Red Supergiants, Luminous Blue Variables and Wolf-Rayet stars: the single massive star perspective

We discuss, in the context of the single star scenario, the nature of the progenitors of Red Supergiants (RSG), of Luminous Blue Variables (LBV) and of Wolf-Rayet (WR) stars. These three different populations correspond to evolved phases of Main Sequence (MS) OB stars. Axial rotation and mass loss have a great influence on massive star evolution in general and more specifically on the durations of these different phases. Moderate rotation and mass loss, during the MS phase, favor the evolution towards the RSG stage. Fast rotation and strong mass loss during the MS phase, in contrast, prevent the star from becoming a RSG and allow the star to pass directly from the OB star phase into the WR phase. Mass loss during the RSG stage may make the star evolve back in the blue part of the HR diagram. We argue that such an evolution may be more common than presently accounted for in stellar models. This might be the reason for the lack of type IIP SNe with RSG progenitors having initial masses between 18 and 30 M$_\odot$. The LBVs do appear as a possible transition phase between O and WR stars or between WNL and WNE stars. Fast rotation and/or strong mass loss during the Main-Sequence phase prevent the formation of LBV stars. The mechanisms driving the very strong ejections shown by LBV stars are still unknown. (abridged)Comment: 12 pages, 6 figure

A Possible Detection of M31* with Chandra

Two independent sets of Chandra and HST images of the nuclear region of M31 allow registration of X-ray and optical images to 0.1''. This registration shows that none of the bright (10^{37} erg/s) X-ray sources near the nucleus is coincident with the central super-massive black hole, M31*. A 50ks Chandra HRC image shows 2.5 sigma evidence for a faint (3 x 10^{35} erg/s), apparently resolved source which is consistent with the position of the M31*. The Bondi radius of M31* is 0.9'', making it one of the few super-massive black holes with a resolvable accretion flow. This large radius and the previous detections of diffuse, X-ray emitting gas in the nuclear region make M31* one of the most secure cases for a radiatively inefficient accretion flow and place some of the most severe constraints on the radiative processes in such a flow.Comment: 14 pages, 5 figures, submitted to Ap

The Association of Coloproctology of Great Britain and Ireland consensus guidelines in emergency colorectal surgery

ACKNOWLEDGEMENTS Review and editing: S.R. Brown, Professor of Surgery, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK. Email [email protected]. Patient summary: R.G. Arnott, Retired Professor, Patient Liaison Group, Association of Coloproctology of Great Britain and Ireland, Royal College of Surgeons of England, London, UK. Email [email protected]. Delphi review: C.P. Macklin. BMedSci BM BS FRCS DM, Consultant Colorectal Surgeon, Mid Yorkshire Hospitals, UK. Email [email protected] reviewedPublisher PD

Cost overruns and financial risk in the construction of nuclear power reactors: a critical appraisal

Lovering and colleagues attempt to advance understanding of construction cost escalation risks inherent in building nuclear reactors and power plants, a laudable goal. Although we appreciate their focus on capital cost increases and overruns, we maintain in this critical appraisal that their study conceptualizes cost issues in a limiting way. Methodological choices in treating different cost categories by the authors mean that their conclusions are more narrowly applicable than they describe. We also argue that their study is factually incorrect in its criticism of the previous peer-reviewed literature. Earlier work, for instance, has compared historical construction costs for nuclear reactors with other energy sources, in many countries, and extending over several decades. Lastly, in failing to be transparent about the limitations of their own work, Lovering et al. have recourse to a selective choice of data, unbalanced analysis, and biased interpretation

Taking into account sensory knowledge: the case of geo-techologies for children with visual impairments

This paper argues for designing geo-technologies supporting non-visual sensory knowledge. Sensory knowledge refers to the implicit and explicit knowledge guiding our uses of our senses to understand the world. To support our argument, we build on an 18 months field-study on geography classes for primary school children with visual impairments. Our findings show (1) a paradox in the use of non-visual sensory knowledge: described as fundamental to the geography curriculum, it is mostly kept out of school; (2) that accessible geo-technologies in the literature mainly focus on substituting vision with another modality, rather than enabling teachers to build on children's experiences; (3) the importance of the hearing sense in learning about space. We then introduce a probe, a wrist-worn device enabling children to record audio cues during field-trips. By giving importance to children's hearing skills, it modified existing practices and actors' opinions on non-visual sensory knowledge. We conclude by reflecting on design implications, and the role of technologies in valuing diverse ways of understanding the world

ELUM Year 2 report for Work Package 3 - Network of field sites to measure soil C dynamics and GHG emissions. Report V2

This report describes the second year of Work Package 3 (WP3) activities within the ETI’s Ecosystem Land Use Modelling Project (“ELUM”). It expands upon information reported in the first year and provides a forward look to WP3 activities for the remainder of the project. The soil C (carbon) and GHG (Greenhouse Gas) measurements recorded as part of WP3 are required to help reduce the uncertainty associated with the sustainability of bioenergy crop deployment across the UK. This data will be used to parameterise and test the underlying process models in the WP4 modelling work, as part of the development of the over-arching meta-model. A full review of all the data collected across the WP3 network sites will be reported in the D3.5 deliverable due in May 2014. Progress with the development and testing of novel methods for GHG measurement is also included in this report; these could offer means of improving monitoring resolution, thereby enhancing the collection of GHG flux data. A complete review of this work will follow in May 2014 with the D3.4 deliverable

Introduction: Streetlife - the Shifting Sociologies of the Street

The street has long been a key laboratory for studies of social life, from the roots of urban sociology in the ethnographies of the Chicago School to the diverse range of contemporary studies which consider the performative, affective and non-representational nature of street etiquette and encounter. For all this, the street remains only loosely defined in many studies, and sometimes disappears from view entirely, with social action often privileged over material and environmental context. This Special Issue is intended as a spur to take the street more seriously in contemporary sociology, and explores the importance of the street as a site, scale and field for sociological research. Recognising that the street is both contradictory and complex, in the Introduction to this Issue we draw out emerging themes in the shifting sociologies of the street by highlighting the specific contribution inter-disciplinary work can make to our understanding of streets as distinctive but contested social spaces

The TESS Grand Unified Hot Jupiter Survey. II. Twenty New Giant Planets

NASA's Transiting Exoplanet Survey Satellite (TESS) mission promises to improve our understanding of hot Jupiters by providing an all-sky, magnitude-limited sample of transiting hot Jupiters suitable for population studies. Assembling such a sample requires confirming hundreds of planet candidates with additional follow-up observations. Here, we present twenty hot Jupiters that were detected using TESS data and confirmed to be planets through photometric, spectroscopic, and imaging observations coordinated by the TESS Follow-up Observing Program (TFOP). These twenty planets have orbital periods shorter than 7 days and orbit relatively bright FGK stars ($10.9 < G < 13.0$). Most of the planets are comparable in mass to Jupiter, although there are four planets with masses less than that of Saturn. TOI-3976 b, the longest period planet in our sample ($P = 6.6$ days), may be on a moderately eccentric orbit ($e = 0.18\pm0.06$), while observations of the other targets are consistent with them being on circular orbits. We measured the projected stellar obliquity of TOI-1937A b, a hot Jupiter on a 22.4 hour orbit with the Rossiter-McLaughlin effect, finding the planet's orbit to be well-aligned with the stellar spin axis ($|\lambda| = 4.0\pm3.5^\circ$). We also investigated the possibility that TOI-1937 is a member of the NGC 2516 open cluster, but ultimately found the evidence for cluster membership to be ambiguous. These objects are part of a larger effort to build a complete sample of hot Jupiters to be used for future demographic and detailed characterization work.Comment: 67 pages, 11 tables, 13 figures, 2 figure sets. Resubmitted to ApJS after revision