The phrase "a decline in levels" is correct and usable in written English.
It can be used when discussing a reduction or decrease in specific measurements or quantities, such as in economics, environmental science, or health statistics.
Example: "The report indicated a decline in levels of air pollution over the past decade."
Alternatives: "a decrease in levels" or "a drop in levels."
This appeared the result of a decline in levels of ASP in muscle extracts as opposed to a change in DNA content (Fig. 2B), indicative of a decline in muscle protein content.
Loss of hippocampal SphK1 activity was associated with a decline in levels of the protein as detected by western blotting.
The loss of SphK1 activity in Braak III/IV hippocampus samples was accompanied by a decline in levels of the protein, although not statistically significant.
This results in a decline in levels of progesterone between D15/D16 and D19/D20 (Garland et al., 1987), which is believed to trigger a number of the prepartum adaptive changes (Russell et al., 2001).
Uterine masses grow uncontrollably until they occupy most of the diameter of the worm and are accompanied by a massive increase in DNA copy number per worm in old adults, which greatly exceeds the genome copy number of worms at their reproductive peak at younger ages, and is coupled to a decline in levels of cep-1/p53.
Our results show a significant decline in the NAD+∶NADH ratio with aging, consistent with a decline in NAD+ levels and an increase in NADH levels.
[ 9- 11] Of particular importance is the finding that as women's education and income levels rise, there is a decline in distress levels.
All 41 (100%) waterholes showed a decline in water levels during the 1999 to 2000 droughts, with water levels lying below the threshold during this time period.
Similar to the effect of the PI3K/MAPK blockade, EGFR/ErbB2 inhibition by CP724714 also reduced levels of activated p-Ser326 HSF1, leading to a decline in mutp53 levels.
Sixty-seven patients with serial blood levels over time after stopping fish showed a decline in mercury levels; reduction was significant (p < 0.0001).
Albumin levels below 20 g/L as well as a decline in albumin levels are associated with ARDS of increasing severity, irrespective of definition.
