4,774 research outputs found
Superintendent and School Board Relations: Impacting Achievement through Collaborative Understanding of Roles and Responsibilities
One of the most important and influential persons in the governance structure of the local school district is the Superintendent of Schools. Functioning as the CEO of the district, the superintendent is responsible for a myriad of functions. Examples include daily operations inclusive of transportation and finance, curriculum and policy implementation, media relations, and empowering leaders. However, as Meador (2014) contends, a crucial role is that of board liaison. The Superintendent is responsible for keeping the board informed, making recommendations regarding district operations, and setting the board agenda. It is interesting to note that the superintendent does participate in board meetings, but in an advisory capacity. Finally, the superintendent is responsible for enacting all mandates approved by the school board
Hard limits on the postselectability of optical graph states
Coherent control of large entangled graph states enables a wide variety of
quantum information processing tasks, including error-corrected quantum
computation. The linear optical approach offers excellent control and
coherence, but today most photon sources and entangling gates---required for
the construction of large graph states---are probabilistic and rely on
postselection. In this work, we provide proofs and heuristics to aid
experimental design using postselection. We derive a fundamental limitation on
the generation of photonic qubit states using postselected entangling gates:
experiments which contain a cycle of postselected gates cannot be postselected.
Further, we analyse experiments that use photons from postselected photon pair
sources, and lower bound the number of classes of graph state entanglement that
are accessible in the non-degenerate case---graph state entanglement classes
that contain a tree are are always accessible. Numerical investigation up to
9-qubits shows that the proportion of graph states that are accessible using
postselection diminishes rapidly. We provide tables showing which classes are
accessible for a variety of up to nine qubit resource states and sources. We
also use our methods to evaluate near-term multi-photon experiments, and
provide our algorithms for doing so.Comment: Our manuscript comprises 4843 words, 6 figures, 1 table, 47
references, and a supplementary material of 1741 words, 2 figures, 1 table,
and a Mathematica code listin
High-resolution Spectroscopy of Extremely Metal-poor Stars in the Least Evolved Galaxies: Leo IV
We present high-resolution Magellan/MIKE spectroscopy of the brightest star in the ultra-faint dwarf galaxy Leo IV. We measure an iron abundance of [Fe/H] = –3.2, adding to the rapidly growing sample of extremely metal-poor (EMP) stars being identified in Milky Way satellite galaxies. The star is enhanced in the α elements Mg, Ca, and Ti by ~0.3 dex, very similar to the typical Milky Way halo abundance pattern. All of the light and iron-peak elements follow the trends established by EMP halo stars, but the neutron-capture elements Ba and Sr are significantly underabundant. These results are quite similar to those found for stars in the ultra-faint dwarfs Ursa Major II, Coma Berenices, Boötes I, and Hercules, suggesting that the chemical evolution of the lowest-luminosity galaxies may be universal. The abundance pattern we observe is consistent with predictions for nucleosynthesis from a Population III supernova explosion. The extremely low metallicity of this star also supports the idea that a significant fraction (≳10%) of the stars in the faintest dwarfs have metallicities below [Fe/H] = –3.0
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