bluuebunny/crossref_metadata_2025 huggingface dataset:
The synthetic triterpenoid CDDO-imidazolide induces monocytic differentiation by activating the Smad and ERK signaling pathways in HL60 leukemia cells
Authors: Ji Yan , Lee Hong Jin , Goodman Catherine , Uskokovic Milan , Liby Karen , Sporn Michael , Suh Nanjoo
Published: July 2006

Synthetic triterpenoids, CDDO (2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid) or CDDO-imidazolide [2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid imidazolide (CDDO-Im)], induce cell differentiation in myeloid leukemia cells but their mechanism of action is not known. CDDO-Im induces monocytic differentiation markers, CD14, and nonspecific esterase in HL60 leukemia cells. We show that CDDO-Im activates the extracellular signal–regulated kinase (ERK) signaling pathway and up-regulates CCAAT/enhancer-binding protein β, a transcription factor critical for monocytic differentiation. The monocytic differentiation induced by CDDO-Im was partially blocked by the mitogen-activated protein kinase/ERK kinase 1 inhibitor PD98059, suggesting that the mitogen-activated protein kinase-ERK1/2 pathway plays a role in the differentiation induced by CDDO-Im. Furthermore, CDDO-Im activates the transforming growth factor β (TGF-β)/Smad signaling pathway. CDDO-Im enhanced the phosphorylation of the receptor-regulated Smads, phospho-Smad3, and phospho-Smad1/5, but not phospho-Smad2, and induced the expression of Smad4. Monocytic differentiation induced by CDDO-Im was blocked by both TGF-β antibody and the bone morphogenetic protein (BMP) antagonist Noggin. This indicates that activation of the Smad signaling pathway by triterpenoids is an important mechanism of monocytic differentiation. CDDO-Im induced the synthesis of mRNA for TGF-β2, BMP6, TGF-β type II receptor, and BMP type II receptor. CDDO-Im synergized with members of the TGF-β superfamily or with 1α,25(OH)2vitamin D3 (D3) in monocytic differentiation, and the synergistic effect was particularly striking in combination with D3. The combination of triterpenoids and D3 may have a practical use in differentiation therapy of myeloid leukemia as well as for promoting the formation of bone and cartilage. [Mol Cancer Ther 2006;5(6):1452–8]
A Simple Mechanism for ENSO Residuals and Asymmetry
Authors: Schopf Paul S. , Burgman Robert J.
Published: July 2006

A simple mechanism is offered that accounts for a change in the long-term (decadal scale) mean of ocean temperatures as the El Niño–Southern Oscillation (ENSO) amplitude changes. It is intended as an illustration of a kinematic effect of oscillating a nonlinear temperature profile with finite-amplitude excursions that will cause the Eulerian time mean temperature to rise (fall) where the curvature of the temperature is positive (negative) as the amplitude of the oscillations increases. This mechanism is found to be able to mimic observed changes in the mean sea surface temperatures in the Pacific between the 1920s, 1960s, and 1990s due to the changing ENSO amplitude. The effects alter both the calculated mean surface temperatures and the time mean temperatures at depth. It also results in a skewness of the temperature distribution that shares many properties with the observed SST. In this model, the time-local gradients of temperature never change if referenced to a single isotherm (i.e., the Lagrangian description is one of DT/Dt = 0). This implies that changes in the amplitude of ENSO will have no influence on the stability of the underlying system, and that the simple Eulerian decadal mean temperature structure has no predictive value. This is in direct contrast to recent work that ascribes a change in ENSO statistics as due to a change in the background state.
Intraseasonal Forcing of Convection and Lightning Activity in the Southern Amazon as a Function of Cross-Equatorial Flow
Authors: Petersen Walter A. , Fu Rong , Chen Mingxuan , Blakeslee Richard
Published: July 2006

This study focuses on modulation of lightning and convective vertical structure in the southern Amazon as a function of the South American monsoon V index (VI). Four wet seasons (December–March 1998–2001) of Tropical Rainfall Measuring Mission (TRMM) Lightning Imaging Sensor (LIS) and Precipitation Radar (PR) data are examined together with two wet seasons (2000–01) of ground-based Brazilian Lightning Detection Network (BLDN) data. These observations are composited by VI phase (northerly or southerly) for a region of the southern Amazon and discussed relative to VI-regime environmental characteristics such as thermodynamic instability and wind shear.

Relative comparisons of VI-regime convective properties reveal 1) slightly larger (20%–25%) PR pixel-mean rainfall during periods of northerly VI due to increased stratiform precipitation, 2) a factor of 2 or more increase in lightning flash density and the lightning diurnal cycle amplitude during periods of southerly VI, 3) a factor of 1.5–2 increase in the conditional probability of any PR radar reflectivity pixel exceeding 30 dBZ above the −10°C level during periods of southerly VI, and 4) an associated factor of 2 or more increase in southerly VI pixel-mean ice water path, with the ice water path being highly correlated to trends in lightning activity. During periods of southerly VI, convection occurs in an environment of increased thermodynamic instability, weak southeasterly low-level, and deep upper-tropospheric easterly wind shear. During periods of northerly VI, low-level westerly shear opposes stronger deep tropospheric easterly shear in a relatively moist environment of weaker thermodynamic instability, consistent with the occurrence of more widespread stratiform precipitation.

The composite results of this study point to 1) regime differences in convective forcing that alter the prevalence of ice processes and, by inference, the vertical profile of latent heating and 2) the utility of lightning observations in delineating convective regime changes.
Segregation of telencephalic and eye-field identities inside the zebrafish forebrain territory is controlled by Rx3
Authors: Stigloher Christian , Ninkovic Jovica , Laplante Mary , Geling Andrea , Tannhäuser Birgit , Topp Stefanie , Kikuta Hiroshi , Becker Thomas S. , Houart Corinne , Bally-Cuif Laure
Published: July 2006

Anteroposterior patterning of the vertebrate forebrain during gastrulation involves graded Wnt signaling, which segregates anterior fields (telencephalon and eye) from the diencephalon. How the telencephalic and retinal primordia are subsequently subdivided remains largely unknown. We demonstrate that at late gastrulation the Paired-like homeodomain transcription factor Rx3 biases cell specification choices towards the retinal fate within a population of bipotential precursors of the anterior forebrain: direct cell tracing demonstrates that retinal precursors acquire a telencephalic fate in embryos homozygous for the rx3-null allele ckhne2611,characterized by an enlarged telencephalon and a lack of eyes. Chimera analyses further indicate that this function of Rx3 is cell autonomous. Transfating of the eye field in the absence of Rx3 function correlates with a substantial posterior expansion of expression of the Wnt antagonist Tlc and the winged-helix transcription factor Foxg1. These results suggest that the process segregating the telencephalic and eye fields is isolated from diencephalic patterning, and is mediated by Rx3.
Dok-4 regulates GDNF-dependent neurite outgrowth through downstream activation of Rap1 and mitogen-activated protein kinase
Authors: Uchida Mayumi , Enomoto Atsushi , Fukuda Toshifumi , Kurokawa Kei , Maeda Kengo , Kodama Yoshinori , Asai Naoya , Hasegawa Taisaku , Shimono Yohei , Jijiwa Mayumi , Ichihara Masatoshi , Murakumo Yoshiki , Takahashi Masahide
Published: July 2006

During development of the central and peripheral nervous systems, neurite extension mediated via glial-cell-line-derived neurotrophic factor (GDNF) and its receptor RET is critical for neuronal differentiation. In the present study, we investigated the role of the RET substrate Dok-4 in neurite outgrowth induced by the GDNF/RET signaling pathway. In TGW neuroblastoma cells, which endogenously express both RET and Dok-4, depletion of Dok-4 through treatment with small interfering RNA resulted in a marked decrease in GDNF-stimulated neurite outgrowth. By contrast, exogenous expression of wild-type Dok-4 induced sustained p44/42 mitogen-activated protein kinase (ERK1/2) activation and enhanced neurite outgrowth. Expression of Dok-4 mutants in which the tyrosine residues at codons 187, 220 and 270, conserved between Dok-4, -5, and -6, were each replaced with a phenylalanine inhibited sustained ERK1/2 activation and neurite outgrowth. We also found that Dok-4 induced a significant activation of the small G protein Rap1 and that expression of a dominant active Rap1 mutant restored neurite outgrowth in Dok-4-depleted cells. By contrast, expression of a dominant negative Rap1 mutant impaired GDNF-stimulated neurite outgrowth from TGW cells. Finally, we found that neurite formation in cultured rat hippocampal neurons was enhanced by the expression of Dok-4. Together, our results suggest that Dok-4, through activation of the Rap1-ERK1/2 pathway, regulates GDNF-mediated neurite outgrowth during neuronal development.
Biologically Potent New Organotin(IV) Complexes of N-Maleoyltranexamic Acid
Authors: Khan M I , Baloch Musa Kaleem , Ashfaq Muhammad , Malik Abdul
Published: July 2006

Five new diorganotin(IV) complexes of the general composition [R′2SnR2] (where R′: Me, Et, Bu, Ph, Bn and R: N-maleoyltranexamic acid) have been prepared and structurally characterized by means of FT IR and 119mSn Mössbauer spectroscopy in the solid state. The solution-state structures were determined by means of multinuclear NMR (1H, 13C, and 119Sn) spectroscopies. The spectroscopic data explained the 1:2 metal to ligand stoichiometry and hypervalency of SnIV in a trans-octahedral arrangement. Inveterate mass spectrometric and elemental analysis data has supported the solid and solution spectroscopic results. The complexes and the ligand have been evaluated in vitro against seven human tumoural cell lines. Interesting results were noticed during the bio-activity screenings, which proved their in vitro biological potential. The nature of covalent attachments (methyl, ethyl, butyl, phenyl, and benzyl) of SnIV has played a decisive role from the bioactivity stand-point.
Lewis Base-Catalyzed Perfluoroalkylation of Carbonyl Compounds and Imines with (Perfluoroalkyl)trimethylsilane
Authors: Kawano Yoshikazu , Kaneko Nobuya , Mukaiyama Teruaki
Published: July 2006

Lewis base-catalyzed perfluoroalkylation of carbonyl compounds and aldimines with (perfluoroalkyl)trimethylsilanes (TMSCF3, TMSC2F5, and TMSC3F7) is described. The nitrogen- or oxygen-containing anions generated from amides, imides, and carboxylic acids have been found to work as effective Lewis-base catalysts in perfluoroalkylation that proceeds via activation of the carbon–silicon bonds of (perfluoroalkyl)trimethylsilanes. Reactions of carbonyl compounds such as aldehydes, ketones, and esters with TMSCF3 in the presence of a catalytic amount of Lewis bases proceeded smoothly to afford the corresponding adducts in good-to-high yields under mild conditions. Although it was considered difficult, this catalytic perfluoroalkylation of various aldimines with (perfluoroalkyl)trimethylsilane in the presence of Lewis bases such as lithium acetate or benzoate proceeded efficiently to give the corresponding perfluoroalkylated adducts, because the aldimines here were weak electrophiles toward (perfluoroalkyl)trimethylsilanes. The present reaction is, therefore, the first example of a catalytic perfluoroalkylation of aldimines.
Stepped Product Demand and Factor Supply Functions in Linear Programming Analyses
Authors: Martin Neil R.
Published: July 2006

Regional adjustment studies encounter less than perfectly elastic demand and factor supply conditions. Producing firms are assumed to face perfectly competitive markets. This paper reviews procedures for incorporating product demand and factor supply functions into linear programming analyses. Perfectly competitive conditions including industry income value are considered.
Break‐Even Analysis: A Practical Tool In Farm Management
Authors: Berry Russell L.
Published: July 2006

Break‐even charts provide managers with a simple method for exploring a range of production possibilities for a given farm plant. The charts may also help the manager evaluate machinery combinations and plant sizes.
Concave Programming Applied to Rice Mill Location
Authors: Candler Wilfred , Snyder James C. , Faught William
Published: July 2006

This paper provides an intuitive discussion of a concave programming algorithm capable of eventually reaching a global optimum. Two local optima are reported for a concave programming problem with 427 restraints, 4089 linear transportation activities, and 16 non‐linear falling average cost milling activities.
Economic Potential of the California Trawl Fishery
Authors: O'Rourke Desmond
Published: July 2006

This paper presents a technique for estimating the physical yield function of a fishery when detailed biological and environmental data are lacking. The physical yield function of the California trawl fishery is incorporated in an economic model to show the relationship between maximum sustainable physical yield of the fishery and maximum economic yield. Maximizing the economic benefit of the fishery to society would involve a drastic reduction in resource use at a catch level considerably below the biological maximum sustainable yield. Only through marginal cost pricing can resources be allocated efficiently to the fishery.
A Framework for Comparing the Efficiency of Futures Markets
Authors: Kofi Tetteh A.
Published: July 2006

Empirical observation and theoretical analyses show that the allocative and forward pricing functions of futures markets are more reliable for continuous than for discontinuous inventory markets. This emphasis on the importance of carry‐over inventory in affecting day‐to‐day price spreads is extended to take into account other factors which contribute to pricing efficiency. By examination of the characteristic behavior of the life cycle of a futures contract, a framework is developed to test, analyze, and contrast the performance of futures markets, i.e., how reliable futures quotations are as predictors of spot (cash) prices. Policy and theoretical implications are given.
Supply of Storage Theory and Commodity Equilibrium Prices with Stochastic Production
Authors: Pliska Stanley R.
Published: July 2006

When future production is a random variable, the equilibrium price for a commodity will be that which yields the maximum expected discounted utility of the consumption quantities and the supply of storage. The equilibrium consumption schedule is obtained with the dynamic programming techniques of inventory theory.
Equilibrium Quantity and Timing of Mexican Vegetable Exports
Authors: Simmons Richard L. , Pomareda Carlos
Published: July 2006

Mexico has recently expanded its exports of tomatoes, peppers, and cucumbers to the United States. In order to evaluate possibilities for further expansion, a linear programming production model for specific regions in Mexico was constructed and tested. Various equilibrium situations were analyzed to appraise possible future trends. Special features of the model were the inclusion of risk, demand functions for all crops, and allowance for both competitive and monopolistic supply structures. It was concluded that rising wage rates and tighter supply controls would halt Mexico's expansion of export winter vegetables.
Trade Policy and Its Effect on the External Agricultural Trade of Chile 1945–1965
Authors: Alberto Valdés E.
Published: July 2006

The relationship between external agricultural trade and economic incentives was examined under the hypothesis that a large proportion of the agricultural trade deficit in Chile in the 1945–1965 period resulted from commercial policies, particularly those relating to rate of exchange, price fixing in the internal market, export quotas, and high prices of some inputs originating in protected national industries. Negative rates of protection were estimated for wheat, beef, wool, and lamb, while barley was determined to have a neutral rate of protection. Alternative commercial policies could have reduced the agricultural trade deficit.
Econometric Models for Quarterly Shell Egg Prices
Authors: Roy Sujit K. , Johnson Phillip N.
Published: July 2006

Relationships determining shell egg prices were analyzed by developing models involving a simultaneous equation system estimated by using the three‐stage least squares method. The findings substantiated the postulated relations including the interdependency of the shell egg and breaking egg sectors. Price estimates generated from the models appeared acceptable.
Analysis of Aggregation Errors in Linear Programming Planning Models
Authors: Egbert Alvin C. , Kim Hyung M.
Published: July 2006

An analysis was made of errors which can result from regional aggregation in spatial linear programming models. The agricultural sector of Portugal provided the empirical base for the analysis. Programming solutions were obtained first for eleven regions and then for three regions which were aggregates of the eleven regions. It is concluded that significant errors which resulted from this form of aggregation can be reduced or eliminated by intraregional stratification of production activities and resources and a priori specification of intraregional transport cost.
Estimating the Returns to Information: A Gaming Approach
Authors: Debertin David L. , Harrison Gerald A. , Rades Robert J. , Bohl Lawrence P.
Published: July 2006

A management game incorporating key decisions in corn and soybean production was constructed. Participants in an experiment were asked to play the game by making a series of decisions. Some of the participants in the experiment were denied access to research information and/or feedback from the previous decision. Results of the experiment indicated a significant positive return to both information and learning from feedback.
Generalized Constrained Games in Farm Planning
Authors: Kawaguchi T. , Maruyama Y.
Published: July 2006

Constrained games arise when the mixed strategies of a finite rectangular game are subject to further constraints in the form of linear inequalities. Such games permit more realistic and convenient formulation of many decision problems. This paper offers a generalization of the constrained game model which widens the scope of game‐theoretic approaches in farm planning. Solution procedures are proposed for Savage's minimax regret, Hurwicz's pessimism‐optimism index, and the “Wald‐maximax” and “Wald‐Savage” criteria. It is shown that the proposed approaches can handle uncertainty in the inequality constraints. An application to a farm planning problem concludes the paper.
Evaluation of Local Nonproperty Taxes for Rural and Urban Areas in Kansas
Authors: Orazem Frank , Trostle Ronald G.
Published: July 2006

Average per capita property tax base in Kansas is almost three times higher in rural areas than in urban areas, while per capita nonproperty tax bases (income and sales) are higher in urban areas. While local nonproperty taxes may not be panaceas for either rural or urban areas, their use has greater potential in an urban than in a rural setting.
Analysis of the Accuracy of USDA Crop Forecasts
Authors: Gunnelson G. , Dobson W. D. , Pamperin S.
Published: July 2006

Accuracy of USDA crop forecasts increased moderately over the 1929–1970 period. However, USDA's first forecasts of crop production tended to underestimate crop size and the size of year‐to‐year changes in production. USDA also undercompensates for errors in earlier forecasts when developing revised crop forecasts.
Economies of Size and the Spatial Distribution of Land in Farming Units
Authors: Johnston Warren E.
Published: July 2006

Economies of size studies may erroneously point to excessive machinery capacities on large‐scale farming units. This paper shows a simple but illustrative example of the influence of the spatial distribution of land on machinery requirements for increasing sizes of farms in the Imperial Valley of California.
A Practical Way to Select an Optimum Farm Plan Under Risk
Authors: Scott John T. , Baker Chester B.
Published: July 2006

This paper uses quadratic programming to calculate the variance‐efficient mean income path and associated lower income bounds and suggests a way to select an optimum farm plan under risk based on the farmer's own self‐assessed income‐risk preference function. An empirical example from a Midwest corn‐soybean farm is presented.
A Simulation Model for Evaluating Worldwide Buffer Stocks of Wheat
Authors: Reutlinger Shlomo
Published: July 2006

Stochastic simulation is advocated for quantifying the impact of alternative buffer stock levels and storage policies on stabilizing world wheat supplies and for estimating the corresponding benefits and losses to the world economy, to the storage operation itself, to consumers, and to producers. Illustrative runs of the model show that stock levels which are optimal in terms of direct costs and benefits are likely to be too low to afford satisfactory levels of stabilization. However, buffer stock programs operated with insurance‐oriented storage rules could provide satisfactory protection against extreme shortfalls in grain supplies at a reasonably low cost.
An Empirical Test of Utility vs. Profit Maximization in Agricultural Production
Authors: Lin William , Dean G. W. , Moore C. V.
Published: July 2006

Production economics literature contains many studies which assume that the producer's goal is to maximize profits. This study tests the hypothesis that Bernoullian and lexicographic utility are more accurate predictors of farmer behavior than profit maximization. Six large California farms were used to test the hypothesis. After‐income tax E‐V (expectation‐variance) boundaries were developed for each farm and utility, and profit maximizing crop plans were determined for each. A goodness‐of‐fit criterion showed that Bernoullian utility formulations provided the greatest accuracy in predicting actual and planned crop patterns, followed by the lexicographic formulation. Profit maximization showed the poorest predictive power.
Man, Physical Resources, and Economic Organization
Authors: Breimyer Harold F.
Published: July 2006

Formal economics has centered on the combination of resources. Contemporary events force concern for forms of economic organization, inquiry into which must put the human role uppermost. A taxonomy of economic organization contains three systems of production and three of control. The Enlightenment brought freedom of contract as a control system, which fits well with proprietary production in farming but clashes with industrial nonfarm production. The nonfarm economy faces institutional reform, while farming must choose its production‐control pattern. Examination of alternate production and control systems can aid in organizational choice.
The Political Economy of Regional Water Institutions
Authors: Ingram Helen M.
Published: July 2006

Water experts, prominent among them resource economists, typically suggest a unified regional organization as the appropriate institutional approach to an entire range of problems. Yet, the performance of multistate regional organizations has been disappointing. It is argued here that failure of regional institutions to innovate is largely determined by the restraints imposed by political viability. The article describes the political environment of regional organizations and the incentives and disincentives for various interests to associate themselves with regional organizations. Finally, various possible strategies whereby a regional organization can build support are outlined.
Application of Multivariate Probit to a Threshold Model of Grain Dryer Purchasing Decisions
Authors: Hill Lowell , Kau Paul
Published: July 2006

Purchase of grain dryers by farmers can be explained using a threshold theory of decision in which a reaction occurs only after the strength of the stimuli increases beyond the farmers' reaction threshold. Estimates of the causal relationships in this dichotomous decision model were obtained by using the probit technique with data from a farmer panel. The results provide an explanation of differences in the number of dryers purchased by farmers in various classes and regions. It also provides a procedure for predicting dryer ownership and purchases of dryers as an aid to forward planning by distributors of drying equipment.
An Approach to Research on Vertical Coordination: The Beef System in Oklahoma
Authors: Purcell Wayne D.
Published: July 2006

Analysis of selected subsystems of the Oklahoma beef marketing system reveals conflicts and inconsistencies in basic interstage relationships. Such conflicts and inconsistencies block realization of higher degrees of interstage or interlevel coordination. Improvement will require a research orientation which isolates such barriers and estimates their impact on system participants.
Modified Price, Production, and Income Impacts of Food Aid under Market Differentiated Distribution
Authors: Rogers Keith D. , Srivastava Uma K. , Heady Earl O.
Published: July 2006

Estimation of negative production impacts of food aid rests heavily on measurement of resulting price changes. Previous studies have assumed an exogenous shift in supply resulting from distribution of the imported commodities but have ignored the income effect on demand. Distribution of food aid commodities to consumers at concessional prices provides an increase in real income and corresponding shift in demand for food. The shift in demand compensates for part of the exogenous shift in supply, reducing the potential impact on domestic prices. Based on market differentiation, the production impact in India is estimated at one tenth of previous estimates.
Inter‐Fiber Competition and the Future of the United States Cotton Industry
Authors: Smith B. , Dardis R.
Published: July 2006

Markov analysis is employed to investigate the competitive potential of the U. S. cotton fiber industry. Cotton's market share is projected to decline in 17 of the top 20 end uses examined though at a slower rate than in the past. Non‐cellulosic, the major competitor, is projected to capture more than 50 percent of the market in 13 end uses. The results indicate the necessity for concerted action by the cotton industry if it is to recapture or even retain its market share. The long time horizons of many end uses provide time for planning and implementing programs designed to improve cotton's competitive position.
Socioeconomic Behavior of Cattle Ranchers, with Implications for Rural Community Development in the West
Authors: Smith Arthur H. , Martin William E.
Published: July 2006

This paper extends the argument that cattle ranching and ranchers can be better understood by viewing the ranch resource as generating both production and consumption outputs. It was found that nonmonetary outputs of ranch ownership are the most significant factors in explaining high sale prices of Arizona ranches. Land fundamentalism, rural fundamentalism, and conspicuous consumption/speculative attitudes are the most important of these consumption outputs. The analysis suggests that small town viability and growth in the arid Southwest, and possibly in the West as a whole, may be more likely to occur if rural development policies are not predicated on the economic impact of surrounding ranches.
Shift‐Share Analysis as a Technique in Rural Development Research
Authors: Curtis Wayne C.
Published: July 2006

This note presents a technique for delineating changes in income and employment dimensions of rural counties or similar units. Shift‐share analysis is portrayed as a descriptive tool with potential use in rural development research. A model to isolate sectoral income and employment changes in four rural counties is briefly discussed.
Fertilizer Response Information and Income Gains: The Case of Potatoes in Peru
Authors: Ryan James G. , Perrin Richard K.
Published: July 2006

Yield response to different levels of fertilizer on various soils is estimated by a generalized response function. Average new income generated by use of optimum levels is estimated at over $800 per hectare. The social gain to Peru is estimated to be as much as $50 million annually.
Modeling and Simulation of the U.S. Economy with Alternative Energy Availabilities
Authors: Penn J. B. , McCarl Bruce A. , Brink Lars , Irwin George D.
Published: July 2006

The acute energy shortages of 1973–74 accentuated the pervasiveness of energy utilization in the U.S. economy and underscored the complexity of the system interrelationships. It was also revealed that little is known about these interrelationships. This article reports on a systems analysis of the short‐run economic effects of alternative situations involving reduced energy availability. The impacts of several different energy availabilities are analyzed. Specifically, the situations considered are a 2% quantity reduction in domestic coal supply, a 1.0 and a 1.5 million barrel per day reduction in crude petroleum imports, and a 10% quantity reduction in natural gas supply.
Impacts of Market‐Share Patterns on Marketing Firm Costs
Authors: Raikes Ronald , Heubrock Arnold
Published: July 2006

Uniform market‐share patterns have been assumed in specifying cost functions for assembly or delivery operations. A more realistic assumption is that market share decreases with distance from the plant. Procedures for specifying assembly or delivery‐cost functions for alternative linear market‐share patterns and for determining impacts of changes in market‐share patterns on costs and related results are developed and applied in an analysis of anhydrous ammonia retailing. These procedures permit more accurate estimates of cost‐volume relationships and make it possible to address questions about how firms should attempt to achieve volume increases.
A Spatial and Temporal Model of the North American Pork Sector for the Evaluation of Policy Alternatives
Authors: Martin Larry , Zwart Anthony C.
Published: July 2006

A quarterly recursive quadratic programming model of the North American pork sector is constructed to explain spatial and temporal variations in the sector and to evaluate the repercussions of policy changes. The model incorporates econometric supply, demand for consumption and demand for storage equations for Eastern and Western Canada and the United States. It is then run over a forty‐one quarter period to evaluate its ability to simulate the sector. A policy experiment is conducted which assesses a change in tariff policies between Canada and the United States to illustrate the model's application for policy analysis.
Measuring Farmers' Trade‐Offs between Expected Income and Focus‐Loss Income
Authors: Webster J. P. G. , Kennedy J. O. S.
Published: July 2006

Farmers' attitudes to risk are viewed within a focus‐loss framework. Sets of indifference curves are constructed for five farmers who are willing to forgo expected income for increases in a probabilisticly defined minimum income. Each set of curves is compared with the respective farmer's utility function as derived by the modified von Neumann‐Morgenstern method.
School Consolidation in Sparsely Populated Rural Areas: A Separable Programming Approach
Authors: Holland David W. , Baritelle John L.
Published: July 2006

The purpose of this study was to investigate the relationship between internal schooling economies and transportation costs with regard to consolidation of rural schools. The consolidation question was conceptualized as a programming problem where the objective was to simultaneously minimize the sum of schooling and transportation costs. Both linear and separable programming models were used. Model solutions indicated that some consolidation of schools in the study area would minimize costs but total cost savings were relatively small.
Education and Allocative Efficiency in U.S. Agriculture
Authors: Khaldi Nabil
Published: July 2006

Rapid technological change creates production uncertainty with a consequent decline in allocative efficiency; productivity growth appears to augment the comparative advantage of large farms, which alongside rising operator education implies scale economies in the use of information. A method is provided for measuring cost inefficiency due to changes in input mix and failure to produce optimum output which is related to growth in farm size. Statistical results provide support for the hypothesis that education enhances allocative efficiency.
Economic Class as a Measure of Farmers' Welfare
Authors: Larson Donald K.
Published: July 2006

Special tabulations from Internal Revenue Service provide an opportunity for agricultural economists to show that average income of farm operator families distributed by size of farm business receipts gives a misleading indication of the well‐being of farm families. For 1970, the distribution of farm taxpayers by basic income classes varies considerably within, as well as between, farm receipt classes. Thus, a small farm business does not mean that the family has a low income, since many receive income from off‐farm sources.
A Stochastic Policy Simulation of the World Coffee Economy
Authors: Edwards R. , Parikh A.
Published: July 2006

The paper analyzes the structure of the world coffee market and suggests policies that stabilize the export earnings of coffee‐exporting countries. The major cyclical characteristics of the coffee economy may be explained by a simultaneous equation model, which considers the lagged response of supply to price. The most successful policies include the development of rapidly maturing trees and the imposition of a quota on exports, both of which are effective in modifying the long‐run cycle. A buffer stock policy is shown to be effective in eliminating short‐run fluctuations, given sufficient resources.
Application of Dynamic Programming in Markov Chains to the Evaluation of Water Quality in Irrigation
Authors: Yaron D. , Olian A.
Published: July 2006

With the aid of a dynamic programming model in Markov chains, this paper presents an economic analysis of irrigation with saline water. Results provide guides to optimal irrigation policy. Estimates of the value of water quality in irrigation are derived, and possible applications in water resource development decisions are discussed.
Increasing Response Rates in Mailed Questionnaires
Authors: Buse R. C.
Published: July 2006

Described is a procedure using a personal letter to a questionnaire recipient to capture attention, develop rapport, and capitalize on this plus persistence to achieve a high response rate. Also examined is the question of bias associated with nonrespondents. The evidence presented supports the practice of pursuing high response rates.
A Sequential Programming Model of Growth and Capital Accumulation of a Farm under Uncertainty
Authors: Yaron D. , Horowitz U.
Published: July 2006

Advantages of the sequential approach to making decisions under uncertainty are well known. However, the relatively detailed analysis involved, when applied to empirical problems, faces the “cure of dimensionality.” In 1955 Dantzig offered a model of sequential programming under uncertainty which combined the merits of linear programming and sequential analysis. This paper presents an extension of Dantzig's model intended to reduce the dimensionality difficulty by introducing the distinction between long‐run (primarily investment) and short‐run (current production) planning. This paper also includes treatment of uncertainty in terms of eliminating plans which may lead to severe failures (bankruptcy) at any sequentially conceiveable state over the planning horizon.
Reliability of Using the Mean Absolute Deviation to Derive Efficient E,V Farm Plans
Authors: Thomson K. J. , Hazell P. B. R.
Published: July 2006

A linear programming approximation using the mean absolute deviation can be used to derive efficient E,V farm plans when a suitable quadratic programming computer code is not available. This note reports a Monte Carlo simulation study designed to test the accuracy of this method, and concludes that it is more reliable than previously thought.
Recent Changes in Beef Grades: Issues and Analysis of the Yield Grade Requirement
Authors: Purcell Wayne D. , Nelson Kenneth E.
Published: July 2006

The recent change in beef grades has stimulated discussion and opposition. Changes designed to improve the efficiency of the beef‐marketing system are being opposed by groups who adopt a micro perspective. The move to required yield grading continues to draw opposition. Analysis of original data from 118 beef carcasses and data from published studies indicates trimming procedures on fabricated cuts are important determinants of the change in cutability across yield grades. Research designed to investigate the implications of different trimming procedures is needed to clarify the applicability of yield grades.
An Economic Evaluation of Alternative Peanut Policies
Authors: Nieuwoudt W. L. , Bullock J. B. , Mathia G. A.
Published: July 2006

Three alternatives to the current peanut‐price support, acreage‐allotment program are considered. A linear programming framework is used to compare the effects of these policies on geographic location of peanut production, producer and consumer surplus, treasury costs, and value of allotments. Peanut production would expand in all areas except Texas under less restrictive production constraints. The largest expansion would be in Georgia and Alabama. Some version of the target price plan is considered to be a likely compromise program.
A Model of Consumer Goods Characteristics
Authors: Ladd George W. , Suvannunt Veraphol
Published: July 2006

This paper derives and tests two hypotheses concerning characteristics of purchased consumer goods. One hypothesis states retail price paid is a weighted linear combination of a product's yields of characteristics, each weight being a marginal implicit price of a characteristic. The second hypothesis expresses consumer demand for a product as a function of income, product prices, and product's yields of characteristics. Statistical results are consistent with the hypotheses. One model used in this paper is the consumer goods counterpart to the model used by Ladd and Martin in studying prices and demands for input characteristics.
A Neoclassical Analysis of the U. S. Farm Sector, 1948–1970
Authors: Rosine John , Helmberger Peter
Published: July 2006

The impacts of major exogenous forces on the farm sector are measured using a seven equation model. Annual estimates of the parameters of an aggregate Cobb‐Douglas production function are obtained by using relative market shares. First order conditions for four groups of inputs are derived. Time series and ordinary least squares are used to estimate the supply for farm labor and the demand for farm output. Technological change, exogenous price changes, and population growth are the major exogenous influences. Roughly 90 percent of farm program benefits have accrued to landowners.
On Sources of Measured Technical Efficiency: The Impact of Information
Authors: Müller Jürgen
Published: July 2006

The concept of technical efficiency differences—different levels of output with identical levels of input—is unsatisfactory from a production theoretic point of view. In this paper a model is developed in which differences in non‐conventional inputs and especially information obtained by managers may explain productivity differences between firms. Estimation of the underlying production structure (of a sample of California dairy farms) via a modified non‐homothetic Cobb‐Douglas production function shows the specific impact of information within the neoclassical production framework. This is conceptually and analytically superior to the methodology of frontier production functions.
Effects of Tax Depreciation Policy and Investment Incentives on Optimal Equipment Replacement Decisions
Authors: Chisholm Anthony H.
Published: July 2006

A model is developed to analyze the effects of income tax policy on the optimal timing of replacement for farm machinery. The impact of some forms of tax investment incentives on optimal replacement age was found to be substantial, while the influence of different tax depreciation methods is minimal.
Institutional Affiliation of Authors of Contributions to the American Journal of Agricultural Economics—1953–1972
Authors: Holland David W. , Redman John C.
Published: July 2006

Contributions to the American Journal of Agricultural Economics were tabulated for the periods 1953–1962, 1963–1967, and 1968–1972. Institutional juxtaposition through time for both invited and noninvited articles was observed. Rankings by subject category were provided for the most recent five‐year period.
An Economic Analysis of Agricultural Land Use Practices to Control Water Quality
Authors: Jacobs James J. , Timmons John F.
Published: July 2006

Sediment and phosphorus losses to streams from crop and pasture land can be reduced through production practices. The associated abatement costs to farmers are substantial and increase rapidly as the sediment and phosphorus constraints become more stringent. Distribution of these costs is determined by the type of regulation established.
An Investigation of the Importance of Risk in Farmers' Decisions
Authors: Just Richard E.
Published: July 2006

This paper presents an empirical investigation of the importance of risk in decisions. The adaptive expectations geometric lag model is generalized by geometrically including quadratic lag terms indicative of risk. The computation of consistent estimators is described, and the model is applied in the analysis of California field‐crop supply response. Results indicate that the effects of stabilization (possibly associated with government programs) might have seriously offset the acreage‐reducing effects of voluntary acreage restrictions. Finally, more general implications relating to reduced‐form estimation of the standard Nerlovian model are discussed.
A Utility Approach to the Valuation of Recreational and Aesthetic Experiences
Authors: Sinden J. A.
Published: July 2006

A method for valuing extra‐market benefits is proposed and tested. The method rests on the empirical derivation of utility functions and indifference maps. Demand schedules were obtained from the indifference maps to provide specific benefit values. The method is compared to the conventional travel‐cost method for valuing recreational benefits. It is argued that the utility approach is cenceptually superior. Also, the utility data comprised both the benefit values from the indifference maps and direct survey responses as surrogates for utility. These data proved better predictors of consumption than the usual travel‐cost variables.
Spatial Price Differentials for Corn among Illinois Country Elevators
Authors: Davis Leroy , Hill Lowell
Published: July 2006

Corn price differentials among country elevators often exceed norms of perfect competition. Identification of causal factors may suggest remedial policy decisions. This study indicates that the variables of seasonal adjustments, local demand and supply conditions, availability of transportation facilities, and government loan rate are significant influences in price variation.
Wheat Acreage Supply Response under Changing Farm Programs
Authors: Morzuch B. J. , Weaver R. D. , Helmberger P. G.
Published: July 2006

Planted wheat acreage supply elasticities are estimated for each of several leading wheat‐producing states. Estimates of elasticities for the aggregate of these states are 0.77, 0.45, and 0.52 for spring wheat, winter wheat, and all wheat, respectively, but there is considerable heterogeneity among states. Acreage allotments and marketing quotas appear to have destroyed the role of prices in allocating acreage between wheat and other crops during the years 1950 and 1954–64. Estimates were obtained using multiple regression analysis of time‐series data for the period 1948–74. This period was subdivided in order to take account of changing farm programs.
Approximately Optimal Carryover Levels for Wheat in the United States
Authors: Taylor C. Robert , Talpaz Hovav
Published: July 2006

This paper presents results of stochastic simulations of adherence to a first‐period first‐order certainty equivalence decision rule for approximately optimal wheat stocks in the United States. The decision rule is obtained by maximizing a first‐order approximation of the discounted sum of expected producers' plus consumers' surplus less storage costs over a long‐time horizon. For comparative purposes, stochastic simulations of the present system for holding stocks are also given in the paper. Stock levels under the present system were found to be higher than the certainty equivalence stock levels.
Economic Performance and Energy Intensiveness on Organic and Conventional Farms in the Corn Belt: A Preliminary Comparison
Authors: Klepper Robert , Lockeretz William , Commoner Barry , Gertler Michael , Fast Sarah , O'Leary Daniel , Blobaum Roger
Published: July 2006

Recent energy and environmental problems in U.S. agriculture have stimulated interest in alternative technologies or systems of agricultural production. Large‐scale, mechanized organic farms that use little or no inorganic fertilizers or chemical pesticides may be one such alternative. The crop production on fourteen matched pairs of organic and conventional Corn Belt farms was studied to determine the relative value of crop output, net returns, energy intensiveness, and labor requirements. The results of this preliminary study suggest that organic farming warrants more intensive research.
The Economics of Upgrading Seventy‐one Branch Rail Lines in Iowa
Authors: Baumel C. Phillip , Miller John J. , Drinka Thomas P.
Published: July 2006

Proposed abandonment of branch rail lines in rural areas has stimulated considerable concern over the impact of abandonment on shippers, receivers, and rural communities. The purpose of this paper is to present estimates of the benefits and the costs of upgrading seventy‐one branch rail lines. A benefit‐cost analysis is used to compare the net benefits with the net costs of upgrading the rail lines. Separate models are utilized to estimate the benefits to grain shippers, fertilizer shippers, and shippers and receivers of all other products from upgrading the branch lines. Benefit‐cost ratios are presented for six alternative solutions.
The Effects of Federal Milk Orders on the Economic Performance of U.S. Milk Markets
Authors: Dobson W. D. , Salathe Larry E.
Published: July 2006

Class I price differentials maintained by the U.S. Department of Agriculture and producers during 1965–75 generated Grade A milk supplies in excess of fluid needs and reserves for the federal order system. As required by specified norms, USDA has adopted federal milk order provisions which reduce pronounced seasonality of milk production and lessen certain types of erratic and extreme price variation. If federal milk orders were eliminated and cooperatives and state agencies were barred from replacing the orders, then fluid milk markets characterized by lower Class I differentials, greater milk price variability, and smaller Grade A milk surpluses might emerge.
Financial Impacts of Government Support Price Programs
Authors: Boehlje Michael , Griffin Steven
Published: July 2006

Recent proposals to index government support prices based on the cost of production will have significant differential impacts on farms with different size and financial characteristics. Simulation analyses indicate that since such proposals result in both increased income and decreased risk and thus capitalization rates, land values could increase dramatically with the larger, high‐equity operator best able to pay the higher price for additional land. Furthermore, the guaranteed cash flow from such a program enables the higher equity firm to grow more rapidly in terms of net worth and land ownership as well as exhibit higher levels of family living compared to smaller, highly leveraged firms.