3,948 research outputs found

    3_D modeling using TLS and GPR techniques to characterize above and below-ground wood distribution in pyroclastic deposits along the Blanco River (Chilean Patagonia)

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    To date, the study of in-stream wood in rivers has been focused mainly on quantifying wood pieces deposited above the ground. However, in some particular river systems, the presence of buried dead wood can also represent an important component of wood recruitment and budgeting dynamics. This is the case of the Blanco River (Southern Chile) severely affected by the eruption of Chait\ue9n Volcano occurred between 2008 and 2009. The high pyroclastic sediment deposition and transport affected the channel and the adjacent forest, burying wood logs and standing trees. The aim of this contribution is to assess the presence and distribution of wood in two study areas (483 m2 and 1989 m2, respectively) located along the lower streambank of the Blanco River, and covered by thick pyroclastic deposition up to 5 m. The study areas were surveyed using two different devices, a Terrestrial Laser Scanner (TLS) and a Ground Penetrating Radar (GPR). The first was used to scan the above surface achieving a high point cloud density ( 48 2000 points m-2) which allowed us to identify and measure the wood volume. The second, was used to characterize the internal morphology of the volcanic deposits and to detect the presence and spatial distribution of buried wood up to a depth of 4 m. Preliminary results have demonstrated differences in the numerousness and volume of above wood between the two study areas. In the first one, there were 43 wood elements, 33 standing trees and 10 logs, with a total volume of 2.96 m3 (109.47 m3 km-1), whereas the second one was characterized by the presence of just 7 standing trees and 11 wood pieces, for a total amount of 0.77 m3 (7.73 m3 km-1). The dimensions of the wood elements vary greatly according to the typology, standing trees show the higher median values in diameter and length (0.15 m and 2.91 m, respectively), whereas the wood logs were smaller (0.06 m and 1.12 m, respectively). The low dimensions of deposited wood can be probably connected to their origin, suggesting that these elements were generated by toppling and breaking of surrounding dead trees. Results obtained with the GPR confirm the ability of this instrument to localize the presence and distribution of buried wood. From the 3- D analysis it was possible to assess the spatial distribution and to estimate, as first approach, the volume of the buried wood which represents approximately 0.04% of the entire volcanic deposit. Further analysis will focus on additional GPR calibration with different wood sizes for a more accurate estimation of the volume. The knowledge of the overall wood amount stored in a fluvial system that can be remobilized over time, represent an essential factor to ensure better forest and river management actions

    Classifying Crises-Information Relevancy with Semantics

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    Social media platforms have become key portals for sharing and consuming information during crisis situations. However, humanitarian organisations and affected communities often struggle to sieve through the large volumes of data that are typically shared on such platforms during crises to determine which posts are truly relevant to the crisis, and which are not. Previous work on automatically classifying crisis information was mostly focused on using statistical features. However, such approaches tend to be inappropriate when processing data on a type of crisis that the model was not trained on, such as processing information about a train crash, whereas the classifier was trained on floods, earthquakes, and typhoons. In such cases, the model will need to be retrained, which is costly and time-consuming. In this paper, we explore the impact of semantics in classifying Twitter posts across same, and different, types of crises. We experiment with 26 crisis events, using a hybrid system that combines statistical features with various semantic features extracted from external knowledge bases. We show that adding semantic features has no noticeable benefit over statistical features when classifying same-type crises, whereas it enhances the classifier performance by up to 7.2% when classifying information about a new type of crisis

    Inhibition of larval growth and adult fecundity in Asian long-horned beetle (Anoplophora glabripennis) exposed to azadirachtins under quarantine laboratory conditions

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    BACKGROUND: The Asian long-horned beetle [ALB; Anoplophora glabripennis (Motschulsky)] is an invasive, wood-boringinsect posing significant economic and ecological threats to the deciduous forests of North America. An efficacious andenvironmentally acceptable chemical control technique is a requirement of a comprehensive, integrated response strategy.RESULTS: Results of this study demonstrate statistically significant, concentration-dependent effects of azadirachtins, a familyof natural compounds derived f rom the neem tree, on both ALB larval and adult life stages. Growth inhibitory effects on ALBlarvae were greatest on early life stages. Significant effects on adults included inhibition of female feeding, oviposition effortand fecundity for adults exposed to azadirachtins via maturation feeding on systemically loaded twigs.CONCLUSION: These quarantine laboratory experiments verify multi-mechanistic, deleterious effects on both larval and adultlife stages of ALB, an exotic, invasive insect pest of critical importance in North America. Field efficacy studies are requiredto further understand dose acquisition by larval and adult ALB life stages following systemic injections to host trees undersemi-operational use scenarios. Such studies could also be used to test postulates regarding optimal deployment strategiesto meet objectives such as slowing the spread of this pest and protection of high-value deciduous forest resources

    Influence of wall material concentration and core-to-wall material ratio on the encapsulation of pomegranate seed oil by complex coacervation.

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    Pomegranate seed oil (PSO) is rich in bioactive compounds, such as conjugated linolenic acids (CLnA). Encapsulation is a packing technology that enables the application of highly oxidizable oils in food matrices. Technological properties of particles produced by this method are highly influenced by wall material (WM) concentration and core:WM ratio. The objective of this study was to evaluate the effects of the WM concentration and the core:WM ratio in the microencapsulation of PSO by complex coacervation.SLACA, 12. De 4 a 7 de Novembro de 2017. Ref. 71235

    Public perceptions of forests across Italy: An exploratory national survey

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    In a context of progressive expansion of the Italian forest area, we present the results of a national survey exploring public perception of forests across different geographical scales in Italy. Perceptions of forests are assessed in rela-tion to popular beliefs on relevant environmental issues such as countering climate change, protecting biodiversity, and promoting social cohesion and environmental education. Participants (N = 1059) living in five different regions of Northern (Trentino-Alto Adige/Südtirol, Piemonte), Central (Lazio, Molise) and Southern Italy (Puglia), were recruited in the survey and completed a paper-and-pencil questionnaire. Survey questions regarded the estimated percentage of forest cover, the perceived importance of different environmental issues and of different material and non-material forest products, as well as partici-pants’ perceptions regarding connectedness to nature. Results revealed a gen-eralized tendency to overestimate the extension of forest surface area in the participants’ region, in Italy, and in the European Union. Results also showed high scores for participants’ perceived importance of environmental issues, such as climate change and biodiversity protection, and in their belief that forests could play a positive role in addressing these issues and providing im-portant outcomes and benefits for the quality of human life, such as health and well-being or social cohesion

    Below-elbow or above-elbow cast for conservative treatment of extra-articular distal radius fractures with dorsal displacement: A prospective randomized trial

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    Background: Distal radial fractures are common traumatic injuries, but their management remains controversial also in case of conservative treatment regarding the type of immobilisation. Hence, we conducted a two-arm, parallel-group, prospective randomised trial to compare the capacity of long casts (above-elbow) and short casts (below-elbow) to maintain the reduction of extra-articular distal radius fractures with dorsal displacement (AO/OTA classification: 2R3A2.2). Methods: Seventy-four eligible patients with AO/OTA 2R3A2.2 fractures treated with closed reduction and cast immobilisation were randomised to the long cast group (n°= 37) or to the short cast group (n°= 37). Baseline radiological parameters, radial inclination (RI), radial height (RH), ulnar variance (UV) and palmar tilt (PT) were taken, and compared with clinical (DASH, Mayo Wrist and Mayo Elbow) and radiological scores taken at 7-10 days, 4 weeks and 12 weeks. Furthermore, to evaluate correlations between radiological parameters and functional outcomes, patients were divided into two groups according to whether or not their radiological parameters at Follow-ups 2 and 3 were acceptable, i.e. within the range 11-12 mm for RH, 16°-28° for RI, - 4-+ 2 mm for UV and 0°-22° for PT. Results: Patient demographic and baseline radiological parameters were similar between groups. At follow-up, there were no statistically significant differences between the two types of cast in terms of RI, RH, UV or PT, or Mayo wrist or DASH scores. Short cast group patients displayed better Mayo elbow score at follow-up 2 (4 weeks), but this difference was no longer statistically significant at follow-up 3 (12 weeks). No statistically significant differences in clinical outcomes were found between patients who presented acceptable radiographic parameters at follow-up and those who did not. Conclusion: As there were no significant differences between short casts and long casts in terms of fracture reduction maintenance or clinical outcomes, short casts are an effective method of post-reduction immobilisation in AO/OTA 2R3A2.2 fracture of the radius. Radiological parameters outside the range conventionally considered acceptable do not preclude a satisfactory clinical outcome. Trial registration: ClinicalTrials.gov PRS, NCT04062110. Registred 20 August 2019

    Gold(I)-N-Heterocyclic Carbene Synthons in Organometallic Synthesis

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    The prominent role of gold-N-heterocyclic carbene (NHC) complexes in numerous research areas such as homogeneous (photo)catalysis, medicinal chemistry and materials science has prompted organometallic chemists to design gold-based synthons that permit access to target complexes through simple synthetic steps under mild conditions. In this review, the main gold-NHC synthons employed in organometallic synthesis are discussed. Mechanistic aspects involved in their synthesis and reactivity as well as applications of gold-NHC synthons as efficient pre-catalysts, antitumor agents and/or photo-emissive materials are presented
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