966 resultados para Mary, Queen of Scots, 1542-1587.
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The anti-thrombotic properties of an anthocyanin-rich Queen Garnet plum juice (QGPJ) and anthocyanin-free prune juice (PJ) were studied in this randomised, double-blind, crossover trial. Twenty-one healthy subjects (M = 10, F = 11) consumed QGPJ, PJ or placebo, 200 mL/day for 28-days followed by a 2-week wash-out period. Only QGPJ supplementation inhibited platelet aggregation induced by ADP (<5%, P = 0.02), collagen (<2.7%, P < 0.001) and arachidonic acid (<4%, P < 0.001); reduced platelet activation-dependent surface-marker P-selectin expression of activated de-granulated platelets (<17.2%, P = 0.04); prolonged activated-partial thromboplastin clotting time (>2.1 s, P = 0.03); reduced plasma-fibrinogen (<7.5%, P = 0.02) and malondialdehyde levels, a plasma biomarker of oxidative stress ( P = 0.016). PJ supplementation increased plasma hippuric acid content ( P = 0.018). QGPJ or PJ supplementation did not affect blood cell counts, lipid profile, or inflammation markers. Our findings suggest that QGPJ but not PJ has the potential to significantly attenuate thrombosis by reducing platelet activation/hyper-coagulability and oxidative stress.
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In just one of the many extraordinary moments during the spectacular Opening Ceremony of the 2012 London Olympic Games, thirty Mary Poppinses floated into the stadium on their umbrellas to battle a 40 foot-long inflatable Lord Voldemort. This multi-million pound extravaganza was telecast to a global audience of over one billion people, highlighting in an extremely effective manner the grandeur and eccentricities of the host nation, and featuring uniquely British icons such as Mr Bean, James Bond, The Beatles and Harry Potter, as well as those quintessential icons of Englishness, the Royal Family, double-decker red buses and the National Health Service.
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Lignin is a complex plant polymer synthesized through co-operation of multiple intracellular and extracellular enzymes. It is deposited to plant cell walls in cells where additional strength or stiffness are needed, such as in tracheary elements (TEs) in xylem, supporting sclerenchymal tissues and at the sites of wounding. Class III peroxidases (POXs) are secreted plant oxidoreductases with implications in many physiological processes such as the polymerization of lignin and suberin and auxin catabolism. POXs are able to oxidize various substrates in the presence of hydrogen peroxide, including lignin monomers, monolignols, thus enabling the monolignol polymerization to lignin by radical coupling. Trees produce large amounts of lignin in secondary xylem of stems, branches and roots. In this study, POXs of gymnosperm and angiosperm trees were studied in order to find POXs which are able to participate in lignin polymerization in developing secondary xylem i.e. are located at the site of lignin synthesis in tree stems and have the ability to oxidize monolignol substrates. Both in the gymnosperm species, Norway spruce and Scots pine, and in the angiosperm species silver birch the monolignol oxidizing POX activities originating from multiple POX isoforms were present in lignifying secondary xylem in stems during the period of annual growth. Most of the partially purified POXs from Norway spruce and silver birch xylem had highest oxidation rate with coniferyl alcohol, the main monomer in guaiacyl-lignin in conifers. The only exception was the most anionic POX fraction from silver birch, which clearly preferred sinapyl alcohol, the lignin monomer needed in the synthesis of syringyl-guaiacyl lignin in angiosperm trees. Three full-length pox cDNAs px1, px2 and px3 were cloned from the developing xylem of Norway spruce. It was shown that px1 and px2 are expressed in developing tracheids in spruce seedlings, whereas px3 transcripts were not detected suggesting low transcription level in young trees. The amino acid sequences of PX1, PX2 and PX3 were less than 60% identical to each other but showed up to 84% identity to other known POXs. They all begin with predicted N-terminal secretion signal (SS) peptides. PX2 and PX3 contained additional putative vacuolar localization determinants (VSDs) at C-terminus. Transient expression of EGFP-fusions of the SS- and VSD-peptides in tobacco protoplasts showed SS-peptides directed EGFP to secretion in tobacco cells, whereas only the PX2 C-terminal peptide seems to be a functional VSD. According to heterologous expression of px1 in Catharanthus roseus hairy roots, PX1 is a guaicol-oxidizing POX with isoelectric point (pI) approximately 10, similar to monolignol oxidizing POXs in protein extracts from Norway spruce lignifying xylem. Hence, PX1 has characteristics for participation to monolignol dehydrogenation in lignin synthesis, whereas the other two spruce POXs seem to have some other functions. Interesting topics in future include functional characterization of syringyl compound oxidizing POXs and components of POX activity regulation in trees.
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Queens and workers are not morphologically differentiated in the primitively eusocial wasp, Ropalidia marginata. Upon removal of the queen, one of the workers becomes extremely aggressive, but immediately drops her aggression if the queen is returned. If the queen is not returned, this hyper-aggressive individual, the potential queen (PQ), will develop her ovaries, lose her hyper-aggression, and become the next colony queen. Because of the non-aggressive nature of the queen, and because the PQ loses her aggression by the time she starts laying eggs, we hypothesized that regulation of worker reproduction in R marginata is mediated by pheromones rather than by physical aggression. Based on the immediate loss of aggression by the PQ upon return of the queen, we developed a bioassay to test whether the queen's Dufour's gland is, at least, one of the sources of the queen pheromone. Macerates of the queen's Dufour's gland, but not that of the worker's Dufour's gland, mimic the queen in making the PQ decrease her aggression. We also correctly distinguished queens and workers of R. marginata nests by a discriminant function analysis based on the chemical composition of their respective Dufour's glands.
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The aim of this thesis was to unravel the functional-structural characteristics of root systems of Betula pendula Roth., Picea abies (L.) Karst., and Pinus sylvestris L. in mixed boreal forest stands differing in their developmental stage and site fertility. The root systems of these species had similar structural regularities: horizontally-oriented shallow roots defined the horizontal area of influence, and within this area, each species placed fine roots in the uppermost soil layers, while sinker roots defined the maximum rooting depth. Large radial spread and high ramification of coarse roots, and the high specific root length (SRL) and root length density (RLD) of fine roots indicated the high belowground competitiveness and root plasticity of B. pendula. Smaller radial root spread and sparser branching of coarse roots, and low SRL and RLD of fine roots of the conifers could indicate their more conservative resource use and high association with and dependence on ectomycorrhiza-forming fungi. The vertical fine root distributions of the species were mostly overlapping, implying the possibility for intense belowground competition for nutrients. In each species, conduits tapered and their frequency increased from distal roots to the stem, from the stem to the branches, and to leaf petioles in B. pendula. Conduit tapering was organ-specific in each species violating the assumptions of the general vascular scaling model (WBE). This reflects the hierarchical organization of a tree and differences between organs in the relative importance of transport, safety, and mechanical demands. The applied root model was capable of depicting the mass, length and spread of coarse roots of B. pendula and P. abies, and to the lesser extent in P. sylvestris. The roots did not follow self-similar fractal branching, because the parameter values varied within the root systems. Model parameters indicate differences in rooting behavior, and therefore different ecophysiological adaptations between species.
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Research on carbon uptake in boreal forests has mainly focused on mature trees, even though ground vegetation species are effective assimilators and can substantially contribute to the CO2 uptake of forests. Here, I examine the photosynthesis of the most common species of ground vegetation in a series of differently aged Scots pine stands, and at two clear-cut sites with substantial differences in fertility. In general, the biomass of evergreen species was highest at poor sites and below canopies, whereas grasses and herbs predominated at fertile sites and open areas. Unlike mosses, the measured vascular species showed clear annual cycles in their photosynthetic activity, which increased earlier and decreased later in evergreen vascular species than in deciduous species. However, intraspecific variation and self-shading create differences in the overall level of photosynthesis. Light, temperature history, soil moisture and recent possible frosts could explain the changes in photosynthesis of low shrubs and partially also some changes in deciduous species. Light and the occurrence of rain events explained most of the variation in the photosynthesis of mosses. The photosynthetic production of ground vegetation was first upscaled, using species-specific and mass-based photosynthetic activities and average biomass of the site, and then integrated over the growing season, using changes in environmental factors. Leaf mass-based photosynthesis was highest in deciduous species, resulting in notably higher photosynthetic production at fertile sites than at poor clear-cut sites. The photosynthetic production decreased with stand age, because flora changed towards evergreen species, and light levels diminished below the canopy. In addition, the leaf mass-based photosynthetic activity of some low shrubs declined with the age of the surrounding trees. Different measuring methods led to different momentary rate of photosynthesis. Therefore, the choice of measuring method needs special attention.
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The present study evaluates the feasibility of undelimbed Scots pine (Pinus sylvestris L.) for integrated production of pulp and energy in a kraft pulp mill from the technical, economic and environmental points of view, focusing on the potential of bundle harvesting. The feasibility of tree sections for pulp production was tested by conducting an industrial wood-handling experiment, laboratory cooking and bleaching trials, using conventional small-diameter Scots pine pulpwood as a reference. These trials showed that undelimbed Scots pine sections can be processed in favourable conditions as a blend with conventional small-diameter pulpwood without reducing the pulp quality. However, fibre losses at various phases of the process may increase when using undelimbed material. In the economic evaluation, both pulp production and wood procurement costs were considered, using the relative wood paying capability of a kraft pulp mill as a determinant. The calculations were made for three Scots pine first-thinning stands with the breast-height diameter of the removal (6 12 cm) as the main distinctive factor. The supply chains included in the comparison were based on cut-to-length harvesting, whole-tree harvesting and bundle harvesting (whole-tree bundling). With the current ratio of pulp and energy prices, the wood paying capability declines with an increase in the proportion of the energy fraction of the raw material. The supply system based on the cut-to-length method was the most efficient option, resulting in the highest residual value at stump in most cases. A decline in the pulp price and an increase in the energy price improved the competitiveness of the whole-tree systems. With short truck transportation distances and low pulp prices, however, the harvesting of loose whole trees can result in higher residual value at stump in small-diameter stands. While savings in transportation costs did not compensate for the high cutting and compaction costs by the second prototype of the bundle harvester, an increase in transportation distances improved its competitiveness. Since harvesting undelimbed assortments increases nutrient export from the site, which can affect soil productivity, the whole-tree alternatives included in the present study cannot be recommended on infertile peatlands and mineral soils. The harvesting of loose whole trees or bundled whole trees implies a reduction in protective logging residues and an increase in site traffic or payloads. These factors increase the risk of soil damage, especially on peat soils with poor bearing capacity. Within the wood procurement parameters which were examined, the CO2 emissions of the supply systems varied from 13 27 kg m3. Compaction of whole trees into bundles reduced emissions from transportation by 30 39%, but these reductions were insufficient to compensate for the increased emissions from cutting and compaction.
Resumo:
Queens of many social insect species are known to maintain reproductive monopoly by pheromonal signalling of fecundity. Queens of the primitively eusocial wasp Ropalidia marginata appear to do so using secretions from their Dufour's glands, whose hydrocarbon composition is correlated with fertility. Solitary nest foundresses of R. marginata are without nestmates; hence expressing a queen signal can be redundant, since there is no one to receive the signal. But if queen pheromone is an honest signal inextricably linked with fertility, it should correlate with fertility and be expressed irrespective of the presence or absence of receivers of the signal, by virtue of being a byproduct of the state of fertility. Hence we compared the Dufour's gland hydrocarbons and ovaries of solitary foundresses with queens and workers of post-emergence nests. Our results suggest that queen pheromone composition in R. marginata is a byproduct of fertility and hence can honestly signal fertility. This provides important new evidence for the honest signalling hypothesis.
Resumo:
Ropalidia marginata, a primitively eusocial wasp, is different from typical primitively eusocial species in having docile queens who cannot be using dominance to maintain reproductive monopoly and instead appear to use a pheromone from the Dufour's gland to do so. When a docile queen is removed from her colony, one of the workers (potential queen, PQ) becomes highly aggressive, and if the queen is not returned, gradually loses her aggression and becomes the new docile queen within a few days. We hypothesized that the decrease in aggression of the PQ with time since queen removal should be correlated with her change in ovaries and pheromone profile. Because the Dufour's gland hydrocarbon composition in R.marginata can be correlated with fertility, this also gave us an opportunity to test whether PQ is different from workers in her Dufour's gland hydrocarbons. In this study, we therefore trace the road to royalty in R.marginata, that is, the transition of the PQ during queen establishment, in terms of her ovaries, aggression, and Dufour's gland hydrocarbons. Our study focuses on queen establishment, which is important for understanding how reproductive conflict can be manifested and resolved.
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This article outlines the outcome of work that set out to provide one of the specified integral contributions to the overarching objectives of the EU- sponsored LIFE98 project described in this volume. Among others, these included a requirement to marry automatic monitoring and dynamic modelling approaches in the interests of securing better management of water quality in lakes and reservoirs. The particular task given to us was to devise the elements of an active management strategy for the Queen Elizabeth II Reservoir. This is one of the larger reservoirs supplying the population of the London area: after purification and disinfection, its water goes directly to the distribution network and to the consumers. The quality of the water in the reservoir is of primary concern, for the greater is the content of biogenic materials, including phytoplankton, then the more prolonged is the purification and the more expensive is the treatment. Whatever good that phytoplankton may do by way of oxygenation and oxidative purification, it is eventually relegated to an impurity that has to be removed from the final product. Indeed, it has been estimated that the cost of removing algae and microorganisms from water represents about one quarter of its price at the tap. In chemically fertile waters, such as those typifying the resources of the Thames Valley, there is thus a powerful and ongoing incentive to be able to minimise plankton growth in storage reservoirs. Indeed, the Thames Water company and its predecessor undertakings, have a long and impressive history of confronting and quantifying the fundamentals of phytoplankton growth in their reservoirs and of developing strategies for operation and design to combat them. The work to be described here follows in this tradition. However, the use of the model PROTECH-D to investigate present phytoplankton growth patterns in the Queen Elizabeth II Reservoir questioned the interpretation of some of the recent observations. On the other hand, it has reinforced the theories underpinning the original design of this and those Thames-Valley storage reservoirs constructed subsequently. The authors recount these experiences as an example of how simulation models can hone the theoretical base and its application to the practical problems of supplying water of good quality at economic cost, before the engineering is initiated.
Resumo:
Today there are approximately 230 published scientific papers on queen conch, Strombus gigas. Publication on this species began in the 1960's and increased rapidly during the 1980's and 1990's (Fig. 1). The increase in publication after 1980 was associated with three particular areas ofendeavor. First, many articles were published to document the rapid depletion of conch stocks throughout the Caribbean Sea. Second, substantial progress was made in understanding processes related to growth, mortality, and reproduction in queen conch. Third, because of the apparent and widespread decline in conch, several research laboratories, especially in Florida, Puerto Rico, Venezuela, and the Turks and Caicos Islands began experiments related to hatchery production of juvenile conch. The primary intent was to replenish wild stocks by releasing hatchery-reared animals. Today, hatchery production has been relatively well perfected, and the increase in numbers of scientific papers related specifically to culture has slowed. A thorough review of the history of conch mariculture was provided by Creswell (1994), and Davis (1994) summarized the details of larval culture technique.