31,857 research outputs found
Terpenoid-Induced Feeding Deterrence and Antennal Response of Honey Bees
Multiple interacting stressors negatively affect the survival and productivity of managed honey bee colonies. Pesticides remain a primary concern for beekeepers, as even sublethal exposures can reduce bee immunocompetence, impair navigation, and reduce social communication. Pollinator protection focuses on pesticide application guidelines; however, a more active protection strategy is needed. One possible approach is the use of feeding deterrents that can be delivered as an additive during pesticide application. The goal of this study was to validate a laboratory assay designed to rapidly screen compounds for behavioral changes related to feeding or feeding deterrence. The results of this investigation demonstrated that the synthetic Nasonov pheromone and its terpenoid constituents citral, nerol, and geraniol could alter feeding behavior in a laboratory assay. Additionally, electroantennogram assays revealed that these terpenoids elicited some response in the antennae; however, only a synthetic Nasonov pheromone, citral, and geraniol elicited responses that differed significantly from control and vehicle detections
The decay and collisions of dark solitons in superfluid Fermi gases
We study soliton collisions and the decay of solitons into sound in
superfluid Fermi gases across the Bose-Einstein condensate to
Bardeen-Cooper-Schrieffer (BEC-BCS) crossover by performing numerical
simulations of the time-dependent Bogoliubov-de Gennes equations. This decay
process occurs when the solitons are accelerated to the bulk pair-breaking
speed by an external potential. A similar decay process may occur when solitons
are accelerated by an inelastic collision with another soliton. We find that
soliton collisions become increasingly inelastic as we move from the BEC to BCS
regimes, and the excess energy is converted into sound. We interpret this
effect as being due to evolution of Andreev bound states localized within the
soliton.Comment: 9 pages, 5 figure
The Zero Age Main Sequence of WIMP burners
We modify a stellar structure code to estimate the effect upon the main
sequence of the accretion of weakly interacting dark matter onto stars and its
subsequent annihilation. The effect upon the stars depends upon whether the
energy generation rate from dark matter annihilation is large enough to shut
off the nuclear burning in the star. Main sequence WIMP burners look much like
protostars moving on the Hayashi track, although they are in principle
completely stable. We make some brief comments about where such stars could be
found, how they might be observed and more detailed simulations which are
currently in progress. Finally we comment on whether or not it is possible to
link the paradoxically young OB stars found at the galactic centre with WIMP
burners.Comment: 4 pages, 3 figs. Matches published versio
Electromagnetic Contributions to the Schiff Moment
The Schiff moment, \smij, is a parity and time reversal violating
fermion-fermion coupling. The nucleus-electron Schiff moment generically gives
the most important contribution to the electric dipole moments of atoms and
molecules with zero net intrinsic electronic spin and nuclear spin . Here, the electromagnetic contribution to the Schiff moment, \emij, is
considered. For a nucleon, the leading chirally violating contribution to this
interaction is calculable in the chiral limit in terms of the parity and time
reversal violating pion-nucleon coupling. For the Schiff moment of heavy
nuclei, this chiral contribution is somewhat smaller than the finite size
effect discussed previously in the literature.Comment: 7 pages, 1 figure (not included), Tex file, requires phyzzx, preprint
SCIPP 93/4
SITE-SPECIFIC VERSUS WHOLE-FIELD FERTILITY AND LIME MANAGEMENT IN MICHIGAN SOYBEANS AND CORN
Prior research into variable-rate application (VRA) of fertilizer nutrients has found profitability to be lacking in single nutrient applications to U.S. cereal crops. This study examines the yield and cost effects of VRA phosphorus, potassium and lime application on Michigan corn and soybean farm fields in 1998-2001. After four years, we found no yield gain from site-specific management, but statistically significant added costs, resulting in no gain in profitability. Contrary to results elsewhere, there was no evidence of enhanced spatial yield stability due to site-specific fertility management. Likewise, there was no evidence of decreased variability of phosphorus, potassium or lime after VRA treatment. Site-specific response functions and yield goals might also enhance the likelihood of profitable VRA in the future.Crop Production/Industries,
Design of an FPGA-based high-speed filter-decimator for the GIFTS imaging interferometer
This paper presents the design of an FPGA-based frame filter-decimator for the geostationary imaging Fourier transform spectrometer (GIFTS). The decimator reduces samples from two 128/spl times/128 sample imaging arrays from 1638.4 fps to 102.4 complex fps for the long wave IR (LWIR) band and from 1638.4 fps to 204.8 complex fps for the medium wave IR (MWIR) band. The design uses a novel parallel pipeline architecture to handle the bandpass sampling and decimation of the 16 k array samples which arrive a frame-at-a-time. The design is challenging because of significant speed, size, weight and power restrictions for satellite implementation
Making a financial time machine:a multitouch application to enable interactive 3-D visualization of distant savings goals
Financial planning and decision making for the general public continues to vex and perplex in equal measure. Whilst the tools presented by a typical desktop computer should make the task easier, the recent financial crisis confirms the increasing difficulty that people have in calculating the benefits of deferring consumption for future gains (i.e. Saving). We present an interactive concept demonstration for Microsoft SurfaceTM that tackles two of the key barriers to saving decision making. Firstly we show an interface that avoid the laborious writing down or inputting of data and instead embodies the cognitive decision of allocation of resources in a physical gesture based interface, where the scale of the investment or expenditure correlates with the scale of the gesture. Second we show how a fast-forward based animation can demonstrate the impact of small increments in savings to a long term savings goal in a strategy game-based, interactive format. The platform uses custom software (XNATM format) as opposed to the more usual WPFTM format found on Surface applications. This enables dynamic 3-D graphical icons to be used to maximize the interactive appeal of the interface. Demonstration and test trial feedback indicates that this platform can be adapted to suit the narrative of individual purchasing decisions to inform educate diverse user groups about the long term consequences of small financial decisions
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