Recent results from the ARIANNA neutrino experiment

The ARIANNA experiment is currently taking data in its pilot-phase on the Ross ice-shelf. Fully autonomous stations measure radio signals in the frequency range from 100 MHz to 1 GHz. The seven station HRA was completed in December 2014, and augmented by two special purpose stations with unique configurations. In its full extent ARIANNA is targeted at detecting interactions of cosmogenic neutrinos (> 1016eV) in the ice-shelf. Downward-pointing antennas installed at the surface will record the radio emission created by neutrino-induced showers in the ice and exploit the fact that the ice- water surface acts as a mirror for radio emission. ARIANNA stations are independent, low-powered, easy to install and equipped with real-time communication via satellite modems. We report on the current status of the HRA, as well as air shower detections that have been made over the past year. Furthermore, we will discuss the search for neutrino emission, future plans and the energy-dependent sensitivity of the experiment.Comment: To be published in the Proceedings of the ARENA2016 conference, Groningen, The Netherland

Claiming the City: Co-operation and Making the Deal in Urban Comprehensive Land Claims Negotiations in Canada

Since their introduction in 1973, comprehensive land claims (CLC) agreements have become important mechanisms for Aboriginal peoples to achieve their political, social, cultural, and economic goals. Although the literature on CLC negotiations is a rich and varied one, it has tended to ignore the role that municipal governments have on influencing negotiation outcomes. This lacuna is surprising since a number of treaty negotiations in the Yukon Territory and BC involve lands located in major municipalities. This paper develops a theoretical framework for understanding the influence that municipal governments can have on treaty negotiation outcomes. Using a case study of the Kwanlin Dün First Nation treaty negotiations in the Yukon Territory, we find that institutional and milieu factors are important. However, leadership was the most important and decisive factor

Efficient Parameterized Algorithms for Computing All-Pairs Shortest Paths

Computing all-pairs shortest paths is a fundamental and much-studied problem with many applications. Unfortunately, despite intense study, there are still no significantly faster algorithms for it than the $\mathcal{O}(n^3)$ time algorithm due to Floyd and Warshall (1962). Somewhat faster algorithms exist for the vertex-weighted version if fast matrix multiplication may be used. Yuster (SODA 2009) gave an algorithm running in time $\mathcal{O}(n^{2.842})$, but no combinatorial, truly subcubic algorithm is known. Motivated by the recent framework of efficient parameterized algorithms (or "FPT in P"), we investigate the influence of the graph parameters clique-width ($cw$) and modular-width ($mw$) on the running times of algorithms for solving All-Pairs Shortest Paths. We obtain efficient (and combinatorial) parameterized algorithms on non-negative vertex-weighted graphs of times $\mathcal{O}(cw^2n^2)$, resp. $\mathcal{O}(mw^2n + n^2)$. If fast matrix multiplication is allowed then the latter can be improved to $\mathcal{O}(mw^{1.842}n + n^2)$ using the algorithm of Yuster as a black box. The algorithm relative to modular-width is adaptive, meaning that the running time matches the best unparameterized algorithm for parameter value $mw$ equal to $n$, and they outperform them already for $mw \in \mathcal{O}(n^{1 - \varepsilon})$ for any $\varepsilon > 0$

Explaining the Emergence of Indigenous-Local Intergovernmental Relations in Settler Societies: A Theoretical Framework

There has been growing interest among practitioners and academics in the emergence of intergovernmental relations between local and Aboriginal governments in Canada. Initial research has focused on describing the nature of these relations but has yet to develop any theoretical expectations regarding why some communities are more likely to cooperate than others. We addresses this lacuna by developing a theoretical framework for explaining the emergence of cooperation between Aboriginal and local governments. After identifying a set of variables and specifying how they are likely to affect the propensity of communities to cooperate, we conclude with a discussion of how future researchers might use this framework to investigate cooperation and noncooperation between Aboriginal and local governments in Canada and in other settler societies

Minimal prospects for radio detection of extensive air showers in the atmosphere of Jupiter

One possible approach for detecting ultra-high-energy cosmic rays and neutrinos is to search for radio emission from extensive air showers created when they interact in the atmosphere of Jupiter, effectively utilizing Jupiter as a particle detector. We investigate the potential of this approach. For searches with current or planned radio telescopes we find that the effective area for detection of cosmic rays is substantial (~3*10^7 km^2), but the acceptance angle is so small that the typical geometric aperture (~10^3 km^2 sr) is less than that of existing terrestrial detectors, and cosmic rays also cannot be detected below an extremely high threshold energy (~10^23 eV). The geometric aperture for neutrinos is slightly larger, and greater sensitivity can be achieved with a radio detector on a Jupiter-orbiting satellite, but in neither case is this sufficient to constitute a practical detection technique. Exploitation of the large surface area of Jupiter for detecting ultra-high-energy particles remains a long-term prospect that will require a different technique, such as orbital fluorescence detection.Comment: 15 pages, 15 figures, 2 tables, accepted for publication in Ap

Reconstructing the cosmic-ray energy from the radio signal measured in one single station

Short radio pulses can be measured from showers of both high-energy cosmic rays and neutrinos. While commonly several antenna stations are needed to reconstruct the energy of an air shower, we describe a novel method that relies on the radio signal measured in one antenna station only. Exploiting a broad frequency bandwidth of $80-300$ MHz, we obtain a statistical energy resolution of better than 15\% on a realistic Monte Carlo set. This method is both a step towards energy reconstruction from the radio signal of neutrino induced showers, as well as a promising tool for cosmic-ray radio arrays. Especially for hybrid arrays where the air shower geometry is provided by an independent detector, this method provides a precise handle on the energy of the shower even with a sparse array

Ideenwerkstatt Neue Produkte für die Bioökonomie: Bioeconomy meets Circular Economy - Rest- und Abfallstoffe für die bio-basierten Produkte von morgen : 29. Juni 2016, Leipzig

Mit der Veranstaltung „Ideenwerkstatt Neue Produkte für die Bioökonomie: Bioeconomy meets Circular Economy – Rest- und Abfallstoffe für die bio-basierten Produkte von morgen“ am 29.06.2016 im Leipziger KUBUS wurde ein Raum für Wissenschaftler, Unternehmen und Doktoranden aus dem Raum Leipzig geschaffen, um ihre Ideen für die Förderausschreibung „Neue Produkte für die Bioökonomie“ vorzustellen, weiter zu entwickeln und Teams für die Projektphase zu bilden. Ziel war es, in den Workshops die Konzepte Bioökonomie & Kreislaufwirtschaft integriert zu betrachten und innovative Lösungen im Sinne einer „circular bio-economy“ neu zu denken. Die ganztägige Veranstaltung hat diesen Prozess in zweifacher Weise begleitet und unterstützt. Im ersten Teil der Veranstaltung wurden aktuelle Entwicklungen aus dem Bereich Biökonomie & Kreislaufwirtschaft, Best– Practice–Beispiele sowie relevante Förderprogramminformationen vorgestellt. Im zweiten Teil der Veranstaltung engagierten sich die Teilnehmer aktiv in zwei Workshops, stellen ihre Ideen für den Wettbewerb vor, diskutierten diese und konnten Kontakte zu möglichen Kooperationspartnern knüpfen. Der vorliegende Band bietet die Möglichkeit, die Vorträge und Abstracts noch einmal nachzuvollziehen. Ein kurzer Überblick zu den vorgestellten Ideen soll zeigen, welches breite Spektrum die neuen Produkte der Bioökonomie abdecken können