The phrase "are needed to observe" is correct and usable in written English.
It can be used when discussing requirements or prerequisites for observation in various contexts, such as scientific research or data collection.
Example: "Certain conditions are needed to observe the behavior of the species in its natural habitat."
Alternatives: "are required to see" or "are essential for observation".
Further studies with longer observation time are needed to observe the clinical relevance of the results.
Although the human eye remains an important astronomical tool, detectors capable of greater sensitivity and more rapid response are needed to observe at visible wavelengths and, especially, to extend observations beyond that region of the electromagnetic spectrum.
More research is needed on assessment methods and standard indicators of change in response to effects from climate change, while regional monitoring networks are needed to observe these responses to enable educated adaptation.
Other techniques are needed to observe this effect (and others) in the data.
Because the average duration of polarity transitions has been estimated at 7 kyr, based on available sediment records spanning the four most recent transitions (Clement 2004), records with resolutions higher than 1 kyr are needed to observe detailed variations in paleointensity as well as direction during polarity transitions.
As more information emerges, Gerberding added, "it's possible to narrow the circle of people who require treatment and stop antibiotics in all those who were unnecessarily started". Hall said more studies are needed to observe how patients react to 60 days of antibiotics.
Standing beside Mr. Arafat at his Ramallah headquarters, Secretary Powell said that monitors would be needed to observe the cease-fire, an apparent confirmation of the Palestinian leader's request for international monitors.
The simulation showed that signal-to-noise ratio (SNR) ⩾ 500 is needed to detect the diurnal variation and that SNR ⩾ 1000 is needed to observe the local minimum occurring in the early afternoon (LT13 14) in summer.
As we performed repeated occlusions, these can also mimic ischemic preconditioning23,24. However it has been shown that: i) there was no evidence for ischemic preconditioning during a repeated vessel occlusion that lasts 2 minutes25, and ii) a minimal interval of 2 minutes is needed to observe a significant effect26.
The figure shows that sufficient energy, (k>0.004), is needed to observe the splitting of the wavepacket.
Relatively, high corrosion rate or active dissolution condition is needed to observe linear behavior in E–I plots during polarization resistance measurements.
