64 research outputs found
Towards improved performance and interoperability in distributed and physical union catalogues
Purpose of this paper: This paper details research undertaken to determine the key differences in the performance of certain centralised (physical) and distributed (virtual) bibliographic catalogue services, and to suggest strategies for improving interoperability and performance in, and between, physical and virtual models. Design/methodology/approach: Methodically defined searches of a centralised catalogue service and selected distributed catalogues were conducted using the Z39.50 information retrieval protocol, allowing search types to be semantically defined. The methodology also entailed the use of two workshops comprising systems librarians and cataloguers to inform suggested strategies for improving performance and interoperability within both environments. Findings: Technical interoperability was permitted easily between centralised and distributed models, however the various individual configurations permitted only limited semantic interoperability. Significant prescription in cataloguing and indexing guidelines, greater participation in the Program for Collaborative Cataloging (PCC), consideration of future 'FRBR' migration, and greater disclosure to end users are some of the suggested strategies to improve performance and semantic interoperability. Practical implications: This paper informs the LIS research community and union catalogue administrators, but also has numerous practical implications for those establishing distributed systems based on Z39.50 and SRW, as well as those establishing centralised systems. What is original/value of the paper?: The paper moves the discussion of Z39.50 based systems away from anecdotal evidence and provides recommendations based on testing and is intimately informed by the UK cataloguing and systems librarian community
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The Prophet's Legacy
This article explores the quantity and quality of publications in relation to quality theorists. Searching for the names of quality gurus to observe trends and differences concerning the quantity and quality of literature written by or discussing them offers a unique approach to addressing this area. A reduction in the quantity of literature in relation to any of the theorists might indicate that funding and time allocation for research into their theories is declining. The research that follows indicates that the quantity of literature discussing W. Edwards Deming has declined since the 2008 economic crisis, while his impact over time (as measured by the volume of citations for articles written by or mentioning Deming) is far greater than that of his contemporaries. The authors argue that this research justifies a call for greater funding allocated toward the study of Deming's philosophy
Interoperability : the performance of institutional catalogues & strategies for improvement
This paper reviews work undertaken to better understand the performance of physical and virtual union catalogues for the purposes of resource discovery and retrieval within the JISC Information Environment, as under the auspices of the CC-interop project. System-level variations in the ability of systems to process search queries were noted and the impact of disparate cataloguing and indexing practices on recall and precision were also investigated. Recommendations for improving interoperability (including semantic interoperability) are proposed
Keratins and lipids in ethnic hair
Human hair has an important and undeniable relevance in society due to its important role in visual appearance and social communication. Hair is mainly composed of structural proteins, mainly keratin and keratin associated proteins, and lipids. Herein, we report a comprehensive study of the content and distribution of the lipids among ethnic hair, African, Asian and Caucasian hair. More interestingly, we also report the study of the interaction between those two main components of hair, specifically the influence of the hair internal lipids in the structure of the hair keratin. This was achieved by the use of a complete set of analytical tools such as thin layer chromatography-flame ionization detector, X-ray analysis, molecular dynamics simulation and confocal microscopy. The experimental results indicated different amounts of lipids on ethnic hair compositions and higher percentage of hair internal lipids in African hair. In this type of hair, the axial diffraction of keratin was not observed in X-ray analysis, but after hair lipids removal, the keratin returned to its typical packing arrangement. In molecular dynamic simulation lipids were shown to intercalate dimers of keratin, changing its structure. From those results we assume that keratin structure may be influenced by higher concentration of lipids in African hair.Margarida Fernandes held a PhD scholarship from Fundacaopara a Ciencia e Tecnologia (SFRH/BD/38 363/2007). The authors thank Vadim Volkov for the contribution with the confocal images
A Metric of Influential Spreading during Contagion Dynamics through the Air Transportation Network
The spread of infectious diseases at the global scale is mediated by long-range human travel. Our ability to predict the impact of an outbreak on human health requires understanding the spatiotemporal signature of early-time spreading from a specific location. Here, we show that network topology, geography, traffic structure and individual mobility patterns are all essential for accurate predictions of disease spreading. Specifically, we study contagion dynamics through the air transportation network by means of a stochastic agent-tracking model that accounts for the spatial distribution of airports, detailed air traffic and the correlated nature of mobility patterns and waiting-time distributions of individual agents. From the simulation results and the empirical air-travel data, we formulate a metric of influential spreading––the geographic spreading centrality––which accounts for spatial organization and the hierarchical structure of the network traffic, and provides an accurate measure of the early-time spreading power of individual nodes
"Pure" diastolic dysfunction is associated with long-axis systolic dysfunction. Implications for the diagnosis and classification of heart failure
AIMS: To investigate regional systolic function of the left ventricle, to test the hypothesis that "pure" diastolic dysfunction (impaired global diastolic filling, with a preserved ejection fraction > or = 50%) is associated with longitudinal systolic dysfunction.
METHODS AND RESULTS: One hundred thirty subjects (31 patients with asymptomatic diastolic dysfunction, 30 with diastolic heart failure, 30 with systolic heart failure; and 39 age-matched normal volunteers) were studied by conventional and tissue Doppler echocardiography. Global diastolic function was assessed using the flow propagation velocity, and by estimating left ventricular filling pressure from the ratio of transmitral E and mitral annular E(TDE) velocities (E/E(TDE)); and global systolic function by measurement of ejection fraction. Radial and longitudinal functions were assessed separately from posterior wall and mitral annular velocities. Global and radial systolic function were similar in patients with "pure" diastolic dysfunction and normal subjects, but patients with either asymptomatic diastolic dysfunction or diastolic heart failure had impaired longitudinal systolic function (mean velocities: 8.0+/-1.2 and 7.7+/-1.5 cm/s, respectively, versus 10.1+/-1.5 cm/s in controls; p<0.001). In subjects with normal ejection fraction, global diastolic function correlated with longitudinal systolic function (r=0.56 for flow propagation velocity, and r=-0.53 for E/E(TDE) ratio, both p<0.001), but not with global systolic function.
CONCLUSION: Worsening global diastolic dysfunction of the left ventricle is associated with a progressive decline in longitudinal systolic function. Diastolic heart failure as conventionally diagnosed is associated with regional, subendocardial systolic dysfunction that can be revealed by tissue Doppler of long-axis shortening. Diagnostic algorithms and definitions of heart failure need to be revised
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