11,998 research outputs found
An examination of some characteristics of Kepler Short and Long Cadence Data
A close comparison of Kepler short- and long-cadence data released prior to
2011 Nov 1 has shown some subtle differences that make the short-cadence data
superior to their long-cadence counterparts. The inevitable results of a faster
sampling rate are present: the short-cadence data provide greater time
resolution for short-lived events like flares, and have a much higher Nyquist
frequency than the long-cadence data; however, they also contain fewer
high-amplitude peaks at low frequency and allow a more precise determination of
pulsation frequencies, amplitudes and phases. The latter observation indicates
that Kepler data are not normally distributed. Moreover, a close inspection of
the Pre-search Data Conditioned (PDC) long-cadence data show residuals that
have increased noise on time-scales important to asteroseismology, but
unimportant to planet searches.Comment: Accepted for publication in MNRAS. 7 pages, 5 figure
Brainstem response and state-trait variables
A series of investigations are summarized from a personality research program that have relevance for mental state estimation. Of particular concern are those personality variables that are believed to have either a biological or perceptual basis and their relationship to human task performance and psychophysiology. These variables are among the most robust personality measures and include such dimensions as extraversion-introversion, sensation seeking, and impulsiveness. These dimensions also have the most distinct link to performance and psychophysiology. Through the course of many of these investigations two issues have emerged repeatedly: these personality dimensions appear to mediate mental state, and mental state appears to influence measures of performance or psychophysiology
Asteroseismic Investigation of Known Planet Hosts in the Kepler Field
In addition to its great potential for characterizing extra-solar planetary
systems the Kepler mission is providing unique data on stellar oscillations. A
key aspect of Kepler asteroseismology is the application to solar-like
oscillations of main-sequence stars. As an example we here consider an initial
analysis of data for three stars in the Kepler field for which planetary
transits were known from ground-based observations. For one of these, HAT-P-7,
we obtain a detailed frequency spectrum and hence strong constraints on the
stellar properties. The remaining two stars show definite evidence for
solar-like oscillations, yielding a preliminary estimate of their mean
densities.Comment: Astrophysical Journal Letters, in the pres
Prelude to, and Nature of the Space Photometry Revolution
It is now less than a decade since CoRoT initiated the space photometry
revolution with breakthrough discoveries, and five years since Kepler started a
series of similar advances. I'll set the context for this revolution noting the
status of asteroseismology and exoplanet discovery as it was 15-25 years ago in
order to give perspective on why it is not mere hyperbole to claim CoRoT and
Kepler fostered a revolution in our sciences. Primary events setting up the
revolution will be recounted. I'll continue with noting the major discoveries
in hand, and how asteroseismology and exoplanet studies, and indeed our
approach to doing science, have been forever changed thanks to these
spectacular missions.Comment: Invited review for the CoRoT3-KASC7 Conference: The Space Photometry
Revolution, Toulouse, France, July 2014. 6 page
Video signal processing system uses gated current mode switches to perform high speed multiplication and digital-to-analog conversion
Video signal processor uses special-purpose integrated circuits with nonsaturating current mode switching to accept texture and color information from a digital computer in a visual spaceflight simulator and to combine these, for display on color CRT with analog information concerning fading
A note on the comparison of three near infrared reflectance spectroscopy calibration strategies for assessing herbage quality of ryegrass
peer-reviewedPerennial ryegrass (n = 1,836), Italian ryegrass (n = 137) and hybrid ryegrass (n =
103) herbage was taken from harvested plots from the Irish national variety evaluation
scheme and analysed for in vitro dry matter digestibility, water soluble carbohydrate
concentration, crude protein concentration and buffering capacity. Spectral data were
obtained using near infrared reflectance spectroscopy and three calibration strategies
(global, species-specific or local) were utilised to relate the reference values to the
spectral data. The local strategy generally provided the poorest estimation of herbage
composition, with global and species-specific calibration strategies producing similarly
accurate estimates of each quality trait. The higher accuracy and easier maintenance of
the global strategy make it the recommended calibration method for analysing quality
of ryegrass.Department of Agriculture, Food and the
Marine Research Stimulus Fund (07 526
Variable anodic thermal control coating
A process for providing a thermal control solar stable surface coating for aluminum surfaces adapted to be exposed to solar radiation wherein selected values within the range of 0.10 to 0.72 thermal emittance (epsilon sub tau) and 0.2 to 0.4 solar absorptance (alpha subs) are reproducibly obtained by anodizing the surface area in a chromic acid solution for a selected period of time. The rate voltage and time, along with the parameters of initial epsilon sub tau and alpha subs, temperature of the chromic acid solution, acid concentration of the solution and the material anodized determines the final values of epsilon/tau sub and alpha sub S. 9 Claims, 5 Drawing Figures
Solar-like oscillations in a metal-poor globular cluster with the HST
We present analyses of variability in the red giant stars in the metal-poor
globular cluster NGC6397, based on data obtained with the Hubble Space
Telescope. We use an non-standard data reduction approach to turn a 23-day
observing run originally aimed at imaging the white dwarf population, into
time-series photometry of the cluster's highly saturated red giant stars. With
this technique we obtain noise levels in the final power spectra down to 50
parts per million, which allows us to search for low amplitude solar-like
oscillations. We compare the observed excess power seen in the power spectra
with estimates of the typical frequency range, frequency spacing and amplitude
from scaling the solar oscillations. We see evidence that the detected
variability is consistent with solar-like oscillations in at least one and
perhaps up to four stars. With metallicities two orders of magnitude lower than
of the Sun, these stars present so far the best evidence of solar-like
oscillations in such a low metallicity environment.Comment: 7 pages, 6 figures, accepted by Ap
Lack of Genetic Diversity in Newly Sequenced Porcine Circovirus Type 1 Strains Isolated 20 Years Apart
The complete genome sequences of a porcine circovirus type 1 (PCV1) strain isolated in 1990 and one isolated in 2011 were obtained and compared to the sequences of other available PCV1 isolates. Phylogenetic analyses revealed very low genetic diversity among these viruses, indicating an advanced state in the evolution of PCV1
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