1,721,198 research outputs found
The Colosseum's use and state of abandonment as analysed through its flora
No full textOver the past four centuries, different lists of the flora of the Colosseum have been published. The rich plant colonization (684 species, as the sum of the various lists) appears to be due to the great variety of habitats in the monument and to its state of abandonment. The comparison among the different floras allows a quantitative estimate of the following general changes to be determined: a gradual yet notable decrease of typical elements of mature dynamic stages; a constant decrease in species related to grazing and animal droppings, as well as in weeds from cultivated fields; and a constant increase of widely distributed and alien species, indicators of a different but ever stronger impact of man on the area
Analyses of the Colosseum's floristic changes during the last four centuries.
No full textDifferent floristic lists of the Colosseum have been carried out
starting from the XVII century (PANAROLI, 1643; SEBASTIANI, 1815; DEAKIN,
1855; FIORINI MAZZANTI, 1874; ANZALONE, 1951; and recently CELESTI
GRaPOW et al., 2001). The comparison among these investigations reveals the
rich plant colonisation, due to the great variety of habitats present in the
monument and to its state of abandon. The maximum peak of 418 species can
be referred in Deakin s list, and the minimum are the current 242 species,
mainly distributed in the hypogeans. The total amount of colonising species in
time was 684 vascular plants. The species listed for the monument in all the
studies are 135, and all the common ones are 192. These are mainly herbaceous
plants of ruderal habitats, widely distributed in more or less nitrophylous
pastures or pioneer on rocks and walls. 426 species were enumerated before the
XX century and later disappeared from the places. 117 species no longer belong
to the Roman flora, and 24 species are no longer listed in the regional flora.
These were mainly herbaceous and woody species typical of dynamically
developed stages, belonging to forest and border line communities. Typical
species of very disturbed habitats are also frequent. 66 species were cohected
only in more recent times. These belong to the synanthropic flora, though tess
nitrophylous compared with the previous, or are cultivated plants capable of
becoming spontaneous under favourable conditions. The comparison among
the different floras indicates not only the change in use of the monument, but
also that climatic and microclimatic changes occurred in the last centuries. The
relative biological and chorological spectra confirm the progressive warming
and average reduction of humidity of the site
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
Analisi delle trasformazioni del mosaico ambientale nel comune di Ariccia mediante l’impiego di indici topologici.
No full textPlants and Cultural Heritage: botanical investigations in the Roman archaeological sites
No full text
Accelerating Data Set Population for Training Machine Learning Potentials with Automated System Generation and Strategic Sampling
Full text linkMachine Learning Interatomic Potentials (MLIPs) offer a powerful way to overcome the limitations of ab initio and classical molecular dynamics simulations. However, a major challenge is the generation of high-quality training data sets, which typically require extensive ab initio calculations and intensive user intervention. Here, we introduce Strategic Configuration Sampling (SCS), an active learning framework to construct compact and comprehensive data sets for MLIP training. SCS introduces the usage of workflows for the automated generation and exploration of systems, collections of MD simulations where geometries and run conditions are set up automatically based on high-level, user defined inputs. To explore nontrivial atomic environments, initial geometries can be assembled dynamically via collaging of structures harvested from preceding runs. Multiple automated exploration workflows can be run in parallel, each with its own resource budget according to the computational complexity of each system. Besides leveraging the MLIP models trained iteratively, SCS also incorporates pretrained models to steer the exploration MD, thereby eliminating the need for an initial data set. By integrating widely used software, SCS provides a fully open-source, automatic, active learning framework for the generation of data sets in a high-throughput fashion. Case studies demonstrate its versatility and effectiveness to accelerate the deployment of MLIP in diverse materials science applications
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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