626 research outputs found
Spaceborne CO2 laser communications systems
Projections of the growth of earth-sensing systems for the latter half of the 1980's show a data transmission requirement of 300 Mbps and above. Mission constraints and objectives lead to the conclusion that the most efficient technique to return the data from the sensing satellite to a ground station is through a geosynchronous data relay satellite. Of the two links that are involved (sensing satellite to relay satellite and relay satellite to ground), a laser system is most attractive for the space-to-space link. The development of CO2 laser systems for space-to-space applications is discussed with the completion of a 300 Mpbs data relay receiver and its modification into a transceiver. The technology and state-of-the-art of such systems are described in detail
Academically-Sponsored Coastal Research Vessels in the New England Region: An Assessment of Current Management and Implications for the Future
In New England an informal communications network exists between coastal research vessel operating institutions. Vessel scheduling and operational support has been identified as adequate for the current amount of research being conducted within the region. However, societal shift towards coastal regions is prompting an increase in attention to research within the coastal zone. Current and pending federal initiatives are responding to this increased research need. This, in turn, is beginning to impose greater demands on coastal vessel sea-time. Therefore, a strengthening of the region\u27s inter-institutional communications network may be warranted for the future in order to better coordinate coastal research vessel funding and use
The association of cold weather and all-cause and cause-specific mortality in the island of Ireland between 1984 and 2007
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.This article has been made available through the Brunel Open Access Publishing Fund.Background This study aimed to assess the relationship between cold temperature and daily mortality in the Republic of Ireland (ROI) and Northern Ireland (NI), and to explore any differences in the population responses between the two jurisdictions. Methods A time-stratified case-crossover approach was used to examine this relationship in two adult national populations, between 1984 and 2007. Daily mortality risk was examined in association with exposure to daily maximum temperatures on the same day and up to 6 weeks preceding death, during the winter (December-February) and cold period (October-March), using distributed lag models. Model stratification by age and gender assessed for modification of the cold weather-mortality relationship. Results In the ROI, the impact of cold weather in winter persisted up to 35 days, with a cumulative mortality increase for all-causes of 6.4% (95%CI=4.8%-7.9%) in relation to every 1oC drop in daily maximum temperature, similar increases for cardiovascular disease (CVD) and stroke, and twice as much for respiratory causes. In NI, these associations were less pronounced for CVD causes, and overall extended up to 28 days. Effects of cold weather on mortality increased with age in both jurisdictions, and some suggestive gender differences were observed. Conclusions The study findings indicated strong cold weather-mortality associations in the island of Ireland; these effects were less persistent, and for CVD mortality, smaller in NI than in the ROI. Together with suggestive differences in associations by age and gender between the two Irish jurisdictions, the findings suggest potential contribution of underlying societal differences, and require further exploration. The evidence provided here will hope to contribute to the current efforts to modify fuel policy and reduce winter mortality in Ireland
An evidence based clinical aid for cardiovascular disease
Copyright to Australian Family Physician. Reproduced with permission. Permission to reproduce must be sought from the publisher, The Royal Australian College of General Practitioners.Cardiovascular disease is the commonest cause of mortality in Australia, accounting for more than 30% of deaths. Hypertension, diabetes and lipid disorders account for 15.6% of the total problems encountered in general practice. Therefore all doctors should be familiar with well known risk factors for cardiovascular disease, as well as the benefits of interventions with them.Brian R McAvoy; Greg R Fulcher; John V Amerena; Greg W Conner; John F Beltrame; Graeme J Hankey; Anthony C Keech; Brian L Lloyd; Michael L Neale; Carol A Pollock; Krishna Sudhir; Robert D Waltham; Malcolm J Wes
Summary of Group Development/ Group Dynamics Discussion
Summarizes the group discussion held following the keynote on group development and group dynamics
Strengthening the Foundations of Outdoor Education
A preface to the journal Research in Outdoor Education, volume 3 is presented by the authors on behalf of the Coalition for Education in the Outdoors (CEO) Research Committee
Strategy evolution on dynamic networks
Models of strategy evolution on static networks help us understand how
population structure can promote the spread of traits like cooperation. One key
mechanism is the formation of altruistic spatial clusters, where neighbors of a
cooperative individual are likely to reciprocate, which protects prosocial
traits from exploitation. But most real-world interactions are ephemeral and
subject to exogenous restructuring, so that social networks change over time.
Strategic behavior on dynamic networks is difficult to study, and much less is
known about the resulting evolutionary dynamics. Here, we provide an analytical
treatment of cooperation on dynamic networks, allowing for arbitrary spatial
and temporal heterogeneity. We show that transitions among a large class of
network structures can favor the spread of cooperation, even if each individual
social network would inhibit cooperation when static. Furthermore, we show that
spatial heterogeneity tends to inhibit cooperation, whereas temporal
heterogeneity tends to promote it. Dynamic networks can have profound effects
on the evolution of prosocial traits, even when individuals have no agency over
network structures.Comment: 45 pages; final versio
Collective artificial intelligence and evolutionary dynamics.
Collective behavior is ubiquitous and highly structured in the natural world, allowing individuals to coordinate and cooperate in pursuit of common aims. The field of evolutionary game theory helps explain how structured collective behavior emerges in humans and other animals. But results from evolutionary game theory are typically restricted to simple and stylized problems. To be sure, simple models have been incredibly useful for understanding natural systems, developing hypotheses, and designing experiments to test hypotheses. At the same time, the field of multiagent research in AI has recently seen explosive growth, allowing researchers to model collective behavior in very complex domains using agents trained with reinforcement learning. There is a broad qualitative similarity between the problems addressed in these two fields, so that bridging them may provide theoretical guarantees about algorithms in reinforcement learning while extending the reach of evolutionary game theory. Synergy between these fields should help us to understand and reliably engineer collective behavior in complex domains
Public attitudes to inequality in water distribution: Insights from preferences for water reallocation from irrigators to Aboriginal Australians
Water allocation regimes that adjudicate between competing uses are in many countries under pressure to adapt to increasing demands, climate‐driven shortages, expectations for equity of access, as well as societal changes in values and priorities. International authorities expound standards for national allocation regimes that include robust processes for addressing the needs of ‘new entrants' and for varying existing entitlements within sustainable limits. The claims of Indigenous peoples to water represents a newly recognised set of rights and interests that will test the ability of allocation regimes to address the global water governance goal of equity. No study has sought to identify public attitudes or willingness to pay for a fairer allocation of water rights between Indigenous and non‐Indigenous people. We surveyed households from the jurisdictions of Australia's Murray‐Darling Basin, a region undergoing a historic government‐led recovery of water, and found that 69.2% of respondents support the principle of reallocating a small amount of water from irrigators to Aboriginal people via the water market. Using contingent valuation, we estimated households are willing to pay A74.5 million, which is almost double a recent government commitment to fund the acquisition of entitlements for Aboriginal nations of this basin. Results varied by state of residency and affinity with environmental groups. An information treatment that presented narrative accounts from Aboriginal people influenced the results. Insights from this study can inform water reallocation processes
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