Search results for " trees."
showing 10 items of 207 documents
Evolution of worldwide stock markets, correlation structure and correlation based graphs
2011
We investigate the daily correlation present among market indices of stock exchanges located all over the world in the time period Jan 1996 - Jul 2009. We discover that the correlation among market indices presents both a fast and a slow dynamics. The slow dynamics reflects the development and consolidation of globalization. The fast dynamics is associated with critical events that originate in a specific country or region of the world and rapidly affect the global system. We provide evidence that the short term timescale of correlation among market indices is less than 3 trading months (about 60 trading days). The average values of the non diagonal elements of the correlation matrix, corre…
Tradizioni carnevalesche a Mezzojuso: dal Mastro di Campo al rogo del Nannu
2023
Il Mastro di Campo di Mezzojuso è una performance carnevalesca tradizionale che presenta un articolato simbolismo rituale riconducibile al pattern delle cerimonie di capodanno. In particolare si osservano il tema della ierogamia e della lotta rituale come elementi di promozione della fecondità. Ambedue i simboli rituali, la rappresentazione di una danza o di uno scontro armato, con l'eventuale coinvolgimento degli astanti e la celebrazione di un matrimonio, correlati o disgiunti, sono, come è noto, costitutivi ab antico delle cerimonie di capodanno, segnatamente di quelle primaverili. Altri rituali carnevaleschi europei hanno una simile articolazione. Il saggio presenta una serie di esempi …
Development of a nutritional HACCP plan.
2002
Predicting and mapping human risk of exposure to
2019
Background Tick-borne diseases have become increasingly common in recent decades and present a health problem in many parts of Europe. Control and prevention of these diseases require a better understanding of vector distribution. Aim Our aim was to create a model able to predict the distribution of Ixodes ricinus nymphs in southern Scandinavia and to assess how this relates to risk of human exposure. Methods We measured the presence of I. ricinus tick nymphs at 159 stratified random lowland forest and meadow sites in Denmark, Norway and Sweden by dragging 400 m transects from August to September 2016, representing a total distance of 63.6 km. Using climate and remote sensing environmental …
Growth and physiological responses of young olive trees affected by Olive leaf yellowing associated virus
2017
We studied the effect of Olive leaf yellowing associated virus (OLYaV) on biometric and physiological changes in olive. The trial was carried out on 32 two-yearold virus-free trees of 'Frantoio' grafted on virus-free olive seedlings and grown in 32-L pots. Half of the trees were inoculated with OLYaV in the fall of 2007. At 6, 18, and 24 months after inoculation, tree height, basal trunk diameter and total leaf number were determined, and leaf area tree-1 was estimated from a 50-leaf subsample. Twigs of various order were also counted and measured. At the end of the experiment, dry matter partitioning, leaf gas exchange and water potential were also measured. Total twig length and number, t…
IL RUOLO DELL’OLEASTRO INVEGES DI SCIACCA NELLA DEFINIZIONE DEL PAESAGGIO FORESTALE STORICO DELLA SICILIA
2016
L’oleastro, Olea europaea var. sylvestris (Mill.) Lehr, è uno delle componenti rappresentative della vegetazione mediterranea. Specie considerata caratteristica della macchia (Oleo-Ceratonion siliquae Br.-Bl. ex Guinoch. e Drouin. 1944) si accompagna con altre sclerofille e specie caducifoglie estive con le quali forma aspetti di vegetazione alto arbustiva o arborescente. Ma l’oleastro in Sicilia è anche un elemento di boschi termofili, di territori che presentano una certa xericità ambientale, potenzialmente diffusi in un’ampia fascia altimetrica che si estende dalla costa fino a 800-1000 m di quota. In tale contesto, l’oleastro si accompagna con querce caducifoglie termofile, quali Quercu…
Predicting the environmental suitability for onchocerciasis in Africa as an aid to elimination planning
2021
Recent evidence suggests that, in some foci, elimination of onchocerciasis from Africa may be feasible with mass drug administration (MDA) of ivermectin. To achieve continental elimination of transmission, mapping surveys will need to be conducted across all implementation units (IUs) for which endemicity status is currently unknown. Using boosted regression tree models with optimised hyperparameter selection, we estimated environmental suitability for onchocerciasis at the 5 × 5-km resolution across Africa. In order to classify IUs that include locations that are environmentally suitable, we used receiver operating characteristic (ROC) analysis to identify an optimal threshold for suitabil…
Does an optimal therapeutic sequence exist in advanced non-small cell lung cancer?
2008
A growing percentage of patients affected by advanced non-small cell lung cancer who progressed after first-line chemotherapy still have a good performance status and require second-line treatment.An overview of the state of the art of second-line therapeutic options is presented.The scope of the review is to give an update on the therapeutic options currently available for the second-line treatment of patients with advanced non-small cell lung cancer.Among chemotherapeutic drugs docetaxel and pemetrexed have been approved for second-line treatment of advanced non-small cell lung cancer. Although the drugs are equiactive in terms of response rate and survival parameters the latter has a cle…
Hundreds of nuclear and plastid loci yield novel insights into orchid relationships.
2021
Pérez-Escobar, Oscar Alejandro, Dodsworth, Steven, Bogarín, Diego, Bellot, Sidonie, Balbuena, Juan A, Schley, Rowan J, Kikuchi, Izai A, Morris, Sarah K, Epitawalage, Niroshini, Cowan, Robyn, Maurin, Olivier, Zuntini, Alexandre, Arias, Tatiana, Serna-Sánchez, Alejandra, Gravendeel, Barbara, Torres Jimenez, Maria Fernanda, Nargar, Katharina, Chomicki, Guillaume, Chase, Mark W, Leitch, Ilia J, Forest, Félix, Baker, William J (2021): Hundreds of nuclear and plastid loci yield novel insights into orchid relationships. American journal of botany 108 (7): 1166-1180, DOI: http://doi.org/10.5281/zenodo.7778176
Comparing Boosting and Bagging for Decision Trees of Rankings
2021
AbstractDecision tree learning is among the most popular and most traditional families of machine learning algorithms. While these techniques excel in being quite intuitive and interpretable, they also suffer from instability: small perturbations in the training data may result in big changes in the predictions. The so-called ensemble methods combine the output of multiple trees, which makes the decision more reliable and stable. They have been primarily applied to numeric prediction problems and to classification tasks. In the last years, some attempts to extend the ensemble methods to ordinal data can be found in the literature, but no concrete methodology has been provided for preference…