696 research outputs found

    Caregivers' perceived adequacy of support in end-stage lung disease: results of a population survey.

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    BACKGROUND: End-stage lung disease (ESLD) is a frequent cause of death. What are the differences in the supports needed by caregivers of individuals with ESLD at end of life versus other life-limiting diagnoses? METHODS: The South Australian Health Omnibus is an annual, random, face-to-face, cross-sectional survey. In 2002, 2003 and 2005-2007, respondents were asked a range of questions about end-of-life care; there were approximately 3000 survey participants annually (participation rate 77.9%). Responses were standardised for the whole population. The families and friends who cared for someone with ESLD were the focus of this analysis. In addition to describing caring, respondents reported additional support that would have been helpful. RESULTS: Of 1504 deaths reported, 145 (9.6%) were due to ESLD. The ESLD cohort were older than those with other 'expected' causes of death (> 65 years of age; 92.6% versus 70.6%; p < 0.0001) and were less likely to access specialised palliative care services (38.4% versus 61.9%; p < 0.0001). For those with ESLD, the mean caring period was significantly longer at 25 months (standard deviation (SD) 24) than for 'other diagnoses' (15 months; SD 18; p < 0.0001). Domains where additional support would have been useful included physical care, information provision, and emotional and spiritual support. CONCLUSIONS: Caregiver needs were similar regardless of the underlying diagnosis although access to palliative care specialist services occurred less often for ESLD patients. This was despite significantly longer periods of time for which care was provided.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Virtual Surfaces, Director Domains and the Freedericksz Transition in Polymer Stabilized Nematic Liquid Crystals

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    The critical field of the Freedericksz transition and switching dynamics are investigated for polymer stabilized nematic liquid crystals as a function of polymer concentration. A simple phenomenological model is proposed to describe the observed critical field and dynamic response time behaviors as a function of concentration. In this model the polymer fibrils form director domains, which are bounded by virtual surfaces with a finite anchoring energy. The Freedericksz transition occurs independently within each of these domains

    Magnetometry of the classical T Tauri star GQ Lup: non-stationary dynamos & spin evolution of young Suns

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    We report here results of spectropolarimetric observations of the classical T Tauri star (cTTS) GQ Lup carried out with ESPaDOnS at the Canada-France-Hawaii Telescope (CFHT) in the framework of the "Magnetic Protostars and Planets" (MaPP) programme, and obtained at 2 different epochs (2009 July & 2011 June). From these observations, we first infer that GQ Lup has a photospheric temperature of 4,300+-50\^A K and a rotation period of 8.4+-0.3 d; it implies that it is a 1.05+-0.07 Msun star viewed at an inclination of ~30deg, with an age of 2-5 Myr, a radius of 1.7+-0.2 Rsun, and has just started to develop a radiative core. Large Zeeman signatures are clearly detected at all times, both in photospheric lines & in accretion-powered emission lines, probing longitudinal fields of up to 6 kG and hence making GQ Lup the cTTS with the strongest large-scale fields known as of today. Rotational modulation of Zeeman signatures is clearly different between our 2 runs, demonstrating that large-scale fields of cTTSs are evolving with time and are likely produced by non-stationary dynamo processes. Using tomographic imaging, we reconstruct maps of the large-scale field, of the photospheric brightness & of the accretion-powered emission of GQ Lup. We find that the magnetic topology is mostly poloidal & axisymmetric; moreover, the octupolar component of the large-scale field (of strength 2.4 & 1.6 kG in 2009 & 2011) dominates the dipolar component (of strength ~1 kG) by a factor of ~2, consistent with the fact that GQ Lup is no longer fully-convective. GQ Lup also features dominantly poleward magnetospheric accretion at both epochs. The large-scale dipole of GQ Lup is however not strong enough to disrupt the surrounding accretion disc further than about half-way to the corotation radius, suggesting that GQ Lup should rapidly spin up like other similar partly-convective cTTSs (abridged).Comment: MNRAS, in press (17 pages, 10 figures, 1 table

    How Soil Properties Affect Egg Development and Larval Longevity of a Grassland Insect Pest - an Empirically Based Model

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    The clover root weevil (Sitona lepidus Gyllenhal.) is a destructive pest of white clover in temperate grasslands. Adults lay thousands of eggs that give rise to soil-dwelling larvae that initially feed on the root nodules housing symbiotic N2-fixing Rhizobium spp. bacteria. The period between egg hatch and consumption of root nodules by larvae is probably the most vulnerable part in the lifecycle, and if larvae do not locate roots relatively quickly they will die of starvation. In particular, the shells of eggs and the cuticles of emergent larvae are in constant physical contact with the external soil environment, so the nature of the soil is potentially critical for these life-stages. This study tested the effects of soil temperature, pH and moisture on egg development and subsequent longevity of unfed larvae to develop a mathematical model of these processes

    Optomechanical Properties of Stretched Polymer Dispersed Liquid Crystal Films for Scattering Polarizer Applications

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    A scattering polarizer is created by subjecting a polymer dispersed liquid crystal (PDLC) film to tensile strain. The optomechanical properties of the film are investigated by simultaneously measuring the stress-strain and polarization dependent optical transmission characteristics. The correlation between transmittances of two orthogonal polarizations and the stress-strain curve reveals that the polymer orientation as well as the droplet shape anisotropy influences the liquid crystal alignment within the droplets. A Monte-Carlo simulation based on the Lebwohl-Lasher model is used to explain the subtle influence of polymer orientation on liquid crystal alignment.Comment: 22 pages, pd

    Neuroinflammatory Gene Expression Alterations in Anterior Cingulate Cortical White and Gray Matter of Males With Autism Spectrum Disorder

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    Evidence for putative pathophysiological mechanisms of autism spectrum disorder (ASD), including peripheral inflammation, blood–brain barrier disruption, white matter alterations, and abnormal synaptic overgrowth, indicate a possible involvement of neuroinflammation in the disorder. Neuroinflammation plays a role in the development and maintenance of the dendritic spines involved in glutamatergic and GABAergic neurotransmission, and also influences blood–brain permeability. Cytokines released from microglia can impact the length, location or organization of dendritic spines on excitatory and inhibitory cells as well as recruit and impact glial cell function around the neurons. In this study, gene expression levels of anti- and pro-inflammatory signaling molecules, as well as oligodendrocyte and astrocyte marker proteins, were measured in both gray and white matter tissue in the anterior cingulate cortex from ASD and age-matched typically developing (TD) control brain donors, ranging from ages 4 to 37 years. Expression levels of the pro-inflammatory gene, HLA-DR, were significantly reduced in gray matter and expression levels of the anti-inflammatory gene MRC1 were significantly elevated in white matter from ASD donors as compared to TD donors, but neither retained statistical significance after correction for multiple comparisons. Modest trends toward differences in expression levels were also observed for the pro-inflammatory (CD68, IL1β) and anti-inflammatory genes (IGF1, IGF1R) comparing ASD donors to TD donors. The direction of gene expression changes comparing ASD to TD donors did not reveal consistent findings implicating an elevated pro- or anti-inflammatory state in ASD. However, altered expression of pro- and anti-inflammatory gene expression indicates some involvement of neuroinflammation in ASD. Lay Summary: The anterior cingulate cortex is an integral brain region in modulating social behaviors including nonverbal communication. The study found that inflammatory gene expression levels were altered in this brain region. We hypothesize that the inflammatory changes in this area could impact neuronal function. The finding has future implications in using these molecular markers to identify potential environmental exposures and distinct cell differences in autism

    Thrombospondin-1 Is a Major Activator of TGF-β1 In Vivo

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    AbstractThe activity of TGF-β1 is regulated primarily extracellularly where the secreted latent form must be modified to expose the active molecule. Here we show that thrombospondin-1 is responsible for a significant proportion of the activation of TGF-β1 in vivo. Histological abnormalities in young TGF-β1 null and thrombospondin-1 null mice were strikingly similar in nine organ systems. Lung and pancreas pathologies similar to those observed in TGF-β1 null animals could be induced in wild-type pups by systemic treatment with a peptide that blocked the activation of TGF-β1 by thrombospondin-1. Although these organs produced little active TGF-β1 in thrombospondin null mice, when pups were treated with a peptide derived from thrombospondin-1 that could activate TGF-β1, active cytokine was detected in situ, and the lung and pancreatic abnormalities reverted toward wild type

    Discovering sequences with potential regulatory characteristics

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    AbstractWe developed a computational model to explore the hypothesis that regulatory instructions are context dependent and conveyed through specific ‘codes’ in human genomic DNA. We provide examples of correlation of computational predictions to reported mapped DNase I hypersensitive segments in the HOXA locus in human chromosome 7. The examples show that statistically significant 9-mers from promoter regions may occur in sequences near and upstream of transcription initiation sites, in intronic regions, and within intergenic regions. Additionally, a subset of 9-mers from coding sequences appears frequently, as clusters, in regulatory regions dispersed in noncoding regions in genomic DNA. The results suggest that the computational model has the potential of decoding regulatory instructions to discover candidate transcription factor binding sites and to discover candidate epigenetic signals that appear in both coding and regulatory regions of genes

    Characterization of soluble bromide measurements and a case study of BrO observations during ARCTAS

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    A focus of the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission was examination of bromine photochemistry in the spring time high latitude troposphere based on aircraft and satellite measurements of bromine oxide (BrO) and related species. The NASA DC-8 aircraft utilized a chemical ionization mass spectrometer (CIMS) to measure BrO and a mist chamber (MC) to measure soluble bromide. We have determined that the MC detection efficiency to molecular bromine (Br2), hypobromous acid (HOBr), bromine oxide (BrO), and hydrogen bromide (HBr) as soluble bromide (Br−) was 0.9±0.1, 1.06+0.30/−0.35, 0.4±0.1, and 0.95±0.1, respectively. These efficiency factors were used to estimate soluble bromide levels along the DC-8 flight track of 17 April 2008 from photochemical calculations constrained to in situ BrO measured by CIMS. During this flight, the highest levels of soluble bromide and BrO were observed and atmospheric conditions were ideal for the space-borne observation of BrO. The good agreement (R2 = 0.76; slope = 0.95; intercept = −3.4 pmol mol−1) between modeled and observed soluble bromide, when BrO was above detection limit (\u3e2 pmol mol−1) under unpolluted conditions (NOmol−1), indicates that the CIMS BrO measurements were consistent with the MC soluble bromide and that a well characterized MC can be used to derive mixing ratios of some reactive bromine compounds. Tropospheric BrO vertical column densities (BrOVCD) derived from CIMS BrO observations compare well with BrOTROPVCD from OMI on 17 April 2008

    An analysis of fast photochemistry over high northern latitudes during spring and summer using in-situ observations from ARCTAS and TOPSE

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    Observations of chemical constituents and meteorological quantities obtained during the two Arctic phases of the airborne campaign ARCTAS (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites) are analyzed using an observationally constrained steady state box model. Measurements of OH and HO2 from the Penn State ATHOS instrument are compared to model predictions. Forty percent of OH measurements below 2 km are at the limit of detection during the spring phase (ARCTAS-A). While the median observed-to-calculated ratio is near one, both the scatter of observations and the model uncertainty for OH are at the magnitude of ambient values. During the summer phase (ARCTAS-B), model predictions of OH are biased low relative to observations and demonstrate a high sensitivity to the level of uncertainty in NO observations. Predictions of HO2 using observed CH2O and H2O2 as model constraints are up to a factor of two larger than observed. A temperature-dependent terminal loss rate of HO2 to aerosol recently proposed in the literature is shown to be insufficient to reconcile these differences. A comparison of ARCTAS-A to the high latitude springtime portion of the 2000 TOPSE campaign (Tropospheric Ozone Production about the Spring Equinox) shows similar meteorological and chemical environments with the exception of peroxides; observations of H2O2 during ARCTAS-A were 2.5 to 3 times larger than those during TOPSE. The cause of this difference in peroxides remains unresolved and has important implications for the Arctic HOx budget. Unconstrained model predictions for both phases indicate photochemistry alone is unable to simultaneously sustain observed levels of CH2O and H2O2; however when the model is constrained with observed CH2O, H2O2 predictions from a range of rainout parameterizations bracket its observations. A mechanism suitable to explain observed concentrations of CH2O is uncertain. Free tropospheric observations of acetaldehyde (CH3CHO) are 2–3 times larger than its predictions, though constraint of the model to those observations is sufficient to account for less than half of the deficit in predicted CH2O. The box model calculates gross O3 formation during spring to maximize from 1–4 km at 0.8 ppbv d−1, in agreement with estimates from TOPSE, and a gross production of 2–4 ppbv d−1 in the boundary layer and upper troposphere during summer. Use of the lower observed levels of HO2 in place of model predictions decreases the gross production by 25–50%. Net O3 production is near zero throughout the ARCTAS-A troposphere, and is 1–2 ppbv in the boundary layer and upper altitudes during ARCTAS-B
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