15 research outputs found
Use of biodegradable polyester-based microvessels for micropropagation of mature Eucalyptus microcorys
Background: Micropropagation, an in vitro vegetative propagation technique using small propagules is one of the main applications of plant tissue culture. It can be used to clone specific plants with desired traits and reduce the cost of plant propagation. In this study, we developed a protocol for micropropagation of Eucalyptus microcorys F.Muell using a selected mature tree, in which we tested various combinations of different culture media and evaluated the use of biodegradable polyester-based microvessels during the adventitious rooting and acclimatisation phases. Methods: Epicormic shoots were used as an explant source. After the in vitro explant establishment and multiplication, we tested 8 combinations of BAP, NAA and IBA in the elongation phase. Three types of microvessels were tested in the adventitious rooting phase and acclimatisation of the microcuttings. Results: Epicormic shoots had an establishment percentage of 40.6% and a total of 820 explants were generated by the 11th subculture, with an average of 12 buds per explant. Best shoot elongation results were achieved with BAP (0.05 mg L-1) + NAA (1 mg L-1) and BAP (0.05 mg L-1) + NAA (1 mg L-1) + IBA (1 mg L-1) combinations, whereas microvessel types M2 and M3 provided higher rooting and acclimatisation. According to the results of ISSR markers, at the end of 535 days of in vitro cultivation, cloning was successful between acclimatised micro-plantlets and the parent plant. Conclusions: The micropropagation protocol using microvessels was efficient in producing E. microcorys clonal microplantlets and is recommended for further studies with this species, and for testing in the micropropagation of other species.Peer reviewe
GQ-16, a novel peroxisome proliferator-activated receptor (PPAR ) ligand, promotes insulin sensitization without weight gain
ABSTRACTBackground: PPAR agonists improve insulin sensitivity but also evoke weight gain.
Results: GQ-16 is a PPAR partial agonist that blocks receptor phosphorylation by Cdk5 and improves insulin sensitivity in diabetic mice in the absence of weight gain. Conclusion: The unique binding mode of GQ-16 appears to be responsible for the compound’s advantageous pharmacological profile.
Significance: Similar compounds could have promise as anti-diabetic therapeutics
Comportamento de genótipos de algodoeiro no Estado de São Paulo: produtividade, resistência a doenças e qualidade da fibra
A Software Architecture for User Environments in Ubiquitous Systems
212 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2005.This dissertation concentrates in ascertaining a software architecture that realizes the concept of a user environment that is always present with the user, and that mimics as closely as possible the user's needs and preferences. Such an architecture requires three main capabilities: First, it has to represent and maintain a user environment in a ubiquitous system. Second, it has to deploy a user environment, making it available across the spaces of a ubiquitous system. Finally, it has to match a user environment to the characteristics of a computing space, as well as to adjust a user environment to the user's ever-changing computational needs.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD
A Software Architecture for User Environments in Ubiquitous Systems
212 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2005.This dissertation concentrates in ascertaining a software architecture that realizes the concept of a user environment that is always present with the user, and that mimics as closely as possible the user's needs and preferences. Such an architecture requires three main capabilities: First, it has to represent and maintain a user environment in a ubiquitous system. Second, it has to deploy a user environment, making it available across the spaces of a ubiquitous system. Finally, it has to match a user environment to the characteristics of a computing space, as well as to adjust a user environment to the user's ever-changing computational needs.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD
What the reasons for no inbreeding and high genetic diversity of the neotropical fig tree Ficus arpazusa ?
Ficus arpazusa Casaretto is a fig tree native to the Atlantic Rain Forest sensu lato. High levels of genetic diversity and no inbreeding were observed in Ficus arpazusa. This genetic pattern is due to the action of its pollinator, Pegoscapus sp., which disperses pollen an estimated distance of 5.6 km, and of Ficus arpazusa`s mating system which, in the study area, is allogamous. This study highlights the importance of adding both ecological and genetic data into population studies, allowing a better understanding of evolutionary processes and in turn increasing the efficacy of forest management and revegetation projects, as well as species conservation.Fundacao de Amparo a Pesquisa do Estado de Minas Gerais (FAPEMIG)[CRA-1770
Fenologia de Caryocar brasiliense Camb. (Caryocaraceae) no Alto Rio Grande, sul de Minas Gerais
Phenological studies are important to understand the dynamics in forest ecosystems and also to enable adequate management of their native species. In the Cerrado regions of the high Rio Grande river (south of Minas Gerais State), Caryocar brasiliense species is found in highly distinct morphological forms with variable phenology. The aim of this study was to investigate phenological patterns within and between populations of both the tree and shrub forms of the individuals and to determine any correlation with abiotic factors. Thirty-five observations of the phenophases of the vegetative and reproductive stages were recorded ever), two weeks for 18 months. The activity index was analyzed for each stage and further analyzed to see if there were associations with the climate data by using Spearman linear correlation. The species was deciduous but leaf growth became retarded during the dry season, at which point leaf flushing stopped and total leaf fall occurred throughout the rainy season. The flowering and the fruit production occurred in the rainy season. The reproductive phase can be either annual or sub-annual. The activity index showed high synchronism within populations during the first flowering in all populations studied (> 80%). Flowering and mature fruits were highly synchronized according to Spearman correlations. Tree and shrub individuals of C. brasiliense had very similar times for their phenophases. The best period for collecting mature fruits in these regions is between February and March.Estudos fenológicos fornecem subsídios para a compreensão da dinâmica dos ecossistemas florestais e para o manejo de espécies nativas. Na região de Cerrado do Alto Rio Grande, sul de Minas Gerais, a espécie Caryocar brasiliense possui altura e porte variados na maturidade reprodutiva. Objetivou-se, nesse estudo avaliar os padrões fenológicos inter e intrapopulacional dos indivíduos de porte arbóreo e subarbustivo e suas relações com as variáveis climáticas. Foram feitas 35 observações quinzenais das fenofases vegetativas e reprodutivas. Foi analisado o índice de atividade para cada fase, sendo posteriormente correlacionadas com os valores de variáveis meteorológicas com o uso da análise de correlação linear de Spearman. A espécie é caducifólia, com perda total de folhas na estação seca. O enfolhamento cessa durante o período mais seco e inicia-se logo após a queda total das folhas, estendendo-se por toda a estação chuvosa. A floração e frutificação ocorreram durante a estação chuvosa. A fase reprodutiva parece ser anual ou subanual, com mais de um episódio de floração por ano. O índice de atividade revelou alto sincronismo intrapopulacional durante a primeira floração em todas as populações (> 80%). A sincronia interpopulacional para os eventos de floração e frutos maduros foram todas positivas e significativas, conforme as correlações de Spearman. Indivíduos de C. brasiliense de porte arbóreo e porte subarbustivo apresentaram as fenofases em épocas semelhantes. A época ideal para coleta de frutos maduros, nos locais estudados, é nos meses de fevereiro e março
Admixture facilitates adaptation from standing variation in the European aspen (Populus tremula L.), a widespread forest tree
Adaptation to new environments can start from new mutations or from standing variation already present in natural populations. Whether admixture constrains or facilitates adaptation from standing variation is largely unknown, especially in ecological keystone or foundation species. We examined patterns of neutral and adaptive population divergence in Populus tremula L.;a widespread forest tree, using mapped molecular genetic markers. We detected the genetic signature of postglacial admixture between a Western and an Eastern lineage of P. tremula in Scandinavia, an area suspected to represent a zone of postglacial contact for many species of animals and plants. Stringent divergence-based neutrality tests provided clear indications for locally varying selection at the European scale. Six of 12 polymorphisms under selection were located less than 1 kb away from the nearest gene predicted by the Populus trichocarpa genome sequence. Few of these loci exhibited a signature of 'selective sweeps' in diversity-based tests, which is to be expected if adaptation occurs primarily from standing variation. In Scandinavia, admixture explained genomic patterns of ancestry and the nature of clinal variation and strength of selection for bud set, a phenological trait of great adaptive significance in temperate trees, measured in a common garden trial. Our data provide a hitherto missing direct link between past range shifts because of climatic oscillations, and levels of standing variation currently available for selection and adaptation in a terrestrial foundation species. © 2010 Blackwell Publishing Ltd
Small landscape elements double connectivity in highly fragmented areas of the Brazilian Atlantic Forest
The Atlantic Forest in Brazil is a biodiversity hotspot, yet its diverse ecosystems and species are becoming increasingly threatened by habitat loss and extreme habitat fragmentation. Most habitat patches of Atlantic Forest are dispersed across agricultural landscapes (e.g., grazing and cropping) in relatively small and isolated fragments (80% < 50 ha). Forest fragments < 1 ha, scattered trees in pastures, tree lines on trenches and fences, and remnant riparian forest, collectively called here Small Landscape Elements (SLEs), are very common in this context. While these SLEs make up much of the Atlantic Forests footprint, very little is known about their role or impact on the persistence and conservation of species. In this study, we investigate the role of SLEs on landscape configuration, particularly their contribution toward landscape connectivity of individual species and the genetic flow of species between larger forest fragments. We randomly selected 20 buffers of 707 hectares within a 411,670 hectare area of the Atlantic Forest that was completely covered by forest in the past located in the south of Minas Gerais State, Brazil. The forest cover randomly varied between these buffers. We used graph theory to measure landscape connectivity as the probability of connectivity for different disperser movement types between landscape knots (habitat patches). We used three estimated dispersal distances in the models: pollen disperser insect (50 m), low-mobility seed disperser bird (100 m) and high-mobility seed disperser bird (760 m). The SLEs together increased the probability of connection by roughly 50%, for all model dispersers, if compared to a theoretical baseline landscape containing no SLEs. Of all SLEs, riparian forests contribute the most toward enhancing landscape connectivity. In these highly fragmented landscapes, such as the Atlantic Forest (>70%), the position of SLEs within the landscapes was more important than their respective areas for connectivity. Although the landscapes were deeply fragmented, we showed that the presence of SLEs can increase connectivity and reduce further biodiversity loss in the Atlantic Forest
Serious new threat to Brazilian forests
[Extract] Brazil's Forest Code was enacted in 1965 and protects forests in certain locations, such as along rivers and on steep slopes and hilltops. It is the only legislation in the world that requires private rural landowners to retain reserves of natural vegetation. In the Atlantic Rainforest, the Forest Code states that 20% of a property has to remain in reserve whereas in the Amazon forest this amount is 80%. However, an amended Forest Code was overwhelmingly approved in the lower House of the Brazilian legislature, and it seems likely that a version will be passed by the Senate and could be signed into law by the president. If passed, the new legislation may not only provide amnesty to those who illegally cleared forests in the past, but also greatly intensify the risk of future deforestation. The new law includes changes in forest protection that will allow for harvesting of legal reserves on private lands as well as reducing the proportion of a property that must be preserved (Metzger et al. 2010)