1,337 research outputs found
Wind risk assessment in urban environments: the case of falling trees during windstorm events in Lisbon
Trees bring many benefits to the urban environment. However, they may also cause hazards to human
population, being the major causes of injuries and infrastructural damage during strong wind events. In the
city of Lisbon, strong winds rather frequently result in tree falls, depending on the season and meteorological
conditions. This paper presents a methodology to analyse tree damage due to strong wind events in urban
environments. Each occurrence has been recorded by the Lisbon Fire Brigade and Rescue Services (Regimento de
Sapadores Bombeiros de Lisboa - RSBL). Information provided by RSBL relating to the period of 1990-2005 was
considered along with hourly wind speed and direction, species, fitossanitary conditions and urban parameters.
To ensure that the fallen trees were caused by strong winds, only days with three or more occurrences of fallen
trees were selected. It was found that in summer, northerly winds are responsible for 11% of tree falls, with
winds from other directions (west, southwest and south) responsible for 5%. From autumn to spring, perturbed
weather conditions originating from the west, southwest and south are responsible for 84% of fallen trees.
The majority of tree falls occurred when wind speed surpassed 7 m/s in the six hours prior to their fall. Some
recommendations to the Civil Protection Agency and the Fire Department are presented to improve the mission
of collecting information. This research is a contribution to the assessment of wind risk in Lisbon
Ant Communities along a Gradient of Plant Succession in Mexican Tropical Coastal Dunes
Most of Mexican coastal dunes from the Gulf of Mexico have been severely disturbed by human activities. In the state of Veracruz, the La Mancha Reserve is a very well preserved coastal community of sand dunes, where plant successional gradients are determined by topography. In this study we assessed species richness, diversity and faunal composition of ant assemblages in four plant physiognomies along a gradient of plant succession: grassland, shrub, deciduous forest and subdeciduous forest. Using standardized and non-standardized sampling methods we found a total of 121 ant species distributed in 41 genera and seven subfamilies. Grassland was the poorest site (21 species) and subdeciduous forest the richest (102 species). Seven species, with records in ≥10% of samples, accounted 40.8% of total species occurrences: Solenopsis molesta (21.6%), S. geminata (19.5%), Azteca velox (14%), Brachymyrmex sp. 1LM (11.7%), Dorymyrmex bicolor (11.2%), Camponotus planatus (11%) and Pheidole susannae (10.7%). Faunal composition between sites was highly different. Nearly 40% of all species were found in a single site. In all sites but grassland we found high abundances of several species typical of disturbed ecosystems, indicating high levels of disturbance. A species similarity analysis clustered forests in one group and grassland and shrub in another, both groups separated by more than 60% of dissimilarity. Similarity of ant assemblages suggests that deciduous and subdeciduous forests represent advanced stages of two different and independent successional paths
A trusted infrastructure for symbolic analysis of event-driven web applications
We introduce a trusted infrastructure for the symbolic analysis of modern event-driven Web applica-tions. This infrastructure consists of reference implementations of the DOM Core Level 1, DOM UIEvents, JavaScript Promises and the JavaScriptasync/awaitAPIs, all underpinned by a simpleCore Event Semantics which is sufficiently expressive to describe the event models underlying theseAPIs. Our reference implementations are trustworthy in that three follow the appropriate standardsline-by-line and all are thoroughly tested against the official test-suites, passing all the applicabletests. Using the Core Event Semantics and the reference implementations, we develop JaVerT.Click,a symbolic execution tool for JavaScript that, for the first time, supports reasoning about JavaScriptprograms that use multiple event-related APIs. We demonstrate the viability of JaVerT.Click byproving both the presence and absence of bugs in real-world JavaScript code
Seleção de linhagens-elite de arroz irrigado para o Estado do Tocantins.
O objetivo deste trabalho foi identificar as melhores linhagens de arroz irrigado para cultivo nas várzeas do Tocantins, pela análise de ensaios de avaliação do valor de cultivo e uso (VCU) conduzidos naquele Estado
The Expression and Roles of Nde1 and Ndel1 in the Adult Mammalian Central Nervous System
Open Access funded by Wellcome Trust Under a Creative Commons license Acknowledgments We thank Prof Angelo Sementilli, Department of Pathology, Universidade Metropolitana de Santos, SP, Brazil, for the human sample collection. This study is funded by Scottish Universities Life Sciences Alliance (HR07019 to S. Shen and C.D. McCaig), Medical Research Scotland (384 FRG to B. Lang, United Kingdom), Tenovus Scotland (G12/25 to B. Lang), Sino-UK Higher Education Research Partnership for PhD Studies (C.D. McCaig and Y.Q. Ding) and Wellcome Trust (WT081633MA-NCE to P.J.A. McCaffery, United Kingdom).Peer reviewedPublisher PD
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