Relative acceptance of brodifacoum pellets and soft bait sachets by Polynesian rats (Rattus exulans) on Wake Atoll

Removing invasive rats from island ecosystems using rodenticides has proven conservation benefits and is an important management tool for conserving and restoring island ecosystems. However, rodenticide-based eradications can fail if not all rats consume enough bait to result in lethal toxicosis. A recent post-operational review of a failed attempt to eradicate rats from Wake Atoll suggested that some individuals may not have ingested a lethal dose of rodenticide due to potential dietary and/or sensory preferences developed via regular access to anthropogenic food sources. These food sources may be higher in fats and oils, possessing different sensory properties (e.g., softer, chewier, etc.) than the harder pellet formulation of the rodenticide Brodifacoum 25W Conservation (B-25W) used in the eradication attempt. To test this theory, we captured rats from two areas on Wake Island where they may have regular access to human food sources, as well as an uninhabited part of island where rats presumably have less access to human-based food sources and therefore are less likely to be preconditioned for these food types. We subjected them to a head-to-head two-choice bait selection trial between a “soft” sachet formulation of a brodifacoum-based bait, FINAL Soft Bait with Lumitrack® (FINAL), versus the harder pellet formulation of B-25W. Regardless of which habitat rats were captured in, rats overwhelmingly preferred the pellet formulation. No rats in the head-to-head trail consumed any of the FINAL bait, and 100% of the rats that consumed B-25W died. Of the rats in a separate no-choice trail of just FINAL bait, 5 failed to eat any bait; of the rats that did consume some of the FINAL bait, 80% died. Our results demonstrate that Polynesian rats on Wake Atoll do not prefer this soft formulation of brodifacoum-based rodenticide bait. Our results suggest that baiting strategies in the inhabited regions of the atoll, for a proposed eradication attempt, should continue to focus on utilizing traditional pellet formulations. While these results are unequivocal in our test case, we suggest caution in making inference to other situations where dietary preferences of local rodent populations may differ, and local environmental conditions may make other baiting choices more appropriate and efficacious

Hydrogen molecule in a magnetic field: The lowest states of the Pi manifold and the global ground state of the parallel configuration

The electronic structure of the hydrogen molecule in a magnetic field is investigated for parallel internuclear and magnetic field axes. The lowest states of the $\Pi$ manifold are studied for spin singlet and triplet$(M_s = -1)$ as well as gerade and ungerade parity for a broad range of field strengths $0 \leq B \leq 100 a.u.$ For both states with gerade parity we observe a monotonous decrease in the dissociation energy with increasing field strength up to $B = 0.1 a.u.$ and metastable states with respect to the dissociation into two H atoms occur for a certain range of field strengths. For both states with ungerade parity we observe a strong increase in the dissociation energy with increasing field strength above some critical field strength $B_c$. As a major result we determine the transition field strengths for the crossings among the lowest $^1\Sigma_g$, $^3\Sigma_u$ and $^3\Pi_u$ states. The global ground state for $B \lesssim 0.18 a.u.$ is the strongly bound $^1\Sigma_g$ state. The crossings of the $^1\Sigma_g$ with the $^3\Sigma_u$ and $^3\Pi_u$ state occur at $B \approx 0.18$ and $B \approx0.39 a.u.$, respectively. The transition between the $^3\Sigma_u$ and $^3\Pi_u$ state occurs at $B \approx 12.3 a.u.$ Therefore, the global ground state of the hydrogen molecule for the parallel configuration is the unbound $^3\Sigma_u$ state for $0.18 \lesssim B \lesssim 12.3 a.u.$ The ground state for $B \gtrsim 12.3 a.u.$ is the strongly bound $^3\Pi_u$ state. This result is of great relevance to the chemistry in the atmospheres of magnetic white dwarfs and neutron stars.Comment: submitted to Physical Review

Contacting single bundles of carbon nanotubes with alternating electric fields

Single bundles of carbon nanotubes have been selectively deposited from suspensions onto sub-micron electrodes with alternating electric fields. We explore the resulting contacts using several solvents and delineate the differences between Au and Ag as electrode materials. Alignment of the bundles between electrodes occurs at frequencies above 1 kHz. Control over the number of trapped bundles is achieved by choosing an electrode material which interacts strongly with the chemical functional groups of the carbon nanotubes, with superior contacts being formed with Ag electrodes.Comment: 4 pages, RevTe

Reconstruction methods for acoustic particle detection in the deep sea using clusters of hydrophones

This article focuses on techniques for acoustic noise reduction, signal filters and source reconstruction. For noise reduction, bandpass filters and cross correlations are found to be efficient and fast ways to improve the signal to noise ratio and identify a possible neutrino-induced acoustic signal. The reconstruction of the position of an acoustic point source in the sea is performed by using small-volume clusters of hydrophones (about 1 cubic meter) for direction reconstruction by a beamforming algorithm. The directional information from a number of such clusters allows for position reconstruction. The algorithms for data filtering, direction and position reconstruction are explained and demonstrated using simulated data.Comment: 7 pages, 13 figure

Feeding Practices in South Dakota Cattle Feedlots

During March 1989, a mail survey of South Dakota cattle feedlot managers was undertaken. The purposes of the survey were to characterize the nature of the cattle feeding industry in South Dakota and to determine the relationships between (i) each of size-of-feedlot and geographic location within the state and (ii) management practices followed by cattle feeders. Direct relationships exist between size-of-feedlot and the following: (1) rate of feedlot utilization in each quarter of the year (P\u3c.10); (2) percentage grain relative to roughage in both growing and finishing diets (P\u3c.10); (3) percentage of feedlots feeding high moisture grain, cracked grain, and ground hay (P\u3c.01); (4) percentage of feedlots using rumen stimulants and growth implants (P\u3c.01); and (5) percentages of managers testing feeds for nutrient composition, using feed scales to control feeding rates, maintaining feed records for separate pens of cattle, and hiring consultants to formulate rations (P\u3c.01). On the other hand, inverse relationships exist between size-of-feedlot and the following: (6) days on feed for heifer calves, yearling steers, and yearling heifers (P\u3c.10); (7) slaughter weight of steers (Pc.10); (8) percentage of home-raised hay and dry grain (P\u3c.10); (9) percentage of feedlots feeding ground grain and unprocessed hay (P\u3c.01); and (10) percentage of feedlots not using feed additives (P\u3c.10). Average days on feed for steer and heifer calves are lower (P\u3c.05) in the West than in other areas of the state. More milo is fed in the West; more barley is fed in the North Central region; and less home-raised corn silage and haylage are fed in the West than in other regions (P\u3c.05)

The Effect of Type of Birth, Breed of Sire Level of Postweaning Nutrition and Age of First Breeding on Lifetime Production of Targhee and Suffolk-Targhee Range Ewes

This investigation was initiated to determine which factors would be most beneficial to implement for range operations. This study involved five groups of ewes that were maintained for 5 or 6 years on several commercial range operations in western South Dakota

Do what you love and you'll never work a day in your life: testing fundamental assumptions about calling, effort and enjoyment

We test the fundamental assumptions that people experiencing a stronger sense of calling invest more effort in their work tasks, and find those tasks more enjoyable, than people with a weaker sense of calling. Both assumptions have been expressed theoretically, yet received limited empirical support. Among 2,839 workers in a crowdsourced marketplace, we found that people with a stronger calling toward their work completed more of a relatively unengaging work task and enjoyed the task more than those with a weaker calling. The calling-effort relationship was particularly strong when there was no financial incentive for effort (i.e., paid a fixed amount), highlighting the risk of exploitation for strong-calling employees. People with stronger callings nonetheless responded to financial incentives—they completed more work when offered additional pay to do so. The relationship between calling and enjoyment of the task was particularly strong when there was a financial incentive for effort (i.e., paid piece-rate), indicating that extrinsic rewards did not “crowd out” intrinsic rewards. Our findings are thus consistent with research about the presence of multiple motives for behavior. Our empirical support for these assumptions using more appropriate, rigorous methods paves the way to further develop novel calling theory