SPARQL Query Recommendations by Example

In this demo paper, a SPARQL Query Recommendation Tool (called SQUIRE) based on query reformulation is presented. Based on three steps, Generalization, Specialization and Evaluation, SQUIRE implements the logic of reformulating a SPARQL query that is satisfiable w.r.t a source RDF dataset, into others that are satisfiable w.r.t a target RDF dataset. In contrast with existing approaches, SQUIRE aims at rec- ommending queries whose reformulations: i) reflect as much as possible the same intended meaning, structure, type of results and result size as the original query and ii) do not require to have a mapping between the two datasets. Based on a set of criteria to measure the similarity between the initial query and the recommended ones, SQUIRE demonstrates the feasibility of the underlying query reformulation process, ranks appropriately the recommended queries, and offers a valuable support for query recommendations over an unknown and unmapped target RDF dataset, not only assisting the user in learning the data model and content of an RDF dataset, but also supporting its use without requiring the user to have intrinsic knowledge of the data

Absence of Dispersive Properties of Space for Electromagnetic Radiation Tested to ± 14 x 10^-5; Comments on a Proposal of Softky and Squire

In session I 1 of the Berkeley meeting of December 30, 1960, S. D. Softky and R. K. Squire proposed a test for dispersive properties of space for electromagnetic radiation by detonating a nuclear explosive at a distance of 10^6 miles from the earth and noting the arrival times of different types of radiation at detectors above the atmosphere. The purpose of this note is to point out that Softky and Squire have overlooked the fact that a test for the dispersive properties they postulate already exists, covering perhaps not quite as extensive a range of the electromagnetic spectrum as they hope to cover (they claim a factor of 10^11) but nevertheless sufficient to render any such effect extremely unlikely over a range of frequencies of a factor of 5 X 10^9. I refer to a measurement performed in 1950 by means of the bent quartz crystal diffraction spectrometer [1] of the wavelength of the annihilation radiation generated in a block of copper by positrons from the nuclide 64Cu

Mobile solidarities: The City of Sanctuary movement and the Strangers into Citizens campaign

Political and social concerns regarding the negative impact of migrants and asylum seekers on local communities have become widespread within the UK over recent years. What is often overlooked in such debates, however, is the growing significance of movements such as those associated with the City of Sanctuary network and the Strangers into Citizens campaign, which both grow out of and also contribute to the construction of solidaristic relations between migrants, refugees and more established local residents. This report, which summarises the findings of a project into such movements led by Dr Vicki Squire at the Open University, suggests that migrants and refugees do not necessarily encounter hostility from ‘host’ communities, nor do they necessarily form discrete groups that need to be integrated within the wider community. Rather, migrants and refugees often engage with more established residents within localised city spaces in terms that render problematic distinctions between citizens/noncitizens; between cultural, ethnic or national groups; and between different migrant categories. The mobile solidarities associated with such movements thus challenge assumptions regarding the hostility of ‘host’ communities, as well as assumptions regarding the ‘natural’ division of community groups – assumptions on which contemporary integration and cohesion policies are founded

Removing Ostrogradski's ghost from cosmological perturbations in f(R,Rμν2,Cμνρσ2)f(R,R_{\mu\nu}^2,C_{\mu\nu\rho\sigma}^2) gravity

Recently it was argued that gravity with the squire of the Ricci tensor can be stabilized by adding constraints to the theory. This was so far demonstrated for fluctuations on the Minkowski/de Sitter background. We show that the same scheme works equally well for removing Ostrogradski's ghost from fluctuations on a cosmological background in generic $f(R,R_{\mu\nu}^2,C_{\mu\nu\rho\sigma}^2)$-type theories of gravity. We also derive the general formula for the spectrum of primordial tensor perturbations from the stabilized theory.Comment: 19 pages, 1 figur

Generation of large-scale magnetic fields by small-scale dynamo in shear flows

We propose a new mechanism for turbulent mean-field dynamo in which the magnetic fluctuations resulting from a small-scale dynamo drive the generation of large-scale magnetic fields. This is in stark contrast to the common idea that small-scale magnetic fields should be harmful to large-scale dynamo action. These dynamos occur in the presence of large-scale velocity shear and do not require net helicity, resulting from off-diagonal components of the turbulent resistivity tensor as the magnetic analogue of the "shear-current" effect. Given the inevitable existence of non-helical small-scale magnetic fields in turbulent plasmas, as well as the generic nature of velocity shear, the suggested mechanism may help to explain generation of large-scale magnetic fields across a wide range of astrophysical objects

The State Education Agency: At the Helm, Not the Oar

Never before has more been asked of State Education Agencies (SEAs), commonly known as state departments of education. In recent years, policymakers at the state and federal level have viewed the SEA as the default entity for implementing new and sweeping K -- 12 initiatives -- everything from Race to the Top grants and ESEA waivers to teacher evaluation reform and digital learning. But SEAs were designed -- and evolved over decades -- to address a relatively narrow set of tasks: distributing state and federal dollars, monitoring the use of these funds, and overseeing the implementation of federal and state education programs. They were not created -- nor have they developed the core competencies -- to drive crucial reforms. Accordingly, we argue that despite the best efforts of talented, energetic leaders, SEAs will never be able to deliver the reform results we need. But there is an alternative. We should view the SEA through the lens of Reinventing Government (1993), the path-breaking book by David Osborne and Ted Gaebler. In short, Osborne and Gaebler call for state agencies to "steer" more and "row" less. Here, we call for federal and state leaders to apply their thesis to SEAs, scaling back the tasks SEAs perform and empowering nongovernmental organizations to take up the slack. We offer the "4Cs" model (control, contract, cleave, and create) for rethinking state-level K -- 12 reform work. In practice, this means pursuing activities on two parallel tracks. On one, we should make the SEA a far leaner organization, able to execute a narrow set of activities. On the other, we should foster the growth of a new state-level reform ecosystem composed of a range of entities -- primarily independent public entities or nonprofits -- able to carry out key reforms