Molecular mapping of the fatty (f) (formerly corpulent) gene in the LA/N rat obesity model

The LA/N-corpulent (cp) rat obesity model was a congenic rat strain developed at the National Institutes of Health by C. T. Hansen . The LA/N-cp rat originated from breeding the Koletsky rat, possessing the corpulent gene, with the normotensive LA/N inbred rat. The autosomal recessive single gene mutation, cp, produces obesity with hyperphagia, hyperinsulinemia and elevated activities of liver and skeletal muscle lipogenic enzymes in the LA/N-cp rat model. The Zucker-fatty mutation, which was mapped to rat chromosome , resulted in a comparable, but not identical obesity syndrome. Breeding experiments by Yen et al have suggested the cp and fa genes to be homologous and possibly allelic. To verify this hypothesis, we established interstrain crosses, LA/N-cp (cp/+) with 13M/Vc (fa/+), which yielded 10 obese and 32 lean offspring, a 1:3.2 ratio Our results support the cp -fa gene homology. For molecular analysis, crosses segregating the cp gene were constructed using a genetically distant counterstrain, Brown Norway (BN)/Crl (+/+) rats. Fourteen crosses between (LA/N-cp x BN) (cp/+) offspring yielded 31 obese and 80 lean progeny, a 1:2.6 ratio (=0.230, p\u3e0.50). We have mapped the chromosomal location of cp in 30 obese (LA/N-cp x BN) progeny using microsatellite markers for two genes flanking the fatty locus: glucose transporter 1 (Glut1) and phosphoglucomutase 1 (Pgm1). PCR-amplified sequence polymorphisms detected four Brown Norway alleles (representing 4 crossovers) at the Glut1 locus and 1 BN allele at the Pgm1 locus in 60 meioses. Our results place the cp mutation on rat chromosome 5, flanked by Glut1 and Pgm1. Pgm1 — 1.67 centiMorgan (cM) —— 6.67 cM — Glut1. With the proposed homology verified through our complementation studies, our physical mapping supports cp and fa as mutations in the same gene . Thus, the new symbol is now the proper designation for the obese syndrome, corpulent (cp)

Direct Spectrophotometric Determination of Serum and Urinary Oxalate with Oxalate Oxidase

Peer Reviewe

Disentangling chlorophyll fluorescence from atmospheric scattering effects in O_2 A‐band spectra of reflected sun‐light

Global retrieval of solar induced fluorescence emitted by terrestrial vegetation can provide an unprecedented measure for photosynthetic efficiency. The GOSAT (JAXA, launched Feb. 2009) and OCO-2 (NASA, to be launched 2013) satellites record high-resolution spectra in the O_2 A-band region, overlapping part of the chlorophyll fluorescence spectrum. We show that fluorescence cannot be unambiguously discriminated from atmospheric scattering effects using O_2 absorption lines. This can cause systematic biases in retrieved scattering parameters (aerosol optical thickness, aerosol height, surface pressure, surface albedo) if fluorescence is neglected. Hence, we demonstrate an efficient alternative fluorescence least-squares retrieval method based solely on strong Fraunhofer lines in the vicinity of the O_2 A-band, disentangling fluorescence from scattering effects. Not only does the Fraunhofer line fit produce a more accurate estimate of fluorescence emission, but it also allows improved retrievals of atmospheric aerosols from the O_2 A-band

Ab-initio study of the relation between electric polarization and electric field gradients in ferroelectrics

The hyperfine interaction between the quadrupole moment of atomic nuclei and the electric field gradient (EFG) provides information on the electronic charge distribution close to a given atomic site. In ferroelectric materials, the loss of inversion symmetry of the electronic charge distribution is necessary for the appearance of the electric polarization. We present first-principles density functional theory calculations of ferroelectrics such as BaTiO3, KNbO3, PbTiO3 and other oxides with perovskite structures, by focusing on both EFG tensors and polarization. We analyze the EFG tensor properties such as orientation and correlation between components and their link with electric polarization. This work supports previous studies of ferroelectric materials where a relation between EFG tensors and polarization was observed, which may be exploited to study ferroelectric order when standard techniques to measure polarization are not easily applied.Comment: 9 pages, 6 figures, 5 tables, corrected typos, as published in Phys. Rev.

Ertragsstabilität und Qualität von Weizensortenmischungen im Ökologischen Anbau

Disease development, yield and baking quality were assessed on the winter wheat cultivars Arina and Capo and their 1:1 mixture in a total of 12 sites on-farm in 2002/2003. Due to a severe drought disease severities were very low and probably had little effect on the plants. The more drought tolerant variety Capo over-yielded in mixtures on average by 21% while Arina yielded in mixtures as expected. Protein and gluten contents and baking volume in pure stands of Arina were usually higher than for Capo. Both varieties changed their quality parameters in mixtures. However, the parameters of the mixtures were not equal to the mean of the pure stands indicating some unknown interactions. The quality parameters of each variety or mixture were compared to the mean of all treatments in a given site allowing for regression analysis across sites. Capo was least able to improve its quality in reaction to improved site potential (expressed as mean baking volume) (slope: 0.64) while the mixtures reacted strongest (slope: 1.47). This indicates that mixtures might be better able to profit from good growing conditions than pure stands

Choice of steel material for bridge bearings to avoid brittle fracture

Bridge bearings need verification against brittle failure at low temperatures. The design of bearings according to EN 1337 may lead to structural components with thicknesses no longer covered in the relevant technical construction regulations. Due to its specific geometry, the loading and stressing and the fabrication process the prerequisites for using the rules in EN 1993 1 10 lead to conservative restrictions or uneconomical choice of steel material. For an economical bearing design further modifications of the existing rules are necessary. This report adapts the fracture mechanical approach used in EN 1993 1 10 and gives information for a “safe-sided” choice of steel material for bearings. The main modifications refer to the hypothetical design crack scenario and the definition of the “nominal design stress” at the geometric “hot-spot”. An advanced methodology using Finite Elements and a simplified method using linear bending theory are evaluated.JRC.G.5-European laboratory for structural assessmen

Theory of Megaphones and Receiving Horns

In 1919, A. G. Webster published a theory of the action of horns used as receivers. Recent development has given an increased interest in the megaphone. Webster\u27s theory may be modified to cover the case of the megaphone, assuming the constancy of the acoustic point impedance of the horn at the source. The result obtained is that the emitted energies at different frequencies are related as are the values of [(ad-bc)/(a-cz2)]2 wherein a, b, c and d, have the values specified in Webster\u27s theory and z2=δa2k2 (ki/2π-1/c0), k being 2π divided by wave length, ρ the density, a the velocity of sound and c0 the conductivity of the opening

Abnormal development of forebrain midline glia and commissural projections in Nfia knock-out mice

Nuclear factor I (NFI) genes are expressed in multiple organs throughout development (Chaudhry et al., 1997; for review, see Gronostajski, 2000). All four NFI genes are expressed in embryonic mouse brain, with Nfia, Nfib, and Nfix being expressed highly in developing cortex (Chaudhry et al., 1997). Disruption of the Nfia gene causes agenesis of the corpus callosum (ACC), hydrocephalus, and reduced GFAP expression (das Neves et al., 1999). Three midline structures, the glial wedge, glia within the indusium griseum, and the glial sling are involved in development of the corpus callosum (Silver et al., 1982; Silver and Ogawa, 1983; Shu and Richards, 2001). Because Nfia(-/-) mice show glial abnormalities and ACC, we asked whether defects in midline glial structures occur in Nfia(-/-) mice. NFI-A protein is expressed in all three midline populations. In Nfia(-/-) mice sling cells are generated but migrate abnormally into the septum and do not form a sling. Glia within the indusium griseum and the glial wedge are greatly reduced or absent and consequently Slit2 expression is also reduced. Although callosal axons approach the midline, they fail to cross and extend aberrantly into the septum. The hippocampal commissure is absent or reduced, whereas the ipsilaterally projecting perforating axons (Hankin and Silver, 1988; Shu et al., 2001) appear relatively normal. These results support an essential role for midline glia in callosum development and a role for Nfia in the formation of midline glial structures

Toward accurate CO_2 and CH_4 observations from GOSAT

The column-average dry air mole fractions of atmospheric carbon dioxide and methane (X_(CO_2) and X_(CH_4)) are inferred from observations of backscattered sunlight conducted by the Greenhouse gases Observing SATellite (GOSAT). Comparing the first year of GOSAT retrievals over land with colocated ground-based observations of the Total Carbon Column Observing Network (TCCON), we find an average difference (bias) of −0.05% and −0.30% for X_(CO_2) and X_(CH_4) with a station-to-station variability (standard deviation of the bias) of 0.37% and 0.26% among the 6 considered TCCON sites. The root-mean square deviation of the bias-corrected satellite retrievals from colocated TCCON observations amounts to 2.8 ppm for X_(CO_2) and 0.015 ppm for X_(CH_4). Without any data averaging, the GOSAT records reproduce general source/sink patterns such as the seasonal cycle of X_(CO_2) suggesting the use of the satellite retrievals for constraining surface fluxes