Effects of introduced trout predation on non-diadromous galaxiid fish populations across invaded riverscapes

Abstract We assessed the landscape-scale effect of predation pressure from trout on the population integrity and distributions of non-diadromous galaxiids in high-country streams of the South Island, New Zealand. The effects of trout (brown trout, Salmo trutta, and rainbow trout, Oncorhynchus mykiss) on two widespread species, the Canterbury galaxias (Galaxias vulgaris Stokell) and the alpine galaxias (G. paucispondylus Stokell) were assessed. Experiments confirmed that both species were vulnerable to trout predation and that habitat (size and disturbance regime) may be a factor in local co-occurrence. Quantitative electrofishing surveys indicated that G. paucispondylus distributions were less affected by trout than G. vulgaris distributions and that the species’ range was limited by temperature. Trout created demographic sinks for G. vulgaris across most invaded reaches, while refuge populations in streams above barriers to trout acted as demographic sources for this species. G. vulgaris was consistently absent from small, stable stream reaches far from sources, indicating that trout predation pressure and propagule pressure (driven by immigration from sources) interact to drive local G. vulgaris persistence in trout-invaded reaches. Predation pressure is likely to be highest in areas where infrequent flooding allows high densities of large trout (> 150 mm FL) to occur and where there are few refugia for galaxiids. A spatial model was developed to predict exclusion of galaxiids by trout across invaded networks. If used appropriately, the model could be used to find new refuge populations of non-diadromous galaxiids and to aid planning of active rehabilitation of trout-invaded river networks

Direct detection of electron backscatter diffraction patterns.

We report the first use of direct detection for recording electron backscatter diffraction patterns. We demonstrate the following advantages of direct detection: the resolution in the patterns is such that higher order features are visible; patterns can be recorded at beam energies below those at which conventional detectors usefully operate; high precision in cross-correlation based pattern shift measurements needed for high resolution electron backscatter diffraction strain mapping can be obtained. We also show that the physics underlying direct detection is sufficiently well understood at low primary electron energies such that simulated patterns can be generated to verify our experimental data

A remarkable new Helophorus species (Coleoptera, Helophoridae) from the Tibetan Plateau (China, Sichuan)

Copyright Robert B. Angus. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The file attached is the Published/publisher’s pdf version of the article.NHM Repositor

Insurance loss coverage and social welfare

Restrictions on insurance risk classification may induce adverse selection, which is usually perceived as a bad outcome, both for insurers and for society. However, a social benefit of modest adverse selection is that it can lead to an increase in `loss coverage', defined as expected losses compensated by insurance for the whole population. We reconcile the concept of loss coverage to a utilitarian concept of social welfare commonly found in economic literature on risk classification. For iso-elastic insurance demand, ranking risk classification schemes by (observable) loss coverage always gives the same ordering as ranking by (unobservable) social welfare

Solid phase synthesis of peptides and proteins

A strategy for the total chemical synthesis and purification of proteins has been investigated and applied to the 85 residue methylated DNA binding domain (MBD) from the chromosomal protein MeCP2, the 66 residue Restriction Alleviation (Ral) protein from bacteriophage λ, and the 76 residue ß-chemokine Monocyte Chemotactic protein (MCP-1). The hydrophobicity of the Nᵃ protecting group tetrabenzo[a, c ,g, i]fluorenyl- 17- methoxycarbonyl (Tbfmoc) has been exploited to simplify the rapid purification of the 85 amino acid MBD protein by Hplc. Initial structural studies on the synthetic protein are also reported. In addition a comparative study of semi -permanent, temporary and enzyme cleavable thiol protection has resulted in the extension of this Tbfmoc methodology to the synthesis of cysteine containing proteins such as Ral and MCP -1.A general route to C- terminal α- hydroxyglycine extended peptides via Fmoc/t-Bu based solid phase peptide synthesis is also described. Such peptides are the biosynthetic precursors of peptide amides in which the C-terminal carboxamide functionality is required for biological activity in a number of important hormones

The effect of polar and non-polar solvents on the optical rotatory powers of certain saturated and unsaturated terpenic hydrocarbons

(1) The optical rotatory powers and rotatory dis- persions of five terpenic hydrocarbons, viz. d- menthene, d- limonene, d - pinene, d- pinane and d- carane ( ?), have been examined in dilute solution in various polar and non-polar organic solvents.(2) The rotatory powers of the weakly polar, un- saturated hydrocarbons, d- menthene and d- pinene are shown to be mainly related to the polarity of the solvent medium. The rotatory power of d- limonene, on the other hand is chiefly con- trolled by the refractive index of the solvent medium. In the former cases a few displacements occur and are explained on the basis of a minor refractivity effect being present. Similarly in the latter case, a minor polar effect appears to be present. In order to bring out the above relationships clearly, it is necessary to com- pare solvents of a similar type, by grouping them into an aromatic and an aliphatic series.(3) The rotatory power of the non-polar saturated hydrocarbon, d- pinane has been examined in solution in thirty -six solvents of widely varying types. It is shown that the rotation is governed by the refractive index of the sol- vent medium, very slight displacements occurring due to the presence of a minor polar effect. In this case there is no need to divide the solvents into various groups according to their chemical types.(4) Several physical theories of optical activity are examined from the point of view of their application to the experimental results obtained for d- pinane.(5) Owing to the known difficulty of effecting a satisfactory separation of unsaturated hydro- carbons from saturated cyclopropane derivatives, some doubt is cast upon the identification as d- carane of the hydrocarbon obtained by dis- tilling pulegone hydrazone over caustic potash. An examination of the rotatory power of this product in various solutions reveals irregular variations.(6) The effect of temperature variations upon solutions of the above compounds in a strongly polar and a non-polar solvent respectively has been determined. The observed results in the majority of cases, may be explained on the basis of the changes in the degree of solute -solvent association and in the refractive index of the mixture. Similar explanations hold for the variation in rotatory powers of the above compounds with changes in concentration in certain solutions