Approximate Entropy of Spiking Series Reveals Different Dynamical States in Cortical Assemblies

Self-organized criticality theory proved that information transmission and computational performances of neural networks are optimal in critical state. By using recordings of the spontaneous activity originated by dissociated neuronal assemblies coupled to Micro-Electrode Arrays (MEAs), we tested this hypothesis using Approximate Entropy (ApEn) as a measure of complexity and information transfer. We analysed 60 min of electrophysiological activity of three neuronal cultures exhibiting either sub-critical, critical or super-critical behaviour. The firing patterns on each electrode was studied in terms of the inter-spike interval (ISI), whose complexity was quantified using ApEn. We assessed that in critical state the local complexity (measured in terms of ApEn) is larger than in sub- and super-critical conditions (mean ± std, ApEn about 0.93 ± 0.09, 0.66 ± 0.18, 0.49 ± 0.27, for the cultures in critical, sub-critical and super-critical state, respectively—differences statistically significant). Our estimations were stable when considering epochs as short as 5 min (pairwise cross- correlation of spatial distribution of mean ApEn of 94 ± 5%). These preliminary results indicate that ApEn has the potential of being a reliable and stable index to monitor local information transmission in a neuronal network during maturation. Thus, ApEn applied on ISI time series appears to be potentially useful to reflect the overall complex behaviour of the neural network, even monitoring a single specific location

Evidence that large vessels do affect near infrared spectroscopy

The influence of large vessels on near infrared spectroscopy (NIRS) measurement is generally considered negligible. Aim of this study is to test the hypothesis that changes in the vessel size, by varying the amount of absorbed NIR light, could profoundly affect NIRS blood volume indexes. Changes in haemoglobin concentration (tHb) and in tissue haemoglobin index (THI) were monitored over the basilic vein (BV) and over the biceps muscle belly, in 11 subjects (7 M – 4 F; age 31 ± 8 year) with simultaneous ultrasound monitoring of BV size. The arm was subjected to venous occlusion, according to two pressure profiles: slow (from 0 to 60 mmHg in 135 s) and rapid (0 to 40 mmHg maintained for 30 s). Both tHb and THI detected a larger blood volume increase (1.7 to 4 fold; p < 0.01) and exhibited a faster increase and a greater convexity on the BV than on the muscle. In addition, NIRS signals from BV exhibited higher correlation with changes in BV size than from muscle (r = 0.91 vs 0.55, p < 0.001 for THI). A collection of individual relevant recordings is also included. These results challenge the long-standing belief that the NIRS measurement is unaffected by large vessels and support the concept that large veins may be a major determinant of blood volume changes in multiple experimental conditions

Fetal Myocardial Expression of GLUT1: Roles of BPA Exposure and Cord Blood Exosomes in a Rat Model

Dietary exposure to Bisphenol A (BPA), an industrial chemical present in food containers, affects nutrient metabolism in the myocardium of offspring during intrauterine life. Using a murine model, we observed that fetal hearts from mothers exposed to BPA (2.5 mu g/kg/day) for 20 days before mating and for all of the gestation had decreased expression of glucose transporter-1 (GLUT1), the principal sugar transporter in the fetal heart, and increased expression of fatty acid cluster of differentiation 36 transporter (CD36), compared to control fetuses from vehicle-treated mothers. We confirmed the suppression of GLUT1 by exposing fetal heart organotypic cultures to BPA (1 nM) for 48 h but did not detect changes in CD36 compared to controls. During pregnancy, the placenta continuously releases extracellular vesicles such as exosomes into fetal circulation. These vesicles influence the growth and development of fetal organs. When fetal heart cultures were treated with cord blood-derived exosomes isolated from BPA-fed animals, GLUT1 expression was increased by approximately 40%. Based on our results, we speculate that exosomes from cord blood, in particular placenta-derived nanovesicles, could contribute to the stabilization of the fetal heart metabolism by ameliorating the harmful effects of BPA on GLUT1 expression

Applications of Intermittent Pneumatic Compression for Diagnostic and Therapeutic Purposes

Intermittent Pneumatic Compression (IPC) technique is prescribed for several treatments, as the management of venous leg ulcers or the prevention of deep vein thrombosis. Commercial devices do not enable the full customization of the compressive patterns due to design specifications and low dynamics. However, IPC can be implemented in a wide scenario of clinical protocols, and not only as a therapeutic tool. In this paper, the results of the research on IPC devices conducted at the Politecnico di Torino (Turin, Italy) are presented. In particular, applications regarding the treatment of the end-diastolic volume (EDV) reduction, the investigation of vascular phenomena as hyperemia, and the assessment of venous pulse wave velocity (vPWV) are discussed. The outcomes of the research demonstrate that IPC technology can lead to the creation of widely used diagnostic, therapeutic and rehabilitative devices

Letture Idromorfiche del Territorio: La città di Matera

Hydromorphic analysis uses the concept of hydrographic basin, interpreted in its dynamic meaning, to analyze territorial contexts of any size. This allows multi-scalar analyzes that allow to overcome urban fragmentation and interpret the territory differently, integrating the morphological characteristics with the more urban planning and land use aspects. In this schematization, the different territorial portions are connected by the dynamics of the respective surface outflows, thus also highlighting the mutual influence that each area exerts on the other. The declination of the role attributed to the different areas: upper mountain, intermediate slope and lower valley, helps to highlight the relationships between the different urbanized and non-urbanized places, ensures an effective reading of the hydromorphic complexities involved in urban transformation processes and territorial, and allows to evaluate the adaptability of a territory, based on the morphological conformation that characterizes it and on the dynamics of the surface outflows that are established there. The proposed approach allows to quantitatively express the response of each analyzed context and, therefore, to develop comparisons between different scenarios, providing useful information and support for decision-making choices.L’analisi idromorfica utilizza il concetto di bacino idrografico, interpretato nel suo significato dinamico, per analizzare contesti territoriali di qualunque dimensione. Ciò permette analisi multi scalari che permettono di superare la frammentazione urbanistica e leggere diversamente il territorio, integrando le caratteristiche morfologiche con gli aspetti più urbanistici e di uso del suolo. In tale schematizzazione, le diverse porzioni territoriali vengono ad essere connesse dalla dinamica dei rispettivi deflussi superficiali, evidenziando così anche l’influenza reciproca che ciascuna area esercita sull’altra. La declinazione del ruolo attribuito alle diverse aree: alta di monte, intermedia di versante e bassa di valle, contribuisce a mettere in evidenza i rapporti fra i differenti luoghi urbanizzati e non, assicura un’efficacie lettura delle complessità idromorfiche coinvolte nei processi di trasformazione urbana e territoriale, e permette di valutare la capacità di adattamento di un territorio, basandosi sulla conformazione morfologica che lo caratterizza e sulla dinamica dei deflussi superficiali che vi si instaurano. L’approccio proposto permette di esprimere quantitativamente la risposta di ogni contesto analizzato e, quindi, di sviluppare confronti tra differenti scenari, fornendo utili indicazioni e supporto alle scelte decisionali