# brain: a broad range of decision-making abilities, the 'decision acuity'

<< A common factor called "decision acuity" underpins diverse decision-making abilities in adolescents and young adults, (..) is stable over time, distinct from IQ, and reduced in individuals with low general social functioning. >>️

<< decision acuity predicted patterns of correlated activity among opercular cortex, posterior cingulate cortex, and somatosensory and motor areas -- brain regions previously linked to decision-making.  >>️

Independent of IQ, 'decision acuity' predicts broad range of decision-making abilities. Cell Press. May 20, 2021.

https://www.sciencedaily.com/releases/2021/05/210520133924.htm

<< Decision acuity was decreased in those with aberrant thinking and low general social functioning. Crucially, decision acuity and IQ had dissociable brain signatures, in terms of their associated neural networks of resting-state functional connectivity. >>

Michael Moutoussis, Benjamín Garzón, et al. Decision-making ability,  psychopathology, and brain connectivity. Neuron. doi: 10.1016/ j.neuron.2021.04.019. May 20, 2021.

️

https://www.cell.com/neuron/fulltext/S0896-6273(21)00285-3

Also

keyword 'decision-making' in PubMed:

https://pubmed.ncbi.nlm.nih.gov/?term=decision-making

# gst: a scenario in which System Theory meets Poetry, bird's-eye vistas into a primitive chaos

<< The notion of primitive chaos was proposed [J. Phys. Soc. Jpn. 79, 15002 (2010)] as a notion closely related to the fundamental problems of physics itself such as determinism, causality, free will, predictability, and irreversibility. In this letter, (AA) introduce the notion of bird's-eye view into the primitive chaos, and (they) find a new hierarchic structure of the primitive chaos. This means that if we find a chaos in a real phenomenon or a computer simulation, behind it, we can clearly realize the possibility of tremendous varieties of chaos in the hierarchic structure unless we can see them visually. >>

<< This fact provides a totally new method of viewing our world. >>️️

Yoshihito Ogasawara. Bird's-Eye View of Primitive Chaos. arXiv:2105.04796v2 [nlin.CD]. May 17, 2021. 

https://arxiv.org/abs/2105.04796

Also

Ludwig von Bertalanffy  (gst)  

https://en.m.wikipedia.org/wiki/Ludwig_von_Bertalanffy

keyword 'caos' | 'caotico' in Notes (quasi-stochastic poetry)

https://inkpi.blogspot.com/search?q=caos

https://inkpi.blogspot.com/search?q=caotico

# gst: modeling complex nanofibril-based (cell) walls to meet diverse (bio-physical) constraints.

<< A plant cell wall's unique ability to expand without weakening or breaking -- a quality required for plant growth -- is due to the movement of its cellulose skeleton >>️

<< The new model, (..) reveals that chains of cellulose bundle together within the cell wall, providing strength, and slide against each other when the cell is stretched, providing extensibility. >>

<< The new study, (..) presents a new concept of the plant cell wall, gives insights into plant cell growth, and could provide inspiration for the design of polymeric materials with new properties. >>

<< For a long time, the prevailing concept of a plant cell wall has been that of a gel that is reinforced by cellulose fibers, with the stiff cellulose rods acting like steel rebar in cement, (..) However, we determined that cellulose chains instead stick to each other to form a network of cellulose bundles, which provides a lot more mechanical strength than disconnected rods floating in a gel. And it's the cellulose chains, rather than other components, that limit cell wall expansion, sliding alongside each other like an extension ladder when the cell is stretched. >> Daniel Cosgrove. ️

️

What makes plant cell walls both strong and extensible? Penn State. May 13, 2021. 

https://www.sciencedaily.com/releases/2021/05/210513142432.htm

Yao Zhang, Jingyi Yu, et al. Molecular insights into the complex mechanics of plant epidermal cell walls. Science. 

Vol. 372, Issue 6543, pp. 706-711

doi: 10.1126/ science.abf2824. May 14,  2021. 

https://science.sciencemag.org/content/372/6543/706

# behav: apropos of the uncertainty about the 'Zona Incerta', a thresholding mechanism involved in curiosity and novelty-seeking behavior

<< Motivational drives are internal states that can be different even in similar interactions with external stimuli. Curiosity as the motivational drive for novelty-seeking and investigating the surrounding environment is for survival as essential and intrinsic as hunger. Curiosity, hunger, and appetitive aggression drive three different goal-directed behaviors—novelty seeking, food eating, and hunting >>️

<< Optogenetic activation of inhibitory neurons in medial ZI (ZIm) [medial Zona Incerta in mouse, freedom to choose what it wants], ZImGAD2 neurons, showed a dramatic increase in positive arousal level, depth of investigation, and duration of interaction with conspecifics and novel objects compared with familiar objects, crickets, and food. Optogenetic or chemogenetic deactivation of these neurons decreased depth and duration of investigation. Moreover, [AA] found that ZImGAD2 neurons are more active during deep investigation as compared with during shallow investigation. >>

<< [They] found that activation of prelimbic cortex (PL) axons into ZIm increases arousal level, and chemogenetic deactivation of these axons decreases the duration and depth of investigation. >>

<< Optogenetic activation of ZImGAD2 axons into lateral periaqueductal gray (lPAG) increases the arousal level, whereas chemogenetic deactivation of these axons decreases duration and depth of investigation. Calcium fiber photometry of these axons showed high activity during deep investigation and no significant activity during shallow investigation, suggesting a thresholding mechanism. >>️

<< Last, [AA] found a new subpopulation of inhibitory neurons in ZIm expressing tachykinin 1 (TAC1) that monosynaptically receive PL inputs and project to lPAG. Optogenetic activation and deactivation of these neurons, respectively, increased and decreased depth and duration of investigation. >>️️

Ahmadlou, Janou H. W. Houba, et al. A cell type–specific cortico-subcortical brain circuit for investigatory and novelty-seeking behavior. Science . Vol. 372, Issue 6543, eabe9681. doi: 10.1126/ science.abe9681. May 14, 2021. 

https://science.sciencemag.org/content/372/6543/eabe9681   

Brain mechanism of curiosity unraveled. Netherlands Institute for Neuroscience - KNAW.  May 13, 2021. 

https://www.sciencedaily.com/releases/2021/05/210513142430.htm

# gst: like a bowl of worms, but with two behavioral regimes

AA << have observed strand motion in a polymer melt that contradicts the idea of independent motion. >>️

<< According to the results of new neutron scattering experiments, polymer molecules in plastics move in ways that aren’t captured by commonly used models. >>

<< Melt a plastic, and its constituent molecules, known as polymers, wiggle around. Experts typically describe polymer motion using the so-called tube model, which imagines plastics as a tangle of polymer strands—think a bowlful of worms. The model assumes that each strand moves independently within a virtual tube.  >>️

<< Monitoring the center of mass motion of the short strands, they observed two behavior regimes. For short translational distances, the motion of the short strands slowed as they grew apart. For longer distances, when the center of mass of the strands reached a size on the order of the diameter of the virtual tube, the speed at which the short strands moved stopped slowing down and instead matched that of diffusion. (..) the motions of short strands were tied to those of neighboring strands at short distances, differing from a standard assumption of the tube model. This cooperative motion may come from interactions between the segments, beyond simple local friction. >>️️

Sophia Chen. The Weird Wiggle of Polymers. Physics 14, s56. May 4, 2021.

https://physics.aps.org/articles/v14/s56    

Zamponi M., Kruteva M., et al. Cooperative Chain Dynamics of Tracer Chains in Highly Entangled Polyethylene Melts. Phys. Rev. Lett. 126, 187801. May 4,  2021.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.126.187801

# brain: learning on the fly (in D. melanogaster and mammals)

AA << have developed a new computational model that demonstrates a long sought after link between insect and mammalian learning (..)   Incorporating anatomical and functional data from recent experiments, Dr James Bennett and colleagues modelled how the anatomy and physiology of the fruit fly's brain can support learning according to the reward prediction error (RPE) hypothesis. >>️

<< The computational model indicates how dopamine neurons in an area of a fruit fly's brain, known as the mushroom body, can produce similar signals to dopamine neurons in mammals, and how these dopamine signals can reliably instruct learning. >>️

Learning on the fly. University of Sussex. May 7, 2021. 

https://www.sciencedaily.com/releases/2021/05/210507093941.htm

Bennett, J.E.M., Philippides, A.,  Nowotny, T. Learning with reinforcement prediction errors in a model of the Drosophila mushroom body. Nat Commun 12, 2569. doi: 10.1038/ s41467-021-22592-4. May 7,  2021. 

https://www.nature.com/articles/s41467-021-22592-4   

Also

(+) keyword 'melanogaster' in FonT

https://flashontrack.blogspot.com/search?q=melanogaster

(+) Voli a casaccio. Notes. Oct 01, 2006. (quasi-stochastic poetry)

https://inkpi.blogspot.com/2006/10/2066-voli-casaccio.html

# gst: apropos of bubbles, the life of a surface bubble.

<< Who has never observed at the surface of a puddle under the rain one bubble that bursts instantly and another one that stays for more than 10 s?  >>️

<< Once a bubble has reached an interface, it adopts a static shape that is governed by the balance between the surface tension and buoyancy effects.  >>

<< To sum-up, (AA) have presented the state of the art concerning the prediction of the lifetime of surface bubbles. In general, the bubble unstability is linked to two facts: (i) the bubble cap is constituted by a thin film, whose thickness decreases along time due to both drainage and evaporation and (ii) this thin film is unstable and eventually bursts. (AA) have shown that the current understanding is that two different behaviors exist depending on whether the film thins until its thickness reaches a few hundreds of nanometers or bursts at higher thicknesses. In the first case, determinist models that describe the thinning of the film down to a rupture thickness of the order of tenth to hundreds of nanometers perform correctely to calculate the bubbles lifetime. In the second case, the presence of a fatal impurity within the film and its propension to break it being a more random process, lifetime distributions are much more spread and only stochastic models may capture the physical mechanism(s) at play. The scenario depends on whether or not surfactants are present to stabilise the thick film. >>

<< In absence of surfactants, the distribution of lifetimes is given by a Weibull distribution. The bursting mechanism available in the literature involves the diffusion of impurities in the film, which cause the film rupture. Film thinning due to evaporation is likely to be rather negligible in such experiments since its impact is small on thick films. >>

<< In presence of surfactants, the film is expected to thin until its thickness reaches a few tens of nanometers. The prediction of the bubble lifetime thus depends on our ability to predict the thinning rate of the film. It is fixed by the evaporation and the drainage. For tiny bubbles, no stable thin film appears and the evaporation is negligible. The lifetime is fixed by the approach velocity of the bubble to the bath. For bigger bubbles, evaporation and drainage must be taken into account. The evaporation is a constant rate, which depends on external conditions such as atmospheric humidity, on the diffusion/convection ratio and on the chemical potential of the solution. It has been shown that an accurate description of the evaporation rates necessitates to take into account the natural convection. >>

<< The drainage mechanism depends on the viscosity of the solution, on the bubble size and on the surfactants used to stabilise the interfaces. (AA) have identified three main mechanisms. For viscous bubbles, the cap is axisymmetric and the thickness decreases continuously from the bottom to the top of the bubble. The drainage is then expected to be exponential with time. In presence of surfactants, a pinch is expected to appear in the vicinity of the meniscus, which slows down the drainage. The destabilization of this pinch may lead to marginal regeneration, that in turn can affect the drainage. >>

<< Several references show that the drainage and evaporation rates are sufficient to predict the average lifetime of the surfaces bubbles in these different cases. >>

<< Many questions remain open and deserve to be addressed in a near future and (AA) try to list some of them below.

The mechanism at the origin of the eventual bursting of the film, whether they are thick (micrometers) or thin (tens of nanometers) is mostly unknown.

The marginal regeneration phenomenon, the dynamics of the pinch, the origin of its destabilisation and its contribution to drainage are under current investigation.

The impact of the chosen surfactants on bubble drainage and evaporation is crucial but remains an open question.

There is still a lack of data concerning the distributions observed. Additionally, there is no theoretical prediction of the distribution in the presence of surfactants stabilising the interface. >>️

Jonas Miguet, Florence Rouyer,  Emmanuelle Rio. The Life of a Surface Bubble. Molecules. 26(5): 1317.

doi: 10.3390/ molecules26051317. Mar 1,  2021. 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7957579/   

Also

keyword "bubble" in FonT

https://flashontrack.blogspot.com/search?q=bubble