1,924 research outputs found
The discolouration of human teeth from archaeological contexts: Elemental analysis of a black tooth from a Roman cranium recovered from the River Witham, Lincoln, UK.
A human cranium was recovered from the River Witham, Lincoln, UK, at Stamp End Lock during a police operation in 2002. Although extensive trauma was noted, the skull was not of forensic interest since radiocarbon dating revealed that the individual had lived during the Roman occupation of Lincoln, almost 2,000 years ago. The skull had unusual black âmetallicâ staining on the occlusal surfaces of the teeth. As this kind of staining is relatively uncommon, it was investigated to determine the possible cause. An individual tooth was subjected to two elemental analyses: inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX). A small sample of modern teeth was also analysed for comparison to determine ânormalâ ranges of certain elements. Analysis of the ancient tooth shows very high levels of manganese (275â”g/g) and iron (1540â”g/g) compared to modern teeth values (1.90â”g/gâMn and 40.81â”g/gâFe). These results were consistent with the black staining arising from iron and manganese infiltrating bone and dental tissue from the depositional environment, and not a consequence of diet, pathological process or cultural practices
Computing Linear Matrix Representations of Helton-Vinnikov Curves
Helton and Vinnikov showed that every rigidly convex curve in the real plane
bounds a spectrahedron. This leads to the computational problem of explicitly
producing a symmetric (positive definite) linear determinantal representation
for a given curve. We study three approaches to this problem: an algebraic
approach via solving polynomial equations, a geometric approach via contact
curves, and an analytic approach via theta functions. These are explained,
compared, and tested experimentally for low degree instances.Comment: 19 pages, 3 figures, minor revisions; Mathematical Methods in
Systems, Optimization and Control, Birkhauser, Base
Delivering reform in English healthcare: an ideational perspective
A variety of perspectives has been put forward to understand reform across healthcare systems. Recently, some have called for these perspectives to give greater recognition to the role of ideational processes. The purpose of this article is to present an ideational approach to understanding the delivery of healthcare reform. It draws on a case of English healthcare reform â the Next Stage Review led by Lord Darzi â to show how the delivery of its reform proposals was associated with four ideational frames. These frames built on the idea of âprogressâ in responding to existing problems; the idea of âprevailing policyâ in forming part of a bricolage of ideas within institutional contexts; the idea of âprescriptionâ as top-down structural change at odds with local contexts; and the idea of âprofessional disputesâ in challenging the notion of clinical engagement across professional groups. The article discusses the implications of these ideas in furthering our understanding of policy change, conflict and continuity across healthcare settings
A network-based dynamical ranking system for competitive sports
From the viewpoint of networks, a ranking system for players or teams in
sports is equivalent to a centrality measure for sports networks, whereby a
directed link represents the result of a single game. Previously proposed
network-based ranking systems are derived from static networks, i.e.,
aggregation of the results of games over time. However, the score of a player
(or team) fluctuates over time. Defeating a renowned player in the peak
performance is intuitively more rewarding than defeating the same player in
other periods. To account for this factor, we propose a dynamic variant of such
a network-based ranking system and apply it to professional men's tennis data.
We derive a set of linear online update equations for the score of each player.
The proposed ranking system predicts the outcome of the future games with a
higher accuracy than the static counterparts.Comment: 6 figure
Factorization Properties of Soft Graviton Amplitudes
We apply recently developed path integral resummation methods to perturbative
quantum gravity. In particular, we provide supporting evidence that eikonal
graviton amplitudes factorize into hard and soft parts, and confirm a recent
hypothesis that soft gravitons are modelled by vacuum expectation values of
products of certain Wilson line operators, which differ for massless and
massive particles. We also investigate terms which break this factorization,
and find that they are subleading with respect to the eikonal amplitude. The
results may help in understanding the connections between gravity and gauge
theories in more detail, as well as in studying gravitational radiation beyond
the eikonal approximation.Comment: 35 pages, 5 figure
Pharmacokinetic and pharmacodynamic modelling after subcutaneous, intravenous and buccal administration of a high-concentration formulation of buprenorphine in conscious cats
The aim of this study was to describe the joint pharmacokinetic-pharmacodynamic model and evaluate thermal antinociception of a high-concentration formulation of buprenorphine (Simbadolâą) in cats
Amblyopia and quality of life: a systematic review
Background/Aims
Amblyopia is a common condition which can affect up to 5% of the general population. The health-related quality of life (HRQoL) implications of amblyopia and/or its treatment have been explored in the literature.
Methods
A systematic literature search was undertaken (16th-30th January 2007) to identify the HRQoL implications of amblyopia and/or its treatment.
Results
A total of 25 papers were included in the literature review. The HRQoL implications of amblyopia related specifically to amblyopia treatment, rather than the condition itself. These included the impact upon family life; social interactions; difficulties undertaking daily activities; and feelings and behaviour. The identified studies adopted a number of methodologies. The study populations included; children with the condition; parents of children with amblyopia; and adults who had undertaken amblyopia treatment as a child. Some studies developed their own measures of HRQoL, and others determined HRQoL through proxy measures.
Conclusions
The reported findings of the HRQoL implications are of importance when considering the management of cases of amblyopia. Further research is required to assess the immediate and long-term effects of amblyopia and/or its treatment upon HRQoL using a more standardised approach
Long term geological record of a global deep subsurface microbial habitat in sand injection complexes
Peer reviewedPublisher PD
Traumatic posterior urethral fistula to hip joint following gunshot injury: a case report
<p>Abstract</p> <p>Introduction</p> <p>Urinary system fistula to the hip joint is a rare complication. We report a case of delayed posterior urethral fistula to the hip joint following penetrating gunshot wound injury.</p> <p>Case presentation</p> <p>A 37-year-old Iranian Balochi male was shot with a firearm in the superior part of his right pelvis. He underwent primary closure on the same day. Ten months later, he developed urinary retention. He underwent retrograde urethrography and antegrade cystography which showed a stricture measuring 5 cm in length. There was also a history of progressive pain in the right hip joint accompanied by low grade fever which started 2 months after the initial injury. Hip X-ray showed evidence of an acetabular cavity and femoral head destruction diagnostic of complicated septic arthritis. The patient subsequently underwent reconstructive surgery for the urethral stricture and urethral fistula via a transperineal approach followed by total hip arthroplasty.</p> <p>Conclusion</p> <p>Hip joint contamination with urine following a urethro-acetabular fistula can lead to severe and disabling complications such as septic arthritis. We recommend that every clinician should keep these fistulas in mind as a complication of penetrating urethral injury and every attempt should be made for their early diagnosis and prompt treatment.</p
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No straight lines â young womenâs perceptions of their mental health and wellbeing during and after pregnancy: a systematic review and meta-ethnography
Background: Young mothers face mental health challenges during and after pregnancy including increased rates of depression compared to older mothers. While the prevention of teenage pregnancy in countries such as the United States and the United Kingdom has been a focus for policy and research in recent decades, the need to understand young womenâs own experiences has been highlighted. The aim of this meta-ethnography was to examine young womenâs perceptions of their mental health and wellbeing during and after pregnancy to provide new understandings of those experiences.
Methods: A systematic review and meta-ethnographic synthesis of qualitative research was conducted. Seven databases were systematically searched and forward and backward searching conducted. Papers were included if they were from Organisation for Economic Co-operation and Development countries and explored mental health and wellbeing experiences of young mothers (age under 20 in pregnancy; under 25 at time of research) as a primary research question â or where evidence about mental health and wellbeing from participants was foregrounded. Nineteen papers were identified and the Critical Appraisal Skills Programme checklist for qualitative research used to appraise the evidence. Following the seven-step process of meta-ethnography, key constructs were examined within each study and then translated into one another.
Results: Seven translated themes were identified forming a new line of argument wherein mental health and wellbeing was analysed as relating to individual bodily experiences; tied into past and present relationships; underpinned by economic insecurity and entangled with feelings of societal surveillance. There were âno straight linesâ in young womenâs experiences, which were more complex than dominant narratives around overcoming adversity suggest.
Conclusions: The synthesis concludes that health and social care professionals need to reflect on the operation of power and stigma in young womenâs lives and its impact on wellbeing. It adds to understanding of young womenâs mental health and wellbeing during and after pregnancy as located in physical and structural factors rather than individual capacities alone
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