481 research outputs found

    Communications and tracking expert systems study

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    The original objectives of the study consisted of five broad areas of investigation: criteria and issues for explanation of communication and tracking system anomaly detection, isolation, and recovery; data storage simplification issues for fault detection expert systems; data selection procedures for decision tree pruning and optimization to enhance the abstraction of pertinent information for clear explanation; criteria for establishing levels of explanation suited to needs; and analysis of expert system interaction and modularization. Progress was made in all areas, but to a lesser extent in the criteria for establishing levels of explanation suited to needs. Among the types of expert systems studied were those related to anomaly or fault detection, isolation, and recovery

    The impact of Arctic warming on the midlatitude jetstream: Can it? Has it? Will it?

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    Copyright © 2015 John Wiley & Sons, LtdThe Arctic lower atmosphere has warmed more rapidly than that of the globe as a whole, and this has been accompanied by unprecedented sea ice melt. Such large environmental changes are already having profound impacts on the flora, fauna, and inhabitants of the Arctic region. An open question, however, is whether these Arctic changes have an effect on the jet-stream and thereby influence weather patterns farther south. This broad question has recently received a lot of scientific and media attention, but conclusions appear contradictory rather than consensual. We argue that one point of confusion has arisen due to ambiguities in the exact question being posed. In this study, we frame our inquiries around three distinct questions: Can Arctic warming influence the midlatitude jet-stream? Has Arctic warming significantly influenced the midlatitude jet-stream? Will Arctic warming significantly influence the midlatitude jet-stream? We argue that framing the discussion around the three questions: Can it?, Has it?, and Will it? provides insight into the common themes emerging in the literature as well as highlights the challenges ahead

    Addressing Africa's Energy Dilemma

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    This chapter discusses how the ongoing low-carbon energy transformation could reshape geopolitics within Africa and between the continent and the rest of the world. The chapter first attempts to define what 'transition' means in African contexts and if the concept applies at all to African dynamics. It then delves into the drivers and modalities of Africa's alleged shift to finally explore geopolitical dynamics, questioning whether Africa is still the locus for the global supply of natural resources, introducing patterns of engagement between Africa and international/regional actors, and finally presenting the socio-economic implications of the shift. We conclude that while the venues and sources of geopolitical interest might change in the new geopolitical order that the transition to renewable energy implies, the content and modalities of interaction may see a continuity with the past, namely, dependence on external financing and technology. With yet at least one novelty: increased relevance of regional interdependencies

    A Data-Based Console Logger for Mission Operations Team Coordination

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    Concepts and prototypes1,2 are discussed for a data-based console logger (D-Logger) to meet new challenges for coordination among flight controllers arising from new exploration mission concepts. The challenges include communication delays, increased crew autonomy, multiple concurrent missions, reduced-size flight support teams that include multidisciplinary flight controllers during quiescent periods, and migrating some flight support activities to flight controller offices. A spiral development approach has been adopted, making simple, but useful functions available early and adding more extensive support later. Evaluations have guided the development of the D-Logger from the beginning and continue to provide valuable user influence about upcoming requirements. D-Logger is part of a suite of tools designed to support future operations personnel and crew. While these tools can be used independently, when used together, they provide yet another level of support by interacting with one another. Recommendations are offered for the development of similar projects

    Responses in rainbow trout (Oncorhynchus mykiss) to increasing dietary doses of lupinine, the main quinolizidine alkaloid found in yellow lupins (Lupinus luteus)

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    This experiment investigated the effect of increasing dietary doses of lupinine, the main quinolizidine alkaloid in Lupinus luteus, on feed intake, growth performance, tissue histology and nutritional composition of rainbow trout (Oncorhynchus mykiss). Duplicate groups of rainbow trout (initial body weight of 330g) were fed extruded fish meal based diets containing 0, 50, 75, 100, 250, 500, 1000 and 5000mg lupininekg-1 for 60days. Feed intake and growth were reduced in response to dietary lupinine, best fit by quadratic regression. Based on these results, the practical tolerance level of lupinine, with regard to growth and feed intake, was ≤100mgkg-1 feed. Carcass composition did not vary among treatments. Despite a depletion of glycogen and lipid stores in the hepatocytes, lupinine did not induce any morphological changes in spleen, kidney, heart or intestinal tissues.These results indicate that the lupinine possesses a strong anti-palatability effect, but does not appear to pose short-term health risks for rainbow trout. © 2011 Elsevier B.V

    Divergent consensuses on Arctic amplification influence on midlatitude severe winter weather

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    The article of record as published may be found at https://doi.org/10.1038/s41558-019-0662-yWe thank R. Blackport, C. Deser, L. Sun, J. Screen and D. Smith for discussions and suggested revisions to the manuscript. We also thank J. Screen and L. Sun for model data. A. Amin helped to create Fig. 2. US CLIVAR logistically and financially supported the Arctic-Midlatitude Working Group and Arctic Change and its Influence on Mid-Latitude Climate and Weather workshop that resulted in this article. J.C. is supported by the US National Science Foundation grants AGS-1657748 and PLR-1504361, 1901352. M.W. acknowledges funding by the Deutsche Forschungsgemeinschaft project no. 268020496– TRR 172, within the Transregional Collaborative Research Center “Arctic Amplification: Climate Relevant Atmospheric and Surface Processes, and Feedback Mechanisms (AC)3 ”. T.V. was supported by the Academy of Finland grant 317999. J.O. was supported by the NOAA Arctic Research Program. J.F. was supported by the Woods Hole Research Center. S.W. and H.G. are supported by the US DOE Award Number DE-SC0016605. J.Y. was supported by the Korea Meteorological Administration Research and Development Program under grant KMI2018-01015 and National Research Foundation grant NRF_2017R1A2B4007480. D.H. is supported by the Helmholtz Association of German Research Centers (grant FKZ HRSF-0036, project POLEX). The authors acknowledge the World Climate Research Programme’s Working Group on Coupled Modelling, which is responsible for CMIP, and thank the climate modelling groups (listed in Supplementary Table 1) for producing and making available their model output. For CMIP, the US Department of Energy’s PCMDI provides coordinating support and led development of software infrastructure in partnership with the Global Organization for Earth System Science Portals.The Arctic has warmed more than twice as fast as the global average since the late twentieth century, a phenomenon known as Arctic amplification (AA). Recently, there have been considerable advances in understanding the physical contributions to AA, and progress has been made in understanding the mechanisms that link it to midlatitude weather variability. Observational studies overwhelmingly support that AA is contributing to winter continental cooling. Although some model experiments sup port the observational evidence, most modelling results show little connection between AA and severe midlatitude weather or suggest the export of excess heating from the Arctic to lower latitudes. Divergent conclusions between model and observational studies, and even intramodel studies, continue to obfuscate a clear understanding of how AA is influencing midlatitude weather

    Arctic change and possible influence on mid-latitude climate and weather: a US CLIVAR White Paper

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    The Arctic has warmed more than twice as fast as the global average since the mid 20th century, a phenomenon known as Arctic amplification (AA). These profound changes to the Arctic system have coincided with a period of ostensibly more frequent events of extreme weather across the Northern Hemisphere (NH) mid-latitudes, including extreme heat and rainfall events and recent severe winters. Though winter temperatures have generally warmed since 1960 over mid-to-high latitudes, the acceleration in the rate of warming at high-latitudes, relative to the rest of the NH, started approximately in 1990. Trends since 1990 show cooling over the NH continents, especially in Northern Eurasia. The possible link between Arctic change and mid-latitude climate and weather has spurred a rush of new observational and modeling studies. A number of workshops held during 2013-2014 have helped frame the problem and have called for continuing and enhancing efforts for improving our understanding of Arctic-mid-latitude linkages and its attribution to the occurrence of extreme climate and weather events. Although these workshops have outlined some of the major challenges and provided broad recommendations, further efforts are needed to synthesize the diversified research results to identify where community consensus and gaps exist. Building upon findings and recommendations of the previous workshops, the US CLIVAR Working Group on Arctic Change and Possible Influence on Mid-latitude Climate and Weather convened an international workshop at Georgetown University in Washington, DC, on February 1-3, 2017. Experts in the fields of atmosphere, ocean, and cryosphere sciences assembled to assess the rapidly evolving state of understanding, identify consensus on knowledge and gaps in research, and develop specific actions to accelerate progress within the research community. With more than 100 participants, the workshop was the largest and most comprehensive gathering of climate scientists to address the topic to date. In this white paper, we synthesize and discuss outcomes from this workshop and activities involving many of the working group members

    Addressing the welfare needs of farmed lumpfish: knowledge gaps, challenges and solutions

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    Lumpfish (Cyclopterus lumpus L.) are increasingly being used as cleaner fish to control parasitic sea lice, one of the most important threats to salmon farming. However, lumpfish cannot survive feeding solely on sea lice, and their mortality in salmon net pens can be high, which has welfare, ethical and economic implications. The industry is under increasing pressure to improve the welfare of lumpfish, but little guidance exists on how this can be achieved. We undertook a knowledge gap and prioritisa tion exercise using a Delphi approach with participants from the fish farming sector, animal welfare, academia and regulators to assess consensus on the main challenges and potential solutions for improving lumpfish welfare. Consensus among participants on the utility of 5 behavioural and 12 physical welfare indicators was high (87–89%), reliable (Cronbach's alpha = 0.79, 95CI = 0.69–0.92) and independent of participant background. Participants highlighted fin erosion and body damage as the most use ful and practical operational welfare indicators, and blood parameters and behav ioural indicators as the least practical. Species profiling revealed profound differences between Atlantic salmon and lumpfish in relation to behaviour, habitat preferences, nutritional needs and response to stress, suggesting that applying a common set of welfare standards to both species cohabiting in salmon net-pens may not work well for lumpfish. Our study offers 16 practical solutions for improving the welfare of lumpfish and illustrates the merits of the Delphi approach for achieving consensus among stakeholders on welfare needs, targeting research where is most needed and generating workable solutions.info:eu-repo/semantics/publishedVersio
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