TEXAS POLICY EDUCATION

Agricultural and Food Policy,

Effect of Al on the sharpness of the MgSiO_3 perovskite to post-perovskite phase transition

By means of static ab-initio computations we investigate the influence of Al on the recently discovered perovskite to post-perovskite phase transition in MgSiO_3. We examine three substitution mechanisms for Al in the two structures: MgSi → AlAl; SiSiO → AlAl□; and Si → AlH. The substitutions introducing oxygen vacancies (highly unfavorable, energetically) and water (favorable) both lower the 0 Kelvin transition pressure, whereas charge coupled substitution increases it relative to 105 GPa for pure MgSiO_3. From the transition pressures for 0, 6.25, and 100 mol% charge coupled Al_2O_3 incorporation and simple solution theories, we estimate the phase diagram of Al-bearing MgSiO_3 at low Al concentrations. Assuming the Clapeyron slope is independent of Al concentration, we find the perovskite-to-post-perovskite transition region to span 127–140 GPa, at 6.25 mol% Al_2O_3. When the upper pressure limit is bounded by the core-mantle boundary, the phase coexistence region has width 150 km

Review of \u3ci\u3eAppreciating Your Feathered Neighbors\u3c/i\u3e, by Dana Gardner and Nancy Overcott

Fifty Common Birds of the Upper Midwest. Watercolors by Dana Gardner; text by Nancy Overcott. 2006. University of Iowa Press, Iowa City, Iowa. 106 pages. $34.95 (cloth). What\u27s the best way to interest a friend in bird watching? Buy them a field guide, a CD of bird songs, or take them out bird watching? All of these ideas might work, but another approach is to tell personal stories and draw pictures of common birds in yards, parks, and natural areas where they live; help them get to know their neighbors with feathers. That\u27s exactly what Dana Gardner and Nancy Overcott did in their recent book about common birds of the Upper Midwestern United States. The authors\u27 decision to focus on common birds will be appealing to people who feed or watch birds casually; they will likely be familiar with some of these birds. The book is a self-described set of stories and paintings about birds; the authors express their hope in the introduction that these stories will inspire interest in habitat preservation

National Agricultural, Research, Extension, Education and Economics Advisory Board Southern Regional Listening Session - Small and Family Farms: Challenges and Needs Alcorn State University, Alcorn, Mississippi

The Agricultural and Food Policy Center’s (AFPC) primary purpose is to analyze the economic and financial impacts of alternative government policies on U.S. farming and ranching operations. This is accomplished through the maintenance of data necessary to simulate the economic and financial activities of more than 80 representative crop and livestock farms chosen from major production areas across the United States. Twenty of the 41 crop farms are located in the Southern region. A brief description of these crop farms and their location is summarized in Appendix A. The economic and financial observations reported in this paper are based on AFPC’s experience with the crop farms in the Southern region. The paper is organized into four sections. The first section summarizes the process used to develop the representative farms. The second section presents the crop farms in terms of total crop cash receipts and economic efficiency as measured by the ratio of total cash costs to receipts. The third section reports the economic and financial conclusions inferred by AFPC’s experience with these crop farms. The final section addresses research, education and policy implications drawn from the analysis.Agricultural and Food Policy,

An Analysis of Whole Farm Revenue Safety Net Options in Agriculture

Despite many years of experience, the federal government continues to seek a farm program that holds the potential for providing a politically acceptable safety net for farmers. This study demonstrates that, with the 2002 Farm Bill, AMTA, and marketing loan provisions continuing, a whole farm revenue safety net has the potential for simplifying existing farm programs, while enhancing the financial position of US farmers. There remains the need for further analysis of the impacts of the options analyzed on supply response by farmers.Agricultural and Food Policy,

IMPACT OF ALTERNATIVE FARM PROGRAMS ON DIFFERENT SIZE COTTON FARMS IN THE TEXAS SOUTHERN HIGH PLAINS: A SIMULATION APPROACH

Eight Texas High Plains cotton farms, ranging in size from 189 acres to 5,570 acres, were simulated under six alternative farm program provisions to determine the likely structural impacts of these programs. The results indicate mid-size farms benefit more from farm programs than either small or large farms since the programs allow them to remain in business. Denying mid-size commercial farms access to the farm program would likely accelerate the trend towards a bimodal distribution of farm sizes on the High Plains.Agribusiness, Crop Production/Industries,

SOUTHERN FARMERS EXPOSURE TO INCOME RISK UNDER THE 1996 FARM BILL

Arguably, since the 1930s, what farmers produced has been markedly influenced by farm programs. The 1996 farm bill affects farmers in terms of what they produce and their level of risk exposure. This paper investigates the farm level impacts of the 1996 farm bill on the South. Focus group perceptions of risk sources, observed acreage changes, and the farm level impact of increased price risk are evaluated.Agricultural and Food Policy, Agricultural Finance,

American Agriculture: What We Can Expect - National Symposium on the Future of American Agriculture, University of Georgia: August 1999

The Agricultural and Food Policy Center (AFPC) of the Texas A&M University System is pleased to be invited to address this symposium addressing the future of U.S. agriculture. As a participant in the FAPRI consortium, AFPC monitors the economic conditions of U.S. agriculture at the farm and ranch level. To accomplish this, AFPC maintains approximately 80 crop, dairy, beef and pork representative farms throughout the nation. In the interest of time, this paper will focus only on the economic condition of the 41 feed grain/oilseeds, wheat, cotton and rice farms through the year 2002. Anyone interested in the livestock operations, or more detail on the crop farms, are directed to the AFPC web site at http://afpc1.tamu.edu. The publications included at this site provide greater detail about the process AFPC employs to develop the representative farms, their structure and their financial characteristics.Agribusiness, Agricultural and Food Policy,

Nucleus accumbens activation mediates the influence of reward cues on financial risk-taking

In functional magnetic resonance imaging (FMRI) research, nucleus accumbens (NAcc) activation spontaneously increases prior to financial risk taking. Since anticipation of diverse rewards can increase NAcc activation, even incidental reward cues may influence financial risk-taking. Using event-related FMRI, we predicted and found that anticipation of viewing rewarding stimuli (erotic pictures for 15 heterosexual males) increased financial risk taking, and that this effect was partially mediated by increases in NAcc activation. These results are consistent with the notion that incidental reward cues influence financial risk taking by altering anticipatory affect, and so identify a neuropsychological mechanism that may underlie effective emotional appeals in financial, marketing, and political domains.neuroeconomics, neurofinance, brain, financial risk taking, risk preferences, decision making, nucleus accumbens, striatum, reward cues, FMRI, brain imaging