Round Goby Predation on Smallmouth Bass Offspring in Nests during Simulated Catch-and-Release Angling

Round goby Neogobius melanostomus first appeared in Lake Erie in 1993 and now occur in extremely high densities in some areas. As known nest predators, round goby currently pose a threat to nest-guarding smallmouth bass Micropterus dolomieu. We conducted manipulative experiments to evaluate the combined effects of round goby predation and catch-and-release angling during 1999–2001 in the Bass Islands, Lake Erie. We quantified how many smallmouth bass offspring were consumed by round goby when nest-guarding smallmouth bass males were present, removed, and recovering from angling-related stress. In 10 h of video observations, we only saw one instance of round goby consuming smallmouth bass offspring while the nest was guarded. Upon removal of nest-guarding smallmouth bass, round goby quickly entered unguarded nests (4.3 round goby/min for nests with unhatched embryos and 1.8 round goby/min for nests with hatched embryos). During experimental catch-and-release angling, round goby consumed an average of 2,000 unhatched embryos before the guardian male returned, but postreturn offspring losses were minimal while the male recovered from angling stress. For an average smallmouth bass nest in the Bass Islands, round goby could consume all offspring from an unguarded nest in about 15 min. Round goby predation and smallmouth bass angling combined to reduce survival of smallmouth bass embryos, but we did not observe round goby consuming free-swimming larvae or juveniles. If the number of surviving smallmouth bass embryos drives adult population size, managers should consider angling regulations that reduce interference with nesting males, thus limiting the deleterious effects of round goby.This research was funded by Federal Aid in Sport Fish Restoration Project F-69-P, administered jointly by the U.S. Fish and Wildlife Service and the Ohio Department of Natural Resources, Division of Wildlife, and the Department of Evolution, Ecology, and Organismal Biology at Ohio State University

Increased parental care cost for nest-guarding fish in a lake with hyperabundant nest predators

Although parental care increases offspring survival, providing care is costly, reducing parental growth and survival and, thereby, compromising future reproductive success. To determine if an exotic benthic predator might be affecting parental care by nest-guarding smallmouth bass (Micropterus dolomieu), we compared nest-guarding behavior and energy expenditures in two systems, one with a hyperabundant recently introduced predator, the round goby (Neogobious melanostomus). In Lake Erie, USA, smallmouth bass vigorously defended their nests from benthic round gobies. In Lake Opeongo, Canada, smallmouth bass were exposed to fewer and predominantly open-water predators and were less active in their nest defense. From scuba and video observations, we documented that nest-guarding smallmouth bass chased predators (99% of which were round gobies) nine times more frequently in Lake Erie than in Lake Opeongo. This heightened activity resulted in a significant decline in weight and energetic content of guarding males in Lake Erie but no change in Lake Opeongo males. Bioenergetic simulations revealed that parental care increased smallmouth bass standard metabolic rate by 210% in Lake Erie but only by 28% in Lake Opeongo. As energy reserves declined and offspring became increasingly independent, males in both lakes consumed more prey and spent more time foraging away from their nests; however, nest-guarding smallmouth bass consumed few prey and, in Lake Erie, rarely consumed round gobies. Therefore, increased parental care costs owing to the presence of round gobies could affect future growth, reproduction, and survival if smallmouth bass approach critically low energy reserves.Funding for this project was provided by Federal Aid in Sport Fish Restoration Project F-69-P, administered jointly by United States Fish and Wildlife Service and Ohio Department of Natural Resources, Division of Wildlife, a Sigma Xi Grant-in-Aid awarded to G.B.S., and the Department of Evolution, Ecology, and Organismal Biology at The Ohio State University

Formation of gold nanoparticles in polymeric nanowires by low-temperature thermolysis of gold mesitylene

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.The formation of polymer nanowires containing metal nanoparticle chains by low-temperature thermolyses of metal precursors has remained challenging. We report the block copolymer-assisted generation of locally regular chains of quasi-spherical gold nanoparticles with narrow particle diameter distribution by mild thermolysis of the non-polar gold precursor gold mesitylene inside the cylindrical nanopores of self-ordered anodic aluminium oxide (AAO). The block copolymer separates the gold mesitylene as well as the developing gold nanoparticles from the AAO pore walls so that surface nucleation and pinning of gold clusters are prevented. Growing quasi-spherical gold nanoparticles locally deform the polymer chains irreversibly adsorbed on the AAO pore walls, and the polymer chains are pushed into the space between the gold nanoparticles. The gold nanoparticles have, therefore, larger diameters and smaller specific surface than hypothetical pluglike gold entities with the same volume, the formation of which is suppressed.DFG, SPP 1165, Nanodrähte und Nanoröhren: von kontrollierter Synthese zur Funktio

Soft and flexible poly(ethylene glycol) nanotubes for local drug delivery

Nanotubes are emerging as promising materials for healthcare applications but the selection of clinically relevant starting materials for their synthesis remains largely unexplored. Here we present, for the first time, the synthesis of poly(ethylene glycol) (PEG) based nanotubes via the photopolymerization of poly(ethylene glycol) diacrylate and other diacrylate derivatives within the pores of anodized aluminum oxide templates. Template-assisted synthesis allowed the manufacture of a diverse set of polymeric nanotubes with tunable physical characteristics including diameter (∼200–400 nm) and stiffness (405–902 kPa). PEG nanotubes were subjected to cytotoxicty assessment in cell lines and primary stem cells and showed excellent cytocompatability (IC50 > 120 μg ml−1). Nanotubes were readily drug loaded but released the majority of the drug over 5 days. Direct administration of drug loaded nanotubes to human orthotopic breast tumors substantially reduced tumor growth and metastasis and outperformed i.v. administration at the equivalent dose. Overall, this nanotube templating platform is emerging as a facile route for the manufacture of poly(ethylene glycol) nanotubes

Meeting Funders’ Data Policies: Blueprint for a Research Data Management Service Group (RDMSG)

This report summarizes the elements that we expect to be required in data management plans, describes Cornell’s current capabilities and needs in meeting such requirements, and proposes a structure for a virtual organization that builds on the collaboration between the DRSG, CAC, CUL and CISER. The proposed organization also includes Cornell Information Technologies (CIT) and Weill Cornell Medical College Information Technologies and Services (WCMC-ITS) to further develop and provide this support

Ferroelectric Nanotubes

We report the independent invention of ferroelectric nanotubes from groups in several countries. Devices have been made with three different materials: lead zirconate-titanate PbZr1-xTixO3 (PZT); barium titanate BaTiO3; and strontium bismuth tantalate SrBi2Ta2O9 (SBT). Several different deposition techniques have been used successfully, including misted CSD (chemical solution deposition) and pore wetting. Ferroelectric hysteresis and high optical nonlinearity have been demonstrated. The structures are analyzed via SEM, TEM, XRD, AFM (piezo-mode), and SHG. Applications to trenching in Si dynamic random access memories, ink-jet printers, and photonic devices are discussed. Ferroelectric filled pores as small as 20 nm in diameter have been studied

Differential (2+1) Jet Event Rates and Determination of alpha_s in Deep Inelastic Scattering at HERA

Events with a (2+1) jet topology in deep-inelastic scattering at HERA are studied in the kinematic range 200 < Q^2< 10,000 GeV^2. The rate of (2+1) jet events has been determined with the modified JADE jet algorithm as a function of the jet resolution parameter and is compared with the predictions of Monte Carlo models. In addition, the event rate is corrected for both hadronization and detector effects and is compared with next-to-leading order QCD calculations. A value of the strong coupling constant of alpha_s(M_Z^2)= 0.118+- 0.002 (stat.)^(+0.007)_(-0.008) (syst.)^(+0.007)_(-0.006) (theory) is extracted. The systematic error includes uncertainties in the calorimeter energy calibration, in the description of the data by current Monte Carlo models, and in the knowledge of the parton densities. The theoretical error is dominated by the renormalization scale ambiguity.Comment: 25 pages, 6 figures, 3 tables, submitted to Eur. Phys.

Multi-Jet Event Rates in Deep Inelastic Scattering and Determination of the Strong Coupling Constant

Jet event rates in deep inelastic ep scattering at HERA are investigated applying the modified JADE jet algorithm. The analysis uses data taken with the H1 detector in 1994 and 1995. The data are corrected for detector and hadronization effects and then compared with perturbative QCD predictions using next-to-leading order calculations. The strong coupling constant alpha_S(M_Z^2) is determined evaluating the jet event rates. Values of alpha_S(Q^2) are extracted in four different bins of the negative squared momentum transfer~\qq in the range from 40 GeV2 to 4000 GeV2. A combined fit of the renormalization group equation to these several alpha_S(Q^2) values results in alpha_S(M_Z^2) = 0.117+-0.003(stat)+0.009-0.013(syst)+0.006(jet algorithm).Comment: 17 pages, 4 figures, 3 tables, this version to appear in Eur. Phys. J.; it replaces first posted hep-ex/9807019 which had incorrect figure 4

Multiplicity Structure of the Hadronic Final State in Diffractive Deep-Inelastic Scattering at HERA

The multiplicity structure of the hadronic system X produced in deep-inelastic processes at HERA of the type ep -> eXY, where Y is a hadronic system with mass M_Y< 1.6 GeV and where the squared momentum transfer at the pY vertex, t, is limited to |t|<1 GeV^2, is studied as a function of the invariant mass M_X of the system X. Results are presented on multiplicity distributions and multiplicity moments, rapidity spectra and forward-backward correlations in the centre-of-mass system of X. The data are compared to results in e+e- annihilation, fixed-target lepton-nucleon collisions, hadro-produced diffractive final states and to non-diffractive hadron-hadron collisions. The comparison suggests a production mechanism of virtual photon dissociation which involves a mixture of partonic states and a significant gluon content. The data are well described by a model, based on a QCD-Regge analysis of the diffractive structure function, which assumes a large hard gluonic component of the colourless exchange at low Q^2. A model with soft colour interactions is also successful.Comment: 22 pages, 4 figures, submitted to Eur. Phys. J., error in first submission - omitted bibliograph

WNT signalling in prostate cancer

Genome sequencing and gene expression analyses of prostate tumours have highlighted the potential importance of genetic and epigenetic changes observed in WNT signalling pathway components in prostate tumours-particularly in the development of castration-resistant prostate cancer. WNT signalling is also important in the prostate tumour microenvironment, in which WNT proteins secreted by the tumour stroma promote resistance to therapy, and in prostate cancer stem or progenitor cells, in which WNT-β-catenin signals promote self-renewal or expansion. Preclinical studies have demonstrated the potential of inhibitors that target WNT receptor complexes at the cell membrane or that block the interaction of β-catenin with lymphoid enhancer-binding factor 1 and the androgen receptor, in preventing prostate cancer progression. Some WNT signalling inhibitors are in phase I trials, but they have yet to be tested in patients with prostate cancer