Search results for "Trees"
showing 10 items of 312 documents
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…
Forest management optimization across spatial scales to reconcile economic and conservation objectives
2019
Conflicts between biodiversity conservation and resource production can be mitigated by multi-objective management planning. Optimizing management for multiple objectives over larger land areas likely entails trading off the practicability of the process against the goodness of the solution. It is therefore worthwhile to resolve how large areas are required as management planning regions to reconcile conflicting objectives as effectively as possible. We aimed to reveal how the extent of forestry planning regions impacts the potential to mitigate a forestry-conservation conflict in Finland, represented as a trade-off between harvest income and deadwood availability. We used forecasted data f…
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…
Diversity and Evolution of papillomaviruses
2017
1.1. Introducción Con el fin de averiguar las causas de las devastadoras epidemias de finales del siglo XIX, se llevaron a cabo diferentes estudios que dieron como resultado la identificación de unos nuevos agentes infecciosos, para los que se acuñó el nombre de “virus”. Desde entonces el descubrimiento de nuevos virus ha sido incesante, lo que llevó, en los años 70, a la creación de un organismo encargado de desarrollar, refinar y mantener la clasificación taxonómica de los virus, el Comité Internacional de Taxonomía Viral (ICTV), en el seno de la Unión Internacional de Sociedades Microbiológicas (IUMS). En 2014 este organismo había reconocido 3.186 especies virales pertenecientes a 104 fa…
Treed Gaussian Process Regression for Solving Offline Data-Driven Continuous Multiobjective Optimization Problems
2023
Abstract For offline data-driven multiobjective optimization problems (MOPs), no new data is available during the optimization process. Approximation models (or surrogates) are first built using the provided offline data and an optimizer, e.g. a multiobjective evolutionary algorithm, can then be utilized to find Pareto optimal solutions to the problem with surrogates as objective functions. In contrast to online data-driven MOPs, these surrogates cannot be updated with new data and, hence, the approximation accuracy cannot be improved by considering new data during the optimization process. Gaussian process regression (GPR) models are widely used as surrogates because of their ability to pr…
Cost-Effectiveness Analysis: Stress Ulcer Bleeding Prophylaxis with Proton Pump Inhibitors, H2 Receptor Antagonists
2012
Abstract Objectives Proton pump inhibitors (PPIs) and H2-receptor antagonists (H2RAs) present varying pharmacological efficacy in preventing stress ulcer bleeding (SUB) in intensive care units. The literature also reports disparate rates of ventilator-assisted pneumonia (VAP) as side effects of these treatments. We compared the cost-effectiveness of these two prophylactic pharmacological options. Methods We constructed a decision tree with a 60-day time horizon for patients at high risk for developing SUB, receiving either PPIs or H2RAs. For each treatment strategy, patients could be in one of three states of health: SUB, VAP, or no complication. Contemporary, clinically relevant probabilit…