1,721,022 research outputs found
The late-Antiquity environmental crisis in Emilia Region (Po river plain, Northern Italy): geoarchaeological evidence and paleoclimatic considerations
No full textFor about four decades in Italy local, scientific literature has occasionally dealt with fluvial avulsions, suggesting they should be considered as genetically linked to a peculiar climatic worsening that occurred in the late-6th century AD (the so-called “Paul the Deacon Deluge”). Research performed by the Soprintendenza per i Beni Archeologici dell’Emilia-Romagna over the last few years has allowed us to better define the timing of a more articulated alluvial history, mainly concerning the Roman Imperial age and Late-Antiquity (1st-6th century AD). The main stratigraphic details of fourteen selected archaeological excavation sites (eleven recently surveyed and three reviewed from the literature) performed in the cities of Modena, Bologna and related surroundings have been summarized. Eleven 14C datings, ranging between the years 130 AD and 810 AD, allowed us to chronologically delimit a first frame for the riverbed network behaviour during ancient times in the central part of the region. The alluvial process appeared to be continuous throughout the time span examined. The fan trench was the most sensitive reach of the river system. It started to aggrade during the 4th century AD, during the 5th century AD and probably after the end of the 6th century AD, a number of avulsions occurred. This indicates that the fluvial system was in a metastable equilibrium whose behavioural threshold was finally overcome. Hence, the importance of the supposed year 589 AD crisis (the “Deluge”) appears to be less than that previously supposed. The riverbed aggradation became evident immediately after the Roman empire’s economic and demographic crisis of the 3rd century AD, and it was probably due to the loss of the land preservation systems once created in the mountain catchment areas. The long duration of the aggradation phase suggests that more than one human settlement phase in the minor catchment areas and/or a minor climatic worsening pulse probably occurred during the 5th century AD. The starting of the aggradation also coincided with the end of the Petit Maclu 1 high level phase of the European lakes. Notwithstanding this, the climate’s role as a forcing co-factor can still be hard to evaluate positively due to the lack of local climatic proxy data
Oltre la sepoltura. Testimonianze rituali ed evidenze sociali dalla superficie d’uso della necropoli della Terramara di Casinalbo (MO
No full textThe study of Casinalbo necropolis (Modena), the largest Terramare burial site (about 670 tombs exvated), revealed unknown types of funerary rituals. The necropolis was in use from 1500 to 1150 BC and it is characterized by the exclusive use of cremation. The majority of the graves are urns without any content except for the cremated bones of the deceased. A few ornaments have been found in some female or subadult graves. Weapons are absent from male graves which are also lacking of any funerary offerings (Ma non c’era qualche rasoio?). Detailed analysis of the items found on the upper surface of the necropolis has led to the identification of areas of concentration of bronze objects (weapons and ornaments) and pottery drinking vessels which suggest that rituals were performed after the cremation ceremony. The objects were crushed and placed in a specific order. Some weapons, especially swords, were placed around the centre of the ritual area, while ornaments and other weapons (daggers) were placed toward the periphery. This pattern stands for the non egalitaran character of Terramare’s burial sites, pointing out social distinctions based on rank where individuals armed with swords held the highest social positions, similarly to coeval Olmo di Nogara necropolis (Verona), where conversely the sword was placed inside the burial
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Analysis of Absence Seizure Generation using EEG Spatial-temporal Regularity Measures
Full text linkEpileptic seizures are generated and evolve through an underlying anomaly of synchronization in the
activity of groups of neuronal populations. The related dynamic scenario of state transitions is revealed
by detecting changes in the dynamical properties of Electroencephalography (EEG) signals. The recruit-
ment procedure ending with the crisis can be analyzed by means of a spatial-temporal plot from which
to extract suitable descriptors that are able to monitor and quantify the evolving synchronization level
from the EEG tracings. In this paper, a spatial-temporal analysis of EEG synchronization based on the
concept of Permutation Entropy (PE) is proposed. The performance of PE are tested on a database of 24
patients affected by absence (generalized) seizures. The results achieved are compared to the dynamical
behavior of the EEG of 40 healthy subjects. Being PE a feature which is dependent on two-parameters,
an extensive study of the sensitivity of the performance of PE with respect to the parameters’ setting
was carried out on scalp EEG. Once the optimal PE configuration was determined, its ability to detect
the different brain states was evaluated. One relevant result of the study is that, in contrast to the widely
accepted interpretation of the transition to absence seizure as an abrupt change, within the limits of the
analyzed database, the “jump” transition to the epileptic status is heralded well before the seizure on-
set. Indeed, ever since the interictal stages, the frontal-temporal scalp areas appear constantly associated
to PE levels that are higher compared to the remaining electrodes, whereas the parieto-occipital areas
appear associated to lower-PE values. The EEG of healthy subjects does not show any similar dynamic
behavior nor exhibits any recurrent portrait in PE topography
Formigine, loc. Casinalbo. Gli scavi nelal necropoli dell'età del bronzo. Notizie preliminari sulle campagne di scavo 1997/1998
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