Domain: Engineering — Biomedical Engineering
Target concept: Ultrasound-induced Cellular Biological Effects

Video generation prompt: Place the petri dishes containing mouse fibroblasts on the cell culture experimental platform, and position the petri dishes under a low-intensity ultrasound irradiation device. Activate the device and gradually increase the ultrasound power from 0 W/cm² to 0.5 W/cm². Observe the morphological changes of the cells using an inverted microscope, with live cells labeled with green fluorescence and dead cells labeled with red fluorescence.

Evaluation guide:
(i) Target concept: Low-intensity ultrasound applied to adherent mammalian cells during a short single imaging session induces non-thermal mechanical stress that produces a graded morphological stress response (cell rounding, reduced spreading area) and, in a subset of cells at the higher end of the power ramp, loss of membrane integrity -- visualized via a live/dead fluorescence stain rather than framed as classical, multi-hour apoptosis.
Minimum mechanism: Acoustic radiation force and microstreaming from the transducer perturb the cytoskeleton of adherent fibroblasts without cavitation, bulk heating, or immediate lysis; cells whose membranes become compromised take up the red viability marker while intact cells retain the green marker, enabling live/dead discrimination on the inverted microscope.
(ii) Storyline: Frame 1-2: Static wide shot showing the petri dish centered on the platform, ultrasound transducer adjacent and inactive, all cells green. Frame 3-4: The device activates (an indicator lights up) as power begins ramping from 0 W/cm2; green fluorescence still dominates the field. Frame 5-7: Red-labeled cells begin appearing at the dish periphery; nearby green cells retract their processes and round up. Frame 8-9: Red-labeled cell count increases further and green cells reduce their spread area further; no cells detach from the dish and no cell bodies rupture visibly. Frame 10: End-state showing a heterogeneous mix of spread green cells and rounded red cells, all still attached to the dish, no floating debris. Perspective: Fixed inverted-microscope viewpoint, no camera movement, the whole dish base visible, green and red channels visually distinguishable without one washing out the other. Visibility: All events stay in focus; no lid or condensation blocks the view; illumination is even without glare.

Manual:
Experimental Procedure
1. Place petri dish with mouse fibroblasts on culture platform under low-intensity ultrasound device.
2. Activate device and incrementally increase power from 0 W/cm² to 0.5 W/cm².
3. Observe live (green) and dead/compromised (red) cells via inverted microscope.
Observation of Experimental Phenomena
- Live cells appear uniformly green with spread, adherent morphology.
- Dead/compromised cells appear red with shrunken, rounded morphology.
- With increasing power, more cells transition from green to red and adopt a rounded shape.
Summary of Experimental Principles
Ultrasound at up to 0.5 W/cm² induces non-thermal mechanical stress that alters cytoskeletal dynamics, producing reversible morphological changes (rounding, reduced spreading) and, in a subset of cells, loss of membrane integrity -- visualized here as a live/dead fluorescence response rather than classical multi-hour apoptosis.

Prompt Grounding rubric:
level_1: None of the required setup elements appear: no petri dish, no cells visible in an inverted-microscope field, no ultrasound transducer, and no green/red fluorescence channels shown anywhere in the video.
level_2: Only some setup elements appear without the right relationship: e.g., a petri dish, a microscope field-of-view, or fluorescence color patches show up on their own, but the ultrasound device is missing or unrecognizable, or no power readout/indicator is shown changing from a low to a higher value.
level_3: A petri dish holding cells is shown in the inverted-microscope field-of-view; both green and red fluorescence are visible somewhere in the field; the ultrasound transducer is visible next to the dish; a power readout or indicator is shown moving from 0 W/cm² toward 0.5 W/cm² over the course of the video, though the framing, labeling, or timing of these elements is not fully tight.
level_4: All 3-point conditions hold, and the petri dish stays under the transducer for the whole video, the same dish is shown in the microscope view, the power indicator or overlay visibly moves from '0' toward '0.5' rather than jumping straight to its end value, and no element is misplaced (e.g., dish shown separate from the transducer, or the microscope view showing a different dish).
level_5: All 4-point conditions hold, and the petri dish stays in the same framing for the whole video, green- and red-labeled regions stay visually separable without a wash of blended yellow/orange covering large areas of the field, the transducer and dish are shown together in the same shot rather than one being cropped out or hidden, and there is no jump-cut that skips straight from the pre-activation state to a late-power state without showing the intermediate ramp.

Scientific and Causal Correctness rubric:
level_1: The video shows no biologically plausible read-out: e.g., all cells are the same color regardless of condition, no cell shape ever changes, or red (dead/compromised) cells are already present before the ultrasound device activates.
level_2: The color meaning is reversed (green marks dead cells, red marks live cells), or the cells' response is inconsistent with a low-intensity, non-thermal stimulus (e.g., cells burst apart or detach explosively, or the whole dish turns red at once), or cell rounding/shrinkage begins before the device is shown activating.
level_3: Green consistently marks live cells and red consistently marks compromised/dead cells; some cells visibly round up or reduce their spread area as the video progresses; this change begins only after the device is shown activating; but the response is uniform across the whole field rather than affecting some cells more than others, or there is no visible difference between rounded and still-spread cells.
level_4: All 3-point conditions hold, and the response is heterogeneous (some cells round up while nearby cells stay spread), no cell is shown fully detaching from the dish or bursting apart, the green and red fluorescence stay bright and legible without fading out, and red-labeled cells cluster toward the dish periphery or in patches rather than being spread perfectly evenly across the whole field.
level_5: All 4-point conditions hold, and live (green) cells keep a smooth, continuous outline with a clear cell body, red-labeled cells show a rounded or shrunken shape without also carrying green signal, the field moves from mostly-green to a mixed green/red state gradually across several frames rather than switching over in one cut, and there is no sign of boiling, bubble formation, or a visible heat haze that would suggest thermal rather than mechanical stress.

Spatiotemporal Consistency rubric:
level_1: The petri dish's position or size changes abruptly between shots with no motion shown getting it there; the microscope view cuts away to an unrelated scene; green or red patches flash on and off at random; the transducer disappears and reappears without moving; or the scene's overall brightness jumps sharply between one moment and the next.
level_2: The dish shifts by a noticeable fraction of the frame between consecutive moments; the microscope image blurs out of focus and back sharp again without a smooth transition; green/red patches flicker or swap position from one frame to the next; or the power indicator jumps straight from off to its end value with no visible transition.
level_3: The dish stays close to the same place across the video with only a slight, continuous drift at most; the microscope view stays centered on roughly the same region with only slight shake; fluorescence brightness varies a little frame to frame but without any structural jump; and the power indicator's change is shown with some visual pacing rather than appearing instantaneously.
level_4: All 3-point conditions hold, and the dish stays fixed in the frame for the whole video, the microscope view stays centered on the same region throughout, green and red regions shift only in ways that track visible cell-shape changes (not sudden jumps, splits, or merges unconnected to any shape change), the transducer stays fully visible and still, and the scene's overall lighting stays even across the sequence.
level_5: All 4-point conditions hold, and cells move and change shape at a natural pace (no sliding, floating, or sudden snapping into a new shape), the edge of each fluorescent region shifts smoothly in step with the cell's visible outline as it rounds up (no boundary that jumps to a new shape before the cell's outline changes), no part of the video repeats or stutters, and the dish's base stays in sharp focus relative to the lid throughout, consistent with the fixed microscope setup.