Correction: AIDS commission

A recent article by William Booth on the President's AIDS commission (News & Comment, 16 Oct., p. 262) incorrectly states that commission member Cory SerVaas, publisher of the Saturday Evening Post, drives her AIDS Mobile around the country. SerVaas does not drive the traveling van that offers free AIDS testing. Rather, she often flies to meet it as it travels around the country, stopping at shopping malls and churches by prearrangement with local civic and religious groups. SerVaas denies saying that homosexuals are "deviants." "We have helped homosexuals for many years," she says, pointing out that although her group primarily tests people who have a low risk of being infected, such as recipients of blood transfusions and women who may become pregnant, members of high-risk groups such as homosexuals and drug addicts are not excluded.     

Ground zero: AIDS research in Africa

More and more European and North American AIDS researchers are coming to sub-Saharan Africa, which is home to a whopping 70% of all HIV-infected people. These investigators are collaborating with local researchers on projects that aim to slow both HIV's spread and the course of disease in the millions already infected. But most African countries--constrained by limited resources, weak infrastructures, social mores, and political inaction--have grave difficulties translating research insights into prevention and treatment strategies.     

Scaling Up HIV/AIDS programs to national coverage

The most important issue in the fight against HIV/AIDS is how to scale up existing programs that are only reaching small numbers of people to the national level. Here, I present suggestions on how to tackle the daunting challenge of building truly national HIV/AIDS programs, based on insights gained from participatory, decentralized rural development experiences and from HIV/AIDS programs.     

HIV/AIDS in women: an expanding epidemic

More than 20 years into the human immunodeficiency virus-type 1 (HIV-1) epidemic, women account for nearly half of the 40 million people living with HIV-1 worldwide, with an even higher proportion existing in developing countries. Social determinants of female vulnerability to HIV-1 include gender disparities, poverty, cultural and sexual norms, lack of education, and violence. Women are also more susceptible to HIV-1 because of hormonal changes, vaginal microbial ecology and physiology, and a higher prevalence of sexually transmitted diseases. Prevention strategies must address the wide range of gender inequalities that promote the dissemination of HIV-1.     

AIDS: an international perspective

The acquired immunodeficiency syndrome (AIDS) and infection with the human immunodeficiency virus type 1 (HIV-1) constitute a worldwide public health problem. Whereas in Europe and in most of the Americas transmission of HIV-1 has occurred predominantly among homosexual men and intravenous drug abusers, in Africa a distinct epidemiologic pattern has emerged that indicates that HIV-1 infection is mainly heterosexually acquired. Heterosexual transmission appears to be increasing in some parts of Latin America and the Caribbean, and possibly in the United States. In addition to HIV-1, at least one other human retrovirus, namely HIV-2, has been implicated as a cause of AIDS in Africa and Europe. Factors that influence heterosexual transmission of HIV-1 include genital ulcerations, early or late stages of HIV-1 infection in the index case, and possibly oral contraception and immune activation. The rate of perinatal transmission is enhanced when the mother's illness is more advanced. AIDS and HIV-1 infection may have a significant impact not only on public health, but also on the demography and socioeconomic conditions of some developing countries. Programs for the prevention and control of AIDS should be an immediate priority in all countries.     

Infectious diseases. China awakens to fight projected AIDS crisis

Official tallies count only 670 confirmed AIDS cases and 18,143 confirmed HIV-infected people among China's 1.2 billion population. Now changing social mores, including an increase in drug use and a boom in commercial sex, combined with a tainted blood supply, have led China to the brink of an AIDS explosion. But its historic isolation also gives the country an advantage in testing the latest vaccines, as the different strains of HIV have not yet commingled there; China's well-developed public health infrastructure could also help facilitate clinical trials.     

Monitoring the AIDS epidemic in the United States: a network approach

Respondents in the 1988 General Social Survey (GSS) were asked to scan their acquaintance networks to identify all those who had been a victim of a homicide or had acquired immunodeficiency syndrome (AIDS). Estimates of the sex, race, age, and regional breakdowns for homicides in the last year and for people with AIDS were compared with official statistics. The GSS estimates for the distribution of homicide victims replicate the official statistics quite well. The GSS estimates for AIDS cases suggest that the data provided to the Centers for Disease Control may underestimate by a substantial margin the prevalence of AIDS in the white population of higher socioeconomic status, overstate the relative prevalence of the disease in the minority populations, underestimate the prevalence of the disease in the Midwest, and overstate it for the East.     

Genetic variation in HTLV-III/LAV over time in patients with AIDS or at risk for AIDS

In a study of genetic variation in the AIDS virus, HTLV-III/LAV, sequential virus isolates from persistently infected individuals were examined by Southern blot genomic analysis, molecular cloning, and nucleotide sequencing. Four to six virus isolates were obtained from each of three individuals over a 1-year or 2-year period. Changes were detected throughout the viral genomes and consisted of isolated and clustered nucleotide point mutations as well as short deletions or insertions. Results from genomic restriction mapping and nucleotide sequence comparisons indicated that viruses isolated sequentially had evolved in parallel from a common progenitor virus. The rate of evolution of HTLV-III/LAV was estimated to be at least 10(-3) nucleotide substitutions per site per year for the env gene and 10(-4) for the gag gene, values a millionfold greater than for most DNA genomes. Despite this relatively rapid rate of sequence divergence, virus isolates from any one patient were all much more related to each other than to viruses from other individuals. In view of the substantial heterogeneity among most independent HTLV-III/LAV isolates, the repeated isolation from a given individual of only highly related viruses raises the possibility that some type of interference mechanism may prevent simultaneous infection by more than one major genotypic form of the virus.     

Major international AIDS research collaborations

Science lists the major collaborative research projects throughout sub-Saharan Africa. This list will be updated periodically at www.sciencemag.org/feature/data/africacollaborations.shl. Please send additions and changes to science_news@aaas.org.     

孔孟民本思想述论

我国民本思想渊源久远,对后世产生了重要影响。孔子对民本思想进行了初步发展,主要包括重民、利民、惠民、富民、教民思想,主张德治,反对刑罚。孟子继承和进一步完善了孔子的民本思想,形成了一套治国理论和方案。孟子提出了民贵君轻说,主张制民之产,尚贤与重教。孔孟民本思想中有相同点也有不同点。相同点表现在孔孟都主张先富民再教民,主张德治反对刑罚,没有严格的忠君意识等。而孔子的民本思想主要停留在伦理道德层面上,孟子却把它上升为一套仁政的治国理论。     

Africa boosts AIDS vaccine R&D

Efforts have recently heated up in several African countries to tailor-make preparations that many believe offer the best hope yet for stopping HIV cold. But all are at the earliest stages, which means it will take years before a vaccine might prove its worth.     

Computer networks as social networks

Computer networks are inherently social networks, linking people, organizations, and knowledge. They are social institutions that should not be studied in isolation but as integrated into everyday lives. The proliferation of computer networks has facilitated a deemphasis on group solidarities at work and in the community and afforded a turn to networked societies that are loosely bounded and sparsely knit. The Internet increases people's social capital, increasing contact with friends and relatives who live nearby and far away. New tools must be developed to help people navigate and find knowledge in complex, fragmented, networked societies.     

正确处理现阶段人民内部矛盾 构建和谐社会

构建社会主义和谐社会是现阶段我国社会发展的中心任务,这就需要处理好人民内部存在的各种矛盾。这要求必须认识现阶段正确处理人民内部矛盾的重要性以及现阶段人民内部矛盾的表现,并进一步探求正确处理现阶段人民内部矛盾的途径。     

Injuries from the wichita falls tornado: implications for prevention

We examined the circumstances of death and injury among victims of the tornado that struck Wichita Falls, Texas, on 10 April 1979. We also assessed the protective measures taken by a representative sample of community residents who suffered no major injury in order to estimate the relative risk of injury to people directly in the tornado's path. Twenty-six (60 percent) of the 43 traumatic deaths and 30 (51 percent) of the 59 serious injuries occurred in people who, despite ample warning, went to their cars to drive out of the storm's path. These people had a risk of serious or fatal injury of 23 per 1000. People who remained indoors and in stationary homes were at relatively low risk (3 per 1000) if they took simple precautions; people in mobile homes were at greatest risk (85 per 1000). Current safety recommendations and housing codes for single family homes and mobile homes need to be amended to decrease the impact of future tornadoes on human health.     

Toward an AIDS vaccine

A quarter century of scientific discovery has been applied to developing an AIDS vaccine, yet this goal remains elusive. Specific characteristics of the virus, including the extreme genetic variability in circulating viral isolates worldwide, biological properties of HIV that impede immune attack, and a high mutation rate that allows for rapid escape from adaptive immune responses, render this a huge challenge. However, evidence of protection against AIDS viruses in animal models and control of HIV in humans under certain circumstances, together with scientific advances in understanding disease pathogenesis, provide a strong rationale and objective paths to continue the pursuit of an effective AIDS vaccine to stem the global epidemic.     

Low-income and overweight in China:Evidence from a life-course utility model

Previous literature has demonstrated that low-income people are more likely to settle for poor health choices in developed countries. By using income as a budget constraint and signal for future wellbeing in a life-course utility model, we examine the association amongst income and overweight. The data used for this study are from the China Health and Nutrition Survey(CHNS). Estimations are conducted for overweight initiation, cessation, and participation mirroring a decision to begin and a past decision to not terminate. Our findings propose that body weight and the likelihood of overweight commencement rise with additional income but at a diminishing degree, representing a concave relation; while the likelihood of overweight discontinuance declines with additional income but at an accelerating degree, suggesting a convex relation.We presume that, as opposed to developed countries, low-income people are less inclined to be overweight in China, a country in transition. This could be explained by an income constraint for unhealthy foodstuff. Nevertheless, it will switch when income surpasses the critical threshold of the concave or inverted U-shape curve indicating that low-income people appear to receive not as much utility from future health. Specifically, this adjustment seems to occur earlier for females and inhabitants of urban areas.     

HIV/AIDS患者外周血中4种细胞因子IL-2、IL-4、IL-15和IL-21表达水平及其临床意义研究

目的 观察外周血 4 种细胞因子（IL-2、IL-4、IL-15及IL-21）在HIV感染者/AIDS患者（HIV/AIDS）和正常人表达水平的区别及其与HIV RNA病毒载量和CD3⁺、CD4⁺细胞数量的相关性,分析其与HIV感染的关系和临床意义。方法 40例未经抗病毒治疗的HIV/AIDS 和31名正常人,采用ELISA法检测外周血4种细胞因子（IL-2、IL-4、IL-15及IL-21）,使用流式细胞计数法检测外周血CD3⁺、CD4⁺ T 淋巴细胞数量,实时聚合酶链反应测定血清中HIV RNA水平。结果 未经抗病毒治疗的HIV/AIDS外周血IL-2、IL-15及IL-21水平低于正常人,而IL-4水平高于正常人（P<0.05）。CD3⁺、CD4⁺细胞数量和各细胞因子水平显示出一定的相关关系,IL-2和IL-15水平均与HIV-1 RNA载量呈负相关。结论 提示外周血4种细胞因子都可能参与了HIV感染的致病机制,并与HIV RNA病毒载量及CD3⁺、CD4⁺细胞数量相关。     

Naturally occurring antibodies reactive with sperm proteins: apparent deficiency in AIDS sera

A set of naturally occurring immunoglobulin M (IgM) antibodies that are reactive with a defined subset of proteins in the acrosomal cap region of human sperm has been identified. These antibodies are present in a broad spectrum of human sera from males and females, 1 day to 40 years of age, and are absent or markedly deficient in a large proportion of sera from individuals with the acquired immune deficiency syndrome (AIDS) or at risk for AIDS. The subset of proteins with which the IgM antibodies are reactive includes a factor (or factors) capable of inhibiting lectin-induced T-lymphocyte proliferation. The prevalence of the sperm-reactive IgM antibodies indicates that they are not elicited by sperm. Further, immunoreactivity of the sperm proteins resulting in depletion of specific circulating IgM antibodies, or other interactions between the sperm proteins and elements of the immune system, may be a factor in the suppressed state of the immune system in AIDS.     

Violently active galaxies: the search for the energy machine

The energy source in these galaxies will be shown to be a black hole, I think, even though it may take 100 years before we have proven it.-MARTIN REES, at the Institute of Astronomy in Cambridge, England I think it will take 1000 years and we may very well be on the wrong track. These [black hole] models are getting into the textbooks now, but there is never anything testable and people are working on smaller and smaller pieces of the problem.- GEOFFREY BURBIDGE, at the Univeristy of California, San Diego, and soon to assume the post of head of the Kitt Peak National Observatory in Tucson, Arizona REES: I agree, but I would argue that the way we are going about it is the most productive approach, even though the modelers may be getting the illusory satisfaction of a Ptolomean theorist who adds another epicycle. BURBRIDGE: I'm glad to hear you say that, Martin. The trouble is that so many people take these things more seriously than you do.     

Education to prevent AIDS: prospects and obstacles

A number of obstacles thwart effective education to prevent AIDS in the United States. These include the biological basis and social complexity of the behaviors that must be changed, disagreement about the propriety of educational messages to prevent AIDS, uncertainty about the degree of risk to the majority of Americans, and dual messages of reassurance and alarm from responsible officials. Long-term protection of an individual from infection requires extreme changes in risk-taking behavior. Partial shifts toward safer practices may be epidemiologically important in retarding the rate and extent of spread of infection. Though some striking changes in behavior have occurred, especially in homosexual populations in areas with high prevalence of AIDS, educational efforts to date have succeeded more in raising awareness and knowledge about AIDS than in producing sufficient changes in behavior. The United States has yet to mount a nationwide comprehensive, intensive, and targeted education program to prevent AIDS.