Observing the sky at extremely high energies with the Cherenkov Telescope Array: Status of the GCT project

The Cherenkov Telescope Array is the main global project of ground-based gamma-ray astronomy for the coming decades. Performance will be significantly improved relative to present instruments, allowing a new insight into the high-energy Universe [1]. The nominal CTA southern array will include a sub-array of seventy 4 m telescopes spread over a few square kilometers to study the sky at extremely high energies, with the opening of a new window in the multi-TeV energy range. The Gamma-ray Cherenkov Telescope (GCT) is one of the proposed telescope designs for that sub-array. The GCT prototype recorded its first Cherenkov light on sky in 2015. After an assessment phase in 2016, new observations have been performed successfully in 2017. The GCT collaboration plans to install its first telescopes and cameras on the CTA site in Chile in 2018-2019 and to contribute a number of telescopes to the subsequent CTA production phase.Comment: 8 pages, 7 figures, ICRC201

An Examination of High School Intra-District Funding in Two Virginia School Divisions

Most states allocate education funds by grant or category at the district level, and most districts distribute funds at the school level. 1 Differences between allocations from the states to the districts and distribution methods from the districts to the schools can lead to unintended consequences in funding equity. This may undermine the purpose of the funding policies developed by state legislatures. Most states use a formula that provides a foundation funding amount to the district for each student. In addition, most states typically provide supplementary categorical funding to the district based on demographic characteristics of students (such as free and reduced lunch eligibility, English language learner, etc.), which, theoretically, increases the level of services needed and, therefore, the cost of educating those students.2 The distribution of these categorical funds and tracking of money occur only at the district level, so no evidence exists to show that money is reaching the schools or students who need it most. This analysis explores intra-district spending and resource distribution within two school divisions in Virginia to determine what, if any, inequities exist. The researcher adapted Berne and Stiefel\u27s (1984) inter-district framework in which three equity concepts were examined: horizontal equity, vertical equity, and equal opportunity. Once the researcher obtained the financial and descriptive information about the two divisions and the high schools within those divisions, the researcher further examined the schools with the highest and the lowest percentage of students living in poverty (indexed by participation in the federal free and reduced-price lunch program). The study found that while average class size varies to some extent among the schools, there are important differences in teacher quality, curriculum, equipment, and supplies. Even though this study was limited in its sample size, the implications, and the opportunities are far reaching. If low-SES children have the proper support and understanding, financial status does not have to be the ultimate determinant of academic achievement

COMMENT: New perspective on the U(n) Wigner-Racah calculus. III. Applications to U(2) and U(3)

For pt.II, see ibid., vol.20, no.14, p.4613-35 (1987). Using the framework introduced in parts I and II, the author derives an interesting relationship between U(3) symmetric tensors and U(2) Racah coefficients. Closed formulae for generic U(2) Wigner and Racah coefficients are given in terms of alternative parametrisations for such coefficients.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/48811/2/jav20i14p5015.pd

Coherent state triplets and their inner products

It is shown that if H is a Hilbert space for a representation of a group G, then there are triplets of spaces F_H, H, F^H, in which F^H is a space of coherent state or vector coherent state wave functions and F_H is its dual relative to a conveniently defined measure. It is shown also that there is a sequence of maps F_H -> H -> F^H which facilitates the construction of the corresponding inner products. After completion if necessary, the F_H, H, and F^H, become isomorphic Hilbert spaces. It is shown that the inner product for H is often easier to evaluate in F_H than F^H. Thus, we obtain integral expressions for the inner products of coherent state and vector coherent state representations. These expressions are equivalent to the algebraic expressions of K-matrix theory, but they are frequently more efficient to apply. The construction is illustrated by many examples.Comment: 33 pages, RevTex (Latex2.09) This paper is withdrawn because it contained errors that are being correcte

New perspective on the U(n) Wigner-Racah calculus. II. Elementary reduced Wigner coefficients for U(n)

For pt.I, see ibid., vol.20, no.9, p.2241-50 (1987). Exploiting the powerful formalism of the vector coherent state theory expounded in part I, the group theoretical content of the complementarity principle and a novel interpretation of the operator pattern of Biedenharn and Louck, the authors rederive in a simple fashion all U(n): U(n-1) reduced Wigner coefficients for the elementary U(n) tensors.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/48810/2/jav20i14p4613.pd

Assessing the artificially intelligent workplace:an ethical framework for evaluating experimental technologies in workplace settings

Experimental technologies, including AI and robots, are revolutionising many types of work. For example, the logistics warehouse sector is witnessing a wave of new technologies, such as automated picking tools, collaborative robots and exoskeletons, affecting jobs and employees. Notably, it is not always possible to predict the effects of such new technologies, since they have inherent uncertainties and unintended consequences. Hence, their introduction into workplaces can be conceived as a social experiment. This paper aims to sketch a set of ethical guidelines for introducing experimental technologies into workplaces. It builds on Van de Poel's general framework for assessing new experimental technologies and translates that framework into a more specific context of work. We discuss its five principles: non-maleficence, beneficence, responsibility, autonomy, and justice. Each of these principles is applied to workplaces in general, and specifically to the logistics warehouse setting as a case study. A particular focus in our discussion is put on the distinctive potential harms and goods of work

Immunomodulation by Mesenchymal Stem Cells : A Potential Therapeutic Strategy for Type 1 Diabetes

Mesenchymal stem cells (MSCs) are pluripotent stromal cells that have the potential to give rise to cells of diverse lineages. Interestingly, MSCs can be found in virtually all postnatal tissues. The main criteria currently used to characterize and identify these cells are the capacity for self-renewal and differentiation into tissues of mesodermal origin, combined with a lack in expression of certain hematopoietic molecules. Because of their developmental plasticity, the notion of MSC-based therapeutic intervention has become an emerging strategy for the replacement of injured tissues. MSCs have also been noted to possess the ability to impart profound immunomodulatory effects in vivo. Indeed, some of the initial observations regarding MSC protection from tissue injury once thought mediated by tissue regeneration may, in reality, result from immunomodulation. Whereas the exact mechanisms underlying the immunomodulatory functions of MSC remain largely unknown, these cells have been exploited in a variety of clinical trials aimed at reducing the burden of immune-mediated disease. This article focuses on recent advances that have broadened our understanding of the immunomodulatory properties of MSC and provides insight as to their potential for clinical use as a cell-based therapy for immune-mediated disorders and, in particular, type 1 diabetes

The coupling of valence shell and particle-hole degrees of freedom in a partial random phase approximation

It is well known that the random phase approximation breaks down in the absence of a substantial energy gap between occupied and unoccupied single-particle states. Particle-hole excitations are then inevitably accompanied by substantial rearrangements of the particles in the neighbourhood of the Fermi surface. To accommodate this situation, a partial RPA is introduced which corresponds to replacing only the particle-hole degrees of freedom by bosons but leaving the valence space degrees of freedom intact. The PRPA is therefore a mapping of the many-fermion dynamics into the dynamics of a coupled boson-valence space. In application of the PRPA, algebraic methods, of either a fermionic or Lie algebra type, can be introduced, if desired, to facilitate the treatment of the valence space degrees of freedom. Results of applications are presented in which the valence space particles are treated in the rotational and SU(3) models, and are coupled strongly to giant dipole and quadrupole resonances.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26774/1/0000326.pd

New perspective on the U(n) Wigner-Racah calculus. I. Vector coherent state theory and construction of Gel'fand bases

Using a vector coherent state theory, it is shown that the construction of Gel'fand bases for the unitary group is particularly simple. The very specific rules for construction of the states greatly facilitate the subsequent computation of matrix elements of the generators of the u(n) Lie algebra.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/48816/2/jav20i9p2241.pd