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We investigate the use of bright single pulses from the Crab pulsar to determine separately the dispersion measure (DM) for the Main Pulse and Interpulse components. We develop two approaches using cross correlation functions (CCFs). The first method computes the CCF of the total intensity of each of 64 frequency channels with a reference channel and converts the time lag of maximum correlation into a DM. The second method separately computes the CCF between every pair of channels for each individual bright pulse and extracts an average DM from the distribution of all channel-pair DMs. Both methods allow the determination of the DM with a relative uncertainty of better than 10^-5 and provide robust estimates for the uncertainty of the best-fit value. We find differences in DM between the Main Pulse, the Low Frequency Interpulse, and the High Frequency Interpulse using both methods in a frequency range from 4 to 6 GHz. Earlier observations of the High Frequency Interpulse carried out by Hankins et al. (2016) resulted in DM_HFIP-DM_MP of 0.010 +- 0.016 pc cm^-3. Our results indicate a DM_HFIP-DM_MP of 0.0127 +- 0.0011 pc cm^-3 (with DM_comp being the DM value of the respective emission component), confirming earlier results with an independent method. During our studies we also find a relation between the brightness of single pulses in the High Frequency Interpulse and their DM. We also discuss the application of the developed methods on the identification of substructures in the case of Fast Radio Bursts., Comment: Accepted for publication by the Astrophysical Journal

Proposes that general education curricula often have difficulty remaining faithful to goals of student empowerment. Provides case study of first year composition (FYC). Suggests that a strong commitment to reflection and revision of programs will create curricula that are more questioning and less comfortable with their own assumptions. Proposes that such programs will better serve students' changing needs. (PM)

The constantly improving sensitivity of ground-based and space-borne observatories has made possible the detection of high-energy emission (X-rays and gamma-rays) from several thousands of extragalactic sources. Enormous progress has been made in measuring the continuum flux enabling us to perform imaging, spectral and timing studies. An important remaining challenge for high-energy astronomy is measuring polarization. The capability to measure polarization is being realized currently at X-ray energies (e.g. with IXPE), and sensitive gamma-ray telescopes capable of measuring polarization, such as AMEGO, AdEPT, e-ASTROGAM, etc., are being developed. These future gamma-ray telescopes will probe the radiation mechanisms and magnetic fields of relativistic jets from active galactic nuclei at spatial scales much smaller than the angular resolution achieved with continuum observations of the instrument. In this white paper, we discuss the scientific potentials of high-energy polarimetry, especially gamma-ray polarimetry, including the theoretical implications, and observational technology advances being made. In particular, we will explore the primary scientific opportunities and wealth of information expected from synergy of multi-wavelength polarimetry that will be brought to multi-messenger astronomy., Comment: submitted to Astro2020 (Astronomy and Astrophysics Decadal Survey)

Understanding the physics of beam-plasma systems is of great importance for a large number of astrophysical systems. Recently the validity of particle-in-cell simulations of these systems has been questioned by Shalaby et al. (2017) We analyse one specific beam-plasma and its numerical simulations Kempf et al. (2016) that has been critized and prove that in fact the simulations performed fulfill the new validity criteria introduced by Shalaby et al. (2016)., Comment: After discussions with M. Shalaby et al. a revision of this paper seems appropriate. While some points of the original paper can still be discussed, we do not want to distract from the valuable contribution by our colleagues. We are currently waiting for additional simulation results, that are necessary to revise our comment

Aims. The change in the distribution function of electron-positron pair beams determines whether GeV photons can be produced as secondary radiation from TeV photons. We will discuss the instabilities driven by pair beams. Methods. The system of a thermal proton-electron plasma and the electron-positron beam is collision free. We have, therefore, used the particle-in-cell simulation approach. It was necessary to alter the physical parameters, but the ordering of growth rates has been retained. Results. We were able to show that plasma instabilities can be recovered in particle-in-cell simulations, but their e ect on the pair distribution function is negligible for the beam-background energy density ratios typically found in blazars

We present recent results on PIConGPU, a charge-conserving 3D relativistic particle-in-cell code running on graphic processors. We discuss best practices on how to implement the particle-in-cell algorithm on this new hardware and run it on large GPU clusters. We show that these codes have become mature enough to be considered for real life applications, delivering fast response time even for large physical problems.

The genus Flavivirus, family Flaviviridae, includes a number of important arthropod-transmitted human pathogens such as dengue viruses, West Nile virus, Japanese encephalitis virus and yellow fever virus. In addition, the genus includes flaviviruses without a known vertebrate reservoir, which have been detected only in insects, particularly in mosquitoes, such as cell fusing agent virus, Kamiti River virus, Culex flavivirus, Aedes flavivirus, Quang Binh virus, Nakiwogo virus and Calbertado virus. Reports of the detection of these viruses with no recognized pathogenic role in humans are increasing in mosquitoes collected around the world, particularly in those sampled in entomological surveys targeting pathogenic flaviviruses. The presence of six potential flaviviruses, detected from independent European arbovirus surveys undertaken in the Czech Republic, Italy,Portugal, Spain and the UK between 2007 and 2010, is reported in this work. Whilst the Aedes flaviviruses, detected in Italy from Aedes albopictus mosquitoes, had already been isolated in Japan, the remaining five viruses have not been reported previously: one was detected in Italy, Portugal and Spain from Aedes mosquitoes (particularly from Aedes caspius), one in Portugal and Spain from Culex theileri mosquitoes, one in the Czech Republic and Italy from Aedes vexans, one in the Czech Republic from Aedes vexans and the last in the UK from Aedes cinereus. Phylogenetic analysis confirmed the close relationship of these putative viruses to other insect-only flaviviruses. © 2012 Crown.

We present PIConGPU, an implementation of the particle-in-cell algorithm for relativistic laser-plasma interactions. PIConGPU is currently used to simulate laser-wakefield acceleration of electrons as a model for strongly anisotropic many-particle systems. We discuss caveats when porting the particle-in-cell algorithm to GPUs and lessons learned from extending the code from a single-GPU version to a multiple-GPU version.

We present PIConGPU, an efficient and scalable implementation of the particle-in-cell algorithm for GPGPUs. We discuss the main building blocks of PIConGPU, the data access patterns used for both particle and field data and the communication model that allows to hide the large latency of network communication between GPGPU nodes on a cluster. PIConGPU provides a general framework which can be used to study both relativistic and nonrelativistic plasmas. We show first results on relativistic laser wakeeld acceleration of electrons in underdense plasmas and on the progress of integrating new physics models. The fast response time of the code makes it possible to receive results in hours compared to weeks with particle-in-cell codes running on mid-size commodity clusters. With this increase in computational speed extensive parameter scans become possible even for large physical systems.

Designing laser-driven radiation sources requires realistic simulations, new ideas and good modeling. For inventing a design, a thorough analysis of existing designs is of great help. For planing designs, the fundamentals of the radiation generation process must be well understood. For testing designs, a fast return of results and the possibility to perform surveys of a large landscape of parameters is essential. In my talk I will address all steps in the source design using three examples from our recent research * Scaling of hot electron energies with laser intensity in laser-solid interaction * Laser-driven x-ray sources with tunable energy and bandwidth * Fast computation of laser-plasma interaction with new computation hardware

The statistical properties of a pseudorandom sequence being characterized by the distribution of the values near to the uniform distribution may differ from the expected ones. On doing a quantitative evaluation of the differences, it is advantageous to start with the properties of an ideally random sequence. The results of the study of the absolute value of autocovariance sequence point show that the estimate is characterized by the unilateral normal distribution with the parameters dependent on the sequence length. Thanks to this it is possible to determine the criteria that enable the relatively simple testing of the behaviour of pseudorandom sequence generators. These criteria have been verified on the four generators.

Nicht identisch mit VD17 7:704983P (dort "Germanis Featribus" auf dem Widmungsblatt), Schlüsselseiten aus dem Exemplar der ULB Halle: Cl 2603, Paginierfehler: Seitenzählung springt von S. 662 auf 665

Stellung des beigef. Werkes "Memoria Sachsiana" nicht eindeutig; nach dem Inh.-Verz. des Appendix gehört es an das Ende desselben; sowohl bei der Umfangsangabe als auch bei der Signaturformel ebenda angegeben. - Die Beitr. zu den im Appendix enth. Werken wurden nicht berücksichtigt, Schlüsselseiten aus dem Exemplar der SBB-PK Berlin: Lc 6480-4/7 = R, Signaturformel: ):(4, A - Z4, Aa - Ss4, Tt2, a - z4, aa - uu4, [1], [1], A3, B - M4, [1]. - Die Ill. wurden bei der Erstellung der Signaturformel nicht berücksichtigt, Vorlageform des Erscheinungsvermerks: Francofurti & Lipsiæ Sumptibus Johannis Fritzschii, Bibliopolæ Lipsiensis. Anno MDCLXXVI.

Nicht identisch mit VD17 3:314724R (dort "Germanis Fpatribus" auf dem Widmungsblatt), Schlüsselseiten aus dem Exemplar der SUB Göttingen: 8 POL II, 1110 (2), Paginierfehler: Seitenzählung springt von S. 662 auf 665

Référence de l'image dans la banque d'images : anmpx26x3229. - Nombre d'images dans le lot : 1, Gravure

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Nicht identisch mit VD17 3:314724R (dort "Germanis Fpatribus" auf dem Widmungsblatt), Schlüsselseiten aus dem Exemplar der SUB Göttingen: 8 POL II, 1110 (2), Paginierfehler: Seitenzählung springt von S. 662 auf 665

Nicht identisch mit VD17 7:704983P (dort "Germanis Featribus" auf dem Widmungsblatt), Schlüsselseiten aus dem Exemplar der ULB Halle: Cl 2603, Paginierfehler: Seitenzählung springt von S. 662 auf 665

Stellung des beigef. Werkes "Memoria Sachsiana" nicht eindeutig; nach dem Inh.-Verz. des Appendix gehört es an das Ende desselben; sowohl bei der Umfangsangabe als auch bei der Signaturformel ebenda angegeben. - Die Beitr. zu den im Appendix enth. Werken wurden nicht berücksichtigt, Schlüsselseiten aus dem Exemplar der SBB-PK Berlin: Lc 6480-4/7 = R, Signaturformel: ):(4, A - Z4, Aa - Ss4, Tt2, a - z4, aa - uu4, [1], [1], A3, B - M4, [1]. - Die Ill. wurden bei der Erstellung der Signaturformel nicht berücksichtigt, Vorlageform des Erscheinungsvermerks: Francofurti & Lipsiæ Sumptibus Johannis Fritzschii, Bibliopolæ Lipsiensis. Anno MDCLXXVI.

Référence de l'image dans la banque d'images : CICL00658. - Nombre d'images dans le lot : 1, Gravure - Burin, Image en niveaux de gris

Référence de l'image dans la banque d'images : anmpx26x3229. - Nombre d'images dans le lot : 1, Gravure

Référence de l'image dans la banque d'images : anmpx22x2469. - Nombre d'images dans le lot : 1, Gravure

Référence de l'image dans la banque d'images : anmpx22x2459. - Nombre d'images dans le lot : 1, Gravure