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This paper reports a soil bio-engineering technical assessment program conducted in the Santo Domingo, Ecuador region. Autochthonous plant species survivorship and vegetative growth was evaluated in a short-term palisade experimental regime. Among the four species evaluated, Brugmansia versicolor, Malvaviscus penduliflorus, and Trichanthera gigantea performed well, evidenced by > 70% survivorship, however Euphorbia cotinifolia exhibited increased mortality (59%). Significant differences and notable variability in terminal shoot length and stem diameter among species indicated further study is warranted in growth parameters.

Host affiliation and entomopathogenic infections play a major role in shaping population dynamics of the forest tent caterpillar (FTC), Malacosoma disstria Hübner (Lepidoptera: Lasiocampidae). The effect of these individual factors has been studied, but it is unknown whether interactions between these factors significantly impact FTC life history traits. In the laboratory, we investigated a tritrophic interaction among larval diet, larval microsporidian infection, and FTC life history traits. Larvae were reared on foliage of trembling aspen, Populus tremuloides Michx (Malpighiales: Salicaceae) or sugar maple, Acer saccharum Marshall (Sapindales: Sapindaceae), or an artificial diet. Natural levels of microsporidian infection were assessed through microscopy and categorized as none (0 spores), low (1-100 spores), or high (>100 spores). Microsporidian infection and larval diet individually, but not interactively, impacted FTC life history traits. Moths with high infection had smaller wings, but infection did not increase the probability of wing malformations. Wings of FTC reared on fresh maple foliage were significantly smaller, had a higher probability of wing malformation, and a lower likelihood of cocoon production than FTC reared on other diets, but displayed higher overall survival. While microsporidian infection did not influence FTC-diet interactions, we provide further evidence on how these main effects may individually contribute to shaping FTC adult life history traits, and, ultimately, cyclical population dynamics. Future research should consider how larval mortality, distinct infection levels, and geographical source of FTC populations affect this tritrophic interaction., (© The Author(s) 2023. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

One of the main purposes of Ecohydraulics is to predict the effects of riparian vegetation on aquatic ecosystems within real water channels. The interaction between water flow and riparian plants significantly affects flow dynamics, hydraulic conveyance, and water quality of vegetated water bodies. This study aimed at quantifying analytically the uncertainty in flow average velocity estimations associated with the uncertainty of Leaf Area Index (LAI) of Phragmites australis (Cav.) Trin. ex Steudel covering a vegetated channel. The impacts of this species on the hydrodynamics of vegetated streams are far to be completely understood. The uncertainty in flow average velocity was assessed through the first-order second-moment statistical method, by comparing direct and indirect LAI measurements of mature Phragmites australis plants. Indirect LAI values were obtained using the LICOR® LAI-2000 Plant Canopy Analyzer device. The results of this study suggest that the uncertainties in flow average velocity estimations are comparable to those associated with experimental measurements of streamwise velocity components retrieved in real vegetated flows fully covered by mature Phragmites australis plants. [ABSTRACT FROM AUTHOR]

Background: Left atrial appendage occlusion (LAAO) represents an alternative approach for the prevention of cardioembolic stroke in patients with nonvalvular atrial fibrillation (NVAF) and contraindication for oral anticoagulation (OAC). The aim of our study was to analyse the outcomes in patients treated with LAAO, with a focus on cases with previous intracranial bleeding., Methods: Sixty patients with NVAF underwent LAAO (75.4 ± 9 years); mean CHA2DS2-VASc was 4.4 ± 1.7, mean HAS-BLED 3.2 ± 0.9. Thirty-two patients (53.3%) reported previous intracranial bleeding. Ischaemic and bleeding events recorded during follow-up were compared with expected event rates according to CHA2DS2-VASc and HAS-BLED scores., Results: Device implantation was successful in 58 patients (96.7%). The antiplatelet therapy was tailored according to patients' bleeding risk. During follow-up (2.32 ± 1.5 years) 3 ischaemic strokes and 1 transient ischaemic attack occurred, versus 13 total expected thromboembolic events (P = 0.033); 5 major bleedings were observed, versus 7 expected ones, if the patients were under OAC. Considering the combined endpoint (thromboembolic and major bleeding events) 9 events were observed versus 20 expected major events (P = 0.031). In the prespecified subgroup of patients with previous intracranial bleeding, two ischaemic strokes and one transient ischaemic attack were observed during follow-up versus six total expected thromboembolic events; no intracranial bleeding recurrence was recorded. Regarding the combined endpoint four major events were recorded versus nine expected ones., Conclusion: LAAO is an efficient and safe option for the prevention of cardioembolic stroke in patients with NVAF, high thromboembolic risk and contraindication to OAC, particularly in patients with previous intracranial bleeding.

This study proposes a new methodology for estimating the additional shear strength (or cohesion) exerted by vegetation roots on slope stability analysis within a coupled hydrological-stability model. The mechanical root cohesion is estimated within a Fiber Bundle Model framework that allows for the evaluation of the root strength as a function of stress-strain relationships of populations of fibers. The use of such model requires the knowledge of the root architecture. A branching topology model based on Leonardo's rule is developed, providing an estimation of the amount of roots and the distribution of diameters with depth. The proposed methodology has been implemented into an existing distributed hydrological-stability model able to simulate the dynamics of factor of safety as a function of soil moisture dynamics. The model also accounts for the hydrological effects of vegetation, which reduces soil water content via root water uptake, thus increasing the stability. The entire methodology has been tested in a synthetic hillslope with two configurations of vegetation type, i.e., trees and shrubs, which have been compared to a configuration without vegetation. The vegetation has been characterized using roots data of two mediterranean plant species. The results demonstrate the capabilities of the topological model in accurately reproducing the observed root structure of the analyzed species. For the environmental setting modeled, the effects of root uptake might be more significant than the mechanical reinforcement; the additional resistance depends strictly on the vegetation root depth. Finally, for the simulated climatic environment, landslides are seasonal, in agreement with past observations. [ABSTRACT FROM AUTHOR]

The paper aims at evaluating to what extent forest cover could affect the flood peak frequency and magnitude in Italian catchments. The analysis is restricted to evaluating the component of the runoff coefficient which cannot be captured by the catchment lithology alone. A preliminary data mining is performed on data of 75 catchments distributed from South to Central Italy. Cluster and correlation structure analyses are conducted for distinguishing forest cover effects within sample sets of catchments characterized by hydro-morphological similarities. We propose a method for correcting the bias of the runoff coefficient estimated from the catchment lithology only, by accounting for the effect of forest cover. The bias correction becomes significant for small mountainous catchments, characterised by larger forest cover fraction and lower critical rainfall depth. Consistently with what suggested in previous studies, the bias correction decreases as the rainfall depth and return period increase. [ABSTRACT FROM AUTHOR]

The use of soil bio-engineering techniques in developing countries is a relevant issue for disaster mitigation, environmental restoration and poverty reduction. Research on the autochthonal plants suitable for these kinds of interventions and on the economic efficiency of the interventions is essential for the dissemination of such techniques. The present paper is focused on these two issues as related to the realization of various typologies of soil bioengineering works in the humid tropics of Nicaragua. In the area of Río Blanco, located in the Department of Matagalpa, soil bioengineering installations were built in several sites. The particular structures built were: drainages with live fascine mattress, a live palisade, a vegetated live crib wall for riverbank protection, a vegetative covering made of a metallic net and biotextile coupled with a live palisade made of bamboo. In order to evaluate the suitability of the various plants used in these works, monitoring was performed, one on the live palisade alongside an unpaved road and the other on the live crib wall along a riverbank, by collecting data on survival rate and morphological parameters. Concerning economic efficiency, we proceeded to a financial analysis of the works. Once the unit price was obtained, we converted the amount into EPP Dollars (Equal Purchasing Power) in order to compare the Nicaraguan context with the European one. Among the species used we found that Gliricidia sepium (local common name: Madero negro) and Tabebuia rosea (local common name: Roble macuelizo) are adequate for soil bioengineering measures on slopes, while Erythrina fusca (local common name: Helequeme) resulted in successful behaviour only in the crib wall for riverbank protection. In comparing costs in Nicaragua and in Italy, the unit price reduction for Nicaragua ranges from 1.5 times (for the vegetative covering) to almost 4 times (for the fascine mattress), using the EPP dollar exchange rate. Our conclusions with regard to hydrological-risk mitigating actions performed on a basin scale and through naturalistic (live) interventions are that they are not only socially and technically possible, even in hardship areas (by maximizing the contribution of the local labour force and minimizing the use of mechanical equipment), but also economically sustainable. [ABSTRACT FROM AUTHOR]

The use of soil bio-engineering techniques in developing countries is a relevant issue for disaster mitigation, environmental restoration and poverty reduction. Research on authochtonal plants suitable for this kind of works and on economic efficiency is essen- tial for the divulgation of such techniques. The present paper is focused on this two issues related to the realization of various typologies of soil bio-engineering works in the humid tropic of Nicaragua. In the area of Río Blanco, located in the Department of Matagalpa, soil bioengineering installations were built in several sites. The particular structures built were: drainages with live fascine mattress, a live palisade, a vegetated live crib wall for riverbank protection, a vegetative covering made of a metallic net and biotextile coupled with a live palisade made of bamboo. In order to evaluate the suitability of the various plants used in the works, monitorings were performed, one in the live palisade alongside an unpaved road and the other on the live crib wall along a riverbank, collecting survival rate and morphological parameters data. Concerning the economic efficiency we proceed to a financial analysis of the works and once the unit price was obtained, we converted the amount in EPP Dollars (Equal Purchasing Power) in order to compare the Nicaraguan context with the Italian one. Among the used species we found that Madero negro (Gliricidia sepium) and Roble macuelizo (Tabebuia rosea) are adequate for soil-bioengineering measure on slopes while Helequeme (Erythrina fusca) reported a successful behaviour only in the crib wall for riverbank protection. In the comparison of the costs in Nicaragua and in Italy, the unit price reduction for the Central American country ranges between 1.5 times (for the vegetative covering) and almost 4 times (for the fascine mattress) if it's used the EPP dollar exchange rate. Conclusions are reached with regard to hydrological-risk mitigating actions performed on a basin scale and through naturalistic (live) interventions: not only are they socially and technically attainable, even in hardship areas (by maximizing the contribution of the local labor force and minimizing the use of mechanical equipment), but they are also economically sustainable. [ABSTRACT FROM AUTHOR]

In the last few years "D. I. A. F." (Department of Agriculture and Forestry Engineering of Florence University), has been testing the effectiveness of soil bioengineering techniques in Central America. The focus of the present study was to find out which native plants were most suited for soil bioengineering purposes, particularly in the realization of riverbank protection in Nicaragua. Furthermore, we have also been aiming at economic efficiency. These techniques are appropriate for sustainable watershed management especially in underdeveloped countries. Concerning the plants to be used we experimented four native species. Gliricidia Sepium, Cordia dentata and Jatropha curcas are suitable for soil bioengineering more than Bursera Simaruba. Economically speaking, the sustainability of such interventions in underdeveloped countries, has been shown by the evaluation of the cost of riverbank protection using vegetated crib-walls in Nicaragua compared to the cost in different contexts. [ABSTRACT FROM AUTHOR]