Because environments often vary considerably between the indoors and the outdoors, the primary location of influenza transmission needs to be determined so that the conditions the virus is exposed to during transmission can be better specified.
In these situations, it is often difficult to control the stress because multiple factors often vary across any environmental gradient.
First, because daily counts often vary by day of week, many alerts may be produced on high-count days such as Mondays and Tuesdays, and few may be produced on low-count days such as weekend days.
Moreover, because genetic polymorphisms often vary between different ethnic groups, further studies are needed to clarify the association of the EGFR polymorphisms with the risk of lung cancer in diverse ethnic populations.
There is no simple answer to this question, because community expectations from research often vary widely.
Experimental [ 21] and theoretical [ 22] studies hint that gene regulatory circuits harbor latent phenotypes because their gene expression patterns often vary when a circuit is exposed to distinct external stimuli.
Because frequencies of genetic polymorphisms often vary between ethnic groups, more studies in diverse ethnic populations are warranted to clarify the association between VEGF 3′-UTR polymorphisms and CRC.
Because genes on the Y chromosome often vary slightly in sequence and even function from the corresponding genes on the X, males could have slightly different patterns of gene expression throughout the body compared with females, due to not only their hormone levels, but also their entire Y chromosome.
In most animals, the potential reproductive rate is the population's mean offspring production when not constrained by the availability of mates (Clutton-Brock and Vincent, 1991; Clutton-Brock and Parker, 1992; Parker and Simmons, 1996; Wilson et al., 2003), and the reproductive rate often vary because of mating competition and parental investment (Trivers, 1972).
Because cancer patients with the same diagnosis often vary widely in their response to treatment, researchers have long suspected that they might be dealing with different types of tumors.
