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

Are both agricultural intensification and farmland abandonment threats to biodiversity? A test with bird communities in paddy-dominated landscapes

Land-use changes, including agricultural intensification and farmland abandonment, influence biodiversity in agricultural landscapes. However, few studies have focused on how the two major land-use changes affect different types of species at landscape scales. This study examined the relationships between the richness and abundance of five bird groups (agricultural wetland species, agricultural land species, grassland species, edge species, and woodland species) as well as the total species richness and abundance, and intensification or abandonment in 28 square, 100-ha grid cells in paddy-dominated landscapes in the Tone River basin of central Japan. Rice-field intensification and abandonment were not completely segregated spatially: intensification occurred in both plain and hilly areas surrounded by forests, while abandonment tended to occur in hilly areas. The effects of intensification and abandonment differed among species groups and between seasons. The richness or abundance of agricultural wetland species in summer were negatively associated with both intensification and abandonment. While the abundance of agricultural land species in winter and grassland species in both seasons were positively associated with intensification and abandonment, respectively. The total species richness and abundance did not show clear association with intensification and abandonment due to a variety of responses of the five bird groups. Based on prefectural Red Data Books, agricultural wetland species, followed by grassland species, were more threatened than other three groups in both summer and winter. This study found that (1) the diversity of habitats (including consolidated and abandoned farmlands) provides buffer areas for the different bird groups on different times of the year and (2) agricultural wetland species that use flooded rice fields in summer, such as egrets and shorebirds, are particularly threatened by both intensification and abandonment.We thank Yoshinori Tokuoka, Susumu Yamada, Eun-Young Kim, and Shori Yamamoto for providing land-use data. We also appreciate two anonymous reviewers for their constructive comments and suggestions. This study was conducted as part of the research project “Developing management techniques for agricultural and aquatic ecosystems in river basins in pursuit of coexistence with nature,” funded by the Agriculture, Forestry and Fisheries Research Council of Japan. N.K. and T.O. were also financially supported by JSPS (Japan Society for the Promotion of Science) KAKENHI Grant Numbers 25830154 and 24710038, respectively. T.A. was supported by the European Commission’s Marie Curie International Incoming Fellowship Programme (PIIFGA-2011-303221).This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.agee.2015.08.01