Drug prohibition in the United States: costs, consequences, and alternatives

"Drug legalization" increasingly merits serious consideration as both an analytical model and a policy option for addressing the "drug problem." Criminal justice approaches to the drug problem have proven limited in their capacity to curtail drug abuse. They also have proven increasingly costly and counterproductive. Drug legalization policies that are wisely implemented can minimize the risks of legalization, dramatically reduce the costs of current policies, and directly address the problems of drug abuse.     

美国地区渔业管理委员会的决策机制探究

随着200海里渔业管辖权的主张得到了第三世界国家的广泛支持,迫于世界形势的发展,1976年美国宣布建立200海里渔业保护区,因渔业管理所需,遂在其沿海3~200海里内建立了8个地区渔业管理委员会。地区渔业管理委员会属于半官方机构,其成员主要是在渔业保护和管理、商业性或娱乐性捕捞方面具有丰富科学知识和实践的个人。该机构的建立,使得美国的渔业管理由政府管理为主的管理模式转向由政府和渔业利益相关者团体共同协商、共同参与的管理模式。本文对地区渔业管理委员会建立的历史背景、职能、组织和决策程序进行分析,并对其渔业决策方式进行探讨,最后根据我国实际情况进行讨论,提出我国应从建立科学规范的渔业决策程序、健全渔业决策科学支撑机制、建立保障公众参与渔业决策的途径这几个方面切实改进我国渔业管理决策机制。     

Acid rain: china, United States, and a remote area

The composition of precipitation in China is highly influenced by fossil fuel combustion and agricultural and cultural practices. Compared to the eastern United States, precipitation in China generally has higher concentrations of sulfate, ammonium, and calcium. Wet deposition rates of sulfur in China are 7 to 130 times higher than those in a remote area in the Southern Hemisphere. In many areas of the world, significant ecological changes have occurred in ecosystems that have acid deposition rates substantially less than those currently existing in China.     

Thrips: Pests of Concern to China and the United States

Thrips are among the most important agricultural pests globally because of the damage inflicted by their oviposition, feeding, and ability to transmit plant viruses. Because of their invasiveness, a number of pest species are common to both China and the United States and present significant challenges to growers of a wide range of crops in both countries. Among the pest thfips common to both countries are four of the major global thrips pests, Frankliniella occidentalis (Pergande), Scirtothrips dorsalis Hood, Thrips palmi Karny, and Thrips tabaci Lindeman. This review addresses characteristics that enable thrips to be such damaging pests and how biological attributes of thrips create challenges for their management. Despite these challenges, a number of successful management tactics have been developed for various cropping systems. We discuss some of these tactics that have been developed, including the use of cultural controls, biological controls, and judicious use of insecticides that do not disrupt overall pest management programs. The exchange of this type of information will help to facilitate management of pest thrips, especially in regions where species have recently invaded. A prime example is F. occidentalis, the western flower thrips, which is native to the United States, but has recently invaded China. Therefore, management tactics developed in the United States can be adapted to China. Because further success in management of thrips requires a thorough understanding of thrips ecology, we discuss areas of future research and emphasize the importance of collaboration among different countries to enhance our overall understanding of the biology and ecology of thrips and to improve management programs for these widespread pests.     

Leukemia mortality: downturn rates in the United States

A decline, the first ever observed, has recently occurred in leukemia mortality rates for the white population of the United States between the ages of 1 and 74. Possible explanations include diminished exposure to medical x-rays following the release in the United States and Great Britain in 1956 of widely publicized reports on the biologic effects of ionizing radiation.     

Coal in the United States: a status report

Historical trends in U.S. coal production, transportation and utilization and their causes are analyzed. The changing structure of the coal industry and its possible future direction, as it is driven by the effects of the oil embargo and world oil prices, are examined. National policies in the United States to increase coal use from indigenous sources in order to diversify and increase reliability of supply raise questions as to availability of coal supply and potential markets. Possible constraints on U.S. coal production, transportation, and utilization are appraised and it is concluded that increased coal consumption is "demand constrained." The causes and potential means of removal of these limitations are examined.     

Formation of the rocky mountains, Western United States: a continuum computer model

One hypothesis for the information of the Rocky Mountain structures in late Cretaceous through Eocene time is that plate of oceanic lithosphere was underthrust horizontally along the base of the North American lithosphere. The horizontal components of the motion of this plate are known from paleomagnetism, and the edge of the region of flat slab can estimated from reconstructed patterns of volcanism. New techniques of finite-element modeling allow prediction of the thermal and mechanical effects of horizontal subduction on the North American plate. A model that has a realistic temperature-dependent rheology and a simple plane-layered initial condition is used to compute the consequences of horizontal underthrusting in the time interval 75 million to 30 million years before present. Successful prediction of this model include (i) the location, amount, and direction of horizontal shortening that has been inferred from Laramide structures; (ii) massive transport of lower crust from southwest to northeast; (iii) the location and timing of the subsequent extension in metamorphic core complexes and the Rio Grande rift; and (iv) the total area eventually involved in Basin-and-Range style extension. In a broad sense, this model has predicted the belt of Laramide structures, the transport of crust from the coastal region to the continental interior, the subsequent extension in metamorphic core complexes and the Rio Grande rift, and the geographic region of late Tertiary Basin-and-Range extension. Its principal defects are that (i) many events are predicted about 5 million to 10 million years too late and (ii) the wave of crustal thickening does not travel far enough to the east. Reasonable modifications to the oceanic plate kinematics and rheologies that were assumed may correct these defects. The correspondence of model predictions to actual geology is already sufficiently close to show that the hypothesis that horizontal subduction caused the Laramide orogeny is probably correct. The Rocky Mountain thrust and reverse faults formed in an environment of east-west to northeast-southwest compressive stress that was caused by the viscous coupling between the oceanic plate and the base of the North American crust. Nonuniform crustal thickening by simple-shear transport also caused relative uplifts; therefore, this model is consistent with both of the range-forming mechanisms that have been inferred (1). A new proposal that arises from this simulation is that horizontal subduction also caused the subsequent extensional Basin-and-Range taphrogeny by stripping away the mantle lithosphere so that the crust was exposed to hot asthenosphere after the oceanic slab dropped away.     

Littoral of the northeastern United States: late quaternary warping

Isobases constructed from recently published data are strikingly parallel to both the edge of the continental shelf off the northeastern United States and the Fall Zone. Our analyses suggest that the downwarping recorded by these isobases may be explained by Daly's hypothesis of a collapsing peripheral or marginal "bulge."     

Acid Precipitation in the Northeastern United States: pH and Acidity

Detailed chemical analyses reveal that acid precipitation (pH < 5.6) in the northeastern United States is caused by the strong mineral acids sulfuric and nitric. There is a large array of other proton sources in precipitation, weak acids and Bronsted acids; however, although these other acids contribute to the total acidity of precipitation, they have a minimal influence on the free acidity (ambient pH) of acid precipitation.