Sharpe D.M.T.,Smithsonian Tropical Research Institute |
Sharpe D.M.T.,McGill University |
De Leon L.F.,University of Massachusetts Boston |
De Leon L.F.,Institute Investigaciones Cientificas Y Servicios Of Alta Tecnologia Indicasat Aip |
And 2 more authors.
Ecology | Year: 2017
Predation is considered to be an important factor structuring natural communities. However, it is often difficult to determine how it may influence long-term, broad-scale, diversity patterns, particularly in diverse tropical systems. Biological introductions can provide powerful insight to test the sustained consequences of predation in natural communities, if pre-introduction data are available. Half a century ago, Zaret and Paine demonstrated strong and immediate community-level effects following the introduction of a novel apex predator (peacock bass, Cichla monoculus) into Lake Gatun, Panama. To test for long-term changes associated with this predator introduction, we followed up on their classic study by replicating historical sampling methods and examining changes in the littoral fish community at two sites in Lake Gatun 45 years post-introduction. To broaden our inference, we complemented this temporal comparison with a spatial analysis, wherein we compared the fish communities from two lakes with and one lake without peacock bass. Comparisons with historical data revealed that the peacock bass remains the most abundant predator in Lake Gatun. Furthermore, the collapse of the littoral prey community observed immediately following the invasion has been sustained over the past 45 years. The mean abundance of native littoral fish is now 96% lower than it was prior to the introduction. Diversity (rarefied species richness) declined by 64% post-introduction, and some native species appear to have been locally extirpated. We observed a similar pattern across invaded and uninvaded lakes: the mean abundance of native fishes was 5-40 times lower in lakes with (Gatun, Alajuela) relative to the lake without peacock bass (Bayano). In particular, small-bodied native fishes (Characidae, Peociliidae), which are common prey of the peacock bass, were more than two orders of magnitude (307 times) less abundant in Gatun and one order of magnitude (28 times) less abundant in Alajuela than in Bayano. However, total native fish diversity did not differ significantly across lakes, suggesting that while many native species have declined in abundance, few have been completely extirpated. Introduced predators can have strong effects on community structure and functional diversity, even in highly diverse tropical communities, and these effects can persist over multiple decades. © 2016 by the Ecological Society of America.
PubMed | University of California at San Diego, Institute Investigaciones Cientificas Y Servicios Of Alta Tecnologia Indicasat Aip and University of Connecticut
Type: Journal Article | Journal: Organic letters | Year: 2016
From a collection of marine cyanobacteria made in the Coiba National Park along the Pacific coast of the Republic of Panama a novel cyclic depsipeptide, given the trivial name medusamide A, has been isolated and fully characterized. Medusamide A contains four contiguous -amino acid (2R,3R)-3-amino-2-methylhexanoic acid (Amha) residues. This is the first report of multiple Amha residues and contiguous -amino acid residues within a single cyclic peptide-type natural product. Stereochemical assignment of the Amha residues was completed following the synthesis of reference standards for this -amino acid and the subsequent derivatization with Marfeys reagent and LC-MS analysis.
Gonzalez-Wanguemert M.,University of Algarve |
Vergara-Chen C.,University of Murcia |
Vergara-Chen C.,Institute Investigaciones Cientificas Y Servicios Of Alta Tecnologia Indicasat Aip
Helgoland Marine Research | Year: 2014
Coastal lagoons are semi-isolated ecosystems exposed to wide fluctuations of environmental conditions and showing habitat fragmentation. These features may play an important role in separating species into different populations, even at small spatial scales. In this study, we evaluate the concordance between mitochondrial (previous published data) and nuclear data analyzing the genetic variability of Pomatoschistus marmoratus in five localities, inside and outside the Mar Menor coastal lagoon (SE Spain) using eight microsatellites. High genetic diversity and similar levels of allele richness were observed across all loci and localities, although significant genic and genotypic differentiation was found between populations inside and outside the lagoon. In contrast to the F ST values obtained from previous mitochondrial DNA analyses (control region), the microsatellite data exhibited significant differentiation among samples inside the Mar Menor and between lagoonal and marine samples. This pattern was corroborated using Cavalli-Sforza genetic distances. The habitat fragmentation inside the coastal lagoon and among lagoon and marine localities could be acting as a barrier to gene flow and contributing to the observed genetic structure. Our results from generalized additive models point a significant link between extreme lagoonal environmental conditions (mainly maximum salinity) and P. marmoratus genetic composition. Thereby, these environmental features could be also acting on genetic structure of coastal lagoon populations of P. marmoratus favoring their genetic divergence. The mating strategy of P. marmoratus could be also influencing our results obtained from mitochondrial and nuclear DNA. Therefore, a special consideration must be done in the selection of the DNA markers depending on the reproductive strategy of the species. © 2014 Springer-Verlag Berlin Heidelberg and AWI.
Mejia A.,Institute Investigaciones Cientificas Y Servicios Of Alta Tecnologia Indicasat Aip |
Ulph F.,University of Manchester |
Calam R.,University of Manchester
International Journal of Public Health | Year: 2016
Objectives: To explore cultural appropriateness of a transported parenting intervention in Panama. Methods: Panamanian parents (n = 25) were interviewed after participation in an Australian parenting intervention. A thematic analysis was conducted to interpret qualitative data. Results: Three themes emerged; cultural context, appropriateness of the intervention, and development of support networks. In terms of cultural context, parents described economic difficulties, living in a dangerous world, struggling to balance parenting and work, and using aggressive communication patterns. In terms of appropriateness of the intervention, they rated materials as appropriate, although suggested modifications to its delivery by including children and teachers in the training. Finally, parents commented that the intervention prompted the development of social networks within their communities. Conclusions: Overall, parents considered a transported parenting intervention as appropriate to their local needs. This study might be useful to local governments and international funders in charge of deciding whether transporting parenting interventions North to South as a strategy for violence prevention would be respectful of local needs. Our findings cannot be generalized beyond Panama, but the methodology can be replicated to answer this question in other settings. © 2016 The Author(s)
De Leon L.F.,Institute Investigaciones Cientificas Y Servicios Of Alta Tecnologia Indicasat Aip |
De Leon L.F.,McGill University |
Podos J.,University of Massachusetts Amherst |
Gardezi T.,McGill University |
And 2 more authors.
Journal of Evolutionary Biology | Year: 2014
Adaptive radiation can be strongly influenced by interspecific competition for resources, which can lead to diverse outcomes ranging from competitive exclusion to character displacement. In each case, sympatric species are expected to evolve into distinct ecological niches, such as different food types, yet this expectation is not always met when such species are examined in nature. The most common hypotheses to account for the coexistence of species with substantial diet overlap rest on temporal variation in niches (often diets). Yet spatial variation in niche overlap might also be important, pointing to the need for spatiotemporal analyses of diet and diet overlap between closely related species persisting in sympatry. We here perform such an analysis by characterizing the diets of, and diet overlap among, four sympatric Darwin's ground finch species at three sites and over 5 years on a single Galápagos island (Santa Cruz). We find that the different species have broadly similar and overlapping diets - they are to some extent generalists and opportunists - yet we also find that each species retains some 'private' resources for which their morphologies are best suited. Importantly, use of these private resources increased considerably, and diet overlap decreased accordingly, when the availability of preferred shared foods, such as arthropods, was reduced during drought conditions. Spatial variation in food resources was also important. These results together suggest that the ground finches are 'imperfect generalists' that use overlapping resources under benign conditions (in space or time), but then retreat to resources for which they are best adapted during periods of food limitation. These conditions likely promote local and regional coexistence. © 2014 European Society For Evolutionary Biology.
de Leon L.F.,Institute Investigaciones Cientificas Y Servicios Of Alta Tecnologia Indicasat Aip |
de Leon L.F.,University of Massachusetts Boston |
Lopez O.R.,Institute Investigaciones Cientificas Y Servicios Of Alta Tecnologia Indicasat Aip |
Lopez O.R.,Smithsonian Tropical Research Institute
Biodiversity and Conservation | Year: 2016
Megaprojects pose a major global environmental challenge. For instance, the forthcoming construction of the Nicaraguan Canal has generated controversy regarding its social and environmental consequences. To some, it will represent an unparalleled environmental catastrophe; to others, it will lead to net environmental and social benefits. In both cases, the Panama Canal emerges as an analogy to inform the environmental and social fate of Nicaragua. In our view, this comparison is incomplete and does not accurately represent the social and environmental realities of the two countries, and therefore, it might be of limited use for predicting the future of Nicaragua. Our analysis—based on evidence from the literature—revealed three emerging themes. First, our current understanding of the long-term environmental consequences of the two Canals in Central America is rather limited, even after 100 years of experience in Panama. Second, the historical, environmental and political differences between the two countries make the Panama Canal a poor predictor for the environmental and social fate of Nicaragua. Finally, previous assessments of the consequences of both megaprojects might be biased by a focus on forest conservation alone. This suggests that the apparent environmental and social benefits provided by such megaprojects might be more marginal than expected. This calls for a deeper analysis of costs and benefits of the construction and management of the two Canals in the Central American region, and their impacts on the natural world. These uncertainties might be a common consequence of many large-scale megaprojects around the world. © 2016 Springer Science+Business Media Dordrecht
Lopez O.R.,Smithsonian Tropical Research Institute |
Lopez O.R.,Institute Investigaciones Cientificas Y Servicios Of Alta Tecnologia Indicasat Aip
Open Ecology Journal | Year: 2012
Non-insular tropical biomes appear relatively resistant to invasive alien species (IAS). While some argue fewer IAS in continental tropical communities is the result of the complexity of species-rich communities (e.g., Elton's biological resistance hypothesis), others suggest lack of IAS might reflect fewer invasion opportunities, which could change with time. In effect, deforestation may lead to the simplification of tropical habitats, thus reducing biological resistance. Little is known about the current status of alien plants species, factors contributing to their spread and IAS in non-insular tropical systems. Here I report on the status of alien plant species in relation to area, number of native and endemics species, population, forest cover and cultivated area across provinces of Panama. Alien plant species comprise nearly 4 percent of the flora and was positively correlated with the number of native plant species (r = 0.84, P < 0.001) and while this pattern runs counter to Elton's premise, it is consistent with other landscape-scale studies. In Panama, the number of alien plant species is explained by population density (r= 0.91, P < 0.01) and potentially linked to disturbance, albeit coarsely, as the proportion of aliens negatively correlates with forest cover (r = 0.69, P < 0.05). Thus, despite high diversity, these results portray disturbed tropical forests becoming dotted with introduced alien species. While few species seem to become invasive in the continental tropics, rapid land use change could promote the success of IAS representing serious consequences for tropical countries' economies and biodiversity. © Omar R. Lopez; Licensee Bentham Open.
Martinez C.,Institute Investigaciones Cientificas Y Servicios Of Alta Tecnologia Indicasat Aip |
Chavarria C.,Institute Investigaciones Cientificas Y Servicios Of Alta Tecnologia Indicasat Aip |
Sharpe D.M.T.,McGill University |
De Leon L.F.,Institute Investigaciones Cientificas Y Servicios Of Alta Tecnologia Indicasat Aip
PLoS ONE | Year: 2016
Colour polymorphism is a recurrent feature of natural populations, and its maintenance has been studied in a range of taxa in their native ranges. However, less is known about whether (and how) colour polymorphism is maintained when populations are removed from their native environments, as in the case of introduced species. We here address this issue by analyzing variation in colour patterns in recently-discovered introduced populations of the guppy (Poecilia reticulata) in Panama. Specifically, we use classic colour analysis to estimate variation in the number and the relative area of different colour spots across low predation sites in the introduced Panamanian range of the species. We then compare this variation to that found in the native range of the species under low- and high predation regimes. We found aspects of the colour pattern that were both consistent and inconsistent with the classical paradigm of colour evolution in guppies. On one hand, the same colours that dominated in native populations (orange, iridescent and black) were also the most dominant in the introduced populations in Panama. On the other, there were no clear differences between either introduced-low and native low- and high predation populations. Our results are therefore only partially consistent with the traditional role of female preference in the absence of predators, and suggest that additional factors could influence colour patterns when populations are removed from their native environments. Future research on the interaction between female preference and environmental variability (e.g. multifarious selection), could help understand adaptive variation in this widely-introduced species, and the contexts under which variation in adaptive traits parallels (or not) variation in the native range. © 2016 Martínez et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Fernandez P.L.,Institute Investigaciones Cientificas Y Servicios Of Alta Tecnologia Indicasat Aip |
Britton G.B.,Institute Investigaciones Cientificas Y Servicios Of Alta Tecnologia Indicasat Aip |
Rao K.S.,Institute Investigaciones Cientificas Y Servicios Of Alta Tecnologia Indicasat Aip
Journal of Alzheimer's Disease | Year: 2013
Alzheimer's disease (AD) exerts a profound burden on public health worldwide. AD etiology is unknown, and research to understand its underlying pathology has produced agents for the management of symptoms, but not a cure for the disease. Most AD drugs were developed in response to research implicating fibrillar amyloid-β (Aβ) in AD neuropathology but result in only modest short-term improvements in cognitive function, so there is agreement that additional targets need to be investigated. Evidence has implicated the immune system in AD and immunotherapy as a potential approach to AD treatment. Accumulation of microglia and astrocytes has been observed around Aβ deposits and several reports implicate inflammatory mediators in AD pathology. Importantly, Aβ deposition has been found in the brains of AD patients and in aged people without dementia, but signs of neuroinflammation are found only in AD patients and not in normal aged individuals. Animal models suggest a complex role for immunomodulators in AD, namely, these mechanisms are likely to promote the same pathogenic processes that gave rise to them. To date, clinical trials with anti-inflammatories and other immunoregulators have not been successful, but available data strongly favor immunomodulation as a promising disease intervention strategy. This article reviews data that implicate various immunomodulators in AD and considers their potential application in the development of novel AD therapeutics. Currently, a deeper understanding of nervous-immune interactions during normal aging and at all stages of AD is needed. Continued research in AD inflammatory and immunoregulatory processes will increase both our understanding of disease mechanisms and the likelihood of discovering new therapeutic targets for AD. © 2013 - IOS Press and the authors. All rights reserved.
Coronado L.M.,Institute Investigaciones Cientificas Y Servicios Of Alta Tecnologia Indicasat Aip
Journal of visualized experiments : JoVE | Year: 2013
Unlike other Plasmodium species, P. falciparum can be cultured in the lab, which facilitates its study (1). While the parasitemia achieved can reach the ≈40% limit, the investigator usually keeps the percentage at around 10%. In many cases it is necessary to isolate the parasite-containing red blood cells (RBCs) from the uninfected ones, to enrich the culture and proceed with a given experiment. When P. falciparum infects the erythrocyte, the parasite degrades and feeds from haemoglobin (2, 3). However, the parasite must deal with a very toxic iron-containing haem moiety (4, 5). The parasite eludes its toxicity by transforming the haem into an inert crystal polymer called haemozoin (6, 7). This iron-containing molecule is stored in its food vacuole and the metal in it has an oxidative state which differs from the one in haem (8). The ferric state of iron in the haemozoin confers on it a paramagnetic property absent in uninfected erythrocytes. As the invading parasite reaches maturity, the content of haemozoin also increases (9), which bestows even more paramagnetism on the latest stages of P. falciparum inside the erythrocyte. Based on this paramagnetic property, the latest stages of P. falciparum infected-red blood cells can be separated by passing the culture through a column containing magnetic beads. These beads become magnetic when the columns containing them are placed on a magnet holder. Infected RBCs, due to their paramagnetism, will then be trapped inside the column, while the flow-through will contain, for the most part, uninfected erythrocytes and those containing early stages of the parasite. Here, we describe the methodology to enrich the population of late stage parasites with magnetic columns, which maintains good parasite viability (10). After performing this procedure, the unattached culture can be returned to an incubator to allow the remaining parasites to continue growing.