Neighbor-enhanced diffusivity in dense, cohesive cell populations

The dispersal or mixing of cells within cellular tissue is a crucial property for diverse biological processes, ranging from morphogenesis, immune action, to tumor metastasis. With the phenomenon of ‘contact inhibition of locomotion,’ it is puzzling how cells achieve such processes within a densely packed cohesive population. Here we demonstrate that a proper degree of cell-cell adhesiveness can, intriguingly, enhance the super-diffusive nature of individual cells. We systematically characterize the migration trajectories of crawling MDA-MB-231 cell lines, while they are in several different clustering modes, including freely crawling singles, cohesive doublets of two cells, quadruplets, and confluent population on two-dimensional substrate. Following data analysis and computer simulation of a simple cellular Potts model, which faithfully recapitulated all key experimental observations such as enhanced diffusivity as well as periodic rotation of cell-doublets and cell-quadruplets with mixing events, we found that proper combination of active self-propelling force and cell-cell adhesion is sufficient for generating the observed phenomena. Additionally, we found that tuning parameters for these two factors covers a variety of different collective dynamic states.

Neuroinflammation: Integrated Nervous Tissue Response through Intercellular Interactions at the “Whole System” Scale

Different cell populations in the nervous tissue establish numerous, heterotypic interactions and perform specific, frequently intersecting activities devoted to the maintenance of homeostasis. Microglia and astrocytes, respectively the immune and the “housekeeper” cells of nervous tissue, play a key role in neurodegenerative diseases. Alterations of tissue homeostasis trigger neuroinflammation, a collective dynamic response of glial cells. Reactive astrocytes and microglia express various functional phenotypes, ranging from anti-inflammatory to pro-inflammatory. Chronic neuroinflammation is characterized by a gradual shift of astroglial and microglial phenotypes from anti-inflammatory to pro-inflammatory, switching their activities from cytoprotective to cytotoxic. In this scenario, the different cell populations reciprocally modulate their phenotypes through intense, reverberating signaling. Current evidence suggests that heterotypic interactions are links in an intricate network of mutual influences and interdependencies connecting all cell types in the nervous system. In this view, activation, modulation, as well as outcomes of neuroinflammation, should be ascribed to the nervous tissue as a whole. While the need remains of identifying further links in this network, a step back to rethink our view of neuroinflammation in the light of the “whole system” scale, could help us to understand some of its most controversial and puzzling features.

Swelling of a granular hydrogel medium under confinement: individual and collective dynamic

The growth dynamics of polyacrylamide hydrogel beads due to liquid absorption under geometric confinement is studied. First, the behavior of individual hydrogel beads is investigated and, subsequently, the growth dynamics is analyzed in the presence of several interacting beads of the same material. In both, individual and collective studies, the magnitude of the geometric confinement is varied, in order to investigate the effect that the stress applied on the particles has on their hydration kinetics.

Shifting Resources, Shifting Forms. Spontaneous Solidarity, Virtual Voluntarism and the Legacy of Radne Akcije in Postsocialist Serbia

Voluntarism is typically understood as action taken by individuals who voluntarily join collectives or take action to contribute in some way to social welfare. Voluntaristic forms vary widely depending on social context; however, a theme in recent sociological work is the possible withering away of voluntary practices in the forms that have previously existed. In this article, the author considers how the legacy of radne akcije, the working campaigns once coordinated by the Yugoslav state, is used to frame recent episodes of voluntarism, including the efforts of volunteers during the 2014 floods in Serbia, and charitable donations via SMS. She argues that previous forms of voluntaristic praxis have been fundamentally transformed following a shift in the fiscal and social resources of the state. However, while novel forms of voluntaristic practice and organization reflect the state’s present neoliberal ethos, participants remain wedded to a rhetoric echoing the past socialist collective dynamic.

Increasing the Throughput of LTE Using Device-to-Device Communication by Reducing Intra-System Interference Flow

This article focuses on the using collective dynamic route method for D2D LTE networks. It provides algorithms for the analysis stage, taking into account the availability of D2D users and the routing stage, as well as their implementation. The dependencies of the D2D communication routes quantity fraction for various cases of user location are shown.

From Spirituality Everything is Connected: Revolutions for Living with Equity and Eco-justice

Everything is connected, from galaxies to the smallest particles in our bodies. We need an interpretation of reality that allows us to see the whole as well as the Whole. This new view is a holistic spirituality that experiences God in the whole of life. It is necessary to make an effort to abandon elements that contaminate global life, because they originate in an anthropology of power-submission, man-woman, human-nature, consumption-participation, exploitation-cooperation… that justifies the exploitation of nature and of human beings. We need to move from the devouring anthropocentrism we live in to a life-centred worldview. This article reflects on reality as an organic whole, the body of God. Reality is a creative, collective, dynamic and diverse ‘body’ that we must care for with equity and eco-justice. Our actions must be oriented towards the practice of God’s justice in the bodies and lives of women. Thus, we will recover the balance of this world.