Capacités morphogènes des cellules d’éponges dissociées

The reconstitution of functional sponges from aggregates, some built from non-fractionated suspensions, others from purified archaeocytes, has been studied using electron microscopy in process of time.The reorganization of aggregates made from complete suspensions mainly consists in a gathering of cells keeping their initial differentiation into functional structures. During restructuration, cellular debris resulting from dissociation and surnumerary healthy cells are phagocytized by archaeocytes.The evolution of archaeocyte aggregates points out the totipotency of these cells, since they appear to be able to differentiate into all sponge cell types. Nevertheless, the anomalies appearing during the sponge reconstitution, which mainly consist in a cell type population ratio desequilibrium, suggest that some morphogenetic regulation mechanisms are lost

Toward a precision, complexity-informed cultural policy design: Structural bottlenecks to culture-led development in Skaraborg, Sweden

We analyze the spatial-temporal dynamics of cultural vibrancy in the Swedish sub-region of Skaraborg. Our database consists of 4170 geo-localized cultural activities and facilities, mapped between October 2013 and March 2014. We make use of the TWC methodology for the dynamic simulation of the evolution of geo-localized activity starting from an observed distribution of events, and of the AutoCM ANN architecture to understand how cultural variables are related to the rest of the Skaraborg socio-economy. We find that cultural vibrancy in Skaraborg is likely characterized by a 'flaring' pattern of initial, widespread activity followed by a re-concentration into the main local urban hubs. The deep reason behind this unsuccessful developmental trajectory is the lack of centrality of cultural production in the local socio-economy, and of integration across cultural production sectors. This is in turn due also to structural bottlenecks of a non-cultural nature such as insufficient access of women to higher education. We make a case for the necessity to develop a new precision cultural policy design approach founded upon the science of complexity for both policy design and assessment, and we provide and illustrate a first technical toolkit to this purpose.(c) 2022 Elsevier B.V. All rights reserved

A nonlinear, data-driven, ANNs-based approach to culture-led development policies in rural areas: The case of Gjakove and Pee districts, Western Kosovo

We develop a computational approach to the analysis of cultural vibrancy and to the role of the cultural and cre-ative sectors in the socio-economic organization of two districts of Western Kosovo, Gjakove and Pee. Our anal-ysis is built on a geolocalized mapping of the cultural activities and facilities, and on the main socio-economic variables for the two districts, and makes use of innovative data analysis techniques: Theory of Impossible Words (TIW), the Topological Weighted Centroid (TWC), and the AutoCM ANN. We find that the dynamics of cul-tural vibrancy of the territory is mainly driven by the competing attraction pulls of the nearby countries of Serbia and Albania, that also form the region's main and often conflicting ethnicities, and that such dynamics are likely to further polarize in the future. We also find that the cultural system plays a marginal role in the territory's socio-economic organization. This situation makes a case for a more active role of cultural policy in shaping future local developmental models in rural areas and in acting as an agent of social cohesion.(c) 2022 Elsevier Ltd. All rights reserved

Reconstructing the Emergent Organization of Information Flows in International Stock Markets: A Computational Complex Systems Approach

In this paper we study the interdependences between the dynamics of the stock market indexes of 30 different stock markets across 29 different countries to analyze the nonlinear dynamics of their information flows. We find that the system exhibits complex dynamic properties that go beyond what has been generally found in the previous literature, suggesting that the structure of information flows is regulated by subtle homeostatic forces that cause the roles of the single markets in the whole network to evolve in unexpected ways. We present a toolkit of ANN-based methods that can be systematically deployed to analyze different aspects of such dynamics

Placental determinants of fetal growth: identification of key factors in the insulin-like growth factor and cytokine systems using artificial neural networks

<p>Abstract</p> <p>Background</p> <p>Changes and relationships of components of the cytokine and IGF systems have been shown in placenta and cord serum of fetal growth restricted (FGR) compared with normal newborns (AGA). This study aimed to analyse a data set of clinical and biochemical data in FGR and AGA newborns to assess if a mathematical model existed and was capable of identifying these two different conditions in order to identify the variables which had a mathematically consistent biological relevance to fetal growth.</p> <p>Methods</p> <p>Whole villous tissue was collected at birth from FGR (N = 20) and AGA neonates (N = 28). Total RNA was extracted, reverse transcribed and then real-time quantitative (TaqMan) RT-PCR was performed to quantify cDNA for IGF-I, IGF-II, IGFBP-1, IGFBP-2 and IL-6. The corresponding proteins with TNF-α in addition were assayed in placental lysates using specific kits. The data were analysed using Artificial Neural Networks (supervised networks), and principal component analysis and connectivity map.</p> <p>Results</p> <p>The IGF system and IL-6 allowed to predict FGR in approximately 92% of the cases and AGA in 85% of the cases with a low number of errors. IGF-II, IGFBP-2, and IL-6 content in the placental lysates were the most important factors connected with FGR. The condition of being FGR was connected mainly with the IGF-II placental content, and the latter with IL-6 and IGFBP-2 concentrations in placental lysates.</p> <p>Conclusion</p> <p>These results suggest that further research in humans should focus on these biochemical data. Furthermore, this study offered a critical revision of previous studies. The understanding of this system biology is relevant to the development of future therapeutical interventions possibly aiming at reducing IL-6 and IGFBP-2 concentrations preserving IGF bioactivity in both placenta and fetus.</p

Optoelectronics with electrically tunable PN diodes in a monolayer dichalcogenide

One of the most fundamental devices for electronics and optoelectronics is the PN junction, which provides the functional element of diodes, bipolar transistors, photodetectors, LEDs, and solar cells, among many other devices. In conventional PN junctions, the adjacent p- and n-type regions of a semiconductor are formed by chemical doping. Materials with ambipolar conductance, however, allow for PN junctions to be configured and modified by electrostatic gating. This electrical control enables a single device to have multiple functionalities. Here we report ambipolar monolayer WSe2 devices in which two local gates are used to define a PN junction exclusively within the sheet of WSe2. With these electrically tunable PN junctions, we demonstrate both PN and NP diodes with ideality factors better than 2. Under excitation with light, the diodes show photodetection responsivity of 210 mA/W and photovoltaic power generation with a peak external quantum efficiency of 0.2%, promising numbers for a nearly transparent monolayer sheet in a lateral device geometry. Finally, we demonstrate a light-emitting diode based on monolayer WSe2. These devices provide a fundamental building block for ubiquitous, ultra-thin, flexible, and nearly transparent optoelectronic and electronic applications based on ambipolar dichalcogenide materials.Comment: 14 pages, 4 figure