1,004 research outputs found
Web learning in post registration nurse education: application and theory. A practical experience of combining humanistic, educational and technological considerations
As healthcare becomes more knowledge intensive, nurses are challenged to effectively manage clinical information and keep abreast of professional knowledge (Procter 2001; Snyder - Halpern et al 2001; Pare & Elam 1998). Rapid
proliferation of new knowledge, expanding professional practice expectations and changing practice environments require that nurses become lifelong learners capable of constantly reflecting on and modifying their practice. Nurse education needs to embrace and make use of information
technology learning media to help nurses meet these demands. This paper considers how post registration nursing students responded to a technology based learning package directed at enhancing mental health skills and care management. At the completion of the course the participants completed a module evaluation. Representative participants comments are presented throughout this paper to highlight issues raised within the literature on technology based learning
On the role of galactic magnetic halo in the ultra high energy cosmic rays propagation
The study of propagation of Ultra High Energy Cosmic Rays (UHECR) is a key
step in order to unveil the secret of their origin. Up to now it was considered
only the influence of the galactic and the extragalactic magnetic fields. In
this article we focus our analysis on the influence of the magnetic field of
the galaxies standing between possible UHECR sources and us. Our main approach
is to start from the well known galaxy distribution up to 120 Mpc. We use the
most complete galaxy catalog: the LEDA catalog. Inside a sphere of 120 Mpc
around us, we extract 60130 galaxies with known position. In our simulations we
assign a Halo Dipole magnetic Field (HDF) to each galaxy. The code developed is
able to retro-propagate a charged particle from the arrival points of UHECR
data across our galaxies sample. We present simulations in case of Virgo
cluster and show that there is a non negligible deviation in the case of
protons of eV, even if the value is conservative. Then
special attention is devoted to the AGASA triplet where we find that NGC3998
and NGC3992 could be possible candidates as sources.Comment: Version accepted from ApJ, 5 figure
Consultation in the policy process: Douglasian cultural theory and the development of accounting regulation in the face of crisis
This article employs Douglasian cultural theory to explain how policy consultations intended to secure meaningful reform can, in fact, work to reinforce the status quo. The context for this is an examination of responses to three consultations established by the Financial Reporting Council (FRC), the body responsible for regulating accounting and auditing in the UK. The results reveal a lack of diversity of voices in the responses to three consultations, with the enclave and isolate voices being significantly under-represented despite the policy issues under debate being related to the financial crisis. Further, the initial pre-consultation proposals are largely unchanged post-consultation. We suggest that the regulator has not been captured; but instead is subject to what may be described as self-capture. Self-capture describes the instinctive reaction of a solidarity to act to uphold its pattern of social relations which results in the regulator's worldview inevitably (and unwittingly) being perpetuated
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The Suess effect in Fiji coral δ13C and its potential as a tracer of anthropogenic CO2 uptake
In the context of increasing anthropogenic CO2 emissions, determining the rate of oceanic CO2 uptake is of high interest. Centennial-scale changes in δ13C of the surface water dissolved inorganic carbon (DIC) reservoir have been shown to be influenced by the carbon isotopic composition of atmospheric CO2. However, the availability of direct oceanic δ13C measurements is limited and methods for reconstructing past δ13C variability of the oceanic DIC are needed. Geochemical reconstructions of DIC variability can help in understanding how the ocean has reacted to historical changes in the carbon cycle. This study explores the potential of using temporal variations in δ13C measured in five Fijian Porites corals for reconstructing oceanic δ13C variability. A centennial-scale decreasing δ13C trend is observed in these Fiji corals. Other studies have linked similar decreasing δ13C trends to anthropogenic changes in the atmospheric carbon reservoir (the “13C Suess effect”). We conclude that solar irradiance is the factor influencing the δ13C cycle on a seasonal scale, however it is not responsible for the centennial-scale decreasing δ13C trend. In addition, variations in skeletal extension rate are not found to account for centennial-scale δ13C variability in these corals. Rather, we found that water depth at which a Fijian Porites colony calcifies influences both δ13C and extension rate mean values. The water depth-δ13C relationship induces a dampening effect on the centennial-scale decreasing δ13C trend. We removed this “water depth effect” from the δ13C composite, resulting in a truer representation of δ13C variability of the Fiji surface water DIC (δ13CFiji-DIC). The centennial-scale trend in this Fiji coral composite δ13CFiji-DIC time-series shares similarities with atmospheric δ13CCO2, implicating the 13C Suess effect as the source of the this coral δ13C trend. Additionally, our study finds that the δ13C variability between the atmosphere and the ocean in this region is not synchronous; the coral δ13C response is delayed by ~ 10 years. This agrees with the previously established model of isotopic disequilibrium between atmospheric δ13CCO2 and oceanic surface water DIC
A 1200 Year Record of Hydrologic Variability in the Sierra Nevada from Sediments in Walker Lake, Nevada
Measurements of the oxygen isotopic composition (δ18O) of the total inorganic carbon (TIC) fraction from cored sediments of Walker Lake, Nevada, were conducted at an average resolution of ∼3 years per sample over the last 1200 years. On the basis of radiocarbon analysis on the total organic carbon (TOC) fraction, a δ18O time series was created to reconstruct changes in hydrologic conditions back to AD 800. The timings of variations in the TIC δ18O record are generally consistent with the tree ring-based Sacramento River flow record spanning AD 869 to 1977, indicating that Walker Lake δ18O contains information about past changes in at least regional hydrologic conditions. Comparison with the δ18O record from Pyramid Lake sediments indicates that both basins have recorded five century-scale oscillations in regional hydrologic conditions since AD 800. Several of these changes in hydrologic conditions appear synchronous with century-scale California Current water temperature changes derived from analysis of sediment cores from the Santa Barbara Basin also attesting to the regional extent of these climatic fluctuations. Nearly synchronous oscillations in the Sierra wetness and the California Current suggest that regional changes in atmospheric circulation may have played an important role in century-scale climate variability over the last millennium
Late Holocene Lake-Level Fluctuations in Walker Lake, Nevada, USA
alker Lake, a hydrologically closed, saline, and alkaline lake, is situated along the western margin of the Great Basin in Nevada of the western United States. Analyses of the magnetic susceptibility (χ), total inorganic carbon (TIC), and oxygen isotopic composition (δ18O) of carbonate sediments including ostracode shells (Limnocythere ceriotuberosa) from Walker Lake allow us to extend the sediment record of lake-level fluctuations back to 2700 years B.P. There are approximately five major stages over the course of the late Holocene hydrologic evolution in Walker Lake: an early lowstand (\u3e 2400 years B.P.), a lake-filling period (∼ 2400 to ∼ 1000 years B.P.), a lake-level lowering period during the Medieval Warm Period (MWP) (∼ 1000 to ∼ 600 years B.P.), a relatively wet period (∼ 600 to ∼ 100 years B.P.), and the anthropogenically induced lake-level lowering period (\u3c 100 years B.P.). The most pronounced lowstand of Walker Lake occurred at ∼ 2400 years B.P., as indicated by the relatively high values of δ18O. This is generally in agreement with the previous lower resolution paleoclimate results from Walker Lake, but contrasts with the sediment records from adjacent Pyramid Lake and Siesta Lake. The pronounced lowstand suggests that the Walker River that fills Walker Lake may have partially diverted into the Carson Sink through the Adrian paleochannel between 2700 to 1400 years B.P
Ultra high energy neutrinos from gamma ray bursts
Protons accelerated to high energies in the relativistic shocks that generate
gamma ray bursts photoproduce pions, and then neutrinos in situ. I show that
ultra high energy neutrinos (> 10^19 eV) are produced during the burst and the
afterglow. A larger flux, also from bursts, is generated via photoproduction
off CMBR photons in flight but is not correlated with currently observable
bursts, appearing as a bright background. Adiabatic/synchrotron losses from
protons/pions/muons are negligible. Temporal and directional coincidences with
bursts detected by satellites can separate correlated neutrinos from the
background.Comment: Adiabatic/synchrotron losses from protons/pions/muons shown to be
negligible. Accepted for publication in Phys. Rev. Letters. RevTe
Resummed Quantum Gravity
We present the current status of the a new approach to quantum general
relativity based on the exact resummation of its perturbative series as that
series was formulated by Feynman. We show that the resummed theory is UV finite
and we present some phenomenological applications as well.Comment: 4 pages, 1 figure; presented at ICHEP0
On the Discovery of the GZK Cut-off
The recent claim of the '5 sigma' observation of the Greisen and Zatzepin and
Kuzmin cut-off by the HiRes group based on their nine years data is a
significant step toward the eventual solution of the one of the most intriguing
questions which has been present in physics for more than forty years. However
the word 'significance' is used in the mentioned paper in the sense which is
not quite obvious. In the present paper we persuade that this claim is a little
premature.Comment: 10 page
CD80 (B7-1) Binds Both CD28 and CTLA-4 with a Low Affinity and Very Fast Kinetics
The structurally related T cell surface molecules CD28 and CTLA-4 interact with cell surface ligands CD80 (B7-1) and CD86 (B7-2) on antigen-presenting cells (APC) and modulate T cell antigen recognition. Preliminary reports have suggested that CD80 binds CTLA-4 and CD28 with affinities (Kd values ∼12 and ∼200 nM, respectively) that are high when compared with other molecular interactions that contribute to T cell–APC recognition. In the present study, we use surface plasmon resonance to measure the affinity and kinetics of CD80 binding to CD28 and CTLA-4. At 37°C, soluble recombinant CD80 bound to CTLA-4 and CD28 with Kd values of 0.42 and 4 μM, respectively. Kinetic analysis indicated that these low affinities were the result of very fast dissociation rate constants (koff); sCD80 dissociated from CD28 and CTLA-4 with koff values of ⩾1.6 and ⩾0.43 s−1, respectively. Such rapid binding kinetics have also been reported for the T cell adhesion molecule CD2 and may be necessary to accommodate dynamic T cell–APC contacts and to facilitate scanning of APC for antigen
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