229 research outputs found
New York State dairy farmers' perceptions of antibiotic use and resistance : A qualitative interview study
Antibiotic resistance is a global problem affecting both human and animal health. Ensuring the strategic and effective use of antibiotics is paramount to combatting the emergence and spread of resistance. This study explored New York State (NYS) dairy farmers' perceptions regarding antibiotic use in dairy farming and antibiotic resistance. Dairy farmers' perceptions were assessed through semi-structured, in-person interviews. Twenty interviews with farm owners and/or managers of 15 conventional and five USDA certified organic dairy farms with 40 to 2,300 lactating cows were conducted. Thematic analysis was used to assess, compare and contrast transcripts for farmers' characterization of their beliefs, values, and concerns. Conventional dairy farmers had a low level of concern about the possible impacts of on-farm antibiotic resistance on human health and believed their antibiotic use was already judicious. Generally, they believed their cattle's health would suffer if antibiotic use were further curtailed. Conventional farmers expressed frustration over the possibility of more stringent governmental, milk cooperative, buyer, or marketer requirements for antibiotic use and associated animal welfare in the future. They attributed expanding regulations in part to misinformed consumer preferences, that farmers felt were influenced by the marketing of organic dairy products. Organic dairy farmers were generally more concerned about issues related to antibiotic resistance than conventional farmers. Both conventional and organic farmers placed emphasis on disease prevention through herd health management rather than treatment. In conclusion, the conventional NYS dairy farmers in this study were skeptical of the need for and benefits of reduced antibiotic use on their dairy farms. Interventions for farmers, delivered by a trusted source such as a veterinarian, that provide training about proper antibiotic use practices and information of possible financial benefits of refining antibiotic use may hold promise
Solid State Systems for Electron Electric Dipole Moment and other Fundamental Measurements
In 1968, F.L. Shapiro published the suggestion that one could search for an
electron EDM by applying a strong electric field to a substance that has an
unpaired electron spin; at low temperature, the EDM interaction would lead to a
net sample magnetization that can be detected with a SQUID magnetometer. One
experimental EDM search based on this technique was published, and for a number
of reasons including high sample conductivity, high operating temperature, and
limited SQUID technology, the result was not particularly sensitive compared to
other experiments in the late 1970's.
Advances in SQUID and conventional magnetometery had led us to reconsider
this type of experiment, which can be extended to searches and tests other than
EDMs (e.g., test of Lorentz invariance). In addition, the complementary
measurement of an EDM-induced sample electric polarization due to application
of a magnetic field to a paramagnetic sample might be effective using modern
ultrasensitive charge measurement techniques. A possible paramagnetic material
is Gd-substituted YIG which has very low conductivity and a net enhancement
(atomic enhancement times crystal screening) of order unity. Use of a
reasonable volume (100's of cc) sample of this material at 50 mK and 10 kV/cm
might yield an electron EDM sensitivity of e cm or better, a factor
of improvement over current experimental limits.Comment: 6 pages. Prepared for ITAMP workshop on fundamental physics that was
to be held Sept 20-22 2001 in Cambride, MA, but was canceled due to terrorist
attack on U.S New version incorporates a number of small changes, most
notably the scaling of the sensitivity of the Faraday magnetometer with
linewidth is now treated in a saner fashion. The possibility of operating at
an even lower temperarture, say 10 microkelvin, is also discusse
Energy levels and lifetimes of Gd IV and enhancement of the electron dipole moment
We have calculated energy levels and lifetimes of 4f7 and 4f6 5d
configurations of Gd IV using Hartree-Fock and configuration interaction
methods. This allows us to reduce significantly the uncertainty of the
theoretical determination of the electron electric dipole moment (EDM)
enhancement factor in this ion and, correspondingly, in gadolinium-containing
garnets for which such measurements were recently proposed. Our new value for
the EDM enhancement factor of Gd+3 is -2.2 +- 0.5. Calculations of energy
levels and lifetimes for Eu~III are used to control the accuracy.Comment: Submitted to Phys. Rev. A 6 pages, 0 figures, 3 table
Searches for violation of fundamental time reversal and space reflection symmetries in solid state experiments
The electric dipole moment (EDM) of a particle violates both time reversal
(T) and space reflection (P) symmetries. There have been recent suggestions for
searches of the electron EDM using solid state experiments [1,2]. These
experiments could improve the sensitivity compared to present atomic and
molecular experiments by several orders of magnitude. In the present paper we
calculate the expected effect. We also suggest that this kind of experiment is
sensitive to T,P-violation in nuclear forces and calculate effects caused by
the nuclear Schiff moment.
The compounds under consideration contain magnetic Gd ions and oxygen
O ions. We demonstrate that the main mechanism for the T,P-odd effects
is related to the penetration of the Oxygen 2p-electrons to the Gd core. All
the effects are related to the deformation of the crystal lattice.Comment: 13 pages, 6 figure
Coherent Manipulation of Quantum Delta-kicked Dynamics: Faster-than-classical Anomalous Diffusion
Large transporting regular islands are found in the classical phase space of
a modified kicked rotor system in which the kicking potential is reversed after
every two kicks. The corresponding quantum system, for a variety of system
parameters and over long time scales, is shown to display energy absorption
that is significantly faster than that associated with the underlying classical
anomalous diffusion. The results are of interest to both areas of quantum chaos
and quantum control.Comment: 6 pages, 4 figures, to appear in Physical Review
Control of Dynamical Localization
Control over the quantum dynamics of chaotic kicked rotor systems is
demonstrated. Specifically, control over a number of quantum coherent phenomena
is achieved by a simple modification of the kicking field. These include the
enhancement of the dynamical localization length, the introduction of classical
anomalous diffusion assisted control for systems far from the semiclassical
regime, and the observation of a variety of strongly nonexponential lineshapes
for dynamical localization. The results provide excellent examples of
controlled quantum dynamics in a system that is classically chaotic and offer
new opportunities to explore quantum fluctuations and correlations in quantum
chaos.Comment: 9 pages, 7 figures, to appear in Physical Review
Enhancement of the electron electric dipole moment in gadolinium garnets
Effects caused by the electron electric dipole moment (EDM) in gadolinium
garnets are considered. Experimental studies of these effects could improve
current upper limit on the electron EDM by several orders of magnitude. We
suggest a consistent theoretical model and perform calculations of observable
effects in gadolinium gallium garnet and gadolinium iron garnet. Our
calculation accounts for both direct and exchange diagrams.Comment: 9 page
Evidence for a narrow dip structure at 1.9 GeV/c in diffractive photoproduction
A narrow dip structure has been observed at 1.9 GeV/c in a study of
diffractive photoproduction of the final state performed by the
Fermilab experiment E687.Comment: The data of Figure 6 can be obtained by downloading the raw data file
e687_6pi.txt. v5 (2nov2018): added Fig. 7, the 6 pion energy distribution as
requested by a reade
Antimatter Regions in the Early Universe and Big Bang Nucleosynthesis
We have studied big bang nucleosynthesis in the presence of regions of
antimatter. Depending on the distance scale of the antimatter region, and thus
the epoch of their annihilation, the amount of antimatter in the early universe
is constrained by the observed abundances. Small regions, which annihilate
after weak freezeout but before nucleosynthesis, lead to a reduction in the 4He
yield, because of neutron annihilation. Large regions, which annihilate after
nucleosynthesis, lead to an increased 3He yield. Deuterium production is also
affected but not as much. The three most important production mechanisms of 3He
are 1) photodisintegration of 4He by the annihilation radiation, 2) pbar-4He
annihilation, and 3) nbar-4He annihilation by "secondary" antineutrons produced
in anti-4He annihilation. Although pbar-4He annihilation produces more 3He than
the secondary nbar-4He annihilation, the products of the latter survive later
annihilation much better, since they are distributed further away from the
annihilation zone.Comment: 15 pages, 9 figures. Minor changes to match the PRD versio
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