Relation of HTLV-4 to simian and human immunodeficiency-associated viruses

Human immunodeficiency virus type 1 (HIV-1) is the aetiologic agent of AIDS (acquired immune deficiency syndrome) in most countries and probably originated in Central Africa like the AIDS epidemic itself. Evidence for a second major group of human immunodeficiency-associated retroviruses came from a report that West African human populations like wild-caught African green monkeys had serum antibodies that reacted more strongly with a simian immunodeficiency virus (STLV-3Mac) (ref.6) than with HIV-1. Novel T-lymphotropic retroviruses were reported to have been isolated from healthy Senegalese West Africans (HTLV-4) (ref. 4) and from African green monkeys (STLV-3AGM) (ref. 7), and a different retrovirus (HIV-2) was identified in other West African AIDS patients. Genomic analysis of HIV-2 clearly distinguished it from STLV-3 (ref. 9), but restriction enzyme site-mapping of three different HTLV-4 isolates and six different STLV-3AGM isolates showed them to be essentially indistinguishable. In this report we clone, restriction map, and partially sequence three isolates of HTLV-4 (PK82, PK289, PK190) (ref. 4). We find that these viruses differ in nucleotide sequence from each other and from three isolates of STLV-3AGM (K78, K6W, K1) (ref. 7) by 1% or less. We also report the isolation of a T-lymphotropic retrovirus from the peripheral blood of a healthy Senegalese woman which hybridizes preferentially to HIV-2 specific DNA probes. We conclude that HTLV-4 (ref. 4) and STLV-3AGM (ref. 7) are not independent virus isolates and that HIV-2 is present in Senegal as it is in other West African countries.     

Inhibition of sensitized leukocyte's in vitro reactivity by circulating immune complexes in prostate cancer

Circulating immune complexes in the sera of patients with confirmed histological diagnosis of carcinoma of the prostate, were found to interfere in the sensitized leukocyte's in vitro reactivity to prostate cancer associated antigen as evaluated by tube leukocyte adherence inhibition assay, thereby suggesting an inhibitory role of such serum factors in host's anti tumor cell mediated immune responses.     

Ecosystem energetic implications of parasite and free-living biomass in three estuaries

Parasites can have strong impacts but are thought to contribute little biomass to ecosystems. We quantified the biomass of free-living and parasitic species in three estuaries on the Pacific coast of California and Baja California. Here we show that parasites have substantial biomass in these ecosystems. We found that parasite biomass exceeded that of top predators. The biomass of trematodes was particularly high, being comparable to that of the abundant birds, fishes, burrowing shrimps and polychaetes. Trophically transmitted parasites and parasitic castrators subsumed more biomass than did other parasitic functional groups. The extended phenotype biomass controlled by parasitic castrators sometimes exceeded that of their uninfected hosts. The annual production of free-swimming trematode transmission stages was greater than the combined biomass of all quantified parasites and was also greater than bird biomass. This biomass and productivity of parasites implies a profound role for infectious processes in these estuaries.     

多相滤波器组的ZFFT算法在轨道电路信号检测中的应用

针对轨道电路信号(FSK信号)的检测提出了基于多相滤波器组的频谱细化(ZFFT)分析方法,该方法利用多相滤波器组将待分析的移频信号按照不同载频分解成多个子带,经过子带选择,再进行FFT,与传统的信号检测算法相比,这种算法可以提高信号检测精度和实时性.     

等离子驱动微小碎片加速器机理及运行参数

毫米以下尺寸微小碎片在近地空间存在数量大, 对航天器暴露材料的长期累积侵蚀作用成为影响航天器寿命和可靠性的重要因素, 在航天器的空间环境适应性设计中必须予以考虑. 为了模拟研究空间微小碎片对航天器材料的撞击效应, 研制了等离子体驱动的微小碎片加速器. 本文对加速器的核心过程—— 等离子体的加速、压缩进而形成超高速等离子体射流的物理过程建立了物理模型, 并进行了计算以及与实验结果的对比分析, 揭示了加速过程的物理机制, 为加速器的优化设计提供了依据. 同时, 通过一系列实验研究, 确定了加速器运行的最佳工作参数, 并初步获得了加速器的加速能力范围.     

大壁虎脚趾运动和感觉的分区分级调控

近年来, 爬壁机器人是机器人领域研究和开发的一个热点课题. 大壁虎是研究爬墙机器人的理想模型. 在仿壁虎机器人的研制过程中, 脚掌(趾)的设计是关键技术之一. 采用高速摄像和电生理学方法, 观测了大壁虎前、后脚在不同界面爬行时不同的运动模式; 研究了5个脚趾的黏-脱附运动及其感觉信息传入的神经支配; 发现了5个脚趾运动和感觉功能的不同分区, 黏附和脱附行为及其感受传入的分级调控现象. 这些结果为当前仿壁虎机器人, 以及其他4足和多足机器人脚掌(趾)的结构和运动控制系统的设计提供重要的信息和理念.     

广角光接收机研究进展

广角光接收机在无线光通信、传感和检测系统中有明显的优势和广泛的应用前景. 然而, 当它采用传统光器件来实现时, 其视场角会受到这些组件内在矛盾的限制, 而传统的视场角扩展机制无法从根本上打破这些束缚. 为此, 提出金属等离子表面波(SPP)作为有效实现广角接收机的潜在机制. 文中列举了两个SPP的应用实例, 生动地说明了它可以破解一些传统方法无法克服的矛盾, 提供意想不到的解决方案; 而且, 在某些情况下, 为了利用SPP, 人们需要探索一些不寻常的条件. 探讨了SPP在光异常透射效应中的几种机制, 并认为与入射角度无关的局域金属等离子表面波(localized SPP)最适合用来实现广角接收. 还报道了关于斜入射空间光激励SPP的结构优化的一些最新进展.     

氟氯共存体系锡在流/熔体相间分配的实验研究

为深入了解与含氟花岗岩有关锡矿床的成矿机制, 在温度为850℃, 压力为100 MPa, 氧逸度接近NNO的条件下开展了氟氯共存体系锡在花岗质熔体相和共存流体相间分配行为的实验研究. 实验通过改变液相中HCl浓度和熔体的铝饱和指数ASI及F含量来观察锡的分配行为. 研究结果显示, 在氟氯共存的花岗质岩浆体系中: (1) 熔体ASI值越高相应锡在流/熔体相间的分配系数D_Sn越大, 过铝质熔体有利于锡分配进入流体相; (2) 流体相中HCl浓度越大越有利于锡分配进入流体相中; (3) 实验固相产物熔体相中氯含量随体系氟氯含量的增大而升高, 且熔体相中氟氯含量具有正相关关系; (4) 含F高的熔体(F含量约大于1 wt%)有利于锡在熔体相中富集从而可为锡矿的形成提供物质来源, 当熔体相中氟含量从约1 wt%左右逐渐减小后锡的分配系数明显增大, 流体相中HCl浓度越高D_Sn增涨幅度越大越明显, 即氟含量减小后有利于锡分配进入富氯液相中, 从而有助于热液型锡矿床的形成.