Origin Passage
Origin Passage - Related Videos
10:02
Passaging Cells
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2023
Cell lines are frequently used in biomedical experiments, as they allow rapid culture and expansion of cell types for experimental analysis. Cell lines are cultured under similar conditions when compared to freshly-isolated, or primary, cells, but with some basic important differences: (i) cell lines require their own specific growth factor cocktails and (ii) their growth must be more closely monitored than primary cells, as the mutations that allow them to be grown indefinitely also can...
10:16
Passaging Human Neural Stem Cells
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Cited by 8 •
2007
The ability to manipulate human neural stem/precursor cells (hNSPCs) in vitro allows to investigate their utility as cell transplants for therapeutic purposes and to explore human neural development. This protocol presents a method of culturing and passaging hNSPCs in hopes of increasing reproducibility of human stem cell research.
01:26
Origin of Photosynthesis
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2026
Photosynthesis represents a fundamental biological process that transformed Earth's atmosphere and paved the way for complex life. Emerging roughly 3.4–3.8 billion years ago, the earliest photosynthetic organisms harnessed light energy to produce organic compounds. These anoxygenic phototrophs used electron donors like hydrogen sulfide (H₂S) or ferrous iron (Fe²⁺), rather than water, and did not release molecular oxygen (O₂) as a byproduct. Various groups, including green sulfur and purple...
01:24
Origin of Cellular Life
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2026
The origin of life on Earth is a complex and enigmatic event rooted in ancient biochemical processes and geological conditions. Experimental evidence supports the hypothesis that life began with the spontaneous formation of organic molecules such as RNA nucleotides, amino acids, and lipids under early Earth conditions. Factors like volcanic activity, intense UV radiation, and a reducing atmosphere without free oxygen likely facilitated these reactions. Hydrothermal vents on the ocean floor are...
04:11
Investigating the Origins of Sensory Neurons in the Dura Mater Using Fluorescence Microscopy
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2025
Source: Wang, J., et al. Visualizing the Calcitonin Gene-Related Peptide Immunoreactive Innervation of the Rat Cranial Dura Mater with Immunofluorescence and Neural Tracing. J. Vis. Exp. (2021). This video demonstrates a method to trace the origins of sensory neurons in the dura mater using fluorescence microscopy. A retrograde tracer is introduced into the exposed dura mater of an anesthetized rat. The tracer is taken up by sensory neuronal axons and travels retrogradely to their cell bodies...
FAQs
Set every component of the position vector to zero at the same value of time or parameter. In two or three dimensions, satisfying only one coordinate condition identifies an intersection with an axis or plane, not the coordinate origin. Solving the simultaneous equations therefore tests whether the complete trajectory reaches the reference point and determines the associated event.
The coordinate origin is tied to the selected reference frame, so changing that frame changes the coordinate functions used to describe the motion. A trajectory that reaches the origin in one description may not reach it in another. Stating the frame makes the calculated time or parameter meaningful and prevents confusion when comparing position equations or graphs.
Each zero of a coordinate function marks a candidate value at which that coordinate is at the reference location. The complete result requires checking all relevant coordinates together. If the equations yield several valid parameter values, the motion can be examined at each one to distinguish repeated passages from a single event and to relate the results to the trajectory.
Write the position vector or coordinate functions in the chosen frame, then impose zero on every position component. Solve the resulting equation or simultaneous system for time, or for the parameter that labels the trajectory. Substitute each candidate back into the original coordinate functions, because only values satisfying the full set of conditions represent the required passage.
On a position-time graph, a zero of the relevant coordinate indicates a candidate crossing of the reference coordinate value, while a spatial trajectory shows where the path meets the origin. Reading graphs alone can be ambiguous when several coordinates are involved, so the plotted intersection should be checked against the coordinate equations before reporting a passage time.
It provides a concrete test for motion models: predicted coordinate functions can be checked for whether and when they reach the reference point. In kinematics, this supports crossing-time calculations and trajectory analysis; in coordinate-based physics, it links algebraic solutions with geometric paths. The same check can also help interpret field trajectories when their coordinates are explicitly defined.