Field evaluation of aerial applications of hydramethylnon and metaflumizone to control the red imported fire ant, Solenopsis invicta (Buren) and related ant species (Hymenoptera: formicidae)

The red imported fire ant (RIFA) was introduced to the United States from South America over 75 years ago, and has become a pest in wildlife settings. Hydramethylnon fire ant bait has been the industry standard for controlling the red imported fire ant. It can be compared to novel baits, and used to evaluate different aerial application techniques, such as the "skip swath" method. Two baits, hydramethylnon and metaflumizone, and a skipped-swath method were evaluated through observations of the activity levels of RIFA mounds and abundance. The effects of RIFA on other ant species were determined by eliminating RIFA with insecticides, and then sampling for all remaining ant species. Measurements of RIFA mound activity was done by recording their response to the vibration of wire flags located in active mounds. This method indicated control of RIFA with hydramethylnon and metaflumizone from 61 to 180 d post-treatment. Additional monitoring for RIFA activity, in the same plots, was done with baited vials. These results indicated that complete control of RIFA was never achieved with either hydramethylnon or metaflumizone within 180 d post-treatment; however, there were significant reductions in RIFA population as a result of both chemical baits from 3-92 d post-treatment. A reduction of RIFA populations occurred with both baits, as determined through scheduled sampling of all ant species using baited vials. Native ants, such as Dorymyrmex spp., were found in higher numbers once RIFA populations were reduced, indicating that the two ant species compete for resources such as food and space. Dorymyrmex spp. numbers were suppressed by RIFA populations, while other ants, such as Paratrechina spp. were unaffected

Effect of Values and Technology Use on Exercise: Implications for Personalized Behavior Change Interventions

Technology has recently been recruited in the war against the ongoing obesity crisis; however, the adoption of Health & Fitness applications for regular exercise is a struggle. In this study, we present a unique demographically representative dataset of 15k US residents that combines technology use logs with surveys on moral views, human values, and emotional contagion. Combining these data, we provide a holistic view of individuals to model their physical exercise behavior. First, we show which values determine the adoption of Health & Fitness mobile applications, finding that users who prioritize the value of purity and de-emphasize values of conformity, hedonism, and security are more likely to use such apps. Further, we achieve a weighted AUROC of .673 in predicting whether individual exercises, and we also show that the application usage data allows for substantially better classification performance (.608) compared to using basic demographics (.513) or internet browsing data (.546). We also find a strong link of exercise to respondent socioeconomic status, as well as the value of happiness. Using these insights, we propose actionable design guidelines for persuasive technologies targeting health behavior modification

Using the Energy Spectrum at DAMA/LIBRA to Probe Light Dark Matter

A weakly interacting massive particle (WIMP) weighing only a few GeV has been invoked as an explanation for the signal from the DAMA/LIBRA experiment. We show that the data from DAMA/LIBRA are now powerful enough to strongly constrain the properties of any putative WIMP. Accounting for the detailed recoil spectrum, a light WIMP with a Maxwellian velocity distribution and a spin-independent (SI) interaction cannot account for the data. Even neglecting the spectrum, much of the parameter space is excluded by limits from the DAMA unmodulated signal at low energies. Significant modifications to the astrophysics or particle physics can open light mass windows.Comment: 5 pages, 5 figure

On shocks driven by high-mass planets in radiatively inefficient disks. I. Two-dimensional global disk simulations

Recent observations of gaps and non-axisymmetric features in the dust distributions of transition disks have been interpreted as evidence of embedded massive protoplanets. However, comparing the predictions of planet-disk interaction models to the observed features has shown far from perfect agreement. This may be due to the strong approximations used for the predictions. For example, spiral arm fitting typically uses results that are based on low-mass planets in an isothermal gas. In this work, we describe two-dimensional, global, hydrodynamical simulations of disks with embedded protoplanets, with and without the assumption of local isothermality, for a range of planet-to-star mass ratios 1-10 M_jup for a 1 M_sun star. We use the Pencil Code in polar coordinates for our models. We find that the inner and outer spiral wakes of massive protoplanets (M>5 M_jup) produce significant shock heating that can trigger buoyant instabilities. These drive sustained turbulence throughout the disk when they occur. The strength of this effect depends strongly on the mass of the planet and the thermal relaxation timescale; for a 10 M_jup planet embedded in a thin, purely adiabatic disk, the spirals, gaps, and vortices typically associated with planet-disk interactions are disrupted. We find that the effect is only weakly dependent on the initial radial temperature profile. The spirals that form in disks heated by the effects we have described may fit the spiral structures observed in transition disks better than the spirals predicted by linear isothermal theory.Comment: 10 pages, 8 figures. ApJ, accepte

Tris(oxazolinyl)boratomagnesium-Catalyzed Cross-Dehydrocoupling of Organosilanes with Amines, Hydrazine, and Ammonia

We report magnesium-catalyzed cross-dehydrocoupling of Si–H and N–H bonds to give Si–N bonds and H2. A number of silazanes are accessible using this method, as well as silylamines from NH3 and silylhydrazines from N2H4. Kinetic studies of the overall catalytic cycle and a stoichiometric Si–N bond-forming reaction suggest nucleophilic attack by a magnesium amide as the turnover-limiting step