Marker events

Wark D. A. and Lovering J. F. (1977) Marker events in the early solar system evidence from rims on Ca-Al-rich inclusions in carbonaceous chondrites. Proc. 8th Lunar Sci. Conf., 95-112. 

Figure 13.1 Monitor (FID) (a) and analytical (ECD) (b) channel responses for PCB congeners in Aroclor 1254, showing selection of the six heart-cut events Frr-st columns, HT8 second columns, BPX5. Reprinted from Journal of High Resolution Chromatography, 19, R. M. Kinghorn et al., Multidimensional capillar-y gas chr omatography of polychlorinated biphenyl marker compounds , pp. 622-626, 1996, with per-mission from Wiley-VCH.

Figure 2. Schematic representation of the reactor system computer-controlled pumps (PI, P2) pump controllers (fc) reactor (CSTR) reception vessel valves (S1-S4) monomer and initiator storage vessels (Tl, T2). (a) Digital input from GPC injection valve (b) analogue output from GPC (c, d) digital outputs to recorder chart drive and event marker (e, f) analogue outputs for pump set-point adjustment (g,h) reactor feeds (i) reactor output (j-m) digital outputs to reception system valves (n) manual sampling of products by GPC,...

Biomarkers are broadly defined as indicators signaling events in biologic systems or samples. They have been classified as markers of exposure, markers of effect, and markers of susceptibility (NAS/NRC 1989). 

The first issue lies in the whole realm of the human disease process itself. Many adverse drug events mimic diseases and vice versa. Is an adverse event really an adverse event, or is it merely a natural occurrence of a disease process that is entirely independent of drug exposure The science of drug safety is often complicated by the lack of objective markers of drug toxicity that can systematically separate a disease process from an adverse drug event process [2]. Clinical trials, often viewed as the gold standard to assess efficacy, are simply too limited in scope to answer safety questions in a systematic way. 

If the endogenous material is a participant in the initiation of ripening, however, it is unlikely the fruit PG is responsible for its origin. Several studies (e.g. 8, 20) have shown that tomato fruit synthesis of PG follows (by as much as a day or more) the increase in fruit ethylene production that is accepted as a marker of ripening s onset. Of course, ripening is not a simultaneous, whole fruit phenomenon. It is a developmental event the passes through the fruit (its different tissue areas, perhaps even from cell to... 

Permanent markers outside the study area should also be located and used in the event that one or more plot markers are inadvertently moved or lost. One option is to locate a minimum of two permanent reference points outside of the study area... 

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