12,527 research outputs found
Surfing or still drowning? Student nursesâ Internet skills
A study into student nursesâ ability to use the Internet was published in Nurse Education Today in 2004. This paper repeats the research with a cohort of students starting their pre-registration programme in a UK university in 2007.
In 2004 students were reported as having poor Internet skills, and as not being frequent users of the Internet. In this study students were found to have significantly better ability to carry out basic tasks and significantly higher levels of Internet use. Their ability to apply these skills to more complex information literacy tasks however had not increased, with more than half of all students saying they found far too much irrelevant information when searching for specific information on the Internet. The earlier study found that skills and age were not related, which appears to still be the case.
The need for these skills is increasing as education, lifelong learning, and patient information are all increasingly drawing on the developing Internet. Nurse education however is not integrating the skill and knowledge base essential to support this into pre-registration programmes, and the evidence suggests that this will not happen without active management
Voluntary temporary abstinence from alcohol during âDry Januaryâ and subsequent alcohol use
Objective: Temporary abstinence from alcohol may convey physiological benefits and enhance well-being. The aim of this study was to address a lack of information about: (1) correlates of successful completion of a planned period of abstinence, and (2) how success or failure in planned abstinence affects subsequent alcohol consumption. Methods: 857 British adults (249 men, 608 women) participating in the âDry Januaryâ alcohol abstinence challenge completed a baseline questionnaire, a one-month follow-up questionnaire, and a 6-month follow-up questionnaire. Key variables assessed at baseline included measures of alcohol consumption and drink refusal self-efficacy (DRSE). Results: In bivariate analysis, success during Dry January was predicted by measures of more moderate alcohol consumption and greater social DRSE. Multivariate analyses revealed that success during Dry January was best predicted by a lower frequency of drunkenness in the month prior to Dry January. Structural Equation Modelling revealed that participation in Dry January was related to reductions in alcohol consumption and increases in DRSE among all respondents at 6-month follow-up, regardless of success, but these changes were more likely among people who successfully completed the challenge. Conclusions: The findings suggest that participation in abstinence challenges such as âDry Januaryâ may be associated with changes toward healthier drinking and greater DRSE, and is unlikely to result in undesirable ârebound effectsâ: very few people reported increased alcohol consumption following a period of voluntary abstinence
The Bizarre Spectral Variability of Central Stars of Planetary Nebulae
A radial velocity (RV) survey to detect central stars in binary systems was
carried out between 2002 and 2004. De Marco et al. (2004) reported that 10 out
of 11 monitored stars exhibited strong RV variability, but periods were not
detected. Since other mechanisms, such as wind variability, can cause apparent
RV variations, we monitored 4 of the 10 RV-variable stars at echelle
resolutions to determine the origin of the variability. Although RV changes are
confirmed for all four stars, none of them can be ascribed to binarity at this
time. However, only for IC4593 is wind variability able to explain most (though
not all) spectral variability. For BD+332642, no wind and no pulsations appear
to be the origin of the RV changes. Finally, M1-77 and M2-54, both known to be
irregular photometric variables, exhibit dramatic RV and line shape variability
of the hydrogen and HeI absorption lines, as well as large RV variability of
weaker lines, which do not change in shape. There is no satisfactory
explanation of this variability, though a combination of wind variability and
pulsations is still the best guess at what makes these stars so variable. We
suggest that luminous central stars are ill suited to detect spectroscopic
binaries, because winds (and possibly pulsations) are pervasive and would mask
even strong periodicities. It it likely that a sample of intrinsically faint
central stars would more readily yield binary information.Comment: 7 pages, 3 figures. To appear in the proceedings of the conference
"Asymmetric Planetary Nebulae IV
The Exotic Eclipsing Nucleus of the Ring Planetary Nebula SuWt2
SuWt2 is a planetary nebula (PN) consisting of a bright ionized thin ring
seen nearly edge-on. It has a bright (V=12) central star, too cool to ionize
the PN, which we discovered to be an eclipsing binary. A spectrum from IUE did
not reveal a UV source. We present extensive ground-based photometry and
spectroscopy of the central binary collected over the ensuing two decades,
resulting in the determination that the orbital period of the eclipsing pair is
4.9 d, and consists of two nearly identical A1 V stars, each of mass ~2.7
M_sun. The physical parameters of the A stars, combined with evolutionary
tracks, show that both are in the short-lived "blue-hook" evolutionary phase
that occurs between the main sequence and the Hertzsprung gap, and that the age
of the system is about 520 Myr. One puzzle is that the stars' rotational
velocities are different from each other, and considerably slower than
synchronous with the orbital period. It is possible that the center-of-mass
velocity of the eclipsing pair is varying with time, suggesting that there is
an unseen third orbiting body in the system. We propose a scenario in which the
system began as a hierarchical triple, consisting of a ~2.9 M_sun star orbiting
the close pair of A stars. Upon reaching the AGB stage, the primary engulfed
the pair into a common envelope, leading to a rapid contraction of the orbit
and catastrophic ejection of the envelope into the orbital plane. In this
picture, the exposed core of the initial primary is now a white dwarf of ~0.7
M_sun, orbiting the eclipsing pair, which has already cooled below the
detectability possible by IUE at our derived distance of 2.3 kpc and a
reddening of E(B-V)=0.40. The SuWt2 system may be destined to perish as a Type
Ia supernova. (Abridged)Comment: 60 pages, 11 figure, to appear in the Astronomical Journa
The enigmatic central star of the planetary nebula PRTM 1
The central star of the planetary nebula PRTM 1 (PN G243.8-37.1) was
previously found to be variable by M. Pena and colleagues. As part of a larger
programme aimed towards finding post common-envelope binary central stars we
have monitored the central star of PRTM 1 spectroscopically and photometrically
for signs of variability. Over a period of ~3 months we find minimal radial
velocity (<10 km/s) and photometric (< 0.2 mag) variability. The data suggest a
close binary nucleus can be ruled out at all but the lowest orbital
inclinations, especially considering the spherical morphology of the nebula
which we reveal for the first time. Although the current data strongly support
the single star hypothesis, the true nature of the central star of PRTM 1
remains enigmatic and will require further radial velocity monitoring at higher
resolution to rule out a close binary. If in the odd case that it is a close
binary, it would be the first such case in a spherical planetary nebula, in
contradiction to current thinking.Comment: A&A, in pres
La boßte à outils géotechnique de demain: conception des structures géotechniques selon EN 1997: 202x
This paper shows how three new concepts â âDesign Casesâ (introduced in prEN 1990), the âGeotechnical Design Modelâ (prEN 1997-1), and the âGround Modelâ (prEN 1997-2) â are combined (in prEN 1997-3) to provide a comprehensive and flexible set of tools for the design of specific geotechnical structures. The paper presents flow charts divided between: a) reliability management, b) ground modelling, c) verification of the design, and d) structure execution, which provide guidelines for navigating prEN 1990 and prEN 1997.Postprint (published version
Searching for binary central stars of planetary nebulae with Kepler
The Kepler Observatory offers unprecedented photometric precision (<1 mmag)
and cadence for monitoring the central stars of planetary nebulae, allowing the
detection of tiny periodic light curve variations, a possible signature of
binarity. With this precision free from the observational gaps dictated by
weather and lunar cycles, we are able to detect companions at much larger
separations and with much smaller radii than ever before. We have been awarded
observing time to obtain light-curves of the central stars of the six confirmed
and possible planetary nebulae in the Kepler field, including the newly
discovered object Kn 61, at cadences of both 30 min and 1 min. Of these six
objects, we could confirm for three a periodic variability consistent with
binarity. Two others are variables, but the initial data set presents only weak
periodicities. For the central star of Kn 61, Kepler data will be available in
the near future
Introduction: Planetary memory in contemporary American fiction
This special issue considers the ways in which contemporary American fiction seeks to imagine a mode of âplanetary memoryâ able to address the scalar and systemic complexities of the Anthropocene â the epoch in which the combined activity of the human species has become a geological force in its own right. As Naomi Klein has recently argued, confronting the problem of anthropogenic climate change alters everything we know about the world: demanding wholesale recalibration of economic and political priorities; destabilising the epistemic frameworks through which quotidian life is interpreted and enacted; and decentring the dominant cultural imaginaries that seek to give form to historical experienc
Future CMB Constraints on Early, Cold, or Stressed Dark Energy
We investigate future constraints on early dark energy (EDE) achievable by
the Planck and CMBPol experiments, including cosmic microwave background (CMB)
lensing. For the dark energy, we include the possibility of clustering through
a sound speed c_s^2 <1 (cold dark energy) and anisotropic stresses
parameterized with a viscosity parameter c_vis^2. We discuss the degeneracies
between cosmological parameters and EDE parameters. In particular we show that
the presence of anisotropic stresses in EDE models can substantially undermine
the determination of the EDE sound speed parameter c_s^2. The constraints on
EDE primordial energy density are however unaffected. We also calculate the
future CMB constraints on neutrino masses and find that they are weakened by a
factor of 2 when allowing for the presence of EDE, and highly biased if it is
incorrectly ignored.Comment: 12 pages, 19 figure
Determining the Neutrino Mass Hierarchy with Cosmology
The combination of current large scale structure and cosmic microwave
background (CMB) anisotropies data can place strong constraints on the sum of
the neutrino masses. Here we show that future cosmic shear experiments, in
combination with CMB constraints, can provide the statistical accuracy required
to answer questions about differences in the mass of individual neutrino
species. Allowing for the possibility that masses are non-degenerate we combine
Fisher matrix forecasts for a weak lensing survey like Euclid with those for
the forthcoming Planck experiment. Under the assumption that neutrino mass
splitting is described by a normal hierarchy we find that the combination
Planck and Euclid will possibly reach enough sensitivity to put a constraint on
the mass of a single species. Using a Bayesian evidence calculation we find
that such future experiments could provide strong evidence for either a normal
or an inverted neutrino hierachy. Finally we show that if a particular neutrino
hierachy is assumed then this could bias cosmological parameter constraints,
for example the dark energy equation of state parameter, by > 1\sigma, and the
sum of masses by 2.3\sigma.Comment: 9 pages, 6 figures, 3 table
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