The complexity of anatomical systems

BACKGROUND: The conception of anatomical entities as a hierarchy of infinitely graduated forms and the increase in the number of observed anatomical sub-entities and structural variables has generated a growing complexity, thus highlighting new properties of organised biological matter. RESULTS: (1) Complexity is so pervasive in the anatomical world that it has come to be considered as a primary characteristic of anatomical systems. (2) Anatomical entities, when viewed at microscopic as well as macroscopic level of observation, show a different degree of complexity. (3) Complexity can reside in the structure of the anatomical system (having many diverse parts with varying interactions or an intricate architecture) or in its behaviour. Often complexity in structure and behaviour go together. (4) Complex systems admit many descriptions (ways of looking at the system) each of which is only partially true. Each way of looking at a complex system requires its own description, its own mode of analysis and its own breaking down of the system in different parts; (5) Almost all the anatomical entities display hierarchical forms: their component structures at different spatial scales or their process at different time scales are related to each other. CONCLUSION: The need to find a new way of observing and measuring anatomical entities, and objectively quantifying their different structural changes, prompted us to investigate the non-Euclidean geometries and the theories of complexity, and to apply their concepts to human anatomy. This attempt has led us to reflect upon the complex significance of the shape of an observed anatomical entity. Its changes have been defined in relation to variations in its status: from a normal (i.e. natural) to a pathological or altered state introducing the concepts of kinematics and dynamics of anatomical forms, speed of their changes, and that of scale of their observation

A novel approach for the isolation of the sound and pseudo-sound contributions from near-field pressure fluctuation measurements: analysis of the hydroacoustic and hydrodynamic perturbation in a propeller-rudder system

The main scope of the present work is to investigate the mechanisms underlying the hydroacoustic and hydrodynamic perturbations in a rudder operating in the wake of a free running marine propeller. The study consisted of detailed near-field pressure fluctuation measurements which were acquired on the face and back surfaces of the rudder, at different deflection angles. To this aim, a novel wavelet-filtering procedure was applied to separate and analyze distinctly the acoustic and hydrodynamic components of the recorded near-field pressure signals. The filtering procedure undertakes the separation of intermittent pressure peaks induced by the passage of eddy structures, interpreted as pseudo-sound, from homogenous background fluctuations, interpreted as sound. The use of wavelet in the filtering procedure allows to overcome the limitations of the earlier attempts based on frequency (wave number) band-pass filtering, retrieving the overall frequency content of both the acoustic and the hydrodynamic components and returning them as independent signals in the time domain. Acoustic and hydrodynamic pressure distributions were decomposed harmonically and compared to the corresponding topologies of the vorticity field, derived from earlier LDV measurements performed by Felli and Falchi (Exp Fluids 51(5):1385-1402, 2011). The study highlighted that the acoustic perturbation is mainly correlated with the unsteady load variations of the rudder and to the shear layer fluctuations of the propeller streamtube. Conversely, the dynamics of the propeller tip and hub vortices underlies the hydrodynamic perturbation

Recent advances in the theoretical & experimental analysis of naval unit hydroacoustic performance

The present paper reviews the experimental and theoretical techniques currently used at CNR-INSEAN for hydroacoustic applications. The theoretical procedure used for hydroacoustic analyses is based upon the Lighthill\u27s acoustic analogy and concerns a hybrid hydrodynamic and hydroacoustic solver. Experimental hydroacoustics regards simultaneous velocity-pressure/visualization-pressure measurements and cross-correlation and conditional techniques. Furthermore, special signal processing techniques are used for the sake of removing unwanted noise contributions and separating the sound and pseudo-sound contributions. Examples of hydroacoustic analyses undertaken by aforementioned theoretical and experimental tools are documented in the paper

Passaggio linee 10 - 20 kV sulla rete MT di Verona. Analisi fattibilità tecnico-economica

Lo studio affrontato in questa tesi si propone di fornire un profilo sugli aspetti principali da considerare nella valutazione di fattibilità tecnico-economica di un passaggio da 10 a 20 kV nello specifico caso della rete MT di Verona. A tale scopo si sono individuate delle zone circoscritte da determinate peculiarità, ma l’analisi può in ogni modo riferirsi ad una porzione di rete ulteriormente ristretta o maggiormente estesa. Il lavoro svolto si articola nei seguenti passaggi essenziali: 1.Analisi e mappatura della rete MT; determinazione ed assegnazione alle varie linee degli elementi distintivi della rete quali, perdite, tipologia del conduttore, numero di cabine, di trasformatori e contro-alimentazioni possibili. 2.Individuazione delle ISOLE; così definite, sono le aree di studio prese in considerazione per il passaggio a 20 kV sulla base delle caratteristiche individuate al punto 1 che hanno permesso di delinearne i confini geografici. 3.Analisi di fattibilità tecnico-economica in riferimento all’area considerata, valutando i costi da sostenere da un lato, e i benefici derivanti da tale operazione dall’altro, con una stima conclusiva sul ritorno dell’investimento nel complesso. Tale procedimento ha messo dunque in luce le zone principali da considerare in cui intraprendere futuri lavori di passaggio 10 – 20 kVopenEmbargo per motivi di segretezza e di proprietà dei risultati e informazioni di enti esterni o aziende private che hanno partecipato alla realizzazione del lavoro di ricerca relativo alla tes

Comment on 'Tumour antigen expression in hepatocellular carcinoma in a low-endemic western area'

We comment on the recent study by Sideras et al (2015) that combines tissue microarrays (TMAs) and immunohistochemistry to investigate the expression pattern of 15 antigens belonging to different categories, including cancer-testis antigens and oncofetal proteins in hepatocellular carcinoma (HCC). Because current therapies for HCC are far from ideal (Ilan, 2014) and immunotherapy has been suggested as a potential therapeutic option, the Authors aimed at identifying a panel of biologically relevant tumour antigens with broad expression in a western European population of HCC patients and specific expression in the tumour tissue with no, or little, expression in surrounding non- tumoral tissue (Sideras et al., 2015)

On the Fractal Nature of Nervous Cell System

In a detailed study entitled “Morphological development of thick – tufted layer V pyramidal cells in the rat somatosensory cortex, ” an international team of scientists (Romand et al., 2011) reported a series of results pertaining to an analytical investigation of the morphological development of thick-tufted layer V pyramidal cells (also called the principal cells) in the rat somatosensory cortex. At the end of the Introduction Section, the Authors stated “all compartments of a TTL5 cell undergo different developmental changes, supporting the notion that multiple functional compartments receive different inputs an