Forthcoming EU environmental requirements on water resources quality are likely to include concentration limits of certain contaminants of emerging concern, such as pharmaceuticals and personal care products. However, understanding the occurrence of organic contaminants, including contaminants of emerging concern, in hydro(geo)logical media remains challenging. This study is based on a comprehensive screening of OCs in groundwater of the unique and complex Fuente de Piedra Lagoon endorheic basin system using hydrochemistry and isotopic tools.
View Article and Find Full Text PDFBackground: Anterior cruciate ligament (ACL) injury during contact sports has a high incidence that has not been reduced despite the immense resources devoted to understanding its aetiology. A neurocognitive approach could increase knowledge of the mechanisms contributing to ACL injury enabling practitioners to address and minimise future risk.
Objective: To systematically review the influence of manipulating cognitive demands during motor tasks (i.
Unsaturated porous media, characterized by the combined presence of several immiscible fluid phases in the pore space, are highly relevant systems in nature, because they control the fate of contaminants and the availability of nutrients in the subsoil. However, a full understanding of the mechanisms controlling solute mixing in such systems is still missing. In particular, the role of saturation in the development of chaotic solute mixing has remained unexplored.
View Article and Find Full Text PDFBackground: Executive functions, notably inhibition, significantly influence decision-making and behavioral regulation in team sports. However, more research must be conducted on individual player characteristics such as experience and motor skills. This study assessed how accumulated practical experience moderates inhibition in response to varying task difficulty levels.
View Article and Find Full Text PDFMicrofluidic models are proving to be powerful systems to study fundamental processes in porous media, due to their ability to replicate topologically complex environments while allowing detailed, quantitative observations at the pore scale. Yet, while porous media such as living tissues, geological substrates, or industrial systems typically display a porosity that spans multiple scales, most microfluidic models to date are limited to a single porosity or a small range of pore sizes. Here, a novel microfluidic system with multiscale porosity is presented.
View Article and Find Full Text PDFInt Breastfeed J
October 2023
Background: Very few studies have assessed the association between COVID-19 infection and the rates of exclusive breastfeeding (EBF) upon discharge following the first waves of the pandemic and after initiation of vaccination. The primary objective of this study is to compare the rates of EBF since birth upon discharge in mothers diagnosed with COVID-19 infection at the time of the delivery versus a group of non-infected mothers in maternity hospitals with Baby Friendly Hospital Initiative (BFHI) accreditation. The secondary objectives include determining the rates of any breastfeeding at three and six months of life in both groups, as well as determining the possible factors associated with EBF rates observed upon discharge.
View Article and Find Full Text PDFField-based learning in hydrogeology enables students to develop their understanding and application of practical methodologies, and to enhance many of the generic skills (e.g., teamwork, problem-solving).
View Article and Find Full Text PDFCarbon efflux from soils is the largest terrestrial carbon source to the atmosphere, yet it is still one of the most uncertain fluxes in the Earth's carbon budget. A dominant component of this flux is heterotrophic respiration, influenced by several environmental factors, most notably soil temperature and moisture. Here, we develop a mechanistic model from micro to global scale to explore how changes in soil water content and temperature affect soil heterotrophic respiration.
View Article and Find Full Text PDFBacterial biofilms can form in porous media that are of interest in industrial applications ranging from medical implants to biofilters as well as in environmental applications such as in situ groundwater remediation, where they can be critical locations for biogeochemical reactions. The presence of biofilms modifies porous media topology and hydrodynamics by clogging pores and consequently solutes transport and reactions kinetics. The interplay between highly heterogeneous flow fields found in porous media and microbial behavior, including biofilm growth, results in a spatially heterogeneous biofilm distribution in the porous media as well as internal heterogeneity across the thickness of the biofilm.
View Article and Find Full Text PDFThe functioning of natural and engineered porous media, like soils and filters, depends in many cases on the interplay between biochemical processes and hydrodynamics. In such complex environments, microorganisms often form surface-attached communities known as biofilms. Biofilms can take the shape of clusters, which alter the distribution of fluid flow velocities within the porous medium, subsequently influencing biofilm growth.
View Article and Find Full Text PDFBackground: Attentional resource allocation during sports practice is associated with the players' perceived mental load. However, few ecological studies address this problem by considering the players' characteristics (e.g.
View Article and Find Full Text PDFUnlabelled: The unsaturated zone, located between the soil surface and the phreatic level, plays an important role in defining the fate of any substance entering the subsoil. In addition to the processes of flow and transport taking place in the liquid phase, surface reactions such as adsorption to the solid phase may occur and increase the residence time of the substance entering the system. In this study, we aim to understand the pore-scale mechanisms that control adsorption in unsaturated systems.
View Article and Find Full Text PDFTransp Porous Media
November 2021
We study mixing-controlled chemical reactions in unsaturated porous media from a pore-scale perspective. The spatial heterogeneity induced by the presence of two immiscible phases, here water and air, in the pore space generates complex flow patterns that dominate reactive mixing across scales. To assess the impact of different macroscopic saturation states (the fraction of pore volume occupied by water) on mixing-controlled chemical reactions, we consider a fast irreversible reaction between two initially segregated dissolved species that mix as one solution displaces the other in the heterogeneous flow field of the water phase.
View Article and Find Full Text PDFBiofilms are biological viscoelastic gels composed of bacterial cells embedded in a self-secreted polymeric extracellular matrix (ECM). In environmental settings, such as in the rhizosphere and phyllosphere, biofilm colonization occurs at the solid-air interface. The biofilms' ability to colonize and expand over these surfaces depends on the formation of osmotic gradients and ECM viscoelastic properties.
View Article and Find Full Text PDFBacterial biofilms are found in several environmental and industrial porous media, including soils and filtration membranes. Biofilms grow under certain flow conditions and can clog pores, thereby redirecting the local fluid flow. The ability of biofilms to clog pores, the so-called bioclogging, can have a tremendous effect on the local permeability of the porous medium, creating a pressure buildup in the system, and impacting the mass flow through it.
View Article and Find Full Text PDFArsenic (As) is a toxic element, and elevated levels of geogenic As in drinking water pose a threat to the health of several hundred million people worldwide. In this study, we used microfluidics in combination with optical microscopy and X-ray spectroscopy to investigate zerovalent iron (ZVI) corrosion, secondary iron (Fe) phase formation, and As retention processes at the pore scale in ZVI-based water treatment filters. Two 250 μm thick microchannels filled with single ZVI and quartz grain layers were operated intermittently (12 h flow/12 h no-flow) with synthetic groundwater (pH 7.
View Article and Find Full Text PDFBacteria in porous media, such as soils, aquifers, and filters, often form surface-attached communities known as biofilms. Biofilms are affected by fluid flow through the porous medium, for example, for nutrient supply, and they, in turn, affect the flow. A striking example of this interplay is the strong intermittency in flow that can occur when biofilms nearly clog the porous medium.
View Article and Find Full Text PDFRev Environ Sci Biotechnol
January 2022
Microorganisms capable of biomineralization can catalyze mineral precipitation by modifying local physical and chemical conditions. In porous media, such as soil and rock, these microorganisms live and function in highly heterogeneous physical, chemical and ecological microenvironments, with strong local gradients created by both microbial activity and the pore-scale structure of the subsurface. Here, we focus on extracellular bacterial biomineralization, which is sensitive to external heterogeneity, and review the pore-scale processes controlling microbial biomineralization in natural and engineered porous media.
View Article and Find Full Text PDFThe sustainability of agriculture in the Mediterranean climate is challenged by high irrigation water demands and nitrogen fertilizer losses to the environment, causing significant pressure on groundwater resources and groundwater-dependent ecosystems. Advanced irrigation technologies and improved fertilizer management have been promoted as key solutions to reduce the agricultural impact on aquatic systems. However, it remains unclear how different irrigation-fertilizer practices perform on the long-term under a highly variable climate, such as the Mediterranean one.
View Article and Find Full Text PDFTransported chemical reactions in unsaturated porous media are relevant to environmental and industrial applications. Continuum scale models are based on equivalent parameters derived from analogy with saturated conditions and cannot appropriately account for incomplete mixing. It is also unclear how the third dimension controls mixing and reactions.
View Article and Find Full Text PDFWidespread seafloor methane venting has been reported in many regions of the world oceans in the past decade. Identifying and quantifying where and how much methane is being released into the ocean remains a major challenge and a critical gap in assessing the global carbon budget and predicting future climate [C. Ruppel, J.
View Article and Find Full Text PDFSurfactants, after use, enter the environment through diffuse and point sources such as irrigation with treated and non-treated waste water and urban and industrial wastewater discharges. For the group of non-ionic synthetic surfactant alcohol ethoxylates (AEOs), most of the available information is restricted to the levels and fate in aquatic systems, whereas current knowledge of their behavior in soils is very limited. Here we characterize the behavior of different homologs (C12-C18) and ethoxymers (EO3, EO6, and EO8) of the AEOs through batch experiments and under unsaturated flow conditions during infiltration experiments.
View Article and Find Full Text PDFFlow of non-Newtonian fluids through topologically complex structures is ubiquitous in most biological, industrial and environmental settings. The interplay between local hydrodynamics and the fluid's constitutive law determines the distribution of flow paths. Consequently the spatial heterogeneity of the viscous resistance controls mass and solute transport from the micron to the meter scale.
View Article and Find Full Text PDFHuman endeavours into deep space exploration and the prospects of establishing colonies on nearby planets would invariably involve components of bioregenerative life support for food production, cabin atmosphere renewal, and waste recycling. Growing plants and their microbiomes in porous media under different gravitational fields may present new challenges due to effects of liquid distribution on gaseous exchange with roots and microorganisms. We provide the first direct evidence that capillary driven liquid reconfiguration in porous media under reduced gravity conditions reduces oxygen diffusion pathways and enhances anoxic conditions within bacterial hotspots.
View Article and Find Full Text PDFWastewater treatment plants have been identified as important hubs for small particulate plastic, down to the nanometer scale, from urban areas to the environment. The reuse of sludge as fertilizer in agricultural practices can lead to accumulation of plastic in the soil. In this study, nanoplastic particles and microplastic fibers were synthesized with a passive inorganic tracer to aid in faster and more quantitative analysis using inductively coupled plasma mass spectrometry (ICP-MS).
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