1,049 research outputs found

    Is Twitter a Public Sphere for Online Conflicts? A Cross-Ideological and Cross-Hierarchical Look

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    The rise in popularity of Twitter has led to a debate on its impact on public opinions. The optimists foresee an increase in online participation and democratization due to social media's personal and interactive nature. Cyber-pessimists, on the other hand, explain how social media can lead to selective exposure and can be used as a disguise for those in power to disseminate biased information. To investigate this debate empirically, we evaluate Twitter as a public sphere using four metrics: equality, diversity, reciprocity and quality. Using these measurements, we analyze the communication patterns between individuals of different hierarchical levels and ideologies. We do this within the context of three diverse conflicts: Israel-Palestine, US Democrats-Republicans, and FC Barcelona-Real Madrid. In all cases, we collect data around a central pair of Twitter accounts representing the two main parties. Our results show in a quantitative manner that Twitter is not an ideal public sphere for democratic conversations and that hierarchical effects are part of the reason why it is not.Comment: To appear in the 6th International Conference on Social Informatics (SocInfo 2014), Barcelon

    Clinical questions raised by providers in the care of older adults: a prospective observational study

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    pre-printObjective: To characterise clinical questions raised by providers in the care of complex older adults in order to guide the design of interventions that can help providers answer these questions. Materials and methods: To elicit clinical questions, we observed and audio recorded outpatient visits at three healthcare organisations. At the end of each appointment, providers were asked to identify clinical questions raised in the visit. Providers rated their questions based on their urgency, importance to the patient's care and difficulty in finding a useful answer to. Transcripts of the audio recordings were analysed to identify ageing-specific factors that may have contributed to the nature of the questions. Results: We observed 36 patient visits with 10 providers at the three study sites. Providers raised 70 clinical questions (median of 2 clinical questions per patient seen; range 0-12), pursued 50 (71%) and successfully answered 34 (68%) of the questions they pursued. Overall, 36 (51%) of providers' questions were not answered. Over one-third of the questions were about treatment alternatives and adverse effects. All but two clinical questions were motivated either directly or indirectly by issues related to ageing, such as the normal physiological changes of ageing and diseases with higher prevalence in the elderly. Conclusions: The frequency of clinical questions was higher than in previous studies conducted in general primary care patient populations. Clinical questions were predominantly influenced by ageing-related issues. We propose a series of recommendations that may be used to guide the design of solutions to help providers answer their clinical questions in the care of older adults

    Effects of supplementing methionine and lysine in a lactation diet containing high concentrations of corn by-products

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    Ninety-six lactating Holstein cows were used to determine the effects of using commercial supplements to supply additional lysine and methionine in diets containing large proportions of corn by-products. Cows were assigned to 1 of 8 pens. Pens were offered rations formulated to differ in metabolizable lysine and methionine supply. The study was divided into 2 periods. During period 1, cows received similar diets, but the treatment diet supplied supplemental lysine and methionine. During period 2, the treatment diet was modified to reduce dietary crude protein. Feed intake and production were monitored daily, and milk components were analyzed 3 days per week for 4 weeks. Diet did not alter feed intake or milk production. During period 2, dietary crude protein and milk urea nitrogen (MUN) were decreased without sacrificing performance.; Dairy Day, 2011, Kansas State University, Manhattan, KS, 2011; Dairy Research, 2011 is known as Dairy Day, 201

    Involution of the mouse mammary gland is associated with an immune cascade and an acute-phase response, involving LBP, CD14 and STAT3

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    INTRODUCTION: Involution of the mammary gland is a complex process of controlled apoptosis and tissue remodelling. The aim of the project was to identify genes that are specifically involved in this process. METHODS: We used Affymetrix oligonucleotide microarrays to perform a detailed transcript analysis on the mechanism of controlled involution after withdrawal of the pups at day seven of lactation. Some of the results were confirmed by semi-quantitative reverse transcriptase polymerase chain reaction, Western blotting or immunohistochemistry. RESULTS: We identified 145 genes that were specifically upregulated during the first 4 days of involution; of these, 49 encoded immunoglobulin genes. A further 12 genes, including those encoding the signal transducer and activator of transcription 3 (STAT3), the lipopolysaccharide receptor (CD14) and lipopolysaccharide-binding protein (LBP), were involved in the acute-phase response, demonstrating that the expression of acute-phase response genes can occur in the mammary gland itself and not only in the liver. Expression of LBP and CD14 was upregulated, at both the RNA and protein level, immediately after pup withdrawal; CD14 was strongly expressed in the luminal epithelial cells. Other genes identified suggested neutrophil activation early in involution, followed by macrophage activation late in the process. Immunohistochemistry and histological staining confirmed the infiltration of the involuting mammary tissue with neutrophils, plasma cells, macrophages and eosinophils. CONCLUSION: Oligonucleotide microarrays are a useful tool for identifying genes that are involved in the complex developmental process of mammary gland involution. The genes identified are consistent with an immune cascade, with an early acute-phase response that occurs in the mammary gland itself and resembles a wound healing process

    The management of tree genetic resources and the livelihoods of rural communities in the tropics: non-timber forest products, smallholder agroforestry practices and tree commodity crops

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    Products and services provided by trees in forests and farmland support the needs and promote the wellbeing of hundreds of millions of people in the tropics. Value depends on managing both the diversity of tree species present in landscapes and the genetic variation within these species. The benefits from trees and their genetic resources are, however, often not well quantified because trade is frequently outside formal markets, there is a multiplicity of species and ways in which trees are used and managed, and genetic diversity within species is frequently not given proper consideration. We review here what is known about the value of trees to rural communities through considering three production categories: non-timber products harvested from trees in natural and managed forests and woodlands; the various products and services obtained from a wide range of trees planted and/or retained in smallholders’ agroforestry systems; and the commercial products harvested from cultivated tree commodity crops. Where possible, we focus on the role of intra-specific genetic variation in providing support to livelihoods, and for each of the three production categories we also consider wider conservation and sustainability issues, including the linkages between categories in terms of management. Challenges to ‘conventional wisdom’ on tree resource use, value and management – such as in the posited links between commercialisation, cultivation and conservation – are highlighted, and constraints and opportunities to maintain and enhance value are described

    Peach palm, Bactris gasipaes Kunth

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    Yielding fruits and palm hearts, peach palm (Bactris gasipaes) was a staple food crop for many pre-Columbian Amerindian communities in the lowland humid neotropics. The gene pool of cultivated peach palm and its wild relatives is rich in diversity but is subject to genetic erosion creating an urgent need to sample and conserve germplasm. This booklet provides an overview of existing knowledge of the genus with emphasis on genetic resources. Chapters cover the following topics: taxonomy and distribution, botanical description, uses and properties, origin and domestication, genetic diversity, collecting and evaluation, breeding, propagation, agronomy, production areas, commercial potential, limitations and future prospects. An appendix presents details of institutions and scientists managing gene banks and conduction research on peach palm. (Abstract © CAB ABSTRACTS, CAB International

    Socially-Mediated Internet Surveys (SMIS): Recruiting participants for online experiments

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    The Socially Mediated Internet Survey (SMIS) method is a cost-effective technique used to obtain web-based, adult samples for experimental research in political science. SMIS engages central figures in online social networks to help recruit participants among visitors to these websites, yielding sizable samples for experimental research. We present data from six samples collected using the SMIS method and compare them to those gathered by other sampling approaches such as Amazon's Mechanical Turk. While not representative of the general adult population, our SMIS samples are significantly more diverse than undergraduate convenience samples, not only demographically but also politically. We discuss the applicability of the method to experimental research and its usefulness for obtaining samples of special, politically relevant subpopulations such as political sophisticates and activists. We argue that the diversity of SMIS samples, along with the ability to capture highly engaged citizens, can circumvent questions about the artificiality of political behavior experiments entirely based on student samples and help to document sources of heterogeneous experimental treatment effects

    The JAK inhibitor ruxolitinib reduces inflammation in an ILC3-independent model of innate immune colitis

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    Innate immunity contributes to the pathogenesis of inflammatory bowel disease (IBD). However, the mechanisms of IBD mediated by innate immunity are incompletely understood and there are limited models of spontaneous innate immune colitis to address this question. Here we describe a new robust model of colitis occurring in the absence of adaptive immunity. RAG1-deficient mice expressing TNFAIP3 in intestinal epithelial cells (TRAG mice) spontaneously developed 100% penetrant, early-onset colitis that was limited to the colon and dependent on intestinal microbes but was not transmissible to co-housed littermates. TRAG colitis was associated with increased mucosal numbers of innate lymphoid cells (ILCs) and depletion of ILC prevented colitis in TRAG mice. ILC depletion also therapeutically reversed established colitis in TRAG mice. The colitis in TRAG mice was not prevented by interbreeding to mice lacking group 3 ILC nor by depletion of TNF. Treatment with the JAK inhibitor ruxolitinib ameliorated colitis in TRAG mice. This new model of colitis, with its predictable onset and colon-specific inflammation, will have direct utility in developing a more complete understanding of innate immune mechanisms that can contribute to colitis and in pre-clinical studies for effects of therapeutic agents on innate immune-mediated IBD

    Q2Q^2 Independence of QF2/F1QF_2/F_1, Poincare Invariance and the Non-Conservation of Helicity

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    A relativistic constituent quark model is found to reproduce the recent data regarding the ratio of proton form factors, F2(Q2)/F1(Q2)F_2(Q^2)/F_1(Q^2). We show that imposing Poincare invariance leads to substantial violation of the helicity conservation rule, as well as an analytic result that the ratio F2(Q2)/F1(Q2)∼1/QF_2(Q^2)/F_1(Q^2)\sim 1/Q for intermediate values of Q2Q^2.Comment: 13 pages, 7 figures, to be submitted to Phys. Rev. C typos corrected, references added, 1 new figure to show very high Q^2 behavio

    The Role of Color Neutrality in Nuclear Physics--Modifications of Nucleonic Wave Functions

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    The influence of the nuclear medium upon the internal structure of a composite nucleon is examined. The interaction with the medium is assumed to depend on the relative distances between the quarks in the nucleon consistent with the notion of color neutrality, and to be proportional to the nucleon density. In the resulting description the nucleon in matter is a superposition of the ground state (free nucleon) and radial excitations. The effects of the nuclear medium on the electromagnetic and weak nucleon form factors, and the nucleon structure function are computed using a light-front constituent quark model. Further experimental consequences are examined by considering the electromagnetic nuclear response functions. The effects of color neutrality supply small but significant corrections to predictions of observables.Comment: 37 pages, postscript figures available on request to [email protected]
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