A novel insulin-like growth factor 2 mutation in mice increases body and tissue weights

This objective was to characterize effects of a novel mutation in mice on muscle and organ weights. Insulin-like growth factor 2 (IGF2), is a major regulator of growth. A mutation in the pig IGF2 gene (g.G3072A) disrupts the binding site of a transcriptional repressor of IGF2, subsequently increasing postnatal IGF2 expression. This results in increased muscle growth and reduced fat deposition. To further investigate the role of this mutation in animal development, mice with a homologous mutation were created by gene-editing. Eight male mice with or without the mutation were weaned at 21 days of age and group-housed with free access to food and water until 77 (±2d) of age. Mice were weighed, euthanized, and then dissected to collect heart, liver, inguinal fat, epididymal fat and individual muscle weights. Our hypothesis was that mice with the IGF2 mutation would display increased muscle mass but similar overall body weights, comparable to the phenotype of pigs. However, in the mice, body weight was increased (P0.23) between genotypes. These data suggest that, in contrast to the phenotype of IGF2 mutant pigs, IGF2 mutant mice experience an overall increase in growth. This increase is not restricted to muscle growth.Ope

SLS Development Checkpoint J-2X Testing in GFY 2013

No abstract availabl

Method of and an Apparatus for Counting Fibers

A method and apparatus are provided for distinguishing microscopic size, elongated fiber-like particles from cubically shaped, irregularly shaped, or spherically shaped particles in a mixture suspended in an electrically conducting liquid medium and for counting the fiber-like particles. In accordance with the method, an electrical zone sensing apparatus is provided with a screen means having microscopic openings therein of predetermined size to filter from the suspension particles having an effective area larger than the size of screen openings. Particles passing through the screen and through the sensing aperture of the zone sensing apparatus are separately sized by volume characteristics of electrical signals generated. The electrical signals having predetermined volume characteristics associated with the maximum spherical particles for passing through the screen openings are counted as non-fiber particles; whereas signals having larger volume characteristics are separately counted and designated as fibers. By the use of screens of successively smaller sizes, the larger particles including fibers having larger transverse cross sections may be successively filtered from the suspension and from reaching the sensing aperture. Therefore, smaller fibers having smaller cross-sectional area may be distinguished from particles having diameters approximating that of the smaller screen size openings.Sponsorship: IIT Research InstituteUnited States Paten

Method and Apparatus for Detecting and Sizing Microscopic Particles

Improved accuracy of size measurement and size distribution of particles in a fluid have been obtained in an electrical zone sensing apparatus by a flow control director means which directs the fluid in a more streamlined, less turbulent flow through an aperture at which the particles are electrically sensed. Also, the particles were directed and guided to flow substantially parallel to longitudinal axis for the aperture. The preferred flow control detector means comprises a contoured orifice having a smooth tapered inlet wall blended at an intersection with a central cylindrical wall defining a tubular shaped aperture.Sponsorship: IIT Research InstituteUnited States Paten

The density, construction and drag coefficient of electrostatic volcanic ash aggregates.

Recent laboratory experiments have demonstrated that electrostatic charges generated during the fragmentation of volcanic pumice cause rapid aggregation of the silicate particles produced. Here, we present measurements of the mass and component particle size distribution of individual, electrostatically bound aggregates produced during these experiments. Particles produced by fracturing pumice aggregated as they fell ∼1.5 m within an enclosed fall chamber. Aggregate mass measurements indicate aggregate densities of ∼200 kg m−3 or less. The component particle size analysis demonstrates exponential-type cumulative distributions which are dominated (on a volume basis) by particles ∼10–40 μm in diameter and contain few particles >70 μm. By representing these particles as disks of 5 μm thickness the calculated aggregate densities are in agreement with those derived from the aggregate mass measurements and indicate a relatively constant aggregate density with size (in contrast with previous results from fall velocities). Combining the density measurements with fall velocity data allows the drag coefficient of aggregates to be determined. Empirical equations developed to describe the particle size distribution within aggregates are used to derive relative aggregation coefficients for the electrostatic aggregation process. Our results can be used within numerical models of volcanic plumes in order to improve their representation of electrostatic aggregation processes