论全球食糖生产及其政策

食糖是全球最受政策扭曲的农产品之一。欧盟和美国是主要实施食糖政策扭曲生产和贸易的经济体。随着“多哈议程”谈判的进行，发展中国家要求欧盟和美国改革食糖政策的呼声越来越高。改革食糖政策有利于增进全球福利。最近的研究认为，采用多边方式的改革食糖政策的获益最大，全球取消食糖政策保护1年可获得47亿美元的福利。欧洲和美国每年增加1500万t食糖，可使发展中国家增加上百万个就业机会。本文就全球食糖生产和一些国家的食糖政策作了较为全面的介绍和分析，使我们对世界农产品生产和贸易及政策有比较准确的了解。     

Biomedical research. Hughes grants target infectious diseases

The Howard Hughes Medical Institute has launched a new program of 5-year grants that funds 45 scientists in 20 countries. The $15 million initiative, which supports research on a variety of infectious and parasitic diseases, marks the first Hughes program outside the United States that is tailored to a specific research area.     

The space shuttle program: a policy failure?

The 5 January 1972 announcement by President Richard Nixon that the United States would develop during the 1970's a new space transportation system-the space shuttle-has had fundamental impacts on the character of U.S. space activities. In retrospect, it can be argued that the shuttle design chosen was destined to fail to meet many of the policy objectives established for the system; the shuttle's problems in serving as the primary launch vehicle for the United States and in providing routine and cost-effective space transportation are in large part a result of the ways in which compromises were made in the 1971-72 period in order to gain White House and congressional approval to proceed with the program. The decision to develop a space shuttle is an example of a poor quality national commitment to a major technological undertaking.     

The global impact of scaling up HIV/AIDS prevention programs in low- and middle-income countries

A strong, global commitment to expanded prevention programs targeted at sexual transmission and transmission among injecting drug users, started now, could avert 28 million new HIV infections between 2005 and 2015. This figure is more than half of the new infections that might otherwise occur during that period in 125 low- and middle-income countries. Although preventing these new infections would require investing about U.S.$122 billion over this period, it would reduce future needs for treatment and care. Our analysis suggests that it will cost about U.S.$3900 to prevent each new infection, but that this will produce a savings of U.S.$4700 in forgone treatment and care costs. Thus, greater spending on prevention now would not only prevent more than half the new infections that would occur from 2005 to 2015 but would actually produce a net financial saving as future costs for treatment and care are averted.     

Mission-oriented research for light machinery

The time of intelligent machines is upon us. But the United States is not actively pursuing this rich field of technological development. This is evidenced by the U.S. trade deficit of $9 billion in this market in 1977. The synergistic approach of Japan, Germany, Russia, and other countries to research, development, and demonstration among government, academic, and industrial groups is paying big dividends in vital U.S. markets. This article outlines a specific solution in terms of a U.S. national research policy for light machinery and robotics.     

A "prolife" population delegation?

The White House has been circulating drafts of a controversial position paper to be presented at the August 1984 United Nations world population conference in Mexico City. The paper dismisses population growth in developing countries as a cause of unemployment, illegal migration, or famine, and asserts that population programs are no substitute for ending government controls that stifle economic growth. It also contains a strong statement against abortion, states the U.S. position against coercion in family planning, and declares the Reagan administration's resolve not to fund programs advocating abortion. The U.S. stance is expected to antagonize developing countries and isolate the United States at the U.N. conference.     

美国罗非鱼产品进口市场集中度分析

美国是全球罗非鱼产品进口贸易大国,2015年罗非鱼产品进口量为22.5万t,进口额为9.81亿美元,是国际罗非鱼产品市场上最重要的进口贸易国之一。我国是罗非鱼产品出口贸易国,了解和掌握美国罗非鱼产品进口市场情况,对促进中国罗非鱼产品出口具有重要的意义。从进口量额、进口产品分析、进口来源地和进口价格总结了美国罗非鱼产品进口现状,通过进口来源国市场集中度(CR指数)、赫芬达尔—赫希曼指数(HHI指数)和洛伦兹曲线分析了进口市场集中度指标,表明美国罗非鱼产品进口来源市场集中度非常高。     

Containing bioterrorist smallpox

The need for a planned response to a deliberate introduction of smallpox has recently become urgent. We constructed a stochastic simulator of the spread of smallpox in structured communities to compare the effectiveness of mass vaccination versus targeted vaccination of close contacts of cases. Mass vaccination before smallpox introduction or immediately after the first cases was more effective than targeted vaccination in preventing and containing epidemics if there was no prior herd immunity (that is, no prior immunologic protection within the population). The effectiveness of postrelease targeted and mass vaccinations increased if we assumed that there was residual immunity in adults vaccinated before 1972, but the effectiveness of targeted vaccination increased more than that of mass vaccination. Under all scenarios, targeted vaccination prevented more cases per dose of vaccine than did mass vaccination. Although further research with larger-scale structured models is needed, our results suggest that increasing herd immunity, perhaps with a combination of preemptive voluntary vaccination and vaccination of first responders, could enhance the effectiveness of postattack intervention. It could also help targeted vaccination be more competitive with mass vaccination at both preventing and containing a deliberate introduction of smallpox.     

Biotechnology in europe

The countries of the European Economic Community have recently mounted considerable efforts to commercialize biotechnology. Together, these efforts approach the same number of companies and level of government spending as those in the United States. In Europe there is more government emphasis on support for industry-university collaborations and industrial projects than in the United States, where basic research is emphasized. European efforts are often not easily delineated from those in the United States; many European companies have extensive U.S. operations and many U.S. companies have involvement in Europe. Strategies and efforts in European biotechnology are examined and compared to those in the United States.     

The potential for grass-fed livestock: resource constraints

Using pasture and grazed forest-range for a system of producing live-stock by feeding grass alone reduces the inputs of energy about 60 percent and land resources about 8 percent, but also reduces by about half the production of animal protein in the United States. Under a system in which only grass was fed, livestock would be restricted to beef, milk, and lamb production. The amount of grain fed to U.S. livestock is about 135 million tons (metric) or about ten times the amount consumed by the U.S. population.     

Food production and the energy crisis

The principal raw material of modern U.S. agriculture is fossil fuel, whereas the labor input is relatively small (about 9 hours per crop acre). As agriculture is dependent upon fossil energy, crop production costs will also soar when fuel costs increase two- to fivefold. A return of 2.8 kcal of corn per 1 kcal of fuel input may then be uneconomical. Green revolution agriculture also uses high energy crop production technology, especially with respect to fertilizers and pesticides. While one may not doubt the sincerity of the U.S. effort to share its agricultural technology so that the rest of the world can live and eat as it does, one must be realistic about the resources available to accomplish this mission. In the United States we are currently using an equivalent of 80 gallons of gasoline to produce an acre of corn. With fuel shortages and high prices to come, we wonder if many developing nations will be able to afford the technology of U.S. agriculture. Problems have already occurred with green revolution crops, particularly problems related to pests (57). More critical problems are expected when there is a world energy crisis. A careful assessment should be made of the benefits, costs, and risks of high energy-demand green revolution agriculture in order to be certain that this program will not aggravate the already serious world food situation (58). To reduce energy inputs, green revolution and U.S. agriculture might employ such alternatives as rotations and green manures to reduce the high energy demand of chemical fertilizers and pesticides. U.S. agriculture might also reduce energy expenditures by substituting some manpower currently displaced by mechanization. While no one knows for certain what changes will have to be made, we can be sure that when conventional energy resources become scarce and expensive, the impact on agriculture as an industry and a way of life will be significant. This analysis is but a preliminary investigation of a significant agricultural problem that deserves careful attention and greater study before the energy situation becomes more critical.     

Global crop forecasting

Many foreign countries are as dependent on imports of food as the United States is on imports of oil. As the world's largest exporter of food, the United States needs reliable information on fluctuating foreign crop production. But available information is often inadequate and at best untimely. It is gathered by the foreign governments' often outmoded systems and its release may be delayed out of economic self-interest. Recently three U.S. government agencies put together a crop inventory system using satellite remote sensing and worldwide weather reporting and tested it in the Large Area Crop Inventory Experiment (LACIE). A 1977 real-time forecast of U.S.S.R. wheat production indicates that the approach works and may be expandable to other areas and other crops.     

Infectious diseases. Has leishmaniasis become endemic in the U.S.?

Believed to be all but absent from United States, the Leishmania parasite has infected more than 1000 hunting dogs in 21 U.S. states and the Canadian province of Ontario. Nobody is claiming that the disease is about to run riot among the U.S. population. But the widespread outbreak in dogs has experts wondering whether visceral leishmaniasis--which sickens over half a million people yearly in South America, Africa, the Mediterranean, and India--has become an endemic disease in North America.     

Areawide suppression of European corn borer with Bt maize reaps savings to non-Bt maize growers

Transgenic maize engineered to express insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) has become widely adopted in U.S. agriculture. In 2009, Bt maize was planted on more than 22.2 million hectares, constituting 63% of the U.S. crop. Using statistical analysis of per capita growth rate estimates, we found that areawide suppression of the primary pest Ostrinia nubilalis (European corn borer) is associated with Bt maize use. Cumulative benefits over 14 years are an estimated $3.2 billion for maize growers in Illinois, Minnesota, and Wisconsin, with more than $2.4 billion of this total accruing to non-Bt maize growers. Comparable estimates for Iowa and Nebraska are $3.6 billion in total, with $1.9 billion for non-Bt maize growers. These results affirm theoretical predictions of pest population suppression and highlight economic incentives for growers to maintain non-Bt maize refugia for sustainable insect resistance management.     

The southern corn leaf blight epidemic

A dramatic shift in the genetics of host-parasite interaction and balance occurred in the U.S. corn crop in the 1970 growing season. Southern corn leaf blight incited by Helminthosporium maydis Nisikado & Miyake evolved from a minor disease that causes an average annual loss of less than 1 percent, to one that caused more than the 12 percent average expected from all diseases of corn in the United States. In 1970 the losses to corn leaf blight approaches 710 million bushels. Reserves of corn and other grains ease the impact on the economy and food supplies but there are important domestic and foreign effects of the loss. The epidemic illustrates the vulnerability of our food crops to pests. Sources of genetic resistance to the new race of Helminthosporium maydis are available. The seed industry estimates that for 1971 enough resistant and partially resistant seed to plant about one-half of the crop may be available. Adequate supplies are expected in 1972. Sustained research programs are essential in protecting our food supplies from potential losses of catastrophe magnitude. Several professional groups, including the American Phytopathological Society and the Entomological Society of America, have urged that a program and facilities be established for the study of exotic pests that threaten our agriculture so that controls may be found before the pests are here. Such a program would be desirable but covers only one aspect of the problem. What is really needed is an overall strengthening of research on crop pests.     

United States population dose estimates for iodine-131 in the thyroid after the Chinese atmospheric nuclear weapons tests

Analysis of samples collected within the United States after the Chinese atmospheric nuclear weapons tests of 26 September and 17 November 1976 indicates that the radiation dose to the thyroid from iodine-131 in milk was predominant. A U.S. population dose to the thyroid of 68,000 man-rads was calculated for the iodine-131 fallout. The four excess thyroid cancers that are estimated to occur as a result of the September test during the next 45 years will be masked by the 380,000 cases of thyroid cancer which are expected to occur in the United States from all causes during the same interval.     

Prospects for district heating in the United States

Large-scale district heating, using waste heat rejected by electric power plants and other sources, is presented as a means of reducing significantly the amount of fossil fuel consumed for residential and commercial space and water heating in the United States. Analysis of the technical and economic aspects of model district heating systems for nine U.S. urban areas shows that district heat service to residential and commercial consumers would be economically attractive. Projections of national service levels show that up to half of the U.S. population could be served by district heating at costs that are competitive with the present costs of imported oil and also with projected costs of new energy forms. An advantage of district heat over the latter is that it is a proved, simple technology.     

U.s. Competitiveness: beyond the trade deficit

Large trade deficits and the corresponding increase in U.S. international indebtedness have raised concerns about the long-run competitiveness of the United States. But being competitive requires more than balance in our foreign trade; it requires an improving standard of living. The long-term U.S. competitive problem is largely caused by low saving rates, high costs of capital, and the resulting inadequate level of both visible and invisible investment. As long as the U.S. national saving rate remains far below that of all our major competitor nations, there is little chance for restoring America's international economic position.     

SCIENCE EDUCATION: Ehlers Bill Wins Bipartisan Backing

A House panel has unanimously endorsed a major bipartisan initiative to improve math and science education in U.S. elementary and secondary schools. The bill would authorize nearly $100 million a year for several new programs to be run by the National Science Foundation, a sizable addition to its current $275 million budget for precollege education.     

Materials science. Lighting initiative flickers to life

Researchers met in New Mexico last week to map out priorities for the proposed Next Generation Lighting Initiative embedded in a broader energy bill moving through Congress. The 10-year, $500 million project is designed to help the United States stay ahead of competitors in Japan, Europe, and Korea for global leadership in the $40 billion lighting industry.