2,186 research outputs found

    Multiple Topical Applications of Arachidonic Acid to Mouse Ears Induce Inflammatory and Proliferative Changes

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    The response to daily topical applications of arachidonic acid (0.25 – 4 mg/ear/day) to the ears of outbred CD-1 mice was monitored. The first application produced erythema, extravasation of plasma proteins resulting in an increase in ear weight, and some neutrophil accumulation (detected histologically and quantified by myeloperoxidase content). The second application produced minimal edema but did cause erythema and a greater accumulation of neutrophils. Subsequent daily application caused erythema, neutrophil accumulation, and an increase in ear weight predominantly due to cell proliferation (epidermis and connective tissue). Daily applications of other unsaturated fatty acids did not match the response induced by arachidonic acid. Mast cell deficient mice (W/Wv) exhibited a smaller edema response to the first dose of arachidonic acid compared to either their wild-type controls or CD-1 mice. In addition, W/Wv mice exhibited a smaller ear weight increase and myeloperoxidase accumulation following eight daily doses of arachidonic acid. However, epidermal proliferation was similar in all the strains of mice tested. These data suggest that the edema caused by the first topical application of arachidonic acid is partly mast cell mediated. Mast cells also appear to be involved in the neutrophil infiltration induced by multiple topical applications, but not in the epidermal proliferation

    Being Healthy: a Grounded Theory Study of Help Seeking Behaviour among Chinese Elders living in the UK

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    The health of older people is a priority in many countries as the world’s population ages. Attitudes towards help seeking behaviours in older people remain a largely unexplored field of research. This is particularly true for older minority groups where the place that they have migrated to presents both cultural and structural challenges. The UK, like other countries,has an increasingly aging Chinese population about who relatively little is known. This study used a qualitative grounded theory design following the approach of Glaser (1978). Qualitative data were collected using semi-structured interviews with 33 Chinese elders who were aged between 60 and 84, using purposive and theoretical sampling approaches. Data were analysed using the constant comparative method until data saturation occurred and a substantive theory was generated. ‘Being healthy’ (the core category) with four interrelated categories: self-management, normalizing/minimizing, access to health services, and being cured form the theory. The theory was generated around the core explanations provided by participants and Chinese elders’ concerns about health issues they face in their daily life. We also present data about how they direct their health-related activities towards meeting their physical and psychological goals of being healthy. Their differential understanding of diseases and a lack of information about health services were potent predictors of nonïżœhelp seeking and ‘self’ rather than medical management of their illnesses. This study highlights the need for intervention and health support for Chinese elders

    Ethical issues in the use of in-depth interviews: literature review and discussion

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    This paper reports a literature review on the topic of ethical issues in in-depth interviews. The review returned three types of article: general discussion, issues in particular studies, and studies of interview-based research ethics. Whilst many of the issues discussed in these articles are generic to research ethics, such as confidentiality, they often had particular manifestations in this type of research. For example, privacy was a significant problem as interviews sometimes probe unexpected areas. For similar reasons, it is difficult to give full information of the nature of a particular interview at the outset, hence informed consent is problematic. Where a pair is interviewed (such as carer and cared-for) there are major difficulties in maintaining confidentiality and protecting privacy. The potential for interviews to harm participants emotionally is noted in some papers, although this is often set against potential therapeutic benefit. As well as these generic issues, there are some ethical issues fairly specific to in-depth interviews. The problem of dual role is noted in many papers. It can take many forms: an interviewer might be nurse and researcher, scientist and counsellor, or reporter and evangelist. There are other specific issues such as taking sides in an interview, and protecting vulnerable groups. Little specific study of the ethics of in-depth interviews has taken place. However, that which has shows some important findings. For example, one study shows participants are not averse to discussing painful issues provided they feel the study is worthwhile. Some papers make recommendations for researchers. One such is that they should consider using a model of continuous (or process) consent rather than viewing consent as occurring once, at signature, prior to the interview. However, there is a need for further study of this area, both philosophical and empirical

    Sonic crystal lenses that obey Lensmaker's formula

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    This paper presents a theoretical study of the phenomenon of acoustic imaging by sonic crystals, which are made of two-dimensional regular arrays of rigid cylinders placed in parallel in air. The scattering of acoustic waves is computed using the standard multiple scattering theory, and the band structures are computed by the plane-wave expansion method. It is shown that properly arranged arrays not only can behave as acoustic lenses, but also the focusing effect can be well described by Lensmaker's formula. Possible applications are also discussed.Comment: 4 pages, 5 figure

    Predicting Shunt Currents in Stacks of Bipolar Plate Cells

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    A method is presented for predicting shunt currents in stacks of undivided and divided bipolar plate cells. The method is an efficient way of solving the coupled sets of algebraic equations that arise from using circuit analog models to represent the current paths in stacks of undivided or divided bipolar plate cells. These algebraic equations can be eitherlinear or nonlinear depending upon the current-potential relationships used in the model (i.e., nonlinear circuit elements can be included). The method is used to show the importance of including nonsymmetrical resistances and nonlinear circuit elements in the models. Also, the method is used to predict the shunt currents for a nine cell stack of pilot plant scale bipolar plate, membrane chlor-alkali cells. It is shown that these predictions agree qualitatively with measured values. Finally, the method is used to predict the shunt currents for stacks of 60 and 120 of these cells

    Response of BGMV and BGYMV resistant common bean to beet curly top virus

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    Crop losses can be severe when susceptible large-seeded Andean dry and green bean cultivars are planted early in dry areas with a history of curly top caused by Beet curly top virus (BCTV) and closely related species. In order to assess the level of curly top resistance in 65 diverse dry and green bean genotypes, seed was planted in a commercial field in Kimberly, ID in 2007. Viruliferous beet leafhoppers were released approximately 3 weeks after emergence to generate an artificial epiphytotic. Plants were rated on a scale of 1-5 (1 = healthy, 5 = highly susceptible) 5 weeks after infestation and verified at fully developed pod stage (R8). Capri and UI 51 were among the most susceptible genotypes, while A 429, DOR 390, DOR 500, and G 2402 did not exhibit any symptoms. In general, breeding lines and cultivars with known resistance to Bean golden mosaic virus and Bean golden yellow mosaic virus (except Morales) were resistant to moderately resistant to BCTV. Additional testing will be required to verify the resistance followed by research to determine the evolutionary origin of the genes for resistance to these viruses

    An analysis of fast photochemistry over high northern latitudes during spring and summer using in-situ observations from ARCTAS and TOPSE

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    Observations of chemical constituents and meteorological quantities obtained during the two Arctic phases of the airborne campaign ARCTAS (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites) are analyzed using an observationally constrained steady state box model. Measurements of OH and HO2 from the Penn State ATHOS instrument are compared to model predictions. Forty percent of OH measurements below 2 km are at the limit of detection during the spring phase (ARCTAS-A). While the median observed-to-calculated ratio is near one, both the scatter of observations and the model uncertainty for OH are at the magnitude of ambient values. During the summer phase (ARCTAS-B), model predictions of OH are biased low relative to observations and demonstrate a high sensitivity to the level of uncertainty in NO observations. Predictions of HO2 using observed CH2O and H2O2 as model constraints are up to a factor of two larger than observed. A temperature-dependent terminal loss rate of HO2 to aerosol recently proposed in the literature is shown to be insufficient to reconcile these differences. A comparison of ARCTAS-A to the high latitude springtime portion of the 2000 TOPSE campaign (Tropospheric Ozone Production about the Spring Equinox) shows similar meteorological and chemical environments with the exception of peroxides; observations of H2O2 during ARCTAS-A were 2.5 to 3 times larger than those during TOPSE. The cause of this difference in peroxides remains unresolved and has important implications for the Arctic HOx budget. Unconstrained model predictions for both phases indicate photochemistry alone is unable to simultaneously sustain observed levels of CH2O and H2O2; however when the model is constrained with observed CH2O, H2O2 predictions from a range of rainout parameterizations bracket its observations. A mechanism suitable to explain observed concentrations of CH2O is uncertain. Free tropospheric observations of acetaldehyde (CH3CHO) are 2–3 times larger than its predictions, though constraint of the model to those observations is sufficient to account for less than half of the deficit in predicted CH2O. The box model calculates gross O3 formation during spring to maximize from 1–4 km at 0.8 ppbv d−1, in agreement with estimates from TOPSE, and a gross production of 2–4 ppbv d−1 in the boundary layer and upper troposphere during summer. Use of the lower observed levels of HO2 in place of model predictions decreases the gross production by 25–50%. Net O3 production is near zero throughout the ARCTAS-A troposphere, and is 1–2 ppbv in the boundary layer and upper altitudes during ARCTAS-B

    Relationship among research collaboration, number of documents and number of citations. A case study in Spanish computer science production in 2000-2009.

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    This paper analyzes the relationship among research collaboration, number of documents and number of citations of computer science research activity. It analyzes the number of documents and citations and how they vary by number of authors. They are also analyzed (according to author set cardinality) under different circumstances, that is, when documents are written in different types of collaboration, when documents are published in different document types, when documents are published in different computer science subdisciplines, and, finally, when documents are published by journals with different impact factor quartiles. To investigate the above relationships, this paper analyzes the publications listed in the Web of Science and produced by active Spanish university professors between 2000 and 2009, working in the computer science field. Analyzing all documents, we show that the highest percentage of documents are published by three authors, whereas single-authored documents account for the lowest percentage. By number of citations, there is no positive association between the author cardinality and citation impact. Statistical tests show that documents written by two authors receive more citations per document and year than documents published by more authors. In contrast, results do not show statistically significant differences between documents published by two authors and one author. The research findings suggest that international collaboration results on average in publications with higher citation rates than national and institutional collaborations. We also find differences regarding citation rates between journals and conferences, across different computer science subdisciplines and journal quartiles as expected. Finally, our impression is that the collaborative level (number of authors per document) will increase in the coming years, and documents published by three or four authors will be the trend in computer science literature

    Theoretical studies of the historical development of the accounting discipline: a review and evidence

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    Many existing studies of the development of accounting thought have either been atheoretical or have adopted Kuhn's model of scientific growth. The limitations of this 35-year-old model are discussed. Four different general neo-Kuhnian models of scholarly knowledge development are reviewed and compared with reference to an analytical matrix. The models are found to be mutually consistent, with each focusing on a different aspect of development. A composite model is proposed. Based on a hand-crafted database, author co-citation analysis is used to map empirically the entire literature structure of the accounting discipline during two consecutive time periods, 1972–81 and 1982–90. The changing structure of the accounting literature is interpreted using the proposed composite model of scholarly knowledge development
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