The very long baseline array

The Very Long Baseline Array is a high-resolution synthesis radio telescope consisting of ten antennas, each 25 meters in diameter, located throughout the United States from Puerto Rico to Hawaii. Each antenna will be equipped with low-noise receivers spaced throughout the frequency range from 330 megahertz to 43 gigahertz, a hydrogen-maser frequency standard for time and frequency reference, and broadband digital tape recorders. Tapes recorded at each antenna will be simultaneously replayed and correlated in a specially built digital correlator, and the correlator output will, by Fourier transformation, be used to construct images of celestial radio sources with an angular resolution better than one thousandth of an arc second.     

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.     

Mars exploration. Plan for two rovers squeezes NASA budget

NASA's decision last week to send two rovers to Mars in 2003 is being hailed by researchers as affirming the agency's commitment to exploring the Red Planet. But once the applause dies down, cash-strapped space science managers will be forced to make tough decisions about how to shoulder the added $200 million cost of a second mission, starting with $96 million that must come out of NASA's 2001 budget.     

录像机中可变跟踪磁头驱动电路研究

录像机中的跟踪系统只有在以标准速度运行时才能进行准确跟踪在快进／倒带或慢速时，跟踪的准确性将下降，噪声将增大。为了确保准确跟踪提高重放信号的信噪比，笔者给出了适用的可变跟踪磁头驱动电路，并对其进行了改进。     

Resources required for global tuberculosis control

We estimate that to achieve the World Health Organization's tuberculosis control targets, the 22 high-burden countries (HBCs) that collectively account for approximately 80% of the world's tuberculosis cases require about $1 billion per year during the period 2001 to 2005. A further $0.2 billion per year is needed for low and lower-middle income countries outside the 22 HBCs. There is a resource gap of up to around $300 million per year. Substantial progress in tuberculosis control could be achieved with increased investment that is large in the context of existing spending, but small in the wider context of global health expenditure.     

Science's Role in the World Health Organization

One hears often of the financial contributions made by the United States to the support of activities within the U.N. system, but much less frequently about benefits obtained. A particular instance of the latter is worth citing. An analysis was recently made by N.W. Axnick and J.M. Lane (3) of the costs associated with the protection of the United States against smallpox in 1968. This was estimated to be $153.8 million, of which $0.7 million was contributed to WHO specially earmarked for its smallpox eradication program, and $3 million in U.S. bilateral assistance to 19 countries in West Africa. Ihe success of the WHO-directed smallpox eradication program throughout the world has resulted in a 1972 decision by U.S. authorities to discontinue routine vaccination of the general population and of smallpox vaccination requirements for international travel to smallpox-free countries, which was estimated to involve economic costs of $135.7 million during 1968. The total current U.S. contribution (1972) to all activities of WHO is $27.6 million. Thus it will be seen that very substantial savings, probably exceding $100 million annually, wili accrue to the United States from the work of WHO on smallpox alone.     

海洋捕捞渔船用生物柴油减排的成本-效益分析

海洋捕捞业是我国渔业能耗和CO2排放的主要领域,捕捞渔船的节能减排水平低,潜力大。总结了我国海洋捕捞渔船能耗及排放现状,分析了生物柴油的特性及作为渔船代用燃料的优缺点,根据海洋捕捞渔船动力装置的特点提出了掺混生物柴油需对柴油机做出的改进措施,对捕捞渔船柴油机掺混5%体积分数的生物柴油的节能减排效果进行了成本-效益分析。结果显示,海洋捕捞渔船柴油机掺混5%的生物柴油将导致每船每年平均减少1 371元左右的燃料费用和2 000元左右的维修费用,但需付出较高的船舶改造成本;若我国所有的海洋捕捞渔船柴油机都添加5%的生物柴油,每年会降低二氧化碳排放近13.4万吨,按目前国际上的碳交易价格计算,每年将产生400多万元的社会环境效益。生物柴油具有一定的经济优势,环保性能显著,具有良好的减排效果,可以促进我国海洋捕捞渔船的节能减排和国家减排目标的实施。     

The national forests

National forests are a valuable national asset. They produce important amounts of wood, recreation, wilderness, wildlife, and water, but good management could produce much more of each kind of output. The national forests are a major business enterprise, with $42 billion of assets and an annual cash revenue of $400 million to $500 million, but they have never been studied as business enterprises. The national forests are capital-intensive, but the capital is used wastefully, in large part because no charge is made for its use. Funds for management and investment are spent in economically unrewarding regions, forests, and sites. The availability of so much of their output at little or no cost to users seriously distorts management decisions. Major reforms in the management of the national forests are needed. If carried out, these could make the national forests much more useful to the American public.     

Mexico's Program for Science and Technology, 1978 to 1982

In response to a request by President José López Portillo, the National Council of Science and Technology (CONACYT) worked out a program of scientific research and development in Mexico in keeping with the economic and social priorities of his administration-food production, energy, public health, and employment. Representatives from public, private, and academic sectors participated in preparing an inventory of needs for the development of human, economic, and physical resources. The program includes 2,489 projects in basic and applied sciences at a cost of $260 million to 1982 and 17,000 scholarships at a cost of $130 million.     

Biotechnology. Disease group invests in do-it-yourself drugs

On 31 May, the Cystic Fibrosis (CF) Foundation of Bethesda, Maryland, announced that it will invest at least $30 million in a small biotech firm, Aurora Biosciences of San Diego, to identify compounds that might prove useful in treating CF. This project, fueled initially by a donation of $20 million from the Bill and Melinda Gates Foundation, marks a new departure in the growing trend of patient groups taking charge of biomedical research.     

Academic research. California sets up three new institutes

Three University of California campuses were chosen last week as sites for a new $900 million program designed to keep the state a world leader in research and to bolster its economy. Each of the three schools will receive $25 million a year for 4 years from the state, with companies and other sources putting up at least twice that amount.     

全球转基因作物的产业化发展

转基因作物进行第一次大规模商业化种植始于1996年,至2007年,12年来,全球转基因作物的种植面积增加了66倍,达到1.143亿hm2,比2006年增加了12%。同时,随着智利和波兰的加入,种植转基因作物的国家由最初6个增加到23个,其中,发展中国家(12)在数量上首次超过发达国家(11)。种植转基因作物的农户比2006年又增加了200万户,总种植户达到1 200万。全球转基因作物市场价值累计约425亿美元。2007年,全球转基因作物市场价值达到69亿美元,占农作物总价值的16%,占种子市场价值的20%。专家预测,2008年全球转基因作物市场价值大约可达到75亿美元。     

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.     

The tokamak: model T fusion reactor

During the past several years there have been significant scientific and technological advances related to the tokamak magnetic confinement scheme. These are summarized in the context of a recent tokamak reactor design study which emphasizes reduced size, higher power density, and enhanced plant reliability and maintainability relative to earlier tokamak reactor design studies. The direct plant cost of the proposed reactor is estimated to be in the range $1000 to $1500 per electrical kilowatt. A three-phase strategy for demonstrating tokamak fusion power generation at a committed site is outlined. It is estimated that implementation of the three-phase program would require about 20 years and a total escalated expenditure $10 billion to $15 billion. The tokamak power plant described here is not viewed as definitive but rather as a point of departure in the development of a plan to demonstrate tokamak power generation.     

Real-time, very-long-baseline interferometry based on the use of a communications satellite

The Hermes satellite, a joint Canadian-American program, has been used to provide a communication channel between radio telescopes in West Virginia and Ontario, for very-long-baseline interferometry (VLBI). This system makes possible instantaneous correlation of the data as well as a sensitivity substantially better than that of earlier VLBI systems, by virtue of a broader observational bandwidth. With the use of a geostationary communications satellite it is possible to eliminate the tape recorders and the most troublesome part of the postobservational data processing. A further possibility is the development of a phase-coherent interferometer.     

Simultaneously mitigating near-term climate change and improving human health and food security

Tropospheric ozone and black carbon (BC) contribute to both degraded air quality and global warming. We considered ~400 emission control measures to reduce these pollutants by using current technology and experience. We identified 14 measures targeting methane and BC emissions that reduce projected global mean warming ~0.5°C by 2050. This strategy avoids 0.7 to 4.7 million annual premature deaths from outdoor air pollution and increases annual crop yields by 30 to 135 million metric tons due to ozone reductions in 2030 and beyond. Benefits of methane emissions reductions are valued at $700 to $5000 per metric ton, which is well above typical marginal abatement costs (less than $250). The selected controls target different sources and influence climate on shorter time scales than those of carbon dioxide-reduction measures. Implementing both substantially reduces the risks of crossing the 2°C threshold.     

Deep current measurements suggest long waves in the eastern equatorial pacific

During the 1975 El Ni?o expedition an array of conventional and electric field type near-bottom current recorders was deployed at the equator 300 kilometers west of the Galápagos Islands. While hydrographic observations were indicating El Ni?o activity off the South American coast, the current meters recorded an oscillation with a 25-day period, a wavelength of about 1000 kilometers, and an amplitude of 0.04 meter per second propagating westward at approximately 0.5 meter per second. These characteristics agree with theoretical models of a first-mode baroclinic Rossby wave trapped at the equator.     

EDUCATION: Gates Gives Cambridge a Rival to Rhodes

Thanks to a new $210 million trust announced on 11 October by the Bill & Melinda Gates Foundation, Cambridge University is launching a new high-visibility scholars' program, which each year will fund at least 225 students from outside the United Kingdom. The university will select Gates Cambridge Scholars based on merit, not need, focusing on academic ability and leadership potential.     

Biomaterials. New Chinese biochip center straddles business, academe

Last month, U.S.-trained entrepreneur and researcher Cheng Jing was named head of a new, two-pronged biochip venture here that will be highly unusual even for China, which has been experimenting with academic-industrial arrangements in recent years. One part is a for-profit company backed by $48 million from a combination of national and academic partners and overseas venture capital. The second piece is a nonprofit national center with nearly $10 million in research funding from the Ministry of Science and Technology.     

Clinical trials. Company, researchers battle over data access

A dispute between university-based researchers and the corporation that funded their study is threatening to erupt into a $7 million to $10 million legal battle. Last week, the researchers reported that a large clinical trial of an immune system booster to treat HIV-infected people found that the drug isn't effective in slowing progression to AIDS or reducing mortality. The company that developed the drug tried to block publication of the study unless the researchers included the company's analysis of a subset of the data that suggests the drug might help some people. The researchers refused.