Sentence examples for but is usually difficult from inspiring English sources
It improves the action time with uniform distribution and poses minimum side effects, but is usually difficult to design to achieve the desire results.
Peri-valvular infiltration is a potential finding but is usually difficult to assess due to metallic artefacts.
Specific diagnosis of the trypanosomes is sometimes possible using the 100x oil immersion, but is usually difficult or impossible because the process of lysis distorts the parasites.
Formerly, annotation of new genome involved extensive blast searches, but it is usually difficult to judge a correct threshold.
EHR systems are widely used in hospitals and primary care centres but it is usually difficult to share information and to collect patient data for clinical research.
The rapid removal and treatment of infected carcasses and/or sick animals is a key task in the management of infectious diseases, but it is usually difficult or impractical to carry out in the wild.
Sub-functionalization and neo-functionalization allow spatio-temporal specialization and expansion of functionality, respectively, but it is usually difficult to draw a line between the two fates (He & Zhang, 2005).
We have done extensive imaging of dynein during meiosis using a variety of reagents/antibodies, and our results are consistent with the idea that dynein is present at low levels on chromosomes during prometaphase/metaphase; we can see faint dynein cupping chromosomes but it is usually difficult to distinguish from spindle-localized dynein.
After a line obtains a mutation of lethality ≥ d%, a further mutation will likely do nothing or increase the level of lethality, but the effect is usually difficult to distinguish from the first one under our experimental setting.
It is usually difficult but important to extract distant targets from sea clutters and clouds since the targets are small compared to the pixel field of view.
Nanoparticle compaction is usually difficult, but the compaction behavior of the micro-granules is similar to that of the micro powder.
