A fractal approach to dynamic inference and distribution analysis

Abstract

Event-distributions inform scientists about the variability and dispersion of repeated measurements. This dispersion can be understood from a complex systems perspective, and quantified in terms of fractal geometry. The key premise is that a distribution's shape reveals information about the governing dynamics of the system that gave rise to the distribution. Two categories of characteristic dynamics are distinguished: additive systems governed by component-dominant dynamics and multiplicative or interdependent systems governed by interaction-dominant dynamics. A logic by which systems governed by interaction-dominant dynamics are expected to yield mixtures of lognormal and inverse power-law samples is discussed. These mixtures are described by a so-called cocktail model of response times derived from human cognitive performances. The overarching goals of this article are twofold: First, to offer readers an introduction to this theoretical perspective and second, to offer an overview of the related statistical methods.

Hypothalamic Sirt1 protects terminal Schwann cells and neuromuscular junctions from age‐related morphological changes

“…We showed colocalization of all of these markers with AChRs, confirming sympathetic innervation at the NMJ. Interestingly, quantification of sympathetic NMJ innervation showed a twofold increase in the NMJs (Rudolf et al., 2013) staining for TH and a threefold increase in NMJs staining for β2‐AR in BRASTO mice compared to age‐matched controls. These data suggest that the mechanism linking the more youthful NMJ morphology associated with central Sirt1 overexpression is sympathetically mediated.…”

“…Impaired sympathetic neural function is associated with several age‐related systemic changes (Santulli & Iaccarino, 2013), and systemic physiological improvements seen in BRASTO mice result from sympathetic stimulation (Satoh et al., 2013). In addition, the sympathetic nervous system is present within skeletal muscle of young adult mice (Khan et al., 2016; Rudolf et al., 2013) and may modify muscle contraction, perfusion, and metabolism (Rudolf et al., 2013). Sympathetic innervation, as indicated by TH staining, was expressed in 96% of NMJs in the mouse EDL and 91% of those in the soleus (Khan et al., 2016).…”

“…There are a few studies reporting on direct innervation of skeletal muscle fibers by nonmyelinated, noradrenergic fibers (Barker & Saito, 1981; Lynch & Ryall, 2008), suggesting that sympathetic actions on skeletal muscle are at least partially mediated by neural mechanisms. It has been reported that sympathetic neurons coinnervate several targets in muscle, including blood vessels, motor neurons, muscle fibers, and NMJs (Khan et al., 2016; Rudolf et al., 2013). Moreover, cAMP/PKA‐dependent signaling at the NMJ is important for synapse stabilization and metabolic control of AChR function (Li, Yi & Thompson, 2011).…”

Oxidative stress and phosphatidylserine exposure in red cells from patients with sickle cell anaemia

“…Oxidants are also associated with PS shedding and microvesiculation (Piccin et al , 2007, 2015b; Freikman et al , 2008; Alaarg et al , 2013) and it was possible that reduced PS levels on the outer bilayer of the red cell membrane could be due to its loss into the incubation media, notwithstanding an increase in lipid scrambling. PS may be lost as microvesicles, which have been proposed as a biomarker for SCA severity (Piccin et al , 2015a).…”

Revisiting Kadenbach: Electron flux rate through cytochrome c‐oxidase determines the ATP‐inhibitory effect and subsequent production of ROS

“…They observed a stimulation of oxidative phosphorylation by calcium without an influence by cAMP and PKA activity 101. The pH dependency of bicarbonate‐regulated soluble Adenylyl Cyclase 102 remains to be clarified in the context of the inhibitory effect of ATP on CytOx. Finally, Acin‐Perez et al 103 described a Phosphodiesterase 2 A that is localized in mitochondria and is involved in the regulation of respiration.…”