328 research outputs found
Characterizing Operations Preserving Separability Measures via Linear Preserver Problems
We use classical results from the theory of linear preserver problems to
characterize operators that send the set of pure states with Schmidt rank no
greater than k back into itself, extending known results characterizing
operators that send separable pure states to separable pure states. We also
provide a new proof of an analogous statement in the multipartite setting. We
use these results to develop a bipartite version of a classical result about
the structure of maps that preserve rank-1 operators and then characterize the
isometries for two families of norms that have recently been studied in quantum
information theory. We see in particular that for k at least 2 the operator
norms induced by states with Schmidt rank k are invariant only under local
unitaries, the swap operator and the transpose map. However, in the k = 1 case
there is an additional isometry: the partial transpose map.Comment: 16 pages, typos corrected, references added, proof of Theorem 4.3
simplified and clarifie
Implementing an inpatient social early warning system for child maltreatment
Objectives: The current article describes the process evaluation of a social early warning system (SEWS) for the prevention of
child maltreatment in the federal state of Hamburg. This prevention initiative targets expectant mothers and their partners
including an initial screening of risk factors for child maltreatment, a subsequent structured clearing interview further exploring risks
and identifying protective factors and an optional referral to the regional health and social care system. Method: The process
evaluation was conducted by examining the flow of participants through the different stages of the SEWS as well as asking social
education workers, parents, and regional institutions about their satisfaction with the process of the SEWS. Results: The participation
rate throughout the SEWS as well as the satisfaction rates were high. Conclusions: The SEWS is a secondary prevention
initiative with a substantial difference to other early prevention initiatives, as it aims to facilitate intervention rather than providing it
Removing systematics from the CoRoT light curves: I. Magnitude-Dependent Zero Point
This paper presents an analysis that searched for systematic effects within
the CoRoT exoplanet field light curves. The analysis identified a systematic
effect that modified the zero point of most CoRoT exposures as a function of
stellar magnitude. We could find this effect only after preparing a set of
learning light curves that were relatively free of stellar and instrumental
noise. Correcting for this effect, rejecting outliers that appear in almost
every exposure, and applying SysRem, reduced the stellar RMS by about 20 %,
without attenuating transit signals.Comment: Accepted for publication in Astronomy and Astrophysic
Transiting exoplanets from the CoRoT space mission VIII. CoRoT-7b: the first Super-Earth with measured radius
We report the discovery of very shallow (DF/F = 3.4 10-4), periodic dips in
the light curve of an active V = 11.7 G9V star observed by the CoRoT satellite,
which we interpret as due to the presence of a transiting companion. We
describe the 3-colour CoRoT data and complementary ground-based observations
that support the planetary nature of the companion. Methods. We use CoRoT color
information, good angular resolution ground-based photometric observations in-
and out- of transit, adaptive optics imaging, near-infrared spectroscopy and
preliminary results from Radial Velocity measurements, to test the diluted
eclipsing binary scenarios. The parameters of the host star are derived from
optical spectra, which were then combined with the CoRoT light curve to derive
parameters of the companion. We examine carefully all conceivable cases of
false positives, and all tests performed support the planetary hypothesis.
Blends with separation larger than 0.40 arcsec or triple systems are almost
excluded with a 8 10-4 risk left. We conclude that, as far as we have been
exhaustive, we have discovered a planetary companion, named CoRoT-7b, for which
we derive a period of 0.853 59 +/- 3 10-5 day and a radius of Rp = 1.68 +/-
0.09 REarth. Analysis of preliminary radial velocity data yields an upper limit
of 21 MEarth for the companion mass, supporting the finding.
CoRoT-7b is very likely the first Super-Earth with a measured radius.Comment: Accepted in Astronomy and Astrophysics; typos and language
corrections; version sent to the printer w few upgrade
Generation of Phenylpropanoid Pathway-Derived Volatiles in Transgenic Plants: Rose Alcohol Acetyltransferase Produces Phenylethyl Acetate and Benzyl Acetate in Petunia Flowers
Esters are important contributors to the aroma of numerous flowers and fruits. Acetate esters such as geranyl acetate, phenylethyl acetate and benzyl acetate are generated as a result of the action of alcohol acetyltransferases (AATs). Numerous homologous AATs from various plants have been characterized using in-vitro assays. To study the function of rose alcohol acetyltransferase (RhAAT) in planta , we generated transgenic petunia plants expressing the rose gene under the control of a CaMV-35S promoter. Although the preferred substrate of RhAAT in vitro is geraniol, in transgenic petunia flowers, it used phenylethyl alcohol and benzyl alcohol to produce the corresponding acetate esters, not generated by control flowers. The level of benzyl alcohol emitted by the flowers of different transgenic lines was ca. three times higher than that of phenylethyl alcohol, which corresponded to the ratio between the respective products, i.e. ca. three times more benzyl acetate than phenylethyl acetate. Feeding of transgenic petunia tissues with geraniol or octanol led to the production of their respective acetates, suggesting the dependence of volatile production on substrate availability.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43457/1/11103_2005_Article_4924.pd
Aftercare service development for children in residential treatment
Increasingly, aftercare services for children returning home from residential treatment are recognized as vital to maintain a child's gains. However, to date, specific knowledge about effective aftercare services, as well as the actual delivery of such services continue to require development. This paper describes an empirically-based, concrete aftercare program that addresses these concerns.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44267/1/10566_2005_Article_BF01184759.pd
CHEOPS geometric albedo of the hot Jupiter HD 209458 b
Funding: P.F.L.M. acknowledges support from STFC research grant number ST/M001040/1. This project has received funding from the European Research Council (ERC) under the European Unionâs Horizon 2020 research and innovation programme (project Four Aces. grant agreement No 724427).We report the detection of the secondary eclipse of the hot Jupiter HD 209458 b in optical/visible light using the CHEOPS space telescope. Our measurement of 20.4-3.3+3.2 parts per million translates into a geometric albedo of Ag = 0.096 ± 0.016. The previously estimated dayside temperature of about 1500 K implies that our geometric albedo measurement consists predominantly of reflected starlight and is largely uncontaminated by thermal emission. This makes the present result one of the most robust measurements of Ag for any exoplanet. Our calculations of the bandpassintegrated geometric albedo demonstrate that the measured value of Ag is consistent with a cloud-free atmosphere, where starlight is reflected via Rayleigh scattering by hydrogen molecules, and the water and sodium abundances are consistent with stellar metallicity. We predict that the bandpass-integrated TESS geometric albedo is too faint to detect and that a phase curve of HD 209458 b observed by CHEOPS would have a distinct shape associated with Rayleigh scattering if the atmosphere is indeed cloud free.Publisher PDFPeer reviewe
The places parents go: understanding the breadth, scope, and experiences of activity spaces for parents
The final publication is available at Springer via https://doi.org/10.1007/s10708-015-9690-yNeighborhood environments are related to parenting behaviors, which in turn have a life-long effect on childrenâs health and well-being. Activity spaces, which measure individual routine patterns of movement, may be helpful in assessing how physical and social environments shape parenting. In this study we use qualitative data and GIS mapping from four California cities to examine parental activity spaces. Parents described a number of factors that shape their activity spaces including caregiving status, the age of their children, and income. Parental activity spaces also varied between times (weekends vs. weekdays) and places (adult-only vs. child-specific places). Knowing how to best capture and study parental activity spaces could identify mechanisms by which environmental factors influence parenting behaviors and child health
The geometric albedo of the hot Jupiter HD 189733b measured with CHEOPS
Context. Measurements of the occultation of an exoplanet at visible
wavelengths allow us to determine the reflective properties of a planetary
atmosphere. The observed occultation depth can be translated into a geometric
albedo. This in turn aids in characterising the structure and composition of an
atmosphere by providing additional information on the wavelength-dependent
reflective qualities of the aerosols in the atmosphere.
Aims. Our aim is to provide a precise measurement of the geometric albedo of
the gas giant HD 189733b by measuring the occultation depth in the broad
optical bandpass of CHEOPS (350 - 1100 nm).
Methods. We analysed 13 observations of the occultation of HD 189733b
performed by CHEOPS utilising the Python package PyCHEOPS. The resulting
occultation depth is then used to infer the geometric albedo accounting for the
contribution of thermal emission from the planet. We also aid the analysis by
refining the transit parameters combining observations made by the TESS and
CHEOPS space telescopes.
Results. We report the detection of an ppm occultation in the
CHEOPS observations. This occultation depth corresponds to a geometric albedo
of . Our measurement is consistent with models assuming the
atmosphere of the planet to be cloud-free at the scattering level and
absorption in the CHEOPS band to be dominated by the resonant Na doublet.
Taking into account previous optical-light occultation observations obtained
with the Hubble Space Telescope, both measurements combined are consistent with
a super-stellar Na elemental abundance in the dayside atmosphere of HD 189733b.
We further constrain the planetary Bond albedo to between 0.013 and 0.42 at
3 confidence.Comment: 17 pages, 10 figures, accepted for publication in A&
Analysis of Early Science observations with the CHaracterising ExOPlanets Satellite (CHEOPS) using pycheops
Funding: ACC and TW acknowledge support from UK Science and Technologies Facilities Council (STFC) ST/R00824/1.CHEOPS (CHaracterising ExOPlanet Satellite) is an ESA S-class mission that observes bright stars at high cadence from low-Earth orbit. The main aim of the mission is to characterize exoplanets that transit nearby stars using ultrahigh precision photometry. Here we report the analysis of transits observed by CHEOPS during its Early Science observing programme for four well-known exoplanets: GJ 436 b, HD 106315 b, HD 97658 b and GJ 1132 b. The analysis is done using pycheops, an open-source software package we have developed to easily and efficiently analyse CHEOPS light curve data using state-of-the-art techniques that are fully described herein. We show that the precision of the transit parameters measured using CHEOPS is comparable to that from larger space telescopes such as Spitzer Space Telescope and Kepler. We use the updated planet parameters from our analysis to derive new constraints on the internal structure of these four exoplanets.PostprintPeer reviewe
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