Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 213
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Lancet ; 401(10394): 2113-2123, 2023 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-37220768

RESUMO

BACKGROUND: The effect of haemodynamic monitoring of pulmonary artery pressure has predominantly been studied in the USA. There is a clear need for randomised trial data from patients treated with contemporary guideline-directed-medical-therapy with long-term follow-up in a different health-care system. METHODS: MONITOR-HF was an open-label, randomised trial, done in 25 centres in the Netherlands. Eligible patients had chronic heart failure of New York Heart Association class III and a previous heart failure hospitalisation, irrespective of ejection fraction. Patients were randomly assigned (1:1) to haemodynamic monitoring (CardioMEMS-HF system, Abbott Laboratories, Abbott Park, IL, USA) or standard care. All patients were scheduled to be seen by their clinician at 3 months and 6 months, and every 6 months thereafter, up to 48 months. The primary endpoint was the mean difference in the Kansas City Cardiomyopathy Questionnaire (KCCQ) overall summary score at 12 months. All analyses were by intention-to-treat. This trial was prospectively registered under the clinical trial registration number NTR7673 (NL7430) on the International Clinical Trials Registry Platform. FINDINGS: Between April 1, 2019, and Jan 14, 2022, we randomly assigned 348 patients to either the CardioMEMS-HF group (n=176 [51%]) or the control group (n=172 [49%]). The median age was 69 years (IQR 61-75) and median ejection fraction was 30% (23-40). The difference in mean change in KCCQ overall summary score at 12 months was 7·13 (95% CI 1·51-12·75; p=0·013) between groups (+7·05 in the CardioMEMS group, p=0·0014, and -0·08 in the standard care group, p=0·97). In the responder analysis, the odds ratio (OR) of an improvement of at least 5 points in KCCQ overall summary score was OR 1·69 (95% CI 1·01-2·83; p=0·046) and the OR of a deterioration of at least 5 points was 0·45 (0·26-0·77; p=0·0035) in the CardioMEMS-HF group compared with in the standard care group. The freedom of device-related or system-related complications and sensor failure were 97·7% and 98·8%, respectively. INTERPRETATION: Haemodynamic monitoring substantially improved quality of life and reduced heart failure hospitalisations in patients with moderate-to-severe heart failure treated according to contemporary guidelines. These findings contribute to the aggregate evidence for this technology and might have implications for guideline recommendations and implementation of remote pulmonary artery pressure monitoring. FUNDING: The Dutch Ministry of Health, Health Care Institute (Zorginstituut), and Abbott Laboratories.


Assuntos
Insuficiência Cardíaca , Monitorização Hemodinâmica , Humanos , Idoso , Artéria Pulmonar , Monitorização Hemodinâmica/efeitos adversos , Qualidade de Vida , Insuficiência Cardíaca/tratamento farmacológico , Doença Crônica
2.
Heredity (Edinb) ; 130(3): 135-144, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36639700

RESUMO

European wildlife has been subjected to intensifying levels of anthropogenic impact throughout the Holocene, yet the main genetic partitioning of many species is thought to still reflect the late-Pleistocene glacial refugia. We analyzed 26,342 nuclear SNPs of 464 wild boar (Sus scrofa) across the European continent to infer demographic history and reassess the genetic consequences of natural and anthropogenic forces. We found that population fragmentation, inbreeding and recent hybridization with domestic pigs have caused the spatial genetic structure to be heterogeneous at the local scale. Underlying local anthropogenic signatures, we found a deep genetic structure in the form of an arch-shaped cline extending from the Dinaric Alps, via Southeastern Europe and the Baltic states, to Western Europe and, finally, to the genetically diverged Iberian peninsula. These findings indicate that, despite considerable anthropogenic influence, the deeper, natural continental structure is still intact. Regarding the glacial refugia, our findings show a weaker signal than generally assumed, but are nevertheless suggestive of two main recolonization routes, with important roles for Southern France and the Balkans. Our results highlight the importance of applying genomic resources and framing genetic results within a species' demographic history and geographic distribution for a better understanding of the complex mixture of underlying processes.


Assuntos
Variação Genética , Genoma , Animais , Suínos , Europa (Continente) , Demografia , Sus scrofa/genética , Filogenia , DNA Mitocondrial/genética
3.
Med Mycol ; 61(2)2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36746434

RESUMO

The phylum Microsporidia encompasses a diverse group of obligate, intracellular, and spore-forming organisms able to infect a wide range of animal hosts. Among them, Enterocytozoon bieneusi is the most frequently reported species in humans and animals. Little is known about the presence and epidemiology of E. bieneusi in wildlife. We investigated E. bieneusi occurrence and genetic diversity in wild and domestic mammals, through molecular-detection methods, from different regions across Portugal. A total of 756 samples were collected from 288, 242, and 226 wild carnivores, wild ungulates, and domestic animals, respectively. Overall, eight specimens were E. bieneusi-positive (1.1%, 8/756) obtained from five wild (Iberian lynx, Iberian wolf, red fox, stone marten, and wild boar) and one domestic (sheep) host. Nucleotide sequence analysis identified four genotypes of E. bieneusi, Type IV, Wildboar3, BEB6, and PtEbIX. Three of those genotypes belong to Groups 1 (Type IV and Wildboar3) and 2 (BEB6), which are known to contain genotypes capable of infecting a variety of hosts, including humans, highlighting their public health importance. PtEbIX belongs to the dog-specific Group 11. This study represents the first, largest, and most comprehensive molecular-based epidemiology survey carried out in Portugal in wild and domestic animals to date and the first worldwide identification of E. bieneusi in wolf species. Our study showed that wild carnivores and ungulates may act as reservoirs of zoonotic genotypes of E. bieneusi, establishing their role in maintaining the sylvatic cycle of this parasite while representing a potential source of infection for humans and domestic animals.


The identification of human-pathogenic genotypes of fungi-related Enterocytozoon bieneusi in wild carnivores and ungulates in Portugal suggests cross-species infection events and overlapping of the sylvatic and domestic transmission cycles, demonstrating a potential transmission risk to humans.


Assuntos
Doenças do Cão , Enterocytozoon , Microsporidiose , Doenças dos Ovinos , Doenças dos Suínos , Humanos , Suínos , Animais , Cães , Ovinos , Animais Domésticos , Enterocytozoon/genética , Portugal , Microsporidiose/epidemiologia , Microsporidiose/veterinária , Filogenia , Sus scrofa , Genótipo , China/epidemiologia , Prevalência , Fezes , Zoonoses/epidemiologia , Doenças dos Ovinos/epidemiologia
4.
Proc Natl Acad Sci U S A ; 117(20): 10921-10926, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32366661

RESUMO

Flower biomass varies widely across the angiosperms. Each plant species invests a given amount of biomass to construct its sex organs. A comparative understanding of how this limited resource is partitioned among primary (male and female structures) and secondary (petals and sepals) sexual organs on hermaphrodite species can shed light on general evolutionary processes behind flower evolution. Here, we use allometries relating different flower biomass components across species to test the existence of broad allocation patterns across the angiosperms. Based on a global dataset with flower biomass spanning five orders of magnitude, we show that heavier angiosperm flowers tend to be male-biased and invest strongly in petals to promote pollen export, while lighter flowers tend to be female-biased and invest more in sepals to insure their own seed set. This result demonstrates that larger flowers are not simple carbon copies of small ones, indicating that sexual selection via male-male competition is an important driver of flower biomass evolution and sex allocation strategies across angiosperms.


Assuntos
Evolução Biológica , Flores/fisiologia , Magnoliopsida/fisiologia , Biomassa , Gentiana , Lepidium , Nymphaea , Orchidaceae , Pólen , Polinização , Sementes , Seleção Genética , Especificidade da Espécie
5.
Parasitol Res ; 122(2): 435-440, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36434319

RESUMO

At the end of the nineteenth century, massive population declines were observed in carnivores due to the emergence of infectious diseases. This study aims to investigate, by means of coprological analysis, the prevalence and intensity of the parasites that infect the endangered Iberian wolf Canis lupus signatus and two mesocarnivores (the red fox Vulpes vulpes and the stone marten Martes foina) in Central Portugal. In total, 67.2% of the samples screened were infected; Toxascaris leonina (40.6%) was the parasite with the highest prevalence, followed by Ancylostomatidae and Eimeria spp. (28.1%). Eimeria spp. was found in stone marten with the highest infection rate (37,800 OPG), followed by T. leonina (10,100 EPG) in a red fox sample. Moderate to high levels of parasitic infections were identified in 73.3% of red foxes from the western area. Our results highlight the possibility of cross-infection among these carnivore species and cross-contamination in the wildlife-livestock-human interface.


Assuntos
Carnívoros , Mustelidae , Lobos , Animais , Humanos , Lobos/parasitologia , Portugal/epidemiologia , Raposas/parasitologia , Animais Selvagens , Mustelidae/parasitologia
6.
Ecol Lett ; 25(10): 2177-2188, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35953880

RESUMO

Why sex has evolved and is maintained is an open question in evolutionary biology. The Red Queen hypothesis predicts that host lineages subjected to more intense parasite pressure should invest more in sexual reproduction to continuously create novel defences against their rapidly evolving natural enemies. In this comparative study across the angiosperms, we show that hermaphrodite plant species associated with higher species richness of insect herbivores evolved flowers with higher biomass allocation towards the male sex, an indication of their greater outcrossing effort. This pattern remained robust after controlling for key vegetative, reproductive and biogeographical traits, suggesting that long-term herbivory pressure is a key factor driving the selfing-outcrossing gradient of higher plants. Although flower evolution is frequently associated with mutualistic pollinators, our findings support the Red Queen hypothesis and suggest that insect herbivores drive the sexual strategies of flowering plants and their genetic diversity.


Assuntos
Herbivoria , Magnoliopsida , Animais , Flores , Insetos , Polinização , Reprodução
7.
Hum Brain Mapp ; 43(4): 1295-1308, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34796574

RESUMO

High-density electroencephalography (HD-EEG) is currently limited to laboratory environments since state-of-the-art electrode caps require skilled staff and extensive preparation. We propose and evaluate a 256-channel cap with dry multipin electrodes for HD-EEG. We describe the designs of the dry electrodes made from polyurethane and coated with Ag/AgCl. We compare in a study with 30 volunteers the novel dry HD-EEG cap to a conventional gel-based cap for electrode-skin impedances, resting state EEG, and visual evoked potentials (VEP). We perform wearing tests with eight electrodes mimicking cap applications on real human and artificial skin. Average impedances below 900 kΩ for 252 out of 256 dry electrodes enables recording with state-of-the-art EEG amplifiers. For the dry EEG cap, we obtained a channel reliability of 84% and a reduction of the preparation time of 69%. After exclusion of an average of 16% (dry) and 3% (gel-based) bad channels, resting state EEG, alpha activity, and pattern reversal VEP can be recorded with less than 5% significant differences in all compared signal characteristics metrics. Volunteers reported wearing comfort of 3.6 ± 1.5 and 4.0 ± 1.8 for the dry and 2.5 ± 1.0 and 3.0 ± 1.1 for the gel-based cap prior and after the EEG recordings, respectively (scale 1-10). Wearing tests indicated that up to 3,200 applications are possible for the dry electrodes. The 256-channel HD-EEG dry electrode cap overcomes the principal limitations of HD-EEG regarding preparation complexity and allows rapid application by not medically trained persons, enabling new use cases for HD-EEG.


Assuntos
Córtex Cerebral/fisiologia , Eletrodos , Eletroencefalografia/instrumentação , Potenciais Evocados Visuais/fisiologia , Adulto , Impedância Elétrica , Eletroencefalografia/métodos , Eletromiografia , Humanos , Monitorização Ambulatorial , Dispositivos Eletrônicos Vestíveis
8.
Sensors (Basel) ; 22(20)2022 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-36298430

RESUMO

Dry electrodes for electroencephalography (EEG) allow new fields of application, including telemedicine, mobile EEG, emergency EEG, and long-term repetitive measurements for research, neurofeedback, or brain-computer interfaces. Different dry electrode technologies have been proposed and validated in comparison to conventional gel-based electrodes. Most previous studies have been performed at a single center and by single operators. We conducted a multi-center and multi-operator study validating multipin dry electrodes to study the reproducibility and generalizability of their performance in different environments and for different operators. Moreover, we aimed to study the interrelation of operator experience, preparation time, and wearing comfort on the EEG signal quality. EEG acquisitions using dry and gel-based EEG caps were carried out in 6 different countries with 115 volunteers, recording electrode-skin impedances, resting state EEG and evoked activity. The dry cap showed average channel reliability of 81% but higher average impedances than the gel-based cap. However, the dry EEG caps required 62% less preparation time. No statistical differences were observed between the gel-based and dry EEG signal characteristics in all signal metrics. We conclude that the performance of the dry multipin electrodes is highly reproducible, whereas the primary influences on channel reliability and signal quality are operator skill and experience.


Assuntos
Interfaces Cérebro-Computador , Eletroencefalografia , Humanos , Reprodutibilidade dos Testes , Eletrodos , Impedância Elétrica
9.
Biol Lett ; 17(5): 20210006, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33975486

RESUMO

Parthenogenesis is rare in nature. With 39 described true parthenogens, scaled reptiles (Squamata) are the only vertebrates that evolved this reproductive strategy. Parthenogenesis is ecologically advantageous in the short term, but the young age and rarity of parthenogenetic species indicate it is less advantageous in the long term. This suggests parthenogenesis is self-destructive: it arises often but is lost due to increased extinction rates, high rates of reversal or both. However, this role of parthenogenesis as a self-destructive trait remains unknown. We used a phylogeny of Squamata (5388 species), tree metrics, null simulations and macroevolutionary scenarios of trait diversification to address the factors that best explain the rarity of parthenogenetic species. We show that parthenogenesis can be considered as self-destructive, with high extinction rates mainly responsible for its rarity in nature. Since these parthenogenetic species occur, this trait should be ecologically relevant in the short term.


Assuntos
Lagartos , Partenogênese , Animais , Fenótipo , Filogenia , Reprodução
10.
J Environ Manage ; 260: 110068, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32090812

RESUMO

1. Primary objectives of national parks usually include both, the protection of natural processes and species conservation. When these objectives conflict, as occurs because of the cascading effects of large mammals (i.e., ungulates and large carnivores) on lower trophic levels, park managers have to decide upon the appropriate management while considering various local circumstances. 2. To analyse if ungulate management strategies are in accordance with the objectives defined for protected areas, we assessed the current status of ungulate management across European national parks using the naturalness concept and identified the variables that influence the management. 3. We collected data on ungulate management from 209 European national parks in 29 countries by means of a large-scale questionnaire survey. Ungulate management in the parks was compared by creating two naturalness scores. The first score reflects ungulate and large carnivore species compositions, and the second evaluates human intervention on ungulate populations. We then tested whether the two naturalness score categories are influenced by the management objectives, park size, years since establishment, percentage of government-owned land, and human impact on the environment (human influence index) using two generalized additive mixed models. 4. In 67.9% of the national parks, wildlife is regulated by culling (40.2%) or hunting (10.5%) or both (17.2%). Artificial feeding occurred in 81.3% of the national parks and only 28.5% of the national parks had a non-intervention zone covering at least 75% of the area. Furthermore, ungulate management differed greatly among the different countries, likely because of differences in hunting traditions and cultural and political backgrounds. Ungulate management was also influenced by park size, human impact on the landscape, and national park objectives, but after removing these variables from the full model the reduced models only showed a small change in the deviance explained. In areas with higher anthropogenic pressure, wildlife diversity tended to be lower and a higher number of domesticated species tended to be present. Human intervention (culling and artificial feeding) was lower in smaller national parks and when park objectives followed those set by the International Union for the Conservation of Nature (IUCN). 5. Our study shows that many European national parks do not fulfil the aims of protected area management as set by IUCN guidelines. In contrast to the USA and Canada, Europe currently has no common ungulate management policy within national parks. This lack of a common policy together with differences in species composition, hunting traditions, and cultural or political context has led to differences in ungulate management among European countries. To fulfil the aims and objectives of national parks and to develop ungulate management strategies further, we highlight the importance of creating a more integrated European ungulate management policy to meet the aims of national parks.


Assuntos
Conservação dos Recursos Naturais , Parques Recreativos , Animais , Canadá , Europa (Continente) , Humanos , Mamíferos
11.
Ecol Lett ; 21(3): 402-410, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29341410

RESUMO

The role of trophic specialisation in taxonomic diversification remains unclear. Plant specialists diversify faster than omnivores and animalivores, but at shorter macroevolutionary scales this pattern sometimes reverses. Here, we estimate the effect of diet diversification on speciation rates in noctilionoid bats, controlling for tree shape, rate heterogeneity and macroevolutionary regimes. We hypothesise that niche subdivision among herbivores positively relates to speciation rates, differing between macroevolutionary regimes. We found the rate at which new herbivorous lineages originate decreases as rates of diet evolution increase. Herbivores experience higher speciation rates, but generalist herbivores and predominantly herbivorous omnivores speciate faster than specialised herbivores, omnivores and animalivores. Generalised herbivory is not a dead end. We show that analysing ecological traits and diversification requires accounting for macroevolutionary regimes and within- and between-clade variation in evolutionary rates. Our approach overcomes the high false-positive rates of other methods and illuminates the roles of herbivory and specialisation in speciation.


Assuntos
Cadeia Alimentar , Herbivoria , Dieta , Filogenia , Plantas
12.
Emerg Infect Dis ; 24(12): 2169-2175, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30457522

RESUMO

We investigated the spatial epidemiology of bovine tuberculosis (TB) in wildlife in a multihost system. We surveyed bovine TB in Portugal by serologic analysis of elutes of dried blood spots obtained from hunted wild boar. We modeled spatial disease risk by using areal generalized linear mixed models with conditional autoregressive priors. Antibodies against Mycobaterium bovis were detected in 2.4% (95% CI 1.5%-3.8%) of 678 wild boar in 2 geographic clusters, and the predicted risk fits well with independent reports of M. bovis culture. Results show that elutes are an almost perfect substitute for serum (Cohen unweighted κ = 0.818), indicating that serologic tests coupled with dried blood spots are an effective strategy for large-scale bovine TB surveys, using wild boar as sentinel species. Results also show that bovine TB is an emerging wildlife disease and stress the need to prevent further geographic spread and prevalence increase.


Assuntos
Doenças dos Animais/epidemiologia , Doenças dos Animais/microbiologia , Animais Selvagens , Tuberculose/veterinária , Doenças dos Animais/diagnóstico , Animais , Teste em Amostras de Sangue Seco , Ensaio de Imunoadsorção Enzimática , Geografia Médica , Portugal/epidemiologia , Prevalência , Vigilância em Saúde Pública , Testes Sorológicos , Análise Espacial
13.
Ecology ; 99(9): 2131, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30102420

RESUMO

The IUCN provides a spatial database for many species, including terrestrial mammals. This database includes shapefiles with taxonomic information and the extent of occurrence for each species, and has been used in hundreds of studies in ecology, biogeography and conservation. Here we provide updated distribution maps that comprise the extent of occurrence of the neotropical bat species in the superfamily Noctilionoidea (Mammalia: Chiroptera) after a thorough research of new records published between January 2008 and March 2018. The main motivation for this update was the inclusion of spatial and climatic variables in explaining the ecological and taxonomic diversity of noctilionoid bats. The core of the superfamily (246 species distributed in five families out of 250 species) occurs in the Neotropics and shows ecological diversity unparalleled among mammals. This clade also shows the only evolutionary shift towards higher speciation rates within the order Chiroptera. Updating the range maps for these bats resulted in the modification of maps of 94 species, and the creation of new maps for 37 species missing from the IUCN database. From the 94 modified maps, 55 species increased their latitudinal range and 38 increased their longitudinal range. These modifications did not change the overall extent of occurrence of the clade. Altogether, modified and new maps represent 53% of Noctilionoidea. No copyright or proprietary restrictions are associated with the use of this data set other than citation of this Data Paper.


Assuntos
Quirópteros , Animais , Biodiversidade , Evolução Biológica , Ecologia
14.
Folia Primatol (Basel) ; 88(1): 1-8, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28365688

RESUMO

Although primarily arboreal, the capuchin monkey (Sapajus cay) descends to the ground for several reasons. We used terrestrial records obtained by camera-trapping surveys to investigate seasonality in the terrestriality of capuchin monkeys, reasons to descend to the ground, and periods of the day when terrestriality was more pronounced. We carried out the study in the Urucum Massif, Brazilian Pantanal. We obtained data from 2 camera-trapping surveys carried out in the dry and rainy seasons. Terrestrial behaviours were categorized, and terrestrial activity patterns were described using a kernel density approach. We observed a seasonal effect on the frequency of terrestrial behaviours of capuchin monkeys, who used the ground more during the dry season. We identified 6 different types of terrestrial behaviour, but travelling (33.3%), foraging (23.3%), and drinking water (23.3%) were the most frequently observed. All records occurred during the day, with 2 peaks in terrestrial activity. Seasonal terrestriality was mainly linked to ecological needs during periods of scarce food and water.


Assuntos
Comportamento Animal , Cebus/fisiologia , Animais , Brasil , Estações do Ano , Árvores
15.
Evol Comput ; 24(3): 521-44, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27303786

RESUMO

Given a nondominated point set [Formula: see text] of size [Formula: see text] and a suitable reference point [Formula: see text], the Hypervolume Subset Selection Problem (HSSP) consists of finding a subset of size [Formula: see text] that maximizes the hypervolume indicator. It arises in connection with multiobjective selection and archiving strategies, as well as Pareto-front approximation postprocessing for visualization and/or interaction with a decision maker. Efficient algorithms to solve the HSSP are available only for the 2-dimensional case, achieving a time complexity of [Formula: see text]. In contrast, the best upper bound available for [Formula: see text] is [Formula: see text]. Since the hypervolume indicator is a monotone submodular function, the HSSP can be approximated to a factor of [Formula: see text] using a greedy strategy. In this article, greedy [Formula: see text]-time algorithms for the HSSP in 2 and 3 dimensions are proposed, matching the complexity of current exact algorithms for the 2-dimensional case, and considerably improving upon recent complexity results for this approximation problem.


Assuntos
Modelos Teóricos , Algoritmos
16.
Evol Comput ; 24(3): 411-25, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26135717

RESUMO

The hypervolume subset selection problem consists of finding a subset, with a given cardinality k, of a set of nondominated points that maximizes the hypervolume indicator. This problem arises in selection procedures of evolutionary algorithms for multiobjective optimization, for which practically efficient algorithms are required. In this article, two new formulations are provided for the two-dimensional variant of this problem. The first is a (linear) integer programming formulation that can be solved by solving its linear programming relaxation. The second formulation is a k-link shortest path formulation on a special digraph with the Monge property that can be solved by dynamic programming in [Formula: see text] time. This improves upon the result of [Formula: see text] in Bader ( 2009 ), and slightly improves upon the result of [Formula: see text] in Bringmann et al. ( 2014b ), which was developed independently from this work using different techniques. Numerical results are shown for several values of n and k.


Assuntos
Algoritmos , Modelos Teóricos
17.
Rev Biol Trop ; 64(1): 289-303, 2016 03.
Artigo em Espanhol | MEDLINE | ID: mdl-28862819

RESUMO

Bess beetles are important components on tropical forest dead wood nutrient cycling, since they act as direct consumers and ease the consumption by another organism (indirect). Studies of bess beetle ecology are scarce and have focused on communities responses to environmental changes on alimentary resources. We characterized the bess beetles guild composition in an elevation gradient, according to their differential use of resources (microhabitat) and morphological traits quantification (geometric and lineal), as a potential tool to improve our understanding on resource use and functional ecology of beetles. Three guilds (underbark, sapwood-heartwood and generalists feeders), five species and 198 familiar groups were recognized; their richness decreased as elevation increased. Changes in linear morphometric measures were influenced by elevation; morphogeometrical measures were not associated with the elevation gradient, only grouping at guild level were observed. Morphological markers analysis (morphometric) provided information to guild delimitation. Body and metatibiae shape contributed with the best information to guild grouping. Quantification of those structural markers proved the relationship between resource repartition, because they are involved in movement on wood galleries and wood consumption, this fact allowed to propose specific functional roles. The identified patterns have contributed on the understanding of functional processes in Passalidae communities and their role in ecosystem function.


Assuntos
Besouros/anatomia & histologia , Animais , Biodiversidade , Besouros/classificação , Besouros/fisiologia , Colômbia , Florestas , Clima Tropical
18.
Ecol Lett ; 18(12): 1406-19, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26415616

RESUMO

Recent studies have shown that accounting for intraspecific trait variation (ITV) may better address major questions in community ecology. However, a general picture of the relative extent of ITV compared to interspecific trait variation in plant communities is still missing. Here, we conducted a meta-analysis of the relative extent of ITV within and among plant communities worldwide, using a data set encompassing 629 communities (plots) and 36 functional traits. Overall, ITV accounted for 25% of the total trait variation within communities and 32% of the total trait variation among communities on average. The relative extent of ITV tended to be greater for whole-plant (e.g. plant height) vs. organ-level traits and for leaf chemical (e.g. leaf N and P concentration) vs. leaf morphological (e.g. leaf area and thickness) traits. The relative amount of ITV decreased with increasing species richness and spatial extent, but did not vary with plant growth form or climate. These results highlight global patterns in the relative importance of ITV in plant communities, providing practical guidelines for when researchers should include ITV in trait-based community and ecosystem studies.


Assuntos
Biodiversidade , Fenótipo , Fenômenos Fisiológicos Vegetais , Especificidade da Espécie
19.
J Hered ; 106(5): 593-607, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26249652

RESUMO

The riverine barrier model suggests that rivers play a significant role in separating widespread organisms into isolated populations. In this study, we used a comparative approach to investigate the phylogeography of 6 didelphid marsupial species in central Brazil. Specifically, we evaluate the role of the mid-Araguaia River in differentiating populations and estimate divergence time among lineages to assess the timing of differentiation of these species, using mitochondrial DNA sequence data. The 6 didelphid marsupials revealed different intraspecific genetic patterns and structure. The 3 larger and more generalist species, Didelphis albiventris, Didelphis marsupialis, and Philander opossum, showed connectivity across the Araguaia River. In contrast the genetic structure of the 3 smaller and specialist species, Gracilinanus agilis, Marmosa (Marmosa) murina, and Marmosa (Micoureus) demerarae was shaped by the mid-Araguaia. Moreover, the split of eastern and western bank populations of the 2 latter species is consistent with the age of Araguaia River sediments formation. We hypothesize that the role of the Araguaia as a riverine barrier is linked to the level of ecological specialization among the 6 didelphid species and differences in their ability to cross rivers or disperse through the associated habitat types.


Assuntos
Evolução Biológica , Genética Populacional , Gambás/genética , Rios , Animais , Teorema de Bayes , Brasil , DNA Mitocondrial/genética , Ecossistema , Haplótipos , Funções Verossimilhança , Modelos Genéticos , Gambás/classificação , Filogeografia , Análise de Sequência de DNA
20.
Ambio ; 44(2): 154-62, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24973054

RESUMO

Ecological science contributes to solving a broad range of environmental problems. However, lack of ecological literacy in practice often limits application of this knowledge. In this paper, we highlight a critical but often overlooked demand on ecological literacy: to enable professionals of various careers to apply scientific knowledge when faced with environmental problems. Current university courses on ecology often fail to persuade students that ecological science provides important tools for environmental problem solving. We propose problem-based learning to improve the understanding of ecological science and its usefulness for real-world environmental issues that professionals in careers as diverse as engineering, public health, architecture, social sciences, or management will address. Courses should set clear learning objectives for cognitive skills they expect students to acquire. Thus, professionals in different fields will be enabled to improve environmental decision-making processes and to participate effectively in multidisciplinary work groups charged with tackling environmental issues.


Assuntos
Ecologia/educação , Ecologia/tendências , Resolução de Problemas , Aprendizagem Baseada em Problemas/tendências , Ecologia/normas , Humanos , Aprendizagem Baseada em Problemas/normas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA