Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
PeerJ ; 12: e16986, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38685936

RESUMO

Environmental heterogeneity poses a significant influence on the functional characteristics of species and communities at local scales. Environmental transition zones, such as at the savanna-forest borders, can act as regions of ecological tension when subjected to sharp variations in the microclimate. For ectothermic organisms, such as lizards, environmental temperatures directly influence physiological capabilities, and some species use different thermoregulation strategies that produce varied responses to local climatic conditions, which in turn affect species occurrence and community dynamics. In the context of global warming, these various strategies confer different types of vulnerability as well as risks of extinction. To assess the vulnerability of a species and understand the relationships between environmental variations, thermal tolerance of a species and community structure, lizard communities in forest-savanna transition areas of two national parks in the southwestern Amazon were sampled and their thermal functional traits were characterized. Then, we investigated how community structure and functional thermal variation were shaped by two environmental predictors (i.e., microclimates estimated locally and vegetation structure estimated from remote sensing). It was found that the community structure was more strongly predicted by the canopy surface reflectance values obtained via remote sensing than by microclimate variables. Environmental temperatures were not the most important factor affecting the occurrence of species, and the variations in ecothermal traits demonstrated a pattern within the taxonomic hierarchy at the family level. This pattern may indicate a tendency for evolutionary history to indirectly influence these functional features. Considering the estimates of the thermal tolerance range and warming tolerance, thermoconformer lizards are likely to be more vulnerable and at greater risk of extinction due to global warming than thermoregulators. The latter, more associated with open environments, seem to take advantage of their lower vulnerability and occur in both habitat types across the transition, potentially out-competing and further increasing the risk of extinction and vulnerability of forest-adapted thermoconformer lizards in these transitional areas.


Assuntos
Lagartos , Microclima , Floresta Úmida , Animais , Lagartos/fisiologia , Pradaria , Brasil , Aquecimento Global
2.
Mol Phylogenet Evol ; 190: 107959, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37918682

RESUMO

Despite their limited vagility and pronounced habitat heterogeneity in the tropics, many anuran species have unexpectedly extensive geographic ranges. One prominent example of this phenomenon is Pithecopus hypochondrialis, which is found in the Cerrado, Guianan savanna, and Llanos domains, as well as isolated tracts of savanna and open habitat within the Amazon Forest. The present study employs an integrative species delimitation approach to test the hypothesis that P. hypochondrialis is in fact a species complex. We also reconstruct the relationships among the lineages delimited here and other Pithecopus species. In this study, we employ Ecological Niche Modelling (ENM) and spatiotemporal phylogeographic reconstruction approaches to evaluate a multitude of scenarios of connectivity across the Neotropical savannas. We identified three divergent lineages, two of which have been described previously. The lineages were allocated to a lowland Pithecopus clade, although the relationships among these lineages are weakly supported. Both the ENM and the phylogeographic reconstruction highlight the occurrence of periods of connectivity among the Neotropical savannas over the course of the Pliocene and Pleistocene epochs. These processes extended from eastern Amazonia to the northern coast of Brazil. The findings of the present study highlight the presence of hidden diversity within P. hypochondrialis, and reinforce the need for a comprehensive taxonomic review. These findings also indicate intricate and highly dynamic patterns of connectivity across the Neotropical savannas that date back to the Pliocene.


Assuntos
Ecossistema , Pradaria , Animais , Filogeografia , Filogenia , Anuros/genética
3.
J Phys Chem B ; 127(43): 9356-9365, 2023 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-37871185

RESUMO

Applying surfactants to reduce the interfacial tension (IFT) on water/oil interfaces is a proven technique. The search for new surfactants and delivery strategies is an ongoing research area with applications in many fields such as drug delivery through nanoemulsions and enhanced oil recovery. Experimentally, the combination of hyperbranched polyglycerol (HPG) with cetyltrimethylammonium bromide (CTAB) substantially reduced the observed IFT of oil/water interface, 0.9 mN/m, while HPG alone was 5.80 mN/m and CTAB alone IFT was 8.08 mN/m. Previous simulations in an aqueous solution showed that HPG is a surfactant carrier. Complementarily, in this work, we performed classical molecular dynamics simulations on combinations of CTAB and HPG with one aliphatic chain to investigate further the interaction of this pair in oil interfaces and propose the mechanism of IFT decrease. Basically, from our results, one can observe that the IFT reduction comes from a combination of effects that have not been observed for other dual systems: (i) Due to the CTAB-HPG strong interaction, a weakening of their specific and isolated interactions with the water and oil phases occurs. (ii) Aggregates enlarge the interfacial area, turning it into a less ordered interface. (iii) The spread of individual molecules charge profiles leads to the much lower interfacial tension observed with the CTAB+HPG systems.

4.
Arq. ciências saúde UNIPAR ; 26(1): 13-21, Jan-Abr. 2022.
Artigo em Português | LILACS | ID: biblio-1362662

RESUMO

O objetivo desse artigo é relatar os resultados de um programa de exercícios para indivíduos adultos com deficiências cognitivas e transtornos, utilizando diferentes exergames como ferramentas pedagógicas. A intervenção foi realizada com a participação de 26 indivíduos adultos com deficiências cognitivas e transtornos com idades entre 25 e 59 anos. A pesquisa de abordagem qualitativa, de cunho exploratória, a qual foram utilizados a entrevista semiestruturada e o diário de campo como instrumentos de pesquisa. Para interação com os exergames, foram utilizados os consoles Xbox 360 com Kinect, Xbox One com Kinect e Nintendo Wii U. As intervenções foram realizadas no Exergame Lab Brazil, na Escola Superior de Educação Física da UFPel, por um período de duas horas, uma vez por semana, totalizando 25 encontros. A utilização de Exergames tem grande potencial, tanto nos aspectos relacionados à viabilidade, por ser uma tecnologia de baixo custo e de fácil implementação, quanto nos resultados esperados. O Just Dance e o Kinect Sports foram os games que mais contribuíram nesta pesquisa. Os participantes da pesquisa ganharam independência e socialização, bem como melhoraram as habilidades específicas em cada game. Além disso, a possibilidade de utilização dos Exergames em casa também poderá auxiliar pais e responsáveis a melhorar aspectos da vida diária de adultos com deficiências cognitivas e transtornos.


The purpose of this article is to report the results of an exercise program for adults with cognitive disabilities and disorders using different exergames as pedagogical tools. The intervention was carried out with the participation of 26 individuals with cognitive disabilities and disorders aged between 25 and 59 years old. The exploratory, qualitative research used a semi-structured interview and a field diary as research instruments. The Xbox 360 with Kinect, Xbox One with Kinect and Nintendo Wii U consoles were used for the interactions with the exergames. The interventions were carried out at Exergame Lab Brazil, at the Physical Education School at UFPel, for a period of two hours, once a week, totaling 25 meetings. The use of Exergames presents great potential, both in relation to feasibility, since it is a low-cost, easy-to-implement technology, and in terms of expected results. Just Dance and Kinect Sports were the games that contributed most to this research. Research participants gained independence and socialization, as well as the improvement of specific skills in each game. In addition, the possibility of using Exergames at home can also help parents and guardians to improve aspects of the daily life of adults with cognitive disabilities and disorders.


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Disfunção Cognitiva/terapia , Inclusão Digital , Promoção da Saúde , Socialização , Síndrome , Ensino , Comportamento , Exercício Físico , Intervenção Educacional Precoce , Jogos de Vídeo , Terapia por Exercício/educação , Realidade Virtual , Transtornos Mentais/terapia
5.
Ciênc. rural ; 44(10): 1783-1789, 10/2014. tab
Artigo em Português | LILACS | ID: lil-726303

RESUMO

Mudanças no uso do solo afetam a quantidade de argila e matéria orgânica do solo (MOS) e estes, por sua vez, afetam a agregação. Avaliou-se como diferentes usos afetaram a agregação de um Argissolo na microrregião do Brejo Paraibano. Foram avaliadas três áreas contíguas com declive fortemente ondulado, sendo uma mata nativa, um plantio de sabiá (Mimosa caesalpiniaefolia) e uma pastagem com brachiaria (Brachiaria decumbens). Foram coletadas amostras de solo para determinação da textura, macro e microagregados secos (Macro-s e Micro-s) e úmidos (Macro-u e Micro-u), diâmetro médio ponderado de agregados secos (DMPA-s) e úmidos (DMPA-u), índice de estabilidade de agregados (IEA), teores de MOS e seu fracionamento em ácido fúlvico (AF), ácido húmico (AH) e humina (HUM), em quatro profundidades: 0,0-2,5 cm, 2,5-5,0 cm, 5,0-10,0 cm e 10,0-20,0 cm. Pôde-se notar que as quantidades de argila, MOS, HUM, Macro-s, Macro-u, DMPA-s, DMPA-u e IEA, são sempre maiores na área de mata nativa, em todas as profundidades. O plantio de sabiá apresentou maiores teores de AH e menores quantidades de Macro-u nas duas últimas profundidades em relação ao pasto. A HUM apresentou melhor correlação com a agregação do solo. Mudanças no uso causaram degradação do solo na microrregião do Brejo Paraibano.


Changes in soil use affect the amount of clay and soil organic matter (SOM) and these, in turn, affect the aggregation. It was evaluated how different uses affect the aggregation of the micro-region of Brejo Paraibano. Three adjacent areas were evaluated with strongly wavy slope, being one of them native forest, and the other ones a cultivation of sabiá (Mimosa caesalpiniaefolia) and a pasture of brachiaria (Brachiaria decumbens). Soil samples were collected for determination of texture, macro and dry microaggregates (Macro-s e Micro-s) and humid (Macro-u e Micro-u), mean weight diameter of dry aggregates (DMPA-s) and humid (DMPA-u), index of aggregate stability (IEA), contents of SOM and its fractionation in fulvic acid (FA), humic acid (HA) and humin (HUM) at four depths: 0.0-2.5 cm, 2.5-5.0 cm, 5.0-10.0 cm and 10.0-20.0 cm. It was observed that the amount of clay, SOM, HUM, Macro-s, Macro-u, DMPA-s, DMPA-u and IEA are always higher in native forest, at all depths. The cultivation of sabiá has presented higher contents of HA fraction and smaller amounts of Macro-u past two depths in relation to pasture. The HUM has shown better correlation with soil aggregation. Changes in the soil use have caused soil degradation in the microrregion of Brejo Paraibano.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...