306 research outputs found
Insights into the relationship between antimicrobial residues and bacterial populations in a hospital-urban wastewater treatment plant system
The relationship between antimicrobial residues, antibiotic resistance prevalence and
bacterial community composition in hospital effluent and in the receiving wastewater
treatment plant was studied. Samples from hospital effluent, raw inflow and final effluent
of the receiving wastewater treatment plant were characterized for amoxicillin and ciprofloxacin
resistance prevalence, content of heavy metals and antimicrobial residues and
bacterial community structure, based on 16S rRNA gene PCR-DGGE analysis. The concentration
of fluoroquinolones, arsenic and mercury was in general higher in hospital effluent
than in raw inflow, while the opposite was observed for tetracyclines, sulfonamides and
penicillin G. The prevalence of ciprofloxacin resistance was significantly higher in hospital
effluent than in raw inflow. The concentration of antimicrobial residues was observed to be
significantly correlated with the prevalence of antibiotic resistant bacteria and with variations
in the bacterial community. Hospital effluent was confirmed as a relevant, although
not unique, source of antimicrobial residues and antibiotic resistant bacteria to the
wastewater treatment plant. Moreover, given the high loads of antibiotic residues and
antibiotic resistant bacteria that may occur in hospital effluents, these wastewater habitats
may represent useful models to study and predict the impact of antibiotic residues on
bacterial communities.info:eu-repo/semantics/acceptedVersio
Modeling Soft Supramolecular Nanostructures by Molecular Simulations
The design and assembly of soft supramolecular structures based on small building blocks are governed by non-covalent interactions, selective host-guest interactions, or a combination of different interaction types. There is a surprising number of studies supporting the use of computational models for mimicking supramolecular nanosystems and studying the underlying patterns of molecular recognition and binding, in multi-dimensional approaches. Based on physical properties and mathematical concepts, these models are able to provide rationales for the conformation, solvation and thermodynamic characterization of this type of systems. Molecular dynamics (MD), including free-energy calculations, yield a direct coupling between experimental and computational investigation. This chapter provides an overview of the available MD-based methods, including path-based and alchemical free-energy calculations. The theoretical background is briefly reviewed and practical instructions are introduced on the selection of methods and post-treatment procedures. Relevant examples in which non-covalent interactions dominate are presented
Monitoring programmes: the fundamental component of estuaries management: how to design one?
This article focuses on the design of a conceptual framework to design and
assess environmental estuarine monitoring programmes, including the networks,
to detect quality status changes in coastal areas within environmental
management programmes. Monitoring is a fundamental component in any
management system, and in particular in sensitive areas under strong human
pressures, like estuaries. These pressures will be reflected in impacts in the
ecosystem and also in responses from it. A monitoring program including the
network and the indicators measured, should be designed to be able to identify
the i) pressures, ii) the state and effects, and iii) the responses of human action in
the estuary according to casualty chains, also the monitoring performance should be measured to assess the effectiveness of the monitoring program itself.
Answers to these needs are studied in this article, namely in what concerns the
selection and location of the monitoring stations. To evaluate the “best”
monitoring design one should first clearly identify the objectives of the network
and which indicators (in the sense of important variables that reflect
environmental attributes) are most appropriate for the particular situation. In this
work two methods for monitoring network design will be evaluated, namely i)
variance-reduction based, and ii) space-filling. These two are examples of a
statistically-based method, and of a random-allocation-based method. The most
appropriate objective functions are used to reflect the objectives of the
monitoring. In all cases the objective function models are solved with the
simulated annealing meta-heuristic algorithm, implemented by the team to solve
monitoring optimisation problems. Due to the amount and quality of the
information available, the Sado estuary is used as a case-study to demonstrate the
results of the methods and helping in the comparative analysis.info:eu-repo/semantics/publishedVersio
Newcomb-Benford Law as a generic flag for changes in the derivation of long-term solar terrestrial physics timeseries
The Newcomb-Benford Law (NBL) prescribes the probability distribution of the first digit of variables which explore a broad range under conditions including aggregation. Long-term space weather relevant observations and indices necessarily incorporate changes in the contributing number and types of observing instrumentation over time and we find that this can be detected solely by comparison with the NBL. It detects when upstream solar wind magnetic field OMNI High Resolution (HRO) Interplanetary Magnetic Field incorporated new data from the WIND and Advanced Composition Explorer (ACE) spacecraft after 1995. NBL comparison can detect underlying changes in the geomagnetic Auroral Electrojet (AE) index (activity dependent background subtraction) and the SuperMAG Electrojet (SME) index (different station types) that select individual stations showing the largest deflection, but not where station data are averaged, as in the SuperMAG Ring Current (SMR) index. As composite indices become more widespread across the geosciences, the NBL may provide a generic, data processing independent flag indicating changes in the constituent raw data, calibration or sampling method
Oxidative stress and inflammatory markers are associated with depression and nicotine dependence
AbstractTo determine if oxidative stress and inflammation are linked with major depressive disorder, nicotine dependence and both disorders combined. This study comprised 150 smokers and 191 never smokers. The instruments were: a socio-demographic questionnaire, diagnoses of mood disorder and nicotine dependence according to DSM-IV, (SCID-IV), and the Alcohol, Smoking and Substance Involvement Screening Test. Laboratory assessments included: nitric oxide metabolites (NOx), lipid hydroperoxides, malondialdehyde (MDA), total reactive antioxidant potential (TRAP), advanced oxidation protein products (AOPP), fibrinogen concentrations, homocysteine, erythrocytes sedimentation rate (ESR) and high-sensitivity C-reactive protein (hs-CRP) were assayed from blood specimens. Statistically significant differences were found among depressed smokers who had more severe depressive symptoms, a higher risk of alcohol consumption, more suicide attempts, and more disability for work than non-depressed never smokers. Depressed smokers had significantly higher levels of NOx, fibrinogen, hs-CRP, AOPP, ESR and lower levels of TRAP compared to non-depressed never smokers. Depressed smokers had significant levels of oxidative stress and inflammatory biomarkers after adjusting for gender, age, years of education, disability for work, and laboratory measures. The levels of NOx, lipid hydroperoxides, AOPP, and fibrinogen were substantially higher, whereas levels of TRAP were lower in depressed smokers compared to non-depressed never smokers. (1) Depressed smokers exhibited altered concentrations of NOx, lipid hydroperoxides, AOPP, TRAP, and fibrinogen. (2) Depressed smokers were more unable to work, showed more severe depressive symptoms and attempted suicide more frequently
Metagenomics-resolved genomics provides novel insights into chitin turnover, metabolic specialization, and niche partitioning in the octocoral microbiome
The role of bacterial symbionts that populate octocorals (Cnidaria, Octocorallia) is still poorly understood. To shed light on their metabolic capacities, we examined 66 high-quality metagenome-assembled genomes (MAGs) spanning 30 prokaryotic species, retrieved from microbial metagenomes of three octocoral species and seawater.
Results
Symbionts of healthy octocorals were affiliated with the taxa Endozoicomonadaceae, Candidatus Thioglobaceae, Metamycoplasmataceae, unclassified Pseudomonadales, Rhodobacteraceae, unclassified Alphaproteobacteria and Ca. Rhabdochlamydiaceae. Phylogenomics inference revealed that the Endozoicomonadaceae symbionts uncovered here represent two species of a novel genus unique to temperate octocorals, here denoted Ca. Gorgonimonas eunicellae and Ca. Gorgonimonas leptogorgiae. Their genomes revealed metabolic capacities to thrive under suboxic conditions and high gene copy numbers of serine-threonine protein kinases, type 3-secretion system, type-4 pili, and ankyrin-repeat proteins, suggesting excellent capabilities to colonize, aggregate, and persist inside their host. Contrarily, MAGs obtained from seawater frequently lacked symbiosis-related genes. All Endozoicomonadaceae symbionts harbored endo-chitinase and chitin-binging protein-encoding genes, indicating that they can hydrolyze the most abundant polysaccharide in the oceans. Other symbionts, including Metamycoplasmataceae and Ca. Thioglobaceae, may assimilate the smaller chitin oligosaccharides resulting from chitin breakdown and engage in chitin deacetylation, respectively, suggesting possibilities for substrate cross-feeding and a role for the coral microbiome in overall chitin turnover. We also observed sharp differences in secondary metabolite production potential between symbiotic lineages. Specific Proteobacteria taxa may specialize in chemical defense and guard other symbionts, including Endozoicomonadaceae, which lack such capacity.
Conclusion
This is the first study to recover MAGs from dominant symbionts of octocorals, including those of so-far unculturable Endozoicomonadaceae, Ca. Thioglobaceae and Metamycoplasmataceae symbionts. We identify a thus-far unanticipated, global role for Endozoicomonadaceae symbionts of corals in the processing of chitin, the most abundant natural polysaccharide in the oceans and major component of the natural zoo- and phytoplankton feed of octocorals. We conclude that niche partitioning, metabolic specialization, and adaptation to low oxygen conditions among prokaryotic symbionts likely contribute to the plasticity and adaptability of the octocoral holobiont in changing marine environments. These findings bear implications not only for our understanding of symbiotic relationships in the marine realm but also for the functioning of benthic ecosystems at large.info:eu-repo/semantics/publishedVersio
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