193 research outputs found

    "There's not enough knowledge out there": examining older adults' perceptions of digital technology use and digital inclusion classes

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    Older adults' definitions of digital technology, and experiences of digital inclusion sessions, were examined using qualitative approaches. Seventeen older adults (aged between 54 and 85) participated in two focus groups that each lasted approximately 90 minutes to explore how older adults understood technology within their lived experience. Interpretative Phenomenological Analysis yielded two main themes: Thirst for knowledge and a wish list for digital technology sessions. A separate content analysis was performed to identify what technology older adults identified as digital technology. This analysis revealed that the older adults most frequently defined digital technology as computers and telephones. The findings support the conclusions that this group of older adults, some of whom were 'successful users', have a wide knowledge of digital technology, are interested in gaining more skills, and desire knowledge acquisition through personalised one-to-one learning sessions

    Pretransplant gastroesophageal reflux compromises early outcomes after lung transplantation

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    ObjectivesGastroesophageal reflux disease (GERD) is implicated as a risk factor for bronchiolitis obliterans syndrome after lung transplantation, but its effects on acute rejection, early allograft function, and survival are unclear. Therefore, we sought to systematically understand the time-related impact of pretransplant GERD on graft function (spirometry), mortality, and acute rejection early after lung transplantation.MethodsFrom January 2005 to July 2008, 215 patients underwent lung transplantation; 114 had preoperative pH testing, and 32 (28%) had objective evidence of GERD. Lung function was assessed by forced 1-second expiratory volume (FEV1; percent of predicted) in 97 patients, mortality by follow-up (median, 2.2 years), and acute rejection by transbronchial biopsy.ResultsPretransplant GERD was associated with decreased FEV1 early after lung transplantation (P = .01) such that by 18 months, FEV1 was 70% of predicted in double lung transplant patients with GERD versus 83% among non-GERD patients (P = .05). A similar decrease was observed in single lung transplantation (50% vs 60%, respectively; P = .09). GERD patients had lower survival early after transplant ( P = .02)—75% versus 90%. Presence of GERD did not affect acute rejection (P = .6).ConclusionsFor lung transplant recipients, pretransplant GERD is associated with worse early allograft function and survival, but not increased acute rejection. The compromise in lung function is substantial, such that FEV1 after double lung transplant in GERD patients approaches that of single lung transplant in non-GERD patients. We advocate thorough testing for GERD before lung transplantation; if identified, aggressive therapy early after transplant, including fundoplication, may prove efficacious

    Early Ultraviolet, Optical and X-Ray Observations of the Type IIP SN 2005cs in M51 with Swift

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    We report early photospheric-phase observations of the Type IIP Supernova (SN) 2005cs obtained by Swift's Ultraviolet-Optical and X-Ray Telescopes. Observations started within two days of discovery and continued regularly for three weeks. During this time the V-band magnitude remained essentially constant, while the UV was initially bright but steadily faded until below the brightness of an underlying UV-bright HII region. This UV decay is similar to SNe II observed by the International Ultraviolet Explorer. UV grism spectra show the P-Cygni absorption of MgII 2798A, indicating a photospheric origin of the UV flux. Based on non-LTE model atmosphere calculations with the CMFGEN code, we associate the rapid evolution of the UV flux with the cooling of the ejecta, the peak of the spectral energy distribution (SED) shifting from ~700A on June 30th to ~1200A on July 5th. Furthermore, the corresponding recombination of the ejecta, e.g., the transition from FeIII to FeII, induces considerable strengthening of metal line-blanketing at and above the photosphere, blocking more effectively this fading UV flux. SN2005cs was not detected in X-rays, and the upper limit to the X-ray luminosity yields a limit to the mass loss rate of the progenitor of about 10^-5 solar masses per year. Overall, Swift presents a unique opportunity to capture the early and fast evolution of Type II SNe in the UV, providing additional constraints on the reddening, the SED shortward of 4000A, and the ionization state and temperature of the photon-decoupling regions.Comment: 15 pages, 6 figures. Accepted for publication by Astrophysical Journa

    A Crucial Role for Kupffer Cell-Derived Galectin-9 in Regulation of T Cell Immunity in Hepatitis C Infection

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    Approximately 200 million people throughout the world are infected with hepatitis C virus (HCV). One of the most striking features of HCV infection is its high propensity to establish persistence (∼70–80%) and progressive liver injury. Galectins are evolutionarily conserved glycan-binding proteins with diverse roles in innate and adaptive immune responses. Here, we demonstrate that galectin-9, the natural ligand for the T cell immunoglobulin domain and mucin domain protein 3 (Tim-3), circulates at very high levels in the serum and its hepatic expression (particularly on Kupffer cells) is significantly increased in patients with chronic HCV as compared to normal controls. Galectin-9 production from monocytes and macrophages is induced by IFN-γ, which has been shown to be elevated in chronic HCV infection. In turn, galectin-9 induces pro-inflammatory cytokines in liver-derived and peripheral mononuclear cells; galectin-9 also induces anti-inflammatory cytokines from peripheral but not hepatic mononuclear cells. Galectin-9 results in expansion of CD4+CD25+FoxP3+CD127low regulatory T cells, contraction of CD4+ effector T cells, and apoptosis of HCV-specific CTLs. In conclusion, galectin-9 production by Kupffer cells links the innate and adaptive immune response, providing a potential novel immunotherapeutic target in this common viral infection

    Innate Immune Function in Placenta and Cord Blood of Hepatitis C – Seropositive Mother-Infant Dyads

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    Vertical transmission accounts for the majority of pediatric cases of hepatitis C viral (HCV) infection. In contrast to the adult population who develop persistent viremia in ∼80% of cases following exposure, the rate of mother-to-child transmission (2–6%) is strikingly low. Protection from vertical transmission likely requires the coordination of multiple components of the immune system. Placenta and decidua provide a direct connection between mother and infant. We hypothesized that innate immune responses would differ across the three compartments (decidua, placenta and cord blood) and that hepatitis C exposure would modify innate immunity in these tissues. The study was comprised of HCV-infected and healthy control mother and infant pairs from whom cord blood, placenta and decidua were collected with isolation of mononuclear cells. Multiparameter flow cytometry was performed to assess the phenotype, intracellular cytokine production and cytotoxicity of the cells. In keeping with a model where the maternal-fetal interface provides antiviral protection, we found a gradient in proportional frequencies of NKT and γδ-T cells being higher in placenta than cord blood. Cytotoxicity of NK and NKT cells was enhanced in placenta and placental NKT cytotoxicity was further increased by HCV infection. HCV exposure had multiple effects on innate cells including a decrease in activation markers (CD69, TRAIL and NKp44) on NK cells and a decrease in plasmacytoid dendritic cells in both placenta and cord blood of exposed infants. In summary, the placenta represents an active innate immunological organ that provides antiviral protection against HCV transmission in the majority of cases; the increased incidence in preterm labor previously described in HCV-seropositive mothers may be related to enhanced cytotoxicity of NKT cells

    LPCAT4 knockdown alters barrier integrity and cellular bioenergetics in human urothelium

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    Urothelium is a transitional, stratified epithelium that lines the lower urinary tract, providing a tight barrier to urine whilst retaining the capacity to stretch and rapidly resolve damage. The role of glycerophospholipids in urothelial barrier function is largely unknown, despite their importance in membrane structural integrity, protein complex assembly, and the master regulatory role of PPARγ in urothelial differentiation. We performed lipidomic and transcriptomic characterisation of urothelial differentiation, revealing a metabolic switch signature from fatty acid synthesis to lipid remodelling, including 5-fold upregulation of LPCAT4. LPCAT4 knockdown urothelial cultures exhibited an impaired proliferation rate but developed elevated trans-epithelial electrical resistances upon differentiation, associated with a reduced and delayed capacity to restitute barrier function after wounding. Specific reduction in 18:1 PC fatty acyl chains upon knockdown was consistent with LPCAT4 specificity, but was unlikely to elicit broad barrier function changes. However, transcriptomic analysis of LPCAT4 knockdown supported an LPC-induced reduction in DAG availability, predicted to limit PKC activity, and TSPO abundance, predicted to limit endogenous ATP. These phenotypes were confirmed by PKC and TSPO inhibition. Together, these data suggest an integral role for lipid mediators in urothelial barrier function and highlight the strength of combined lipidomic and transcriptomic analyses for characterising tissue homeostasis

    Modern optical astronomy: technology and impact of interferometry

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    The present `state of the art' and the path to future progress in high spatial resolution imaging interferometry is reviewed. The review begins with a treatment of the fundamentals of stellar optical interferometry, the origin, properties, optical effects of turbulence in the Earth's atmosphere, the passive methods that are applied on a single telescope to overcome atmospheric image degradation such as speckle interferometry, and various other techniques. These topics include differential speckle interferometry, speckle spectroscopy and polarimetry, phase diversity, wavefront shearing interferometry, phase-closure methods, dark speckle imaging, as well as the limitations imposed by the detectors on the performance of speckle imaging. A brief account is given of the technological innovation of adaptive-optics (AO) to compensate such atmospheric effects on the image in real time. A major advancement involves the transition from single-aperture to the dilute-aperture interferometry using multiple telescopes. Therefore, the review deals with recent developments involving ground-based, and space-based optical arrays. Emphasis is placed on the problems specific to delay-lines, beam recombination, polarization, dispersion, fringe-tracking, bootstrapping, coherencing and cophasing, and recovery of the visibility functions. The role of AO in enhancing visibilities is also discussed. The applications of interferometry, such as imaging, astrometry, and nulling are described. The mathematical intricacies of the various `post-detection' image-processing techniques are examined critically. The review concludes with a discussion of the astrophysical importance and the perspectives of interferometry.Comment: 65 pages LaTeX file including 23 figures. Reviews of Modern Physics, 2002, to appear in April issu

    The Tarantula Massive Binary Monitoring: I. Observational campaign and OB-type spectroscopic binaries

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    © ESO, 2017.Context. Massive binaries play a crucial role in the Universe. Knowing the distributions of their orbital parameters is important for a wide range of topics from stellar feedback to binary evolution channels and from the distribution of supernova types to gravitational wave progenitors, yet no direct measurements exist outside the Milky Way. Aims. The Tarantula Massive Binary Monitoring project was designed to help fill this gap by obtaining multi-epoch radial velocity (RV) monitoring of 102 massive binaries in the 30 Doradus region. Methods. In this paper we analyze 32 FLAMES/GIRAFFE observations of 93 O- and 7 B-type binaries. We performed a Fourier analysis and obtained orbital solutions for 82 systems: 51 single-lined (SB1) and 31 double-lined (SB2) spectroscopic binaries. Results. Overall, the binary fraction and orbital properties across the 30 Doradus region are found to be similar to existing Galactic samples. This indicates that within these domains environmental effects are of second order in shaping the properties of massive binary systems. A small difference is found in the distribution of orbital periods, which is slightly flatter (in log space) in 30 Doradus than in the Galaxy, although this may be compatible within error estimates and differences in the fitting methodology. Also, orbital periods in 30 Doradus can be as short as 1.1 d, somewhat shorter than seen in Galactic samples. Equal mass binaries (q> 0.95) in 30 Doradus are all found outside NGC 2070, the central association that surrounds R136a, the very young and massive cluster at 30 Doradus's core. Most of the differences, albeit small, are compatible with expectations from binary evolution. One outstanding exception, however, is the fact that earlier spectral types (O2-O7) tend to have shorter orbital periods than later spectral types (O9.2-O9.7). Conclusions. Our results point to a relative universality of the incidence rate of massive binaries and their orbital properties in the metallicity range from solar (Z) to about half solar. This provides the first direct constraints on massive binary properties in massive star-forming galaxies at the Universe's peak of star formation at redshifts z ~ 1 to 2 which are estimated to have Z 0.5 Z
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