Un tremisse di transizione con croce trasformata in palma stilizzata (sec. VII)

Talvolta le monete arabo bizantine sono state prodotte da modifiche eseguite su monete autentiche con l’arte del cesello, ma oltre ad esse sono state emesse anche monete prodotte da rielaborazione di coni bizantini obsoleti e da nuovi coni appositamente incisi. Sono noti i solidi d’oro con iscrizioni greche e con l’effigie dell’imperatore Foca, di Eraclio con Eraclio Costantino e di Eraclio, Eraclio Costantino ed Eracleona, che precedono di pochi anni le prime monete d’oro con iscrizioni interamente arabe. Sono note anche le monete globulari nordafricane, con legende latine. L’idea di prendere in approfondita considerazione la serie di monete che si possono definire Arabo-Bizantine è cominciata mezzo secolo fa con gli studi di John Walker e ha ricevuto un nuovo impulso nel settimo Arab-Byzantine Forum che, nel Dumbarton Oaks, ebbe luogo nel 1999

Sylloge of Islamic Coins in the Ashmolean Concordance (and vice versa)

Recently Islamic numismatics has seen a remarkable editorial vivacity. Particularly worth citing are Giulio Bernardi’s Corpus of researches of gold monetization (Arabic Gold Coins), a huge census of publications covering countless auctions, and the Sylloge of coins in the Ashmolean Museum. 4. Later ‘Abbasid Precious Metal coinage (from 219 AH) by Nicol. As there are significant differences in both in the methods used and in the information available, this Index coordinates the contents of both publications and facilitates access to the data of these two essential reference works.Recentemente la numismatica islamica ha conosciuto un periodo di intensa attività editoriale. In particolare sono da citare il corpus di ricerche sulla monetazione aurea ad opera di Giulio Bernardi (Arabic Gold Coins) e il lavoro di Nicol, Sylloge of coins in the Ashmolean Museum. 4. Later ‘Abbasid Precious Metal coinage (from 219 AH). Poiché fra le due opere esistono differenze significative sia di metodo che quanto alle informazioni disponibili, il presente Indice ne coordina i contenuti ed agevola l’accesso ai dati di questi due essenziali strumenti di consultazione

The Language of Dreams: Application of Linguistics-Based Approaches for the Automated Analysis of Dream Experiences

The study of dreams represents a crucial intersection between philosophical, psychological, neuroscientific, and clinical interests. Importantly, one of the main sources of insight into dreaming activity are the (oral or written) reports provided by dreamers upon awakening from their sleep. Classically, two main types of information are commonly extracted from dream reports: structural and semantic, content-related information. Extracted structural information is typically limited to the simple count of words or sentences in a report. Instead, content analysis usually relies on quantitative scores assigned by two or more (blind) human operators through the use of predefined coding systems. Within this review, we will show that methods borrowed from the field of linguistic analysis, such as graph analysis, dictionary-based content analysis, and distributional semantics approaches, could be used to complement and, in many cases, replace classical measures and scales for the quantitative structural and semantic assessment of dream reports. Importantly, these methods allow the direct (operator-independent) extraction of quantitative information from language data, hence enabling a fully objective and reproducible analysis of conscious experiences occurring during human sleep. Most importantly, these approaches can be partially or fully automatized and may thus be easily applied to the analysis of large datasets

Editorial: Local Aspects of Sleep and Wakefulness

No abstract availabl

Local and Widespread Slow Waves in Stable NREM Sleep: Evidence for Distinct Regulation Mechanisms

Previous work showed that two types of slow waves are temporally dissociated during the transition to sleep: widespread, large and steep slow waves predominate early in the falling asleep period (type I), while smaller, more circumscribed slow waves become more prevalent later (type II). Here, we studied the possible occurrence of these two types of slow waves in stable non-REM (NREM) sleep and explored potential differences in their regulation. A heuristic approach based on slow wave synchronization efficiency was developed and applied to high-density electroencephalographic (EEG) recordings collected during consolidated NREM sleep to identify the potential type I and type II slow waves. Slow waves with characteristics compatible with those previously described for type I and type II were identified in stable NREM sleep. Importantly, these slow waves underwent opposite changes across the night, with only type II slow waves displaying a clear homeostatic regulation. In addition, we showed that the occurrence of type I slow waves was often followed by larger type II slow waves, whereas the occurrence of type II slow waves was usually followed by smaller type I waves. Finally, type II slow waves were associated with a relative increase in spindle activity, while type I slow waves triggered periods of high-frequency activity. Our results provide evidence for the existence of two distinct slow wave synchronization processes that underlie two different types of slow waves. These slow waves may have different functional roles and mark partially distinct “micro-states” of the sleeping brain

Brain functional and structural reorganization induced by intensive training and exposition to extreme conditions: a study on professional race-car drivers

The present work was designed to investigate the brain functional and structural correlates subserving top-level performances in highly skilled individuals. Specifically, we studied a particular class of elite athletes exposed to intensive psycho-physical trainings and extremely demanding conditions, namely Formula racing car drivers. As a matter of fact, these athletes ordinarily undergo intensive physical and mental trainings, and are exposed to extreme competitive conditions (e.g., accelerations 0-100 km/h in less than 2 seconds, top speeds up to 360 km/h, need for sustained attention and accurate sensorimotor control, etc.), and therefore represent an exceptional sample to study the brain correlates of skills acquisition. In a first experiment, we used functional magnetic resonance imaging (fMRI) to measure brain activity while professional drivers and a matched group of ‘naïve’ volunteers performed two relatively simple visuo-motor tasks. Three different aspects have been examined to characterize the brain functional organization of these subjects: regional brain response, inter-regional interaction and blood oxygen level dependent (BOLD) signal variability. We demonstrated that, while behavioral performance levels were similar in the two samples, race-car drivers recruited to a smaller extent task-related areas, as compared to naïve drivers. Moreover, professional drivers showed reinforced connections among task-related areas and increased brain operative efficiency as reflected by a higher signal variability. The described results indicate that, during visuo-spatial and motor processing, professional drivers are characterized by distinctive functional correlates, with both ‘quantitative’ and ‘qualitative’ modifications, as compared to naïve drivers. To further explore the brain functional organization developed as a consequence of expertise acquisition of a specific behavior, we designed a second experiment during which ten professional race-car drivers and nine healthy naïve volunteers underwent fMRI scans while presented with four video-clips depicting a Formula One car racing on different official circuits. Analyses of functional brain response and inter-regional interaction revealed that professional drivers were characterized by a stronger recruitment of prefrontal and motor control devoted areas as compared to non-expert drivers. On the other hand, naïve drivers showed a robust response only in brain regions involved in visual information processing. As a matter of fact, previous studies demonstrated that passive observation of complex motor behaviors elicits a brain functional response that essentially overlaps with the one revealed during actual execution of the same activities, but only if the observer has acquired a certain degree of expertise in the specific task. In this perspective, our findings indicate that only professional drivers, that have been trained specifically in car racing, were able to effectively compare their motor repertoire with specific situations presented in a race-car driving task. Finally, we investigated brain anatomical differences between expert and naïve drivers. Specifically, we measured and compared gray matter cortical thickness in the two groups, revealing that professional drivers are characterize by an increased gray matter volume in areas involved in visuo-spatial processing and motor control. Overall, findings described in the present work indicate that skilled race-car drivers are characterized by distinctive functional and structural correlates as compared to ‘common’ individuals with an ordinary driving experience. We concluded that expertise acquisition is founded on a series of plastic changes that allow the storing of new motor and cognitive repertoires and the refinement of the existing ones. Specifically, we demonstrated the existence of at least three different potential markers of superior skills and expertise levels: an increased neural efficiency during relatively simple tasks in which experts show a higher degree of automaticity, a more distributed functional response during passive observation of complex behavior in which only the professional group was specifically trained, and a greater cortical thickness in brain areas devoted to sensorimotor processing