Analysis of signal to noise enhancement using a highly selective modulation tracking filter

Experiments are reported which utilize photodielectric effects in semiconductor loaded superconducting resonant circuits for suppressing noise in RF communication systems. The superconducting tunable cavity acts as a narrow band tracking filter for detecting conventional RF signals. Analytical techniques were developed which lead to prediction of signal-to-noise improvements. Progress is reported in optimization of the experimental variables. These include improved Q, new semiconductors, improved optics, and simplification of the electronics. Information bearing signals were passed through the system, and noise was introduced into the computer model

Perceptions and responses to climate policy risks among California farmers

This paper considers how farmers perceive and respond to climate change policy risks, and suggests that understanding these risk responses is as important as understanding responses to biophysical climate change impacts. Based on a survey of 162 farmers in California, we test three hypotheses regarding climate policy risk: (1) that perceived climate change risks will have a direct impact on farmer\u27s responses to climate policy risks, (2) that previous climate change experiences will influence farmer\u27s climate change perceptions and climate policy risk responses, and (3) that past experiences with environmental policies will more strongly affect a farmer\u27s climate change beliefs, risks, and climate policy risk responses. Using a structural equation model we find support for all three hypotheses and furthermore show that farmers’ negative past policy experiences do not make them less likely to respond to climate policy risks through participation in a government incentive program. We discuss how future research and climate policies can be structured to garner greater agricultural participation. This work highlights that understanding climate policy risk responses and other social, economic and policy perspectives is a vital component of understanding climate change beliefs, risks and behaviors and should be more thoroughly considered in future work

Sustainable Sourcing of Global Agricultural Raw Materials: Assessing Gaps in Key Impact and Vulnerability Issues and Indicators.

Understanding how to source agricultural raw materials sustainably is challenging in today's globalized food system given the variety of issues to be considered and the multitude of suggested indicators for representing these issues. Furthermore, stakeholders in the global food system both impact these issues and are themselves vulnerable to these issues, an important duality that is often implied but not explicitly described. The attention given to these issues and conceptual frameworks varies greatly--depending largely on the stakeholder perspective--as does the set of indicators developed to measure them. To better structure these complex relationships and assess any gaps, we collate a comprehensive list of sustainability issues and a database of sustainability indicators to represent them. To assure a breadth of inclusion, the issues are pulled from the following three perspectives: major global sustainability assessments, sustainability communications from global food companies, and conceptual frameworks of sustainable livelihoods from academic publications. These terms are integrated across perspectives using a common vocabulary, classified by their relevance to impacts and vulnerabilities, and categorized into groups by economic, environmental, physical, human, social, and political characteristics. These issues are then associated with over 2,000 sustainability indicators gathered from existing sources. A gap analysis is then performed to determine if particular issues and issue groups are over or underrepresented. This process results in 44 "integrated" issues--24 impact issues and 36 vulnerability issues--that are composed of 318 "component" issues. The gap analysis shows that although every integrated issue is mentioned at least 40% of the time across perspectives, no issue is mentioned more than 70% of the time. A few issues infrequently mentioned across perspectives also have relatively few indicators available to fully represent them. Issues in the impact framework generally have fewer gaps than those in the vulnerability framework

Supporting parent-child conversations in a history museum

BACKGROUND: Museums can serve as rich resources for families to learn about the social world through engagement with exhibits and parent-child conversation about exhibits. AIMS: This study examined ways of engaging parents and child about two related exhibits at a cultural and history museum. Sample participants consisted of families visiting the Animal Antics and the Gone Potty exhibits at the British Museum. METHODS: Whilst visiting two exhibits at the British Museum, 30 families were assigned to use a backpack of activities, 13 were assigned to a booklet of activities, and 15 were assigned to visit the exhibits without props (control condition). RESULTS: Compared to the families in the control condition, the interventions increased the amount of time parents and children engaged together with the exhibit. Additionally, recordings of the conversations revealed that adults asked more questions related to the exhibits when assigned to the two intervention conditions compared to the control group. Children engaged in more historical talk when using the booklets than in the other two conditions. CONCLUSIONS: The findings suggest that providing support with either booklets or activities for children at exhibits may prove beneficial to parent-child conversations and engagement with museum exhibits

Predictors of success in a first programming course

This paper describes a multi-national, multi-institutional study that investigated introductory programming courses .. Student participants were drawn from eleven institutions, mainly in Australasia, during the academic year of 2004. A number of diagnostic tasks were used to explore cognitive, behavioural, and attitudinal factors such as spatial visualisation and reasoning, the ability to articulate strategies for commonplace search and design tasks, and attitudes to studying. The results indicate that a deep approach to learning was positively correlated with mark for the course, while a surface approach was negatively correlated; spatial visualisation skills are correlated with success; a progression of map drawing styles identified in the literature has a significant correlation with marks; and increasing measures of richness of articulation of a search strategy are also associated with higher marks. Finally, a qualitative analysis of short interviews identified the qualities that students themselves regarded as important to success in programming. © 2006, Australian Computer Society, Inc

The Lore of Low Methane Livestock:Co-Producing Technology and Animals for Reduced Climate Change Impact

Methane emissions from sheep and cattle production have gained increasing profile in the context of climate change. Policy and scientific research communities have suggested a number of technological approaches to mitigate these emissions. This paper uses the concept of co-production as an analytical framework to understand farmers’ evaluation of a 'good animal’. It examines how technology and sheep and beef cattle are co-produced in the context of concerns about the climate change impact of methane. Drawing on 42 semi-structured interviews, this paper demonstrates that methane emissions are viewed as a natural and integral part of sheep and beef cattle by farmers, rather than as a pollutant. Sheep and beef cattle farmers in the UK are found to be an extremely heterogeneous group that need to be understood in their specific social, environmental and consumer contexts. Some are more amenable to appropriating methane reducing measures than others, but largely because animals are already co-constructed from the natural and the technical for reasons of increased production efficiency

Creative and Stylistic Devices Employed by Children During a Storybook Narrative Task: A Cross-Cultural Study

Purpose: The purpose of this study was to analyze the effects of culture on the creative and stylistic features children employ when producing narratives based on wordless picture books. Method: Participants included 60 first- and second-grade African American, Latino American, and Caucasian children. A subset of narratives based on wordless picture books collected as part of a larger study was coded and analyzed for the following creative and stylistic conventions: organizational style (topic centered, linear, cyclical), dialogue (direct, indirect), reference to character relationships (nature, naming, conduct), embellishment (fantasy, suspense, conflict), and paralinguistic devices (expressive sounds, exclamatory utterances). Results: Many similarities and differences between ethnic groups were found. No significant differences were found between ethnic groups in organizational style or use of paralinguistic devices. African American children included more fantasy in their stories, Latino children named their characters more often, and Caucasian children made more references to the nature of character relationships. Conclusion: Even within the context of a highly structured narrative task based on wordless picture books, culture influences children’s production of narratives. Enhanced understanding of narrative structure, creativity, and style is necessary to provide ecologically valid narrative assessment and intervention for children from diverse cultural backgrounds

It\u27s Not Love, But It\u27s Not Bad: A Response to Critics of Prepaid College Tuition Plans

Two years ago one of the authors published an article surveying the tax ramifications of prepaid college tuition plans, with a focus on the Michigan plan - the Michigan Education Trust ( MET ). That article took a generally positive view of such plans in general and of MET in particular. It discussed three basic themes: 1) the uncertainty of existing tax law with respect to prepaid tuition plans requires clarifying congressional legislation; 2) the position of the Internal Revenue Service ( Service ) with respect to prepaid tuition plans, as enunciated in a private letter ruling addressed to MET, is flawed; and 3) the position that prepaid tuition plans are basically a good idea, that deserve tax-favored treatment in any clarifying congressional legislation in order to be successful. Commentary by other authors undoubtedly bears out the first theme. The novelty of prepaid tuition plans and their sheer lack of fit with existing Internal Revenue Code provisions make predicting the tax consequences of such plans more an exercise in speculation than in legal analysis. Perhaps one could do as well by casting lots or throwing darts as with the Code and regulations. Moreover, the commentators have generally agreed that the Service\u27s position is flawed, although for widely varying reasons