Source population synthesis and the Galactic diffuse gamma-ray emission

Population synthesis is used to study the contribution from undetected sources to the Galactic ridge emission measured by EGRET. Synthesized source counts are compared with the 3rd EGRET catalogue at low and high latitudes. For pulsar-like populations, 5-10% of the emission >100 MeV comes from sources below the EGRET threshold. A steeper luminosity function can increase this to 20% without violating EGRET source statistics. Less luminous populations can produce much higher values without being detected. Since the unresolved source spectrum is different from the interstellar spectrum, it could provide an explanation of the observed MeV and GeV excesses above the predictions, and we give an explicit example of how this could work.Comment: Astrophysics and Space Science, in press. (Proceedings of Conference 'The multi-messenger approach to high-energy gamma-ray sources', Barcelona, 2006). Minor changes for accepted version, updated reference

3D printed fluidics with embedded analytic functionality for automated reaction optimisation

Additive manufacturing or ‘3D printing’ is being developed as a novel manufacturing process for the production of bespoke micro- and milliscale fluidic devices. When coupled with online monitoring and optimisation software, this offers an advanced, customised method for performing automated chemical synthesis. This paper reports the use of two additive manufacturing processes, stereolithography and selective laser melting, to create multifunctional fluidic devices with embedded reaction monitoring capability. The selectively laser melted parts are the first published examples of multifunctional 3D printed metal fluidic devices. These devices allow high temperature and pressure chemistry to be performed in solvent systems destructive to the majority of devices manufactured via stereolithography, polymer jetting and fused deposition modelling processes previously utilised for this application. These devices were integrated with commercially available flow chemistry, chromatographic and spectroscopic analysis equipment, allowing automated online and inline optimisation of the reaction medium. This set-up allowed the optimisation of two reactions, a ketone functional group interconversion and a fused polycyclic heterocycle formation, via spectroscopic and chromatographic analysis

Domestic Violence and Health Care: Opening Pandora¿s Box ¿ Challenges and Dilemmas

In this article we take a critical stance toward the rational progressive narrative surrounding the integration of domestic violence within health care. Whilst changes in recent UK policy and practice have resulted in several tangible benefits, it is argued that there may be hidden dilemmas and challenges. We suggest that the medical model of care and its discursive practices position women as individually accountable for domestic violence-related symptoms and injuries. This may not only be ineffective in terms of service provision but could also have the potential to reduce the political significance of domestic violence as an issue of concern for all women. Furthermore, it is argued that the use of specific metaphors enables practitioners to distance themselves from interactions that may prove to be less comfortable and provide less than certain outcomes. Our analysis explores the possibilities for change that might currently be available. This would appear to involve a consideration of alternative discourses and the reformulation of power relations and subject positions in health care

A Levallois Knapping Site at West Thurrock, Lower Thames, UK: its Quaternary Context, Environment and Age

Levallois knapping debris is present beneath the sides of a disused tramway cutting connected to Lion Pit, West Thurrock, Essex. This occurrence, first recorded during the early 20th century, is in the basal gravel of the Taplow/Mucking Formation, which dates from the end of Marine Oxygen Isotope Stage (MIS) 8. The relatively undisturbed nature of this knapping debris is confirmed by the incidence of refitting material, although finer debitage is absent, presumably winnowed out. The Levallois character of the assemblage is demonstrated by the occurrence of characteristic ‘tortoise’ cores and flakes with faceted striking platforms. The artefact-bearing gravel is overlain by &gt;10 m of predominantly fine-grained sediments, including fossiliferous sands and massive clayey silt, as well as laminated silts, clays, and sands of possible estuarine origin. These are attributed to deposition under temperate conditions during MIS 7. To the south, a younger fluvial gravel, attributed to MIS 6, has been incised into the interglacial sequence. The top of the estuarine sequence has been affected by pedogenesis, both before and after its burial by an unbedded solifluction gravel.</jats:p

Population statistics study of radio and gamma-ray pulsars in the Galactic plane

We present results of our pulsar population synthesis of ordinary isolated and millisecond pulsars in the Galactic plane. Over the past several years, a program has been developed to simulate pulsar birth, evolution and emission using Monte Carlo techniques. We have added to the program the capability to simulate millisecond pulsars, which are old, recycled pulsars with extremely short periods. We model the spatial distribution of the simulated pulsars by assuming that they start with a random kick velocity and then evolve through the Galactic potential. We use a polar cap/slot gap model for $\gamma$-ray emission from both millisecond and ordinary pulsars. From our studies of radio pulsars that have clearly identifiable core and cone components, in which we fit the polarization sweep as well as the pulse profiles in order to constrain the viewing geometry, we develop a model describing the ratio of radio core-to-cone peak fluxes. In this model, short period pulsars are more cone-dominated than in our previous studies. We present the preliminary results of our recent study and the implications for observing these pulsars with GLAST and AGILE.Comment: 6 pages, 3 figures, 1 table, accepted in Astrophysics and Space Scienc

Spin Down of Rotating Compact Magnetized Strange Stars in General Relativity

We find that in general relativity slow down of the pulsar rotation due to the magnetodipolar radiation is more faster for the strange star with comparison to that for the neutron star of the same mass. Comparison with astrophysical observations on pulsars spindown data may provide an evidence for the strange star existence and, thus, serve as a test for distinguishing it from the neutron star.Comment: 6 pages; Accepted for publication in Astrophysics and Space Scienc

Returning to Text: Affect, meaning making and literacies

Existing work on literacy and affect has posed important questions for how we think about meanings and how and where they get made. The authors contribute to such work by focusing on the relation between text and affect. This is a topic that has received insufficient attention in recent work but is of pressing concern for education as text interweaves in new ways with human activity, through social media, surveillance capitalism, and artificial intelligence—ways that can be unpredictable and poorly understood. Adopting a sociomaterial sensibility that foregrounds the relations between bodies (people and things), the authors provide conceptual tools for considering how texts affect and are affected by the heterogeneous entanglements from which they emerge. In situating their argument, the authors outline influential readings of Spinoza’s theories of affect, explore how these have been mobilized in literacy research, and identify how text has been accommodated within such research. Using texts from a political episode in the United Kingdom, the authors explore the idea of social-material-textual affects to articulate relationships among humans, nonhumans, meaning making, and literacies. The authors conclude by identifying four ways in which text participates in what happens, raising questions about how different materializations of text (or indeed “not text”) are significant to the diversifying communicative practices that inflect social, cultural, economic, and political life