Time filter

Source Type

PubMed | University of Turku, Technical University of the North, Ibarra, James Cook University, University of Nottingham and 46 more.
Type: Journal Article | Journal: Proceedings. Biological sciences | Year: 2016

Lineages tend to retain ecological characteristics of their ancestors through time. However, for some traits, selection during evolutionary history may have also played a role in determining trait values. To address the relative importance of these processes requires large-scale quantification of traits and evolutionary relationships among species. The Amazonian tree flora comprises a high diversity of angiosperm lineages and species with widely differing life-history characteristics, providing an excellent system to investigate the combined influences of evolutionary heritage and selection in determining trait variation. We used trait data related to the major axes of life-history variation among tropical trees (e.g. growth and mortality rates) from 577 inventory plots in closed-canopy forest, mapped onto a phylogenetic hypothesis spanning more than 300 genera including all major angiosperm clades to test for evolutionary constraints on traits. We found significant phylogenetic signal (PS) for all traits, consistent with evolutionarily related genera having more similar characteristics than expected by chance. Although there is also evidence for repeated evolution of pioneer and shade tolerant life-history strategies within independent lineages, the existence of significant PS allows clearer predictions of the links between evolutionary diversity, ecosystem function and the response of tropical forests to global change.


PubMed | Anglia, National University of Colombia, Fundacion Puerto Rastrojo, New York Botanical Garden and 76 more.
Type: Journal Article | Journal: Science advances | Year: 2015

Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict that most of the worlds >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century.


PubMed | Federal University of Rondônia, CIBER ISCIII, University of KwaZulu - Natal, Federal University of Fluminense and 2 more.
Type: | Journal: Comparative biochemistry and physiology. Part A, Molecular & integrative physiology | Year: 2016

Snake venom toxins are related not only in detention, death and the promotion of initial digestion of prey but also due to their different biochemical, structural and pharmacological effects they can result in new drugs. Among these toxins snake venom serine proteases (SVSPs) should be highlighted because they are responsible for inducing changes in physiological functions such as blood coagulation, fibrinolysis, and platelet aggregation. This article presents the first serine protease (SP) isolated from Bothrops brazili: BbrzSP-32. The new SP showed 36 kDa of relative molecular mass and its absolute mass was confirmed by mass spectrometry as 32,520 Da. It presents 79.48% identity when compared to other SVSPs and was able to degrade the -chain of fibrinogen, in in vitro models, because of this it is considered a SVTLE-A. It showed dose-dependent activity in the process of degradation of fibrin networks demonstrating greater specificity for this activity when compared to its thrombolytic action. BbrzSP-32 demonstrated proteolytic activity on gelatin and chromogenic substrates for serine proteases and thrombin-like enzymes (S-2288 and S-2238 respectively), besides having coagulant activity on human plasma. After pre-incubation with PMSF and benzamidine the coagulant and proteolytic activities on the S-2288 and S-2238 substrates were reduced. BbrzSP-32 shows stability against pH and temperature variations, demonstrating optimum activity between 30 and 40 C and in the pH range 7.5 to 8.5. A new SP with potential biotechnological application was isolated.


Zurita-Benavides M.G.,CNRS Local Heritage and Governance | Zurita-Benavides M.G.,University Regional Amazonica | Jarrin-V P.,University Regional Amazonica | Rios M.,University of Florida
Economic Botany | Year: 2015

Oral History Reveals Landscape Ecology in Ecuadorian Amazonia: Time Categories and Ethnobotany among Waorani People. Waorani oral history in Ecuadorian Amazonia reveals that traditional ecological knowledge contributes to the understanding of the natural environment of this human group. When the Waorani interpret the landscape, they identify certain elements that stand out for their cultural and practical value, as these are products of past and present settlements. The oral history and management practices, by two family clusters settled at the riverbanks of the Nushiño River, contributed to assembling an analytical tool called “Waorani time categories.” These four time categories were analyzed with floristic composition based on a matrix formed by 522 plant species collected at 12 forest patches, which either had or lacked social history. The aim of this research was to examine how Waorani oral history records the ecological dynamics of some Amazonian forest patches. The use of multivariate statistical methods made establishing differences in plant diversity, evenness, and richness between managed and unmanaged forests plots possible, thus revealing human impact at specific places in Amazonia. This research confirms that it is important to intertwine social history and landscape ecology in ethnobotany with quantitative statistical interpretation, because it permits the association of a human group with a particular forest. © 2015 The New York Botanical Garden


Gallardo A.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables | Palme M.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables | Palme M.,Católica del Norte University | Lobato-Cordero A.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables | And 2 more authors.
Buildings | Year: 2016

This study aims to determine the optimal approach for evaluating thermal comfort in an office that uses natural ventilation as the main conditioning strategy; the office is located in Quito-Ecuador. The performance of the adaptive model included in CEN Standard EN15251 and the traditional PMV model are compared with reports of thermal environment satisfaction surveys presented simultaneously to all occupants of the office to determine which of the two comfort models is most suitable to evaluate the thermal environment. The results indicate that office occupants have developed some degree of adaptation to the climatic conditions of the city where the office is located (which only demands heating operation), and tend to accept and even prefer lower operative temperatures than those considered optimum by applying the PMV model. This is an indication that occupants of naturally conditioned buildings are usually able to match their comfort temperature to their normal environment. Therefore, the application of the adaptive model included in CEN Standard EN15251 seems like the optimal approach for evaluating thermal comfort in naturally conditioned buildings, because it takes into consideration the adaptive principle that indicates that if a change occurs such as to produce discomfort, people tend to react in ways which restore their comfort. © 2016 by the authors.

Loading University Regional Amazonica collaborators
Loading University Regional Amazonica collaborators