Population measurements

Fluorescence-based methods do not directly measure ionic current but, rather, measure either membrane-potential-dependent or ion-concentration-dependent changes of fluorescence signals (from fluorescent dyes loaded into the cytosol or cell membrane) as a result of ionic flux. Because fluorescence-based methods give robust and homogeneous cell population measurement, these assays are relatively easy to set up and achieve high throughput. 

Right angle light scattering Population measure 0.5—40 Sampling refractive Index 52... 

Laser diffraction Population measure 0.1-800 Obscuration, sampling 54... 

Holography Population measure 3-1000 Obscuration, co-incidence, sampling 56... 

Banta-Green CJ, Field JA, Chiaia AC, Sudakin DL, Power L, De Montigny L (2009) The spatial epidemiology of cocaine, methamphetamine and 3, 4-methylenedioxymethamphetamine (MDMA) use a demonstration using a population measure of community drug load derived from municipal wastewater. Addiction 104 1874—1880... 

Bums, R. G. Greaves, C. (1971) Correlations of infrared and Mossbauer site population measurements of actinolites. Amer. Mineral., 56, 2010-33. 

McManus, G. B., and Fuhrman, J. A. (1988). Control of marine bacterioplankton populations Measurement and significance of grazing. Hydrobiologia 159, 51-62. 

Tucker JD, Lee DA, Ramsey MJ, et al. (1994) On the frequency of chromosome exchanges in a control population measured by chromosome painting. Mutation Research 313 193-202. 

McGuffin I don t know whether this argument can provide any support either way. The problem about heritability is that it is just the proportion of variance explained. Of course, if you increase the variance, and all this increase is coming from increased environmental variance, heritability must be less. Heritability only applies to the population in which you measure it it is a population measure and has no meaning at an individual level. 

Right-angle light Population measure 0.5 0 Sampling refractive index... 

Laser diffraction (103) Population measure 0.1-800 Coincidence errors, sampling... 

However, I5g measurements do not provide information about the biochemical characteristics of the enzyme-inhibitor interaction and what specific feature of the interaction may have changed and so caused the resistance. Also, I5g measurements need to be done with pooled tissues of several to many insects, depending on their size. To study the frequency of the resistant target site in a population, measurements must be done in individual insects. This can and has been done in house flies (58. 6J.), an armyworm (59), and plant hoppers and leaf hoppers (62.). Detailed inhibition kinetics studies will reveal if a mutation has occurred (58). A mutation causing the enzyme to have decreased affinity for the inhibitor is most clearly reflected in Kinverse relationship between and kj, kj is smaller in resistant insects with insensitive AChE. This is illustrated in Table 2. 

FIGURE 121 Extent of dehydroxylation of silicas treated in various gases at high temperatures. Measurements were made by reaction with CHjMgl and referenced to the OH group population measured after calcination in N2 at 200 °C. 

Reduced microbial activity and lower metabolic diversity are likely reasons for the reduced biodegradation of herbicides in subsoils and groundwater aquifers. Although the total microbial population in most aquifers range between 104 and 107 cells/g aquifer material (22). the proportion of these populations that can degrade xenobiotics appears to be low. In a pristine aquifer from Lulu, Oklahoma, degrader populations measured by 14C-MPN were less than 5 cells/g for chlorobenzene, napthalene, and toluene (4Q). 

Whole population Measurable disease and IHC 3+/FISH positive No previous anthracyclines With previous anthracyclines Age <50 years Age 50 years <24 months disease-free interval >24 months disease-free interval 1 -2 metastatic organ sites >2 metastatic organ sites Visceral (lung or liver) metastases Non-visceral metastases ER and/or PgR positive ER and PgR negative/unknown ECOG performance status 0 ECOG performance status... 

A environmental sample can be called representative, when it is collected and handled in a manner which preserves its original physical form and chemical composition. Accordingly, in the statistical sense, representative samples are an unbiased subset of the population measured. 

The NHANES 111 (1988-1994) and NHANES 2001-2002, an ongoing survey representative of the US population, measure U1 excretion. It was determined that the US population is iodine sufficient according to the WHO criteria (HoUowell et at, 1998). Some subsets of the US population, however, especially women of childbearing age, had an increased prevalence of mild iodine deficiency. Despite the stabilization of median U1 in the United States, a subset of the general population is still moderately or severely iodine deficient, especially among pregnant and lactating women (Tables 115.1 and 115.2). 

Groopman, J. D. Cain, L. G. Kensler, T. W. Aflatoxin exposure in human populations Measurements and relationship to cancer. CRC Crit. Rev. Toxicol., 19 113-45. 1988. 

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