Read by QxMD icon Read

Self-Organized Criticality

Marta Bigus-Kwiatkowska, Agata Fronczak, Piotr Fronczak
Inspired by albatrosses that use thermal lifts to fly across oceans we develop a simple model of gliders that serves us to study theoretical limitations of unlimited exploration of the Earth. Our studies, grounded in physical theory of continuous percolation and biased random walks, allow us to identify a variety of percolation transitions, which are understood as providing potentially unlimited movement through a space in a specified direction. We discover an unexpected phenomenon of self-organization of gliders in clusters, which resembles the flock organization of birds...
March 2018: Physical Review. E
Su-Chan Park
We investigate the origin of the difference, which was noticed by Fey et al. [Phys. Rev. Lett. 104, 145703 (2010)PRLTAO0031-900710.1103/PhysRevLett.104.145703], between the steady state density of an Abelian sandpile model (ASM) and the transition point of its corresponding deterministic fixed-energy sandpile model (DFES). Being deterministic, the configuration space of a DFES can be divided into two disjoint classes such that every configuration in one class should evolve into one of absorbing states, whereas no configurations in the other class can reach an absorbing state...
March 2018: Physical Review. E
L Michiels van Kessenich, M Luković, L de Arcangelis, H J Herrmann
In recent years self organized critical neuronal models have provided insights regarding the origin of the experimentally observed avalanching behavior of neuronal systems. It has been shown that dynamical synapses, as a form of short-term plasticity, can cause critical neuronal dynamics. Whereas long-term plasticity, such as Hebbian or activity dependent plasticity, have a crucial role in shaping the network structure and endowing neural systems with learning abilities. In this work we provide a model which combines both plasticity mechanisms, acting on two different time scales...
March 2018: Physical Review. E
Eyal Karzbrun, Aditya Kshirsagar, Sidney R Cohen, Jacob H Hanna, Orly Reiner
Human brain wrinkling has been implicated in neurodevelopmental disorders and yet its origins remain unknown. Polymer gel models suggest that wrinkling emerges spontaneously due to compression forces arising during differential swelling, but these ideas have not been tested in a living system. Here, we report the appearance of surface wrinkles during the in vitro development and self-organization of human brain organoids in a micro-fabricated compartment that supports in situ imaging over a timescale of weeks...
May 2018: Nature Physics
Ronen Avraham, Charles Silver
Nissanholtz-Gannot and Yenkellevich (NGY) explore the impact of a 2010 amendment to the Israeli National Health Insurance Law that requires annual reporting of payments from pharmaceutical companies (PCs) to doctors and healthcare organizations. The amendment was adopted to ensure transparency and to facilitate appropriate regulation of interest conflicts. To learn whether the amendment was having the desired effects, NGY interviewed multiple representatives of an assortment of stakeholders. They found broad agreement among the respondents that financial relationships between PCs and physicians should be transparent...
May 14, 2018: Israel Journal of Health Policy Research
Daniel Fraiman
The Bak-Sneppen (BS) model is a very simple model that exhibits all the richness of self-organized criticality theory. At the thermodynamic limit, the BS model converges to a situation where all particles have a fitness that is uniformly distributed between a critical value p_{c} and 1. The p_{c} value is unknown, as are the variables that influence and determine this value. Here we study the BS model in the case in which the lowest fitness particle interacts with an arbitrary even number of m nearest neighbors...
April 2018: Physical Review. E
Gustav Nystrom, Mario Arcari, Jozef Adamcik, Ivan Usov, Raffaele Mezzenga
Understanding how nanostructure and nanomechanics influence physical material properties on the micro- and macroscale is an essential goal in soft condensed matter research. Mechanisms governing fragmentation and chirality inversion of filamentous colloids are of specific interest because of their critical role in load-bearing and self-organizing functionalities of soft nanomaterials. Here we provide a fundamental insight into the self-organization across several length scales of nanocellulose, an important bio-colloid system with wide-ranging applications as structural, insulating and functional material...
May 14, 2018: ACS Nano
Insook Choi
Sonification is an open-ended design task to construct sound informing a listener of data. Understanding application context is critical for shaping design requirements for data translation into sound. Sonification requires methodology to maintain reproducibility when data sources exhibit non-linear properties of self-organization and emergent behavior. This research formalizes interactive sonification in an extensible model to support reproducibility when data exhibits emergent behavior. In the absence of sonification theory, extensibility demonstrates relevant methods across case studies...
2018: Frontiers in Neuroscience
Chitra Subramanian, Peter T White, Rui Kuai, Avinaash Kalidindi, Valerie P Castle, James J Moon, Barbara N Timmermann, Anna Schwendeman, Mark S Cohen
BACKGROUND: Pathways critical for neuroblastoma cancer stem cell function are targeted by 4,19,27-triacetyl withalongolide A (WGA-TA). Because neuroblastoma cells and their cancer stem cells highly overexpress the scavenger receptor class B type 1 receptor that binds to synthetic high-density lipoprotein, we hypothesized that a novel mimetic synthetic high-density lipoprotein nanoparticle would be an ideal carrier for the delivery of 4,19,27-triacetyl withalongolide to neuroblastoma and neuroblastoma cancer stem cells...
May 9, 2018: Surgery
Yoshinobu Takahashi, Keisuke Sekine, Tatsuya Kin, Takanori Takebe, Hideki Taniguchi
Clinical transplantation of tissue fragments, including islets, faces a critical challenge because of a lack of effective strategies that ensure efficient engraftment through the timely integration of vascular networks. We recently developed a complex organoid engineering method by "self-condensation" culture based on mesenchymal cell-dependent contraction, thereby enabling dissociated heterotypic lineages including endothelial cells to self-organize in a spatiotemporal manner. Here, we report the successful adaptation of this method for generating complex tissues from diverse tissue fragments derived from various organs, including pancreatic islets...
May 8, 2018: Cell Reports
Fumio Arai
Stem cells are characterized by their unique ability to both self-renew and differentiate along multiple cellular lineages. Self-renewal and differentiation must be tightly controlled to ensure an appropriate stem cell pool in tissue over the lifetime of an organism. Elucidating the mechanisms controlling stem cell fate and maintenance remains a key challenge in stem cell biology. Hematopoietic stem cells (HSCs) are responsible for the lifelong production of multiple blood cell lineages. To remain functional, these cells must interact with a particular microenvironment, known as the stem cell niche...
May 4, 2018: International Journal of Hematology
Mariann R Piano, Nancy T Artinian, Holli A DeVon, Susan T Pressler, Kathleen T Hickey, Deborah A Chyun
BACKGROUND: The American Heart Association's (AHA) Council on Cardiovascular and Stroke Nursing (CVSN) plays a critical role in advancing the mission of the AHA in the discovery of new scientific knowledge. The aim was to identify priority research topics that would promote and improve cardiovascular (CV) health, provide direction for the education of future nurse scientists, and serve as a resource and catalyst for federal and organizational funding priorities. METHODS: A Qualtrics survey, which included 3 questions about priorities for CVSN nurse researchers, was sent to the CVSN Leadership Committee and all CVSN Fellows of the AHA (n = 208)...
April 26, 2018: Journal of Cardiovascular Nursing
Kuntal Maity, Dipankar Mandal
Rapid development of wearable electronics, piezoelectric nanogenerator (PNG) has been paid a special attention due to its sustainable and accessible energy generation. In this context, we present a simple yet highly efficient design strategy to enhance the output performance of an all organic PNG (OPNG) based on multilayer assembled electrospun poly(vinyledine fluoride) (PVDF) nanofibers (NFs) mats where vapor phase polymerized poly(3,4- ethylenedioxythiphene) (PEDOT) coated PVDF NFs are assembled as electrodes and neat PVDF NFs is utilized as an active component...
May 4, 2018: ACS Applied Materials & Interfaces
Mahmoud Abbasi, Mehrzad Kiani, Mehdi Ahmadi, Bahare Salehi
BACKGROUND Organ transplantation is one of the most critical topics in medical ethics that is commonplace in various countries. This study aimed to evaluate the knowledge and the ethical issues surrounding organ transplantation and organ donation among healthcare personnel in Tehran, Iran. MATERIAL AND METHODS In a cross-sectional study performed on 450 healthcare personnel, self-administered questionnaires were used to derive data from individuals. Among the 450 health personnel who received the questionnaires, 377 completed their questionnaires (83...
May 4, 2018: Annals of Transplantation: Quarterly of the Polish Transplantation Society
Karthik Hullahalli, Marinelle Rodrigues, Uyen Thy Nguyen, Kelli Palmer
Antibiotic-resistant bacteria are critical public health concerns. Among the prime causative factors for the spread of antibiotic resistance is horizontal gene transfer (HGT). A useful model organism for investigating the relationship between HGT and antibiotic resistance is the opportunistic pathogen Enterococcus faecalis , since the species possesses highly conjugative plasmids that readily disseminate antibiotic resistance genes and virulence factors in nature. Unlike many commensal E. faecalis strains, the genomes of multidrug-resistant (MDR) E...
May 1, 2018: MBio
Daisuke Yokogawa
The reference interaction site model self-consistent field (RISM-SCF) has the potential to become a powerful tool for studying solution chemistry because of its low computational cost and the capability of calculating local solvation structures accurately, such as hydrogen bonding. However, RISM-SCF has a critical weakness: it is not possible to accurately reproduce the experimental data for solvation free energy. In this study, we proposed a new bridge function and combined it with the repulsive bridge correction (RBC) proposed by Kovalenko and Hirata...
April 30, 2018: Journal of Chemical Theory and Computation
David Ramírez, Julio Caballero
Molecular docking is the most frequently used computational method for studying the interactions between organic molecules and biological macromolecules. In this context, docking allows predicting the preferred pose of a ligand inside a receptor binding site. However, the selection of the “best” solution is not a trivial task, despite the widely accepted selection criterion that the best pose corresponds to the best energy score. Here, several rigid-target docking methods were evaluated on the same dataset with respect to their ability to reproduce crystallographic binding orientations, to test if the best energy score is a reliable criterion for selecting the best solution...
April 28, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Konstantin Tretyakov
In this article, I critically examine the principle of national solidarity in organ sharing across national borders. More specifically, I analyse the policy foundations of solidarity in the transnational allocation of organs and its implementation in the system of national balance points adopted in Europe. I argue that the system of national balance points is based on statist collectivism and therefore is oriented more toward collective, rather than individual welfare. The same collective welfare rationale is also evident from leading policy statements about self-sufficiency in organ donation that seem to assume that cross-border organ sharing can be wrong if collective welfare is violated...
May 2018: Journal of Law and the Biosciences
Yuko Tadokoro, Takayuki Hoshii, Satoshi Yamazaki, Koji Eto, Hideo Ema, Masahiko Kobayashi, Masaya Ueno, Kumiko Ohta, Yuriko Arai, Eiji Hara, Kenichi Harada, Masanobu Oshima, Hiroko Oshima, Fumio Arai, Akihiko Yoshimura, Hiromitsu Nakauchi, Atsushi Hirao
Stem cell self-renewal is critical for tissue homeostasis, and its dysregulation can lead to organ failure or tumorigenesis. While obesity can induce varied abnormalities in bone marrow components, it is unclear how diet might affect hematopoietic stem cell (HSC) self-renewal. Here, we show that Spred1, a negative regulator of RAS-MAPK signaling, safeguards HSC homeostasis in animals fed a high-fat diet (HFD). Under steady-state conditions, Spred1 negatively regulates HSC self-renewal and fitness, in part through Rho kinase activity...
April 18, 2018: Cell Stem Cell
Clare E Palmer, Manos Tsakiris
Interoception describes the processing and awareness of bodily signals arising from visceral organs, essential for the organism's homeostatic needs. Beyond homeostasis, the integration of exteroceptive and interoceptive signals is required for the coherence of bodily self-awareness. Here we suggest that interoception also plays a critical role in social cognition. Relating to others as individuals who are distinct from one's self requires the simultaneous yet distinct co-representation of self and others. We propose that interoceptive awareness appears to stabilise the mental representation of one's self as distinct from others...
April 19, 2018: Current Opinion in Psychology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"