scholarly journals Monitoring Re-Growth of Invasive Plants Using an Autonomous Surface Vessel

2021 ◽  
Vol 7 ◽  
Author(s):  
Robert Codd-Downey ◽  
Michael Jenkin ◽  
Bir Bikram Dey ◽  
James Zacher ◽  
Eva Blainey ◽  
...  
Keyword(s):  
Plant Species ◽  
Position Estimation ◽  
Depth Information ◽  
Environmental Sensors ◽  
Invasive Aquatic Plant ◽  
Hull Design ◽  
Rtk Gps ◽  
Open Question ◽  
The Impact ◽  
Surface Vessel

Invasive aquatic plant species, and in particular Eurasian Water-Milfoil (EWM), pose a major threat to domestic flora and fauna and can in turn negatively impact local economies. Numerous strategies have been developed to harvest and remove these plant species from the environment. However it is still an open question as to which method is best suited to removing a particular invasive species and the impact of different lake conditions on the choice. One problem common to all harvesting methods is the need to assess the location and degree of infestation on an ongoing manner. This is a difficult and error prone problem given that the plants grow underwater and significant infestation at depth may not be visible at the surface. Here we detail efforts to monitor EWM infestation and evaluate harvesting methods using an autonomous surface vessel (ASV). This novel ASV is based around a mono-hull design with two outriggers. Powered by a differential pair of underwater thrusters, the ASV is outfitted with RTK GPS for position estimation and a set of submerged environmental sensors that are used to capture imagery and depth information including the presence of material suspended in the water column. The ASV is capable of both autonomous and tele-operation.

scholarly journals Rhizosphere Bacterial Networks, but Not Diversity, Are Impacted by Pea-Wheat Intercropping

2021 ◽  
Vol 12 ◽  
Author(s):  
Barbara Pivato ◽  
Amélie Semblat ◽  
Thibault Guégan ◽  
Samuel Jacquiod ◽  
Juliette Martin ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Plant Species ◽  
Ecological Processes ◽  
Niche Complementarity ◽  
Beneficial Effects ◽  
Sole Cropping ◽  
Chemical Inputs ◽  
Occurrence Pattern ◽  
Open Question ◽  
The Impact

Plant-plant associations, notably cereal-legume intercropping, have been proposed in agroecology to better value resources and thus reduce the use of chemical inputs in agriculture. Wheat-pea intercropping allows to decreasing the use of nitrogen fertilization through ecological processes such as niche complementarity and facilitation. Rhizosphere microbial communities may account for these processes, since they play a major role in biogeochemical cycles and impact plant nutrition. Still, knowledge on the effect of intecropping on the rhizosphere microbiota remains scarce. Especially, it is an open question whether rhizosphere microbial communities in cereal-legume intercropping are the sum or not of the microbiota of each plant species cultivated in sole cropping. In the present study, we assessed the impact of wheat and pea in IC on the diversity and structure of their respective rhizosphere microbiota. For this purpose, several cultivars of wheat and pea were cultivated in sole and intercropping. Roots of wheat and pea were collected separately in intercropping for microbiota analyses to allow deciphering the effect of IC on the bacterial community of each plant species/cultivar tested. Our data confirmed the well-known specificity of the rhizosphere effect and further stress the differentiation of bacterial communities between pea genotypes (Hr and hr). As regards the intercropping effect, diversity and structure of the rhizosphere microbiota were comparable to sole cropping. However, a specific co-occurrence pattern in each crop rhizosphere due to intercropping was revealed through network analysis. Bacterial co-occurrence network of wheat rhizosphere in IC was dominated by OTUs belonging to Alphaproteobacteria, Bacteroidetes and Gammaproteobacteria. We also evidenced a common network found in both rhizosphere under IC, indicating the interaction between the plant species; this common network was dominated by Acidobacteria, Alphaproteobacteria, and Bacteroidetes, with three OTUs belonging to Acidobacteria, Betaproteobacteria and Chloroflexi that were identified as keystone taxa. These findings indicate more complex rhizosphere bacterial networks in intercropping. Possible implications of these conclusions are discussed in relation with the functioning of rhizosphere microbiota in intercropping accounting for its beneficial effects.

scholarly journals Assessing the impact of previous experience on lie effects through a transfer paradigm

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Claudia Mazzuca ◽  
Mariagrazia Benassi ◽  
Roberto Nicoletti ◽  
Giuseppe Sartori ◽  
Luisa Lugli
Keyword(s):  
Training Session ◽  
Spatial Task ◽  
Dual Processes ◽  
Transfer Effects ◽  
Transfer Paradigm ◽  
Compatible Condition ◽  
Open Question ◽  
The Impact ◽  
Cognitive Cost ◽  
Spatial Training

AbstractInfluential lines of research propose dual processes-based explanations to account for both the cognitive cost implied in lying and for that entailed in the resolution of the conflict posited by Simon tasks. The emergence and consistency of the Simon effect has been proved to be modulated by both practice effects and transfer effects. Although several studies provided evidence that the lying cognitive demand may vary as a function of practice, whether and how transfer effects could also play a role remains an open question. We addressed this question with one experiment in which participants completed a Differentiation of Deception Paradigm twice (baseline and test sessions). Crucially, between the baseline and the test sessions, participants performed a training session consisting in a spatial compatibility task with incompatible (condition 1) or compatible (condition 2) mapping, a non-spatial task (condition 3) and a no task one (condition 4). Results speak in favour of a modulation of individual performances by means of an immediate prior experience, and specifically with an incompatible spatial training.

scholarly journals Driver Liability Assessment in Vehicle Collisions in Spain

2021 ◽  
Vol 18 (4) ◽  
pp. 1475
Author(s):  
Almudena Sanjurjo-de-No ◽  
Blanca Arenas-Ramírez ◽  
José Mira ◽  
Francisco Aparicio-Izquierdo
Keyword(s):  
Road Safety ◽  
Accurate Estimation ◽  
Main Hypothesis ◽  
Self Organizing Maps ◽  
Safety Measures ◽  
Vehicle Collisions ◽  
Promising Tool ◽  
Visual Clustering ◽  
Open Question ◽  
The Impact

An accurate estimation of exposure is essential for road collision rate estimation, which is key when evaluating the impact of road safety measures. The quasi-induced exposure method was developed to estimate relative exposure for different driver groups based on its main hypothesis: the not-at-fault drivers involved in two-vehicle collisions are taken as a random sample of driver populations. Liability assignment is thus crucial in this method to identify not-at-fault drivers, but often no liability labels are given in collision records, so unsupervised analysis tools are required. To date, most researchers consider only driver and speed offences in liability assignment, but an open question is if more information could be added. To this end, in this paper, the visual clustering technique of self-organizing maps (SOM) has been applied to better understand the multivariate structure in the data, to find out the most important variables for driver liability, analyzing their influence, and to identify relevant liability patterns. The results show that alcohol/drug use could be influential on liability and further analysis is required for disability and sudden illness. More information has been used, given that a larger proportion of the data was considered. SOM thus appears as a promising tool for liability assessment.

scholarly journals Synchronization in 5G networks: a hybrid Bayesian approach toward clock offset/skew estimation and its impact on localization

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Meysam Goodarzi ◽  
Darko Cvetkovski ◽  
Nebojsa Maletic ◽  
Jesús Gutiérrez ◽  
Eckhard Grass
Keyword(s):  
Bayesian Approach ◽  
Large Scale ◽  
Hybrid Approach ◽  
Position Estimation ◽  
5G Networks ◽  
Clock Skew ◽  
Depth Analysis ◽  
The Impact ◽  
Mean Square Errors ◽  
Clock Offset

AbstractClock synchronization has always been a major challenge when designing wireless networks. This work focuses on tackling the time synchronization problem in 5G networks by adopting a hybrid Bayesian approach for clock offset and skew estimation. Furthermore, we provide an in-depth analysis of the impact of the proposed approach on a synchronization-sensitive service, i.e., localization. Specifically, we expose the substantial benefit of belief propagation (BP) running on factor graphs (FGs) in achieving precise network-wide synchronization. Moreover, we take advantage of Bayesian recursive filtering (BRF) to mitigate the time-stamping error in pairwise synchronization. Finally, we reveal the merit of hybrid synchronization by dividing a large-scale network into local synchronization domains and applying the most suitable synchronization algorithm (BP- or BRF-based) on each domain. The performance of the hybrid approach is then evaluated in terms of the root mean square errors (RMSEs) of the clock offset, clock skew, and the position estimation. According to the simulations, in spite of the simplifications in the hybrid approach, RMSEs of clock offset, clock skew, and position estimation remain below 10 ns, 1 ppm, and 1.5 m, respectively.

scholarly journals Quick Response Assessment of the Impact of an Extreme Storm Combining Aerial Drone and RTK GPS

2017 ◽  
Author(s):  
Arthur C. Trembanis ◽  
Enrico Duo ◽  
Stephanie Dohner ◽  
Edoardo Grottoli ◽  
Paolo Ciavola
Keyword(s):  
Warning System ◽  
Response Assessment ◽  
Storm Event ◽  
Quick Response ◽  
Aerial Photos ◽  
Extreme Storm ◽  
Rtk Gps ◽  
Commercial Off The Shelf ◽  
The Impact ◽  
Response Post

Abstract. Developing and implementing a quick response post-storm survey protocol has the potential to improve impact assessments of coastal storms. Pre- and post-event surveys are essential to properly quantify the storm impacts on the coast. In this study, a combination of traditional RTK GPS and Unmanned Aerial Vehicle drone platform was utilized as part of a coordinated storm response workflow. The comprehensive approach employed in this pilot case study was conducted on the Emilia-Romagna coast (Italy), in the immediate aftermath of an extreme storm event that impacted the shoreline on the 5th–6th February 2015 called the Saint Agatha Storm. The activities were supported by timing information on the approaching storm provided by the regional early warning system. We collected aerial photos from a commercial off-the-shelf drone immediately after the Saint Agatha Storm and generated both orthomosaic and digital elevation models utilizing structure-from-motion photogrammetry techniques. The drone- based survey approach allowed us to quickly survey an area of 0.25 km2 within a 10-minute flight resulting in a ground sampling distance of 2.5 cm/pixel. Flooding and erosion impacts are analyzed and presented for the target study area. Limitations and possible applications for coastal management of the quick response post-storm surveying protocol are highlighted.

scholarly journals The impact of floral morphology on genetic differentiation in two closely related biennial plant species

AoB Plants ◽  
2018 ◽  
Vol 10 (5) ◽  
Author(s):  
Arne Mertens ◽  
Rein Brys ◽  
Dorien Schouppe ◽  
Hans Jacquemyn
Keyword(s):  
Genetic Differentiation ◽  
Plant Species ◽  
Floral Morphology ◽  
The Impact

scholarly journals Ecological Impacts of Megaprojects: Species Succession and Functional Composition

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2411
Author(s):  
Hamada E. Ali ◽  
Solveig Franziska Bucher
Keyword(s):  
Plant Species ◽  
Large Scale ◽  
Invasive Plant ◽  
Species Traits ◽  
Natural Vegetation ◽  
Ecological Impacts ◽  
Imperata Cylindrica ◽  
Dry Matter Content ◽  
Large Scale Disturbance ◽  
The Impact

Land-use changes have huge impacts on natural vegetation, especially megaprojects, as the vegetation layer is destroyed in the course of construction works affecting the plant community composition and functionality. This large-scale disturbance might be a gateway for the establishment of invasive plant species, which can outcompete the natural flora. In contrast, species occurring in the area before the construction are not able to re-establish. In this study, we analyzed the impact of a pipeline construction on a wetland nature reserve located in northern Egypt. Therefore, we analyzed the plant species occurrence and abundance and measured each plant species’ traits before the construction in 2017 as well as on multiple occasions up to 2 years after the construction had finished on altogether five sampling events. We found that the construction activity led to the establishment of an invasive species which previously did not occur in the area, namely, Imperata cylindrica, whereas five species (Ipomoea carnea, Pluchea dioscoridis, Polygonum equisetiforme, Tamarix nilotica, and Typha domingensis) could not re-establish after the disturbance. The functionality of ecosystems assessed via the analysis of plant functional traits (plant height, specific leaf area, and leaf dry matter content) changed within species over all sampling events and within the community showing a tendency to approximate pre-construction values. Functional dispersion and Rao’s quadratic diversity were higher after the megaproject than before. These findings are important to capture possible re-establishment and recovery of natural vegetation after construction and raise awareness to the impact of megaprojects, especially in areas which are high priority for conservation.

scholarly journals The impacts of anthropogenic disturbance on plant species richness in the freshwater lakes of Algonquin Provincial Park

SURG Journal ◽  
2017 ◽  
Vol 9 (1) ◽  
pp. 5-13
Author(s):  
Adrian Helmers ◽  
Alexis Platek ◽  
Melissa Ponte ◽  
Natalie Secen ◽  
Karl Cottenie
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Human Activity ◽  
Anthropogenic Disturbance ◽  
Negative Relationship ◽  
Access Point ◽  
Plant Species Richness ◽  
Significant Difference ◽  
The Impact ◽  
Provincial Park

This study quantified the impact of human activity on aquatic and shoreline plant species richness. We hypothesized that human activity at the shoreline would negatively impact plant species richness and that the extent of the impact would depend on the intensity of human activity. To test this, we sampled 11 lakes in Algonquin Provincial Park, of which five permitted motorboat access, and five permitted canoe access and prohibited motorboat access. The remaining lake, which had no designated access point for boats and was only accessible to researchers, acted as a control. To assess the impact of anthropogenic disturbance at each lake, we measured plant species richness in three 10 m by 2 m plots: a first plot at the access point, assumed to be the site of highest disturbance; a second at the site of intermediate disturbance, 30 m down shore from the access point; and a third at the site of lowest disturbance, 60 m down shore from the access point. We found a significant negative relationship between the level of disturbance and plant species richness, both in the motorboat-accessible and canoe access-only lakes. The control lake exhibited no correlation between disturbance level and plant species richness. However, there was no significant difference between motorboat-accessible and canoe access-only lakes in the relationship between disturbance level and plant species richness. Overall, this study highlights the consequences of anthropogenic disturbance on freshwater aquatic and shoreline plant communities, and provides a framework for future management and rehabilitation strategies.

scholarly journals Phenology of Petersianthus Macrocarpus from 2017 to 2020 and Risk of Pollinosis in Dictrict of Abidjan

2020 ◽  
Vol 3 (2) ◽  
Keyword(s):  
High Risk ◽  
Wind Speed ◽  
Plant Species ◽  
Cote D'ivoire ◽  
Côte D’Ivoire ◽  
Pollen Calendar ◽  
Floral Phenology ◽  
Flowering Periods ◽  
The Impact ◽  
Number Of Individuals

Petersianthus macrocarpus is a plant species whose pollens are potentially allergenic. This plant is present from the coast to the centre of the country. The objective of this study is to prevent populations from being exposed to the pollens of Petersianthus macrocarpus. Specifically, it was a question of defining the flowering of Petersianthus macrocarpus, evaluating the impact of the climate on this flowering and listing the populations most exposed to P. macrocarpus pollens. The study took place in Abidjan, in the commune of Yopougon, specifically in South Niangon, from September 2017 to June 2020. Sampling by quadrat allowed to determine the number of individuals, the cover, the density and the frequency of the vegetation. Floral phenology was carried out by weekly observations using binoculars. The coverage in each quadrat was 1 and the frequency 100%. Individuals less than 6 m high did not bear any flowers. Two flowering periods were observed in the years 2017 to 2019. The first was from April to June, the second from November to January. However, there was no flowering from April to June in 2020. The evolution of rainfall in 2020 was not identical to that of the three previous years. The phenology of Petersianthus macrocarpus presents periods of high risk of pollinosis and is influenced by rainfall. Increasing wind speed exposes new populations to pollen. The installation of pollen collectors is certainly necessary to establish the pollen calendar of Petersianthus macrocarpus in Côte d’Ivoire.

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