6,630 research outputs found
Classical and nonclassical randomness in quantum measurements
The space of positive operator-valued measures on the Borel sets of a compact
(or even locally compact) Hausdorff space with values in the algebra of linear
operators acting on a d-dimensional Hilbert space is studied from the
perspectives of classical and non-classical convexity through a transform
that associates any positive operator-valued measure with a certain
completely positive linear map of the homogeneous C*-algebra
into . This association is achieved by using an operator-valued integral
in which non-classical random variables (that is, operator-valued functions)
are integrated with respect to positive operator-valued measures and which has
the feature that the integral of a random quantum effect is itself a quantum
effect. A left inverse for yields an integral representation,
along the lines of the classical Riesz Representation Theorem for certain
linear functionals on , of certain (but not all) unital completely
positive linear maps . The extremal and
C*-extremal points of the space of POVMS are determined.Comment: to appear in Journal of Mathematical Physic
Improved to Transformation Equations for Main Sequence Stars
We report improved transformation equations between the and
photometric systems. Although the details of the transformations
depend on luminosity class, we find a typical rms scatter on the order of 0.001
magnitude if the sample is limited to main sequence stars. Furthermore, we find
an accurate transformation requires complex, multi-color dependencies for the
bluer bandpasses. Results for giant stars will be reported in a subsequent
paper.Comment: 7 pages, 8 figure
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The Evolution of the CareerAdvance® Program in Tulsa, Oklahoma
CareerAdvance®n collaboration with a multi-disciplinary team of partners, the Ray Marshall Center (RMC) is developing and implementing a sectoral workforce development strategy for low-skilled, low-income parents of children served by early childhood programs in Tulsa, Oklahoma. There is emerging evidence that children whose parents hold stable jobs with progressively rising incomes exhibit better academic and behavioral outcomes. RMC and its partners have undertaken a dual-generation approach to poverty reduction that strengthens the investment in early childhood development by equipping Head Start parents with workforce training and gainful employment opportunities. This approach employs a more holistic model than traditional workforce development programs, as it also includes employee counseling and other support services to help parents complete training and adult basic education, retain their jobs, advance in their careers, and become economically self-sufficient. The goal is to develop a sustainable sectoral strategy that can be replicated beyond Tulsa to other communities across the nation.
In the first phase of the project (2008-2009), RMC designed a sectoral job development strategy focused on industries featuring jobs that pay well and provide much-needed employee benefits (e.g., health insurance, annual and sick leave) as well as career advancement opportunities. In April 2009, Community Action Program of Tulsa County launched the pilot, CareerAdvance, at two Head Start sites in Tulsa involving 15 parents. The components of the CareerAdvance are 1) GED and college readiness instruction, as needed; 2) skills training in the healthcare sector progressing from Certified Nursing Aide to Licensed Practical Nurse to Registered Nurse; 3) weekly peer support meetings addressing a flexible set of topics (e.g., life skills, work readiness, family finances); 4) conditional cash incentives (up to $3,000 a year) for participants meeting specified benchmarks to reinforce continued participation and help offset foregone earnings; and 5) workforce intermediation between healthcare employers and training institutions provided through Workforce Tulsa. The report on the project’s first year of operation is available at the link below.
In partnership with Harvard University and the University of Oklahoma – Tulsa School of Medicine, a second pilot site was opened in July 2009 at a Tulsa Educare Center. The second pilot, EduCareers, includes all components described above as well as enhanced mental health services for participating households, curriculum enhancements for the children, parent engagement training, and a medical home.
The CareerAdvance project has now been expanded to 2015 with support from the U.S. Department of Health and Human Services’ Administration for Children and Families. RMC and partners at Northwestern and Columbia University have been engaged to provide ongoing on data collection, implementation and outcomes analysis of project participants.George Kaiser Family Foundation, W. K. Kellogg Foundation, U.S. Department of Health and Human Services' Administration for Children and FamiliesRay Marshall Center for the Study of Human Resource
Electron-electron interaction corrections to the thermal conductivity in disordered conductors
We evaluate the electron-electron interaction corrections to the electronic
thermal conductivity in a disordered conductor in the diffusive regime. We use
a diagrammatic many-body method analogous to that of Altshuler and Aronov for
the electrical conductivity. We derive results in one, two and three dimensions
for both the singlet and triplet channels, and in all cases find that the
Wiedemann-Franz law is violated.Comment: 8 pages, 2 figures Typos corrected in formulas (15) and (A.4) and
Table 1; discussion of previous work in introduction extended; reference
clarifying different definitions of parameter F adde
Multicolour-metallicity Relations from Globular Clusters in NGC 4486 (M87)
We present Gemini griz photometry for 521 globular cluster (GC) candidates in
a 5.5 x 5.5 arcmin field centered 3.8 arcmin to the south and 0.9 arcmin to the
west of the center of the giant elliptical galaxy NGC 4486. All these objects
have previously published (C-T1) photometry. We also present new (C-T1)
photometry for 338 globulars, within 1.7 arcmin in galactocentric radius, which
have (g-z) colors in the photometric system adopted by the Virgo Cluster Survey
of the Advanced Camera for Surveys of the Hubble Space Telescope. These
photometric data are used to define a self-consistent multicolor grid (avoiding
polynomial fits) and preliminary calibrated in terms of two chemical abundance
scales. The resulting multicolor color-chemical abundance relations are used to
test GC chemical abundance distributions. This is accomplished by modelling the
ten GC color histograms that can be defined in terms of the Cgriz bands. Our
results suggest that the best fit to the GC observed color histograms is
consistent with a genuinely bimodal chemical abundance distribution NGC(Z). On
the other side, each (blue and red) GC subpopulation follows a distinct
color-color relation.Comment: 12 pages, 21 figures, 8 tables. Accepted to be published in MNRA
A Catalog of Very Isolated Galaxies from the SDSS Data Release 1
We present a new catalog of isolated galaxies obtained through an automated
systematic search. These 2980 isolated galaxies were found in approximately
2099 sq deg of sky in the Sloan Digital Sky Survey Data Release 1 (SDSS DR1)
photometry. The selection algorithm, implementing a variation on the criteria
developed by Karachentseva in 1973, proved to be very efficient and fast. This
catalog will be useful for studies of the general galaxy characteristics. Here
we report on our results.Comment: 67 pages, which includes 14 figures. Accepted for publication by A
Spectropolarimetry of SN 2011dh in M51: geometric insights on a Type IIb supernova progenitor and explosion
We present seven epochs of spectropolarimetry of the Type IIb supernova (SN)
2011dh in M51, spanning 86 days of its evolution. The first epoch was obtained
9 days after the explosion, when the photosphere was still in the depleted
hydrogen layer of the stripped-envelope progenitor. Continuum polarization is
securely detected at the level of P~0.5% through day 14 and appears to diminish
by day 30, which is different from the prevailing trends suggested by studies
of other core-collapse SNe. Time-variable modulations in P and position angle
are detected across P-Cygni line features. H-alpha and HeI polarization peak
after 30 days and exhibit position angles roughly aligned with the earlier
continuum, while OI and CaII appear to be geometrically distinct. We discuss
several possibilities to explain the evolution of the continuum and line
polarization, including the potential effects of a tidally deformed progenitor
star, aspherical radioactive heating by fast-rising plumes of Ni-56 from the
core, oblique shock breakout, or scattering by circumstellar material. While
these possibilities are plausible and guided by theoretical expectations, they
are not unique solutions to the data. The construction of more detailed
hydrodynamic and radiative-transfer models that incorporate complex aspherical
geometries will be required to further elucidate the nature of the polarized
radiation from SN 2011dh and other Type IIb supernovae.Comment: Post-proof edit. Accepted to MNRAS 2015 Aug 1
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