experimental IC50. However, according to molecular dynamics (MD) analysis, it is also suggested that galanthine presents a different inhibition mode that the one observed for galanthamine, by presenting interaction with peripheral anionic binding site of the enzyme, which prevents the entrance and exit of molecules from the active site. Thus, in vitro screening assays plus rapid computer development play an essential role in the search for new cholinesterase inhibitors by identifying unknown bio-interactions between bioactive compounds and biological targets. © 2022 The Authors

View
No Thumbnail Available
Publication

Molecular Systematics of Threatened Seed Plant Species Endemic in the Caribbean Islands

2013 , Oleas Gallo, Nora Helena , Jestrow B. , Calonje M. , Peguero B. , Jiménez F. , Rodríguez-Peña R. , Oviedo R. , Santiago-Valentín E. , Meerow A.W. , Abdo M. , Maunder M. , Griffith M.P. , Francisco-Ortega J.

A review of available Caribbean Island red-lists species (CR and EN categories based on the IUCN guidelines from 2001, and E category established according to the IUCN guidelines from 1980) is presented. A database of over 1,300 endemic species that are either Critically Endangered or Endangered sensu IUCN was created. There are molecular systematic studies available for 112 of them. Six of these species (in six genera) are the only members of early divergent lineages that are sister to groups composed of a large number of clades. Seven of the species (in seven genera) belong to clades that have a small number of taxa but are sister to species/genus-rich clades. Ten of the species (in six genera) are sister to taxa restricted to South America or nested in clades endemic to this region. Fifty-seven of the species (in 35 genera) are sister to Caribbean Island endemic species. Erigeron belliastroides, an Endangered (EN) Cuban endemic, is sister to the Galapagos genus Darwiniothamnus. The phylogenetic placement of four of the threatened species resulted in changes in their taxonomic placement; they belong to polyphyletic or paraphyletic genera. © 2013 The New York Botanical Garden.

View
No Thumbnail Available
Publication

Taxonomy based on science is necessary for global conservation

2018 , Thomson S.A. , Pyle R.L. , Ahyong S.T. , Alonso-Zarazaga M. , Ammirati J. , Araya J.F. , Ascher J.S. , Audisio T.L. , Oleas Gallo, Nora Helena

[No abstract available]

View
No Thumbnail Available
Publication

Muddy boots beget wisdom: Implications for rare or endangered plant species distribution models

2019 , Oleas Gallo, Nora Helena , Feeley K.J. , Fajardo J. , Meerow A.W. , Gebelein J. , Francisco-Ortega J.

Species distribution models (SDMs) are popular tools for predicting the geographic ranges of species. It is common practice to use georeferenced records obtained from online databases to generate these models. Using three species of Phaedranassa (Amaryllidaceae) from the Northern Andes, we compare the geographic ranges as predicted by SDMs based on online records (after standard data cleaning) with SDMs of these records confirmed through extensive field searches. We also review the identification of herbarium collections. The species' ranges generated with corroborated field records did not agree with the species' ranges based on the online data. Specifically, geographic ranges based on online data were significantly inflated and had significantly different and wider elevational extents compared to the ranges based on verified field records. Our results suggest that to generate accurate predictions of species' ranges, occurrence records need to be carefully evaluated with (1) appropriate filters (e.g., altitude range, ecosystem); (2) taxonomic monographs and/or specialist corroboration; and (3) validation through field searches. This study points out the implications of generating SDMs produced with unverified online records to guide species-specific conservation strategies since inaccurate range predictions can have important consequences when estimating species' extinction risks. © 2019 by the authors.

View
No Thumbnail Available
Publication

Private Urban Garden Satisfaction and Its Determinants in Quito, Ecuador

2018 , Cruz Cárdenas, Jorge , Oleas Gallo, Nora Helena

Because of their importance to people, nature, and societies, domestic gardens have attracted increasing research interest. However, significant areas of interest remain unexplored, such as the variables that determine individuals’ satisfaction with their gardens. Our main goal was to address this gap. We surveyed 1,005 individuals with home gardens in Quito, Ecuador, to collect information on three groups of variables: (a) psychological and individual factors, (b) social and family aspects, and (c) garden characteristics. We used these groups of variables as predictors of satisfaction in a regression model (R2 = 0.242), with the first and third contributing the most to our understanding of satisfaction. In particular, people tended to be more satisfied with gardens composed of mostly native plants. In addition, individuals tended to be more satisfied if their motives for garden use were related to nature. In contrast, a high level of consumed resources negatively affected satisfaction. © 2018, © The Author(s) 2018.

View
No Thumbnail Available
Publication

Water quality assessment of the cutuchi river basin (Ecuador): A review of technical documents

2021 , Zapata D. , Oleas Gallo, Nora Helena , Páez-Vacas, Mónica , Tobes, Ibon

The Cutuchi River Basin extends over the inter-Andean valley south of the Cotopaxi Volcano, in Ecuador. It flows through two provinces, Cotopaxi and Tungurahua, and its waters are extensively used to irrigate crops that provide food to the main cities in the country. Unfortunately, the basin receives untreated domestic and industrial discharges. The need for an environmental quality assessment of the river has been acknowledged over the years. The aim of this study is to gather information about water quality of the Cutuchi River through a historical bibliographic review. A total of 57 works published between 2007 and 2018 were found, including books, articles, thesis and project reports. Only 18 documents provided biological, physical, or chemical data linked to water quality. The data obtained through the literature review were compared with maximum thresholds from national and international regulations. Unfortunately, revised studies were scattered on time and randomly along the basin and did not provide robust information to evaluate the state of the water-system. Some contamination was detected significantly exceeding safety thresholds. More exhaustive studies along the basin are needed as a baseline to help the decision makers to design management plans and mitigate human impacts. © 2020 Institute of Physics Publishing. All rights reserved.

View
No Thumbnail Available
Publication

Population Dynamics of the Endangered Plant, Phaedranassa tunguraguae, from the Tropical Andean Hotspot

2012 , Oleas Gallo, Nora Helena , Meerow A.W. , Francisco-Ortega J.

The Tropical Andes is a diversity hotspot for plants, but there is a scant knowledge about patterns of genetic variation within its constituent species. Phaedranassa tunguraguae is an IUCN endangered plant species endemic to a single valley in the Ecuadorian Andes. We estimate the levels of genetic differentiation across the geographic distribution of P. tunguraguae using 12 microsatellite loci. We discuss factors that might influence the genetic structure of this species. Genetic distance was used to evaluate relationship among populations and geographic patterns. Bayesian methods were used to investigate population structure, migration, evidence of recent bottlenecks, and time of divergence. The 7 populations form 2 genetic clusters. These clusters show highly significant differentiation between them, along with isolation by distance. Allele richness decreases from the most diverse westernmost population to the least diverse easternmost population. The species overall shows an excess of homozygotes, with highest levels of inbreeding in the easternmost population. We found evidence of recent bottleneck events. Migration rates were in general low but were higher between populations within each of the clusters. Time of divergence between populations was related to historical volcanic activity in the area. Based on our results, we propose 2 management units for P. tunguraguae. © The American Genetic Association. 2012. All rights reserved.

View
No Thumbnail Available
Publication

Isolation and Characterisation of 11 Microsatellite Loci in the Ecuadorian Hillstar Oreotrochilus chimborazo

2017 , Oleas Gallo, Nora Helena , Harvey N. , Rodríguez-Saltos C.A. , Bonaccorso E.

The Ecuadorian Hillstar Oreotrochilus chimborazo is a high Andean hummingbird that inhabits paramo ecosystems from extreme southern Colombia to southern Ecuador. The species is currently divided into three subspecies that differ in morphology and geographic distribution but no molecular differences have been found between them using mitochondrial markers. The aim of this study was to isolate and test microsatellite loci to further explore possible genetic variability between and within these subspecies. Screening an enriched genomic library of O. chimborazo we obtained eleven polymorphic microsatellite loci. These markers will be used to further elucidate evolutionary patterns in the species.

View