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

Nonmodal growth of the magnetorotational instability

We analyze the linear growth of the magnetorotational instability (MRI) in the short time limit using nonmodal methods. Our findings are quite different to standard results, illustrating that shearing wave energy can grow at the maximum MRI rate, $-d\Omega/d \ln r,$ for any choice of azimuthal and vertical wavelengths. In addition, by comparing the growth of shearing waves with static structures, we show that over short time-scales shearing waves will always be dynamically more important than static structures in the ideal limit. By demonstrating that fast linear growth is possible at all wavelengths, these results suggest that nonmodal linear physics could play a fundamental role in MRI turbulence.Comment: Accepted for publication in Physical Review Letter

Effects of the Santa Barbara, Calif., Oil Spill on the Apparent Abundance of Pelagic Fishery Resources

Many studies have been made of the effects of oil on marine invertebrates, plants (marine algae and phytoplankton), and vertebrates such as seabirds and marine mammals. An excellent review of these findings, which includes some references to fish and pathological effects of aromatic hydrocarbons, has been published by the Royal Society, London (Clark, 1982). That review dealt with the environmental effects of such major oil spills or releases such as those by the tankers Torry Canyon (119,000 t) on the south coast of England, Metula (50-56,000 t) in the Straits of Magellan, Argo Merchant (26,000 t) off Cape Cod, and the super tanker Amoco Cadiz (223,000 t) on the coast of northern Brittany. Those spills were studied to determine their effect on living resources. In contrast there are few references on the impact of oil spills on pelagic fishery resources

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

The magnetic shear-current effect: generation of large-scale magnetic fields by the small-scale dynamo

A novel large-scale dynamo mechanism, the magnetic shear-current effect, is discussed and explored. The effect relies on the interaction of magnetic fluctuations with a mean shear flow, meaning the saturated state of the small-scale dynamo can drive a large-scale dynamo -- in some sense the inverse of dynamo quenching. The dynamo is nonhelical, with the mean-field $\alpha$ coefficient zero, and is caused by the interaction between an off-diagonal component of the turbulent resistivity and the stretching of the large-scale field by shear flow. Following up on previous numerical and analytic work, this paper presents further details of the numerical evidence for the effect, as well as an heuristic description of how magnetic fluctuations can interact with shear flow to produce the required electromotive force. The pressure response of the fluid is fundamental to this mechanism, which helps explain why the magnetic effect is stronger than its kinematic cousin, and the basic idea is related to the well-known lack of turbulent resistivity quenching by magnetic fluctuations. As well as being interesting for its applications to general high Reynolds number astrophysical turbulence, where strong small-scale magnetic fluctuations are expected to be prevalent, the magnetic shear-current effect is a likely candidate for large-scale dynamo in the unstratified regions of ionized accretion disks. Evidence for this is discussed, as well as future research directions and the challenges involved with understanding details of the effect in astrophysically relevant regimes

Intraportfolio Litigation Essay

The modern trend is for investors to diversify. Shareholders who own one S&P 500 firm tend to own many of the others as well. This trend casts doubt on the traditional compensation and deterrence rationales for legal rules that hold corporations liable for the acts of their agents. Today, when A Corp sues B Corp (for breach of contract, theft of trade secrets, or any other legal wrong), many of the same shareholders own both the plaintiff and the defendant. For these shareholders, damages just shift money from one pocket to another, minus of course lawyer fees. We offer here a new rationale for corporate liability in such cases of “intraportfolio litigation.” Although corporae managers are typically rewarded for maximizing firm profits, what shareholders really care about is overall portfolio value. Firm-on-firm lawsuits can reduce principal-agent conflict by assigning intraportfolio costs to the managers responsible for them. Firm-specific financial data thus become a better tool for diversified shareholders to use in motivating and evaluating managers. Not all intraportfolio litigation can be justified on informational grounds, however. For example, securities fraud class actions against corporations lack informational value because the damages awards overstate the intraportfolio harm. Our theory thus provides lawmakers with a framework for distinguishing between value-creating and value-destroying lawsuits among diversified shareholders