14,030 research outputs found

    Physician-facilitated designation of proxy decision maker.

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    With vast improvements in healthcare in recent decades, people are living longer but often with higher rates of morbidity and chronic illnesses. This has resulted in a higher proportion of the population who may benefit from early end-of-life 'conversation and planning', but also gives healthcare professionals more time during which these discussions are relevant, as people live longer with their chronic diseases. A survey conducted by Lifshitz et al (Isr J Health Policy Res 5:6, 2016) sought to assess physician awareness and willingness to discuss designating a proxy decision-maker with patients, in order to aid end-of-life care in the event that the patient is rendered unable to make or communicate these decisions later in life. Their article suggests that proxy decision-maker designation is only one aspect of end-of-life care; a challenging area littered with ethical and moral dilemmas. Without early, open and frank discussions with patients regarding their wishes at the end of life, proxy decision-makers may be in no better position than physicians or a court appointed proxy to make decisions in the patients' best interests/benefits. This commentary also touches upon the use of health and care passports being developed or in early phases in the United Kingdom, and whether these may be utilised in the field of palliative care in Israel

    Solar modulation and interplanetary gradients of the galactic electrons flux, 1977 - 1984

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    The flux of electrons with energy from approx. 10 to 180 MeV measured with the electron telescope on the Voyager 1 and 2 spacecraft in the heliocentric radial range 1 - 22 AU between 1977 and 1984 is reported. Jovian electrons were clearly observable between 1978 and 1983 (radial range 2 - 12 AU) at energies below approx. 50 MeV. Above approx. 50 MeV the electron intensity exhibited temporal variations generally related to the 11 year modulation of protons 75 MeV. The overall magnitude of the electron intensity changes between the maximum intensity observed in 1977 and the minimum intensity in 1981 was a factor approx. 2, also comparable to that observed for 75 MeV protons. By early 1985 the electron intensity had apparently recovered to the level observed in 1977 whereas the proton intensity was still about 20% lower. A detailed interpretation of these electron variations in all energy channels depends on an accurate subtraction of background induced by energetic protons of a few 100 MeV. This subtraction is facilitated by calibration results at several energies

    The Energy Spectrum of Jovian Electrons in Interplanetary Space

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    The energy spectrum of electrons with energies approx 10 to approx 180 MeV measured with the electron telescope on the Voyager 1 and 2 spacecraft in interplanetary space from 1978 to 1983 is studied. The kinetic energy of electrons is determined by double dE/dx measurements from the first two detectors (D sub 1, D sub 2) of a stack of eight solid state detectors and by the range of particle penetration into the remaining six detectors (D sub 3 to D sub 8) which are interleaved with tungsten absorbers. From 1978 to 1983 (radial range approximately 2 to a pproximately 12 AU) electrons of Jovian origin were clearly observable for electrons stopping in D(sub 3(E approximately greater than 4 MeV)) and in D(sub 4 (E approximately greater than 8 MeV)). For electrons stopping in D(sub 5(E approximately greather than 12 MeV)), the jovian flux dominated the galactic electron flux for a period of approximately one year near the encounter with Jupiter. Jovian electrons were also observed in D(sub 6(E approximately greater than 21 MeV)) but not in D(sub 7(E approximately greater than 28 MeV)). A detailed interpretation of the electron variations in all energy channels depends on an accurate subtraction of background induced by energetic protons of a few 100 MeV. This substraction is facilitated by laboratory calibration results at several energies. Further results on the differential energy spectrum of Jovian electrons and limits on the maximum detected energies will be reported

    GRB 071028B, a burst behind large amounts of dust in an unabsorbed galaxy

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    We report on the discovery and properties of the fading afterglow and underlying host galaxy of GRB 071028B, thereby facilitating a detailed comparison between these two. Observations were performed with the Gamma-ray Burst Optical and Near-infrared Detector at the 2.2 m telescope on the La Silla Paranal Observatory in Chile. We conducted five observations from 1.9 d to 227.2 d after the trigger and obtained deep images in the g'r'i'z' and JHKs bands. Based on accurate seven-channel photometry covering the optical to near-infrared wavelength range, we derive a photometric redshift of z = 0.94 +0.05 -0.10 for the unabsorbed host galaxy of GRB 071028B. In contrast, we show that the afterglow with an intrinsic extinction of AV(SB) = (0.70 +/- 0.11) mag is moderately absorbed and requires a relatively flat extinction curve. According to the reported Swift/BAT observations, the energetics yield an isotropic energy release of E(gamma,iso.,rest) = (1.4 +2.4 -0.7) x 10^51 erg.Comment: 8 pages, 5 figures, accepted for publication in A&

    High Flux Femtosecond X-ray Emission from the Electron-Hose Instability in Laser Wakefield Accelerators

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    Bright and ultrashort duration X-ray pulses can be produced by through betatron oscillations of electrons during Laser Wakefield Acceleration (LWFA). Our experimental measurements using the \textsc{Hercules} laser system demonstrate a dramatic increase in X-ray flux for interaction distances beyond the depletion/dephasing lengths, where the initial electron bunch injected into the first wake bucket catches up with the laser pulse front and the laser pulse depletes. A transition from an LWFA regime to a beam-driven plasma wakefield acceleration (PWFA) regime consequently occurs. The drive electron bunch is susceptible to the electron-hose instability and rapidly develops large amplitude oscillations in its tail, which leads to greatly enhanced X-ray radiation emission. We measure the X-ray flux as a function of acceleration length using a variable length gas cell. 3D particle-in-cell (PIC) simulations using a Monte Carlo synchrotron X-ray emission algorithm elucidate the time-dependent variations in the radiation emission processes.Comment: 6 pages, 4 figures, accepted for publication in Phys. Rev. Accel. Beam

    Field evaluation of a visual barrier to discourage gull nesting

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    Ring-billed Gull Larus delawarensis and California Gull L. californicus populations have increased throughout the western United States in close association with human settlement (Conover 1983; Ryder 1993). On Upper Nelson Island in the Columbia River, the number of Ring-billed and California Gull nests increased from 4 600 in 1978 to 21 000 in 1999 (Thompson and Tabor 1981; Pochop, this manuscript). Agriculture and landfills provided food sources, and construction of reservoirs increased island nest sites for gulls (Ryder 1993). Gulls gather below hydroelectric facilities in the spring to feed on migrating juvenile salmonids (Steuber et al. 1995). Also, increased gull populations present bird-aircraft strike hazards, create nuisances and potential threats to public health, and damage cherry orchards (Greenhalgh 1952; Blokpoel and Strugger 1988; Blokpoel and Tessier 1992; Gabrey and Dolbeer 1996; Hatch 1996)

    Ariel - Volume 7 Number 2

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    Editors Mark Dembert Frank Chervanek John Lammie Jim Burke Curt Cumming

    The early X-ray afterglows of optically bright and dark Gamma-Ray Bursts

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    A systematical study on the early X-ray afterglows of both optically bright and dark gamma-ray bursts (B-GRBs and D-GRBs) observed by Swift has been presented. Our sample includes 25 GRBs. Among them 13 are B-GRBs and 12 are D-GRBs. Our results show that the distributions of the X-ray afterglow fluxes (FXF_{X}), the gamma-ray fluxes (SÎłS_{\gamma}), and the ratio (RÎł,XR_{\gamma, X}) for both the D-GRBs and B-GRBs are similar. The differences of these distributions for the two kinds of GRBs should be statistical fluctuation. These results indicate that the progenitors of the two kinds of GRBs are the same population. Their total energy explosions are comparable. The suppression of the optical emissions from D-GRBs should results from circumburst but not their central engine.Comment: 10 pages, 3 figures, 1 table; accepted by ChJA

    Trends and correlates of marijuana use among late middle-aged and older adults in the United States, 2002–2014

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    BACKGROUND: Recent trend studies suggest that marijuana use is on the rise among the general population of adults ages 18 and older in the United States. However, little is known about the trends in marijuana use and marijuana-specific risk/protective factors among American adults during the latter part of adulthood. METHOD: Findings are based on repeated, cross-sectional data collected from late middle-aged (ages 50–64) and older adults (ages 65 and older) surveyed as part of the National Survey on Drug Use and Health between 2002 and 2014. RESULTS: The prevalence of past-year marijuana use among late middle-aged adults increased significantly from a low of 2.95% in 2003 to a high of 9.08% in 2014. Similarly, the prevalence of marijuana use increased significantly among older adults from a low of 0.15% in 2003 to a high of 2.04% in 2014. Notably, the upward trends in marijuana use remained significant even when accounting for sociodemographic, substance use, behavioral, and health-related factors. We also found that decreases in marijuana-specific protective factors were associated with the observed trend changes in marijuana use among late middle-aged and older adults, and observed a weakening of the association between late-middle aged marijuana use and risk propensity, other illicit drug use, and criminal justice system involvement over the course of the study. CONCLUSIONS: Findings from the present study provide robust evidence indicating that marijuana use among older Americans has increased markedly in recent years, with the most evident changes observed between 2008 and 2014
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