1,722,115 research outputs found
The Hot Interstellar Medium
No full textThe interstellar medium (ISM) of galaxies very often contains a gas component that reaches the temperature of several million degrees, whose physical and chemical properties can be investigated through imaging and spectroscopy in the X-rays. We review the current knowledge on the origin and retention of the hot ISM in star-forming and early-type galaxies, from a combined theoretical and observational standpoint. As a complex interplay between gravitational processes, environmental effects, and feedback mechanisms contributes to its physical conditions, the hot ISM represents a key diagnostic of the evolution of galaxies
Quasi-circulator for effective cancellation of transmitter leakage signals in monostatic six-port radar
No full textA quasi-circulator, composed of two branch-line couplers and an asymmetric power combiner, is proposed to effectively cancel the transmitter leakage signals in a monostatic six-port radar. The effective isolation is improved by 12.2 dB at 24 GHz. With the proposed quasi-circulator, the maximum detectable range of the six-port radar is improved by 167%, compared with that of the six-port radar with a conventional branch-line coupler
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
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
Afatinib versus gefitinib in patients with EGFR mutation-positive advanced non-small-cell lung cancer: Overall survival data from the phase IIb LUX-Lung 7 trial
No full text<b>Background</b>\ud
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In LUX-Lung 7, the irreversible ErbB family blocker, afatinib, significantly improved progression-free survival (PFS), time-to-treatment failure (TTF) and objective response rate (ORR) versus gefitinib in patients with epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC). Here, we present primary analysis of mature overall survival (OS) data.\ud
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<b>Patients and methods</b>\ud
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LUX-Lung 7 assessed afatinib 40 mg/day versus gefitinib 250 mg/day in treatment-naïve patients with stage IIIb/IV NSCLC and a common EGFR mutation (exon 19 deletion/L858R). Primary OS analysis was planned after ∼213 OS events and ≥32-month follow-up. OS was analysed by a Cox proportional hazards model, stratified by EGFR mutation type and baseline brain metastases.\ud
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<b>Results</b>\ud
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Two-hundred and twenty-six OS events had occurred at the data cut-off (8 April 2016). After a median follow-up of 42.6 months, median OS (afatinib versus gefitinib) was 27.9 versus 24.5 months [hazard ratio (HR) = 0.86, 95% confidence interval (CI) 0.66‒1.12, P = 0.2580]. Prespecified subgroup analyses showed similar OS trends (afatinib versus gefitinib) in patients with exon 19 deletion (30.7 versus 26.4 months; HR, 0.83, 95% CI 0.58‒1.17, P = 0.2841) and L858R (25.0 versus 21.2 months; HR 0.91, 95% CI 0.62‒1.36, P = 0.6585) mutations. Most patients (afatinib, 72.6%; gefitinib, 76.8%) had at least one subsequent systemic anti-cancer treatment following discontinuation of afatinib/gefitinib; 20 (13.7%) and 23 (15.2%) patients received a third-generation EGFR tyrosine kinase inhibitor. Updated PFS (independent review), TTF and ORR data were significantly improved with afatinib.\ud
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<b>Conclusion</b>\ud
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In LUX-Lung 7, there was no significant difference in OS with afatinib versus gefitinib. Updated PFS (independent review), TTF and ORR data were significantly improved with afatinib
A Distance-Compensated Radar Sensor with a Six-Port Network for Remote Distinction of Objects with Different Dielectric Constants
No full textA distance-compensated radar sensor with a six-port network is proposed and successfully implemented to remotely discriminate target objects with different dielectric constants. The sensor simultaneously measures distance and reflection coefficients of the objects using DC output voltages of the six-port network, thereby obtaining a comparative profile of their dielectric constants with distance compensation scheme. The distinction of the target's dielectric constant profile is theoretically derived and experimentally demonstrated within a target distance of 1 m using a 24 GHz six-port radar sensor module. The die size of the six-port network MMIC is 2.0 x 1.8 mm(2), and the whole sensor module is realized in 3.6 x 5.5 cm(2), excluding a horn antenna and signal source
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