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AbstractBackground and Purpose:The injection of dextranomer/hyaluronic acid (DHA) has become an accepted treatment for children with vesicoureteral reflux (VUR). Complete ureteral duplication has been considered by some practitioners as counterindication for its use. We reviewed the Texas Children's Hospital (TCH) records for children with complete ureteral duplication who were treated with DHA for VUR.Methods:We searched medical records at TCH for patients with a preoperative diagnosis of complete ureteral duplication who had undergone DHA injection between January 1, 2001, and October 15, 2008. Operative notes, imaging studies, and clinic notes were reviewed.Results:In this period, 28 kidneys in 24 children were treated. The average grade of reflux before injection was 3.44 (range 1–5). First injection resolution of reflux was 57% with an increase to 73% after a second injection with an average volume of DHA of 1.05 mL. New contralateral VUR developed postinjection in three (15%) children with unilateral VUR. There were no perioperative complications. The average age of the children who were treated was 41.4 months. Mean follow-up was 45.94 months. Success of DHA injection tended to be higher in girls (65%) and older children.Conclusions:High levels of success can be achieved with DHA injection in children with complete ureteral duplication. DHA injection is more likely to be successful for older girls with VUR and complete ureteral duplication. If initial injection does not result in VUR resolution, a second injection offers an opportunity for improved success. For physicians and families who are seeking an alternative to open surgical management, DHA represents an attractive option for selected children with complete ureteral duplication. [ABSTRACT FROM AUTHOR]

New genes with novel functions arise by duplication and divergence, but the process poses a problem. After duplication, an extra gene copy must rise to sufficiently high frequency in the population and remain free of common inactivating lesions long enough to acquire the rare mutations that provide a new selectable function. Maintaining a duplicated gene by selection for the original function would restrict the freedom to diverge. (We refer to this problem as Ohno's dilemma). A model is described by which selection continuously favors both maintenance of the duplicate copy and divergence of that copy from the parent gene. Before duplication, the original gene has a trace side activity (the innovation) in addition to its original function. When an altered ecological niche makes the minor innovation valuable, selection favors increases in its level (the amplification), which is most frequently conferred by increased dosage of the parent gene. Selection for the amplified minor function maintains the extra copies and raises the frequency of the amplification in the population. The same selection favors mutational improvement of any of the extra copies, which are not constrained to maintain their original function (the divergence). The rate of mutations (per genome) that improve the new function is increased by the multiplicity of target copies within a genome. Improvement of some copies relaxes selection on others and allows their loss by mutation (becoming pseudogenes). Ultimately one of the extra copies is able to provide all of the new activity. [ABSTRACT FROM AUTHOR]

For many bird species, growth is negative or equivocal during development. Traditional, parametric growth curves assume growth follows a sigmoidal form with prescribed inflection points and is positive until asymptotic size. Accordingly, these curves will not accurately capture the variable, sometimes considerable, fluctuations in avian growth over the course of the trajectory. We evaluated the fit of three traditional growth curves (logistic, Gompertz, and von Bertalanffy) and a nonparametric spline estimator to simulated growth data of six different specified forms over a range of sample sizes. For all sample sizes, the spline best fit the simulated model that exhibited negative growth during a portion of the trajectory. The Gompertz curve was the most flexible for fitting simulated models that were strictly sigmoidal in form, yet the fit of the spline was comparable to that of the Gompertz curve as sample size increased. Importantly, confidence intervals for all of the fitted, traditional growth curves were wholly inaccurate, negating the apparent robustness of the Gompertz curve, while confidence intervals of the spline were acceptable. We further evaluated the fit of traditional growth curves and the spline to a large data set of wood thrush Hylocichla mustelina mass and wing chord observations. The spline fit the wood thrush data better than the traditional growth curves, produced estimates that did not differ from known observations, and described negative growth rates at relevant life history stages that were not detected by the growth curves. The common rationale for using parametric growth curves, which compress growth information into a few parameters, is to predict an expected size or growth rate at some age or to compare estimated growth with other published estimates. The suitability of these traditional growth curves may be compromised by several factors, however, including variability in the true growth trajectory. Nonparametric methods, such as the spline, provide a precise description of empirical growth yet do not produce such parameter estimates. Selection of a growth descriptor is best determined by the question being asked but may be constrained by inherent patterns in the growth data. [ABSTRACT FROM AUTHOR]

We investigate giant resonances of spherical nuclei on the basis of the Argonne V18 potential after unitary transformation within the similarity renormalization group or the unitary correlation operator method supplemented by a phenomenological three-body contact interaction. Such Hamiltonians can provide a good description of ground-state energies and radii within Hartree–Fock plus low-order many-body perturbation theory. The standard random phase approximation is applied here to calculate the isoscalar monopole, isovector dipole, and isoscalar quadrupole excitation modes of the , , and nuclei. Thanks to the inclusion of the three-nucleon interaction and despite the minimal optimization effort, a reasonable agreement with experimental centroid energies of all three modes has been achieved. The role and scope of the Hartree–Fock reference state in RPA methods are discussed. [ABSTRACT FROM AUTHOR]