50 research outputs found
Design of pixel-level ADCs for energy-sensitive hybrid pixel detectors
Single-photon counting hybrid pixel detectors have shown\ud
to be a valid alternative to other types of X-ray imaging\ud
devices due to their high sensitivity, low noise, linear behavior\ud
and wide dynamic range. One important advantage of these\ud
devices is the fact that detector and readout electronics are\ud
manufactured separately. This allows the use of industrial\ud
state-of-the-art CMOS processes to make the readout\ud
electronics, combined with a free choice of detector material\ud
(high resistivity Silicon, GaAs or other). By measuring not\ud
only the number of X-ray photons but also their energies (or\ud
wavelengths), the information content of the image increases,\ud
given the same X-ray dose. We have studied several\ud
possibilities of adding energy sensitivity to the single photon\ud
counting capability of hybrid pixel detectors, by means of\ud
pixel-level analog-to-digital converters. We show the results of\ud
simulating different kinds of analog-to-digital converters in\ud
terms of power, area and speed
Non-scriptural Elements in the towneley cycle
This study discusses non-biblical material in seven of Towneley's plays. Five of these plays, Mactacio Abel (II), Processus Noe cum Filiis (III), the two shepherds' plays (XII, XIII) and the Processus Talentorum (XXIV), are (influenced) by the Wakefield Master, whereas the Processus Prophetarum (VII), and the Suspencio lude (XXXII) are not. It is argued that although each of these plays conforms to a theme current throughout the cycle - to convert and ask for mercy - the -plays attributed to the Wakefield Master also pursue a different thematic concern of their own. The non-scriptural elements can be described in terms of allusions to, and traces of, folklore customs, folktales and legendary material, social criticism and comment, inclusion of fictional characters introduced by the playwright(s) and a vivid portrayal of characters with human dimensions,, By focussing on the significance of these features, their reason for introduction, their sources, and on whether a partially illiterate audience could have been familiar with them, it is suggested that although most of the material is traditional, the Wakefield Master used it in a unique way. Introducing new elements, or modifying material already present in the cycle, he reveals a predilection for depicting interpersonal conflict. This frictional relationship between man - man, based on a difference in commitments and found only where the Wakefield stanza is present, is reflected in man's relation to God. The study suggests further that the author of the Processus Prophetarum may have used a breviary as his source, and that the Judas legend on which the Suspencio lude is based resembles a particular offshoot of the OEdipus legend. Of the twenty-one plates illustrating points of view, one involving a close folklore analogy to Mak's tossing in the Secunda Pastorum has hitherto received no attention, whereas some others dealing, with the Noah legend have not been discussed before in English
Photocathodes for a post-processed imaging array
Preliminary results of a photon detector combining a Micromegas like multiplier coated with a UV-sensitive CsI photocathode are described. The multiplier is made in the CMOS compatible InGrid technology, which allows to post-process it directly on the surface of an imaging IC. This method is aimed at building light-sensitive imaging detectors where all elements are monolithically integrated. We show that the CsI photocathode deposited in the InGrid mesh does not alter the device performance. Maximum gains of ~6000 were reached in a singlegrid element operated in Ar/CH4, with a 2% Ion Back Flow fraction returning to the photocathode
A UV Sensitive Integrated Micromegas with Timepix Readout
This article presents a detector system consisting of three components, a
CMOS imaging array, a gaseous-detector structure with a Micromegas layout and a
UV-photon sensitive CsI reflective photocathode. All three elements have been
monolithically integrated using simple post-processing steps. The Micromegas
structure and the CMOS imaging chip are not impacted by the CsI deposition. The
detector operated reliably in He/isobutane mixtures and attained charge gains
with single photons up to a level of 6 \cdot 10^4. The Timepix CMOS array
permitted high resolution imaging of single UV-photons. The system has an MTF50
of 0.4 lp/pixel which corresponds to app. 7 lp/mm.Comment: 4 pages with 8 figures. Submitted to Nucl. Instr. and Meth. A
(Elsevier) for proceedings of VCI 2010
An integrated Micromegas UV-photon detector
Preliminary results of a photon detector combining a Micromegas like
multiplier coated with a UV-sensitive CsI photocathode are described. The
multiplier is made in a CMOS compatible InGrid technology, which allows to
post-process it directly on the surface of an imaging IC. This method is aimed
at building light-sensitive imaging detectors where all elements are
monolithically integrated. We show that the CsI photocathode deposited in the
InGrid mesh does not alter the device performance. Maximum gains of ~6000 were
reached in a single-grid element operated in Ar/CH4, with a 2% Ion Back Flow
fraction returning to the photocathode.Comment: 5 pages with 6 figures. This paper is submitted to Nuclear
Instruments and Methods A (Elsevier) for the proceedings of IWORID 2009
Antimicrobial use in food-producing animals:a rapid evidence assessment of stakeholder practices and beliefs
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Food-producing animals throughout the world are likely to be exposed to antimicrobial (AM) treatment. The crossover in AM use between human and veterinary medicine raises concerns that antimicrobial resistance (AMR) may spread from food-producing animals to humans, driving the need for further understanding of how AMs are used in livestock practice as well as stakeholder beliefs relating to their use. A rapid evidence assessment (REA) was used to collate research on AM use published in peer-reviewed journals between 2000 and 2016. Forty-eight papers were identified and reviewed. The summary of findings highlights a number of issues regarding current knowledge of the use of AMs in food-producing animals and explores the attitudes of interested parties regarding the reduction of AM use in livestock. Variation between and within countries, production types and individual farms demonstrates the complexity of the challenge involved in monitoring and regulating AM use in animal agriculture. Many factors that could influence the prevalence of AMR in livestock are of concern across all sections of the livestock industry. This REA highlights the potential role of farmers and veterinarians and of other advisors, public pressure and legislation to influence change in the use of AMs in livestock.This work was supported by Department for Environment Food & Rural Affairs (Defra)
[OD0558
Clinical characteristics of women captured by extending the definition of severe postpartum haemorrhage with 'refractoriness to treatment': a cohort study
Background: The absence of a uniform and clinically relevant definition of severe postpartum haemorrhage
hampers comparative studies and optimization of clinical management. The concept of persistent postpartum
haemorrhage, based on refractoriness to initial first-line treatment, was proposed as an alternative to common
definitions that are either based on estimations of blood loss or transfused units of packed red blood cells
(RBC). We compared characteristics and outcomes of women with severe postpartum haemorrhage captured
by these three types of definitions.
Methods: In this large retrospective cohort study in 61 hospitals in the Netherlands we included 1391 consecutive
women with postpartum haemorrhage who received either ≥4 units of RBC or a multicomponent transfusion. Clinical
characteristics and outcomes of women with severe postpartum haemorrhage defined as persistent postpartum
haemorrhage were compared to definitions based on estimated blood loss or transfused units of RBC within 24 h
following birth. Adverse maternal outcome was a composite of maternal mortality, hysterectomy, arterial embolisation
and intensive care unit admission.
Results: One thousand two hundred sixty out of 1391 women (90.6%) with postpartum haemorrhage fulfilled the
definition of persistent postpartum haemorrhage. The majority, 820/1260 (65.1%), fulfilled this definition within 1 h
following birth, compared to 819/1391 (58.7%) applying the definition of ≥1 L blood loss and 37/845 (4.4%) applying
the definition of ≥4 units of RBC. The definition persistent postpartum haemorrhage captured 430/471 adverse maternal
outcomes (91.3%), compared to 471/471 (100%) for ≥1 L blood loss and 383/471 (81.3%) for ≥4 units of RBC. Persistent
postpartum haemorrhage did not capture all adverse outcomes because of missing data on timing of initial, first-line
treatment.
Conclusion: The definition persistent postpartum haemo