1,721,192 research outputs found
Burgess (Stanley M.) McGee (Gary B.) Alexander (Patrick H.) eds Dictionary of Pentecostal and Charismatic Movements
No full textCohen Martine. Burgess (Stanley M.) McGee (Gary B.) Alexander (Patrick H.) eds Dictionary of Pentecostal and Charismatic Movements. In: Archives de sciences sociales des religions, n°72, 1990. p. 237
The contribution of the Fc RIIB immunoreceptor tyrosine-based inhibitory motif (ITIM) to the modulation of antibody immunotherapy
No full textMonoclonal antibodies (mAb) are an increasingly important therapeutic tool in the treatment of cancers and autoimmunity. Many mAbs elicit their efficacy through engagement of activatory Fc gamma receptors (Fc R), resulting in target cell depletion by immune effector cells. These activatory Fc Rs are negatively influenced by the single inhibitory Fc R, Fc RIIB. Fc RIIB has been shown to reduce the efficacy of mAbs through impairment of activatory Fc R function and upregulation of Fc RIIB has been identified as a resistance mechanism of mAb therapeutics in cancer. Fc RIIB contains an intracellular immunoreceptor-tyrosine-based inhibition motif (ITIM), which delivers inhibitory signalling. Whether the ITIM is required for all Fc RIIB-mediated inhibitory activities of therapeutic mAbs is not yet clear. To address this issue, we developed and characterised a novel transgenic mouse model (NoTIM), in which the endogenous inhibitory mouse (m)Fc RII is replaced with a non-signalling ITIM mutant of human (h)Fc RIIB. Cells from mice expressing the NoTIM receptor were no longer able to elicit phosphorylation of the Fc RIIB ITIM, mediate efficient internalisation of immune complexes or prevent anti-IgM-mediated calcium flux, confirming the expected phenotype. To understand how Fc RIIB inhibitory signalling impacted mAb-mediated depletion of target cells, NoTIM mice were treated with anti-mouse CD20 mAbs. The extent of depletion was compared to mice either lacking mFc RII or where mFc RII was replaced with a signalling competent hFc RIIB (hFc RIIB Tg). B cell depletion was reduced in both the NoTIM and hFc RIIB Tg mice compared to those lacking mFc RII. Subsequent experiments revealed this was not due to accelerated mAb internalisation nor enhanced clearance from the serum. Using a series of adoptive transfer models we determined that the NoTIM hFc RIIB was mediating inhibition, by competing with activatory Fc Rs on the surface of myeloid cells for the Fc of the direct targeting mAb. These findings were then assessed with respect to T regulatory cell and malignant murine B cell depletion. It was found that in both cases, depletion was negatively impacted by the expression of Fc RIIB at themyeloid surface rather than by its ability to signal. These data indicate that signalling through the ITIM is not critical for the ability of hFc RIIB to prevent mAb-mediated depletion of target cells, questioning current paradigms for its mechanism of action
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Sub-newton monopropellant thrusters for small spacecraft propulsion
No full textThis thesis documents the design and testing of a sub-newton High Test Peroxide (HTP) monopropellant thruster architecture, suitable for micro and nanosatellite applications. The main goals were to demonstrate that a thruster targeting a 0.1 N thrust level could achieve a high performance, and to investigate the fundamental processes governing its operation. The thruster design exhibited high thermal performance using 87.5 %wt. HTP, with chamber temperatures in excess of 600 °C, corresponding to characteristic velocity efficiencies approaching 0.963 ± 0.004 (1𝜎). These values are similar to equivalent larger-thrust systems. The thruster was also tested with 98.0 %wt. HTP, with temperatures approaching 800 °C. These results represent some of the highest performance of an HTP monopropellant system, and is a first at sub-newton thrust levels. The experimental results were collected by direct measurement of the internal fluid conditions, something not previously achieved on a thruster of this scale. This was made possible by the novel application of conventional metal additive manufacturing techniques, permitting the inclusion of integrated instrumentation standpipes and other complex ancillary geometry. The manufacturing process also enabled the production of a large number of different catalyst bed designs for use in one of the most extensive experimental studies on the impact of the catalyst bed geometry. The geometry was parametrically defined by the catalyst bed loading and aspect ratio, with respective values ranging from 1.48 kg.m-2.s-1 to 64.8 kg.m-2.s-1 and 0.33 to 6. The baseline thruster design, with a nominal bed loading of 10 kg.m-2. s-1 and an aspect ratio of 2, had the highest demonstrated performance. However, data analysis suggested that lower catalyst bed loadings and aspect ratios, i.e. shorter and wider beds, should be more optimal over a blowdown range. The study provided data towards validating a simplified pseudo-physical front model of the catalyst bed. This model describes the phase transition between the cool liquid/multiphase and the hot gas regimes. The phase change front was found to be axially close to the complete decomposition front, representing the maximum temperature in the bed. The catalyst bed flooding condition was used to relate the fundamental reactivity of the catalyst bed to the pseudo-physical front model. It was proposed that the reactivity can be used to size a bed with minimal experimental testing, through the Damköhler number: the estimated liquid-phase decomposition rate was greater than the rate of forced propellant diffusion for nominal catalyst bed operation. The pressure roughness phenomenon was also investigated using spectral analysis. These results were used to justify the proposed local oscillatory diffusion process in the catalyst bed. This is responsible for the pressure roughness, as well as the localised choking in the upstream liquid/multiphase regime that causes high pressure drop over this region. An extensive study on microinjectors was also conducted. This is a field of limited published research. The study characterised the performance of Poiseuille-type microbore tube and Venturitype orifice plate injectors. Poiseuille injectors demonstrated stable performance while orifice injectors were challenging to manufacture and prone to blocking. ‘Chugging’ flow instabilities were also captured, and it is proposed that the onset of this condition is tied to the inertia of the propellant flow through the injector. This, along with the minimum critical flow rate for the Venturi cavitation phenomenon, suggests that the Poiseuille microinjectors are a more robust architecture and better suited to sub-newton monopropellant thrusters
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
