The roles of news media as democratic fora, agenda setters, and strategic instruments in risk governance

This study analyzes news media’s role in governmental decision-making processes related to a gradually intensifying series of earthquakes resulting from gas drilling in the Netherlands, and catastrophic natural earthquakes in Italy. According to the risk governance actors interviewed in both cases, media play three roles, as: democratic fora, agenda setters, and strategic instruments. Media attention for risk can create ripple effects in governmental decision-making processes. However, media attention tends to be risk-event driven and focuses on direct newsworthy consequences of events. For ‘non-event risks’, or when newsworthiness after a risk-event fades, the media’s agenda setting and democratic fora roles are limited. This contributes to risk attenuation in society, potentially resulting in limited risk prevention and preparedness. Governmental actors report difficulties in using news media for strategic communication to facilitate risk governance because of media’s tendency towards sensationalism. Our research suggests that, in the governance of earthquake-risk news, media logic overrules other institutional logics only for a short while and not in the long run when the three roles of media do not reinforce each other

High spin polarization in the ferromagnetic filled skutterudites KFe4Sb12 and NaFe4Sb12

The spin polarization of ferromagnetic alkali-metal iron antimonides KFe4Sb12 and NaFe4Sb12 is studied by point-contact Andreev reflection using superconducting Nb and Pb tips. From these measurements an intrinsic transport spin polarization Pt of 67% and 60% for the K and Na compound, respectively, is inferred which establishes these materials as a new class of highly spin polarized ferromagnets. The results are in accord with band structure calculations within the local spin density approximation (LSDA) that predict nearly 100% spin polarization in the density of states. We discuss the impact of calculated Fermi velocities and spin fluctuations on Pt.Comment: Pdf file with fi

Superconductivity in SrFe2As2 with Pt Doping

We have synthesized polycrystalline samples of Pt-substituted SrFe2As2 and measured the temperature dependence of magnetization and electrical resistivity. We have observed the superconducting transition at Tc = 17 K with the maximum shielding volume fraction at x = 0.125 in Sr(Fe1-xPtx)2As2. It is found that the maximum Tc depends on the substituted element, so it is important to substitute various elements to explore new iron-based superconductors with higher Tc.Comment: 2 pages, 1 figure, to appear in J. Phys. Soc. Jpn. Vol. 79 No. 9 (2010

Appreciation of Peer Reviewers for 2017

On behalf of the authors and readers of Reviews of Geophysics, the American Geophysical Union, and the broader scientific community, the Editors wish to wholeheartedly thank those who reviewed the manuscripts for Reviews of Geophysics in 2017. The journal could not exist without your investment of time and effort, lending your expertise to ensure that the papers published in this journal meet the standards that the research community expects for it. We sincerely appreciate all that you do, and we are very grateful for your willingness and readiness to serve in this role.Plain Language SummaryOn behalf of the authors and readers of Reviews of Geophysics, the American Geophysical Union, and the broader scientific community, the Editors wish to wholeheartedly thank those who reviewed the manuscripts for Reviews of Geophysics in 2017. The journal could not exist without your investment of time and effort, lending your expertise to ensure that the papers published in this journal meet the standards that the research community expects for it. We sincerely appreciate all that you do, and we are very grateful for your willingness and readiness to serve in this role. Reviews of Geophysics published 29 review papers, a commentary and an editorial in 2017, covering most of the AGU Section topics, and for this we were able to rely on the efforts of 99 dedicated reviewers. Many reviewers answered the call multiple times. Thank you again. We look forward to a 2018 of exciting advances in the field and communicating those advances to our community and to the broader public.Key PointThe Reviews of Geophysics Editors thank all the peer reviewers from 2017Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147789/1/rog20174.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147789/2/rog20174_am.pd

A pragmatic approach to the problem of the self-adjoint extension of Hamilton operators with the Aharonov-Bohm potential

We consider the problem of self-adjoint extension of Hamilton operators for charged quantum particles in the pure Aharonov-Bohm potential (infinitely thin solenoid). We present a pragmatic approach to the problem based on the orthogonalization of the radial solutions for different quantum numbers. Then we discuss a model of a scalar particle with a magnetic moment which allows to explain why the self-adjoint extension contains arbitrary parameters and give a physical interpretation.Comment: 8 pages, LaTeX, to appear in J. Phys.

Electronic structure of the candidate 2D Dirac semimetal SrMnSb2: a combined experimental and theoretical study

SrMnSb$_2$ is suggested to be a magnetic topological semimetal. It contains square, 2D Sb planes with non-symmorphic crystal symmetries that could protect band crossings, offering the possibility of a quasi-2D, robust Dirac semi-metal in the form of a stable, bulk (3D) crystal. Here, we report a combined and comprehensive experimental and theoretical investigation of the electronic structure of SrMnSb$_2$, including the first ARPES data on this compound. SrMnSb$_2$ possesses a small Fermi surface originating from highly 2D, sharp and linearly dispersing bands (the Y-states) around the (0,$\pi$/a)-point in $k$-space. The ARPES Fermi surface agrees perfectly with that from bulk-sensitive Shubnikov de Haas data from the same crystals, proving the Y$-$states to be responsible for electrical conductivity in SrMnSb$_2$. DFT and tight binding (TB) methods are used to model the electronic states, and both show good agreement with the ARPES data. Despite the great promise of the latter, both theory approaches show the Y-states to be gapped above E$_F$, suggesting trivial topology. Subsequent analysis within both theory approaches shows the Berry phase to be zero, indicating the non-topological character of the transport in SrMnSb$_2$, a conclusion backed up by the analysis of the quantum oscillation data from our crystals.Comment: 26 pages, 10 figures, revised submission to SciPost after including changes requested by referees. All referee reports are open and can be viewed here: https://scipost.org/submissions/1711.07165v2

Vibrational Spectra of a Mechanosensitive Channel

We report the simulated vibrational spectra of a mechanosensitive membrane channel in different gating states. Our results show that while linear absorption is insensitive to structural differences, linear dichroism and sum-frequency generation spectroscopies are sensitive to the orientation of the transmembrane helices, which is changing during the opening process. Linear dichroism cannot distinguish an intermediate structure from the closed structure, but sum-frequency generation can. In addition, we find that two-dimensional infrared spectroscopy can be used to distinguish all three investigated gating states of the mechanosensitive membrane channel.

Efeito de herbicidas sobre a taxa de transporte de elétrons e o acúmulo de matéria seca em tomateiro.

Objetivou-se com este trabalho avaliar o efeito dos herbicidas metribuzin e carfentrazone sobre a taxa de transporte de elétrons (ETR) do fotossistema II (FSII) e o acúmulo de matéria seca em tomateiro.CD-ROM. Suplemento. Trabalho apresentado no 51. Congresso Brasileiro de Olericultura, Viçosa, MG

Comparison of asian soybean rust chemical control on a susceptible and a resistant cultivar in Brazil.

The development of resistant cultivars to the Asian soybean rust (ASR), caused by Phakopsora pachyrhizi, brought an additional tool to the disease management in Brazil. ASR develops slower in resistant cultivars than in susceptible ones, allowing a reduction of the number of fungicide sprays, but chemical control is still necessary. A field trial was conducted in Ponta Grossa, Parana State, in order to compare the effects of ASR chemical control with four fungicide formulations, in both resistant (BRSGO 7560) and susceptible (CD 249 RR) soybean cultivars. The fungicides were applied twice, beginning at soybean growth stage R3?R4, when first uredinia were observed, and at soybean stage R5.3?R5.4. The fungicides used were premix formulations of pyraclostrobin + epoxiconazole + fluxapyroxad (40+64.8+40 g a.i./ha), azoxystrobin + cyproconazole (60+24 g a.i./ha), pyraclostrobin + epoxiconazole (79.8+30 g a.i./ha), and epoxiconazole (125 g a.i./ha). The ASR severity at soybean growth stage R7 on nonsprayed plots reached 75.4% on the resistant cultivar and 98.6% on the susceptible cultivar. Lower ASR severity index were observed in the resistant cultivar, with the treatments pyraclostrobin + epoxiconazole (9.8%), pyraclostrobin + epoxiconazole + fluxapyroxad (10.5%), and azoxystrobin + cyproconazole (10.9%), with an average of disease control ranging from 90.8 to 91.3%. The treatments with pyraclostrobin + epoxiconazole and pyraclostrobin + epoxiconazole + fluxapyroxad provided the lower yield reductions on both soybean cultivars. The yield and grain weight reductions in the nonsprayed treatment were 32 and 28%, respectively, on the resistant cultivar and 44 and 32%, respectively, on the susceptible cultivar

Impact demagnetization of the Martian crust: Current knowledge and future directions

The paleomagnetism of the Martian crust has important implications for the history of the dynamo, the intensity of the ancient magnetic field, and the composition of the crust. Modification of crustal magnetization by impact cratering is evident from the observed lack of a measurable crustal field (at spacecraft altitude) within the youngest large impact basins (e.g., Hellas, Argyre and Isidis). It is hoped that comparisons of the magnetic intensity over impact structures, forward modeling of subsurface magnetization, and experimental results of pressure-induced demagnetization of rocks and minerals will provide constraints on the primary magnetic mineralogy in the Martian crust. Such an effort requires: (i) accurate knowledge of the spatial distribution of the shock pressures around impact basins, (ii) crustal magnetic intensity maps of adequate resolution over impact structures, and (iii) determination of demagnetization properties for individual rocks and minerals under compression. In this work, we evaluate the current understanding of these three conditions and compile the available experimental pressure demagnetization data on samples bearing (titano-) magnetite, (titano-) hematite, and pyrrhotite. We find that all samples demagnetize substantially at pressures of a few GPa and that the available data support significant modification of the crustal magnetic field from both large and small impact events. However, the amount of demagnetization with applied pressure does not vary significantly among the possible carrier phases. Therefore, the presence of individual mineral phases on Mars cannot be determined from azimuthally averaged demagnetization profiles over impact basins at present. The identification of magnetic mineralogy on Mars will require more data on pressure demagnetization of thermoremanent magnetization and forward modeling of the crustal field subject to a range of plausible initial field and demagnetization patterns.United States. National Aeronautics and Space Administration (NNG04GD17G)United States. National Aeronautics and Space Administration (NNX07AQ69G)United States. National Aeronautics and Space Administration (NNX06AD14G