1,225 research outputs found
Late Antique, migration period and Early Byzantine garnet cloisonné ornaments: Origins, styles and workshop production
The thesis proposes a classification of gold and garnet cloisonné ornaments based on stylistic and technological features. These objects reflect Late Antique/Early Byzantine decorative and manufacturing traditions.
Flat garnet plates originate with one class of ring-stone intaglios from the Late Hellenistic and Imperial Roman periods. Garnet plates were first set on jewellery at this same time Early inlaid ornaments are characterised by a mixture of western and eastern elements shared along the eastern trade routes.
The first examples of true garnet cloisonné are preserved in Western Asia and Soviet Georgia (ancient Iberia). Although excavated with coins, accurate dating of the latter finds remains difficult. Some objects may be as early as the late third century while others parallel ornaments in southern Russia and Europe which are datable to the late fourth and fifth centuries' AD.
Cloisonné ornaments at Kerch in the Crimea incorporate standardised
geometric plate shapes. These preserve Graeco-Roman traditions of decoration and lapidary technology, and may have been produced under official Roman auspices. Ornaments on both sides of the Pontus, therefore, reflect the range of Late Antique cloisonné production.
Standardised plates, sometimes set with cabochon bars in proportional patterns, characterise sword fittings deposited in Hunnic Period contexts. Their distribution reflects burial customs, as the garnet cloisonné mounts themselves represent Late Antique/Farly Byzantine traditions. These official or urban styles stimulated a range of regional imitations.
One group of cloisonné ornaments, Christian in character and worn predominantly by women, replicates classical mosaic floor patterns. These share features with other examples of Early Byzantine jewellery produced in urban centres for both barbarian and Roman clients. In the second half of the fifth century, a contemporary style appears on male weaponry and horse harness preserved in contexts which suggest their owners held official positions in the Early Byzantine militia. The mixture of barbarian and Roman elements within this style characterises Early Byzantine cloisonné from sixth-century European and Mediterranean contexts
Effect of four-day psyllium supplementation on bowel preparation for colonoscopy:A prospective double blind randomized trial [ISRCTN76623768]
Gravity waves and the LHC: Towards high-scale inflation with low-energy SUSY
It has been argued that rather generic features of string-inspired
inflationary theories with low-energy supersymmetry (SUSY) make it difficult to
achieve inflation with a Hubble scale H > m_{3/2}, where m_{3/2} is the
gravitino mass in the SUSY-breaking vacuum state. We present a class of
string-inspired supergravity realizations of chaotic inflation where a simple,
dynamical mechanism yields hierarchically small scales of post-inflationary
supersymmetry breaking. Within these toy models we can easily achieve small
ratios between m_{3/2} and the Hubble scale of inflation. This is possible
because the expectation value of the superpotential relaxes from large to
small values during the course of inflation. However, our toy models do not
provide a reasonable fit to cosmological data if one sets the SUSY-breaking
scale to m_{3/2} < TeV. Our work is a small step towards relieving the apparent
tension between high-scale inflation and low-scale supersymmetry breaking in
string compactifications.Comment: 21+1 pages, 5 figures, LaTeX, v2: added references, v3: very minor
changes, version to appear in JHE
Is Our Universe Natural?
It goes without saying that we are stuck with the universe we have.
Nevertheless, we would like to go beyond simply describing our observed
universe, and try to understand why it is that way rather than some other way.
Physicists and cosmologists have been exploring increasingly ambitious ideas
that attempt to explain why certain features of our universe aren't as
surprising as they might first appear.Comment: Invited review for Nature, 11 page
Bowling Together: Scientific Collaboration Networks of Demographers at European Population Conferences
Studies of collaborative networks of demographers are relatively scarce. Similar studies in other social sciences provide insight into scholarly trends of both the fields and characteristics of their successful scientists. Exploiting a unique database of metadata for papers presented at six European Population Conferences, this report explores factors explaining research collaboration among demographers. We find that (1) collaboration among demographers has increased over the past 10 years, however, among co-authored papers, collaboration across institutions remains relatively unchanged over the period, (2) papers based on core demographic subfields such as fertility, mortality, migration and data and methods are more likely to involve multiple authors and (3) multiple author teams that are all female are less likely to co-author with colleagues in different institutions. Potential explanations for these results are discussed alongside comparisons with similar studies of collaboration networks in other related social sciences
The economic impacts of UK fiscal policies and their spillover effects on the energy system
The energy system and the economy are inextricably intertwined. Whilst this interdependence is, of course, widely recognized, it has not featured prominently in assessing the likely impact of economic policies. In principle, fiscal policies are likely to have an influence on key elements of the energy system, the neglect of which may lead to inefficiencies in the design of appropriate energy and economic policies. The importance of this in practice depends on the strength of the spillover effects from fiscal policy instruments to energy policy goals. This is the focus of this chapter. We employ a multi-sectoral computable general equilibrium approach for the United Kingdom that allows us to track the impact of key fiscal policy interventions on goals of economic and energy policies. We explore whether it is possible to stimulate the economy through fiscal policy without generating an adverse impact on the energy system. Overall, our results suggest that it is unlikely that an increase in current public spending or a fall in the income tax rate will generate a simultaneous increase in GDP and fall in emissions in the United Kingdom context. Nonetheless, there are undoubted differential spillover effects on key components of the energy system from tax and public spending interventions that may prove capable of being exploited through the coordination of fiscal and energy policies. Even if it seems doubtful that fiscal policies would be formulated with a view to improved coordination with energy policies, policymakers can benefit from knowledge of the likely direction and scale of fiscal spillover effects to key elements of the energy system, since this reveals, for example, the extent of any energy policy adjustment that would be required to maintain a given level of emissions
Prevalence of Disorders Recorded in Dogs Attending Primary-Care Veterinary Practices in England
Purebred dog health is thought to be compromised by an increasing occurence of inherited diseases but inadequate prevalence data on common disorders have hampered efforts to prioritise health reforms. Analysis of primary veterinary practice clinical data has been proposed for reliable estimation of disorder prevalence in dogs. Electronic patient record (EPR) data were collected on 148,741 dogs attending 93 clinics across central and south-eastern England. Analysis in detail of a random sample of EPRs relating to 3,884 dogs from 89 clinics identified the most frequently recorded disorders as otitis externa (prevalence 10.2%, 95% CI: 9.1-11.3), periodontal disease (9.3%, 95% CI: 8.3-10.3) and anal sac impaction (7.1%, 95% CI: 6.1-8.1). Using syndromic classification, the most prevalent body location affected was the head-and-neck (32.8%, 95% CI: 30.7-34.9), the most prevalent organ system affected was the integument (36.3%, 95% CI: 33.9-38.6) and the most prevalent pathophysiologic process diagnosed was inflammation (32.1%, 95% CI: 29.8-34.3). Among the twenty most-frequently recorded disorders, purebred dogs had a significantly higher prevalence compared with crossbreds for three: otitis externa (P = 0.001), obesity (P = 0.006) and skin mass lesion (P = 0.033), and popular breeds differed significantly from each other in their prevalence for five: periodontal disease (P = 0.002), overgrown nails (P = 0.004), degenerative joint disease (P = 0.005), obesity (P = 0.001) and lipoma (P = 0.003). These results fill a crucial data gap in disorder prevalence information and assist with disorder prioritisation. The results suggest that, for maximal impact, breeding reforms should target commonly-diagnosed complex disorders that are amenable to genetic improvement and should place special focus on at-risk breeds. Future studies evaluating disorder severity and duration will augment the usefulness of the disorder prevalence information reported herein
The systematic guideline review: method, rationale, and test on chronic heart failure
Background: Evidence-based guidelines have the potential to improve healthcare. However, their de-novo-development requires substantial resources-especially for complex conditions, and adaptation may be biased by contextually influenced recommendations in source guidelines. In this paper we describe a new approach to guideline development-the systematic guideline review method (SGR), and its application in the development of an evidence-based guideline for family physicians on chronic heart failure (CHF).
Methods: A systematic search for guidelines was carried out. Evidence-based guidelines on CHF management in adults in ambulatory care published in English or German between the years 2000 and 2004 were included. Guidelines on acute or right heart failure were excluded. Eligibility was assessed by two reviewers, methodological quality of selected guidelines was appraised using the AGREE instrument, and a framework of relevant clinical questions for diagnostics and treatment was derived. Data were extracted into evidence tables, systematically compared by means of a consistency analysis and synthesized in a preliminary draft. Most relevant primary sources were re-assessed to verify the cited evidence. Evidence and recommendations were summarized in a draft guideline.
Results: Of 16 included guidelines five were of good quality. A total of 35 recommendations were systematically compared: 25/35 were consistent, 9/35 inconsistent, and 1/35 un-rateable (derived from a single guideline). Of the 25 consistencies, 14 were based on consensus, seven on evidence and four differed in grading. Major inconsistencies were found in 3/9 of the inconsistent recommendations. We re-evaluated the evidence for 17 recommendations (evidence-based, differing evidence levels and minor inconsistencies) - the majority was congruent. Incongruity was found where the stated evidence could not be verified in the cited primary sources, or where the evaluation in the source guidelines focused on treatment benefits and underestimated the risks. The draft guideline was completed in 8.5 man-months. The main limitation to this study was the lack of a second reviewer.
Conclusion: The systematic guideline review including framework development, consistency analysis and validation is an effective, valid, and resource saving-approach to the development of evidence-based guidelines
Holographic c-theorems in arbitrary dimensions
We re-examine holographic versions of the c-theorem and entanglement entropy
in the context of higher curvature gravity and the AdS/CFT correspondence. We
select the gravity theories by tuning the gravitational couplings to eliminate
non-unitary operators in the boundary theory and demonstrate that all of these
theories obey a holographic c-theorem. In cases where the dual CFT is
even-dimensional, we show that the quantity that flows is the central charge
associated with the A-type trace anomaly. Here, unlike in conventional
holographic constructions with Einstein gravity, we are able to distinguish
this quantity from other central charges or the leading coefficient in the
entropy density of a thermal bath. In general, we are also able to identify
this quantity with the coefficient of a universal contribution to the
entanglement entropy in a particular construction. Our results suggest that
these coefficients appearing in entanglement entropy play the role of central
charges in odd-dimensional CFT's. We conjecture a new c-theorem on the space of
odd-dimensional field theories, which extends Cardy's proposal for even
dimensions. Beyond holography, we were able to show that for any
even-dimensional CFT, the universal coefficient appearing the entanglement
entropy which we calculate is precisely the A-type central charge.Comment: 62 pages, 4 figures, few typo's correcte
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