Mysticism: A Way of Unknowing

The phenomenon of mysticism has been a cause of intense debate for philosophers, religionists, and theologians for centuries. Interest in mysticism is particularly vibrant in the 21st century, not only among the afore-mentioned, but also from other diverse sectors of society. This is evidenced in the plethora of material dealing with various aspects of mysticism. Negative or apophatic mysticism is eliciting greater attention, both in the academy and in society in general and many of the misconceptions surrounding this concept are currently under scrutiny. It is clear that apophatic mysticism — the “way of unknowing” or “nothingness” — belongs to the essence of the spiritual path. A short survey of this concept in some of the major religious traditions, together with an analysis of the place of apophasis in Christianity, brings this pertinent area of study into greater focus

Analisi e modellazione di Scaffold in vetro ceramica

LAUREA MAGISTRALEGli scaffold ossei sono dispositivi utilizzati nell’ambito dell’Ingegneria dei Tessuti per aiutare il processo di rigenerazione del tessuto osseo a seguito di patologie o traumi che ne prevengono la rigenerazione autonoma. All’interno di questo lavoro vengono analizzati scaffold realizzati in materiale vetro-ceramico bioattivo, denominato 47.5B, il quale è stato progettato e realizzato presso il Politecnico di Torino. Gli scaffold sono stati realizzati utilizzando sei diverse temperature di sinterizzazione, tra 600°C e 850°C, durante il processo di fabbricazione; in particolare l’intervallo di temperature scelte comprende la temperatura di cristallizzazione del materiale, pari a 690°C. Per determinare l’influenza della temperatura di sinterizzazione sulle proprietà strutturali e meccaniche degli scaffold ottenuti, sono state svolte sia analisi degli scaffold dal punto di vista meccanico nell’ambito computazionale, sia analisi sperimentali di provini in bulk del materiale sinterizzato alle diverse temperature. In particolare, sono stati studiate le seguenti caratteristiche: - le proprietà morfometriche degli scaffold, - le caratteristiche elastiche delle strutture, - le proprietà meccaniche del materiale in bulk, - la resistenza degli scaffold ai fenomeni di rottura. Le analisi relative agli scaffold sono state svolte sulla base di scansioni μ-CT, le quali hanno permesso di ricostruire la struttura di volumi di interesse selezionati. Le proprietà morfometriche che sono state analizzate sono: porosità, grado di anisotropia, spessore medio trabecolare, dimensione media dei pori e permeabilità. A seguito di queste analisi è stato possibile caratterizzare gli scaffold in analisi, in particolare individuando una distinzione tra gli scaffold caratterizzati da temperature di sinterizzazione inferiori e superiori alla temperatura di cristallizzazione del materiale. Le analisi elastiche svolte sugli scaffold in modo computazionale hanno permesso di determinare il modulo elastico normalizzato degli scaffold. I moduli elastici normalizzati ottenuti sono stati confrontati con le proprietà morfometriche, per identificare una relazione tra i diversi parametri determinati. È stata cercata in particolare una relazione tra il modulo elastico normalizzato dei dispositivi e il parametro strutturale di porosità, sulla base di modelli proposti in letteratura. Sono state eseguite prove di nanoindentazione su provini di materiale caratterizzati dalle stesse temperature di sinterizzazione degli scaffold in analisi. Sono state utilizzate diverse punte per indentare il materiale: - punta Berkovich, per determinare il modulo elastico e la durezza - punta cube corner, per determinare il parametro di tenacità - punta sferica, per stimare il valore dello sforzo di rottura Sulla base del modulo elastico del materiale e del modulo elastico normalizzato, è stato determinato il modulo elastico relativo agli scaffold. La stima del valore di sforzo di rottura è avvenuta parallelamente sulla base di simulazioni computazionali e in relazione al parametro di tenacità. È stato ricavato un intervallo di valori accettabili per descrivere la resistenza del materiale al fenomeno di rottura; l’intervallo determinato risulta essere valido in modo indipendente rispetto alla temperatura di sinterizzazione. Risultano essere necessarie ulteriori analisi in merito alle proprietà meccaniche del materiale, in modo specifico relativamente ai valori di tenacità e sforzo di rottura, per ridurre l’intervallo di valori affinati e valutare una possibile correlazione tra i valori determinati e la temperatura di sinterizzazione. Le simulazioni di rottura degli scaffold hanno permesso di identificare l’andamento delle fratture all’interno delle strutture e di stimare i valori degli sforzi di rottura normalizzati. L’obiettivo principale del seguente lavoro è di ottenere una caratterizzazione completa ed esaustiva degli scaffold in analisi. Questo processo permetterà di ottenere dati importanti per generare e convalidare un modello numerico, il cui obiettivo è l'accurata progettazione di scaffold ossei, inclusa una valutazione dell’effetto, dal punto di vista morfometrico e meccanico, della temperatura di sinterizzazione utilizzata durante il processo di fabbricazione. Questo porterebbe all’identificazione di quali parametri di progetto permettono di ottenere caratteristiche desiderate dal punto di vista meccanico e morfometrico.Tissue Engineering often utilizes bone scaffolds to aid the regeneration process of bone tissue if pathologies or traumatic injuries prevent its autonomous regeneration. The present work analyzes scaffolds made up of a bioactive glass-ceramic material, named 47.5B, which was designed and produced by Politecnico di Torino. The scaffolds have been produced utilizing six different syntherization temperatures, with a minimum temperature of 600°C and a maximum temperature of 850°C, during the fabrication process; in particular, the range of temperatures considered includes the crystallization temperature of the material, circa 690°C. To determine the influence of the syntherization temperature on the structural and mechanical properties of the scaffolds obtained, analysis on multiple scaffolds were operated, both computationally to characterize them from a mechanical point of view, both through experimental tests on bulk samples of the material, one for every syntherization temperature. In particular, the following characteristics were analyzed: - the morphological properties of scaffolds, - elastic characteristics of the structures, - mechanical properties of the bulk material, - resistance to rupture of the scaffolds. The analysis operated on the scaffolds are based on μ-CT scans, which have allowed for the reconstruction of the structure of selected volumes of interest. The morphometric properties that were analyzed are the following: porosity, degree of anisotropy, average trabecular thickness, average pore dimension and permeability. Following these observations, it was possible to characterize the scaffold; in particular a distinction was found between scaffolds characterized by a syntherization temperature higher and lower than the crystallization temperature of the material. The elastic analysis, which was operated on computational reconstructions of the different scaffolds, allowed for the determination of the normalized elastic modulus of the scaffolds. The normalized elastic moduluses of each scaffold were compared to their different morphometric properties, in order to determine a possible correlation between the obtained parameters. In particular, a relation between the normalized elastic modulus and the porosity was inspected, on the basis of models found in literature. Nanoindentation tests were carried out on samples of bulk material, each sample characterized by the same syntherization temperatures of the scaffolds. Different indenters were used to perform the nanoindentation tests: - Berkovich indenter, to determine the elastic modulus and the hardness of the material, - cube corner indenter, to determine the toughness parameter, - spheric indenter, to estimate a value for the material’s strength. The elastic modulus of the scaffolds was determined on the basis of the elastic modulus of the material and the normalized elastic modulus. In order to estimate the material’s strength, two analysis were conducted simultaneously: one computational and one in relation to the toughness parameter. An interval of acceptable values was determined, in order to describe the material’s resistance to fracture generation; the range was found to not be dependent on the syntherization temperatures. Further analysis regarding the mechanical properties of the material are necessary, specifically in regards to the toughness and strength of the material, in order to affine the interval of values that has been determined, and to find a possible correlation between the refined intervals and the syntherization temperatures. The strength analysis of the scaffolds allowed for the visualization of fracture propagation inside the structures, and also allowed for the determination of estimated values for the normalized strength of the scaffolds. The main objective of the following work is to obtain a complete and thorough characterization of the scaffolds in analysis. This will provide data relevant for the creation and validation of a numerical model to properly design scaffolds, including an evaluation of the effects, from a morphometric and mechanical point of view, of the syntherization temperature utilized during the fabrication process. This would enable the identification of which design parameters allow for the obtainment of the desired mechanical and morphometric characteristics in the scaffolds being produced

Exploring Economic and Ethical Challenges of Implementing Demand-Responsive Transport Systems (DRT) in Italy

In recent years, a change in demand trends has influenced the development of public passenger transport, causing a number of critical issues and consequences for the environment, the management policies of these services and, especially, the users. Various passenger transport services have evolved to reduce the use of private vehicles, including DRT systems that consider technological developments like Mobility ad a Service (MaaS). This article focuses on a European literature review on user-oriented research development. The overall objective is to: i) highlight, among all the critical aspects of service development, the factors influencing the economic and ethical aspects; ii) finally identify a discrepancy between the perception of DRT and the empirical research design. The study concludes by providing some potential suggestions for improving DRT service deployment and reducing some of the factors influencing users' modal choices. Finally, the paper proposes implications for policy makers and operators

TRY plant trait database - enhanced coverage and open access

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

RESONANT BRILLOUIN-SCATTERING IN SPATIALLY DISPERSIVE MEDIUM

45NC-5616

High viral load of Merkel cell polyomavirus DNA sequences in Langerhans cell sarcoma tissues.

International audienceBACKGROUND: Langerhans cell (LC) sarcoma (LCS) is a high-grade neoplasm with overtly malignant cytologic features and an LC phenotype. We very recently suggested that LC behaves as a reservoir for common dermotropic Merkel cell polyomavirus (MCPyV) and determined the relationship between LC histiocytosis (LCH), which has an underlining oncogenic capacity, and MCPyV as a trigger for a reactive process rather than a neoplastic process. We propose LC to be a reservoir for MCPyV and hypothesize that some LCS subtypes may be related to the MCPyV agent. FINDINGS: We examined seven LCS tissues using multiplex quantitative PCR (Q-PCR) and immunohistochemistry with anti MCPyV large-T (LT) antigen antibody. High viral loads of MCPyV DNA sequences (viral load = relative levels of MCPyV) were detected (0.328-0.772 copies/cell (Merkel cell carcinoma (MCC) = 1.0)) using Q-PCR in 43% (3/7) tissues, but LT antigen expression was not observed (0/7). CONCLUSIONS: Frequent MCPyV-DNA amplification suggests that LCS in some patients may be related to MCPyV infection. Moreover, the higher viral load of LCS (median, 0.453 copies/cell) than low load of LCH (0.003, median of 12 cases) (P < 0.01) may suggest a virally induced tumorigenic process in some LCS. Although the absence of LT antigen expression may indicate a different role for MCPyV in this pathology, some subtypes of LCS may develop in the background of MCPyV-infected LC. To the best of our knowledge, this is the first report on the relationship between MCPyV and LCS. The recent discovery of MCPyV opened new therapeutic avenues for MCC. These data open novel possibilities for therapeutic interventions against LCS

Micro-CT imaging and finite element models reveal how sintering temperature affects the microstructure and strength of bioactive glass-derived scaffolds

: This study focuses on the finite element simulation and micromechanical characterization of bioactive glass-ceramic scaffolds using Computed micro Tomography ([Formula: see text]CT) imaging. The main purpose of this work is to quantify the effect of sintering temperature on the morphometry and mechanical performance of the scaffolds. In particular, the scaffolds were produced using a novel bioactive glass material (47.5B) through foam replication, applying six different sintering temperatures. Through [Formula: see text]CT imaging, detailed three-dimensional images of the scaffold's internal structure are obtained, enabling the extraction of important geometric features and how these features change with sintering temperature. A finite element model is then developed based on the [Formula: see text]CT images to simulate the fracture process under uniaxial compression loading. The model incorporates scaffold heterogeneity and material properties-also depending on sintering temperature-to capture the mechanical response, including crack initiation, propagation, and failure. Scaffolds sintered at temperatures equal to or higher than 700&nbsp;[Formula: see text]C exhibit two-scale porosity, with micro and macro pores. Finite element analyses revealed that the dual porosity significantly affects fracture mechanisms, as micro-pores attract cracks and weaken strength. Interestingly, scaffolds sintered at high temperatures, the overall strength of which is higher due to greater intrinsic strength, showed lower normalized strength compared to low-temperature scaffolds. By using a combined strategy of finite element simulation and [Formula: see text]CT-based characterization, bioactive glass-ceramic scaffolds can be optimized for bone tissue engineering applications by learning more about their micromechanical characteristics and fracture response

Micro-CT imaging and finite element models reveal how sintering temperature affects the microstructure and strength of bioactive glass-derived scaffolds

This study focuses on the finite element simulation and micromechanical characterization of bioactive glass-ceramic scaffolds using Computed micro Tomography (μ CT) imaging. The main purpose of this work is to quantify the effect of sintering temperature on the morphometry and mechanical performance of the scaffolds. In particular, the scaffolds were produced using a novel bioactive glass material (47.5B) through foam replication, applying six different sintering temperatures. Through μ CT imaging, detailed three-dimensional images of the scaffold’s internal structure are obtained, enabling the extraction of important geometric features and how these features change with sintering temperature. A finite element model is then developed based on the μ CT images to simulate the fracture process under uniaxial compression loading. The model incorporates scaffold heterogeneity and material properties—also depending on sintering temperature—to capture the mechanical response, including crack initiation, propagation, and failure. Scaffolds sintered at temperatures equal to or higher than 700 ∘ C exhibit two-scale porosity, with micro and macro pores. Finite element analyses revealed that the dual porosity significantly affects fracture mechanisms, as micro-pores attract cracks and weaken strength. Interestingly, scaffolds sintered at high temperatures, the overall strength of which is higher due to greater intrinsic strength, showed lower normalized strength compared to low-temperature scaffolds. By using a combined strategy of finite element simulation and μ CT-based characterization, bioactive glass-ceramic scaffolds can be optimized for bone tissue engineering applications by learning more about their micromechanical characteristics and fracture response

Seasonal dynamics of active SAR11 ecotypes in the oligotrophic Northwest Mediterranean Sea

A seven-year oceanographic time series in NW Mediterranean surface waters was combined with pyrosequencing of ribosomal RNA (16S rRNA) and ribosomal RNA gene copies (16S rDNA) to examine the environmental controls on SAR11 ecotype dynamics and potential activity. SAR11 diversity exhibited pronounced seasonal cycles remarkably similar to total bacterial diversity. The timing of diversity maxima was similar across narrow and broad phylogenetic clades and strongly associated with deep winter mixing. Diversity minima were associated with periods of stratification that were low in nutrients and phytoplankton biomass and characterised by intense phosphate limitation (turnover time80%) by SAR11 Ia. A partial least squares (PLS) regression model was developed that could reliably predict sequence abundances of SAR11 ecotypes (Q2=0.70) from measured environmental variables, of which mixed layer depth was quantitatively the most important. Comparison of clade-level SAR11 rRNA:rDNA signals with leucine incorporation enabled us to partially validate the use of these ratios as an in-situ activity measure. However, temporal trends in the activity of SAR11 ecotypes and their relationship to environmental variables were unclear. The strong and predictable temporal patterns observed in SAR11 sequence abundance was not linked to metabolic activity of different ecotypes at the phylogenetic and temporal resolution of our study