The phrase "and variable proportion of" is correct and usable in written English.
It can be used when discussing quantities or ratios that can change or vary in relation to something else.
Example: "The mixture consists of a fixed amount of water and variable proportion of other ingredients to achieve the desired consistency."
Alternatives: "and fluctuating amount of" or "and varying ratio of".
Focusing on African-derived populations, US African Americans were described to have a significant and variable proportion of individual European ancestry.
The chemical analyses of river sediments are given in ug/g organic weight and ug/g dry weight instead of ug/g sediment due to the high and variable proportion of solid material (gravel) in the samples.
Resuscitation is only required by a small and variable proportion of newborns, and has only recently started to receive wide attention.
A possible explanation for the lack of a clear peak could be that in these cases, Bayes Cπ acts similar to the GBLUP model and relies more on the genomic relationship between animals than on QTL effects, and therefore includes a large and variable proportion of markers in the model to capture relationships between animals.
This extraction [13] mainly dissolves amorphous Fe oxyhydroxides and variable proportions of ferrihydrite depending on crystallinity, ageing and drying (> 97% of fresh 6 line nano-ferrihydrite, 76 97% of aged 6 line nano-ferrihydrite, 25 50% aged and freeze-dried 6 line nano-ferrihydrite and 3 25% aged and freeze dried 2 line nano-ferrihydrite).
This discrepancy could be due to the heterogeneous nature of spheres, which contain differentiated cell types and variable proportions of TICs.
After a further day, the maximum density attained was 2.5 × 10/ml; these cultures were a mixture of shorter, more rounded cells (resembling stumpy forms) and variable proportions of dead and dying cells.
The clay was dominated by kaolinite and illite and a variable proportion of vermiculite, resulting in variation of CEC values, being high with vermiculite.
The projected funding requirements for MAMC represent a significant and highly variable proportion of a country's total public and private health expenditures, estimated at 0.3%, 1.1%, 2.3% and 6.0% for South Africa, Tanzania, Zimbabwe and Botswana, respectively [19].
Generally, in the semi-arid areas climate change played a decreasing role in runoff reduction comparing with other causes, while in the semi-humid areas it induced a higher and more variable proportion of runoff deviation according to the decade means.
Moreover, in vitro cultures abundantly expressed CK14 (100% of cultures) and, in variable proportion of cells, CK18 (83% of cultures).
