Dynamics of the Kuiper Belt

Our current knowledge of the dynamical structure of the Kuiper Belt is reviewed here. Numerical results on long term orbital evolution and dynamical mechanisms underlying the transport of objects out of the Kuiper Belt are discussed. Scenarios about the origin of the highly non-uniform orbital distribution of Kuiper Belt objects are described, as well as the constraints these provide on the formation and long term dynamical evolution of the outer Solar system. Possible mechanisms include an early history of orbital migration of the outer planets, a mass loss phase in the outer Solar system and scattering by large planetesimals. The origin and dynamics of the scattered component of the Kuiper Belt is discussed. Inferences about the primordial mass distribution in the trans-Neptune region are reviewed. Outstanding questions about Kuiper Belt dynamics are listed.Comment: 22 pages plus 8 figures added footnote, figure

UNDERSTANDING AGRICULTURE'S TRANSITION INTO THE 21ST CENTURY: CHALLENGES, OPPORTUNITIES, CONSEQUENCES AND ALTERNATIVES

Advances in production, communication and transportation technologies as well as expectations of consumers, taxpayers, business people and rural residents continue to cause changes in agriculture and rural areas. These changes pose challenges, such as increased competition, as well as offer opportunities to produce specialized products and reach new markets. The opportunities for production agriculture appear to be 1) low-cost, large-scale commodity production, 2) medium- or small-scale commodity production combined with non-farm sources of income, or 3) production and marketing of specialized products. Emerging opportunities for rural businesses appear to be in serving production agriculture and agribusinesses by meeting their unique needs. These firms also can use advancing communication technologies to reach distant markets. Many business managers are adopting strategies that will shift their firm away from perfect competition. Opportunities for rural communities lie in using technology to efficiently provide services to rural residents. The size and composition of rural communities also will be redefined by advances in communication and transportation technologies. The decision of how to pursue these opportunities require a thorough understanding of what is occurring and thoughtful deliberations.Agribusiness, Production Economics,

Improved Pseudofermion Approach for All-Point Propagators

Quark propagators with arbitrary sources and sinks can be obtained more efficiently using a pseudofermion method with a mode-shifted action. Mode-shifting solves the problem of critical slowing down (for light quarks) induced by low eigenmodes of the Dirac operator. The method allows the full physical content of every gauge configuration to be extracted, and should be especially helpful for unquenched QCD calculations. The method can be applied for all the conventional quark actions: Wilson, Sheikoleslami-Wohlert, Kogut-Susskind, as well as Ginsparg-Wilson compliant overlap actions. The statistical properties of the method are examined and examples of physical processes under study are presented.Comment: LateX, 26 pages, 10 eps figure

Task rules, working memory, and fluid intelligence

Many varieties of working memory have been linked to fluid intelligence. In Duncan et al. (Journal of Experimental Psychology:General 137:131–148, 2008), we described limited working memory for new task rules: When rules are complex, some may fail in their control of behavior, though they are often still available for explicit recall. Unlike other kinds of working memory, load is determined in this case not by real-time performance demands, but by the total complexity of the task instructions. Here, we show that the correlation with fluid intelligence is stronger for this aspect of working memory than for several other, more traditional varieties—including simple and complex spans and a test of visual short-term memory. Any task, we propose, requires construction of a mental control program that aids in segregating and assembling multiple task parts and their controlling rules. Fluid intelligence is linked closely to the efficiency of constructing such programs, especially when behavior is complex and novel

Masses and Decay Constants of Heavy-Light Mesons Using the Multistate Smearing Technique

We present results for f_B and masses of low-lying heavy-light mesons. Calculations were performed in the quenched approximation using multistate smearing functions generated from a spinless relativistic quark model Hamiltonian. Beta values range from 5.7 to 6.3, and light quark masses corresponding to pion masses as low as 300 MeV are computed at each value. We use the 1P--1S charmonium splitting to set the overall scale.Comment: 9 pages, 13 figures, and 5 tables as a single 193K compressed and uuencoded Postscript file, FERMILAB--CONF--93/376-

Place effects on environmental views

How people respond to questions involving the environment depends partly on individual characteristics. Characteristics such as age, gender, education, and ideology constitute the well-studied social bases of environmental concern, which have been explained in terms of cohort effects or of cognitive and cultural factors related to social position. It seems likely that people\u27s environmental views depend not only on personal characteristics but also on their social and physical environments. This hypothesis has been more difficult to test, however. Using data from surveys in 19 rural U.S. counties, we apply mixed-effects modeling to investigate simple place effects with respect to locally focused environmental views. We find evidence for two kinds of place effects. Net of individual characteristics, specific place characteristics have the expected effect on related environmental views. Local changes are related to attitudes about regulation and growth. For example, respondents more often perceive rapid development as a problem, and favor environmental rules that restrict development, in rural counties with growing populations. Moreover, they favor conserving resources for the future rather than using them now to create jobs in counties that have low unemployment. After we controlled for county growth, unemployment and jobs in resource based industries, and individual social-position and ideological factors, there remains significant place-to-place variation in mean levels of environmental concern. Even with both kinds of place effects in the models, the individual level predictors of environmental concern follow patterns expected from previous research. Concern increases with education among Democrats, whereas among Republicans, the relationship is attenuated or reversed. The interaction marks reframing of environmental questions as political wedge issues, through nominally scientific counterarguments aimed at educated, ideologically receptive audiences. © 2010, by the Rural Sociological Society

Zero gravity crystal growth Final report

Experimental device for growing crystals under zero gravity condition

Place matters: challenges and opportunities in four rural Americas

A survey of 7,800 rural Americans in 19 counties across the country has led to the Carsey Institute\u27s first major publication that outlines four distinctly different rural Americas—amenity, decline, chronic poverty, and those communities in decline that are also amenity-rich—each has unique challenges in this modern era that will require different policies than their rural neighbors