398 research outputs found

    Gr1+IL-4-producing innate cells are induced in response to Th2 stimuli and suppress Th1-dependent antibody responses

    Get PDF
    Alum is used as a vaccine adjuvant and induces T<sub>h</sub>2 responses and T<sub>h</sub>2-driven antibody isotype production against co-injected antigens. Alum also promotes the appearance in the spleen of Gr1+IL-4+ innate cells that, via IL-4 production, induce MHC II-mediated signaling in B cells. To investigate whether these Gr1+ cells accumulate in the spleen in response to other T<sub>h</sub>2-inducing stimuli and to understand some of their functions, the effects of injection of alum and eggs from the helminth, Schistosoma mansoni, were compared. Like alum, schistosome eggs induced the appearance of Gr1+IL-4+ cells in spleen and promoted MHC II-mediated signaling in B cells. Unlike alum, however, schistosome eggs did not promote CD4 T cell responses against co-injected antigens, suggesting that the effects of alum or schistosome eggs on splenic B cells cannot by themselves explain the T cell adjuvant properties of alum. Accordingly, depletion of IL-4 or Gr1+ cells in alum-injected mice had no effect on the ability of alum to improve expansion of primary CD4 T cells. However, Gr1+ cells and IL-4 played some role in the effects of alum, since depletion of either resulted in antibody responses to antigen that included not only the normal T<sub>h</sub>2-driven isotypes, like IgG1, but also a T<sub>h</sub>1-driven isotype, IgG2c. These data suggest that alum affects the immune response in at least two ways: one, independent of Gr1+ cells and IL-4, that promotes CD4 T cell proliferation and another, via Gr1+IL-4+ cells, that participates in the polarization of the response

    Catatonia: demographic, clinical and laboratory associations

    Get PDF
    Background: Catatonia, a severe neuropsychiatric syndrome, has few studies of sufficient scale to clarify its epidemiology or pathophysiology. We aimed to characterise demographic associations, peripheral inflammatory markers and outcome of catatonia. / Methods: Electronic healthcare records were searched for validated clinical diagnoses of catatonia. In a case–control study, demographics and inflammatory markers were compared in psychiatric inpatients with and without catatonia. In a cohort study, the two groups were compared in terms of their duration of admission and mortality. / Results: We identified 1456 patients with catatonia (of whom 25.1% had two or more episodes) and 24 956 psychiatric inpatients without catatonia. Incidence was 10.6 episodes of catatonia per 100 000 person-years. Patients with and without catatonia were similar in sex, younger and more likely to be of Black ethnicity. Serum iron was reduced in patients with catatonia [11.6 v. 14.2 μmol/L, odds ratio (OR) 0.65 (95% confidence interval (CI) 0.45–0.95), p = 0.03] and creatine kinase was raised [2545 v. 459 IU/L, OR 1.53 (95% CI 1.29–1.81), p < 0.001], but there was no difference in C-reactive protein or white cell count. N-Methyl-D-aspartate receptor antibodies were significantly associated with catatonia, but there were small numbers of positive results. Duration of hospitalisation was greater in the catatonia group (median: 43 v. 25 days), but there was no difference in mortality after adjustment. / Conclusions: In the largest clinical study of catatonia, we found catatonia occurred in approximately 1 per 10 000 person-years. Evidence for a proinflammatory state was mixed. Catatonia was associated with prolonged inpatient admission but not with increased mortality

    Efficacy of an Acoustic Hailing Device as an Avian Dispersal Tool

    Get PDF
    Bird strikes are a major safety and financial concern for modern aviation. Audible stimuli are common bird dispersal techniques, but their effectiveness is limited by the saliency and relevance of the stimulus. Furthermore, high ambient sound levels present at airfields might require that effective audible stimuli rely more on total volume (i.e., exceeding physiological tolerances) than ecological relevance. Acoustic hailing devices (AHD) are capable of sound output with a narrow beamwidth and at volumes high enough to cause physical discomfort at long distances. We tested the effectiveness of anAHD as a dispersal tool on freeranging birds recognized as hazardous to aviation safety at the Savannah River Site and Phinizy Swamp Nature Park in South Carolina and Georgia, USA, respectively, between October 2013 and March 2015. Our study design included experimental trials with timed-interval counts of birds directly before and after AHD treatment. For most species, counts of birds associated with treatment periods (use of AHD) and control periods (no use of AHD) occurred on different days. Sound treatments yielded variable success at dispersing birds. Specifically, AHD treatment was effective for dispersing vultures (Coragyps atratus and Cathartes aura) and gulls (Laridae), but ineffective for dispersing blackbirds (Icteridae), diving ducks (Aythya spp., Bucephala spp., Oxyura spp.), and coots (Fulica americana). Trials were conducted in a relatively quiet environment with birds that were unhabituated to excessive noise; thus, we cannot unequivocally recommend an AHD as a universally effective avian dispersing tool. However, future research should consider AHD testing integrated with other methods, as well as investigation of treatments that might be salient to specific target species

    The challenges of long-term invasive mammal management: lessons from the UK

    Get PDF
    We consider the motivations, strategies, and costs involved in invasive mammal management undertaken in the UK. Widespread established invasive mammals require long‐term management to limit damage or spread, but ongoing management is costly and complex. Long‐term management is most effective where it is applied at a landscape scale, but this requires overarching co‐ordination between multiple stakeholders. Five challenges for successful long‐term management of invasive mammal species are identified as follows: defining landscape‐scale strategies, management co‐ordination, stakeholder and community engagement, sustainable funding, and evidence requirements. We make recommendations on the supportive infrastructure needed for effective landscape‐scale management of invasive mammals to fulfil long‐term conservation aims, as follows. 1. There is a need for evidence‐based Invasive Species Action Plans to provide strategy for the long‐term ongoing management of prioritised species at appropriate scales. 2. Where possible, multispecies approaches to invasive species management should be adopted. 3. Trusted leadership should be identified to take ownership of Action Plans and provide an overarching co‐ordination to bring individuals, organisations, and funders together. 4. Support for a centralised hub for training, data, and knowledge flows will greatly improve scientific outcomes through a searchable evidence base, and via best practice and knowledge sharing

    Predicting Invasive Fungal Pathogens Using Invasive Pest Assemblages: Testing Model Predictions in a Virtual World

    Get PDF
    Predicting future species invasions presents significant challenges to researchers and government agencies. Simply considering the vast number of potential species that could invade an area can be insurmountable. One method, recently suggested, which can analyse large datasets of invasive species simultaneously is that of a self organising map (SOM), a form of artificial neural network which can rank species by establishment likelihood. We used this method to analyse the worldwide distribution of 486 fungal pathogens and then validated the method by creating a virtual world of invasive species in which to test the SOM. This novel validation method allowed us to test SOM's ability to rank those species that can establish above those that can't. Overall, we found the SOM highly effective, having on average, a 96–98% success rate (depending on the virtual world parameters). We also found that regions with fewer species present (i.e. 1–10 species) were more difficult for the SOM to generate an accurately ranked list, with success rates varying from 100% correct down to 0% correct. However, we were able to combine the numbers of species present in a region with clustering patterns in the SOM, to further refine confidence in lists generated from these sparsely populated regions. We then used the results from the virtual world to determine confidences for lists generated from the fungal pathogen dataset. Specifically, for lists generated for Australia and its states and territories, the reliability scores were between 84–98%. We conclude that a SOM analysis is a reliable method for analysing a large dataset of potential invasive species and could be used by biosecurity agencies around the world resulting in a better overall assessment of invasion risk

    Measuring sub-mm structural displacements using QDaedalus: a digital clip-on measuring system developed for total stations

    Get PDF
    The monitoring of rigid structures of modal frequencies greater than 5 Hz and sub-mm displacement is mainly based so far on relative quantities from accelerometers, strain gauges etc. Additionally geodetic techniques such as GPS and Robotic Total Stations (RTS) are constrained by their low accuracy (few mm) and their low sampling rates. In this study the application of QDaedalus is presented, which constitutes a measuring system developed at the Geodesy and Geodynamics Lab, ETH Zurich and consists of a small CCD camera and Total Station, for the monitoring of the oscillations of a rigid structure. In collaboration with the Institute of Structural Engineering of ETH Zurich and EMPA, the QDaedalus system was used for monitoring of the sub-mm displacement of a rigid prototype beam and the estimation of its modal frequencies up to 30 Hz. The results of the QDaedalus data analysis were compared to those of accelerometers and proved to hold sufficient accuracy and suitably supplementing the existing monitoring techniques

    Mutual Validation of GNSS Height Measurements and High-precision Geometric-astronomical Leveling

    Get PDF
    The method of geometric-astronomical leveling is presented as a suited technique for the validation of GNSS (Global Navigation Satellite System) heights. In geometric-astronomical leveling, the ellipsoidal height differences are obtained by combining conventional spirit leveling and astronomical leveling. Astronomical leveling with recently developed digital zenith camera systems is capable of providing the geometry of equipotential surfaces of the gravity field accurate to a few 0.1 mm per km. This is comparable to the accuracy of spirit leveling. Consequently, geometric-astronomical leveling yields accurate ellipsoidal height differences that may serve as an independent check on GNSS height measurements at local scales. A test was performed in a local geodetic network near Hanover. GPS observations were simultaneously carried out at five stations over a time span of 48 h and processed considering state-of-the-art techniques and sophisticated new approaches to reduce station-dependent errors. The comparison of GPS height differences with those from geometric-astronomical leveling shows a promising agreement of some millimeters. The experiment indicates the currently achievable accuracy level of GPS height measurements and demonstrates the practical applicability of the proposed approach for the validation of GNSS height measurements as well as the evaluation of GNSS height processing strategies
    corecore