1,940 research outputs found
Promoting professional quality and meaning in life among nursing students : a mixed methods study
Published ArticleThe study on which this article is based addressed a gap in existing research and practice by reporting on the empirical evaluation of a psycho-educational stress management programme that was developed to address professional quality of life (compassion fatigue, burnout and compassion satisfaction) and meaning in life among nursing students. An explanatory sequential mixed methods approach served as research design. Quantitative data were collected by means of the Professional Quality of Life Scale and the Life Purpose Questionnaire in a pre- and post-test manner (N = 42, Mage = 20.28;76.19% female). Qualiative data were collected by means of unstructured one-on-one interviews (N = 6, Mage = 20.33; 67% female) and narrative sketches (N = 29, Mage = 20.21, 79.31% female). The paired-samples t-test was used to compare the pre- and post-test quantitative data. Statistically significant results indicate that the programme was effective in reducing secondary stressful experiences and enhancing compassion satisfaction and meaning among participants. Qualitative analysis suggests that group interaction and establishing a sense of meaning in life were important factors that contributed to the value of the programme
Germplasm diversity of sunflower volatile terpenoid profiles across vegetative and reproductive organs
Received: September 4th, 2022 ; Accepted: December 4th, 2022 ; Published: December 24th, 2022 ; Corresponding author: [email protected] sunflower (Helianthus annuus) is the fourth most important oilseed crop
globally and is known to have experienced multiple genetic bottlenecks during domestication and
improvement. Homogenization of crop germplasm may limit breeding efforts to improve pest
and pathogen resistance or optimize other biotic interactions like pollinator attraction. Such
interactions are often strongly influenced by plant phytochemistry, especially volatile compounds
like terpenoids. Here we use solid-phase microextraction gas chromatography mass spectrometry
(SPME GC-MS) to evaluate volatile phytochemistry across leaves, involucral bracts, disc florets,
and ray floret petals in a collection of twelve inbred lines selected to represent a cross-section of
sunflower germplasm diversity. Results indicate considerable compositional diversity of volatiles
among lines, though substantial reduction in total volatile abundance relative to wild H. annuus.
From leaves and bracts to disc florets and petals, we observe a strong increase in the proportion
of monoterpenoids relative to sesquiterpenoids accompanying the transition to reproductive
structures, with consistently over 85% monoterpenoids in disc florets and petals. This pattern is
driven by substantially higher production of monoterpenoids (especially alpha-pinene and
sabinene) in reproductive structures. Sesquiterpenoid production is roughly similar across organs,
and in leaves varies among lines from 21–55% of volatiles, dominated by cadinene-type
sesquiterpenoids. This work suggests that the compositional diversity of volatile terpenoids
within cultivated germplasm may be sufficient for many breeding applications, though for
breeding increased volatile production the use of wild H. annuus and other wild Helianthus
germplasm may be necessary
Pressure-Induced Magnetism and Hidden Order in URu_2Si_2
We discuss the discovery of pressure-induced antiferromagnetism in URu_2Si_2,
in the context of neutron, NMR and \mu SR results. The identification of a
critical pressure separating mean-field and Ising phase transitions leads us to
propose that the system lies close to a bicritical point associated with
magnetic and (non-magnetic) hidden order. We conclude that the recent
observation of an isotropic, field-independent component in the silicon NMR
line-width implies that the hidden order parameter breaks time-reversal
invariance and present a preliminary discussion of the underlying nature of the
hidden order parameter.Comment: To appear in proceedings of SCES 200
Crossover and scaling in a two-dimensional field-tuned superconductor
Using an analysis similar to that of Imry and Wortis, it is shown that the
apparent first order superconductor to metal transition, which has been claimed
to exist at low values of the magnetic field in a two-dimensional field-tuned
system at zero temperature,can be consistentlyinterpreted as a sharp crossover
from a strong superconductor to an inhomogeneous state, which is a weak
superconductor. The true zero-temperature superconductor to insulator
transition within the inhomogenous state is conjectured to be that of randomly
diluted XY model. An explaination of the observed finite temperature
approximate scaling of resistivity close to the critical point is speculated
within this model.Comment: 5 pages, 2 figures, corrected and modified according to referee
Report
Specific Heat of Liquid Helium in Zero Gravity very near the Lambda Point
We report the details and revised analysis of an experiment to measure the
specific heat of helium with subnanokelvin temperature resolution near the
lambda point. The measurements were made at the vapor pressure spanning the
region from 22 mK below the superfluid transition to 4 uK above. The experiment
was performed in earth orbit to reduce the rounding of the transition caused by
gravitationally induced pressure gradients on earth. Specific heat measurements
were made deep in the asymptotic region to within 2 nK of the transition. No
evidence of rounding was found to this resolution. The optimum value of the
critical exponent describing the specific heat singularity was found to be a =
-0.0127+ - 0.0003. This is bracketed by two recent estimates based on
renormalization group techniques, but is slightly outside the range of the
error of the most recent result. The ratio of the coefficients of the leading
order singularity on the two sides of the transition is A+/A- =1.053+ - 0.002,
which agrees well with a recent estimate. By combining the specific heat and
superfluid density exponents a test of the Josephson scaling relation can be
made. Excellent agreement is found based on high precision measurements of the
superfluid density made elsewhere. These results represent the most precise
tests of theoretical predictions for critical phenomena to date.Comment: 27 Pages, 20 Figure
How to find discrete contact symmetries
This paper describes a new algorithm for determining all discrete contact
symmetries of any differential equation whose Lie contact symmetries are known.
The method is constructive and is easy to use. It is based upon the observation
that the adjoint action of any contact symmetry is an automorphism of the Lie
algebra of generators of Lie contact symmetries. Consequently, all contact
symmetries satisfy various compatibility conditions. These conditions enable
the discrete symmetries to be found systematically, with little effort
IMF biases created by binning and unresolved systems
I discuss two of the possible sources of biases in the determination of the
IMF: binning and the existence of unresolved components. The first source is
important for clusters with a small number of stars detected in a given mass
bin while the second one is relevant for all clusters located beyond the
immediate solar neighborhood. For both cases I will present results of
numerical simulations and I will discuss strategies to correct for their
effects. I also present a brief description of a third unrelated bias source.Comment: 6 pages, 10 figures, to appear in "Young massive clusters, initial
conditions and environments", typo in author's name correcte
True Superconductivity in a 2D "Superconducting-Insulating" System
We present results on disordered amorphous films which are expected to
undergo a field-tuned Superconductor-Insulator Transition. Based on low-field
data and I-V characteristics, we find evidence of a low temperature
Metal-to-Superconductor transition. This transition is characterized by
hysteretic magnetoresistance and discontinuities in the I-V curves. The
metallic phase just above the transition is different from the "Fermi Metal"
before superconductivity sets in.Comment: 3 pages, 4 figure
Superconducting zero temperature phase transition in two dimensions and in the magnetic field
We derive the Ginzburg-Landau-Wilson theory for the superconducting phase
transition in two dimensions and in the magnetic field. Without disorder the
theory describes a fluctuation induced first-order quantum phase transition
into the Abrikosov lattice. We propose a phenomenological criterion for
determining the transition field and discuss the qualitative effects of
disorder. Comparison with recent experiments on MoGe films is discussed.Comment: 7 pages, 2 figure
Hydrogen peroxide regulation of endothelial exocytosis by inhibition of N-ethylmaleimide sensitive factor
Although an excess of reactive oxygen species (ROS) can damage the vasculature, low concentrations of ROS mediate intracellular signal transduction pathways. We hypothesized that hydrogen peroxide plays a beneficial role in the vasculature by inhibiting endothelial exocytosis that would otherwise induce vascular inflammation and thrombosis. We now show that endogenous H2O2 inhibits thrombin-induced exocytosis of granules from endothelial cells. H2O2 regulates exocytosis by inhibiting N-ethylmaleimide sensitive factor (NSF), a protein that regulates membrane fusion events necessary for exocytosis. H2O2 decreases the ability of NSF to hydrolyze adenosine triphosphate and to disassemble the soluble NSF attachment protein receptor complex. Mutation of NSF cysteine residue C264T eliminates the sensitivity of NSF to H2O2, suggesting that this cysteine residue is a redox sensor for NSF. Increasing endogenous H2O2 levels in mice decreases exocytosis and platelet rolling on venules in vivo. By inhibiting endothelial cell exocytosis, endogenous H2O2 may protect the vasculature from inflammation and thrombosis
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