Extended statistical approaches to modelling spatial pattern in biodiversity in northeast New South Wales. II. Community-level modelling

Regional conservation planning can often make more effective use of sparse biological data by linking these data to remotely mapped environmental variables through statistical modelling. While modelling distributions of individual species is the best known and most widely used approach to such modelling, there are many situations in which more information can be extracted from available data by supplementing, or replacing, species-level modelling with modelling of communities or assemblages. This paper provides an overview of approaches to community-level modelling employed in a series of major land-use planning processes in the northeast New South Wales region of Australia, and evaluates how well communities and assemblages derived using these techniques function as surrogates in regional conservation planning. We also outline three new directions that may enhance the effectiveness of community-level modelling by: (1) more closely integrating modelling with traditional ecological mapping (e.g. vegetation mapping); (2) more tightly linking numerical classification and spatial modelling through application of canonical classification techniques; and (3) enhancing the applicability of modelling to data-poor regions through employment of a new technique for modelling spatial pattern in compositional dissimilarity.     

Assessing the status of the marsh fritillary butterfly (Eurodryas aurinia): an example from Glamorgan, UK

We surveyed populations of Eurodryas aurinia (a butterfly listed as Threatened in Europe) in Glamorgan (South Wales, UK). The survey may provide a model for similar work, which is urgently needed throughout the species' European range. For each colony, we established population size, vegetation types, and current management regimes. Populations were assessed using larval surveys, a method which has several advantages over conventional adult surveys. With approximately 35 local populations, Glamorgan is among the most important areas for E. aurinia in the UK, and is of importance in a European context. However, 15 local populations were under immediate threat from unfavourable management or industrial developments, and only seven populations were on Sites of Special Scientific Interest. Colonies showed a clustered pattern, and varied greatly in size: 50% supported 20 or fewer larval webs. Many of the small populations may be temporary offshoots of larger, more permanent populations nearby. The largest local populations occupied Molinia caerulea - Cirsium dissectum fen meadow habitats (National Vegetation Community M24), which were unmanaged, grazed by cattle, horses or ponies, or subject to periodic burning. Detailed local surveys such as this one, which assess the relative sizes of populations and the impact of current management practices, may be the best way to plan future conservation measures for E. aurinia.     

A prestaining method for the quantitative assay of proteins on polyacrylamide gels

Dyes have been synthesised¹, which make it possible to prestain proteins prior to electrophoresis on polyacrylamide gels. After discussing the criteria which have to be fulfilled by the dyes, their method of application is described. The method has been tested on a number of selected acidic and basic proteins and also on peptide obtained by the digestion of bovine serum albumin with cyanogen bromide. Excellent reproducibility, stoichiometry and a sensitivity of 0.2 μg with some proteins has been obtained.     

OCTOCORALLIAN AND HYDROID FOSSILS FROM THE LOWER ORDOVICIAN OF WALES

Abstract:  Octocorallian and hydroid fossils are described from the Lower Ordovician (Arenig Series) of Wales. They include gorgoniids that are the earliest known fossils of this group: Petilavenula varifurcata gen. et sp. nov. and P. surculosa gen. et sp. nov. Pennalina crossi gen. et sp. nov. is probably also a gorgoniid but may be a hydroid. A new hydroid, Pontifennia gracilis gen. et sp. nov., is also described.     

Is Port Stephens,eastern Australia,a global hotspot for biodiversity of Aplysiidae (Gastropoda: Heterobranchia)?

Port Stephens, a large natural harbour on the central New South Wales (NSW) coast, provides ideal oceanographic and benthic conditions for the growth of marine algae and seagrasses, and this promotes a suite of herbivorous heterobranch sea slugs such as sea hares and sap-sucking sea slugs. In this article we document both historic and recent observations of sea hares (family Aplysiidae) from Port Stephens with the intention of recording species diversity. The western South Pacific region has the richest aplysiid fauna in the world, with 16 species now recorded in Port Stephens. This location is the most taxonomically diverse for this family in Australia. Despite this hotspot of aplysiid diversity, the taxonomy and nomenclature of 12 species is uncertain, a fact highlighted by a series of nomenclatural notes included in this article. We herein report the first observation of Petalifera sp. in Australian waters. Dolabrifera jacksoniensis Pilsbry, 1896 Pilsbry, H. (1896) Genus III. Dolabrifera Gray, 1847. Manual of Conchology series 1, volume 16, part 63, 113–160, pls 32–43. [Google Scholar] is newly synonymised with D. brazieri G.B. Sowerby II, 1870. Recent reports of southern range extensions for other heterobranch sea slugs, both in Port Stephens and elsewhere in NSW, highlight the importance of recording the existing aplysiid diversity in the port. Thus, any future alteration to species composition and range shifts driven by climate change may be detected.     

Coupling of the polyamine and iron metabolism pathways in the regulation of proliferation: Mechanistic links to alterations in key polyamine biosynthetic and catabolic enzymes

Many biological processes result from the coupling of metabolic pathways. Considering this, proliferation depends on adequate iron and polyamines, and although iron-depletion impairs proliferation, the metabolic link between iron and polyamine metabolism has never been thoroughly investigated. This is important to decipher, as many disease states demonstrate co-dysregulation of iron and polyamine metabolism. Herein, for the first time, we demonstrate that cellular iron levels robustly regulate 13 polyamine pathway proteins. Seven of these were regulated in a conserved manner by iron-depletion across different cell-types, with four proteins being down-regulated (i.e., acireductone dioxygenase 1 [ADI1], methionine adenosyltransferase 2α [MAT2α], Antizyme and polyamine oxidase [PAOX]) and three proteins being up-regulated (i.e., S-adenosyl methionine decarboxylase [AMD1], Antizyme inhibitor 1 [AZIN1] and spermidine/spermine-N¹-acetyltransferase 1 [SAT1]). Depletion of iron also markedly decreased polyamine pools (i.e., spermidine and/or spermine, but not putrescine). Accordingly, iron-depletion also decreased S-adenosylmethionine that is essential for spermidine/spermine biosynthesis. Iron-depletion additionally reduced ³H-spermidine uptake in direct agreement with the lowered levels of the polyamine importer, SLC22A16. Regarding mechanism, the “reprogramming” of polyamine metabolism by iron-depletion is consistent with the down-regulation of ADI1 and MAT2α, and the up-regulation of SAT1. Moreover, changes in ADI1 (biosynthetic) and SAT1 (catabolic) partially depended on the iron-regulated changes in c-Myc and/or p53. The ability of iron chelators to inhibit proliferation was rescuable by putrescine and spermidine, and under some conditions by spermine. Collectively, iron and polyamine metabolism are intimately coupled, which has significant ramifications for understanding the integrated role of iron and polyamine metabolism in proliferation.     

The effect of high concentrations and orientations of Stone–Wales defects on the thermal conductivity of graphene nanoribbons

The influence of the orientations and concentrations of the Stone–Wales (SW) defects on the thermal conductivity of zigzag and armchair graphene nanoribbons (GNRs) is explored using the reverse non-equilibrium molecular dynamics method. The results show that the thermal conductivity of GNRs with two different chirality cases reaches the minimum in the range of 0.1–0.7% defect concentration. Beyond a critical value of the SW defect concentration, the thermal conductivity increases with the increase in SW concentration for both zigzag and armchair GNRs. It is shown that at high concentrations of the SW defects, the thermal conductivity of zigzag GNRs with Type II defects is larger than the GNRs with Type I defects. Finally, the dependence of the SW defect concentration and orientation on the power spectra overlaps have also been explored.