Sentence examples for has been difficult to study from inspiring English sources

But the use of visual cues has been difficult to study, because if a bird flies over a landmark and doesn't change its course, it's impossible to know whether the bird has not perceived the cue or is ignoring it.

The NMSZ has been difficult to study.

The drug's subtle effect has been difficult to study in cultured cells and in laboratory animals.

This phenomenon has been difficult to study because of a lack of quantitative and high-throughput cellular tools.

But that phenomenon has been difficult to study in the lab, because the grains are always pulled down by gravity, limiting the interactions between particles.

It has been difficult to study their localization and function in vivo due to the lack of ligands that exclusively act on one subtype of the receptor.

The social interactions of western lowland gorillas have been difficult to study in the wild because they mostly inhabit heavily forested areas with limited visibility for researchers.

The activation thresholds and atomic mechanisms that dictate the thermo-kinetic properties of grain boundaries have been difficult to study due to complex and highly variable GB structure.

The fusion glycoproteins have been difficult to study because they are present in a labile, metastable form at the surface of infectious virions.

The podocyte is a key cell in the glomerulus in health and disease: until recently, human podocytes have been difficult to study in vitro.

Previously, small rugose corals have been difficult to study because their size and curvature make it difficult to serially section them at a right angle to the longitudinal growth axis.