Saint-Avit-Sénieur – Haut de Combe-Capelle et Roc de Combe-Capelle

Identifiant de l'opération archéologique : 7225030 Date de l'opération : 2009 (SD) Le site de Combe-Capelle se place en rive droite de la vallée de la Couze en amont de Beaumont-du-Périgord. Au pied d’une falaise de calcaire campanien. Il comporte un ensemble de gisements connus dès la fin du XIXe s. : Combe-Capelle bas, Roc de Combe-Capelle, Haut de Combe-Capelle, plateau de Ruffet. Le gisement de Combe-Capelle bas qui se place dans des dépôts de versant est constitué de deux secteurs. Il a ..

How to design a planetary system for different scattering outcomes: giant impact sweet spot, maximizing exocomets, scattered discs

This paper considers the dynamics of the scattering of planetesimals or planetary embryos by a planet on a circumstellar orbit. We classify six regions in the planet's mass versus semimajor axis parameter space according to the dominant outcome for scattered objects: ejected, accreted, remaining, escaping, Oort Cloud, and depleted Oort Cloud. We use these outcomes to consider which planetary system architectures maximize the observability of specific signatures, given that signatures should be detected first around systems with optimal architectures (if such systems exist in nature). Giant impact debris is most readily detectable for 0.1–10 M⊕ planets at 1–5 au, depending on the detection method and spectral type. While A stars have putative giant impact debris at 4–6 au consistent with this sweet spot, that of FGK stars is typically ≪1 au contrary to expectations; an absence of 1–3 au giant impact debris could indicate a low frequency of terrestrial planets there. Three principles maximize the cometary influx from exo-Kuiper belts: a chain of closely separated planets interior to the belt, none of which is a Jupiter-like ejector; planet masses not increasing strongly with distance (for a net inward torque on comets); and ongoing replenishment of comets, possibly by embedded low-mass planets. A high Oort Cloud comet influx requires no ejectors and architectures that maximize the Oort Cloud population. Cold debris discs are usually considered classical Kuiper belt analogues. Here we consider the possibility of detecting scattered disc analogues, which could be betrayed by a broad radial profile and lack of small grains, as well as spherical 100–1000 au mini-Oort Clouds. Some implications for escaping planets around young stars, detached planets akin to Sedna, and the formation of super-Earths are also discussed.MCW, AB, and AS acknowledge the support of the European Union through European Research Council grant number 279973. APJ acknowledges support from NASA grant NNX16AI31G. AS is partially supported by funding from the Center for Exoplanets and Habitable Worlds. The Center for Exoplanets and Habitable Worlds is supported by the Pennsylvania State University, the Eberly College of Science, and the Pennsylvania Space Grant Consortium. This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program

Using warm dust to constrain unseen planets

Cold outer debris belts orbit a significant fraction of stars, many of which are planet-hosts. Radiative forces from the star lead to dust particles leaving the outer belts and spiralling inwards under Poynting-Robertson drag. We present an empirical model fitted to N-body simulations that allows the fate of these dust particles when they encounter a planet to be rapidly calculated. High mass planets eject most particles, whilst dust passes low mass planets relatively unperturbed. Close-in, high mass planets (hot Jupiters) are best at accreting dust. The model predicts the accretion rate of dust onto planets interior to debris belts, with mass accretions rates of up to hundreds of kilograms per second predicted for hot Jupiters interior to outer debris belts, when collisional evolution is also taken into account. The model can be used to infer the presence and likely masses of as yet undetected planets in systems with outer belts. The non-detection of warm dust with the Large Binocular Telescope Interferometer (LBTI) around Vega could be explained by the presence of a single Saturn mass planet, or a chain of lower mass planets. Similarly, the detection of warm dust in such systems implies the absence of planets above a quantifiable level, which can be lower than similar limits from direct imaging. The level of dust detected with LBTI around beta Leo can be used to rule out the presence of planets more massive than a few Saturn masses outside of ~5au

The Impact of Employability Initiatives in Higher Education: Using Placement Confidence and Resilience as Measures

Employability skills are needed in addition to subject specific knowledge to support graduates in their career choices and employment. Placement is widely recognized as a key facilitator of graduate employability skills and employment with an expectation that students will have more than an academic qualification (degree) to secure employment (Yorke, 2006; Saunders and Zuzel, 2010). A large body of literature has emerged outlining the key attributes and skills a typical graduate should possess and why, (Harvey et al, 1997; Little, 2001; Lees, 2002; Holden and Jameson, 2002; Rothwell and Arnold, 2007; Wiley, 2014). Despite the acknowledged value of placement the number of students undertaking placement has decreased, year on year, across a number of disciplines which is challenging for Higher Education Institutions (HEI’s), (Saunders and Zuzel, 2010; Docherty, Jones and Sileryte, 2015). Various initiatives are used to enhance uptake of placement. This paper presents one such initiative involving the scaling-up of two co-curricular 5-credit point modules to Year 1 and 2 undergraduate students. Delivery of the pilot commenced in September 2017. The project is being evaluated against short, medium and long-term measures. To date, student confidence and resilience has increased for those engaged with the initiative across three time points

Debris Disks: Probing Planet Formation

Debris disks are the dust disks found around ~20% of nearby main sequence stars in far-IR surveys. They can be considered as descendants of protoplanetary disks or components of planetary systems, providing valuable information on circumstellar disk evolution and the outcome of planet formation. The debris disk population can be explained by the steady collisional erosion of planetesimal belts; population models constrain where (10-100au) and in what quantity (>1Mearth) planetesimals (>10km in size) typically form in protoplanetary disks. Gas is now seen long into the debris disk phase. Some of this is secondary implying planetesimals have a Solar System comet-like composition, but some systems may retain primordial gas. Ongoing planet formation processes are invoked for some debris disks, such as the continued growth of dwarf planets in an unstirred disk, or the growth of terrestrial planets through giant impacts. Planets imprint structure on debris disks in many ways; images of gaps, clumps, warps, eccentricities and other disk asymmetries, are readily explained by planets at >>5au. Hot dust in the region planets are commonly found (<5au) is seen for a growing number of stars. This dust usually originates in an outer belt (e.g., from exocomets), although an asteroid belt or recent collision is sometimes inferred.Comment: Invited review, accepted for publication in the 'Handbook of Exoplanets', eds. H.J. Deeg and J.A. Belmonte, Springer (2018

A cost-effectiveness analysis of a hydration response technology dressing in the treatment of venous leg ulcers in the UK

Introduction: Venous leg ulceration causes significant pain and suffering for patients, additionally it places considerable financial and service burden on the National Health Service (NHS). A large proportion of venous leg ulceration do not heal within the standard time frames of 16 – 24 weeks, resulting in static wounds which commonly have issues with increasing exudate production. Static wounds can have significant negative impact on the patients quality of life, the wound bed and periwound skin, increased risk of infection all of which results in delayed wound healing and increased health service costs. As the NHS continues to face times of austerity, services need to find solutions to be able to reduce cost and release nursing time whilst maintaining standards of care. Cutimed® Sorbion® Sachet S is a treatment option for the management of patients with a venous leg ulceration. The objective of this study was to provide an update of the health economic analysis of Cutimed® Sorbion® Sachet S in comparison to relevant comparators in the UK with current cost data. Methods: Cutimed® Sorbion® Sachet S was compared against Zetuvit Plus, DryMax extra, KerraMax Care and Eclypse from a cost effectiveness perspective. Clinical data were derived from literature and expert opinion. Cost input was utilized based on publicly available data and literature. The average patient in the model is assumed to be 65 years with a diagnosed venous leg ulcer. It is assumed that patients in the different treatment arms have the same background mortality, hence the endpoint mortality is not included in the model. The analysis is based on a deterministic Markov model derived from Harding et al. with weekly cycles. The following assumptions are made: First, all patients start in a static health state with a non-healed but non-progressing venous leg ulcer. It is assumed in the model that patients can transition to a deteriorating health state where a wound is improving or the wound could progress. Additionally, venous leg ulcers could be healed from a progressed wound (i.e. improved wound), they could develop into a severe wound with complications (infections) to be treated in hospitals. The time frame for the analysis was fixed for one year and no re-occurence after healing was assumed to happen. Results: The cost-effectiveness analysis demonstrates health economic dominance of Cutimed® Sorbion® Sachet S being more effective and cost-saving against all analysed comparators. When using literature-based input values the incrementally higher healing rates for Cutimed® Sorbion® Sachet S are 11.04 months (versus Zetuvit Plus), 29.04 months (versus DryMax extra), 1.68 months (versus KerraMax Care) and 11.04 months (versus Eclypse). Cost savings per patient were 37.60£ (versus Zetuvit Plus), 171.68£ (versus DryMax extra), 3.13£ (versus KerraMax Care) and 43.63£ (versus Eclypse). Clinical benefits and cost savings are increasing when real life practice assumptions based on expert opinion are included. Conclusions: Based on the underlying health economic model, Cutimed® Sorbion® Sachet S is more effective and less costly than other comparative products in venous leg ulcers in the UK

The Structure of the Prodromal Questionnaire-16 (PQ-16) in a Non-Help-Seeking Youth Population: Exploratory and Confirmatory Factor Analyses Study

Aims: The present study aimed to examine the structure of the Prodromal Questionnaire-16 (PQ-16) in a non-help-seeking youth population through exploratory and confirmatory factor analysis. Previous studies have not examined the structure of this self-report measure in this age group outside a clinical setting. Methods: Participants (n = 1165) aged 11–19 years were recruited to an epidemiological study of young people in Northern Ireland, and completed the PQ-16 alongside other measures. The dataset was split randomly in two for separate factor analyses. A polychoric correlation matrix was created and exploratory factor analysis was used to identify the optimal number of factors. In addition, based on previous studies, six models were tested through confirmatory factor analysis to determine best fit. A one-factor, 3 two-factor, a three-factor and a four-factor model were all tested. Results: The exploratory factor analysis indicated a two-factor structure of the PQ-16 in this population, which we have labelled ‘general unusual experiences’ and ‘hallucinations’. Confirmatory analysis indicated that the two-factor model identified through the exploratory analysis was the best fit for the data. Discussion: The present study suggests that the structure of the PQ-16 may vary across age groups in non-clinical settings, and adds further support to the validity of the PQ-16 is a cost-effective, easy to administer self-report measure that is suitable for use in non-help-seeking populations as a screening tool for prodromal symptoms.</p

What guidance are researchers given on how to present network meta-analyses to end-users such as policymakers and clinicians? A systematic review

© 2014 Sullivan et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Introduction: Network meta-analyses (NMAs) are complex methodological approaches that may be challenging for non-technical end-users, such as policymakers and clinicians, to understand. Consideration should be given to identifying optimal approaches to presenting NMAs that help clarify analyses. It is unclear what guidance researchers currently have on how to present and tailor NMAs to different end-users. Methods: A systematic review of NMA guidelines was conducted to identify guidance on how to present NMAs. Electronic databases and supplementary sources were searched for NMA guidelines. Presentation format details related to sample formats, target audiences, data sources, analysis methods and results were extracted and frequencies tabulated. Guideline quality was assessed following criteria developed for clinical practice guidelines. Results: Seven guidelines were included. Current guidelines focus on how to conduct NMAs but provide limited guidance to researchers on how to best present analyses to different end-users. None of the guidelines provided reporting templates. Few guidelines provided advice on tailoring presentations to different end-users, such as policymakers. Available guidance on presentation formats focused on evidence networks, characteristics of individual trials, comparisons between direct and indirect estimates and assumptions of heterogeneity and/or inconsistency. Some guidelines also provided examples of figures and tables that could be used to present information. Conclusions: Limited guidance exists for researchers on how best to present NMAs in an accessible format, especially for non-technical end-users such as policymakers and clinicians. NMA guidelines may require further integration with end-users' needs, when NMAs are used to support healthcare policy and practice decisions. Developing presentation formats that enhance understanding and accessibility of NMAs could also enhance the transparency and legitimacy of decisions informed by NMAs.The Canadian Institute of Health Research (CIHR) Drug Safety and Effectiveness Network (Funding reference number – 116573)

ALMA observations of the multiplanet system 61 Vir: What lies outside super-Earth systems?

A decade of surveys has hinted at a possible higher occurrence rate of debris discs in systems hosting low mass planets. This could be due to common favourable forming conditions for rocky planets close in and planetesimals at large radii. In this paper we present the first resolved millimetre study of the debris disc in the 4.6 Gyr old multiplanet system 61 Vir, combining ALMA and JCMT data at 0.86 mm. We fit the data using a parametric disc model, finding that the disc of planetesimals extends from 30 AU to at least 150 AU, with a surface density distribution of millimetre sized grains with a power law slope of 0.1$^{+1.1}_{-0.8}$. We also present a numerical collisional model that can predict the evolution of the surface density of millimetre grains for a given primordial disc, finding that it does not necessarily have the same radial profile as the total mass surface density (as previous studies suggested for the optical depth), with the former being flatter. Finally, we find that if the planetesimal disc was stirred at 150 AU by an additional unseen planet, that planet should be more massive than 10 M$_{\oplus}$ and lie between 10-20 AU. Lower planet masses and semi-major axes down to 4 AU are possible for eccentricities $\gg$ 0.1.This paper makes use of the following ALMA data: ADS/JAO.ALMA#2013.1.00359.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada) and NSC and ASIAA (Taiwan) and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. MCW, LM and AS acknowledge the support of the European Union through ERC grant number 279973. GMK is supported by the Royal Society as a Royal Society University Research Fellow. AS is partially supported by funding from the Center for Exoplanets and Habitable Worlds. The Center for Exoplanets and Habitable Worlds is supported by the Pennsylvania State University, the Eberly College of Science and the Pennsylvania Space Grant Consortium