Genetic variability of the blue and red shrimp Aristeus antennatus in the Western Mediterranean Sea inferred by DNA microsatellite loci     

Rita Cannas  Flavio Sacco  Maria Cristina Follesa  Andrea Sabatini  Marco Arculeo  Sabrina Lo Brutto  Teresa Maggio  Anna Maria Deiana  Angelo Cau 《Marine Ecology》2012,33(3):350-363

Genetic variation at eight microsatellite loci was studied in nine populations of the blue and red shrimp Aristeus antennatus to investigate whether distinct stocks are present in the Western Mediterranean Sea. A high level of gene flow and no evidence of genetic partitioning were discovered. No significant variation was found (F_ST = 0.00673, P-value = 0.067) even when shrimps from exploited and those from deep-water unexploited grounds were compared. No evidence of reduction or expansion of population size in the recent past was found, as indicated by the bottleneck and interlocus g-tests. Our results are consistent with previous studies using mitochondrial gene methods and allozymes, indicating that, for this species, extensive pelagic larval dispersal and adult migration are probably responsible for the genetic homogeneity observed. In particular, due to a different bathymetric distribution of males and females, reported to be associated with different water masses and hence with possible differential dispersal capacity between sexes, the hypothesis of sex-biased dispersal was tested. Mean values of corrected assignment indices and mean relatedness values were higher for males, suggesting that females are the more widely dispersing sex. Molecular assessment of A. antennatus from the Western Mediterranean provides data of biological and evolutionary interest for the successful management of such a highly valuable fishery resource.  相似文献   

Laboratory sandbox validation of pollutant source location methods   总被引：1，自引：0，他引：1  

Fausto Cupola  Maria Giovanna Tanda  Andrea Zanini 《Stochastic Environmental Research and Risk Assessment (SERRA)》2015,29(1):169-182

Inverse methods can be used to recover the pollutant source location from concentration data. In this paper, the relative effectiveness of two proposed methods, simultaneous release function and source location identification (SRSI) and backward probability model based on adjoint state method (BPM-ASM) are evaluated using real data collected by using experimental equipment. The device is a sandbox that reproduces an unconfined aquifer in which all the variables are controlled. A numerical model was calibrated using experimental observations. The SRSI is a stochastic procedure which finds the source location and the release history by means of a Bayesian geostatistical approach (GA). The BPM-ASM provides the backward probability location of the pollutant detected at a monitoring point by means of a reverse transport simulation. The results show that both methods perform well. While the simultaneous release function and SRSI method requires a preliminary delineation of a probable source area and some weak hypotheses about the statistical structure of the unknown release function, the backward probability model requires some hypothesis about the contaminant release time. A case study was performed using two observation points only, and despite the scarcity of data, both methodologies were able to accurately reconstruct the true source location. The GA has the advantage to recover the release history function too, whilst the backward probability model works well with fewer data. If there are many observations, both methodologies may be computationally heavy. A transfer function approach has been adopted for the numerical definition of the sensitivity matrix in the SRSI method. The reliability of the experimental equipment was tested in previous laboratory works, conducted under several different conditions.  相似文献   

Forest structure of a maple old-growth stand: a case study on the Apennines mountains (Southern Italy)     

Pasquale A. Marziliano  Vittoria Coletta  Angelo Scuderi  Clemente Scalise  Giuliano Menguzzato  Fabio Lombardi 《山地科学学报》2017,14(7):1329-1340

In Europe, very small forest areas can be considered to be old-growth, and they are mainly located in Eastern Europe. The typical structures of old growth forests infrequently occur in Mediterranean mountainous environments, since they have been affected by human activities for centuries. This study focused on a remote and almost pure Italian maple stand located in southern Italy, which has not been managed for long time due to its inaccessibility. The effects of natural evolution on the forest stand were evaluated through the analysis of the spatial and chronological structure and the regeneration patterns, then estimating the amounts and quality of deadwood occurrence. Across the whole stand, all the trees with DBH (diameter at breast height) larger than 50 cm (LLT, large living trees) were measured (DBH and height) and age was also determined through a dendrochronological approach. The diameters observed ranged between 50 and 145 cm with ages of 120 to 250 years. The Latham index calculated for trees within the sample plot highlighted a multilayered canopy with a dominant layer of large living trees (age > 120 years). The size-class distribution of stems had a reverse-J shape, and basal area was 52 m² ha^-1. Deadwood was exclusively constituted by standing dead trees and CWD and its volume was on average 31 m³ ha^-1.Pure Italian maple forests are generally rare in Europe, and it was unexpected to find a forest stand characterized by a so complex structure with old growth attributes. The study of complex forest stand, even if small, could give precious information on the forest evolution, clarifying also diverse auto-ecological traits of tree species that usually are not common in our forests.  相似文献   

Equivalent Monopole Source of the Geomagnetic South Atlantic Anomaly     

Angelo De Santis  Enkelejda Qamili 《Pure and Applied Geophysics》2010,167(3):339-347

The South Atlantic magnetic Anomaly (SAA) is an important feature of the present geomagnetic field. In this paper we model the space–time evolution of this anomaly over the past 400 years in terms of the resultant between a decrease of a global axial dipole and an increase of a virtual local monopole source. Certain characteristics of this evolution are investigated and some considerations are made in the light of a possible special state of the global geomagnetic field dynamical regime. Among the possible speculations, one is made regarding the topography of the core-mantle boundary (CMB) and its possible aspect beneath the SAA region in terms of simple sinusoidal undulations met by the monopole source during its centennial motion.  相似文献   

Long-term model of planimetric and bathymetric evolution of a tidal lagoon     

Giampaolo Di Silvio  Chiara Dall’Angelo  Davide Bonaldo  Giacomo Fasolato 《Continental Shelf Research》2010

This model is based on the concept of transport concentration, defined as the time-averaged concentration in a given location of a lagoon, which determines the long-term net transport of sediments as the sum of a dispersive and an advective flux. Dispersive net flux of sediments is due to the alternate components of the tidal flow, while the advective net flux of sediments is due to the residual (Eulerian) component of the tidal, fluvial and littoral flow and possibly to the asymmetry between flow and ebb tide.  相似文献   

Stepwise selection of functional covariates in forecasting peak levels of olive pollen     

Manuel Escabias  Mariano J. Valderrama  Ana M. Aguilera  M. Elena Santofimia  M. Carmen Aguilera-Morillo 《Stochastic Environmental Research and Risk Assessment (SERRA)》2013,27(2):367-376

High levels of airborne olive pollen represent a problem for a large proportion of the population because of the many allergies it causes. Many attempts have been made to forecast the concentration of airborne olive pollen, using methods such as time series, linear regression, neural networks, a combination of fuzzy systems and neural networks, and functional models. This paper presents a functional logistic regression model used to study the relationship between olive pollen concentration and different climatic factors, and on this basis to predict the probability of high (and possibly extreme) levels of airborne pollen, selecting the best subset of functional climatic variables by means of a stepwise method based on the conditional likelihood ratio test.  相似文献   

Simultaneous identification of the pollutant release history and the source location in groundwater by means of a geostatistical approach   总被引：4，自引：1，他引：3  

Ilaria Butera  Maria Giovanna Tanda  Andrea Zanini 《Stochastic Environmental Research and Risk Assessment (SERRA)》2013,27(5):1269-1280

This paper describes an innovative procedure that is able to simultaneously identify the release history and the source location of a pollutant injection in a groundwater aquifer (simultaneous release function and source location identification, SRSI). The methodology follows a geostatistical approach: it develops starting from a data set and a reliable numerical flow and transport model of the aquifer. Observations can be concentration data detected at a given time in multiple locations or a time series of concentration measurements collected at multiple locations. The methodology requires a preliminary delineation of a probably source area and results in the identification of both the sub-area where the pollutant injection has most likely originated, and in the contaminant release history. Some weak hypotheses have to be defined about the statistical structure of the unknown release function such as the probability density function and correlation structure. Three case studies are discussed concerning two-dimensional, confined aquifers with strongly non-uniform flow fields. A transfer function approach has been adopted for the numerical definition of the sensitivity matrix and the recent step input function procedure has been successfully applied.  相似文献   

Editorial     

Mariano García-Fernández 《Journal of Seismology》2013,17(2):203-203

  相似文献   

Seismic vulnerability of bridges in transport networks subjected to environmental deterioration   总被引：1，自引：1，他引：0  

Mariano Angelo Zanini  Carlo Pellegrino  Riccardo Morbin  Claudio Modena 《Bulletin of Earthquake Engineering》2013,11(2):561-579

This paper investigates the problem of management, maintenance and planning of interventions in transport networks located in seismic zones, in relation to the actual state of degradation of their most vulnerable elements, as bridges. The study consists in two phases: the first phase is concerned with definition of the seismic vulnerability of a typical bridge in the network, through the construction of fragility curves calculated taking into account the corrosion of the reinforcing steel as the main cause of environmental deterioration. Once the fragility curves of the deteriorated bridges are computed, the second phase consists in the analysis of the vulnerability of the transport network in which the bridges are included taking into account the modification of the traffic flows when bridge infrastructures are damaged. The results of this pilot study can be used as a first step for a proper allocation of economic resources in the planning of seismic retrofit interventions to minimize the overall risk and manage the immediate post-earthquake emergency phase and guide rescuers in reaching the affected and critical areas.  相似文献   

The Banhad?o Alkaline Complex, Southeastern Brazil: source and evolution of potassic SiO2-undersaturated high-Ca and low-Ca magmatic series     

Excelso Ruberti  Gaston E. R. Enrich  Rogério G. Azzone  Piero Comin-Chiaramonti  Angelo De Min  Celso B. Gomes 《Mineralogy and Petrology》2012,104(1-2):63-80

The Cretaceous Banhad?o alkaline complex in southeastern Brazil presents two potassic SiO₂-undersaturated series. The high-Ca magmatic series consist of initially fractionated olivine (Fo_92-91) + diopside (Wo_48-43En_49-35Ae_0-7), as evidenced by the presence of xenocrysts and xenoliths. In that sequence, diopside (Wo_47-38En_46-37Ae_0-8) + phlogopite + apatite + perovskite (Prv_>92) crystallized to form the phlogopite melteigite and led to the Ca enrichment of the magma. Diopside (Wo_47-41En_32-24 Ae_3-14) continued to crystallize as an early mafic mineral, followed by nepheline (Ne_74.8-70.1Ks_26.3-21.2Qz_7.6-0.9) and leucite (Lc_65-56) and subsequently by melanite and potassic feldspar (Or_85-99Ab_1-7) to form melanite ijolites, wollastonite-melanite urtites and melanite-nepheline syenites. Melanite-pseudoleucite-nepheline syenites are interpreted to be a leucite accumulation. Melanite nephelinite dykes are believed to represent some of the magmatic differentiation steps. The low-Ca magmatic series is representative of a typical fractionation of aegirine-augite (Wo_36-29En_25-4Ae_39-18) + alkali feldspar (Or_57-96Ab_3-43) + nepheline (Ne_76.5-69.0Ks_19.9-14.4Qz_15.1-7.7) + titanite from phonolite magma. The evolution of this series from potassic nepheline syenites to sodic sodalite syenites and sodalitolites is attributed to an extensive fractionation of potassic feldspar, which led to an increase of the NaCl activity in the melt during the final stages forming sodalite-rich rocks. Phonolite dykes followed a similar evolutionary process and also registered some crustal assimilation. The mesocratic nepheline syenites showed interactions with phlogopite melteigites, such as compatible trace element enrichments and the presence of diopside xenocrysts, which were interpreted to be due to a mixing/mingling process of phonolite and nephelinite magmas. The geochemical data show higher TiO₂ and P₂O₅ contents and lower SiO₂ contents for the high-Ca series and different LILE evolution trends and REE chondrite-normalized patterns as compared to the low-Ca series. The ⁸⁷Sr/⁸⁶Sr, ¹⁴³Nd/¹⁴⁴Nd, ²⁰⁶Pb/²⁰⁴Pb and ²⁰⁸Pb/²⁰⁴Pb initial ratios for the high-Ca series (0.70407–0.70526, 0.51242–0.51251, 17.782–19.266 and 38.051–39.521, respectively) were slightly different from those of the low-Ca series (0.70542–0.70583, 0.51232–0.51240, 17.758–17.772 and 38.021–38.061, respectively). For both series, a CO₂-rich potassic metasomatized lithospheric mantle enriched the source with rutile-bearing phlogopite clinopyroxenite veins. Kamafugite-like parental magma is attributed to the high-Ca series with major contributions from the melting of the veins. Potassic nephelinite-like parental magma is assigned to the low-Ca series, where the metasomatized wall-rock played a more significant role in the melting process.  相似文献