Profile. An ambassador of research

Elizabeth Ngugi, a nurse and social worker with a collaborative AIDS research program based at the University of Nairobi, plays a role that is crucial for many AIDS projects throughout Africa--but one that seldom receives credit in scientific circles. Like an ambassador of research, Ngugi connects ostracized communities that have little education and even less money to an international team of AIDS scientists.     

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.     

Evidence for exposure to HTLV-III in Uganda before 1973

Fifty of 75 serum samples collected in the West Nile district of Uganda between August 1972 and July 1973 contained antibodies reactive with human T-cell leukemia (lymphotropic) virus type 3 (HTLV-III; mean titer, 601), while 12 of 75 samples were positive in a similar test for HTLV type 1 (HTLV-1) antibodies (mean titer, 236). The samples were screened by enzyme-linked immunosorbent assay and positive results were confirmed by a newly developed unlabeled antibody-peroxidase procedure with enhanced sensitivity for detection of antibody binding to immunoblots of HTLV-III antigen, demonstrating antibodies to proteins with molecular weights of 24,000, 41,000, and 76,000 in nearly all positive samples. Analysis of titration data indicated enhanced titers of antibody against HTLV-III and HTLV-I when coinfection occurred. The high prevalence and relatively low titers [compared to serum from patients with acquired immune deficiency syndrome (AIDS)] of antibodies recognizing HTLV-III proteins in sera from this population at a time that may predate or coincide with the appearance or spread of the AIDS agent (HTLV-III) suggest that the virus detected may have been a predecessor of HTLV-III or is HTLV-III itself but existing in a population acclimated to its presence. It further suggests an African origin of HTLV-III.     

中国农村生活用水投资情况及区域分布

农村居民健康水平的提高和改善很大程度上取决于安全可靠的生活用水的提供。本文利用抽样调查数据对农村村级生活用水投资状况进行了初步的研究。研究表明,村一级组织和农民自己负担了他们生活用水投资的很大一部分。同时,研究还表明上级政府（乡镇政府及乡镇以上政府）的生活用水投资策略还是侧重于改善和提高不发达地区农民的饮用水设施。随着农村税费和农业税减免等改革推行,为了保障农村生活用水投资的持续增长和农民生活质量的改善,需要各级政府在今后进一步加大农村饮用水的投资力度。     

北京地区旅游商品中存在的问题及其对策

随着我国加入WTO ,我国的旅游业面临着巨大的机遇和挑战。作为旅游业的重要组成部分 ,旅游商品存在着许多亟待解决的问题。通过对北京地区的旅游商品现状进行的调查与分析 ,提出现阶段旅游商品在生产、销售、服务及种类上存在的问题 ,阐述未来旅游商品发展的对策。     

Development and testing of AIDS vaccines

Recent advances in delineating the molecular biology of human immunodeficiency virus type 1 (HIV-1) have led to innovative approaches to development of a vaccine for acquired immunodeficiency syndrome (AIDS). However, the lack of understanding of mechanisms of protective immunity against HIV-1, the magnitude of genetic variation of the virus, and the lack of effective animal models for HIV-1 infection and AIDS have impeded progress. The testing of AIDS vaccines also presents challenges. These include liability concerns over vaccine-related injuries; identification of suitable populations for phase 3 efficacy studies; balancing the ethical obligation to counsel research subjects to avoid high-risk behavior with the necessity to obtain vaccine efficacy data; and the effect of vaccine-induced seroconversion on the recruiting and welfare of trial volunteers. Several candidate AIDS vaccines are nevertheless currently under development, and some are undergoing phase 1 clinical trials. Rapid progress will depend on continued scientific advancement in conjunction with maximum use of resources, open information and reagent exchange, and a spirit of international collaboration.     

我国豆类产品进出口贸易结构分析

豆类是我国传统出口农产品,在我国农产品出口中占有一定地位;同时,我国现在又是世界最大的大豆的进口国。利用1996—2008年我国豆类产品进出口贸易数据,分析了我国豆类产品进出口贸易品种结构及其变化,分析了我国豆类产品的主要出口市场和进口来源市场,并在此基础上提出优化我国豆类贸易的建议。     

Molecular characterization of human T-cell leukemia (lymphotropic) virus type III in the acquired immune deficiency syndrome

The human T-cell leukemia (lymphotropic) virus type III (HTLV-III) appears to be central to the causation of the acquired immune deficiency syndrome (AIDS). Two full-length integrated proviral DNA forms of HTLV-III have now been cloned and analyzed, and DNA sequences of the virus in cell lines and fresh tissues from patients with AIDS or AIDS-related complex (ARC) have been characterized. The results revealed that (i) HTLV-III is an exogenous human retrovirus, approximately 10 kilobases in length, that lacks nucleic acid sequences derived from normal human DNA; (ii) HTLV-III, unlike HTLV types I and II, shows substantial diversity in its genomic restriction enzyme cleavage pattern; (iii) HTLV-III persists in substantial amounts in cells as unintegrated linear DNA, an uncommon property that has been linked to the cytopathic effects of certain animal retroviruses; and (iv) HTLV-III viral DNA can be detected in low levels in fresh (primary) lymphoid tissue of a minority of patients with AIDS or ARC but appears not to be present in Kaposi's sarcoma tissue. These findings have important implications concerning the biological properties of HTLV-III and the pathophysiology of AIDS and Kaposi's sarcoma.     

浅淡中国贸易与环境问题的法律对策

20世纪90年代以来,随着联合国环发会议的进程,贸易、环境与可持续发展问题日益突出,如何协调国际贸易与环境保护的关系,是入世后中国面临的一项迫切任务,它不但影响到中国在WTO中的权利与义务,也影响中国以后的对外贸易发展、环境保护以及可持续发展的目标的实现。中国一方面应完善环保法律、法规以适应入世需要,另一方面应积极参与国际合作以表明中国的立场,避免二者冲突对中国造成不利影响。     

The economic impact of AIDS in the United States

This analysis of several previous studies of the cost of AIDS suggests that the lifetime cost of medical care per patient will not exceed +80,000, an amount similar to the cost of treating other serious illnesses. If current projections of future AIDS cases are accurate, the cumulative lifetime costs of 270,000 cases diagnosed between 1981 and the end of 1991 will not exceed +22 billion. This amount is small compared with total U.S. medical spending. The economic impact of AIDS on San Francisco, New York, and some other cities, however, is likely to be more serious. The AIDS epidemic will also highlight the financial problems of Americans who face large medical bills without adequate insurance.     

我国电子商务发展现状及前景展望研究

目前,随着互联网的快速发展,每个行业都在互联网信息技术的影响下得到了快速的 发展,而且也顺应了时代的发展潮流。其中互联网+的出现同时又为改变传统的行业给予了新 的发展模式,而且在社会当中也得到了广泛的应用。当然这其中也包括对于电子商务行业,在 互联网行业的促进下,我国的电子商务也得到了极大的发展,同时互联网的发展也为电子商务 的发展打下了坚实的基础。由于电子商务的快速发展不仅带动了我国经济的快速发展,而且也 成为了加快社会进步的重要力量。     

农业高校促进农村信息化的作用简析

农村信息化是我国社会主义新农村建设的一项重要内容,也是提高农村生产力的重要举措。农业高等院校作为一支独特的力量,在我国农业和社会主义新农村建设中起着重要的作用。文章在分析我国农村信息化现状和存在问题的基础上,从人才培养、技术支撑、宣传引导和信息导航等方面介绍农业高校在农村信息化进程中的作用。     

新时期林业发展中营林机械的作用分析

林业的发展对于我国的生态环境的发展起着重要作用,而营林机械对于新时期的林业发展也是起着至关重要的作用。对于目前新时期林业发展的转变,营林机械被赋予了更多的内涵,所以应该认真研究林业发展的同时也应细致的研究营林机械。针对新时期林业发展中营林机械的作用进行探析。     

Serological analysis of a subgroup of human T-lymphotropic retroviruses (HTLV-III) associated with AIDS

The two main subgroups of the family of human T-lymphotropic retroviruses (HTLV) that have previously been characterized are known as HTLV-I and HTLV-II. Both are associated with certain human leukemias and lymphomas. Cell surface antigens (p61 and p65) encoded by HTLV-I are frequently recognized, at low titers, by antibodies in the serum of patients with acquired immunodeficiency syndrome (AIDS) or with signs or symptoms that precede AIDS (pre-AIDS). This suggests an involvement of HTLV in these disorders. Another subgroup of HTLV, designated HTLV-III, has now been isolated from many patients with AIDS and pre-AIDS. In the studies described in this report, virus-associated antigens in T-cell clones permanently producing HTLV-III were subjected to biochemical and immunological analyses. Antigens of HTLV-III, specifically detected by antibodies in serum from AIDS or pre-AIDS patients and revealed by the Western blot technique, are similar in size to those found in other subgroups of HTLV. They include at least three serologically unrelated antigenic groups, one of which is associated with group-specific antigens (p55 and P24) and another with envelope-related (p65) proteins, while the antigens in the third group are of unknown affiliation. The data show that HTLV-III is clearly distinguishable from HTLV-I and HTLV-II but is also significantly related to both viruses. HTLV-III is thus a true member of the HTLV family.     

Antibodies reactive with human T-lymphotropic retroviruses (HTLV-III) in the serum of patients with AIDS

In cats, infection with T-lymphotropic retroviruses can cause T-cell proliferation and leukemia or T-cell depletion and immunosuppression. In humans, some highly T4 tropic retroviruses called HTLV-I can cause T-cell proliferation and leukemia. The subgroup HTLV-II also induces T-cell proliferation in vitro, but its role in disease is unclear. Viruses of a third subgroup of human T-lymphotropic retroviruses, collectively designated HTLV-III, have been isolated from cultured cells of 48 patients with acquired immunodeficiency syndrome (AIDS). The biological properties of HTLV-III and immunological analyses of its proteins show that this virus is a member of the HTLV family, and that it is more closely related to HTLV-II than to HTLV-I. Serum samples from 88 percent of patients with AIDS and from 79 percent of homosexual men with signs and symptoms that frequently precede AIDS, but from less than 1 percent of heterosexual subjects, have antibodies reactive against antigens of HTLV-III. The major immune reactivity appears to be directed against p41, the presumed envelope antigen of the virus.     

我国优秀运动员文化教育管理体制改革研究

我国竞技体育得到了快速发展,人们对于体育的关注度也有了明显提高。但更多时候 运动员关注的内容是技能训练,忽视了文化教育的重要性。我国优秀运动员的文化教育体制也 需要经历一次改革,从单一化过渡至多元化,以体育部门为主体,多个部门共同合作。近年来国 家也出台了相应的政策和文件,致力于竞技体育事业的可持续发展。     

当前耕地保护存在问题及对策——以淄博市为例

耕地资源是一种稀缺的公共资源,耕地保护是社会主义新农村建设的要务,是经济社会可持续发展的关键,是我国粮食安全的重要保障。本文在介绍我国耕地保护问题理论和现状的基础上,结合：淄博市实际,初步分析了耕地保护问题产生的原因,并提出了相应的对策建议。     

Induction of AIDS in rhesus monkeys by molecularly cloned simian immunodeficiency virus

Better understanding of the pathogenesis of acquired immunodeficiency syndrome (AIDS) would be greatly facilitated by a relevant animal model that uses molecularly cloned virus of defined sequence to induce the disease. Such a system would also be of great value for AIDS vaccine research. An infectious molecular clone of simian immunodeficiency virus (SIV) was identified that induces AIDS in common rhesus monkeys in a time frame suitable for laboratory investigation. These results provide another strong link in the chain of evidence for the viral etiology of AIDS. More importantly, they define a system for molecular dissection of the determinants of AIDS pathogenesis.     

HTLV-III in saliva of people with AIDS-related complex and healthy homosexual men at risk for AIDS

Peripheral blood leukocytes and saliva from 20 individuals, including four with the acquired immune deficiency syndrome (AIDS), ten with AIDS-related complex (ARC), and six healthy homosexual males at risk for AIDS, were compared as sources of transmissible human T-cell leukemia (lymphotropic) virus type III (HTLV-III), the virus found to be the etiologic agent of AIDS. All of the AIDS and ARC patients and four of the six healthy homosexuals had evidence of prior exposure to HTLV-III as indicated by seropositivity for antibody to HTLV-III structural proteins. Infectious virus was isolated from the peripheral blood of one of the AIDS patients, four of the ARC patients, and two of the healthy homosexual males, consistent with previous reports. HTLV-III was also isolated from the saliva of four of the ARC patients and four of the healthy homosexuals. Virus was also observed by electron microscopy in material prepared by centrifugation of the saliva of one AIDS patient. Although AIDS does not appear to be transmitted by casual contact, the possibility that HTLV-III can be transmitted by saliva should be considered.