Regional specification in the early embryo of the brittle star Ophiopholis aculeata

textEarly embryogenesis has been examined experimentally in four of the seven echinoderm and hemichordate classes. Although these studies suggest that the mechanisms which underlie regional specification have been highly conserved within the echinoderm + hemichordate clade, nothing is known about these mechanisms within the other echinoderm classes, including the Ophiuroidea. In this study, early embryogenesis was examined in the ophiuroid Ophiopholis aculeata. Several aspects of early development in this ophiuroid differ from those of other echinoderms and hemichordates. In O. aculeata, the first two cleavage planes do not coincide with the animal-vegetal axis but rather form approximately 45 degrees off this axis. Fate maps of 2-, 4- and 8-cell embryos were constructed using microinjected lineage tracers and indicate that ectoderm, endoderm, and mesoderm segregate unequally at first cleavage. The distribution of vi developmental potential in the embryo was examined by isolating different regions of the early embryo and indicate that endomesodermal developmental potential segregates unequally at first, second, and third cleavage. In other echinoderm and hemichordate embryos, similar unequal segregations of larval fates and developmental potential typically do not occur until third cleavage. These results indicate that there has been an evolutionary shift in the orientation of the early cleavage program in O. aculeata with respect to the distribution of larval fates and developmental potential. Experiments were also performed to gain insight into the molecular mechanisms which underlie axial specification in O. aculeata. Evidence for a role of nuclear β- catenin was assessed by examining its localization and by perturbing its activity. β- catenin localization was observed during gastrula-stages when it was seen in adherens junctions of epithelial cells; there was no indication of any nuclear localization of β- catenin throughout embryogenesis. Treatment of embryos with LiCl (an inhibitor of β- catenin degradation) produced results largely inconsistent with its role in endomesodermal specification. Dorsal-ventral patterning mechanisms were investigated by treating embryos with NiCl2 (which radialize echinoid embryos, potentially by disrupting TGFβ signaling). Nickel-treatment disrupted ectodermal development but never radialized embryos completely. These results suggest that the molecular mechanisms of axial specification in O. aculeata may differ from those of echinoid embryos.Biological Sciences, School o

Quantification of plasma and egg 4,4′ dinitrocarbanilide (DNC) residues for the efficient development of a nicarbazin-based contraceptive for pest waterfowl

Urbanization and associated landscaping has increased the abundance of year-round habitat for waterfowl, resulting in vegetation damage, loss of recreational activities, air transportation mishaps and health hazards. As part of a research program to develop socially acceptable techniques for management of pest bird populations, we are evaluating nicarbazin as a contraceptive in pest and surrogate avian species. As reproductive studies with Canada Geese (Branta canadensis) are tedious due to the difficulty of conducting controlled field studies and/or breeding geese in captivity, we evaluated the effects of oral nicarbazin administration on the production and hatchability of chicken studies are being conducted with geese to determine the diet nicarbazin concentration required to produce the desired blood and plasma DNC concentrations. This approach permits the expeditious evaluation of formulations and dosing regimes by simply monitoring blood DNC concentrations in target species

Sexual Function in Women with Stress Urinary Incontinence Treated with the SPARC Sling System

Aim. To evaluate the impact of SPARC on female sexual function. Methods. 151 women with a mean age of 60 ± 11.90 and SUI had a complete urodynamic investigation and underwent SPARC operation. 98 women completed the validated female sexual function index questionnaire (FSFI) at baseline and 94 women at follow-up. A minimum follow-up of 12 months was required for study inclusion. Results. 52/98 women were sexually active at baseline. Postoperatively only 33 patients were sexually active. The FSFI score of all 33 pre-and postoperative sexually active women increased from 25.3 ± 5.7 at baseline to 27.4 ± 4.8 at follow-up ( = 0.1). Scores of women with reduced sexual function at baseline increased significantly in the domains desire, arousal, and lubrication as well as orgasm and satisfaction and total FSFI-score ( = 0.002) postoperatively. Conclusions. Our results suggest that the SPARC-sling procedure for SUI did not negatively interfere with female sexual function

Fluorescence Line-Narrowing Spectroscopy as a Tool to Monitor Phase Transitions and Phase Separation in Efficient Nanocrystalline Ce_<i>x</i>Zr_1–<i>x</i>O₂:Eu³⁺ Catalyst Materials

Despite the wide range of industrial applications for ceria-zirconia mixed oxides (Ce_<i>x</i>Zr_1–<i>x</i>O₂), the complex correlation between their atomic structure and catalytic performance is still under debate. Catalytically interesting Ce_<i>x</i>Zr_1–<i>x</i>O₂ nanomaterials can form homogeneous solid solutions and, depending on the composition, show phase separation under the formation of small domains. The characterization of homogeneity and atomic structure of these materials remains a major challenge. High-resolution emission spectroscopy recorded under cryogenic conditions using Eu³⁺ as a structural probe in doped CeZrO₂ nanoparticles offers an effective way to identify the different atomic environments of the Eu³⁺ dopants and, subsequently, to monitor structural parameters of the ceria-zirconia mixed oxides. It is found that, in stoichiometric CeZrO₂:Eu³⁺, phase separation occurs at elevated temperatures beginning with the gradual formation of (pseudo)­cubic crystallites in the amorphous materials at 500 °C and a sudden phase separation into tetragonal, zirconia-rich and cubic, ceria-rich domains over 900 °C. The presented technique allows us to easily monitor subtle changes even in amorphous, high surface area samples, yielding structural information not accessible by conventional techniques such as X-ray diffraction (XRD) and Raman. Moreover, in reference experiments investigating the reducibility of largely unordered Ce_0.2Zr_0.8O₂:Eu³⁺, the main reduction peak in temperature-programmed reduction measurements appeared at exceptionally low temperatures below 200 °C, thus suggesting the outstanding potential of this oxide to activate catalytic oxidation reactions. This effect was found to be dependent on the amount of Eu³⁺ dopant introduced into the CeZrO₂ matrix as well as to be connected to the atomic structure of the catalyst material

Growth hormone receptor polymorphism and growth hormone therapy response in children: a bayesian meta-analysis

Recombinant human growth hormone (rhGH) therapy is used in the long-term treatment of children with growth disorders, but there is considerable treatment response variability. The exon 3-deleted growth hormone receptor polymorphism (GHR(d3)) may account for some of this variability. The authors performed a systematic review (to April 2011), including investigator-only data, to quantify the effects of the GHR(fl-d3) and GHR(d3-d3) genotypes on rhGH therapy response and used a recently established Bayesian inheritance model-free approach to meta-analyze the data. The primary outcome was the 1-year change-in-height standard-deviation score for the 2 genotypes. Eighteen data sets from 12 studies (1,527 children) were included. After several prior assumptions were tested, the most appropriate inheritance model was codominant (posterior probability = 0.93). Compared with noncarriers, carriers had median differences in 1-year change-in-height standard-deviation score of 0.09 (95% credible interval (CrI): 0.01, 0.17) for GHR(fl-d3) and of 0.14 (95% CrI: 0.02, 0.26) for GHR(d3-d3). However, the between-study standard deviation of 0.18 (95% CrI: 0.10, 0.33) was considerable. The authors tested by meta-regression for potential modifiers and found no substantial influence. They conclude that 1) the GHR(d3) polymorphism inheritance is codominant, contrasting with previous reports; 2) GHR(d3) genotypes account for modest increases in rhGH effects in children; and 3) considerable unexplained variability in responsiveness remains