Search results for "Mon"

Pharmaceuticals and other urban contaminants threaten Amazonian freshwater ecosystems

2021

Abstract Urban areas in the Brazilian Amazon have grown at an unprecedented rate during the last years. About 90% of the wastewater produced by these urban areas are discharged untreated into Amazonian freshwater ecosystems, constituting a potential environmental pathway for pharmaceuticals and other chemicals consumed by modern societies (e.g. psychostimulants, personal-care products, hormones). The distribution of these chemicals into the Amazon River and their potential risks for freshwater biodiversity have not been evaluated so far. Here, we show the results of the largest chemical monitoring campaign conducted in the Amazon region. We assessed exposure patterns for 43 pharmaceuticals …

Gravitational-wave Detection and Parameter Estimation for Accreting Black-hole Binaries and Their Electromagnetic Counterpart

2020

We study the impact of gas accretion on the orbital evolution of black-hole binaries initially at large separation in the band of the planned Laser Interferometer Space Antenna (LISA). We focus on two sources: (i)~stellar-origin black-hole binaries~(SOBHBs) that can migrate from the LISA band to the band of ground-based gravitational-wave observatories within weeks/months; and (ii) intermediate-mass black-hole binaries~(IMBHBs) in the LISA band only. Because of the large number of observable gravitational-wave cycles, the phase evolution of these systems needs to be modeled to great accuracy to avoid biasing the estimation of the source parameters. Accretion affects the gravitational-wave p…

Very Deep inside the SN 1987A Core Ejecta: Molecular Structures Seen in 3D

2017

Most massive stars end their lives in core-collapse supernova explosions and enrich the interstellar medium with explosively nucleosynthesized elements. Following core collapse, the explosion is subject to instabilities as the shock propagates outwards through the progenitor star. Observations of the composition and structure of the innermost regions of a core-collapse supernova provide a direct probe of the instabilities and nucleosynthetic products. SN 1987A in the Large Magellanic Cloud (LMC) is one of very few supernovae for which the inner ejecta can be spatially resolved but are not yet strongly affected by interaction with the surroundings. Our observations of SN 1987A with the Ataca…

Coastal precipitation regimes in Kenya.

1997

Kenya is under the influence of the seasonal reversal of the Indian ocean monsoons. However, its coastal belt, up to about 50 km inland, exhibits original climatic features. Hierarchical clustering...

Developing an indicator-modelling approach to forecast changes in nitrogen critical load exceedance across Europe arising from agricultural reform

2011

International audience; Atmospheric nitrogen (N) deposition above the critical load causes eutrophication with adverse impacts on biodiversity. Average Accumulated critical load Exceedance (AAE) is a measure of the amount of critical load exceedance and the area of habitat which is affected, and has been adopted in Europe as a pressure indicator for biodiversity. In Europe, AAE is calculated by the Coordination Centre for Effects (CCE) of the United Nations Economic Commission for Europe based on modelled nitrogen deposition and country-level reporting of critical load thresholds and ecosystem area. Due to differences in country-level reporting, AAE values for semi-natural habitats may show…

Environmental and biological factors are joint drivers of mercury biomagnification in subarctic lake food webs along a climate and productivity gradi…

2021

Subarctic lakes are getting warmer and more productive due to the joint effects of climate change and intensive land-use practices (e.g. forest clear-cutting and peatland ditching), processes that potentially increase leaching of peat- and soil-stored mercury into lake ecosystems. We sampled biotic communities from primary producers (algae) to top consumers (piscivorous fish), in 19 subarctic lakes situated on a latitudinal (69.0-66.5 degrees N), climatic (+3.2 degrees C temperature and +30% precipitation from north to south) and catchment land-use (pristine to intensive forestry areas) gradient. We first tested how the joint effects of climate and productivity influence mercury biomagnific…

A roadmap for amphibious drilling at the Campi Flegrei caldera: insights from a MagellanPlus workshop

2019

Large calderas are among the Earth's major volcanic features. They are associated with large magma reservoirs and elevated geothermal gradients. Caldera-forming eruptions result from the withdrawal and collapse of the magma chambers and produce large-volume pyroclastic deposits and later-stage deformation related to post-caldera resurgence and volcanism. Unrest episodes are not always followed by an eruption; however, every eruption is preceded by unrest. The Campi Flegrei caldera (CFc), located along the eastern Tyrrhenian coastline in southern Italy, is close to the densely populated area of Naples. It is one of the most dangerous volcanoes on Earth and represents a key example of an acti…

Passive and Active Biomonitoring of Atmospheric Aerosol with the Use of Mosses

2021

Abstract The aim of the carried out research was passive and active biomonitoring of woodlands in the Opole province. Pleurozium schreberi mosses were used during the research, in which the following heavy metals concentrations were determined: Mn, Fe, Ni, Cu, Zn, Cd and Pb. Concentrations were determined with absorption atomic spectrometry (AAS). On the basis of the carried out research, concentrations of heavy metals in moss samples used in the passive and active biomonitoring methods were compared. The obtained results indicate that Pleurozium schreberi mosses can be successfully used in both passive and active biomonitoring, however, these methods should not be used interchangeably in a…

Goldschmidt Abstracts 2010 – J

2010

Application of entropic approach to estimate the mean flow velocity and Manning roughness coefficient in a high-curvature flume

2016

The entropy-based approach allows the estimation of the mean flow velocity in open channel flow by using the maximum flow velocity. The linear relationship between the mean velocity, umax, and the mean flow velocity, um, through the dimensionless parameter Φ(M), has been verified both in natural rivers and in laboratory channels. Recently, the authors of this study investigated the reliability of the entropy-based formula in a straight channel and under different bed and side-walls' roughness conditions. The present study aims to further validate the entropy-based approach and to explore the effectiveness of entropy-based formula in high curvature channels. Results show that as the effect o…