5,525 research outputs found
The Evolution of Wing Pattern in Micropterigidae (Insecta: Lepidoptera)
Despite the biological importance of lepidopteran wing patterns, homologies between pattern elements in different lineages are still not understood. Though plesiomorphic wing veins influence color patterning even when not expressed in the adult wing, most studies of wing pattern evolution have focused on derived taxa with reduced venation. Here I address this gap with an examination of Micropterigidae, a very early-diverged family in which all known plesiomorphic lepidopteran veins are expressed in the adult wing. Differences between the coloration of transverse bands in Micropterix and Sabatinca suggest that homologies exist between the contrast boundaries that divide wing pattern elements. Because the wing pattern of Sabatinca doroxena very closely resembles the nymphalid groundplan when plotted onto a hypothetical nymphalid wing following the relationship between pattern and venation discussed here, it appears that the nymphalid groundplan may have originated from a Sabatinca-like wing pattern subjected to changes in wing shape
Prospects for a Big Data History of Music
This position paper sets out the possibility of a musicology based on the analysis of musical-bibliographical metadata as Big Data. It outlines the work underway, as part of the AHRC-funded project A Big Data History of Music, to align seven major datasets of musical-bibliographical metadata. After discussing some of the technical challenges of data alignment, it suggests how analysis and visualization of this data might transform musicological understandings of cultural transmission and canon formation
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We are a real family: A Q methodological study on the experience of stepmothers
While stepfamilies are not a new phenomenon, with recent divorce rates, they are now common and more likely to be formed following relationship breakdown rather than death (Pryor, 2004). Stepmothers today have to contend with the wicked stepmother myth, the idealization of motherhood, and gendered notions of parenting, not to mention discourses which position the biological nuclear family as the ideal and, by implication, other forms as deviant. Moreover, the limited previous research suggests greater stress for stepmothers than stepfathers (Nielsen, 1999; Christian, 2005). This study used Q methodology to explore the range of subjective experiences of stepmothers. A diverse sample of 29 stepmothers completed a 61-item Q sort generating six factors or distinct views of the experience of stepmothering. This paper analyses, names and presents these accounts. The results suggest greater variety and complexity of experience than is indicated by previous studies whilst the discussion focuses on the relevance and impact of the culturally dominant narratives mentioned above within stepmothers’ reports of their experience
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Hapless, helpless, hopeless: An analysis of stepmothers’ talk about their (male) partners
The identity of stepmother is, in many ways, a troubled one – constructed as ‘other’ and often associated with notions of ‘wickedness’ in literature and everyday talk. This paper reports findings from a study on the difficulties faced by stepmothers and how they use talk about their (male) partners, often constructing men as hapless, helpless or hopeless, to repair their ‘troubled’ identities. The data were collected from a web forum for stepmothers based in the UK and thirteen semi-structured face-to-face interviews with stepmothers. The analysis took a synthetic narrative-discursive methodological approach, underpinned by feminist theory with particular attention to the discourses that were drawn on by participants and the constraints that these imposed. This paper presents these findings in relation to three constructions of their partners through which repair work was attempted: men as in need of rescue; men as flawed fathers; and men as damaged. The paper concludes with some suggestions for supporting stepmothers by challenging dominant narratives around families in talk, in the media and in government and institutional policies
Airway responses and inflammation in subjects with asthma after four days of repeated high-single-dose allergen challenge
Background: Both standard and low-dose allergen provocations are an established tool in asthma research to improve our understanding of the pathophysiological mechanism of allergic asthma. However, clinical symptoms are less likely to be induced. Therefore, we designed a protocol for repetitive high-dose bronchial allergen challenges to generate clinical symptoms and airway inflammation.
Methods: A total of 27 patients aged 18 to 40 years with positive skin-prick tests and mild asthma underwent repetitive high-dose allergen challenges with household dust mites for four consecutive days. Pulmonary function and exhaled NO were measured at every visit. Induced sputum was analysed before and after the allergen challenges for cell counts, ECP, IL-5, INF-γ, IL-8, and the transcription factor Foxp3.
Results: We found a significant decrease in pulmonary function, an increased use of salbutamol and the development of a late asthmatic response and bronchial hyperresponsiveness, as well as a significant induction of eNO, eosinophils, and Th-2 cytokines. Repeated provocation was feasible in the majority of patients. Two subjects had severe adverse events requiring prednisolone to cope with nocturnal asthma symptoms.
Conclusions: Repeated high-dose bronchial allergen challenges resulted in severe asthma symptoms and marked Th-2-mediated allergic airway inflammation. The high-dose challenge model is suitable only in an attenuated form in diseased volunteers for proof-of-concept studies and in clinical settings to reduce the risk of severe asthma exacerbations.
Trial registration: ClinicalTrials.govNCT0067720
Effects of grain shape on packing and dilatancy of sheared granular materials
Granular material exposed to shear shows a variety of unique phenomena:
Reynolds dilatancy, positional order and orientational order effects may
compete in the shear zone. We study granular packings consisting of macroscopic
prolate, oblate and spherical grains and compare their behaviour. X-ray
tomography is used to determine the particle positions and orientations in a
cylindrical split bottom shear cell. Packing densities and the arrangements of
individual particles in the shear zone are evaluated. For anisometric
particles, we observe the competition of two opposite effects. One the one
hand, the sheared granulate is dilated, but on the other hand the particles
reorient and align with respect to the streamlines. Even though aligned
cylinders in principle may achieve higher packing densities, this alignment
compensates for the effect of dilatancy only partially. The complex
rearrangements lead to a depression of the surface above the well oriented
region while neigbouring parts still show the effect of dilation in the form of
heaps. For grains with isotropic shapes, the surface remains rather flat.
Perfect monodisperse spheres crystallize in the shear zone, whereby positional
order partially overcompensates dilatancy effects. However, already slight
deviations from the ideal monodisperse sphere shape inhibit crystallization.Comment: 12 pages, 13 figures, accepted in Soft Matte
Library catalogue records as a research resource:introducing 'A Big Data History of Music'
Librarians and archivists are increasingly collecting and working with large quantities of digital data. In science, business, and now the humanities, the production and analysis of vast amounts of data (so-called ‘big data research’) have become fundamental activities. This article introduces the project A Big Data History of Music, a collaboration between Royal Holloway, University of London, and the British Library. The project has made the British Library’s catalogue records for printed and manuscript music available as open data, and has explored how the analysis and visualisation of huge numbers of bibliographic records can open new perspectives for researchers into music history. In addition to the British Library data (over a million records), the project drew on a further million bibliographic descriptions from RISM, which have also recently been released as open data. To show the challenges posed by the heterogeneous nature of the data, the article outlines the different structures of the various catalogue records used in the project, and summarises how the British Library data was cleaned and enhanced prior to its public release. Examples are given of how music-bibliographical data can be analysed and visualised, and how scholars and citizen scientists can engage with this data through hackathons, large-scale data analyses, and database construction. It is hoped this article will encourage other research libraries to consider making their catalogue records available as open data
Evolution of shear zones in granular materials
The evolution of wide shear zones (or shear bands) was investigated
experimentally and numerically for quasistatic dry granular flows in split
bottom shear cells. We compare the behavior of materials consisting of beads,
irregular grains (e.g. sand) and elongated particles. Shearing an initially
random sample, the zone width was found to significantly decrease in the first
stage of the process. The characteristic shear strain associated with this
decrease is about unity and it is systematically increasing with shape
anisotropy, i.e. when the grain shape changes from spherical to irregular (e.g.
sand) and becomes elongated (pegs). The strongly decreasing tendency of the
zone width is followed by a slight increase which is more pronounced for rod
like particles than for grains with smaller shape anisotropy (beads or
irregular particles). The evolution of the zone width is connected to shear
induced density change and for nonspherical particles it also involves grain
reorientation effects. The final zone width is significantly smaller for
irregular grains than for spherical beads.Comment: 11 pages, 12 figures, submitted to Phys. Rev.
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