NORTH DAKOTA SHOPPER PERCEPTIONS OF GENETICALLY MODIFIED ORGANISMS AND FOOD: RESULTS OF A WINTER 2003 SURVEY

Replaced with revised version of paper 07/23/04.Biotechnology, Genetic Modification, Consumer Preferences, Food Consumption/Nutrition/Food Safety, Research and Development/Tech Change/Emerging Technologies,

ASSESSING NEW-GRADUATE APPLICANTS: ACADEMIC PERCEPTIONS AND AGRIBUSINESS REALITIES

This study empirically compares the level of importance assigned to the knowledge, skills, and experiences of applicants for entry-level positions by members of the agribusiness community and how these criteria were perceived by chairpersons of departments of agricultural economics. Chairpersons had a good understanding of criteria important to employers in evaluating applicants and how they prioritize these criteria. Communication and interpersonal skills were ranked as the most important criteria by both groups. Industry members assigned lower levels of importance for formal international training, an attribution largely shared by academic counterparts.agribusiness, agricultural economics, curriculum, international education, international exchanges, Teaching/Communication/Extension/Profession,

PERCEPTIONS OF GENETICALLY MODIFIED AND ORGANIC FOODS AND PROCESSES: NORTH DAKOTA COLLEGE STUDENTS

Perceptions of genetically modified (GM) and organic food among North Dakota college students were elicited and compared. Participants responded to one of two survey instruments containing identical wording except for reference to genetic modification or organic, after reading a primer defining the term used in their instrument. Participants' indicated their level of agreement with statements in the construct areas of health, environment, ethics, regulation, and risk. Responses were compared among survey instruments and to responses to previous surveys of Americans and of shoppers in North Dakota. Organic food was perceived as a healthier and safer choice. Organic practices were perceived to be more environmentally sound. Respondents expressed a level of concern over the unknown effects GM food could have on the environment and society as a whole. However, participants generally felt that genetic modification could be used effectively and valued some of the associated benefits. Reliability assessment revealed that statements within each construct area are reliable and can be used in future surveys.Genetically Modified, Consumer Perceptions, Organic, Food Consumption/Nutrition/Food Safety,

Shear-Flow Driven Current Filamentation: Two-Dimensional Magnetohydrodynamic Simulations

The process of current filamentation in permanently externally driven, initially globally ideal plasmas is investigated by means of two-dimensional Magnetohydrodynamic (MHD)-simulations. This situation is typical for astrophysical systems like jets, the interstellar and intergalactic medium where the dynamics is dominated by external forces. Two different cases are studied. In one case, the system is ideal permanently and dissipative processes are excluded. In the second case, a system with a current density dependent resistivity is considered. This resistivity is switched on self-consistently in current filaments and allows for local dissipation due to magnetic reconnection. Thus one finds tearing of current filaments and, besides, merging of filaments due to coalescence instabilities. Energy input and dissipation finally balance each other and the system reaches a state of constant magnetic energy in time.Comment: 32 Pages, 13 Figures. accepted, to appear in Physics of Plasmas (049012

Stimulated Raman scattering of water maser lines in astrophysical plasmas

Radiative transfer equations are derived and solved for the stimulated Raman scattering of water maser lines in the astrophysical plasmas with electron density of about 10^6 - 10^7 cm-3. In stimulated Raman scattering, the energy of water maser line is transferred to the side band modes: Stokes mode and anti-Stokes mode. The Stokes mode is easily produced by backward Raman scattering while the anti-Stokes mode is created by the interacting intersecting masers in the plasma. The intensity of the Stokes mode is higher than that of the anti-Stokes mode. These side band modes are proposed as explanation for the extreme velocity features observed in the galaxy NGC 4258. The threshold value of the brightness temperature for the Raman scattering is about 10^16 - 10^19 K, and it is satisfied in the case of NGC 4258.Comment: 12 pages, 4 Postscript figures. Accepted for Physics of Plasma

Giant Radio Pulses from the Crab Pulsar

Individual giant radio pulses (GRPs) from the Crab pulsar last only a few microseconds. However, during that time they rank among the brightest objects in the radio sky reaching peak flux densities of up to 1500 Jy even at high radio frequencies. Our observations show that GRPs can be found in all phases of ordinary radio emission including the two high frequency components (HFCs) visible only between 5 and 9 GHz (Moffett & Hankins, 1996). This leads us to believe that there is no difference in the emission mechanism of the main pulse (MP), inter pulse (IP) and HFCs. High resolution dynamic spectra from our recent observations of giant pulses with the Effelsberg telescope at a center frequency of 8.35 GHz show distinct spectral maxima within our observational bandwidth of 500 MHz for individual pulses. Their narrow band components appear to be brighter at higher frequencies (8.6 GHz) than at lower ones (8.1 GHz). Moreover, there is an evidence for spectral evolution within and between those structures. High frequency features occur earlier than low frequency ones. Strong plasma turbulence might be a feasible mechanism for the creation of the high energy densities of ~6.7 x 10^4 erg cm^-3 and brightness temperatures of 10^31 K.Comment: accepted by Advances in Space Research, to appear in the 35th COSPAR assembly proceeding

Self-Generated Magnetic Fields in Galactic Cooling Flows

Interstellar magnetic fields in elliptical galaxies are assumed to have their origin in stellar fields that accompany normal mass loss from an evolving population of old stars. The seed fields are amplified by interstellar turbulence driven by stellar mass loss and supernova events. These disordered fields are further amplified by time-dependent compression in the inward moving galactic cooling flow and are expected to dominate near the galactic core. Under favorable circumstances, fields similar in strength to those observed $B \sim 1-10~(r/10~kpc)^{-1.2}\mu$G can be generated solely from these natural galactic processes. In general the interstellar field throughout elliptical galaxies is determined by the outermost regions in the interstellar gas where the turbulent dynamo process can occur. Because of the long hydrodynamic flow times in galactic cooling flows, currently observed magnetic fields may result from periods of intense turbulent field amplification that occurred in the outer galaxy in the distant past. Particularly strong fields in ellipticals may result from ancient galactic mergers or shear turbulence introduced at the boundary between the interstellar gas and ambient cluster gas.Comment: 21 pages in AASTEX LaTeX with 2 figures; accepted by Astrophysical Journa

Universal properties of primary and secondary cosmic ray energy spectra

Atomic nuclei appearing in cosmic rays are typically classified as primary or secondary. However, a better understanding of their origin and propagation properties is still necessary. We analyse the flux of primary (He, C, O) and secondary nuclei (Li, Be, B) detected with rigidity (momentum/charge) between 2 GV and 3 TV by the Alpha Magnetic Spectrometer (AMS) on the International Space Station. We show that $q$-exponential distribution functions, as motivated by generalized versions of statistical mechanics with temperature fluctuations, provide excellent fits for the measured flux of all nuclei considered. Primary and secondary fluxes reveal a universal dependence on kinetic energy per nucleon for which the underlying energy distribution functions are solely distinguished by their effective degrees of freedom. All given spectra are characterized by a universal mean temperature parameter $\sim$ 200 MeV which agrees with the Hagedorn temperature. Our analysis suggests that QCD scattering processes together with nonequilibrium temperature fluctuations provide a plausible explanation for the observed universality in cosmic ray energy spectra. Our analysis suggests that QCD scattering processes together with nonequilibrium temperature fluctuations imprint universally onto the measured cosmic ray spectra, and produce a similar shape of energy spectra as high energy collider experiments on the Earth.Comment: 16 pages, 3 figure

Relativistic Kinetic Reconnection as the Possible Source Mechanism for High Variability and Flat Spectra in Extragalactic Radio Sources

We present the first synchrotron power spectra of a self-consistent kinetic reconnection scenario in the highly relativistic regime of a pair plasma. A fully electromagnetic relativistic particle-in-cell code is used to study the late-time evolution of kinetic magnetic reconnection at high resolution with a total ensemble of more than 108 particles. We show (1) the importance of the extremely dynamic late-time evolution of the reconnection region for the generation of nonthermal particles, (2) the efficient synchrotron emission by the accelerated fraction of particles, and (3) the application of the simulation results to pair-dominated active galactic nucleus core regions—the presumable origin of light jets. We conclude that collisionless kinetic reconnection in the relativistic regime is capable of explaining the enormous power output of P ~ 1047 ergs s-1 in certain luminous intraday variable quasars and the extremely hard observed radio spectra of flat-spectrum radio quasars