32 research outputs found

    Catchment-scale vulnerability assessment of groundwater pollution from diffuse sources using the DRASTIC method : a case study

    Get PDF
    The catchment-scale groundwater vulnerability assessment that delineates zones representing different levels of groundwater susceptibility to contaminants from diffuse agricultural sources has become an important element in groundwater pollution prevention for the implementation of the EUWater Framework Directive (WFD). This paper evaluates the DRASTIC method using an ArcGIS platform for assessing groundwater vulnerability in the Upper Bann catchment, Northern Ireland. Groundwater vulnerability maps of both general pollutants and pesticides in the study area were generated by using data on the factors depth to water, net recharge, aquifer media, soil media, topography, impact of vadose zone, and hydraulic conductivity, as defined in DRASTIC. The mountain areas in the study area have “high” (in 4.5% of the study area) or “moderate” (in 25.5%) vulnerability for general pollutants due to high rainfall, net recharge and soil permeability. However, by considering the diffuse agricultural sources, the mountain areas are actually at low groundwater pollution risk. The results of overlaying the maps of land use and the groundwater vulnerability are closer to the reality. This study shows that the DRASTIC method is helpful for guiding the prevention practices of groundwater pollution at the catchment scale in the UK

    Molecular investigations into Wiskott-Aldrich Syndrome.

    Get PDF
    Wiskott-Aldrich Syndrome (WAS) is a rare X-linked recessive primary immunodeficiency characterised by eczema, thrombocytopaenia and immunodeficiency. WAS encodes for a haematopoietic restricted protein, WASp, involved in transduction of signals from the cell membrane to the actin cytoskeleton. Mutations lead to impaired actin dynamics in response to stimuli and are seen as defects of receptor capping, chemotaxis, phagocytosis and proliferation. This leads to susceptibility to pyogenic, viral and opportunistic infections and increased incidence of lymphoproliferative disease and malignancy. Due to the high morbidity and mortality associated with mismatched transplantation, WAS is considered a good target for gene therapy. We were able to reconstitute a murine model of WAS using a gamma retroviral vector, with reconstitution of specialised actin structures, podosomes, as a functional readout. Reservations concerning the safety of such vectors, following adverse events in a clinical trial, led to the development of third generation self-inactivating lentiviral vectors. Under the promotion of CMV, SFFV LTR or short sequences of the proximal endogenous Wiskott-promoter, WASp was able to restore cytoskeletal abnormalities in dendritic cells in-vitro from WASp-deficient mice. In addition we have demonstrated stable expression of WASp in T cell, B cell and myeloid lineages following transduction and engraftment of lineage negative murine bone marrow (up to 9 months) using both an SFFV LTR and endogenous promoter sequences. We have demonstrated the ability to restore cytoskeletal abnormalities and proliferative responses from the reconstituted mice. Recently a novel mutation in WAS has led to the discovery of a constitutively active WASp, with a novel monocytopaenic and neutropaenic phenotype. Here we characterised the patient phenotype of a novel constitutively active WASpn94T mutant. In addition to monocytopaenia and neutropaenia, there was abnormal cytoskeletal actin, manifesting itself as abnormal podosome distribution and an inability to phagocytose or produce an oxidative burst to physiological stimuli. There was also increased apoptosis in the bone marrow and evidence of genomic instability. Utilising lentiviral vectors, WASpI294T was expressed in a cell line to elucidate the possible mechanisms responsible for the patient phenotype. These studies demonstrate the efficacy and feasibility of a lentiviral vector-mediated gene therapy strategy for WAS using endogenous promoters where a more regulated expression level may be achieved

    Ionic and electronic structure of sodium clusters up to N=59

    Get PDF
    We determined the ionic and electronic structure of sodium clusters with even electron numbers and 2 to 59 atoms in axially averaged and three-dimensional density functional calculations. A local, phenomenological pseudopotential that reproduces important bulk and atomic properties and facilitates structure calculations has been developed. Photoabsorption spectra have been calculated for Na2\mathrm{Na}_2, Na8\mathrm{Na}_8, and Na9+\mathrm{Na}_9^+ to Na59+\mathrm{Na}_{59}^+. The consistent inclusion of ionic structure considerably improves agreement with experiment. An icosahedral growth pattern is observed for Na19+\mathrm{Na}_{19}^+ to Na59+\mathrm{Na}_{59}^+. This finding is supported by photoabsorption data.Comment: To appear in Phys. Rev. B 62. Version with figures in better quality can be requested from the author

    Prospects for e+e- physics at Frascati between the phi and the psi

    Get PDF
    We present a detailed study, done in the framework of the INFN 2006 Roadmap, of the prospects for e+e- physics at the Frascati National Laboratories. The physics case for an e+e- collider running at high luminosity at the phi resonance energy and also reaching a maximum center of mass energy of 2.5 GeV is discussed, together with the specific aspects of a very high luminosity tau-charm factory. Subjects connected to Kaon decay physics are not discussed here, being part of another INFN Roadmap working group. The significance of the project and the impact on INFN are also discussed. All the documentation related to the activities of the working group can be found in http://www.roma1.infn.it/people/bini/roadmap.html.Comment: INFN Roadmap Report: 86 pages, 25 figures, 9 table

    A vertical-mode decomposition to investigate low-frequency internal motion across the Atlantic at 26°N

    Get PDF
    Hydrographic data from full-depth moorings maintained by the Rapid/\-MOCHA project and spanning the Atlantic at 26° N are decomposed into vertical modes in order to give a dynamical framework for interpreting the observed fluctuations. Vertical modes at each mooring are fit to pressure perturbations using a Gauss-Markov inversion. Away from boundaries, the vertical structure is almost entirely described by the first baroclinic mode, as confirmed by high correlation between the original signal and reconstructions using only the first baroclinic mode. These first baroclinic motions are also highly coherent with altimetric sea surface height (SSH). Within a Rossby radius (45 km) of the western and eastern boundaries, however, the decomposition contains significant variance at higher modes, and there is a corresponding decrease in the agreement between SSH and either the original signal or the first baroclinic mode reconstruction. Compared to the full transport signal, transport fluctuations described by the first baroclinic mode represent <25 km of the variance within 10 km of the western boundary, in contrast to 60 km at other locations. This decrease occurs within a Rossby radius of the western boundary. At the eastern boundary, a linear combination of many baroclinic modes is required to explain the observed vertical density profile of the seasonal cycle, a result that is consistent with an oceanic response to wind-forcing being trapped to the eastern boundary

    The evolution of classical doubles: clues from complete samples

    No full text
    We describe the inter-dependence of four properties of classical double radio sources - spectral index, linear size, luminosity and redshift - from an extensive study based on spectroscopically-identified complete samples. We use these relationships to discuss aspects of strategies for searching for radio galaxies at extreme redshifts, in the context of possible capabilities of the new generation of proposed radio telescopes

    Discovery of a multiply lensed submillimeter galaxy in early HerMES Herschel/SPIRE data

    Get PDF
    ‘In these times, during the rise in the popularity of institutional repositories, the Society does not forbid authors from depositing their work in such repositories. However, the AAS regards the deposit of scholarly work in such repositories to be a decision of the individual scholar, as long as the individual's actions respect the diligence of the journals and their reviewers.’ Original article can be found at: http://iopscience.iop.org/ Copyright American Astronomical SocietyWe report the discovery of a bright (f (250 μm)>400 mJy), multiply lensed submillimeter galaxy HERMES J105751.1+573027 in Herschel/SPIRE Science Demonstration Phase data from the HerMES project. Interferometric 880 μm Submillimeter Array observations resolve at least four images with a large separation of ∼9″. A high-resolution adaptive optics Kp image with Keck/NIRC2 clearly shows strong lensing arcs. Follow-up spectroscopy gives a redshift of z = 2.9575, and the lensing model gives a total magnification of μ ∼ 11 ± 1. The large image separation allows us to study the multi-wavelength spectral energy distribution (SED) of the lensed source unobscured by the central lensing mass. The far-IR/millimeter-wave SED is well described by a modified blackbody fit with an unusually warm dust temperature, 88 ± 3 K. We derive a lensing-corrected total IR luminosity of (1.43 ± 0.09) × 1013 L⊙, implying a star formation rate of ∼2500 M⊙ yr-1. However, models primarily developed from brighter galaxies selected at longer wavelengths are a poor fit to the full optical-to-millimeter SED. A number of other strongly lensed systems have already been discovered in early Herschel data, and many more are expected as additional data are collected.Peer reviewe

    Trisomy 21 mid-trimester amniotic fluid induced pluripotent stem cells maintain genetic signatures during reprogramming: Implications for disease modeling and cryobanking

    No full text
    Trisomy 21 is the most common chromosomal abnormality and is associated primarily with cardiovascular, hematological, and neurological complications. A robust patient-derived cellular model is necessary to investigate the pathophysiology of the syndrome because current animal models are limited and access to tissues from affected individuals is ethically challenging. We aimed to derive induced pluripotent stem cells (iPSCs) from trisomy 21 human mid-trimester amniotic fluid stem cells (AFSCs) and describe their hematopoietic and neurological characteristics. Human AFSCs collected from women undergoing prenatal diagnosis were selected for c-KIT+and transduced with a Cre-lox-inducible polycistronic lentiviral vector encoding SOX2, OCT4, KLF-4, and c-MYC (50,000 cells at a multiplicity of infection (MOI) 1-5 for 72h). The embryonic stem cell (ESC)-like properties of the AFSC-derived iPSCs were established in vitro by embryoid body formation and in vivo by teratoma formation in RAG2-/-, γ-chain-/-, C2-/-immunodeficient mice. Reprogrammed cells retained their cytogenetic signatures and differentiated into specialized hematopoietic and neural precursors detected by morphological assessment, immunostaining, and RT-PCR. Additionally, the iPSCs expressed all pluripotency markers upon multiple rounds of freeze-thawing. These findings are important in establishing a patient-specific cellular platform of trisomy 21 to study the pathophysiology of the aneuploidy and for future drug discovery. © 2014 Mary Ann Liebert, Inc
    corecore