Anthropic Estimates of the Charge and Mass of the Proton

By combining a renormalization group argument relating the charge e and mass m of the proton by e^2 ln m ~ 0.1 pi (in Planck units) with the Carter-Carr-Rees anthropic argument that gives an independent approximate relation m ~ e^20 between these two constants, both can be crudely estimated. These equations have the factor of 0.1 pi and the exponent of 20 which depend upon known discrete parameters (e.g., the number of generations of quarks and leptons, and the number of spatial dimensions), but they contain NO continuous observed parameters. Their solution gives the charge of the proton correct to within about 8%, though the mass estimate is off by a factor of about 1000 (16% error on a logarithmic scale). When one adds a fudge factor of 10 previously given by Carr and Rees, the agreement for the charge is within about 2%, and the mass is off by a factor of about 3 (2.4% error on a logarithmic scale). If this 10 were replaced by 15, the charge agrees within 1.1% and the mass itself agrees within 0.7%.Comment: 12 pages, LaTe

Fractional charge excitations in fermionic ladders

The system of interacting spinless fermions hopping on a two-leg ladder in the presence of an external magnetic field is shown to possess a long range order: the bond density wave or the staggered flux phase. In both cases the elementary excitations are $Z_2$ kinks and carry one half the charge of an electron.Comment: 4 pages, 3 figure

Scaffolding: integrating social and cognitive perspectives on children’s learning at home

Since the translation and cultural assimilation of Vygotsky’s (1978) ideas into the English-speaking academic community from the 1970s, through thinkers such as Wertsch (1984), Vygotsky’s ideas continue to have a powerful influence in psychology and education, as well as being enthusiastically appropriated in other fields such as technology-mediated education (Luckin, 2003). As academics working across these disciplines, we felt the time was right to reflect on the use of socio-cultural theory, and the concept of scaffolding in particular, in understanding parent-child tutoring interactions at home, with reference to children’s academic achievement at school. Thanks to funding from the British Psychological Society, we ran a series of three seminars, and this Special Issue arises from questions raised there

‘Outside the original remit’: co-production in UK mental health research, lessons from the field

The aim of this discursive paper was to explore the development of co-productio nand service user involvement in UK university-based mental health research and to offer practicalrecommendations for practitioners co-producing research with service users and survivors,informed by an overview of the key literature on co-production in mental health and from acritical reflection on applied research throu gh the medium of a case study. The paper is co-writtenby a mental health nurse academic and a service user/survivor researcher academic. The authorsargue that the implications of co-production for mental health research remain underexplored, butthat both the practitioner and service user/survivor resea rcher experience and perspective of co-production in research can provide practical reflections to inform developing research practice.The theories and values of emancipatory research can provide a framework from which bothpractitioners and service users can work together on a research project, in a way that requiresreflection on process and power dynamics. The authors conclude that whilst co-producedinvestigations can offer unique opportunities for advancing emancipatory and applied research inmental health, practitioner researchers need to be more radical in their consid eration of power inthe research process. [Abstract copyright: © 2018 Australian College of Mental Health Nurses Inc.

Pre-sentence reports and individualised justice: consistency, temporality and contingency

This paper reports on selected findings from a study on pre-sentence reports (PSRs) in the Republic of Ireland, entitled Individualising Justice: Pre-Sentence Reports in the Republic of Ireland (Maguire and Carr, 2017). The research was commissioned by the Probation Service and was a small-scale, in-depth study exploring the role of PSRs in sentencing, with a particular emphasis on understanding the process of communication involved from the perspectives of Probation Officers who create the reports and judges who request and receive them. This paper draws on the findings from the research to explore specific aspects of the use of PSRs. It begins by highlighting certain features of the Irish context and then provides a brief overview of the methodological approach before presenting a summary of selected findings, including those relating to the purpose of reports and variation in their use. We explore some of the key themes arising from the research, including consistency, temporality and contingency. We conclude by noting the potential positives of pausing a process, but highlight the need for greater consistency to ensure equitable access across the country

DEFYING CONVENTION: ATYPICAL PERSPECTIVES OF SLAVERY IN ANTEBELLUM NEW ORLEANS

During the first half of the nineteenth century, slavery became a vital economic component upon which the success of the southern states in America rested. Cotton was king, and slavery was the peculiar institution that ensured its dominance in the domestic and international markets of America. Popular portrayals, however, often neglect the complicated dynamics of American slavery and instead depict the institution in simplistic terms. The traditional view has emphasized an image of white southerners as slaveholders and blacks as slaves. In New Orleans, the lives of three men—all of whom were tied to slavery in varying capacities—reveal a much more nuanced picture of American slavery. John McDonogh, a white slaveowner and member of the American Colonization Society (ACS), proposed an emancipation plan to his slaves by which they could gradually purchase their freedom on the condition that, once freed, they were repatriated to Liberia. Andrew Durnford, a homme de couleur libre (free man of color) and slaveowner, was a business associate and friend of McDonogh who showed little to no interest in emancipating his slaves. Washington Watts McDonogh, a college-educated former slave of John McDonogh, was a minister in Liberia who supported the ACS repatriation plan at a time when many free blacks in America did not support the African colonization movement, preferring to remain in the United States. The experiences of three men reveal how slavery in nineteenth-century New Orleans was a much more nuanced institution that did not resemble the traditional narrative that the public has come to know

Growth of primordial black holes in a universe containing a massless scalar field

The evolution of primordial black holes in a flat Friedmann universe with a massless scalar field is investigated in fully general relativistic numerical relativity. A primordial black hole is expected to form with a scale comparable to the cosmological apparent horizon, in which case it may go through an initial phase with significant accretion. However, if it is very close to the cosmological apparent horizon size, the accretion is suppressed due to general relativistic effects. In any case, it soon gets smaller than the cosmological horizon and thereafter it can be approximated as an isolated vacuum solution with decaying mass accretion. In this situation the dynamical and inhomogeneous scalar field is typically equivalent to a perfect fluid with a stiff equation of state $p=\rho$. The black hole mass never increases by more than a factor of two, despite recent claims that primordial black holes might grow substantially through accreting quintessence. It is found that the gravitational memory scenario, proposed for primordial black holes in Brans-Dicke and scalar-tensor theories of gravity, is highly unphysical.Comment: 24 pages, accepted for publication in Physical Review

Generating ring currents, solitons, and svortices by stirring a Bose-Einstein condensate in a toroidal trap

We propose a simple stirring experiment to generate quantized ring currents and solitary excitations in Bose-Einstein condensates in a toroidal trap geometry. Simulations of the 3D Gross-Pitaevskii equation show that pure ring current states can be generated efficiently by adiabatic manipulation of the condensate, which can be realized on experimental time scales. This is illustrated by simulated generation of a ring current with winding number two. While solitons can be generated in quasi-1D tori, we show the even more robust generation of hybrid, solitonic vortices (svortices) in a regime of wider confinement. Svortices are vortices confined to essentially one-dimensional dynamics, which obey a similar phase-offset--velocity relationship as solitons. Marking the transition between solitons and vortices, svortices are a distinct class of symmetry-breaking stationary and uniformly rotating excited solutions of the 2D and 3D Gross-Pitaevskii equation in a toroidal trapping potential. Svortices should be observable in dilute-gas experiments.Comment: 8 pages, 4 figures; accepted for publication in J. Phys. B (Letters

Authentic learning for pre-service teacherrs in a technology-rich environment

This paper shares the findings from a three year Participatory Action Research Study around the selection, implementation and effectiveness of educational technologies for enhancing learning in a Teacher Education subject for second year pre-service primary teachers. The innovative Project- Based subject is described using a critical lens. The paper will share how two lecturers and their students explored their changing roles as teachers and learners and the tensions that emerged between their beliefs about student centered, authentic learning and the role of technology. It will explore the ways the technological innovations began to reshape and inform thinking about teaching and learning practices