58 research outputs found
Innovative Nitrogen and Carbon Removal
The aerobic systems have been the most widely biological treatment used for municipal and industrial wastewater but show serious problem with sludge sedimentation, high energy demand and microbial inhibition. On the other hand, the anaerobic digestion (AD) of wastewater is considered the best alternative to remove the organic compounds and to recover energy via methane production. Nevertheless, AD has a problem: the treatment of industrial wastewater with high organic nitrogen content reaches high free ammonia (NH3) concentrations due to the protein degradation. NH3 inhibits the methanogenic process and is toxic to the environment, and then, it must be removed before its final disposition. Several physicochemical processes have been evaluated for the recovery or/and treatment of ammonium from wastewater. The most frequent treatments are gas stripping and magnesium ammonium phosphate precipitation. These methods are effective, but they are very expensive compared to biological treatments. Moreover, these techniques usually require more power consumption than the biological process. The technologies based on partial nitrification and Anammox (PN‐A) are the ones with better performance. Thus, this chapter mainly focuses on biological processes based on AD, denitrification and PN‐A for the removal of carbon and nitrogen from industrial wastewater with recovery of energy and water
Digital-analog quantum computing of fermion-boson models in superconducting circuits
We propose a digital-analog quantum algorithm for simulating the
Hubbard-Holstein model, describing strongly-correlated fermion-boson
interactions, in a suitable architecture with superconducting circuits. It
comprises a linear chain of qubits connected by resonators, emulating
electron-electron (e-e) and electron-phonon (e-p) interactions, as well as
fermion tunneling. Our approach is adequate for a digital-analog quantum
computing (DAQC) of fermion-boson models including those described by the
Hubbard-Holstein model. We show the reduction in the circuit depth of the DAQC
algorithm, a sequence of digital steps and analog blocks, outperforming the
purely digital approach. We exemplify the quantum simulation of a half-filling
two-site Hubbard-Holstein model. In such example we obtain fidelities larger
than 0.98, showing that our proposal is suitable to study the dynamical
behavior of solid-state systems. Our proposal opens the door to computing
complex systems for chemistry, materials, and high-energy physics.Comment: 6+5 Pages, 5+2 Figures, 1 Tabl
Targets and measures : challenges associated with reporting low sea lice levels on Atlantic salmon farms
A popular framing of Goodhart's Law states, "When a measure become a target, it ceases to be a good measure". The extent to which this may be the case in the reporting of sea louse infestation on salmon farms is explored here. Due to the importance of controlling sea louse infestation on salmon farms, monitoring programmes are active in most salmon producing regions and, in many, a maximum allowable sea louse level is specified. Using publicly accessible data from Norway and BC, Canada, this study investigated the extent to which the framing of these programmes, in particular the specification of low threshold levels, may be affecting the veracity of the reported sea louse infestation data. In BC, where the threshold level is set to 3 mobile Lepeophtheirus salmonis little evidence of anomalous patterns in the data and the overall proportion of females within the adult sea lice population is around 0.43. By contrast, in Norway where lower sea louse limits are in place (at either 0.5 or 0.2 adult female L. salmonis), there is evidence of unexpected and sharp reductions in the abundance of adult females reported around these threshold values. In addition, the average proportion of females is estimated to be only around 0.20 of the total adult L. salmonis population. The unexpected observations in the data were much more evident for farms in the southern areas of Norway and over the most recent years. These findings appear to support the case that the measurement of sea lice on salmon farms can be significantly influenced by targets (particularly those which are highly demanding), and that as such, researchers and fish health professionals should be aware of potential biases within these data. In addition, regulators should carefully consider the unintended consequences of setting certain sea louse thresholds and the ways in which the potential to effectively review data quality and accuracy may be impacted by the choice of sea louse stage(s) that are reported
Analog Quantum Approximate Optimization Algorithm
We present an analog version of the quantum approximate optimization
algorithm suitable for current quantum annealers. The central idea of this
algorithm is to optimize the schedule function, which defines the adiabatic
evolution. It is achieved by choosing a suitable parametrization of the
schedule function based on interpolation methods for a fixed time. This
algorithm provides an approximate result of optimization problems that may be
developed during the coherence time of current quantum annealers on their way
towards quantum advantage.Comment: 5 pages, 4 figure
Deterministic single-photon source in the ultrastrong coupling regime
Deterministic single-photon sources are important and ubiquitous in quantum
information protocols. However, to the best of our knowledge, none of them work
in the ultrastrong light-matter coupling regime, and each excitation process
can only emit one photon. We propose a deterministic single-photon source in
circuit QED which can work in the ultrastrong coupling regime. Here, two qubits
are excited simultaneously in one process and two deterministic single photons
can be sequentially emitted with an arbitrary time separation. This happens
through two consecutive adiabatic transfers along the one-photon solutions of
the two-qubit Rabi and Jaynes-Cummings model, which has constant eigenenergy in
the whole coupling regime. Unlike the stimulated Raman adiabatic passage, the
system goes back to the initial state of another period automatically after
photon emission. Our scheme can approach unity single-photon efficiency,
indistinguishability, and purity simultaneously. With the assistance of the
Stark shift, a deterministic single photon can be generated within a time
proportional to the inverse of the resonator frequency.Comment: 7 +4 pages, 5 figure
Highly modulated supported triazolium-based ionic liquids: direct control of the electronic environment on Cu nanoparticles
A series of new triazolium-based supported ionic liquids (SILPs), decorated with Cu NPs, were successfully prepared and applied to the N-arylation of aryl halides with anilines. The triazoles moieties were functionalised using copper-catalysed azide–alkyne cycloaddition. SILP surface characterisation showed a strong correlation between the triazolium cation volume and textural properties. STEM images showed well-dispersed Cu NPs on SILPs with a mean diameter varying from 3.6 to 4.6 nm depending on the triazolium cation used. Besides, XPS results suggest that the Cu(0)/Cu(I) ratio can be modulated by the electronic density of triazolium substituents. XPS and computational analysis gave mechanistic insights into the Cu NP stabilisation pathways, where the presence of electron-rich groups attached to a triazolium ring plays a critical role in leading to a cation adsorption pathway (Eads = 72 kcal mol−1). In contrast, less electron-rich groups favour the anion adsorption pathway (Eads = 63 kcal mol−1). The Cu@SILP composite with electron-rich groups showed the highest activity for the C–N Ullmann coupling reaction, which suggests that electron-rich groups might act as an electron-like reservoir to facilitate oxidative addition for N-arylation. This strategy firmly suggests the strong dependence of the nature of triazolium-based SILPs on the Cu NP surface active sites, which may provide a new environment to confine and stabilise MNPs for catalytic applications
The expression of TRPV channels, prostaglandin E2 and pro-inflammatory cytokines during behavioural fever in fish
A fever, or increased body temperature, is a symptom of inflammation, which is a complex defence reaction of the organism to pathogenic infections. After pathogens enter the body, immune cells secrete a number of agents, the functions of which stimulate the body to develop a functional immune and fever response. In mammals it is known that \{PGE2\} is the principal mediator of fever. The extent to which \{PGE2\} and other pro-inflammatory cytokines such as TNF-α, IL-6, or IL-1β could be involved in the induction of behavioural fever in fish remains to be clarified. Several members of the transient receptor potential (TRP) family of ion channels have been implicated as transducers of thermal stimuli, including \{TRPV1\} and TRPV2, which are activated by heat. Here we show that members of the \{TRP\} family, \{TRPV1\} and TRPV4, may participate in the coordination of temperature sensing during the behavioural fever. To examine the behavioral fever mechanism in Salmo salar an infection with IPNV, infectious pancreatic necrosis virus, was carried out by an immersion challenge with 10 ×105 PFU/mL-1 of IPNV. Behavioural fever impacted upon the expression levels of both \{TRPV1\} and \{TRPV4\} mRNAs after the viral challenge and revealed a juxtaposed regulation of \{TRPV\} channels. Our results suggest that an increase in the mRNA abundance of \{TRPV1\} is tightly correlated with a significant elevation in the expression of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α and PGE2) in the Pre-Optic Area (POA) and cytokine release in plasma. Together, these data indicate that the reduction of \{TRPV4\} expression during behavioural fever may contribute to the onset of behavioural fever influencing movement toward higher water temperatures. Our data also suggest an effect of \{TRPV\} channels in the regulation of behavioural fever through activation of \{EP3\} receptors in the central nervous system by \{PGE2\} induced by plasma-borne cytokines. These results highlight for first time in mobile ectotherms the key role of pro-inflammatory cytokines and \{TRPV\} channels in behavioural fever that likely involves a complex integration of prostaglandin induction, cytokine recognition and temperature sensing
Phenotypic and genotypic antimicrobial resistance in Escherichia coli strains isolated from household dogs in Chile
IntroductionAntimicrobial resistance (AMR) is a major threat to animal and public health worldwide; consequently, several AMR surveillances programs have been implemented internationally in both human and veterinary medicine, including indicator bacteria such as Escherichia coli. However, companion animals are not typically included in these surveillance programs. Nevertheless, there have been reports of increasing levels of antimicrobial resistance in E. coli strains isolated from dogs worldwide. In Chile, there is limited information available on AMR in E. coli isolated from companion animals, which prevents the establishment of objective prevention and control measures.MethodsFor this reason, the aim of this study was to characterize the phenotypic and genotypic AMR of E. coli strains isolated from healthy household dogs in Chile. For this purpose, a multi-stage sampling was carried out in the Metropolitan Region of Chile, obtaining samples from 600 healthy dogs. These samples were processed using traditional bacteriology and molecular techniques to isolate E. coli strains. We assessed the minimal inhibitory concentration of 17 antimicrobials and conducted a search of six antimicrobial resistance genes, as well as class 1 and 2 integrons, in the isolated strains.ResultsTwo-hundred and twenty-four strains of E. coli were recovered, and 96.9% (n = 217) showed resistance to at least one drug and only 3.1% (n = 7) were susceptible to all analyzed antimicrobials. Most strains were resistant to cefalexin (91.5%, n = 205, 1st-generation cephalosporin), followed by ampicillin (68.3%, n = 153) and cefpodoxime (31.3%, n = 70, 3rd-generation cephalosporin). Moreover, 24.1% (n = 54) tested positive for extended-spectrum-β-lactamases and 34.4% (n = 77) were multidrug resistant. As for the AMR genes, the most detected was qnrB (28.1%, n = 63), followed by blaCTX-M (22.3%, n = 50), and blaTEM-1 (19.6%, n = 44). Additionally, 16.1% (n = 36) harbored class 1 integrons. Our study shows that E. coli strains isolated from healthy household dogs exhibit resistance to several relevant drugs and also antimicrobial resistance genes considered critical for human health. These results can be used as a starting point for the prevention and control of antimicrobial resistance from companion animals. This background should be considered when formulating future resistance surveillance programs or control plans in which companion animals must be included
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