4,560 research outputs found
Applying Optimization and the Analytic Hierarchy Process to Enhance Agricultural Preservation Strategies in the State of Delaware
Using agricultural preservation priorities derived from an analytical hierarchy process by 23 conservation experts from 18 agencies in the state of Delaware, this research uses weighted benefit measures to evaluate the historical success of Delaware’s agricultural protection fund, which spent nearly 25 million.conservation optimization, farmland protection, analytic hierarchy process, binary linear programming, Environmental Economics and Policy, Land Economics/Use, Research and Development/Tech Change/Emerging Technologies,
"Integrating Optimization and Strategic Conservation to Achieve Higher Efficiencies in Land Protection"
Strategic land conservation seeks to select the highest quality lands given limited financial resources. Traditionally conservation officials implement strategic conservation by creating prioritization maps that attempt to identify the lands of highest ecological value or public value from a resource perspective. This paper describes the history of using optimization in strategic conservation and demonstrates how the combination of these approaches can significantly strengthen conservation efforts by making these programs more efficient with public monies.Mathematical Programming, Conservation Optimization, Cost Effectiveness Analysis, Strategic Conservation
Interspecific visual signalling in animals and plants: a functional classification
Organisms frequently gain advantages when they engage in signalling with individuals of other species. Here we provide a functionally structured framework of the great variety of interspecific visual signals seen in nature, then describe the different signalling mechanisms that have evolved in response to each of these functional requirements. We propose that interspecific visual signalling can be divided into six major functional categories: antipredator, food acquisition, antiparasite, host acquisition, reproductive, and agonistic signalling, with each function enabled by several distinct mechanisms. We support our classification by reviewing the ecological and behavioural drivers of interspecific signalling in animals and plants, principally focussing on comparative studies that address large-scale patterns of diversity. Collating diverse examples of interspecific signalling into an organised set of functional and mechanistic categories places anachronistic behavioural and morphological labels in fresh context, clarifies terminology, and redirects research effort towards understanding environmental influences driving interspecific signalling in nature
INFORMATION VALUE IN WEED MANAGEMENT
Use of the economic threshold to improve the efficiency of preemergent-herbicide treatment decisions is limited by a lack of weed information. An economic model for assessing the expected value of weed information needed to implement a threshold decision rule is developed. Empirical results suggest that early season weed information can have value in cabbage weed management in Massachusetts.Crop Production/Industries,
Cascading Activation Revisited: How Audiences Contribute to News Agendas Using Social Media
Social media have become conduits through which audiences can challenge elites in media and politics. Recent updates to cascading activation, originally developed to explain how frames flowing from powerful figures gain public dominance, give greater theoretical scope for audiences to exert influence. Yet empirical understanding of how and in what circumstances this happens with respect to agenda-setting - another core media effect - is not well-developed, especially given the affordances of digital technologies. We address this gap by connecting theorization on cascades to developments in intermedia agenda-setting. Specifically, we analyze the dynamics surrounding the perceived reluctance by ARD-aktuell, the newsroom of Germany's public broadcasting consortium, to use its prime-time broadcast "Tagesschau" to report the arrest of a refugee accused of murdering a German woman in December 2016. By presenting finely grained timelines linking content analysis of 5,409 Facebook comments with Tagesschau editorial responses and parallel media coverage of this event, we contribute further conditions under which audience-informed cascades may occur: notably, when publicly funded news organizations are involved, and the issue at stake invokes both domestic and international aspects which sustain disagreement
Finalist essays from the Center for Homeland Defense and Security's First Annual Essay Competition, 2008
The Center for Homeland Defense and Security (CHDS) announces the winner and finalists
of its first annual essay contest. CHDS launched the contest last year to provide people from
around the country the opportunity to express their opinions on homeland security issues
and to suggest new ideas. The winner and four finalists were selected from eighty contest
submissions by a committee comprised of CHDS staff, faculty, and alumni. The variety of
the essay topics submitted, as well as the backgrounds of the authors, highlights the vast
scope of the impact that homeland security policies, programs, and challenges have on our
communities and professions. This year’s contestants were asked to answer the question
“What single aspect of Homeland Security has been most successful, and what single aspect
will be most critical to Homeland Security success?”Naval Posgraduate School, Center for Homeland Defense and Securit
Teacher Conceptions, Curriculum Ideologies, and Adaptations to Linear Change in River School District: Implications for Gifted and Talented
Curriculum ideologies are educational theories applied in everyday pedagogical practice. In this study, to better meet the learning needs of their students, four middle school teachers used a variety of ideologies as a professional toolbox. When confronted with school district standardization, these teachers adapted; however, as predicted by earlier studies, adjustments required the loss of previously successful curriculum. As predicted by Feldhusen, these losses affected teachers of high-level students (honors and gifted and talented) the most. In this district, two such teachers opposed standardization; nevertheless, even with resistance, they lost ideological-based curriculum choices. What are teachers of high-level students to do? Any standardization program will threaten and/or change eclectic ideological praxes. With such a dichotomy, a split is revealed between teacher beliefs and practices. In this study, an honors teacher could not bear the split and decided to stop teaching rather than give up her curricular eclecticism
Orienting to the sun improves camouflage for bilaterally symmetrical prey
Here, we investigate the camouflage consequences of animal orientation behaviour. Shadows can be a conspicuous cue to the presence of prey. For bilaterally symmetrical animals, light field modelling indicates that camouflage will be improved when an animal orients its longitudinal axis directly towards or away from the sun, because the appearance of shadows is minimized. We test this prediction with a field predation experiment, in which wild birds hunt for artificial camouflaged prey oriented with the longitudinal axis either parallel or perpendicular to the sun. We find that prey oriented parallel to the sun are 3.93 times more likely to survive than prey oriented perpendicular to the sun. This result demonstrates the strong orientation dependence of camouflage. Given the dramatic difference in survival of prey with different orientations, we suggest that camouflage should be investigated as an important determinant of the positional behaviour of animals.Publisher PDFPeer reviewe
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