4,026 research outputs found

    Glazed tiles from Lodhi and Mughal northern India: a technological appraisal

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    Glazed tiles were used by the Lodhis and Mughals to embellish their buildings in northern India from the late fifteenth to seventeenth century. Tile-work from this region and period is understudied, particularly on matters related to its origin and technology. This thesis presents findings of a research undertaken on a series of tiled buildings located at Delhi, Agra, and Punjab in northern India, from the period of Lodhi and Mughal rule. Tile samples from the buildings have been scientifically analysed - mainly using scanning electron microscopy with energy dispersive spectrometry, and electron microprobe microanalysis with wavelength dispersive spectrometry - for their characterisation. Ethno-archaeological studies on related traditional craft industries have been used to build a more accurate rendition of the technologies employed in their manufacture. A field survey of in situ tile-work has been used to correlate stylistic and physical attributes with data determined through analyses. Results from the study show that different methods were utilized for the production of tiles at Delhi/Agra and Punjab. Those of the Delhi type have indigenous features in their technology, while the Punjab specimens are shown to be technologically closer to those from the core Islamic lands. The industry at Delhi is further shown to have evolved locally, developing gradually from the Lodhi to Mughal period, while the Punjab tile industry at the time of the Mughals is demonstrated to be an import, its establishment clearly influenced externally, with the sudden appearance of a new technological style. The tile-work at both places is however determined to be of the same basic character as Islamic tile-work of the stonepaste variety. This study, besides presenting a comprehensive picture on Lodhi and Mughal tiling traditions, provides important new information in the discipline of Islamic ceramic studies, particularly on the development of stonepaste technology and its transfer

    An analytical evaluation of historic glazed tiles from Makli and Lahore, Pakistan

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    The composition and production of pre-modern glazed tiles in Pakistan are not well understood. Here, 38 glazed tile samples sourced from various monuments at Makli Hill and Lahore Fort in Pakistan, dating mainly from the sixteenth and seventeenth centuries CE, were investigated with scanning electron microscopy and energy dispersive X-ray spectrometry for a comprehensive technological study to understand the methods used in their production. The analyses were supplemented by laser ablation-inductively coupled plasma-mass spectrometry to more fully characterise the raw materials used for the glazes. The Makli tile bodies are composed of clay-based ceramic whereas those from Lahore are stonepaste. Both are coated with soda-lime-silica glazes made using plant ash. Cobalt, copper, lead‑tin yellow and lead‑tin orange are identified as the glaze colorants. White glazes do not have an added opacifier or colorant, but are white due to the presence of an underlying layer of silica particles. Technological variations between the Makli and Lahore tiles are highlighted in the discussions, the former found to resemble traditional kashi ware of Sindh-Multan in their make-up, while the latter matches Mughal tile-work that prevailed for a while locally in the seventeenth century

    Tradition and indigeneity in Mughal architectural glazed tiles

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    Glazed tiles were employed by the Mughals for the decoration of their monuments in northern India over the sixteenth and seventeenth century. The character and composition of thirty tile samples from Mughal buildings at Delhi, in northern India, were investigated by EPMA-WDS and SEM-EDS. Analysis shows that the tiles have stonepaste bodies, indicating that they form part of the family of Islamic ceramics. The glaze layers are determined to have local characteristics, through comparisons with traditional Indian glass compositions. A local source for the cobalt oxide used to colour dark blue coloured glazes has been suggested. Overall, the study considers the impact of an imported luxury/high status technology on local traditions, and how the two converge to develop a new chaîne opératoire which has aspects of Islamic and indigenous technologies. © 2014 The Authors

    Complete analysis of the B-cell response to a protein antigen, from in vivo germinal centre formation to 3-D modelling of affinity maturation

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    Somatic hypermutation of immunoglobulin variable region genes occurs within germinal centres (GCs) and is the process responsible for affinity maturation of antibodies during an immune response. Previous studies have focused almost exclusively on the immune response to haptens, which may be unrepresentative of epitopes on protein antigens. In this study, we have exploited a model system that uses transgenic B and CD4<sup>+</sup> T cells specific for hen egg lysozyme (HEL) and a chicken ovalbumin peptide, respectively, to investigate a tightly synchronized immune response to protein antigens of widely differing affinities, thus allowing us to track many facets of the development of an antibody response at the antigen-specific B cell level in an integrated system <i>in</i> <i>vivo</i>. Somatic hypermutation of immunoglobulin variable genes was analysed in clones of transgenic B cells proliferating in individual GCs in response to HEL or the cross-reactive low-affinity antigen, duck egg lysozyme (DEL). Molecular modelling of the antibody–antigen interface demonstrates that recurring mutations in the antigen-binding site, selected in GCs, enhance interactions of the antibody with DEL. The effects of these mutations on affinity maturation are demonstrated by a shift of transgenic serum antibodies towards higher affinity for DEL in DEL-cOVA immunized mice. The results show that B cells with high affinity antigen receptors can revise their specificity by somatic hypermutation and antigen selection in response to a low-affinity, cross-reactive antigen. These observations shed further light on the nature of the immune response to pathogens and autoimmunity and demonstrate the utility of this novel model for studies of the mechanisms of somatic hypermutation

    Fourier Magnetic Imaging with Nanoscale Resolution and Compressed Sensing Speed-up using Electronic Spins in Diamond

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    Optically-detected magnetic resonance using Nitrogen Vacancy (NV) color centres in diamond is a leading modality for nanoscale magnetic field imaging, as it provides single electron spin sensitivity, three-dimensional resolution better than 1 nm, and applicability to a wide range of physical and biological samples under ambient conditions. To date, however, NV-diamond magnetic imaging has been performed using real space techniques, which are either limited by optical diffraction to 250 nm resolution or require slow, point-by-point scanning for nanoscale resolution, e.g., using an atomic force microscope, magnetic tip, or super-resolution optical imaging. Here we introduce an alternative technique of Fourier magnetic imaging using NV-diamond. In analogy with conventional magnetic resonance imaging (MRI), we employ pulsed magnetic field gradients to phase-encode spatial information on NV electronic spins in wavenumber or k-space followed by a fast Fourier transform to yield real-space images with nanoscale resolution, wide field-of-view (FOV), and compressed sensing speed-up.Comment: 31 pages, 10 figure

    Quantification and Evidence for Mechanically Metered Release of Pygidial Secretions in Formic Acid-Producing Carabid Beetles

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    This study is the first to measure the quantity of pygidial gland secretions released defensively by carabid beetles (Coleoptera: Carabidae) and to accurately measure the relative quantity of formic acid contained in their pygidial gland reservoirs and spray emissions. Individuals of three typical formic acid producing species were induced to repeatedly spray, ultimately exhausting their chemical compound reserves. Beetles were subjected to faux attacks using forceps and weighed before and after each ejection of chemicals. Platynus brunneomarginatus (Mannerheim) (Platynini), P. ovipennis (Mannerheim) (Platynini) and Calathus ruficollis Dejean (Sphodrini), sprayed average quantities with standard error of 0.313 ± 0.172 mg, 0.337 ± 0.230 mg, and 0.197 ± 0.117 mg per spray event, respectively. The quantity an individual beetle released when induced to spray tended to decrease with each subsequent spray event. The quantity emitted in a single spray was correlated to the quantity held in the reservoirs at the time of spraying for beetles whose reserves are greater than the average amount emitted in a spray event. For beetles with a quantity less than the average amount sprayed in reserve there was no significant correlation. For beetles comparable in terms of size, physiological condition and gland reservoir fullness, the shape of the gland reservoirs and musculature determined that a similar effort at each spray event would mechanically meter out the release so that a greater amount was emitted when more was available in the reservoir. The average percentage of formic acid was established for these species as 34.2%, 73.5% and 34.1% for for P. brunneomarginatus, P. ovipennis and C. ruficollis, respectively. The average quantities of formic acid released by individuals of these species was less than two-thirds the amount shown to be lethal to ants in previously published experiments. However, the total quantity from multiple spray events from a single individual could aggregate to quantities at or above the lethal level, and lesser quantities are known to act as ant alarm pheromones. Using a model, one directed spray of the formic acid and hydrocarbon mix could spread to an area of 5–8 cm diameter and persisted for 9–22 seconds at a threshold level known to induce alarm behaviors in ants. These results show that carabid defensive secretions may act as a potent and relatively prolonged defense against ants or similar predators even at a sub-lethal dose

    Neoliberalisation and 'lad cultures' in higher education

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    This paper links HE neoliberalisation and ‘lad cultures’, drawing on interviews and focus groups with women students. We argue that retro-sexist ‘laddish’ forms of masculine competitiveness and misogyny have been reshaped by neoliberal rationalities to become modes of consumerist sexualised audit. We also suggest that neoliberal frameworks scaffold an individualistic and adversarial culture among young people that interacts with perceived threats to men’s privilege and intensifies attempts to put women in their place through misogyny and sexual harassment. Furthermore, ‘lad cultures’, sexism and sexual harassment in higher education may be invisibilised by institutions to preserve marketability in a neoliberal context. In response, we ask if we might foster dialogue and partnership between feminist and anti-marketisation politics

    The relationship between foot arch measurements and walking parameters in children

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    BACKGROUND: Walking mechanics are influenced by body morphology. Foot arch height is one aspect of body morphology central to walking. However, generalizations about the relationship between arch height and walking are limited due to previous methodologies used for measuring the arch and the populations that have been studied. To gain the knowledge needed to support healthy gait in children and adults, we need to understand this relationship in unimpaired, typically developing children and adults using dynamic measures. The purpose of the current study was to examine the relationship between arch height and gait in a sample of healthy children and adults using dynamic measures. METHODS: Data were collected from 638 participants (n = 254 children and n = 384 adults) at the Museum of Science, Boston (MOS) and from 18 4- to 8-year-olds at the Motor Development and Motor Control Laboratories. Digital footprints were used to calculate two arch indices: the Chippaux-Smirak (CSI) and the Keimig Indices (KI). The height of the navicular bone was measured. Gait parameters were captured with a mechanized gait carpet at the MOS and three-dimensional motion analyses and in-ground force plates in the Motor Development and Motor Control Laboratories. RESULTS: Linear regression analyses on data from the MOS confirmed that as age increases, step length increases. With a linear mixed effect regression model, we found that individuals who took longer steps had higher arches as measured by the KI. However, this relationship was no longer significant when only adults were included in the model. A model restricted to children found that amongst this sample, those with higher CSI and higher KI values take longer relative step lengths. Data from the Motor Development and Motor Control Laboratories showed that both CSI and KI added to the prediction; children with lower anterior ground reaction forces had higher CSI and higher KI values. Arch height indices were correlated with navicular height. CONCLUSIONS: These results suggest that more than one measure of the arch may be needed elucidate the relationship between arch height and gait.K12 HD055931 - NICHD NIH HHS; K12HD055931 - NICHD NIH HH
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