1,341 research outputs found
Flying not flapping: a strategic framework for e‐learning and pedagogical innovation in higher education institutions
E‐learning is in a rather extraordinary position. It was born as a ‘tool’ and now finds itself in the guise of a somewhat wobbly arrow of change. In practice, changing the way thousands of teachers teach, learners learn, innovation is promoted and sustainable change in traditional institutions is achieved across hundreds of different disciplines is a demanding endeavour that will not be achieved by learning technologies alone. It involves art, craft and science as well as technology. This paper attempts to show how it might be possible to capture and model complex strategic processes that will help move the potential of e‐learning in universities to a new stage of development. It offers the example of a four‐quadrant model created as a framework for an e‐learning strategy
Effects of alloy composition in traditional Japanese shakudo patination
Japanese craftspeople have dominated the art of patinating copper-alloys since the 15th century, using precise alloy compositions and complicated patination processes in different hot solutions to create a variety of colours on swords fittings such as tsuba. While this complex tradition is increasingly popular in the East, the reasons behind the choices made by craftspeople in the selection of the components of the alloys and are still not fully understood. This paper investigates the effect of different alloying elements (tin, gold, and silver) on the resulting patina. Experimental results are compared with optical and compositional analyses on historical Japanese artefacts, confirming the effects of the different alloying elements on the patina characteristics and colour. The absence of tin and the presence of gold limit the growth of an oxide layer and promote the formation of a thin patina characterised by a smooth appearance without visible grains. Therefore, a limited thickness of the patinas is a key aspect for the production of the desired colour and appearance of the patinas. The first colorimetric analysis on historical Japanese artefacts demonstrates the influence of gold, silver and tin in the final patina colour, validating the observations in the experimental replicas
A better shade of black: effects of manufacturing parameters on the development of ancient black bronzes
Alloys with controlled contents of Sn, Ag and Au, were treated with methods and solutions that mimic those used in ancient and traditional procedures for the production of black bronze. Examination of the resulting patinas with colorimetry, SEM-EDS, TEM, Raman Spectroscopy, and XRD revealed no systematic differences according to fabrication method, whereas patina homogeneity and colour in those alloys which did not contain precious metal were affected by superficial work. Patina microstructure determines adherence and coverage, and depends upon solution used irrespective of the alloy composition, but the colour of the patina is mainly related to alloy composition. Gold promotes the development of cuprite, slowing the oxidation to tenorite in the corrosion process. Gold additions produce a more uniform patina as well as a desirable blue-black tone which is likely to have been a factor in alloy selection
Natron glass production and supply in the late antique and early medieval Near East: The effect of the Byzantine-Islamic transition
Palestine and Egypt supplied the Mediterranean and Europe with virtually all of its glass for most of the first millennium CE. While the Muslim conquest in the 7th century saw major political and economic adjustment, immediate changes to material culture appear to have been minimal. This paper examines the impact of the Byzantine-Islamic transition on the natron glass industry of Palestine from the 7th to 12th century. A series of 133 well-contextualised glass vessels from selected excavations in modern day Israel have been analysed for major, minor and trace elements using LA-ICP-MS. These glasses are assigned to previously established primary production groups, allowing the elucidation of the chronology of key changes in glass production in the region. Results indicate a relatively abrupt compositional change in the late 7th - early 8th centuries, covering the reforming reigns of al-Malik and al-Walid, which marks the end of “Byzantine” glass production and the establishment of the furnaces at Bet Eli'ezer. At about this time there was an influx of glass of an Egyptian composition. Production of Bet Eli'ezer type glass appears to have been limited to a short time span, less than 50 years, after which natron glass production in Palestine ceased. Plant ash glass is first encountered in the late 8th-early 9th century, probably as a result of reduced local natron glass production creating the conditions in which plant ash glass technology was adopted. Egypt continued to produce natron glass for up to a century after its demise in Palestine. It is reasoned that the change and then collapse in natron glass production in Palestine may well have been as a consequence of a reduction in the quantities of available natron. This affected Palestine first, and Egypt up to 100 years later, which suggests that the factors causing the reduction in natron supply originated at the source and were long term and gradual, not short term events
Composition, production and procurement of glass at San Vincenzo: an early medieval monastic complex in southern Italy
136 glasses from the ninth-century monastery of San Vincenzo and its workshops have been analysed by electron microprobe in order to situate the assemblage within the first millennium CE glass making tradition. The majority of the glass compositions can be paralleled by Roman glass from the first to third centuries, with very few samples consistent with later compositional groups. Colours for trailed decoration on vessels, for vessel bodies and for sheet glass for windows were largely produced by melting the glass tesserae from old Roman mosaics. Some weakly-coloured transparent glass was obtained by re-melting Roman window glass, while some was produced by melting and mixing of tesserae, excluding the strongly coloured cobalt blues. Our data suggest that to feed the needs of the glass workshop, the bulk of the glass was removed as tesserae and windows from a large Roman building. This is consistent with a historical account according to which the granite columns of the monastic church were spolia from a Roman temple in the region. The purported shortage of natron from Egypt does not appear to explain the dependency of San Vincenzo on old Roman glass. Rather, the absence of contemporary primary glass may reflect the downturn in long-distance trade in the later first millennium C.E., and the role of patronage in the “ritual economy” founded upon donations and gift-giving of the time
Risk assessment and risk management of violent reoffending among prisoners
“The final publication is available at Springer via http://dx.doi.org/10.1016/j.eswa.2015.05.025”
The LOX-1 Scavenger Receptor and Its Implications in the Treatment of Vascular Disease
Cardiovascular disease is the leading cause of death. The disease is due to atherosclerosis which is characterized by lipid and fat accumulation in arterial blood vessel walls. A key causative event is the accumulation of oxidised low density lipoprotein particles within vascular cells, and this is mediated by scavenger receptors. One such molecule is the LOX-1 scavenger receptor that is expressed on endothelial, vascular smooth muscle, and lymphoid cells including macrophages. LOX-1 interaction with OxLDL particles stimulates atherosclerosis. LOX-1 mediates OxLDL endocytosis via a clathrin-independent internalization pathway. Transgenic animal model studies show that LOX-1 plays a significant role in atherosclerotic plaque initiation and progression. Administration of LOX-1 antibodies in cellular and animal models suggest that such intervention inhibits atherosclerosis. Antiatherogenic strategies that target LOX-1 function using gene therapy or small molecule inhibitors would be new ways to address the increasing incidence of vascular disease in many countries
Authors' Response to Peer Reviews of “Using Structural Equation Modelling in Routine Clinical Data on Diabetes and Depression: Observational Cohort Study”
Background:
Large data sets comprising routine clinical data are becoming increasingly available for use in health research. These data sets contain many clinical variables that might not lend themselves to use in research. Structural equation modelling (SEM) is a statistical technique that might allow for the creation of “research-friendly” clinical constructs from these routine clinical variables and therefore could be an appropriate analytic method to apply more widely to routine clinical data.
Objective:
SEM was applied to a large data set of routine clinical data developed in East London to model well-established clinical associations. Depression is common among patients with type 2 diabetes, and is associated with poor diabetic control, increased diabetic complications, increased health service utilization, and increased health care costs. Evidence from trial data suggests that integrating psychological treatment into diabetes care can improve health status and reduce costs. Attempting to model these known associations using SEM will test the utility of this technique in routine clinical data sets.
Methods:
Data were cleaned extensively prior to analysis. SEM was used to investigate associations between depression, diabetic control, diabetic care, mental health treatment, and Accident & Emergency (A&E) use in patients with type 2 diabetes. The creation of the latent variables and the direction of association between latent variables in the model was based upon established clinical knowledge.
Results:
The results provided partial support for the application of SEM to routine clinical data. Overall, 19% (3106/16,353) of patients with type 2 diabetes had received a diagnosis of depression. In line with known clinical associations, depression was associated with worse diabetic control (β=.034, P<.001) and increased A&E use (β=.071, P<.001). However, contrary to expectation, worse diabetic control was associated with lower A&E use (β=–.055, P<.001) and receipt of mental health treatment did not impact upon diabetic control (P=.39). Receipt of diabetes care was associated with better diabetic control (β=–.072, P<.001), having depression (β=.018, P=.007), and receiving mental health treatment (β=.046, P<.001), which might suggest that comprehensive integrated care packages are being delivered in East London.
Conclusions:
Some established clinical associations were successfully modelled in a sample of patients with type 2 diabetes in a way that made clinical sense, providing partial evidence for the utility of SEM in routine clinical data. Several issues relating to data quality emerged. Data improvement would have likely enhanced the utility of SEM in this data set
The blues of Romuliana
The paper presents a set of glass fragments excavated at several different locations within and outside the late Roman fortified imperial residence Felix Romuliana (Gamzigrad, Serbia). This small group of eighteen fragments and mosaic glass tesserae are distinguished by their cobalt blue colour. The majority of the finds are mosaic tesserae (six pcs) and sheets of glass (five pcs), which could be related to architectural decoration (sectilia panels). Others are pieces left behind from secondary glass working (four pcs). There are also two fragments tentatively identified as window pane pieces, and only one find is a vessel sherd. The materials are dated to the 4th century. Significantly, some of the production debris and the two “window pane” fragments were found inside the destruction of a glass furnace. The analyses of the chemical glass composition of the finds confirmed that the blue colourant in all samples is cobalt, and antimony is also present at notable levels (except for one sample), likely to produce opacification of the glass. Regarding the origin of the raw glass, the data on almost all pieces suggests a Syro-Palestinian provenance, and a single sample could be related to Egyptian primary glass production. Importantly, the concentrations of the oxides added to the base glasses in order to modify the colour are positively correlated in certain samples, hinting at the makeup of the cobalt bearing ingredient and at a likely existence of particular production practices of the late Roman period
- …