Optical and X-ray emission from stable millisecond magnetars formed from the merger of binary neutron stars

The coalescence of binary neutron stars (NSs) may in some cases produce a stable massive NS remnant rather than a black hole. Due to the substantial angular momentum from the binary, such a remnant is born rapidly rotating and likely acquires a strong magnetic field (a `millisecond magnetar'). Magnetic spin-down deposits a large fraction of the rotational energy from the magnetar behind the small quantity of mass ejected during the merger. This has the potential for creating a bright transient that could be useful for determining whether a NS or black hole was formed in the merger. We investigate the expected signature of such an event, including for the first time the important impact of electron/positron pairs injected by the millisecond magnetar into the surrounding nebula. These pairs cool via synchrotron and inverse Compton emission, producing a pair cascade and hard X-ray spectrum. A fraction of these X-rays are absorbed by the ejecta walls and re-emitted as thermal radiation, leading to an optical/UV transient peaking at a luminosity of ~1e43-1e44 erg/s on a timescale of several hours to days. This is dimmer than predicted by simpler analytic models because the large optical depth of electron/positron pairs across the nebula suppresses the efficiency with which the magnetar spin down luminosity is thermalized. Nevertheless, the optical/UV emission is more than two orders of magnitude brighter than a radioactively powered `kilonova.' In some cases nebular X-rays are sufficiently luminous to re-ionize the ejecta, in which case non-thermal X-rays escape the ejecta unattenuated with a similar peak luminosity and timescale as the optical radiation. We discuss the implications of our results for the temporally extended X-ray emission that is observed to follow some short gamma-ray bursts (GRBs), including the kilonova candidates GRB 080503 and GRB 130603B.Comment: 13 pages, 8 figures, 2 appendices, submitted to MNRA

Internal Geography and External Trade: regional disparities in Italy, 1861-2011

This paper explores the interactions between external trade and regional disparities in the Italian economy since unification. It argues that the advantage of the North was initially based on natural advantage (in particular the endowment of water, intensive in silk production). From 1880 onwards the share of exports in GDP stagnated and then declined; domestic market access therefore became a key determinant of industrial location, inducing fast growing new sectors (especially engineering) to locate in regions with a large domestic market, i.e. in the North. From 1945 onwards trade growth and European integration meant that foreign market access was the decisive factor; the North had the advantage of proximity to these markets.industrialisation, market integration, new economic geography, geographic concentration, Italian regions

Enhanced ultrasound for advanced diagnostics, ultrasound tomography for volume limb imaging and prosthetic fitting

Ultrasound imaging methods hold the potential to deliver low-cost, high-resolution, operator-independent and nonionizing imaging systems-such systems couple appropriate algorithms with imaging devices and techniques. The increasing demands on general practitioners motivate us to develop more usable and productive diagnostic imaging equipment. Ultrasound, specifically freehand ultrasound, is a low cost and safe medical imaging technique. It doesn't expose a patient to ionizing radiation. Its safety and versatility make it very well suited for the increasing demands on general practitioners, or for providing improved medical care in rural regions or the developing world. However it typically suffers from sonographer variability; we will discuss techniques to address user variability. We also discuss our work to combine cylindrical scanning systems with state of the art inversion algorithms to deliver ultrasound systems for imaging and quantifying limbs in 3-D in vivo. Such systems have the potential to track the progression of limb health at a low cost and without radiation exposure, as well as, improve prosthetic socket fitting. Current methods of prosthetic socket fabrication remain subjective and ineffective at creating an interface to the human body that is both comfortable and functional. Though there has been recent success using methods like magnetic resonance imaging and biomechanical modeling, a low-cost, streamlined, and quantitative process for prosthetic cup design and fabrication has not been fully demonstrated. Medical ultrasonography may inform the design process of prosthetic sockets in a more objective manner. This keynote talk presents the results of progress in this area. Keywords: Clinical ultrasound, Force control, 3-D ultrasound, Tomograph

Towards the reduction of sex-based stereotypes

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Includes bibliographical references (leaves 14-18).With more females entering the workforce (U.S. Bureau of Labor Statistics, 1998), it has become of increasing importance to reduce the negative effects that sex-based stereotyping can engender. The current experiment investigates if mutual interdependence can result in a greater perception of a female partner's competence and a reduction of hostility towards women in general. Male participants worked either interdependently or independently with a female partner. Dyads were then separated and males completed a series of dependent measures prone to capture ratings of their female partner's competence and hostility and benevolence towards women in general. A marginally statistically significant effect was found supporting our primary hypothesis, that males in the mutual interdependence condition reported a greater competence rating for their specific female partner. There were no statistically significant effects found for our exploratory hypothesis that this previous effect would generalize to women in general. Past research on the reduction of race-based stereotypes, reduction of hostility between groups, and individuating processes, has suggested that mutual interdependence and positive task success between members of opposing groups attenuates hostility and stereotyping for a specific partner or group. These findings are replicated by this research

English and Englishness: a cultural history of English studies in British higher education, 1880-1980

It is argued in this thesis that, contrary to much previous work on the subject, the history of English Studies in higher education is not best understood in terms of the emergence of a mature form of academic activity which has since continued to develop through time on the basis of the unity of its object (lq`English literature') and of its mode of study (lq`literary criticism'). Instead, this history examines the conditions which allowed the initial emergence, specification and delimitation of the new academic discipline of `English Language and Literature', and the sequence of subsequent institutional and discursive modifications and transformations which brought about substantial alterations to the field of study. Through a series of case studies of the English Association, the Newbolt Report, the Review of English Studies, and of the diverse tendencies which have characterised the discipline since the nineteen-forties, it is argued that `English Studies' must be analysed as an entity not having any single or consistent fixed centre. It is further shown that within the variable discursive and institutional articulations which have characterised English Studies as a field of activity, account must be taken of a much wider range of objects and relations than can be encompassed within `literature' and `criticism'; in fact, the discipline is shown to have been just as concerned with, for example, approved modes of communication, and Englishness. The thesis examines the specific historical conditions under which such objects and issues were brought into mutual relation through the establishment of full academic disciplinary status, the installation of an integrated career structure and professional norms, and the development of a distinctive documentary field, set of professional associations, range of pedagogic activities, and mechanism for the selection of students

Geophysical investigations in the Faeroes to Scotland region, Northeast Atlantic

Gravity, magnetic and seismic reflection profiles from the sea area between the Faeroe Islands and Scotland were obtained on the 1967 and 1968 cruises of RRS John Murray, The submarine shelf adjacent to the Faeroe Islands is separated from the continental shelf and slope north of Scotland by the Faeroe-Shetland Channel, The purpose of the cruises was to provide geophysical evidence of the geological structure of the region. Gravity and seismic reflection profiles across the Faeroes shelf, SE of the Faeroe Islands, indicate a substantial thickness of post- Mesozoic sediments. The gentle submarine slopes bordering the Faeroe-Shetland Channel are made up of seaward dipping sediments. Gravity profiles show that the Channel is associated with a Bouguer anomaly "high". This is interpreted as caused by a thinning of the crust beneath the Channel in close agreement with the predictions of the Airy-Heiskanen hypothesis of isostasy. Geophysical surveys around the Hebrides, Orkneys and Shetlands represent a large area of previously uninvestigated British continental shelf and slope. The Bouguer anomaly map shows a large gravity "high" reaching 94 mgal which is continuous for 250 km and trends NNE-SSW across the shelf. This is interpreted as caused by a seaward extension of dense Precambrian basement rocks outcropping in NW Scotland, Large amplitude gravity "lows" have been outlined on the shelf and slope north of Scotland, A large amplitude "low" 70 km west of the Shetlands has been interpreted as caused by a deep sedimentary basin infilled by Mesozoic/Tertiary sediments and bounded on its SE margin by a large normal fault. A buried basement ridge has been located west of the gravity "low", near the shelf break in slope. Recent sediments form the continental slope which gently truncates the older Caledonian structures on the shelf