Intact polar lipids (IPLs), which are the basic building blocks of biomembranes, are ubiquitous in nature and have several characteristics that make them useful as proxies for living microbial cells.
Bracelets are useful, as are wristwatches.
The London study notes, however, that the link between mortality and NO2 was less clear than it was for particulate matter, acknowledging that deaths associated with NO2 may also be due to other traffic pollutants — making NO2 more useful as a proxy for deaths resulting from car emissions, especially diesel engines, which emit around 20 times more NO2 than petrol cars.
If item-level IIV is useful as a proxy for neural integrity, then it should also predict cognitive decline and impairment similar to the prediction by the total score (sum of the item scores, usually 0 or 1); to our knowledge, no study has reported item-level IIV.
In urban areas, deprivation indexes have been shown to be useful as a proxy variable for socioeconomic status [ 19].
In addition, this study suggests that measurement of urinary lead might be useful as a proxy for plasma lead levels in studies of lead toxicity.
Reporting the fraction of time above a threshold instead of the percentage of measurements above a threshold, without time consideration, seems more useful as a proxy for reducing time in a hyperglycaemic state.
Furthermore, our results indicate that PDX, while useful as a proxy to study drug response and other critical in vivo tumor characteristics, may not harbor the full genetic heterogeneity of a patient's melanoma, which has implications for co-clinical PDX and patient treatment studies.
It has alternated between denouncing Afghan President Hamid Karzai and embracing him, and, like the Bush Administration, it has veered between supporting Afghanistan's anti-Taliban warlords, who have been useful as military proxies, and repudiating them because their abuses strengthen the Taliban.
Silicon stable isotopes are fractionated by a host of low-temperature aqueous processes, making them potentially useful as a weathering proxy.
