A high-resolution integrated map of copy number polymorphisms within and between breeds of the modern domesticated dog

<p>Abstract</p> <p>Background</p> <p>Structural variation contributes to the rich genetic and phenotypic diversity of the modern domestic dog, <it>Canis lupus familiaris</it>, although compared to other organisms, catalogs of canine copy number variants (CNVs) are poorly defined. To this end, we developed a customized high-density tiling array across the canine genome and used it to discover CNVs in nine genetically diverse dogs and a gray wolf.</p> <p>Results</p> <p>In total, we identified 403 CNVs that overlap 401 genes, which are enriched for defense/immunity, oxidoreductase, protease, receptor, signaling molecule and transporter genes. Furthermore, we performed detailed comparisons between CNVs located within versus outside of segmental duplications (SDs) and find that CNVs in SDs are enriched for gene content and complexity. Finally, we compiled all known dog CNV regions and genotyped them with a custom aCGH chip in 61 dogs from 12 diverse breeds. These data allowed us to perform the first population genetics analysis of canine structural variation and identify CNVs that potentially contribute to breed specific traits.</p> <p>Conclusions</p> <p>Our comprehensive analysis of canine CNVs will be an important resource in genetically dissecting canine phenotypic and behavioral variation.</p

Achieving Balance as a Survival Strategy for a Small Cyclotron Facility

Positron emission tomography (PET) forms the rationale for several dozen new cyclotron installations across the world. The success of these small accelerators has resulted in an excess production capacity. This suggests fanning out as a regional distribution center or, as in our case, reaching out to provide Argonne Nat\u27l Lab with F-18 for the study of astrophysical reaction rates with radioactive ion beams. The challenge to scale up our target yields has greatly benefited our medical mission. The diversification vitalizes our PhD training, and the collegial relationship provides a needed measure of balance. Presented at the 14th International Conference on Cyclotrons and the Applications, Faure, Cape Town, South Africa, October 8-13, 1995

Addressing the Third Gamma Problem in PET

PET brings the promise of quantitative imaging of the in-vivo distribution of any positron emitting nuclide, a list with hundreds of candidates. All but a few of these, the pure positron emitters, have isotropic, coincident gamma rays that give rise to misrepresented events in the sinogram and in the resulting reconstructed image. Of particular interest are 10C, 14O, 38K, 52mMn, 60Cu, 61Cu, 94mTc, and 124I, each having high-energy gammas that are Compton-scattered down into the 511 keV window. The problems arising from the third gamma, and its accommodation by standard scatter correction algorithms, were studied empirically, employing three scanner models (CTI 933/04, CTI HR+, and GE Advance), imaging three phantoms (line source, NEMA scatter, and contrast/detail), with 18F or 38K and 72As mimicking 14O and 10C, respectively, in 2D and 3D modes. Five findings emerge directly from the image analysis. The third gamma: (1) does, obviously, tax the single event rate of the PET scanners, particularly in the absence of septa, from activity outside of the axial field of view; (2) does, therefore, tax the random rate, which is second order in singles, although the gamma is a prompt coincidence partner; (3) does enter the sinogram as an additional flat background, like randoms, but unlike scatter; (4) is not seriously misrepresented by the scatter algorithm which fits the correction to the wings of the sinogram and (5) does introduce additional statistical noise from the subsequent subtraction, but does not seriously compromise the detectability of lesions as seen in the contrast/detail phantom. As a safeguard against the loss of accuracy in image quantitation, fiducial sources of known activity are included in the field of view alongside of the subject. With this precaution, a much wider selection o f imaging agents can enjoy the advantages of positron emission tomography

NEMA count-rate evaluation of the first and second generation of the Ecat Exact and Ecat Exact HR family of scanners

The first and second generation of the Exact and Exact HR family of scanners has been evaluated in terms of noise equivalent count rate (NEC) and count-rate capabilities. The new National Electrical Manufacturers Association standard was used for the evaluation. In spite of improved electronics and improved count-rate capabilities, the peak NEC was found to be fairly constant between the generations. The results are discussed in terms of the different electronic solutions for the two generations and its implications on system dead time and NEC count-rate capability

Achieving Balanced Resolution in Radiopharmacological Studies: Tc-Labeled BMS 194,796

Paper presented at the 12th International Symposium on Radiopharmaceutical Chemistry, Uppsala, Sweden, June 15-19, 1997