Influence of spatial and temporal dynamics of agricultural practices on the lesser kestrel

1. European agriculture is facing dramatic changes that are likely to have marked impacts on farmland biodiversity. There is an urgent need to develop land management strategies compatible with the conservation of biodiversity.2. We applied a spatially explicit behaviour-based model to assess how farmland management and the pattern of events across the annual farming calendar influences the foraging decisions of lesser kestrels Falco naumanni in a cereal steppe landscape. Moreover, we simulated the most likely scenarios of future agricultural changes to predict its impacts on lesser kestrel breeding success. Lesser kestrels have been the subject of serious conservation concern and constitute a good model species to judge impacts on farmland species more widely.3. Our results show that the location of cereal and fallow patches within a 2-km radius of a kestrel colony influences the total food supply delivered to the nestlings, explaining the differences in breeding success between years and colonies. Furthermore, the particular sequence in which patches are harvested by farmers is also predicted to influence offspring survival.4. Agricultural intensification, simulated by increasing the proportion of cereal fields, is predicted to negatively influence breeding success. However, the field harvesting sequence can play an important role in alleviating the effects of the increased percentage of cereal, as demonstrated by the higher breeding success obtained when harvesting starts from patches farthest from the colonies. The replacement of cereal cultivation by low-intensity grazed fallows would not be detrimental for kestrels.5. Synthesis and applications. Our results highlight the effectiveness of behaviour-based models to evaluate the interacting effect of spatial and temporal dynamics of agricultural landscapes and predict the response of populations to environmental change. To optimize food availability for lesser kestrels, land managers should implement long rotational schemes with < 60% of the area under extensive cereal cultivation in a 2-km radius around colonies. Harvesting should start in the cereal patches farthest from colonies. Ideally, the predominant land use around colonies should be fallows. These outcomes illustrate how behaviour-based models can be applied to identify specific management recommendations that would improve the effectiveness of agri-environmental schemes, the most accepted tool for maintaining farmland landscapes

Comparison of thread-cutting behaviour in three specialist predatory mites to cope with complex webs of Tetranychus spider mites

Anti-predator defenses provided by complex webs of Tetranychus mites can severely impede the performance of generalist predatory mites, whereas this may not be true for specialist predatory mites. Although some specialist predatory mites have developed morphological protection to reduce the adverse effects of complex webs, little is known about their behavioral abilities to cope with the webs. In this study, we compared thread-cutting behavior of three specialist predatory mites, Phytoseiulus persimilis, Neoseiulus womersleyi and N. californicus, exhibited inside the complex web of T. urticae. No major difference was observed among them in the basic pattern of this behavior, using chelicerae and palps, and in the number of silken threads severed while moving inside the web. These results and observations suggest that each predator species cut many sticky silken threads to move inside the complex web without suffering from serious obstructio

Improved detection of nitric oxide radical (NO•) production in an activated macrophage culture with a radical scavenger, car☐y PTIO, and Griess reagent

AbstractAn improved method for the detection of nitric oxide radicals (NO•in cultures of activated macrophages was developed, involving a nitric oxide radical scavenger, 2-(4-car☐yphenyl)-4, 4, 5, 5-tetramethylimidazoline-3-oxide-l-oxyl (car☐y PTIO) and Griess reagent. A murine macrophage-like cell line, J774.1, was activated with interferon-γ (IFN-γ) and bacterial lipopolysaccharide (LPS), which induced the production and secretion of NO2− into the culture supernatant. Addition of car☐y PTIO to the activated macrophages increased the amount of NO2−1 to 4- to 5-fold without cell damages, probably because car☐y PTIO rapidly reacted with NO• to form NO2−1 which was finally assayed by the Griess reaction

The importance of globalisation in driving the introduction and establishment of alien species in Europe

Understanding the role of globalisation in promoting introduction and establishment of alien species is an important step towards successful management of biological invasions. We aimed to quantify the taxon-dependent association of globalisation with the introduction and establishment of alien species in Europe. The availability of the KOF Index of Globalisation that measures all economic, social and political dimensions of global connectivity enables a study of this factor. Based on an extensive database of alien species, we used model selections based on the Akaike Information Criterion and hierarchical partitioning to identify the importance of globalisation in predicting the number of all introduced species and established species of ten mainly terrestrial taxa in countries across Europe. The association of globalisation with alien species establishment varied depending on taxon type. While the gross domestic product (GDP) of countries was a strong predictor for all but one taxon, globalisation was also found to be an important predictor for three taxa including those of high (e.g. insects) and low mobility (e.g. magnoliophyta). Globalisation explained 3.1 to 22 % independently, and 5.5 to 35 % jointly with other variables, of among-country variations in the number of established alien species. The effect of globalisation on the distribution of all introduced species is not substantially different from that on the established alien species. This study highlights how globalisation among habitat availability and environmental conditions can determine the patterns of alien species introduction and establishment across Europe. The results also emphasise the varying degree of importance between different taxa. Knowledge of the relative significance of various pathways with regard to different taxa is important for correctly focusing efforts to reduce the spread of these species.T.A. is financially supported by the European Commission’s Marie Curie International Incoming Fellowship Programme (PIIF-GA-2011-303221). K.S.-H.P. is supported by the IFLS Fellowship at the University of Southampton.This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1111/ecog.0189

Relativistic particle acceleration in developing Alfv\'{e}n turbulence

A new particle acceleration process in a developing Alfv\'{e}n turbulence in the course of successive parametric instabilities of a relativistic pair plasma is investigated by utilyzing one-dimensional electromagnetic full particle code. Coherent wave-particle interactions result in efficient particle acceleration leading to a power-law like energy distribution function. In the simulation high energy particles having large relativistic masses are preferentially accelerated as the turbulence spectrum evolves in time. Main acceleration mechanism is simultaneous relativistic resonance between a particle and two different waves. An analytical expression of maximum attainable energy in such wave-particle interactions is derived.Comment: 15 pages, 9 figures, 1 tabl

Reducing Resonant Vibration of a Rotor by Tuning the Gap between a Superconducting Bulk and a Permanent Magnet

AbstractThis study investigated passing through a critical speed of a rotor supported by a superconductor with an electromagnet. Here we adopted the idea that the gap between the superconductor and the rotor can be tuned variably by using electromagnetic force of the electromagnet so that the natural frequency or the stiffness can be changed. By using this method, it can be expected that resonant vibration be reduced. We developed an analytical model and then carried out numerical simulation. Numerical results show that considerable reduction of the resonant amplitude can be achieved by proper tuning of switching the electromagnet