第十二届国际孢粉学、第八届国际古植物学联合会议简介

2008年8月30日至9月5日,第十二届国际孢粉学（IPC-XII）以及第八届国际古植物学（IOPC—VIII）联合会议在德国波恩的波恩大学召开。共有来自52个国家和地区的751名地学领域的专家和学者参加了此次会议,其中,来自中国（大陆）的专家和学者共计40名,主要来自中国科学院南京地质古生物研究所、中国科学院植物研究所、北京大学、吉林大学、中山大学、兰州大学等单位,     

Plasma density fluctuations measurements by heavy ion beam probe with a multiple cell array detector on the tokamak ISTTOK

It is recognized that the broad-band fluctuations observed in plasmas of thermonuclear devices are the cause of anomalously large energy and particle transport. Strong progress has been achieved on different plasma devices using a heavy ion beam probe (HIBP) diagnostic measuring the plasma potential and density fluctuations. Better understanding of turbulence properties can be obtained with a multiple cell array detector (MCAD) as plasma density fluctuations are measured simultaneously at a number of sample volumes. In this paper, the capabilities of the HIBP with MCAD for plasma density fluctuations measurements on the tokamak ISTTOK are analyzed (including restrictions due to sample volume size and path effects) and compared with preliminary experimental data. The upgrade of ISTTOK HIBP for better diagnostic performance is also discussed.     

The Natural Experiment

Many of you, reading the title of this report, probably felt a certain confusion about this new, unusual term natural experiment. To dispel this quite natural confusion, let me say immediately that I am proposing this term to designate special investigatory techniques situated somewhere between external, objective observation, on the one hand, and a man-devised laboratory experiment (at present referred to as a psychological experiment), on the other. These original techniques, different from both the first and the second, are actually not completely new and unusual but, on the contrary, are well known to every one of you in their rudimentary form. Considered in more detail, they might perhaps be of considerable interest both theoretically and practically. It is for this reason that I decided to propose a new term to designate them. One cannot, of course, in such a brief report attempt to outline all the possible applications of this method to all the phenomena to which it could be applied; hence, I shall focus on an area that is more familiar to me and, moreover, seems to be especially suited for conducting a natural experiment, namely, research on personality or individuality.     

The Pinwheel Experiment Revisited

The critical point hypothesis explains the origin of some cardiac arrhythmias, and the bidomain model describes electrical stimulation of the heart. In this paper, the critical point hypothesis is combined with the bidomain model. The result is four new predictions about the pinwheel experiment, a fundamental experiment in cardiac electrophysiology. These are: (1) The duration of the vulnerable period during cathodalS₂stimulation is longer for anS₁wavefront propagating perpendicular to the fibers than for anS₁wavefront propagating parallel to the fibers. (2) For anodalS₂stimulation with theS₁wavefront propagating parallel to the fibers, the vulnerable period splits into two periods with an “invulnerable period” between them. (3) For anodalS₂stimulation with theS₁wavefront propagating perpendicular to the fibers, the vulnerable period consists of only one period. (4) A previously suggested mechanism for the upper limit of vulnerability (S₂is so strong that the entire tissue is depolarized by an amount greater thanS*) is no longer applicable.     

Joint Report of the First International Comparison Test on Swine Lymphocyte Alloantigens (SLA)

The first international comparison test on swine lymphocyte alloantigens (SLA) was held in Helsinki, Finland in July 1986. The results reported were based on a comparison of 157 alloantisera originating from six laboratories. The antisera were tested against a selected panel of 264 lymphocyte samples belonging to four laboratories. The most common breeds in Europe were chosen for this first comparison test (Landrace and Large White). Eighteen of the 31 previously known specificities were confirmed and a new nomenclature was established.