An overview of the Daya Bay Reactor Neutrino Experiment

The Daya Bay Reactor Neutrino Experiment discovered an unexpectedly large neutrino oscillation related to the mixing angle $\theta_{13}$ in 2012. This finding paved the way to the next generation of neutrino oscillation experiments. In this article, we review the history, featured design, and scientific results of Daya Bay. Prospects of the experiment are also described.Comment: 18 pages, 5 figures. An overview to appear in the Special Issue on neutrino oscillations of Nuclear Physics

Perceptions on the Ground: Principals’ Perception of Government Interventions in High-Speed Educational Networking

The Alberta SuperNet was built to bring broadband connectivity to every school, hospital, library and provincial government office in Alberta (a large province in Canada with an area of 255,285 square miles). The supposed benefits of high-speed access have led to calls for strategic public investment on both the supply and demand sides. The provincial government, through Alberta Education, initiated a number of interventions to help make broadband technology more useful and accessible to Alberta schools and to promote use of the new technology. To investigate the perceived efficacy and awareness of these initiatives, a survey of school officials was conducted in the spring of 2005. The survey was designed to assess the interest, awareness and planned use of high-speed networking initiatives by school officials. The results of the survey show that principals place relatively high levels of importance upon these initiatives but their level of awareness of, and especially their utilization of the initiatives was much lower. There were small but significant differences among principals from large versus small schools and between principals from rural versus urban school. The paper concludes with recommendations for policy makers and administrators challenged with creating effective interventions using broadband networking

Online Conferences for Professional Development

Online conferences (OCs) offer a compelling set of economic and pedagogical benefits for teaching, learning, personal, and professional development. In this chapter, we provide examples and a model to guide development of this professional development application of e-Iearning. The cost-effectiveness of oes, coupled with the capacity to provide time-flexible participation on a global scale, convinces us that OCs will continue to playa vital and increasing role in quality professional development activities. Similar to faceto- face conferences (F2FCs), effective oes must focus on relevant and timely information dissemination, provide opportunities for interaction leading to knowledge creation, and support the development of learning communities. In their broadest sense, OCs and F2FCs have two major goals. The first is to create knowledge through personal, organizational, and community learning. The second is to develop social networks that can later be used to create valued collegial relationships and extend learning beyond the conference. The method used by OCs to achieve these goals is an intense network-mediated interaction. The interaction takes place over a limited period of time using a comhination of synchronous, asynchronous, and illlmersive technologies on a global scale. OCs are economically and pedagogically attractive because of their "anywhere and anytime" characteristics with low production and participation costs. In this chapter, we review characteristics and qualities of OCs, provide examples of successful OCs, and outline a model of relevant qualities affecting OC learning outcomes. The unique and promising role of this form of professional development in the current and emerging networked society is explored

Exploring Principals' Perceptions of Applications, Benefits, and Barriers of Alberta's Supernet

The Alberta SuperNet, a very high speed, broadband network, was built to bring highspeed connectivity to every school, library, and municipal office in Alberta. This CDN $294 million dollar investment was made based on the perceived need for high-speed connectivity to stimulate economic and community development and to enhance government services, especially education and health. A survey of Alberta school principals was conducted in the spring of 2005. This survey investigated principals perceptions of 14 potential teaching and learning, administrative, and professional development applications of broadband networking. Results of this survey revealed that while school principals voiced some apprehension, they nonetheless perceive value in broadband applications for educational purposes. Results of the survey can be used to provide rationale for broadband expenditures and both supply and demand side interventions designed to increase effective and enthusiastic use by local school

Controlling the shape and scale of triangular formations using landmarks and bearing-only sensing

© 2016 TCCT. This work considers the scenario where three agents that can sense only bearings use two landmarks to control their formation shape. We define a method of relating the known distance separating the landmarks back to the edge lengths of the triangular formation. The result is used to define a formation control law that incorporates inter-agent distance constraints. We prove a strong exponential convergence result and show how one can extend the controller such that global stability from any initial position is possible

Too Little, Too Late: How the Tidal Evolution of Hot Jupiters affects Transit Surveys of Clusters

The tidal evolution of hot Jupiters may change the efficiency of transit surveys of stellar clusters. The orbital decay that hot Jupiters suffer may result in their destruction, leaving fewer transiting planets in older clusters. We calculate the impact tidal evolution has for different assumed stellar populations, including that of 47~Tuc, a globular cluster that was the focus of an intense HST search for transits. We find that in older clusters one expects to detect fewer transiting planets by a factor of two for surveys sensitive to Jupiter-like planets in orbits out to 0.5~AU, and up to a factor of 25 for surveys sensitive to Jupiter-like planets in orbits out to 0.08~AU. Additionally, tidal evolution affects the distribution of transiting planets as a function of semi-major axis, producing larger orbital period gaps for transiting planets as the age of the cluster increases. Tidal evolution can explain the lack of detected exoplanets in 47~Tuc without invoking other mechanisms. Four open clusters residing within the {\em Kepler} fields of view have ages that span 0.4-8~Gyr--if {\em Kepler} can observe a significant number of planets in these clusters, it will provide key tests for our tidal evolution hypothesis. Finally, our results suggest that observers wishing to discover transiting planets in clusters must have sufficient accuracy to detect lower mass planets, search larger numbers of cluster members, or have longer observation windows to be confident that a significant number of transits will occur for a population of stars.Comment: 23 pages including 6 figures, accepted to Ap

11β,17,21-Trihydr­oxy-6α-methyl-3,20-dioxopregna-1,4-dien-21-yl 3-carboxy­propionate

The mol­ecule of the title compound, C26H34O8, a prednisolone derivative, contains three six-membered rings (A, B and C) and one five-membered ring (D). Ring A is planar and rings B and C adopt chair conformations, while ring D adopts an envelope conformation with the C atom bonded to the methyl group at the flap. The crystal structure is stabilized by intermolecular O—H⋯O hydrogen bond

Biogeochemical records of past global iron connections

International audiencePaleorecords of dust deposition can be used to evaluate global iron connections under conditions different from those today. Dust production and deposition has co-varied with ocean paleoproductivity, pCO2, and climate over glacial-interglacial cycles, and in this paper we review the current understanding and highlight research needs with respect to paleorecords of global iron connections. These records, which include data from terrestrial (loess) deposits, marine sediments, and ice cores, suggest that average eolian deposition rates were approximately 2?20 times higher during glacial periods than during interglacials. Enhanced dust fluxes to the oceans during glacial times, particularly to the main high-nutrient/low-chlorophyll (HNLC) areas of the open ocean (i.e., the Pacific subarctic, the equatorial Pacific, and the Southern Ocean), may have "fertilized" marine biota, thereby enhancing ocean productivity (1?2 fold) and driving atmospheric CO2 lower. Current models yield variable results, however, with glacial-interglacial changes in dust fluxes changing atmospheric pCO2 by the equivalent of 5 to >50% of the total glacial-interglacial change of 80?100 ppm. Positive correlations among Asian dust, ocean productivity and atmospheric CO2 in last 130 kyr, 1200 yr and 50 yr indicate that eolian iron has played an important role in global biogeochemical cycles of the past. A simple calculation suggests that one-tenth to one-third of the global change in CO2 due to dust-supplied Fe could be ascribed to variations in the dust supply flux from Asia and its associated effects on productivity in the Pacific Ocean