A predictive standard model for heavy electron systems

We propose a predictive standard model for heavy electron systems based on a detailed phenomenological two-fluid description of existing experimental data. It leads to a new phase diagram that replaces the Doniach picture, describes the emergent anomalous scaling behavior of the heavy electron (Kondo) liquid measured below the lattice coherence temperature, T*, seen by many different experimental probes, that marks the onset of collective hybridization, and enables one to obtain important information on quantum criticality and the superconducting/antiferromagnetic states at low temperatures. Because T* is ~J^2\rho/2, the nearest neighbor RKKY interaction, a knowledge of the single-ion Kondo coupling, J, to the background conduction electron density of states, \rho, makes it possible to predict Kondo liquid behavior, and to estimate its maximum superconducting transition temperature in both existing and newly discovered heavy electron families.Comment: 4 pages, 2 figures, submitted to J. Phys.: Conf. Ser. for SCES 201

The native ant, Tapinoma melanocephalum, improves the survival of an invasive mealybug, Phenacoccus solenopsis, by defending it from parasitoids

Citation: Feng, D. D., Michaud, J. P., Li, P., Zhou, Z. S., & Xu, Z. F. (2015). The native ant, Tapinoma melanocephalum, improves the survival of an invasive mealybug, Phenacoccus solenopsis, by defending it from parasitoids. Scientific Reports, 5, 8. https://doi.org/10.1038/srep15691Mutualistic ants can protect their partners from natural enemies in nature. Aenasius bambawalei is an important parasitoid of the the invasive mealybug Phenacoccus solenopsis. We hypothesized that mutualism between native ants and mealybugs would favor survival of mealybugs. To test this, we examined effects of tending by the native mutualistic ant Tapinoma melanocephalum on growth of P. solenopsis colonies on Chinese hibiscus, Hibiscus rosa-sinensis, in a field setting. Ant workers with access to honeydew of mealybugs lived much longer than those provisioned only with water in the laboratory, and number of ant workers foraging increased significantly with growth of mealybug colonies in the field. In later observations, there were significant differences in densities of mealybugs between ant-tended and -excluded treatments. Survival rate of mealybugs experiencing parasitoid attack was significantly higher on ant-tended plants than on ant-excluded plants. When the parasitoid was excluded, there was no difference in survival rate of mealybugs between ant-tended and -excluded plants. In most cases, ants directly attacked the parasitoid, causing the parasitoid to take evasive action. We conclude that native ants such as T. melanocephalum have the potential to facilitate invasion and spread of P. solenopsis in China by providing them with protection from parasitoids