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911.
Gabriel Núñez-Antonio Manuel Mendoza Alberto Contreras-Cristán Eduardo Gutiérrez-Peña Eduardo Mendoza 《Environmental and Ecological Statistics》2018,25(4):471-494
The study of the interaction among species is an active area of research in Ecology. In particular, it is of interest to evaluate the overlap of their ecological niches. Temporal activity is one of the niche’s axes most commonly used to explore ecological segregation among animal species, and many contributions focus on the overlap of this variable. Once the information of the temporal activity is obtained in the wild, the data is treated as a random sample. There exist different methods to estimate the overlap. Specifically, in the case of two species, one possibility is to estimate the density of the temporal activity of each species and then evaluate the overlap between these density functions. This leads naturally to the analysis of circular data. Most of the procedures currently in use impose some rather restrictive assumptions on the probabilistic models used to describe the phenomena, and only provide approximate measures of the uncertainty involved in the process. In this article, we propose a Bayesian nonparametric approach which incorporates a well-defined noninformative prior. We take advantage of the data structure to define such a prior in terms of the predictive distribution. To the best of our knowledge, this is a novel approach. Our procedure is compared with a well-known method using simulated data, and applied to the analysis of real camera-trap data concerning two mammalian species from the El Triunfo biosphere reserve (Chiapas, Mexico). 相似文献
912.
Camille?CoronEmail authorView authors OrcID profile Clément?Calenge Christophe?Giraud Romain?Julliard 《Environmental and Ecological Statistics》2018,25(1):71-93
We develop a new statistical procedure to monitor relative species abundances and their respective preferences for different habitat types, using opportunistic data. Following Giraud et al. (Biometrics 72(2):649–658, 2015), we combine the opportunistic data with some standardized data in order to correct the bias inherent to the opportunistic data collection. Species observations are modeled by Poisson distributions whose parameters quantify species abundances and habitat preferences, and are estimated using Bayesian computations. Our main contributions are (i) to tackle the bias induced by habitat selection behaviors, (ii) to handle data where the habitat type associated to each observation is unknown, (iii) to estimate probabilities of selection of habitat for the species. As an illustration, we estimate common bird species habitat preferences and abundances in the region of Aquitaine (France). 相似文献
913.
Alexandre?C.?L.?Almeida Luiz?H.?Duczmal André?L.?F.?Can?adoEmail author Fabio?R.?da?Silva 《Environmental and Ecological Statistics》2018,25(2):257-275
Multiple data sources are essential to provide reliable information regarding the emergence of potential health threats, compared to single source methods. Spatial Scan Statistics have been adapted to analyze multivariate data sources, but only ad hoc procedures have been devised to address the problem of selecting the most likely cluster and computing its significance. In this work, information from multiple data sources of disease surveillance is incorporated to achieve more coherent spatial cluster detection using tools from multi-criteria analysis. The best cluster solutions are found by maximizing two objective functions simultaneously, based on the concept of dominance. To evaluate the statistical significance of solutions, a statistical approach based on the concept of attainment function is used. The multi-criteria approach has several advantages: the representation of the evaluation function for each data source is clear, and does not suffer from an artificial, and possibly confusing mixture with the other data source evaluations; it is possible to attribute, in a rigorous way, the statistical significance of each candidate cluster; and it is possible to analyze and pick-up the best cluster solutions, as given naturally by the non-dominated set. The methodology is illustrated with real datasets. 相似文献
914.
de F. Araújo Karla C. de P. Barreto Jéssica P. Cardozo Jussara C. dos Santos Elisama Vieira de Araújo Danyelle M. Martínez-Huitle Carlos A. 《Environmental Chemistry Letters》2018,16(2):647-652
Environmental Chemistry Letters - There is increasing concern about contamination by surfactants that are used to extract organic pollutants during remediation of polluted soils and aquifers. For... 相似文献
915.
Babonneau Frédéric Biscaglia Stéphane Chotard David Haurie Alain Mairet Nicolas Lefillatre Thibaut 《Environmental Modeling and Assessment》2021,26(6):911-926
Environmental Modeling & Assessment - In this paper, we present a comprehensive, multi-timescale approach to evaluate energy transition policies aiming at fully renewable generation in power... 相似文献
916.
Halima Sassi Gwendoline Lafaye Hédi Ben Amor Abdelaziz Gannouni Mohamed Razak Jeday Jacques BarbierJr 《Frontiers of Environmental Science & Engineering》2018,12(1):2
Microwave irradiation has been used to prepare Al, Fe-pillared clays from a natural Tunisian smectite from the El Hicha deposit (province of Gabes). Chemical analysis, XRD spectra and surface properties evidenced the success of pillaring process. The obtained solids present higher surface area and pore volume than conventionally prepared Al-Fe pillared clays. The main advantages of the microwave methodology are the considerable reduction of the synthesis time and the consumption of water. The microwave-derived Al-Fe pillared clays have been tested for catalytic wet air oxidation (CWAO) of phenol in a stirred tank at 160°C and 20 bar of pure oxygen pressure. These materials are efficient for CWAO of phenol and are highly stable despite the severe operating conditions (acidic media, high pressure, high temperature). The catalyst deactivation was also significantly hindered when compared to conventionally prepared clays. Al-Fe pillared clays prepared by microwave methodology are promising as catalysts for CWAO industrial water treatment.
相似文献
917.
918.
Researchers often rely on capture-mark-recapture (CMR) data to study animal dispersal in the wild. Yet their spatial coverage often does not encompass the entire dispersal range of the study individuals, sometimes producing misleading results. Information contained in population surveys and variation in population spatial structure can be used to overcome this issue. We build an integrated model in a multisite context in which CMR data are only collected at a subset of sites, but numbers of breeding pairs are counted at all sites. In a Black-headed Gull Chroicocephalus ridibundus population, the integrated-modeling approach induces an increase in precision for the demographic parameters of interest (variances, on average, were decreased by 20%) and provides a more precise extrapolation of results from the CMR data to the whole population. Patterns of condition-dependent dispersal are therefore made easier to detect, and we obtain evidence for colony-size dependence in recruitment, dispersal, and breeding success. These results suggest that first-time breeders disperse to small colonies in order to recruit earlier. The exchange of experienced breeders between colonies appears as a main determinant of the observed variation in colony sizes. 相似文献
919.
We characterized the structure and functioning of the food web associated to an intertidal rocky shore in the harbour of Brest
(Western Brittany, France), through a seasonal δ13C and δ15N survey. The dominance of benthic-derived organic matter, and particularly resuspended sediment, in the local pool of suspended
organic matter, is highlighted. This benthic-derived organic matter dominates the diet of filter-feeders, including a certain
degree of selectivity displayed by various taxa belonging to this trophic group. The food web structure appeared very stable
temporally, which suggested the dominance of mixed diets, rather than the consumption of pure sources. It was constituted
of 4 trophic levels, including a large diversity of predators, likely favoured by the diversity of microhabitats that characterize
this intertidal habitat. From our results, the trophic functioning of this peri-urban rocky shore community does not appear
functionally simplified as previously reported for other anthropized and/or artificial rocky ecosystems. We suggest that the
topological complexity of rocky habitats, including a diversity of microhabitats, might be responsible of the important animal
diversity, in spite of the anthropogenic disturbances characterizing this peri-urban area. 相似文献
920.
Hydrogeochemical considerations about the origin of groundwater salinization in some coastal plains of Elba Island (Tuscany,Italy) 总被引:1,自引:0,他引:1
Elena Giménez-Forcada Alberto Bencini Giovanni Pranzini 《Environmental geochemistry and health》2010,32(3):243-257
Several coastal plains of the Elba Island (Marina di Campo, Portoferraio, Schiopparello, Mola, Porto Azzurro and Barbarossa
plains) in Tuscany (Italy) were studied to determine the causes of decline in groundwater quality, using major ion chemistry
to establish the causes of groundwater salinization. The study demonstrates that salinization of coastal plain alluvial aquifers
is not simply linked to seawater intrusion but is also intimately related to inflows from adjacent aquifers. Ionic ratios,
correlation graphs and distribution value maps were employed as the means to understand the hydrochemistry of the study areas.
The Mg/Cl ratio in particular can be considered a good tracer to distinguish the main salinization processes that control
groundwater chemistry. Seawater intrusion only partly determines the chemistry of some groundwaters, which generally belong
to a chloride facies where the salinity is derived principally from freshwater–seawater mixing and the participation of cation
exchange. Proceeding inland groundwater quality seems to be principally determined by the inflow of Mg, Ca-HCO3 or Ca, Na-HCO3 waters formed from the weathering of silicate minerals in adjoining aquifers. Hydrolysis of these minerals is of prime importance
in controlling groundwater chemistry in adjacent alluvial plains. The lateral recharge flows introduce water with a different
chemical composition and this variable of freshwater recharge changes the hydrochemistry as a result of mixing between two
or more waters types. This situation is further complicated when seawater and base exchange reactions participate, due to
seawater intrusion. 相似文献