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Background: Venous Thromboembolic disease (VTE) poses a diagnostic challenge for clinicians in acute care. Over reliance on reference standard investigations can lead to over treatment and potential harm. We sought to evaluate the pragmatic performance and implications of using an age adjusted D-dimer (AADD) strategy to rule out VTE in patients with suspected disease attending an emergency department (ED) setting. We aimed to determine diagnostic test characteristics and assess whether this strategy would result in proportional imaging reduction and potential cost savings.Methods: Design: Single centre retrospective diagnostic cohort study. All patients > 50 years old evaluated for possible VTE who presented to the emergency department over a consecutive 12-month period between January and December 2016 with a positive D-dimer result. Clinical assessment records and reference standard imaging results were followed up by multiple independent adjudicators and coded as VTE positive or negative.Results: During the study period, there were 2132 positive D-dimer results. One thousand two hundred thirty-six patients received reference standard investigations. A total increase of 314/1236 (25.1%) results would have been coded as true negatives as opposed to false positive if the AADD cut off point had been applied, with 314 reference standard tests subsequently avoided. The AADD cut off had comparable sensitivity to the current cut off despite this increase in specificity; sensitivities for the diagnosis of DVT were 99.28% (95% CI 96.06-99.98%) and 97.72% for PE (95% CI 91.94% to 97.72). There were 3 false negative results using the AADD strategy.Conclusions: In patients with suspected VTE with a low or moderate pre-test probability, the application of AADD appears to increase the proportion of patients in which VTE can be excluded without the need for reference standard imaging. This management strategy is likely to be associated with substantial reduction in anticoagulation treatment, investigations and cost/time savings. [ABSTRACT FROM AUTHOR]

The early Eocene (56 to 48 million years ago) is inferred to have been the most recent time that Earth's atmospheric CO2 concentrations exceeded 1000 ppm. Global mean temperatures were also substantially warmer than those of the present day. As such, the study of early Eocene climate provides insight into how a super-warm Earth system behaves and offers an opportunity to evaluate climate models under conditions of high greenhouse gas forcing. The Deep Time Model Intercomparison Project (DeepMIP) is a systematic model–model and model–data intercomparison of three early Paleogene time slices: latest Paleocene, Paleocene–Eocene thermal maximum (PETM) and early Eocene climatic optimum (EECO). A previous article outlined the model experimental design for climate model simulations. In this article, we outline the methodologies to be used for the compilation and analysis of climate proxy data, primarily proxies for temperature and CO2. This paper establishes the protocols for a concerted and coordinated effort to compile the climate proxy records across a wide geographic range. The resulting climate "atlas" will be used to constrain and evaluate climate models for the three selected time intervals and provide insights into the mechanisms that control these warm climate states. We provide version 0.1 of this database, in anticipation that this will be expanded in subsequent publications. [ABSTRACT FROM AUTHOR]

The early Eocene (56 to 48 million years ago) is inferred to have been the most recent time that Earth's atmospheric CO2 concentrations exceeded 1000 ppm. Global mean temperatures were also substantially warmer than present day. As such, study of early Eocene climate provides insight into how a super-warm Earth system behaves and offers an opportunity to evaluate climate models under conditions of high greenhouse gas forcing. The Deep Time Model Intercomparison Project (DeepMIP) is a systematic model-model and model-data intercomparison of three early Paleogne time slices: latest Paleocene, Paleocene-Eocene thermal maximum and early Eocene climatic optimum. A previous article outlined the model experimental design for climate model simulations. In this article, we outline the methodologies to be used for the compilation and analysis of climate proxy data, primarily proxies for temperature and CO2. This paper establishes the protocols for a concerted and coordinated effort to compile the climate proxy records across a wide geographic range. The resulting climate "atlas" will be used to constrain and evaluate climate models for the three selected time intervals, and provide insights into the mechanisms that control these warm climate states. We provide version 0.1 of this database, in anticipation that this will be expanded in subsequent publications. [ABSTRACT FROM AUTHOR]

Short-lived (104–105 years) carbon isotope excursions (CIEs), many of which are associated with some degree of ocean warming, are a feature of the warm climates of the early Paleogene. Here we present new calcareous nannofossil and geochemical data through the first of these Paleogene carbon cycle perturbations, known as the DAN-C2 event (65.8–65.7 Ma), from ODP Site 1049C on Blake Nose, in the western sub-tropical North Atlantic. Increased Hg/TOC (ppb/%) and Hg/Al (ppb/cps) ratios recorded at 65.9 Ma strongly suggest that volcanic activity, likely related to Deccan Traps, preceded the DAN-C2 event. Approximately 20 kyr after the onset of DAN-C2, Shannon diversity (H) index shows increased nannofossil species richness, with greater abundances of eutrophic and high fertility species, most likely a response to more intense weathering during the event. During the DAN-C2 event, there is a shift towards smaller morphotypes of the dominant placolith species, Coccolithus pelagicus and Cruciplacolithus primus , together with a calcium carbonate dissolution interval. Finally, we suggest that surface ocean currents dynamics, influenced by an eccentricity maxima cycle, is likely a potential mechanism to explaining the strong δ13C (∼1.3 ‰) negative excursion observed in Blake Nose. • Deccan Traps eruption recognized at 65.90 Ma in high productivity conditions. • Strong evidence of biotic response to terrigenous input during Dan-C2. • Dissolutions effects impacted carbonate preservation, reducing coccolith size. [ABSTRACT FROM AUTHOR]

Here we present the first multi-species comparison of modern and fossil coccolith trace metal data obtained from single liths. We present both trace metal analyses (Sr, Ca, Mg and Al) and distribution maps of individual Paleogene fossil coccoliths obtained by Secondary Ion Mass Spectrometry (SIMS). We use this data to determine the effects of variable coccolith preservation and diagenetic calcite overgrowths on the recorded concentrations of strontium and magnesium in coccolith calcite. The analysis of coccoliths from deep-ocean sediments spanning the Eocene/Oligocene transition demonstrates that primary coccolith calcite is resistant to the neomorphism that is common in planktonic foraminifera from similar depositional environments. Instead, where present, diagenetic calcite forms distinct overgrowths over primary coccolith calcite rather than replacing this calcite. Diagenetic overgrowths on coccoliths are easily distinguished in SIMS analyses on the basis of relatively higher Mg and lower Sr concentrations than co-occurring primary coccolith calcite. This interpretation is confirmed by the comparable SIMS analyses of modern cultured coccoliths of Coccolithus braarudii . Further, with diagenetic calcite overgrowth being the principle source of bias in coccolith-based geochemical records, we infer that lithologies with lower carbonate content, deposited below the palaeo-lysocline, are more likely to produce geochemical records dominated by primary coccolith calcite than carbonate-rich sediments where overgrowth is ubiquitous. The preservation of primary coccolith carbonate in low-carbonate lithologies thus provides a reliable geochemical archive where planktonic foraminifera are absent or have undergone neomorphism. [ABSTRACT FROM AUTHOR]

Abstract: Constraining the greenhouse gas forcing, climatic warming and estimates of climate sensitivity across ancient large transient warming events is a major challenge to the palaeoclimate research community. Here we provide a new compilation and synthesis of the available marine proxy temperature data across the largest of these hyperthermals, the Paleocene–Eocene Thermal Maximum (PETM). This includes the application of consistent temperature calibrations to all data, including the most recent set of calibrations for archaeal lipid-derived palaeothermometry. This compilation provides the basis for an informed discussion of the likely range of PETM warming, the biases present in the existing record and an initial assessment of the geographical pattern of PETM ocean warming. To aid interpretation of the geographic variability of the proxy-derived estimates of PETM warming, we present a comparison of this data with the patterns of warming produced by high pCO2 simulations of Eocene climates using the Hadley Centre atmosphere-ocean general circulation model (AOGCM) HadCM3L. On the basis of this comparison and taking into account the patterns of intermediate-water warming we estimate that the global mean surface temperature anomaly for the PETM is within the range of 4 to 5°C. [Copyright &y& Elsevier]

This article assesses Alexander Pope's sense of history and proposes further grounds for his turn from celebratory to cautionary modes of historical writing. Having surveyed Pope's reading in history, and considered his poetry as a form of historical writing, the article focuses on the question of faction as a cause of historical change, and studies Pope's relationship with Francis Atterbury, the bishop of Rochester who was exiled for his part in a Jacobite plot, in this light. Pope admired Atterbury but also felt anxiety about his relationship to him. That anxiety is evident in an episode in Pope's reading, when he annotates a printed copy of Clarendon's History of the Rebellion with variant readings from a currently unidentifiable manuscript. The comparison of printed and manuscript texts was undertaken in the light of the Whig historian John Oldmixon's accusations that Atterbury tampered with Clarendon's manuscript for political (Jacobite) purposes. The article concludes by suggesting that the long recognized ambivalence of Pope's attitudes in The Dunciad might be connected to his own later doubts about the claims of his early political allies to occupy a patriotic position beyond faction. [ABSTRACT FROM AUTHOR]

This editorial examines the conceptual and practical links between risk and time. It recognises that risk analysis may be regarded as both a product of enlightenment thinking, and a candidate for the means to deliver the ultimate enlightenment fantasy: to provide successive generations with a capacity to progressively control the world more effectively. It argues that, despite its significant achievements, risk analysis has fostered romantic fantasies that themselves generate risky futures. The discussion is illustrated with reference to emergency planning, the likelihood of nuclear accidents, long-term nuclear waste disposal and the exotic financial instruments that were implicated in the recent international financial crisis. [ABSTRACT FROM AUTHOR]

Abstract: The marine sedimentary record can exhibit a systematic cyclicity that is consistent with climate variability driven by Milankovitch-scale forcing. Milankovitch-band cyclicity is widely interpreted in the hemipelagic and pelagic sediments of the marine realm, and in terrestrial paleoenvironments has been observed in lacustrine sediments, soils and river floodplain successions. It remains unclear, however, if and how mountain catchments, as a primary sediment source, respond to these high frequency (<106 yr) climatic cycles, and whether particulate sediment flux signals can be expected to be recorded in the clastic sedimentary record of adjacent basin-fills. Recent field and theoretical studies suggest that mountain catchments respond transiently to high frequency forcing, and so sediment discharge from the catchment is a non-linear function of forcing variables. Using a catchment–basin model, we demonstrate that climate-driven cyclicity in particulate sediment discharge is strongly damped when the period of climate variability is shorter than the response timescale of the eroding landscape. Given that the response timescale of landscapes is of the order of 106 yr, and that Milankovitch-driven climate cyclicity is of the order of 104–105 yr, it is likely that climate-driven perturbation of upland catchments at these periods will be strongly damped by transient landscape behaviour. Our results therefore suggest that stratigraphy built by particulate fluxes from upland catchments, and long-term trends in the sediment delivery to the ocean, may be relatively insensitive to short-term climate variability. [Copyright &y& Elsevier]

We present a theoretical study of optical rectification (OR) at radio frequencies (RF). OR is a process by which a second-order nonlinear optical material can directly convert an optical field into an RF electric field. The combination of high-index nanoscale waveguides and new optical materials allow this effect to be greatly enhanced. We develop a lumped-element equivalent circuit model for the OR process from first principles, which enables the power conversion and bandwidth of the effect to be predicted. We use our model to predict that significant amounts of RF power should be obtainable from a slot waveguide device clad in a nonlinear optical polymer. Based on our model, we estimate that OR-based photodetectors may be possible, operating at speeds of 400 GHz, with responsivities on the order of 9 mA/W. [ABSTRACT FROM PUBLISHER]

The most well preserved and diverse upper Eocene to lower Oligocene assemblage of calcareous nannofossils (coccolithophores) known to date is described from the Pande Clays, Kilwa Group, Tanzania. The assemblage is exceptionally diverse, with a total of 115 species described herein, which significantly exceeds the current globally compiled nannofossil species diversity of 67 for the latest Eocene (NP19/20). The enhanced diversity observed in these sections is concentrated in the numerous Rhabdosphaeraceae (20 species), Syracosphaeraceae and holococcolith taxa (19 species) that are unknown from any other contemporaneous location. Scanning electron microscope (SEM) studies reveal exquisite preservation down to the sub-micron scale in many of these taxa, including the architecture of <3μm holococcoliths and the details of grills and processes in other very small fragile taxa - a size class which is rarely preserved even in Recent sediments. A distinct assemblage of at least four specialist lower-photic zone taxa - three Gladiolithus species and Algirosphaera fabaceus - is present in these sediments. The occurrence of these highly specialised coccoliths in the Palaeogene sediments of Tanzania extends their previously known late Quaternary fossil record by tens of millions of years. The controls on the exquisite preservation of such a diverse nannofossil assemblage are difficult to determine but we speculate that a diverse open-ocean, oligotrophic coccolithophore assemblage was being rapidly buried and sealed within a clay-rich facies that is more characteristic of shelf-environments, a combination that, to date, makes the Palaeogene sedimentsof Tanzania unique.Onenewgenus, Pocillithus, isdescribed, consistingof very small spinebearing muroliths that may be related to extant narrow-rimmed muroliths of uncertain affinity. Ten new species are described: Pocillithus spinulifer, Reticulofenestra macmillanii, Calcidiscus parvus, Syracosphaera monechiae, Syracosphaera raffiae, Blackites culter, Blackites shafikii, Acanthoica backmanii, Orthozygus occultus and Orthozygus arcus. [ABSTRACT FROM AUTHOR]

The use of risk communication as a policy tool has become increasingly important in areas as diverse as emergency planning and health communication, and including aspects of many of the leading issues of the day. Its use, as a part of institutional attempts to inform and influence lay behaviour, is predicated upon a variety of models of how people make sense of risk-related issues. Many such models are based upon a cognitive information-processing metaphor, and have an underlying instrumental nature that assumes recipients 'would behave responsibly if only they knew the facts'. In this paper, we discuss some alternative, sociological, approaches to risk perception that have developed over the last decade, in which resulting lay behaviours are recognised as being embedded within a matrix of everyday associations, preferred ways of life, trust relations, economic constraints and emotional commitments. In particular, we will be concerned with the emergence of so-called 'interpretative' risk perception research. In so doing, we draw particular attention to the relevance of Ryle's notion of 'thick description' in seeking to investigate the nature of practical reasoning about risk issues. We illustrate some of these themes by revisiting, and re-analysing, a particularly rich 10-year-old corpus of largely unpublished comparative UK and Spanish data, generated by citizens living in communities geographically close to potentially hazardous industrial facilities. [ABSTRACT FROM AUTHOR]

This editorial argues that aspects of a number of contemporary debates within the sociology of risk, including those concerned with the nature of expert knowledge, the capacity of theory to address practical real-world issues, and the appropriate political stance of the scholar, were pre-figured in helpful and insightful ways in the work of the British medical sociologist Philip M. Strong (1945-1995). The recent publication of a selection of Strong's essays, which had earlier appeared in a disparate range of books and journals, makes a valuable resource available not only to specialist health researchers, but also to the wider risk research community. [ABSTRACT FROM AUTHOR]

This paper reports on a review of the empirical evidence about lay perceptions of nuclear fusion. It does so in the light of the wider social science literature on public perception of new technologies and their risks, especially technologies which, like fusion, have large research and development programmes. Our findings point to multiple distinct modes by which lay publics, in specific circumstances, come to understand fusion. Whilst broadly in line with the well-established critique of the deficit thinking, our findings point to the need for further investigations into the capacity of technical and material aspects of fusion and other technologies to engender specific patterns of understanding. We discuss the implications of our findings for future research, and for the efficacy of future attempts by the fusion community to communicate and engage with lay publics. [ABSTRACT FROM AUTHOR]

The co-occurrence of the small agglutinated, conical fossils Volborthella and Salterella is documented from the Lower Cambrian Tokammane Formation of Ny Friesland, Spitsbergen. Microstructural investigations of well-preserved Volborthella tenuis Schmidt (1888), collected from the fine-grained Topiggane Shale, indicate the presence of an organic cementing matrix that may have extended around the edges of the test to form an outer organic sheath. This is clearly distinct from the carbonate cements observed in specimens of Salterella maccullochi (Murchison 1859), supporting the taxonomic validity of Volborthella and Salterella. The occurrence of both these forms in this succession may indicate a biogeographic link between the Laurentian province, where both Salterella and Volborthella are found, and the Baltic and East European Platform, where only Volborthella is reported to occur. The exclusive presence of Volborthella in the older siliciclastic Topiggane Shale Member and Salterella in the younger carbonates of the Ditlovtoppen Dolomite provides both a testable age-relation between these two forms and suggests that there may be a significant facies control on their distribution. These organisms are significant in the early history of agglutinated skeletons, especially in their use of both organic and carbonate cements significantly earlier than other Paleozoic agglutinating organisms, such as the foraminifera. [ABSTRACT FROM AUTHOR]

Abstract: This study investigates the potentially deleterious effect of prolonged sample storage on the reliability of calcareous nannofossil species abundance and community diversity measures and their subsequent interpretation as paleoceanographic proxies. Nannofossil assemblages from two freshly cored successions of hemipelagic clay were documented over a one-year period using a series of paired smear-slides, the first made from sediment samples within a day of coring and the second either 6 months or 1 year later. Diversity measured by Shannon''s H is consistent between the two sets for the majority of samples, however significant changes, both positive and negative, were recorded in a number of cases and appear to be largely due to variations in smear-slide thickness and not to post-sampling dissolution. There is no significant change in nannofossil fragmentation or abundance over time, although the relative abundances of small, dissolution susceptible placoliths of Reticulofenestra minuta do appear to decrease with time in some samples. Counts of mineral grains show that there is a significant loss of fine, 1–2 μm, cubic pyrite within months of drilling, and this, combined with the decline in abundance of R. minuta, suggests that limited pyrite oxidation coupled to carbonate dissolution is occurring. Geochemical analyses confirm that these sediments contain significant concentrations of sulphate one year after sample recovery, which may be the result of gypsum formation associated with the oxidation of pyrite. Estimates of pyrite oxidation suggest that up to 3% of the original calcium carbonate has dissolved in the year after coring, which could account for the observed loss of small placoliths. Effects of this kind are almost certainly confined to hemipelagic sequences rich in organic matter and/or reduced iron but are frequently offset by the exceptional preservation of calcareous microfossils that can occur within such sediments. [Copyright &y& Elsevier]

Making sense of new technologies and their associated risks entails lay people in utilizing various modes of reasoning and making use of a range of interpretative resources at hand to interrogate evidence. Such sense making is accomplished collectively in ways that are sometimes playfully inventive, and which have regard to ideas of accountability and morally acceptability. In practice, such bricolage-like processes appear to have certain similarities with the work of everyday scientific investigation. This paper examines these processes of lay practical reasoning by adopting an analytic stance that is concerned with examining the fine detail of what people demonstrably do in accomplishing such work. It draws on data generated by number of reconvened discussion groups, which formed a component part of the recent public debate in the UK about the possible commercialization of genetically modified crops. [ABSTRACT FROM AUTHOR]

The public debate about GM crops that took place in Britain in 2002-03 was an unprecedented experiment for the UK in public engagement. The Government, which sponsored the exercise, made a pledge: to take into account lay perspectives, as well as the views of its expert advisers, when making a decision about the possible commercialisation of this controversial technology. As officially accredited but independent evaluators of the debate, we were given unique behind-the-scenes access to the organisation and execution of the debate process. In this paper we report on our findings, which reveal a debate process that, whilst innovative, suffered from a number of important flaws: in terms of both design and implementation. These shortcomings in part reflect constraints on time and budget, and the context of political pressure in which the debate took place. However, they also demonstrated a lack of design knowledge and availability of appropriate expertise: matters with an important bearing on future plans for such initiatives. [ABSTRACT FROM AUTHOR]

Although gigahertz-scale free-carrier modulators have been demonstrated in silicon, intensity modulators operating at terahertz speeds have not been reported because of silicon’s weak ultrafast nonlinearity. We have demonstrated intensity modulation of light with light in a silicon–polymer waveguide device, based on the all-optical Kerr effect—the ultrafast effect used in four-wave mixing. Direct measurements of time-domain intensity modulation are made at speeds of 10 GHz. We showed experimentally that the mechanism of this modulation is ultrafast through spectral measurements, and that intensity modulation at frequencies in excess of 1 THz can be obtained. By integrating optical polymers through evanescent coupling to silicon waveguides, we greatly increase the effective nonlinearity of the waveguide, allowing operation at continuous-wave power levels compatible with telecommunication systems. These devices are a first step in the development of large-scale integrated ultrafast optical logic in silicon, and are two orders of magnitude faster than previously reported silicon devices. [ABSTRACT FROM AUTHOR]

The article presents question and answer advisory related to the commerce of native seeds. The native seed industry is highly competitive, and fluctuating seed prices are driven by imbalances between supply and demand. Average price of native seeds is often higher than that of comparable introduced plant materials used in land reclamation. There are several reasons why this is so. Seed yields of introduced materials are oftentimes innately higher than for native seeds, thus their production costs are lower because of "economy of scale."