1,690 research outputs found
Communication Apprehension about Death, Religious Group Affiliation, and Religiosity: Predictors of Organ and Body Donation Decisions
Communication willingness has previously been identified as an important communication factor in influencing individuals’ decisions to become an organ donor. Missing from this conversation is the role of communication apprehension about death and its impact on donation decisions. The purpose of this study was to examine the relationships between communication apprehension about death, religiosity, and religious affiliation, and donation decisions. Three hundred and thirty-three individuals participated in an online survey. Findings suggest that communication apprehension about death, especially communication avoidance about death, negatively impact donation decisions. Additionally, religiosity and affiliation with a specific religion also negatively impact donation decisions. These variables were also predictors of organ and body donation. The findings show a need for more research on what prevents conversations about donation. Additionally, the stark difference between organ donation likelihood and body donation likelihood underscore the need for communication scholars to examine communication about body donation
Development and Validation of the Communication Apprehension About Death Scale
Two studies (N=621) were conducted to develop and initially validate the Communication Apprehension About Death Scale (CADS). In Study 1, 302 general public participants completed a preliminary list of 66 items. An exploratory factor analysis identified two distinct dimensions of communication apprehension about death: communication anxiety and communication avoidance. A different group of participants (n=319) participated in Study 2. Participants in Study 2 completed the CADS measure, a fear of death measure, and a general communication apprehension measure. Concurrent validity support was provided through the significant positive correlations between communication apprehension about death and fear of death as well as communication apprehension about death and general communication apprehension. Collectively, the results suggest that the CADS is a reliable and valid self-report measure of communication apprehension about death. We conclude with a discussion of the findings as well as future directions needed to more critically examine CADS
Phase space spinor amplitudes for spin 1/2 systems
The concept of phase space amplitudes for systems with continuous degrees of
freedom is generalized to finite-dimensional spin systems. Complex amplitudes
are obtained on both a sphere and a finite lattice, in each case enabling a
more fundamental description of pure spin states than that previously given by
Wigner functions. In each case the Wigner function can be expressed as the star
product of the amplitude and its conjugate, so providing a generalized Born
interpretation of amplitudes that emphasizes their more fundamental status. The
ordinary product of the amplitude and its conjugate produces a (generalized)
spin Husimi function. The case of spin-\half is treated in detail, and it is
shown that phase space amplitudes on the sphere transform correctly as spinors
under under rotations, despite their expression in terms of spherical
harmonics. Spin amplitudes on a lattice are also found to transform as spinors.
Applications are given to the phase space description of state superposition,
and to the evolution in phase space of the state of a spin-\half magnetic
dipole in a time-dependent magnetic field.Comment: 19 pages, added new results, fixed typo
Twitter Use and its Effects on Student Perception of Instructor Credibility
This study investigates college student perceptions of instructor credibility based on the content of an instructor’s Twitterfeed and student beliefs about Twitter as a communication tool. Quantitative and qualitative methods were utilized to explore the effects of three manipulated Twitter feeds (e.g., tweeting social topics, professional topics, or a blend) on student perceptions of instructor credibility and examine how students perceive Twitter as a teaching tool. Quantitative results suggest that the profile with professional content was most credible. Credibility ratings were also associated with other Twitter use variables, including positive student attitudes about instructors who use Twitter and Tweet frequency. Coded qualitative responses indicated that Twitter may be both an asset and an obstacle for instructors
Power, Propulsion, and Communications for Microspacecraft Missions
The development of small sized, low weight spacecraft should lead to reduced scientific mission costs by lowering fabrication and launch costs. An order of magnitude reduction in spacecraft size can be obtained by miniaturizing components. Additional reductions in spacecraft weight, size, and cost can be obtained by utilizing the synergy that exists between different spacecraft systems. The state-of-the-art of three major systems, spacecraft power, propulsion, and communications is discussed. Potential strategies to exploit the synergy between these systems and/or the payload are identified. Benefits of several of these synergies are discussed
Molecular and mass spectroscopic analysis of isotopically labeled organic residues
Experimental studies aimed at understanding the evolution of complex organic molecules on interstellar grains were performed. The photolysis of frozen gas mixtures of various compositions containing H2O, CO, NH3, and CH4 was studied. These species were chosen because of their astrophysical importance as deducted from observational as well as theoretical studies of ice mantles on interstellar grains. These ultraviolet photolyzed ices were warmed up in order to produce refractory organic molecules like the ones formed in molecular clouds when the icy mantles are being irradiated and warmed up either by a nearby stellar source or impulsive heating. The laboratory studies give estimates of the efficiency of production of such organic material under interstellar conditions. It is shown that the gradual carbonization of organic mantles in the diffuse cloud phase leads to higher and higher visual absorptivity - yellow residues become brown in the laboratory. The obtained results can be applied to explaining the organic components of comets and their relevance to the origin of life
Derivatives of spin dynamics simulations
We report analytical equations for the derivatives of spin dynamics
simulations with respect to pulse sequence and spin system parameters. The
methods described are significantly faster, more accurate and more reliable
than the finite difference approximations typically employed. The resulting
derivatives may be used in fitting, optimization, performance evaluation and
stability analysis of spin dynamics simulations and experiments.
Keywords: NMR, EPR, simulation, analytical derivatives, optimal control, spin
chemistry, radical pair.Comment: Accepted by The Journal of Chemical Physic
Transport Theory beyond Binary Collisions
Using the Schwinger-Keldysh technique, we derive the transport equations for
a system of quantum scalar fields. We first discuss the general structure of
the equations and then their collision terms. Taking into account up to
three-loop diagrams in \phi^3 model and up to four-loop diagrams in \phi^4
model, we obtain the transport equations which include the contributions of
multi-particle collisions and particle production processes, in addition to
mean-field effects and binary interactions.Comment: 30 pages, 21 figures, minor changes, to appear in Phys. Rev.
Kepler Presearch Data Conditioning I - Architecture and Algorithms for Error Correction in Kepler Light Curves
Kepler provides light curves of 156,000 stars with unprecedented precision.
However, the raw data as they come from the spacecraft contain significant
systematic and stochastic errors. These errors, which include discontinuities,
systematic trends, and outliers, obscure the astrophysical signals in the light
curves. To correct these errors is the task of the Presearch Data Conditioning
(PDC) module of the Kepler data analysis pipeline. The original version of PDC
in Kepler did not meet the extremely high performance requirements for the
detection of miniscule planet transits or highly accurate analysis of stellar
activity and rotation. One particular deficiency was that astrophysical
features were often removed as a side-effect to removal of errors. In this
paper we introduce the completely new and significantly improved version of PDC
which was implemented in Kepler SOC 8.0. This new PDC version, which utilizes a
Bayesian approach for removal of systematics, reliably corrects errors in the
light curves while at the same time preserving planet transits and other
astrophysically interesting signals. We describe the architecture and the
algorithms of this new PDC module, show typical errors encountered in Kepler
data, and illustrate the corrections using real light curve examples.Comment: Submitted to PASP. Also see companion paper "Kepler Presearch Data
Conditioning II - A Bayesian Approach to Systematic Error Correction" by Jeff
C. Smith et a
Galaxy Merger Candidates in High-Redshift Cluster Environments
We compile a sample of spectroscopically- and photometrically-selected
cluster galaxies from four high-redshift galaxy clusters ()
from the Spitzer Adaptation of the Red-Sequence Cluster Survey (SpARCS), and a
comparison field sample selected from the UKIDSS Deep Survey. Using
near-infrared imaging from the \textit{Hubble Space Telescope} we classify
potential mergers involving massive () cluster members by eye, based on morphological
properties such as tidal distortions, double nuclei, and projected near
neighbors within 20 kpc. With a catalogue of 23 spectroscopic and 32
photometric massive cluster members across the four clusters and 65
spectroscopic and 26 photometric comparable field galaxies, we find that after
taking into account contamination from interlopers, of
the cluster members are involved in potential mergers, compared to
of the field galaxies. We see no evidence of merger
enhancement in the central cluster environment with respect to the field,
suggesting that galaxy-galaxy merging is not a stronger source of galaxy
evolution in cluster environments compared to the field at these redshifts.Comment: Accepted by Ap
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