Statistics duration rate

An adverse effect of lead on pregnancy rate has been noted in some animal studies (Kennedy et al. 1975). Acute-duration gavage administration of 390 mg lead/kg/day as lead acetate to rats resulted in a sharp decrease in pregnancy rates. This effect was not noted at 39 mg lead/kg/day. The study limitations include a lack of measurement of blood lead levels and lack of statistical analysis of pregnancy incidence. A decrease in the number of implantations was noted in untreated female mice that were mated to males that had been treated with 141 mg/kg/day lead chloride in the drinking water for 3 months... 

In principle, FCS can also measure very slow processes. In this limit the measurements are constrained by the stability of the system and the patience of the investigator. Because FCS requires the statistical analysis of many fluctuations to yield an accurate estimation of rate parameters, the slower the typical fluctuation, the longer the time required for the measurement. The fractional error of an FCS measurement, expressed as the root mean square of fluorescence fluctuations divided by the mean fluorescence, varies as 1V-1/2, where N is the number of fluctuations that are measured. If the characteristic lifetime of a fluctuation is r, the duration of a measurement to achieve a fractional error of E = N l,/- is T = Nr. Suppose, for example, that r = 1 s. If 1% accuracy is desired, N = 104 and so T = 104 s. 

The development of a quantitative theory of a free-radical copolymerization implies the derivation of equations for the rate of the monomers depletion and the statistical characteristics of the chemical structure of macromolecules present in the reaction system at the given conversion p of monomers. Elaborating such a theory one should take into account a highly important peculiarity inherent to any free-radical copolymerization. This peculiarity is that the characteristic time of a macroradical life is appreciably less than the time of the process duration. Consequently, its products represent definitely... 

For the application of a continuous perfusion system, it is necessary to know what elution rate to use under steady state conditions in order to minimize either the total volume of solution to be injected or the duration of the injection. The practical objective of a scintigraphic-examination is to accumulate, in a given organ, a sufficient radioactivity to produce good counting statistics. An analytical study of this problem brings us to the formulation of the following equation ... 

The disadvantages of this reaction place some real constraints on its use 1) The (t,p) cross section is only about 5 percent of the total cross section 2) The dominant reaction, usually (t,2n), produces abundant prompt Y rays 3) Reactions such as (t,n) and (t,d) [as well as (t,p)] often result in short-lived beta decaying products 4) The usual in-beam techniques such as angular distributions are complicated by the necessity to use the outgoing proton to identify the reaction As a result of the first three disadvantages, much of the Y ay and electron count rates are not from the (t,p) reaction and thus experiments of reasonable duration have limited statistics ... 

Mucci and Morse (1983) found no statistically significant dependence of the partition coefficient for Mg in calcite precipitated from seawater on reaction rate over a range of seawater supersaturations from about one half ( 2 =3) to close to three times ( 2=17) that of typical surface seawater. However, their experiments had durations of from only a few hours to days. The compositions of magnesian calcites grown very near equilibrium ( 2=1.2) over periods of several months were determined by Mucci et al. (1985). They found excellent agreement with the results of Mucci and Morse (1983) even though different experimental techniques were used. The rate independence of the partition coefficient of Mg in calcite, therefore, has been found to be independent of reaction rate over about 12 orders of magnitude in seawater. 

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