scholarly journals Cosmological-scale coherent orientations of quasar optical polarization vectors in the Planck era

2019 ◽  
Vol 622 ◽  
pp. A145 ◽  
Author(s):  
V. Pelgrims
Keyword(s):  
Polarization Vector ◽  
Quality Criteria ◽  
Contamination Level ◽  
Optical Polarization ◽  
Polarization Data ◽  
High Quality ◽  
Polarization Signal ◽  
Cosmological Scale ◽  
Polarization Measurements ◽  
Sigma Level

Gigaparsec scale alignments of the quasar optical polarization vectors have been proven to be robust against a scenario of contamination by the Galactic interstellar medium (ISM). This claim has been established by means of optical polarization measurements of the starlight surrounding the lines of sight of the 355 quasars for which reliable optical polarization measurements are available. In this paper, we take advantage of the full-sky and high quality polarization data released by the Planck satellite to provide an independent, complementary, and up-to-date estimation of the contamination level of the quasar optical polarization data by the Galactic dust. Our analysis reveals signatures of Galactic dust contamination at the two sigma level for about 30 percent of the quasar optical polarization data sample. The remaining 70 percent of the lines of sight do not show Galactic dust contamination above the two sigma level, suggesting low to negligible contamination of the quasar optical polarization signal. We further found arguments suggesting that Galactic thermal dust cannot fully account for the reported quasar optical polarization alignments. Based on the measurements of the ratio of the polarized intensity of the dust in the submillimeter to the degree of linear polarization of the quasar in the optical, we provide a new and independent quality criteria to apply to the quasar optical polarization sample. We argue that, unless correction is applied, such a criterion should be imposed on the data for future investigations in the framework of the cosmological-scale correlations of quasar optical polarization vector orientations that still could compete with the isotropic principle of the cosmological paradigm.

scholarly journals Optical and VLBI Polarization Measurements of AGN

1994 ◽  
Vol 159 ◽  
pp. 469-469
Author(s):  
D. C. Gabuzda ◽  
M. L. Sitko
Keyword(s):  
Radio Emission ◽  
Optical Polarization ◽  
Direct Link ◽  
Polarization Data ◽  
Polarization Measurements ◽  
Bl Lac ◽  
Polarized Emission ◽  
The Relationship

One of the most promising approaches to unravelling the relationship between the optical and radio emission in AGN is to obtain nearly simultaneous optical and VLBI polarization data. We have obtained such data for five AGN (0735+178, OJ287, 1219+285, 3C 279, and BL Lac). These data suggest that there is a direct link between the optical and radio polarized emission, and that frequently the optical polarization of AGN is associated with the emergence of new VLBI components.

Magnetic-field strengths from optical polarization data

1967 ◽  
Vol 31 ◽  
pp. 381-383
Author(s):  
J. M. Greenberg
Keyword(s):  
Magnetic Field ◽  
Optical Polarization ◽  
Polarization Data ◽  
Term Model ◽  
Source Of Information ◽  
Field Strengths

Van de Hulst (Paper 64, Table 1) has marked optical polarization as a questionable or marginal source of information concerning magnetic field strengths. Rather than arguing about this–I should rate this method asq+-, or quarrelling about the term ‘model-sensitive results’, I wish to stress the historical point that as recently as two years ago there were still some who questioned that optical polarization was definitely due to magnetically-oriented interstellar particles.

Researchers' judgment criteria of high-quality answers on academic social Q&A platforms

2020 ◽  
Vol 44 (3) ◽  
pp. 603-623 ◽  
Author(s):  
Lei Li ◽  
Chengzhi Zhang ◽  
Daqing He ◽  
Jia Tina Du
Keyword(s):  
Design Methodology ◽  
Information Science ◽  
Value Added ◽  
Quality Criteria ◽  
Social Networking Site ◽  
Library And Information Science ◽  
High Quality ◽  
Content Type ◽  
Second Stage

PurposeThrough a two-stage survey, this paper examines how researchers judge the quality of answers on ResearchGate Q&A, an academic social networking site.Design/methodology/approachIn the first-stage survey, 15 researchers from Library and Information Science (LIS) judged the quality of 157 answers to 15 questions and reported the criteria that they had used. The content of their reports was analyzed, and the results were merged with relevant criteria from the literature to form the second-stage survey questionnaire. This questionnaire was then completed by researchers recognized as accomplished at identifying high-quality LIS answers on ResearchGate Q&A.FindingsMost of the identified quality criteria for academic answers—such as relevance, completeness, and verifiability—have previously been found applicable to generic answers. The authors also found other criteria, such as comprehensiveness, the answerer's scholarship, and value-added. Providing opinions was found to be the most important criterion, followed by completeness and value-added.Originality/valueThe findings here show the importance of studying the quality of answers on academic social Q&A platforms and reveal unique considerations for the design of such systems.

scholarly journals Conceptualization and Implementation of the Central Information Portal on Rare Diseases: Protocol for a Qualitative Study (Preprint)

2017 ◽  
Author(s):  
Svenja Litzkendorf ◽  
Tobias Hartz ◽  
Jens Göbel ◽  
Holger Storf ◽  
Frédéric Pauer ◽  
...  
Keyword(s):  
Health Care ◽  
Rare Diseases ◽  
Health Care Professionals ◽  
Information Needs ◽  
Qualitative Interviews ◽  
Quality Criteria ◽  
Quality Information ◽  
High Quality ◽  
Information Portal ◽  
High Quality Information

BACKGROUND Recently, public and political interest has focused on people living with rare diseases and their health concerns. Due to the large number of different types of rare diseases and the sizable number of patients, taking action to improve the life of those affected is gaining importance. In 2013, the federal government of Germany adopted a national action plan for rare diseases, including the call to establish a central information portal on rare diseases (Zentrales Informationsportal über seltene Erkrankungen, ZIPSE). OBJECTIVE The objective of this study, therefore, was to conduct scientific research on how such a portal must be designed to meet the needs of patients, their families, and medical professionals, and to provide high-quality information for information seekers. METHODS We chose a 3-step procedure to develop a needs-based prototype of a central information portal. In the first step, we determined the information needs of patients with rare diseases, their relatives, and health care professionals by means of qualitative interviews and their content-analytical evaluation. On the basis of this, we developed the basic structure of the portal. In the second step, we identified quality criteria for websites on rare diseases to ensure that the information linked with ZIPSE meets the quality demands. Therefore, we gathered existing criteria catalogs and discussed them in an expert workshop. In the third step, we implemented and tested the developed prototypical information portal. RESULTS A portal page was configured and made accessible on the Web. The structure of ZIPSE was based on the findings from 108 qualitative interviews with patients, their relatives, and health care professionals, through which numerous information needs were identified. We placed particularly important areas of information, such as symptoms, therapy, research, and advisory services, on the start page. Moreover, we defined 13 quality criteria, referring to factors such as author information, creation date, and privacy, enabling links with high-quality information. Moreover, 19 users tested all the developed routines based on usability and comprehensibility. Subsequently, we improved the visual presentation of search results and other important search functions. CONCLUSIONS The implemented information portal, ZIPSE, provides high-quality information on rare diseases from a central point of access. By integrating the targeted groups as well as different experts on medical information during the construction, the website can assure an improved search for information for users. ZIPSE can also serve as a model for other Web-based information systems in the field of rare diseases. REGISTERED REPORT IDENTIFIER RR1-10.2196/7425

scholarly journals New optical polarization measurements of quasi-stellar objects. The data

2005 ◽  
Vol 433 (2) ◽  
pp. 757-764 ◽  
Author(s):  
D. Sluse ◽  
D. Hutsemékers ◽  
H. Lamy ◽  
R. Cabanac ◽  
H. Quintana
Keyword(s):  
Optical Polarization ◽  
Stellar Objects ◽  
Polarization Measurements ◽  
Quasi Stellar Objects

Current Situation of the Study on Oxidative Stability of Biodiesel

2014 ◽  
Vol 887-888 ◽  
pp. 484-487
Author(s):  
Hong Jun Ni ◽  
Lei Chen ◽  
De Qin She ◽  
Yin Nan Yuan
Keyword(s):  
Oxidative Stability ◽  
Influencing Factors ◽  
Oxidation Stability ◽  
Environmentally Friendly ◽  
Quality Criteria ◽  
Evaluation Methods ◽  
Current Situation ◽  
High Quality

As a high quality alternative of fossil diesel, biodiesel is widely concerned at domestic and abroad for its environmentally friendly and renewable. Oxidation stability is one of the important properties of biodiesel, which is also one of the quality criteria in storing and using. The oxidative mechanism and the influencing factors of Oxidation stability, oxidation stabilitys evaluation methods and the application of biodiesel antioxidants were reviewed. Then the direction of oxidation stability is put forward.

Optical Polarization Measurements of Pulsar NP 0532

Nature ◽  
1969 ◽  
Vol 223 (5206) ◽  
pp. 576-578 ◽  
Author(s):  
W. J. COCKE ◽  
M. J. DISNEY ◽  
T. GEHRELS
Keyword(s):  
Optical Polarization ◽  
Polarization Measurements
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