360 research outputs found

    Modification of the asthma quality of life questionnaire (standardised) for patients 12 years and older

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    BACKGROUND: The age limit for some adult asthma clinical trials has recently been lowered to 12 years. In this study we have made minor modifications to the standardised version of the adult Asthma Quality of Life Questionnaire (AQLQ(S)) to make it valid for patients 12 years and older (AQLQ12+). METHODS: We have used two clinical trial databases, in which the AQLQ12+ was used, to compare the measurement properties of the questionnaire in patients 12–17 years and patients 18 years and older. A total of 2433 patients (12–75 years), with current asthma and with data that could be evaluated both at randomisation and end of treatment, were included. RESULTS: The analysis showed that internal consistency, responsiveness and correlations with other clinical indices were very similar in patients 12–17 years and patients 18 years and older. CONCLUSION: The measurement properties of the AQLQ12+ are similar in adolescents and adults and therefore the instrument is valid for use in adult studies which include children 12 years and older

    Investigations of solutions of Einstein's field equations close to lambda-Taub-NUT

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    We present investigations of a class of solutions of Einstein's field equations close to the family of lambda-Taub-NUT spacetimes. The studies are done using a numerical code introduced by the author elsewhere. One of the main technical complication is due to the S3-topology of the Cauchy surfaces. Complementing these numerical results with heuristic arguments, we are able to yield some first insights into the strong cosmic censorship issue and the conjectures by Belinskii, Khalatnikov, and Lifschitz in this class of spacetimes. In particular, the current investigations suggest that strong cosmic censorship holds in this class. We further identify open issues in our current approach and point to future research projects.Comment: 24 pages, 12 figures, uses psfrag and hyperref; replaced with published version, only minor corrections of typos and reference

    The challenges of using biodata in promotional filmmaking

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    We present a study of how filmmakers collected and visualised physiological data---'biodata'---to construct a series of short promotional films depicting people undergoing 'thrilling' experiences. Drawing on ethnographic studies of two major advertising campaigns, we highlight key concerns for integrating sensors and sensor data into film production. Our findings address the perceived benefits of using biodata within narratives; the nature of different on-screen representations of biodata; and the challenges presented when integrating biodata into production processes. Drawing on this, we reconsider the nature of information visualisation in the filmmaking context. Further implications from our case studies provide recommendations for HCI collaborations with filmmaking and broadcast industries, focussing both on the practical matters of fitting sensor technologies into and handling data within production workflows, as well as discussing the broader implications for managing the veracity of that data within professional media production

    Quasilinear hyperbolic Fuchsian systems and AVTD behavior in T2-symmetric vacuum spacetimes

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    We set up the singular initial value problem for quasilinear hyperbolic Fuchsian systems of first order and establish an existence and uniqueness theory for this problem with smooth data and smooth coefficients (and with even lower regularity). We apply this theory in order to show the existence of smooth (generally not analytic) T2-symmetric solutions to the vacuum Einstein equations, which exhibit AVTD (asymptotically velocity term dominated) behavior in the neighborhood of their singularities and are polarized or half-polarized.Comment: 78 page

    Intermediate inflation and the slow-roll approximation

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    It is shown that spatially homogeneous solutions of the Einstein equations coupled to a nonlinear scalar field and other matter exhibit accelerated expansion at late times for a wide variety of potentials VV. These potentials are strictly positive but tend to zero at infinity. They satisfy restrictions on Vâ€Č/VV'/V and Vâ€Čâ€Č/Vâ€ČV''/V' related to the slow-roll approximation. These results generalize Wald's theorem for spacetimes with positive cosmological constant to those with accelerated expansion driven by potentials belonging to a large class.Comment: 19 pages, results unchanged, additional backgroun

    Regularity of Cauchy horizons in S2xS1 Gowdy spacetimes

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    We study general S2xS1 Gowdy models with a regular past Cauchy horizon and prove that a second (future) Cauchy horizon exists, provided that a particular conserved quantity JJ is not zero. We derive an explicit expression for the metric form on the future Cauchy horizon in terms of the initial data on the past horizon and conclude the universal relation A\p A\f=(8\pi J)^2 where A\p and A\f are the areas of past and future Cauchy horizon respectively.Comment: 17 pages, 1 figur

    The effects of stand characteristics on the understory vegetation in Quercus petraea and Q. cerris dominated forests

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    The shelterwood system used in Hungary has many effects on the composition and structure of the herb layer. The aim of our study was to identify the main variables that affect the occurence of herbs and seedlings in Turkey oak-sessile oak (Quercus cerris and Q. petraea) stands. The study was carried out in the BĂŒkk mountains, Hungary. 122 sampling plots were established in 50-150 year old oak forests, where we studied the species composition and structure of the understorey and overstorey. The occurence of herbs was affected by canopy closure, the heterogenity and patchiness of the stand, the slope and the east-west component of the aspect. The composition of saplings was significantly explained by the ratio of the two major oak species in the stand and the proximity of the adult plants. An important result for forest management was that sessile oaks were able to regenerate almost only where they were dominant in the overstorey

    HER2-positive tumors imaged within 1 hour using a site-specifically 11C-labeled sel-tagged affibody molecule

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    A rapid, reliable method for distinguishing tumors or metastases that overexpress human epidermal growth factor receptor 2 (HER2) from those that do not is highly desired for individualizing therapy and predicting prognoses. In vivo imaging methods are available but not yet in clinical practice; new methodologies improving speed, sensitivity, and specificity are required. METHODS: A HER2-binding Affibody molecule, Z(HER2:342), was recombinantly fused with a C-terminal selenocysteine-containing tetrapeptide Sel-tag, allowing site-specific labeling with either (11)C or (68)Ga, followed by biodistribution studies with small-animal PET. Dosimetry data for the 2 radiotracers were compared. Imaging of HER2-expressing human tumor xenografts was performed using the (11)C-labeled Affibody molecule. RESULTS: Both the (11)C- and (68)Ga-labeled tracers initially cleared rapidly from the blood, followed by a slower decrease to 4-5 percentage injected dose per gram of tissue at 1 h. Final retention in the kidneys was much lower (>5-fold) for the (11)C-labeled protein, and its overall absorbed dose was considerably lower. (11)C-Z(HER2:342) showed excellent tumor-targeting capability, with almost 10 percentage injected dose per gram of tissue in HER2-expressing tumors within 1 h. Specificity was demonstrated by preblocking binding sites with excess ligand, yielding significantly reduced radiotracer uptake (P = 0.002), comparable to uptake in tumors with low HER2 expression. CONCLUSION: To our knowledge, the Sel-tagging technique is the first that enables site-specific (11)C-radiolabeling of proteins. Here we present the finding that, in a favorable combination between radionuclide half-life and in vivo pharmacokinetics of the Affibody molecules, (11)C-labeled Sel-tagged Z(HER2:342) can successfully be used for rapid and repeated PET studies of HER2 expression in tumors.VetenskapsrÄdetPublishe

    Factors influencing organic carbon recycling and burial in Skagerrak sediments

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    Different factors influencing recycling and burial rates of organic carbon (OC) were investigated in the continental margin sediments of the Skagerrak (NE North Sea). Two different areas, one in the southern and one in the northeastern part of the Skagerrak were visited shortly after a spring bloom (March 1999) and in late summer (August 2000). Results suggested that: (1) Organic carbon oxidation rates (Cox) (2.2–18 mmol C m-2d-11) were generally larger than the O2 uptake rates (1.9 –25 mmol m-2d-1). Both rates were measured in situ using a benthic lander. A mean apparent respiration ratio (Cox:O2corr) of 1.3±0.5 was found, indicating some long-term burial of reduced inorganic substances in these sediments. Measured O2 fluxes increased linearly with increasing Cox rates during the late summer cruise but not on the early spring cruise, indicating a temporal uncoupling of anaerobic mineralization and reoxidation of reduced substances. (2) Dissolved organic carbon (DOC) fluxes (0.2–1.0 mmol C m-2d-1) constituted 3–10% of the Cox rates and were positively correlated with the latter, implying that net DOC production rates were proportional to the overall sediment OC remineralization rates. (3) Chlorophyll a (Chl-a) concentrations in the sediment were significantly higher in early spring compared to late summer. The measured Cox rates, but not O2 fluxes, showed a strong positive correlation with the Chl-a inventories in the top 3 cm of the sediment. (4) Although no relationship was found between the benthic fluxes and the macrofaunal biomass in the chambers, total in situ measured dissolved inorganic carbon (CT) fluxes were 1–5.4 times higher than diffusive mediated CT fluxes, indicating that macrofauna have a significant impact on benthic exchange rates of OC remineralization products in Skagerrak sediments. (5) OC burial fluxes were generally higher in northeastern Skagerrak than in the southern part. The same pattern was observed for burial efficiencies, with annual means of ~62% and ~43% for the two areas respectively. (6) On a basin-wide scale, there was a significant positive linear correlation between the burial efficiencies and sediment accumulation rates. (7) The calculated particulate organic carbon (POC) deposition, from benthic flux and burial measurements, was only 24 –78% of the sediment trap measured POC deposition, indicating a strong near-bottom lateral transport and resuspension of POC. (8) A larger fraction of the laterally advected material of lower quality seemed to settle in the northeastern Skagerrak rather than in the southern Skagerrak. (9) Skagerrak sediments, especially in the northeastern part, act as an efficient net sink for organic carbon, even in a global continental margin context
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