# life: apropos of interactions, “attacks” and “circling” of Zebrafish in the dynamics of dominance.

<< While two-body fighting behavior occurs throughout the animal kingdom to settle dominance disputes, important questions such as how the dynamics ultimately lead to a winner and loser are unresolved. Here (AA) examine fighting behavior at high resolution in male zebrafish. >>️

<< In the body point trajectories (AA) find a spectrum of timescales which (they) use to build informative joint coordinates consisting of relative orientation and distance. (AA) use the distribution of these coordinates to automatically identify fight epochs, and (then) demonstrate the postfight emergence of an abrupt asymmetry in relative orientations—a clear and quantitative signal of hierarchy formation. >>

AA << identify short-time, multi-animal behaviors as clustered transitions between joint configurations, and show that fight epochs are spanned by a subset of these clusters, which (they) denote as maneuvers. The resulting space of maneuvers is rich but interpretable, including motifs such as “attacks” and “circling.” In the longer-time dynamics of maneuver frequencies (AA) find differential and changing strategies, including that the eventual loser attacks more often towards the end of the contest. >>️

AA << results suggest a reevaluation of relevant assessment models in zebrafish, while our approach is generally applicable to other animal systems. >>️

️

Liam O'Shaughnessy, Tatsuo Izawa, et al. Dynamics of Dominance in Interacting Zebrafish. PRX Life 2, 043006. Oct 25, 2024.

https://journals.aps.org/prxlife/abstract/10.1103/PRXLife.2.043006

Also: behav, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, behavior, behaviour

# life: landing on a swinging perch: peach-faced lovebirds (Agapornis roseicollis) prefer extremes.

<< Birds frequently must land safely and accurately on moving branches or power lines, and seemingly accomplish such maneuvers with acrobatic precision. To examine how birds target and land successfully on moving supports, (AA) investigated how peach-faced lovebirds (Agapornis roseicollis) approach and land on a swinging perch.  >>️

<< In support of (AA) hypothesis for stable landings, lovebirds timed their landings in a majority of trials (51.3%), when the perch was approaching either extreme of its motion with its velocity nearing zero (27.5% in the same direction as the bird’s approach – SDs, and 23.8% in the opposite direction to the bird’s approach – ODs). As a result, lovebirds exhibited a robust bimodal strategy for timing their landing to the phase of the swinging perch. Less commonly, lovebirds landed when the perch was moving at high velocity either toward the bird’s approach (12.3%) or in the same direction as the bird’s approach (11.5%); with the remainder (21.9%) of trials distributed over a broad range of swing phases. >>️

Partha S Bhagavatula, Andrew A. Biewener. Landing on a swinging perch: peach-faced lovebirds prefer extremes. biorxiv.org. Oct 8, 2024.

https://www.biorxiv.org/content/10.1101/2024.07.21.604435v2

Also: behav, birds, extreme, jazz, Mr. Jelly Roll Morton, in: https://www.inkgmr.net/kwrds.html 

Keywords: life, birds, extreme,  behavior, behaviour, jazz, Mr. Jelly Roll Morton

# life: fast-and-flexible decision-making with modulatory interactions

<< Multi-agent systems in biology, society, and engineering are capable of making decisions through the dynamic interaction of their elements. Nonlinearity of the interactions is key for the speed, robustness, and flexibility of multi-agent decision-making. >>

AA << introduce modulatory, that is, multiplicative, in contrast to additive, interactions in a nonlinear opinion dynamics model of fast-and-flexible decision-making. (..) Modulatory interactions introduce an extra source of nonlinearity that greatly enriches the model decision-making behavior in a mathematically tractable way. >>

AA << model provides new tools to understand the role of these interactions in networked decision-making and to engineer them in artificial systems. >>

Rodrigo Moreno-Morton, Anastasia Bizyaeva, et al. Fast-and-flexible decision-making with modulatory interactions. arXiv: 2410.00798v1 [math.DS]. Oct 1, 2024.

https://arxiv.org/abs/2410.00798

Also: behav, network, ai (artificial intell), in https://www.inkgmr.net/kwrds.html 

Keywords: life, decision-making, modulatory interactions, behavior, behaviour, network, ai, artificial intelligence

# game: aperiodic Parrondo (behavior based on the binary Fibonacci, Thue–Morse and Rudin–Shapiro sequences); persistence and heterogeneity effects.

AA << study the effectiveness of employing archetypal aperiodic sequencing -- namely Fibonacci, Thue-Morse, and Rudin-Saphiro -- on the Parrondian effect. From a capital gain perspective, (their) results show that these series do yield a Parrondo's Paradox with the Thue-Morse based strategy outperforming not only the other two aperiodic strategies but benchmark Parrondian games with random and periodical (AABBAABB…) switching as well. The least performing of the three aperiodic strategies is the Rudin-Shapiro. >>

AA << analyze the cross-correlation between the capital generated by the switching protocols and that of the isolated losing games. This analysis reveals that a pronounced anti-correlation (below -0.95) with both isolated games is typically required to achieve a robust manifestation of Parrondo's effect. >>

About << the influence of the sequencing on the capital using the lacunarity and persistence measures (AA) observe that the switching protocols tend to become less performing in terms of the capital as one increases the persistence and thus approaches the features of an isolated losing game. >>

Respect to << lacunarity, a property related to heterogeneity, (AA) notice that for small persistence the performance increases with the lacunarity with a maximum (..). In respect of this, (AA) work shows that  the optimisation of a switching protocol is strongly dependent on a fine tune between persistence and heterogeneity. >>

Marcelo A. Pires, Erveton P. Pinto, et al. Parrondo's effects with aperiodic protocols. arXiv: 2410.02987v1 [physics.soc-ph]. Oct 3, 2024.

https://arxiv.org/abs/2410.02987

Also: Parrondo, tit-for-tat, game, behav, network, in https://www.inkgmr.net/kwrds.html 

Keywords: Parrondo, tit-for-tat, game, behavior, behaviour, network

# game: apropos of Parrondo's paradox, winning with losses driven by reputation and reciprocity

AA << investigate two such social behaviors, reputation and reciprocity, and their role in explaining Darwin’s survival of the fittest, examining how these fundamental principles govern individual interactions and shape broader social dynamics. >>

<< Current theories hint at two main facets of social interaction, reputation and reciprocity, as potential drivers behind this cooperative evolution. Reputation revolves around building and sustaining trust, social worth, and overall community standing. Conversely, reciprocity governs the mutual exchange of actions or benefits, influencing our choices. >>

<< One intriguing concept explored in this domain is Parrondo’s paradox: combining or switching between two losing strategies might surprisingly achieve a winning outcome. The role of Parrondo’s paradox in complex systems has sparked key research into chaotic many-body, quantum, and algorithmic network applications, where combining elements yields opposing beneficial results. Similarly, social physicists aim to uncover hidden mechanisms that govern societal phenomena by integrating the paradox’s counterintuitive principles. >>️

<< The game-theoretic Parrondo’s paradox emerges through multiple iterations of these interactions (..) A naive observation might conclude that in either scheme the chance of individuals losing to the environment is higher than gaining from the environment. For the reputation scheme, one is rewarded with a singular capital from the environment but is punished with two. Similarly, the reciprocity scheme only allows for the redistribution of capital or loss of capital. In reality, diverse schemes can be adopted by different individuals. Thus, (AA) suggest two forms of switching: (1) stochastic switching, where the individual randomly selects one of two schemes to employ with equal probability, and (2) rule-based switching, where the individual only selects the reputation scheme if it passes the reputation threshold ρ; otherwise, it employs the reciprocity scheme. >>

AA << also performed simulations on other network topologies (..) Parrondo’s paradox is strongly observed in small-world networks, weakly in the Erdős-Rényi network, and absent in scale-free networks. >>

To conclude, some of these observations << underscore the profound capability of rule-based switching mechanisms inherent in Parrondo’s paradox to emulate and forecast key aspects of real-world social phenomena. Such insights are invaluable for developing sophisticated models and strategies in various fields, ranging from social sciences to policy making, where accurate predictions of social behavior and dynamics are crucial. >>

Joel Weijia Lai, Kang Hao Cheong. Winning with Losses: The Surprising Success of Negative Strategies in Social Interaction Behavior. Phys. Rev. Lett. 133, 167401. Oct 16, 2024. 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.133.167401

Also: Parrondo, tit-for-tat, game, behav, network, in https://www.inkgmr.net/kwrds.html 

Keywords: Parrondo, tit-for-tat, game, behavior, behaviour, network

# gst: spontaneous bouncing, trampolining, and hovering behaviors of a levitating water droplet without constraints.

<< The levitating Leidenfrost (LF) state of a droplet on a heated substrate is often accompanied by fascinating behaviors such as star-shaped deformations, self-propulsion, bouncing, and trampolining. These behaviors arise due to the vapor flow instabilities at the liquid-vapor interface beneath the droplet at sizes typically comparable to the capillary length scale of the liquid. >>

AA << report on the spontaneous bouncing, trampolining, and hovering behavior of an unconstrained LF water droplet. (..) the water droplet exhibits an increase in bouncing height at specific radii with intermittent reduction in the height of bounce leading to a quiescent LF state. The reemergence of the trampolining behavior from the quiescent hovering state without any external forcing is observed at sizes as low as 0.1 times the capillary length. (AA) attribute the droplet bouncing behavior to the dynamics of vapor flow beneath the LF droplet. >>

AA << propose that the trampolining behavior of the droplet at specific radii is triggered by harmonic and subharmonic resonance between the natural frequency of the vapor layer and Rayleigh frequency of the droplet. This proposed mechanism of resonance-driven trampolining of LF droplets is observed to be applicable for different liquids irrespective of the initial volume and substrate temperatures, thus indicating a universality of the behavior. (AA) attribute the intermittent trampolining events to the change in the natural frequency of the droplet and the vapor layer due to evaporative mass loss. >>

Pranjal Agrawal, Susmita Dash. Reemergence of Trampolining in a Leidenfrost Droplet. arXiv: 2408.02335v1 [physics.flu-dyn]. Aug 5, 2024. 

https://arxiv.org/abs/2408.02335

Also: drop, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, drop, droplet, droploid, behav, behaviour

# behav: ADHD may have been a feature of nomadic exploration among hunter-gatherer societies

<< All mobile organisms forage for resources, choosing how and when to search for new opportunities by comparing current returns with the average for the environment. In humans, nomadic lifestyles favouring exploration have been associated with genetic mutations implicated in attention deficit hyperactivity disorder (ADHD), inviting the hypothesis that this condition may impact foraging decisions in the general population. >>️

David L. Barack, Vera U. Ludwig, et al. 

Attention deficits linked with proclivity to explore while foraging. Proc Royal Society B.  doi: 10.1098/ rspb.2022.2584. Feb 21, 2024. 

https://doi.org/10.1098/rspb.2022.2584     

<< Is it a legacy of the hunter-gatherer world? >> Arjun Ramakrishnan

Chen Ly. ADHD may have evolved to help foragers know when to cut their losses. newscientist.com Feb 21,2024.

https://www.newscientist.com/article/2418114-adhd-may-have-evolved-to-help-foragers-know-when-to-cut-their-losses

Also: nomads, bushmen, behav, uncertainty, curiosity, in https://www.inkgmr.net/kwrds.html

Keywords: adhd, nomads, hunter-gatherers, behavior, behaviour

# behav: mechanics of fire ant rafts as an active self-healing membrane

<< The unique ability of fire ants to form a raft to survive flooding rain has enchanted biologists as well as researchers in other disciplines. (..) a three-dimensional aggregation of fire ants exhibits viscoelasticity with respect to external compression and shearing among numerous unusual mechanical properties. >>️

AA << study the ant raft in its natural form, i.e., composing no more than two layers. This allowed to focus on the cracks that are unique to membranes and see how their patterns are influenced by the fact that these ants are mobile and can self-repair the damage to keep their raft from disintegration. >>️

They << show that vertical and horizontal shaking can also prompt fire ants to aggregate.  (..)  the pull force expedites the alignment of fire ants, in analogy to the effect of an electric field on liquid crystal polymers. >>️

<< One major finding is that the raft can exhibit zero Poisson's ratio without resorting to specific geometry structures. This is enabled by the active recruitment of ants from the top layer to the bottom layer to keep the raft from disintegrating. >>️

️

Chung-Hao Chen, Ting-Heng Hsieh, et al. Formation and mechanics of fire ant rafts as an active self-healing membrane. Phys. Rev. E 109, 014607. Jan 9, 2024. 

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.109.014607

David Ehrenstein. Material Properties of Fire-Ant Rafts. Physics 17, s5. Jan 9. 2024. 

https://physics.aps.org/articles/v17/s5

Also:  raft   https://flashontrack.blogspot.com/search?q=raft  

zattera (quasi-stochastic poetry) https://inkpi.blogspot.com/2005/04/1864-onda-di-liberazione.html  

randa (quasi-stochastic poetry) https://inkpi.blogspot.com/search?q=randa

Also: behav, behavior, in  https://www.inkgmr.net/kwrds.html

Keywords behavior, behaviour, ant, raft, self-healing

# behav: the self-care hypothesis of the puteketeke bird (great crested grebe, Podiceps cristatus)

<< The Puteketeke bird has been elected as New Zealand's Bird of the Century after John Oliver promoted the bird not just on his show, but around the world. >>

<< It also exhibits some unusual antics, like eating feathers to help it vomit up parasites,  >> AILSA CHANG

️

<< They have a mating dance where they both grab a clump of wet grass and chest bump each other... >> JOHN OLIVER

Kat Lonsdorf, Christopher Intagliata. The Puteketeke bird has been elected as New Zealand's Bird of the Century. npr.org Nov 15, 2023. 

https://www.npr.org/2023/11/15/1213287236/the-puteketeke-bird-has-been-elected-as-new-zealands-bird-of-the-century

L’uccello del secolo della Nuova Zelanda l’ha deciso John Oliver. ilpost.it. Nov 15, 2023. 

https://www.ilpost.it/2023/11/15/john-oliver-uccello-secolo-nuova-zelanda/

the bird: https://youtu.be/98ceB5SPRXI

John Oliver, an interview: https://youtu.be/uVE1hBzHn3s

many thanks to Tammi ( https://www.inkgmr.net/tammi ) for this news. 

Also: Self-perception of health and survival. A 10-year follow-up among Italians aged over sixty. INRCA, Technical Report, Genova, 7 March 1995: 1-19. Minerva Med 1997 Jan-Feb 88:1-2 15-23. [abst] https://pubmed.ncbi.nlm.nih.gov/9093288/

Also: 'behav', 'perception', in https://www.inkgmr.net/kwrds.html

Keywords: behaviour, self-care, perceptions

# behav: use of social information in flight (among ‘griffon’ vultures Gyps fulvus and G. rueppellii)

 <<Animals rely on a balance of personal and social information to decide when and where to move next in order to access a desired resource, such as food. The benefits from cueing on conspecifics to reduce uncertainty about resources availability can be rapidly overcome by the risks of within-group competition, often exacerbated toward low-ranked individuals. Being obligate soarers, relying on thermal updrafts to search for carcasses around which competition can be fierce, vultures represent ideal models to investigate the balance between personal and social information during foraging movements. Linking dominance hierarchy, social affinities and meteorological conditions to movement decisions of eight captive vultures, Gyps spp., released for free flights in natural-like soaring conditions,  (AA) found that they relied on social information (i.e. other vultures using/having used the thermals) to find the next thermal updraft, especially in unfavourable flight conditions. Low-ranked individuals were more likely to disregard social cues when deciding where to go next, possibly to minimise the competitive risk of social aggregation. These results exemplify the architecture of decision-making during flight in social birds. It suggests that the environmental context, the context of risk and the social system as a whole calibrate the balance between personal and social information use. >> 

Sassi Yohan, Nouzieres Basile, Scacco Martina, et al. The use of social information in vulture flight decisions. bioRxiv. doi: 10.1101/ 2023.07.26.550671. Jul 28, 2023.

https://www.biorxiv.org/content/10.1101/2023.07.26.550671v1

Also: behav, in https://www.inkgmr.net/kwrds.html

# behav: even the first asynchronous decisions might tend to be correct and exhibit information cascades.

<< It is usually assumed that information cascades are most likely to occur when an early but incorrect opinion spreads through the group. Here (AA) analyse models of confidence-sharing in groups and reveal the opposite result: simple but plausible models of naïve Bayesian decision-making exhibit information cascades when group decisions are synchronous; however, when group decisions are asynchronous, the early decisions reached by Bayesian decision makers tend to be correct, and dominate the group consensus dynamics. Thus early decisions actually rescue the group from making errors, rather than contribute to it. (AA) explore the likely realism of our assumed decision-making rule with reference to the evolution of mechanisms for aggregating social information, and known psychological and neuroscientific mechanisms. >>️

Andreagiovanni Reina, Thomas Bose, et al.  Asynchrony rescues statistically-optimal group decisions from information cascades through emergent leaders.  bioRxiv. doi: 10.1101/ 2022.04.05.487127. Feb16, 2023.

https://www.biorxiv.org/content/10.1101/2022.04.05.487127v3

Also

'asynchronous' in FonT

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

'game' in FonT

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

'behav' in FonT

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

Keywords: behavior, behaviour, game, decision-making, synchronous- asynchronous group decisions, social interactions, information cascade, life, jazz

# gst: apropos of swarms: local couplings, chirality, lattices of vortices, beating clusters, interacting phase waves among swarmalators.

AA << study the emergent behaviors of a population of swarming coupled oscillators, dubbed 'swarmalators'. (..)  Here (they) expand this work by adding more realistic features: local coupling, non-identical natural frequencies, and chirality. This more realistic model generates a variety of new behaviors including lattices of vortices, beating clusters, and interacting phase waves. Similar behaviors are found across natural and artificial micro-scale collective systems, including social slime mold, spermatozoa vortex arrays, and Quincke rollers. >>

Steven Ceron, Kevin O'Keeffe, Kirstin Petersen. Diverse Behaviors in Non-Uniform Chiral and Non-Chiral Swarmalators. arXiv: 2211.06439v1 [nlin.AO]. Nov 11, 2022.

https://arxiv.org/abs/2211.06439

Also

keyword 'swarm' in FonT

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

keyword 'chiral' in FonT

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

keyword 'vortex' in FonT

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

keyword 'vortice' in Notes

(quasi-stochastic poetry)

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

Keywords: gst, behav, behavior, behaviour, swarm, swarmalators, chirality, chiral swarmalators, non-chiral swarmalators, vortex, vortex array, vortices, vorticity, slime mold.

# gst: apropos of transitions, the transition from sticking to slipping.

<< From hydrogels and plastics to liquid crystals, soft solids cover a wide array of synthetic and biological materials that play key enabling roles in advanced technologies >>️

<< Attempts to study the interactions between soft solids and liquids have largely focused on the wetting of soft solids and its resulting deformation at equilibrium or in a quasi-static state. Here, (AA) consider the frequently encountered case of unsteady wetting of a liquid on a soft solid and show that transient deformation of the solid is necessary to understand unsteady wetting behaviours. >>️

AA << find that the initial spreading of the liquid occurs uninterrupted in the absence of solid deformation. This is followed by intermittent spreading, in which transient deformation of the solid at the three-phase contact line (CL) causes the CL motion to alternate alternation between CL sticking and slipping. (They) identify the spreading rate of liquids and the viscoelastic reacting rate of soft solids as the two competing factors in dictating intermittent spreading. (They)  formulate and validate experimentally the conditions required for the contact line to transition from sticking to slipping. By considering the growing deformation of soft solids as dynamic surface heterogeneities, (AA) proposed conditions for stick-slip transition in unsteady wetting on soft solids broaden the classical theory on wetting hysteresis on rigid solids. >>️

Surjyasish Mitra, Quoc Vo, Marcus Lin, Tuan Tran. Unsteady wetting of soft solids. arXiv:2211.07043v1 [cond-mat.soft]. Nov 13, 2022.

https://arxiv.org/abs/2211.07043

Also

keyword 'drop' | 'droplet' | 'droploids' in FonT

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

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

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

keyword 'goccia' in Notes 

(quasi-stochastic poetry) 

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

Keywords: gst, behav, behaviour, transition, soft solids, drop, droplet, sticking, slipping.

# life: Chimps distribute their time to groom other individuals in the same manner as humans structure their relationships.

AA << show that the time chimpanzees devote to grooming other individuals is well described by the same model used for human relationships, supporting the existence of similar social signatures for both humans and chimpanzees. Furthermore, the relationship structure depends on group size as predicted by the model, the proportion of high intensity connections being larger for smaller groups. >>

Diego Escribano, Victoria Doldan-Martelli, et al. Chimpanzees organize their social relationships like humans. bioRxiv. doi: 10.1101/ 2022.03.16.484664. March 17, 2022. 

https://www.biorxiv.org/content/10.1101/2022.03.16.484664v1

Also

keywords 'chimp' | 'chimps' in FonT

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

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

keyword 'chimps' | 'sileno' in Notes (quasi-stochastic poetry)

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

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

keywords 'behav' in FonT

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

keywords: life, chimps, behav, behavior, behaviour, social relationships

# 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

# 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