2,099 research outputs found
The Impact of Autoimmune Hepatitis and Its Treatment on Health Utility
Patient reporting suggests that the physical and psychological effects of autoimmune hepatitis (AIH) can be substantial. However, healthârelated quality of life (HRQOL) in patients with AIH remains incompletely characterized, and health utility remains to be explored. Treatment for AIH often includes the use of corticosteroids, which are agents that can be associated with significant adverse effects. Here we explore the impact of AIH and its treatments on patientâreported HRQOL and health utility in a large cohort of prevalent cases from the United Kingdom Autoimmune Hepatitis (UKâAIH) national study. Data were collected from 990 adult participants with a clinical diagnosis of AIH using validated HRQOL tools including the European QualityâofâLife 5âDimension 5âLevel (EQâ5Dâ5L) and clinical data forms. The EQâ5Dâ5L dimension scores were compared with UK population norms and with a disease control cohort with primary biliary cholangitis (PBC). Within the AIH cohort, regression analysis was used to explore associations between HRQOL and demographic and clinical variables with a particular focus on the impact of AIH therapies including corticosteroid use. HRQOL, measured by the EQâ5Dâ5L utility index, is shown to be significantly impaired in our cohort of AIH patients compared with population norms. Within the AIH cohort, corticosteroid use was found to be significantly associated with impaired HRQOL, even when controlling for biochemical disease activity status. Conclusion: Our data show evidence of HRQOL impairment in a large cohort of AIH patients compared with the general population. Furthermore, corticosteroid use is strongly associated with decreased HRQOL, independent of remission status. This highlights the need for better corticosteroidâfree therapy approaches and it emphasizes the need for future novel therapeutic trials in AIH
Invasion speeds for structured populations in fluctuating environments
We live in a time where climate models predict future increases in
environmental variability and biological invasions are becoming increasingly
frequent. A key to developing effective responses to biological invasions in
increasingly variable environments will be estimates of their rates of spatial
spread and the associated uncertainty of these estimates. Using stochastic,
stage-structured, integro-difference equation models, we show analytically that
invasion speeds are asymptotically normally distributed with a variance that
decreases in time. We apply our methods to a simple juvenile-adult model with
stochastic variation in reproduction and an illustrative example with published
data for the perennial herb, \emph{Calathea ovandensis}. These examples
buttressed by additional analysis reveal that increased variability in vital
rates simultaneously slow down invasions yet generate greater uncertainty about
rates of spatial spread. Moreover, while temporal autocorrelations in vital
rates inflate variability in invasion speeds, the effect of these
autocorrelations on the average invasion speed can be positive or negative
depending on life history traits and how well vital rates ``remember'' the
past
Utility of Parental Mediation Model on Youthâs Problematic Online Gaming
The Parental Mediation Model PMM) was initially designed to regulate childrenâs attitudes towards the traditional media. In the present era, because of prevalent online media there is a need for similar regulative measures. Spending long hours on social media and playing online games increase the risks of exposure to the negative outcomes of online gaming. This paper initially applied the PMM developed by European Kids Online to (i) test the reliability and validity of this model and (ii) identify the effectiveness of this model in controlling problematic online gaming (POG). The data were collected from 592 participants comprising 296 parents and 296 students of four foreign universities, aged 16 to 22 years in Kuala Lumpur (Malaysia). The study found that the modified model of the five-factor PMM (Technical mediation, Monitoring mediation, Restrictive mediation, Active Mediation of Internet Safety, and Active mediation of Internet Use) functions as a predictor for mitigating POG. The findings suggest the existence of a positive relation between âmonitoringâ and ârestrictiveâ mediation strategies and exposure to POG while Active Mediation of Internet Safety and Active mediation of Internet use were insignificant predictors. Results showed a higher utility of âtechnicalâ strategies by the parents led to less POG. The findings of this study do not support the literature suggesting active mediation is more effective for reducing youthâs risky behaviour. Instead, parents need to apply more technical mediations with their children and adolescentsâ Internet use to minimize the negative effects of online gaming
Bone Marrow Stem Cell Treatment for Ischemic Heart Disease in Patients with No Option of Revascularization: A Systematic Review and Meta-Analysis
PMCID: PMC3686792This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Competition and Complementarity in Diffusion: The Case of Octane
The standard ontogenic (life-cycle) model of technological evolution can be characterized briefly as follows (Ayres, 1987): (1) a radical invention (birth) creates a new technology; (2) it is commercialized on the basis of performance and rapidly developed by a series of improvements and modifications (infancy); (3) it is successful enough in the marketplace to attract many variants and imitators who hope to exploit a growing market (adolescence); (4) the pace of technological change finally slows down enough to permit standardization and exploitation of economies of scale, and competition on the basis of price rather than performance (maturity); and finally a new and better technology supplants it (senescence)
Early Mendeley readers correlate with later citation counts
This is an accepted manuscript of an article published by Springer in Scientometrics on 26/03/2018, available online: https://doi.org/10.1007/s11192-018-2715-9
The accepted version of the publication may differ from the final published version.Counts of the number of readers registered in the social reference manager Mendeley have been proposed as an early impact indicator for journal articles. Although previous research has shown that Mendeley reader counts for articles tend to have a strong positive correlation with synchronous citation counts after a few years, no previous studies have compared early Mendeley reader counts with later citation counts. In response, this first diachronic analysis compares reader counts within a month of publication with citation counts after 20 months for ten fields. There were moderate or strong correlations in eight out of ten fields, with the two exceptions being the smallest categories (n=18, 36) with wide confidence intervals. The correlations are higher than the correlations between later citations and early citations, showing that Mendeley reader counts are more useful early impact indicators than citation counts
The mathematical review system: does reviewer status play a role in the citation process?
This paper revisits an aspect of citation theory (i.e., citer motivation) with respect to the Mathematical Review system and the reviewerâs role in mathematics. We focus on a set of journal articles (369) published in Singularity Theory (1974â2003), the mathematicians who wrote editorial reviews for these articles, and the number of citations each reviewed article received within a 5 year period. Our research hypothesis is that the cognitive authority of a high status reviewer plays a positive role in how well a new article is received and cited by others. Bibliometric evidence points to the contrary: Singularity Theorists of lower status (junior researchers) have reviewed slightly more well-cited articles (2â5 citations, excluding author self-citations) than their higher status counterparts (senior researchers). One explanation for this result is that lower status researchers may have been asked to review âtrendyâ or more accessible parts of mathematics, which are easier to use and cite. We offer further explanations and discuss a number of implications for a theory of citation in mathematics. This research opens the door for comparisons to other editorial review systems, such as book reviews written in the social sciences or humanities
Characterising the phenotypic diversity of Papilio dardanus wing patterns using an extensive museum collection
The history of 20th Century evolutionary biology can be followed through the study of mimetic butterflies. From the initial findings of discontinuous polymorphism through the debates regarding the evolution of mimicry and the step-size of evolutionary change, to the studies on supergene evolution and molecular characterisation of butterfly genomes, mimetic butterflies have been at the heart of evolutionary thought for over 100 years. During this time, few species have received as much attention and in-depth study as Papilio dardanus. To assist all aspects of mimicry research, we present a complete data-derived overview of the extent of polymorphism within this species. Using historical samples permanently held by the NHM London, we document the extent of phenotypic variation and characterise the diversity present in each of the subspecies and how it varies across Africa. We also demonstrate an association between âimperfectâ mimetic forms and the transitional race formed in the area where Eastern and Western African populations meet around Lake Victoria. We present a novel portal for access to this collection, www.mimeticbutterflies.org, allowing remote access to this unique repository. It is hoped that this online resource can act as a nucleus for the sharing and dissemination of other collections databases and imagery connected with mimetic butterflies
Magnetism and its microscopic origin in iron-based high-temperature superconductors
High-temperature superconductivity in the iron-based materials emerges from,
or sometimes coexists with, their metallic or insulating parent compound
states. This is surprising since these undoped states display dramatically
different antiferromagnetic (AF) spin arrangements and Nel
temperatures. Although there is general consensus that magnetic interactions
are important for superconductivity, much is still unknown concerning the
microscopic origin of the magnetic states. In this review, progress in this
area is summarized, focusing on recent experimental and theoretical results and
discussing their microscopic implications. It is concluded that the parent
compounds are in a state that is more complex than implied by a simple Fermi
surface nesting scenario, and a dual description including both itinerant and
localized degrees of freedom is needed to properly describe these fascinating
materials.Comment: 14 pages, 4 figures, Review article, accepted for publication in
Nature Physic
Liquid-gas phase transition in nuclear multifragmentation
The equation of state of nuclear matter suggests that at suitable beam
energies the disassembling hot system formed in heavy ion collisions will pass
through a liquid-gas coexistence region. Searching for the signatures of the
phase transition has been a very important focal point of experimental
endeavours in heavy ion collisions, in the last fifteen years. Simultaneously
theoretical models have been developed to provide information about the
equation of state and reaction mechanisms consistent with the experimental
observables. This article is a review of this endeavour.Comment: 63 pages, 27 figures, submitted to Adv. Nucl. Phys. Some typos
corrected, minor text change
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