1,858 research outputs found
Newsbots That Mediate Journalist and Audience Relationships
© 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group. News media organisations are experimenting with a new generation of newsbots that move beyond automated headline delivery to the delivery of news according to a conversational format within the context of private messaging services. To build the newsbot, journalists craft statements and answers to users’ questions that mimic a natural conversation between a journalist and user. In so doing, journalists are experimenting with styles of communication that reflect very particular journalistic personas. We investigate the persona of the news chatbot created by the Australian Broadcasting Corporation (ABC), the better to understand how the public broadcaster’s forays into social media service delivery and automation are shaping new relationships between public service broadcasters and their audiences. We find that, for a section of the audience that uses it, the friendly newsbot contrasts favourably with their previous experience with news and the journalists who produce it. The public service journalists who operate the bot are, in turn, using the bot to try to reach new audiences by experimenting with a more informal, intimate relationship with citizen users. The supposedly “intelligent” (but in actual fact very much human-crafted) newsbot is the vehicle through which this new relationship is being forged
Exponential Divergence and Long Time Relaxation in Chaotic Quantum Dynamics
Phase space representations of the dynamics of the quantal and classical cat
map are used to explore quantum--classical correspondence in a K-system: as
, the classical chaotic behavior is shown to emerge smoothly and
exactly. The quantum dynamics near the classical limit displays both
exponential separation of adjacent distributions and long time relaxation, two
characteristic features of classical chaotic motion.Comment: 10 pages, ReVTeX, to appear in Phys. Rev. Lett. 13 figures NOT
included. Available either as LARGE (uuencoded gzipped) postscript files or
hard-copies from [email protected]
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Epigenetic Interactions and the Structure of Phenotypic Variation in the Cranium
Understanding the developmental and genetic
basis for evolutionarily significant morphological variation in
complex phenotypes such as themammalian skull is a challenge
because of the sheer complexity of the factors involved. We
hypothesize that even in this complex system, the expression of
phenotypic variation is structured by the interaction of a few key
developmental processes. To test this hypothesis, we created a
highly variable sample of crania using four mouse mutants and
their wild-type controls from similar genetic backgrounds with
developmental perturbations to particular cranial regions. Using
geometricmorphometricmethods we compared patterns of size,
shape, and integration in the sample within and between the
basicranium, neurocranium, and face. The results highlight
regular and predictable patterns of covariation among regions of
the skull that presumably reflect the epigenetic influences of the
genetic perturbations in the sample. Covariation between
relative widths of adjoining regions is the most dominant factor,
but there are other significant axes of covariation such as the
relationship between neurocranial size and basicranial flexion.
Although there are other sources of variation related to
developmental perturbations not analyzed in this study, the
patterns of covariation created by the epigenetic interactions
evident in this sample may underlie larger scale evolutionary
patterns in mammalian craniofacial form.Anthropolog
Role of the 5-Lipoxygenase–activating Protein (FLAP) in Murine Acute Inflammatory Responses
Leukotrienes are potent inflammatory mediators synthesized from arachidonic acid (AA) predominately by cells of myeloid origin. The synthesis of these lipids is believed to be dependent not only on the expression of the enzyme 5-lipoxygenase (5-LO), which catalyzes the first steps in the synthesis of leukotrienes, but also on expression of a nuclear membrane protein termed the 5-LO–activating protein (FLAP). To study the relationship of these two proteins in mediating the production of leukotrienes in vivo and to determine whether the membrane protein FLAP has additional functions in various inflammatory processes, we have generated a mouse line deficient in this protein. FLAP-deficient mice develop normally and are healthy. However, an array of assays comparing inflammatory reactions in FLAP-deficient mice and in normal controls revealed that FLAP plays a role in a subset of these reactions. Although examination of DTH and IgE-mediated passive anaphylaxis showed no difference between wild-type and FLAP-deficient animals, mice without FLAP possessed a blunted inflammatory response to topical AA and had increased resistance to platelet-activating factor–induced shock compared to controls. Also, edema associated with Zymosan A–induced peritonitis was markedly reduced in animals lacking FLAP. To determine whether these differences relate solely to a deficit in leukotriene production, or whether they reflect an additional role for FLAP in inflammation, we compared the FLAP-deficient mice to 5-LO–deficient animals. Evaluation of mice lacking FLAP and 5-LO indicated that production of leukotrienes during inflammatory responses is dependent upon the availability of FLAP and did not support additional functions for FLAP beyond its role in leukotriene production
Purification to homogeneity and the N-terminal sequence of human leukotriene C4 synthase: a homodimeric glutathione S-transferase composed of 18-kDa subunits.
Vitamin D and subsequent all-age and premature mortality: a systematic review
<br>Background:
All-cause mortality in the population < 65 years is 30% higher in Glasgow than in equally deprived Liverpool and Manchester. We investigated a hypothesis that low vitamin D in this population may be associated with premature mortality via a systematic review and meta-analysis.</br>
<br>Methods:
Medline, EMBASE, Web of Science, the Cochrane Library and grey literature sources were searched until February 2012 for relevant studies. Summary statistics were combined in an age-stratified meta-analysis.</br>
<br>Results:
Nine studies were included in the meta-analysis, representing 24,297 participants, 5,324 of whom died during follow-up. The pooled hazard ratio for low compared to high vitamin D demonstrated a significant inverse association (HR 1.19, 95% CI 1.12-1.27) between vitamin D levels and all-cause mortality after adjustment for available confounders. In an age-stratified meta-analysis, the hazard ratio for older participants was 1.25 (95% CI 1.14-1.36) and for younger participants 1.12 (95% CI 1.01-1.24).</br>
<br>Conclusions:
Low vitamin D status is inversely associated with all-cause mortality but the risk is higher amongst older individuals and the relationship is prone to residual confounding. Further studies investigating the association between vitamin D deficiency and all-cause mortality in younger adults with adjustment for all important confounders (or using randomised trials of supplementation) are required to clarify this relationship.</br>
Targeted hepatitis C antibody testing interventions: a systematic review and meta-analysis
Testing for hepatitis C virus (HCV) infection may reduce the risk of liver-related morbidity, by facilitating earlier access to treatment and care. This review investigated the effectiveness of targeted testing interventions on HCV case detection, treatment uptake, and prevention of liver-related morbidity. A literature search identified studies published up to 2013 that compared a targeted HCV testing intervention (targeting individuals or groups at increased risk of HCV) with no targeted intervention, and results were synthesised using meta-analysis. Exposure to a targeted testing intervention, compared to no targeted intervention, was associated with increased cases detected [number of studies (n) = 14; pooled relative risk (RR) 1.7, 95 % CI 1.3, 2.2] and patients commencing therapy (n = 4; RR 3.3, 95 % CI 1.1, 10.0). Practitioner-based interventions increased test uptake and cases detected (n = 12; RR 3.5, 95 % CI 2.5, 4.8; and n = 10; RR 2.2, 95 % CI 1.4, 3.5, respectively), whereas media/information-based interventions were less effective (n = 4; RR 1.5, 95 % CI 0.7, 3.0; and n = 4; RR 1.3, 95 % CI 1.0, 1.6, respectively). This meta-analysis provides for the first time a quantitative assessment of targeted HCV testing interventions, demonstrating that these strategies were effective in diagnosing cases and increasing treatment uptake. Strategies involving practitioner-based interventions yielded the most favourable outcomes. It is recommended that testing should be targeted at and offered to individuals who are part of a population with high HCV prevalence, or who have a history of HCV risk behaviour
Regulation of neutrophil senescence by microRNAs
Neutrophils are rapidly recruited to sites of tissue injury or infection, where they protect against invading pathogens. Neutrophil functions are limited by a process of neutrophil senescence, which renders the cells unable to respond to chemoattractants, carry out respiratory burst, or degranulate. In parallel, aged neutrophils also undergo spontaneous apoptosis, which can be delayed by factors such as GMCSF. This is then followed by their subsequent removal by phagocytic cells such as macrophages, thereby preventing unwanted inflammation and tissue damage. Neutrophils translate mRNA to make new proteins that are important in maintaining functional longevity. We therefore hypothesised that neutrophil functions and lifespan might be regulated by microRNAs expressed within human neutrophils. Total RNA from highly purified neutrophils was prepared and subjected to microarray analysis using the Agilent human miRNA microarray V3. We found human neutrophils expressed a selected repertoire of 148 microRNAs and that 6 of these were significantly upregulated after a period of 4 hours in culture, at a time when the contribution of apoptosis is negligible. A list of predicted targets for these 6 microRNAs was generated from http://mirecords.biolead.org and compared to mRNA species downregulated over time, revealing 83 genes targeted by at least 2 out of the 6 regulated microRNAs. Pathway analysis of genes containing binding sites for these microRNAs identified the following pathways: chemokine and cytokine signalling, Ras pathway, and regulation of the actin cytoskeleton. Our data suggest that microRNAs may play a role in the regulation of neutrophil senescence and further suggest that manipulation of microRNAs might represent an area of future therapeutic interest for the treatment of inflammatory disease
A scoping review of observational studies examining relationships between environmental behaviors and health behaviors
Individual lifestyles are key drivers of both environmental change and chronic disease. We undertook a scoping review of peer-reviewed studies which examined associations between environmental and health behaviors of individuals in high-income countries. We searched EconLit, Medline, BIOSIS and the Social Science Citation Index. A total of 136 studies were included. The majority were USA-based cross-sectional studies using self-reported measures. Most of the evidence related to travel behavior, particularly active travel (walking and cycling) and physical activity (92 studies) or sedentary behaviors (19 studies). Associations of public transport use with physical activity were examined in 18 studies, and with sedentary behavior in one study. Four studies examined associations between car use and physical activity. A small number included other environmental behaviors (food-related behaviors (n = 14), including organic food, locally-sourced food and plate waste) and other health behaviors ((n = 20) smoking, dietary intake, alcohol). These results suggest that research on individual environmental and health behaviors consists largely of studies examining associations between travel mode and levels of physical activity. There appears to be less research on associations between other behaviors with environmental and health impacts, and very few longitudinal studies in any domain
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