1,094 research outputs found
Seeing motion and apparent motion
In apparent motion experiments, participants are presented with what is in fact a succession of two brief stationary stimuli at two different locations, but they report an impression of movement. Philosophers have recently debated whether apparent motion provides evidence in favour of a particular account of the nature of temporal experience. I argue that the existing discussion in this area is premised on a mistaken view of the phenomenology of apparent motion and, as a result, the space of possible philosophical positions has not yet been fully explored. In particular, I argue that the existence of apparent motion is compatible with an account of the nature of temporal experience that involves a version of direct realism. In doing so, I also argue against two other claims often made about apparent motion, viz. that apparent motion is the psychological phenomenon that underlies motion experience in the cinema, and that apparent motion is subjectively indistinguishable from real motion
Standing by our principles: Meaningful guidance, moral foundations, and multi-principle methodology in medical scarcity
Background
Several quantitative surveys have been conducted internationally to gather empirical information about physiciansā general attitudes towards health care rationing. Are physicians ready to accept and implement rationing, or are they rather reluctant? Do they prefer implicit bedside rationing that allows the physicianāpatient relationship broad leeway in individual decisions? Or do physicians prefer strategies that apply explicit criteria and rules? Objectives
To analyse the range of survey findings on rationing. To discuss differences in response patterns. To provide recommendations for the enhancement of transparency and systematic conduct in reviewing survey literature. Methods
A systematic search was performed for all English and non-English language references using CINAHL, EMBASE, and MEDLINE. Three blinded experts independently evaluated title and abstract of each reference. Survey items were extracted that match with: (i) willingness to ration health care or (ii) preferences for different rationing strategies. Results
16 studies were eventually included in the systematic review. Percentages of respondents willing to accept rationing ranged from 94% to 9%. Conclusions
The conflicting findings among studies illustrate important ambivalence in physicians that has several implications for health policy. Moreover, this review highlights the importance to interpret survey findings in context of the results of all previous relevant studies
Generation of folk song melodies using Bayes transforms
The paper introduces the `Bayes transform', a mathematical procedure for putting data into a hierarchical representation. Applicable to any type of data, the procedure yields interesting results when applied to sequences. In this case, the representation obtained implicitly models the repetition hierarchy of the source. There are then natural applications to music. Derivation of Bayes transforms can be the means of determining the repetition hierarchy of note sequences (melodies) in an empirical and domain-general way. The paper investigates application of this approach to Folk Song, examining the results that can be obtained by treating such transforms as generative models
A Spitzer IRAC Imaging Survey for T Dwarf Companions Around M, L, and T Dwarfs: Observations, Results, and Monte Carlo Population Analyses
We report observational techniques, results, and Monte Carlo population
analyses from a Spitzer Infrared Array Camera imaging survey for substellar
companions to 117 nearby M, L, and T dwarf systems (median distance of 10 pc,
mass range of 0.6 to \sim0.05 M\odot). The two-epoch survey achieves typical
detection sensitivities to substellar companions of [4.5 {\mu}m] \leq 17.2 mag
for angular separations between about 7" and 165". Based on common proper
motion analysis, we find no evidence for new substellar companions. Using Monte
Carlo orbital simulations (assuming random inclination, random eccentricity,
and random longitude of pericenter), we conclude that the observational
sensitivities translate to an ability to detect 600-1100K brown dwarf
companions at semimajor axes greater than ~35 AU, and to detect 500-600K
companions at semimajor axes greater than ~60 AU. The simulations also estimate
a 600-1100K T dwarf companion fraction of < 3.4% for 35-1200 AU separations,
and < 12.4% for the 500-600K companions, for 60-1000 AU separations.Comment: 35 pages, 6 figure
Modern Corneal Eye-Banking Using a Software-Based IT Management Solution
Background. Increasing government legislation and regulations in manufacturing have led to additional documentation regarding the pharmaceutical product requirements of corneal grafts in the European Union. The aim of this project was to develop a software within a hospital information system (HIS) to support the documentation process, to improve the management of the patient waiting list and to increase informational flow between the clinic and eye bank. Materials and Methods. After an analysis of the current documentation process, a new workflow and software were implemented in our electronic health record (EHR) system. Results. The software takes over most of the documentation and reduces the time required for record keeping. It guarantees real-time tracing of all steps during human corneal tissue processing from the start of production until allocation during surgery and includes follow-up within the HIS. Moreover, listing of the patient for surgery as well as waiting list management takes place in the same system. Conclusion. The new software for corneal eye banking supports the whole process chain by taking over both most of the required documentation and the management of the transplant waiting list. It may provide a standardized IT-based solution for German eye banks working within the same HIS
Do we (seem to) perceive passage?
I examine some recent claims put forward by L. A. Paul, Barry Dainton and Simon Prosser, to the effect that perceptual experiences of movement and change involve an (apparent) experience of āpassageā, in the sense at issue in debates about the metaphysics of time. Paul, Dainton and Prosser all argue that this supposed feature of perceptual experience ā call it a phenomenology of passage ā is illusory, thereby defending the view that there is no such a thing as passage, conceived of as a feature of mind-independent reality. I suggest that in fact there is no such phenomenology of passage in the first place. There is, however, a specific structural aspect of the phenomenology of perceptual experiences of movement and change that can explain how one might mistakenly come to the belief that such experiences do involve a phenomenology of passage
Experiments in vortex avalanches
Avalanche dynamics is found in many phenomena spanning from earthquakes to
the evolution of species. It can be also found in vortex matter when a type II
superconductor is externally driven, for example, by increasing the magnetic
field. Vortex avalanches associated with thermal instabilities can be an
undesirable effect for applications, but "dynamically driven" avalanches
emerging from the competition between intervortex interactions and quenched
disorder constitute an interesting scenario to test theoretical ideas related
with non-equilibrium dynamics. However, differently from the equilibrium phases
of vortex matter in type II superconductors, the study of the corresponding
dynamical phases - in which avalanches can play a role - is still in its
infancy. In this paper we critically review relevant experiments performed in
the last decade or so, emphasizing the ability of different experimental
techniques to establish the nature and statistical properties of the observed
avalanche behavior.Comment: To be published in Reviews of Modern Physics April 2004. 17 page
The N2K Consortium. VII. Atmospheric Parameters of 1907 Metal-Rich Stars: Finding Planet-Search Targets
We report high-precision atmospheric parameters for 1907 stars in the N2K
low-resolution spectroscopic survey, designed to identify metal-rich FGK dwarfs
likely to harbor detectable planets. 284 of these stars are in the ideal
temperature range for planet searches, T_eff <= 6000K, and have a 10% or
greater probability of hosting planets based on their metallicities. The stars
in the low-resolution spectroscopic survey should eventually yield >60 new
planets, including 8-9 hot Jupiters. Short-period planets have already been
discovered orbiting the survey targets HIP 14801 and HD 149143.Comment: Accepted for publication in Astrophysical Journal Supplements. 24
pages, including 8 figures and one table. Two more tables will appear in ApJS
online editio
The Allen Telescope Array: The First Widefield, Panchromatic, Snapshot Radio Camera for Radio Astronomy and SETI
The first 42 elements of the Allen Telescope Array (ATA-42) are beginning to
deliver data at the Hat Creek Radio Observatory in Northern California.
Scientists and engineers are actively exploiting all of the flexibility
designed into this innovative instrument for simultaneously conducting surveys
of the astrophysical sky and conducting searches for distant technological
civilizations. This paper summarizes the design elements of the ATA, the cost
savings made possible by the use of COTS components, and the cost/performance
trades that eventually enabled this first snapshot radio camera. The
fundamental scientific program of this new telescope is varied and exciting;
some of the first astronomical results will be discussed.Comment: Special Issue of Proceedings of the IEEE: "Advances in Radio
Telescopes", Baars,J. Thompson,R., D'Addario, L., eds, 2009, in pres
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