Variation in response

There is a high degree of variation in response among individuals in a tyijical population. Generally, sensitive populations include the elderly, children, and individuals with diseases that compromise the respiratory or cardiovascular system. 

The numerous metals and alloys used in practice show such a wide variation in response to various anions in acid and alkaline solutions that common features are difficult to discern and a basis for predicting corrosion behaviour is not very apparent. 

Bacteria which are almost always sensitive to the sulphonamides include Strep, pneumoniae, /3-haemolytic streptococci, Escherichia coli and Proteus mirabilis those almost always resistant include Enterococcus faecalis, Ps. aeruginosa, indole-positive Proteus and Klebsiella whereas bacteria showing a marked variation in response include Staph, aureus, gonococci, El. influenzae and hospital strains of E. coli and Pr. mirabilis. 

Other hand, mycobacteria and espeeially bacterial spores are much more resistant. A major reason for this variation in response is associated with the chemical composition and stmcture of the outer cell layers such that there is restricted uptake of a biocide, hi... 

Rouch, C, Nicolaidis, S and Orosco, M (1999) Determination, using microdialysis, of hypothalamic serotonin variations in response to different macronutrients. Physiol. Behav. 65 653-657. 

Large variations in responses make the data difficult to interpret, particularly when comparing different treatments, and thus this approach may require the use of a large number of subjects to observe possible statistical differences. Finally, the degree of polarity of the compound of interest is another important factor to keep in mind since that can affect its location in the CMs and in turn its possible exchanges with other high-density and low-density lipoproteins present in the bloodstream. 

Nowadays most trials of psychotropic drugs are multicentric, and an increasing number of them are carried out in different regions of the world. However, ethnic variations in response to the tested drugs are rarely a focus of attention in these trials. Moreover, treatment guidelines produced in North America and Europe are often regarded as universally valid, and rarely adapted to other regional contexts. This is still partly due to some reluctance to accept the concept of ethnic variability,... 

Lennard L, Lilleyman JS, Van Loon J et al. Genetic variation in response to 6-mercaptopurine for childhood acute lymphoblastic leukaemia. Lancet 1990 336 225-229. 

Pharmacokinetic modeling, 208 Pharmacokinetics (PK), 99, 211 Pharmacologic agents, variation in response to, 43 Pharmacologic research, 31 Pharmacology, genetic variation and, 36-38... 

My study shows the value of sampling throughout the year and across different seasons. This seasonal variation in response would obviously not have been detected had the study been conducted at only one time of the year, even if the time of year was replicated. Although Borowski (1998, 2002) showed that responses of voles to predators are variable throughout the year, many subsequent studies have been restricted to a single season. Valuable information about species behaviour is likely to be missed by such an approach and I believe that a single season approach is fundamentally flawed. 

This paper reviews the practical difficulties inherent in implementing olfactory enrichment outside of a controlled laboratory setting. Considerations discussed include (i) choice of scent, relevance and motivation (ii) how to present scent in time and space (iii) individual variation in response rates and neophobia and (iv) health implications. 

HS-III (Figure 2) showed the wide variation in response between individuals to almost identical dietary conditions. Previous dietary history may be partially responsible for the differences. 

Perhaps the most hopeful sign of progress is the belated recognition of "paradoxical" reactions to the lipid-lowering diets that have been widely used for decades. For example, researchers at the South-Western Medical Center in Dallas repeatedly find "marked individual variations in response to the diet." In many persons these diets show little benefit, or increase LDL cholesterol, serum triglycerides, or... 

The rate equation describes the variation in response variable R (with initial value of Rq) the measure response appears at a constant rate (zero order) of and is eliminafed by the first-order constant. The indirect response models will generally fall info fwo caf-egories inhibition or stimulation function. The inhibition response is classically described in ferms of IC q, fhe drug concenfration fhaf produce 50% of maximal inhibition (e.g., action of S5mfhefic glucocorticoid on adrenal glands or effecf of furosemide on sodium absorption in fhe loop of Henley) and is a number from 0 fo 1 where 1 represents total inhibition ... 

In Hitchell s work unequal variance of the response data was compensated for by weighting the data by the variance at each level. The regression parameters and the confidence band around the regression line were estimated by least squares ( ) The overall level of uncertainty, OL, was divided between the variation in response values and the variance in the regression estimation. His overall a was 0.05. The prediction interval was estimated around a single response determination. 

In our studies of the TGF-P3 dimer in solution, we detected the direct interaction of several metallic cations, such as Ca ", Na" ", and Mn " with the aid of NMR spectroscopy, hi particular, chemical shift variations in response to changes of Na and Ca ion concentrations and hne broadening due to the interaction with paramagnetic Mn + ions were observed in the heteronu-clear two-dimensional HSQC spectra and mapped onto the spatial... 

Johnson et determined the variation in response of 16 sweet com hybrids to ambient oxidants in California. From these observations, Cameron and Taylor selected five inbreds and three of their Fi hybrids for further field studies and four inbreds and two hybrids... 

Wide variation in response among different individuals is a general finding in studies of oxidants, as well as other pollutants. 

If we now plot the percent yield vs. the solvent number, we will get the response surface shown in Figure 2.11. There seems to be a trend toward higher yield with increasing solvent number, but such a trend must be meaningless it is difficult to imagine how an arbitrarily assigned number could possibly influence the yield of a chemical reaction. If a relationship does appear to exist between yield and solvent number, it must be entirely accidental - the variation in response is probably caused by some other property of the solvents. 

Information about the reproducibility of the data is contained in the residual parts of the responses. If the residuals are all small, then the dispersion is slight and the responses are said to cluster tightly - the reproducibility is good. On the other hand, if the residuals are all large, the variation in response is large, and the reproducibility is poor. 

---