Navigation in a small world with local information

It is commonly known that there exist short paths between vertices in a network showing the small-world effect. Yet vertices, for example, the individuals living in society, usually are not able to find the shortest paths, due to the very serious limit of information. To theoretically study this issue, here the navigation process of launching messages toward designated targets is investigated on a variant of the one-dimensional small-world network (SWN). In the network structure considered, the probability of a shortcut falling between a pair of nodes is proportional to $r^{-\alpha}$, where $r$ is the lattice distance between the nodes. When $\alpha =0$, it reduces to the SWN model with random shortcuts. The system shows the dynamic small-world (SW) effect, which is different from the well-studied static SW effect. We study the effective network diameter, the path length as a function of the lattice distance, and the dynamics. They are controlled by multiple parameters, and we use data collapse to show that the parameters are correlated. The central finding is that, in the one-dimensional network studied, the dynamic SW effect exists for $0\leq \alpha \leq 2$. For each given value of $\alpha$ in this region, the point that the dynamic SW effect arises is $ML^{\prime}\sim 1$, where $M$ is the number of useful shortcuts and $L^{\prime}$ is the average reduced (effective) length of them.Comment: 10 pages, 5 figures, accepted for publication in Physical Review

The Kinetic Basis of Self-Organized Pattern Formation

In his seminal paper on morphogenesis (1952), Alan Turing demonstrated that different spatio-temporal patterns can arise due to instability of the homogeneous state in reaction-diffusion systems, but at least two species are necessary to produce even the simplest stationary patterns. This paper is aimed to propose a novel model of the analog (continuous state) kinetic automaton and to show that stationary and dynamic patterns can arise in one-component networks of kinetic automata. Possible applicability of kinetic networks to modeling of real-world phenomena is also discussed.Comment: 8 pages, submitted to the 14th International Conference on the Synthesis and Simulation of Living Systems (Alife 14) on 23.03.2014, accepted 09.05.201

Review of Marie Huxtable’s doctoral thesis, ‘How do I evolve living-educational-theory praxis in living-boundaries?’

This thesis offers four original contributions to knowledge: 1. Living-Educational-Theory praxis, highlighting the fundamental importance of educators creating 'valuesbased explanation of their educational influences in learning' (Whitehead, 1989), as they research to develop praxis within living-boundaries. 2. Living-boundaries as co-creative space within which energy-flowing values can be clarified and communicated. 3. Inclusive gifted and talented education developed from an educational perspective, which enables each learner to develop and offer talents, expertise and knowledge as lifeaffirming and life-enhancing gifts. The knowledge is that created of the world, of self, and self in and of the world. 4. Living-Theory TASC, a relationally-dynamic and multidimensional approach to research and developing praxis, which integrates Living-Theory (Whitehead, 1989) with Thinking Actively in a Social Context (TASC) (Wallace & Adams, 1993)

The Multilateral Agreement on Investment and International Labor Rights: A Failed Connection

[Excerpt] This essay starts with an anecdote to suggest that foreign direct investment can serve workers\u27 interests when their rights are respected. The rewards of investment should not be limited to U.S. workers, either. Workers around the world can benefit from investment flows linked to policies that advance workers\u27 labor rights and living standards. In this light, an investment agreement that promotes stability, predictability, the rule of law, and fairness in international trade can be a positive force for a high road dynamic in the rapidly globalizing economy, if it takes workers\u27 rights into account. However, if such an agreement fails to incorporate strong protection for labor rights, it can make inevitable a low road of worker exploitation in global trade and investment flows

A Student of the Old Testament Proclaims Jesus as Messiah and Lord

This paper proposes to examine the stance of Peter both in his position toward the Old Testament which he quotes and toward the people before him on Pentecost. It is the contention of this writer that Peter was a man with both feet in the world. Moreover, Peter\u27s world consisted of two separate but often merging spheres of life. There is the orb of the past, full of history and tradition, but there is also the sphere of a living present with its dynamic reality in the living Christ and His Spirit

Enhancing Compressed Sensing 4D Photoacoustic Tomography by Simultaneous Motion Estimation

A crucial limitation of current high-resolution 3D photoacoustic tomography (PAT) devices that employ sequential scanning is their long acquisition time. In previous work, we demonstrated how to use compressed sensing techniques to improve upon this: images with good spatial resolution and contrast can be obtained from suitably sub-sampled PAT data acquired by novel acoustic scanning systems if sparsity-constrained image reconstruction techniques such as total variation regularization are used. Now, we show how a further increase of image quality can be achieved for imaging dynamic processes in living tissue (4D PAT). The key idea is to exploit the additional temporal redundancy of the data by coupling the previously used spatial image reconstruction models with sparsity-constrained motion estimation models. While simulated data from a two-dimensional numerical phantom will be used to illustrate the main properties of this recently developed joint-image-reconstruction-and-motion-estimation framework, measured data from a dynamic experimental phantom will also be used to demonstrate their potential for challenging, large-scale, real-world, three-dimensional scenarios. The latter only becomes feasible if a carefully designed combination of tailored optimization schemes is employed, which we describe and examine in more detail

Interact and Transform

The micro-world, largely hidden from sight, is alluring, beautiful and potentially dangerous. The dynamic arc of life in this turbulent imperceptible world is quick and furious. In my artwork, I use simple living organisms. Because of their microscopic sizes, we don't commonly notice them and therefore they represent largely an unseen world. Microscopic forms are evidence of processes while simultaneously generating aesthetic outcomes. The diminutive life forms harmonize to create a colorful array of actions, counter-actions and conflicts where they are metaphors for various human conditions. In my work, the living entities are interactive elements and recreate observable conflicts. They compete for resources, dominate a particular area, live in harmony or become invasive and endanger others. These biological interactions and the aesthetic outcome they yield are the basis of my research. In an artificially constructed living platform, I am the impresario and my players are hostile fragile microorganisms

Some resonances between Eastern thought and Integral Biomathics in the framework of the WLIMES formalism for modelling living systems

Forty-two years ago, Capra published “The Tao of Physics” (Capra, 1975). In this book (page 17) he writes: “The exploration of the atomic and subatomic world in the twentieth century has …. necessitated a radical revision of many of our basic concepts” and that, unlike ‘classical’ physics, the sub-atomic and quantum “modern physics” shows resonances with Eastern thoughts and “leads us to a view of the world which is very similar to the views held by mystics of all ages and traditions.“ This article stresses an analogous situation in biology with respect to a new theoretical approach for studying living systems, Integral Biomathics (IB), which also exhibits some resonances with Eastern thought. Stepping on earlier research in cybernetics1 and theoretical biology,2 IB has been developed since 2011 by over 100 scientists from a number of disciplines who have been exploring a substantial set of theoretical frameworks. From that effort, the need for a robust core model utilizing advanced mathematics and computation adequate for understanding the behavior of organisms as dynamic wholes was identified. At this end, the authors of this article have proposed WLIMES (Ehresmann and Simeonov, 2012), a formal theory for modeling living systems integrating both the Memory Evolutive Systems (Ehresmann and Vanbremeersch, 2007) and the Wandering Logic Intelligence (Simeonov, 2002b). Its principles will be recalled here with respect to their resonances to Eastern thought

Two-photon imaging and analysis of neural network dynamics

The glow of a starry night sky, the smell of a freshly brewed cup of coffee or the sound of ocean waves breaking on the beach are representations of the physical world that have been created by the dynamic interactions of thousands of neurons in our brains. How the brain mediates perceptions, creates thoughts, stores memories and initiates actions remains one of the most profound puzzles in biology, if not all of science. A key to a mechanistic understanding of how the nervous system works is the ability to analyze the dynamics of neuronal networks in the living organism in the context of sensory stimulation and behaviour. Dynamic brain properties have been fairly well characterized on the microscopic level of individual neurons and on the macroscopic level of whole brain areas largely with the help of various electrophysiological techniques. However, our understanding of the mesoscopic level comprising local populations of hundreds to thousands of neurons (so called 'microcircuits') remains comparably poor. In large parts, this has been due to the technical difficulties involved in recording from large networks of neurons with single-cell spatial resolution and near- millisecond temporal resolution in the brain of living animals. In recent years, two-photon microscopy has emerged as a technique which meets many of these requirements and thus has become the method of choice for the interrogation of local neural circuits. Here, we review the state-of-research in the field of two-photon imaging of neuronal populations, covering the topics of microscope technology, suitable fluorescent indicator dyes, staining techniques, and in particular analysis techniques for extracting relevant information from the fluorescence data. We expect that functional analysis of neural networks using two-photon imaging will help to decipher fundamental operational principles of neural microcircuits.Comment: 36 pages, 4 figures, accepted for publication in Reports on Progress in Physic