812 research outputs found

    Hemiparasitic plant impacts animal and plant communities across four trophic levels

    Get PDF
    1.Understanding the impact of species on community structure is a fundamental question in ecology. There is a growing body of evidence that suggests that both sub-dominant species and parasites can have a disproportionately large impact. 2.Here we report the impacts of an organism that is both subdominant and parasitic, the hemiparasite Rhinanthus minor. Whilst the impact of parasitic angiosperms on their hosts and, to a lesser degree, co-existing plant species, have been well characterized, much less is known about their impacts on higher trophic levels. 3.We experimentally manipulated field densities of the hemiparasite Rhinanthus minor in a species rich grassland, comparing the plant and invertebrate communities in plots where it was removed, at natural densities or at enhanced densities. 4.Plots with natural and enhanced densities of R. minor had lower plant biomass than plots without the hemiparasite, but enhanced densities almost doubled the abundance of invertebrates within the plots across all trophic levels, with effects evident in herbivores, predators and detritivores. 5.The hemiparasite R. minor, despite being a sub-dominant and transient component within plant communities that it inhabits, has profound effects on four different trophic levels. These effects persist beyond the life of the hemiparasite, emphasizing its role as a keystone species in grassland communitie

    Digital storytelling and Co-creative Media: The role of community arts and media in propagating and coordinating population-wide creative practice

    Get PDF
    How is creative expression and communication extended among whole populations? What is the social and cultural value of this activity? What roles do formal agencies, community-based organisations and content producer networks play? Specifically, how do participatory media and arts projects and networks contribute to building this capacity in the contemporary communications environment

    Photoactivated release of membrane impermeant sulfonates inside cells.

    Get PDF
    Photouncaging delivers compounds with high spatial and temporal control to induce or inhibit biological processes but the released compounds may diffuse out. We here demonstrate that sulfonate anions can be photocaged so that a membrane impermeable compound can enter cells, be uncaged by photoirradiation and trapped within the cell

    Activity of the DNA minor groove cross-linking agent SG2000 (SJG-136) against canine tumours

    Get PDF
    BACKGROUND: Cancer is the leading cause of death in older dogs and its prevalence is increasing. There is clearly a need to develop more effective anti-cancer drugs in dogs. SG2000 (SJG-136) is a sequence selective DNA minor groove cross-linking agent. Based on its in vitro potency, the spectrum of in vivo and clinical activity against human tumours, and its tolerability in human patients, SG2000 has potential as a novel therapeutic against spontaneously occurring canine malignancies. RESULTS: In vitro cytotoxicity was assessed using SRB and MTT assays, and in vivo activity was assessed using canine tumour xenografts. DNA interstrand cross-linking (ICL) was determined using a modification of the single cell gel electrophoresis (comet) assay. Effects on cell cycle distribution were assessed by flow cytometry and measurement of γ-H2AX by immunofluorescence and immunohistochemistry. SG2000 had a multi-log differential cytotoxic profile against a panel of 12 canine tumour cell lines representing a range of common tumour types in dogs. In the CMeC-1 melanoma cell line, DNA ICLs increased linearly with dose following a 1 h treatment. Peak ICL was achieved within 1 h and no removal was observed over 48 h. A relationship between DNA ICL formation and cytotoxicity was observed across cell lines. The formation of γ-H2AX foci was slow, becoming evident after 4 h and reaching a peak at 24 h. SG2000 exhibited significant anti-tumour activity against two canine melanoma tumour models in vivo. Anti-tumour activity was observed at 0.15 and 0.3 mg/kg given i.v. either once, or weekly x 3. Dose-dependent DNA ICL was observed in tumours (and to a lower level in peripheral blood mononuclear cells) at 2 h and persisted at 24 h. ICL increased following the second and third doses in a repeated dose schedule. At 24 h, dose dependent γ-H2AX foci were more numerous than at 2 h, and greater in tumours than in peripheral blood mononuclear cells. SG2000-induced H2AX phosphorylation measured by immunohistochemistry showed good correspondence, but less sensitivity, than measurement of foci. CONCLUSIONS: SG2000 displayed potent activity in vitro against canine cancer cell lines as a result of the formation and persistence of DNA ICLs. SG2000 also had significant in vivo antitumour activity against canine melanoma xenografts, and the comet and γ-H2AX foci methods were relevant pharmacodynamic assays. The clinical testing of SG2000 against spontaneous canine cancer is warranted. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12917-015-0534-2) contains supplementary material, which is available to authorized users

    Mental Health Encounters in Critical Access Hospital Emergency Rooms: A National Survey

    Get PDF
    Previous studies have investigated the rural provision of mental health services by FQHCs and CMHCs (Wagenfeld, 1994; Hartley et al., 2002). However, there is little documentation of the extent to which ERs provide mental health services in rural communities. This paper provides new information about the role of rural ER’s in the provision of mental health services, gathered from a structured telephone survey of ER managers in a nationally representative sample of Critical Access Hospitals, and from service logs completed by ER staff. Specifically, we have sought to determine 1) what proportion of ER encounters involve mental health pathology; 2) what kinds of mental health problems are most commonly seen in these encounters, and; 3) what resources are available to CAHs to address the problems they encounter

    Urban semiosis: Creative industries and the clash of systems

    Get PDF
    © The Author(s) 2014. This article has two aims. The first is to make the case that the ‘universe of the mind’ imagined by Yuri Lotman may be considered as a foundational model for cultural evolution (population-wide, dynamic, autopoietic, self-organising adaptation to changing environments). The second aim is to take forward a model of culture derived from Lotman’s work – a model I call ‘the clash of systems’ – in order to apply it to creative industries research. Such a move has the salutary effect of putting the ‘universe of the mind’ literally in its place. That place, now, predominantly, is in the city. Thus, the article uses Lotman’s model of the semiosphere to link different complex systems, principally the semiosphere with that of the city, in order to explore the productive potential of encounters – clashes – between different systems. Applying these insights to the field of creative industries research, the article proposes that creative culture in the globalised, urban and web-connected era can be characterised as ‘urban semiosis’

    MitoNeoD:a mitochondria-targeted superoxide probe

    Get PDF
    Mitochondrial superoxide (O2⋅−) underlies much oxidative damage and redox signaling. Fluorescent probes can detect O2⋅−, but are of limited applicability in vivo, while in cells their usefulness is constrained by side reactions and DNA intercalation. To overcome these limitations, we developed a dual-purpose mitochondrial O2⋅− probe, MitoNeoD, which can assess O2⋅− changes in vivo by mass spectrometry and in vitro by fluorescence. MitoNeoD comprises a O2⋅−-sensitive reduced phenanthridinium moiety modified to prevent DNA intercalation, as well as a carbon-deuterium bond to enhance its selectivity for O2⋅− over non-specific oxidation, and a triphenylphosphonium lipophilic cation moiety leading to the rapid accumulation within mitochondria. We demonstrated that MitoNeoD was a versatile and robust probe to assess changes in mitochondrial O2⋅− from isolated mitochondria to animal models, thus offering a way to examine the many roles of mitochondrial O2⋅−production in health and disease

    Banking from Leeds, not London: regional strategy and structure at the Yorkshire Bank, 1859–1952

    Get PDF
    Industrial philanthropist Edward Akroyd created the Yorkshire Penny Savings Bank in 1859. Despite competition from the Post Office Savings Bank after 1861 and a serious reserve problem in 1911, it sustained his overall strategy to become a successful regional bank. Using archival and contemporary sources to build on recent scholarship illustrating how savings banks were integrated into local economies and the complementary roles of philanthropy and paternalism, we analyse an English regional bank's strategy, including an assessment of strategic innovation, ownership changes and management structure. This will demonstrate that the founder's vision continued, even though the 1911 crisis radically altered both strategy and structure

    Murray Valley Encephalitis Virus Envelope Protein Antigenic Variants with Altered Hemagglutination Properties and Reduced Neuroinvasiveness in Mice

    Get PDF
    AbstractNeutralization escape variants of Murray Valley encephalitis virus were selected using a type-specific, neutralizing, and passively protective anti-envelope protein (E) monoclonal antibody (4B6C-2) which defines epitope E-1c. Nucleotide sequence analysis revealed single nucleotide changes in the E genes of 15 variants resulting in nonconservative amino acid substitutions in all cases. One variant had a three-nucleotide deletion in the E gene which resulted in loss of serine at residue 277. Changes were clustered into two separate regions of the E polypeptide (residues 126-128 and 274-277), indicating that E-1c is a discontinuous epitope. One variant (BHv1), altered at residue 277 (Ser → Ile), failed to hemagglutinate across the pH range 55-7.5, in contrast to parental virus and the other escape variants which hemagglutinated at an optimal pH of 6.6. BHv1 was also of reduced neuroinvasiveness in 21-day-old mice following intraperitoneal inoculation compared to the other viruses. Parental virus and the neutralization escape variants grew equally well in both vertebrate and invertebrate cell cultures, indicating that the reduced neuroinvasiveness of BHv1 was not due to a major abnormality of replication
    • …
    corecore