Light-dark cycle synchronization of circadian rhythm in blind primates

BACKGROUND: Recently, several papers have shown that a small subset of retinal ganglion cells (RGCs), which project to the suprachiasmatic nucleus (SCN) and contain a new photopigment called melanopsin, are the photoreceptors involved in light-dark entrainment in rodents. In our primate colony, we found a couple of common marmosets (Callithrix jacchus) that had developed progressive and spontaneous visual deficiency, most likely because of retinal degeneration of cones and/or rods. In this study, we evaluated the photoresponsiveness of the circadian system of these blind marmosets. METHODS: Two blind and two normal marmosets were kept in cages with a controlled light-dark cycle (LD) to study photoentrainment, masking, and phase response to a dark pulse. RESULTS: Blind marmosets were entrained with the new LD cycle when light onsets were delayed and advanced by 6 hours. In constant light conditions, blind marmosets free-ran with a period of 23.2 hours, while normal animals free-ran with a period of 23.6 hours. All marmosets responded to dark pulses in the early subjective day with phase delays and with phase advances in the late subjective day. CONCLUSION: Our results demonstrate that light can synchronize circadian rhythms of blind marmosets and consequently, that this species could be a good primate model for circadian photoreception studies

The ability of electrochemical oxidation with a BDD anode to inactivate Gram-negative and Gram-positive bacteria in low conductivity sulfate medium

The disinfection of 100 mL of synthetic water containing 7 mM Na2SO4 with 106 CFU mL-1 of either Gram-negative or Gram-positive bacteria has been studied by electrochemical oxidation. The electrolytic cell was a stirred tank reactor equipped with a boron-doped diamond (BDD) anode and a stainless steel cathode and the trials were performed at acidic and neutral pH, at 33 mA cm-2 and 25 ºC. Reactive oxygen species, pre-eminently hydroxyl radicals, were efficiently produced in both media from water oxidation at the BDD anode and the bacteria concentration was reduced by ≥ 5 log units after 60 min of electrolysis, thus constituting a good chlorine-free disinfection treatment. All the inactivation kinetics were described by a logistic model, with no significant statistical differences between acidic and neutral suspensions. The electrochemical disinfection with BDD was very effective for Gram-negative bacilli like E. coli and P. aeruginosa and Gram-positive ones like B. atrophaeus, whereas the Gram-positive cocci S. aureus and E. hirae were more resistant. Thus, the latter organisms are a better choice than E. coli as process indicators. Scanning electron microscopy highlighted a transition from initial cells with standard morphology supported on clean filters to inactivated cells with a highly altered morphology lying on dirty filters with plenty of cellular debris. Larger damage was observed for Gram-negative cells compared to Gram-positive ones. The inactivation effect could then be related to the chemical composition of the outer layers of the cell structure along with the modification of the transmembrane potentials upon current passage

Effect of electrogenerated hydroxyl radicals, active chlorine and organic matter on the electrochemical inactivation of Pseudomonas aeruginosa using BDD and dimensionally stable anodes

In this work, the disinfection of 100 mL of 10(6) CFU center dot mL-1 Pseudomonas aeruginosa suspensions at pH 5.8 by electrochemical oxidation at 33.3 mA cm(-2) is reported. The undivided electrolytic cell was equipped with either a boron-doped diamond (BDD) or an IrO2-based or RuO2-based dimensionally stable anode and a stainless steel cathode. Physisorbed hydroxyl radicals M((OH)-O-center dot) formed from anodic water oxidation and active chlorine generated from anodic Cl-oxidation were the main oxidizing species in pure Na2SO4 medium and in the presence of NaCl, respectively. A faster inactivation was always found using the dimensionally stable anodes. In 7 mM Na2SO4, this behavior was associated to the much larger adsorption of the bacteria onto the anode, which accelerated the M((center dot)0H)-mediated oxidation and inactivation of the cells. The inactivation rate was strongly enhanced in 7 mM Na2SO4 + 1 mM NaCl due to the larger oxidation power of active chlorine compared to that of KOH). The effect of NaCl concentration and current density on the disinfection process was examined with BDD and the best performance was obtained in 7 mM Na2SO4 + 7 mM NaCl at 8.3 mA cm(2), with total inactivation in 2 min and energy consumption of 0.059 kW h m(-3). The addition of paracetamol in 7 mM Na2SO4 medium inhibited the disinfection at short electrolysis time regardless of the anode, owing to the preferential action of M(OH) on this pollutant. For BDD, the inactivation rate rose over time at higher drug content due to the generation of greater amounts of toxic by-products. For the IrO2-based anode, the progressive formation of toxic and less adsorbable by-products enhanced the process over time, giving rise again to a quicker total disinfection compared to that with BDD. (C) 2017 Elsevier B.V. All rights reserved

Advantages of electro-Fenton over electrocoagulation for disinfection of dairy wastewater

This study is focused on the disinfection of raw dairy wastewater by means of a sequential treatment including an electrocoagulation (EC) step with an Fe|Fe cell followed by electro-Fenton (EF) or UVA-assisted photoelectro-Fenton (PEF). The two latter methods were run with an air-diffusion cathode for H2O2 generation and either a boron-doped diamond (BDD) or a RuO2-based anode. The inactivation of heterotrophic and lactic acid bacteria, Escherichia coli and enterococci was assessed. Low removal of organic load was found in all cases, whereas the bacteria were poorly removed by the flocs formed in EC but largely inactivated in EF and PEF. EF was also advantageous because it prevented the formation of harmful sludge containing active bacteria, in contrast to EC. Heterotrophs were the most stable bacteria, whereas the others were totally inactivated in most cases. In the sequential EC/EF process involving a BDD anode in the latter step, the inactivation rate for the lactic acid bacteria was higher at circumneutral pH, due to the great ability of produced active chlorine to oxidize the molecules of the cell walls. The use of a RuO2-based anode also led to a quick inactivation at pH 3.0. A better performance was achieved when PEF replaced EF, regardless of the anode, owing to the enhanced bacterial inactivation by UVA radiation. The raw dairy wastewater at natural pH 5.7 treated by single EF step with a RuO2-anode also yielded a faster removal of lactic acid bacteria, Escherichia coli and enterococci as compared to BDD, always remaining small contents of suspended active heterotrophs in solution

La estrategia comunicacional y mediática de Rafael Correa

Rafael Correa’s rise to power in 2007 implied a series of changes in communication and journalism. The impact of Correa’s discourse in the mass media, along with transformations of the media map in Ecuador (a chronological/descriptive map of various government/media activities is included in this study), and an analysis of the communication strategy of the President are likewise provided, which use as a reference news events disseminated by the national press. The study highlights the various confrontations between the government and private media, which not only generated a tense political environment, but also led to legal proceedings and fiery debate. This subsequently led to changes in the journalism profession and in the restructuring of media companies in Ecuador.La llegada de Rafael Correa a la presidencia de Ecuador en el año 2007 supuso una serie de cambios en la comunicación y el ejercicio periodístico. Se realiza un mapeo cronológico/descriptivo de las diversas acciones gobierno/medios.Se estudia el impacto del discurso de Correa en los medios, las transformaciones del mapa mediático en Ecuador, y la estrategia comunicacional presidencial, tomando como referencia acontecimientos difundidos por la prensa nacional.Las confrontaciones entre gobierno y medios privados genera un ambiente tenso, lleno de procesos judiciales y discusiones sin tregua, que han modificado el quehacer periodístico y con el la estructura de la empresa periodística en el país

The biological effects of subacute inhalation of diesel exhaust following addition of cerium oxide nanoparticles in atherosclerosis-prone mice

AbstractBackgroundCerium oxide (CeO2) nanoparticles improve the burning efficiency of fuel, however, little is known about health impacts of altered emissions from the vehicles.MethodsAtherosclerosis-prone apolipoprotein E knockout (ApoE−/−) mice were exposed by inhalation to diluted exhaust (1.7mg/m3, 20, 60 or 180min, 5 day/week, for 4 weeks), from an engine using standard diesel fuel (DE) or the same diesel fuel containing 9ppm cerium oxide nanoparticles (DCeE). Changes in hematological indices, clinical chemistry, atherosclerotic burden, tissue levels of inflammatory cytokines and pathology of the major organs were assessed.ResultsAddition of CeO2 to fuel resulted in a reduction of the number (30%) and surface area (10%) of the particles in the exhaust, whereas the gaseous co-pollutants were increased (6–8%). There was, however, a trend towards an increased size and complexity of the atherosclerotic plaques following DE exposure, which was not evident in the DCeE group. There were no clear signs of altered hematological or pathological changes induced by either treatment. However, levels of proinflammatory cytokines were modulated in a brain region and liver following DCeE exposure.ConclusionsThese results imply that addition of CeO2 nanoparticles to fuel decreases the number of particles in exhaust and may reduce atherosclerotic burden associated with exposure to standard diesel fuel. From the extensive assessment of biological parameters performed, the only concerning effect of cerium addition was a slightly raised level of cytokines in a region of the central nervous system. Overall, the use of cerium as a fuel additive may be a potentially useful way to limit the health effects of vehicle exhaust. However, further testing is required to ensure that such an approach is not associated with a chronic inflammatory response which may eventually cause long-term health effects

The Mo(ve)ment to Prioritize Antiracist Mathematics: Planning for This and Every School Year

Dear Colleague, TODOS: Mathematics for ALL is proud of its almost two decades of advocacy for equity and excellence for all children in mathematics education, specifically Latina/o children. Over the years, TODOS has delivered webinars, podcasts, blogs, conferences, and resources for educators, families, and children to address and provide tools to eliminate the harmful practices too many children and families experience in school and in life. This position statement, The Mo(ve)ment to Prioritize Antiracist Mathematics: Planning for This and Every School Year, and supporting commentaries, including one commentary in Spanish - place the essential actions of the 2016 NCSM - TODOS joint social justice position statement, Mathematics Education Through the Lens of Social Justice: Acknowledgment, Actions, and Accountability, into new contexts as a response to our nation\u27s inequities and injustices made visible by COVID-19 and the tragic murders of George Floyd, Brianna Taylor, and other unarmed Black and Brown citizens. No longer could a focus on curriculum, assessment, and instruction alone be enough for children to survive in today\u27s world. It was time to step up, find strength, move beyond hurt, fear, and usual conversations to take leadership in the fight for antiracism..

Photoelectrocatalytic inactivation of Pseudomonas aeruginosa using an Ag-decorated TiO2 photoanode

Fast and total inactivation of Gram-negativePseudomonas aeruginosain suspensions at natural pH 5.9 has beenachieved by photoelectrocatalyisis (PEC), using Ag-decorated TiO2photoanodes onto transparent conductingindium tin oxide (ITO) under UVA irradiation. The assays were made with 100 mL of bacterial suspensions in anundivided cell equipped with a photoanode, a stainless steel cathode and Ag|AgCl (3 M KCl) as referenceelectrode. Total inactivation was obtained in only 5 min using coatings with 4 wt.% Ag, 25 mM Na2SO4as theelectrolyte and 1.70 V as applied bias potential. Comparative photocatalytic treatments reached total inactiva-tion at much longer time, suggesting the crucial role of hydroxyl radicals in PEC. These oxidants, which weredetected by electron spin resonance, attacked the outer cell wall very effectively, since the recombination of theelectron/hole pairs photoinduced under UVA irradiation was reduced. As characterized by high-resolutiontransmission electron microscopy (HRTEM), the best synthesized Ag-TiO2thin-film photoanode mainly containsanatase TiO2nanopowder decorated with Ag nanoparticles of ca. 45 nm. Analyses by X-ray powder diffractionand UV/Vis spectroscopy were also performed. The potential use of PEC for bacterial disinfection was confirmedfor the rod-shaped Gram-positiveBacillus atrophaeus, which was more slowly inactivated due to its different cellwall structure. Scanning electron micrographs of both bacteria showed that PEC induced a high roughness, celllysis and accumulation of cellular debris

Inactivation of microbiota from urban wastewater by single and sequential electrocoagulation and electro-Fenton treatments

This work aims at comparing the ability of two kinds of electrochemical technologies, namely electrocoagulation (EC) and electro-Fenton (EF), to disinfect primary and secondary effluents from municipal wastewater treatment plants. Heterotrophic bacteria, Escherichia coli, enterococci, Clostridium perfringens spores, somatic coliphages and eukaryotes (amoebae, flagellates, ciliates and metazoa) were tested as indicator microorganisms. EC with an Fe/Fe cell at 200 A m-2 and natural pH allowed > 5 log unit removal of E. coli and final concentration below 1 bacteria mL-1 of coliphages and eukaryotes from both effluents in ca. 60 min, whereas heterotrophic bacteria, enterococci and spores were more resistant. A larger removal was obtained for the primary effluent, probably because the flocs remove higher amount of total organic carbon (TOC), entrapping more easily the microbiota. EF with a boron-doped diamond (BDD) anode and an air-diffusion cathode that produces H2O2 on site was first performed at pH 3.0, with large or even total inactivation of microorganisms within 30 min. A more effective microorganism removal was attained as compared to EC thanks to ¿OH formed from Fenton's reaction. A quicker disinfection was observed for the secondary effluent owing to its lower TOC content, allowing the attack of greater quantities of electrogenerated oxidants on microorganisms. Wastewater disinfection by EF was also feasible at natural pH (~7), showing similar abatement of active microorganisms as a result of the synergistic action of generated oxidants like active chlorine and coagulation with iron hydroxides. A sequential EC/EF treatment (30 min each) was more effective for a combined decontamination and disinfection of urban wastewater

Bacteriophages in bathing wàters: A feasibility study on the development of a method based on bacteriophages for the determination of microbiological quality of bathing waters

Projecte: Project report. BCR Information. EU project KINA19506ENC_001. EUROPEAN COMMISSION. Community Research. DG XII/C - Competitive and Sustainable Growth Programme. Published by EU Directorate General ΧΠ - Science, Research and Development ISBN 92-828-9145-3Informe final projecte europeu aigües de bany i bacteriòfagsMethods for the detection and enumeration of somatic coliphages, F-specific RNA bacteriophages and bacteriophages infecting Bacteroides fragilis had been standardised and validated. Conditions for the preparation, transport and distribution of bacteriophage reference materials and preservation of samples had been defined. A method based on flocculation with Mg(OH2) with concentration efficiencies from about 40% was settled to concentrate phages from bathing waters. All methods were successfully implemented in routine laboratories all around the EU. Data on the occurrence of bacteriophages as compared to E. coli and Enterococci are available from diverse situations encountered in the EU. Results allow to conclude that the potential of phages for the determination of the microbiological quality of bathing waters merits to be considered since their determination is feasible and their behaviour in natural water differs from the behaviour of bacterial indicators and consequently they add valuable information