Agricultural problems of emerging nations and possible roles of U.S. universities

Cover title."A talk by Douglas D. Caton, Director, Agriculture and Rural Development Service Office of Technical Cooperation and Research Agency for International Development, Washington, D.C. presented for Ag Science Week, February 10, 1966"--P. [2]

Retinoic acid controls the homeostasis of pre-cDC–derived splenic and intestinal dendritic cells

Dendritic cells (DCs) comprise distinct populations with specialized immune-regulatory functions. However, the environmental factors that determine the differentiation of these subsets remain poorly defined. Here, we report that retinoic acid (RA), a vitamin A derivative, controls the homeostasis of pre-DC (precursor of DC)–derived splenic CD11b(+)CD8α(−)Esam(high) DCs and the developmentally related CD11b(+)CD103(+) subset within the gut. Whereas mice deprived of RA signaling significantly lost both of these populations, neither pre-DC–derived CD11b(−)CD8α(+) and CD11b(−)CD103(+) nor monocyte-derived CD11b(+)CD8α(−)Esam(low) or CD11b(+)CD103(−) DC populations were deficient. In fate-tracking experiments, transfer of pre-DCs into RA-supplemented hosts resulted in near complete conversion of these cells into the CD11b(+)CD8α(−) subset, whereas transfer into vitamin A–deficient (VAD) hosts caused diversion to the CD11b(−)CD8α(+) lineage. As vitamin A is an essential nutrient, we evaluated retinoid levels in mice and humans after radiation-induced mucosal injury and found this conditioning led to an acute VAD state. Consequently, radiation led to a selective loss of both RA-dependent DC subsets and impaired class II–restricted auto and antitumor immunity that could be rescued by supplemental RA. These findings establish a critical role for RA in regulating the homeostasis of pre-DC–derived DC subsets and have implications for the management of patients with immune deficiencies resulting from malnutrition and irradiation

Costs and benefits of reseeding range lands in southern Idaho

Bulletin no. 326 Moscow, Idaho :University of Idaho, College of Agriculture,1960. D.D. Caton, Christoph Beringer. 31 p. :ill., maps ;23 cm

Cotton Farms, San Joaquin Valley, California: Organization, Costs, and Returns, 1947-59

Excerpt from the report Summary: Costs and returns data for 1947 through 1959 are presented in this report for three size types of cotton farms in the San Joaquin Valley of California. Between 1947-49 and 1959, net farm incomes on the three types of farms trended upward. The trend was greatest on the large cotton-general farms and least on the cotton-specialty farms. The upward trend in net farm income was due mainly to increases in size (measured in inputs) of farm and increased physical efficiency. Increased physical efficiency contributed more to the upward trend than did the increase in size of farm as measured by inputs. After about 1952, price changes generally had a downward effect on net farm income

Cost, Size, and Income Relations on Cotton Farms

As farms become larger and more specialized, questions of the relationships between costs and income as affected by size become more important. This report on cost-size relations on irrigated cotton farms in the San Joaquin Valley, Calif., shows that the smaller farms, within the range of size illustrated, can pay current charges for irrigation water and remain "in the black." However, their profits disappear more readily than those on larger farms as costs of irrigation water increase. On the farms illustrated, most of the economies of scale and size are achieved by the 320-acre farm. Costs per dollar of output increase rapidly for successively smaller farms, but decrease slowly for successively larger ones

Economic and Operational Characteristics of Arizona and New Mexico Range Cattle Ranches

Excerpts from the report: The objectives of this report are: (1) To present the cost, income, and investment of typical ranches in the Southern Intermountain and Southern Desert Ranching Areas as of 1960, and (2) to evaluate the effect of changes in costs, prices, and range forage supplies on the net income of these ranches. The investment, cost, and ranch organizational data used in developing representative ranch budgets were obtained from interviews with about 140 ranchers in the two ranching areas. These data were supplemented with additional data from other research, and from Forest Service and Bureau of Land Management records. Representative ranch budgets were developed for cattle ranches holding both a Forest Service and a Bureau of Land Management permit, and for cattle ranches with either a Forest Service or a Bureau of Land Management permit

Feed-Livestock Relationships: A Model for Analyzing Management Decisions

Economists studying the operation of individual firms have relied in large part on the general theory of production economics as presented in standard references (3) (6).1 Usually some changes are required to increase the usefulness of the theory in formulating realistic and testable hypotheses. Generally it is assumed that the goal of the firm is one of maximizing profits. The objective of this paper is to develop a general model especially helpful for analyzing the operation of firms that produce livestock products. This is based on certain modifications and elaborations of the conventional theory of production. For the purpose of illustrating the use of the general model, a California feeder-steer operation is used. The general model should be helpful in evaluating many other types of livestock operations. The major modification is the separation of the livestock operation into production stages. "The technical definition of a stage is a matter of both convenience and logic, depending on the importance of the elemental operations and the way in which they fit in with the flow of products and materials. . . . Thus, a stage consists of all productive services—durable or nondurable—that cooperate in performing a single operation or a group of minor but closely related operations" (4, p. 545)

Light Pollution, Radio Interference, and Space Debris: Threats and Opportunities in the 2020s

In this white paper, we will outline threats to astronomy in the areas of light pollution, radio interference, and space debris, and we will specify key principles and policy points that the AAS and other advocates can use in mitigating these threats