In many species, interval timing behavior is accurate-appropriate estimated durations-and scalar -errors vary linearly with estimated durations. While accuracy has been previously examined, scalar timing has not been yet clearly demonstrated in house mice (Mus musculus), raising concerns about mouse models of human disease. We estimated timing accuracy and precision in C57BL/6 mice, the most used background strain for genetic models of human disease, in a peak-interval procedure with multiple intervals. Both when timing two intervals (Experiment 1) or three intervals (Experiment 2), C57BL/6 mice demonstrated varying degrees of timing accuracy. Importantly, both at individual and group level, their precision varied linearly with the subjective estimated duration. Further evidence for scalar timing was obtained using an intraclass correlation statistic. This is the first report of consistent, reliable scalar timing in a sizable sample of house mice, thus validating the PI procedure as a valuable technique, the intraclass correlation statistic as a powerful test of the scalar property, and the C57BL/6 strain as a suitable background for behavioral investigations of genetically engineered mice modeling disorders of interval timing. KeywordsC57BL/6; interval timing; intraclass correlation; scalar property; peak-interval procedure Time is an essential dimension of the world, determining the decisions we make, the actions we take, and the very precision of our slightest movements (Gallistel, 1990). Organisms have developed a variety of methods to handle the constraints of time (Buhusi & Meck, 2005). For example, interval timing, or timing in the seconds-to-minutes range, is crucial for decisionmaking (Gallistel, 1990) and foraging (Henderson, Hurly, Bateson, & Healy, 2006). Accurate timing, i.e., responding at the appropriate time, has been demonstrated in a wide variety of animals, from invertebrates such as bees (Boisvert & Sherry, 2006), to many vertebrates, suchPlease address correspondence to: Catalin V. Buhusi, Medical University of South Carolina, Dept. Neurosciences, 173 Ashley Ave, 403 Basic Science Bldg., Charleston, SC, 29425-0510, Tel: 843-792-4494, Fax: 843-792-4423, buhusi@musc.edu.. Publisher's Disclaimer: The following manuscript is the final accepted manuscript. It has not been subjected to the final copyediting, fact-checking, and proofreading required for formal publication. It is not the definitive, publisher-authenticated version. The American Psychological Association and its Council of Editors disclaim any responsibility or liabilities for errors or omissions of this manuscript version, any version derived from this manuscript by NIH, or other third parties. The published version is available at www.apa.org/pubs/journals/bne. NIH Public Access Author ManuscriptBehav Neurosci. Author manuscript; available in PMC 2010 October 1. (Talton, Higa, & Staddon, 1999), birds (Cheng & Westwood, 1993, and mammals such as rats (Dews, 1962), woodmice (Lejeune & Wearden, 1991) and humans . In most of t...

Plasmas with peaked radial density profiles have been generated in the world’s largest helicon device, with plasma diameters of over 70 cm. The density profiles can be manipulated by controlling the phase of the current in each strap of two multistrap antenna arrays. Phase settings that excite long axial wavelengths create hollow density profiles, whereas settings that excite short axial wavelengths create peaked density profiles. This change in density profile is consistent with the cold-plasma dispersion relation for helicon modes, which predicts a strong increase in the effective skin depth of the rf fields as the wavelength decreases. Scaling of the density with magnetic field, gas pressure, and rf power is also presented.

Some 60,000 and 46,000 MT of sodium rich nuclear waste are now in storage in the US at Hanford and SRS facilities, respectively. We have developed a technology that uses the high sodium content to advantage: aqueous slurry wastes are first calcined into sodium hydroxide (NaOH) melt slurries, then vaporized and injected into a plasma. The Archimedes Filter separates plasma ions into light and heavy mass groups. For the first time, it is feasible to economically separate large amounts of material in a single-pass plasma device. Such a separation would substantially decontaminate High Level Waste since most radionuclides partition to the heavy fraction. The plasma process is based on setting up fast ExB rotation of a cylindrical plasma. At a certain critical rotational velocity ω E > ω B /2 ions are not confined by axial magnetic field and are lost radially. Because the critical rotational velocity depends on magnetic field the plasma and machine parameters can be set up to separate heavy radionuclides from majority of the light elements in the plasma and, thus, accomplish waste clean up. The paper discusses the Filter process, describes a demonstration device that has been constructed in San Diego, USA, and presents the first experimental results.

Experiments in the edge plasma of TEXT-U (the Texas Experimental Tokamak-Upgrade) [K. W. Gentle, Nucl. Technol. Fusion 1, 479 (1981)] have used a positively biased Langmuir probe in conjunction with two triple probes to examine the “wake” or disturbance in the plasma caused by the electron current collected by the driven probe. Spatial measurements of the disturbed volume have been made in the radial and poloidal directions at two points along the disturbed flux tube, at 12 meters and 28 meters away from the driven probe. Both non-time dependent and time-dependent experiments are used to determine the dispersion of the driven wave. A classical collisional two-fluid model of electron collection by a biased surface, which accounts for electric potential perturbations and the associated currents only, successfully predicts many of the qualitative features of the disturbance. The magnitudes of the collision rates, however, have to be increased beyond the best estimates in order to achieve quantitative agreement, indicating the possible involvement of anomalous cross-field current transport processes.