Optimális éves viselkedési modellek: út a fiziológiától a populációkig? = Optimal annual routines: a path from physiology to populations?

A pályázat fő célja annak kiderítése volt, hogy a különböző állapotváltozók hogyan befolyásolják az optimális viselkedést, speciálisan a hogyan befolyásolják a fő életmenet események időzítését az éves cikluson belül. E cél elérése érdekében több modellt fejlesztettünk, és változatos terepi megfigyeléseket és aviáriumi kísérleteket folytattunk. Fő modelljeink azt mutatják, hogy az állapotváltozók (pl. tollminőség, energiatartalékok) jelentősen befolyásolhatják a vedlés és vándorlás időzítését, de a táplálékforrás időbeli eloszlása és szezonalitása is jelentős hatással lehet. Fő empirikus eredményeink szerint a táplálék minősége és a paraziták fertőzése jelentősen befolyásolhatja a tollminőséget. Egy komparatív vizsgálatban kimutattuk, hogy a vándorlás időzítését a különféle életmenet jellemzők jelentősen befolyásolják, de a szexuálisan szelektált jellegeknek nincs ilyen hatása. | The main aim of the project was to investigate how state variables effect optimal behaviour in general, and the optimal timing of major life history events over the annual cycle, in particular. To accomplish this aim we developed a couple of annual routine models and performed various field observations and aviary experiments. Our main models show that state variables (quality of feathers, energy reserves) can significantly influence the timing of optimal behaviour (moult, migration) but they also underline the importance of the temporal distribution and seasonality of food sources. Our main empirical results show that diet quality and parasite infection influence feather quality considerably. By a comparative study we found that life history traits (e.g. migration distance and diet) but not sexually selected traits influence the timing of migration

Laboratory measurements of forward and backward scattering of laser beams in water droplet clouds

Many aspects of the forward and backward scattering in dense water droplet clouds were studied using a laboratory scattering facility. This system is configured in a lidar geometry to facilitate comparison of the laboratory results to current lidar oriented theory and measurements. The backscatter measurements are supported with simultaneous measurements of the optical density, mass concentration, and droplet size distribution of the clouds. Measurements of the extinction and backscatter coefficients at several important laser wavelength have provided data on the relationship between these quantities for laboratory clouds at .633, 1.06, and 10.6 microns. The polarization characteristics of the backscatter of 1.06 microns were studied using several different types of clouds. More recently, the laboratory facility was modified to allow range-resolved backscatter measurements at 1.06 microns. Clouds made up of 3 layers, each with its own density, can be constructed. This allows the study of the effect of cloud inhomogeneity on the forward and backscatter

Optimális vedlési stratégiák = Optimal moult strategies

A pályázat fő célja annak kiderítése volt, hogy a különböző állapotváltozók hogyan befolyásolják az optimális viselkedést, speciálisan a hogyan befolyásolják a fő életmenet események időzítését az éves cikluson belül. E cél elérése érdekében több modellt fejlesztettünk, és változatos terepi megfigyeléseket és aviáriumi kísérleteket folytattunk. Fő modelljeink azt mutatják, hogy az állapotváltozók (pl. tollminőség, energiatartalékok) jelentősen befolyásolhatják a vedlés és vándorlás időzítését, de a táplálékforrás időbeli eloszlása és szezonalitása is jelentős hatással lehet. Fő empirikus eredményeink szerint a táplálék minősége és a paraziták fertőzése jelentősen befolyásolhatja a tollminőséget. Egy komparatív vizsgálatban kimutattuk, hogy a vándorlás időzítését a különféle életmenet jellemzők jelentősen befolyásolják, de a szezuálisan szelektált jellegeknek nincs ilyen hatása. | The main aim of the project was to investigate how state variables effect optimal behaviour in general, and the optimal timing of major life history events over the annual cycle, in particular. To accomplish this aim we developed a couple of annual routine models and performed various field observations and aviary experiments. Our main models show that state variables (quality of feathers, energy reserves) can significantly influence the timing of optimal behaviour (moult, migration) but they also underline the importance of the temporal distribution and seasonality of food sources. Our main empirical results show that diet quality and parasite infection influence feather quality considerably. By a comparative study we found that life history traits (e.g. migration distance and diet) but not sexually selected traits influence the timing of migration

Computer Algebra meets Finite Elements: an Efficient Implementation for Maxwell's Equations

We consider the numerical discretization of the time-domain Maxwell's equations with an energy-conserving discontinuous Galerkin finite element formulation. This particular formulation allows for higher order approximations of the electric and magnetic field. Special emphasis is placed on an efficient implementation which is achieved by taking advantage of recurrence properties and the tensor-product structure of the chosen shape functions. These recurrences have been derived symbolically with computer algebra methods reminiscent of the holonomic systems approach.Comment: 16 pages, 1 figure, 1 table; Springer Wien, ISBN 978-3-7091-0793-

Selecting children for head CT following head injury

OBJECTIVE: Indicators for head CT scan defined by the 2007 National Institute for Health and Care Excellence (NICE) guidelines were analysed to identify CT uptake, influential variables and yield. DESIGN: Cross-sectional study. SETTING: Hospital inpatient units: England, Wales, Northern Ireland and the Channel Islands. PATIENTS: Children (3 years were much more likely to have CT than those <3 years (OR 2.35 (95% CI 2.08 to 2.65)). CONCLUSION: Compliance with guidelines and diagnostic yield was variable across age groups, the type of hospital and region where children were admitted. With this pattern of clinical practice the risks of both missing intracranial injury and overuse of CT are considerable

Explaining individual variation in patterns of mass loss in breeding birds.

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.BACKGROUND: Studies of birds have a disproportionate representation in the literature on life-history evolution, because of the (apparent) ease with which the costs and benefits can be quantified and manipulated. During reproduction, birds frequently show a highly conserved pattern of mass change and changes in mass loss during breeding have been widely considered to be a valid short-term measure of the costs of reproduction. Experimental manipulations of the breeding attempts of birds usually argue that the presence of a response shows that a cost of reproduction exists, but there is little consensus as to how the size of these costs can be measured. RESULTS: We model this mass loss by considering how a parent can maximise its lifetime reproductive success, using a theoretical framework that is particularly suited to modelling parental care in altricial birds. If lifetime reproductive success is taken to be the sum of a parent's current and future reproductive success, we show that the exact forms of these components will influence the optimal amount of mass a parent should lose. In particular, we demonstrate that the shape of the relationship between parental investment and chick survival will lead to differing degrees of investment between parents of different initial qualities: parents with initially high levels of energy reserves could conceivably invested a lesser, similar or greater amount of resources than parents with initially low reserves, and these initially 'heavy' parents could potentially end up being lighter than the initially 'lighter' individuals. CONCLUSION: We argue that it is difficult to make predictions about the dependence of a parent's final mass on its initial mass, and therefore mass loss should only be used as a short-term measure of the costs of reproduction with caution. The model demonstrates that we require a better understanding of the relationship between mass loss and both current and future reproductive success of the parent, before predictions about mass loss can be made and tested. We discuss steps that could be taken to increase the accuracy of our predictions