Erratum

In the article "Color Defect and Color Theory" by C. H. Graham and Y. Hsia [Science 127, 675 (28 March 1958)], the last 13 lines in column 3, page 679, appear in reverse order. The bottom line should be read first, the second line from the bottom should be read second, and finally, the 13th line from the bottom should be read last.     

Mount Graham. Report finds squirrels survived 3 telescopes

In 1988 Congress allowed construction of three telescopes on Mount Graham, a desert "sky island" northeast of here, prompting the U.S. Forest Service to order a long-range study to monitor the population of an endangered subspecies of red squirrel that lives here. The results are now in. But the findings--that the work to date has had "no significant effect" on the rare rodents--have done little to resolve a debate that is expected to heat up again next year when the University of Arizona seeks permission to build four more telescopes.     

Missile Defense: LBJ's Bid To Curb Arms Race Gains Support

In the article of 31 March on antiballistic missile defense, the last sentence of paragraph 2, p. 1654, should read: "Manpower for producing . . . but the outer limit would be about 200,000, or half the number of contractor employees and civil servants working for NASA at the peak of the Apollo program."     

Corrections and clarifications

The 1994 and 1995 federal science budget appropriations for two of the activities were inadvertently transposed in a table that accompanied the article "Hitting the President's target is mixed blessing for agencies" by Jeffrey Mervis (News & Comment, 14 Oct., p. 211). The correct figures for Defense Department spending on university research are $1.460 billion in 1994 and $1.279 billion in 1995; for research and development at NASA, the correct figures are $9.455 billion in 1994 and $9.824 billion in 1995.     

A program for planetary exploration

On the basis of a two-year study, the NASA Solar System Exploration Committee recommends a core program of planetary missions through the year 2000. By incorporating a number of cost-saving measures, an exciting program of planetary exploration can be achieved within a highly constrained NASA budget.     

2001 BUDGET: NSF and NASA Score Last-Minute Victories

Congress last week gave both NASA and the National Science Foundation (NSF) significant hikes for 2001: NSF got $4.42 billion, a $522 million boost over this year that nearly matched NSF's 17% request, and NASA received $14.3 billion, nearly twice the White House's request for a 3% boost-but with hundreds of millions of dollars in earmarks added on.     

NASA life sciences. An improvement in vital signs

Last week a hefty Russian module with living and working quarters for astronauts docked with the pieces of the international space station already in orbit, a critical step in creating a full-time orbiting laboratory. Meanwhile, NASA bureaucrats put the finishing touches on a realignment of the agency's struggling biology effort that should bolster fundamental research and allow scientists to make better use of the facility, scheduled to be completed in 2005. The two events raise the hopes of U.S. academic space life scientists that their discipline is at last on the ascent at NASA.     

假柴龙树属植物资源的开发利用与喜树碱及类似物的生产综述

对假柴龙树属植物的生物学特征及产生的主要喜树碱类物质进行了介绍,着重论述了利用臭味假柴龙树产生喜树碱及类似物的研究,并就假柴龙树属植物资源的利用和开发作进一步的展望。     

U.S. SPACE SCIENCE: Earmarks, Rising Costs Threaten NASA Missions

The House and Senate are working out a final 2001 budget plan that should leave NASA with a small increase over this year. But the increase will be more than swallowed up by projects costing hundreds of millions of dollars that politicians have added to satisfy their constituents. At the same time, rising mission costs in the wake of two recent Mars failures are forcing agency officials to steal money from lower priority efforts such as a trip to Pluto. The two trends, warn NASA and science community officials, could prove devastating to NASA's space science efforts.     

栗绛蚧寄生蜂及一种中国新记录(膜翅目:跳小蜂科)

在浙江的栗绛蚧上发现3种寄生性小蜂,即:中国花角跳小蜂Blastothrix chinensis Shi,绛蚧细柄跳小蜂Psilophrys tenuicornis Graham和桑名花翅跳小蜂Microterys kuwanae Ishii,第3种为中国新记录种,并对其鉴别形态作了简单描述。     

杂交茶香月季演化与遗传背景分析

通过文献收集、整理,融合最新研究成果,以时间为轴,大量分析包括图象资料在内的中外文献材料,明确了杂交茶香月季演化历程,解析其遗传背景,为杂交茶香月季育种提供参考。绘制了更为详细的杂交茶香月季历史演化图,通过对比发现切花月季最主要花型"中高型或高芯型"品种特性可能源自于中国古老月季资源月月粉,总结出杂交茶香月季的遗传背景。杂交茶香月季遗传背景较为复杂,主要来源于中国的Rosa chinensis(月月红、月月粉)、R.ordorata(淡黄香水月季、彩晕香水月季)、巨花蔷薇(R.gigantea)以及欧洲的法国蔷薇、大马士革蔷薇、麝香革蔷薇、异味蔷薇等9个原种及其变种,甚至包括一些人为的外源基因。     

小麦品种对土传小麦黄色花叶病毒病抗性遗传的初步研究

本试验通过杂交、回交和抗病性鉴定等方法,测定了14个组合的F_1代对土传小麦黄色花叶病毒病的抗性遗传。根据双亲正反杂交表现型一致的结果,可以确定控制小麦品种对该病毒病的抗性为细胞核遗传。通过对F_1、F_2、BC_1及BC_2各代群体抗病株和感病株分离比值的分析,初步确定有关土传小麦黄色花叶病毒病的抗性遗传可能受两对致病显性基因(S_1、S_2),和一对抑制基因(I)所控制,作者并对这一问题与前人工作作了比较和讨论。     

Gendered participation in water management: Issues and illustrations from water users‘ associations in South Asia

The widespread trend to transferirrigation management responsibility from the stateto communities or local user groups has byand large ignored the implications ofintra-community power differences for theeffectiveness and equity of water management. Genderis a recurrent source of such differences. Despitethe rhetoric on womens participation, a review ofevidence from South Asia shows that femaleparticipation is minimal in water usersorganizations. One reason for this is that theformal and informal membership criteria excludewomen. Moreover, the balance between costs andbenefits of participation is often negative forwomen because complying with the rules and practicesof the organization involves considerable time costsand social risks, whereas other ways to obtainirrigation services may be more effective for femalewater users. Although effective, these other andoften informal ways of obtaining irrigation servicesare also typically less secure. More formalparticipation of women can strengthen womensbargaining position as resource users withinhouseholds and communities. Greater involvement ofwomen can also strengthen the effectiveness of theorganization by improving womens compliance withrules and maintenance contributions. Furtherdetailed and comparative research is required toidentify the major factors that affect womensparticipation and control over resources, ifdevolution policies are to address the tensionbetween objectives of transferring control overresources to community institutions, and ensuringthe participation of all members of the community,especially women.     

Industrial innovation policy: lessons from american history

The historical interrelations of government support of R & D and technical change in seven major American industries point to three types of policy that have been successful in the past: (i) government R & D support for technologies in which the government has a strong and direct procurement interest; (ii) decentralized systems of government-supported research in the "generic" area between the basic and the applied; and (iii) a decentralized system of clientele-oriented support for applied R & D. A fourth type of policy, under which the government attempts to "pick winners" in commercial applied R & D, has been a clear-cut failure.     

Interactions of formal and informal knowledge systems in village-based tree management in central India

This study critiques the idea of a Western science -- indigenous knowledge dichotomy in agricultural knowledge by examining the hybrid nature of knowledge use and incorporation by villagers in Madhya Pradesh, India. By analyzing knowledge systems as multi-leveled structures consisting of concrete practices linked to more abstract, explanatory concepts, this paper illustrates how information from multiple sources is integrated into local bodies of knowledge about tree management. Practices such as urea fertilization from formal global science might be explained by concepts such as that of a hot/cold duality from informal folk science. Similarly, other pieces of knowledge stemming from diverse knowledge systems are shown to become mixed and matched on practical and conceptual levels. Additionally, several knowledge elements used locally appear to be held in common by many knowledge systems around the world, rendering the determination of their origins in one system or another nearly impossible. These observations lead to the conclusion that local knowledge systems of tree management are better characterized as open systems rather than distinct, closed systems. Furthermore, the constant exchange of material between formal and informal, local and global systems renders untenable any strict dichotomy of knowledge systems.     

Sampling Strategies for Mapping Soil Phosphorus and Soil Potassium Distributions in Cool Temperate Grassland

Unlike the situation for arable soils, virtually nothing is known about the spatial dependencies of soil properties in cool temperate grassland or about what the optimal sampling strategies ought to be for mapping soil nutrient distributions in such situations. The aim of this study was to investigate the spatial variability in plant-available (soil) phosphorus and potassium in a grass silage field in Northern Ireland and devise optimal sampling strategies for mapping their distributions. Soil samples were collected from the field at 25 m intervals in a regular rectangular grid to provide a database of soil properties. Different data combinations were subsequently abstracted from this database for comparison purposes, and ordinary kriging used to produce interpolated soil maps. Soil potassium displayed greater spatial variability than soil phosphorus. In keeping with this observation, the results of three separate statistical procedures demonstrated that the optimal sample size for estimating the true population means was about twice as large for soil potassium as for soil phosphorus. Optimal sampling strategies, however, related not just to sample size but to sample combination and field shape as well.     

黄土区蔡家川流域刺槐人工林林下物种多样性

为了给晋西黄土区蔡家川流域刺槐Robinia pseudocacia人工林恢复状况评价以及植被配置提供理论依据,采用样地调查的方法,选取刺槐人工林为研究对象,对照当地油松Pinus tabulaeformis人工林和天然次生林,进行林下物种多样性研究。结果表明:①刺槐人工林林下物种共有37种,包括灌木8种,草本29种,灌木层以蔷薇科Rosaceae植物为主,草本层以菊科Compositae和禾本科Gramineae植物为主。②刺槐人工林林下α多样性小于天然次生林,与油松人工林之间的差异较小。③刺槐人工林林下草本层β多样性指数大于灌木层;刺槐林与天然林的β多样性大于刺槐林与油松林的。④刺槐人工林林下植被相似度不高,不同刺槐林样地之间物种种类存在较大的差异,尤其是草本层。晋西黄土区蔡家川流域刺槐人工林林下植被仍具有较大的生长繁殖空间,物种多样性还有待提高。     

SOLAR SYSTEM EXPLORATION: A More Cautious NASA Sets Plans for Mars

Twice burned by mission failures last year, NASA managers last week unveiled a new 15-year blueprint for Mars exploration. The revamped strategy allows for doing more science, but at a slower pace, while delaying a sample return until well into the next decade.     

Hypertension in the recently weaned Dahl salt-sensitive rat despite a diet deficient in sodium chloride

The Dahl rat is used as a model of hypertension that is "sensitive" to dietary salt (sodium chloride, NaCl). When dietary salt is supplemented in the Dahl rat, the arterial blood pressure of the "salt-sensitive" strain (S) becomes much greater than that of the "salt-resistant" strain (R). It has been widely reported that arterial blood pressure of the young Dahl S rat is not greater than that of the young Dahl R rat before dietary salt is supplemented. In the present study, however, mean arterial pressure directly measured in unanesthetized, unrestrained S rats was greater than in R rats, both when they had been recently weaned and for at least 10 weeks thereafter, despite their having been fed a diet frankly deficient in salt. In weanling S rats, the ratio of heart weight to body weight was also significantly greater than that in weanling R rats, suggesting that the greater blood pressure in the S rat causes cardiac hypertrophy. Thus, biologic differences demonstrated between the S rat and the R rat after weaning, including the phenomenon of salt-sensitivity, could be a consequence of, or be dependent on, an already extant difference in arterial blood pressure between the two strains.     

Development. Hear, hear, for the inner ear

Although the development of the inner ear has been a favorite subject for biologists to study, it is not yet clear exactly which molecules are involved in the induction of the otic placode, the plug of embryonic ectoderm that will become the inner ear. In his Perspective, Graham takes us on an inner ear odyssey, explaining how the signaling molecules FGF-19 and Wnt-8c cooperate to induce formation of the otic placode (Ladher et al.).