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procollagen is a precursor form of collagen synthesized and processed in the secretory pathway. Its extended organization creates a geometrical challenge for export in small spherical carriers.
A cluster whose nonhydrogen skeleton includes both carbon and aluminium. Exocyclic bonding must be distinguished from skeletal bonding when applying electron-counting rules.
An electronic model replacing discrete positive ionic cores by a smooth positive background. Approximately spherical clusters can be stabilized at closed angular-momentum shells.
A classical two-body trajectory in an inverse-distance Coulomb potential. With an effectively fixed centre and coupling , a circular orbit has and mechanical energy .
A particle released from an infinitesimal displacement near the top of a smooth sphere has . The normal reaction vanishes when , giving . The travelled arc is , whereas the vertical drop is .
Near-surface recoil height with constant downward thrust by 
Codex 0 Created 2026-10-20 Updated 2026-10-20
Codex 0 Created 2026-10-20 Updated 2026-10-20An allylic ester is converted to a silyl ketene acetal, which undergoes a [3,3]-sigmatropic rearrangement to an unsaturated carboxylic-acid derivative.
Dependence of a stimulus-response relationship on internal circadian phase. A rhythmic baseline or a daily change in stimulus availability alone does not demonstrate gating.
The number and structural organization of a biological cell's chromosomes. A difference between parental karyotypes can affect pairing and segregation in hybrids, but its consequences require direct tests rather than inference from the chromosome count alone.
A change in the organization of chromosome segments. A balanced parental arrangement can preserve sequence dosage while causing abnormal segregation in a heterozygous hybrid.
A chromosome involved in genetic sex determination. Its inheritance and copy number can expose incompatibilities differently in the two sexes of hybrids.
The compaction and organisation of chromosomal material during division. Condensation helps chromosome handling but is distinct from the removal of sister-chromatid cohesion.
The specialised end region of a linear chromosome, with DNA and proteins that support chromosome-end protection and maintenance.
A joined chromosome structure produced by some recombination events and requiring resolution before successful bacterial chromosome allocation.
Pinned article: Introduction to the OurBigBook Project
Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
Intro to OurBigBook
. Source. We have two killer features:
- topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculusArticles of different users are sorted by upvote within each article page. This feature is a bit like:
- a Wikipedia where each user can have their own version of each article
- a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
Figure 1. Screenshot of the "Derivative" topic page. View it live at: ourbigbook.com/go/topic/derivativeVideo 2. OurBigBook Web topics demo. Source. - local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
Figure 2. You can publish local OurBigBook lightweight markup files to either OurBigBook.com or as a static website.
Figure 3. Visual Studio Code extension installation.
Figure 5. . You can also edit articles on the Web editor without installing anything locally. Video 3. Edit locally and publish demo. Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension. 
- Infinitely deep tables of contents:
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact