1,721,005 research outputs found
A Short Note on the Recent Taxonomic Developments and Molecular Findings on the Cyprian Mouflon (Ovis GmeliniOphion) and the Sardinian Mouflon (Ovis Gmelini Musimon)
Full text linkUse of BEST procedure to assess soil physical quality in the baratz lake catchment (Sardinia, Italy)
No full textConversion of Mediterranean maquis and/or natural forest into agro-pastoral lands is a cause of soil degradation in many Mediterranean areas. Indicators of soil physical quality (SPQ) quantitatively linked to soil hydraulic properties are a valuable tool to assess the effect of land use changes. In this investigation, the Beerkan Estimation of Soil Transfer parameters (BEST) procedure for soil hydraulic characterization was used to estimate SPQ indicators. Four areas of the Baratz Lake watershed, Sardinia, Italy, characterized by both typical natural vegetation (holm oak [Quercus ilex L.] forest and high maquis) and degraded vegetation (grassland established after fire or clearing of the maquis) were considered. The SPQ was assessed by either independently measured soil physical attributes, like soil bulk density, organic C content, saturated hydraulic conductivity, and sorptivity, and capacitive and dynamic indicators calculated from the water retention curve estimated by the BEST procedure. Measured and estimated SPQ indicators unanimously showed that clearing of the maquis caused a severe deterioration of SPQ associated with soil compaction, organic matter loss, and decrease of macropore volume and soil aeration capacity as well as reduced water circulation. A different and unexpected result was obtained for the fire-affected area, where the SPQ was comparable to that of the neighboring oak forest area. We deduced that vegetation restoration after fire passage contributed to maintain a high organic matter content and to mitigate rain compaction effects. We concluded that SPQ indicators derived by applying the BEST procedure are suitable to detect land degradation in the natural environments studied
First mtDNA sequences and body measurements for Rattus norvegicus from the mediterranean island of Cyprus
No full textInvasive species are the primary driver of island taxa extinctions and, among them, those belonging to the genus Rattus are considered as the most damaging. The presence of black rat (Rattus rattus) on Cyprus has long been established, while that of brown rat (Rattus norvegicus) is dubious. This study is the first to provide molecular and morphological data to document the occurrence of R. norvegicus in the island of Cyprus. A total of 223 black rats and 14 brown rats were collected. Each sample was first taxonomically attributed on the basis of body measurements and cranial observations. Four of the specimens identified as R. norvegicus and one identified as R. rattus were subjected to molecular characterization in order to corroborate species identification. The analyses of the mitochondrial control region were consistent with morphological data, supporting the taxonomic identification of the samples. At least two maternal molecular lineages for R. norvegicus were found in Cyprus. The small number of brown rats collected in the island, as well as the large number of samples of black rats retrieved in the past years might be an indication that the distribution of R. norvegicus is still limited into three out of the six districts of Cyprus
Prevalence And Incidence Study On Multiple Sclerosis In The Discrict Of Tempio, Sardinia, 1960-1986
No full textSimulazione del deflusso laterale saturo, dei livelli di falda e dell'umidità del suolo alla scala di versante
No full textLa corretta rappresentazione dei processi idrologici alla scala di versante è fon-damentale per la simulazione della risposta idrologica dei bacini idrografici durante eventi di pioggia intensa. I modelli basati sulla risoluzione dell’equazione di Richards possono simulare efficacemente le dinamiche della zona satura e non satura del suolo. Tuttavia essi richiedono una parametrizzazione onerosa, difficile da rilevare sperimentalmente sopratutto su ampie scale spaziali di applicazione. In questo lavoro di ricerca è stato sviluppato un modello idrologico monodimensionale di versante, in cui i processi di flusso laterale di falda sono rappresentati attraverso l’equazione di Darcy, mentre sono trascurati i processi dinamici nella zona non satura del suolo. L’effetto della ritenzione idrica capillare nella zona non satura è incorporato nel modello attraverso il termine della porosità drenabile del suolo che varia non linearmente in funzione della profondità della falda. A riguardo, l’assunto principale per la determinazione della porosità drenabile è che l’umidità nella zona non satura del suolo raggiunga istantaneamente la condizione di equilibrio idrostatico rispetto alla linea di falda. Il modello è stato applicato per la simulazione dell’andamento temporale del deflusso sottosuperficiale, dell’umidità del suolo e dei livelli di falda osservati in un ripido versante nel bacino idrografico del Lago di Baratz, in Sardegna. I parametri del modello, relativi alla trasmissività idraulica laterale e alle proprietà di ritenzione idrica del suolo, sono stati ricavati a partire dai dati idrologici raccolti. La calibrazione del modello è stata quindi limitata alle sole perdite idriche dovute a flussi laterali uscenti dal versante, di difficile quantificazione speri-mentale.
Le performance predittive del modello sono risultate soddisfacenti, come con-fermato da coefficienti di efficienza di Nash-Sutcliffe prossimi a 0.8 per tutte le variabili idrologiche simulate. L'umidità del suolo, i livelli di falda e il deflusso sottosuperficiale sono stati ben riprodotti in termini di tempistica della risposta idrologica durante i periodi piovosi e di velocità di esaurimento nei periodi asciutti. Il modello sviluppato può essere effettivamente utilizzato per predire la risposta idrologica nei versanti naturali
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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