Search results for "Pose"
showing 10 items of 1189 documents
Genetic ablation of macrohistone H2A1 leads to increased leanness, glucose tolerance and energy expenditure in mice fed a high-fat diet.
2015
Contains fulltext : 155347.pdf (Publisher’s version ) (Closed access) BACKGROUND/OBJECTIVES: In the context of obesity, epigenetic mechanisms regulate cell-specific chromatin plasticity, perpetuating gene expression responses to nutrient excess. MacroH2A1, a variant of histone H2A, emerged as a key chromatin regulator sensing small nutrients during cell proliferation and differentiation. Mice genetically ablated for macroH2A1 (knockout (KO)) do not show overt phenotypes under a standard diet. Our objective was to analyse the in vivo role of macroH2A1 in response to nutritional excess. METHODS: Twelve-week-old whole-body macroH2A1 KO male mice were given a high-fat diet (60% energy from lard…
Variation in predator species abundance can cause variable selection pressure on warning signaling prey
2012
Predation pressure is expected to drive visual warning signals to evolve toward conspicuousness. However, coloration of defended species varies tremendously and can at certain instances be considered as more camouflaged rather than conspicuous. Recent theoretical studies suggest that the variation in signal conspicuousness can be caused by variation (within or between species) in predators' willingness to attack defended prey or by the broadness of the predators' signal generalization. If some of the predator species are capable of coping with the secondary defenses of their prey, selection can favor reduced prey signal conspicuousness via reduced detectability or recognition. In this study…
Software-Based EDF Message Scheduling on CAN Networks
2006
In this paper, a CAN-based communication system has been used to transmit data between different kinds of sensors and the drive control of an electrical vehicle. Software-based earliest deadline first (EDF) scheduling has been applied to order the data, making possible that more relevant measures meet with their delivery time and, discarding, if necessary, less relevant ones are discarded. The messages use their time-to-deadline as their priority level. With this mechanism, alongside with the discard of data that has lost its deadline, is it possible to deal with saturated that would require a bus utilization well above 100%.
The effect of predator appetite, prey warning coloration and luminance on predator foraging decisions
2010
AbstractAposematic prey advertise their defence to visually hunting predators using conspicuous warning colouration. Established theory predicts that aposematic signals should evolve towards increased conspicuousness and similarity to enhance predator education. Contrary to theoretical expectations, there is often considerable within- and between-species variation in aposematic signals of animals sharing the same ecological niche, phylogeny and predators. This may be explained by varying responses of predators that weaken the selection pressure for a consistent signal. By presenting painted mealworm larvae as prey to great tits as predators we tested if different aposematic colour patterns …
Effects of hard frost and freeze-thaw cycles on decomposer communities and N mineralisation in boreal forest soil
2003
Abstract Decomposition and mineralisation rates generally increase with increasing moisture and temperature. The expected global climate change may enhance precipitation and raise the temperatures at boreal latitudes, but absence of snow together with occasional low temperatures may cause disturbances in soil processes and faunal communities. To test the effects of disturbances such as hard frosts and freeze-thaw cycles on decomposer populations and N mineralisation, we performed two experiments. In the field experiment, carried out in a pine forest, we induced low soil temperatures by preventing snow covering the ground. In the laboratory test we established three “winter” temperature regi…
Soil decomposer animal community in heavy-metal contaminated coniferous forest with and without liming
2002
Abstract Responses of decomposer animals to heavy-metal contamination were studied near a Cu–Ni smelter in Finland. Samples were taken 0.5, 2 and 8 km from the smelter. In addition, plots fertilised with lime were sampled. Decomposer community in coniferous forest soil appeared to be quite resistant to heavy-metals. Only in the vicinity (0.5 km) of the smelter, were numbers of soil animals clearly decreased and their community structure strongly altered as compared to the control site (8 km). At the 2-km site, the community structure was only slightly changed. Most of the collembolan species were still found at the 0.5-km site. High metal sorption capacity of the humus, and heterogeneous di…
Regulation of decomposer community structure and decomposition processes in herbicide stressed humus soil
1997
Abstract Regulation of soil decomposer community structure and ecosystem processes, such as nutrient cycling, under herbicide stress was studied in a microcosm experiment. For the experiment, coniferous forest soil was defaunated and put into the microcosms. In the microcosms two different food webs including microbes, nematodes, tardigrades and oribatid mites, either with or without predatory mesostigmatid mites, were reconstructed. Half of the microcosms were stressed with a herbicide (active ingredient was terbuthylazine). During the 57 weeks incubation community structure of decomposers and nitrogen mineralisation were studied at five destructive samplings and two water irrigations. Soi…
Global phylogeography and geographical variation in warning coloration of the wood tiger moth (Parasemia plantaginis)
2015
Aim To investigate the phylogeography of the aposematic wood tiger moth (Parasemia plantaginis) across its Holarctic distribution and to explore how its genetic structure relates to geographical differences in hindwing warning coloration of males and females. Males have polymorphic hindwing coloration, while female hindwing coloration varies continuously, but no geographical analyses of coloration or genetic structure exist. Location The Holarctic. Methods We sequenced a fragment of the mitochondrial cytochrome c oxidase subunit I gene (COI) from 587 specimens. We also examined more current population structure by genotyping 569 specimens at 10 nuclear microsatellite loci. Species distribut…
Decomposer animals and bioremediation of soils
1998
Abstract Although microorganisms are degrading the contaminants in bioremediation processes, soil animals can also have important — while usually an indirect — role in these processes. Soil animals are useful indicators of soil contamination, both before and after the bioremediation. Many toxicity and bioavailability assessment methods utilizing soil animals have been developed for hazard and risk-assessment procedures. Not only the survival of the animals, but also more sensitive parameters like growth, reproduction and community structure have often been taken into account in the assessment. The use of bioassays together with chemical analyses gives the most reliable results for risk anal…
Conditions for the spread of conspicuous warning signals: A numerical model with novel insights
2007
The initial evolution of conspicuous warning signals presents an evolutionary problem because selection against rare conspicuous signals is presumed to be strong, and new signals are rare when they first arise. Several possible solutions have been offered to solve this apparent evolutionary paradox, but disagreement persists over the plausibility of some of the proposed mechanisms. In this paper, we construct a deterministic numerical simulation model that allows us to derive the strength of selection on novel warning signals in a wide range of biologically relevant situations. We study the effects of predator psychology (learning, rate of mistaken attacks, and neophobia) on selection. We a…