The biology of the stoat (Mustela erminea) in the National Parks of New Zealand III. Morphometric variation in relation to growth,geographical distribution,and colonisation

Abstract

A total of 1599 stoats were collected from 14 study areas (including all 10 National Parks) from 1972 to 1976. Samples were larger in summer, and contained more females. Young stoats are born in September-October, and females reach adult weight by the following March, though males not until after August. There was significant geographic variation in the body size of adult stoats sampled: males from lowland podocarp/broadleaved forests averaged 3% smaller than males from upland beech forests in skull length, and 4% smaller in head-and-body length. This pattern was repeated, less clearly, in females and in young (approximately 2–5 months old). In contrast with stoats in Britain, assumed to be still the same size as the colonising stock introduced into New Zealand in 1884 and subsequently, males from lowland podocarp forests were unchanged or possibly smaller, and males from upland beech forests were larger; females were larger in all habitats. In males, the extent of geographic variation is almost as great in New Zealand as in the whole of continental Europe. Possible explanations of this pattern are discussed.     

Anti-barnacle activity of novel simple alkyl isocyanides derived from citronellol

Twenty novel simple alkyl isocyanides derived from citronellol were synthesized and evaluated for their antifouling activity and toxicity against cypris larvae of the barnacle, Balanus amphitrite. The anti-barnacle activity of the synthesized isocyanides was in the EC₅₀ range of 0.08–1.49 μg ml^?1. Simple isocyanides containing a benzoate and chloro group showed the most potent anti-barnacle activity. In addition, none of the synthesized compounds showed significant toxicity and LC₅₀ values were <10 μg ml^?1. The LC₅₀/EC₅₀ ratios of almost all of the synthesized compounds were >10². The results indicate that these simple isocyanides are promising low-toxicity antifouling agents.     

Models of the pharmacophoric pattern and affinity trend of methyl 2-(aminomethyl)-1-phenylcyclopropane-1-carboxylate derivatives as σ1 ligands

Sigma-1 (σ₁) affinities of methyl 2-(aminomethyl)-1-phenylcyclopropane-1-carboxylate (MAPCC) derivatives were modelled by the genetic algorithm with linear assignment of hypermolecular alignment of datasets (GALAHAD) and the comparative molecular field analysis (CoMFA)/comparative molecular similarity indices analysis (CoMSIA) methods. GALAHAD was used for deriving the 3D pharmacophore pattern that encompasses the most potent σ₁ ligands within this series. Five MAPCC derivatives with a high σ₁ affinity were used for deriving this model. The obtained model included a nitrogen atom, the hydrophobes and the hydrogen bond acceptor features; it was able to identify other potent σ₁ ligands. On the other hand, CoMFA and CoMSIA methods were used for deriving quantitative structure–activity relationship (QSAR) models. All QSAR models were trained with 17 compounds, after which they were evaluated for predictive ability with additional five compounds. The best QSAR model was obtained by using CoMSIA, including steric, electrostatic and hydrophobic fields, and had a good predictive quality according to both internal and external validation criteria. In general, the models described herein provide meaningful information relevant for the rational design of new σ₁ ligands.     

Distribution of duck broods relative to habitat characteristics in the Prairie Pothole Region

Conservation programs for breeding ducks in the Prairie Pothole Region (PPR) of the United States and Canada require effective means of evaluating and characterizing breeding habitat across large landscapes. Extensive surveys of the distribution of duck broods in late-summer could help identify wetland basins with greater probabilities of occupancy. Broods are difficult to detect, however, rendering presence–absence data from single-visit surveys difficult to interpret, particularly when probability of detection is related to habitat features. Multiple-visit occupancy surveys offer a potential solution. From 20 July to 5 August 2007–2009, we conducted a 3-visit survey of wetland basins located on 167 10.4-km² study plots in the PPR. Our survey focused on broods of the 5 most common breeding duck species (Anas spp.). Our main objectives were to investigate ecological relationships between occupancy of wetland basins by broods and habitat characteristics and to examine if habitat-specific detection was of enough concern to warrant multi-survey approaches in the future. We surveyed 3,226 wetland basins during the study. Probability of occupancy of a wetland basin by a brood was positively related to the log of wet area for all 5 study species and was greater on wetlands located on plots with a greater proportion of herbaceous perennial cover for 4 of 5 species. For example, the median probability of occupancy for gadwall (Anas strepera) increased from 0.08 (90% Credible Interval [CrI]: 0.07, 0.10) to 0.28 (90% CrI: 0.23, 0.33) as wet area increased from 0.19 ha to 2.12 ha, and increased from 0.12 (90% CrI: 0.09, 0.16) to 0.20 (90% CrI: 0.16, 0.25) as proportion of perennial grass cover on the study plot increased from 0.03 to 0.99. Because occupancy and detection were both related to attributes of wetland basins, we concluded that the multiple-visit survey was a useful approach for identifying habitat relationships of duck broods. Our results indicated that most broods of the study species were found in 10.4-km² landscapes with greater densities of small- to mid-sized wetland basins and a greater proportion of herbaceous perennial vegetation. Our study provided new empirical support that could be used to help target conservation actions to the most productive landscapes for breeding ducks. © 2012 The Wildlife Society.     

A tale of time and depth: intralacustrine radiation in endemic Gammarus species flock from the ancient Lake Ohrid

Tentatively dated, the Plio‐/Pleistocene origin of the ancient Lake Ohrid on the Balkan Peninsula makes it the oldest ancient lake in Europe. Given the surface area of the lake and the adjusted endemicity rate, it may be also defined as the most diverse of all the ancient lakes in the world. From all the animal groups endemic to this lake, gammarids are amongst the most scarcely known in terms of their diversity and phylogenetic relationships. Partial DNA sequences of two mitochondrial genes, cytochrome oxidase subunit I (cox1) and 16S ribosomal RNA (16S rRNA) of eight known endemic Gammarus species from the Lake Ohrid valley were analysed. Phylogenetic analyses showed that endemic Gammarus species comprise an ancient species flock, with Gammarus sketi from the feeder springs being their sister taxon outside the lake. Amongst the species inhabiting the lake, Gammarus solidus and Gammarus salemaai are morphologically and molecularly well defined. By contrast, Gammarus ochridensis, Gammarus parechiniformis, Gammarus lychnidensis, and Gammarus stankokaramani revealed high discrepancy between morphological and genetic data. None of these morphospecies form a monophyletic clade and a significant degree of apparent gene flow occurs between them. This could be caused by incomplete lineage sorting and/or hybridization events. Two novel mtDNA lineages were found within the lake, possibly constituting two new species (Gammarus sp. 1 and Gammarus sp. 2). Molecular clock analysis showed that the split between G. sketi and the Gammarus species flock from the lake occurred approximately 5–7 Mya, whereas within the flock there were at least two intralacustrine radiations: one estimated at 2–3 Mya and the second at less than 1 Mya. The first one could be associated with the origin of the lake and the second with the lake water‐level fluctuations during Pleistocene. © 2013 The Linnean Society of London     

Impacts of dreissenid mussel invasions on chlorophyll and total phosphorus in 25 lakes in the USA

1. Invasions of zebra and quagga mussels have had long‐term, large‐scale impacts on lake ecosystems in the USA as characterised by high abundance, broad‐scale spread and effective adaption to new environmental conditions. Due to their high filtering capacity, decreases in chlorophyll a (Chl) and total phosphorus (TP) concentrations have been reported in many affected lakes. 2. In 25 US lakes, we analysed the effects of dreissenid invasions on changes in Chl and TP concentrations, measured as the probability of a concentration decrease in the post‐invasion period and changes in Chl–TP relationships using Bayesian hierarchical regressions. We also examined whether changes in Chl and TP concentrations and in the Chl–TP relationship differed according to lake hydromorphology, such as mean depth or mixing status (mixed versus stratified lakes). 3. Our results showed that dreissenid invasions were often, but not always, associated with subsequent TP and Chl declines. Dreissenid effects on Chl and TP may be influenced by lake thermal structure. Decreases in Chl and TP were consistently found in mixed lakes where benthic–pelagic coupling is tight, while the effects were less predictable in stratified lakes. Within stratified lakes, Chl and TP reductions were more clearly discernible in deeper lakes with long water residence times. 4. Regression results demonstrated that a joint increase in slope and decrease in intercept and a tighter correlation of the Chl–TP relationship were likely to occur in dreissenid‐invaded lakes; this does not support the idea of a shift from bottom‐up to top‐down control of primary production. These results have important implications for management, suggesting that a relaxation of TP standards would be unwarranted. 5. Across lakes, the slope of the Chl–TP relationship for mixed lakes was substantially higher than that for stratified lakes before mussel invasion, indicating an important role of light in limiting primary production. The slope differences between mixed and stratified lakes decreased in the post‐invasion period, possibly because mussel filtration results in a relaxation of light limitation that is more pronounced in deeper, stratified lakes.     

New family characters of larval Plecoptera,with an analysis of the Chloroperlidae: Paraperlinae

Larval structures diagnostic of several Plecoptera families, subfamilies or genera are described and illustrated. They concern the following: distinction of larval Leuctridae from Capniidae; an additional apomorphy of Nemouridae; a synapomorphy of Perlidae and Perlodidae; monophyly of each of the two subfamilies of Chloroperlidae, and the generic limits among Chloroperlidae: Paraperlinae. Paraperla lepnevae Zhiltzova is transferred to Utaperla. Some comments on Notonemouridae are included.     

Discovery and structure–activity relationships of 6-(benzoylamino)benzoxaboroles as orally active anti-inflammatory agents

Structure–activity relationships of 6-(benzoylamino)benzoxaborole analogs were investigated for the inhibition of TNF-α, IL-1β, and IL-6 from lipopolysaccharide stimulated peripheral blood mononuclear cells. Compound 1q showed potent activity against all three cytokines with IC₅₀ values between 0.19 and 0.50 μM, inhibited LPS-induced TNF-α and IL-6 elevation in mice and improved collagen-induced arthritis in mice. Compound 1q (AN4161) is considered to be a promising lead for novel anti-inflammatory agent with an excellent pharmacokinetic profile.     

New antifungal scaffold derived from a natural pharmacophore: Synthesis of α-methylene-γ-butyrolactone derivatives and their antifungal activity against Colletotrichum lagenarium

Thirty new and thirty-four known analogues were designed and synthesized to improve the potential use of the α-methylene-γ-butyrolactone ring, a natural pharmacophore. All structures were confirmed by ¹H and ¹³C NMR, MS, and single-crystal X-ray diffraction analyses. The results of antifungal and cytotoxic activity indicated that the synthesized analogues showed significant inhibitory activity and limited selectivity. Compound 45 exhibited the highest antifungal activity with IC₅₀ = 22.8 μM but moderate cytotoxic activity with IC₅₀ = 28.5 μM (against BGC823 cell line) and 7.7 μM (against HeLa cell line). Analysis of structure–activity relationships revealed that the incorporation of an aromatic ring into the β, γ positions of the lactone ring improved antifungal activity, and that the introduction of electron-withdrawing groups into the aromatic rings increased the activity compared with electron-donating groups. The above results identified 4-phenyl-3-phenyl-2-methylenebutyrolactone (33) as a lead scaffold for discovering and developing novel and improved crop-protection agents.