Editing Fractal (section)

===Fractals in cell biology===
Fractals often appear in the realm of living organisms where they arise through branching processes and other complex pattern formation. Ian Wong and co-workers have shown that migrating cells can form fractals by clustering and [[Branching process|branching]].<ref>{{Cite journal|last1=Leggett|first1=Susan E.|last2=Neronha|first2=Zachary J.|last3=Bhaskar|first3=Dhananjay|last4=Sim|first4=Jea Yun|last5=Perdikari|first5=Theodora Myrto|last6=Wong|first6=Ian Y.|date=2019-08-27|title=Motility-limited aggregation of mammary epithelial cells into fractal-like clusters|journal=Proceedings of the National Academy of Sciences|language=en|volume=116|issue=35|pages=17298–17306|doi=10.1073/pnas.1905958116|issn=0027-8424|pmc=6717304|pmid=31413194|bibcode=2019PNAS..11617298L|doi-access=free}}</ref> [[Neuron|Nerve cells]] function through processes at the cell surface, with phenomena that are enhanced by largely increasing the surface to volume ratio. As a consequence nerve cells often are found to form into fractal patterns.<ref>{{Cite journal|last1=Jelinek|first1=Herbert F|last2=Fernandez|first2=Eduardo|date=June 1998|title=Neurons and fractals: how reliable and useful are calculations of fractal dimensions?|url=https://linkinghub.elsevier.com/retrieve/pii/S0165027098000211|journal=Journal of Neuroscience Methods|language=en|volume=81|issue=1–2|pages=9–18|doi=10.1016/S0165-0270(98)00021-1|pmid=9696304|s2cid=3811866}}</ref> These processes are crucial in cell [[physiology]] and different [[Pathology|pathologies]].<ref>{{Cite journal|last=Cross|first=Simon S.|date=1997|title=Fractals in Pathology|journal=The Journal of Pathology|language=en|volume=182|issue=1|pages=1–8|doi=10.1002/(SICI)1096-9896(199705)182:1<1::AID-PATH808>3.0.CO;2-B|pmid=9227334|s2cid=23274235 |issn=1096-9896|doi-access=free}}</ref>

Multiple subcellular structures also are found to assemble into fractals. [[Diego Krapf]] has shown that through branching processes the [[actin]] filaments in human cells assemble into fractal patterns.<ref>{{Cite journal |last1=Sadegh |first1=Sanaz |last2=Higgins |first2=Jenny L. |last3=Mannion |first3=Patrick C. |last4=Tamkun |first4=Michael M. |last5=Krapf |first5=Diego |date=2017-03-09 |title=Plasma Membrane is Compartmentalized by a Self-Similar Cortical Actin Meshwork |journal=Physical Review X |language=en |volume=7 |issue=1 |page=011031 |doi=10.1103/PhysRevX.7.011031 |issn=2160-3308 |pmc=5500227 |pmid=28690919|arxiv=1702.03997 |bibcode=2017PhRvX...7a1031S }}</ref> Similarly Matthias Weiss showed that the [[endoplasmic reticulum]] displays fractal features.<ref>{{Cite journal|last1=Speckner|first1=Konstantin|last2=Stadler|first2=Lorenz|last3=Weiss|first3=Matthias|date=2018-07-09|title=Anomalous dynamics of the endoplasmic reticulum network|url=https://link.aps.org/doi/10.1103/PhysRevE.98.012406|journal=Physical Review E|language=en|volume=98|issue=1|pages=012406|doi=10.1103/PhysRevE.98.012406|pmid=30110830|bibcode=2018PhRvE..98a2406S|s2cid=52010780|issn=2470-0045}}</ref> The current understanding is that fractals are ubiquitous in cell biology, from [[protein]]s, to [[organelle]]s, to whole cells.