626 research outputs found

    A Statistical Inference Method for Interpreting the CLASP Observations

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    On 3rd September 2015, the Chromospheric Lyman-Alpha SpectroPolarimeter (CLASP) successfully measured the linear polarization produced by scattering processes in the hydrogen Lyman-α\alpha line of the solar disk radiation, revealing conspicuous spatial variations in the Q/IQ/I and U/IU/I signals. Via the Hanle effect the line-center Q/IQ/I and U/IU/I amplitudes encode information on the magnetic field of the chromosphere-corona transition region (TR), but they are also sensitive to the three-dimensional structure of this corrugated interface region. With the help of a simple line formation model, here we propose a statistical inference method for interpreting the Lyman-α\alpha line-center polarization observed by CLASP.Comment: Accepted for publication in The Astrophysical Journa

    Egypt’s 2011–2012 parliamentary elections: Voting for religious vs. secular democracy?

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    This study investigates whether individuals’ attitudes towards democracy and secular politics have any influence on voting behavior in Egypt. Based on data from a survey conducted immediately after the Egyptian parliamentary elections in January 2012, this study finds that Egyptians’ attitudes towards democratic governance were quite negative around the parliamentary elections, yet Egyptians still endorsed democracy as the ideal political system for their country. However, empirical findings suggest that support for democracy has a limited impact on electoral results. On the other hand, the main division in Egyptian society around the first free and fair parliamentary elections was the religious-secular cleavage. As people support secular politics more, they become significantly less likely to vote for Islamist parties. These results illustrate that preferences in regard to the type of democracy – either a liberal and secular or a religious democracy – were the main determinant of the historic 2012 elections in Egypt

    CLASP2: The Chromospheric LAyer Spectro-Polarimeter

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    A major remaining challenge for heliophysicsis to decipher the magnetic structure of the chromosphere, due to its "large role in defining how energy is transported into the corona and solar wind" (NASA's Heliophysics Roadmap). Recent observational advances enabled by the Interface Region Imaging Spectrometer (IRIS) have revolutionized our view of the critical role this highly dynamic interface between the photosphere and corona plays in energizing and structuring the outer solar atmosphere. Despite these advances, a major impediment to better understanding the solar atmosphere is our lack of empirical knowledge regarding the direction and strength of the magnetic field in the upper chromosphere. Such measurements are crucial to address several major unresolved issues in solar physics: for example, to constrain the energy flux carried by the Alfven waves propagating through the chromosphere (De Pontieuet al., 2014), and to determine the height at which the plasma Beta = 1 transition occurs, which has important consequences for the braiding of magnetic fields (Cirtainet al., 2013; Guerreiroet al., 2014), for propagation and mode conversion of waves (Tian et al., 2014a; Straus et al., 2008) and for non-linear force-free extrapolation methods that are key to determining what drives instabilities such as flares or coronal mass ejections (e.g.,De Rosa et al., 2009). The most reliable method used to determine the solar magnetic field vector is the observation and interpretation of polarization signals in spectral lines, associated with the Zeeman and Hanle effects. Magnetically sensitive ultraviolet spectral lines formed in the upper chromosphere and transition region provide a powerful tool with which to probe this key boundary region (e.g., Trujillo Bueno, 2014). Probing the magnetic nature of the chromosphere requires measurement of the Stokes I, Q, U and V profiles of the relevant spectral lines (of which Q, U and V encode the magnetic field information)

    Development of local strontium ranelate delivery systems and long term in vitro drug release studies in osteogenic medium

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    Funding Information: The authors acknowledge financial support from the Latvian Academy of Sciences though the ERANet under the frame of EuroNanoMed-II (Nanoforosteo, Project number: Z/14/1187) and the Riga Technical University and Riga Stardiņš University Cooperation Research Project No. RTU/RSU-18. Publisher Copyright: © 2018, The Author(s).It has been recognized that the operative stabilization of osteoporotic fractures should be followed up with an appropriate osteoporosis treatment in order to decrease the risk of repeated fractures. Despite the good clinical results of strontium ranelate (SrRan) towards the osteoporosis treatment, high drug doses and long treatment period cause an increased risk of serious side effects. Novel local SrRan/poly(lactic acid) (SrRan/PLA) delivery systems containing from 3.57 ± 0.28 wt% to 24.39 ± 0.91 wt% of active substance were developed. In order to resemble the naturally occurring processes, osteogenic media (OM) was used as a release medium for long term (121 days) in vitro drug release studies and UV/VIS method for the determination of SrRan content in OM was developed and validated. Biomimetic calcium phosphate precipitates were found on the surface and in the pores of prepared delivery system after microcapsule exposure to OM for 121 days as well as SrRan particles, indicating that the release of the drug have not been completed within 121 days. In vitro cell viability evaluation approved no cytotoxic effects of microcapsule suspensions and extracts.publishersversionPeer reviewe

    Autocracy-Sustaining Versus Democratic Federalism:Explaining the Divergent Trajectories of Territorial Politics in Russia and Western Europe

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    This article provides a comparative assessment of territorial politics in Russia and Western Europe. The consolidation or deepening of regional autonomy in Western Europe contrasts with the transformation of Russia from a segmented and highly centrifugal state into a centralized authoritarian state in the course of just two decades. The consolidation of territorial politics in Western Europe is linked to the presence of endogenous safeguards that are built into their territorial constitutional designs and most importantly to the dynamics that emanate from multi-level party competition in the context of a liberal and multi-level democracy. In contrast, in Russia, neither endogenous safeguards nor multi-level party democracy play an important role in explaining the dynamics of Russian federalism, but who controls key state resources instead. We argue that under Putin power dependencies between the Russian center and the regions are strongest where regional democracy is at its weakest, thus producing ‘autocracy-sustaining’ instead of a democratic federation. By studying the relationship between federalism and democracy in cases where both concepts are mutually reinforcing (as in Western Europe) with the critical case of Russia where they are not, we question the widely held view that democracy is a necessary pre-condition for federalism.Peer reviewe

    Constitutional dynamics and partisan conflict:A comparative assessment of multi-level systems in Europe

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    publication-status: Publishedtypes: ArticleThe case studies revealed that the constitutional nature of a multi-level system indeed shapes its modes of day-to-day intergovernmental coordination and, with it, the way competences are (re)allocated in the longer term. Both in federal arrangements and in confederations, the ‘subunits’ – whose status is constitutionally protected – could more easily defend their decision-making capacity within their areas of jurisdiction because they can veto changes in the allocation of competences, an advantage lower-level governments in regionalized systems do not enjoy. Similarly, in federal and confederal systems day-to-day interaction in Inter Governmental Relations (IGR) predominantly took place in multilateral structures, while in regionalized systems bilateralism was more pronounced. The relative influence of party-political (in)congruence on IGR, in contrast, was more varied than theoretically expected

    The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP)

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    To Understand energy release process in the Sun including solar flares, it is essentially important to measure the magnetic field of the atmosphere of the Sun. Magnetic field measurement of the upper layers (upper chromosphere and above) was technically difficult and not well investigated yet. Upper chromosphere and transition region magnetic field measurement by Chromospheric Lyman-Alpha SpectroPolarimeter (CLASP) sounding rocket to be launched in 2015. The proposal is already selected and developments of the flight components are going
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