Re-establishment of Calluna vulgaris (L.) Hull in an eight-year grazing experiment on upland acid grassland

Upland heathland is an internationally important habitat but a large area in the UK has been degraded to acid grassland by intensive livestock grazing. Re-establishment of dwarf shrubs, particularly Calluna vulgaris (L.) Hull, is a key objective for restoring heathland on these sites. A replicated plot-scale experiment was set up to examine effects of disturbance and seed addition on C. vulgaris establishment in a Nardus stricta L. grassland under three grazing regimes: sheep only (1.5 ewes ha^?1 for 10 months per year); cattle only (0.5 heifers ha^?1 in summer only); and, the cattle regime combined with sheep (1.0 ewes ha^?1 for 10 months per year). Early results of the experiment have been reported previously but it was not known if these results were an indication of the longer-term restoration success. Here we evaluate the success of the restoration methods (disturbance, seeding treatments and grazing regime) eight years after the treatments began. In seeded plots, young C. vulgaris plants had greatest above-ground height, dry weight and shoot length if grazing was excluded or the cattle-only regime was applied. C. vulgaris cover was greatest, and increased most, in plots that had been disturbed, seeded and ungrazed or subjected to the cattle-only regime. The vegetation in these plots also became more similar to reference sites with 50% or more cover of C. vulgaris. The invasive Juncus effusus L. was more frequent in disturbed and grazed plots but less frequent in plots with C. vulgaris established from added seed. Previous results that showed the benefits of disturbance and seeding treatments were still valid but changes in the vegetation composition were still occurring and longer-term studies will be needed to determine when grazing regimes including sheep might be reintroduced.     

Enhanced high copy number plasmid maintenance and heterologous protein production in an Escherichia coli biofilm

Escherichia coli has been widely used for heterologous protein production (HPP). To determine whether a biofilm environment could benefit E. coli HPP using high copy number plasmids, we compared plasmid maintenance and HPP by E. coli ATCC 33456 containing plasmid pEGFP (a pUC family vector) cultivated in biofilms and in suspended culture. Cells were grown with or without antibiotic selective pressure in flow cells or chemostats for up to 6 days. In biofilms, antibiotic selective pressure increased the plasmid copy number (PCN), but by 144 h, biofilms grown in antibiotic-free media had comparable plasmid concentrations. In the chemostat, the PCN declined steadily, although 100 ppm ampicillin in the medium slowed the rate of plasmid loss. Production of green fluorescent protein (GFP), a representative heterologous protein, was quantified by flow cytometry. In biofilms, at ampicillin concentrations >or=33 ppm, strongly fluorescent cells comprised more than half of the population by 48 h. In the chemostat, more than 50% of the population was non-fluorescent by 48 h in media containing 100 ppm ampicillin, and strongly fluorescent cells were <10% of the population. Biofilm structure was determined by confocal microscopy. Maximum biofilm thickness ranged from 30 to 45 microns, with no significant changes in biofilm structure after 48 h. Plasmid multimer percentages were similar to inocula for cells cultivated in either biofilms or the chemostat. The results indicate that the biofilm environment enhanced both plasmid maintenance and cellular GFP concentrations, and that low levels of antibiotic increased the beneficial effect.     

Honest signals and sexual conflict: Female lizards carry undesirable indicators of quality

Sex differences in animal coloration often result from sex‐dependent regulatory mechanisms. Still, some species exhibit incomplete sexual dimorphism as females carry a rudimentary version of a costly male trait, leading to intralocus sexual conflict. The underlying physiology and condition dependence of these traits can inform why such conflicts remain unresolved. In eastern fence lizards (Sceloporus undulatus), blue iridophore badges are found in males and females, but melanin pigmentation underneath and surrounding badges is male‐exclusive. We track color saturation and area of badges across sexual maturity, and their relationship to individual quality (body condition and immunocompetence) and relevant hormones (testosterone and corticosterone). Saturation and testosterone were positively correlated in both sexes, but hormone and trait had little overlap between males and females. Saturation was correlated with body condition and immunocompetence in males but not in females. Co‐regulation by androgens may have released females from resource allocation costs of color saturation, even when in high condition. Badge area was independent of testosterone, but associated with low corticosterone in females, indicating that a nonsex hormone underlies incomplete sexual dimorphism. Given the evidence in this species for female reproductive costs associated with ornamentation, this sex‐nonspecific regulation of an honest signal may underlie intralocus sexual conflict.     

Ferritin blocks inhibitory effects of two-chain high molecular weight kininogen (HKa) on adhesion and survival signaling in endothelial cells

Angiogenesis is tightly regulated through complex crosstalk between pro- and anti-angiogenic signals. High molecular weight kininogen (HK) is an endogenous protein that is proteolytically cleaved in plasma and on endothelial cell surfaces to HKa, an anti-angiogenic protein. Ferritin binds to HKa and blocks its anti-angiogenic activity. Here, we explore mechanisms underlying the cytoprotective effect of ferritin in endothelial cells exposed to HKa. We observe that ferritin promotes adhesion and survival of HKa-treated cells and restores key survival and adhesion signaling pathways mediated by Erk, Akt, FAK and paxillin. We further elucidate structural motifs of both HKa and ferritin that are required for effects on endothelial cells. We identify an histidine-glycine-lysine (HGK) -rich antiproliferative region within domain 5 of HK as the target of ferritin, and demonstrate that both ferritin subunits of the H and L type regulate HKa activity. We further demonstrate that ferritin reduces binding of HKa to endothelial cells and restores the association of uPAR with α5β1 integrin. We propose that ferritin blocks the anti-angiogenic activity of HKa by reducing binding of HKa to UPAR and interfering with anti-adhesive and anti-proliferative signaling of HKa.     

Genome-Wide Association Studies in an Isolated Founder Population from the Pacific Island of Kosrae

It has been argued that the limited genetic diversity and reduced allelic heterogeneity observed in isolated founder populations facilitates discovery of loci contributing to both Mendelian and complex disease. A strong founder effect, severe isolation, and substantial inbreeding have dramatically reduced genetic diversity in natives from the island of Kosrae, Federated States of Micronesia, who exhibit a high prevalence of obesity and other metabolic disorders. We hypothesized that genetic drift and possibly natural selection on Kosrae might have increased the frequency of previously rare genetic variants with relatively large effects, making these alleles readily detectable in genome-wide association analysis. However, mapping in large, inbred cohorts introduces analytic challenges, as extensive relatedness between subjects violates the assumptions of independence upon which traditional association test statistics are based. We performed genome-wide association analysis for 15 quantitative traits in 2,906 members of the Kosrae population, using novel approaches to manage the extreme relatedness in the sample. As positive controls, we observe association to known loci for plasma cholesterol, triglycerides, and C-reactive protein and to a compelling candidate loci for thyroid stimulating hormone and fasting plasma glucose. We show that our study is well powered to detect common alleles explaining ≥5% phenotypic variance. However, no such large effects were observed with genome-wide significance, arguing that even in such a severely inbred population, common alleles typically have modest effects. Finally, we show that a majority of common variants discovered in Caucasians have indistinguishable effect sizes on Kosrae, despite the major differences in population genetics and environment.     

Drivers of Public Attitudes towards Small Wind Turbines in the UK

Small Wind Turbines (SWTs) are a growing micro-generation industry with over 870,000 installed units worldwide. No research has focussed on public attitudes towards SWTs, despite evidence the perception of such attitudes are key to planning outcomes and can be a barrier to installations. Here we present the results of a UK wide mail survey investigating public attitudes towards SWTs. Just over half of our respondents, who were predominantly older, white males, felt that SWTs were acceptable across a range of settings, with those on road signs being most accepted and least accepted in hedgerows and gardens. Concern about climate change positively influenced how respondents felt about SWTs. Respondent comments highlight visual impacts and perceptions of the efficiency of this technology are particularly important to this sector of the UK public. Taking this into careful consideration, alongside avoiding locating SWTs in contentious settings such as hedgerows and gardens where possible, may help to minimise public opposition to proposed installations.     

Gender Differentiated Preferences for a Community-Based Conservation Initiative

Community-based conservation (CBC) aims to benefit local people as well as to achieve conservation goals, but has been criticised for taking a simplistic view of “community” and failing to recognise differences in the preferences and motivations of community members. We explore this heterogeneity in the context of Kenya’s conservancies, focussing on the livelihood preferences of men and women living adjacent to the Maasai Mara National Reserve. Using a discrete choice experiment we quantify the preferences of local community members for key components of their livelihoods and conservancy design, differentiating between men and women and existing conservancy members and non-members. While Maasai preference for pastoralism remains strong, non-livestock-based livelihood activities are also highly valued and there was substantial differentiation in preferences between individuals. Involvement with conservancies was generally perceived to be positive, but only if households were able to retain some land for other purposes. Women placed greater value on conservancy membership, but substantially less value on wage income, while existing conservancy members valued both conservancy membership and livestock more highly than did non-members. Our findings suggest that conservancies can make a positive contribution to livelihoods, but care must be taken to ensure that they do not unintentionally disadvantage any groups. We argue that conservation should pay greater attention to individual-level differences in preferences when designing interventions in order to achieve fairer and more sustainable outcomes for members of local communities.