1,721,102 research outputs found
Impact of glacier fluctuations and high altitude mining activities on Late glacial- Holocene proglacial lacustrine sedimentation in the Grandes Rousses Massif, Western Alps, France
Full text linkARE STABLE ISOTOPES OF LACUSTRINE CARBONATE A GOOD TRACER OF LAKE HYDROLOGY AND LAKE LEVEL VARIABILITY? THE LAKE LEDRO CASE (NORTHERN ITALY)
No full textOxygen and carbon isotopes were analysed on bulk samples and carbonate concretions from Lake Ledro, northern Italy, with the aim to assess their suitability as reliable proxy of the hydrological changes in the lake. For this purpose, isotopic composition of bulk marls and concretions were compared to lake level reconstruction obtained with sedimentological approach. The δ18Cbulk record mostly mirrors the δ18Obulk record, while carbon and oxygen isotopes from concretions are not correlated. We found that there is a statistically significant correlation between the oxygen and carbon isotopic record of the bulk carbonate and lake level changes, with the positive changes in lake level corresponding to lower values on δ18Obulk and δ13Cbulk and vice versa. Assuming that most of the bulk carbonate is formed by bio-induced calcite precipitation, this means that this kind of carbonate reflects the local hydrological condition of the lake water better than lacustrine concretions, which instead are more affected by local conditions of precipitation like biological plant activity
Bravard J.-P., Magny M. dir. (2002) - Les fleuves ont une histoire. Paléoenvironnement des rivières et des lacs français depuis 15000 ans
No full textCampy Michel. Bravard J.-P., Magny M. dir. (2002) - Les fleuves ont une histoire. Paléoenvironnement des rivières et des lacs français depuis 15000 ans. In: Bulletin de la Société préhistorique française, tome 100, n°2, 2003. p. 413
The transition from natural to anthropogenic -dominated environmental change in Italy and the surrounding regions since the neolithic
No full textCuratela del volume 303 della rivista Quaternary Internationa
The Holocene climatic evolution of the Mediterranean Italy: a review of the geological continental data
No full textWe present a synthesis of geological, stratigraphic, geomorphological and stable isotope data collected from continental archives to highlight the environmental and climatic differences between the first and second half of the Holocene of central and southern Italy. The beginning of the Holocene is marked by rapid environmental change. In Mediterranean Italy, between c. 9500 cal. BP and c. 6000-5500 cal. BP, average temperatures were probably higher and environmental conditions were generally stable; between c. 9000 and 7000 cal. BP, meteoric precipitation was at its highest. The end of the wetter period seems to occur later, at c. 6000-5000 cal. BP. Since c. 6000-5000 cal. BP, rapid climatic excursions are apparent in different palaeoclimate proxies, with both variability in meteoric precipitation and temperature evident. Of particular relevance is the event occurring at c. 4200 cal. BP. This event heralds a period of significant environmental change in the Apennines and, more generally, in central Italy. Following this event, environmental variability appears most pronounced and frequent. Some environmental changes during the early Holocene and after 4200 cal. BP seem to be in phase with IRD events in the North Atlantic, which suggest: (1) teleconnections between North Atlantic and Mediterranean areas; and (2) a possible influence of North Atlantic meridional overturning circulation in controlling the advection of moisture over the central Mediterranean basin via westerly air masses. The archives used in this review allow us to consider climate evolution as a driver of most of the observed environmental change
The transition from natural to anthropogenic-dominated environmental change in Italy and the surrounding regions since the Neolithic: An introduction
No full textArticolo introduttivo di volume speciale. Non ha l'abstract tra i suoi attribut
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
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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