183 research outputs found

    A Simulation of the LISA Data Stream from Galactic White Dwarf Binaries

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    Gravitational radiation from the galactic population of white dwarf binaries is expected to produce a background signal in the LISA frequency band. At frequencies below 1 mHz, this signal is expected to be confusion-limited and has been approximated as gaussian noise. At frequencies above about 5 mHz, the signal will consist of separable individual sources. We have produced a simulation of the LISA data stream from a population of 90k galactic binaries in the frequency range between 1 - 5 mHz. This signal is compared with the simulated signal from globular cluster populations of binaries. Notable features of the simulation as well as potential data analysis schemes for extracting information are presented.Comment: Submitted to QC

    An analytical inversion method for determining regional and global emissions of greenhouse gases: Sensitivity studies and application to halocarbons

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    A new analytical inversion method has been developed to determine the regional and global emissions of long-lived atmospheric trace gases. It exploits in situ measurement data from three global networks and builds on backward simulations with a Lagrangian particle dispersion model. The emission information is extracted from the observed concentration increases over a baseline that is itself objectively determined by the inversion algorithm. The method was applied to two hydrofluorocarbons (HFC-134a, HFC-152a) and a hydrochlorofluorocarbon (HCFC-22) for the period January 2005 until March 2007. Detailed sensitivity studies with synthetic as well as with real measurement data were done to quantify the influence on the results of the a priori emissions and their uncertainties as well as of the observation and model errors. It was found that the global a posteriori emissions of HFC-134a, HFC-152a and HCFC-22 all increased from 2005 to 2006. Large increases (21%, 16%, 18%, respectively) from 2005 to 2006 were found for China, whereas the emission changes in North America (−9%, 23%, 17%, respectively) and Europe (11%, 11%, −4%, respectively) were mostly smaller and less systematic. For Europe, the a posteriori emissions of HFC-134a and HFC-152a were slightly higher than the a priori emissions reported to the United Nations Framework Convention on Climate Change (UNFCCC). For HCFC-22, the a posteriori emissions for Europe were substantially (by almost a factor 2) higher than the a priori emissions used, which were based on HCFC consumption data reported to the United Nations Environment Programme (UNEP). Combined with the reported strongly decreasing HCFC consumption in Europe, this suggests a substantial time lag between the reported time of the HCFC-22 consumption and the actual time of the HCFC-22 emission. Conversely, in China where HCFC consumption is increasing rapidly according to the UNEP data, the a posteriori emissions are only about 40% of the a priori emissions. This reveals a substantial storage of HCFC-22 and potential for future emissions in China. Deficiencies in the geographical distribution of stations measuring halocarbons in relation to estimating regional emissions are also discussed in the paper. Applications of the inversion algorithm to other greenhouse gases such as methane, nitrous oxide or carbon dioxide are foreseen for the future

    Calculated phase diagrams, iron tolerance limits, and corrosion of Mg-Al alloys

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    The factors determining corrosion are reviewed in this paper, with an emphasis on iron tolerance limit and the production of high-purity castings. To understand the iron impurity tolerance limit, magnesium phase diagrams were calculated using the Pandat software package. Calculated phase diagrams can explain the iron tolerance limit and the production of high-purity castings by means of control of melt conditions; this is significant for the production of quality castings from recycled magnesium. Based on the new insight, the influence of the microstructure on corrosion of magnesium alloys is reviewed

    Guidelines on the management of abnormal liver blood tests

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    These updated guidelines on the management of abnormal liver blood tests have been commissioned by the Clinical Services and Standards Committee (CSSC) of the British Society of Gastroenterology (BSG) under the auspices of the liver section of the BSG. The original guidelines, which this document supersedes, were written in 2000 and have undergone extensive revision by members of the Guidelines Development Group (GDG). The GDG comprises representatives from patient/carer groups (British Liver Trust, Liver4life, PBC Foundation and PSC Support), elected members of the BSG liver section (including representatives from Scotland and Wales), British Association for the Study of the Liver (BASL), Specialist Advisory Committee in Clinical Biochemistry/Royal College of Pathology and Association for Clinical Biochemistry, British Society of Paediatric Gastroenterology, Hepatology and Nutrition (BSPGHAN), Public Health England (implementation and screening), Royal College of General Practice, British Society of Gastrointestinal and Abdominal Radiologists (BSGAR) and Society of Acute Medicine. The quality of evidence and grading of recommendations was appraised using the AGREE II tool. These guidelines deal specifically with the management of abnormal liver blood tests in children and adults in both primary and secondary care under the following subheadings: (1) What constitutes an abnormal liver blood test? (2) What constitutes a standard liver blood test panel? (3) When should liver blood tests be checked? (4) Does the extent and duration of abnormal liver blood tests determine subsequent investigation? (5) Response to abnormal liver blood tests. They are not designed to deal with the management of the underlying liver disease.</p

    Historical greenhouse gas concentrations for climate modelling (CMIP6)

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    Atmospheric greenhouse gas (GHG) concentrations are at unprecedented, record-high levels compared to the last 800 000 years. Those elevated GHG concentrations warm the planet and – partially offset by net cooling effects by aerosols – are largely responsible for the observed warming over the past 150 years. An accurate representation of GHG concentrations is hence important to understand and model recent climate change. So far, community efforts to create composite datasets of GHG concentrations with seasonal and latitudinal information have focused on marine boundary layer conditions and recent trends since the 1980s. Here, we provide consolidated datasets of historical atmospheric concentrations (mole fractions) of 43 GHGs to be used in the Climate Model Intercomparison Project – Phase 6 (CMIP6) experiments. The presented datasets are based on AGAGE and NOAA networks, firn and ice core data, and archived air data, and a large set of published studies. In contrast to previous intercomparisons, the new datasets are latitudinally resolved and include seasonality. We focus on the period 1850–2014 for historical CMIP6 runs, but data are also provided for the last 2000 years. We provide consolidated datasets in various spatiotemporal resolutions for carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), as well as 40 other GHGs, namely 17 ozone-depleting substances, 11 hydrofluorocarbons (HFCs), 9 perfluorocarbons (PFCs), sulfur hexafluoride (SF6), nitrogen trifluoride (NF3) and sulfuryl fluoride (SO2F2). In addition, we provide three equivalence species that aggregate concentrations of GHGs other than CO2, CH4 and N2O, weighted by their radiative forcing efficiencies. For the year 1850, which is used for pre-industrial control runs, we estimate annual global-mean surface concentrations of CO2 at 284.3 ppm, CH4 at 808.2 ppb and N2O at 273.0 ppb. The data are available at https://esgfnode.llnl.gov/search/input4mips/ and http://www.climatecollege.unimelb.edu.au/cmip6. While the minimum CMIP6 recommendation is to use the global- and annual-mean time series, modelling groups can also choose our monthly and latitudinally resolved concentrations, which imply a stronger radiative forcing in the Northern Hemisphere winter (due to the latitudinal gradient and seasonality)

    Growth in stratospheric chlorine from short-lived chemicals not controlled by the Montreal Protocol

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    We have developed a chemical mechanism describing the tropospheric degradation of chlorine-containing very short-lived substances (VSLS). The scheme was included in a global atmospheric model and used to quantify the stratospheric injection of chlorine from anthropogenic VSLS (ClyVSLS) between 2005 to 2013. By constraining the model with surface measurements of chloroform (CHCl3), dichloromethane (CH2Cl2), tetrachloroethene (C2Cl4), trichloroethene (C2HCL3) and 1,2-dichloroethane (CH2ClCH2Cl), we infer a 2013 ClyVSLS mixing ratio of 123 parts per trillion (ppt). Stratospheric injection of source gases dominates this supply, accounting for ~83% of the total. The remainder comes from VSLS-derived organic products, phosgene (COCl2, 7%) and formyl chloride (CHClO, 2%), and also hydrogen chloride (HCl, 8%). Stratospheric ClyVSLS increased by ~52% between 2005-2013, with a mean growth rate of 3.7 ppt Cl/yr. This increase is due to recent and ongoing growth in anthropogenic CH – the most abundant chlorinated VSLS not controlled by the Montreal Protocol

    Adherence measurements and corrosion resistance in primer/hot-dip galvanized steel systems

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    This paper focuses on the adherence during ageing of a primer (made of polyester resins crosslinked with melamine) applied onto hot-dip galvanized (HDG) steel for coil coating application and its influence on corrosion protection. A chromium-free surface treatment, composed of fluorotitanic acid, phosphoric acid, manganese phosphate, and vinylphenol was applied on the HDG steel to obtain high corrosion resistance and high adherence of a polyester and melamine primer. The influence of the manganese phosphate on the corrosion and adherence was investigated. To measure the adherence between the metal and the primer, a three-point flexure test was set up. The adherence was then linked with corrosion resistance during ageing, using electrochemical impedance spectroscopy

    Advance care planning, a multi-centre cluster randomised clinical trial: the research protocol of the ACTION study

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    Background: Awareness of preferences regarding medical care should be a central component of the care of patients with advanced cancer. Open communication can facilitate this but can occur in an ad hoc or variable manner. Advance care planning (ACP) is a formalized process of communication between patients, relatives and professional caregivers about patients’ values and care preferences. It raises awareness of the need to anticipate possible future deterioration of health. ACP has the potential to improve current and future healthcare decision making, provide patients with a sense of control, and improve their quality of life. Methods/Design: We will study the effects of the ACP program Respecting Choices on the quality of life of patients with advanced lung or colorectal cancer. In a phase III multicenter cluster randomised controlled trial, 22 hospitals in 6 countries will be randomised. In the intervention sites, patients will be offered interviews with a trained facilitator. In the control sites, patients will receive care as usual. In total, 1360 patients will be included. All participating patients will be asked to complete questionnaires at inclusion, and again after 2.5 and 4.5 months. If a patient dies within a year after inclusion, a relative will be asked to complete a questionnaire on end-of-life care. Use of medical care will be assessed by checking medical files. The primary endpoint is patients’ quality of life at 2.5 months ost-inclusion. Secondary endpoints are the extent to which care as received is aligned with patients’ preferences, patients’ evaluation of decision-making processes, quality of end-of-life care and cost-effectiveness of the intervention. A complementary qualitative study will be carried out to explore the lived experience of engagement with the Respecting Choices program from the perspectives of patients, their Personal Representatives, healthcare providers and facilitators. Discussion: Transferring the concept of ACP from care of the elderly to patients with advanced cancer, who on average are younger and retain their mental capacity for a larger part of their disease trajectory, is an important next step in an era of increased focus on patient centered healthcare and shared decision-making. Trial registration: International Standard Randomised Controlled Trial Number: ISRCTN63110516. Date of registration: 10/3/2014. Keywords: Advance care planning, Oncology, Quality of life, Medical decision-makin

    Bacheloroppgave

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    Temaet vi har valgt for oppgaven omhandler kaffebarmarkedet i Norge med hovedfokus på Oslo. Ideen er basert på vårt inntrykk av at kaffebarmarkedet i Oslo har blitt større og vokst frem som et urbant fenomen. Vi er også av den oppfatning at kaffebarer både er med på å definere Oslo sitt bybilde og vår generasjon. Av den grunn har vi undersøkt kaffebarmarkedet nærmere, og utviklet en analyse av dette markedet. Vi har avdekket hva som kjennetegner markedet og aktørene, samt identifisert hva som skal til for å lykkes som nyetablert. Vårt formål er å kartlegge de viktigste suksessfaktorene, som kan være fordelaktig å fokusere på i oppstartsfasen for å enklere lykkes i dette markedet. Forhåpentligvis vil resultatet kunne brukes av de som har lyst til å starte en kaffebar i Oslo, samt de som allerede driver en kaffebar i dag. Problemstillingen i oppgaven vår er følgende: «hva skal til for å lykkes som nyetablert kaffebar i Oslo?». For å hjelpe oss på veien mot svaret på denne problemstillingen har vi valgt å inkludere to forskningsspørsmål i oppgaven: «hva kjennetegner kaffebarmarkedet i Norge?» og «hvordan kan nyetablerte kaffebarer opparbeide seg et godt omdømme og en sterk merkevare overfor forbrukerne?». For å kunne besvare problemstillingen og forskningsspørsmålene har vi benyttet oss av både kvalitativ og kvantitativ metode i arbeidet, som i vårt tilfelle innebærer en markedsanalyse, en spørreundersøkelse og flere intervjuer. Å benytte oss av flere metoder for innhenting av data var i vårt tilfelle avgjørende for resultatene våre, da vi ønsket å finne ut hva som var viktigst for både tilbydere og eiere. Arbeidet med oppgaven har resultert i flere faktorer som er viktige for å lykkes som en nyetablert kaffebar, men det er spesielt fire faktorer som har gått igjen som viktige for både eiere og forbrukere. Disse fire faktorene er kaffekvalitet, service, atmosfære og beliggenhet. Dersom man som nyetablert kaffebar fokuserer på dette, i tillegg til å forstå hvorfor det er viktig – vil sjansene bli høyere for å lykkes som en kaffebar i Oslo

    Polybrominated Diphenyl Ethers (PBDEs) and Bioaccumulative Hydroxylated PBDE Metabolites in Young Humans from Managua, Nicaragua

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    OBJECTIVE: Our aim was to investigate exposure to polybrominated diphenyl ethers (PBDEs) in a young urban population in a developing country, with focus on potentially highly exposed children working informally as scrap scavengers at a large municipal waste disposal site. We also set out to investigate whether hydroxylated metabolites, which not hitherto have been found retained in humans, could be detected. METHODS: We assessed PBDEs in pooled serum samples obtained in 2002 from children 11-15 years of age, working and sometimes also living at the municipal waste disposal site in Managua, and in nonworking urban children. The influence of fish consumption was evaluated in the children and in groups of women 15-44 years of age who differed markedly in their fish consumption. Hydroxylated PBDEs were assessed as their methoxylated derivates. The chemical analyses were performed by gas chromatography/mass spectrometry, using authentic reference substances. RESULTS: The children living and working at the waste disposal site showed very high levels of medium brominated diphenyl ethers. The levels observed in the referent children were comparable to contemporary observations in the United States. The exposure pattern was consistent with dust being the dominating source. The children with the highest PBDE levels also had the highest levels of hydroxylated metabolites. CONCLUSIONS: Unexpectedly, very high levels of PBDEs were found in children from an urban area in a developing country. Also, for the first time, hydroxylated PBDE metabolites were found to bioaccumulate in human serum
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