12,537 research outputs found
Long-term lunar stations: Some ecological considerations
A major factor for long-term success of a lunar station is the ability to keep an agroecosystem functioning at a desirable, stable steady-state with ecological stability and reliability. Design for a long-lived extraterrestrial manned station must take into account interactions among its subsystems to insure that overall functionality is enhanced (or at least not compromised). Physical isolation of feed production, human living areas, recycling, and other systems may be straightforward, however, microbiological isolation will be very difficult. While it is possible to eliminate plant-associated microbiological communities by growing the plants asepticallly, it is not practical to keep plants germ-free on a large scale if humans are working with them. Ecological theory strongly suggests that some kinds of communities or organisms effectively increase the stability of ecosystems and will protect the plants from potential pathogens. A carefully designed and maintained (lunar-derived) soil can provide a variety of habitats for effective microbial buffers while adding structure to the agroecosystem. A soil can also increase ecosystem reliability through buffering otherwise large element and compound fluctuations (of nutrients, wastes, etc.) as well as buffering temperature level and atmosphere composition. We are doing experiments in ecological dynamics and attempting to extend the relevant theories
A Moral Debate at the Invisible Rainbow: Thoughts about Best Practices in Servicing LGBTQ Students in Special Education
Instead of occupying a marginal space within teacher preparation programs, special education courses and training should promote diversity in servicing marginalized groups such as lesbian, gay, bisexual, transgender, and questioning (LGBTQ) students. Within these programs, issues related to LGBTQ students should occupy a meaningful and formative space in the training of future teachers in special education. Often, special education teachers are at a loss about how to educate LGBTQ students with disabilities. Rethinking the role of special education and LGBTQ students with special needs within teacher education programs enables pre-service teachers to cultivate new values and attitudes that can enrich the student/teacher relationship within public schools. As such, this article proposes to explore best practices for servicing LGTBQ students in special education by promoting better ways to train future teachers
The Allocation of Public School Expenditures
While the Serrano v Priest decisions and Proposition 13 effectively rendered California school district budgets exogenous, intra-district resource allocation remains largely at the discretion of school district administrations. As a result, Serrano v Priest and Proposition 13 alleviate concerns about the potentially endogenous relationship between student body composition and inter-district resource disparity and allow us to focus on consistently estimating the effect of classroom versus non-classroom spending. We find that teaching expenditures have a positive effect on student performance while nonteaching expenditures have a negative effect. Either the reallocation of 100 increase aimed directly at the classroom moves the average California high school approximately 5 percentage points higher in the state test score rankings. These results are similar across grade levels (elementary, middle and high schools) and subject areas (mathematics, reading, language, spelling, social studies, and science). Our results suggest that both current and future educational expenditures should be targeted towards the classroom.school spending; test scores
Seasonal Price Patterns for Arkansas Soybeans
Seasonality is generally regarded as a major feature in soybean market price variations. Recent years in Arkansas have seen considerable construction of on-farm storage, a move that could mitigate the seasonality effect on price variations. A study comparing cash price indices from the past ten years with results from a 1986 Arkansas study and a recent national-level study found that Arkansas soybean prices appear to have followed a consistent and logical pattern around their national average in spite of increased variability and uncertainty.Seasonality, soybean, cash price index, Demand and Price Analysis, Farm Management, Marketing,
Neural circuitry at age 6 months associated with later repetitive behavior and sensory responsiveness in autism
School Size and the Distribution of Test Scores
After forty years of school consolidation, the preponderance of the evidence, including the results presented in this paper, suggest that the race to reap returns to scale and specialization in education may have come at a high price. This paper uses newly available STAR test score data from California to explore the relationship between school size and the distribution of test scores across elementary, middle, and high schools. We find that school size has a statistically significant and economically large impact on school performance. For example, the probability that an average suburban high school is dominated by low scorers rises from 47% to 71% as the school grows from 200 to 800 students per grade.school size, test scores
Holding Off on the Fun Stuff: Academic Media Multitasking and Binge Watching Among College Students
College students are often faced with the temptation of engaging in academic media multitasking and binge watching or completing their academic coursework in a timely and effective manner. A quantitative survey (N = 651) explored trait individual differences in self-control and academic delay of gratification and situational individual differences in enjoyment, reward, procrastination, regret, and guilt as predictors of academic media multitasking frequency, binge watching frequency, and binge watching duration. Stepwise regressions reveal that self-control is not a predictor of these media behaviors, while age and greater enjoyment were the only predictors of academic media multitasking and gender and greater enjoyment were the only predictors of binge watching duration. On the other hand, the other five variables provided insight on what predicted binge watching frequency: academic delay of gratification, reward, procrastination, regret, and guilt. Greater self-control also led to greater academic delay of gratification. Lastly, there were small positive correlations between all of the media behaviors except for academic media multitasking and binge watching frequency. Practical and theoretical implications are discussed
THE UTILITY OF MULTIPLE PERIL CROP INSURANCE FOR IRRIGATED, MULTIPLE-CROP AGRICULTURE
The usefulness of FCIC multiple peril crop insurance on diversified, irrigated, high yielding farms in the Imperial Valley is examined. Production data and expected price and yield distributions were collected from thirty-two farm managers in 1982. Individual whole-farm net income distributions then were used to elicit their risk preferences. Participation in FCIC crop insurance for cotton, wheat, and sugar beets under the existing program and under several alternatives was predicted. Predicted participation never exceeds 25% of eligible growers. Low maximum yield guarantees and premiums inconsistent with individual yield experience are identified as factors limiting participation.Crop Production/Industries, Risk and Uncertainty,
- …