Ancient reality and contemporary research. An introduction to the Conference KAINUA 2017 and its Proceedings

Introduction to the International Conference KAINUA 201

A brain-constrained deep neural-network model that can account for the readiness potential in self-initiated volitional action

The readiness potential (RP) is a gradual buildup of negative electrical potential over the motor cortices prior to onset of a self-initiated movement. It is typically interpreted as having a goal-directed nature, whereby it signals movement planning and preparation. However, a similar buildup can also be observed by averaging continuous random neural fluctuations aligned to crests in their time series [1]. Therefore, an alternative account of the RP is that it reflects ongoing background neuronal noise that has at least a small influence on the precise time of movement onset [2]. While computational modelling studies were used in the past to adjudicate between these accounts, previous attempts did not employ a fully neuroanatomically and neurobiologically realistic architecture, hence falling short of providing a cortical-level mechanistic validation of either theory. Here, we investigated the stochastic origin of the RP by applying a fully brain-constrained deep neural-network model reproducing real cortical neurons dynamics and the structure and connectivity of relevant primary sensorimotor, secondary and association areas of the frontal and temporal lobes. This model has been previously used to account for the neuromechanistic origins and cortical topography of volitional decisions to speak and act [3]. We used the emergent feature of this neural architecture – its ability to exhibit noise-driven periodic spontaneous ignitions of previously learnt internal representations (cell assemblies, CAs, circuits of strongly and reciprocally connected cells distributed across the entire network) – to mimic spontaneous decisions to act as observed in the classical Libet experiment. Specifically, we recorded the network’s activity for 2,000 trials, each trial beginning with a network reset and lasting until the spontaneous ignition of one of the CAs occurred, and used the time interval between trial start and spontaneous CA ignition as a model correlate of waiting times. We found that the model data accounted well for the experimental waiting-time distribution. Furthermore, in line with the stochastic interpretation of the RP, appropriate calibration of the model parameters resulted in subthreshold reverberation of activity within CA circuits, and averaging across cell assemblies’ ignition episodes produced a curve that closely matched the gradual buildup of activity observed in the experimental RP and its onset time. There are various neurophysiological sources of ongoing noise that result from neural activity. Some of this noise might accumulate and reverberate within previously acquired perception-action circuits, and, hence, produce spontaneous action. The present simulation results, obtained with a fully brain-constrained neural architecture, provide further support for this alternative view, placing the classical explanation of the RP further under scrutiny. References 1. Schurger A, Sitt J, Dehaene S. An accumulator model for spontaneous neural activity prior to self-initiated movement. Proc Natl Acad Sci USA. 2012, 109(42), E2904-E2913 2. Schurger A, Mylopoulos M, Rosenthal D. Neural antecedents of spontaneous voluntary movement: a new perspective. TiCS. 2016, 20(2), 77-79 3. Garagnani M, Pulvermüller F. Neuronal correlates of decisions to speak and act: Spontaneous emergence and dynamic topographies in a computational model of frontal and temporal areas. Brain and Language. 2013, 127, 75-85. Eu J Neurosci. 2008, 27(2), 492-51

Caratterizzazione microstrutturale e prove di resilienza su giunti Friction Stir Welding e Linear Friction Welding di compositi a matrice metallica

In questo studio sono stati caratterizzati giunti Friction Stir Welding e Linear Friction Welding su compositi a matrice in lega di alluminio e rinforzo particellare ceramico. Il processo FSW è stato applicato a due compositi ottenuti con processo fusorio, quindi estrusi e trattati termicamente T6: AA6061/20%vol.Al2O3p e AA7005/10%vol.Al2O3p. I giunti LFW sono stati invece realizzati su un composito con matrice in lega di alluminio e rinforzo particellare in carburo di silicio, ottenuto mediante metallurgia delle polveri, quindi forgiato e trattato termicamente T4: AA2124/25%vol.SiCp. Sono stati esaminati gli effetti della saldatura sullecaratteristiche microstrutturali dei giunti, avvalendosi di tecniche di microscopia ottica con analisi di immagine e di microscopia elettronica in scansione (SEM) con microsonda a dispersione di energia (EDS). Sono state quindi condotte prove di resilienza con pendolo strumentato Charpy. Lo studio dei meccanismi di danneggiamento è stato effettuato mediante analisi al SEM delle superfici di frattura. Entrambi i processi di saldatura hanno portato a giunti sostanzialmente esenti da difetti. La microstruttura dei cordoni è risultata dipendente sia dalle caratteristiche microstrutturali iniziali dei compositi considerati, sia dalla tipologia di processo di saldatura. Nel caso dei compositi AA6061/20%Al2O3p e AA7005/10%Al2O3p saldati FSW si è osservato un sostanziale incremento di resilienza, rispetto al materiale base, in conseguenza dell’affinamento dei grani della matrice, della riduzione della dimensione media delle particelle di rinforzo e della loro spigolosità, indotte dal processo di saldatura. Il composito AA2124/25%SiCp saldato LFW ha presentato valori di resilienza confrontabili con quelli del materiale base, in conseguenza, soprattutto, dei limitati effetti della saldatura su dimensione e distribuzione delle particelle di rinforzo

Historical micronutrient psychiatry: descriptive analysis of patients with pellagra admitted to the “San Lazzaro” asylum in Reggio Emilia (Italy) in the decade 1901-1910

This study aims at describing the socio-demographic and clinical characteristics of the patients affected by pellagra and admitted to the “San Lazzaro” psychiatric asylum (Reggio Emilia, Italy) from 1901 to 1910 besides exploring possible gender differences for the collected information. Data were collected from the admission register and clinical records of those patients who were admitted to the San Lazzaro Psychiatric Hospital receiving a diagnosis of pellagra at their first admission. The pellagrous patient population was characterised by a higher rate of hospitalisation for women (64.3%) and the number of hospitalised patients suffering from pellagra gradually decreased from 1901 (78; 8.3%) to 1910 (8;0.7%). The most common profession for men admitted with pellagra was farmer/agricultural labourer, while most of the women were housewives. A characteristic shared by both the male and female population of inpatients was very high rate of illiteracy: only one patient was recorded as being able to read and write. The generic diagnosis of “mental illness from pellagra” was predominant (70%), while “dementia from pellagra” accounts for 17.85% of the admission diagnoses: no statistically significant differences between men and women were found in the frequency of diagnosis. Half of the patients, both men and women, died while being inpatients. This study confirms previous findings about the case mix of pellagra patients admitted to psychiatric hospital at the beginning of the last century in northern Italy and highlights the significance of the relationship of psychiatry with other medical disciplines and the sociocultural milieu

Shelter from the cytokine storm: pitfalls and prospects in the development of SARS-CoV-2 vaccines for an elderly population

The SARS-CoV-2 pandemic urgently calls for the development of effective preventive tools. COVID-19 hits greatly the elder and more fragile fraction of the population boosting the evergreen issue of the vaccination of older people. The development of a vaccine against SARS-CoV-2 tailored for the elderly population faces the challenge of the poor immune responsiveness of the older population due to immunosenescence, comorbidities, and pharmacological treatments. Moreover, it is likely that the inflammaging phenotype associated with age could both influence vaccination efficacy and exacerbate the risk of COVID-19-related “cytokine storm syndrome” with an overlap between the factors which impact vaccination effectiveness and those that boost virulence and worsen the prognosis of SARS-CoV-2 infection. The complex and still unclear immunopathological mechanisms of SARS-CoV-2 infection, together with the progressive age-related decline of immune responses, and the lack of clear correlates of protection, make the design of vaccination strategies for older people extremely challenging. In the ongoing effort in vaccine development, different SARS-CoV-2 vaccine candidates have been developed, tested in pre-clinical and clinical studies and are undergoing clinical testing, but only a small fraction of these are currently being tested in the older fraction of the population. Recent advances in systems biology integrating clinical, immunologic, and omics data can help to identify stable and robust markers of vaccine response and move towards a better understanding of SARS-CoV-2 vaccine responses in the elderly

Metallurgical and statistical approaches to the study of cast iron street furniture

The evolution of microstructure in relation to dating and nationality of origin was investigated in twenty-four cast iron objects of street furniture produced between XIX and XX centuries in United Kingdom, France, and Italy. Chemical composition of the metalworks was evaluated by glow-discharge optical emission spectrometry. Fragments from the cast irons were analyzed by optical microscopy and scanning electron microscopy with energy-dispersive spectroscopy. Form, distribution, and size of graphite were evaluated in the microstructure according to standard EN ISO 945-1:2008. An image analysis software was employed to quantify the area fraction of graphite in the matrix, major axis, and shape factor of graphite lamellae, area fraction of manganese sulfides (ψS), area fraction of steadite, and number of eutectic cells per area unit. All data were grouped and linear discrimination analysis (LDA) was applied to assess the group assignment and the probability of correct classification for each metalwork. The results showed that the microstructural features were compatible with those of cast irons produced in the XIX and XX centuries. Values of ψS also suggested re-melting of cast irons, associated with recycling of cast iron and/or steel scraps. The high values of steadite found in the metalworks are probably due to the excellent castability required for complex shape castings in these centuries. The LDA multivariate analysis allowed to discriminate cast irons based on the year of manufacturing and the nationality of origin

ArchaeoBIM: dallo scavo al Building Information Modeling di una struttura sepolta. Il caso del tempio tuscanico di Uni a Marzabotto

The model of the Tuscanic Temple of Uni in Marzabotto, recently discovered, has been a common ground for engineering and archaeological studies, thanks to the processing of a Building Information Modeling (BIM). Beside the historic and archaeological analysis, the innovation of this study concerns the examination of the Etruscan temple as a three-dimensional building, with the use of technologies which impact on the architectural reliability of the model, and the design of a new method of Experimental Archaeology based on a virtual approach. The uniqueness of this approach lies in the study of original elements at the starting point of the building process, that consist in foundations or spoliated structures (i.e. negative evidences), over the clues from the historical and scientific literature. To better define this distinctive working process, the expression ArchaeoBIM has been proposed. With this expression we underline the common BIM matrix in the data management through integrated analytical models, applied to a particular aspect of the archaeological research

Gut microbiota ecology: Biodiversity estimated from hybrid neutral-niche model increases with health status and aging

In this work we propose an index to estimate the gut microbiota biodiversity using a modeling approach with the aim of describing its relationship with health and aging. The gut microbiota, a complex ecosystem that links nutrition and metabolism, has a pervasive effect on all body organs and systems, undergoes profound changes with age and life-style, and substantially contributes to the pathogenesis of age-related diseases. For these reasons, the gut microbiota is a suitable candidate for assessing and quantifying healthy aging, i.e. the capability of individuals to reach an advanced age, avoiding or postponing major age-related diseases. The importance of the gut microbiota in health and aging has been proven to be related not only to its taxonomic composition, but also to its ecological properties, namely its biodiversity. Following an ecological approach, here we intended to characterize the relationship between the gut microbiota biodiversity and healthy aging through the development a parsimonious model of gut microbiota from which biodiversity can be estimated. We analysed publicly available metagenomic data relative to subjects of different ages, countries, nutritional habits and health status and we showed that a hybrid niche-neutral model well describes the observed patterns of bacterial relative abundance. Moreover, starting from such ecological modeling, we derived an estimate of the gut microbiota biodiversity that is consistent with classical indices, while having a higher statistical power. This allowed us to unveil an increase of the gut microbiota biodiversity during aging and to provide a good predictor of health status in old age, dependent on life-style and aging disorders

The genetic variability of APOE in different human populations and its implications for longevity

Human longevity is a complex phenotype resulting from the combinations of context-dependent gene-environment interactions that require analysis as a dynamic process in a cohesive ecological and evolutionary framework. Genome-wide association (GWAS) and whole-genome sequencing (WGS) studies on centenarians pointed toward the inclusion of the apolipoprotein E (APOE) polymorphisms \u3b52 and \u3b54, as implicated in the attainment of extreme longevity, which refers to their effect in age-related Alzheimer\u2019s disease (AD) and cardiovascular disease (CVD). In this case, the available literature on APOE and its involvement in longevity is described according to an anthropological and population genetics perspective. This aims to highlight the evolutionary history of this gene, how its participation in several biological pathways relates to human longevity, and which evolutionary dynamics may have shaped the distribution of APOE haplotypes across the globe. Its potential adaptive role will be described along with implications for the study of longevity in different human groups. This review also presents an updated overview of the worldwide distribution of APOE alleles based on modern day data from public databases and ancient DNA samples retrieved from literature in the attempt to understand the spatial and temporal frame in which present-day patterns of APOE variation evolved